Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 | /*
* linux/arch/arm/mm/flush.c
*
* Copyright (C) 1995-2002 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.
*/
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <asm/cacheflush.h>
#include <asm/system.h>
#include <asm/tlbflush.h>
#ifdef CONFIG_CPU_CACHE_VIPT
#define ALIAS_FLUSH_START 0xffff4000
#define TOP_PTE(x) pte_offset_kernel(top_pmd, x)
static void flush_pfn_alias(unsigned long pfn, unsigned long vaddr)
{
unsigned long to = ALIAS_FLUSH_START + (CACHE_COLOUR(vaddr) << PAGE_SHIFT);
const int zero = 0;
set_pte(TOP_PTE(to), pfn_pte(pfn, PAGE_KERNEL));
flush_tlb_kernel_page(to);
asm( "mcrr p15, 0, %1, %0, c14\n"
" mcr p15, 0, %2, c7, c10, 4\n"
" mcr p15, 0, %2, c7, c5, 0\n"
:
: "r" (to), "r" (to + PAGE_SIZE - L1_CACHE_BYTES), "r" (zero)
: "cc");
}
void flush_cache_mm(struct mm_struct *mm)
{
if (cache_is_vivt()) {
if (cpu_isset(smp_processor_id(), mm->cpu_vm_mask))
__cpuc_flush_user_all();
return;
}
if (cache_is_vipt_aliasing()) {
asm( "mcr p15, 0, %0, c7, c14, 0\n"
" mcr p15, 0, %0, c7, c5, 0\n"
" mcr p15, 0, %0, c7, c10, 4"
:
: "r" (0)
: "cc");
}
}
void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
{
if (cache_is_vivt()) {
if (cpu_isset(smp_processor_id(), vma->vm_mm->cpu_vm_mask))
__cpuc_flush_user_range(start & PAGE_MASK, PAGE_ALIGN(end),
vma->vm_flags);
return;
}
if (cache_is_vipt_aliasing()) {
asm( "mcr p15, 0, %0, c7, c14, 0\n"
" mcr p15, 0, %0, c7, c5, 0\n"
" mcr p15, 0, %0, c7, c10, 4"
:
: "r" (0)
: "cc");
}
}
void flush_cache_page(struct vm_area_struct *vma, unsigned long user_addr, unsigned long pfn)
{
if (cache_is_vivt()) {
if (cpu_isset(smp_processor_id(), vma->vm_mm->cpu_vm_mask)) {
unsigned long addr = user_addr & PAGE_MASK;
__cpuc_flush_user_range(addr, addr + PAGE_SIZE, vma->vm_flags);
}
return;
}
if (cache_is_vipt_aliasing())
flush_pfn_alias(pfn, user_addr);
}
#else
#define flush_pfn_alias(pfn,vaddr) do { } while (0)
#endif
void __flush_dcache_page(struct address_space *mapping, struct page *page)
{
/*
* Writeback any data associated with the kernel mapping of this
* page. This ensures that data in the physical page is mutually
* coherent with the kernels mapping.
*/
__cpuc_flush_dcache_page(page_address(page));
/*
* If this is a page cache page, and we have an aliasing VIPT cache,
* we only need to do one flush - which would be at the relevant
* userspace colour, which is congruent with page->index.
*/
if (mapping && cache_is_vipt_aliasing())
flush_pfn_alias(page_to_pfn(page),
page->index << PAGE_CACHE_SHIFT);
}
static void __flush_dcache_aliases(struct address_space *mapping, struct page *page)
{
struct mm_struct *mm = current->active_mm;
struct vm_area_struct *mpnt;
struct prio_tree_iter iter;
pgoff_t pgoff;
/*
* There are possible user space mappings of this page:
* - VIVT cache: we need to also write back and invalidate all user
* data in the current VM view associated with this page.
* - aliasing VIPT: we only need to find one mapping of this page.
*/
pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
flush_dcache_mmap_lock(mapping);
vma_prio_tree_foreach(mpnt, &iter, &mapping->i_mmap, pgoff, pgoff) {
unsigned long offset;
/*
* If this VMA is not in our MM, we can ignore it.
*/
if (mpnt->vm_mm != mm)
continue;
if (!(mpnt->vm_flags & VM_MAYSHARE))
continue;
offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
flush_cache_page(mpnt, mpnt->vm_start + offset, page_to_pfn(page));
}
flush_dcache_mmap_unlock(mapping);
}
/*
* Ensure cache coherency between kernel mapping and userspace mapping
* of this page.
*
* We have three cases to consider:
* - VIPT non-aliasing cache: fully coherent so nothing required.
* - VIVT: fully aliasing, so we need to handle every alias in our
* current VM view.
* - VIPT aliasing: need to handle one alias in our current VM view.
*
* If we need to handle aliasing:
* If the page only exists in the page cache and there are no user
* space mappings, we can be lazy and remember that we may have dirty
* kernel cache lines for later. Otherwise, we assume we have
* aliasing mappings.
*
* Note that we disable the lazy flush for SMP.
*/
void flush_dcache_page(struct page *page)
{
struct address_space *mapping = page_mapping(page);
#ifndef CONFIG_SMP
if (mapping && !mapping_mapped(mapping))
set_bit(PG_dcache_dirty, &page->flags);
else
#endif
{
__flush_dcache_page(mapping, page);
if (mapping && cache_is_vivt())
__flush_dcache_aliases(mapping, page);
}
}
EXPORT_SYMBOL(flush_dcache_page);
|