1/* 2 * linux/arch/arm/mm/arm925.S: MMU functions for ARM925 3 * 4 * Copyright (C) 1999,2000 ARM Limited 5 * Copyright (C) 2000 Deep Blue Solutions Ltd. 6 * Copyright (C) 2002 RidgeRun, Inc. 7 * Copyright (C) 2002-2003 MontaVista Software, Inc. 8 * 9 * Update for Linux-2.6 and cache flush improvements 10 * Copyright (C) 2004 Nokia Corporation by Tony Lindgren <tony@atomide.com> 11 * 12 * hacked for non-paged-MM by Hyok S. Choi, 2004. 13 * 14 * This program is free software; you can redistribute it and/or modify 15 * it under the terms of the GNU General Public License as published by 16 * the Free Software Foundation; either version 2 of the License, or 17 * (at your option) any later version. 18 * 19 * This program is distributed in the hope that it will be useful, 20 * but WITHOUT ANY WARRANTY; without even the implied warranty of 21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 22 * GNU General Public License for more details. 23 * 24 * You should have received a copy of the GNU General Public License 25 * along with this program; if not, write to the Free Software 26 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 27 * 28 * 29 * These are the low level assembler for performing cache and TLB 30 * functions on the arm925. 31 * 32 * CONFIG_CPU_ARM925_CPU_IDLE -> nohlt 33 * 34 * Some additional notes based on deciphering the TI TRM on OMAP-5910: 35 * 36 * NOTE1: The TI925T Configuration Register bit "D-cache clean and flush 37 * entry mode" must be 0 to flush the entries in both segments 38 * at once. This is the default value. See TRM 2-20 and 2-24 for 39 * more information. 40 * 41 * NOTE2: Default is the "D-cache clean and flush entry mode". It looks 42 * like the "Transparent mode" must be on for partial cache flushes 43 * to work in this mode. This mode only works with 16-bit external 44 * memory. See TRM 2-24 for more information. 45 * 46 * NOTE3: Write-back cache flushing seems to be flakey with devices using 47 * direct memory access, such as USB OHCI. The workaround is to use 48 * write-through cache with CONFIG_CPU_DCACHE_WRITETHROUGH (this is 49 * the default for OMAP-1510). 50 */ 51 52#include <linux/linkage.h> 53#include <linux/init.h> 54#include <asm/assembler.h> 55#include <asm/hwcap.h> 56#include <asm/pgtable-hwdef.h> 57#include <asm/pgtable.h> 58#include <asm/page.h> 59#include <asm/ptrace.h> 60#include "proc-macros.S" 61 62/* 63 * The size of one data cache line. 64 */ 65#define CACHE_DLINESIZE 16 66 67/* 68 * The number of data cache segments. 69 */ 70#define CACHE_DSEGMENTS 2 71 72/* 73 * The number of lines in a cache segment. 74 */ 75#define CACHE_DENTRIES 256 76 77/* 78 * This is the size at which it becomes more efficient to 79 * clean the whole cache, rather than using the individual 80 * cache line maintenance instructions. 81 */ 82#define CACHE_DLIMIT 8192 83 84 .text 85/* 86 * cpu_arm925_proc_init() 87 */ 88ENTRY(cpu_arm925_proc_init) 89 ret lr 90 91/* 92 * cpu_arm925_proc_fin() 93 */ 94ENTRY(cpu_arm925_proc_fin) 95 mrc p15, 0, r0, c1, c0, 0 @ ctrl register 96 bic r0, r0, #0x1000 @ ...i............ 97 bic r0, r0, #0x000e @ ............wca. 98 mcr p15, 0, r0, c1, c0, 0 @ disable caches 99 ret lr 100 101/* 102 * cpu_arm925_reset(loc) 103 * 104 * Perform a soft reset of the system. Put the CPU into the 105 * same state as it would be if it had been reset, and branch 106 * to what would be the reset vector. 