linux/arch/arm/mm/cache-v4wb.S
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   1/*
   2 *  linux/arch/arm/mm/cache-v4wb.S
   3 *
   4 *  Copyright (C) 1997-2002 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/linkage.h>
  11#include <linux/init.h>
  12#include <asm/assembler.h>
  13#include <asm/memory.h>
  14#include <asm/page.h>
  15#include "proc-macros.S"
  16
  17/*
  18 * The size of one data cache line.
  19 */
  20#define CACHE_DLINESIZE 32
  21
  22/*
  23 * The total size of the data cache.
  24 */
  25#if defined(CONFIG_CPU_SA110)
  26# define CACHE_DSIZE    16384
  27#elif defined(CONFIG_CPU_SA1100)
  28# define CACHE_DSIZE    8192
  29#else
  30# error Unknown cache size
  31#endif
  32
  33/*
  34 * This is the size at which it becomes more efficient to
  35 * clean the whole cache, rather than using the individual
  36 * cache line maintenance instructions.
  37 *
  38 *  Size  Clean (ticks) Dirty (ticks)
  39 *   4096   21  20  21    53  55  54
  40 *   8192   40  41  40   106 100 102
  41 *  16384   77  77  76   140 140 138
  42 *  32768  150 149 150   214 216 212 <---
  43 *  65536  296 297 296   351 358 361
  44 * 131072  591 591 591   656 657 651
  45 *  Whole  132 136 132   221 217 207 <---
  46 */
  47#define CACHE_DLIMIT    (CACHE_DSIZE * 4)
  48
  49        .data
  50        .align  2
  51flush_base:
  52        .long   FLUSH_BASE
  53        .text
  54
  55/*
  56 *      flush_icache_all()
  57 *
  58 *      Unconditionally clean and invalidate the entire icache.
  59 */
  60ENTRY(v4wb_flush_icache_all)
  61        mov     r0, #0
  62        mcr     p15, 0, r0, c7, c5, 0           @ invalidate I cache
  63        ret     lr
  64ENDPROC(v4wb_flush_icache_all)
  65
  66/*
  67 *      flush_user_cache_all()
  68 *
  69 *      Clean and invalidate all cache entries in a particular address
  70 *      space.
  71 */
  72ENTRY(v4wb_flush_user_cache_all)
  73        /* FALLTHROUGH */
  74/*
  75 *      flush_kern_cache_all()
  76 *
  77 *      Clean and invalidate the entire cache.
  78 */
  79ENTRY(v4wb_flush_kern_cache_all)
  80        mov     ip, #0
  81        mcr     p15, 0, ip, c7, c5, 0           @ invalidate I cache
  82__flush_whole_cache:
  83        ldr     r3, =flush_base
  84        ldr     r1, [r3, #0]
  85        eor     r1, r1, #CACHE_DSIZE
  86        str     r1, [r3, #0]
  87        add     r2, r1, #CACHE_DSIZE
  881:      ldr     r3, [r1], #32
  89        cmp     r1, r2
  90        blo     1b
  91#ifdef FLUSH_BASE_MINICACHE
  92        add     r2, r2, #FLUSH_BASE_MINICACHE - FLUSH_BASE
  93        sub     r1, r2, #512                    @ only 512 bytes
  941:      ldr     r3, [r1], #32
  95        cmp     r1, r2
  96        blo     1b
  97#endif
  98        mcr     p15, 0, ip, c7, c10, 4          @ drain write buffer
  99        ret     lr
 100
 101/*
 102 *      flush_user_cache_range(start, end, flags)
 103 *
 104 *      Invalidate a range of cache entries in the specified
 105 *      address space.
 106 *
 107 *      - start - start address (inclusive, page aligned)
 108 *      - end   - end address (exclusive, page aligned)
 109 *      - flags - vma_area_struct flags describing address space
 110 */
 111ENTRY(v4wb_flush_user_cache_range)
 112        mov     ip, #0
 113        sub     r3, r1, r0                      @ calculate total size
 114        tst     r2, #VM_EXEC                    @ executable region?
 115        mcrne   p15, 0, ip, c7, c5, 0           @ invalidate I cache
 116
 117        cmp     r3, #CACHE_DLIMIT               @ total size >= limit?
 118        bhs     __flush_whole_cache             @ flush whole D cache
 119
 1201:      mcr     p15, 0, r0, c7, c10, 1          @ clean D entry
 121        mcr     p15, 0, r0, c7, c6, 1           @ invalidate D entry
 122        add     r0, r0, #CACHE_DLINESIZE
 123        cmp     r0, r1
 124        blo     1b
 125        tst     r2, #VM_EXEC
 126        mcrne   p15, 0, ip, c7, c10, 4          @ drain write buffer
 127        ret     lr
 128
 129/*
 130 *      flush_kern_dcache_area(void *addr, size_t size)
 131 *
 132 *      Ensure no D cache aliasing occurs, either with itself or
 133 *      the I cache
 134 *
 135 *      - addr  - kernel address
 136 *      - size  - region size
 137 */
 138ENTRY(v4wb_flush_kern_dcache_area)
 139        add     r1, r0, r1
 140        /* fall through */
 141
 142/*
 143 *      coherent_kern_range(start, end)
 144 *
 145 *      Ensure coherency between the Icache and the Dcache in the
 146 *      region described by start.  If you have non-snooping
 147 *      Harvard caches, you need to implement this function.
