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Diffstat (limited to 'include/asm-arm/tlb.h')
-rw-r--r-- | include/asm-arm/tlb.h | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/include/asm-arm/tlb.h b/include/asm-arm/tlb.h new file mode 100644 index 0000000..9bb325c --- /dev/null +++ b/include/asm-arm/tlb.h @@ -0,0 +1,102 @@ +/* + * linux/include/asm-arm/tlb.h + * + * Copyright (C) 2002 Russell King + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Experimentation shows that on a StrongARM, it appears to be faster + * to use the "invalidate whole tlb" rather than "invalidate single + * tlb" for this. + * + * This appears true for both the process fork+exit case, as well as + * the munmap-large-area case. + */ +#ifndef __ASMARM_TLB_H +#define __ASMARM_TLB_H + +#include <asm/cacheflush.h> +#include <asm/tlbflush.h> +#include <asm/pgalloc.h> + +/* + * 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; + unsigned int freed; + unsigned int fullmm; + + unsigned int flushes; + unsigned int avoided_flushes; +}; + +DECLARE_PER_CPU(struct mmu_gather, mmu_gathers); + +static inline struct mmu_gather * +tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush) +{ + int cpu = smp_processor_id(); + struct mmu_gather *tlb = &per_cpu(mmu_gathers, cpu); + + tlb->mm = mm; + tlb->freed = 0; + tlb->fullmm = full_mm_flush; + + return tlb; +} + +static inline void +tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) +{ + struct mm_struct *mm = tlb->mm; + unsigned long freed = tlb->freed; + int rss = get_mm_counter(mm, rss); + + if (rss < freed) + freed = rss; + add_mm_counter(mm, rss, -freed); + + if (tlb->fullmm) + flush_tlb_mm(mm); + + /* keep the page table cache within bounds */ + check_pgt_cache(); +} + +static inline unsigned int tlb_is_full_mm(struct mmu_gather *tlb) +{ + return tlb->fullmm; +} + +#define tlb_remove_tlb_entry(tlb,ptep,address) do { } while (0) + +/* + * 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); +} + +static inline void +tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vma) +{ + if (!tlb->fullmm) + flush_tlb_range(vma, vma->vm_start, vma->vm_end); +} + +#define tlb_remove_page(tlb,page) free_page_and_swap_cache(page) +#define pte_free_tlb(tlb,ptep) pte_free(ptep) +#define pmd_free_tlb(tlb,pmdp) pmd_free(pmdp) + +#define tlb_migrate_finish(mm) do { } while (0) + +#endif |