Nouveau - Oct 2020 - [PATCH v4 05/10] drm/ttm: Add vmap/vunmap to TTM and TTM GEM helpers

DRM's fbdev console uses regular load and store operations to update
framebuffer memory. The bochs driver on sparc64 requires the use of
I/O-specific load and store operations. We have a workaround, but need
a long-term solution to the problem.

This patchset changes GEM's vmap/vunmap interfaces to forward pointers
of type struct dma_buf_map and updates the generic fbdev emulation to
use them correctly. This enables I/O-memory operations on all framebuffers
that require and support them.

Patches #1 to #4 prepare VRAM helpers and drivers.

Next is the update of the GEM vmap functions. Patch #5 adds vmap and vunmap
that is usable with TTM-based GEM drivers, and patch #6 updates GEM's
vmap/vunmap callback to forward instances of type struct dma_buf_map. While
the patch touches many files throughout the DRM modules, the applied changes
are mostly trivial interface fixes. Several TTM-based GEM drivers now use
the new vmap code. Patch #7 updates GEM's internal vmap/vunmap functions to
forward struct dma_buf_map.

With struct dma_buf_map propagated through the layers, patches #9 and #10
convert DRM clients and generic fbdev emulation to use it. Updating the
fbdev framebuffer will select the correct functions, either for system or
I/O memory.

v4:
	* provide TTM vmap/vunmap plus GEM helpers and convert drivers
	  over (Christian, Daniel)
	* remove several empty functions
	* more TODOs and documentation (Daniel)

v3:
	* recreate the whole patchset on top of struct dma_buf_map

v2:
	* RFC patchset

Thomas Zimmermann (10):
  drm/vram-helper: Remove invariant parameters from internal kmap
    function
  drm/cma-helper: Remove empty drm_gem_cma_prime_vunmap()
  drm/etnaviv: Remove empty etnaviv_gem_prime_vunmap()
  drm/exynos: Remove empty exynos_drm_gem_prime_{vmap,vunmap}()
  drm/ttm: Add vmap/vunmap to TTM and TTM GEM helpers
  drm/gem: Use struct dma_buf_map in GEM vmap ops and convert GEM
    backends
  drm/gem: Update internal GEM vmap/vunmap interfaces to use struct
    dma_buf_map
  drm/gem: Store client buffer mappings as struct dma_buf_map
  dma-buf-map: Add memcpy and pointer-increment interfaces
  drm/fb_helper: Support framebuffers in I/O memory

 Documentation/gpu/todo.rst                  |  37 ++-
 drivers/gpu/drm/Kconfig                     |   2 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c |  36 ---
 drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h |   2 -
 drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c     |   5 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_object.h  |   1 -
 drivers/gpu/drm/ast/ast_cursor.c            |  27 ++-
 drivers/gpu/drm/ast/ast_drv.h               |   7 +-
 drivers/gpu/drm/bochs/bochs_kms.c           |   1 -
 drivers/gpu/drm/drm_client.c                |  38 ++--
 drivers/gpu/drm/drm_fb_helper.c             | 238 ++++++++++++++++++--
 drivers/gpu/drm/drm_gem.c                   |  29 ++-
 drivers/gpu/drm/drm_gem_cma_helper.c        |  27 +--
 drivers/gpu/drm/drm_gem_shmem_helper.c      |  48 ++--
 drivers/gpu/drm/drm_gem_ttm_helper.c        |  38 ++++
 drivers/gpu/drm/drm_gem_vram_helper.c       | 117 +++++-----
 drivers/gpu/drm/drm_internal.h              |   5 +-
 drivers/gpu/drm/drm_prime.c                 |  14 +-
 drivers/gpu/drm/etnaviv/etnaviv_drv.h       |   3 +-
 drivers/gpu/drm/etnaviv/etnaviv_gem.c       |   1 -
 drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c |  12 +-
 drivers/gpu/drm/exynos/exynos_drm_gem.c     |  12 -
 drivers/gpu/drm/exynos/exynos_drm_gem.h     |   2 -
 drivers/gpu/drm/lima/lima_gem.c             |   6 +-
 drivers/gpu/drm/lima/lima_sched.c           |  11 +-
 drivers/gpu/drm/mgag200/mgag200_mode.c      |  10 +-
 drivers/gpu/drm/nouveau/Kconfig             |   1 +
 drivers/gpu/drm/nouveau/nouveau_bo.h        |   2 -
 drivers/gpu/drm/nouveau/nouveau_gem.c       |   6 +-
 drivers/gpu/drm/nouveau/nouveau_gem.h       |   2 -
 drivers/gpu/drm/nouveau/nouveau_prime.c     |  20 --
 drivers/gpu/drm/panfrost/panfrost_perfcnt.c |  14 +-
 drivers/gpu/drm/qxl/qxl_display.c           |  11 +-
 drivers/gpu/drm/qxl/qxl_draw.c              |  14 +-
 drivers/gpu/drm/qxl/qxl_drv.h               |  11 +-
 drivers/gpu/drm/qxl/qxl_object.c            |  31 ++-
 drivers/gpu/drm/qxl/qxl_object.h            |   2 +-
 drivers/gpu/drm/qxl/qxl_prime.c             |  12 +-
 drivers/gpu/drm/radeon/radeon.h             |   1 -
 drivers/gpu/drm/radeon/radeon_gem.c         |   7 +-
 drivers/gpu/drm/radeon/radeon_prime.c       |  20 --
 drivers/gpu/drm/rockchip/rockchip_drm_gem.c |  22 +-
 drivers/gpu/drm/rockchip/rockchip_drm_gem.h |   4 +-
 drivers/gpu/drm/tiny/cirrus.c               |  10 +-
 drivers/gpu/drm/tiny/gm12u320.c             |  10 +-
 drivers/gpu/drm/ttm/ttm_bo_util.c           |  72 ++++++
 drivers/gpu/drm/udl/udl_modeset.c           |   8 +-
 drivers/gpu/drm/vboxvideo/vbox_mode.c       |  11 +-
 drivers/gpu/drm/vc4/vc4_bo.c                |   7 +-
 drivers/gpu/drm/vc4/vc4_drv.h               |   2 +-
 drivers/gpu/drm/vgem/vgem_drv.c             |  16 +-
 drivers/gpu/drm/xen/xen_drm_front_gem.c     |  18 +-
 drivers/gpu/drm/xen/xen_drm_front_gem.h     |   6 +-
 include/drm/drm_client.h                    |   7 +-
 include/drm/drm_gem.h                       |   5 +-
 include/drm/drm_gem_cma_helper.h            |   3 +-
 include/drm/drm_gem_shmem_helper.h          |   4 +-
 include/drm/drm_gem_ttm_helper.h            |   6 +
 include/drm/drm_gem_vram_helper.h           |  14 +-
 include/drm/drm_mode_config.h               |  12 -
 include/drm/ttm/ttm_bo_api.h                |  28 +++
 include/linux/dma-buf-map.h                 |  92 +++++++-
 62 files changed, 817 insertions(+), 423 deletions(-)

-- 
2.28.0

The parameters map and is_iomem are always of the same value. Removed them
to prepares the function for conversion to struct dma_buf_map.

v4:
	* don't check for !kmap->virtual; will always be false

Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/drm_gem_vram_helper.c | 18 ++++--------------
 1 file changed, 4 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem_vram_helper.c
b/drivers/gpu/drm/drm_gem_vram_helper.c
index 3213429f8444..2d5ed30518f1 100644
--- a/drivers/gpu/drm/drm_gem_vram_helper.c
+++ b/drivers/gpu/drm/drm_gem_vram_helper.c
@@ -382,32 +382,22 @@ int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo)
 }
 EXPORT_SYMBOL(drm_gem_vram_unpin);
 
-static void *drm_gem_vram_kmap_locked(struct drm_gem_vram_object *gbo,
-				      bool map, bool *is_iomem)
+static void *drm_gem_vram_kmap_locked(struct drm_gem_vram_object *gbo)
 {
 	int ret;
 	struct ttm_bo_kmap_obj *kmap = &gbo->kmap;
+	bool is_iomem;
 
 	if (gbo->kmap_use_count > 0)
 		goto out;
 
-	if (kmap->virtual || !map)
-		goto out;
-
 	ret = ttm_bo_kmap(&gbo->bo, 0, gbo->bo.num_pages, kmap);
 	if (ret)
 		return ERR_PTR(ret);
 
 out:
-	if (!kmap->virtual) {
-		if (is_iomem)
-			*is_iomem = false;
-		return NULL; /* not mapped; don't increment ref */
-	}
 	++gbo->kmap_use_count;
-	if (is_iomem)
-		return ttm_kmap_obj_virtual(kmap, is_iomem);
-	return kmap->virtual;
+	return ttm_kmap_obj_virtual(kmap, &is_iomem);
 }
 
 static void drm_gem_vram_kunmap_locked(struct drm_gem_vram_object *gbo)
@@ -452,7 +442,7 @@ void *drm_gem_vram_vmap(struct drm_gem_vram_object *gbo)
 	ret = drm_gem_vram_pin_locked(gbo, 0);
 	if (ret)
 		goto err_ttm_bo_unreserve;
-	base = drm_gem_vram_kmap_locked(gbo, true, NULL);
+	base = drm_gem_vram_kmap_locked(gbo);
 	if (IS_ERR(base)) {
 		ret = PTR_ERR(base);
 		goto err_drm_gem_vram_unpin_locked;
-- 
2.28.0

The function drm_gem_cma_prime_vunmap() is empty. Remove it before
changing the interface to use struct drm_buf_map.

Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
---
 drivers/gpu/drm/drm_gem_cma_helper.c | 17 -----------------
 drivers/gpu/drm/vc4/vc4_bo.c         |  1 -
 include/drm/drm_gem_cma_helper.h     |  1 -
 3 files changed, 19 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c
b/drivers/gpu/drm/drm_gem_cma_helper.c
index 2165633c9b9e..d527485ea0b7 100644
--- a/drivers/gpu/drm/drm_gem_cma_helper.c
+++ b/drivers/gpu/drm/drm_gem_cma_helper.c
@@ -537,23 +537,6 @@ void *drm_gem_cma_prime_vmap(struct drm_gem_object *obj)
 }
 EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vmap);
 
-/**
- * drm_gem_cma_prime_vunmap - unmap a CMA GEM object from the kernel's
virtual
- *     address space
- * @obj: GEM object
- * @vaddr: kernel virtual address where the CMA GEM object was mapped
- *
- * This function removes a buffer exported via DRM PRIME from the kernel's
- * virtual address space. This is a no-op because CMA buffers cannot be
- * unmapped from kernel space. Drivers using the CMA helpers should set this
- * as their &drm_gem_object_funcs.vunmap callback.
- */
-void drm_gem_cma_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
-{
-	/* Nothing to do */
-}
-EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vunmap);
-
 static const struct drm_gem_object_funcs drm_gem_cma_default_funcs = {
 	.free = drm_gem_cma_free_object,
 	.print_info = drm_gem_cma_print_info,
diff --git a/drivers/gpu/drm/vc4/vc4_bo.c b/drivers/gpu/drm/vc4/vc4_bo.c
index f432278173cd..557f0d1e6437 100644
--- a/drivers/gpu/drm/vc4/vc4_bo.c
+++ b/drivers/gpu/drm/vc4/vc4_bo.c
@@ -387,7 +387,6 @@ static const struct drm_gem_object_funcs
vc4_gem_object_funcs = {
 	.export = vc4_prime_export,
 	.get_sg_table = drm_gem_cma_prime_get_sg_table,
 	.vmap = vc4_prime_vmap,
-	.vunmap = drm_gem_cma_prime_vunmap,
 	.vm_ops = &vc4_vm_ops,
 };
 
diff --git a/include/drm/drm_gem_cma_helper.h b/include/drm/drm_gem_cma_helper.h
index 2bfa2502607a..a064b0d1c480 100644
--- a/include/drm/drm_gem_cma_helper.h
+++ b/include/drm/drm_gem_cma_helper.h
@@ -104,7 +104,6 @@ drm_gem_cma_prime_import_sg_table(struct drm_device *dev,
 int drm_gem_cma_prime_mmap(struct drm_gem_object *obj,
 			   struct vm_area_struct *vma);
 void *drm_gem_cma_prime_vmap(struct drm_gem_object *obj);
-void drm_gem_cma_prime_vunmap(struct drm_gem_object *obj, void *vaddr);
 
 struct drm_gem_object *
 drm_gem_cma_create_object_default_funcs(struct drm_device *dev, size_t size);
-- 
2.28.0

The function etnaviv_gem_prime_vunmap() is empty. Remove it before
changing the interface to use struct drm_buf_map.

Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
---
 drivers/gpu/drm/etnaviv/etnaviv_drv.h       | 1 -
 drivers/gpu/drm/etnaviv/etnaviv_gem.c       | 1 -
 drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c | 5 -----
 3 files changed, 7 deletions(-)

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_drv.h
b/drivers/gpu/drm/etnaviv/etnaviv_drv.h
index 914f0867ff71..9682c26d89bb 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_drv.h
+++ b/drivers/gpu/drm/etnaviv/etnaviv_drv.h
@@ -52,7 +52,6 @@ int etnaviv_gem_mmap(struct file *filp, struct vm_area_struct
*vma);
 int etnaviv_gem_mmap_offset(struct drm_gem_object *obj, u64 *offset);
 struct sg_table *etnaviv_gem_prime_get_sg_table(struct drm_gem_object *obj);
 void *etnaviv_gem_prime_vmap(struct drm_gem_object *obj);
-void etnaviv_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr);
 int etnaviv_gem_prime_mmap(struct drm_gem_object *obj,
 			   struct vm_area_struct *vma);
 struct drm_gem_object *etnaviv_gem_prime_import_sg_table(struct drm_device
*dev,
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c
b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
index 67d9a2b9ea6a..bbd235473645 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
@@ -571,7 +571,6 @@ static const struct drm_gem_object_funcs
etnaviv_gem_object_funcs = {
 	.unpin = etnaviv_gem_prime_unpin,
 	.get_sg_table = etnaviv_gem_prime_get_sg_table,
 	.vmap = etnaviv_gem_prime_vmap,
-	.vunmap = etnaviv_gem_prime_vunmap,
 	.vm_ops = &vm_ops,
 };
 
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
index 135fbff6fecf..a6d9932a32ae 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
@@ -27,11 +27,6 @@ void *etnaviv_gem_prime_vmap(struct drm_gem_object *obj)
 	return etnaviv_gem_vmap(obj);
 }
 
-void etnaviv_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
-{
-	/* TODO msm_gem_vunmap() */
-}
-
 int etnaviv_gem_prime_mmap(struct drm_gem_object *obj,
 			   struct vm_area_struct *vma)
 {
-- 
2.28.0

The functions exynos_drm_gem_prime_{vmap,vunmap}() are empty. Remove
them before changing the interface to use struct drm_buf_map. As a side
effect of removing drm_gem_prime_vmap(), the error code changes from
ENOMEM to EOPNOTSUPP.

Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
---
 drivers/gpu/drm/exynos/exynos_drm_gem.c | 12 ------------
 drivers/gpu/drm/exynos/exynos_drm_gem.h |  2 --
 2 files changed, 14 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c
b/drivers/gpu/drm/exynos/exynos_drm_gem.c
index e7a6eb96f692..13a35623ac04 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_gem.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c
@@ -137,8 +137,6 @@ static const struct vm_operations_struct
exynos_drm_gem_vm_ops = {
 static const struct drm_gem_object_funcs exynos_drm_gem_object_funcs = {
 	.free = exynos_drm_gem_free_object,
 	.get_sg_table = exynos_drm_gem_prime_get_sg_table,
-	.vmap = exynos_drm_gem_prime_vmap,
-	.vunmap	= exynos_drm_gem_prime_vunmap,
 	.vm_ops = &exynos_drm_gem_vm_ops,
 };
 
@@ -471,16 +469,6 @@ exynos_drm_gem_prime_import_sg_table(struct drm_device
*dev,
 	return &exynos_gem->base;
 }
 
-void *exynos_drm_gem_prime_vmap(struct drm_gem_object *obj)
-{
-	return NULL;
-}
-
-void exynos_drm_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
-{
-	/* Nothing to do */
-}
-
 int exynos_drm_gem_prime_mmap(struct drm_gem_object *obj,
 			      struct vm_area_struct *vma)
 {
diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.h
b/drivers/gpu/drm/exynos/exynos_drm_gem.h
index 74e926abeff0..a23272fb96fb 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_gem.h
+++ b/drivers/gpu/drm/exynos/exynos_drm_gem.h
@@ -107,8 +107,6 @@ struct drm_gem_object *
 exynos_drm_gem_prime_import_sg_table(struct drm_device *dev,
 				     struct dma_buf_attachment *attach,
 				     struct sg_table *sgt);
-void *exynos_drm_gem_prime_vmap(struct drm_gem_object *obj);
-void exynos_drm_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr);
 int exynos_drm_gem_prime_mmap(struct drm_gem_object *obj,
 			      struct vm_area_struct *vma);
 
-- 
2.28.0

The new functions ttm_bo_{vmap,vunmap}() map and unmap a TTM BO in kernel
address space. The mapping's address is returned as struct dma_buf_map.
Each function is a simplified version of TTM's existing kmap code. Both
functions respect the memory's location ani/or writecombine flags.

On top TTM's functions, GEM TTM helpers got drm_gem_ttm_{vmap,vunmap}(),
two helpers that convert a GEM object into the TTM BO and forward the call
to TTM's vmap/vunmap. These helpers can be dropped into the rsp GEM object
callbacks.

v4:
	* drop ttm_kmap_obj_to_dma_buf() in favor of vmap helpers (Daniel,
	  Christian)

Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
---
 drivers/gpu/drm/drm_gem_ttm_helper.c | 38 +++++++++++++++
 drivers/gpu/drm/ttm/ttm_bo_util.c    | 72 ++++++++++++++++++++++++++++
 include/drm/drm_gem_ttm_helper.h     |  6 +++
 include/drm/ttm/ttm_bo_api.h         | 28 +++++++++++
 include/linux/dma-buf-map.h          | 20 ++++++++
 5 files changed, 164 insertions(+)

diff --git a/drivers/gpu/drm/drm_gem_ttm_helper.c
b/drivers/gpu/drm/drm_gem_ttm_helper.c
index 0e4fb9ba43ad..db4c14d78a30 100644
--- a/drivers/gpu/drm/drm_gem_ttm_helper.c
+++ b/drivers/gpu/drm/drm_gem_ttm_helper.c
@@ -49,6 +49,44 @@ void drm_gem_ttm_print_info(struct drm_printer *p, unsigned
int indent,
 }
 EXPORT_SYMBOL(drm_gem_ttm_print_info);
 
+/**
+ * drm_gem_ttm_vmap() - vmap &ttm_buffer_object
+ * @gem: GEM object.
+ * @map: [out] returns the dma-buf mapping.
+ *
+ * Maps a GEM object with ttm_bo_vmap(). This function can be used as
+ * &drm_gem_object_funcs.vmap callback.
+ *
+ * Returns:
+ * 0 on success, or a negative errno code otherwise.
+ */
+int drm_gem_ttm_vmap(struct drm_gem_object *gem,
+		     struct dma_buf_map *map)
+{
+	struct ttm_buffer_object *bo = drm_gem_ttm_of_gem(gem);
+
+	return ttm_bo_vmap(bo, map);
+
+}
+EXPORT_SYMBOL(drm_gem_ttm_vmap);
+
+/**
+ * drm_gem_ttm_vunmap() - vunmap &ttm_buffer_object
+ * @gem: GEM object.
+ * @map: dma-buf mapping.
+ *
+ * Unmaps a GEM object with ttm_bo_vunmap(). This function can be used as
+ * &drm_gem_object_funcs.vmap callback.
+ */
+void drm_gem_ttm_vunmap(struct drm_gem_object *gem,
+			struct dma_buf_map *map)
+{
+	struct ttm_buffer_object *bo = drm_gem_ttm_of_gem(gem);
+
+	ttm_bo_vunmap(bo, map);
+}
+EXPORT_SYMBOL(drm_gem_ttm_vunmap);
+
 /**
  * drm_gem_ttm_mmap() - mmap &ttm_buffer_object
  * @gem: GEM object.
diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c
b/drivers/gpu/drm/ttm/ttm_bo_util.c
index bdee4df1f3f2..80c42c774c7d 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -32,6 +32,7 @@
 #include <drm/ttm/ttm_bo_driver.h>
 #include <drm/ttm/ttm_placement.h>
 #include <drm/drm_vma_manager.h>
+#include <linux/dma-buf-map.h>
 #include <linux/io.h>
 #include <linux/highmem.h>
 #include <linux/wait.h>
@@ -526,6 +527,77 @@ void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map)
 }
 EXPORT_SYMBOL(ttm_bo_kunmap);
 
+int ttm_bo_vmap(struct ttm_buffer_object *bo, struct dma_buf_map *map)
+{
+	struct ttm_resource *mem = &bo->mem;
+	int ret;
+
+	ret = ttm_mem_io_reserve(bo->bdev, mem);
+	if (ret)
+		return ret;
+
+	if (mem->bus.is_iomem) {
+		void __iomem *vaddr_iomem;
+		unsigned long size = bo->num_pages << PAGE_SHIFT;
+
+		if (mem->bus.addr)
+			vaddr_iomem = (void *)(((u8 *)mem->bus.addr));
+		else if (mem->placement & TTM_PL_FLAG_WC)
+			vaddr_iomem = ioremap_wc(mem->bus.offset, size);
+		else
+			vaddr_iomem = ioremap(mem->bus.offset, size);
+
+		if (!vaddr_iomem)
+			return -ENOMEM;
+
+		dma_buf_map_set_vaddr_iomem(map, vaddr_iomem);
+
+	} else {
+		struct ttm_operation_ctx ctx = {
+			.interruptible = false,
+			.no_wait_gpu = false
+		};
+		struct ttm_tt *ttm = bo->ttm;
+		pgprot_t prot;
+		void *vaddr;
+
+		BUG_ON(!ttm);
+
+		ret = ttm_tt_populate(bo->bdev, ttm, &ctx);
+		if (ret)
+			return ret;
+
+		/*
+		 * We need to use vmap to get the desired page protection
+		 * or to make the buffer object look contiguous.
+		 */
+		prot = ttm_io_prot(mem->placement, PAGE_KERNEL);
+		vaddr = vmap(ttm->pages, bo->num_pages, 0, prot);
+		if (!vaddr)
+			return -ENOMEM;
+
+		dma_buf_map_set_vaddr(map, vaddr);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(ttm_bo_vmap);
+
+void ttm_bo_vunmap(struct ttm_buffer_object *bo, struct dma_buf_map *map)
+{
+	if (dma_buf_map_is_null(map))
+		return;
+
+	if (map->is_iomem)
+		iounmap(map->vaddr_iomem);
+	else
+		vunmap(map->vaddr);
+	dma_buf_map_clear(map);
+
+	ttm_mem_io_free(bo->bdev, &bo->mem);
+}
+EXPORT_SYMBOL(ttm_bo_vunmap);
+
 static int ttm_bo_wait_free_node(struct ttm_buffer_object *bo,
 				 bool dst_use_tt)
 {
diff --git a/include/drm/drm_gem_ttm_helper.h b/include/drm/drm_gem_ttm_helper.h
index 118cef76f84f..7c6d874910b8 100644
--- a/include/drm/drm_gem_ttm_helper.h
+++ b/include/drm/drm_gem_ttm_helper.h
@@ -10,11 +10,17 @@
 #include <drm/ttm/ttm_bo_api.h>
 #include <drm/ttm/ttm_bo_driver.h>
 
+struct dma_buf_map;
+
 #define drm_gem_ttm_of_gem(gem_obj) \
 	container_of(gem_obj, struct ttm_buffer_object, base)
 
 void drm_gem_ttm_print_info(struct drm_printer *p, unsigned int indent,
 			    const struct drm_gem_object *gem);
+int drm_gem_ttm_vmap(struct drm_gem_object *gem,
+		     struct dma_buf_map *map);
+void drm_gem_ttm_vunmap(struct drm_gem_object *gem,
+			struct dma_buf_map *map);
 int drm_gem_ttm_mmap(struct drm_gem_object *gem,
 		     struct vm_area_struct *vma);
 
diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
index 37102e45e496..2c59a785374c 100644
--- a/include/drm/ttm/ttm_bo_api.h
+++ b/include/drm/ttm/ttm_bo_api.h
@@ -48,6 +48,8 @@ struct ttm_bo_global;
 
 struct ttm_bo_device;
 
+struct dma_buf_map;
+
 struct drm_mm_node;
 
 struct ttm_placement;
@@ -494,6 +496,32 @@ int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long
start_page,
  */
 void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);
 
+/**
+ * ttm_bo_vmap
+ *
+ * @bo: The buffer object.
+ * @map: pointer to a struct dma_buf_map representing the map.
+ *
+ * Sets up a kernel virtual mapping, using ioremap or vmap to the
+ * data in the buffer object. The parameter @map returns the virtual
+ * address as struct dma_buf_map. Unmap the buffer with ttm_bo_vunmap().
+ *
+ * Returns
+ * -ENOMEM: Out of memory.
+ * -EINVAL: Invalid range.
+ */
+int ttm_bo_vmap(struct ttm_buffer_object *bo, struct dma_buf_map *map);
+
+/**
+ * ttm_bo_vunmap
+ *
+ * @bo: The buffer object.
+ * @map: Object describing the map to unmap.
+ *
+ * Unmaps a kernel map set up by ttm_bo_vmap().
+ */
+void ttm_bo_vunmap(struct ttm_buffer_object *bo, struct dma_buf_map *map);
+
 /**
  * ttm_bo_mmap_obj - mmap memory backed by a ttm buffer object.
  *
diff --git a/include/linux/dma-buf-map.h b/include/linux/dma-buf-map.h
index fd1aba545fdf..2e8bbecb5091 100644
--- a/include/linux/dma-buf-map.h
+++ b/include/linux/dma-buf-map.h
@@ -45,6 +45,12 @@
  *
  *	dma_buf_map_set_vaddr(&map. 0xdeadbeaf);
  *
+ * To set an address in I/O memory, use dma_buf_map_set_vaddr_iomem().
+ *
+ * .. code-block:: c
+ *
+ *	dma_buf_map_set_vaddr_iomem(&map. 0xdeadbeaf);
+ *
  * Test if a mapping is valid with either dma_buf_map_is_set() or
  * dma_buf_map_is_null().
  *
@@ -118,6 +124,20 @@ static inline void dma_buf_map_set_vaddr(struct dma_buf_map
*map, void *vaddr)
 	map->is_iomem = false;
 }
 
+/**
+ * dma_buf_map_set_vaddr_iomem - Sets a dma-buf mapping structure to an address
in I/O memory
+ * @map:		The dma-buf mapping structure
+ * @vaddr_iomem:	An I/O-memory address
+ *
+ * Sets the address and the I/O-memory flag.
+ */
+static inline void dma_buf_map_set_vaddr_iomem(struct dma_buf_map *map,
+					       void __iomem *vaddr_iomem)
+{
+	map->vaddr_iomem = vaddr_iomem;
+	map->is_iomem = true;
+}
+
 /**
  * dma_buf_map_is_equal - Compares two dma-buf mapping structures for equality
  * @lhs:	The dma-buf mapping structure
-- 
2.28.0

This patch replaces the vmap/vunmap's use of raw pointers in GEM object
functions with instances of struct dma_buf_map. GEM backends are
converted as well. For most of them, this simply changes the returned type.

