Linux Virtualization - Jan 2023 - [PATCH 1/8] iommu: Add a gfp parameter to iommu_map()

The internal mechanisms support this, but instead of exposting the gfp to
the caller it wrappers it into iommu_map() and iommu_map_atomic()

Fix this instead of adding more variants for GFP_KERNEL_ACCOUNT.

Signed-off-by: Jason Gunthorpe <jgg at nvidia.com>
---
 arch/arm/mm/dma-mapping.c                       | 11 +++++++----
 .../gpu/drm/nouveau/nvkm/subdev/instmem/gk20a.c |  3 ++-
 drivers/gpu/drm/tegra/drm.c                     |  2 +-
 drivers/gpu/host1x/cdma.c                       |  2 +-
 drivers/infiniband/hw/usnic/usnic_uiom.c        |  4 ++--
 drivers/iommu/dma-iommu.c                       |  2 +-
 drivers/iommu/iommu.c                           | 17 ++++++-----------
 drivers/iommu/iommufd/pages.c                   |  6 ++++--
 drivers/media/platform/qcom/venus/firmware.c    |  2 +-
 drivers/net/ipa/ipa_mem.c                       |  6 ++++--
 drivers/net/wireless/ath/ath10k/snoc.c          |  2 +-
 drivers/net/wireless/ath/ath11k/ahb.c           |  4 ++--
 drivers/remoteproc/remoteproc_core.c            |  5 +++--
 drivers/vfio/vfio_iommu_type1.c                 |  9 +++++----
 drivers/vhost/vdpa.c                            |  2 +-
 include/linux/iommu.h                           |  4 ++--
 16 files changed, 43 insertions(+), 38 deletions(-)

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index c135f6e37a00ca..8bc01071474ab7 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -984,7 +984,8 @@ __iommu_create_mapping(struct device *dev, struct page
**pages, size_t size,
 
 		len = (j - i) << PAGE_SHIFT;
 		ret = iommu_map(mapping->domain, iova, phys, len,
-				__dma_info_to_prot(DMA_BIDIRECTIONAL, attrs));
+				__dma_info_to_prot(DMA_BIDIRECTIONAL, attrs),
+				GFP_KERNEL);
 		if (ret < 0)
 			goto fail;
 		iova += len;
@@ -1207,7 +1208,8 @@ static int __map_sg_chunk(struct device *dev, struct
scatterlist *sg,
 
 		prot = __dma_info_to_prot(dir, attrs);
 
-		ret = iommu_map(mapping->domain, iova, phys, len, prot);
+		ret = iommu_map(mapping->domain, iova, phys, len, prot,
+				GFP_KERNEL);
 		if (ret < 0)
 			goto fail;
 		count += len >> PAGE_SHIFT;
@@ -1379,7 +1381,8 @@ static dma_addr_t arm_iommu_map_page(struct device *dev,
struct page *page,
 
 	prot = __dma_info_to_prot(dir, attrs);
 
-	ret = iommu_map(mapping->domain, dma_addr, page_to_phys(page), len, prot);
+	ret = iommu_map(mapping->domain, dma_addr, page_to_phys(page), len,
+			prot, GFP_KERNEL);
 	if (ret < 0)
 		goto fail;
 
@@ -1443,7 +1446,7 @@ static dma_addr_t arm_iommu_map_resource(struct device
*dev,
 
 	prot = __dma_info_to_prot(dir, attrs) | IOMMU_MMIO;
 
-	ret = iommu_map(mapping->domain, dma_addr, addr, len, prot);
+	ret = iommu_map(mapping->domain, dma_addr, addr, len, prot, GFP_KERNEL);
 	if (ret < 0)
 		goto fail;
 
diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/gk20a.c
b/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/gk20a.c
index 648ecf5a8fbc2a..a4ac94a2ab57fc 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/gk20a.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/gk20a.c
@@ -475,7 +475,8 @@ gk20a_instobj_ctor_iommu(struct gk20a_instmem *imem, u32
npages, u32 align,
 		u32 offset = (r->offset + i) << imem->iommu_pgshift;
 
 		ret = iommu_map(imem->domain, offset, node->dma_addrs[i],
-				PAGE_SIZE, IOMMU_READ | IOMMU_WRITE);
+				PAGE_SIZE, IOMMU_READ | IOMMU_WRITE,
+				GFP_KERNEL);
 		if (ret < 0) {
 			nvkm_error(subdev, "IOMMU mapping failure: %d\n", ret);
 
diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
index 7bd2e65c2a16c5..6ca9f396e55be4 100644
--- a/drivers/gpu/drm/tegra/drm.c
+++ b/drivers/gpu/drm/tegra/drm.c
@@ -1057,7 +1057,7 @@ void *tegra_drm_alloc(struct tegra_drm *tegra, size_t
size, dma_addr_t *dma)
 
 	*dma = iova_dma_addr(&tegra->carveout.domain, alloc);
 	err = iommu_map(tegra->domain, *dma, virt_to_phys(virt),
-			size, IOMMU_READ | IOMMU_WRITE);
+			size, IOMMU_READ | IOMMU_WRITE, GFP_KERNEL);
 	if (err < 0)
 		goto free_iova;
 
diff --git a/drivers/gpu/host1x/cdma.c b/drivers/gpu/host1x/cdma.c
index 103fda055394ab..4ddfcd2138c95b 100644
--- a/drivers/gpu/host1x/cdma.c
+++ b/drivers/gpu/host1x/cdma.c
@@ -105,7 +105,7 @@ static int host1x_pushbuffer_init(struct push_buffer *pb)
 
