3 * Generic TLB shootdown code
5 * Copyright 2001 Red Hat, Inc.
6 * Based on code from mm/memory.c Copyright Linus Torvalds and others.
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
13 #ifndef _ASM_GENERIC__TLB_H
14 #define _ASM_GENERIC__TLB_H
16 #include <linux/config.h>
17 #include <linux/swap.h>
18 #include <linux/vs_memory.h>
19 #include <asm/pgalloc.h>
20 #include <asm/tlbflush.h>
23 * For UP we don't need to worry about TLB flush
24 * and page free order so much..
27 #define FREE_PTE_NR 506
28 #define tlb_fast_mode(tlb) ((tlb)->nr == ~0U)
31 #define tlb_fast_mode(tlb) 1
34 /* struct mmu_gather is an opaque type used by the mm code for passing around
35 * any data needed by arch specific code for tlb_remove_page. This structure
36 * can be per-CPU or per-MM as the page table lock is held for the duration of
41 unsigned int nr; /* set to ~0U means fast mode */
42 unsigned int need_flush;/* Really unmapped some ptes? */
43 unsigned int fullmm; /* non-zero means full mm flush */
45 struct page * pages[FREE_PTE_NR];
48 /* Users of the generic TLB shootdown code must declare this storage space. */
49 DECLARE_PER_CPU(struct mmu_gather, mmu_gathers);
52 * Return a pointer to an initialized struct mmu_gather.
54 static inline struct mmu_gather *
55 tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush)
57 struct mmu_gather *tlb = &per_cpu(mmu_gathers, smp_processor_id());
61 /* Use fast mode if only one CPU is online */
62 tlb->nr = num_online_cpus() > 1 ? 0U : ~0U;
64 tlb->fullmm = full_mm_flush;
71 tlb_flush_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
77 if (!tlb_fast_mode(tlb)) {
78 free_pages_and_swap_cache(tlb->pages, tlb->nr);
84 * Called at the end of the shootdown operation to free up any resources
85 * that were required. The page table lock is still held at this point.
88 tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
90 int freed = tlb->freed;
91 struct mm_struct *mm = tlb->mm;
96 vx_rsspages_sub(mm, freed);
97 tlb_flush_mmu(tlb, start, end);
99 /* keep the page table cache within bounds */
103 static inline unsigned int
104 tlb_is_full_mm(struct mmu_gather *tlb)
110 * Must perform the equivalent to __free_pte(pte_get_and_clear(ptep)), while
111 * handling the additional races in SMP caused by other CPUs caching valid
112 * mappings in their TLBs.
114 static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
117 if (tlb_fast_mode(tlb)) {
118 free_page_and_swap_cache(page);
121 tlb->pages[tlb->nr++] = page;
122 if (tlb->nr >= FREE_PTE_NR)
123 tlb_flush_mmu(tlb, 0, 0);
127 * tlb_remove_tlb_entry - remember a pte unmapping for later tlb invalidation.
129 * Record the fact that pte's were really umapped in ->need_flush, so we can
130 * later optimise away the tlb invalidate. This helps when userspace is
131 * unmapping already-unmapped pages, which happens quite a lot.
133 #define tlb_remove_tlb_entry(tlb, ptep, address) \
135 tlb->need_flush = 1; \
136 __tlb_remove_tlb_entry(tlb, ptep, address); \
139 #define pte_free_tlb(tlb, ptep) \
141 tlb->need_flush = 1; \
142 __pte_free_tlb(tlb, ptep); \
145 #ifndef __ARCH_HAS_4LEVEL_HACK
146 #define pud_free_tlb(tlb, pudp) \
148 tlb->need_flush = 1; \
149 __pud_free_tlb(tlb, pudp); \
153 #define pmd_free_tlb(tlb, pmdp) \
155 tlb->need_flush = 1; \
156 __pmd_free_tlb(tlb, pmdp); \
159 #define tlb_migrate_finish(mm) do {} while (0)
161 #endif /* _ASM_GENERIC__TLB_H */