TTM-based drivers now return information about the location of the memory,
either system or I/O memory. GEM VRAM helpers and qxl now use ttm_bo_vmap()
et al. Amdgpu, nouveau and radeon use drm_gem_ttm_vmap() et al instead of
implementing their own vmap callbacks.

v4:
	* use ttm_bo_vmap(), drm_gem_ttm_vmap(), et al. (Daniel, Christian)
	* fix a trailing { in drm_gem_vmap()
	* remove several empty functions instead of converting them (Daniel)
	* comment uses of raw pointers with a TODO (Daniel)
	* TODO list: convert more helpers to use struct dma_buf_map

Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
---
 Documentation/gpu/todo.rst                  |  18 ++++
 drivers/gpu/drm/Kconfig                     |   2 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c |  36 -------
 drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h |   2 -
 drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c     |   5 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_object.h  |   1 -
 drivers/gpu/drm/ast/ast_cursor.c            |  27 +++--
 drivers/gpu/drm/ast/ast_drv.h               |   7 +-
 drivers/gpu/drm/drm_gem.c                   |  23 +++--
 drivers/gpu/drm/drm_gem_cma_helper.c        |  10 +-
 drivers/gpu/drm/drm_gem_shmem_helper.c      |  48 +++++----
 drivers/gpu/drm/drm_gem_vram_helper.c       | 107 ++++++++++----------
 drivers/gpu/drm/etnaviv/etnaviv_drv.h       |   2 +-
 drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c |   9 +-
 drivers/gpu/drm/lima/lima_gem.c             |   6 +-
 drivers/gpu/drm/lima/lima_sched.c           |  11 +-
 drivers/gpu/drm/mgag200/mgag200_mode.c      |  10 +-
 drivers/gpu/drm/nouveau/Kconfig             |   1 +
 drivers/gpu/drm/nouveau/nouveau_bo.h        |   2 -
 drivers/gpu/drm/nouveau/nouveau_gem.c       |   6 +-
 drivers/gpu/drm/nouveau/nouveau_gem.h       |   2 -
 drivers/gpu/drm/nouveau/nouveau_prime.c     |  20 ----
 drivers/gpu/drm/panfrost/panfrost_perfcnt.c |  14 +--
 drivers/gpu/drm/qxl/qxl_display.c           |  11 +-
 drivers/gpu/drm/qxl/qxl_draw.c              |  14 ++-
 drivers/gpu/drm/qxl/qxl_drv.h               |  11 +-
 drivers/gpu/drm/qxl/qxl_object.c            |  31 +++---
 drivers/gpu/drm/qxl/qxl_object.h            |   2 +-
 drivers/gpu/drm/qxl/qxl_prime.c             |  12 +--
 drivers/gpu/drm/radeon/radeon.h             |   1 -
 drivers/gpu/drm/radeon/radeon_gem.c         |   7 +-
 drivers/gpu/drm/radeon/radeon_prime.c       |  20 ----
 drivers/gpu/drm/rockchip/rockchip_drm_gem.c |  22 ++--
 drivers/gpu/drm/rockchip/rockchip_drm_gem.h |   4 +-
 drivers/gpu/drm/tiny/cirrus.c               |  10 +-
 drivers/gpu/drm/tiny/gm12u320.c             |  10 +-
 drivers/gpu/drm/udl/udl_modeset.c           |   8 +-
 drivers/gpu/drm/vboxvideo/vbox_mode.c       |  11 +-
 drivers/gpu/drm/vc4/vc4_bo.c                |   6 +-
 drivers/gpu/drm/vc4/vc4_drv.h               |   2 +-
 drivers/gpu/drm/vgem/vgem_drv.c             |  16 ++-
 drivers/gpu/drm/xen/xen_drm_front_gem.c     |  18 ++--
 drivers/gpu/drm/xen/xen_drm_front_gem.h     |   6 +-
 include/drm/drm_gem.h                       |   5 +-
 include/drm/drm_gem_cma_helper.h            |   2 +-
 include/drm/drm_gem_shmem_helper.h          |   4 +-
 include/drm/drm_gem_vram_helper.h           |  14 +--
 47 files changed, 321 insertions(+), 295 deletions(-)

diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst
index 700637e25ecd..7e6fc3c04add 100644
--- a/Documentation/gpu/todo.rst
+++ b/Documentation/gpu/todo.rst
@@ -446,6 +446,24 @@ Contact: Ville Syrj?l?, Daniel Vetter
 
 Level: Intermediate
 
+Use struct dma_buf_map throughout codebase
+------------------------------------------
+
+Pointers to shared device memory are stored in struct dma_buf_map. Each
+instance knows whether it refers to system or I/O memory. Most of the DRM-wide
+interface have been converted to use struct dma_buf_map, but implementations
+often still use raw pointers.
+
+The task is to use struct dma_buf_map where it makes sense.
+
+* Memory managers should use struct dma_buf_map for dma-buf-imported buffers.
+* TTM might benefit from using struct dma_buf_map internally.
+* Framebuffer copying and blitting helpers should operate on struct
dma_buf_map.
+
+Contact: Thomas Zimmermann <tzimmermann at suse.de>, Christian K?nig,
Daniel Vetter
+
+Level: Intermediate
+
 
 Core refactorings
 ================diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 147d61b9674e..319839b87d37 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -239,6 +239,7 @@ config DRM_RADEON
 	select FW_LOADER
         select DRM_KMS_HELPER
         select DRM_TTM
+	select DRM_TTM_HELPER
 	select POWER_SUPPLY
 	select HWMON
 	select BACKLIGHT_CLASS_DEVICE
@@ -259,6 +260,7 @@ config DRM_AMDGPU
 	select DRM_KMS_HELPER
 	select DRM_SCHED
 	select DRM_TTM
+	select DRM_TTM_HELPER
 	select POWER_SUPPLY
 	select HWMON
 	select BACKLIGHT_CLASS_DEVICE
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
index 5b465ab774d1..e5919efca870 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
@@ -41,42 +41,6 @@
 #include <linux/dma-fence-array.h>
 #include <linux/pci-p2pdma.h>
 
-/**
- * amdgpu_gem_prime_vmap - &dma_buf_ops.vmap implementation
- * @obj: GEM BO
- *
- * Sets up an in-kernel virtual mapping of the BO's memory.
- *
- * Returns:
- * The virtual address of the mapping or an error pointer.
- */
-void *amdgpu_gem_prime_vmap(struct drm_gem_object *obj)
-{
-	struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj);
-	int ret;
-
-	ret = ttm_bo_kmap(&bo->tbo, 0, bo->tbo.num_pages,
-			  &bo->dma_buf_vmap);
-	if (ret)
-		return ERR_PTR(ret);
-
-	return bo->dma_buf_vmap.virtual;
-}
-
-/**
- * amdgpu_gem_prime_vunmap - &dma_buf_ops.vunmap implementation
- * @obj: GEM BO
- * @vaddr: Virtual address (unused)
- *
- * Tears down the in-kernel virtual mapping of the BO's memory.
- */
-void amdgpu_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
-{
-	struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj);
-
-	ttm_bo_kunmap(&bo->dma_buf_vmap);
-}
-
 /**
  * amdgpu_gem_prime_mmap - &drm_driver.gem_prime_mmap implementation
  * @obj: GEM BO
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h
b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h
index 2c5c84a06bb9..39b5b9616fd8 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h
@@ -31,8 +31,6 @@ struct drm_gem_object *amdgpu_gem_prime_import(struct
drm_device *dev,
 					    struct dma_buf *dma_buf);
 bool amdgpu_dmabuf_is_xgmi_accessible(struct amdgpu_device *adev,
 				      struct amdgpu_bo *bo);
-void *amdgpu_gem_prime_vmap(struct drm_gem_object *obj);
-void amdgpu_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr);
 int amdgpu_gem_prime_mmap(struct drm_gem_object *obj,
 			  struct vm_area_struct *vma);
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
index be08a63ef58c..576659827e74 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
@@ -33,6 +33,7 @@
 
 #include <drm/amdgpu_drm.h>
 #include <drm/drm_debugfs.h>
+#include <drm/drm_gem_ttm_helper.h>
 
 #include "amdgpu.h"
 #include "amdgpu_display.h"
@@ -220,8 +221,8 @@ static const struct drm_gem_object_funcs
amdgpu_gem_object_funcs = {
 	.open = amdgpu_gem_object_open,
 	.close = amdgpu_gem_object_close,
 	.export = amdgpu_gem_prime_export,
-	.vmap = amdgpu_gem_prime_vmap,
-	.vunmap = amdgpu_gem_prime_vunmap,
+	.vmap = drm_gem_ttm_vmap,
+	.vunmap = drm_gem_ttm_vunmap,
 };
 
 /*
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
index 132e5f955180..01296ef0d673 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
@@ -100,7 +100,6 @@ struct amdgpu_bo {
 	struct amdgpu_bo		*parent;
 	struct amdgpu_bo		*shadow;
 
-	struct ttm_bo_kmap_obj		dma_buf_vmap;
 	struct amdgpu_mn		*mn;
 
 
diff --git a/drivers/gpu/drm/ast/ast_cursor.c b/drivers/gpu/drm/ast/ast_cursor.c
index e0f4613918ad..742d43a7edf4 100644
--- a/drivers/gpu/drm/ast/ast_cursor.c
+++ b/drivers/gpu/drm/ast/ast_cursor.c
@@ -39,7 +39,7 @@ static void ast_cursor_fini(struct ast_private *ast)
 
 	for (i = 0; i < ARRAY_SIZE(ast->cursor.gbo); ++i) {
 		gbo = ast->cursor.gbo[i];
-		drm_gem_vram_vunmap(gbo, ast->cursor.vaddr[i]);
+		drm_gem_vram_vunmap(gbo, &ast->cursor.map[i]);
 		drm_gem_vram_unpin(gbo);
 		drm_gem_vram_put(gbo);
 	}
@@ -60,7 +60,7 @@ int ast_cursor_init(struct ast_private *ast)
 	struct drm_device *dev = &ast->base;
 	size_t size, i;
 	struct drm_gem_vram_object *gbo;
-	void __iomem *vaddr;
+	struct dma_buf_map map;
 	int ret;
 
 	size = roundup(AST_HWC_SIZE + AST_HWC_SIGNATURE_SIZE, PAGE_SIZE);
@@ -77,16 +77,15 @@ int ast_cursor_init(struct ast_private *ast)
 			drm_gem_vram_put(gbo);
 			goto err_drm_gem_vram_put;
 		}
-		vaddr = drm_gem_vram_vmap(gbo);
-		if (IS_ERR(vaddr)) {
-			ret = PTR_ERR(vaddr);
+		ret = drm_gem_vram_vmap(gbo, &map);
+		if (ret) {
 			drm_gem_vram_unpin(gbo);
 			drm_gem_vram_put(gbo);
 			goto err_drm_gem_vram_put;
 		}
 
 		ast->cursor.gbo[i] = gbo;
-		ast->cursor.vaddr[i] = vaddr;
+		ast->cursor.map[i] = map;
 	}
 
 	return drmm_add_action_or_reset(dev, ast_cursor_release, NULL);
@@ -95,7 +94,7 @@ int ast_cursor_init(struct ast_private *ast)
 	while (i) {
 		--i;
 		gbo = ast->cursor.gbo[i];
-		drm_gem_vram_vunmap(gbo, ast->cursor.vaddr[i]);
+		drm_gem_vram_vunmap(gbo, &ast->cursor.map[i]);
 		drm_gem_vram_unpin(gbo);
 		drm_gem_vram_put(gbo);
 	}
@@ -170,6 +169,7 @@ int ast_cursor_blit(struct ast_private *ast, struct
drm_framebuffer *fb)
 {
 	struct drm_device *dev = &ast->base;
 	struct drm_gem_vram_object *gbo;
+	struct dma_buf_map map;
 	int ret;
 	void *src;
 	void __iomem *dst;
@@ -183,18 +183,17 @@ int ast_cursor_blit(struct ast_private *ast, struct
drm_framebuffer *fb)
 	ret = drm_gem_vram_pin(gbo, 0);
 	if (ret)
 		return ret;
-	src = drm_gem_vram_vmap(gbo);
-	if (IS_ERR(src)) {
-		ret = PTR_ERR(src);
+	ret = drm_gem_vram_vmap(gbo, &map);
+	if (ret)
 		goto err_drm_gem_vram_unpin;
-	}
+	src = map.vaddr; /* TODO: Use mapping abstraction properly */
 
-	dst = ast->cursor.vaddr[ast->cursor.next_index];
+	dst = ast->cursor.map[ast->cursor.next_index].vaddr_iomem;
 
 	/* do data transfer to cursor BO */
 	update_cursor_image(dst, src, fb->width, fb->height);
 
-	drm_gem_vram_vunmap(gbo, src);
+	drm_gem_vram_vunmap(gbo, &map);
 	drm_gem_vram_unpin(gbo);
 
 	return 0;
@@ -257,7 +256,7 @@ void ast_cursor_show(struct ast_private *ast, int x, int y,
 	u8 __iomem *sig;
 	u8 jreg;
 
-	dst = ast->cursor.vaddr[ast->cursor.next_index];
+	dst = ast->cursor.map[ast->cursor.next_index].vaddr;
 
 	sig = dst + AST_HWC_SIZE;
 	writel(x, sig + AST_HWC_SIGNATURE_X);
diff --git a/drivers/gpu/drm/ast/ast_drv.h b/drivers/gpu/drm/ast/ast_drv.h
index 467049ca8430..f963141dd851 100644
--- a/drivers/gpu/drm/ast/ast_drv.h
+++ b/drivers/gpu/drm/ast/ast_drv.h
@@ -28,10 +28,11 @@
 #ifndef __AST_DRV_H__
 #define __AST_DRV_H__
 
-#include <linux/types.h>
-#include <linux/io.h>
+#include <linux/dma-buf-map.h>
 #include <linux/i2c.h>
 #include <linux/i2c-algo-bit.h>
+#include <linux/io.h>
+#include <linux/types.h>
 
 #include <drm/drm_connector.h>
 #include <drm/drm_crtc.h>
@@ -131,7 +132,7 @@ struct ast_private {
 
 	struct {
 		struct drm_gem_vram_object *gbo[AST_DEFAULT_HWC_NUM];
-		void __iomem *vaddr[AST_DEFAULT_HWC_NUM];
+		struct dma_buf_map map[AST_DEFAULT_HWC_NUM];
 		unsigned int next_index;
 	} cursor;
 
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 1da67d34e55d..a89ad4570e3c 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -36,6 +36,7 @@
 #include <linux/pagemap.h>
 #include <linux/shmem_fs.h>
 #include <linux/dma-buf.h>
+#include <linux/dma-buf-map.h>
 #include <linux/mem_encrypt.h>
 #include <linux/pagevec.h>
 
@@ -1207,26 +1208,30 @@ void drm_gem_unpin(struct drm_gem_object *obj)
 
 void *drm_gem_vmap(struct drm_gem_object *obj)
 {
-	void *vaddr;
+	struct dma_buf_map map;
+	int ret;
 
-	if (obj->funcs->vmap)
-		vaddr = obj->funcs->vmap(obj);
-	else
-		vaddr = ERR_PTR(-EOPNOTSUPP);
+	if (!obj->funcs->vmap)
+		return ERR_PTR(-EOPNOTSUPP);
 
-	if (!vaddr)
-		vaddr = ERR_PTR(-ENOMEM);
+	ret = obj->funcs->vmap(obj, &map);
+	if (ret)
+		return ERR_PTR(ret);
+	else if (dma_buf_map_is_null(&map))
+		return ERR_PTR(-ENOMEM);
 
-	return vaddr;
+	return map.vaddr;
 }
 
 void drm_gem_vunmap(struct drm_gem_object *obj, void *vaddr)
 {
+	struct dma_buf_map map = DMA_BUF_MAP_INIT_VADDR(vaddr);
+
 	if (!vaddr)
 		return;
 
 	if (obj->funcs->vunmap)
-		obj->funcs->vunmap(obj, vaddr);
+		obj->funcs->vunmap(obj, &map);
 }
 
 /**
diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c
b/drivers/gpu/drm/drm_gem_cma_helper.c
index d527485ea0b7..b57e3e9222f0 100644
--- a/drivers/gpu/drm/drm_gem_cma_helper.c
+++ b/drivers/gpu/drm/drm_gem_cma_helper.c
@@ -519,6 +519,8 @@ EXPORT_SYMBOL_GPL(drm_gem_cma_prime_mmap);
  * drm_gem_cma_prime_vmap - map a CMA GEM object into the kernel's virtual
  *     address space
  * @obj: GEM object
+ * @map: Returns the kernel virtual address of the CMA GEM object's backing
+ *       store.
  *
  * This function maps a buffer exported via DRM PRIME into the kernel's
  * virtual address space. Since the CMA buffers are already mapped into the
@@ -527,13 +529,15 @@ EXPORT_SYMBOL_GPL(drm_gem_cma_prime_mmap);
  * driver's &drm_gem_object_funcs.vmap callback.
  *
  * Returns:
- * The kernel virtual address of the CMA GEM object's backing store.
+ * 0 on success, or a negative error code otherwise.
  */
-void *drm_gem_cma_prime_vmap(struct drm_gem_object *obj)
+int drm_gem_cma_prime_vmap(struct drm_gem_object *obj, struct dma_buf_map *map)
 {
 	struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj);
 
-	return cma_obj->vaddr;
+	dma_buf_map_set_vaddr(map, cma_obj->vaddr);
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vmap);
 
diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c
b/drivers/gpu/drm/drm_gem_shmem_helper.c
index fb11df7aced5..5553f58f68f3 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -258,19 +258,25 @@ void drm_gem_shmem_unpin(struct drm_gem_object *obj)
 }
 EXPORT_SYMBOL(drm_gem_shmem_unpin);
 
-static void *drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem)
+static int drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem, struct
dma_buf_map *map)
 {
 	struct drm_gem_object *obj = &shmem->base;
-	struct dma_buf_map map;
 	int ret = 0;
 
-	if (shmem->vmap_use_count++ > 0)
-		return shmem->vaddr;
+	if (shmem->vmap_use_count++ > 0) {
+		dma_buf_map_set_vaddr(map, shmem->vaddr);
+		return 0;
+	}
 
 	if (obj->import_attach) {
-		ret = dma_buf_vmap(obj->import_attach->dmabuf, &map);
-		if (!ret)
-			shmem->vaddr = map.vaddr;
+		ret = dma_buf_vmap(obj->import_attach->dmabuf, map);
+		if (!ret) {
+			if (WARN_ON(map->is_iomem)) {
+				ret = -EIO;
+				goto err_put_pages;
+			}
+			shmem->vaddr = map->vaddr;
+		}
 	} else {
 		pgprot_t prot = PAGE_KERNEL;
 
@@ -284,6 +290,8 @@ static void *drm_gem_shmem_vmap_locked(struct
drm_gem_shmem_object *shmem)
 				    VM_MAP, prot);
 		if (!shmem->vaddr)
 			ret = -ENOMEM;
+		else
+			dma_buf_map_set_vaddr(map, shmem->vaddr);
 	}
 
 	if (ret) {
@@ -291,7 +299,7 @@ static void *drm_gem_shmem_vmap_locked(struct
drm_gem_shmem_object *shmem)
 		goto err_put_pages;
 	}
 
-	return shmem->vaddr;
+	return 0;
 
 err_put_pages:
 	if (!obj->import_attach)
@@ -299,12 +307,14 @@ static void *drm_gem_shmem_vmap_locked(struct
drm_gem_shmem_object *shmem)
 err_zero_use:
 	shmem->vmap_use_count = 0;
 
-	return ERR_PTR(ret);
+	return ret;
 }
 
 /*
  * drm_gem_shmem_vmap - Create a virtual mapping for a shmem GEM object
  * @shmem: shmem GEM object
+ * @map: Returns the kernel virtual address of the SHMEM GEM object's
backing
+ *       store.
  *
  * This function makes sure that a contiguous kernel virtual address mapping
  * exists for the buffer backing the shmem GEM object.
@@ -318,26 +328,25 @@ static void *drm_gem_shmem_vmap_locked(struct
drm_gem_shmem_object *shmem)
  * Returns:
  * 0 on success or a negative error code on failure.
  */
-void *drm_gem_shmem_vmap(struct drm_gem_object *obj)
+int drm_gem_shmem_vmap(struct drm_gem_object *obj, struct dma_buf_map *map)
 {
 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
-	void *vaddr;
 	int ret;
 
 	ret = mutex_lock_interruptible(&shmem->vmap_lock);
 	if (ret)
-		return ERR_PTR(ret);
-	vaddr = drm_gem_shmem_vmap_locked(shmem);
+		return ret;
+	ret = drm_gem_shmem_vmap_locked(shmem, map);
 	mutex_unlock(&shmem->vmap_lock);
 
-	return vaddr;
+	return ret;
 }
 EXPORT_SYMBOL(drm_gem_shmem_vmap);
 
-static void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem)
+static void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem,
+					struct dma_buf_map *map)
 {
 	struct drm_gem_object *obj = &shmem->base;
-	struct dma_buf_map map = DMA_BUF_MAP_INIT_VADDR(shmem->vaddr);
 
 	if (WARN_ON_ONCE(!shmem->vmap_use_count))
 		return;
@@ -346,7 +355,7 @@ static void drm_gem_shmem_vunmap_locked(struct
drm_gem_shmem_object *shmem)
 		return;
 
 	if (obj->import_attach)
-		dma_buf_vunmap(obj->import_attach->dmabuf, &map);
+		dma_buf_vunmap(obj->import_attach->dmabuf, map);
 	else
 		vunmap(shmem->vaddr);
 
@@ -357,6 +366,7 @@ static void drm_gem_shmem_vunmap_locked(struct
drm_gem_shmem_object *shmem)
 /*
  * drm_gem_shmem_vunmap - Unmap a virtual mapping fo a shmem GEM object
  * @shmem: shmem GEM object
+ * @map: Kernel virtual address where the SHMEM GEM object was mapped
  *
  * This function cleans up a kernel virtual address mapping acquired by
  * drm_gem_shmem_vmap(). The mapping is only removed when the use count drops
to
@@ -366,12 +376,12 @@ static void drm_gem_shmem_vunmap_locked(struct
drm_gem_shmem_object *shmem)
  * also be called by drivers directly, in which case it will hide the
  * differences between dma-buf imported and natively allocated objects.
  */
-void drm_gem_shmem_vunmap(struct drm_gem_object *obj, void *vaddr)
+void drm_gem_shmem_vunmap(struct drm_gem_object *obj, struct dma_buf_map *map)
 {
 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
 
 	mutex_lock(&shmem->vmap_lock);
-	drm_gem_shmem_vunmap_locked(shmem);
+	drm_gem_shmem_vunmap_locked(shmem, map);
 	mutex_unlock(&shmem->vmap_lock);
 }
 EXPORT_SYMBOL(drm_gem_shmem_vunmap);
diff --git a/drivers/gpu/drm/drm_gem_vram_helper.c
b/drivers/gpu/drm/drm_gem_vram_helper.c
index 2d5ed30518f1..4d8553b28558 100644
--- a/drivers/gpu/drm/drm_gem_vram_helper.c
+++ b/drivers/gpu/drm/drm_gem_vram_helper.c
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
+#include <linux/dma-buf-map.h>
 #include <linux/module.h>
 
 #include <drm/drm_debugfs.h>
@@ -113,8 +114,8 @@ static void drm_gem_vram_cleanup(struct drm_gem_vram_object
*gbo)
 	 * up; only release the GEM object.
 	 */
 
-	WARN_ON(gbo->kmap_use_count);
-	WARN_ON(gbo->kmap.virtual);
+	WARN_ON(gbo->vmap_use_count);
+	WARN_ON(dma_buf_map_is_set(&gbo->map));
 
 	drm_gem_object_release(&gbo->bo.base);
 }
@@ -382,29 +383,37 @@ int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo)
 }
 EXPORT_SYMBOL(drm_gem_vram_unpin);
 
-static void *drm_gem_vram_kmap_locked(struct drm_gem_vram_object *gbo)
+static int drm_gem_vram_kmap_locked(struct drm_gem_vram_object *gbo,
+				    struct dma_buf_map *map)
 {
 	int ret;
-	struct ttm_bo_kmap_obj *kmap = &gbo->kmap;
-	bool is_iomem;
 
-	if (gbo->kmap_use_count > 0)
+	if (gbo->vmap_use_count > 0)
 		goto out;
 
-	ret = ttm_bo_kmap(&gbo->bo, 0, gbo->bo.num_pages, kmap);
+	ret = ttm_bo_vmap(&gbo->bo, &gbo->map);
 	if (ret)
-		return ERR_PTR(ret);
+		return ret;
 
 out:
-	++gbo->kmap_use_count;
-	return ttm_kmap_obj_virtual(kmap, &is_iomem);
+	++gbo->vmap_use_count;
+	*map = gbo->map;
+
+	return 0;
 }
 