 		pb->dma = iova_dma_addr(&host1x->iova, alloc);
 		err = iommu_map(host1x->domain, pb->dma, pb->phys, size,
-				IOMMU_READ);
+				IOMMU_READ, GFP_KERNEL);
 		if (err)
 			goto iommu_free_iova;
 	} else {
diff --git a/drivers/infiniband/hw/usnic/usnic_uiom.c
b/drivers/infiniband/hw/usnic/usnic_uiom.c
index c301b3be9f303d..aeeaca65ace96a 100644
--- a/drivers/infiniband/hw/usnic/usnic_uiom.c
+++ b/drivers/infiniband/hw/usnic/usnic_uiom.c
@@ -277,7 +277,7 @@ static int usnic_uiom_map_sorted_intervals(struct list_head
*intervals,
 				usnic_dbg("va 0x%lx pa %pa size 0x%zx flags 0x%x",
 					va_start, &pa_start, size, flags);
 				err = iommu_map(pd->domain, va_start, pa_start,
-							size, flags);
+						size, flags, GFP_KERNEL);
 				if (err) {
 					usnic_err("Failed to map va 0x%lx pa %pa size 0x%zx with err
%d\n",
 						va_start, &pa_start, size, err);
@@ -294,7 +294,7 @@ static int usnic_uiom_map_sorted_intervals(struct list_head
*intervals,
 				usnic_dbg("va 0x%lx pa %pa size 0x%zx flags 0x%x\n",
 					va_start, &pa_start, size, flags);
 				err = iommu_map(pd->domain, va_start, pa_start,
-						size, flags);
+						size, flags, GFP_KERNEL);
 				if (err) {
 					usnic_err("Failed to map va 0x%lx pa %pa size 0x%zx with err
%d\n",
 						va_start, &pa_start, size, err);
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index f798c44e090337..8bdb65e7686ff9 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -1615,7 +1615,7 @@ static struct iommu_dma_msi_page
*iommu_dma_get_msi_page(struct device *dev,
 	if (!iova)
 		goto out_free_page;
 
-	if (iommu_map(domain, iova, msi_addr, size, prot))
+	if (iommu_map(domain, iova, msi_addr, size, prot, GFP_KERNEL))
 		goto out_free_iova;
 
 	INIT_LIST_HEAD(&msi_page->list);
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index de91dd88705bd3..fe29fc2140b132 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -930,7 +930,7 @@ static int iommu_create_device_direct_mappings(struct
iommu_group *group,
 			if (map_size) {
 				ret = iommu_map(domain, addr - map_size,
 						addr - map_size, map_size,
-						entry->prot);
+						entry->prot, GFP_KERNEL);
 				if (ret)
 					goto out;
 				map_size = 0;
@@ -2360,31 +2360,26 @@ static int __iommu_map(struct iommu_domain *domain,
unsigned long iova,
 	return ret;
 }
 
-static int _iommu_map(struct iommu_domain *domain, unsigned long iova,
-		      phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
+int iommu_map(struct iommu_domain *domain, unsigned long iova,
+	      phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
 {
 	const struct iommu_domain_ops *ops = domain->ops;
 	int ret;
 
+	might_sleep_if(gfpflags_allow_blocking(gfp));
+
 	ret = __iommu_map(domain, iova, paddr, size, prot, gfp);
 	if (ret == 0 && ops->iotlb_sync_map)
 		ops->iotlb_sync_map(domain, iova, size);
 
 	return ret;
 }
-
-int iommu_map(struct iommu_domain *domain, unsigned long iova,
-	      phys_addr_t paddr, size_t size, int prot)
-{
-	might_sleep();
-	return _iommu_map(domain, iova, paddr, size, prot, GFP_KERNEL);
-}
 EXPORT_SYMBOL_GPL(iommu_map);
 
 int iommu_map_atomic(struct iommu_domain *domain, unsigned long iova,
 	      phys_addr_t paddr, size_t size, int prot)
 {
-	return _iommu_map(domain, iova, paddr, size, prot, GFP_ATOMIC);
+	return iommu_map(domain, iova, paddr, size, prot, GFP_ATOMIC);
 }
 EXPORT_SYMBOL_GPL(iommu_map_atomic);
 
diff --git a/drivers/iommu/iommufd/pages.c b/drivers/iommu/iommufd/pages.c
index 1e1d3509efae5e..22cc3bb0c6c55a 100644
--- a/drivers/iommu/iommufd/pages.c
+++ b/drivers/iommu/iommufd/pages.c
@@ -456,7 +456,8 @@ static int batch_iommu_map_small(struct iommu_domain
*domain,
 			size % PAGE_SIZE);
 
 	while (size) {
-		rc = iommu_map(domain, iova, paddr, PAGE_SIZE, prot);
+		rc = iommu_map(domain, iova, paddr, PAGE_SIZE, prot,
+			       GFP_KERNEL);
 		if (rc)
 			goto err_unmap;
 		iova += PAGE_SIZE;
@@ -500,7 +501,8 @@ static int batch_to_domain(struct pfn_batch *batch, struct
iommu_domain *domain,
 		else
 			rc = iommu_map(domain, iova,
 				       PFN_PHYS(batch->pfns[cur]) + page_offset,
-				       next_iova - iova, area->iommu_prot);
+				       next_iova - iova, area->iommu_prot,
+				       GFP_KERNEL);
 		if (rc)
 			goto err_unmap;
 		iova = next_iova;
diff --git a/drivers/media/platform/qcom/venus/firmware.c
b/drivers/media/platform/qcom/venus/firmware.c
index 142d4c74017c04..07d4dceb5e72c7 100644
--- a/drivers/media/platform/qcom/venus/firmware.c
+++ b/drivers/media/platform/qcom/venus/firmware.c
@@ -158,7 +158,7 @@ static int venus_boot_no_tz(struct venus_core *core,
phys_addr_t mem_phys,
 	core->fw.mapped_mem_size = mem_size;
 
