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

commit 97a644208d1a08b7104d1fe2ace8cef011222711 upstream.

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.

Signed-off-by: Yifan Zhang <zhangyf@marvell.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index e46a88700b6824c735967118281c9f7feb6e41b0..e3168a2513c2214435dac7f5f75f4304b5a437a1 100644 (file)
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -1317,6 +1317,11 @@ 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);
@@ -1325,8 +1330,6 @@ 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);
 
@@ -1346,6 +1349,11 @@ 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);
@@ -1354,8 +1362,6 @@ 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);