-static void drm_gem_vram_kunmap_locked(struct drm_gem_vram_object *gbo)
+static void drm_gem_vram_kunmap_locked(struct drm_gem_vram_object *gbo,
+				       struct dma_buf_map *map)
 {
-	if (WARN_ON_ONCE(!gbo->kmap_use_count))
+	struct drm_device *dev = gbo->bo.base.dev;
+
+	if (drm_WARN_ON_ONCE(dev, !gbo->vmap_use_count))
 		return;
-	if (--gbo->kmap_use_count > 0)
+
+	if (drm_WARN_ON_ONCE(dev, !dma_buf_map_is_equal(&gbo->map, map)))
+		return; /* BUG: map not mapped from this BO */
+
+	if (--gbo->vmap_use_count > 0)
 		return;
 
 	/*
@@ -418,7 +427,9 @@ static void drm_gem_vram_kunmap_locked(struct
drm_gem_vram_object *gbo)
 /**
  * drm_gem_vram_vmap() - Pins and maps a GEM VRAM object into kernel address
  *                       space
- * @gbo:	The GEM VRAM object to map
+ * @gbo: The GEM VRAM object to map
+ * @map: Returns the kernel virtual address of the VRAM GEM object's
backing
+ *       store.
  *
  * The vmap function pins a GEM VRAM object to its current location, either
  * system or video memory, and maps its buffer into kernel address space.
@@ -427,48 +438,44 @@ static void drm_gem_vram_kunmap_locked(struct
drm_gem_vram_object *gbo)
  * unmap and unpin the GEM VRAM object.
  *
  * Returns:
- * The buffer's virtual address on success, or
- * an ERR_PTR()-encoded error code otherwise.
+ * 0 on success, or a negative error code otherwise.
  */
-void *drm_gem_vram_vmap(struct drm_gem_vram_object *gbo)
+int drm_gem_vram_vmap(struct drm_gem_vram_object *gbo, struct dma_buf_map *map)
 {
 	int ret;
-	void *base;
 
 	ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);
 	if (ret)
-		return ERR_PTR(ret);
+		return ret;
 
 	ret = drm_gem_vram_pin_locked(gbo, 0);
 	if (ret)
 		goto err_ttm_bo_unreserve;
-	base = drm_gem_vram_kmap_locked(gbo);
-	if (IS_ERR(base)) {
-		ret = PTR_ERR(base);
+	ret = drm_gem_vram_kmap_locked(gbo, map);
+	if (ret)
 		goto err_drm_gem_vram_unpin_locked;
-	}
 
 	ttm_bo_unreserve(&gbo->bo);
 
-	return base;
+	return 0;
 
 err_drm_gem_vram_unpin_locked:
 	drm_gem_vram_unpin_locked(gbo);
 err_ttm_bo_unreserve:
 	ttm_bo_unreserve(&gbo->bo);
-	return ERR_PTR(ret);
+	return ret;
 }
 EXPORT_SYMBOL(drm_gem_vram_vmap);
 
 /**
  * drm_gem_vram_vunmap() - Unmaps and unpins a GEM VRAM object
- * @gbo:	The GEM VRAM object to unmap
- * @vaddr:	The mapping's base address as returned by drm_gem_vram_vmap()
+ * @gbo: The GEM VRAM object to unmap
+ * @map: Kernel virtual address where the VRAM GEM object was mapped
  *
  * A call to drm_gem_vram_vunmap() unmaps and unpins a GEM VRAM buffer. See
  * the documentation for drm_gem_vram_vmap() for more information.
  */
-void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, void *vaddr)
+void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, struct dma_buf_map
*map)
 {
 	int ret;
 
@@ -476,7 +483,7 @@ void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo,
void *vaddr)
 	if (WARN_ONCE(ret, "ttm_bo_reserve_failed(): ret=%d\n", ret))
 		return;
 
-	drm_gem_vram_kunmap_locked(gbo);
+	drm_gem_vram_kunmap_locked(gbo, map);
 	drm_gem_vram_unpin_locked(gbo);
 
 	ttm_bo_unreserve(&gbo->bo);
@@ -567,15 +574,13 @@ static void drm_gem_vram_bo_driver_move_notify(struct
drm_gem_vram_object *gbo,
 					       bool evict,
 					       struct ttm_resource *new_mem)
 {
-	struct ttm_bo_kmap_obj *kmap = &gbo->kmap;
+	struct ttm_buffer_object *bo = &gbo->bo;
+	struct drm_device *dev = bo->base.dev;
 
-	if (WARN_ON_ONCE(gbo->kmap_use_count))
+	if (drm_WARN_ON_ONCE(dev, gbo->vmap_use_count))
 		return;
 
-	if (!kmap->virtual)
-		return;
-	ttm_bo_kunmap(kmap);
-	kmap->virtual = NULL;
+	ttm_bo_vunmap(bo, &gbo->map);
 }
 
 static int drm_gem_vram_bo_driver_move(struct drm_gem_vram_object *gbo,
@@ -832,37 +837,33 @@ static void drm_gem_vram_object_unpin(struct
drm_gem_object *gem)
 }
 
 /**
- * drm_gem_vram_object_vmap() - \
-	Implements &struct drm_gem_object_funcs.vmap
- * @gem:	The GEM object to map
+ * drm_gem_vram_object_vmap() -
+ *	Implements &struct drm_gem_object_funcs.vmap
+ * @gem: The GEM object to map
+ * @map: Returns the kernel virtual address of the VRAM GEM object's
backing
+ *       store.
  *
  * Returns:
- * The buffers virtual address on success, or
- * NULL otherwise.
+ * 0 on success, or a negative error code otherwise.
  */
-static void *drm_gem_vram_object_vmap(struct drm_gem_object *gem)
+static int drm_gem_vram_object_vmap(struct drm_gem_object *gem, struct
dma_buf_map *map)
 {
 	struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
-	void *base;
 
-	base = drm_gem_vram_vmap(gbo);
-	if (IS_ERR(base))
-		return NULL;
-	return base;
+	return drm_gem_vram_vmap(gbo, map);
 }
 
 /**
- * drm_gem_vram_object_vunmap() - \
-	Implements &struct drm_gem_object_funcs.vunmap
- * @gem:	The GEM object to unmap
- * @vaddr:	The mapping's base address
+ * drm_gem_vram_object_vunmap() -
+ *	Implements &struct drm_gem_object_funcs.vunmap
+ * @gem: The GEM object to unmap
+ * @map: Kernel virtual address where the VRAM GEM object was mapped
  */
-static void drm_gem_vram_object_vunmap(struct drm_gem_object *gem,
-				       void *vaddr)
+static void drm_gem_vram_object_vunmap(struct drm_gem_object *gem, struct
dma_buf_map *map)
 {
 	struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);
 
-	drm_gem_vram_vunmap(gbo, vaddr);
+	drm_gem_vram_vunmap(gbo, map);
 }
 
 /*
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_drv.h
b/drivers/gpu/drm/etnaviv/etnaviv_drv.h
index 9682c26d89bb..f5be627e1de0 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_drv.h
+++ b/drivers/gpu/drm/etnaviv/etnaviv_drv.h
@@ -51,7 +51,7 @@ int etnaviv_ioctl_gem_submit(struct drm_device *dev, void
*data,
 int etnaviv_gem_mmap(struct file *filp, struct vm_area_struct *vma);
 int etnaviv_gem_mmap_offset(struct drm_gem_object *obj, u64 *offset);
 struct sg_table *etnaviv_gem_prime_get_sg_table(struct drm_gem_object *obj);
-void *etnaviv_gem_prime_vmap(struct drm_gem_object *obj);
+int etnaviv_gem_prime_vmap(struct drm_gem_object *obj, struct dma_buf_map
*map);
 int etnaviv_gem_prime_mmap(struct drm_gem_object *obj,
 			   struct vm_area_struct *vma);
 struct drm_gem_object *etnaviv_gem_prime_import_sg_table(struct drm_device
*dev,
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
index a6d9932a32ae..bc2543dd987d 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
@@ -22,9 +22,14 @@ struct sg_table *etnaviv_gem_prime_get_sg_table(struct
drm_gem_object *obj)
 	return drm_prime_pages_to_sg(obj->dev, etnaviv_obj->pages, npages);
 }
 
-void *etnaviv_gem_prime_vmap(struct drm_gem_object *obj)
+int etnaviv_gem_prime_vmap(struct drm_gem_object *obj, struct dma_buf_map *map)
 {
-	return etnaviv_gem_vmap(obj);
+	void *vaddr = etnaviv_gem_vmap(obj);
+	if (!vaddr)
+		return -ENOMEM;
+	dma_buf_map_set_vaddr(map, vaddr);
+
+	return 0;
 }
 
 int etnaviv_gem_prime_mmap(struct drm_gem_object *obj,
diff --git a/drivers/gpu/drm/lima/lima_gem.c b/drivers/gpu/drm/lima/lima_gem.c
index 11223fe348df..832e5280a6ed 100644
--- a/drivers/gpu/drm/lima/lima_gem.c
+++ b/drivers/gpu/drm/lima/lima_gem.c
@@ -182,14 +182,14 @@ static int lima_gem_pin(struct drm_gem_object *obj)
 	return drm_gem_shmem_pin(obj);
 }
 
-static void *lima_gem_vmap(struct drm_gem_object *obj)
+static int lima_gem_vmap(struct drm_gem_object *obj, struct dma_buf_map *map)
 {
 	struct lima_bo *bo = to_lima_bo(obj);
 
 	if (bo->heap_size)
-		return ERR_PTR(-EINVAL);
+		return -EINVAL;
 
-	return drm_gem_shmem_vmap(obj);
+	return drm_gem_shmem_vmap(obj, map);
 }
 
 static int lima_gem_mmap(struct drm_gem_object *obj, struct vm_area_struct
*vma)
diff --git a/drivers/gpu/drm/lima/lima_sched.c
b/drivers/gpu/drm/lima/lima_sched.c
index dc6df9e9a40d..a070a85f8f36 100644
--- a/drivers/gpu/drm/lima/lima_sched.c
+++ b/drivers/gpu/drm/lima/lima_sched.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0 OR MIT
 /* Copyright 2017-2019 Qiang Yu <yuq825 at gmail.com> */
 
+#include <linux/dma-buf-map.h>
 #include <linux/kthread.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
@@ -303,6 +304,8 @@ static void lima_sched_build_error_task_list(struct
lima_sched_task *task)
 	struct lima_dump_chunk_buffer *buffer_chunk;
 	u32 size, task_size, mem_size;
 	int i;
+	struct dma_buf_map map;
+	int ret;
 
 	mutex_lock(&dev->error_task_list_lock);
 
@@ -388,15 +391,15 @@ static void lima_sched_build_error_task_list(struct
lima_sched_task *task)
 		} else {
 			buffer_chunk->size = lima_bo_size(bo);
 
-			data = drm_gem_shmem_vmap(&bo->base.base);
-			if (IS_ERR_OR_NULL(data)) {
+			ret = drm_gem_shmem_vmap(&bo->base.base, &map);
+			if (ret) {
 				kvfree(et);
 				goto out;
 			}
 
-			memcpy(buffer_chunk + 1, data, buffer_chunk->size);
+			memcpy(buffer_chunk + 1, map.vaddr, buffer_chunk->size);
 
-			drm_gem_shmem_vunmap(&bo->base.base, data);
+			drm_gem_shmem_vunmap(&bo->base.base, &map);
 		}
 
 		buffer_chunk = (void *)(buffer_chunk + 1) + buffer_chunk->size;
diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c
b/drivers/gpu/drm/mgag200/mgag200_mode.c
index 38672f9e5c4f..8ef76769b97f 100644
--- a/drivers/gpu/drm/mgag200/mgag200_mode.c
+++ b/drivers/gpu/drm/mgag200/mgag200_mode.c
@@ -9,6 +9,7 @@
  */
 
 #include <linux/delay.h>
+#include <linux/dma-buf-map.h>
 
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_atomic_state_helper.h>
@@ -1556,15 +1557,18 @@ mgag200_handle_damage(struct mga_device *mdev, struct
drm_framebuffer *fb,
 		      struct drm_rect *clip)
 {
 	struct drm_device *dev = &mdev->base;
+	struct dma_buf_map map;
 	void *vmap;
+	int ret;
 
-	vmap = drm_gem_shmem_vmap(fb->obj[0]);
-	if (drm_WARN_ON(dev, !vmap))
+	ret = drm_gem_shmem_vmap(fb->obj[0], &map);
+	if (drm_WARN_ON(dev, ret))
 		return; /* BUG: SHMEM BO should always be vmapped */
+	vmap = map.vaddr; /* TODO: Use mapping abstraction properly */
 
 	drm_fb_memcpy_dstclip(mdev->vram, vmap, fb, clip);
 
-	drm_gem_shmem_vunmap(fb->obj[0], vmap);
+	drm_gem_shmem_vunmap(fb->obj[0], &map);
 
 	/* Always scanout image at VRAM offset 0 */
 	mgag200_set_startadd(mdev, (u32)0);
diff --git a/drivers/gpu/drm/nouveau/Kconfig b/drivers/gpu/drm/nouveau/Kconfig
index 5dec1e5694b7..9436310d0854 100644
--- a/drivers/gpu/drm/nouveau/Kconfig
+++ b/drivers/gpu/drm/nouveau/Kconfig
@@ -6,6 +6,7 @@ config DRM_NOUVEAU
 	select FW_LOADER
 	select DRM_KMS_HELPER
 	select DRM_TTM
+	select DRM_TTM_HELPER
 	select BACKLIGHT_CLASS_DEVICE if DRM_NOUVEAU_BACKLIGHT
 	select ACPI_VIDEO if ACPI && X86 && BACKLIGHT_CLASS_DEVICE
&& INPUT
 	select X86_PLATFORM_DEVICES if ACPI && X86
diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.h
b/drivers/gpu/drm/nouveau/nouveau_bo.h
index 641ef6298a0e..6045b85a762a 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bo.h
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.h
@@ -39,8 +39,6 @@ struct nouveau_bo {
 	unsigned mode;
 
 	struct nouveau_drm_tile *tile;
-
-	struct ttm_bo_kmap_obj dma_buf_vmap;
 };
 
 static inline struct nouveau_bo *
diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c
b/drivers/gpu/drm/nouveau/nouveau_gem.c
index 9a421c3949de..f942b526b0a5 100644
--- a/drivers/gpu/drm/nouveau/nouveau_gem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
@@ -24,6 +24,8 @@
  *
  */
 
+#include <drm/drm_gem_ttm_helper.h>
+
 #include "nouveau_drv.h"
 #include "nouveau_dma.h"
 #include "nouveau_fence.h"
@@ -176,8 +178,8 @@ const struct drm_gem_object_funcs nouveau_gem_object_funcs =
{
 	.pin = nouveau_gem_prime_pin,
 	.unpin = nouveau_gem_prime_unpin,
 	.get_sg_table = nouveau_gem_prime_get_sg_table,
-	.vmap = nouveau_gem_prime_vmap,
-	.vunmap = nouveau_gem_prime_vunmap,
+	.vmap = drm_gem_ttm_vmap,
+	.vunmap = drm_gem_ttm_vunmap,
 };
 
 int
diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.h
b/drivers/gpu/drm/nouveau/nouveau_gem.h
index b35c180322e2..3b919c7c931c 100644
--- a/drivers/gpu/drm/nouveau/nouveau_gem.h
+++ b/drivers/gpu/drm/nouveau/nouveau_gem.h
@@ -37,7 +37,5 @@ extern void nouveau_gem_prime_unpin(struct drm_gem_object *);
 extern struct sg_table *nouveau_gem_prime_get_sg_table(struct drm_gem_object
*);
 extern struct drm_gem_object *nouveau_gem_prime_import_sg_table(
 	struct drm_device *, struct dma_buf_attachment *, struct sg_table *);
-extern void *nouveau_gem_prime_vmap(struct drm_gem_object *);
-extern void nouveau_gem_prime_vunmap(struct drm_gem_object *, void *);
 
 #endif
diff --git a/drivers/gpu/drm/nouveau/nouveau_prime.c
b/drivers/gpu/drm/nouveau/nouveau_prime.c
index a8264aebf3d4..2f16b5249283 100644
--- a/drivers/gpu/drm/nouveau/nouveau_prime.c
+++ b/drivers/gpu/drm/nouveau/nouveau_prime.c
@@ -35,26 +35,6 @@ struct sg_table *nouveau_gem_prime_get_sg_table(struct
drm_gem_object *obj)
 	return drm_prime_pages_to_sg(obj->dev, nvbo->bo.ttm->pages, npages);
 }
 
-void *nouveau_gem_prime_vmap(struct drm_gem_object *obj)
-{
-	struct nouveau_bo *nvbo = nouveau_gem_object(obj);
-	int ret;
-
-	ret = ttm_bo_kmap(&nvbo->bo, 0, nvbo->bo.num_pages,
-			  &nvbo->dma_buf_vmap);
-	if (ret)
-		return ERR_PTR(ret);
-
-	return nvbo->dma_buf_vmap.virtual;
-}
-
-void nouveau_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
-{
-	struct nouveau_bo *nvbo = nouveau_gem_object(obj);
-
-	ttm_bo_kunmap(&nvbo->dma_buf_vmap);
-}
-
 struct drm_gem_object *nouveau_gem_prime_import_sg_table(struct drm_device
*dev,
 							 struct dma_buf_attachment *attach,
 							 struct sg_table *sg)
diff --git a/drivers/gpu/drm/panfrost/panfrost_perfcnt.c
b/drivers/gpu/drm/panfrost/panfrost_perfcnt.c
index fdbc8d949135..5ab03d605f57 100644
--- a/drivers/gpu/drm/panfrost/panfrost_perfcnt.c
+++ b/drivers/gpu/drm/panfrost/panfrost_perfcnt.c
@@ -5,6 +5,7 @@
 #include <drm/drm_gem_shmem_helper.h>
 #include <drm/panfrost_drm.h>
 #include <linux/completion.h>
+#include <linux/dma-buf-map.h>
 #include <linux/iopoll.h>
 #include <linux/pm_runtime.h>
 #include <linux/slab.h>
@@ -72,6 +73,7 @@ static int panfrost_perfcnt_enable_locked(struct
panfrost_device *pfdev,
 {
 	struct panfrost_file_priv *user = file_priv->driver_priv;
 	struct panfrost_perfcnt *perfcnt = pfdev->perfcnt;
+	struct dma_buf_map map;
 	struct drm_gem_shmem_object *bo;
 	u32 cfg, as;
 	int ret;
@@ -103,11 +105,10 @@ static int panfrost_perfcnt_enable_locked(struct
panfrost_device *pfdev,
 		goto err_close_bo;
 	}
 
-	perfcnt->buf = drm_gem_shmem_vmap(&bo->base);
-	if (IS_ERR(perfcnt->buf)) {
-		ret = PTR_ERR(perfcnt->buf);
+	ret = drm_gem_shmem_vmap(&bo->base, &map);
+	if (ret)
 		goto err_put_mapping;
-	}
+	perfcnt->buf = map.vaddr;
 
 	/*
 	 * Invalidate the cache and clear the counters to start from a fresh
@@ -163,7 +164,7 @@ static int panfrost_perfcnt_enable_locked(struct
panfrost_device *pfdev,
 	return 0;
 
 err_vunmap:
-	drm_gem_shmem_vunmap(&bo->base, perfcnt->buf);
+	drm_gem_shmem_vunmap(&bo->base, &map);
 err_put_mapping:
 	panfrost_gem_mapping_put(perfcnt->mapping);
 err_close_bo:
@@ -180,6 +181,7 @@ static int panfrost_perfcnt_disable_locked(struct
panfrost_device *pfdev,
 {
 	struct panfrost_file_priv *user = file_priv->driver_priv;
 	struct panfrost_perfcnt *perfcnt = pfdev->perfcnt;
+	struct dma_buf_map map = DMA_BUF_MAP_INIT_VADDR(perfcnt->buf);
 
 	if (user != perfcnt->user)
 		return -EINVAL;
@@ -192,7 +194,7 @@ static int panfrost_perfcnt_disable_locked(struct
panfrost_device *pfdev,
 		  GPU_PERFCNT_CFG_MODE(GPU_PERFCNT_CFG_MODE_OFF));
 
 	perfcnt->user = NULL;
-	drm_gem_shmem_vunmap(&perfcnt->mapping->obj->base.base,
perfcnt->buf);
+	drm_gem_shmem_vunmap(&perfcnt->mapping->obj->base.base,
&map);
 	perfcnt->buf = NULL;
 	panfrost_gem_close(&perfcnt->mapping->obj->base.base, file_priv);
 	panfrost_mmu_as_put(pfdev, perfcnt->mapping->mmu);
diff --git a/drivers/gpu/drm/qxl/qxl_display.c
b/drivers/gpu/drm/qxl/qxl_display.c
index 45fd76e04bdc..e165fa9b2089 100644
--- a/drivers/gpu/drm/qxl/qxl_display.c
+++ b/drivers/gpu/drm/qxl/qxl_display.c
@@ -25,6 +25,7 @@
 
 #include <linux/crc32.h>
 #include <linux/delay.h>
+#include <linux/dma-buf-map.h>
 
 #include <drm/drm_drv.h>
 #include <drm/drm_atomic.h>
@@ -581,6 +582,8 @@ static void qxl_cursor_atomic_update(struct drm_plane
*plane,
 	struct drm_gem_object *obj;
 	struct qxl_bo *cursor_bo = NULL, *user_bo = NULL, *old_cursor_bo = NULL;
 	int ret;
+	struct dma_buf_map user_map;
+	struct dma_buf_map cursor_map;
 	void *user_ptr;
 	int size = 64*64*4;
 
@@ -595,9 +598,10 @@ static void qxl_cursor_atomic_update(struct drm_plane
*plane,
 		user_bo = gem_to_qxl_bo(obj);
 
 		/* pinning is done in the prepare/cleanup framevbuffer */
-		ret = qxl_bo_kmap(user_bo, &user_ptr);
+		ret = qxl_bo_kmap(user_bo, &user_map);
 		if (ret)
 			goto out_free_release;
+		user_ptr = user_map.vaddr; /* TODO: Use mapping abstraction properly */
 
 		ret = qxl_alloc_bo_reserved(qdev, release,
 					    sizeof(struct qxl_cursor) + size,
@@ -613,7 +617,7 @@ static void qxl_cursor_atomic_update(struct drm_plane
*plane,
 		if (ret)
 			goto out_unpin;
 
-		ret = qxl_bo_kmap(cursor_bo, (void **)&cursor);
+		ret = qxl_bo_kmap(cursor_bo, &cursor_map);
 		if (ret)
 			goto out_backoff;
 
@@ -1133,6 +1137,7 @@ int qxl_create_monitors_object(struct qxl_device *qdev)
 {
 	int ret;
 	struct drm_gem_object *gobj;
+	struct dma_buf_map map;
 	int monitors_config_size = sizeof(struct qxl_monitors_config) +
 		qxl_num_crtc * sizeof(struct qxl_head);
 
@@ -1149,7 +1154,7 @@ int qxl_create_monitors_object(struct qxl_device *qdev)
 	if (ret)
 		return ret;
 
-	qxl_bo_kmap(qdev->monitors_config_bo, NULL);
+	qxl_bo_kmap(qdev->monitors_config_bo, &map);
 
 	qdev->monitors_config = qdev->monitors_config_bo->kptr;
 	qdev->ram_header->monitors_config diff --git
a/drivers/gpu/drm/qxl/qxl_draw.c b/drivers/gpu/drm/qxl/qxl_draw.c
index 3599db096973..7b7acb910780 100644
--- a/drivers/gpu/drm/qxl/qxl_draw.c
+++ b/drivers/gpu/drm/qxl/qxl_draw.c
@@ -20,6 +20,8 @@
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
+#include <linux/dma-buf-map.h>
+
 #include <drm/drm_fourcc.h>
 
 #include "qxl_drv.h"
@@ -42,13 +44,15 @@ static struct qxl_rect *drawable_set_clipping(struct
qxl_device *qdev,
 					      unsigned int num_clips,
 					      struct qxl_bo *clips_bo)
 {
+	struct dma_buf_map map;
 	struct qxl_clip_rects *dev_clips;
 	int ret;
 
-	ret = qxl_bo_kmap(clips_bo, (void **)&dev_clips);
-	if (ret) {
+	ret = qxl_bo_kmap(clips_bo, &map);
+	if (ret)
 		return NULL;
-	}
+	dev_clips = map.vaddr; /* TODO: Use mapping abstraction properly */
+
 	dev_clips->num_rects = num_clips;
 	dev_clips->chunk.next_chunk = 0;
 	dev_clips->chunk.prev_chunk = 0;
@@ -142,6 +146,7 @@ void qxl_draw_dirty_fb(struct qxl_device *qdev,
 	int stride = fb->pitches[0];
 	/* depth is not actually interesting, we don't mask with it */
 	int depth = fb->format->cpp[0] * 8;
+	struct dma_buf_map surface_map;
 	uint8_t *surface_base;
 	struct qxl_release *release;
 	struct qxl_bo *clips_bo;
@@ -197,9 +202,10 @@ void qxl_draw_dirty_fb(struct qxl_device *qdev,
 	if (ret)
 		goto out_release_backoff;
 
-	ret = qxl_bo_kmap(bo, (void **)&surface_base);
+	ret = qxl_bo_kmap(bo, &surface_map);
 	if (ret)
 		goto out_release_backoff;
+	surface_base = surface_map.vaddr; /* TODO: Use mapping abstraction properly */
 
 	ret = qxl_image_init(qdev, release, dimage, surface_base,
 			     left - dumb_shadow_offset,
diff --git a/drivers/gpu/drm/qxl/qxl_drv.h b/drivers/gpu/drm/qxl/qxl_drv.h
index 3602e8b34189..eb437fea5d9e 100644
--- a/drivers/gpu/drm/qxl/qxl_drv.h
+++ b/drivers/gpu/drm/qxl/qxl_drv.h
@@ -30,6 +30,7 @@
  * Definitions taken from spice-protocol, plus kernel driver specific bits.
  */
 
