From fb7332a9fedfd62b1ba6530c86f39f0fa38afd49 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Wed, 29 Oct 2014 10:03:09 +0000 Subject: mmu_gather: move minimal range calculations into generic code On architectures with hardware broadcasting of TLB invalidation messages , it makes sense to reduce the range of the mmu_gather structure when unmapping page ranges based on the dirty address information passed to tlb_remove_tlb_entry. arm64 already does this by directly manipulating the start/end fields of the gather structure, but this confuses the generic code which does not expect these fields to change and can end up calculating invalid, negative ranges when forcing a flush in zap_pte_range. This patch moves the minimal range calculation out of the arm64 code and into the generic implementation, simplifying zap_pte_range in the process (which no longer needs to care about start/end, since they will point to the appropriate ranges already). With the range being tracked by core code, the need_flush flag is dropped in favour of checking that the end of the range has actually been set. Cc: Benjamin Herrenschmidt Cc: Peter Zijlstra Cc: Russell King - ARM Linux Cc: Michal Simek Acked-by: Linus Torvalds Signed-off-by: Will Deacon --- arch/arm64/include/asm/tlb.h | 67 ++------------------------------------------ 1 file changed, 3 insertions(+), 64 deletions(-) (limited to 'arch/arm64/include/asm') diff --git a/arch/arm64/include/asm/tlb.h b/arch/arm64/include/asm/tlb.h index a82c0c5c8b52..c028fe37456f 100644 --- a/arch/arm64/include/asm/tlb.h +++ b/arch/arm64/include/asm/tlb.h @@ -19,10 +19,6 @@ #ifndef __ASM_TLB_H #define __ASM_TLB_H -#define __tlb_remove_pmd_tlb_entry __tlb_remove_pmd_tlb_entry - -#include - #include #include @@ -37,71 +33,22 @@ static inline void __tlb_remove_table(void *_table) #define tlb_remove_entry(tlb, entry) tlb_remove_page(tlb, entry) #endif /* CONFIG_HAVE_RCU_TABLE_FREE */ -/* - * There's three ways the TLB shootdown code is used: - * 1. Unmapping a range of vmas. See zap_page_range(), unmap_region(). - * tlb->fullmm = 0, and tlb_start_vma/tlb_end_vma will be called. - * 2. Unmapping all vmas. See exit_mmap(). - * tlb->fullmm = 1, and tlb_start_vma/tlb_end_vma will be called. - * Page tables will be freed. - * 3. Unmapping argument pages. See shift_arg_pages(). - * tlb->fullmm = 0, but tlb_start_vma/tlb_end_vma will not be called. - */ +#include + static inline void tlb_flush(struct mmu_gather *tlb) { if (tlb->fullmm) { flush_tlb_mm(tlb->mm); - } else if (tlb->end > 0) { + } else { struct vm_area_struct vma = { .vm_mm = tlb->mm, }; flush_tlb_range(&vma, tlb->start, tlb->end); - tlb->start = TASK_SIZE; - tlb->end = 0; - } -} - -static inline void tlb_add_flush(struct mmu_gather *tlb, unsigned long addr) -{ - if (!tlb->fullmm) { - tlb->start = min(tlb->start, addr); - tlb->end = max(tlb->end, addr + PAGE_SIZE); - } -} - -/* - * Memorize the range for the TLB flush. - */ -static inline void __tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep, - unsigned long addr) -{ - tlb_add_flush(tlb, addr); -} - -/* - * In the case of tlb vma handling, we can optimise these away in the - * case where we're doing a full MM flush. When we're doing a munmap, - * the vmas are adjusted to only cover the region to be torn down. - */ -static inline void tlb_start_vma(struct mmu_gather *tlb, - struct vm_area_struct *vma) -{ - if (!tlb->fullmm) { - tlb->start = TASK_SIZE; - tlb->end = 0; } } -static inline void tlb_end_vma(struct mmu_gather *tlb, - struct vm_area_struct *vma) -{ - if (!tlb->fullmm) - tlb_flush(tlb); -} - static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte, unsigned long addr) { pgtable_page_dtor(pte); - tlb_add_flush(tlb, addr); tlb_remove_entry(tlb, pte); } @@ -109,7 +56,6 @@ static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte, static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp, unsigned long addr) { - tlb_add_flush(tlb, addr); tlb_remove_entry(tlb, virt_to_page(pmdp)); } #endif @@ -118,15 +64,8 @@ static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp, static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pudp, unsigned long addr) { - tlb_add_flush(tlb, addr); tlb_remove_entry(tlb, virt_to_page(pudp)); } #endif -static inline void __tlb_remove_pmd_tlb_entry(struct mmu_gather *tlb, pmd_t *pmdp, - unsigned long address) -{ - tlb_add_flush(tlb, address); -} - #endif -- cgit v1.2.3