2 * linux/arch/arm/mm/flush.c
4 * Copyright (C) 1995-2002 Russell King
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.
10 #include <linux/module.h>
12 #include <linux/pagemap.h>
14 #include <asm/cacheflush.h>
15 #include <asm/cachetype.h>
16 #include <asm/smp_plat.h>
17 #include <asm/system.h>
18 #include <asm/tlbflush.h>
22 #ifdef CONFIG_CPU_CACHE_VIPT
24 #define ALIAS_FLUSH_START 0xffff4000
26 static void flush_pfn_alias(unsigned long pfn, unsigned long vaddr)
28 unsigned long to = ALIAS_FLUSH_START + (CACHE_COLOUR(vaddr) << PAGE_SHIFT);
31 set_pte_ext(TOP_PTE(to), pfn_pte(pfn, PAGE_KERNEL), 0);
32 flush_tlb_kernel_page(to);
34 asm( "mcrr p15, 0, %1, %0, c14\n"
35 " mcr p15, 0, %2, c7, c10, 4"
37 : "r" (to), "r" (to + PAGE_SIZE - L1_CACHE_BYTES), "r" (zero)
41 void flush_cache_mm(struct mm_struct *mm)
43 if (cache_is_vivt()) {
44 vivt_flush_cache_mm(mm);
48 if (cache_is_vipt_aliasing()) {
49 asm( "mcr p15, 0, %0, c7, c14, 0\n"
50 " mcr p15, 0, %0, c7, c10, 4"
57 void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
59 if (cache_is_vivt()) {
60 vivt_flush_cache_range(vma, start, end);
64 if (cache_is_vipt_aliasing()) {
65 asm( "mcr p15, 0, %0, c7, c14, 0\n"
66 " mcr p15, 0, %0, c7, c10, 4"
72 if (vma->vm_flags & VM_EXEC)
76 void flush_cache_page(struct vm_area_struct *vma, unsigned long user_addr, unsigned long pfn)
78 if (cache_is_vivt()) {
79 vivt_flush_cache_page(vma, user_addr, pfn);
83 if (cache_is_vipt_aliasing()) {
84 flush_pfn_alias(pfn, user_addr);
88 if (vma->vm_flags & VM_EXEC && icache_is_vivt_asid_tagged())
92 #define flush_pfn_alias(pfn,vaddr) do { } while (0)
96 static void flush_ptrace_access_other(void *args)
103 void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
104 unsigned long uaddr, void *kaddr, unsigned long len)
106 if (cache_is_vivt()) {
107 if (cpumask_test_cpu(smp_processor_id(), mm_cpumask(vma->vm_mm))) {
108 unsigned long addr = (unsigned long)kaddr;
109 __cpuc_coherent_kern_range(addr, addr + len);
114 if (cache_is_vipt_aliasing()) {
115 flush_pfn_alias(page_to_pfn(page), uaddr);
116 __flush_icache_all();
120 /* VIPT non-aliasing cache */
121 if (vma->vm_flags & VM_EXEC) {
122 unsigned long addr = (unsigned long)kaddr;
123 __cpuc_coherent_kern_range(addr, addr + len);
125 if (cache_ops_need_broadcast())
126 smp_call_function(flush_ptrace_access_other,
133 * Copy user data from/to a page which is mapped into a different
134 * processes address space. Really, we want to allow our "user
135 * space" model to handle this.
137 * Note that this code needs to run on the current CPU.
139 void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
140 unsigned long uaddr, void *dst, const void *src,
146 memcpy(dst, src, len);
147 flush_ptrace_access(vma, page, uaddr, dst, len);
153 void __flush_dcache_page(struct address_space *mapping, struct page *page)
155 void *addr = page_address(page);
158 * Writeback any data associated with the kernel mapping of this
159 * page. This ensures that data in the physical page is mutually
160 * coherent with the kernels mapping.
162 #ifdef CONFIG_HIGHMEM
164 * kmap_atomic() doesn't set the page virtual address, and
165 * kunmap_atomic() takes care of cache flushing already.
169 __cpuc_flush_dcache_area(addr, PAGE_SIZE);
172 * If this is a page cache page, and we have an aliasing VIPT cache,
173 * we only need to do one flush - which would be at the relevant
174 * userspace colour, which is congruent with page->index.
176 if (mapping && cache_is_vipt_aliasing())
177 flush_pfn_alias(page_to_pfn(page),
178 page->index << PAGE_CACHE_SHIFT);
181 static void __flush_dcache_aliases(struct address_space *mapping, struct page *page)
183 struct mm_struct *mm = current->active_mm;
184 struct vm_area_struct *mpnt;
185 struct prio_tree_iter iter;
189 * There are possible user space mappings of this page:
190 * - VIVT cache: we need to also write back and invalidate all user
191 * data in the current VM view associated with this page.
192 * - aliasing VIPT: we only need to find one mapping of this page.
194 pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
196 flush_dcache_mmap_lock(mapping);
197 vma_prio_tree_foreach(mpnt, &iter, &mapping->i_mmap, pgoff, pgoff) {
198 unsigned long offset;
201 * If this VMA is not in our MM, we can ignore it.
203 if (mpnt->vm_mm != mm)
205 if (!(mpnt->vm_flags & VM_MAYSHARE))
207 offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
208 flush_cache_page(mpnt, mpnt->vm_start + offset, page_to_pfn(page));
210 flush_dcache_mmap_unlock(mapping);
214 * Ensure cache coherency between kernel mapping and userspace mapping
217 * We have three cases to consider:
218 * - VIPT non-aliasing cache: fully coherent so nothing required.
219 * - VIVT: fully aliasing, so we need to handle every alias in our
221 * - VIPT aliasing: need to handle one alias in our current VM view.
223 * If we need to handle aliasing:
224 * If the page only exists in the page cache and there are no user
225 * space mappings, we can be lazy and remember that we may have dirty
226 * kernel cache lines for later. Otherwise, we assume we have
229 * Note that we disable the lazy flush for SMP.
231 void flush_dcache_page(struct page *page)
233 struct address_space *mapping;
236 * The zero page is never written to, so never has any dirty
237 * cache lines, and therefore never needs to be flushed.
239 if (page == ZERO_PAGE(0))
242 mapping = page_mapping(page);
245 if (!PageHighMem(page) && mapping && !mapping_mapped(mapping))
246 set_bit(PG_dcache_dirty, &page->flags);
250 __flush_dcache_page(mapping, page);
251 if (mapping && cache_is_vivt())
252 __flush_dcache_aliases(mapping, page);
254 __flush_icache_all();
257 EXPORT_SYMBOL(flush_dcache_page);
260 * Flush an anonymous page so that users of get_user_pages()
261 * can safely access the data. The expected sequence is:
265 * memcpy() to/from page
266 * if written to page, flush_dcache_page()
268 void __flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr)
272 /* VIPT non-aliasing caches need do nothing */
273 if (cache_is_vipt_nonaliasing())
277 * Write back and invalidate userspace mapping.
279 pfn = page_to_pfn(page);
280 if (cache_is_vivt()) {
281 flush_cache_page(vma, vmaddr, pfn);
284 * For aliasing VIPT, we can flush an alias of the
285 * userspace address only.
287 flush_pfn_alias(pfn, vmaddr);
288 __flush_icache_all();
292 * Invalidate kernel mapping. No data should be contained
293 * in this mapping of the page. FIXME: this is overkill
294 * since we actually ask for a write-back and invalidate.
296 __cpuc_flush_dcache_area(page_address(page), PAGE_SIZE);