1 /* 2 * arch/xtensa/mm/cache.c 3 * 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. 7 * 8 * Copyright (C) 2001-2006 Tensilica Inc. 9 * 10 * Chris Zankel <chris@zankel.net> 11 * Joe Taylor 12 * Marc Gauthier 13 * 14 */ 15 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> 27 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> 35 36 /* 37 * Note: 38 * The kernel provides one architecture bit PG_arch_1 in the page flags that 39 * can be used for cache coherency. 40 * 41 * I$-D$ coherency. 42 * 43 * The Xtensa architecture doesn't keep the instruction cache coherent with 44 * the data cache. We use the architecture bit to indicate if the caches 45 * are coherent. The kernel clears this bit whenever a page is added to the 46 * page cache. At that time, the caches might not be in sync. We, therefore, 47 * define this flag as 'clean' if set. 48 * 49 * D-cache aliasing. 50 * 51 * With cache aliasing, we have to always flush the cache when pages are 52 * unmapped (see tlb_start_vma(). So, we use this flag to indicate a dirty 53 * page. 54 * 55 * 56 * 57 */ 58 59 #if (DCACHE_WAY_SIZE > PAGE_SIZE) 60 static inline void kmap_invalidate_coherent(struct page *page, 61 unsigned long vaddr) 62 { 63 if (!DCACHE_ALIAS_EQ(page_to_phys(page), vaddr)) { 64 unsigned long kvaddr; 65 66 if (!PageHighMem(page)) { 67 kvaddr = (unsigned long)page_to_virt(page); 68 69 __invalidate_dcache_page(kvaddr); 70 } else { 71 kvaddr = TLBTEMP_BASE_1 + 72 (page_to_phys(page) & DCACHE_ALIAS_MASK); 73 74 __invalidate_dcache_page_alias(kvaddr, 75 page_to_phys(page)); 76 } 77 } 78 } 79 80 static inline void *coherent_kvaddr(struct page *page, unsigned long base, 81 unsigned long vaddr, unsigned long *paddr) 82 { 83 if (PageHighMem(page) || !DCACHE_ALIAS_EQ(page_to_phys(page), vaddr)) { 84 *paddr = page_to_phys(page); 85 return (void *)(base + (vaddr & DCACHE_ALIAS_MASK)); 86 } else { 87 *paddr = 0; 88 return page_to_virt(page); 89 } 90 } 91 92 void clear_user_highpage(struct page *page, unsigned long vaddr) 93 { 94 unsigned long paddr; 95 void *kvaddr = coherent_kvaddr(page, TLBTEMP_BASE_1, vaddr, &paddr); 96 97 preempt_disable(); 98 kmap_invalidate_coherent(page, vaddr); 99 set_bit(PG_arch_1, &page->flags); 100 clear_page_alias(kvaddr, paddr); 101 preempt_enable(); 102 } 103 EXPORT_SYMBOL(clear_user_highpage); 104 105 void copy_user_highpage(struct page *dst, struct page *src, 106 unsigned long vaddr, struct vm_area_struct *vma) 107 { 108 unsigned long dst_paddr, src_paddr; 109 void *dst_vaddr = coherent_kvaddr(dst, TLBTEMP_BASE_1, vaddr, 110 &dst_paddr); 111 void *src_vaddr = coherent_kvaddr(src, TLBTEMP_BASE_2, vaddr, 112 &src_paddr); 113 114 preempt_disable(); 115 kmap_invalidate_coherent(dst, vaddr); 116 set_bit(PG_arch_1, &dst->flags); 117 copy_page_alias(dst_vaddr, src_vaddr, dst_paddr, src_paddr); 118 preempt_enable(); 119 } 120 EXPORT_SYMBOL(copy_user_highpage); 121 122 /* 123 * Any time the kernel writes to a user page cache page, or it is about to 124 * read from a page cache page this routine is called. 125 * 126 */ 127 128 void flush_dcache_page(struct page *page) 129 { 130 struct address_space *mapping = page_mapping(page); 131 132 /* 133 * If we have a mapping but the page is not mapped to user-space 134 * yet, we simply mark this page dirty and defer flushing the 135 * caches until update_mmu(). 136 */ 137 138 if (mapping && !mapping_mapped(mapping)) { 139 if (!test_bit(PG_arch_1, &page->flags)) 140 set_bit(PG_arch_1, &page->flags); 141 return; 142 143 } else { 144 145 unsigned long phys = page_to_phys(page); 146 unsigned long temp = page->index << PAGE_SHIFT; 147 unsigned long alias = !(DCACHE_ALIAS_EQ(temp, phys)); 148 unsigned long virt; 149 150 /* 151 * Flush the page in kernel space and user space. 152 * Note that we can omit that step if aliasing is not 153 * an issue, but we do have to synchronize I$ and D$ 154 * if we have a mapping. 155 */ 156 157 if (!alias && !mapping) 158 return; 159 160 virt = TLBTEMP_BASE_1 + (phys & DCACHE_ALIAS_MASK); 161 __flush_invalidate_dcache_page_alias(virt, phys); 162 163 virt = TLBTEMP_BASE_1 + (temp & DCACHE_ALIAS_MASK); 164 165 if (alias) 166 __flush_invalidate_dcache_page_alias(virt, phys); 167 168 if (mapping) 169 __invalidate_icache_page_alias(virt, phys); 170 } 171 172 /* There shouldn't be an entry in the cache for this page anymore. */ 173 } 174 EXPORT_SYMBOL(flush_dcache_page); 175 176 /* 177 * For now, flush the whole cache. FIXME?? 