1/* 2 * linux/arch/arm/mm/proc-arm920.S: MMU functions for ARM920 3 * 4 * Copyright (C) 1999,2000 ARM Limited 5 * Copyright (C) 2000 Deep Blue Solutions Ltd. 6 * hacked for non-paged-MM by Hyok S. Choi, 2003. 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 21 * 22 * 23 * These are the low level assembler for performing cache and TLB 24 * functions on the arm920. 25 * 26 * CONFIG_CPU_ARM920_CPU_IDLE -> nohlt 27 */ 28#include <linux/linkage.h> 29#include <linux/init.h> 30#include <asm/assembler.h> 31#include <asm/hwcap.h> 32#include <asm/pgtable-hwdef.h> 33#include <asm/pgtable.h> 34#include <asm/page.h> 35#include <asm/ptrace.h> 36#include "proc-macros.S" 37 38/* 39 * The size of one data cache line. 40 */ 41#define CACHE_DLINESIZE 32 42 43/* 44 * The number of data cache segments. 45 */ 46#define CACHE_DSEGMENTS 8 47 48/* 49 * The number of lines in a cache segment. 50 */ 51#define CACHE_DENTRIES 64 52 53/* 54 * This is the size at which it becomes more efficient to 55 * clean the whole cache, rather than using the individual 56 * cache line maintainence instructions. 57 */ 58#define CACHE_DLIMIT 65536 59 60 61 .text 62/* 63 * cpu_arm920_proc_init() 64 */ 65ENTRY(cpu_arm920_proc_init) 66 mov pc, lr 67 68/* 69 * cpu_arm920_proc_fin() 70 */ 71ENTRY(cpu_arm920_proc_fin) 72 stmfd sp!, {lr} 73 mov ip, #PSR_F_BIT | PSR_I_BIT | SVC_MODE 74 msr cpsr_c, ip 75#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH 76 bl arm920_flush_kern_cache_all 77#else 78 bl v4wt_flush_kern_cache_all 79#endif 80 mrc p15, 0, r0, c1, c0, 0 @ ctrl register 81 bic r0, r0, #0x1000 @ ...i............ 82 bic r0, r0, #0x000e @ ............wca. 83 mcr p15, 0, r0, c1, c0, 0 @ disable caches 84 ldmfd sp!, {pc} 85 86/* 87 * cpu_arm920_reset(loc) 88 * 89 * Perform a soft reset of the system. Put the CPU into the 90 * same state as it would be if it had been reset, and branch 91 * to what would be the reset vector. 92 * 93 * loc: location to jump to for soft reset 94 */ 95 .align 5 96ENTRY(cpu_arm920_reset) 97 mov ip, #0 98 mcr p15, 0, ip, c7, c7, 0 @ invalidate I,D caches 99 mcr p15, 0, ip, c7, c10, 4 @ drain WB 100#ifdef CONFIG_MMU 101 mcr p15, 0, ip, c8, c7, 0 @ invalidate I & D TLBs 102#endif 103 mrc p15, 0, ip, c1, c0, 0 @ ctrl register 104 bic ip, ip, #0x000f @ ............wcam 105 bic ip, ip, #0x1100 @ ...i...s........ 106 mcr p15, 0, ip, c1, c0, 0 @ ctrl register 107 mov pc, r0 108 109/* 110 * cpu_arm920_do_idle() 111 */ 112 .align 5 113ENTRY(cpu_arm920_do_idle) 114 mcr p15, 0, r0, c7, c0, 4 @ Wait for interrupt 115 mov pc, lr 116 117 118#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH 119 120/* 121 * flush_user_cache_all() 122 * 123 * Invalidate all cache entries in a particular address 124 * space. 125 */ 126ENTRY(arm920_flush_user_cache_all) 127 /* FALLTHROUGH */ 128 129/* 130 * flush_kern_cache_all() 131 * 132 * Clean and invalidate the entire cache. 