+#include <linux/dma-buf-map.h>
 #include <linux/dma-fence.h>
 #include <linux/firmware.h>
 #include <linux/platform_device.h>
@@ -50,6 +51,8 @@
 
 #include "qxl_dev.h"
 
+struct dma_buf_map;
+
 #define DRIVER_AUTHOR		"Dave Airlie"
 
 #define DRIVER_NAME		"qxl"
@@ -79,7 +82,7 @@ struct qxl_bo {
 	/* Protected by tbo.reserved */
 	struct ttm_place		placements[3];
 	struct ttm_placement		placement;
-	struct ttm_bo_kmap_obj		kmap;
+	struct dma_buf_map		map;
 	void				*kptr;
 	unsigned int                    map_count;
 	int                             type;
@@ -335,7 +338,6 @@ int qxl_gem_object_open(struct drm_gem_object *obj, struct
drm_file *file_priv);
 void qxl_gem_object_close(struct drm_gem_object *obj,
 			  struct drm_file *file_priv);
 void qxl_bo_force_delete(struct qxl_device *qdev);
-int qxl_bo_kmap(struct qxl_bo *bo, void **ptr);
 
 /* qxl_dumb.c */
 int qxl_mode_dumb_create(struct drm_file *file_priv,
@@ -445,8 +447,9 @@ struct sg_table *qxl_gem_prime_get_sg_table(struct
drm_gem_object *obj);
 struct drm_gem_object *qxl_gem_prime_import_sg_table(
 	struct drm_device *dev, struct dma_buf_attachment *attach,
 	struct sg_table *sgt);
-void *qxl_gem_prime_vmap(struct drm_gem_object *obj);
-void qxl_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr);
+int qxl_gem_prime_vmap(struct drm_gem_object *obj, struct dma_buf_map *map);
+void qxl_gem_prime_vunmap(struct drm_gem_object *obj,
+			  struct dma_buf_map *map);
 int qxl_gem_prime_mmap(struct drm_gem_object *obj,
 				struct vm_area_struct *vma);
 
diff --git a/drivers/gpu/drm/qxl/qxl_object.c b/drivers/gpu/drm/qxl/qxl_object.c
index 940e99354f49..755df4d8f95f 100644
--- a/drivers/gpu/drm/qxl/qxl_object.c
+++ b/drivers/gpu/drm/qxl/qxl_object.c
@@ -23,10 +23,12 @@
  *          Alon Levy
  */
 
+#include <linux/dma-buf-map.h>
+#include <linux/io-mapping.h>
+
 #include "qxl_drv.h"
 #include "qxl_object.h"
 
-#include <linux/io-mapping.h>
 static void qxl_ttm_bo_destroy(struct ttm_buffer_object *tbo)
 {
 	struct qxl_bo *bo;
@@ -152,24 +154,27 @@ int qxl_bo_create(struct qxl_device *qdev,
 	return 0;
 }
 
-int qxl_bo_kmap(struct qxl_bo *bo, void **ptr)
+int qxl_bo_kmap(struct qxl_bo *bo, struct dma_buf_map *map)
 {
-	bool is_iomem;
 	int r;
 
 	if (bo->kptr) {
-		if (ptr)
-			*ptr = bo->kptr;
 		bo->map_count++;
-		return 0;
+		goto out;
 	}
-	r = ttm_bo_kmap(&bo->tbo, 0, bo->tbo.num_pages, &bo->kmap);
+	r = ttm_bo_vmap(&bo->tbo, &bo->map);
 	if (r)
 		return r;
-	bo->kptr = ttm_kmap_obj_virtual(&bo->kmap, &is_iomem);
-	if (ptr)
-		*ptr = bo->kptr;
 	bo->map_count = 1;
+
+	/* TODO: Remove kptr in favor of map everywhere. */
+	if (bo->map.is_iomem)
+		bo->kptr = (void *)bo->map.vaddr_iomem;
+	else
+		bo->kptr = bo->map.vaddr;
+
+out:
+	*map = bo->map;
 	return 0;
 }
 
@@ -180,6 +185,7 @@ void *qxl_bo_kmap_atomic_page(struct qxl_device *qdev,
 	void *rptr;
 	int ret;
 	struct io_mapping *map;
+	struct dma_buf_map bo_map;
 
 	if (bo->tbo.mem.mem_type == TTM_PL_VRAM)
 		map = qdev->vram_mapping;
@@ -196,9 +202,10 @@ void *qxl_bo_kmap_atomic_page(struct qxl_device *qdev,
 		return rptr;
 	}
 
-	ret = qxl_bo_kmap(bo, &rptr);
+	ret = qxl_bo_kmap(bo, &bo_map);
 	if (ret)
 		return NULL;
+	rptr = bo_map.vaddr; /* TODO: Use mapping abstraction properly */
 
 	rptr += page_offset * PAGE_SIZE;
 	return rptr;
@@ -212,7 +219,7 @@ void qxl_bo_kunmap(struct qxl_bo *bo)
 	if (bo->map_count > 0)
 		return;
 	bo->kptr = NULL;
-	ttm_bo_kunmap(&bo->kmap);
+	ttm_bo_vunmap(&bo->tbo, &bo->map);
 }
 
 void qxl_bo_kunmap_atomic_page(struct qxl_device *qdev,
diff --git a/drivers/gpu/drm/qxl/qxl_object.h b/drivers/gpu/drm/qxl/qxl_object.h
index 09a5c818324d..ebf24c9d2bf2 100644
--- a/drivers/gpu/drm/qxl/qxl_object.h
+++ b/drivers/gpu/drm/qxl/qxl_object.h
@@ -63,7 +63,7 @@ extern int qxl_bo_create(struct qxl_device *qdev,
 			 bool kernel, bool pinned, u32 domain,
 			 struct qxl_surface *surf,
 			 struct qxl_bo **bo_ptr);
-extern int qxl_bo_kmap(struct qxl_bo *bo, void **ptr);
+extern int qxl_bo_kmap(struct qxl_bo *bo, struct dma_buf_map *map);
 extern void qxl_bo_kunmap(struct qxl_bo *bo);
 void *qxl_bo_kmap_atomic_page(struct qxl_device *qdev, struct qxl_bo *bo, int
page_offset);
 void qxl_bo_kunmap_atomic_page(struct qxl_device *qdev, struct qxl_bo *bo, void
*map);
diff --git a/drivers/gpu/drm/qxl/qxl_prime.c b/drivers/gpu/drm/qxl/qxl_prime.c
index 7d3816fca5a8..4aa949799446 100644
--- a/drivers/gpu/drm/qxl/qxl_prime.c
+++ b/drivers/gpu/drm/qxl/qxl_prime.c
@@ -54,20 +54,20 @@ struct drm_gem_object *qxl_gem_prime_import_sg_table(
 	return ERR_PTR(-ENOSYS);
 }
 
-void *qxl_gem_prime_vmap(struct drm_gem_object *obj)
+int qxl_gem_prime_vmap(struct drm_gem_object *obj, struct dma_buf_map *map)
 {
 	struct qxl_bo *bo = gem_to_qxl_bo(obj);
-	void *ptr;
 	int ret;
 
-	ret = qxl_bo_kmap(bo, &ptr);
+	ret = qxl_bo_kmap(bo, map);
 	if (ret < 0)
-		return ERR_PTR(ret);
+		return ret;
 
-	return ptr;
+	return 0;
 }
 
-void qxl_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
+void qxl_gem_prime_vunmap(struct drm_gem_object *obj,
+			  struct dma_buf_map *map)
 {
 	struct qxl_bo *bo = gem_to_qxl_bo(obj);
 
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 5d54bccebd4d..44cb5ee6fc20 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -509,7 +509,6 @@ struct radeon_bo {
 	/* Constant after initialization */
 	struct radeon_device		*rdev;
 
-	struct ttm_bo_kmap_obj		dma_buf_vmap;
 	pid_t				pid;
 
 #ifdef CONFIG_MMU_NOTIFIER
diff --git a/drivers/gpu/drm/radeon/radeon_gem.c
b/drivers/gpu/drm/radeon/radeon_gem.c
index 0ccd7213e41f..d2876ce3bc9e 100644
--- a/drivers/gpu/drm/radeon/radeon_gem.c
+++ b/drivers/gpu/drm/radeon/radeon_gem.c
@@ -31,6 +31,7 @@
 #include <drm/drm_debugfs.h>
 #include <drm/drm_device.h>
 #include <drm/drm_file.h>
+#include <drm/drm_gem_ttm_helper.h>
 #include <drm/radeon_drm.h>
 
 #include "radeon.h"
@@ -40,8 +41,6 @@ struct dma_buf *radeon_gem_prime_export(struct drm_gem_object
*gobj,
 struct sg_table *radeon_gem_prime_get_sg_table(struct drm_gem_object *obj);
 int radeon_gem_prime_pin(struct drm_gem_object *obj);
 void radeon_gem_prime_unpin(struct drm_gem_object *obj);
-void *radeon_gem_prime_vmap(struct drm_gem_object *obj);
-void radeon_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr);
 
 static const struct drm_gem_object_funcs radeon_gem_object_funcs;
 
@@ -235,8 +234,8 @@ static const struct drm_gem_object_funcs
radeon_gem_object_funcs = {
 	.pin = radeon_gem_prime_pin,
 	.unpin = radeon_gem_prime_unpin,
 	.get_sg_table = radeon_gem_prime_get_sg_table,
-	.vmap = radeon_gem_prime_vmap,
-	.vunmap = radeon_gem_prime_vunmap,
+	.vmap = drm_gem_ttm_vmap,
+	.vunmap = drm_gem_ttm_vunmap,
 };
 
 /*
diff --git a/drivers/gpu/drm/radeon/radeon_prime.c
b/drivers/gpu/drm/radeon/radeon_prime.c
index b9de0e51c0be..088d39a51c0d 100644
--- a/drivers/gpu/drm/radeon/radeon_prime.c
+++ b/drivers/gpu/drm/radeon/radeon_prime.c
@@ -39,26 +39,6 @@ struct sg_table *radeon_gem_prime_get_sg_table(struct
drm_gem_object *obj)
 	return drm_prime_pages_to_sg(obj->dev, bo->tbo.ttm->pages, npages);
 }
 
-void *radeon_gem_prime_vmap(struct drm_gem_object *obj)
-{
-	struct radeon_bo *bo = gem_to_radeon_bo(obj);
-	int ret;
-
-	ret = ttm_bo_kmap(&bo->tbo, 0, bo->tbo.num_pages,
-			  &bo->dma_buf_vmap);
-	if (ret)
-		return ERR_PTR(ret);
-
-	return bo->dma_buf_vmap.virtual;
-}
-
-void radeon_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
-{
-	struct radeon_bo *bo = gem_to_radeon_bo(obj);
-
-	ttm_bo_kunmap(&bo->dma_buf_vmap);
-}
-
 struct drm_gem_object *radeon_gem_prime_import_sg_table(struct drm_device *dev,
 							struct dma_buf_attachment *attach,
 							struct sg_table *sg)
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
index 7d5ebb10323b..7971f57436dd 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
@@ -532,26 +532,32 @@ rockchip_gem_prime_import_sg_table(struct drm_device *drm,
 	return ERR_PTR(ret);
 }
 
-void *rockchip_gem_prime_vmap(struct drm_gem_object *obj)
+int rockchip_gem_prime_vmap(struct drm_gem_object *obj, struct dma_buf_map
*map)
 {
 	struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
 
-	if (rk_obj->pages)
-		return vmap(rk_obj->pages, rk_obj->num_pages, VM_MAP,
-			    pgprot_writecombine(PAGE_KERNEL));
+	if (rk_obj->pages) {
+		void *vaddr = vmap(rk_obj->pages, rk_obj->num_pages, VM_MAP,
+				  pgprot_writecombine(PAGE_KERNEL));
+		if (!vaddr)
+			return -ENOMEM;
+		dma_buf_map_set_vaddr(map, vaddr);
+		return 0;
+	}
 
 	if (rk_obj->dma_attrs & DMA_ATTR_NO_KERNEL_MAPPING)
-		return NULL;
+		return -ENOMEM;
+	dma_buf_map_set_vaddr(map, rk_obj->kvaddr);
 
-	return rk_obj->kvaddr;
+	return 0;
 }
 
-void rockchip_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
+void rockchip_gem_prime_vunmap(struct drm_gem_object *obj, struct dma_buf_map
*map)
 {
 	struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
 
 	if (rk_obj->pages) {
-		vunmap(vaddr);
+		vunmap(map->vaddr);
 		return;
 	}
 
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_gem.h
b/drivers/gpu/drm/rockchip/rockchip_drm_gem.h
index 7ffc541bea07..5a70a56cd406 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_gem.h
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_gem.h
@@ -31,8 +31,8 @@ struct drm_gem_object *
 rockchip_gem_prime_import_sg_table(struct drm_device *dev,
 				   struct dma_buf_attachment *attach,
 				   struct sg_table *sg);
-void *rockchip_gem_prime_vmap(struct drm_gem_object *obj);
-void rockchip_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr);
+int rockchip_gem_prime_vmap(struct drm_gem_object *obj, struct dma_buf_map
*map);
+void rockchip_gem_prime_vunmap(struct drm_gem_object *obj, struct dma_buf_map
*map);
 
 /* drm driver mmap file operations */
 int rockchip_gem_mmap(struct file *filp, struct vm_area_struct *vma);
diff --git a/drivers/gpu/drm/tiny/cirrus.c b/drivers/gpu/drm/tiny/cirrus.c
index 744a8e337e41..c02e35ed6e76 100644
--- a/drivers/gpu/drm/tiny/cirrus.c
+++ b/drivers/gpu/drm/tiny/cirrus.c
@@ -17,6 +17,7 @@
  */
 
 #include <linux/console.h>
+#include <linux/dma-buf-map.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 
@@ -314,6 +315,7 @@ static int cirrus_fb_blit_rect(struct drm_framebuffer *fb,
 			       struct drm_rect *rect)
 {
 	struct cirrus_device *cirrus = to_cirrus(fb->dev);
+	struct dma_buf_map map;
 	void *vmap;
 	int idx, ret;
 
@@ -321,10 +323,10 @@ static int cirrus_fb_blit_rect(struct drm_framebuffer *fb,
 	if (!drm_dev_enter(&cirrus->dev, &idx))
 		goto out;
 
-	ret = -ENOMEM;
-	vmap = drm_gem_shmem_vmap(fb->obj[0]);
-	if (!vmap)
+	ret = drm_gem_shmem_vmap(fb->obj[0], &map);
+	if (ret)
 		goto out_dev_exit;
+	vmap = map.vaddr; /* TODO: Use mapping abstraction properly */
 
 	if (cirrus->cpp == fb->format->cpp[0])
 		drm_fb_memcpy_dstclip(cirrus->vram,
@@ -343,7 +345,7 @@ static int cirrus_fb_blit_rect(struct drm_framebuffer *fb,
 	else
 		WARN_ON_ONCE("cpp mismatch");
 
-	drm_gem_shmem_vunmap(fb->obj[0], vmap);
+	drm_gem_shmem_vunmap(fb->obj[0], &map);
 	ret = 0;
 
 out_dev_exit:
diff --git a/drivers/gpu/drm/tiny/gm12u320.c b/drivers/gpu/drm/tiny/gm12u320.c
index cc397671f689..12a890cea6e9 100644
--- a/drivers/gpu/drm/tiny/gm12u320.c
+++ b/drivers/gpu/drm/tiny/gm12u320.c
@@ -248,6 +248,7 @@ static void gm12u320_copy_fb_to_blocks(struct
gm12u320_device *gm12u320)
 {
 	int block, dst_offset, len, remain, ret, x1, x2, y1, y2;
 	struct drm_framebuffer *fb;
+	struct dma_buf_map map;
 	void *vaddr;
 	u8 *src;
 
@@ -262,11 +263,12 @@ static void gm12u320_copy_fb_to_blocks(struct
gm12u320_device *gm12u320)
 	y1 = gm12u320->fb_update.rect.y1;
 	y2 = gm12u320->fb_update.rect.y2;
 
-	vaddr = drm_gem_shmem_vmap(fb->obj[0]);
-	if (IS_ERR(vaddr)) {
-		GM12U320_ERR("failed to vmap fb: %ld\n", PTR_ERR(vaddr));
+	ret = drm_gem_shmem_vmap(fb->obj[0], &map);
+	if (ret) {
+		GM12U320_ERR("failed to vmap fb: %d\n", ret);
 		goto put_fb;
 	}
+	vaddr = map.vaddr; /* TODO: Use mapping abstraction properly */
 
 	if (fb->obj[0]->import_attach) {
 		ret = dma_buf_begin_cpu_access(
@@ -318,7 +320,7 @@ static void gm12u320_copy_fb_to_blocks(struct
gm12u320_device *gm12u320)
 			GM12U320_ERR("dma_buf_end_cpu_access err: %d\n", ret);
 	}
 vunmap:
-	drm_gem_shmem_vunmap(fb->obj[0], vaddr);
+	drm_gem_shmem_vunmap(fb->obj[0], &map);
 put_fb:
 	drm_framebuffer_put(fb);
 	gm12u320->fb_update.fb = NULL;
diff --git a/drivers/gpu/drm/udl/udl_modeset.c
b/drivers/gpu/drm/udl/udl_modeset.c
index fef43f4e3bac..42eeba1dfdbf 100644
--- a/drivers/gpu/drm/udl/udl_modeset.c
+++ b/drivers/gpu/drm/udl/udl_modeset.c
@@ -276,6 +276,7 @@ static int udl_handle_damage(struct drm_framebuffer *fb, int
x, int y,
 	struct urb *urb;
 	struct drm_rect clip;
 	int log_bpp;
+	struct dma_buf_map map;
 	void *vaddr;
 
 	ret = udl_log_cpp(fb->format->cpp[0]);
@@ -296,11 +297,12 @@ static int udl_handle_damage(struct drm_framebuffer *fb,
int x, int y,
 			return ret;
 	}
 
-	vaddr = drm_gem_shmem_vmap(fb->obj[0]);
-	if (IS_ERR(vaddr)) {
+	ret = drm_gem_shmem_vmap(fb->obj[0], &map);
+	if (ret) {
 		DRM_ERROR("failed to vmap fb\n");
 		goto out_dma_buf_end_cpu_access;
 	}
+	vaddr = map.vaddr; /* TODO: Use mapping abstraction properly */
 
 	urb = udl_get_urb(dev);
 	if (!urb)
@@ -333,7 +335,7 @@ static int udl_handle_damage(struct drm_framebuffer *fb, int
x, int y,
 	ret = 0;
 
 out_drm_gem_shmem_vunmap:
-	drm_gem_shmem_vunmap(fb->obj[0], vaddr);
+	drm_gem_shmem_vunmap(fb->obj[0], &map);
 out_dma_buf_end_cpu_access:
 	if (import_attach) {
 		tmp_ret = dma_buf_end_cpu_access(import_attach->dmabuf,
diff --git a/drivers/gpu/drm/vboxvideo/vbox_mode.c
b/drivers/gpu/drm/vboxvideo/vbox_mode.c
index 931c55126148..f268fb258c83 100644
--- a/drivers/gpu/drm/vboxvideo/vbox_mode.c
+++ b/drivers/gpu/drm/vboxvideo/vbox_mode.c
@@ -9,6 +9,8 @@
  *          Michael Thayer <michael.thayer at oracle.com,
  *          Hans de Goede <hdegoede at redhat.com>
  */
+
+#include <linux/dma-buf-map.h>
 #include <linux/export.h>
 
 #include <drm/drm_atomic.h>
@@ -384,6 +386,8 @@ static void vbox_cursor_atomic_update(struct drm_plane
*plane,
 	u32 height = plane->state->crtc_h;
 	size_t data_size, mask_size;
 	u32 flags;
+	struct dma_buf_map map;
+	int ret;
 	u8 *src;
 
 	/*
@@ -397,8 +401,8 @@ static void vbox_cursor_atomic_update(struct drm_plane
*plane,
 
 	vbox_crtc->cursor_enabled = true;
 
-	src = drm_gem_vram_vmap(gbo);
-	if (IS_ERR(src)) {
+	ret = drm_gem_vram_vmap(gbo, &map);
+	if (ret) {
 		/*
 		 * BUG: we should have pinned the BO in prepare_fb().
 		 */
@@ -406,6 +410,7 @@ static void vbox_cursor_atomic_update(struct drm_plane
*plane,
 		DRM_WARN("Could not map cursor bo, skipping update\n");
 		return;
 	}
+	src = map.vaddr; /* TODO: Use mapping abstraction properly */
 
 	/*
 	 * The mask must be calculated based on the alpha
@@ -416,7 +421,7 @@ static void vbox_cursor_atomic_update(struct drm_plane
*plane,
 	data_size = width * height * 4 + mask_size;
 
 	copy_cursor_image(src, vbox->cursor_data, width, height, mask_size);
-	drm_gem_vram_vunmap(gbo, src);
+	drm_gem_vram_vunmap(gbo, &map);
 
 	flags = VBOX_MOUSE_POINTER_VISIBLE | VBOX_MOUSE_POINTER_SHAPE |
 		VBOX_MOUSE_POINTER_ALPHA;
diff --git a/drivers/gpu/drm/vc4/vc4_bo.c b/drivers/gpu/drm/vc4/vc4_bo.c
index 557f0d1e6437..f290a9a942dc 100644
--- a/drivers/gpu/drm/vc4/vc4_bo.c
+++ b/drivers/gpu/drm/vc4/vc4_bo.c
@@ -785,16 +785,16 @@ int vc4_prime_mmap(struct drm_gem_object *obj, struct
vm_area_struct *vma)
 	return drm_gem_cma_prime_mmap(obj, vma);
 }
 
-void *vc4_prime_vmap(struct drm_gem_object *obj)
+int vc4_prime_vmap(struct drm_gem_object *obj, struct dma_buf_map *map)
 {
 	struct vc4_bo *bo = to_vc4_bo(obj);
 
 	if (bo->validated_shader) {
 		DRM_DEBUG("mmaping of shader BOs not allowed.\n");
-		return ERR_PTR(-EINVAL);
+		return -EINVAL;
 	}
 
-	return drm_gem_cma_prime_vmap(obj);
+	return drm_gem_cma_prime_vmap(obj, map);
 }
 
 struct drm_gem_object *
diff --git a/drivers/gpu/drm/vc4/vc4_drv.h b/drivers/gpu/drm/vc4/vc4_drv.h
index cc79b1aaa878..904f2c36c963 100644
--- a/drivers/gpu/drm/vc4/vc4_drv.h
+++ b/drivers/gpu/drm/vc4/vc4_drv.h
@@ -806,7 +806,7 @@ int vc4_prime_mmap(struct drm_gem_object *obj, struct
vm_area_struct *vma);
 struct drm_gem_object *vc4_prime_import_sg_table(struct drm_device *dev,
 						 struct dma_buf_attachment *attach,
 						 struct sg_table *sgt);
-void *vc4_prime_vmap(struct drm_gem_object *obj);
+int vc4_prime_vmap(struct drm_gem_object *obj, struct dma_buf_map *map);
 int vc4_bo_cache_init(struct drm_device *dev);
 void vc4_bo_cache_destroy(struct drm_device *dev);
 int vc4_bo_inc_usecnt(struct vc4_bo *bo);
diff --git a/drivers/gpu/drm/vgem/vgem_drv.c b/drivers/gpu/drm/vgem/vgem_drv.c
index fa54a6d1403d..b2aa26e1e4a2 100644
--- a/drivers/gpu/drm/vgem/vgem_drv.c
+++ b/drivers/gpu/drm/vgem/vgem_drv.c
@@ -361,24 +361,30 @@ static struct drm_gem_object
*vgem_prime_import_sg_table(struct drm_device *dev,
 	return &obj->base;
 }
 
-static void *vgem_prime_vmap(struct drm_gem_object *obj)
+static int vgem_prime_vmap(struct drm_gem_object *obj, struct dma_buf_map *map)
 {
 	struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
 	long n_pages = obj->size >> PAGE_SHIFT;
 	struct page **pages;
+	void *vaddr;
 
 	pages = vgem_pin_pages(bo);
 	if (IS_ERR(pages))
-		return NULL;
+		return PTR_ERR(pages);
+
+	vaddr = vmap(pages, n_pages, 0, pgprot_writecombine(PAGE_KERNEL));
+	if (!vaddr)
+		return -ENOMEM;
+	dma_buf_map_set_vaddr(map, vaddr);
 
-	return vmap(pages, n_pages, 0, pgprot_writecombine(PAGE_KERNEL));
+	return 0;
 }
 
-static void vgem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
+static void vgem_prime_vunmap(struct drm_gem_object *obj, struct dma_buf_map
*map)
 {
 	struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
 
-	vunmap(vaddr);
+	vunmap(map->vaddr);
 	vgem_unpin_pages(bo);
 }
 
diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.c
b/drivers/gpu/drm/xen/xen_drm_front_gem.c
index 4f34ef34ba60..74db5a840bed 100644
--- a/drivers/gpu/drm/xen/xen_drm_front_gem.c
+++ b/drivers/gpu/drm/xen/xen_drm_front_gem.c
@@ -290,22 +290,28 @@ int xen_drm_front_gem_mmap(struct file *filp, struct
vm_area_struct *vma)
 	return gem_mmap_obj(xen_obj, vma);
 }
 
-void *xen_drm_front_gem_prime_vmap(struct drm_gem_object *gem_obj)
+int xen_drm_front_gem_prime_vmap(struct drm_gem_object *gem_obj, struct
dma_buf_map *map)
 {
 	struct xen_gem_object *xen_obj = to_xen_gem_obj(gem_obj);
+	void *vaddr;
 
 	if (!xen_obj->pages)
-		return NULL;
+		return -ENOMEM;
 
