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 }; 40 41 DECLARE_PER_CPU(struct mmu_gather, mmu_gathers); 42 43 static inline struct mmu_gather * 44 tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush) 45 { 46 struct mmu_gather *tlb = &get_cpu_var(mmu_gathers); 47 48 tlb->mm = mm; 49 tlb->fullmm = full_mm_flush; 50 51 return tlb; 52 } 53 54 static inline void 55 tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) 56 { 57 if (tlb->fullmm) 58 flush_tlb_mm(tlb->mm); 59 60 /* keep the page table cache within bounds */ 61 check_pgt_cache(); 62 63 put_cpu_var(mmu_gathers); 64 } 65 66 #define tlb_remove_tlb_entry(tlb,ptep,address) do { } while (0) 67 68 /* 69 * In the case of tlb vma handling, we can optimise these away in the 70 * case where we're doing a full MM flush. When we're doing a munmap, 71 * the vmas are adjusted to only cover the region to be torn down. 72 */ 73 static inline void 74 tlb_start_vma(struct mmu_gather *tlb, struct vm_area_struct *vma) 75 { 76 if (!tlb->fullmm) 77 flush_cache_range(vma, vma->vm_start, vma->vm_end); 78 } 79 80 static inline void 81 tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vma) 82 { 83 if (!tlb->fullmm) 84 flush_tlb_range(vma, vma->vm_start, vma->vm_end); 85 } 86 87 #define tlb_remove_page(tlb,page) free_page_and_swap_cache(page) 88 #define pte_free_tlb(tlb, ptep) pte_free((tlb)->mm, ptep) 89 #define pmd_free_tlb(tlb, pmdp) pmd_free((tlb)->mm, pmdp) 90 91 #define tlb_migrate_finish(mm) do { } while (0) 92 93 #endif /* CONFIG_MMU */ 94 #endif 95