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

Catalin Marinas catalin.marinas at arm.com
Wed May 11 06:23:19 EDT 2011

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.

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

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

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

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)
+	tlb_add_flush(tlb, addr);
+	tlb_flush(tlb);
+	pmd_free((tlb)->mm, pmdp);
 #define pte_free_tlb(tlb, ptep, addr)	__pte_free_tlb(tlb, ptep, addr)
-#define pmd_free_tlb(tlb, pmdp, addr)	pmd_free((tlb)->mm, pmdp)
+#define pmd_free_tlb(tlb, pmdp, addr)	__pmd_free_tlb(tlb, pmdp, addr)
 #define pud_free_tlb(tlb, pudp, addr)	pud_free((tlb)->mm, pudp)
 #define tlb_migrate_finish(mm)		do { } while (0)

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