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: 99fb8afa16ad ("iommupt: Directly call iommupt's unmap_range()")
Fixes: d6c65b0fd621 ("iommupt: Avoid rewalking during map")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Pranjal Shrivastava <praan@google.com>
Reviewed-by: Samiullah Khawaja <skhawaja@google.com>
Reviewed-by: Mostafa Saleh <smostafa@google.com>
Tested-by: Josua Mayer <josua@solid-run.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 05f78cfd1f1d0f60fc1dc5de7b3af1778cf17934..c21d1e3c4876bfd4f9a89698265ca1557044109c 100644 (file)
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -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;
+       } else {
+               ret = __iommu_map_domain_pgtbl(domain, iova, paddr, size, prot,
+                                              gfp);
+               if (ret)
+                       return ret;
        }
-       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