LXR linux/arch/um/include/asm/tlb.h

   1#ifndef __UM_TLB_H
   2#define __UM_TLB_H
   3
   4#include <linux/pagemap.h>
   5#include <linux/swap.h>
   6#include <asm/percpu.h>
   7#include <asm/pgalloc.h>
   8#include <asm/tlbflush.h>
   9
  10#define tlb_start_vma(tlb, vma) do { } while (0)
  11#define tlb_end_vma(tlb, vma) do { } while (0)
  12#define tlb_flush(tlb) flush_tlb_mm((tlb)->mm)
  13
  14/* struct mmu_gather is an opaque type used by the mm code for passing around
  15 * any data needed by arch specific code for tlb_remove_page.
  16 */
  17struct mmu_gather {
  18        struct mm_struct        *mm;
  19        unsigned int            need_flush; /* Really unmapped some ptes? */
  20        unsigned long           start;
  21        unsigned long           end;
  22        unsigned int            fullmm; /* non-zero means full mm flush */
  23};
  24
  25/* Users of the generic TLB shootdown code must declare this storage space. */
  26DECLARE_PER_CPU(struct mmu_gather, mmu_gathers);
  27
  28static inline void __tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep,
  29                                          unsigned long address)
  30{
  31        if (tlb->start > address)
  32                tlb->start = address;
  33        if (tlb->end < address + PAGE_SIZE)
  34                tlb->end = address + PAGE_SIZE;
  35}
  36
  37static inline void init_tlb_gather(struct mmu_gather *tlb)
  38{
  39        tlb->need_flush = 0;
  40
  41        tlb->start = TASK_SIZE;
  42        tlb->end = 0;
  43
  44        if (tlb->fullmm) {
  45                tlb->start = 0;
  46                tlb->end = TASK_SIZE;
  47        }
  48}
  49
  50/* tlb_gather_mmu
  51 *      Return a pointer to an initialized struct mmu_gather.
  52 */
  53static inline struct mmu_gather *
  54tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush)
  55{
  56        struct mmu_gather *tlb = &get_cpu_var(mmu_gathers);
  57
  58        tlb->mm = mm;
  59        tlb->fullmm = full_mm_flush;
  60
  61        init_tlb_gather(tlb);
  62
  63        return tlb;
  64}
  65
  66extern void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
  67                               unsigned long end);
  68
  69static inline void
  70tlb_flush_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
  71{
  72        if (!tlb->need_flush)
  73                return;
  74
  75        flush_tlb_mm_range(tlb->mm, tlb->start, tlb->end);
  76        init_tlb_gather(tlb);
  77}
  78
  79/* tlb_finish_mmu
  80 *      Called at the end of the shootdown operation to free up any resources
  81 *      that were required.
  82 */
  83static inline void
  84tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
  85{
  86        tlb_flush_mmu(tlb, start, end);
  87
  88        /* keep the page table cache within bounds */
  89        check_pgt_cache();
  90
  91        put_cpu_var(mmu_gathers);
  92}
  93
  94/* tlb_remove_page
  95 *      Must perform the equivalent to __free_pte(pte_get_and_clear(ptep)),
  96 *      while handling the additional races in SMP caused by other CPUs
  97 *      caching valid mappings in their TLBs.
  98 */
  99static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
 100{
 101        tlb->need_flush = 1;
 102        free_page_and_swap_cache(page);
 103        return;
 104}
 105
 106/**
 107 * tlb_remove_tlb_entry - remember a pte unmapping for later tlb invalidation.
 108 *
 109 * Record the fact that pte's were really umapped in ->need_flush, so we can
 110 * later optimise away the tlb invalidate.   This helps when userspace is
 111 * unmapping already-unmapped pages, which happens quite a lot.
 112 */
 113#define tlb_remove_tlb_entry(tlb, ptep, address)                \
 114        do {                                                    \
 115                tlb->need_flush = 1;                            \
 116                __tlb_remove_tlb_entry(tlb, ptep, address);     \
 117        } while (0)
 118
 119#define pte_free_tlb(tlb, ptep, addr) __pte_free_tlb(tlb, ptep, addr)
 120
 121#define pud_free_tlb(tlb, pudp, addr) __pud_free_tlb(tlb, pudp, addr)
 122
 123#define pmd_free_tlb(tlb, pmdp, addr) __pmd_free_tlb(tlb, pmdp, addr)
 124
 125#define tlb_migrate_finish(mm) do {} while (0)
 126
 127#endif
 128