 	ret = iommu_map(iommu, VENUS_FW_START_ADDR, mem_phys, mem_size,
-			IOMMU_READ | IOMMU_WRITE | IOMMU_PRIV);
+			IOMMU_READ | IOMMU_WRITE | IOMMU_PRIV, GFP_KERNEL);
 	if (ret) {
 		dev_err(dev, "could not map video firmware region\n");
 		return ret;
diff --git a/drivers/net/ipa/ipa_mem.c b/drivers/net/ipa/ipa_mem.c
index 9ec5af323f731d..991a7d39f06661 100644
--- a/drivers/net/ipa/ipa_mem.c
+++ b/drivers/net/ipa/ipa_mem.c
@@ -466,7 +466,8 @@ static int ipa_imem_init(struct ipa *ipa, unsigned long
addr, size_t size)
 	size = PAGE_ALIGN(size + addr - phys);
 	iova = phys;	/* We just want a direct mapping */
 
-	ret = iommu_map(domain, iova, phys, size, IOMMU_READ | IOMMU_WRITE);
+	ret = iommu_map(domain, iova, phys, size, IOMMU_READ | IOMMU_WRITE,
+			GFP_KERNEL);
 	if (ret)
 		return ret;
 
@@ -574,7 +575,8 @@ static int ipa_smem_init(struct ipa *ipa, u32 item, size_t
size)
 	size = PAGE_ALIGN(size + addr - phys);
 	iova = phys;	/* We just want a direct mapping */
 
-	ret = iommu_map(domain, iova, phys, size, IOMMU_READ | IOMMU_WRITE);
+	ret = iommu_map(domain, iova, phys, size, IOMMU_READ | IOMMU_WRITE,
+			GFP_KERNEL);
 	if (ret)
 		return ret;
 
diff --git a/drivers/net/wireless/ath/ath10k/snoc.c
b/drivers/net/wireless/ath/ath10k/snoc.c
index cfcb759a87deac..9a82f0336d9537 100644
--- a/drivers/net/wireless/ath/ath10k/snoc.c
+++ b/drivers/net/wireless/ath/ath10k/snoc.c
@@ -1639,7 +1639,7 @@ static int ath10k_fw_init(struct ath10k *ar)
 
 	ret = iommu_map(iommu_dom, ar_snoc->fw.fw_start_addr,
 			ar->msa.paddr, ar->msa.mem_size,
-			IOMMU_READ | IOMMU_WRITE);
+			IOMMU_READ | IOMMU_WRITE, GFP_KERNEL);
 	if (ret) {
 		ath10k_err(ar, "failed to map firmware region: %d\n", ret);
 		goto err_iommu_detach;
diff --git a/drivers/net/wireless/ath/ath11k/ahb.c
b/drivers/net/wireless/ath/ath11k/ahb.c
index d34a4d6325b2b4..df8fdc7067f99c 100644
--- a/drivers/net/wireless/ath/ath11k/ahb.c
+++ b/drivers/net/wireless/ath/ath11k/ahb.c
@@ -1021,7 +1021,7 @@ static int ath11k_ahb_fw_resources_init(struct ath11k_base
*ab)
 
 	ret = iommu_map(iommu_dom, ab_ahb->fw.msa_paddr,
 			ab_ahb->fw.msa_paddr, ab_ahb->fw.msa_size,
-			IOMMU_READ | IOMMU_WRITE);
+			IOMMU_READ | IOMMU_WRITE, GFP_KERNEL);
 	if (ret) {
 		ath11k_err(ab, "failed to map firmware region: %d\n", ret);
 		goto err_iommu_detach;
@@ -1029,7 +1029,7 @@ static int ath11k_ahb_fw_resources_init(struct ath11k_base
*ab)
 
 	ret = iommu_map(iommu_dom, ab_ahb->fw.ce_paddr,
 			ab_ahb->fw.ce_paddr, ab_ahb->fw.ce_size,
-			IOMMU_READ | IOMMU_WRITE);
+			IOMMU_READ | IOMMU_WRITE, GFP_KERNEL);
 	if (ret) {
 		ath11k_err(ab, "failed to map firmware CE region: %d\n", ret);
 		goto err_iommu_unmap;
diff --git a/drivers/remoteproc/remoteproc_core.c
b/drivers/remoteproc/remoteproc_core.c
index 1cd4815a6dd197..80072b6b628358 100644
--- a/drivers/remoteproc/remoteproc_core.c
+++ b/drivers/remoteproc/remoteproc_core.c
@@ -643,7 +643,8 @@ static int rproc_handle_devmem(struct rproc *rproc, void
*ptr,
 	if (!mapping)
 		return -ENOMEM;
 
-	ret = iommu_map(rproc->domain, rsc->da, rsc->pa, rsc->len,
rsc->flags);
+	ret = iommu_map(rproc->domain, rsc->da, rsc->pa, rsc->len,
rsc->flags,
+			GFP_KERNEL);
 	if (ret) {
 		dev_err(dev, "failed to map devmem: %d\n", ret);
 		goto out;
@@ -737,7 +738,7 @@ static int rproc_alloc_carveout(struct rproc *rproc,
 		}
 
 		ret = iommu_map(rproc->domain, mem->da, dma, mem->len,
-				mem->flags);
+				mem->flags, GFP_KERNEL);
 		if (ret) {
 			dev_err(dev, "iommu_map failed: %d\n", ret);
 			goto free_mapping;
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 23c24fe98c00d4..e14f86a8ef5258 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -1480,7 +1480,8 @@ static int vfio_iommu_map(struct vfio_iommu *iommu,
dma_addr_t iova,
 
 	list_for_each_entry(d, &iommu->domain_list, next) {
 		ret = iommu_map(d->domain, iova, (phys_addr_t)pfn << PAGE_SHIFT,
-				npage << PAGE_SHIFT, prot | IOMMU_CACHE);
+				npage << PAGE_SHIFT, prot | IOMMU_CACHE,
+				GFP_KERNEL);
 		if (ret)
 			goto unwind;
 