107 * 108 * loc: location to jump to for soft reset 109 */ 110 .align 5 111 .pushsection .idmap.text, "ax" 112ENTRY(cpu_arm925_reset) 113 /* Send software reset to MPU and DSP */ 114 mov ip, #0xff000000 115 orr ip, ip, #0x00fe0000 116 orr ip, ip, #0x0000ce00 117 mov r4, #1 118 strh r4, [ip, #0x10] 119ENDPROC(cpu_arm925_reset) 120 .popsection 121 122 mov ip, #0 123 mcr p15, 0, ip, c7, c7, 0 @ invalidate I,D caches 124 mcr p15, 0, ip, c7, c10, 4 @ drain WB 125#ifdef CONFIG_MMU 126 mcr p15, 0, ip, c8, c7, 0 @ invalidate I & D TLBs 127#endif 128 mrc p15, 0, ip, c1, c0, 0 @ ctrl register 129 bic ip, ip, #0x000f @ ............wcam 130 bic ip, ip, #0x1100 @ ...i...s........ 131 mcr p15, 0, ip, c1, c0, 0 @ ctrl register 132 ret r0 133 134/* 135 * cpu_arm925_do_idle() 136 * 137 * Called with IRQs disabled 138 */ 139 .align 10 140ENTRY(cpu_arm925_do_idle) 141 mov r0, #0 142 mrc p15, 0, r1, c1, c0, 0 @ Read control register 143 mcr p15, 0, r0, c7, c10, 4 @ Drain write buffer 144 bic r2, r1, #1 << 12 145 mcr p15, 0, r2, c1, c0, 0 @ Disable I cache 146 mcr p15, 0, r0, c7, c0, 4 @ Wait for interrupt 147 mcr p15, 0, r1, c1, c0, 0 @ Restore ICache enable 148 ret lr 149 150/* 151 * flush_icache_all() 152 * 153 * Unconditionally clean and invalidate the entire icache. 154 */ 155ENTRY(arm925_flush_icache_all) 156 mov r0, #0 157 mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache 158 ret lr 159ENDPROC(arm925_flush_icache_all) 160 161/* 162 * flush_user_cache_all() 163 * 164 * Clean and invalidate all cache entries in a particular 165 * address space. 166 */ 167ENTRY(arm925_flush_user_cache_all) 168 /* FALLTHROUGH */ 169 170/* 171 * flush_kern_cache_all() 172 * 173 * Clean and invalidate the entire cache. 174 */ 175ENTRY(arm925_flush_kern_cache_all) 176 mov r2, #VM_EXEC 177 mov ip, #0 178__flush_whole_cache: 179#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH 180 mcr p15, 0, ip, c7, c6, 0 @ invalidate D cache 181#else 182 /* Flush entries in both segments at once, see NOTE1 above */ 183 mov r3, #(CACHE_DENTRIES - 1) << 4 @ 256 entries in segment 1842: mcr p15, 0, r3, c7, c14, 2 @ clean+invalidate D index 185 subs r3, r3, #1 << 4 186 bcs 2b @ entries 255 to 0 187#endif 188 tst r2, #VM_EXEC 189 mcrne p15, 0, ip, c7, c5, 0 @ invalidate I cache 190 mcrne p15, 0, ip, c7, c10, 4 @ drain WB 191 ret lr 192 193/* 194 * flush_user_cache_range(start, end, flags) 195 * 196 * Clean and invalidate a range of cache entries in the 197 * specified address range. 198 * 199 * - start - start address (inclusive) 200 * - end - end address (exclusive) 201 * - flags - vm_flags describing address space 202 */ 203ENTRY(arm925_flush_user_cache_range) 204 mov ip, #0 205 sub r3, r1, r0 @ calculate total size 206 cmp r3, #CACHE_DLIMIT 207 bgt __flush_whole_cache 2081: tst r2, #VM_EXEC 209#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH 210 mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry 211 mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry 212 add r0, r0, #CACHE_DLINESIZE 213 mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry 214 mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry 215 add r0, r0, #CACHE_DLINESIZE 216#else 217 mcr p15, 0, r0, c7, c14, 1 @ clean and invalidate D entry 218 mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry 219 add r0, r0, #CACHE_DLINESIZE 220 mcr p15, 0, r0, c7, c14, 1 @ clean and invalidate D entry 221 mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry 222 add r0, r0, #CACHE_DLINESIZE 223#endif 224 cmp r0, r1 225 blo 1b 226 tst r2, #VM_EXEC 227 mcrne p15, 0, ip, c7, c10, 4 @ drain WB 228 ret lr 229 230/* 231 * coherent_kern_range(start, end) 232 * 233 * Ensure coherency between the Icache and the Dcache in the 234 * region described by start, end. If you have non-snooping 235 * Harvard caches, you need to implement this function. 236 * 237 * - start - virtual start address 238 * - end - virtual end address 239 */ 240ENTRY(arm925_coherent_kern_range) 241 /* FALLTHROUGH */ 242 243/* 244 * coherent_user_range(start, end) 245 * 246 * Ensure coherency between the Icache and the Dcache in the 247 * region described by start, end. If you have non-snooping 248 * Harvard caches, you need to implement this function. 