 	/* Please see comment in gem_mmap_obj on mapping and attributes. */
-	return vmap(xen_obj->pages, xen_obj->num_pages,
-		    VM_MAP, PAGE_KERNEL);
+	vaddr = vmap(xen_obj->pages, xen_obj->num_pages,
+		     VM_MAP, PAGE_KERNEL);
+	if (!vaddr)
+		return -ENOMEM;
+	dma_buf_map_set_vaddr(map, vaddr);
+
+	return 0;
 }
 
 void xen_drm_front_gem_prime_vunmap(struct drm_gem_object *gem_obj,
-				    void *vaddr)
+				    struct dma_buf_map *map)
 {
-	vunmap(vaddr);
+	vunmap(map->vaddr);
 }
 
 int xen_drm_front_gem_prime_mmap(struct drm_gem_object *gem_obj,
diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.h
b/drivers/gpu/drm/xen/xen_drm_front_gem.h
index a39675fa31b2..a4e67d0a149c 100644
--- a/drivers/gpu/drm/xen/xen_drm_front_gem.h
+++ b/drivers/gpu/drm/xen/xen_drm_front_gem.h
@@ -12,6 +12,7 @@
 #define __XEN_DRM_FRONT_GEM_H
 
 struct dma_buf_attachment;
+struct dma_buf_map;
 struct drm_device;
 struct drm_gem_object;
 struct file;
@@ -34,10 +35,11 @@ void xen_drm_front_gem_free_object_unlocked(struct
drm_gem_object *gem_obj);
 
 int xen_drm_front_gem_mmap(struct file *filp, struct vm_area_struct *vma);
 
-void *xen_drm_front_gem_prime_vmap(struct drm_gem_object *gem_obj);
+int xen_drm_front_gem_prime_vmap(struct drm_gem_object *gem_obj,
+				 struct dma_buf_map *map);
 
 void xen_drm_front_gem_prime_vunmap(struct drm_gem_object *gem_obj,
-				    void *vaddr);
+				    struct dma_buf_map *map);
 
 int xen_drm_front_gem_prime_mmap(struct drm_gem_object *gem_obj,
 				 struct vm_area_struct *vma);
diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index c38dd35da00b..5e6daa1c982f 100644
--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -39,6 +39,7 @@
 
 #include <drm/drm_vma_manager.h>
 
+struct dma_buf_map;
 struct drm_gem_object;
 
 /**
@@ -138,7 +139,7 @@ struct drm_gem_object_funcs {
 	 *
 	 * This callback is optional.
 	 */
-	void *(*vmap)(struct drm_gem_object *obj);
+	int (*vmap)(struct drm_gem_object *obj, struct dma_buf_map *map);
 
 	/**
 	 * @vunmap:
@@ -148,7 +149,7 @@ struct drm_gem_object_funcs {
 	 *
 	 * This callback is optional.
 	 */
-	void (*vunmap)(struct drm_gem_object *obj, void *vaddr);
+	void (*vunmap)(struct drm_gem_object *obj, struct dma_buf_map *map);
 
 	/**
 	 * @mmap:
diff --git a/include/drm/drm_gem_cma_helper.h b/include/drm/drm_gem_cma_helper.h
index a064b0d1c480..caf98b9cf4b4 100644
--- a/include/drm/drm_gem_cma_helper.h
+++ b/include/drm/drm_gem_cma_helper.h
@@ -103,7 +103,7 @@ drm_gem_cma_prime_import_sg_table(struct drm_device *dev,
 				  struct sg_table *sgt);
 int drm_gem_cma_prime_mmap(struct drm_gem_object *obj,
 			   struct vm_area_struct *vma);
-void *drm_gem_cma_prime_vmap(struct drm_gem_object *obj);
+int drm_gem_cma_prime_vmap(struct drm_gem_object *obj, struct dma_buf_map
*map);
 
 struct drm_gem_object *
 drm_gem_cma_create_object_default_funcs(struct drm_device *dev, size_t size);
diff --git a/include/drm/drm_gem_shmem_helper.h
b/include/drm/drm_gem_shmem_helper.h
index 5381f0c8cf6f..3449a0353fe0 100644
--- a/include/drm/drm_gem_shmem_helper.h
+++ b/include/drm/drm_gem_shmem_helper.h
@@ -113,8 +113,8 @@ int drm_gem_shmem_get_pages(struct drm_gem_shmem_object
*shmem);
 void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem);
 int drm_gem_shmem_pin(struct drm_gem_object *obj);
 void drm_gem_shmem_unpin(struct drm_gem_object *obj);
-void *drm_gem_shmem_vmap(struct drm_gem_object *obj);
-void drm_gem_shmem_vunmap(struct drm_gem_object *obj, void *vaddr);
+int drm_gem_shmem_vmap(struct drm_gem_object *obj, struct dma_buf_map *map);
+void drm_gem_shmem_vunmap(struct drm_gem_object *obj, struct dma_buf_map *map);
 
 int drm_gem_shmem_madvise(struct drm_gem_object *obj, int madv);
 
diff --git a/include/drm/drm_gem_vram_helper.h
b/include/drm/drm_gem_vram_helper.h
index 128f88174d32..c0d28ba0f5c9 100644
--- a/include/drm/drm_gem_vram_helper.h
+++ b/include/drm/drm_gem_vram_helper.h
@@ -10,6 +10,7 @@
 #include <drm/ttm/ttm_bo_api.h>
 #include <drm/ttm/ttm_bo_driver.h>
 
+#include <linux/dma-buf-map.h>
 #include <linux/kernel.h> /* for container_of() */
 
 struct drm_mode_create_dumb;
@@ -29,9 +30,8 @@ struct vm_area_struct;
 
 /**
  * struct drm_gem_vram_object - GEM object backed by VRAM
- * @gem:	GEM object
  * @bo:		TTM buffer object
- * @kmap:	Mapping information for @bo
+ * @map:	Mapping information for @bo
  * @placement:	TTM placement information. Supported placements are \
 	%TTM_PL_VRAM and %TTM_PL_SYSTEM
  * @placements:	TTM placement information.
@@ -50,15 +50,15 @@ struct vm_area_struct;
  */
 struct drm_gem_vram_object {
 	struct ttm_buffer_object bo;
-	struct ttm_bo_kmap_obj kmap;
+	struct dma_buf_map map;
 
 	/**
-	 * @kmap_use_count:
+	 * @vmap_use_count:
 	 *
 	 * Reference count on the virtual address.
 	 * The address are un-mapped when the count reaches zero.
 	 */
-	unsigned int kmap_use_count;
+	unsigned int vmap_use_count;
 
 	/* Supported placements are %TTM_PL_VRAM and %TTM_PL_SYSTEM */
 	struct ttm_placement placement;
@@ -97,8 +97,8 @@ u64 drm_gem_vram_mmap_offset(struct drm_gem_vram_object *gbo);
 s64 drm_gem_vram_offset(struct drm_gem_vram_object *gbo);
 int drm_gem_vram_pin(struct drm_gem_vram_object *gbo, unsigned long pl_flag);
 int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo);
-void *drm_gem_vram_vmap(struct drm_gem_vram_object *gbo);
-void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, void *vaddr);
+int drm_gem_vram_vmap(struct drm_gem_vram_object *gbo, struct dma_buf_map
*map);
+void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, struct dma_buf_map
*map);
 
 int drm_gem_vram_fill_create_dumb(struct drm_file *file,
 				  struct drm_device *dev,
-- 
2.28.0

GEM's vmap and vunmap interfaces now wrap memory pointers in struct
dma_buf_map.

Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/drm_client.c   | 18 +++++++++++-------
 drivers/gpu/drm/drm_gem.c      | 26 +++++++++++++-------------
 drivers/gpu/drm/drm_internal.h |  5 +++--
 drivers/gpu/drm/drm_prime.c    | 14 ++++----------
 4 files changed, 31 insertions(+), 32 deletions(-)

diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
index 495f47d23d87..ac0082bed966 100644
--- a/drivers/gpu/drm/drm_client.c
+++ b/drivers/gpu/drm/drm_client.c
@@ -3,6 +3,7 @@
  * Copyright 2018 Noralf Tr?nnes
  */
 
+#include <linux/dma-buf-map.h>
 #include <linux/list.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
@@ -304,7 +305,8 @@ drm_client_buffer_create(struct drm_client_dev *client, u32
width, u32 height, u
  */
 void *drm_client_buffer_vmap(struct drm_client_buffer *buffer)
 {
-	void *vaddr;
+	struct dma_buf_map map;
+	int ret;
 
 	if (buffer->vaddr)
 		return buffer->vaddr;
@@ -317,13 +319,13 @@ void *drm_client_buffer_vmap(struct drm_client_buffer
*buffer)
 	 * fd_install step out of the driver backend hooks, to make that
 	 * final step optional for internal users.
 	 */
-	vaddr = drm_gem_vmap(buffer->gem);
-	if (IS_ERR(vaddr))
-		return vaddr;
+	ret = drm_gem_vmap(buffer->gem, &map);
+	if (ret)
+		return ERR_PTR(ret);
 
-	buffer->vaddr = vaddr;
+	buffer->vaddr = map.vaddr;
 
-	return vaddr;
+	return map.vaddr;
 }
 EXPORT_SYMBOL(drm_client_buffer_vmap);
 
@@ -337,7 +339,9 @@ EXPORT_SYMBOL(drm_client_buffer_vmap);
  */
 void drm_client_buffer_vunmap(struct drm_client_buffer *buffer)
 {
-	drm_gem_vunmap(buffer->gem, buffer->vaddr);
+	struct dma_buf_map map = DMA_BUF_MAP_INIT_VADDR(buffer->vaddr);
+
+	drm_gem_vunmap(buffer->gem, &map);
 	buffer->vaddr = NULL;
 }
 EXPORT_SYMBOL(drm_client_buffer_vunmap);
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index a89ad4570e3c..4d5fff4bd821 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -1206,32 +1206,32 @@ void drm_gem_unpin(struct drm_gem_object *obj)
 		obj->funcs->unpin(obj);
 }
 
-void *drm_gem_vmap(struct drm_gem_object *obj)
+int drm_gem_vmap(struct drm_gem_object *obj, struct dma_buf_map *map)
 {
-	struct dma_buf_map map;
 	int ret;
 
 	if (!obj->funcs->vmap)
-		return ERR_PTR(-EOPNOTSUPP);
+		return -EOPNOTSUPP;
 
-	ret = obj->funcs->vmap(obj, &map);
+	ret = obj->funcs->vmap(obj, map);
 	if (ret)
-		return ERR_PTR(ret);
-	else if (dma_buf_map_is_null(&map))
-		return ERR_PTR(-ENOMEM);
+		return ret;
+	else if (dma_buf_map_is_null(map))
+		return -ENOMEM;
 
-	return map.vaddr;
+	return 0;
 }
 
-void drm_gem_vunmap(struct drm_gem_object *obj, void *vaddr)
+void drm_gem_vunmap(struct drm_gem_object *obj, struct dma_buf_map *map)
 {
-	struct dma_buf_map map = DMA_BUF_MAP_INIT_VADDR(vaddr);
-
-	if (!vaddr)
+	if (dma_buf_map_is_null(map))
 		return;
 
 	if (obj->funcs->vunmap)
-		obj->funcs->vunmap(obj, &map);
+		obj->funcs->vunmap(obj, map);
+
+	/* Always set the mapping to NULL. Callers may rely on this. */
+	dma_buf_map_clear(map);
 }
 
 /**
diff --git a/drivers/gpu/drm/drm_internal.h b/drivers/gpu/drm/drm_internal.h
index b65865c630b0..58832d75a9bd 100644
--- a/drivers/gpu/drm/drm_internal.h
+++ b/drivers/gpu/drm/drm_internal.h
@@ -33,6 +33,7 @@
 
 struct dentry;
 struct dma_buf;
+struct dma_buf_map;
 struct drm_connector;
 struct drm_crtc;
 struct drm_framebuffer;
@@ -187,8 +188,8 @@ void drm_gem_print_info(struct drm_printer *p, unsigned int
indent,
 
 int drm_gem_pin(struct drm_gem_object *obj);
 void drm_gem_unpin(struct drm_gem_object *obj);
-void *drm_gem_vmap(struct drm_gem_object *obj);
-void drm_gem_vunmap(struct drm_gem_object *obj, void *vaddr);
+int drm_gem_vmap(struct drm_gem_object *obj, struct dma_buf_map *map);
+void drm_gem_vunmap(struct drm_gem_object *obj, struct dma_buf_map *map);
 
 /* drm_debugfs.c drm_debugfs_crc.c */
 #if defined(CONFIG_DEBUG_FS)
diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 89e2a2496734..cb8fbeeb731b 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -667,21 +667,15 @@ EXPORT_SYMBOL(drm_gem_unmap_dma_buf);
  *
  * Sets up a kernel virtual mapping. This can be used as the
&dma_buf_ops.vmap
  * callback. Calls into &drm_gem_object_funcs.vmap for device specific
handling.
+ * The kernel virtual address is returned in map.
  *
- * Returns the kernel virtual address or NULL on failure.
+ * Returns 0 on success or a negative errno code otherwise.
  */
 int drm_gem_dmabuf_vmap(struct dma_buf *dma_buf, struct dma_buf_map *map)
 {
 	struct drm_gem_object *obj = dma_buf->priv;
-	void *vaddr;
 
-	vaddr = drm_gem_vmap(obj);
-	if (IS_ERR(vaddr))
-		return PTR_ERR(vaddr);
-
-	dma_buf_map_set_vaddr(map, vaddr);
-
-	return 0;
+	return drm_gem_vmap(obj, map);
 }
 EXPORT_SYMBOL(drm_gem_dmabuf_vmap);
 
@@ -697,7 +691,7 @@ void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, struct
dma_buf_map *map)
 {
 	struct drm_gem_object *obj = dma_buf->priv;
 
-	drm_gem_vunmap(obj, map->vaddr);
+	drm_gem_vunmap(obj, map);
 }
 EXPORT_SYMBOL(drm_gem_dmabuf_vunmap);
 
-- 
2.28.0

Kernel DRM clients now store their framebuffer address in an instance
of struct dma_buf_map. Depending on the buffer's location, the address
refers to system or I/O memory.

Callers of drm_client_buffer_vmap() receive a copy of the value in
the call's supplied arguments. It can be accessed and modified with
dma_buf_map interfaces.

Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/drm_client.c    | 34 +++++++++++++++++++--------------
 drivers/gpu/drm/drm_fb_helper.c | 23 +++++++++++++---------
 include/drm/drm_client.h        |  7 ++++---
 3 files changed, 38 insertions(+), 26 deletions(-)

diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
index ac0082bed966..fe573acf1067 100644
--- a/drivers/gpu/drm/drm_client.c
+++ b/drivers/gpu/drm/drm_client.c
@@ -235,7 +235,7 @@ static void drm_client_buffer_delete(struct
drm_client_buffer *buffer)
 {
 	struct drm_device *dev = buffer->client->dev;
 
-	drm_gem_vunmap(buffer->gem, buffer->vaddr);
+	drm_gem_vunmap(buffer->gem, &buffer->map);
 
 	if (buffer->gem)
 		drm_gem_object_put(buffer->gem);
@@ -291,25 +291,31 @@ drm_client_buffer_create(struct drm_client_dev *client,
u32 width, u32 height, u
 /**
  * drm_client_buffer_vmap - Map DRM client buffer into address space
  * @buffer: DRM client buffer
+ * @map_copy: Returns the mapped memory's address
  *
  * This function maps a client buffer into kernel address space. If the
- * buffer is already mapped, it returns the mapping's address.
+ * buffer is already mapped, it returns the existing mapping's address.
  *
  * Client buffer mappings are not ref'counted. Each call to
  * drm_client_buffer_vmap() should be followed by a call to
  * drm_client_buffer_vunmap(); or the client buffer should be mapped
  * throughout its lifetime.
  *
+ * The returned address is a copy of the internal value. In contrast to
+ * other vmap interfaces, you don't need it for the client's vunmap
+ * function. So you can modify it at will during blit and draw operations.
+ *
  * Returns:
- *	The mapped memory's address
+ *	0 on success, or a negative errno code otherwise.
  */
-void *drm_client_buffer_vmap(struct drm_client_buffer *buffer)
+int
+drm_client_buffer_vmap(struct drm_client_buffer *buffer, struct dma_buf_map
*map_copy)
 {
-	struct dma_buf_map map;
+	struct dma_buf_map *map = &buffer->map;
 	int ret;
 
-	if (buffer->vaddr)
-		return buffer->vaddr;
+	if (dma_buf_map_is_set(map))
+		goto out;
 
 	/*
 	 * FIXME: The dependency on GEM here isn't required, we could
@@ -319,13 +325,14 @@ void *drm_client_buffer_vmap(struct drm_client_buffer
*buffer)
 	 * fd_install step out of the driver backend hooks, to make that
 	 * final step optional for internal users.
 	 */
-	ret = drm_gem_vmap(buffer->gem, &map);
+	ret = drm_gem_vmap(buffer->gem, map);
 	if (ret)
-		return ERR_PTR(ret);
+		return ret;
 
-	buffer->vaddr = map.vaddr;
+out:
+	*map_copy = *map;
 
-	return map.vaddr;
+	return 0;
 }
 EXPORT_SYMBOL(drm_client_buffer_vmap);
 
@@ -339,10 +346,9 @@ EXPORT_SYMBOL(drm_client_buffer_vmap);
  */
 void drm_client_buffer_vunmap(struct drm_client_buffer *buffer)
 {
-	struct dma_buf_map map = DMA_BUF_MAP_INIT_VADDR(buffer->vaddr);
+	struct dma_buf_map *map = &buffer->map;
 
-	drm_gem_vunmap(buffer->gem, &map);
-	buffer->vaddr = NULL;
+	drm_gem_vunmap(buffer->gem, map);
 }
 EXPORT_SYMBOL(drm_client_buffer_vunmap);
 
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index c2f72bb6afb1..6212cd7cde1d 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -378,7 +378,7 @@ static void drm_fb_helper_dirty_blit_real(struct
drm_fb_helper *fb_helper,
 	unsigned int cpp = fb->format->cpp[0];
 	size_t offset = clip->y1 * fb->pitches[0] + clip->x1 * cpp;
 	void *src = fb_helper->fbdev->screen_buffer + offset;
-	void *dst = fb_helper->buffer->vaddr + offset;
+	void *dst = fb_helper->buffer->map.vaddr + offset;
 	size_t len = (clip->x2 - clip->x1) * cpp;
 	unsigned int y;
 
@@ -400,7 +400,8 @@ static void drm_fb_helper_dirty_work(struct work_struct
*work)
 	struct drm_clip_rect *clip = &helper->dirty_clip;
 	struct drm_clip_rect clip_copy;
 	unsigned long flags;
-	void *vaddr;
+	struct dma_buf_map map;
+	int ret;
 
 	spin_lock_irqsave(&helper->dirty_lock, flags);
 	clip_copy = *clip;
@@ -413,8 +414,8 @@ static void drm_fb_helper_dirty_work(struct work_struct
*work)
 
 		/* Generic fbdev uses a shadow buffer */
 		if (helper->buffer) {
-			vaddr = drm_client_buffer_vmap(helper->buffer);
-			if (IS_ERR(vaddr))
+			ret = drm_client_buffer_vmap(helper->buffer, &map);
+			if (ret)
 				return;
 			drm_fb_helper_dirty_blit_real(helper, &clip_copy);
 		}
@@ -2060,7 +2061,8 @@ static int drm_fb_helper_generic_probe(struct
drm_fb_helper *fb_helper,
 	struct drm_framebuffer *fb;
 	struct fb_info *fbi;
 	u32 format;
-	void *vaddr;
+	struct dma_buf_map map;
+	int ret;
 
 	drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n",
 		    sizes->surface_width, sizes->surface_height,
@@ -2096,11 +2098,14 @@ static int drm_fb_helper_generic_probe(struct
drm_fb_helper *fb_helper,
 		fb_deferred_io_init(fbi);
 	} else {
 		/* buffer is mapped for HW framebuffer */
-		vaddr = drm_client_buffer_vmap(fb_helper->buffer);
-		if (IS_ERR(vaddr))
-			return PTR_ERR(vaddr);
+		ret = drm_client_buffer_vmap(fb_helper->buffer, &map);
+		if (ret)
+			return ret;
+		if (map.is_iomem)
+			fbi->screen_base = map.vaddr_iomem;
+		else
+			fbi->screen_buffer = map.vaddr;
 
-		fbi->screen_buffer = vaddr;
 		/* Shamelessly leak the physical address to user-space */
 #if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
 		if (drm_leak_fbdev_smem && fbi->fix.smem_start == 0)
diff --git a/include/drm/drm_client.h b/include/drm/drm_client.h
index 7aaea665bfc2..f07f2fb02e75 100644
--- a/include/drm/drm_client.h
+++ b/include/drm/drm_client.h
@@ -3,6 +3,7 @@
 #ifndef _DRM_CLIENT_H_
 #define _DRM_CLIENT_H_
 
+#include <linux/dma-buf-map.h>
 #include <linux/lockdep.h>
 #include <linux/mutex.h>
 #include <linux/types.h>
@@ -141,9 +142,9 @@ struct drm_client_buffer {
 	struct drm_gem_object *gem;
 
 	/**
-	 * @vaddr: Virtual address for the buffer
+	 * @map: Virtual address for the buffer
 	 */
-	void *vaddr;
+	struct dma_buf_map map;
 
 	/**
 	 * @fb: DRM framebuffer
@@ -155,7 +156,7 @@ struct drm_client_buffer *
 drm_client_framebuffer_create(struct drm_client_dev *client, u32 width, u32
height, u32 format);
 void drm_client_framebuffer_delete(struct drm_client_buffer *buffer);
 int drm_client_framebuffer_flush(struct drm_client_buffer *buffer, struct
drm_rect *rect);
-void *drm_client_buffer_vmap(struct drm_client_buffer *buffer);
+int drm_client_buffer_vmap(struct drm_client_buffer *buffer, struct dma_buf_map
*map);
 void drm_client_buffer_vunmap(struct drm_client_buffer *buffer);
 
 int drm_client_modeset_create(struct drm_client_dev *client);
-- 
2.28.0

To do framebuffer updates, one needs memcpy from system memory and a
pointer-increment function. Add both interfaces with documentation.

Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
---
 include/linux/dma-buf-map.h | 72 +++++++++++++++++++++++++++++++------
 1 file changed, 62 insertions(+), 10 deletions(-)

diff --git a/include/linux/dma-buf-map.h b/include/linux/dma-buf-map.h
index 2e8bbecb5091..6ca0f304dda2 100644
--- a/include/linux/dma-buf-map.h
+++ b/include/linux/dma-buf-map.h
@@ -32,6 +32,14 @@
  * accessing the buffer. Use the returned instance and the helper functions
  * to access the buffer's memory in the correct way.
  *
+ * The type :c:type:`struct dma_buf_map <dma_buf_map>` and its helpers
are
+ * actually independent from the dma-buf infrastructure. When sharing buffers
+ * among devices, drivers have to know the location of the memory to access
+ * the buffers in a safe way. :c:type:`struct dma_buf_map <dma_buf_map>`
+ * solves this problem for dma-buf and its users. If other drivers or
+ * sub-systems require similar functionality, the type could be generalized
+ * and moved to a more prominent header file.
+ *
  * Open-coding access to :c:type:`struct dma_buf_map <dma_buf_map>` is
  * considered bad style. Rather then accessing its fields directly, use one
  * of the provided helper functions, or implement your own. For example,
@@ -51,6 +59,14 @@
  *
  *	dma_buf_map_set_vaddr_iomem(&map. 0xdeadbeaf);
  *
+ * Instances of struct dma_buf_map do not have to be cleaned up, but
+ * can be cleared to NULL with dma_buf_map_clear(). Cleared mappings
+ * always refer to system memory.
+ *
+ * .. code-block:: c
+ *
+ *	dma_buf_map_clear(&map);
+ *
  * Test if a mapping is valid with either dma_buf_map_is_set() or
  * dma_buf_map_is_null().
  *
@@ -73,17 +89,19 @@
  *	if (dma_buf_map_is_equal(&sys_map, &io_map))
  *		// always false
  *
- * Instances of struct dma_buf_map do not have to be cleaned up, but
- * can be cleared to NULL with dma_buf_map_clear(). Cleared mappings
- * always refer to system memory.
+ * A set up instance of struct dma_buf_map can be used to access or manipulate
+ * the buffer memory. Depending on the location of the memory, the provided
+ * helpers will pick the correct operations. Data can be copied into the memory
+ * with dma_buf_map_memcpy_to(). The address can be manipulated with
+ * dma_buf_map_incr().
  *
- * The type :c:type:`struct dma_buf_map <dma_buf_map>` and its helpers
are
- * actually independent from the dma-buf infrastructure. When sharing buffers
- * among devices, drivers have to know the location of the memory to access
- * the buffers in a safe way. :c:type:`struct dma_buf_map <dma_buf_map>`
- * solves this problem for dma-buf and its users. If other drivers or
- * sub-systems require similar functionality, the type could be generalized
- * and moved to a more prominent header file.
+ * .. code-block:: c
+ *
+ *	const void *src = ...; // source buffer
+ *	size_t len = ...; // length of src
+ *
+ *	dma_buf_map_memcpy_to(&map, src, len);
+ *	dma_buf_map_incr(&map, len); // go to first byte after the memcpy
  */
 
 /**
@@ -210,4 +228,38 @@ static inline void dma_buf_map_clear(struct dma_buf_map
*map)
 	}
 }
 
+/**
+ * dma_buf_map_memcpy_to - Memcpy into dma-buf mapping
+ * @dst:	The dma-buf mapping structure
+ * @src:	The source buffer
+ * @len:	The number of byte in src
+ *
+ * Copies data into a dma-buf mapping. The source buffer is in system
+ * memory. Depending on the buffer's location, the helper picks the correct
+ * method of accessing the memory.
+ */
+static inline void dma_buf_map_memcpy_to(struct dma_buf_map *dst, const void
*src, size_t len)
+{
+	if (dst->is_iomem)
+		memcpy_toio(dst->vaddr_iomem, src, len);
+	else
+		memcpy(dst->vaddr, src, len);
+}
+
+/**
+ * dma_buf_map_incr - Increments the address stored in a dma-buf mapping
+ * @map:	The dma-buf mapping structure
+ * @incr:	The number of bytes to increment
+ *
+ * Increments the address stored in a dma-buf mapping. Depending on the
+ * buffer's location, the correct value will be updated.
+ */
+static inline void dma_buf_map_incr(struct dma_buf_map *map, size_t incr)
+{
+	if (map->is_iomem)
+		map->vaddr_iomem += incr;
+	else
+		map->vaddr += incr;
+}
+
 #endif /* __DMA_BUF_MAP_H__ */
-- 
2.28.0

At least sparc64 requires I/O-specific access to framebuffers. This
patch updates the fbdev console accordingly.