@@ -1777,8 +1778,8 @@ static int vfio_iommu_replay(struct vfio_iommu *iommu,
 				size = npage << PAGE_SHIFT;
 			}
 
-			ret = iommu_map(domain->domain, iova, phys,
-					size, dma->prot | IOMMU_CACHE);
+			ret = iommu_map(domain->domain, iova, phys, size,
+					dma->prot | IOMMU_CACHE, GFP_KERNEL);
 			if (ret) {
 				if (!dma->iommu_mapped) {
 					vfio_unpin_pages_remote(dma, iova,
@@ -1866,7 +1867,7 @@ static void vfio_test_domain_fgsp(struct vfio_domain
*domain)
 		return;
 
 	ret = iommu_map(domain->domain, 0, page_to_phys(pages), PAGE_SIZE * 2,
-			IOMMU_READ | IOMMU_WRITE | IOMMU_CACHE);
+			IOMMU_READ | IOMMU_WRITE | IOMMU_CACHE, GFP_KERNEL);
 	if (!ret) {
 		size_t unmapped = iommu_unmap(domain->domain, 0, PAGE_SIZE);
 
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 166044642fd5cc..e555c3bd1c030b 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -777,7 +777,7 @@ static int vhost_vdpa_map(struct vhost_vdpa *v, struct
vhost_iotlb *iotlb,
 			r = ops->set_map(vdpa, asid, iotlb);
 	} else {
 		r = iommu_map(v->domain, iova, pa, size,
-			      perm_to_iommu_flags(perm));
+			      perm_to_iommu_flags(perm), GFP_KERNEL);
 	}
 	if (r) {
 		vhost_iotlb_del_range(iotlb, iova, iova + size - 1);
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 46e1347bfa2286..d2020994f292db 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -467,7 +467,7 @@ extern int iommu_sva_unbind_gpasid(struct iommu_domain
*domain,
 extern struct iommu_domain *iommu_get_domain_for_dev(struct device *dev);
 extern struct iommu_domain *iommu_get_dma_domain(struct device *dev);
 extern int iommu_map(struct iommu_domain *domain, unsigned long iova,
-		     phys_addr_t paddr, size_t size, int prot);
+		     phys_addr_t paddr, size_t size, int prot, gfp_t gfp);
 extern int iommu_map_atomic(struct iommu_domain *domain, unsigned long iova,
 			    phys_addr_t paddr, size_t size, int prot);
 extern size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova,
@@ -773,7 +773,7 @@ static inline struct iommu_domain
*iommu_get_domain_for_dev(struct device *dev)
 }
 
 static inline int iommu_map(struct iommu_domain *domain, unsigned long iova,
-			    phys_addr_t paddr, size_t size, int prot)
+			    phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
 {
 	return -ENODEV;
 }
-- 
2.39.0

On 2023-01-06 16:42, Jason Gunthorpe wrote:
> The internal mechanisms support this, but instead of exposting the gfp to
> the caller it wrappers it into iommu_map() and iommu_map_atomic()
> 
> Fix this instead of adding more variants for GFP_KERNEL_ACCOUNT.
FWIW, since we *do* have two variants already, I think I'd have a mild 
preference for leaving the regular map calls as-is (i.e. implicit 
GFP_KERNEL), and just generalising the _atomic versions for the special 
cases.

However, echoing the recent activity over on the DMA API side of things, 
I think it's still worth proactively constraining the set of permissible 
flags, lest we end up with more weird problems if stuff that doesn't 
really make sense, like GFP_COMP or zone flags, manages to leak through 
(that may have been part of the reason for having the current wrappers 
rather than a bare gfp argument in the first place, I forget now).

