1 /* 2 * linux/arch/arm/mm/flush.c 3 * 4 * Copyright (C) 1995-2002 Russell King 5 * 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. 9 */ 10 #include <linux/module.h> 11 #include <linux/mm.h> 12 #include <linux/pagemap.h> 13 14 #include <asm/cacheflush.h> 15 #include <asm/system.h> 16 #include <asm/tlbflush.h> 17 18 #include "mm.h" 19 20 #ifdef CONFIG_CPU_CACHE_VIPT 21 22 #define ALIAS_FLUSH_START 0xffff4000 23 24 static void flush_pfn_alias(unsigned long pfn, unsigned long vaddr) 25 { 26 unsigned long to = ALIAS_FLUSH_START + (CACHE_COLOUR(vaddr) << PAGE_SHIFT); 27 const int zero = 0; 28 29 set_pte_ext(TOP_PTE(to), pfn_pte(pfn, PAGE_KERNEL), 0); 30 flush_tlb_kernel_page(to); 31 32 asm( "mcrr p15, 0, %1, %0, c14\n" 33 " mcr p15, 0, %2, c7, c10, 4\n" 34 " mcr p15, 0, %2, c7, c5, 0\n" 35 : 36 : "r" (to), "r" (to + PAGE_SIZE - L1_CACHE_BYTES), "r" (zero) 37 : "cc"); 38 } 39 40 void flush_cache_mm(struct mm_struct *mm) 41 { 42 if (cache_is_vivt()) { 43 if (cpu_isset(smp_processor_id(), mm->cpu_vm_mask)) 44 __cpuc_flush_user_all(); 45 return; 46 } 47 48 if (cache_is_vipt_aliasing()) { 49 asm( "mcr p15, 0, %0, c7, c14, 0\n" 50 " mcr p15, 0, %0, c7, c5, 0\n" 51 " mcr p15, 0, %0, c7, c10, 4" 52 : 53 : "r" (0) 54 : "cc"); 55 } 56 } 57 58 void flush_cache_range(struct vm_area_struct *vma, unsigned long start, unsigned long end) 59 { 60 if (cache_is_vivt()) { 61 if (cpu_isset(smp_processor_id(), vma->vm_mm->cpu_vm_mask)) 62 __cpuc_flush_user_range(start & PAGE_MASK, PAGE_ALIGN(end), 63 vma->vm_flags); 64 return; 65 } 66 67 if (cache_is_vipt_aliasing()) { 68 asm( "mcr p15, 0, %0, c7, c14, 0\n" 69 " mcr p15, 0, %0, c7, c5, 0\n" 70 " mcr p15, 0, %0, c7, c10, 4" 71 : 72 : "r" (0) 73 : "cc"); 74 } 75 } 76 77 void flush_cache_page(struct vm_area_struct *vma, unsigned long user_addr, unsigned long pfn) 78 { 79 if (cache_is_vivt()) { 80 if (cpu_isset(smp_processor_id(), vma->vm_mm->cpu_vm_mask)) { 81 unsigned long addr = user_addr & PAGE_MASK; 82 __cpuc_flush_user_range(addr, addr + PAGE_SIZE, vma->vm_flags); 83 } 84 return; 85 } 86 87 if (cache_is_vipt_aliasing()) 88 flush_pfn_alias(pfn, user_addr); 89 } 90 91 void flush_ptrace_access(struct vm_area_struct *vma, struct page *page, 92 unsigned long uaddr, void *kaddr, 93 unsigned long len, int write) 94 { 95 if (cache_is_vivt()) { 96 if (cpu_isset(smp_processor_id(), vma->vm_mm->cpu_vm_mask)) { 97 unsigned long addr = (unsigned long)kaddr; 98 __cpuc_coherent_kern_range(addr, addr + len); 99 } 100 return; 101 } 102 103 if (cache_is_vipt_aliasing()) { 104 flush_pfn_alias(page_to_pfn(page), uaddr); 105 return; 106 } 107 108 /* VIPT non-aliasing cache */ 109 if (cpu_isset(smp_processor_id(), vma->vm_mm->cpu_vm_mask) && 110 vma->vm_flags & VM_EXEC) { 111 unsigned long addr = (unsigned long)kaddr; 112 /* only flushing the kernel mapping on non-aliasing VIPT */ 113 __cpuc_coherent_kern_range(addr, addr + len); 114 } 115 } 116 #else 117 #define flush_pfn_alias(pfn,vaddr) do { } while (0) 118 #endif 119 120 void __flush_dcache_page(struct address_space *mapping, struct page *page) 121 { 122 /* 123 * Writeback any data associated with the kernel mapping of this 124 * page. This ensures that data in the physical page is mutually 125 * coherent with the kernels mapping. 126 */ 127 __cpuc_flush_dcache_page(page_address(page)); 128 129 /* 130 * If this is a page cache page, and we have an aliasing VIPT cache, 131 * we only need to do one flush - which would be at the relevant 132 * userspace colour, which is congruent with page->index. 