1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * linux/arch/arm/mm/proc-arm922.S: MMU functions for ARM922 4 * 5 * Copyright (C) 1999,2000 ARM Limited 6 * Copyright (C) 2000 Deep Blue Solutions Ltd. 7 * Copyright (C) 2001 Altera Corporation 8 * hacked for non-paged-MM by Hyok S. Choi, 2003. 9 * 10 * These are the low level assembler for performing cache and TLB 11 * functions on the arm922. 12 * 13 * CONFIG_CPU_ARM922_CPU_IDLE -> nohlt 14 */ 15 #include <linux/linkage.h> 16 #include <linux/init.h> 17 #include <linux/pgtable.h> 18 #include <asm/assembler.h> 19 #include <asm/hwcap.h> 20 #include <asm/pgtable-hwdef.h> 21 #include <asm/page.h> 22 #include <asm/ptrace.h> 23 #include "proc-macros.S" 24 25 /* 26 * The size of one data cache line. 27 */ 28 #define CACHE_DLINESIZE 32 29 30 /* 31 * The number of data cache segments. 32 */ 33 #define CACHE_DSEGMENTS 4 34 35 /* 36 * The number of lines in a cache segment. 37 */ 38 #define CACHE_DENTRIES 64 39 40 /* 41 * This is the size at which it becomes more efficient to 42 * clean the whole cache, rather than using the individual 43 * cache line maintenance instructions. (I think this should 44 * be 32768). 45 */ 46 #define CACHE_DLIMIT 8192 47 48 49 .text 50 /* 51 * cpu_arm922_proc_init() 52 */ 53 ENTRY(cpu_arm922_proc_init) 54 ret lr 55 56 /* 57 * cpu_arm922_proc_fin() 58 */ 59 ENTRY(cpu_arm922_proc_fin) 60 mrc p15, 0, r0, c1, c0, 0 @ ctrl register 61 bic r0, r0, #0x1000 @ ...i............ 62 bic r0, r0, #0x000e @ ............wca. 63 mcr p15, 0, r0, c1, c0, 0 @ disable caches 64 ret lr 65 66 /* 67 * cpu_arm922_reset(loc) 68 * 69 * Perform a soft reset of the system. Put the CPU into the 70 * same state as it would be if it had been reset, and branch 71 * to what would be the reset vector. 72 * 73 * loc: location to jump to for soft reset 74 */ 75 .align 5 76 .pushsection .idmap.text, "ax" 77 ENTRY(cpu_arm922_reset) 78 mov ip, #0 79 mcr p15, 0, ip, c7, c7, 0 @ invalidate I,D caches 80 mcr p15, 0, ip, c7, c10, 4 @ drain WB 81 #ifdef CONFIG_MMU 82 mcr p15, 0, ip, c8, c7, 0 @ invalidate I & D TLBs 83 #endif 84 mrc p15, 0, ip, c1, c0, 0 @ ctrl register 85 bic ip, ip, #0x000f @ ............wcam 86 bic ip, ip, #0x1100 @ ...i...s........ 87 mcr p15, 0, ip, c1, c0, 0 @ ctrl register 88 ret r0 89 ENDPROC(cpu_arm922_reset) 90 .popsection 91 92 /* 93 * cpu_arm922_do_idle() 94 */ 95 .align 5 96 ENTRY(cpu_arm922_do_idle) 97 mcr p15, 0, r0, c7, c0, 4 @ Wait for interrupt 98 ret lr 99 100 101 #ifndef CONFIG_CPU_DCACHE_WRITETHROUGH 102 103 /* 104 * flush_icache_all() 105 * 106 * Unconditionally clean and invalidate the entire icache. 107 */ 108 ENTRY(arm922_flush_icache_all) 109 mov r0, #0 110 mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache 111 ret lr 112 ENDPROC(arm922_flush_icache_all) 113 114 /* 115 * flush_user_cache_all() 116 * 117 * Clean and invalidate all cache entries in a particular 118 * address space. 