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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 "assembler.h"
  16 #include <asm/unwind.h>
  17
  18 #include "proc-macros.S"
  19
  20 /*
  21  *      v7_flush_icache_all()
  22  *
  23  *      Flush the whole I-cache.
  24  *
  25  *      Registers:
  26  *      r0 - set to 0
  27  */
  28 ENTRY(v7_flush_icache_all)
  29         mov     r0, #0
  30         ALT_SMP(mcr     p15, 0, r0, c7, c1, 0)          @ invalidate I-cache inner shareable
  31         ALT_UP(mcr      p15, 0, r0, c7, c5, 0)          @ I+BTB cache invalidate
  32         mov     pc, lr
  33 ENDPROC(v7_flush_icache_all)
  34
  35 /*
  36  *      v7_flush_dcache_all()
  37  *
  38  *      Flush the whole D-cache.
  39  *
  40  *      Corrupted registers: r0-r7, r9-r11 (r6 only in Thumb mode)
  41  *
  42  *      - mm    - mm_struct describing address space
  43  */
  44 ENTRY(v7_flush_dcache_all)
  45         dmb                                     @ ensure ordering with previous memory accesses
  46         mrc     p15, 1, r0, c0, c0, 1           @ read clidr
  47         ands    r3, r0, #0x7000000              @ extract loc from clidr
  48         mov     r3, r3, lsr #23                 @ left align loc bit field
  49         beq     finished                        @ if loc is 0, then no need to clean
  50         mov     r10, #0                         @ start clean at cache level 0
  51 loop1:
  52         add     r2, r10, r10, lsr #1            @ work out 3x current cache level
  53         mov     r1, r0, lsr r2                  @ extract cache type bits from clidr
  54         and     r1, r1, #7                      @ mask of the bits for current cache only
  55         cmp     r1, #2                          @ see what cache we have at this level
  56         blt     skip                            @ skip if no cache, or just i-cache
  57         mcr     p15, 2, r10, c0, c0, 0          @ select current cache level in cssr
  58         isb                                     @ isb to sych the new cssr&csidr
  59         mrc     p15, 1, r1, c0, c0, 0           @ read the new csidr
  60         and     r2, r1, #7                      @ extract the length of the cache lines
  61         add     r2, r2, #4                      @ add 4 (line length offset)
  62         ldr     r4, =0x3ff
  63         ands    r4, r4, r1, lsr #3              @ find maximum number on the way size
  64         clz     r5, r4                          @ find bit position of way size increment
  65         ldr     r7, =0x7fff
  66         ands    r7, r7, r1, lsr #13             @ extract max number of the index size
  67 loop2:
  68         mov     r9, r4                          @ create working copy of max way size
  69 loop3:
  70  ARM(   orr     r11, r10, r9, lsl r5    )       @ factor way and cache number into r11
  71  THUMB( lsl     r6, r9, r5              )
  72  THUMB( orr     r11, r10, r6            )       @ factor way and cache number into r11
  73  ARM(   orr     r11, r11, r7, lsl r2    )       @ factor index number into r11
  74  THUMB( lsl     r6, r7, r2              )
  75  THUMB( orr     r11, r11, r6            )       @ factor index number into r11
  76         mcr     p15, 0, r11, c7, c14, 2         @ clean & invalidate by set/way
  77         subs    r9, r9, #1                      @ decrement the way
  78         bge     loop3
  79         subs    r7, r7, #1                      @ decrement the index
  80         bge     loop2
  81 skip:
  82         add     r10, r10, #2                    @ increment cache number
  83         cmp     r3, r10
  84         bgt     loop1
  85 finished:
  86         mov     r10, #0                         @ swith back to cache level 0
  87         mcr     p15, 2, r10, c0, c0, 0          @ select current cache level in cssr
  88         dsb
  89         isb
  90         mov     pc, lr
  91 ENDPROC(v7_flush_dcache_all)
  92
  93 /*
  94  *      v7_flush_cache_all()
  95  *
  96  *      Flush the entire cache system.
