arch/mips/mm/cache.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 1994 - 2003, 06, 07 by Ralf Baechle (ralf@linux-mips.org)
   7  * Copyright (C) 2007 MIPS Technologies, Inc.
   8  */
   9 #include <linux/fs.h>
  10 #include <linux/fcntl.h>
  11 #include <linux/init.h>
  12 #include <linux/kernel.h>
  13 #include <linux/linkage.h>
  14 #include <linux/module.h>
  15 #include <linux/sched.h>
  16 #include <linux/mm.h>
  17
  18 #include <asm/cacheflush.h>
  19 #include <asm/processor.h>
  20 #include <asm/cpu.h>
  21 #include <asm/cpu-features.h>
  22
  23 /* Cache operations. */
  24 void (*flush_cache_all)(void);
  25 void (*__flush_cache_all)(void);
  26 void (*flush_cache_mm)(struct mm_struct *mm);
  27 void (*flush_cache_range)(struct vm_area_struct *vma, unsigned long start,
  28         unsigned long end);
  29 void (*flush_cache_page)(struct vm_area_struct *vma, unsigned long page,
  30         unsigned long pfn);
  31 void (*flush_icache_range)(unsigned long start, unsigned long end);
  32 void (*local_flush_icache_range)(unsigned long start, unsigned long end);
  33
  34 void (*__flush_cache_vmap)(void);
  35 void (*__flush_cache_vunmap)(void);
  36
  37 /* MIPS specific cache operations */
  38 void (*flush_cache_sigtramp)(unsigned long addr);
  39 void (*local_flush_data_cache_page)(void * addr);
  40 void (*flush_data_cache_page)(unsigned long addr);
  41 void (*flush_icache_all)(void);
  42
  43 EXPORT_SYMBOL_GPL(local_flush_data_cache_page);
  44 EXPORT_SYMBOL(flush_data_cache_page);
  45
  46 #ifdef CONFIG_DMA_NONCOHERENT
  47
  48 /* DMA cache operations. */
  49 void (*_dma_cache_wback_inv)(unsigned long start, unsigned long size);
  50 void (*_dma_cache_wback)(unsigned long start, unsigned long size);
  51 void (*_dma_cache_inv)(unsigned long start, unsigned long size);
  52
  53 EXPORT_SYMBOL(_dma_cache_wback_inv);
  54
  55 #endif /* CONFIG_DMA_NONCOHERENT */
  56
  57 /*
  58  * We could optimize the case where the cache argument is not BCACHE but
  59  * that seems very atypical use ...
  60  */
  61 asmlinkage int sys_cacheflush(unsigned long addr,
  62         unsigned long bytes, unsigned int cache)
  63 {
  64         if (bytes == 0)
  65                 return 0;
  66         if (!access_ok(VERIFY_WRITE, (void __user *) addr, bytes))
  67                 return -EFAULT;
  68
  69         flush_icache_range(addr, addr + bytes);
  70
  71         return 0;
  72 }
  73
  74 void __flush_dcache_page(struct page *page)
  75 {
  76         struct address_space *mapping = page_mapping(page);
  77         unsigned long addr;
  78
  79         if (PageHighMem(page))
  80                 return;
  81         if (mapping && !mapping_mapped(mapping)) {
  82                 SetPageDcacheDirty(page);
  83                 return;
  84         }
  85
  86         /*
  87          * We could delay the flush for the !page_mapping case too.  But that
  88          * case is for exec env/arg pages and those are %99 certainly going to
  89          * get faulted into the tlb (and thus flushed) anyways.
  90          */
  91         addr = (unsigned long) page_address(page);
  92         flush_data_cache_page(addr);
  93 }
  94
  95 EXPORT_SYMBOL(__flush_dcache_page);
  96
  97 void __flush_anon_page(struct page *page, unsigned long vmaddr)
  98 {
  99         unsigned long addr = (unsigned long) page_address(page);
 100
 101         if (pages_do_alias(addr, vmaddr)) {
 102                 if (page_mapped(page) && !Page_dcache_dirty(page)) {
 103                         void *kaddr;
 104
 105                         kaddr = kmap_coherent(page, vmaddr);
 106                         flush_data_cache_page((unsigned long)kaddr);
 107                         kunmap_coherent();
 108                 } else
 109                         flush_data_cache_page(addr);
 110         }
 111 }
 112
 113 EXPORT_SYMBOL(__flush_anon_page);
 114
 115 void __update_cache(struct vm_area_struct *vma, unsigned long address,
 116         pte_t pte)
 117 {
 118         struct page *page;
 119         unsigned long pfn, addr;
 120         int exec = (vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc;
 121
 122         pfn = pte_pfn(pte);
 123         if (unlikely(!pfn_valid(pfn)))
 124                 return;
 125         page = pfn_to_page(pfn);
 126         if (page_mapping(page) && Page_dcache_dirty(page)) {
 127                 addr = (unsigned long) page_address(page);
 128                 if (exec || pages_do_alias(addr, address & PAGE_MASK))
 129                         flush_data_cache_page(addr);
 130                 ClearPageDcacheDirty(page);
 131         }
 132 }
 133
 134 unsigned long _page_cachable_default;
 135 EXPORT_SYMBOL_GPL(_page_cachable_default);
 136
 137 static inline void setup_protection_map(void)
 138 {
 139         protection_map[0] = PAGE_NONE;
 140         protection_map[1] = PAGE_READONLY;
 141         protection_map[2] = PAGE_COPY;
 142         protection_map[3] = PAGE_COPY;
 143         protection_map[4] = PAGE_READONLY;
 144         protection_map[5] = PAGE_READONLY;
 145         protection_map[6] = PAGE_COPY;
 146         protection_map[7] = PAGE_COPY;
 147         protection_map[8] = PAGE_NONE;
 148         protection_map[9] = PAGE_READONLY;
 149         protection_map[10] = PAGE_SHARED;
 150         protection_map[11] = PAGE_SHARED;
 151         protection_map[12] = PAGE_READONLY;
 152         protection_map[13] = PAGE_READONLY;
 153         protection_map[14] = PAGE_SHARED;
 154         protection_map[15] = PAGE_SHARED;
 155 }
 156
 157 void __devinit cpu_cache_init(void)
 158 {
 159         if (cpu_has_3k_cache) {
 160                 extern void __weak r3k_cache_init(void);
 161
 162                 r3k_cache_init();
 163         }
 164         if (cpu_has_6k_cache) {
 165                 extern void __weak r6k_cache_init(void);
 166
 167                 r6k_cache_init();
 168         }
 169         if (cpu_has_4k_cache) {
 170                 extern void __weak r4k_cache_init(void);
 171
 172                 r4k_cache_init();
 173         }
 174         if (cpu_has_8k_cache) {
 175                 extern void __weak r8k_cache_init(void);
 176
 177                 r8k_cache_init();
 178         }
 179         if (cpu_has_tx39_cache) {
 180                 extern void __weak tx39_cache_init(void);
 181
 182                 tx39_cache_init();
 183         }
 184
 185         setup_protection_map();
 186 }
 187
 188 int __weak __uncached_access(struct file *file, unsigned long addr)
 189 {
 190         if (file->f_flags & O_SYNC)
 191                 return 1;
 192
 193         return addr >= __pa(high_memory);
 194 }