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>
13 #include <linux/highmem.h>
15 #include <asm/cacheflush.h>
16 #include <asm/cachetype.h>
17 #include <asm/highmem.h>
18 #include <asm/smp_plat.h>
19 #include <asm/tlbflush.h>
23 #ifdef CONFIG_CPU_CACHE_VIPT
25 static void flush_pfn_alias(unsigned long pfn, unsigned long vaddr)
27 unsigned long to = FLUSH_ALIAS_START + (CACHE_COLOUR(vaddr) << PAGE_SHIFT);
30 set_top_pte(to, pfn_pte(pfn, PAGE_KERNEL));
32 asm( "mcrr p15, 0, %1, %0, c14\n"
33 " mcr p15, 0, %2, c7, c10, 4"
35 : "r" (to), "r" (to + PAGE_SIZE - L1_CACHE_BYTES), "r" (zero)
39 static void flush_icache_alias(unsigned long pfn, unsigned long vaddr, unsigned long len)
41 unsigned long va = FLUSH_ALIAS_START + (CACHE_COLOUR(vaddr) << PAGE_SHIFT);
42 unsigned long offset = vaddr & (PAGE_SIZE - 1);
45 set_top_pte(va, pfn_pte(pfn, PAGE_KERNEL));
47 flush_icache_range(to, to + len);
50 void flush_cache_mm(struct mm_struct *mm)
52 if (cache_is_vivt()) {
53 vivt_flush_cache_mm(mm);
57 if (cache_is_vipt_aliasing()) {
58 asm( "mcr p15, 0, %0, c7, c14, 0\n"
59 " mcr p15, 0, %0, c7, c10, 4"
66 void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end)
68 if (cache_is_vivt()) {
69 vivt_flush_cache_range(vma, start, end);
73 if (cache_is_vipt_aliasing()) {
74 asm( "mcr p15, 0, %0, c7, c14, 0\n"
75 " mcr p15, 0, %0, c7, c10, 4"
81 if (vma->vm_flags & VM_EXEC)
85 void flush_cache_page(struct vm_area_struct *vma, unsigned long user_addr, unsigned long pfn)
87 if (cache_is_vivt()) {
88 vivt_flush_cache_page(vma, user_addr, pfn);
92 if (cache_is_vipt_aliasing()) {
93 flush_pfn_alias(pfn, user_addr);
97 if (vma->vm_flags & VM_EXEC && icache_is_vivt_asid_tagged())
102 #define flush_pfn_alias(pfn,vaddr) do { } while (0)
103 #define flush_icache_alias(pfn,vaddr,len) do { } while (0)
106 static void flush_ptrace_access_other(void *args)
108 __flush_icache_all();
112 void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
113 unsigned long uaddr, void *kaddr, unsigned long len)
115 if (cache_is_vivt()) {
116 if (cpumask_test_cpu(smp_processor_id(), mm_cpumask(vma->vm_mm))) {
117 unsigned long addr = (unsigned long)kaddr;
118 __cpuc_coherent_kern_range(addr, addr + len);
123 if (cache_is_vipt_aliasing()) {
124 flush_pfn_alias(page_to_pfn(page), uaddr);
125 __flush_icache_all();
129 /* VIPT non-aliasing D-cache */
130 if (vma->vm_flags & VM_EXEC) {
131 unsigned long addr = (unsigned long)kaddr;
132 if (icache_is_vipt_aliasing())
133 flush_icache_alias(page_to_pfn(page), uaddr, len);
135 __cpuc_coherent_kern_range(addr, addr + len);
136 if (cache_ops_need_broadcast())
137 smp_call_function(flush_ptrace_access_other,
143 * Copy user data from/to a page which is mapped into a different
144 * processes address space. Really, we want to allow our "user
145 * space" model to handle this.
147 * Note that this code needs to run on the current CPU.
149 void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
150 unsigned long uaddr, void *dst, const void *src,
156 memcpy(dst, src, len);
157 flush_ptrace_access(vma, page, uaddr, dst, len);
163 void __flush_dcache_page(struct address_space *mapping, struct page *page)
166 * Writeback any data associated with the kernel mapping of this
167 * page. This ensures that data in the physical page is mutually
168 * coherent with the kernels mapping.
170 if (!PageHighMem(page)) {
171 __cpuc_flush_dcache_area(page_address(page), PAGE_SIZE);
175 if (cache_is_vipt_nonaliasing()) {
176 addr = kmap_atomic(page);
177 __cpuc_flush_dcache_area(addr, PAGE_SIZE);
180 addr = kmap_high_get(page);
182 __cpuc_flush_dcache_area(addr, PAGE_SIZE);
189 * If this is a page cache page, and we have an aliasing VIPT cache,
190 * we only need to do one flush - which would be at the relevant
191 * userspace colour, which is congruent with page->index.
