Christoph Hellwig
2023-May-18 13:42 UTC
[Nouveau] [PATCH 3/4] drm/nouveau: stop using is_swiotlb_active
Drivers have no business looking into dma-mapping internals and check
what backend is used. Unfortunstely the DRM core is still broken and
tries to do plain page allocations instead of using DMA API allocators
by default and uses various bandaids on when to use dma_alloc_coherent.
Switch nouveau to use the same (broken) scheme as amdgpu and radeon
to remove the last driver user of is_swiotlb_active.
Signed-off-by: Christoph Hellwig <hch at lst.de>
---
drivers/gpu/drm/nouveau/nouveau_ttm.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/nouveau_ttm.c
b/drivers/gpu/drm/nouveau/nouveau_ttm.c
index 1469a88910e45d..486f39f31a38df 100644
--- a/drivers/gpu/drm/nouveau/nouveau_ttm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_ttm.c
@@ -24,9 +24,9 @@
*/
#include <linux/limits.h>
-#include <linux/swiotlb.h>
#include <drm/ttm/ttm_range_manager.h>
+#include <drm/drm_cache.h>
#include "nouveau_drv.h"
#include "nouveau_gem.h"
@@ -265,7 +265,6 @@ nouveau_ttm_init(struct nouveau_drm *drm)
struct nvkm_pci *pci = device->pci;
struct nvif_mmu *mmu = &drm->client.mmu;
struct drm_device *dev = drm->dev;
- bool need_swiotlb = false;
int typei, ret;
ret = nouveau_ttm_init_host(drm, 0);
@@ -300,13 +299,10 @@ nouveau_ttm_init(struct nouveau_drm *drm)
drm->agp.cma = pci->agp.cma;
}
-#if IS_ENABLED(CONFIG_SWIOTLB) && IS_ENABLED(CONFIG_X86)
- need_swiotlb = is_swiotlb_active(dev->dev);
-#endif
-
ret = ttm_device_init(&drm->ttm.bdev, &nouveau_bo_driver,
drm->dev->dev,
dev->anon_inode->i_mapping,
- dev->vma_offset_manager, need_swiotlb,
+ dev->vma_offset_manager,
+ drm_need_swiotlb(drm->client.mmu.dmabits),
drm->client.mmu.dmabits <= 32);
if (ret) {
NV_ERROR(drm, "error initialising bo driver, %d\n", ret);
--
2.39.2
Lyude Paul
2023-May-18 20:30 UTC
[Nouveau] [PATCH 3/4] drm/nouveau: stop using is_swiotlb_active
Reviewed-by: Lyude Paul <lyude at redhat.com> Thanks for getting to this! On Thu, 2023-05-18 at 15:42 +0200, Christoph Hellwig wrote:> Drivers have no business looking into dma-mapping internals and check > what backend is used. Unfortunstely the DRM core is still broken and > tries to do plain page allocations instead of using DMA API allocators > by default and uses various bandaids on when to use dma_alloc_coherent. > > Switch nouveau to use the same (broken) scheme as amdgpu and radeon > to remove the last driver user of is_swiotlb_active. > > Signed-off-by: Christoph Hellwig <hch at lst.de> > --- > drivers/gpu/drm/nouveau/nouveau_ttm.c | 10 +++------- > 1 file changed, 3 insertions(+), 7 deletions(-) > > diff --git a/drivers/gpu/drm/nouveau/nouveau_ttm.c b/drivers/gpu/drm/nouveau/nouveau_ttm.c > index 1469a88910e45d..486f39f31a38df 100644 > --- a/drivers/gpu/drm/nouveau/nouveau_ttm.c > +++ b/drivers/gpu/drm/nouveau/nouveau_ttm.c > @@ -24,9 +24,9 @@ > */ > > #include <linux/limits.h> > -#include <linux/swiotlb.h> > > #include <drm/ttm/ttm_range_manager.h> > +#include <drm/drm_cache.h> > > #include "nouveau_drv.h" > #include "nouveau_gem.h" > @@ -265,7 +265,6 @@ nouveau_ttm_init(struct nouveau_drm *drm) > struct nvkm_pci *pci = device->pci; > struct nvif_mmu *mmu = &drm->client.mmu; > struct drm_device *dev = drm->dev; > - bool need_swiotlb = false; > int typei, ret; > > ret = nouveau_ttm_init_host(drm, 0); > @@ -300,13 +299,10 @@ nouveau_ttm_init(struct nouveau_drm *drm) > drm->agp.cma = pci->agp.cma; > } > > -#if IS_ENABLED(CONFIG_SWIOTLB) && IS_ENABLED(CONFIG_X86) > - need_swiotlb = is_swiotlb_active(dev->dev); > -#endif > - > ret = ttm_device_init(&drm->ttm.bdev, &nouveau_bo_driver, drm->dev->dev, > dev->anon_inode->i_mapping, > - dev->vma_offset_manager, need_swiotlb, > + dev->vma_offset_manager, > + drm_need_swiotlb(drm->client.mmu.dmabits), > drm->client.mmu.dmabits <= 32); > if (ret) { > NV_ERROR(drm, "error initialising bo driver, %d\n", ret);-- Cheers, Lyude Paul (she/her) Software Engineer at Red Hat