iommu/arm-smmu: fix pud/pmd entry fill sequence

The ARM SMMU driver's population of puds and pmds is broken, since we
iterate over the next level of table repeatedly setting the current
level descriptor to point at the pmd being initialised. This is clearly
wrong when dealing with multiple pmds/puds.

This patch fixes the problem by moving the pud/pmd population out of the
loop and instead performing it when we allocate the next level (like we
correctly do for ptes already). The starting address for the next level
is then calculated prior to entering the loop.

Cc: <stable@vger.kernel.org>
Signed-off-by: Yifan Zhang <zhangyf@marvell.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 8911850c94445fa5adf3b41de168293e5adf7721..9f210de6537e2fb58c3ac9c48a8b67e63cd9220d 100644 (file)
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -1320,6 +1320,11 @@ static int arm_smmu_alloc_init_pmd(struct arm_smmu_device *smmu, pud_t *pud,
                pmd = pmd_alloc_one(NULL, addr);
                if (!pmd)
                        return -ENOMEM;
+
+               pud_populate(NULL, pud, pmd);
+               arm_smmu_flush_pgtable(smmu, pud, sizeof(*pud));
+
+               pmd += pmd_index(addr);
        } else
 #endif
                pmd = pmd_offset(pud, addr);
@@ -1328,8 +1333,6 @@ static int arm_smmu_alloc_init_pmd(struct arm_smmu_device *smmu, pud_t *pud,
                next = pmd_addr_end(addr, end);
                ret = arm_smmu_alloc_init_pte(smmu, pmd, addr, end, pfn,
                                              flags, stage);
-               pud_populate(NULL, pud, pmd);
-               arm_smmu_flush_pgtable(smmu, pud, sizeof(*pud));
                phys += next - addr;
        } while (pmd++, addr = next, addr < end);
 
@@ -1349,6 +1352,11 @@ static int arm_smmu_alloc_init_pud(struct arm_smmu_device *smmu, pgd_t *pgd,
                pud = pud_alloc_one(NULL, addr);
                if (!pud)
                        return -ENOMEM;
+
+               pgd_populate(NULL, pgd, pud);
+               arm_smmu_flush_pgtable(smmu, pgd, sizeof(*pgd));
+
+               pud += pud_index(addr);
        } else
 #endif
                pud = pud_offset(pgd, addr);
@@ -1357,8 +1365,6 @@ static int arm_smmu_alloc_init_pud(struct arm_smmu_device *smmu, pgd_t *pgd,
                next = pud_addr_end(addr, end);
                ret = arm_smmu_alloc_init_pmd(smmu, pud, addr, next, phys,
                                              flags, stage);
-               pgd_populate(NULL, pud, pgd);
-               arm_smmu_flush_pgtable(smmu, pgd, sizeof(*pgd));
                phys += next - addr;
        } while (pud++, addr = next, addr < end);