Thanks,
Robin.
> Signed-off-by: Jason Gunthorpe <jgg at nvidia.com>
> ---
>   arch/arm/mm/dma-mapping.c                       | 11 +++++++----
>   .../gpu/drm/nouveau/nvkm/subdev/instmem/gk20a.c |  3 ++-
>   drivers/gpu/drm/tegra/drm.c                     |  2 +-
>   drivers/gpu/host1x/cdma.c                       |  2 +-
>   drivers/infiniband/hw/usnic/usnic_uiom.c        |  4 ++--
>   drivers/iommu/dma-iommu.c                       |  2 +-
>   drivers/iommu/iommu.c                           | 17 ++++++-----------
>   drivers/iommu/iommufd/pages.c                   |  6 ++++--
>   drivers/media/platform/qcom/venus/firmware.c    |  2 +-
>   drivers/net/ipa/ipa_mem.c                       |  6 ++++--
>   drivers/net/wireless/ath/ath10k/snoc.c          |  2 +-
>   drivers/net/wireless/ath/ath11k/ahb.c           |  4 ++--
>   drivers/remoteproc/remoteproc_core.c            |  5 +++--
>   drivers/vfio/vfio_iommu_type1.c                 |  9 +++++----
>   drivers/vhost/vdpa.c                            |  2 +-
>   include/linux/iommu.h                           |  4 ++--
>   16 files changed, 43 insertions(+), 38 deletions(-)
> 
> diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
> index c135f6e37a00ca..8bc01071474ab7 100644
> --- a/arch/arm/mm/dma-mapping.c
> +++ b/arch/arm/mm/dma-mapping.c
> @@ -984,7 +984,8 @@ __iommu_create_mapping(struct device *dev, struct page
**pages, size_t size,
>   
>   		len = (j - i) << PAGE_SHIFT;
>   		ret = iommu_map(mapping->domain, iova, phys, len,
> -				__dma_info_to_prot(DMA_BIDIRECTIONAL, attrs));
> +				__dma_info_to_prot(DMA_BIDIRECTIONAL, attrs),
> +				GFP_KERNEL);
>   		if (ret < 0)
>   			goto fail;
>   		iova += len;
> @@ -1207,7 +1208,8 @@ static int __map_sg_chunk(struct device *dev, struct
scatterlist *sg,
>   
>   		prot = __dma_info_to_prot(dir, attrs);
>   
> -		ret = iommu_map(mapping->domain, iova, phys, len, prot);
> +		ret = iommu_map(mapping->domain, iova, phys, len, prot,
> +				GFP_KERNEL);
>   		if (ret < 0)
>   			goto fail;
>   		count += len >> PAGE_SHIFT;
> @@ -1379,7 +1381,8 @@ static dma_addr_t arm_iommu_map_page(struct device
*dev, struct page *page,
>   
>   	prot = __dma_info_to_prot(dir, attrs);
>   
> -	ret = iommu_map(mapping->domain, dma_addr, page_to_phys(page), len,
prot);
> +	ret = iommu_map(mapping->domain, dma_addr, page_to_phys(page), len,
> +			prot, GFP_KERNEL);
>   	if (ret < 0)
>   		goto fail;
>   
> @@ -1443,7 +1446,7 @@ static dma_addr_t arm_iommu_map_resource(struct
device *dev,
>   
>   	prot = __dma_info_to_prot(dir, attrs) | IOMMU_MMIO;
>   
> -	ret = iommu_map(mapping->domain, dma_addr, addr, len, prot);
> +	ret = iommu_map(mapping->domain, dma_addr, addr, len, prot,
GFP_KERNEL);
>   	if (ret < 0)
>   		goto fail;
>   
> diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/gk20a.c
b/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/gk20a.c
> index 648ecf5a8fbc2a..a4ac94a2ab57fc 100644
> --- a/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/gk20a.c
> +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/gk20a.c
> @@ -475,7 +475,8 @@ gk20a_instobj_ctor_iommu(struct gk20a_instmem *imem,
u32 npages, u32 align,
>   		u32 offset = (r->offset + i) << imem->iommu_pgshift;
>   
>   		ret = iommu_map(imem->domain, offset, node->dma_addrs[i],
> -				PAGE_SIZE, IOMMU_READ | IOMMU_WRITE);
> +				PAGE_SIZE, IOMMU_READ | IOMMU_WRITE,
> +				GFP_KERNEL);
>   		if (ret < 0) {
>   			nvkm_error(subdev, "IOMMU mapping failure: %d\n", ret);
>   
> diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
> index 7bd2e65c2a16c5..6ca9f396e55be4 100644
> --- a/drivers/gpu/drm/tegra/drm.c
> +++ b/drivers/gpu/drm/tegra/drm.c
> @@ -1057,7 +1057,7 @@ void *tegra_drm_alloc(struct tegra_drm *tegra, size_t
size, dma_addr_t *dma)
>   
>   	*dma = iova_dma_addr(&tegra->carveout.domain, alloc);
>   	err = iommu_map(tegra->domain, *dma, virt_to_phys(virt),
> -			size, IOMMU_READ | IOMMU_WRITE);
> +			size, IOMMU_READ | IOMMU_WRITE, GFP_KERNEL);
>   	if (err < 0)
>   		goto free_iova;
>   
> diff --git a/drivers/gpu/host1x/cdma.c b/drivers/gpu/host1x/cdma.c
> index 103fda055394ab..4ddfcd2138c95b 100644
> --- a/drivers/gpu/host1x/cdma.c
> +++ b/drivers/gpu/host1x/cdma.c
> @@ -105,7 +105,7 @@ static int host1x_pushbuffer_init(struct push_buffer
*pb)
>   
>   		pb->dma = iova_dma_addr(&host1x->iova, alloc);
>   		err = iommu_map(host1x->domain, pb->dma, pb->phys, size,
> -				IOMMU_READ);
> +				IOMMU_READ, GFP_KERNEL);
>   		if (err)
>   			goto iommu_free_iova;
>   	} else {
> diff --git a/drivers/infiniband/hw/usnic/usnic_uiom.c
b/drivers/infiniband/hw/usnic/usnic_uiom.c
> index c301b3be9f303d..aeeaca65ace96a 100644
> --- a/drivers/infiniband/hw/usnic/usnic_uiom.c
> +++ b/drivers/infiniband/hw/usnic/usnic_uiom.c
> @@ -277,7 +277,7 @@ static int usnic_uiom_map_sorted_intervals(struct
list_head *intervals,
>   				usnic_dbg("va 0x%lx pa %pa size 0x%zx flags 0x%x",
>   					va_start, &pa_start, size, flags);
>   				err = iommu_map(pd->domain, va_start, pa_start,
> -							size, flags);
> +						size, flags, GFP_KERNEL);
>   				if (err) {
>   					usnic_err("Failed to map va 0x%lx pa %pa size 0x%zx with err
%d\n",
>   						va_start, &pa_start, size, err);
> @@ -294,7 +294,7 @@ static int usnic_uiom_map_sorted_intervals(struct
list_head *intervals,
>   				usnic_dbg("va 0x%lx pa %pa size 0x%zx flags 0x%x\n",
>   					va_start, &pa_start, size, flags);
>   				err = iommu_map(pd->domain, va_start, pa_start,
> -						size, flags);
> +						size, flags, GFP_KERNEL);
>   				if (err) {
>   					usnic_err("Failed to map va 0x%lx pa %pa size 0x%zx with err
%d\n",
>   						va_start, &pa_start, size, err);
> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> index f798c44e090337..8bdb65e7686ff9 100644
> --- a/drivers/iommu/dma-iommu.c
> +++ b/drivers/iommu/dma-iommu.c
> @@ -1615,7 +1615,7 @@ static struct iommu_dma_msi_page
*iommu_dma_get_msi_page(struct device *dev,
>   	if (!iova)
>   		goto out_free_page;
>   
> -	if (iommu_map(domain, iova, msi_addr, size, prot))
> +	if (iommu_map(domain, iova, msi_addr, size, prot, GFP_KERNEL))
>   		goto out_free_iova;
>   
>   	INIT_LIST_HEAD(&msi_page->list);
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index de91dd88705bd3..fe29fc2140b132 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -930,7 +930,7 @@ static int iommu_create_device_direct_mappings(struct
iommu_group *group,
>   			if (map_size) {
>   				ret = iommu_map(domain, addr - map_size,
>   						addr - map_size, map_size,
> -						entry->prot);
> +						entry->prot, GFP_KERNEL);
>   				if (ret)
>   					goto out;
>   				map_size = 0;
> @@ -2360,31 +2360,26 @@ static int __iommu_map(struct iommu_domain *domain,
unsigned long iova,
>   	return ret;
>   }
>   
> -static int _iommu_map(struct iommu_domain *domain, unsigned long iova,
> -		      phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
> +int iommu_map(struct iommu_domain *domain, unsigned long iova,
> +	      phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
>   {
>   	const struct iommu_domain_ops *ops = domain->ops;
>   	int ret;
>   
> +	might_sleep_if(gfpflags_allow_blocking(gfp));
> +
>   	ret = __iommu_map(domain, iova, paddr, size, prot, gfp);
>   	if (ret == 0 && ops->iotlb_sync_map)
>   		ops->iotlb_sync_map(domain, iova, size);
>   
>   	return ret;
>   }
> -
> -int iommu_map(struct iommu_domain *domain, unsigned long iova,
> -	      phys_addr_t paddr, size_t size, int prot)
> -{
> -	might_sleep();
> -	return _iommu_map(domain, iova, paddr, size, prot, GFP_KERNEL);
> -}
>   EXPORT_SYMBOL_GPL(iommu_map);
>   
>   int iommu_map_atomic(struct iommu_domain *domain, unsigned long iova,
>   	      phys_addr_t paddr, size_t size, int prot)
>   {
> -	return _iommu_map(domain, iova, paddr, size, prot, GFP_ATOMIC);
> +	return iommu_map(domain, iova, paddr, size, prot, GFP_ATOMIC);
>   }
>   EXPORT_SYMBOL_GPL(iommu_map_atomic);
>   
> diff --git a/drivers/iommu/iommufd/pages.c b/drivers/iommu/iommufd/pages.c