193 if (mapping && cache_is_vipt_aliasing())
194 flush_pfn_alias(page_to_pfn(page),
195 page->index << PAGE_CACHE_SHIFT);
198 static void __flush_dcache_aliases(struct address_space *mapping, struct page *page)
200 struct mm_struct *mm = current->active_mm;
201 struct vm_area_struct *mpnt;
205 * There are possible user space mappings of this page:
206 * - VIVT cache: we need to also write back and invalidate all user
207 * data in the current VM view associated with this page.
208 * - aliasing VIPT: we only need to find one mapping of this page.
210 pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
212 flush_dcache_mmap_lock(mapping);
213 vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) {
214 unsigned long offset;
217 * If this VMA is not in our MM, we can ignore it.
219 if (mpnt->vm_mm != mm)
221 if (!(mpnt->vm_flags & VM_MAYSHARE))
223 offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
224 flush_cache_page(mpnt, mpnt->vm_start + offset, page_to_pfn(page));
226 flush_dcache_mmap_unlock(mapping);
229 #if __LINUX_ARM_ARCH__ >= 6
230 void __sync_icache_dcache(pte_t pteval)
234 struct address_space *mapping;
236 if (cache_is_vipt_nonaliasing() && !pte_exec(pteval))
237 /* only flush non-aliasing VIPT caches for exec mappings */
239 pfn = pte_pfn(pteval);
243 page = pfn_to_page(pfn);
244 if (cache_is_vipt_aliasing())
245 mapping = page_mapping(page);
249 if (!test_and_set_bit(PG_dcache_clean, &page->flags))
250 __flush_dcache_page(mapping, page);
252 if (pte_exec(pteval))
253 __flush_icache_all();
258 * Ensure cache coherency between kernel mapping and userspace mapping
261 * We have three cases to consider:
262 * - VIPT non-aliasing cache: fully coherent so nothing required.
263 * - VIVT: fully aliasing, so we need to handle every alias in our
265 * - VIPT aliasing: need to handle one alias in our current VM view.
267 * If we need to handle aliasing:
268 * If the page only exists in the page cache and there are no user
269 * space mappings, we can be lazy and remember that we may have dirty
270 * kernel cache lines for later. Otherwise, we assume we have
273 * Note that we disable the lazy flush for SMP configurations where
274 * the cache maintenance operations are not automatically broadcasted.
276 void flush_dcache_page(struct page *page)
278 struct address_space *mapping;
281 * The zero page is never written to, so never has any dirty
282 * cache lines, and therefore never needs to be flushed.
284 if (page == ZERO_PAGE(0))
287 mapping = page_mapping(page);
289 if (!cache_ops_need_broadcast() &&
290 mapping && !mapping_mapped(mapping))
291 clear_bit(PG_dcache_clean, &page->flags);
293 __flush_dcache_page(mapping, page);
294 if (mapping && cache_is_vivt())
295 __flush_dcache_aliases(mapping, page);
297 __flush_icache_all();
298 set_bit(PG_dcache_clean, &page->flags);
301 EXPORT_SYMBOL(flush_dcache_page);
304 * Ensure cache coherency for the kernel mapping of this page. We can
305 * assume that the page is pinned via kmap.
307 * If the page only exists in the page cache and there are no user
308 * space mappings, this is a no-op since the page was already marked
309 * dirty at creation. Otherwise, we need to flush the dirty kernel
310 * cache lines directly.
312 void flush_kernel_dcache_page(struct page *page)
314 if (cache_is_vivt() || cache_is_vipt_aliasing()) {
315 struct address_space *mapping;
317 mapping = page_mapping(page);
319 if (!mapping || mapping_mapped(mapping)) {
322 addr = page_address(page);
324 * kmap_atomic() doesn't set the page virtual
325 * address for highmem pages, and
326 * kunmap_atomic() takes care of cache
329 if (!IS_ENABLED(CONFIG_HIGHMEM) || addr)
330 __cpuc_flush_dcache_area(addr, PAGE_SIZE);
334 EXPORT_SYMBOL(flush_kernel_dcache_page);
337 * Flush an anonymous page so that users of get_user_pages()
338 * can safely access the data. The expected sequence is:
342 * memcpy() to/from page
343 * if written to page, flush_dcache_page()
345 void __flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr)
349 /* VIPT non-aliasing caches need do nothing */
350 if (cache_is_vipt_nonaliasing())
354 * Write back and invalidate userspace mapping.
356 pfn = page_to_pfn(page);
357 if (cache_is_vivt()) {
358 flush_cache_page(vma, vmaddr, pfn);
361 * For aliasing VIPT, we can flush an alias of the
362 * userspace address only.
364 flush_pfn_alias(pfn, vmaddr);
365 __flush_icache_all();
369 * Invalidate kernel mapping. No data should be contained
370 * in this mapping of the page. FIXME: this is overkill
371 * since we actually ask for a write-back and invalidate.
373 __cpuc_flush_dcache_area(page_address(page), PAGE_SIZE);