  97  *  The data cache flush is now achieved using atomic clean / invalidates
  98  *  working outwards from L1 cache. This is done using Set/Way based cache
  99  *  maintenance instructions.
 100  *  The instruction cache can still be invalidated back to the point of
 101  *  unification in a single instruction.
 102  *
 103  */
 104 ENTRY(v7_flush_kern_cache_all)
 105  ARM(   stmfd   sp!, {r4-r5, r7, r9-r11, lr}    )
 106  THUMB( stmfd   sp!, {r4-r7, r9-r11, lr}        )
 107         bl      v7_flush_dcache_all
 108         mov     r0, #0
 109         ALT_SMP(mcr     p15, 0, r0, c7, c1, 0)  @ invalidate I-cache inner shareable
 110         ALT_UP(mcr      p15, 0, r0, c7, c5, 0)  @ I+BTB cache invalidate
 111  ARM(   ldmfd   sp!, {r4-r5, r7, r9-r11, lr}    )
 112  THUMB( ldmfd   sp!, {r4-r7, r9-r11, lr}        )
 113         mov     pc, lr
 114 ENDPROC(v7_flush_kern_cache_all)
 115
 116 /*
 117  *      v7_flush_cache_all()
 118  *
 119  *      Flush all TLB entries in a particular address space
 120  *
 121  *      - mm    - mm_struct describing address space
 122  */
 123 ENTRY(v7_flush_user_cache_all)
 124         /*FALLTHROUGH*/
 125
 126 /*
 127  *      v7_flush_cache_range(start, end, flags)
 128  *
 129  *      Flush a range of TLB entries in the specified address space.
 130  *
 131  *      - start - start address (may not be aligned)
 132  *      - end   - end address (exclusive, may not be aligned)
 133  *      - flags - vm_area_struct flags describing address space
 134  *
 135  *      It is assumed that:
 136  *      - we have a VIPT cache.
 137  */
 138 ENTRY(v7_flush_user_cache_range)
 139         mov     pc, lr
 140 ENDPROC(v7_flush_user_cache_all)
 141 ENDPROC(v7_flush_user_cache_range)
 142
 143 /*
 144  *      v7_coherent_kern_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_kern_range)
 157         /* FALLTHROUGH */
 158
 159 /*
 160  *      v7_coherent_user_range(start,end)
 161  *
 162  *      Ensure that the I and D caches are coherent within specified
 163  *      region.  This is typically used when code has been written to
 164  *      a memory region, and will be executed.
 165  *
 166  *      - start   - virtual start address of region
 167  *      - end     - virtual end address of region
 168  *
 169  *      It is assumed that:
 170  *      - the Icache does not read data from the write buffer
 171  */
 172 ENTRY(v7_coherent_user_range)
 173  UNWIND(.fnstart                )
 174         dcache_line_size r2, r3
 175         sub     r3, r2, #1
 176         bic     r12, r0, r3
 177 1:
 178  USER(  mcr     p15, 0, r12, c7, c11, 1 )       @ clean D line to the point of unification
 179         add     r12, r12, r2
 180         cmp     r12, r1
 181         blo     1b
 182         dsb
 183         icache_line_size r2, r3
 184         sub     r3, r2, #1
 185         bic     r12, r0, r3
 186 2:
 187  USER(  mcr     p15, 0, r12, c7, c5, 1  )       @ invalidate I line
 188         add     r12, r12, r2
 189         cmp     r12, r1
 190         blo     2b
 191 3:
 192         mov     r0, #0
 193         ALT_SMP(mcr     p15, 0, r0, c7, c1, 6)  @ invalidate BTB Inner Shareable
 194         ALT_UP(mcr      p15, 0, r0, c7, c5, 6)  @ invalidate BTB
 195         dsb
 196         isb
 197         mov     pc, lr
 198
 199 /*
 200  * Fault handling for the cache operation above. If the virtual address in r0
 201  * isn't mapped, just try the next page.