178 */ 179 180 void local_flush_cache_range(struct vm_area_struct *vma, 181 unsigned long start, unsigned long end) 182 { 183 __flush_invalidate_dcache_all(); 184 __invalidate_icache_all(); 185 } 186 EXPORT_SYMBOL(local_flush_cache_range); 187 188 /* 189 * Remove any entry in the cache for this page. 190 * 191 * Note that this function is only called for user pages, so use the 192 * alias versions of the cache flush functions. 193 */ 194 195 void local_flush_cache_page(struct vm_area_struct *vma, unsigned long address, 196 unsigned long pfn) 197 { 198 /* Note that we have to use the 'alias' address to avoid multi-hit */ 199 200 unsigned long phys = page_to_phys(pfn_to_page(pfn)); 201 unsigned long virt = TLBTEMP_BASE_1 + (address & DCACHE_ALIAS_MASK); 202 203 __flush_invalidate_dcache_page_alias(virt, phys); 204 __invalidate_icache_page_alias(virt, phys); 205 } 206 EXPORT_SYMBOL(local_flush_cache_page); 207 208 #endif /* DCACHE_WAY_SIZE > PAGE_SIZE */ 209 210 void 211 update_mmu_cache(struct vm_area_struct * vma, unsigned long addr, pte_t *ptep) 212 { 213 unsigned long pfn = pte_pfn(*ptep); 214 struct page *page; 215 216 if (!pfn_valid(pfn)) 217 return; 218 219 page = pfn_to_page(pfn); 220 221 /* Invalidate old entry in TLBs */ 222 223 flush_tlb_page(vma, addr); 224 225 #if (DCACHE_WAY_SIZE > PAGE_SIZE) 226 227 if (!PageReserved(page) && test_bit(PG_arch_1, &page->flags)) { 228 unsigned long phys = page_to_phys(page); 229 unsigned long tmp; 230 231 tmp = TLBTEMP_BASE_1 + (phys & DCACHE_ALIAS_MASK); 232 __flush_invalidate_dcache_page_alias(tmp, phys); 233 tmp = TLBTEMP_BASE_1 + (addr & DCACHE_ALIAS_MASK); 234 __flush_invalidate_dcache_page_alias(tmp, phys); 235 __invalidate_icache_page_alias(tmp, phys); 236 237 clear_bit(PG_arch_1, &page->flags); 238 } 239 #else 240 if (!PageReserved(page) && !test_bit(PG_arch_1, &page->flags) 241 && (vma->vm_flags & VM_EXEC) != 0) { 242 unsigned long paddr = (unsigned long)kmap_atomic(page); 243 __flush_dcache_page(paddr); 244 __invalidate_icache_page(paddr); 245 set_bit(PG_arch_1, &page->flags); 246 kunmap_atomic((void *)paddr); 247 } 248 #endif 249 } 250 251 /* 252 * access_process_vm() has called get_user_pages(), which has done a 253 * flush_dcache_page() on the page. 254 */ 255 256 #if (DCACHE_WAY_SIZE > PAGE_SIZE) 257 258 void copy_to_user_page(struct vm_area_struct *vma, struct page *page, 259 unsigned long vaddr, void *dst, const void *src, 260 unsigned long len) 261 { 262 unsigned long phys = page_to_phys(page); 263 unsigned long alias = !(DCACHE_ALIAS_EQ(vaddr, phys)); 264 265 /* Flush and invalidate user page if aliased. */ 266 267 if (alias) { 268 unsigned long t = TLBTEMP_BASE_1 + (vaddr & DCACHE_ALIAS_MASK); 269 __flush_invalidate_dcache_page_alias(t, phys); 270 } 271 272 /* Copy data */ 273 274 memcpy(dst, src, len); 275 276 /* 277 * Flush and invalidate kernel page if aliased and synchronize 278 * data and instruction caches for executable pages. 279 */ 280 281 if (alias) { 282 unsigned long t = TLBTEMP_BASE_1 + (vaddr & DCACHE_ALIAS_MASK); 283 284 __flush_invalidate_dcache_range((unsigned long) dst, len); 285 if ((vma->vm_flags & VM_EXEC) != 0) 286 __invalidate_icache_page_alias(t, phys); 287 288 } else if ((vma->vm_flags & VM_EXEC) != 0) { 289 __flush_dcache_range((unsigned long)dst,len); 290 __invalidate_icache_range((unsigned long) dst, len); 291 } 292 } 293 294 extern void copy_from_user_page(struct vm_area_struct *vma, struct page *page, 295 unsigned long vaddr, void *dst, const void *src, 296 unsigned long len) 297 { 298 unsigned long phys = page_to_phys(page); 299 unsigned long alias = !(DCACHE_ALIAS_EQ(vaddr, phys)); 300 301 /* 302 * Flush user page if aliased. 303 * (Note: a simply flush would be sufficient) 304 */ 305 306 if (alias) { 307 unsigned long t = TLBTEMP_BASE_1 + (vaddr & DCACHE_ALIAS_MASK); 308 __flush_invalidate_dcache_page_alias(t, phys); 309 } 310 311 memcpy(dst, src, len); 312 } 313 314 #endif 315