> index 1e1d3509efae5e..22cc3bb0c6c55a 100644
> --- a/drivers/iommu/iommufd/pages.c
> +++ b/drivers/iommu/iommufd/pages.c
> @@ -456,7 +456,8 @@ static int batch_iommu_map_small(struct iommu_domain
*domain,
>   			size % PAGE_SIZE);
>   
>   	while (size) {
> -		rc = iommu_map(domain, iova, paddr, PAGE_SIZE, prot);
> +		rc = iommu_map(domain, iova, paddr, PAGE_SIZE, prot,
> +			       GFP_KERNEL);
>   		if (rc)
>   			goto err_unmap;
>   		iova += PAGE_SIZE;
> @@ -500,7 +501,8 @@ static int batch_to_domain(struct pfn_batch *batch,
struct iommu_domain *domain,
>   		else
>   			rc = iommu_map(domain, iova,
>   				       PFN_PHYS(batch->pfns[cur]) + page_offset,
> -				       next_iova - iova, area->iommu_prot);
> +				       next_iova - iova, area->iommu_prot,
> +				       GFP_KERNEL);
>   		if (rc)
>   			goto err_unmap;
>   		iova = next_iova;
> diff --git a/drivers/media/platform/qcom/venus/firmware.c
b/drivers/media/platform/qcom/venus/firmware.c
> index 142d4c74017c04..07d4dceb5e72c7 100644
> --- a/drivers/media/platform/qcom/venus/firmware.c
> +++ b/drivers/media/platform/qcom/venus/firmware.c
> @@ -158,7 +158,7 @@ static int venus_boot_no_tz(struct venus_core *core,
phys_addr_t mem_phys,
>   	core->fw.mapped_mem_size = mem_size;
>   
>   	ret = iommu_map(iommu, VENUS_FW_START_ADDR, mem_phys, mem_size,
> -			IOMMU_READ | IOMMU_WRITE | IOMMU_PRIV);
> +			IOMMU_READ | IOMMU_WRITE | IOMMU_PRIV, GFP_KERNEL);
>   	if (ret) {
>   		dev_err(dev, "could not map video firmware region\n");
>   		return ret;
> diff --git a/drivers/net/ipa/ipa_mem.c b/drivers/net/ipa/ipa_mem.c
> index 9ec5af323f731d..991a7d39f06661 100644
> --- a/drivers/net/ipa/ipa_mem.c
> +++ b/drivers/net/ipa/ipa_mem.c
> @@ -466,7 +466,8 @@ static int ipa_imem_init(struct ipa *ipa, unsigned long
addr, size_t size)
>   	size = PAGE_ALIGN(size + addr - phys);
>   	iova = phys;	/* We just want a direct mapping */
>   
> -	ret = iommu_map(domain, iova, phys, size, IOMMU_READ | IOMMU_WRITE);
> +	ret = iommu_map(domain, iova, phys, size, IOMMU_READ | IOMMU_WRITE,
> +			GFP_KERNEL);
>   	if (ret)
>   		return ret;
>   
> @@ -574,7 +575,8 @@ static int ipa_smem_init(struct ipa *ipa, u32 item,
size_t size)
>   	size = PAGE_ALIGN(size + addr - phys);
>   	iova = phys;	/* We just want a direct mapping */
>   
> -	ret = iommu_map(domain, iova, phys, size, IOMMU_READ | IOMMU_WRITE);
> +	ret = iommu_map(domain, iova, phys, size, IOMMU_READ | IOMMU_WRITE,
> +			GFP_KERNEL);
>   	if (ret)
>   		return ret;
>   
> diff --git a/drivers/net/wireless/ath/ath10k/snoc.c
b/drivers/net/wireless/ath/ath10k/snoc.c
> index cfcb759a87deac..9a82f0336d9537 100644
> --- a/drivers/net/wireless/ath/ath10k/snoc.c
> +++ b/drivers/net/wireless/ath/ath10k/snoc.c
> @@ -1639,7 +1639,7 @@ static int ath10k_fw_init(struct ath10k *ar)
>   
>   	ret = iommu_map(iommu_dom, ar_snoc->fw.fw_start_addr,
>   			ar->msa.paddr, ar->msa.mem_size,
> -			IOMMU_READ | IOMMU_WRITE);
> +			IOMMU_READ | IOMMU_WRITE, GFP_KERNEL);
>   	if (ret) {
>   		ath10k_err(ar, "failed to map firmware region: %d\n", ret);
>   		goto err_iommu_detach;
> diff --git a/drivers/net/wireless/ath/ath11k/ahb.c
b/drivers/net/wireless/ath/ath11k/ahb.c
> index d34a4d6325b2b4..df8fdc7067f99c 100644
> --- a/drivers/net/wireless/ath/ath11k/ahb.c
> +++ b/drivers/net/wireless/ath/ath11k/ahb.c
> @@ -1021,7 +1021,7 @@ static int ath11k_ahb_fw_resources_init(struct
ath11k_base *ab)
>   
>   	ret = iommu_map(iommu_dom, ab_ahb->fw.msa_paddr,
>   			ab_ahb->fw.msa_paddr, ab_ahb->fw.msa_size,
> -			IOMMU_READ | IOMMU_WRITE);
> +			IOMMU_READ | IOMMU_WRITE, GFP_KERNEL);
>   	if (ret) {
>   		ath11k_err(ab, "failed to map firmware region: %d\n", ret);
>   		goto err_iommu_detach;
> @@ -1029,7 +1029,7 @@ static int ath11k_ahb_fw_resources_init(struct
ath11k_base *ab)
>   
>   	ret = iommu_map(iommu_dom, ab_ahb->fw.ce_paddr,
>   			ab_ahb->fw.ce_paddr, ab_ahb->fw.ce_size,
> -			IOMMU_READ | IOMMU_WRITE);
> +			IOMMU_READ | IOMMU_WRITE, GFP_KERNEL);
>   	if (ret) {
>   		ath11k_err(ab, "failed to map firmware CE region: %d\n",
ret);
>   		goto err_iommu_unmap;
> diff --git a/drivers/remoteproc/remoteproc_core.c
b/drivers/remoteproc/remoteproc_core.c
> index 1cd4815a6dd197..80072b6b628358 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -643,7 +643,8 @@ static int rproc_handle_devmem(struct rproc *rproc,
void *ptr,
>   	if (!mapping)
>   		return -ENOMEM;
>   
> -	ret = iommu_map(rproc->domain, rsc->da, rsc->pa, rsc->len,
rsc->flags);
> +	ret = iommu_map(rproc->domain, rsc->da, rsc->pa, rsc->len,
rsc->flags,
> +			GFP_KERNEL);
>   	if (ret) {
>   		dev_err(dev, "failed to map devmem: %d\n", ret);
>   		goto out;
> @@ -737,7 +738,7 @@ static int rproc_alloc_carveout(struct rproc *rproc,
>   		}
>   
>   		ret = iommu_map(rproc->domain, mem->da, dma, mem->len,
> -				mem->flags);
> +				mem->flags, GFP_KERNEL);
>   		if (ret) {
>   			dev_err(dev, "iommu_map failed: %d\n", ret);
>   			goto free_mapping;
> diff --git a/drivers/vfio/vfio_iommu_type1.c
b/drivers/vfio/vfio_iommu_type1.c
> index 23c24fe98c00d4..e14f86a8ef5258 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -1480,7 +1480,8 @@ static int vfio_iommu_map(struct vfio_iommu *iommu,
dma_addr_t iova,
>   
>   	list_for_each_entry(d, &iommu->domain_list, next) {
>   		ret = iommu_map(d->domain, iova, (phys_addr_t)pfn <<
PAGE_SHIFT,
> -				npage << PAGE_SHIFT, prot | IOMMU_CACHE);
> +				npage << PAGE_SHIFT, prot | IOMMU_CACHE,
> +				GFP_KERNEL);
>   		if (ret)
>   			goto unwind;
>   
> @@ -1777,8 +1778,8 @@ static int vfio_iommu_replay(struct vfio_iommu
*iommu,
>   				size = npage << PAGE_SHIFT;
>   			}
>   
> -			ret = iommu_map(domain->domain, iova, phys,
> -					size, dma->prot | IOMMU_CACHE);
> +			ret = iommu_map(domain->domain, iova, phys, size,
> +					dma->prot | IOMMU_CACHE, GFP_KERNEL);
>   			if (ret) {
>   				if (!dma->iommu_mapped) {
>   					vfio_unpin_pages_remote(dma, iova,
> @@ -1866,7 +1867,7 @@ static void vfio_test_domain_fgsp(struct vfio_domain
*domain)
>   		return;
>   
>   	ret = iommu_map(domain->domain, 0, page_to_phys(pages), PAGE_SIZE *
2,
> -			IOMMU_READ | IOMMU_WRITE | IOMMU_CACHE);
> +			IOMMU_READ | IOMMU_WRITE | IOMMU_CACHE, GFP_KERNEL);
>   	if (!ret) {
>   		size_t unmapped = iommu_unmap(domain->domain, 0, PAGE_SIZE);
>   
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index 166044642fd5cc..e555c3bd1c030b 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -777,7 +777,7 @@ static int vhost_vdpa_map(struct vhost_vdpa *v, struct
vhost_iotlb *iotlb,
>   			r = ops->set_map(vdpa, asid, iotlb);
>   	} else {
>   		r = iommu_map(v->domain, iova, pa, size,
> -			      perm_to_iommu_flags(perm));
> +			      perm_to_iommu_flags(perm), GFP_KERNEL);
>   	}
>   	if (r) {
>   		vhost_iotlb_del_range(iotlb, iova, iova + size - 1);
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index 46e1347bfa2286..d2020994f292db 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -467,7 +467,7 @@ extern int iommu_sva_unbind_gpasid(struct iommu_domain
*domain,
>   extern struct iommu_domain *iommu_get_domain_for_dev(struct device *dev);
>   extern struct iommu_domain *iommu_get_dma_domain(struct device *dev);
>   extern int iommu_map(struct iommu_domain *domain, unsigned long iova,
> -		     phys_addr_t paddr, size_t size, int prot);
> +		     phys_addr_t paddr, size_t size, int prot, gfp_t gfp);
>   extern int iommu_map_atomic(struct iommu_domain *domain, unsigned long
iova,
>   			    phys_addr_t paddr, size_t size, int prot);
>   extern size_t iommu_unmap(struct iommu_domain *domain, unsigned long
iova,
> @@ -773,7 +773,7 @@ static inline struct iommu_domain
*iommu_get_domain_for_dev(struct device *dev)
>   }
>   
>   static inline int iommu_map(struct iommu_domain *domain, unsigned long
iova,
> -			    phys_addr_t paddr, size_t size, int prot)
> +			    phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
>   {
>   	return -ENODEV;
>   }

