diff options
| -rw-r--r-- | arch/arm64/include/asm/tlbflush.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h index 84a05a0bd2b6..55b50e1d4a84 100644 --- a/arch/arm64/include/asm/tlbflush.h +++ b/arch/arm64/include/asm/tlbflush.h @@ -304,11 +304,26 @@ static inline void arch_tlbbatch_add_pending(struct arch_tlbflush_unmap_batch *b __flush_tlb_page_nosync(mm, uaddr); } +/* + * If mprotect/munmap/etc occurs during TLB batched flushing, we need to + * synchronise all the TLBI issued with a DSB to avoid the race mentioned in + * flush_tlb_batched_pending(). + */ static inline void arch_flush_tlb_batched_pending(struct mm_struct *mm) { dsb(ish); } +/* + * To support TLB batched flush for multiple pages unmapping, we only send + * the TLBI for each page in arch_tlbbatch_add_pending() and wait for the + * completion at the end in arch_tlbbatch_flush(). Since we've already issued + * TLBI for each page so only a DSB is needed to synchronise its effect on the + * other CPUs. + * + * This will save the time waiting on DSB comparing issuing a TLBI;DSB sequence + * for each page. + */ static inline void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch) { dsb(ish); |