For drivers with direct access to the framebuffer memory, the callback
functions in struct fb_ops test for the type of memory and call the rsp
fb_sys_ of fb_cfb_ functions.

For drivers that employ a shadow buffer, fbdev's blit function retrieves
the framebuffer address as struct dma_buf_map, and uses dma_buf_map
interfaces to access the buffer.

The bochs driver on sparc64 uses a workaround to flag the framebuffer as
I/O memory and avoid a HW exception. With the introduction of struct
dma_buf_map, this is not required any longer. The patch removes the rsp
code from both, bochs and fbdev.

v4:
	* move dma_buf_map changes into separate patch (Daniel)
	* TODO list: comment on fbdev updates (Daniel)

Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
---
 Documentation/gpu/todo.rst        |  19 ++-
 drivers/gpu/drm/bochs/bochs_kms.c |   1 -
 drivers/gpu/drm/drm_fb_helper.c   | 217 ++++++++++++++++++++++++++++--
 include/drm/drm_mode_config.h     |  12 --
 4 files changed, 220 insertions(+), 29 deletions(-)

diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst
index 7e6fc3c04add..638b7f704339 100644
--- a/Documentation/gpu/todo.rst
+++ b/Documentation/gpu/todo.rst
@@ -197,13 +197,28 @@ Convert drivers to use drm_fbdev_generic_setup()
 ------------------------------------------------
 
 Most drivers can use drm_fbdev_generic_setup(). Driver have to implement
-atomic modesetting and GEM vmap support. Current generic fbdev emulation
-expects the framebuffer in system memory (or system-like memory).
+atomic modesetting and GEM vmap support. Historically, generic fbdev emulation
+expected the framebuffer in system memory or system-like memory. By employing
+struct dma_buf_map, drivers with frambuffers in I/O memory can be supported
+as well.
 
 Contact: Maintainer of the driver you plan to convert
 
 Level: Intermediate
 
+Reimplement functions in drm_fbdev_fb_ops without fbdev
+-------------------------------------------------------
+
+A number of callback functions in drm_fbdev_fb_ops could benefit from
+being rewritten without dependencies on the fbdev module. Some of the
+helpers could further benefit from using struct dma_buf_map instead of
+raw pointers.
+
+Contact: Thomas Zimmermann <tzimmermann at suse.de>, Daniel Vetter
+
+Level: Advanced
+
+
 drm_framebuffer_funcs and drm_mode_config_funcs.fb_create cleanup
 -----------------------------------------------------------------
 
diff --git a/drivers/gpu/drm/bochs/bochs_kms.c
b/drivers/gpu/drm/bochs/bochs_kms.c
index 13d0d04c4457..853081d186d5 100644
--- a/drivers/gpu/drm/bochs/bochs_kms.c
+++ b/drivers/gpu/drm/bochs/bochs_kms.c
@@ -151,7 +151,6 @@ int bochs_kms_init(struct bochs_device *bochs)
 	bochs->dev->mode_config.preferred_depth = 24;
 	bochs->dev->mode_config.prefer_shadow = 0;
 	bochs->dev->mode_config.prefer_shadow_fbdev = 1;
-	bochs->dev->mode_config.fbdev_use_iomem = true;
 	bochs->dev->mode_config.quirk_addfb_prefer_host_byte_order = true;
 
 	bochs->dev->mode_config.funcs = &bochs_mode_funcs;
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 6212cd7cde1d..462b0c130ebb 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -372,24 +372,22 @@ static void drm_fb_helper_resume_worker(struct work_struct
*work)
 }
 
 static void drm_fb_helper_dirty_blit_real(struct drm_fb_helper *fb_helper,
-					  struct drm_clip_rect *clip)
+					  struct drm_clip_rect *clip,
+					  struct dma_buf_map *dst)
 {
 	struct drm_framebuffer *fb = fb_helper->fb;
 	unsigned int cpp = fb->format->cpp[0];
 	size_t offset = clip->y1 * fb->pitches[0] + clip->x1 * cpp;
 	void *src = fb_helper->fbdev->screen_buffer + offset;
-	void *dst = fb_helper->buffer->map.vaddr + offset;
 	size_t len = (clip->x2 - clip->x1) * cpp;
 	unsigned int y;
 
-	for (y = clip->y1; y < clip->y2; y++) {
-		if (!fb_helper->dev->mode_config.fbdev_use_iomem)
-			memcpy(dst, src, len);
-		else
-			memcpy_toio((void __iomem *)dst, src, len);
+	dma_buf_map_incr(dst, offset); /* go to first pixel within clip rect */
 
+	for (y = clip->y1; y < clip->y2; y++) {
+		dma_buf_map_memcpy_to(dst, src, len);
+		dma_buf_map_incr(dst, fb->pitches[0]);
 		src += fb->pitches[0];
-		dst += fb->pitches[0];
 	}
 }
 
@@ -417,8 +415,9 @@ static void drm_fb_helper_dirty_work(struct work_struct
*work)
 			ret = drm_client_buffer_vmap(helper->buffer, &map);
 			if (ret)
 				return;
-			drm_fb_helper_dirty_blit_real(helper, &clip_copy);
+			drm_fb_helper_dirty_blit_real(helper, &clip_copy, &map);
 		}
+
 		if (helper->fb->funcs->dirty)
 			helper->fb->funcs->dirty(helper->fb, NULL, 0, 0,
 						 &clip_copy, 1);
@@ -755,6 +754,136 @@ void drm_fb_helper_sys_imageblit(struct fb_info *info,
 }
 EXPORT_SYMBOL(drm_fb_helper_sys_imageblit);
 
+static ssize_t drm_fb_helper_cfb_read(struct fb_info *info, char __user *buf,
+				      size_t count, loff_t *ppos)
+{
+	unsigned long p = *ppos;
+	u8 *dst;
+	u8 __iomem *src;
+	int c, err = 0;
+	unsigned long total_size;
+	unsigned long alloc_size;
+	ssize_t ret = 0;
+
+	if (info->state != FBINFO_STATE_RUNNING)
+		return -EPERM;
+
+	total_size = info->screen_size;
+
+	if (total_size == 0)
+		total_size = info->fix.smem_len;
+
+	if (p >= total_size)
+		return 0;
+
+	if (count >= total_size)
+		count = total_size;
+
+	if (count + p > total_size)
+		count = total_size - p;
+
+	src = (u8 __iomem *)(info->screen_base + p);
+
+	alloc_size = min(count, PAGE_SIZE);
+
+	dst = kmalloc(alloc_size, GFP_KERNEL);
+	if (!dst)
+		return -ENOMEM;
+
+	while (count) {
+		c = min(count, alloc_size);
+
+		memcpy_fromio(dst, src, c);
+		if (copy_to_user(buf, dst, c)) {
+			err = -EFAULT;
+			break;
+		}
+
+		src += c;
+		*ppos += c;
+		buf += c;
+		ret += c;
+		count -= c;
+	}
+
+	kfree(dst);
+
+	if (err)
+		return err;
+
+	return ret;
+}
+
+static ssize_t drm_fb_helper_cfb_write(struct fb_info *info, const char __user
*buf,
+				       size_t count, loff_t *ppos)
+{
+	unsigned long p = *ppos;
+	u8 *src;
+	u8 __iomem *dst;
+	int c, err = 0;
+	unsigned long total_size;
+	unsigned long alloc_size;
+	ssize_t ret = 0;
+
+	if (info->state != FBINFO_STATE_RUNNING)
+		return -EPERM;
+
+	total_size = info->screen_size;
+
+	if (total_size == 0)
+		total_size = info->fix.smem_len;
+
+	if (p > total_size)
+		return -EFBIG;
+
+	if (count > total_size) {
+		err = -EFBIG;
+		count = total_size;
+	}
+
+	if (count + p > total_size) {
+		/*
+		 * The framebuffer is too small. We do the
+		 * copy operation, but return an error code
+		 * afterwards. Taken from fbdev.
+		 */
+		if (!err)
+			err = -ENOSPC;
+		count = total_size - p;
+	}
+
+	alloc_size = min(count, PAGE_SIZE);
+
+	src = kmalloc(alloc_size, GFP_KERNEL);
+	if (!src)
+		return -ENOMEM;
+
+	dst = (u8 __iomem *)(info->screen_base + p);
+
+	while (count) {
+		c = min(count, alloc_size);
+
+		if (copy_from_user(src, buf, c)) {
+			err = -EFAULT;
+			break;
+		}
+		memcpy_toio(dst, src, c);
+
+		dst += c;
+		*ppos += c;
+		buf += c;
+		ret += c;
+		count -= c;
+	}
+
+	kfree(src);
+
+	if (err)
+		return err;
+
+	return ret;
+}
+
 /**
  * drm_fb_helper_cfb_fillrect - wrapper around cfb_fillrect
  * @info: fbdev registered by the helper
@@ -2027,6 +2156,66 @@ static int drm_fbdev_fb_mmap(struct fb_info *info, struct
vm_area_struct *vma)
 		return -ENODEV;
 }
 
+static ssize_t drm_fbdev_fb_read(struct fb_info *info, char __user *buf,
+				 size_t count, loff_t *ppos)
+{
+	struct drm_fb_helper *fb_helper = info->par;
+	struct drm_client_buffer *buffer = fb_helper->buffer;
+
+	if (drm_fbdev_use_shadow_fb(fb_helper) || !buffer->map.is_iomem)
+		return drm_fb_helper_sys_read(info, buf, count, ppos);
+	else
+		return drm_fb_helper_cfb_read(info, buf, count, ppos);
+}
+
+static ssize_t drm_fbdev_fb_write(struct fb_info *info, const char __user *buf,
+				  size_t count, loff_t *ppos)
+{
+	struct drm_fb_helper *fb_helper = info->par;
+	struct drm_client_buffer *buffer = fb_helper->buffer;
+
+	if (drm_fbdev_use_shadow_fb(fb_helper) || !buffer->map.is_iomem)
+		return drm_fb_helper_sys_write(info, buf, count, ppos);
+	else
+		return drm_fb_helper_cfb_write(info, buf, count, ppos);
+}
+
+static void drm_fbdev_fb_fillrect(struct fb_info *info,
+				  const struct fb_fillrect *rect)
+{
+	struct drm_fb_helper *fb_helper = info->par;
+	struct drm_client_buffer *buffer = fb_helper->buffer;
+
+	if (drm_fbdev_use_shadow_fb(fb_helper) || !buffer->map.is_iomem)
+		drm_fb_helper_sys_fillrect(info, rect);
+	else
+		drm_fb_helper_cfb_fillrect(info, rect);
+}
+
+static void drm_fbdev_fb_copyarea(struct fb_info *info,
+				  const struct fb_copyarea *area)
+{
+	struct drm_fb_helper *fb_helper = info->par;
+	struct drm_client_buffer *buffer = fb_helper->buffer;
+
+	if (drm_fbdev_use_shadow_fb(fb_helper) || !buffer->map.is_iomem)
+		drm_fb_helper_sys_copyarea(info, area);
+	else
+		drm_fb_helper_cfb_copyarea(info, area);
+}
+
+static void drm_fbdev_fb_imageblit(struct fb_info *info,
+				   const struct fb_image *image)
+{
+	struct drm_fb_helper *fb_helper = info->par;
+	struct drm_client_buffer *buffer = fb_helper->buffer;
+
+	if (drm_fbdev_use_shadow_fb(fb_helper) || !buffer->map.is_iomem)
+		drm_fb_helper_sys_imageblit(info, image);
+	else
+		drm_fb_helper_cfb_imageblit(info, image);
+}
+
 static const struct fb_ops drm_fbdev_fb_ops = {
 	.owner		= THIS_MODULE,
 	DRM_FB_HELPER_DEFAULT_OPS,
@@ -2034,11 +2223,11 @@ static const struct fb_ops drm_fbdev_fb_ops = {
 	.fb_release	= drm_fbdev_fb_release,
 	.fb_destroy	= drm_fbdev_fb_destroy,
 	.fb_mmap	= drm_fbdev_fb_mmap,
-	.fb_read	= drm_fb_helper_sys_read,
-	.fb_write	= drm_fb_helper_sys_write,
-	.fb_fillrect	= drm_fb_helper_sys_fillrect,
-	.fb_copyarea	= drm_fb_helper_sys_copyarea,
-	.fb_imageblit	= drm_fb_helper_sys_imageblit,
+	.fb_read	= drm_fbdev_fb_read,
+	.fb_write	= drm_fbdev_fb_write,
+	.fb_fillrect	= drm_fbdev_fb_fillrect,
+	.fb_copyarea	= drm_fbdev_fb_copyarea,
+	.fb_imageblit	= drm_fbdev_fb_imageblit,
 };
 
 static struct fb_deferred_io drm_fbdev_defio = {
diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
index 5ffbb4ed5b35..ab424ddd7665 100644
--- a/include/drm/drm_mode_config.h
+++ b/include/drm/drm_mode_config.h
@@ -877,18 +877,6 @@ struct drm_mode_config {
 	 */
 	bool prefer_shadow_fbdev;
 
-	/**
-	 * @fbdev_use_iomem:
-	 *
-	 * Set to true if framebuffer reside in iomem.
-	 * When set to true memcpy_toio() is used when copying the framebuffer in
-	 * drm_fb_helper.drm_fb_helper_dirty_blit_real().
-	 *
-	 * FIXME: This should be replaced with a per-mapping is_iomem
-	 * flag (like ttm does), and then used everywhere in fbdev code.
-	 */
-	bool fbdev_use_iomem;
-
 	/**
 	 * @quirk_addfb_prefer_xbgr_30bpp:
 	 *
-- 
2.28.0

Am 15.10.20 um 14:37 schrieb Thomas Zimmermann:
> The parameters map and is_iomem are always of the same value. Removed them
> to prepares the function for conversion to struct dma_buf_map.
>
> v4:
> 	* don't check for !kmap->virtual; will always be false
>
> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
> Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
Reviewed-by: Christian K?nig <christian.koenig at amd.com>
> ---
>   drivers/gpu/drm/drm_gem_vram_helper.c | 18 ++++--------------
>   1 file changed, 4 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_gem_vram_helper.c
b/drivers/gpu/drm/drm_gem_vram_helper.c
> index 3213429f8444..2d5ed30518f1 100644
> --- a/drivers/gpu/drm/drm_gem_vram_helper.c
> +++ b/drivers/gpu/drm/drm_gem_vram_helper.c
> @@ -382,32 +382,22 @@ int drm_gem_vram_unpin(struct drm_gem_vram_object
*gbo)
>   }
>   EXPORT_SYMBOL(drm_gem_vram_unpin);
>   
> -static void *drm_gem_vram_kmap_locked(struct drm_gem_vram_object *gbo,
> -				      bool map, bool *is_iomem)
> +static void *drm_gem_vram_kmap_locked(struct drm_gem_vram_object *gbo)
>   {
>   	int ret;
>   	struct ttm_bo_kmap_obj *kmap = &gbo->kmap;
> +	bool is_iomem;
>   
>   	if (gbo->kmap_use_count > 0)
>   		goto out;
>   
> -	if (kmap->virtual || !map)
> -		goto out;
> -
>   	ret = ttm_bo_kmap(&gbo->bo, 0, gbo->bo.num_pages, kmap);
>   	if (ret)
>   		return ERR_PTR(ret);
>   
>   out:
> -	if (!kmap->virtual) {
> -		if (is_iomem)
> -			*is_iomem = false;
> -		return NULL; /* not mapped; don't increment ref */
> -	}
>   	++gbo->kmap_use_count;
> -	if (is_iomem)
> -		return ttm_kmap_obj_virtual(kmap, is_iomem);
> -	return kmap->virtual;
> +	return ttm_kmap_obj_virtual(kmap, &is_iomem);
>   }
>   
>   static void drm_gem_vram_kunmap_locked(struct drm_gem_vram_object *gbo)
> @@ -452,7 +442,7 @@ void *drm_gem_vram_vmap(struct drm_gem_vram_object
*gbo)
>   	ret = drm_gem_vram_pin_locked(gbo, 0);
>   	if (ret)
>   		goto err_ttm_bo_unreserve;
> -	base = drm_gem_vram_kmap_locked(gbo, true, NULL);
> +	base = drm_gem_vram_kmap_locked(gbo);
>   	if (IS_ERR(base)) {
>   		ret = PTR_ERR(base);
>   		goto err_drm_gem_vram_unpin_locked;

Am 15.10.20 um 14:37 schrieb Thomas Zimmermann:
> The function drm_gem_cma_prime_vunmap() is empty. Remove it before
> changing the interface to use struct drm_buf_map.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
Reviewed-by: Christian K?nig <christian.koenig at amd.com>
> ---
>   drivers/gpu/drm/drm_gem_cma_helper.c | 17 -----------------
>   drivers/gpu/drm/vc4/vc4_bo.c         |  1 -
>   include/drm/drm_gem_cma_helper.h     |  1 -
>   3 files changed, 19 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c
b/drivers/gpu/drm/drm_gem_cma_helper.c
> index 2165633c9b9e..d527485ea0b7 100644
> --- a/drivers/gpu/drm/drm_gem_cma_helper.c
> +++ b/drivers/gpu/drm/drm_gem_cma_helper.c
> @@ -537,23 +537,6 @@ void *drm_gem_cma_prime_vmap(struct drm_gem_object
*obj)
>   }
>   EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vmap);
>   
> -/**
> - * drm_gem_cma_prime_vunmap - unmap a CMA GEM object from the kernel's
virtual
> - *     address space
> - * @obj: GEM object
> - * @vaddr: kernel virtual address where the CMA GEM object was mapped
> - *
> - * This function removes a buffer exported via DRM PRIME from the
kernel's
> - * virtual address space. This is a no-op because CMA buffers cannot be
> - * unmapped from kernel space. Drivers using the CMA helpers should set
this
> - * as their &drm_gem_object_funcs.vunmap callback.
> - */
> -void drm_gem_cma_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
> -{
> -	/* Nothing to do */
> -}
> -EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vunmap);
> -
>   static const struct drm_gem_object_funcs drm_gem_cma_default_funcs = {
>   	.free = drm_gem_cma_free_object,
>   	.print_info = drm_gem_cma_print_info,
> diff --git a/drivers/gpu/drm/vc4/vc4_bo.c b/drivers/gpu/drm/vc4/vc4_bo.c
> index f432278173cd..557f0d1e6437 100644
> --- a/drivers/gpu/drm/vc4/vc4_bo.c
> +++ b/drivers/gpu/drm/vc4/vc4_bo.c
> @@ -387,7 +387,6 @@ static const struct drm_gem_object_funcs
vc4_gem_object_funcs = {
>   	.export = vc4_prime_export,
>   	.get_sg_table = drm_gem_cma_prime_get_sg_table,
>   	.vmap = vc4_prime_vmap,
> -	.vunmap = drm_gem_cma_prime_vunmap,
>   	.vm_ops = &vc4_vm_ops,
>   };
>   
> diff --git a/include/drm/drm_gem_cma_helper.h
b/include/drm/drm_gem_cma_helper.h
> index 2bfa2502607a..a064b0d1c480 100644
> --- a/include/drm/drm_gem_cma_helper.h
> +++ b/include/drm/drm_gem_cma_helper.h
> @@ -104,7 +104,6 @@ drm_gem_cma_prime_import_sg_table(struct drm_device
*dev,
>   int drm_gem_cma_prime_mmap(struct drm_gem_object *obj,
>   			   struct vm_area_struct *vma);
>   void *drm_gem_cma_prime_vmap(struct drm_gem_object *obj);
> -void drm_gem_cma_prime_vunmap(struct drm_gem_object *obj, void *vaddr);
>   
>   struct drm_gem_object *
>   drm_gem_cma_create_object_default_funcs(struct drm_device *dev, size_t
size);

Am 15.10.20 um 14:37 schrieb Thomas Zimmermann:
> The function etnaviv_gem_prime_vunmap() is empty. Remove it before
> changing the interface to use struct drm_buf_map.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
Acked-by: Christian K?nig <christian.koenig at amd.com>
> ---
>   drivers/gpu/drm/etnaviv/etnaviv_drv.h       | 1 -
>   drivers/gpu/drm/etnaviv/etnaviv_gem.c       | 1 -
>   drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c | 5 -----
>   3 files changed, 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_drv.h
b/drivers/gpu/drm/etnaviv/etnaviv_drv.h
> index 914f0867ff71..9682c26d89bb 100644
> --- a/drivers/gpu/drm/etnaviv/etnaviv_drv.h
> +++ b/drivers/gpu/drm/etnaviv/etnaviv_drv.h
> @@ -52,7 +52,6 @@ int etnaviv_gem_mmap(struct file *filp, struct
vm_area_struct *vma);
>   int etnaviv_gem_mmap_offset(struct drm_gem_object *obj, u64 *offset);
>   struct sg_table *etnaviv_gem_prime_get_sg_table(struct drm_gem_object
*obj);
>   void *etnaviv_gem_prime_vmap(struct drm_gem_object *obj);
> -void etnaviv_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr);
>   int etnaviv_gem_prime_mmap(struct drm_gem_object *obj,
>   			   struct vm_area_struct *vma);
>   struct drm_gem_object *etnaviv_gem_prime_import_sg_table(struct
drm_device *dev,
> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c
b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
> index 67d9a2b9ea6a..bbd235473645 100644
> --- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c
> +++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
> @@ -571,7 +571,6 @@ static const struct drm_gem_object_funcs
etnaviv_gem_object_funcs = {
>   	.unpin = etnaviv_gem_prime_unpin,
>   	.get_sg_table = etnaviv_gem_prime_get_sg_table,
>   	.vmap = etnaviv_gem_prime_vmap,
> -	.vunmap = etnaviv_gem_prime_vunmap,
>   	.vm_ops = &vm_ops,
>   };
>   
> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
> index 135fbff6fecf..a6d9932a32ae 100644
> --- a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
> +++ b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
> @@ -27,11 +27,6 @@ void *etnaviv_gem_prime_vmap(struct drm_gem_object *obj)
>   	return etnaviv_gem_vmap(obj);
>   }
>   
> -void etnaviv_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
> -{
> -	/* TODO msm_gem_vunmap() */
> -}
> -
>   int etnaviv_gem_prime_mmap(struct drm_gem_object *obj,
>   			   struct vm_area_struct *vma)
>   {

Am 15.10.20 um 14:38 schrieb Thomas Zimmermann:
> The functions exynos_drm_gem_prime_{vmap,vunmap}() are empty. Remove
> them before changing the interface to use struct drm_buf_map. As a side
> effect of removing drm_gem_prime_vmap(), the error code changes from
> ENOMEM to EOPNOTSUPP.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
Acked-by: Christian K?nig <christian.koenig at amd.com>
> ---
>   drivers/gpu/drm/exynos/exynos_drm_gem.c | 12 ------------
>   drivers/gpu/drm/exynos/exynos_drm_gem.h |  2 --
>   2 files changed, 14 deletions(-)
>
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c
b/drivers/gpu/drm/exynos/exynos_drm_gem.c
> index e7a6eb96f692..13a35623ac04 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_gem.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c
> @@ -137,8 +137,6 @@ static const struct vm_operations_struct
exynos_drm_gem_vm_ops = {
>   static const struct drm_gem_object_funcs exynos_drm_gem_object_funcs = {
>   	.free = exynos_drm_gem_free_object,
>   	.get_sg_table = exynos_drm_gem_prime_get_sg_table,
> -	.vmap = exynos_drm_gem_prime_vmap,
> -	.vunmap	= exynos_drm_gem_prime_vunmap,
>   	.vm_ops = &exynos_drm_gem_vm_ops,
>   };
>   
> @@ -471,16 +469,6 @@ exynos_drm_gem_prime_import_sg_table(struct drm_device
*dev,
>   	return &exynos_gem->base;
>   }
>   
> -void *exynos_drm_gem_prime_vmap(struct drm_gem_object *obj)
> -{
> -	return NULL;
> -}
> -
> -void exynos_drm_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
> -{
> -	/* Nothing to do */
> -}
> -
>   int exynos_drm_gem_prime_mmap(struct drm_gem_object *obj,
>   			      struct vm_area_struct *vma)
>   {
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.h
b/drivers/gpu/drm/exynos/exynos_drm_gem.h
> index 74e926abeff0..a23272fb96fb 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_gem.h
> +++ b/drivers/gpu/drm/exynos/exynos_drm_gem.h
> @@ -107,8 +107,6 @@ struct drm_gem_object *
>   exynos_drm_gem_prime_import_sg_table(struct drm_device *dev,
>   				     struct dma_buf_attachment *attach,
>   				     struct sg_table *sgt);
> -void *exynos_drm_gem_prime_vmap(struct drm_gem_object *obj);
> -void exynos_drm_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr);
>   int exynos_drm_gem_prime_mmap(struct drm_gem_object *obj,
>   			      struct vm_area_struct *vma);
>

