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 */ 29ENTRY(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 36loop1: 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 52loop2: 53 mov r9, r4 @ create working copy of max way size 54loop3: 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 66skip: 67 add r10, r10, #2 @ increment cache number 68 cmp r3, r10 69 bgt loop1 70finished: 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 76ENDPROC(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 */ 89ENTRY(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 98ENDPROC(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 */ 107ENTRY(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 */ 122ENTRY(v7_flush_user_cache_range) 123 mov pc, lr 124ENDPROC(v7_flush_user_cache_all) 125ENDPROC(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 */ 140ENTRY(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 */ 156ENTRY(v7_coherent_user_range) 157 UNWIND(.fnstart ) 158 dcache_line_size r2, r3 159 sub r3, r2, #1 160 bic r0, r0, r3 1611: 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 1662: 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 */ 1799001: 180 mov r0, r0, lsr #12 181 mov r0, r0, lsl #12 182 add r0, r0, #4096 183 b 2b 184 UNWIND(.fnend ) 185ENDPROC(v7_coherent_kern_range) 186ENDPROC(v7_coherent_user_range) 187 188/* 189 * v7_flush_kern_dcache_area(void *addr, size_t size) 190 * 191 * Ensure that the data held in the page kaddr is written back 192 * to the page in question. 193 * 194 * - addr - kernel address 195 * - size - region size 196 */ 197ENTRY(v7_flush_kern_dcache_area) 198 dcache_line_size r2, r3 199 add r1, r0, r1 2001: 201 mcr p15, 0, r0, c7, c14, 1 @ clean & invalidate D line / unified line 202 add r0, r0, r2 203 cmp r0, r1 204 blo 1b 205 dsb 206 mov pc, lr 207ENDPROC(v7_flush_kern_dcache_area) 208 209/* 210 * v7_dma_inv_range(start,end) 211 * 212 * Invalidate the data cache within the specified region; we will 213 * be performing a DMA operation in this region and we want to 214 * purge old data in the cache. 215 * 216 * - start - virtual start address of region 217 * - end - virtual end address of region 218 */ 219v7_dma_inv_range: 220 dcache_line_size r2, r3 221 sub r3, r2, #1 222 tst r0, r3 223 bic r0, r0, r3 224 mcrne p15, 0, r0, c7, c14, 1 @ clean & invalidate D / U line 225 226 tst r1, r3 227 bic r1, r1, r3 228 mcrne p15, 0, r1, c7, c14, 1 @ clean & invalidate D / U line 2291: 230 mcr p15, 0, r0, c7, c6, 1 @ invalidate D / U line 231 add r0, r0, r2 232 cmp r0, r1 233 blo 1b 234 dsb 235 mov pc, lr 236ENDPROC(v7_dma_inv_range) 237 238/* 239 * v7_dma_clean_range(start,end) 240 * - start - virtual start address of region 241 * - end - virtual end address of region 242 */ 243v7_dma_clean_range: 244 dcache_line_size r2, r3 245 sub r3, r2, #1 246 bic r0, r0, r3 2471: 248 mcr p15, 0, r0, c7, c10, 1 @ clean D / U line 249 add r0, r0, r2 250 cmp r0, r1 251 blo 1b 252 dsb 253 mov pc, lr 254ENDPROC(v7_dma_clean_range) 255 256/* 257 * v7_dma_flush_range(start,end) 258 * - start - virtual start address of region 259 * - end - virtual end address of region 260 */ 261ENTRY(v7_dma_flush_range) 262 dcache_line_size r2, r3 263 sub r3, r2, #1 264 bic r0, r0, r3 2651: 266 mcr p15, 0, r0, c7, c14, 1 @ clean & invalidate D / U line 267 add r0, r0, r2 268 cmp r0, r1 269 blo 1b 270 dsb 271 mov pc, lr 272ENDPROC(v7_dma_flush_range) 273 274/* 275 * dma_map_area(start, size, dir) 276 * - start - kernel virtual start address 277 * - size - size of region 278 * - dir - DMA direction 279 */ 280ENTRY(v7_dma_map_area) 281 add r1, r1, r0 282 cmp r2, #DMA_TO_DEVICE 283 beq v7_dma_clean_range 284 bcs v7_dma_inv_range 285 b v7_dma_flush_range 286ENDPROC(v7_dma_map_area) 287 288/* 289 * dma_unmap_area(start, size, dir) 290 * - start - kernel virtual start address 291 * - size - size of region 292 * - dir - DMA direction 293 */ 294ENTRY(v7_dma_unmap_area) 295 mov pc, lr 296ENDPROC(v7_dma_unmap_area) 297 298 __INITDATA 299 300 .type v7_cache_fns, #object 301ENTRY(v7_cache_fns) 302 .long v7_flush_kern_cache_all 303 .long v7_flush_user_cache_all 304 .long v7_flush_user_cache_range 305 .long v7_coherent_kern_range 306 .long v7_coherent_user_range 307 .long v7_flush_kern_dcache_area 308 .long v7_dma_map_area 309 .long v7_dma_unmap_area 310 .long v7_dma_flush_range 311 .size v7_cache_fns, . - v7_cache_fns 312