release/src-rt-6.x.4708/linux/linux-2.6.36/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/syscalls.h>
  17 #include <linux/mm.h>
  18
  19 #include <asm/cacheflush.h>
  20 #include <asm/processor.h>
  21 #include <asm/cpu.h>
  22 #include <asm/cpu-features.h>
  23
  24 /* Cache operations. */
  25 void (*flush_cache_all)(void);
  26 void (*__flush_cache_all)(void);
  27 void (*flush_cache_mm)(struct mm_struct *mm);
  28 void (*flush_cache_range)(struct vm_area_struct *vma, unsigned long start,
  29         unsigned long end);
  30 void (*flush_cache_page)(struct vm_area_struct *vma, unsigned long page,
  31         unsigned long pfn);
  32 void (*flush_icache_range)(unsigned long start, unsigned long end);
  33 void (*local_flush_icache_range)(unsigned long start, unsigned long end);
  34
  35 void (*__flush_cache_vmap)(void);
  36 void (*__flush_cache_vunmap)(void);
  37
  38 /* MIPS specific cache operations */
  39 void (*flush_cache_sigtramp)(unsigned long addr);
  40 void (*local_flush_data_cache_page)(void * addr);
  41 void (*flush_data_cache_page)(unsigned long addr);
  42 void (*flush_icache_all)(void);
  43
  44 EXPORT_SYMBOL_GPL(local_flush_data_cache_page);
  45 EXPORT_SYMBOL(flush_data_cache_page);
  46
  47 #ifdef CONFIG_DMA_NONCOHERENT
  48
  49 /* DMA cache operations. */
  50 void (*_dma_cache_wback_inv)(unsigned long start, unsigned long size);
  51 void (*_dma_cache_wback)(unsigned long start, unsigned long size);
  52 void (*_dma_cache_inv)(unsigned long start, unsigned long size);
  53
  54 EXPORT_SYMBOL(_dma_cache_wback_inv);
  55
  56 #endif /* CONFIG_DMA_NONCOHERENT */
  57
  58 /*
  59  * We could optimize the case where the cache argument is not BCACHE but
  60  * that seems very atypical use ...
  61  */
  62 SYSCALL_DEFINE3(cacheflush, unsigned long, addr, unsigned long, bytes,
  63         unsigned int, cache)
  64 {
  65         if (bytes == 0)
  66                 return 0;
  67         if (!access_ok(VERIFY_WRITE, (void __user *) addr, bytes))
  68                 return -EFAULT;
  69
  70         flush_icache_range(addr, addr + bytes);
  71
  72         return 0;
  73 }
  74
  75 void __flush_dcache_page(struct page *page)
  76 {
  77         unsigned long addr;
  78
  79         if (PageHighMem(page))
  80                 return;
  81         if (page_mapping(page) && !page_mapped(page)) {
  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         ClearPageDcacheDirty(page);
  94 }
  95
  96 EXPORT_SYMBOL(__flush_dcache_page);
  97
  98 void __flush_anon_page(struct page *page, unsigned long vmaddr)
  99 {
 100         unsigned long addr = (unsigned long) page_address(page);
 101
 102         if (pages_do_alias(addr, vmaddr)) {
 103                 if (page_mapped(page) && !Page_dcache_dirty(page)) {
 104                         void *kaddr;
 105
 106                         kaddr = kmap_coherent(page, vmaddr);
 107                         flush_data_cache_page((unsigned long)kaddr);
 108                         kunmap_coherent();
 109                 } else {
 110                         flush_data_cache_page(addr);
 111                         ClearPageDcacheDirty(page);
 112                 }
 113         }
 114 }
 115
 116 EXPORT_SYMBOL(__flush_anon_page);
 117
 118 void __update_cache(struct vm_area_struct *vma, unsigned long address,
 119         pte_t pte)
 120 {
 121         struct page *page;
 122         unsigned long pfn, addr;
 123         int exec = (vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc;
 124
 125         pfn = pte_pfn(pte);
 126         if (unlikely(!pfn_valid(pfn)))
 127                 return;
 128         page = pfn_to_page(pfn);
 129         if (page_mapped(page) && Page_dcache_dirty(page)) {
 130                 addr = (unsigned long) page_address(page);
 131                 if (exec || (cpu_has_dc_aliases &&
 132                     pages_do_alias(addr, address & PAGE_MASK))) {
 133                         flush_data_cache_page(addr);
 134                         ClearPageDcacheDirty(page);
