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   1 /*
   2  *  linux/arch/arm/mm/cache-v7.S
   3  *
   4  *  Copyright (C) 2001 Deep Blue Solutions Ltd.
   5  *  Copyright (C) 2005 ARM Ltd.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  *  This is the "shell" of the ARMv7 processor support.
  12  */
  13 #include <linux/linkage.h>
  14 #include <linux/init.h>
  15 #include <asm/assembler.h>
  16 #include <asm/unwind.h>
  17
  18 #include "proc-macros.S"
  19
  20 /*
  21  *      v7_flush_dcache_all()
  22  *
  23  *      Flush the whole D-cache.
  24  *
  25  *      Corrupted registers: r0-r7, r9-r11 (r6 only in Thumb mode)
  26  *
  27  *      - mm    - mm_struct describing address space
  28  */
  29 ENTRY(v7_flush_dcache_all)
  30         dmb                                     @ ensure ordering with previous memory accesses
  31         mrc     p15, 1, r0, c0, c0, 1           @ read clidr
  32         ands    r3, r0, #0x7000000              @ extract loc from clidr
  33         mov     r3, r3, lsr #23                 @ left align loc bit field
  34         beq     finished                        @ if loc is 0, then no need to clean
  35         mov     r10, #0                         @ start clean at cache level 0
  36 loop1:
  37         add     r2, r10, r10, lsr #1            @ work out 3x current cache level
  38         mov     r1, r0, lsr r2                  @ extract cache type bits from clidr
  39         and     r1, r1, #7                      @ mask of the bits for current cache only
  40         cmp     r1, #2                          @ see what cache we have at this level
  41         blt     skip                            @ skip if no cache, or just i-cache
  42         mcr     p15, 2, r10, c0, c0, 0          @ select current cache level in cssr
  43         isb                                     @ isb to sych the new cssr&csidr
  44         mrc     p15, 1, r1, c0, c0, 0           @ read the new csidr
  45         and     r2, r1, #7                      @ extract the length of the cache lines
  46         add     r2, r2, #4                      @ add 4 (line length offset)
  47         ldr     r4, =0x3ff
  48         ands    r4, r4, r1, lsr #3              @ find maximum number on the way size
  49         clz     r5, r4                          @ find bit position of way size increment
  50         ldr     r7, =0x7fff
  51         ands    r7, r7, r1, lsr #13             @ extract max number of the index size
  52 loop2:
  53         mov     r9, r4                          @ create working copy of max way size
  54 loop3:
  55  ARM(   orr     r11, r10, r9, lsl r5    )       @ factor way and cache number into r11
  56  THUMB( lsl     r6, r9, r5              )
  57  THUMB( orr     r11, r10, r6            )       @ factor way and cache number into r11
  58  ARM(   orr     r11, r11, r7, lsl r2    )       @ factor index number into r11
  59  THUMB( lsl     r6, r7, r2              )
  60  THUMB( orr     r11, r11, r6            )       @ factor index number into r11
  61         mcr     p15, 0, r11, c7, c14, 2         @ clean & invalidate by set/way
  62         subs    r9, r9, #1                      @ decrement the way
  63         bge     loop3
  64         subs    r7, r7, #1                      @ decrement the index
  65         bge     loop2
  66 skip:
  67         add     r10, r10, #2                    @ increment cache number
  68         cmp     r3, r10
  69         bgt     loop1
  70 finished:
  71         mov     r10, #0                         @ swith back to cache level 0
  72         mcr     p15, 2, r10, c0, c0, 0          @ select current cache level in cssr
  73         dsb
  74         isb
  75         mov     pc, lr
  76 ENDPROC(v7_flush_dcache_all)
  77
  78 /*
  79  *      v7_flush_cache_all()
  80  *
  81  *      Flush the entire cache system.
  82  *  The data cache flush is now achieved using atomic clean / invalidates
  83  *  working outwards from L1 cache. This is done using Set/Way based cache
  84  *  maintainance instructions.
