1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * ARC Cache Management 4 * 5 * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com) 6 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) 7 */ 8 9 #include <linux/module.h> 10 #include <linux/mm.h> 11 #include <linux/sched.h> 12 #include <linux/cache.h> 13 #include <linux/mmu_context.h> 14 #include <linux/syscalls.h> 15 #include <linux/uaccess.h> 16 #include <linux/pagemap.h> 17 #include <asm/cacheflush.h> 18 #include <asm/cachectl.h> 19 #include <asm/setup.h> 20 21 #ifdef CONFIG_ISA_ARCV2 22 #define USE_RGN_FLSH 1 23 #endif 24 25 static int l2_line_sz; 26 static int ioc_exists; 27 int slc_enable = 1, ioc_enable = 1; 28 unsigned long perip_base = ARC_UNCACHED_ADDR_SPACE; /* legacy value for boot */ 29 unsigned long perip_end = 0xFFFFFFFF; /* legacy value */ 30 31 void (*_cache_line_loop_ic_fn)(phys_addr_t paddr, unsigned long vaddr, 32 unsigned long sz, const int op, const int full_page); 33 34 void (*__dma_cache_wback_inv)(phys_addr_t start, unsigned long sz); 35 void (*__dma_cache_inv)(phys_addr_t start, unsigned long sz); 36 void (*__dma_cache_wback)(phys_addr_t start, unsigned long sz); 37 38 char *arc_cache_mumbojumbo(int c, char *buf, int len) 39 { 40 int n = 0; 41 struct cpuinfo_arc_cache *p; 42 43 #define PR_CACHE(p, cfg, str) \ 44 if (!(p)->line_len) \ 45 n += scnprintf(buf + n, len - n, str"\t\t: N/A\n"); \ 46 else \ 47 n += scnprintf(buf + n, len - n, \ 48 str"\t\t: %uK, %dway/set, %uB Line, %s%s%s\n", \ 49 (p)->sz_k, (p)->assoc, (p)->line_len, \ 50 (p)->vipt ? "VIPT" : "PIPT", \ 51 (p)->alias ? " aliasing" : "", \ 52 IS_USED_CFG(cfg)); 53 54 PR_CACHE(&cpuinfo_arc700[c].icache, CONFIG_ARC_HAS_ICACHE, "I-Cache"); 55 PR_CACHE(&cpuinfo_arc700[c].dcache, CONFIG_ARC_HAS_DCACHE, "D-Cache"); 56 57 p = &cpuinfo_arc700[c].slc; 58 if (p->line_len) 59 n += scnprintf(buf + n, len - n, 60 "SLC\t\t: %uK, %uB Line%s\n", 61 p->sz_k, p->line_len, IS_USED_RUN(slc_enable)); 62 63 n += scnprintf(buf + n, len - n, "Peripherals\t: %#lx%s%s\n", 64 perip_base, 65 IS_AVAIL3(ioc_exists, ioc_enable, ", IO-Coherency (per-device) ")); 66 67 return buf; 68 } 69 70 /* 71 * Read the Cache Build Confuration Registers, Decode them and save into 72 * the cpuinfo structure for later use. 73 * No Validation done here, simply read/convert the BCRs 74 */ 75 static void read_decode_cache_bcr_arcv2(int cpu) 76 { 77 struct cpuinfo_arc_cache *p_slc = &cpuinfo_arc700[cpu].slc; 78 struct bcr_generic sbcr; 79 80 struct bcr_slc_cfg { 81 #ifdef CONFIG_CPU_BIG_ENDIAN 82 unsigned int pad:24, way:2, lsz:2, sz:4; 83 #else 84 unsigned int sz:4, lsz:2, way:2, pad:24; 85 #endif 86 } slc_cfg; 87 88 struct bcr_clust_cfg { 89 #ifdef CONFIG_CPU_BIG_ENDIAN 90 unsigned int pad:7, c:1, num_entries:8, num_cores:8, ver:8; 91 #else 92 unsigned int ver:8, num_cores:8, num_entries:8, c:1, pad:7; 93 #endif 94 } cbcr; 95 96 struct bcr_volatile { 97 #ifdef CONFIG_CPU_BIG_ENDIAN 98 unsigned int start:4, limit:4, pad:22, order:1, disable:1; 99 #else 100 unsigned int disable:1, order:1, pad:22, limit:4, start:4; 101 #endif 102 } vol; 103 104 105 READ_BCR(ARC_REG_SLC_BCR, sbcr); 106 if (sbcr.ver) { 107 READ_BCR(ARC_REG_SLC_CFG, slc_cfg); 108 p_slc->sz_k = 128 << slc_cfg.sz; 109 l2_line_sz = p_slc->line_len = (slc_cfg.lsz == 0) ? 