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author | Jeff Dike <jdike@addtoit.com> | 2008-02-04 22:31:07 -0800 |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2008-02-05 09:44:29 -0800 |
commit | 0b4e273fb83bce5dd8e166a4defb16ebdd215abf (patch) | |
tree | 18f30fe9092dacf9a7e3474a9b0d692d91962242 /include | |
parent | 909e90d3c410b684e564729145f7c20dad887757 (diff) | |
download | kernel_samsung_smdk4412-0b4e273fb83bce5dd8e166a4defb16ebdd215abf.zip kernel_samsung_smdk4412-0b4e273fb83bce5dd8e166a4defb16ebdd215abf.tar.gz kernel_samsung_smdk4412-0b4e273fb83bce5dd8e166a4defb16ebdd215abf.tar.bz2 |
uml: customize tlb.h
Customize the hooks in tlb.h to optimize TLB flushing some more.
Add start and end fields to tlb_gather_mmu, which are used to limit
the address space range scanned when a region is unmapped.
The interfaces which just free page tables, without actually changing
mappings, don't need to cause a TLB flush.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
-rw-r--r-- | include/asm-um/tlb.h | 122 |
1 files changed, 121 insertions, 1 deletions
diff --git a/include/asm-um/tlb.h b/include/asm-um/tlb.h index c640033..39fc475 100644 --- a/include/asm-um/tlb.h +++ b/include/asm-um/tlb.h @@ -1,6 +1,126 @@ #ifndef __UM_TLB_H #define __UM_TLB_H -#include <asm/arch/tlb.h> +#include <linux/swap.h> +#include <asm/percpu.h> +#include <asm/pgalloc.h> +#include <asm/tlbflush.h> + +#define tlb_start_vma(tlb, vma) do { } while (0) +#define tlb_end_vma(tlb, vma) do { } while (0) +#define tlb_flush(tlb) flush_tlb_mm((tlb)->mm) + +/* struct mmu_gather is an opaque type used by the mm code for passing around + * any data needed by arch specific code for tlb_remove_page. + */ +struct mmu_gather { + struct mm_struct *mm; + unsigned int need_flush; /* Really unmapped some ptes? */ + unsigned long start; + unsigned long end; + unsigned int fullmm; /* non-zero means full mm flush */ +}; + +/* Users of the generic TLB shootdown code must declare this storage space. */ +DECLARE_PER_CPU(struct mmu_gather, mmu_gathers); + +static inline void __tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep, + unsigned long address) +{ + if (tlb->start > address) + tlb->start = address; + if (tlb->end < address + PAGE_SIZE) + tlb->end = address + PAGE_SIZE; +} + +static inline void init_tlb_gather(struct mmu_gather *tlb) +{ + tlb->need_flush = 0; + + tlb->start = TASK_SIZE; + tlb->end = 0; + + if (tlb->fullmm) { + tlb->start = 0; + tlb->end = TASK_SIZE; + } +} + +/* tlb_gather_mmu + * Return a pointer to an initialized struct mmu_gather. + */ +static inline struct mmu_gather * +tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush) +{ + struct mmu_gather *tlb = &get_cpu_var(mmu_gathers); + + tlb->mm = mm; + tlb->fullmm = full_mm_flush; + + init_tlb_gather(tlb); + + return tlb; +} + +extern void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start, + unsigned long end); + +static inline void +tlb_flush_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) +{ + if (!tlb->need_flush) + return; + + flush_tlb_mm_range(tlb->mm, tlb->start, tlb->end); + init_tlb_gather(tlb); +} + +/* tlb_finish_mmu + * Called at the end of the shootdown operation to free up any resources + * that were required. + */ +static inline void +tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) +{ + tlb_flush_mmu(tlb, start, end); + + /* keep the page table cache within bounds */ + check_pgt_cache(); + + put_cpu_var(mmu_gathers); +} + +/* tlb_remove_page + * Must perform the equivalent to __free_pte(pte_get_and_clear(ptep)), + * while handling the additional races in SMP caused by other CPUs + * caching valid mappings in their TLBs. + */ +static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page) +{ + tlb->need_flush = 1; + free_page_and_swap_cache(page); + return; +} + +/** + * tlb_remove_tlb_entry - remember a pte unmapping for later tlb invalidation. + * + * Record the fact that pte's were really umapped in ->need_flush, so we can + * later optimise away the tlb invalidate. This helps when userspace is + * unmapping already-unmapped pages, which happens quite a lot. + */ +#define tlb_remove_tlb_entry(tlb, ptep, address) \ + do { \ + tlb->need_flush = 1; \ + __tlb_remove_tlb_entry(tlb, ptep, address); \ + } while (0) + +#define pte_free_tlb(tlb, ptep) __pte_free_tlb(tlb, ptep) + +#define pud_free_tlb(tlb, pudp) __pud_free_tlb(tlb, pudp) + +#define pmd_free_tlb(tlb, pmdp) __pmd_free_tlb(tlb, pmdp) + +#define tlb_migrate_finish(mm) do {} while (0) #endif |