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[linux-ginger.git] / arch / xtensa / mm / cache.c
blob3ba990c67676c0b40976ff60d03638ceefba94cd
1 /*
2 * arch/xtensa/mm/cache.c
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License. See the file "COPYING" in the main directory of this archive
6 * for more details.
8 * Copyright (C) 2001-2006 Tensilica Inc.
10 * Chris Zankel <chris@zankel.net>
11 * Joe Taylor
12 * Marc Gauthier
16 #include <linux/init.h>
17 #include <linux/signal.h>
18 #include <linux/sched.h>
19 #include <linux/kernel.h>
20 #include <linux/errno.h>
21 #include <linux/string.h>
22 #include <linux/types.h>
23 #include <linux/ptrace.h>
24 #include <linux/bootmem.h>
25 #include <linux/swap.h>
26 #include <linux/pagemap.h>
28 #include <asm/bootparam.h>
29 #include <asm/mmu_context.h>
30 #include <asm/tlb.h>
31 #include <asm/tlbflush.h>
32 #include <asm/page.h>
33 #include <asm/pgalloc.h>
34 #include <asm/pgtable.h>
36 //#define printd(x...) printk(x)
37 #define printd(x...) do { } while(0)
39 /*
40 * Note:
41 * The kernel provides one architecture bit PG_arch_1 in the page flags that
42 * can be used for cache coherency.
44 * I$-D$ coherency.
46 * The Xtensa architecture doesn't keep the instruction cache coherent with
47 * the data cache. We use the architecture bit to indicate if the caches
48 * are coherent. The kernel clears this bit whenever a page is added to the
49 * page cache. At that time, the caches might not be in sync. We, therefore,
50 * define this flag as 'clean' if set.
52 * D-cache aliasing.
54 * With cache aliasing, we have to always flush the cache when pages are
55 * unmapped (see tlb_start_vma(). So, we use this flag to indicate a dirty
56 * page.
62 #if (DCACHE_WAY_SIZE > PAGE_SIZE) && XCHAL_DCACHE_IS_WRITEBACK
65 * Any time the kernel writes to a user page cache page, or it is about to
66 * read from a page cache page this routine is called.
70 void flush_dcache_page(struct page *page)
72 struct address_space *mapping = page_mapping(page);
75 * If we have a mapping but the page is not mapped to user-space
76 * yet, we simply mark this page dirty and defer flushing the
77 * caches until update_mmu().
80 if (mapping && !mapping_mapped(mapping)) {
81 if (!test_bit(PG_arch_1, &page->flags))
82 set_bit(PG_arch_1, &page->flags);
83 return;
85 } else {
87 unsigned long phys = page_to_phys(page);
88 unsigned long temp = page->index << PAGE_SHIFT;
89 unsigned long alias = !(DCACHE_ALIAS_EQ(temp, phys));
90 unsigned long virt;
92 /*
93 * Flush the page in kernel space and user space.
94 * Note that we can omit that step if aliasing is not
95 * an issue, but we do have to synchronize I$ and D$
96 * if we have a mapping.
99 if (!alias && !mapping)
100 return;
102 __flush_invalidate_dcache_page((long)page_address(page));
104 virt = TLBTEMP_BASE_1 + (temp & DCACHE_ALIAS_MASK);
106 if (alias)
107 __flush_invalidate_dcache_page_alias(virt, phys);
109 if (mapping)
110 __invalidate_icache_page_alias(virt, phys);
113 /* There shouldn't be an entry in the cache for this page anymore. */
118 * For now, flush the whole cache. FIXME??
121 void flush_cache_range(struct vm_area_struct* vma,
122 unsigned long start, unsigned long end)
124 __flush_invalidate_dcache_all();
125 __invalidate_icache_all();
129 * Remove any entry in the cache for this page.
131 * Note that this function is only called for user pages, so use the
132 * alias versions of the cache flush functions.