119 */ 120 ENTRY(arm922_flush_user_cache_all) 121 /* FALLTHROUGH */ 122 123 /* 124 * flush_kern_cache_all() 125 * 126 * Clean and invalidate the entire cache. 127 */ 128 ENTRY(arm922_flush_kern_cache_all) 129 mov r2, #VM_EXEC 130 mov ip, #0 131 __flush_whole_cache: 132 mov r1, #(CACHE_DSEGMENTS - 1) << 5 @ 8 segments 133 1: orr r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries 134 2: mcr p15, 0, r3, c7, c14, 2 @ clean+invalidate D index 135 subs r3, r3, #1 << 26 136 bcs 2b @ entries 63 to 0 137 subs r1, r1, #1 << 5 138 bcs 1b @ segments 7 to 0 139 tst r2, #VM_EXEC 140 mcrne p15, 0, ip, c7, c5, 0 @ invalidate I cache 141 mcrne p15, 0, ip, c7, c10, 4 @ drain WB 142 ret lr 143 144 /* 145 * flush_user_cache_range(start, end, flags) 146 * 147 * Clean and invalidate a range of cache entries in the 148 * specified address range. 149 * 150 * - start - start address (inclusive) 151 * - end - end address (exclusive) 152 * - flags - vm_flags describing address space 153 */ 154 ENTRY(arm922_flush_user_cache_range) 155 mov ip, #0 156 sub r3, r1, r0 @ calculate total size 157 cmp r3, #CACHE_DLIMIT 158 bhs __flush_whole_cache 159 160 1: mcr p15, 0, r0, c7, c14, 1 @ clean+invalidate D entry 161 tst r2, #VM_EXEC 162 mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry 163 add r0, r0, #CACHE_DLINESIZE 164 cmp r0, r1 165 blo 1b 166 tst r2, #VM_EXEC 167 mcrne p15, 0, ip, c7, c10, 4 @ drain WB 168 ret lr 169 170 /* 171 * coherent_kern_range(start, end) 172 * 173 * Ensure coherency between the Icache and the Dcache in the 174 * region described by start, end. If you have non-snooping 175 * Harvard caches, you need to implement this function. 176 * 177 * - start - virtual start address 178 * - end - virtual end address 179 */ 180 ENTRY(arm922_coherent_kern_range) 181 /* FALLTHROUGH */ 182 183 /* 184 * coherent_user_range(start, end) 185 * 186 * Ensure coherency between the Icache and the Dcache in the 187 * region described by start, end. If you have non-snooping 188 * Harvard caches, you need to implement this function. 189 * 190 * - start - virtual start address 191 * - end - virtual end address 192 */ 193 ENTRY(arm922_coherent_user_range) 194 bic r0, r0, #CACHE_DLINESIZE - 1 195 1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry 196 mcr p15, 0, r0, c7, c5, 1 @ invalidate I entry 197 add r0, r0, #CACHE_DLINESIZE 198 cmp r0, r1 199 blo 1b 200 mcr p15, 0, r0, c7, c10, 4 @ drain WB 201 mov r0, #0 202 ret lr 203 204 /* 205 * flush_kern_dcache_area(void *addr, size_t size) 206 * 207 * Ensure no D cache aliasing occurs, either with itself or 208 * the I cache 209 * 210 * - addr - kernel address 211 * - size - region size 212 */ 213 ENTRY(arm922_flush_kern_dcache_area) 214 add r1, r0, r1 215 1: mcr p15, 0, r0, c7, c14, 1 @ clean+invalidate D entry 216 add r0, r0, #CACHE_DLINESIZE 217 cmp r0, r1 218 blo 1b 219 mov r0, #0 220 mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache 221 mcr p15, 0, r0, c7, c10, 4 @ drain WB 222 ret lr 223 224 /* 225 * dma_inv_range(start, end) 226 * 227 * Invalidate (discard) the specified virtual address range. 