  85  *  The instruction cache can still be invalidated back to the point of
  86  *  unification in a single instruction.
  87  *
  88  */
  89 ENTRY(v7_flush_kern_cache_all)
  90  ARM(   stmfd   sp!, {r4-r5, r7, r9-r11, lr}    )
  91  THUMB( stmfd   sp!, {r4-r7, r9-r11, lr}        )
  92         bl      v7_flush_dcache_all
  93         mov     r0, #0
  94         mcr     p15, 0, r0, c7, c5, 0           @ I+BTB cache invalidate
  95  ARM(   ldmfd   sp!, {r4-r5, r7, r9-r11, lr}    )
  96  THUMB( ldmfd   sp!, {r4-r7, r9-r11, lr}        )
  97         mov     pc, lr
  98 ENDPROC(v7_flush_kern_cache_all)
  99
 100 /*
 101  *      v7_flush_cache_all()
 102  *
 103  *      Flush all TLB entries in a particular address space
 104  *
 105  *      - mm    - mm_struct describing address space
 106  */
 107 ENTRY(v7_flush_user_cache_all)
 108         /*FALLTHROUGH*/
 109
 110 /*
 111  *      v7_flush_cache_range(start, end, flags)
 112  *
 113  *      Flush a range of TLB entries in the specified address space.
 114  *
 115  *      - start - start address (may not be aligned)
 116  *      - end   - end address (exclusive, may not be aligned)
 117  *      - flags - vm_area_struct flags describing address space
 118  *
 119  *      It is assumed that:
 120  *      - we have a VIPT cache.
 121  */
 122 ENTRY(v7_flush_user_cache_range)
 123         mov     pc, lr
 124 ENDPROC(v7_flush_user_cache_all)
 125 ENDPROC(v7_flush_user_cache_range)
 126
 127 /*
 128  *      v7_coherent_kern_range(start,end)
 129  *
 130  *      Ensure that the I and D caches are coherent within specified
 131  *      region.  This is typically used when code has been written to
 132  *      a memory region, and will be executed.
 133  *
 134  *      - start   - virtual start address of region
 135  *      - end     - virtual end address of region
 136  *
 137  *      It is assumed that:
 138  *      - the Icache does not read data from the write buffer
 139  */
 140 ENTRY(v7_coherent_kern_range)
 141         /* FALLTHROUGH */
 142
 143 /*
 144  *      v7_coherent_user_range(start,end)
 145  *
 146  *      Ensure that the I and D caches are coherent within specified
 147  *      region.  This is typically used when code has been written to
 148  *      a memory region, and will be executed.
 149  *
 150  *      - start   - virtual start address of region
 151  *      - end     - virtual end address of region
 152  *
 153  *      It is assumed that:
 154  *      - the Icache does not read data from the write buffer
 155  */
 156 ENTRY(v7_coherent_user_range)
 157  UNWIND(.fnstart                )
 158         dcache_line_size r2, r3
 159         sub     r3, r2, #1
 160         bic     r0, r0, r3
 161 1:
 162  USER(  mcr     p15, 0, r0, c7, c11, 1  )       @ clean D line to the point of unification
 163         dsb
 164  USER(  mcr     p15, 0, r0, c7, c5, 1   )       @ invalidate I line
 165         add     r0, r0, r2
 166 2:
 167         cmp     r0, r1
 168         blo     1b
 169         mov     r0, #0
 170         mcr     p15, 0, r0, c7, c5, 6           @ invalidate BTB
 171         dsb
 172         isb
 173         mov     pc, lr
 174
 175 /*
 176  * Fault handling for the cache operation above. If the virtual address in r0
 177  * isn't mapped, just try the next page.