249 * 250 * - start - virtual start address 251 * - end - virtual end address 252 */ 253ENTRY(arm925_coherent_user_range) 254 bic r0, r0, #CACHE_DLINESIZE - 1 2551: mcr p15, 0, r0, c7, c10, 1 @ clean D entry 256 mcr p15, 0, r0, c7, c5, 1 @ invalidate I entry 257 add r0, r0, #CACHE_DLINESIZE 258 cmp r0, r1 259 blo 1b 260 mcr p15, 0, r0, c7, c10, 4 @ drain WB 261 mov r0, #0 262 ret lr 263 264/* 265 * flush_kern_dcache_area(void *addr, size_t size) 266 * 267 * Ensure no D cache aliasing occurs, either with itself or 268 * the I cache 269 * 270 * - addr - kernel address 271 * - size - region size 272 */ 273ENTRY(arm925_flush_kern_dcache_area) 274 add r1, r0, r1 2751: mcr p15, 0, r0, c7, c14, 1 @ clean+invalidate D entry 276 add r0, r0, #CACHE_DLINESIZE 277 cmp r0, r1 278 blo 1b 279 mov r0, #0 280 mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache 281 mcr p15, 0, r0, c7, c10, 4 @ drain WB 282 ret lr 283 284/* 285 * dma_inv_range(start, end) 286 * 287 * Invalidate (discard) the specified virtual address range. 288 * May not write back any entries. If 'start' or 'end' 289 * are not cache line aligned, those lines must be written 290 * back. 291 * 292 * - start - virtual start address 293 * - end - virtual end address 294 * 295 * (same as v4wb) 296 */ 297arm925_dma_inv_range: 298#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH 299 tst r0, #CACHE_DLINESIZE - 1 300 mcrne p15, 0, r0, c7, c10, 1 @ clean D entry 301 tst r1, #CACHE_DLINESIZE - 1 302 mcrne p15, 0, r1, c7, c10, 1 @ clean D entry 303#endif 304 bic r0, r0, #CACHE_DLINESIZE - 1 3051: mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry 306 add r0, r0, #CACHE_DLINESIZE 307 cmp r0, r1 308 blo 1b 309 mcr p15, 0, r0, c7, c10, 4 @ drain WB 310 ret lr 311 312/* 313 * dma_clean_range(start, end) 314 * 315 * Clean the specified virtual address range. 316 * 317 * - start - virtual start address 318 * - end - virtual end address 319 * 320 * (same as v4wb) 321 */ 322arm925_dma_clean_range: 323#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH 324 bic r0, r0, #CACHE_DLINESIZE - 1 3251: mcr p15, 0, r0, c7, c10, 1 @ clean D entry 326 add r0, r0, #CACHE_DLINESIZE 327 cmp r0, r1 328 blo 1b 329#endif 330 mcr p15, 0, r0, c7, c10, 4 @ drain WB 331 ret lr 332 333/* 334 * dma_flush_range(start, end) 335 * 336 * Clean and invalidate the specified virtual address range. 337 * 338 * - start - virtual start address 339 * - end - virtual end address 340 */ 341ENTRY(arm925_dma_flush_range) 342 bic r0, r0, #CACHE_DLINESIZE - 1 3431: 344#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH 345 mcr p15, 0, r0, c7, c14, 1 @ clean+invalidate D entry 346#else 347 mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry 348#endif 349 add r0, r0, #CACHE_DLINESIZE 350 cmp r0, r1 351 blo 1b 352 mcr p15, 0, r0, c7, c10, 4 @ drain WB 353 ret lr 354 355/* 356 * dma_map_area(start, size, dir) 357 * - start - kernel virtual start address 358 * - size - size of region 359 * - dir - DMA direction 360 */ 361ENTRY(arm925_dma_map_area) 362 add r1, r1, r0 363 cmp r2, #DMA_TO_DEVICE 364 beq arm925_dma_clean_range 365 bcs arm925_dma_inv_range 366 b arm925_dma_flush_range 367ENDPROC(arm925_dma_map_area) 368 369/* 370 * dma_unmap_area(start, size, dir) 371 * - start - kernel virtual start address 372 * - size - size of region 373 * - dir - DMA direction 374 */ 375ENTRY(arm925_dma_unmap_area) 376 ret lr 377ENDPROC(arm925_dma_unmap_area) 378 379 .globl arm925_flush_kern_cache_louis 380 .equ arm925_flush_kern_cache_louis, arm925_flush_kern_cache_all 381 382 @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S) 383 define_cache_functions arm925 384 385ENTRY(cpu_arm925_dcache_clean_area) 386#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH 3871: mcr p15, 0, r0, c7, c10, 1 @ clean D entry 388 add