From b5bc66b713108710e341bb164f8ffbc11896706e Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Mon, 12 Dec 2016 16:42:34 -0800 Subject: [PATCH] mm: update mmu_gather range correctly We use __tlb_adjust_range to update range convered by mmu_gather struct. We later use the 'start' and 'end' to do a mmu_notifier_invalidate_range in tlb_flush_mmu_tlbonly(). Update the 'end' correctly in __tlb_adjust_range so that we call mmu_notifier_invalidate_range with the correct range values. Wrt tlbflush, this should not have any impact, because a flush with correct start address will flush tlb mapping for the range. Also add comment w.r.t updating the range when we free pagetable pages. For now we don't support a range based page table cache flush. Link: http://lkml.kernel.org/r/20161026084839.27299-3-aneesh.kumar@linux.vnet.ibm.com Signed-off-by: Aneesh Kumar K.V Cc: "Kirill A. Shutemov" Cc: Dan Williams Cc: Ross Zwisler Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-generic/tlb.h | 43 ++++++++++++++++++++++++++++----------- 1 file changed, 31 insertions(+), 12 deletions(-) diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h index c6d667187608..dba727becd5f 100644 --- a/include/asm-generic/tlb.h +++ b/include/asm-generic/tlb.h @@ -125,10 +125,11 @@ extern bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page, int page_size); static inline void __tlb_adjust_range(struct mmu_gather *tlb, - unsigned long address) + unsigned long address, + unsigned int range_size) { tlb->start = min(tlb->start, address); - tlb->end = max(tlb->end, address + PAGE_SIZE); + tlb->end = max(tlb->end, address + range_size); /* * Track the last address with which we adjusted the range. This * will be used later to adjust again after a mmu_flush due to @@ -153,7 +154,7 @@ static inline void tlb_remove_page_size(struct mmu_gather *tlb, if (__tlb_remove_page_size(tlb, page, page_size)) { tlb_flush_mmu(tlb); tlb->page_size = page_size; - __tlb_adjust_range(tlb, tlb->addr); + __tlb_adjust_range(tlb, tlb->addr, page_size); __tlb_remove_page_size(tlb, page, page_size); } } @@ -177,7 +178,7 @@ static inline bool __tlb_remove_pte_page(struct mmu_gather *tlb, struct page *pa /* active->nr should be zero when we call this */ VM_BUG_ON_PAGE(tlb->active->nr, page); tlb->page_size = PAGE_SIZE; - __tlb_adjust_range(tlb, tlb->addr); + __tlb_adjust_range(tlb, tlb->addr, PAGE_SIZE); return __tlb_remove_page(tlb, page); } @@ -215,7 +216,7 @@ static inline bool __tlb_remove_pte_page(struct mmu_gather *tlb, struct page *pa */ #define tlb_remove_tlb_entry(tlb, ptep, address) \ do { \ - __tlb_adjust_range(tlb, address); \ + __tlb_adjust_range(tlb, address, PAGE_SIZE); \ __tlb_remove_tlb_entry(tlb, ptep, address); \ } while (0) @@ -227,29 +228,47 @@ static inline bool __tlb_remove_pte_page(struct mmu_gather *tlb, struct page *pa #define __tlb_remove_pmd_tlb_entry(tlb, pmdp, address) do {} while (0) #endif -#define tlb_remove_pmd_tlb_entry(tlb, pmdp, address) \ - do { \ - __tlb_adjust_range(tlb, address); \ - __tlb_remove_pmd_tlb_entry(tlb, pmdp, address); \ +#define tlb_remove_pmd_tlb_entry(tlb, pmdp, address) \ + do { \ + __tlb_adjust_range(tlb, address, HPAGE_PMD_SIZE); \ + __tlb_remove_pmd_tlb_entry(tlb, pmdp, address); \ } while (0) +/* + * For things like page tables caches (ie caching addresses "inside" the + * page tables, like x86 does), for legacy reasons, flushing an + * individual page had better flush the page table caches behind it. This + * is definitely how x86 works, for example. And if you have an + * architected non-legacy page table cache (which I'm not aware of + * anybody actually doing), you're going to have some architecturally + * explicit flushing for that, likely *separate* from a regular TLB entry + * flush, and thus you'd need more than just some range expansion.. + * + * So if we ever find an architecture + * that would want something that odd, I think it is up to that + * architecture to do its own odd thing, not cause pain for others + * http://lkml.kernel.org/r/CA+55aFzBggoXtNXQeng5d_mRoDnaMBE5Y+URs+PHR67nUpMtaw@mail.gmail.com + * + * For now w.r.t page table cache, mark the range_size as PAGE_SIZE + */ + #define pte_free_tlb(tlb, ptep, address) \ do { \ - __tlb_adjust_range(tlb, address); \ + __tlb_adjust_range(tlb, address, PAGE_SIZE); \ __pte_free_tlb(tlb, ptep, address); \ } while (0) #ifndef __ARCH_HAS_4LEVEL_HACK #define pud_free_tlb(tlb, pudp, address) \ do { \ - __tlb_adjust_range(tlb, address); \ + __tlb_adjust_range(tlb, address, PAGE_SIZE); \ __pud_free_tlb(tlb, pudp, address); \ } while (0) #endif #define pmd_free_tlb(tlb, pmdp, address) \ do { \ - __tlb_adjust_range(tlb, address); \ + __tlb_adjust_range(tlb, address, PAGE_SIZE); \ __pmd_free_tlb(tlb, pmdp, address); \ } while (0) -- 2.20.1