 135                 }
 136         }
 137 }
 138
 139 unsigned long _page_cachable_default;
 140 EXPORT_SYMBOL(_page_cachable_default);
 141
 142 static inline void setup_protection_map(void)
 143 {
 144         if (kernel_uses_smartmips_rixi) {
 145                 protection_map[0]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ);
 146                 protection_map[1]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC);
 147                 protection_map[2]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ);
 148                 protection_map[3]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC);
 149                 protection_map[4]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_READ);
 150                 protection_map[5]  = __pgprot(_page_cachable_default | _PAGE_PRESENT);
 151                 protection_map[6]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_READ);
 152                 protection_map[7]  = __pgprot(_page_cachable_default | _PAGE_PRESENT);
 153
 154                 protection_map[8]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ);
 155                 protection_map[9]  = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC);
 156                 protection_map[10] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE | _PAGE_NO_READ);
 157                 protection_map[11] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE);
 158                 protection_map[12] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_READ);
 159                 protection_map[13] = __pgprot(_page_cachable_default | _PAGE_PRESENT);
 160                 protection_map[14] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_WRITE  | _PAGE_NO_READ);
 161                 protection_map[15] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_WRITE);
 162
 163         } else {
 164                 protection_map[0] = PAGE_NONE;
 165                 protection_map[1] = PAGE_READONLY;
 166                 protection_map[2] = PAGE_COPY;
 167                 protection_map[3] = PAGE_COPY;
 168                 protection_map[4] = PAGE_READONLY;
 169                 protection_map[5] = PAGE_READONLY;
 170                 protection_map[6] = PAGE_COPY;
 171                 protection_map[7] = PAGE_COPY;
 172                 protection_map[8] = PAGE_NONE;
 173                 protection_map[9] = PAGE_READONLY;
 174                 protection_map[10] = PAGE_SHARED;
 175                 protection_map[11] = PAGE_SHARED;
 176                 protection_map[12] = PAGE_READONLY;
 177                 protection_map[13] = PAGE_READONLY;
 178                 protection_map[14] = PAGE_SHARED;
 179                 protection_map[15] = PAGE_SHARED;
 180         }
 181 }
 182
 183 void __cpuinit cpu_cache_init(void)
 184 {
 185         if (cpu_has_3k_cache) {
 186                 extern void __weak r3k_cache_init(void);
 187
 188                 r3k_cache_init();
 189         }
 190         if (cpu_has_6k_cache) {
 191                 extern void __weak r6k_cache_init(void);
 192
 193                 r6k_cache_init();
 194         }
 195         if (cpu_has_4k_cache) {
 196                 extern void __weak r4k_cache_init(void);
 197
 198                 r4k_cache_init();
 199         }
 200         if (cpu_has_8k_cache) {
 201                 extern void __weak r8k_cache_init(void);
 202
 203                 r8k_cache_init();
 204         }
 205         if (cpu_has_tx39_cache) {
 206                 extern void __weak tx39_cache_init(void);
 207
 208                 tx39_cache_init();
 209         }
 210
 211         if (cpu_has_octeon_cache) {
 212                 extern void __weak octeon_cache_init(void);
 213
 214                 octeon_cache_init();
 215         }
 216
 217         setup_protection_map();
 218 }
 219
 220 int __weak __uncached_access(struct file *file, unsigned long addr)
 221 {
 222         if (file->f_flags & O_DSYNC)
 223                 return 1;
 224
 225         return addr >= __pa(high_memory);
 226 }