128 : 64; 110 } 111 112 READ_BCR(ARC_REG_CLUSTER_BCR, cbcr); 113 if (cbcr.c) { 114 ioc_exists = 1; 115 116 /* 117 * As for today we don't support both IOC and ZONE_HIGHMEM enabled 118 * simultaneously. This happens because as of today IOC aperture covers 119 * only ZONE_NORMAL (low mem) and any dma transactions outside this 120 * region won't be HW coherent. 121 * If we want to use both IOC and ZONE_HIGHMEM we can use 122 * bounce_buffer to handle dma transactions to HIGHMEM. 123 * Also it is possible to modify dma_direct cache ops or increase IOC 124 * aperture size if we are planning to use HIGHMEM without PAE. 125 */ 126 if (IS_ENABLED(CONFIG_HIGHMEM) || is_pae40_enabled()) 127 ioc_enable = 0; 128 } else { 129 ioc_enable = 0; 130 } 131 132 /* HS 2.0 didn't have AUX_VOL */ 133 if (cpuinfo_arc700[cpu].core.family > 0x51) { 134 READ_BCR(AUX_VOL, vol); 135 perip_base = vol.start << 28; 136 /* HS 3.0 has limit and strict-ordering fields */ 137 if (cpuinfo_arc700[cpu].core.family > 0x52) 138 perip_end = (vol.limit << 28) - 1; 139 } 140 } 141 142 void read_decode_cache_bcr(void) 143 { 144 struct cpuinfo_arc_cache *p_ic, *p_dc; 145 unsigned int cpu = smp_processor_id(); 146 struct bcr_cache { 147 #ifdef CONFIG_CPU_BIG_ENDIAN 148 unsigned int pad:12, line_len:4, sz:4, config:4, ver:8; 149 #else 150 unsigned int ver:8, config:4, sz:4, line_len:4, pad:12; 151 #endif 152 } ibcr, dbcr; 153 154 p_ic = &cpuinfo_arc700[cpu].icache; 155 READ_BCR(ARC_REG_IC_BCR, ibcr); 156 157 if (!ibcr.ver) 158 goto dc_chk; 159 160 if (ibcr.ver <= 3) { 161 BUG_ON(ibcr.config != 3); 162 p_ic->assoc = 2; /* Fixed to 2w set assoc */ 163 } else if (ibcr.ver >= 4) { 164 p_ic->assoc = 1 << ibcr.config; /* 1,2,4,8 */ 165 } 166 167 p_ic->line_len = 8 << ibcr.line_len; 168 p_ic->sz_k = 1 << (ibcr.sz - 1); 169 p_ic->vipt = 1; 170 p_ic->alias = p_ic->sz_k/p_ic->assoc/TO_KB(PAGE_SIZE) > 1; 171 172 dc_chk: 173 p_dc = &cpuinfo_arc700[cpu].dcache; 174 READ_BCR(ARC_REG_DC_BCR, dbcr); 175 176 if (!dbcr.ver) 177 goto slc_chk; 178 179 if (dbcr.ver <= 3) { 180 BUG_ON(dbcr.config != 2); 181 p_dc->assoc = 4; /* Fixed to 4w set assoc */ 182 p_dc->vipt = 1; 183 p_dc->alias = p_dc->sz_k/p_dc->assoc/TO_KB(PAGE_SIZE) > 1; 184 } else if (dbcr.ver >= 4) { 185 p_dc->assoc = 1 << dbcr.config; /* 1,2,4,8 */ 186 p_dc->vipt = 0; 187 p_dc->alias = 0; /* PIPT so can't VIPT alias */ 188 } 189 190 p_dc->line_len = 16 << dbcr.line_len; 191 p_dc->sz_k = 1 << (dbcr.sz - 1); 192 193 slc_chk: 194 if (is_isa_arcv2()) 195 read_decode_cache_bcr_arcv2(cpu); 196 } 197 198 /* 199 * Line Operation on {I,D}-Cache 200 */ 201 202 #define OP_INV 0x1 203 #define OP_FLUSH 0x2 204 #define OP_FLUSH_N_INV 0x3 205 #define OP_INV_IC 0x4 206 207 /* 208 * Cache Flush programming model 209 * 210 * ARC700 MMUv3 I$ and D$ are both VIPT and can potentially alias. 211 * Programming model requires both paddr and vaddr irrespecive of aliasing 212 * considerations: 213 * - vaddr in {I,D}C_IV?L 214 * - paddr in {I,D}C_PTAG 215 * 216 * In HS38x (MMUv4), D$ is PIPT, I$ is VIPT and can still alias. 