Am 15.10.20 um 14:38 schrieb Thomas Zimmermann:
> The new functions ttm_bo_{vmap,vunmap}() map and unmap a TTM BO in kernel
> address space. The mapping's address is returned as struct dma_buf_map.
> Each function is a simplified version of TTM's existing kmap code. Both
> functions respect the memory's location ani/or writecombine flags.
>
> On top TTM's functions, GEM TTM helpers got
drm_gem_ttm_{vmap,vunmap}(),
> two helpers that convert a GEM object into the TTM BO and forward the call
> to TTM's vmap/vunmap. These helpers can be dropped into the rsp GEM
object
> callbacks.
>
> v4:
> 	* drop ttm_kmap_obj_to_dma_buf() in favor of vmap helpers (Daniel,
> 	  Christian)
Bunch of minor comments below, but over all look very solid to me.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
> ---
>   drivers/gpu/drm/drm_gem_ttm_helper.c | 38 +++++++++++++++
>   drivers/gpu/drm/ttm/ttm_bo_util.c    | 72 ++++++++++++++++++++++++++++
>   include/drm/drm_gem_ttm_helper.h     |  6 +++
>   include/drm/ttm/ttm_bo_api.h         | 28 +++++++++++
>   include/linux/dma-buf-map.h          | 20 ++++++++
>   5 files changed, 164 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_gem_ttm_helper.c
b/drivers/gpu/drm/drm_gem_ttm_helper.c
> index 0e4fb9ba43ad..db4c14d78a30 100644
> --- a/drivers/gpu/drm/drm_gem_ttm_helper.c
> +++ b/drivers/gpu/drm/drm_gem_ttm_helper.c
> @@ -49,6 +49,44 @@ void drm_gem_ttm_print_info(struct drm_printer *p,
unsigned int indent,
>   }
>   EXPORT_SYMBOL(drm_gem_ttm_print_info);
>   
> +/**
> + * drm_gem_ttm_vmap() - vmap &ttm_buffer_object
> + * @gem: GEM object.
> + * @map: [out] returns the dma-buf mapping.
> + *
> + * Maps a GEM object with ttm_bo_vmap(). This function can be used as
> + * &drm_gem_object_funcs.vmap callback.
> + *
> + * Returns:
> + * 0 on success, or a negative errno code otherwise.
> + */
> +int drm_gem_ttm_vmap(struct drm_gem_object *gem,
> +		     struct dma_buf_map *map)
> +{
> +	struct ttm_buffer_object *bo = drm_gem_ttm_of_gem(gem);
> +
> +	return ttm_bo_vmap(bo, map);
> +
> +}
> +EXPORT_SYMBOL(drm_gem_ttm_vmap);
> +
> +/**
> + * drm_gem_ttm_vunmap() - vunmap &ttm_buffer_object
> + * @gem: GEM object.
> + * @map: dma-buf mapping.
> + *
> + * Unmaps a GEM object with ttm_bo_vunmap(). This function can be used as
> + * &drm_gem_object_funcs.vmap callback.
> + */
> +void drm_gem_ttm_vunmap(struct drm_gem_object *gem,
> +			struct dma_buf_map *map)
> +{
> +	struct ttm_buffer_object *bo = drm_gem_ttm_of_gem(gem);
> +
> +	ttm_bo_vunmap(bo, map);
> +}
> +EXPORT_SYMBOL(drm_gem_ttm_vunmap);
> +
>   /**
>    * drm_gem_ttm_mmap() - mmap &ttm_buffer_object
>    * @gem: GEM object.
> diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c
b/drivers/gpu/drm/ttm/ttm_bo_util.c
> index bdee4df1f3f2..80c42c774c7d 100644
> --- a/drivers/gpu/drm/ttm/ttm_bo_util.c
> +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
> @@ -32,6 +32,7 @@
>   #include <drm/ttm/ttm_bo_driver.h>
>   #include <drm/ttm/ttm_placement.h>
>   #include <drm/drm_vma_manager.h>
> +#include <linux/dma-buf-map.h>
>   #include <linux/io.h>
>   #include <linux/highmem.h>
>   #include <linux/wait.h>
> @@ -526,6 +527,77 @@ void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map)
>   }
>   EXPORT_SYMBOL(ttm_bo_kunmap);
>   
> +int ttm_bo_vmap(struct ttm_buffer_object *bo, struct dma_buf_map *map)
> +{
> +	struct ttm_resource *mem = &bo->mem;
> +	int ret;
> +
> +	ret = ttm_mem_io_reserve(bo->bdev, mem);
> +	if (ret)
> +		return ret;
> +
> +	if (mem->bus.is_iomem) {
> +		void __iomem *vaddr_iomem;
> +		unsigned long size = bo->num_pages << PAGE_SHIFT;
Please use uint64_t here and make sure to cast bo->num_pages before 
shifting.

We have an unit tests of allocating a 8GB BO and that should work on a 
32bit machine as well :)
> +
> +		if (mem->bus.addr)
> +			vaddr_iomem = (void *)(((u8 *)mem->bus.addr));
> +		else if (mem->placement & TTM_PL_FLAG_WC)
I've just nuked the TTM_PL_FLAG_WC flag in drm-misc-next. There is a new 
mem->bus.caching enum as replacement.
> +			vaddr_iomem = ioremap_wc(mem->bus.offset, size);
> +		else
> +			vaddr_iomem = ioremap(mem->bus.offset, size);
> +
> +		if (!vaddr_iomem)
> +			return -ENOMEM;
> +
> +		dma_buf_map_set_vaddr_iomem(map, vaddr_iomem);
> +
> +	} else {
> +		struct ttm_operation_ctx ctx = {
> +			.interruptible = false,
> +			.no_wait_gpu = false
> +		};
> +		struct ttm_tt *ttm = bo->ttm;
> +		pgprot_t prot;
> +		void *vaddr;
> +
> +		BUG_ON(!ttm);
I think we can drop this, populate will just crash badly anyway.
> +
> +		ret = ttm_tt_populate(bo->bdev, ttm, &ctx);
> +		if (ret)
> +			return ret;
> +
> +		/*
> +		 * We need to use vmap to get the desired page protection
> +		 * or to make the buffer object look contiguous.
> +		 */
> +		prot = ttm_io_prot(mem->placement, PAGE_KERNEL);
The calling convention has changed on drm-misc-next as well, but should 
be trivial to adapt.

Regards,
Christian.
> +		vaddr = vmap(ttm->pages, bo->num_pages, 0, prot);
> +		if (!vaddr)
> +			return -ENOMEM;
> +
> +		dma_buf_map_set_vaddr(map, vaddr);
> +	}
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(ttm_bo_vmap);
> +
> +void ttm_bo_vunmap(struct ttm_buffer_object *bo, struct dma_buf_map *map)
> +{
> +	if (dma_buf_map_is_null(map))
> +		return;
> +
> +	if (map->is_iomem)
> +		iounmap(map->vaddr_iomem);
> +	else
> +		vunmap(map->vaddr);
> +	dma_buf_map_clear(map);
> +
> +	ttm_mem_io_free(bo->bdev, &bo->mem);
> +}
> +EXPORT_SYMBOL(ttm_bo_vunmap);
> +
>   static int ttm_bo_wait_free_node(struct ttm_buffer_object *bo,
>   				 bool dst_use_tt)
>   {
> diff --git a/include/drm/drm_gem_ttm_helper.h
b/include/drm/drm_gem_ttm_helper.h
> index 118cef76f84f..7c6d874910b8 100644
> --- a/include/drm/drm_gem_ttm_helper.h
> +++ b/include/drm/drm_gem_ttm_helper.h
> @@ -10,11 +10,17 @@
>   #include <drm/ttm/ttm_bo_api.h>
>   #include <drm/ttm/ttm_bo_driver.h>
>   
> +struct dma_buf_map;
> +
>   #define drm_gem_ttm_of_gem(gem_obj) \
>   	container_of(gem_obj, struct ttm_buffer_object, base)
>   
>   void drm_gem_ttm_print_info(struct drm_printer *p, unsigned int indent,
>   			    const struct drm_gem_object *gem);
> +int drm_gem_ttm_vmap(struct drm_gem_object *gem,
> +		     struct dma_buf_map *map);
> +void drm_gem_ttm_vunmap(struct drm_gem_object *gem,
> +			struct dma_buf_map *map);
>   int drm_gem_ttm_mmap(struct drm_gem_object *gem,
>   		     struct vm_area_struct *vma);
>   
> diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
> index 37102e45e496..2c59a785374c 100644
> --- a/include/drm/ttm/ttm_bo_api.h
> +++ b/include/drm/ttm/ttm_bo_api.h
> @@ -48,6 +48,8 @@ struct ttm_bo_global;
>   
>   struct ttm_bo_device;
>   
> +struct dma_buf_map;
> +
>   struct drm_mm_node;
>   
>   struct ttm_placement;
> @@ -494,6 +496,32 @@ int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned
long start_page,
>    */
>   void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);
>   
> +/**
> + * ttm_bo_vmap
> + *
> + * @bo: The buffer object.
> + * @map: pointer to a struct dma_buf_map representing the map.
> + *
> + * Sets up a kernel virtual mapping, using ioremap or vmap to the
> + * data in the buffer object. The parameter @map returns the virtual
> + * address as struct dma_buf_map. Unmap the buffer with ttm_bo_vunmap().
> + *
> + * Returns
> + * -ENOMEM: Out of memory.
> + * -EINVAL: Invalid range.
> + */
> +int ttm_bo_vmap(struct ttm_buffer_object *bo, struct dma_buf_map *map);
> +
> +/**
> + * ttm_bo_vunmap
> + *
> + * @bo: The buffer object.
> + * @map: Object describing the map to unmap.
> + *
> + * Unmaps a kernel map set up by ttm_bo_vmap().
> + */
> +void ttm_bo_vunmap(struct ttm_buffer_object *bo, struct dma_buf_map *map);
> +
>   /**
>    * ttm_bo_mmap_obj - mmap memory backed by a ttm buffer object.
>    *
> diff --git a/include/linux/dma-buf-map.h b/include/linux/dma-buf-map.h
> index fd1aba545fdf..2e8bbecb5091 100644
> --- a/include/linux/dma-buf-map.h
> +++ b/include/linux/dma-buf-map.h
> @@ -45,6 +45,12 @@
>    *
>    *	dma_buf_map_set_vaddr(&map. 0xdeadbeaf);
>    *
> + * To set an address in I/O memory, use dma_buf_map_set_vaddr_iomem().
> + *
> + * .. code-block:: c
> + *
> + *	dma_buf_map_set_vaddr_iomem(&map. 0xdeadbeaf);
> + *
>    * Test if a mapping is valid with either dma_buf_map_is_set() or
>    * dma_buf_map_is_null().
>    *
> @@ -118,6 +124,20 @@ static inline void dma_buf_map_set_vaddr(struct
dma_buf_map *map, void *vaddr)
>   	map->is_iomem = false;
>   }
>   
> +/**
> + * dma_buf_map_set_vaddr_iomem - Sets a dma-buf mapping structure to an
address in I/O memory
> + * @map:		The dma-buf mapping structure
> + * @vaddr_iomem:	An I/O-memory address
> + *
> + * Sets the address and the I/O-memory flag.
> + */
> +static inline void dma_buf_map_set_vaddr_iomem(struct dma_buf_map *map,
> +					       void __iomem *vaddr_iomem)
> +{
> +	map->vaddr_iomem = vaddr_iomem;
> +	map->is_iomem = true;
> +}
> +
>   /**
>    * dma_buf_map_is_equal - Compares two dma-buf mapping structures for
equality
>    * @lhs:	The dma-buf mapping structure

Hi Thomas.

On Thu, Oct 15, 2020 at 02:38:05PM +0200, Thomas Zimmermann
wrote:
> To do framebuffer updates, one needs memcpy from system memory and a
> pointer-increment function. Add both interfaces with documentation.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
Looks good.
Reviewed-by: Sam Ravnborg <sam at ravnborg.org>
> ---
>  include/linux/dma-buf-map.h | 72 +++++++++++++++++++++++++++++++------
>  1 file changed, 62 insertions(+), 10 deletions(-)
> 
> diff --git a/include/linux/dma-buf-map.h b/include/linux/dma-buf-map.h
> index 2e8bbecb5091..6ca0f304dda2 100644
> --- a/include/linux/dma-buf-map.h
> +++ b/include/linux/dma-buf-map.h
> @@ -32,6 +32,14 @@
>   * accessing the buffer. Use the returned instance and the helper
functions
>   * to access the buffer's memory in the correct way.
>   *
> + * The type :c:type:`struct dma_buf_map <dma_buf_map>` and its
helpers are
> + * actually independent from the dma-buf infrastructure. When sharing
buffers
> + * among devices, drivers have to know the location of the memory to
access
> + * the buffers in a safe way. :c:type:`struct dma_buf_map
<dma_buf_map>`
> + * solves this problem for dma-buf and its users. If other drivers or
> + * sub-systems require similar functionality, the type could be
generalized
> + * and moved to a more prominent header file.
> + *
>   * Open-coding access to :c:type:`struct dma_buf_map <dma_buf_map>`
is
>   * considered bad style. Rather then accessing its fields directly, use
one
>   * of the provided helper functions, or implement your own. For example,
> @@ -51,6 +59,14 @@
>   *
>   *	dma_buf_map_set_vaddr_iomem(&map. 0xdeadbeaf);
>   *
> + * Instances of struct dma_buf_map do not have to be cleaned up, but
> + * can be cleared to NULL with dma_buf_map_clear(). Cleared mappings
> + * always refer to system memory.
> + *
> + * .. code-block:: c
> + *
> + *	dma_buf_map_clear(&map);
> + *
>   * Test if a mapping is valid with either dma_buf_map_is_set() or
>   * dma_buf_map_is_null().
>   *
> @@ -73,17 +89,19 @@
>   *	if (dma_buf_map_is_equal(&sys_map, &io_map))
>   *		// always false
>   *
> - * Instances of struct dma_buf_map do not have to be cleaned up, but
> - * can be cleared to NULL with dma_buf_map_clear(). Cleared mappings
> - * always refer to system memory.
> + * A set up instance of struct dma_buf_map can be used to access or
manipulate
> + * the buffer memory. Depending on the location of the memory, the
provided
> + * helpers will pick the correct operations. Data can be copied into the
memory
> + * with dma_buf_map_memcpy_to(). The address can be manipulated with
> + * dma_buf_map_incr().
>   *
> - * The type :c:type:`struct dma_buf_map <dma_buf_map>` and its
helpers are
> - * actually independent from the dma-buf infrastructure. When sharing
buffers
> - * among devices, drivers have to know the location of the memory to
access
> - * the buffers in a safe way. :c:type:`struct dma_buf_map
<dma_buf_map>`
> - * solves this problem for dma-buf and its users. If other drivers or
> - * sub-systems require similar functionality, the type could be
generalized
> - * and moved to a more prominent header file.
> + * .. code-block:: c
> + *
> + *	const void *src = ...; // source buffer
> + *	size_t len = ...; // length of src
> + *
> + *	dma_buf_map_memcpy_to(&map, src, len);
> + *	dma_buf_map_incr(&map, len); // go to first byte after the memcpy
>   */
>  
>  /**
> @@ -210,4 +228,38 @@ static inline void dma_buf_map_clear(struct
dma_buf_map *map)
>  	}
>  }
>  
> +/**
> + * dma_buf_map_memcpy_to - Memcpy into dma-buf mapping
> + * @dst:	The dma-buf mapping structure
> + * @src:	The source buffer
> + * @len:	The number of byte in src
> + *
> + * Copies data into a dma-buf mapping. The source buffer is in system
> + * memory. Depending on the buffer's location, the helper picks the
correct
> + * method of accessing the memory.
> + */
> +static inline void dma_buf_map_memcpy_to(struct dma_buf_map *dst, const
void *src, size_t len)
> +{
> +	if (dst->is_iomem)
> +		memcpy_toio(dst->vaddr_iomem, src, len);
> +	else
> +		memcpy(dst->vaddr, src, len);
> +}
> +
> +/**
> + * dma_buf_map_incr - Increments the address stored in a dma-buf mapping
> + * @map:	The dma-buf mapping structure
> + * @incr:	The number of bytes to increment
> + *
> + * Increments the address stored in a dma-buf mapping. Depending on the
> + * buffer's location, the correct value will be updated.
> + */
> +static inline void dma_buf_map_incr(struct dma_buf_map *map, size_t incr)
> +{
> +	if (map->is_iomem)
> +		map->vaddr_iomem += incr;
> +	else
> +		map->vaddr += incr;
> +}
> +
>  #endif /* __DMA_BUF_MAP_H__ */
> -- 
> 2.28.0

Hi Thomas.

On Thu, Oct 15, 2020 at 02:38:06PM +0200, Thomas Zimmermann
wrote:
> At least sparc64 requires I/O-specific access to framebuffers. This
> patch updates the fbdev console accordingly.
> 
> For drivers with direct access to the framebuffer memory, the callback
> functions in struct fb_ops test for the type of memory and call the rsp
> fb_sys_ of fb_cfb_ functions.
> 
> For drivers that employ a shadow buffer, fbdev's blit function
retrieves
> the framebuffer address as struct dma_buf_map, and uses dma_buf_map
> interfaces to access the buffer.
> 
> The bochs driver on sparc64 uses a workaround to flag the framebuffer as
> I/O memory and avoid a HW exception. With the introduction of struct
> dma_buf_map, this is not required any longer. The patch removes the rsp
> code from both, bochs and fbdev.
> 
> v4:
> 	* move dma_buf_map changes into separate patch (Daniel)
> 	* TODO list: comment on fbdev updates (Daniel)
I have been offline for a while so have not followed all the threads on
this. So may comments below may well be addressed but I failed to see
it.

If the point about fb_sync is already addressed/considered then:
Reviewed-by: Sam Ravnborg <sam at ravnborg.org>

> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
> ---
>  Documentation/gpu/todo.rst        |  19 ++-
>  drivers/gpu/drm/bochs/bochs_kms.c |   1 -
>  drivers/gpu/drm/drm_fb_helper.c   | 217 ++++++++++++++++++++++++++++--
>  include/drm/drm_mode_config.h     |  12 --
>  4 files changed, 220 insertions(+), 29 deletions(-)
> 
> diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst
> index 7e6fc3c04add..638b7f704339 100644
> --- a/Documentation/gpu/todo.rst
> +++ b/Documentation/gpu/todo.rst
> @@ -197,13 +197,28 @@ Convert drivers to use drm_fbdev_generic_setup()
>  ------------------------------------------------
>  
>  Most drivers can use drm_fbdev_generic_setup(). Driver have to implement
> -atomic modesetting and GEM vmap support. Current generic fbdev emulation
> -expects the framebuffer in system memory (or system-like memory).
> +atomic modesetting and GEM vmap support. Historically, generic fbdev
emulation
> +expected the framebuffer in system memory or system-like memory. By
employing
> +struct dma_buf_map, drivers with frambuffers in I/O memory can be
supported
> +as well.
>  
>  Contact: Maintainer of the driver you plan to convert
>  
>  Level: Intermediate
>  
> +Reimplement functions in drm_fbdev_fb_ops without fbdev
> +-------------------------------------------------------
> +
> +A number of callback functions in drm_fbdev_fb_ops could benefit from
> +being rewritten without dependencies on the fbdev module. Some of the
> +helpers could further benefit from using struct dma_buf_map instead of
> +raw pointers.
> +
> +Contact: Thomas Zimmermann <tzimmermann at suse.de>, Daniel Vetter
> +
> +Level: Advanced
> +
> +
>  drm_framebuffer_funcs and drm_mode_config_funcs.fb_create cleanup
>  -----------------------------------------------------------------
>  
> diff --git a/drivers/gpu/drm/bochs/bochs_kms.c
b/drivers/gpu/drm/bochs/bochs_kms.c
> index 13d0d04c4457..853081d186d5 100644
> --- a/drivers/gpu/drm/bochs/bochs_kms.c
> +++ b/drivers/gpu/drm/bochs/bochs_kms.c
> @@ -151,7 +151,6 @@ int bochs_kms_init(struct bochs_device *bochs)
>  	bochs->dev->mode_config.preferred_depth = 24;
>  	bochs->dev->mode_config.prefer_shadow = 0;
>  	bochs->dev->mode_config.prefer_shadow_fbdev = 1;
> -	bochs->dev->mode_config.fbdev_use_iomem = true;
>  	bochs->dev->mode_config.quirk_addfb_prefer_host_byte_order = true;
>  
>  	bochs->dev->mode_config.funcs = &bochs_mode_funcs;
Good to see this workaround gone again!
> diff --git a/drivers/gpu/drm/drm_fb_helper.c
b/drivers/gpu/drm/drm_fb_helper.c
> index 6212cd7cde1d..462b0c130ebb 100644
> --- a/drivers/gpu/drm/drm_fb_helper.c
> +++ b/drivers/gpu/drm/drm_fb_helper.c
> @@ -372,24 +372,22 @@ static void drm_fb_helper_resume_worker(struct
work_struct *work)
>  }
>  
>  static void drm_fb_helper_dirty_blit_real(struct drm_fb_helper *fb_helper,
> -					  struct drm_clip_rect *clip)
> +					  struct drm_clip_rect *clip,
> +					  struct dma_buf_map *dst)
>  {
>  	struct drm_framebuffer *fb = fb_helper->fb;
>  	unsigned int cpp = fb->format->cpp[0];
>  	size_t offset = clip->y1 * fb->pitches[0] + clip->x1 * cpp;
>  	void *src = fb_helper->fbdev->screen_buffer + offset;
> -	void *dst = fb_helper->buffer->map.vaddr + offset;
>  	size_t len = (clip->x2 - clip->x1) * cpp;
>  	unsigned int y;
>  
> -	for (y = clip->y1; y < clip->y2; y++) {
> -		if (!fb_helper->dev->mode_config.fbdev_use_iomem)
> -			memcpy(dst, src, len);
> -		else
> -			memcpy_toio((void __iomem *)dst, src, len);
> +	dma_buf_map_incr(dst, offset); /* go to first pixel within clip rect */
>  
> +	for (y = clip->y1; y < clip->y2; y++) {
> +		dma_buf_map_memcpy_to(dst, src, len);
> +		dma_buf_map_incr(dst, fb->pitches[0]);
>  		src += fb->pitches[0];
> -		dst += fb->pitches[0];
>  	}
>  }
>  
> @@ -417,8 +415,9 @@ static void drm_fb_helper_dirty_work(struct work_struct
*work)
>  			ret = drm_client_buffer_vmap(helper->buffer, &map);
>  			if (ret)
>  				return;
> -			drm_fb_helper_dirty_blit_real(helper, &clip_copy);
> +			drm_fb_helper_dirty_blit_real(helper, &clip_copy, &map);
>  		}
> +
>  		if (helper->fb->funcs->dirty)
>  			helper->fb->funcs->dirty(helper->fb, NULL, 0, 0,
>  						 &clip_copy, 1);
> @@ -755,6 +754,136 @@ void drm_fb_helper_sys_imageblit(struct fb_info
*info,
>  }
>  EXPORT_SYMBOL(drm_fb_helper_sys_imageblit);
>  
So far everything looks good.
> +static ssize_t drm_fb_helper_cfb_read(struct fb_info *info, char __user
*buf,
> +				      size_t count, loff_t *ppos)
> +{
> +	unsigned long p = *ppos;
> +	u8 *dst;
> +	u8 __iomem *src;
> +	int c, err = 0;
> +	unsigned long total_size;
> +	unsigned long alloc_size;
> +	ssize_t ret = 0;
> +
> +	if (info->state != FBINFO_STATE_RUNNING)
> +		return -EPERM;
> +
> +	total_size = info->screen_size;
> +
> +	if (total_size == 0)
> +		total_size = info->fix.smem_len;
> +
> +	if (p >= total_size)
> +		return 0;
> +
> +	if (count >= total_size)
> +		count = total_size;
> +
> +	if (count + p > total_size)
> +		count = total_size - p;
> +
> +	src = (u8 __iomem *)(info->screen_base + p);
screen_base is a char __iomem * - so this cast looks semi redundant.
> +
> +	alloc_size = min(count, PAGE_SIZE);
> +
> +	dst = kmalloc(alloc_size, GFP_KERNEL);
> +	if (!dst)
> +		return -ENOMEM;
> +
Same comment as below about fb_sync.

> +	while (count) {
> +		c = min(count, alloc_size);
> +
> +		memcpy_fromio(dst, src, c);
> +		if (copy_to_user(buf, dst, c)) {
> +			err = -EFAULT;
> +			break;
> +		}
> +
> +		src += c;
> +		*ppos += c;
> +		buf += c;
> +		ret += c;
> +		count -= c;
> +	}
> +
> +	kfree(dst);
> +
> +	if (err)
> +		return err;
> +
> +	return ret;
> +}
> +
> +static ssize_t drm_fb_helper_cfb_write(struct fb_info *info, const char
__user *buf,
> +				       size_t count, loff_t *ppos)
> +{
> +	unsigned long p = *ppos;
> +	u8 *src;
> +	u8 __iomem *dst;
> +	int c, err = 0;
> +	unsigned long total_size;
> +	unsigned long alloc_size;
> +	ssize_t ret = 0;
> +
> +	if (info->state != FBINFO_STATE_RUNNING)
> +		return -EPERM;
> +
> +	total_size = info->screen_size;
> +
> +	if (total_size == 0)
> +		total_size = info->fix.smem_len;
> +
> +	if (p > total_size)
> +		return -EFBIG;
> +
> +	if (count > total_size) {
> +		err = -EFBIG;
> +		count = total_size;
> +	}
> +
> +	if (count + p > total_size) {
> +		/*
> +		 * The framebuffer is too small. We do the
> +		 * copy operation, but return an error code
> +		 * afterwards. Taken from fbdev.
> +		 */
> +		if (!err)
> +			err = -ENOSPC;
> +		count = total_size - p;
> +	}
> +
> +	alloc_size = min(count, PAGE_SIZE);
> +
> +	src = kmalloc(alloc_size, GFP_KERNEL);
> +	if (!src)
> +		return -ENOMEM;
> +
> +	dst = (u8 __iomem *)(info->screen_base + p);
> +
The fbdev variant call the fb_sync callback here.
noveau and gma500 implments the fb_sync callback - but no-one else.

