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/highmem.h>
17 #include <asm/smp_plat.h>
18 #include <asm/system.h>
19 #include <asm/tlbflush.h>
23 #ifdef CONFIG_CPU_CACHE_VIPT
25 #define ALIAS_FLUSH_START 0xffff4000
27 static void flush_pfn_alias(unsigned long pfn
, unsigned long vaddr
)
29 unsigned long to
= ALIAS_FLUSH_START
+ (CACHE_COLOUR(vaddr
) << PAGE_SHIFT
);
32 set_pte_ext(TOP_PTE(to
), pfn_pte(pfn
, PAGE_KERNEL
), 0);
33 flush_tlb_kernel_page(to
);
35 asm( "mcrr p15, 0, %1, %0, c14\n"
36 " mcr p15, 0, %2, c7, c10, 4"
38 : "r" (to
), "r" (to
+ PAGE_SIZE
- L1_CACHE_BYTES
), "r" (zero
)
42 void flush_cache_mm(struct mm_struct
*mm
)
44 if (cache_is_vivt()) {
45 vivt_flush_cache_mm(mm
);
49 if (cache_is_vipt_aliasing()) {
50 asm( "mcr p15, 0, %0, c7, c14, 0\n"
51 " mcr p15, 0, %0, c7, c10, 4"
58 void flush_cache_range(struct vm_area_struct
*vma
, unsigned long start
, unsigned long end
)
60 if (cache_is_vivt()) {
61 vivt_flush_cache_range(vma
, start
, end
);
65 if (cache_is_vipt_aliasing()) {
66 asm( "mcr p15, 0, %0, c7, c14, 0\n"
67 " mcr p15, 0, %0, c7, c10, 4"
73 if (vma
->vm_flags
& VM_EXEC
)
77 void flush_cache_page(struct vm_area_struct
*vma
, unsigned long user_addr
, unsigned long pfn
)
79 if (cache_is_vivt()) {
80 vivt_flush_cache_page(vma
, user_addr
, pfn
);
84 if (cache_is_vipt_aliasing()) {
85 flush_pfn_alias(pfn
, user_addr
);
89 if (vma
->vm_flags
& VM_EXEC
&& icache_is_vivt_asid_tagged())
93 #define flush_pfn_alias(pfn,vaddr) do { } while (0)
97 static void flush_ptrace_access_other(void *args
)
104 void flush_ptrace_access(struct vm_area_struct
*vma
, struct page
*page
,
105 unsigned long uaddr
, void *kaddr
, unsigned long len
)
107 if (cache_is_vivt()) {
108 if (cpumask_test_cpu(smp_processor_id(), mm_cpumask(vma
->vm_mm
))) {
109 unsigned long addr
= (unsigned long)kaddr
;
110 __cpuc_coherent_kern_range(addr
, addr
+ len
);
115 if (cache_is_vipt_aliasing()) {
116 flush_pfn_alias(page_to_pfn(page
), uaddr
);
117 __flush_icache_all();
121 /* VIPT non-aliasing cache */
122 if (vma
->vm_flags
& VM_EXEC
) {
123 unsigned long addr
= (unsigned long)kaddr
;
124 __cpuc_coherent_kern_range(addr
, addr
+ len
);
126 if (cache_ops_need_broadcast())
127 smp_call_function(flush_ptrace_access_other
,
134 * Copy user data from/to a page which is mapped into a different
135 * processes address space. Really, we want to allow our "user
136 * space" model to handle this.
138 * Note that this code needs to run on the current CPU.
140 void copy_to_user_page(struct vm_area_struct
*vma
, struct page
*page
,
141 unsigned long uaddr
, void *dst
, const void *src
,
147 memcpy(dst
, src
, len
);
148 flush_ptrace_access(vma
, page
, uaddr
, dst
, len
);
154 void __flush_dcache_page(struct address_space
*mapping
, struct page
*page
)
157 * Writeback any data associated with the kernel mapping of this
158 * page. This ensures that data in the physical page is mutually
159 * coherent with the kernels mapping.
