[v2,08/11] alpha/tlb: Fix __p*_free_tlb()

Commit Message

Peter Zijlstra July 17, 2020, 11:10 a.m. UTC

Just like regular pages, page directories need to observe the
following order:

 1) unhook
 2) TLB invalidate
 3) free

to ensure it is safe against concurrent accesses.

Since Alpha has page based PMDs, no software walkers and IPI based TLB
invalidation, it can use the simple tlb_remove_page() based freeer.

Signed-off-by: Peter Zijlstra (Intel) <[e-mail]>
---
 arch/alpha/include/asm/tlb.h |   13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

Patch

--- a/arch/alpha/include/asm/tlb.h
+++ b/arch/alpha/include/asm/tlb.h
@@ -4,7 +4,16 @@ 
 
 #include <asm-generic/tlb.h>
 
-#define __pte_free_tlb(tlb, pte, address)		pte_free((tlb)->mm, pte)
-#define __pmd_free_tlb(tlb, pmd, address)		pmd_free((tlb)->mm, pmd)
+extern void ___pte_free_tlb(struct mmu_gather *tlb, pte_t *pte);
+extern void ___pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd);
+
+#define __pte_free_tlb(tlb, pte, address)	\
+do {						\
+	pgtable_pte_page_dtor(pte);		\
+	tlb_remove_table((tlb), (pte));		\
+} while (0)
+
+#define __pmd_free_tlb(tlb, pmd, address)	\
+	tlb_remove_table((tlb), virt_to_page(pmd))
  
 #endif