On Fri, Jan 06, 2023 at 05:15:28PM +0000, Robin Murphy
wrote:
> On 2023-01-06 16:42, Jason Gunthorpe wrote:
> > The internal mechanisms support this, but instead of exposting the gfp
to
> > the caller it wrappers it into iommu_map() and iommu_map_atomic()
> > 
> > Fix this instead of adding more variants for GFP_KERNEL_ACCOUNT.
> 
> FWIW, since we *do* have two variants already, I think I'd have a mild
> preference for leaving the regular map calls as-is (i.e. implicit
> GFP_KERNEL), and just generalising the _atomic versions for the special
> cases.
I think it is just better to follow kernel convention and have
allocation functions include the GFP because it is a clear signal to
the user that there is an allocation hidden inside the API. The whole
point of gfp is not to have multitudes of every function for every
allocation mode.

There are not so many callers that it seems worth worrying about
removing the extra GFP_KERNEL argument.
> However, echoing the recent activity over on the DMA API side of things, I
> think it's still worth proactively constraining the set of permissible
> flags, lest we end up with more weird problems if stuff that doesn't
really
> make sense, like GFP_COMP or zone flags, manages to leak through (that may
> have been part of the reason for having the current wrappers rather than a
> bare gfp argument in the first place, I forget now).
Yeah, that can be done