133 */ 134ENTRY(arm920_flush_kern_cache_all) 135 mov r2, #VM_EXEC 136 mov ip, #0 137__flush_whole_cache: 138 mov r1, #(CACHE_DSEGMENTS - 1) << 5 @ 8 segments 1391: orr r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries 1402: mcr p15, 0, r3, c7, c14, 2 @ clean+invalidate D index 141 subs r3, r3, #1 << 26 142 bcs 2b @ entries 63 to 0 143 subs r1, r1, #1 << 5 144 bcs 1b @ segments 7 to 0 145 tst r2, #VM_EXEC 146 mcrne p15, 0, ip, c7, c5, 0 @ invalidate I cache 147 mcrne p15, 0, ip, c7, c10, 4 @ drain WB 148 mov pc, lr 149 150/* 151 * flush_user_cache_range(start, end, flags) 152 * 153 * Invalidate a range of cache entries in the specified 154 * address space. 155 * 156 * - start - start address (inclusive) 157 * - end - end address (exclusive) 158 * - flags - vm_flags for address space 159 */ 160ENTRY(arm920_flush_user_cache_range) 161 mov ip, #0 162 sub r3, r1, r0 @ calculate total size 163 cmp r3, #CACHE_DLIMIT 164 bhs __flush_whole_cache 165 1661: mcr p15, 0, r0, c7, c14, 1 @ clean+invalidate D entry 167 tst r2, #VM_EXEC 168 mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry 169 add r0, r0, #CACHE_DLINESIZE 170 cmp r0, r1 171 blo 1b 172 tst r2, #VM_EXEC 173 mcrne p15, 0, ip, c7, c10, 4 @ drain WB 174 mov pc, lr 175 176/* 177 * coherent_kern_range(start, end) 178 * 179 * Ensure coherency between the Icache and the Dcache in the 180 * region described by start, end. If you have non-snooping 181 * Harvard caches, you need to implement this function. 182 * 183 * - start - virtual start address 184 * - end - virtual end address 185 */ 186ENTRY(arm920_coherent_kern_range) 187 /* FALLTHROUGH */ 188 189/* 190 * coherent_user_range(start, end) 191 * 192 * Ensure coherency between the Icache and the Dcache in the 193 * region described by start, end. If you have non-snooping 194 * Harvard caches, you need to implement this function. 195 * 196 * - start - virtual start address 197 * - end - virtual end address 198 */ 199ENTRY(arm920_coherent_user_range) 200 bic r0, r0, #CACHE_DLINESIZE - 1 2011: mcr p15, 0, r0, c7, c10, 1 @ clean D entry 202 mcr p15, 0, r0, c7, c5, 1 @ invalidate I entry 203 add r0, r0, #CACHE_DLINESIZE 204 cmp r0, r1 205 blo 1b 206 mcr p15, 0, r0, c7, c10, 4 @ drain WB 207 mov pc, lr 208 209/* 210 * flush_kern_dcache_area(void *addr, size_t size) 211 * 212 * Ensure no D cache aliasing occurs, either with itself or 213 * the I cache 214 * 215 * - addr - kernel address 216 * - size - region size 217 */ 218ENTRY(arm920_flush_kern_dcache_area) 219 add r1, r0, r1 2201: mcr p15, 0, r0, c7, c14, 1 @ clean+invalidate D entry 221 add r0, r0, #CACHE_DLINESIZE 222 cmp r0, r1 223 blo 1b 224 mov r0, #0 225 mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache 226 mcr p15, 0, r0, c7, c10, 4 @ drain WB 227 mov pc, lr 228 229/* 230 * dma_inv_range(start, end) 231 * 232 * Invalidate (discard) the specified virtual address range. 