135 void flush_cache_page(struct vm_area_struct* vma, unsigned long address,
136 unsigned long pfn)
138 /* Note that we have to use the 'alias' address to avoid multi-hit */
140 unsigned long phys = page_to_phys(pfn_to_page(pfn));
141 unsigned long virt = TLBTEMP_BASE_1 + (address & DCACHE_ALIAS_MASK);
143 __flush_invalidate_dcache_page_alias(virt, phys);
144 __invalidate_icache_page_alias(virt, phys);
147 #endif
149 void
150 update_mmu_cache(struct vm_area_struct * vma, unsigned long addr, pte_t pte)
152 unsigned long pfn = pte_pfn(pte);
153 struct page *page;
155 if (!pfn_valid(pfn))
156 return;
158 page = pfn_to_page(pfn);
160 /* Invalidate old entry in TLBs */
162 invalidate_itlb_mapping(addr);
163 invalidate_dtlb_mapping(addr);
165 #if (DCACHE_WAY_SIZE > PAGE_SIZE) && XCHAL_DCACHE_IS_WRITEBACK
167 if (!PageReserved(page) && test_bit(PG_arch_1, &page->flags)) {
169 unsigned long vaddr = TLBTEMP_BASE_1 + (addr & DCACHE_ALIAS_MASK);
170 unsigned long paddr = (unsigned long) page_address(page);
171 unsigned long phys = page_to_phys(page);
173 __flush_invalidate_dcache_page(paddr);
175 __flush_invalidate_dcache_page_alias(vaddr, phys);
176 __invalidate_icache_page_alias(vaddr, phys);
178 clear_bit(PG_arch_1, &page->flags);
180 #else
181 if (!PageReserved(page) && !test_bit(PG_arch_1, &page->flags)
182 && (vma->vm_flags & VM_EXEC) != 0) {
183 unsigned long paddr = (unsigned long) page_address(page);
184 __flush_dcache_page(paddr);
185 __invalidate_icache_page(paddr);
186 set_bit(PG_arch_1, &page->flags);
188 #endif
192 * access_process_vm() has called get_user_pages(), which has done a
193 * flush_dcache_page() on the page.
196 #if (DCACHE_WAY_SIZE > PAGE_SIZE) && XCHAL_DCACHE_IS_WRITEBACK
198 void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
199 unsigned long vaddr, void *dst, const void *src,
200 unsigned long len)
202 unsigned long phys = page_to_phys(page);
203 unsigned long alias = !(DCACHE_ALIAS_EQ(vaddr, phys));
205 /* Flush and invalidate user page if aliased. */
207 if (alias) {
208 unsigned long temp = TLBTEMP_BASE_1 + (vaddr & DCACHE_ALIAS_MASK);
209 __flush_invalidate_dcache_page_alias(temp, phys);
212 /* Copy data */
214 memcpy(dst, src, len);
217 * Flush and invalidate kernel page if aliased and synchronize
218 * data and instruction caches for executable pages.
221 if (alias) {
222 unsigned long temp = TLBTEMP_BASE_1 + (vaddr & DCACHE_ALIAS_MASK);
224 __flush_invalidate_dcache_range((unsigned long) dst, len);
225 if ((vma->vm_flags & VM_EXEC) != 0) {
226 __invalidate_icache_page_alias(temp, phys);
229 } else if ((vma->vm_flags & VM_EXEC) != 0) {
230 __flush_dcache_range((unsigned long)dst,len);
231 __invalidate_icache_range((unsigned long) dst, len);
235 extern void copy_from_user_page(struct vm_area_struct *vma, struct page *page,
236 unsigned long vaddr, void *dst, const void *src,
237 unsigned long len)
239 unsigned long phys = page_to_phys(page);
240 unsigned long alias = !(DCACHE_ALIAS_EQ(vaddr, phys));
243 * Flush user page if aliased.
244 * (Note: a simply flush would be sufficient)
247 if (alias) {
248 unsigned long temp = TLBTEMP_BASE_1 + (vaddr & DCACHE_ALIAS_MASK);
249 __flush_invalidate_dcache_page_alias(temp, phys);
252 memcpy(dst, src, len);
255 #endif