[PATCH 20/19] ARM: LPAE: Invalidate the TLB before freeing the PMD

On Wed, 2011-05-11 at 11:31 +0100, Sergei Shtylyov wrote:

quoted

Similar to the PTE freeing, this patch introduced __pmd_free_tlb() which
invalidates the TLB before freeing a PMD page. This is needed because on
newer processors the entry in the upper page table may be cached by the
TLB and point to random data after the PMD has been freed.

quoted

Signed-off-by: Catalin Marinas<catalin.marinas@arm.com>
---

quoted

This patch should be part of the LPAE series but I haven't included it in the
latest series post.

quoted

  arch/arm/include/asm/tlb.h |   12 +++++++++++-
  1 files changed, 11 insertions(+), 1 deletions(-)

quoted

diff --git a/arch/arm/include/asm/tlb.h b/arch/arm/include/asm/tlb.h
index f9f6ecd..ef72f19 100644
--- a/arch/arm/include/asm/tlb.h
+++ b/arch/arm/include/asm/tlb.h

@@ -181,8 +181,18 @@ static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte,
      tlb_remove_page(tlb, pte);
  }

+static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp,
+                               unsigned long addr)
+{
+#ifdef CONFIG_ARM_LPAE
+     tlb_add_flush(tlb, addr);
+     tlb_flush(tlb);
+     pmd_free((tlb)->mm, pmdp);

    This is not a macro, so parens around 'tlb' are not needed.

True, just copy/paste error.

quoted

+#endif
+}
+

    Perhaps a better style would be (as SubmittingPatches suggest):

+#ifdef CONFIG_ARM_LPAE
+static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp,
+                                 unsigned long addr)
+{
+       tlb_add_flush(tlb, addr);
+       tlb_flush(tlb);
+       pmd_free(tlb->mm, pmdp);
+}
+#else
+static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp,
+                                 unsigned long addr) {}
+#endif
+

WBR, Sergei

No real preference here though smaller number of lines changed in my
initial patch.

Thanks.

-- 
Catalin