217 * Programming model is different for aliasing vs. non-aliasing I$ 218 * - D$ / Non-aliasing I$: only paddr in {I,D}C_IV?L 219 * - Aliasing I$: same as ARC700 above (so MMUv3 routine used for MMUv4 I$) 220 * 221 * - If PAE40 is enabled, independent of aliasing considerations, the higher 222 * bits needs to be written into PTAG_HI 223 */ 224 225 static inline 226 void __cache_line_loop_v3(phys_addr_t paddr, unsigned long vaddr, 227 unsigned long sz, const int op, const int full_page) 228 { 229 unsigned int aux_cmd, aux_tag; 230 int num_lines; 231 232 if (op == OP_INV_IC) { 233 aux_cmd = ARC_REG_IC_IVIL; 234 aux_tag = ARC_REG_IC_PTAG; 235 } else { 236 aux_cmd = op & OP_INV ? ARC_REG_DC_IVDL : ARC_REG_DC_FLDL; 237 aux_tag = ARC_REG_DC_PTAG; 238 } 239 240 /* Ensure we properly floor/ceil the non-line aligned/sized requests 241 * and have @paddr - aligned to cache line and integral @num_lines. 242 * This however can be avoided for page sized since: 243 * -@paddr will be cache-line aligned already (being page aligned) 244 * -@sz will be integral multiple of line size (being page sized). 245 */ 246 if (!full_page) { 247 sz += paddr & ~CACHE_LINE_MASK; 248 paddr &= CACHE_LINE_MASK; 249 vaddr &= CACHE_LINE_MASK; 250 } 251 num_lines = DIV_ROUND_UP(sz, L1_CACHE_BYTES); 252 253 /* 254 * MMUv3, cache ops require paddr in PTAG reg 255 * if V-P const for loop, PTAG can be written once outside loop 256 */ 257 if (full_page) 258 write_aux_reg(aux_tag, paddr); 259 260 /* 261 * This is technically for MMU v4, using the MMU v3 programming model 262 * Special work for HS38 aliasing I-cache configuration with PAE40 263 * - upper 8 bits of paddr need to be written into PTAG_HI 264 * - (and needs to be written before the lower 32 bits) 265 * Note that PTAG_HI is hoisted outside the line loop 266 */ 267 if (is_pae40_enabled() && op == OP_INV_IC) 268 write_aux_reg(ARC_REG_IC_PTAG_HI, (u64)paddr >> 32); 269 270 while (num_lines-- > 0) { 271 if (!full_page) { 272 write_aux_reg(aux_tag, paddr); 273 paddr += L1_CACHE_BYTES; 274 } 275 276 write_aux_reg(aux_cmd, vaddr); 277 vaddr += L1_CACHE_BYTES; 278 } 279 } 280 281 #ifndef USE_RGN_FLSH 282 283 /* 284 */ 285 static inline 286 void __cache_line_loop_v4(phys_addr_t paddr, unsigned long vaddr, 287 unsigned long sz, const int op, const int full_page) 288 { 289 unsigned int aux_cmd; 290 int num_lines; 291 292 if (op == OP_INV_IC) { 293 aux_cmd = ARC_REG_IC_IVIL; 294 } else { 295 /* d$ cmd: INV (discard or wback-n-discard) OR FLUSH (wback) */ 296 aux_cmd = op & OP_INV ? ARC_REG_DC_IVDL : ARC_REG_DC_FLDL; 297 } 298 299 /* Ensure we properly floor/ceil the non-line aligned/sized requests 300 * and have @paddr - aligned to cache line and integral @num_lines. 301 * This however can be avoided for page sized since: 302 * -@paddr will be cache-line aligned already (being page aligned) 303 * -@sz will be integral multiple of line size (being page sized). 