233 * May not write back any entries. If 'start' or 'end' 234 * are not cache line aligned, those lines must be written 235 * back. 236 * 237 * - start - virtual start address 238 * - end - virtual end address 239 * 240 * (same as v4wb) 241 */ 242ENTRY(arm920_dma_inv_range) 243 tst r0, #CACHE_DLINESIZE - 1 244 bic r0, r0, #CACHE_DLINESIZE - 1 245 mcrne p15, 0, r0, c7, c10, 1 @ clean D entry 246 tst r1, #CACHE_DLINESIZE - 1 247 mcrne p15, 0, r1, c7, c10, 1 @ clean D entry 2481: mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry 249 add r0, r0, #CACHE_DLINESIZE 250 cmp r0, r1 251 blo 1b 252 mcr p15, 0, r0, c7, c10, 4 @ drain WB 253 mov pc, lr 254 255/* 256 * dma_clean_range(start, end) 257 * 258 * Clean the specified virtual address range. 259 * 260 * - start - virtual start address 261 * - end - virtual end address 262 * 263 * (same as v4wb) 264 */ 265ENTRY(arm920_dma_clean_range) 266 bic r0, r0, #CACHE_DLINESIZE - 1 2671: mcr p15, 0, r0, c7, c10, 1 @ clean D entry 268 add r0, r0, #CACHE_DLINESIZE 269 cmp r0, r1 270 blo 1b 271 mcr p15, 0, r0, c7, c10, 4 @ drain WB 272 mov pc, lr 273 274/* 275 * dma_flush_range(start, end) 276 * 277 * Clean and invalidate the specified virtual address range. 278 * 279 * - start - virtual start address 280 * - end - virtual end address 281 */ 282ENTRY(arm920_dma_flush_range) 283 bic r0, r0, #CACHE_DLINESIZE - 1 2841: mcr p15, 0, r0, c7, c14, 1 @ clean+invalidate D entry 285 add r0, r0, #CACHE_DLINESIZE 286 cmp r0, r1 287 blo 1b 288 mcr p15, 0, r0, c7, c10, 4 @ drain WB 289 mov pc, lr 290 291ENTRY(arm920_cache_fns) 292 .long arm920_flush_kern_cache_all 293 .long arm920_flush_user_cache_all 294 .long arm920_flush_user_cache_range 295 .long arm920_coherent_kern_range 296 .long arm920_coherent_user_range 297 .long arm920_flush_kern_dcache_area 298 .long arm920_dma_inv_range 299 .long arm920_dma_clean_range 300 .long arm920_dma_flush_range 301 302#endif 303 304 305ENTRY(cpu_arm920_dcache_clean_area) 3061: mcr p15, 0, r0, c7, c10, 1 @ clean D entry 307 add r0, r0, #CACHE_DLINESIZE 308 subs r1, r1, #CACHE_DLINESIZE 309 bhi 1b 310 mov pc, lr 311 312/* =============================== PageTable ============================== */ 313 314/* 315 * cpu_arm920_switch_mm(pgd) 316 * 317 * Set the translation base pointer to be as described by pgd. 318 * 319 * pgd: new page tables 320 */ 321 .align 5 322ENTRY(cpu_arm920_switch_mm) 323#ifdef CONFIG_MMU 324 mov ip, #0 325#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH 326 mcr p15, 0, ip, c7, c6, 0 @ invalidate D cache 327#else 328@ && 'Clean & Invalidate whole DCache' 329@ && Re-written to use Index Ops. 330@ && Uses registers r1, r3 and ip 331 332 mov r1, #(CACHE_DSEGMENTS - 1) << 5 @ 8 segments 3331: orr r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries 3342: mcr p15, 0, r3, c7, c14, 2 @ clean & invalidate D index 335 subs r3, r3, #1 << 26 336 bcs 2b @ entries 63 to 0 337 subs r1, r1, #1 << 5 338 bcs 1b @ segments 7 to 0 339#endif 340 mcr p15, 0, ip, c7, c5, 0 @ invalidate I cache 341 