From b78180b97dcf667350aac716cd3f32356eaf4984 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 4 Sep 2018 14:09:30 +0200 Subject: [PATCH] arm/tlb: Convert to generic mmu_gather Generic mmu_gather provides everything that ARM needs: - range tracking - RCU table free - VM_EXEC tracking - VIPT cache flushing The one notable curiosity is the 'funny' range tracking for classical ARM in __pte_free_tlb(). No change in behavior intended. Signed-off-by: Peter Zijlstra (Intel) Acked-by: Will Deacon Cc: Andrew Morton Cc: Andy Lutomirski Cc: Aneesh Kumar K.V Cc: Borislav Petkov Cc: Dave Hansen Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Nick Piggin Cc: Peter Zijlstra Cc: Rik van Riel Cc: Russell King Cc: Thomas Gleixner Signed-off-by: Ingo Molnar --- arch/arm/include/asm/tlb.h | 254 ++----------------------------------- 1 file changed, 13 insertions(+), 241 deletions(-) diff --git a/arch/arm/include/asm/tlb.h b/arch/arm/include/asm/tlb.h index d644c3c7c6f3..bc6d04a09899 100644 --- a/arch/arm/include/asm/tlb.h +++ b/arch/arm/include/asm/tlb.h @@ -33,270 +33,42 @@ #include #include -#define MMU_GATHER_BUNDLE 8 - -#ifdef CONFIG_HAVE_RCU_TABLE_FREE static inline void __tlb_remove_table(void *_table) { free_page_and_swap_cache((struct page *)_table); } -struct mmu_table_batch { - struct rcu_head rcu; - unsigned int nr; - void *tables[0]; -}; +#include -#define MAX_TABLE_BATCH \ - ((PAGE_SIZE - sizeof(struct mmu_table_batch)) / sizeof(void *)) - -extern void tlb_table_flush(struct mmu_gather *tlb); -extern void tlb_remove_table(struct mmu_gather *tlb, void *table); - -#define tlb_remove_entry(tlb, entry) tlb_remove_table(tlb, entry) -#else -#define tlb_remove_entry(tlb, entry) tlb_remove_page(tlb, entry) -#endif /* CONFIG_HAVE_RCU_TABLE_FREE */ - -/* - * TLB handling. This allows us to remove pages from the page - * tables, and efficiently handle the TLB issues. - */ -struct mmu_gather { - struct mm_struct *mm; -#ifdef CONFIG_HAVE_RCU_TABLE_FREE - struct mmu_table_batch *batch; - unsigned int need_flush; +#ifndef CONFIG_HAVE_RCU_TABLE_FREE +#define tlb_remove_table(tlb, entry) tlb_remove_page(tlb, entry) #endif - unsigned int fullmm; - struct vm_area_struct *vma; - unsigned long start, end; - unsigned long range_start; - unsigned long range_end; - unsigned int nr; - unsigned int max; - struct page **pages; - struct page *local[MMU_GATHER_BUNDLE]; -}; - -DECLARE_PER_CPU(struct mmu_gather, mmu_gathers); - -/* - * This is unnecessarily complex. 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. - * tlb->vma will be non-NULL. - * 2. Unmapping all vmas. See exit_mmap(). - * tlb->fullmm = 1, and tlb_start_vma/tlb_end_vma will be called. - * tlb->vma will be non-NULL. Additionally, 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. - * tlb->vma will be NULL. - */ -static inline void tlb_flush(struct mmu_gather *tlb) -{ - if (tlb->fullmm || !tlb->vma) - flush_tlb_mm(tlb->mm); - else if (tlb->range_end > 0) { - flush_tlb_range(tlb->vma, tlb->range_start, tlb->range_end); - tlb->range_start = TASK_SIZE; - tlb->range_end = 0; - } -} - -static inline void tlb_add_flush(struct mmu_gather *tlb, unsigned long addr) -{ - if (!tlb->fullmm) { - if (addr < tlb->range_start) - tlb->range_start = addr; - if (addr + PAGE_SIZE > tlb->range_end) - tlb->range_end = addr + PAGE_SIZE; - } -} - -static inline void __tlb_alloc_page(struct mmu_gather *tlb) -{ - unsigned long addr = __get_free_pages(GFP_NOWAIT | __GFP_NOWARN, 0); - - if (addr) { - tlb->pages = (void *)addr; - tlb->max = PAGE_SIZE / sizeof(struct page *); - } -} - -static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb) -{ - tlb_flush(tlb); -#ifdef CONFIG_HAVE_RCU_TABLE_FREE - tlb_table_flush(tlb); -#endif -} - -static inline void tlb_flush_mmu_free(struct mmu_gather *tlb) -{ - free_pages_and_swap_cache(tlb->pages, tlb->nr); - tlb->nr = 0; - if (tlb->pages == tlb->local) - __tlb_alloc_page(tlb); -} - -static inline void tlb_flush_mmu(struct mmu_gather *tlb) -{ - tlb_flush_mmu_tlbonly(tlb); - tlb_flush_mmu_free(tlb); -} static inline void -arch_tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, - unsigned long start, unsigned long end) -{ - tlb->mm = mm; - tlb->fullmm = !