 178  */
 179 9001:
 180         mov     r0, r0, lsr #12
 181         mov     r0, r0, lsl #12
 182         add     r0, r0, #4096
 183         b       2b
 184  UNWIND(.fnend          )
 185 ENDPROC(v7_coherent_kern_range)
 186 ENDPROC(v7_coherent_user_range)
 187
 188 /*
 189  *      v7_flush_kern_dcache_page(kaddr)
 190  *
 191  *      Ensure that the data held in the page kaddr is written back
 192  *      to the page in question.
 193  *
 194  *      - kaddr   - kernel address (guaranteed to be page aligned)
 195  */
 196 ENTRY(v7_flush_kern_dcache_page)
 197         dcache_line_size r2, r3
 198         add     r1, r0, #PAGE_SZ
 199 1:
 200         mcr     p15, 0, r0, c7, c14, 1          @ clean & invalidate D line / unified line
 201         add     r0, r0, r2
 202         cmp     r0, r1
 203         blo     1b
 204         dsb
 205         mov     pc, lr
 206 ENDPROC(v7_flush_kern_dcache_page)
 207
 208 /*
 209  *      v7_dma_inv_range(start,end)
 210  *
 211  *      Invalidate the data cache within the specified region; we will
 212  *      be performing a DMA operation in this region and we want to
 213  *      purge old data in the cache.
 214  *
 215  *      - start   - virtual start address of region
 216  *      - end     - virtual end address of region
 217  */
 218 ENTRY(v7_dma_inv_range)
 219         dcache_line_size r2, r3
 220         sub     r3, r2, #1
 221         tst     r0, r3
 222         bic     r0, r0, r3
 223         mcrne   p15, 0, r0, c7, c14, 1          @ clean & invalidate D / U line
 224
 225         tst     r1, r3
 226         bic     r1, r1, r3
 227         mcrne   p15, 0, r1, c7, c14, 1          @ clean & invalidate D / U line
 228 1:
 229         mcr     p15, 0, r0, c7, c6, 1           @ invalidate D / U line
 230         add     r0, r0, r2
 231         cmp     r0, r1
 232         blo     1b
 233         dsb
 234         mov     pc, lr
 235 ENDPROC(v7_dma_inv_range)
 236
 237 /*
 238  *      v7_dma_clean_range(start,end)
 239  *      - start   - virtual start address of region
 240  *      - end     - virtual end address of region
 241  */
 242 ENTRY(v7_dma_clean_range)
 243         dcache_line_size r2, r3
 244         sub     r3, r2, #1
 245         bic     r0, r0, r3
 246 1:
 247         mcr     p15, 0, r0, c7, c10, 1          @ clean D / U line
 248         add     r0, r0, r2
 249         cmp     r0, r1
 250         blo     1b
 251         dsb
 252         mov     pc, lr
 253 ENDPROC(v7_dma_clean_range)
 254
 255 /*
 256  *      v7_dma_flush_range(start,end)
 257  *      - start   - virtual start address of region
 258  *      - end     - virtual end address of region
 259  */
 260 ENTRY(v7_dma_flush_range)
 261         dcache_line_size r2, r3
 262         sub     r3, r2, #1
 263         bic     r0, r0, r3
 264 1:
 265         mcr     p15, 0, r0, c7, c14, 1          @ clean & invalidate D / U line
 266         add     r0, r0, r2
 267         cmp     r0, r1
 268         blo     1b
 269         dsb
 270         mov     pc, lr
 271 ENDPROC(v7_dma_flush_range)
 272
 273         __INITDATA
 274
 275         .type   v7_cache_fns, #object
 276 ENTRY(v7_cache_fns)
 277         .long   v7_flush_kern_cache_all
 278         .long   v7_flush_user_cache_all
 279         .long   v7_flush_user_cache_range
 280         .long   v7_coherent_kern_range
 281         .long   v7_coherent_user_range
 282         .long   v7_flush_kern_dcache_page
 283         .long   v7_dma_inv_range
 284         .long   v7_dma_clean_range
 285         .long   v7_dma_flush_range
 286         .size   v7_cache_fns, . - v7_cache_fns