[v2,10/11] riscv/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 RISC-V 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/riscv/include/asm/pgalloc.h |   11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

Patch

--- a/arch/riscv/include/asm/pgalloc.h
+++ b/arch/riscv/include/asm/pgalloc.h
@@ -73,14 +73,15 @@  static inline void pmd_free(struct mm_st
 	free_page((unsigned long)pmd);
 }
 
-#define __pmd_free_tlb(tlb, pmd, addr)  pmd_free((tlb)->mm, pmd)
+#define __pmd_free_tlb(tlb, pmd, addr)	\
+	tlb_remove_table((tlb), virt_to_page(pmd))
 
 #endif /* __PAGETABLE_PMD_FOLDED */
 
-#define __pte_free_tlb(tlb, pte, buf)   \
-do {                                    \
-	pgtable_pte_page_dtor(pte);     \
-	tlb_remove_page((tlb), pte);    \
+#define __pte_free_tlb(tlb, pte, buf)	\
+do {					\
+	pgtable_pte_page_dtor(pte);	\
+	tlb_remove_table((tlb), (pte));	\
 } while (0)
 #endif /* CONFIG_MMU */