1 /* 2 * arch/arm/include/asm/tlb.h 3 * 4 * Copyright (C) 2002 Russell King 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 * 10 * Experimentation shows that on a StrongARM, it appears to be faster 11 * to use the "invalidate whole tlb" rather than "invalidate single 12 * tlb" for this. 13 * 14 * This appears true for both the process fork+exit case, as well as 15 * the munmap-large-area case. 16 */ 17 #ifndef __ASMARM_TLB_H 18 #define __ASMARM_TLB_H 19 20 #include <asm/cacheflush.h> 21 #include <asm/tlbflush.h> 22 23 #ifndef CONFIG_MMU 24 25 #include <linux/pagemap.h> 26 #include <asm-generic/tlb.h> 27 28 #else /* !CONFIG_MMU */ 29 30 #include <asm/pgalloc.h> 31 32 /* 33 * TLB handling. This allows us to remove pages from the page 34 * tables, and efficiently handle the TLB issues. 35 */ 36 struct mmu_gather { 37 struct mm_struct *mm; 38 unsigned int fullmm; 39 unsigned long range_start; 40 unsigned long range_end; 41 }; 42 43 DECLARE_PER_CPU(struct mmu_gather, mmu_gathers); 44 45 static inline struct mmu_gather * 46 tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush) 47 { 48 struct mmu_gather *tlb = &get_cpu_var(mmu_gathers); 49 50 tlb->mm = mm; 51 tlb->fullmm = full_mm_flush; 52 53 return tlb; 54 } 55 56 static inline void 57 tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) 58 { 59 if (tlb->fullmm) 60 flush_tlb_mm(tlb->mm); 61 62 /* keep the page table cache within bounds */ 63 check_pgt_cache(); 64 65 put_cpu_var(mmu_gathers); 66 } 67 68 /* 69 * Memorize the range for the TLB flush. 70 */ 71 static inline void 72 tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep, unsigned long addr) 73 { 74 if (!tlb->fullmm) { 75 if (addr < tlb->range_start) 76 tlb->range_start = addr; 77 if (addr + PAGE_SIZE > tlb->range_end) 78 tlb->range_end = addr + PAGE_SIZE; 79 } 80 } 81 82 /* 83 * In the case of tlb vma handling, we can optimise these away in the 84 * case where we're doing a full MM flush. When we're doing a munmap, 85 * the vmas are adjusted to only cover the region to be torn down. 86 */ 87 static inline void 88 tlb_start_vma(struct mmu_gather *tlb, struct vm_area_struct *vma) 89 { 90 if (!tlb->fullmm) { 91 flush_cache_range(vma, vma->vm_start, vma->vm_end); 92 tlb->range_start = TASK_SIZE; 93 tlb->range_end = 0; 94 } 95 } 96 97 static inline void 98 tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vma) 99 { 100 if (!tlb->fullmm && tlb->range_end > 0) 101 flush_tlb_range(vma, tlb->range_start, tlb->range_end); 102 } 103 104 #define tlb_remove_page(tlb,page) free_page_and_swap_cache(page) 105 #define pte_free_tlb(tlb, ptep, addr) pte_free((tlb)->mm, ptep) 106 #define pmd_free_tlb(tlb, pmdp, addr) pmd_free((tlb)->mm, pmdp) 107 108 #define tlb_migrate_finish(mm) do { } while (0) 109 110 #endif /* CONFIG_MMU */ 111 #endif 112