 202  */
 203 9001:
 204         mov     r12, r12, lsr #12
 205         mov     r12, r12, lsl #12
 206         add     r12, r12, #4096
 207         b       3b
 208  UNWIND(.fnend          )
 209 ENDPROC(v7_coherent_kern_range)
 210 ENDPROC(v7_coherent_user_range)
 211
 212 /*
 213  *      v7_flush_kern_dcache_area(void *addr, size_t size)
 214  *
 215  *      Ensure that the data held in the page kaddr is written back
 216  *      to the page in question.
 217  *
 218  *      - addr  - kernel address
 219  *      - size  - region size
 220  */
 221 ENTRY(v7_flush_kern_dcache_area)
 222         dcache_line_size r2, r3
 223         add     r1, r0, r1
 224 1:
 225         mcr     p15, 0, r0, c7, c14, 1          @ clean & invalidate D line / unified line
 226         add     r0, r0, r2
 227         cmp     r0, r1
 228         blo     1b
 229         dsb
 230         mov     pc, lr
 231 ENDPROC(v7_flush_kern_dcache_area)
 232
 233 /*
 234  *      v7_dma_inv_range(start,end)
 235  *
 236  *      Invalidate the data cache within the specified region; we will
 237  *      be performing a DMA operation in this region and we want to
 238  *      purge old data in the cache.
 239  *
 240  *      - start   - virtual start address of region
 241  *      - end     - virtual end address of region
 242  */
 243 v7_dma_inv_range:
 244         dcache_line_size r2, r3
 245         sub     r3, r2, #1
 246         tst     r0, r3
 247         bic     r0, r0, r3
 248         mcrne   p15, 0, r0, c7, c14, 1          @ clean & invalidate D / U line
 249
 250         tst     r1, r3
 251         bic     r1, r1, r3
 252         mcrne   p15, 0, r1, c7, c14, 1          @ clean & invalidate D / U line
 253 1:
 254         mcr     p15, 0, r0, c7, c6, 1           @ invalidate D / U line
 255         add     r0, r0, r2
 256         cmp     r0, r1
 257         blo     1b
 258         dsb
 259         mov     pc, lr
 260 ENDPROC(v7_dma_inv_range)
 261
 262 /*
 263  *      v7_dma_clean_range(start,end)
 264  *      - start   - virtual start address of region
 265  *      - end     - virtual end address of region
 266  */
 267 v7_dma_clean_range:
 268         dcache_line_size r2, r3
 269         sub     r3, r2, #1
 270         bic     r0, r0, r3
 271 1:
 272         mcr     p15, 0, r0, c7, c10, 1          @ clean D / U line
 273         add     r0, r0, r2
 274         cmp     r0, r1
 275         blo     1b
 276         dsb
 277         mov     pc, lr
 278 ENDPROC(v7_dma_clean_range)
 279
 280 /*
 281  *      v7_dma_flush_range(start,end)
 282  *      - start   - virtual start address of region
 283  *      - end     - virtual end address of region
 284  */
 285 ENTRY(v7_dma_flush_range)
 286         dcache_line_size r2, r3
 287         sub     r3, r2, #1
 288         bic     r0, r0, r3
 289 1:
 290         mcr     p15, 0, r0, c7, c14, 1          @ clean & invalidate D / U line
 291         add     r0, r0, r2
 292         cmp     r0, r1
 293         blo     1b
 294         dsb
 295         mov     pc, lr
 296 ENDPROC(v7_dma_flush_range)
 297
 298         __INITDATA
 299
 300         .type   v7_cache_fns, #object
 301 ENTRY(v7_cache_fns)
 302         .long   v7_flush_icache_all
 303         .long   v7_flush_kern_cache_all
 304         .long   v7_flush_user_cache_all
 305         .long   v7_flush_user_cache_range
 306         .long   v7_coherent_kern_range
 307         .long   v7_coherent_user_range
 308         .long   v7_flush_kern_dcache_area
 309         .long   v7_dma_flush_range
 310         .size   v7_cache_fns, . - v7_cache_fns