arch/arm/mm/cache-v4wt.S

   1 /*
   2  *  linux/arch/arm/mm/cache-v4wt.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  *  ARMv4 write through cache operations support.
  11  *
  12  *  We assume that the write buffer is not enabled.
  13  */
  14 #include <linux/linkage.h>
  15 #include <linux/init.h>
  16 #include <asm/page.h>
  17 #include "proc-macros.S"
  18
  19 /*
  20  * The size of one data cache line.
  21  */
  22 #define CACHE_DLINESIZE 32
  23
  24 /*
  25  * The number of data cache segments.
  26  */
  27 #define CACHE_DSEGMENTS 8
  28
  29 /*
  30  * The number of lines in a cache segment.
  31  */
  32 #define CACHE_DENTRIES  64
  33
  34 /*
  35  * This is the size at which it becomes more efficient to
  36  * clean the whole cache, rather than using the individual
  37  * cache line maintenance instructions.
  38  *
  39  * *** This needs benchmarking
  40  */
  41 #define CACHE_DLIMIT    16384
  42
  43 /*
  44  *      flush_icache_all()
  45  *
  46  *      Unconditionally clean and invalidate the entire icache.
  47  */
  48 ENTRY(v4wt_flush_icache_all)
  49         mov     r0, #0
  50         mcr     p15, 0, r0, c7, c5, 0           @ invalidate I cache
  51         mov     pc, lr
  52 ENDPROC(v4wt_flush_icache_all)
  53
  54 /*
  55  *      flush_user_cache_all()
  56  *
  57  *      Invalidate all cache entries in a particular address
  58  *      space.
  59  */
  60 ENTRY(v4wt_flush_user_cache_all)
  61         /* FALLTHROUGH */
  62 /*
  63  *      flush_kern_cache_all()
  64  *
  65  *      Clean and invalidate the entire cache.
  66  */
  67 ENTRY(v4wt_flush_kern_cache_all)
  68         mov     r2, #VM_EXEC
  69         mov     ip, #0
  70 __flush_whole_cache:
  71         tst     r2, #VM_EXEC
  72         mcrne   p15, 0, ip, c7, c5, 0           @ invalidate I cache
  73         mcr     p15, 0, ip, c7, c6, 0           @ invalidate D cache
  74         mov     pc, lr
  75
  76 /*
  77  *      flush_user_cache_range(start, end, flags)
  78  *
  79  *      Clean and invalidate a range of cache entries in the specified
  80  *      address space.
  81  *
  82  *      - start - start address (inclusive, page aligned)
  83  *      - end   - end address (exclusive, page aligned)
  84  *      - flags - vma_area_struct flags describing address space
  85  */
  86 ENTRY(v4wt_flush_user_cache_range)
  87         sub     r3, r1, r0                      @ calculate total size
  88         cmp     r3, #CACHE_DLIMIT
  89         bhs     __flush_whole_cache
  90
  91 1:      mcr     p15, 0, r0, c7, c6, 1           @ invalidate D entry
  92         tst     r2, #VM_EXEC
  93         mcrne   p15, 0, r0, c7, c5, 1           @ invalidate I entry
  94         add     r0, r0, #CACHE_DLINESIZE
  95         cmp     r0, r1
  96         blo     1b
  97         mov     pc, lr
  98
  99 /*
 100  *      coherent_kern_range(start, end)
 101  *
 102  *      Ensure coherency between the Icache and the Dcache in the
 103  *      region described by start.  If you have non-snooping
 104  *      Harvard caches, you need to implement this function.
 105  *
 106  *      - start  - virtual start address
 107  *      - end    - virtual end address
 108  */
 109 ENTRY(v4wt_coherent_kern_range)
 110         /* FALLTRHOUGH */
 111
 112 /*
 113  *      coherent_user_range(start, end)
 114  *
 115  *      Ensure coherency between the Icache and the Dcache in the
 116  *      region described by start.  If you have non-snooping
 117  *      Harvard caches, you need to implement this function.
 118  *
 119  *      - start  - virtual start address
 120  *      - end    - virtual end address
 121  */
 122 ENTRY(v4wt_coherent_user_range)
 123         bic     r0, r0, #CACHE_DLINESIZE - 1
 124 1:      mcr     p15, 0, r0, c7, c5, 1           @ invalidate I entry
 125         add     r0, r0, #CACHE_DLINESIZE
 126         cmp     r0, r1
 127         blo     1b
 128         mov     pc, lr
 129
 130 /*
 131  *      flush_kern_dcache_area(void *addr, size_t size)
 132  *
 133  *      Ensure no D cache aliasing occurs, either with itself or
 134  *      the I cache
 135  *
 136  *      - addr  - kernel address
 137  *      - size  - region size
 138  */
 139 ENTRY(v4wt_flush_kern_dcache_area)
 140         mov     r2, #0
 141         mcr     p15, 0, r2, c7, c5, 0           @ invalidate I cache
 142         add     r1, r0, r1
 143         /* fallthrough */
 144
 145 /*
 146  *      dma_inv_range(start, end)
 147  *
 148  *      Invalidate (discard) the specified virtual address range.
 149  *      May not write back any entries.  If 'start' or 'end'
 150  *      are not cache line aligned, those lines must be written
 151  *      back.
 152  *
 153  *      - start  - virtual start address
 154  *      - end    - virtual end address
 155  */
 156 v4wt_dma_inv_range:
 157         bic     r0, r0, #CACHE_DLINESIZE - 1
 158 1:      mcr     p15, 0, r0, c7, c6, 1           @ invalidate D entry
 159         add     r0, r0, #CACHE_DLINESIZE
 160         cmp     r0, r1
 161         blo     1b
 162         mov     pc, lr
 163
 164 /*
 165  *      dma_flush_range(start, end)
 166  *
 167  *      Clean and invalidate the specified virtual address range.
 168  *
 169  *      - start  - virtual start address
 170  *      - end    - virtual end address
 171  */
 172         .globl  v4wt_dma_flush_range
 173         .equ    v4wt_dma_flush_range, v4wt_dma_inv_range
 174
 175 /*
 176  *      dma_unmap_area(start, size, dir)
 177  *      - start - kernel virtual start address
 178  *      - size  - size of region
 179  *      - dir   - DMA direction
 180  */
 181 ENTRY(v4wt_dma_unmap_area)
 182         add     r1, r1, r0
 183         teq     r2, #DMA_TO_DEVICE
 184         bne     v4wt_dma_inv_range
 185         /* FALLTHROUGH */
 186
 187 /*
 188  *      dma_map_area(start, size, dir)
 189  *      - start - kernel virtual start address
 190  *      - size  - size of region
 191  *      - dir   - DMA direction
 192  */
 193 ENTRY(v4wt_dma_map_area)
 194         mov     pc, lr
 195 ENDPROC(v4wt_dma_unmap_area)
 196 ENDPROC(v4wt_dma_map_area)
 197
 198         __INITDATA
 199
 200         .type   v4wt_cache_fns, #object
 201 ENTRY(v4wt_cache_fns)
 202         .long   v4wt_flush_icache_all
 203         .long   v4wt_flush_kern_cache_all
 204         .long   v4wt_flush_user_cache_all
 205         .long   v4wt_flush_user_cache_range
 206         .long   v4wt_coherent_kern_range
 207         .long   v4wt_coherent_user_range
 208         .long   v4wt_flush_kern_dcache_area
 209         .long   v4wt_dma_map_area
 210         .long   v4wt_dma_unmap_area
 211         .long   v4wt_dma_flush_range
 212         .size   v4wt_cache_fns, . - v4wt_cache_fns