Commit b948a872 authored by Jason Gunthorpe's avatar Jason Gunthorpe Committed by Joerg Roedel
Browse files

iommu: Fix up map/unmap debugging for iommupt domains 



Sashiko noticed a few issues in this path, and a few more were
found on review. Tidy them up further. These are intertwined
because the debug code depends on some of the WARN_ONs to function
right:

Lift into iommu_map_nosync():
- The might_sleep_if()
- 0 pgsize_bitmap WARN_ON
- Promote the illegal domain->type to a WARN_ON
- WARN_ON for illegal gfp flags

Then remove the return 0 since it is now safe to call
iommu_debug_map().

Lift into __iommu_unmap():
- 0 pgsize_bitmap WARN_ON
- Promote the illegal domain->type to a WARN_ON
- iommu_debug_unmap_begin()

This now pairs with the unconditional iommu_debug_map() on the
mapping side. Thus iommu debugging now works for iommupt along
with some of the other debugging features.

Fixes: 99fb8afa ("iommupt: Directly call iommupt's unmap_range()")
Fixes: d6c65b0f ("iommupt: Avoid rewalking during map")
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Reviewed-by: default avatarPranjal Shrivastava <praan@google.com>
Reviewed-by: default avatarSamiullah Khawaja <skhawaja@google.com>
Reviewed-by: default avatarMostafa Saleh <smostafa@google.com>
Tested-by: default avatarJosua Mayer <josua@solid-run.com>
Signed-off-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
parent 6fc7e8a3

drivers/iommu/iommu.c

+22 −21
Original line number Diff line number Diff line
@@ -2623,19 +2623,9 @@ static int __iommu_map_domain_pgtbl(struct iommu_domain *domain, 
	size_t orig_size = size;

	int ret = 0;



	might_sleep_if(gfpflags_allow_blocking(gfp));



	if (unlikely(!(domain->type & __IOMMU_DOMAIN_PAGING)))

		return -EINVAL;



	if (WARN_ON(!ops->map_pages || domain->pgsize_bitmap == 0UL))

	if (WARN_ON(!ops->map_pages))

		return -ENODEV;



	/* Discourage passing strange GFP flags */

	if (WARN_ON_ONCE(gfp & (__GFP_COMP | __GFP_DMA | __GFP_DMA32 |

				__GFP_HIGHMEM)))

		return -EINVAL;



	/* find out the minimum page size supported */

	min_pagesz = 1 << __ffs(domain->pgsize_bitmap);
@@ -2697,6 +2687,15 @@ int iommu_map_nosync(struct iommu_domain *domain, unsigned long iova, 
	struct pt_iommu *pt = iommupt_from_domain(domain);

	int ret;



	might_sleep_if(gfpflags_allow_blocking(gfp));



	/* Discourage passing strange GFP flags or illegal domains */

	if (WARN_ON_ONCE(!(domain->type & __IOMMU_DOMAIN_PAGING) ||

			 !domain->pgsize_bitmap ||

			 (gfp & (__GFP_COMP | __GFP_DMA | __GFP_DMA32 |

				 __GFP_HIGHMEM))))

		return -EINVAL;



	if (pt) {

		size_t mapped = 0;
@@ -2706,11 +2705,12 @@ int iommu_map_nosync(struct iommu_domain *domain, unsigned long iova, 
			iommu_unmap(domain, iova, mapped);

			return ret;

		}

		return 0;

	}

	ret = __iommu_map_domain_pgtbl(domain, iova, paddr, size, prot, gfp);

	} else {

		ret = __iommu_map_domain_pgtbl(domain, iova, paddr, size, prot,

					       gfp);

		if (ret)

			return ret;

	}



	trace_map(iova, paddr, size);

	iommu_debug_map(domain, paddr, size);
@@ -2742,10 +2742,7 @@ __iommu_unmap_domain_pgtbl(struct iommu_domain *domain, unsigned long iova, 
	size_t unmapped_page, unmapped = 0;

	unsigned int min_pagesz;



	if (unlikely(!(domain->type & __IOMMU_DOMAIN_PAGING)))

		return 0;



	if (WARN_ON(!ops->unmap_pages || domain->pgsize_bitmap == 0UL))

	if (WARN_ON(!ops->unmap_pages))

		return 0;



	/* find out the minimum page size supported */
@@ -2764,8 +2761,6 @@ __iommu_unmap_domain_pgtbl(struct iommu_domain *domain, unsigned long iova, 


	pr_debug("unmap this: iova 0x%lx size 0x%zx\n", iova, size);



	iommu_debug_unmap_begin(domain, iova, size);



	/*

	 * Keep iterating until we either unmap 'size' bytes (or more)

	 * or we hit an area that isn't mapped.
@@ -2801,6 +2796,12 @@ static size_t __iommu_unmap(struct iommu_domain *domain, unsigned long iova, 
	struct pt_iommu *pt = iommupt_from_domain(domain);

	size_t unmapped;



	if (WARN_ON_ONCE(!(domain->type & __IOMMU_DOMAIN_PAGING) ||

			 !domain->pgsize_bitmap))

		return 0;



	iommu_debug_unmap_begin(domain, iova, size);



	if (pt)

		unmapped = pt->ops->unmap_range(pt, iova, size, iotlb_gather);

	else