228 * May not write back any entries. If 'start' or 'end' 229 * are not cache line aligned, those lines must be written 230 * back. 231 * 232 * - start - virtual start address 233 * - end - virtual end address 234 * 235 * (same as v4wb) 236 */ 237 arm922_dma_inv_range: 238 tst r0, #CACHE_DLINESIZE - 1 239 bic r0, r0, #CACHE_DLINESIZE - 1 240 mcrne p15, 0, r0, c7, c10, 1 @ clean D entry 241 tst r1, #CACHE_DLINESIZE - 1 242 mcrne p15, 0, r1, c7, c10, 1 @ clean D entry 243 1: mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry 244 add r0, r0, #CACHE_DLINESIZE 245 cmp r0, r1 246 blo 1b 247 mcr p15, 0, r0, c7, c10, 4 @ drain WB 248 ret lr 249 250 /* 251 * dma_clean_range(start, end) 252 * 253 * Clean the specified virtual address range. 254 * 255 * - start - virtual start address 256 * - end - virtual end address 257 * 258 * (same as v4wb) 259 */ 260 arm922_dma_clean_range: 261 bic r0, r0, #CACHE_DLINESIZE - 1 262 1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry 263 add r0, r0, #CACHE_DLINESIZE 264 cmp r0, r1 265 blo 1b 266 mcr p15, 0, r0, c7, c10, 4 @ drain WB 267 ret lr 268 269 /* 270 * dma_flush_range(start, end) 271 * 272 * Clean and invalidate the specified virtual address range. 273 * 274 * - start - virtual start address 275 * - end - virtual end address 276 */ 277 ENTRY(arm922_dma_flush_range) 278 bic r0, r0, #CACHE_DLINESIZE - 1 279 1: mcr p15, 0, r0, c7, c14, 1 @ clean+invalidate D entry 280 add r0, r0, #CACHE_DLINESIZE 281 cmp r0, r1 282 blo 1b 283 mcr p15, 0, r0, c7, c10, 4 @ drain WB 284 ret lr 285 286 /* 287 * dma_map_area(start, size, dir) 288 * - start - kernel virtual start address 289 * - size - size of region 290 * - dir - DMA direction 291 */ 292 ENTRY(arm922_dma_map_area) 293 add r1, r1, r0 294 cmp r2, #DMA_TO_DEVICE 295 beq arm922_dma_clean_range 296 bcs arm922_dma_inv_range 297 b arm922_dma_flush_range 298 ENDPROC(arm922_dma_map_area) 299 300 /* 301 * dma_unmap_area(start, size, dir) 302 * - start - kernel virtual start address 303 * - size - size of region 304 * - dir - DMA direction 305 */ 306 ENTRY(arm922_dma_unmap_area) 307 ret lr 308 ENDPROC(arm922_dma_unmap_area) 309 310 .globl arm922_flush_kern_cache_louis 311 .equ arm922_flush_kern_cache_louis, arm922_flush_kern_cache_all 312 313 @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S) 314 define_cache_functions arm922 315 #endif 316 317 318 ENTRY(cpu_arm922_dcache_clean_area) 319 #ifndef CONFIG_CPU_DCACHE_WRITETHROUGH 320 1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry 321 add r0, r0, #CACHE_DLINESIZE 322 subs r1, r1, #CACHE_DLINESIZE 323 bhi 1b 324 #endif 325 ret lr 326 327 /* =============================== PageTable ============================== */ 328 329 /* 330 * cpu_arm922_switch_mm(pgd) 331 * 332 * Set the translation base pointer to be as described by pgd. 333 * 334 * pgd: new page tables 335 */ 336 .align 