Thanks,
Jason

On Fri, Jan 06, 2023 at 05:15:28PM +0000, Robin Murphy wrote:
> However, echoing the recent activity over on the DMA API side of things, I
> think it's still worth proactively constraining the set of permissible
> flags, lest we end up with more weird problems if stuff that doesn't
really
> make sense, like GFP_COMP or zone flags, manages to leak through (that may
> have been part of the reason for having the current wrappers rather than a
> bare gfp argument in the first place, I forget now).
I did it like this:

--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2368,6 +2368,11 @@ int iommu_map(struct iommu_domain *domain, unsigned long
iova,
 
 	might_sleep_if(gfpflags_allow_blocking(gfp));
 
+	/* Discourage passing strange GFP flags */
+	if (WARN_ON_ONCE(gfp & (__GFP_COMP | __GFP_DMA | __GFP_DMA32 |
+				__GFP_HIGHMEM)))
+		return -EINVAL;
+
 	ret = __iommu_map(domain, iova, paddr, size, prot, gfp);
 	if (ret == 0 && ops->iotlb_sync_map)
 		ops->iotlb_sync_map(domain, iova, size);
@@ -2477,6 +2482,11 @@ ssize_t iommu_map_sg(struct iommu_domain *domain,
unsigned long iova,
 
 	might_sleep_if(gfpflags_allow_blocking(gfp));
 
+	/* Discourage passing strange GFP flags */
+	if (WARN_ON_ONCE(gfp & (__GFP_COMP | __GFP_DMA | __GFP_DMA32 |
+				__GFP_HIGHMEM)))
+		return -EINVAL;
+
 	while (i <= nents) {
 		phys_addr_t s_phys = sg_phys(sg);
 
Will post a v2 when the driver people take a look

Thanks,
Jason