304 */ 305 if (!full_page) { 306 sz += paddr & ~CACHE_LINE_MASK; 307 paddr &= CACHE_LINE_MASK; 308 } 309 310 num_lines = DIV_ROUND_UP(sz, L1_CACHE_BYTES); 311 312 /* 313 * For HS38 PAE40 configuration 314 * - upper 8 bits of paddr need to be written into PTAG_HI 315 * - (and needs to be written before the lower 32 bits) 316 */ 317 if (is_pae40_enabled()) { 318 if (op == OP_INV_IC) 319 /* 320 * Non aliasing I-cache in HS38, 321 * aliasing I-cache handled in __cache_line_loop_v3() 322 */ 323 write_aux_reg(ARC_REG_IC_PTAG_HI, (u64)paddr >> 32); 324 else 325 write_aux_reg(ARC_REG_DC_PTAG_HI, (u64)paddr >> 32); 326 } 327 328 while (num_lines-- > 0) { 329 write_aux_reg(aux_cmd, paddr); 330 paddr += L1_CACHE_BYTES; 331 } 332 } 333 334 #else 335 336 /* 337 * optimized flush operation which takes a region as opposed to iterating per line 338 */ 339 static inline 340 void __cache_line_loop_v4(phys_addr_t paddr, unsigned long vaddr, 341 unsigned long sz, const int op, const int full_page) 342 { 343 unsigned int s, e; 344 345 /* Only for Non aliasing I-cache in HS38 */ 346 if (op == OP_INV_IC) { 347 s = ARC_REG_IC_IVIR; 348 e = ARC_REG_IC_ENDR; 349 } else { 350 s = ARC_REG_DC_STARTR; 351 e = ARC_REG_DC_ENDR; 352 } 353 354 if (!full_page) { 355 /* for any leading gap between @paddr and start of cache line */ 356 sz += paddr & ~CACHE_LINE_MASK; 357 paddr &= CACHE_LINE_MASK; 358 359 /* 360 * account for any trailing gap to end of cache line 361 * this is equivalent to DIV_ROUND_UP() in line ops above 362 */ 363 sz += L1_CACHE_BYTES - 1; 364 } 365 366 if (is_pae40_enabled()) { 367 /* TBD: check if crossing 4TB boundary */ 368 if (op == OP_INV_IC) 369 write_aux_reg(ARC_REG_IC_PTAG_HI, (u64)paddr >> 32); 370 else 371 write_aux_reg(ARC_REG_DC_PTAG_HI, (u64)paddr >> 32); 372 } 373 374 /* ENDR needs to be set ahead of START */ 375 write_aux_reg(e, paddr + sz); /* ENDR is exclusive */ 376 write_aux_reg(s, paddr); 377 378 /* caller waits on DC_CTRL.FS */ 379 } 380 381 #endif 382 383 #ifdef CONFIG_ARC_MMU_V3 384 #define __cache_line_loop __cache_line_loop_v3 385 #else 386 #define __cache_line_loop __cache_line_loop_v4 387 #endif 388 389 #ifdef CONFIG_ARC_HAS_DCACHE 390 391 /*************************************************************** 392 * Machine specific helpers for Entire D-Cache or Per Line ops 393 */ 394 395 #ifndef USE_RGN_FLSH 396 /* 397 * this version avoids extra read/write of DC_CTRL for flush or invalid ops 398 * in the non region flush regime (such as for ARCompact) 399 */ 400 static inline void __before_dc_op(const int op) 401 { 402 if (op == OP_FLUSH_N_INV) { 403 /* Dcache provides 2 cmd: FLUSH or INV 404 * INV inturn has sub-modes: DISCARD or FLUSH-BEFORE 405 * flush-n-inv is achieved by INV cmd but with IM=1 406 * So toggle INV sub-mode depending on op request and default 407 */ 408 const unsigned int ctl = ARC_REG_DC_CTRL; 409 write_aux_reg(ctl, read_aux_reg(ctl) | DC_CTRL_INV_MODE_FLUSH); 410 } 411 } 412 413 #else 414 415 static inline void __before_dc_op(const int op) 416 { 417 const unsigned int ctl = ARC_REG_DC_CTRL; 418 unsigned int val = read_aux_reg(ctl); 419 420 if (op == OP_FLUSH_N_INV) { 421 val |= DC_CTRL_INV_MODE_FLUSH; 422 } 423 424 if (op != OP_INV_IC) { 425 /* 426 * Flush / Invalidate is provided by DC_CTRL.RNG_OP 0 or 1 427 * combined Flush-n-invalidate uses DC_CTRL.IM = 1 set above 428 */ 429 val &= ~DC_CTRL_RGN_OP_MSK; 430 if (op & OP_INV) 431 val |= DC_CTRL_RGN_OP_INV; 432 } 433 write_aux_reg(ctl, val); 434 } 435 436 #endif 437 438 439 static inline void __after_dc_op(const int op) 440 { 441 if (op & OP_FLUSH) { 