5 337 ENTRY(cpu_arm922_switch_mm) 338 #ifdef CONFIG_MMU 339 mov ip, #0 340 #ifdef CONFIG_CPU_DCACHE_WRITETHROUGH 341 mcr p15, 0, ip, c7, c6, 0 @ invalidate D cache 342 #else 343 @ && 'Clean & Invalidate whole DCache' 344 @ && Re-written to use Index Ops. 345 @ && Uses registers r1, r3 and ip 346 347 mov r1, #(CACHE_DSEGMENTS - 1) << 5 @ 4 segments 348 1: orr r3, r1, #(CACHE_DENTRIES - 1) << 26 @ 64 entries 349 2: mcr p15, 0, r3, c7, c14, 2 @ clean & invalidate D index 350 subs r3, r3, #1 << 26 351 bcs 2b @ entries 63 to 0 352 subs r1, r1, #1 << 5 353 bcs 1b @ segments 7 to 0 354 #endif 355 mcr p15, 0, ip, c7, c5, 0 @ invalidate I cache 356 mcr p15, 0, ip, c7, c10, 4 @ drain WB 357 mcr p15, 0, r0, c2, c0, 0 @ load page table pointer 358 mcr p15, 0, ip, c8, c7, 0 @ invalidate I & D TLBs 359 #endif 360 ret lr 361 362 /* 363 * cpu_arm922_set_pte_ext(ptep, pte, ext) 364 * 365 * Set a PTE and flush it out 366 */ 367 .align 5 368 ENTRY(cpu_arm922_set_pte_ext) 369 #ifdef CONFIG_MMU 370 armv3_set_pte_ext 371 mov r0, r0 372 mcr p15, 0, r0, c7, c10, 1 @ clean D entry 373 mcr p15, 0, r0, c7, c10, 4 @ drain WB 374 #endif /* CONFIG_MMU */ 375 ret lr 376 377 .type __arm922_setup, #function 378 __arm922_setup: 379 mov r0, #0 380 mcr p15, 0, r0, c7, c7 @ invalidate I,D caches on v4 381 mcr p15, 0, r0, c7, c10, 4 @ drain write buffer on v4 382 #ifdef CONFIG_MMU 383 mcr p15, 0, r0, c8, c7 @ invalidate I,D TLBs on v4 384 #endif 385 adr r5, arm922_crval 386 ldmia r5, {r5, r6} 387 mrc p15, 0, r0, c1, c0 @ get control register v4 388 bic r0, r0, r5 389 orr r0, r0, r6 390 ret lr 391 .size __arm922_setup, . - __arm922_setup 392 393 /* 394 * R 395 * .RVI ZFRS BLDP WCAM 396 * ..11 0001 ..11 0101 397 * 398 */ 399 .type arm922_crval, #object 400 arm922_crval: 401 crval clear=0x00003f3f, mmuset=0x00003135, ucset=0x00001130 402 403 __INITDATA 404 @ define struct processor (see <asm/proc-fns.h> and proc-macros.S) 405 define_processor_functions arm922, dabort=v4t_early_abort, pabort=legacy_pabort 406 407 .section ".rodata" 408 409 string cpu_arch_name, "armv4t" 410 string cpu_elf_name, "v4" 411 string cpu_arm922_name, "ARM922T" 412 413 .align 414 415 .section ".proc.info.init", "a" 416 417 .type __arm922_proc_info,#object 418 __arm922_proc_info: 419 .long 0x41009220 420 .long 0xff00fff0 421 .long PMD_TYPE_SECT | \ 422 PMD_SECT_BUFFERABLE | \ 423 PMD_SECT_CACHEABLE | \ 424 PMD_BIT4 | \ 425 PMD_SECT_AP_WRITE | \ 426 PMD_SECT_AP_READ 427 .long PMD_TYPE_SECT | \ 428 PMD_BIT4 | \ 429 PMD_SECT_AP_WRITE | \ 430 PMD_SECT_AP_READ 431 initfn __arm922_setup, __arm922_proc_info 432 .long cpu_arch_name 433 .long cpu_elf_name 434 .long HWCAP_SWP | HWCAP_HALF | HWCAP_THUMB 435 .long cpu_arm922_name 436 .long arm922_processor_functions 437 .long v4wbi_tlb_fns 438 .long v4wb_user_fns 439 #ifndef CONFIG_CPU_DCACHE_WRITETHROUGH 440 .long arm922_cache_fns 441 #else 442 .long v4wt_cache_fns 443 #endif 444 .size __arm922_proc_info, . - __arm922_proc_info 445