(start | (end+1)); - tlb->start = start; - tlb->end = end; - tlb->vma = NULL; - tlb->max = ARRAY_SIZE(tlb->local); - tlb->pages = tlb->local; - tlb->nr = 0; - __tlb_alloc_page(tlb); - -#ifdef CONFIG_HAVE_RCU_TABLE_FREE - tlb->batch = NULL; -#endif -} - -static inline void -arch_tlb_finish_mmu(struct mmu_gather *tlb, - unsigned long start, unsigned long end, bool force) -{ - if (force) { - tlb->range_start = start; - tlb->range_end = end; - } - - tlb_flush_mmu(tlb); - - /* keep the page table cache within bounds */ - check_pgt_cache(); - - if (tlb->pages != tlb->local) - free_pages((unsigned long)tlb->pages, 0); -} - -/* - * 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); -} - -#define tlb_remove_huge_tlb_entry(h, tlb, ptep, address) \ - tlb_remove_tlb_entry(tlb, ptep, address) -/* - * 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) { - flush_cache_range(vma, vma->vm_start, vma->vm_end); - tlb->vma = vma; - tlb->range_start = TASK_SIZE; - tlb->range_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 bool __tlb_remove_page(struct mmu_gather *tlb, struct page *page) -{ - tlb->pages[tlb->nr++] = page; - VM_WARN_ON(tlb->nr > tlb->max); - if (tlb->nr == tlb->max) - return true; - return false; -} - -static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page) -{ - if (__tlb_remove_page(tlb, page)) - tlb_flush_mmu(tlb); -} - -static inline bool __tlb_remove_page_size(struct mmu_gather *tlb, - struct page *page, int page_size) -{ - return __tlb_remove_page(tlb, page); -} - -static inline void tlb_remove_page_size(struct mmu_gather *tlb, - struct page *page, int page_size) -{ - return tlb_remove_page(tlb, page); -} - -static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte, - unsigned long addr) +__pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte, unsigned long addr) { pgtable_page_dtor(pte); -#ifdef CONFIG_ARM_LPAE - tlb_add_flush(tlb, addr); -#else +#ifndef CONFIG_ARM_LPAE /* * With the classic ARM MMU, a pte page has two corresponding pmd * entries, each covering 1MB. */ - addr &= PMD_MASK; - tlb_add_flush(tlb, addr + SZ_1M - PAGE_SIZE); - tlb_add_flush(tlb, addr + SZ_1M); + addr = (addr & PMD_MASK) + SZ_1M; + __tlb_adjust_range(tlb, addr - PAGE_SIZE, 2 * PAGE_SIZE); #endif - tlb_remove_entry(tlb, pte); -} - -static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp, - unsigned long addr) -{ -#ifdef CONFIG_ARM_LPAE - tlb_add_flush(tlb, addr); - tlb_remove_entry(tlb, virt_to_page(pmdp)); -#endif + tlb_remove_table(tlb, pte); } static inline void -tlb_remove_pmd_tlb_entry(struct mmu_gather *tlb, pmd_t *pmdp, unsigned long addr) +__pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmdp, unsigned long addr) { - tlb_add_flush(tlb, addr); -} +#ifdef CONFIG_ARM_LPAE + struct page *page = virt_to_page(pmdp); -#define pte_free_tlb(tlb, ptep, addr) __pte_free_tlb(tlb, ptep, addr) -#define pmd_free_tlb(tlb, pmdp, addr) __pmd_free_tlb(tlb, pmdp, addr) -#define pud_free_tlb(tlb, pudp, addr) pud_free((tlb)->mm, pudp) - -#define tlb_migrate_finish(mm) do { } while (0) - -static inline void tlb_change_page_size(struct mmu_gather *tlb, - unsigned int page_size) -{ -} - -static inline void tlb_flush_remove_tables(struct mm_struct *mm) -{ -} - -static inline void tlb_flush_remove_tables_local(void *arg) -{ + tlb_remove_table(tlb, page); +#endif } #endif /* CONFIG_MMU */