161 if (!PageHighMem(page
)) {
162 __cpuc_flush_dcache_area(page_address(page
), PAGE_SIZE
);
164 void *addr
= kmap_high_get(page
);
166 __cpuc_flush_dcache_area(addr
, PAGE_SIZE
);
168 } else if (cache_is_vipt()) {
170 addr
= kmap_high_l1_vipt(page
, &saved_pte
);
171 __cpuc_flush_dcache_area(addr
, PAGE_SIZE
);
172 kunmap_high_l1_vipt(page
, saved_pte
);
177 * If this is a page cache page, and we have an aliasing VIPT cache,
178 * we only need to do one flush - which would be at the relevant
179 * userspace colour, which is congruent with page->index.
181 if (mapping
&& cache_is_vipt_aliasing())
182 flush_pfn_alias(page_to_pfn(page
),
183 page
->index
<< PAGE_CACHE_SHIFT
);
186 static void __flush_dcache_aliases(struct address_space
*mapping
, struct page
*page
)
188 struct mm_struct
*mm
= current
->active_mm
;
189 struct vm_area_struct
*mpnt
;
190 struct prio_tree_iter iter
;
194 * There are possible user space mappings of this page:
195 * - VIVT cache: we need to also write back and invalidate all user
196 * data in the current VM view associated with this page.
197 * - aliasing VIPT: we only need to find one mapping of this page.
199 pgoff
= page
->index
<< (PAGE_CACHE_SHIFT
- PAGE_SHIFT
);
201 flush_dcache_mmap_lock(mapping
);
202 vma_prio_tree_foreach(mpnt
, &iter
, &mapping
->i_mmap
, pgoff
, pgoff
) {
203 unsigned long offset
;
206 * If this VMA is not in our MM, we can ignore it.
208 if (mpnt
->vm_mm
!= mm
)
210 if (!(mpnt
->vm_flags
& VM_MAYSHARE
))
212 offset
= (pgoff
- mpnt
->vm_pgoff
) << PAGE_SHIFT
;
213 flush_cache_page(mpnt
, mpnt
->vm_start
+ offset
, page_to_pfn(page
));
215 flush_dcache_mmap_unlock(mapping
);
219 * Ensure cache coherency between kernel mapping and userspace mapping
222 * We have three cases to consider:
223 * - VIPT non-aliasing cache: fully coherent so nothing required.
224 * - VIVT: fully aliasing, so we need to handle every alias in our
226 * - VIPT aliasing: need to handle one alias in our current VM view.
228 * If we need to handle aliasing:
229 * If the page only exists in the page cache and there are no user
230 * space mappings, we can be lazy and remember that we may have dirty
231 * kernel cache lines for later. Otherwise, we assume we have
234 * Note that we disable the lazy flush for SMP.
236 void flush_dcache_page(struct page
*page
)
238 struct address_space
*mapping
;
241 * The zero page is never written to, so never has any dirty
242 * cache lines, and therefore never needs to be flushed.
244 if (page
== ZERO_PAGE(0))
247 mapping
= page_mapping(page
);
250 if (!PageHighMem(page
) && mapping
&& !mapping_mapped(mapping
))
251 set_bit(PG_dcache_dirty
, &page
->flags
);
255 __flush_dcache_page(mapping
, page
);
256 if (mapping
&& cache_is_vivt())
257 __flush_dcache_aliases(mapping
, page
);
259 __flush_icache_all();
262 EXPORT_SYMBOL(flush_dcache_page
);
265 * Flush an anonymous page so that users of get_user_pages()
266 * can safely access the data. The expected sequence is:
270 * memcpy() to/from page
271 * if written to page, flush_dcache_page()
273 void __flush_anon_page(struct vm_area_struct
*vma
, struct page
*page
, unsigned long vmaddr
)
277 /* VIPT non-aliasing caches need do nothing */
278 if (cache_is_vipt_nonaliasing())
282 * Write back and invalidate userspace mapping.
284 pfn
= page_to_pfn(page
);
285 if (cache_is_vivt()) {
286 flush_cache_page(vma
, vmaddr
, pfn
);
289 * For aliasing VIPT, we can flush an alias of the
290 * userspace address only.
292 flush_pfn_alias(pfn
, vmaddr
);
293 __flush_icache_all();
297 * Invalidate kernel mapping. No data should be contained
298 * in this mapping of the page. FIXME: this is overkill
299 * since we actually ask for a write-back and invalidate.
301 __cpuc_flush_dcache_area(page_address(page
), PAGE_SIZE
);