This is a note to let you know that I've just added the patch titled
iommu/arm-smmu: fix table flushing during initial allocations
to the 3.13-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iommu-arm-smmu-fix-table-flushing-during-initial-allocations.patch
and it can be found in the queue-3.13 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 6dd35f45b8dac827b6f9dd86f5aca6436cdd2410 Mon Sep 17 00:00:00 2001
From: Will Deacon <will.deacon@xxxxxxx>
Date: Wed, 5 Feb 2014 17:49:34 +0000
Subject: iommu/arm-smmu: fix table flushing during initial allocations
From: Will Deacon <will.deacon@xxxxxxx>
commit 6dd35f45b8dac827b6f9dd86f5aca6436cdd2410 upstream.
Now that we populate page tables as we traverse them ("iommu/arm-smmu:
fix pud/pmd entry fill sequence"), we need to ensure that we flush out
our zeroed tables after initial allocation, to prevent speculative TLB
fills using bogus data.
This patch adds additional calls to arm_smmu_flush_pgtable during
initial table allocation, and moves the dsb required by coherent table
walkers into the helper.
Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/iommu/arm-smmu.c | 51 ++++++++++++++++++++++++-----------------------
1 file changed, 27 insertions(+), 24 deletions(-)
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -78,7 +78,6 @@
#define ARM_SMMU_PTE_CONT_SIZE (PAGE_SIZE * ARM_SMMU_PTE_CONT_ENTRIES)
#define ARM_SMMU_PTE_CONT_MASK (~(ARM_SMMU_PTE_CONT_SIZE - 1))
-#define ARM_SMMU_PTE_HWTABLE_SIZE (PTRS_PER_PTE * sizeof(pte_t))
/* Stage-1 PTE */
#define ARM_SMMU_PTE_AP_UNPRIV (((pteval_t)1) << 6)
@@ -631,6 +630,28 @@ static irqreturn_t arm_smmu_global_fault
return IRQ_HANDLED;
}
+static void arm_smmu_flush_pgtable(struct arm_smmu_device *smmu, void *addr,
+ size_t size)
+{
+ unsigned long offset = (unsigned long)addr & ~PAGE_MASK;
+
+
+ /* Ensure new page tables are visible to the hardware walker */
+ if (smmu->features & ARM_SMMU_FEAT_COHERENT_WALK) {
+ dsb();
+ } else {
+ /*
+ * If the SMMU can't walk tables in the CPU caches, treat them
+ * like non-coherent DMA since we need to flush the new entries
+ * all the way out to memory. There's no possibility of
+ * recursion here as the SMMU table walker will not be wired
+ * through another SMMU.
+ */
+ dma_map_page(smmu->dev, virt_to_page(addr), offset, size,
+ DMA_TO_DEVICE);
+ }
+}
+
static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain)
{
u32 reg;
@@ -714,6 +735,8 @@ static void arm_smmu_init_context_bank(s
}
/* TTBR0 */
+ arm_smmu_flush_pgtable(smmu, root_cfg->pgd,
+ PTRS_PER_PGD * sizeof(pgd_t));
reg = __pa(root_cfg->pgd);
writel_relaxed(reg, cb_base + ARM_SMMU_CB_TTBR0_LO);
reg = (phys_addr_t)__pa(root_cfg->pgd) >> 32;
@@ -1176,23 +1199,6 @@ static void arm_smmu_detach_dev(struct i
arm_smmu_domain_remove_master(smmu_domain, master);
}
-static void arm_smmu_flush_pgtable(struct arm_smmu_device *smmu, void *addr,
- size_t size)
-{
- unsigned long offset = (unsigned long)addr & ~PAGE_MASK;
-
- /*
- * If the SMMU can't walk tables in the CPU caches, treat them
- * like non-coherent DMA since we need to flush the new entries
- * all the way out to memory. There's no possibility of recursion
- * here as the SMMU table walker will not be wired through another
- * SMMU.
- */
- if (!(smmu->features & ARM_SMMU_FEAT_COHERENT_WALK))
- dma_map_page(smmu->dev, virt_to_page(addr), offset, size,
- DMA_TO_DEVICE);
-}
-
static bool arm_smmu_pte_is_contiguous_range(unsigned long addr,
unsigned long end)
{
@@ -1213,8 +1219,7 @@ static int arm_smmu_alloc_init_pte(struc
if (!table)
return -ENOMEM;
- arm_smmu_flush_pgtable(smmu, page_address(table),
- ARM_SMMU_PTE_HWTABLE_SIZE);
+ arm_smmu_flush_pgtable(smmu, page_address(table), PAGE_SIZE);
if (!pgtable_page_ctor(table)) {
__free_page(table);
return -ENOMEM;
@@ -1318,6 +1323,7 @@ static int arm_smmu_alloc_init_pmd(struc
if (!pmd)
return -ENOMEM;
+ arm_smmu_flush_pgtable(smmu, pmd, PAGE_SIZE);
pud_populate(NULL, pud, pmd);
arm_smmu_flush_pgtable(smmu, pud, sizeof(*pud));
@@ -1350,6 +1356,7 @@ static int arm_smmu_alloc_init_pud(struc
if (!pud)
return -ENOMEM;
+ arm_smmu_flush_pgtable(smmu, pud, PAGE_SIZE);
pgd_populate(NULL, pgd, pud);
arm_smmu_flush_pgtable(smmu, pgd, sizeof(*pgd));
@@ -1418,10 +1425,6 @@ static int arm_smmu_handle_mapping(struc
out_unlock:
spin_unlock(&smmu_domain->lock);
- /* Ensure new page tables are visible to the hardware walker */
- if (smmu->features & ARM_SMMU_FEAT_COHERENT_WALK)
- dsb();
-
return ret;
}
Patches currently in stable-queue which might be from will.deacon@xxxxxxx are
queue-3.13/perf-fix-hotplug-splat.patch
queue-3.13/iommu-arm-smmu-really-fix-page-table-locking.patch
queue-3.13/arm-7953-1-mm-ensure-tlb-invalidation-is-complete-before-enabling-mmu.patch
queue-3.13/iommu-arm-smmu-set-cbarn.bpshcfg-to-nsh-for-s1-s2-bypass-contexts.patch
queue-3.13/iommu-arm-smmu-fix-table-flushing-during-initial-allocations.patch
queue-3.13/iommu-arm-smmu-fix-pud-pmd-entry-fill-sequence.patch
queue-3.13/arm-7955-1-spinlock-ensure-we-have-a-compiler-barrier-before-sev.patch
--
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