r0, r0, #CACHE_DLINESIZE 389 subs r1, r1, #CACHE_DLINESIZE 390 bhi 1b 391#endif 392 mcr p15, 0, r0, c7, c10, 4 @ drain WB 393 ret lr 394 395/* =============================== PageTable ============================== */ 396 397/* 398 * cpu_arm925_switch_mm(pgd) 399 * 400 * Set the translation base pointer to be as described by pgd. 401 * 402 * pgd: new page tables 403 */ 404 .align 5 405ENTRY(cpu_arm925_switch_mm) 406#ifdef CONFIG_MMU 407 mov ip, #0 408#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH 409 mcr p15, 0, ip, c7, c6, 0 @ invalidate D cache 410#else 411 /* Flush entries in bothe segments at once, see NOTE1 above */ 412 mov r3, #(CACHE_DENTRIES - 1) << 4 @ 256 entries in segment 4132: mcr p15, 0, r3, c7, c14, 2 @ clean & invalidate D index 414 subs r3, r3, #1 << 4 415 bcs 2b @ entries 255 to 0 416#endif 417 mcr p15, 0, ip, c7, c5, 0 @ invalidate I cache 418 mcr p15, 0, ip, c7, c10, 4 @ drain WB 419 mcr p15, 0, r0, c2, c0, 0 @ load page table pointer 420 mcr p15, 0, ip, c8, c7, 0 @ invalidate I & D TLBs 421#endif 422 ret lr 423 424/* 425 * cpu_arm925_set_pte_ext(ptep, pte, ext) 426 * 427 * Set a PTE and flush it out 428 */ 429 .align 5 430ENTRY(cpu_arm925_set_pte_ext) 431#ifdef CONFIG_MMU 432 armv3_set_pte_ext 433 mov r0, r0 434#ifndef CONFIG_CPU_DCACHE_WRITETHROUGH 435 mcr p15, 0, r0, c7, c10, 1 @ clean D entry 436#endif 437 mcr p15, 0, r0, c7, c10, 4 @ drain WB 438#endif /* CONFIG_MMU */ 439 ret lr 440 441 .type __arm925_setup, #function 442__arm925_setup: 443 mov r0, #0 444 445 /* Transparent on, D-cache clean & flush mode. See NOTE2 above */ 446 orr r0,r0,#1 << 1 @ transparent mode on 447 mcr p15, 0, r0, c15, c1, 0 @ write TI config register 448 449 mov r0, #0 450 mcr p15, 0, r0, c7, c7 @ invalidate I,D caches on v4 451 mcr p15, 0, r0, c7, c10, 4 @ drain write buffer on v4 452#ifdef CONFIG_MMU 453 mcr p15, 0, r0, c8, c7 @ invalidate I,D TLBs on v4 454#endif 455 456#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH 457 mov r0, #4 @ disable write-back on caches explicitly 458 mcr p15, 7, r0, c15, c0, 0 459#endif 460 461 adr r5, arm925_crval 462 ldmia r5, {r5, r6} 463 mrc p15, 0, r0, c1, c0 @ get control register v4 464 bic r0, r0, r5 465 orr r0, r0, r6 466#ifdef CONFIG_CPU_CACHE_ROUND_ROBIN 467 orr r0, r0, #0x4000 @ .1.. .... .... .... 468#endif 469 ret lr 470 .size __arm925_setup, . - __arm925_setup 471 472 /* 473 * R 474 * .RVI ZFRS BLDP WCAM 475 * .011 0001 ..11 1101 476 * 477 */ 478 .type arm925_crval, #object 479arm925_crval: 480 crval clear=0x00007f3f, mmuset=0x0000313d, ucset=0x00001130 481 482 __INITDATA 483 @ define struct processor (see <asm/proc-fns.h> and proc-macros.S) 484 define_processor_functions arm925, dabort=v4t_early_abort, pabort=legacy_pabort 485 486 .section ".rodata" 487 488 string cpu_arch_name, "armv4t" 489 string cpu_elf_name, "v4" 490 string cpu_arm925_name, "ARM925T" 491 492 .align 493 494 .section ".proc.info.init", #alloc 495 496.macro arm925_proc_info name:req, cpu_val:req, cpu_mask:req, cpu_name:req, cache 497 .type __\name\()_proc_info,#object 498__\name\()_proc_info: 499 .long \cpu_val 500 .long \cpu_mask 501 .long PMD_TYPE_SECT | \ 502 PMD_SECT_CACHEABLE | \ 503 PMD_BIT4 | \ 504 PMD_SECT_AP_WRITE | \ 505 PMD_SECT_AP_READ 506 .long PMD_TYPE_SECT | \ 507 PMD_BIT4 | \ 508 PMD_SECT_AP_WRITE | \ 509 PMD_SECT_AP_READ 510 initfn __arm925_setup, __\name\()_proc_info 511 .long cpu_arch_name 512 .long cpu_elf_name 513 .long HWCAP_SWP | HWCAP_HALF | HWCAP_THUMB 514 .long cpu_arm925_name 515 .long arm925_processor_functions 516 .long v4wbi_tlb_fns 517 .long v4wb_user_fns 518 .long arm925_cache_fns 519 .size __\name\()_proc_info, . - __\name\()_proc_info 520.endm 521 522 arm925_proc_info arm925, 0x54029250, 0xfffffff0, cpu_arm925_name 523 arm925_proc_info arm915, 0x54029150, 0xfffffff0, cpu_arm925_name 524