133 */ 134 if (mapping && cache_is_vipt_aliasing()) 135 flush_pfn_alias(page_to_pfn(page), 136 page->index << PAGE_CACHE_SHIFT); 137 } 138 139 static void __flush_dcache_aliases(struct address_space *mapping, struct page *page) 140 { 141 struct mm_struct *mm = current->active_mm; 142 struct vm_area_struct *mpnt; 143 struct prio_tree_iter iter; 144 pgoff_t pgoff; 145 146 /* 147 * There are possible user space mappings of this page: 148 * - VIVT cache: we need to also write back and invalidate all user 149 * data in the current VM view associated with this page. 150 * - aliasing VIPT: we only need to find one mapping of this page. 151 */ 152 pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT); 153 154 flush_dcache_mmap_lock(mapping); 155 vma_prio_tree_foreach(mpnt, &iter, &mapping->i_mmap, pgoff, pgoff) { 156 unsigned long offset; 157 158 /* 159 * If this VMA is not in our MM, we can ignore it. 160 */ 161 if (mpnt->vm_mm != mm) 162 continue; 163 if (!(mpnt->vm_flags & VM_MAYSHARE)) 164 continue; 165 offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT; 166 flush_cache_page(mpnt, mpnt->vm_start + offset, page_to_pfn(page)); 167 } 168 flush_dcache_mmap_unlock(mapping); 169 } 170 171 /* 172 * Ensure cache coherency between kernel mapping and userspace mapping 173 * of this page. 174 * 175 * We have three cases to consider: 176 * - VIPT non-aliasing cache: fully coherent so nothing required. 177 * - VIVT: fully aliasing, so we need to handle every alias in our 178 * current VM view. 179 * - VIPT aliasing: need to handle one alias in our current VM view. 180 * 181 * If we need to handle aliasing: 182 * If the page only exists in the page cache and there are no user 183 * space mappings, we can be lazy and remember that we may have dirty 184 * kernel cache lines for later. Otherwise, we assume we have 185 * aliasing mappings. 186 * 187 * Note that we disable the lazy flush for SMP. 188 */ 189 void flush_dcache_page(struct page *page) 190 { 191 struct address_space *mapping = page_mapping(page); 192 193 #ifndef CONFIG_SMP 194 if (mapping && !mapping_mapped(mapping)) 195 set_bit(PG_dcache_dirty, &page->flags); 196 else 197 #endif 198 { 199 __flush_dcache_page(mapping, page); 200 if (mapping && cache_is_vivt()) 201 __flush_dcache_aliases(mapping, page); 202 } 203 } 204 EXPORT_SYMBOL(flush_dcache_page); 205 206 /* 207 * Flush an anonymous page so that users of get_user_pages() 208 * can safely access the data. The expected sequence is: 209 * 210 * get_user_pages() 211 * -> flush_anon_page 212 * memcpy() to/from page 213 * if written to page, flush_dcache_page() 214 */ 215 void __flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr) 216 { 217 unsigned long pfn; 218 219 /* VIPT non-aliasing caches need do nothing */ 220 if (cache_is_vipt_nonaliasing()) 221 return; 222 223 /* 224 * Write back and invalidate userspace mapping. 225 */ 226 pfn = page_to_pfn(page); 227 if (cache_is_vivt()) { 228 flush_cache_page(vma, vmaddr, pfn); 229 } else { 230 /* 231 * For aliasing VIPT, we can flush an alias of the 232 * userspace address only. 233 */ 234 flush_pfn_alias(pfn, vmaddr); 235 } 236 237 /* 238 * Invalidate kernel mapping. No data should be contained 239 * in this mapping of the page. FIXME: this is overkill 240 * since we actually ask for a write-back and invalidate. 241 */ 242 __cpuc_flush_dcache_page(page_address(page)); 243 } 244