 148 *
 149 *      - start  - virtual start address
 150 *      - end    - virtual end address
 151 */
 152ENTRY(v4wb_coherent_kern_range)
 153        /* fall through */
 154
 155/*
 156 *      coherent_user_range(start, end)
 157 *
 158 *      Ensure coherency between the Icache and the Dcache in the
 159 *      region described by start.  If you have non-snooping
 160 *      Harvard caches, you need to implement this function.
 161 *
 162 *      - start  - virtual start address
 163 *      - end    - virtual end address
 164 */
 165ENTRY(v4wb_coherent_user_range)
 166        bic     r0, r0, #CACHE_DLINESIZE - 1
 1671:      mcr     p15, 0, r0, c7, c10, 1          @ clean D entry
 168        mcr     p15, 0, r0, c7, c6, 1           @ invalidate D entry
 169        add     r0, r0, #CACHE_DLINESIZE
 170        cmp     r0, r1
 171        blo     1b
 172        mov     r0, #0
 173        mcr     p15, 0, r0, c7, c5, 0           @ invalidate I cache
 174        mcr     p15, 0, r0, c7, c10, 4          @ drain WB
 175        ret     lr
 176
 177
 178/*
 179 *      dma_inv_range(start, end)
 180 *
 181 *      Invalidate (discard) the specified virtual address range.
 182 *      May not write back any entries.  If 'start' or 'end'
 183 *      are not cache line aligned, those lines must be written
 184 *      back.
 185 *
 186 *      - start  - virtual start address
 187 *      - end    - virtual end address
 188 */
 189v4wb_dma_inv_range:
 190        tst     r0, #CACHE_DLINESIZE - 1
 191        bic     r0, r0, #CACHE_DLINESIZE - 1
 192        mcrne   p15, 0, r0, c7, c10, 1          @ clean D entry
 193        tst     r1, #CACHE_DLINESIZE - 1
 194        mcrne   p15, 0, r1, c7, c10, 1          @ clean D entry
 1951:      mcr     p15, 0, r0, c7, c6, 1           @ invalidate D entry
 196        add     r0, r0, #CACHE_DLINESIZE
 197        cmp     r0, r1
 198        blo     1b
 199        mcr     p15, 0, r0, c7, c10, 4          @ drain write buffer
 200        ret     lr
 201
 202/*
 203 *      dma_clean_range(start, end)
 204 *
 205 *      Clean (write back) the specified virtual address range.
 206 *
 207 *      - start  - virtual start address
 208 *      - end    - virtual end address
 209 */
 210v4wb_dma_clean_range:
 211        bic     r0, r0, #CACHE_DLINESIZE - 1
 2121:      mcr     p15, 0, r0, c7, c10, 1          @ clean D entry
 213        add     r0, r0, #CACHE_DLINESIZE
 214        cmp     r0, r1
 215        blo     1b
 216        mcr     p15, 0, r0, c7, c10, 4          @ drain write buffer
 217        ret     lr
 218
 219/*
 220 *      dma_flush_range(start, end)
 221 *
 222 *      Clean and invalidate the specified virtual address range.
 223 *
 224 *      - start  - virtual start address
 225 *      - end    - virtual end address
 226 *
 227 *      This is actually the same as v4wb_coherent_kern_range()
 228 */
 229        .globl  v4wb_dma_flush_range
 230        .set    v4wb_dma_flush_range, v4wb_coherent_kern_range
 231
 232/*
 233 *      dma_map_area(start, size, dir)
 234 *      - start - kernel virtual start address
 235 *      - size  - size of region
 236 *      - dir   - DMA direction
 237 */
 238ENTRY(v4wb_dma_map_area)
 239        add     r1, r1, r0
 240        cmp     r2, #DMA_TO_DEVICE
 241        beq     v4wb_dma_clean_range
 242        bcs     v4wb_dma_inv_range
 243        b       v4wb_dma_flush_range
 244ENDPROC(v4wb_dma_map_area)
 245
 246/*
 247 *      dma_unmap_area(start, size, dir)
 248 *      - start - kernel virtual start address
 249 *      - size  - size of region
 250 *      - dir   - DMA direction
 251 */
 252ENTRY(v4wb_dma_unmap_area)
 253        ret     lr
 254ENDPROC(v4wb_dma_unmap_area)
 255
 256        .globl  v4wb_flush_kern_cache_louis
 257        .equ    v4wb_flush_kern_cache_louis, v4wb_flush_kern_cache_all
 258
 259        __INITDATA
 260
 261        @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S)
 262        define_cache_functions v4wb
 263