1/*
2 *  linux/include/asm-arm/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 */
36struct mmu_gather {
37	struct mm_struct	*mm;
38	unsigned int		fullmm;
39};
40
41DECLARE_PER_CPU(struct mmu_gather, mmu_gathers);
42
43static inline struct mmu_gather *
44tlb_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
54static inline void
55tlb_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 */
73static inline void
74tlb_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
80static inline void
81tlb_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(ptep)
89#define pmd_free_tlb(tlb,pmdp)		pmd_free(pmdp)
90
91#define tlb_migrate_finish(mm)		do { } while (0)
92
93#endif /* CONFIG_MMU */
94#endif
95