> +	while (count) {
> +		c = min(count, alloc_size);
> +
> +		if (copy_from_user(src, buf, c)) {
> +			err = -EFAULT;
> +			break;
> +		}
> +		memcpy_toio(dst, src, c);
When we rewrite this part to use dma_buf_map_memcpy_to() then we can
merge the two variants of helper_{sys,cfb}_read()?
Which is part of the todo - so OK
> +
> +		dst += c;
> +		*ppos += c;
> +		buf += c;
> +		ret += c;
> +		count -= c;
> +	}
> +
> +	kfree(src);
> +
> +	if (err)
> +		return err;
> +
> +	return ret;
> +}
> +
>  /**
>   * drm_fb_helper_cfb_fillrect - wrapper around cfb_fillrect
>   * @info: fbdev registered by the helper
> @@ -2027,6 +2156,66 @@ static int drm_fbdev_fb_mmap(struct fb_info *info,
struct vm_area_struct *vma)
>  		return -ENODEV;
>  }
>  
> +static ssize_t drm_fbdev_fb_read(struct fb_info *info, char __user *buf,
> +				 size_t count, loff_t *ppos)
> +{
> +	struct drm_fb_helper *fb_helper = info->par;
> +	struct drm_client_buffer *buffer = fb_helper->buffer;
> +
> +	if (drm_fbdev_use_shadow_fb(fb_helper) || !buffer->map.is_iomem)
> +		return drm_fb_helper_sys_read(info, buf, count, ppos);
> +	else
> +		return drm_fb_helper_cfb_read(info, buf, count, ppos);
> +}
> +
> +static ssize_t drm_fbdev_fb_write(struct fb_info *info, const char __user
*buf,
> +				  size_t count, loff_t *ppos)
> +{
> +	struct drm_fb_helper *fb_helper = info->par;
> +	struct drm_client_buffer *buffer = fb_helper->buffer;
> +
> +	if (drm_fbdev_use_shadow_fb(fb_helper) || !buffer->map.is_iomem)
> +		return drm_fb_helper_sys_write(info, buf, count, ppos);
> +	else
> +		return drm_fb_helper_cfb_write(info, buf, count, ppos);
> +}
> +
> +static void drm_fbdev_fb_fillrect(struct fb_info *info,
> +				  const struct fb_fillrect *rect)
> +{
> +	struct drm_fb_helper *fb_helper = info->par;
> +	struct drm_client_buffer *buffer = fb_helper->buffer;
> +
> +	if (drm_fbdev_use_shadow_fb(fb_helper) || !buffer->map.is_iomem)
> +		drm_fb_helper_sys_fillrect(info, rect);
> +	else
> +		drm_fb_helper_cfb_fillrect(info, rect);
> +}
> +
> +static void drm_fbdev_fb_copyarea(struct fb_info *info,
> +				  const struct fb_copyarea *area)
> +{
> +	struct drm_fb_helper *fb_helper = info->par;
> +	struct drm_client_buffer *buffer = fb_helper->buffer;
> +
> +	if (drm_fbdev_use_shadow_fb(fb_helper) || !buffer->map.is_iomem)
> +		drm_fb_helper_sys_copyarea(info, area);
> +	else
> +		drm_fb_helper_cfb_copyarea(info, area);
> +}
> +
> +static void drm_fbdev_fb_imageblit(struct fb_info *info,
> +				   const struct fb_image *image)
> +{
> +	struct drm_fb_helper *fb_helper = info->par;
> +	struct drm_client_buffer *buffer = fb_helper->buffer;
> +
> +	if (drm_fbdev_use_shadow_fb(fb_helper) || !buffer->map.is_iomem)
> +		drm_fb_helper_sys_imageblit(info, image);
> +	else
> +		drm_fb_helper_cfb_imageblit(info, image);
> +}
> +
>  static const struct fb_ops drm_fbdev_fb_ops = {
>  	.owner		= THIS_MODULE,
>  	DRM_FB_HELPER_DEFAULT_OPS,
> @@ -2034,11 +2223,11 @@ static const struct fb_ops drm_fbdev_fb_ops = {
>  	.fb_release	= drm_fbdev_fb_release,
>  	.fb_destroy	= drm_fbdev_fb_destroy,
>  	.fb_mmap	= drm_fbdev_fb_mmap,
> -	.fb_read	= drm_fb_helper_sys_read,
> -	.fb_write	= drm_fb_helper_sys_write,
> -	.fb_fillrect	= drm_fb_helper_sys_fillrect,
> -	.fb_copyarea	= drm_fb_helper_sys_copyarea,
> -	.fb_imageblit	= drm_fb_helper_sys_imageblit,
> +	.fb_read	= drm_fbdev_fb_read,
> +	.fb_write	= drm_fbdev_fb_write,
> +	.fb_fillrect	= drm_fbdev_fb_fillrect,
> +	.fb_copyarea	= drm_fbdev_fb_copyarea,
> +	.fb_imageblit	= drm_fbdev_fb_imageblit,
>  };
>  
>  static struct fb_deferred_io drm_fbdev_defio = {
> diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
> index 5ffbb4ed5b35..ab424ddd7665 100644
> --- a/include/drm/drm_mode_config.h
> +++ b/include/drm/drm_mode_config.h
> @@ -877,18 +877,6 @@ struct drm_mode_config {
>  	 */
>  	bool prefer_shadow_fbdev;
>  
> -	/**
> -	 * @fbdev_use_iomem:
> -	 *
> -	 * Set to true if framebuffer reside in iomem.
> -	 * When set to true memcpy_toio() is used when copying the framebuffer in
> -	 * drm_fb_helper.drm_fb_helper_dirty_blit_real().
> -	 *
> -	 * FIXME: This should be replaced with a per-mapping is_iomem
> -	 * flag (like ttm does), and then used everywhere in fbdev code.
> -	 */
> -	bool fbdev_use_iomem;
> -
>  	/**
>  	 * @quirk_addfb_prefer_xbgr_30bpp:
>  	 *
> -- 
> 2.28.0

Hi Thomas.

On Thu, Oct 15, 2020 at 02:38:05PM +0200, Thomas Zimmermann
wrote:
> To do framebuffer updates, one needs memcpy from system memory and a
> pointer-increment function. Add both interfaces with documentation.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
> ---
>  include/linux/dma-buf-map.h | 72 +++++++++++++++++++++++++++++++------
>  1 file changed, 62 insertions(+), 10 deletions(-)
> 
> diff --git a/include/linux/dma-buf-map.h b/include/linux/dma-buf-map.h
> index 2e8bbecb5091..6ca0f304dda2 100644
> --- a/include/linux/dma-buf-map.h
> +++ b/include/linux/dma-buf-map.h
> @@ -32,6 +32,14 @@
>   * accessing the buffer. Use the returned instance and the helper
functions
>   * to access the buffer's memory in the correct way.
>   *
> + * The type :c:type:`struct dma_buf_map <dma_buf_map>` and its
helpers are
> + * actually independent from the dma-buf infrastructure. When sharing
buffers
> + * among devices, drivers have to know the location of the memory to
access
> + * the buffers in a safe way. :c:type:`struct dma_buf_map
<dma_buf_map>`
> + * solves this problem for dma-buf and its users. If other drivers or
> + * sub-systems require similar functionality, the type could be
generalized
> + * and moved to a more prominent header file.
> + *
>   * Open-coding access to :c:type:`struct dma_buf_map <dma_buf_map>`
is
>   * considered bad style. Rather then accessing its fields directly, use
one
>   * of the provided helper functions, or implement your own. For example,
> @@ -51,6 +59,14 @@
>   *
>   *	dma_buf_map_set_vaddr_iomem(&map. 0xdeadbeaf);
>   *
> + * Instances of struct dma_buf_map do not have to be cleaned up, but
> + * can be cleared to NULL with dma_buf_map_clear(). Cleared mappings
> + * always refer to system memory.
> + *
> + * .. code-block:: c
> + *
> + *	dma_buf_map_clear(&map);
> + *
>   * Test if a mapping is valid with either dma_buf_map_is_set() or
>   * dma_buf_map_is_null().
>   *
> @@ -73,17 +89,19 @@
>   *	if (dma_buf_map_is_equal(&sys_map, &io_map))
>   *		// always false
>   *
> - * Instances of struct dma_buf_map do not have to be cleaned up, but
> - * can be cleared to NULL with dma_buf_map_clear(). Cleared mappings
> - * always refer to system memory.
> + * A set up instance of struct dma_buf_map can be used to access or
manipulate
> + * the buffer memory. Depending on the location of the memory, the
provided
> + * helpers will pick the correct operations. Data can be copied into the
memory
> + * with dma_buf_map_memcpy_to(). The address can be manipulated with
> + * dma_buf_map_incr().
>   *
> - * The type :c:type:`struct dma_buf_map <dma_buf_map>` and its
helpers are
> - * actually independent from the dma-buf infrastructure. When sharing
buffers
> - * among devices, drivers have to know the location of the memory to
access
> - * the buffers in a safe way. :c:type:`struct dma_buf_map
<dma_buf_map>`
> - * solves this problem for dma-buf and its users. If other drivers or
> - * sub-systems require similar functionality, the type could be
generalized
> - * and moved to a more prominent header file.
> + * .. code-block:: c
> + *
> + *	const void *src = ...; // source buffer
> + *	size_t len = ...; // length of src
> + *
> + *	dma_buf_map_memcpy_to(&map, src, len);
> + *	dma_buf_map_incr(&map, len); // go to first byte after the memcpy
>   */
>  
>  /**
> @@ -210,4 +228,38 @@ static inline void dma_buf_map_clear(struct
dma_buf_map *map)
>  	}
>  }
>  
> +/**
> + * dma_buf_map_memcpy_to - Memcpy into dma-buf mapping
> + * @dst:	The dma-buf mapping structure
> + * @src:	The source buffer
> + * @len:	The number of byte in src
> + *
> + * Copies data into a dma-buf mapping. The source buffer is in system
> + * memory. Depending on the buffer's location, the helper picks the
correct
> + * method of accessing the memory.
> + */
> +static inline void dma_buf_map_memcpy_to(struct dma_buf_map *dst, const
void *src, size_t len)
> +{
> +	if (dst->is_iomem)
> +		memcpy_toio(dst->vaddr_iomem, src, len);
> +	else
> +		memcpy(dst->vaddr, src, len);
sparc64 needs "#include <linux/string.h>" to build as is does
not get
this via io.h

	Sam
> +}
> +
> +/**
> + * dma_buf_map_incr - Increments the address stored in a dma-buf mapping
> + * @map:	The dma-buf mapping structure
> + * @incr:	The number of bytes to increment
> + *
> + * Increments the address stored in a dma-buf mapping. Depending on the
> + * buffer's location, the correct value will be updated.
> + */
> +static inline void dma_buf_map_incr(struct dma_buf_map *map, size_t incr)
> +{
> +	if (map->is_iomem)
> +		map->vaddr_iomem += incr;
> +	else
> +		map->vaddr += incr;
> +}
> +
>  #endif /* __DMA_BUF_MAP_H__ */
> -- 
> 2.28.0

Hi Thomas.

On Thu, Oct 15, 2020 at 02:38:06PM +0200, Thomas Zimmermann
wrote:
> At least sparc64 requires I/O-specific access to framebuffers. This
> patch updates the fbdev console accordingly.
> 
> For drivers with direct access to the framebuffer memory, the callback
> functions in struct fb_ops test for the type of memory and call the rsp
> fb_sys_ of fb_cfb_ functions.
> 
> For drivers that employ a shadow buffer, fbdev's blit function
retrieves
> the framebuffer address as struct dma_buf_map, and uses dma_buf_map
> interfaces to access the buffer.
> 
> The bochs driver on sparc64 uses a workaround to flag the framebuffer as
> I/O memory and avoid a HW exception. With the introduction of struct
> dma_buf_map, this is not required any longer. The patch removes the rsp
> code from both, bochs and fbdev.
> 
> v4:
> 	* move dma_buf_map changes into separate patch (Daniel)
> 	* TODO list: comment on fbdev updates (Daniel)
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
The original workaround fixed it so we could run qemu with the
-nographic option.

So I went ahead and tried to run quemu version:
v5.0.0-1970-g0b100c8e72-dirty.
And with the BOCHS driver built-in.

With the following command line:
qemu-system-sparc64 -m 512 -kernel vmlinux -append console=ttyS0 -nographic

Behaviour was the same before and after applying this patch.
(panic due to VFS: Unable to mount root fs on unknown-block(0,0))
So I consider it fixed for real now and not just a workaround.

I also tested with:
qemu-system-sparc64 -m 512 -kernel vmlinux -append console=ttyS0 -serial stdio

and it worked in both cases too.

All the comments above so future-me have an easier time finding how to
reproduce.

Tested-by: Sam Ravnborg <sam at ravnborg.org>

	Sam
> ---
>  Documentation/gpu/todo.rst        |  19 ++-
>  drivers/gpu/drm/bochs/bochs_kms.c |   1 -
>  drivers/gpu/drm/drm_fb_helper.c   | 217 ++++++++++++++++++++++++++++--
>  include/drm/drm_mode_config.h     |  12 --
>  4 files changed, 220 insertions(+), 29 deletions(-)
> 
> diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst
> index 7e6fc3c04add..638b7f704339 100644
> --- a/Documentation/gpu/todo.rst
> +++ b/Documentation/gpu/todo.rst
> @@ -197,13 +197,28 @@ Convert drivers to use drm_fbdev_generic_setup()
>  ------------------------------------------------
>  
>  Most drivers can use drm_fbdev_generic_setup(). Driver have to implement
> -atomic modesetting and GEM vmap support. Current generic fbdev emulation
> -expects the framebuffer in system memory (or system-like memory).
> +atomic modesetting and GEM vmap support. Historically, generic fbdev
emulation
> +expected the framebuffer in system memory or system-like memory. By
employing
> +struct dma_buf_map, drivers with frambuffers in I/O memory can be
supported
> +as well.
>  
>  Contact: Maintainer of the driver you plan to convert
>  
>  Level: Intermediate
>  
> +Reimplement functions in drm_fbdev_fb_ops without fbdev
> +-------------------------------------------------------
> +
> +A number of callback functions in drm_fbdev_fb_ops could benefit from
> +being rewritten without dependencies on the fbdev module. Some of the
> +helpers could further benefit from using struct dma_buf_map instead of
> +raw pointers.
> +
> +Contact: Thomas Zimmermann <tzimmermann at suse.de>, Daniel Vetter
> +
> +Level: Advanced
> +
> +
>  drm_framebuffer_funcs and drm_mode_config_funcs.fb_create cleanup
>  -----------------------------------------------------------------
>  
> diff --git a/drivers/gpu/drm/bochs/bochs_kms.c
b/drivers/gpu/drm/bochs/bochs_kms.c
> index 13d0d04c4457..853081d186d5 100644
> --- a/drivers/gpu/drm/bochs/bochs_kms.c
> +++ b/drivers/gpu/drm/bochs/bochs_kms.c
> @@ -151,7 +151,6 @@ int bochs_kms_init(struct bochs_device *bochs)
>  	bochs->dev->mode_config.preferred_depth = 24;
>  	bochs->dev->mode_config.prefer_shadow = 0;
>  	bochs->dev->mode_config.prefer_shadow_fbdev = 1;
> -	bochs->dev->mode_config.fbdev_use_iomem = true;
>  	bochs->dev->mode_config.quirk_addfb_prefer_host_byte_order = true;
>  
>  	bochs->dev->mode_config.funcs = &bochs_mode_funcs;
> diff --git a/drivers/gpu/drm/drm_fb_helper.c
b/drivers/gpu/drm/drm_fb_helper.c
> index 6212cd7cde1d..462b0c130ebb 100644
> --- a/drivers/gpu/drm/drm_fb_helper.c
> +++ b/drivers/gpu/drm/drm_fb_helper.c
> @@ -372,24 +372,22 @@ static void drm_fb_helper_resume_worker(struct
work_struct *work)
>  }
>  
>  static void drm_fb_helper_dirty_blit_real(struct drm_fb_helper *fb_helper,
> -					  struct drm_clip_rect *clip)
> +					  struct drm_clip_rect *clip,
> +					  struct dma_buf_map *dst)
>  {
>  	struct drm_framebuffer *fb = fb_helper->fb;
>  	unsigned int cpp = fb->format->cpp[0];
>  	size_t offset = clip->y1 * fb->pitches[0] + clip->x1 * cpp;
>  	void *src = fb_helper->fbdev->screen_buffer + offset;
> -	void *dst = fb_helper->buffer->map.vaddr + offset;
>  	size_t len = (clip->x2 - clip->x1) * cpp;
>  	unsigned int y;
>  
> -	for (y = clip->y1; y < clip->y2; y++) {
> -		if (!fb_helper->dev->mode_config.fbdev_use_iomem)
> -			memcpy(dst, src, len);
> -		else
> -			memcpy_toio((void __iomem *)dst, src, len);
> +	dma_buf_map_incr(dst, offset); /* go to first pixel within clip rect */
>  
> +	for (y = clip->y1; y < clip->y2; y++) {
> +		dma_buf_map_memcpy_to(dst, src, len);
> +		dma_buf_map_incr(dst, fb->pitches[0]);
>  		src += fb->pitches[0];
> -		dst += fb->pitches[0];
>  	}
>  }
>  
> @@ -417,8 +415,9 @@ static void drm_fb_helper_dirty_work(struct work_struct
*work)
>  			ret = drm_client_buffer_vmap(helper->buffer, &map);
>  			if (ret)
>  				return;
> -			drm_fb_helper_dirty_blit_real(helper, &clip_copy);
> +			drm_fb_helper_dirty_blit_real(helper, &clip_copy, &map);
>  		}
> +
>  		if (helper->fb->funcs->dirty)
>  			helper->fb->funcs->dirty(helper->fb, NULL, 0, 0,
>  						 &clip_copy, 1);
> @@ -755,6 +754,136 @@ void drm_fb_helper_sys_imageblit(struct fb_info
*info,
>  }
>  EXPORT_SYMBOL(drm_fb_helper_sys_imageblit);
>  
> +static ssize_t drm_fb_helper_cfb_read(struct fb_info *info, char __user
*buf,
> +				      size_t count, loff_t *ppos)
> +{
> +	unsigned long p = *ppos;
> +	u8 *dst;
> +	u8 __iomem *src;
> +	int c, err = 0;
> +	unsigned long total_size;
> +	unsigned long alloc_size;
> +	ssize_t ret = 0;
> +
> +	if (info->state != FBINFO_STATE_RUNNING)
> +		return -EPERM;
> +
> +	total_size = info->screen_size;
> +
> +	if (total_size == 0)
> +		total_size = info->fix.smem_len;
> +
> +	if (p >= total_size)
> +		return 0;
> +
> +	if (count >= total_size)
> +		count = total_size;
> +
> +	if (count + p > total_size)
> +		count = total_size - p;
> +
> +	src = (u8 __iomem *)(info->screen_base + p);
> +
> +	alloc_size = min(count, PAGE_SIZE);
> +
> +	dst = kmalloc(alloc_size, GFP_KERNEL);
> +	if (!dst)
> +		return -ENOMEM;
> +
> +	while (count) {
> +		c = min(count, alloc_size);
> +
> +		memcpy_fromio(dst, src, c);
> +		if (copy_to_user(buf, dst, c)) {
> +			err = -EFAULT;
> +			break;
> +		}
> +
> +		src += c;
> +		*ppos += c;
> +		buf += c;
> +		ret += c;
> +		count -= c;
> +	}
> +
> +	kfree(dst);
> +
> +	if (err)
> +		return err;
> +
> +	return ret;
> +}
> +
> +static ssize_t drm_fb_helper_cfb_write(struct fb_info *info, const char
__user *buf,
> +				       size_t count, loff_t *ppos)
> +{
> +	unsigned long p = *ppos;
> +	u8 *src;
> +	u8 __iomem *dst;
> +	int c, err = 0;
> +	unsigned long total_size;
> +	unsigned long alloc_size;
> +	ssize_t ret = 0;
> +
> +	if (info->state != FBINFO_STATE_RUNNING)
> +		return -EPERM;
> +
> +	total_size = info->screen_size;
> +
> +	if (total_size == 0)
> +		total_size = info->fix.smem_len;
> +
> +	if (p > total_size)
> +		return -EFBIG;
> +
> +	if (count > total_size) {
> +		err = -EFBIG;
> +		count = total_size;
> +	}
> +
> +	if (count + p > total_size) {
> +		/*
> +		 * The framebuffer is too small. We do the
> +		 * copy operation, but return an error code
> +		 * afterwards. Taken from fbdev.
> +		 */
> +		if (!err)
> +			err = -ENOSPC;
> +		count = total_size - p;
> +	}
> +
> +	alloc_size = min(count, PAGE_SIZE);
> +
> +	src = kmalloc(alloc_size, GFP_KERNEL);
> +	if (!src)
> +		return -ENOMEM;
> +
> +	dst = (u8 __iomem *)(info->screen_base + p);
> +
> +	while (count) {
> +		c = min(count, alloc_size);
> +
> +		if (copy_from_user(src, buf, c)) {
> +			err = -EFAULT;
> +			break;
> +		}
> +		memcpy_toio(dst, src, c);
> +
> +		dst += c;
> +		*ppos += c;
> +		buf += c;
> +		ret += c;
> +		count -= c;
> +	}
> +
> +	kfree(src);
> +
> +	if (err)
> +		return err;
> +
> +	return ret;
> +}
> +
>  /**
>   * drm_fb_helper_cfb_fillrect - wrapper around cfb_fillrect
>   * @info: fbdev registered by the helper
> @@ -2027,6 +2156,66 @@ static int drm_fbdev_fb_mmap(struct fb_info *info,
struct vm_area_struct *vma)
>  		return -ENODEV;
>  }
>  
> +static ssize_t drm_fbdev_fb_read(struct fb_info *info, char __user *buf,
> +				 size_t count, loff_t *ppos)
> +{
> +	struct drm_fb_helper *fb_helper = info->par;
> +	struct drm_client_buffer *buffer = fb_helper->buffer;
> +
> +	if (drm_fbdev_use_shadow_fb(fb_helper) || !buffer->map.is_iomem)
> +		return drm_fb_helper_sys_read(info, buf, count, ppos);
> +	else
> +		return drm_fb_helper_cfb_read(info, buf, count, ppos);
> +}
> +
> +static ssize_t drm_fbdev_fb_write(struct fb_info *info, const char __user
*buf,
> +				  size_t count, loff_t *ppos)
> +{
> +	struct drm_fb_helper *fb_helper = info->par;
> +	struct drm_client_buffer *buffer = fb_helper->buffer;
> +
> +	if (drm_fbdev_use_shadow_fb(fb_helper) || !buffer->map.is_iomem)
> +		return drm_fb_helper_sys_write(info, buf, count, ppos);
> +	else
> +		return drm_fb_helper_cfb_write(info, buf, count, ppos);
> +}
> +
> +static void drm_fbdev_fb_fillrect(struct fb_info *info,
> +				  const struct fb_fillrect *rect)
> +{
> +	struct drm_fb_helper *fb_helper = info->par;
> +	struct drm_client_buffer *buffer = fb_helper->buffer;
> +
> +	if (drm_fbdev_use_shadow_fb(fb_helper) || !buffer->map.is_iomem)
> +		drm_fb_helper_sys_fillrect(info, rect);
> +	else
> +		drm_fb_helper_cfb_fillrect(info, rect);
> +}
> +
> +static void drm_fbdev_fb_copyarea(struct fb_info *info,
> +				  const struct fb_copyarea *area)
> +{
> +	struct drm_fb_helper *fb_helper = info->par;
> +	struct drm_client_buffer *buffer = fb_helper->buffer;
> +
> +	if (drm_fbdev_use_shadow_fb(fb_helper) || !buffer->map.is_iomem)
> +		drm_fb_helper_sys_copyarea(info, area);
> +	else
> +		drm_fb_helper_cfb_copyarea(info, area);
> +}
> +
> +static void drm_fbdev_fb_imageblit(struct fb_info *info,
> +				   const struct fb_image *image)
> +{
> +	struct drm_fb_helper *fb_helper = info->par;
> +	struct drm_client_buffer *buffer = fb_helper->buffer;
> +
> +	if (drm_fbdev_use_shadow_fb(fb_helper) || !buffer->map.is_iomem)
> +		drm_fb_helper_sys_imageblit(info, image);
> +	else
> +		drm_fb_helper_cfb_imageblit(info, image);
> +}
> +
>  static const struct fb_ops drm_fbdev_fb_ops = {
>  	.owner		= THIS_MODULE,
>  	DRM_FB_HELPER_DEFAULT_OPS,
> @@ -2034,11 +2223,11 @@ static const struct fb_ops drm_fbdev_fb_ops = {
>  	.fb_release	= drm_fbdev_fb_release,
>  	.fb_destroy	= drm_fbdev_fb_destroy,
>  	.fb_mmap	= drm_fbdev_fb_mmap,
> -	.fb_read	= drm_fb_helper_sys_read,
> -	.fb_write	= drm_fb_helper_sys_write,
> -	.fb_fillrect	= drm_fb_helper_sys_fillrect,
> -	.fb_copyarea	= drm_fb_helper_sys_copyarea,
> -	.fb_imageblit	= drm_fb_helper_sys_imageblit,
> +	.fb_read	= drm_fbdev_fb_read,
> +	.fb_write	= drm_fbdev_fb_write,
> +	.fb_fillrect	= drm_fbdev_fb_fillrect,
> +	.fb_copyarea	= drm_fbdev_fb_copyarea,
> +	.fb_imageblit	= drm_fbdev_fb_imageblit,
>  };
>  
>  static struct fb_deferred_io drm_fbdev_defio = {
> diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
> index 5ffbb4ed5b35..ab424ddd7665 100644
> --- a/include/drm/drm_mode_config.h
> +++ b/include/drm/drm_mode_config.h
> @@ -877,18 +877,6 @@ struct drm_mode_config {
>  	 */
>  	bool prefer_shadow_fbdev;
>  
> -	/**
> -	 * @fbdev_use_iomem:
> -	 *
> -	 * Set to true if framebuffer reside in iomem.
> -	 * When set to true memcpy_toio() is used when copying the framebuffer in
> -	 * drm_fb_helper.drm_fb_helper_dirty_blit_real().
> -	 *
> -	 * FIXME: This should be replaced with a per-mapping is_iomem
> -	 * flag (like ttm does), and then used everywhere in fbdev code.
> -	 */
> -	bool fbdev_use_iomem;
> -
>  	/**
>  	 * @quirk_addfb_prefer_xbgr_30bpp:
>  	 *
> -- 
> 2.28.0