Merge branch 'iommu-memory-accounting' into core

Merge patch-set from Jason:

	"Let iommufd charge IOPTE allocations to the memory cgroup"

Description:

IOMMUFD follows the same design as KVM and uses memory cgroups to limit
the amount of kernel memory a iommufd file descriptor can pin down. The
various internal data structures already use GFP_KERNEL_ACCOUNT to charge
its own memory.

However, one of the biggest consumers of kernel memory is the IOPTEs
stored under the iommu_domain and these allocations are not tracked.

This series is the first step in fixing it.

The iommu driver contract already includes a 'gfp' argument to the
map_pages op, allowing iommufd to specify GFP_KERNEL_ACCOUNT and then
having the driver allocate the IOPTE tables with that flag will capture a
significant amount of the allocations.

Update the iommu_map() API to pass in the GFP argument, and fix all call
sites. Replace iommu_map_atomic().

Audit the "enterprise" iommu drivers to make sure they do the right thing.
Intel and S390 ignore the GFP argument and always use GFP_ATOMIC. This is
problematic for iommufd anyhow, so fix it. AMD and ARM SMMUv2/3 are
already correct.

A follow up series will be needed to capture the allocations made when the
iommu_domain itself is allocated, which will complete the job.

Link: https://lore.kernel.org/linux-iommu/0-v3-76b587fe28df+6e3-iommu_map_gfp_jgg@nvidia.com/

1 files changed, 7 insertions, 24 deletions

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index a8063f26ff69..3589d1b8f922 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -471,19 +471,15 @@ 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);
-extern int iommu_map_atomic(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 size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova,
 			  size_t size);
 extern size_t iommu_unmap_fast(struct iommu_domain *domain,
 			       unsigned long iova, size_t size,
 			       struct iommu_iotlb_gather *iotlb_gather);
 extern ssize_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
-		struct scatterlist *sg, unsigned int nents, int prot);
-extern ssize_t iommu_map_sg_atomic(struct iommu_domain *domain,
-				   unsigned long iova, struct scatterlist *sg,
-				   unsigned int nents, int prot);
+			    struct scatterlist *sg, unsigned int nents,
+			    int prot, gfp_t gfp);
 extern phys_addr_t iommu_iova_to_phys(struct iommu_domain *domain, dma_addr_t iova);
 extern void iommu_set_fault_handler(struct iommu_domain *domain,
 			iommu_fault_handler_t handler, void *token);
@@ -777,14 +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)
-{
-	return -ENODEV;
-}
-
-static inline int iommu_map_atomic(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;
 }
@@ -804,14 +793,7 @@ static inline size_t iommu_unmap_fast(struct iommu_domain *domain,
 
 static inline ssize_t iommu_map_sg(struct iommu_domain *domain,
 				   unsigned long iova, struct scatterlist *sg,
-				   unsigned int nents, int prot)
-{
-	return -ENODEV;
-}
-
-static inline ssize_t iommu_map_sg_atomic(struct iommu_domain *domain,
-				  unsigned long iova, struct scatterlist *sg,
-				  unsigned int nents, int prot)
+				   unsigned int nents, int prot, gfp_t gfp)
 {
 	return -ENODEV;
 }
@@ -1122,7 +1104,8 @@ iommu_get_domain_for_dev_pasid(struct device *dev, ioasid_t pasid,
 static inline size_t iommu_map_sgtable(struct iommu_domain *domain,
 			unsigned long iova, struct sg_table *sgt, int prot)
 {
-	return iommu_map_sg(domain, iova, sgt->sgl, sgt->orig_nents, prot);
+	return iommu_map_sg(domain, iova, sgt->sgl, sgt->orig_nents, prot,
+			    GFP_KERNEL);
 }
 
 #ifdef CONFIG_IOMMU_DEBUGFS