mcr p15, 0, ip, c7, c10, 4 @ drain WB 342 mcr p15, 0, r0, c2, c0, 0 @ load page table pointer 343 mcr p15, 0, ip, c8, c7, 0 @ invalidate I & D TLBs 344#endif 345 mov pc, lr 346 347/* 348 * cpu_arm920_set_pte(ptep, pte, ext) 349 * 350 * Set a PTE and flush it out 351 */ 352 .align 5 353ENTRY(cpu_arm920_set_pte_ext) 354#ifdef CONFIG_MMU 355 armv3_set_pte_ext 356 mov r0, r0 357 mcr p15, 0, r0, c7, c10, 1 @ clean D entry 358 mcr p15, 0, r0, c7, c10, 4 @ drain WB 359#endif 360 mov pc, lr 361 362 __INIT 363 364 .type __arm920_setup, #function 365__arm920_setup: 366 mov r0, #0 367 mcr p15, 0, r0, c7, c7 @ invalidate I,D caches on v4 368 mcr p15, 0, r0, c7, c10, 4 @ drain write buffer on v4 369#ifdef CONFIG_MMU 370 mcr p15, 0, r0, c8, c7 @ invalidate I,D TLBs on v4 371#endif 372 adr r5, arm920_crval 373 ldmia r5, {r5, r6} 374 mrc p15, 0, r0, c1, c0 @ get control register v4 375 bic r0, r0, r5 376 orr r0, r0, r6 377 mov pc, lr 378 .size __arm920_setup, . - __arm920_setup 379 380 /* 381 * R 382 * .RVI ZFRS BLDP WCAM 383 * ..11 0001 ..11 0101 384 * 385 */ 386 .type arm920_crval, #object 387arm920_crval: 388 crval clear=0x00003f3f, mmuset=0x00003135, ucset=0x00001130 389 390 __INITDATA 391 392/* 393 * Purpose : Function pointers used to access above functions - all calls 394 * come through these 395 */ 396 .type arm920_processor_functions, #object 397arm920_processor_functions: 398 .word v4t_early_abort 399 .word legacy_pabort 400 .word cpu_arm920_proc_init 401 .word cpu_arm920_proc_fin 402 .word cpu_arm920_reset 403 .word cpu_arm920_do_idle 404 .word cpu_arm920_dcache_clean_area 405 .word cpu_arm920_switch_mm 406 .word cpu_arm920_set_pte_ext 407 .size arm920_processor_functions, . - arm920_processor_functions 408 409 .section ".rodata" 410 411 .type cpu_arch_name, #object 412cpu_arch_name: 413 .asciz "armv4t" 414 .size cpu_arch_name, . - cpu_arch_name 415 416 .type cpu_elf_name, #object 417cpu_elf_name: 418 .asciz "v4" 419 .size cpu_elf_name, . - cpu_elf_name 420 421 .type cpu_arm920_name, #object 422cpu_arm920_name: 423 .asciz "ARM920T" 424 .size cpu_arm920_name, . - cpu_arm920_name 425 426 .align 427 428 .section ".proc.info.init", #alloc, #execinstr 429 430 .type __arm920_proc_info,#object 431__arm920_proc_info: 432 .long 0x41009200 433 .long 0xff00fff0 434 .long PMD_TYPE_SECT | \ 435 PMD_SECT_BUFFERABLE | \ 436 PMD_SECT_CACHEABLE | \ 437 PMD_BIT4 | \ 438 PMD_SECT_AP_WRITE | \ 439 PMD_SECT_AP_READ 440 .long PMD_TYPE_SECT | \ 441 PMD_BIT4 | \ 442 PMD_SECT_AP_WRITE | \ 443 PMD_SECT_AP_READ 444 b __arm920_setup 445 .long cpu_arch_name 446 .long cpu_elf_name 447 .long HWCAP_SWP | HWCAP_HALF | HWCAP_THUMB 448 .long cpu_arm920_name 449 .long arm920_processor_functions 450 .long v4wbi_tlb_fns 451 .long v4wb_user_fns 452#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH 453 .long arm920_cache_fns 454#else 455 .long v4wt_cache_fns 456#endif 457 .size __arm920_proc_info, . - __arm920_proc_info 458