442 const unsigned int ctl = ARC_REG_DC_CTRL; 443 unsigned int reg; 444 445 /* flush / flush-n-inv both wait */ 446 while ((reg = read_aux_reg(ctl)) & DC_CTRL_FLUSH_STATUS) 447 ; 448 449 /* Switch back to default Invalidate mode */ 450 if (op == OP_FLUSH_N_INV) 451 write_aux_reg(ctl, reg & ~DC_CTRL_INV_MODE_FLUSH); 452 } 453 } 454 455 /* 456 * Operation on Entire D-Cache 457 * @op = {OP_INV, OP_FLUSH, OP_FLUSH_N_INV} 458 * Note that constant propagation ensures all the checks are gone 459 * in generated code 460 */ 461 static inline void __dc_entire_op(const int op) 462 { 463 int aux; 464 465 __before_dc_op(op); 466 467 if (op & OP_INV) /* Inv or flush-n-inv use same cmd reg */ 468 aux = ARC_REG_DC_IVDC; 469 else 470 aux = ARC_REG_DC_FLSH; 471 472 write_aux_reg(aux, 0x1); 473 474 __after_dc_op(op); 475 } 476 477 static inline void __dc_disable(void) 478 { 479 const int r = ARC_REG_DC_CTRL; 480 481 __dc_entire_op(OP_FLUSH_N_INV); 482 write_aux_reg(r, read_aux_reg(r) | DC_CTRL_DIS); 483 } 484 485 static void __dc_enable(void) 486 { 487 const int r = ARC_REG_DC_CTRL; 488 489 write_aux_reg(r, read_aux_reg(r) & ~DC_CTRL_DIS); 490 } 491 492 /* For kernel mappings cache operation: index is same as paddr */ 493 #define __dc_line_op_k(p, sz, op) __dc_line_op(p, p, sz, op) 494 495 /* 496 * D-Cache Line ops: Per Line INV (discard or wback+discard) or FLUSH (wback) 497 */ 498 static inline void __dc_line_op(phys_addr_t paddr, unsigned long vaddr, 499 unsigned long sz, const int op) 500 { 501 const int full_page = __builtin_constant_p(sz) && sz == PAGE_SIZE; 502 unsigned long flags; 503 504 local_irq_save(flags); 505 506 __before_dc_op(op); 507 508 __cache_line_loop(paddr, vaddr, sz, op, full_page); 509 510 __after_dc_op(op); 511 512 local_irq_restore(flags); 513 } 514 515 #else 516 517 #define __dc_entire_op(op) 518 #define __dc_disable() 519 #define __dc_enable() 520 #define __dc_line_op(paddr, vaddr, sz, op) 521 #define __dc_line_op_k(paddr, sz, op) 522 523 #endif /* CONFIG_ARC_HAS_DCACHE */ 524 525 #ifdef CONFIG_ARC_HAS_ICACHE 526 527 static inline void __ic_entire_inv(void) 528 { 529 write_aux_reg(ARC_REG_IC_IVIC, 1); 530 read_aux_reg(ARC_REG_IC_CTRL); /* blocks */ 531 } 532 533 static inline void 534 __ic_line_inv_vaddr_local(phys_addr_t paddr, unsigned long vaddr, 535 unsigned long sz) 536 { 537 const int full_page = __builtin_constant_p(sz) && sz == PAGE_SIZE; 538 unsigned long flags; 539 540 local_irq_save(flags); 541 (*_cache_line_loop_ic_fn)(paddr, vaddr, sz, OP_INV_IC, full_page); 542 local_irq_restore(flags); 543 } 544 545 #ifndef CONFIG_SMP 546 547 #define __ic_line_inv_vaddr(p, v, s) __ic_line_inv_vaddr_local(p, v, s) 548 549 #else 550 551 struct ic_inv_args { 552 phys_addr_t paddr, vaddr; 553 int sz; 554 }; 555 556 static void __ic_line_inv_vaddr_helper(void *info) 557 { 558 struct ic_inv_args *ic_inv = info; 559 560 __ic_line_inv_vaddr_local(ic_inv->paddr, ic_inv->vaddr, ic_inv->sz); 561 } 562 563 static void __ic_line_inv_vaddr(phys_addr_t paddr, unsigned long vaddr, 564 unsigned long sz) 565 { 566 struct ic_inv_args ic_inv = { 567 .paddr = paddr, 568 .vaddr = vaddr, 569 .sz = sz 570 }; 571 572 on_each_cpu(__ic_line_inv_vaddr_helper, &ic_inv, 1); 573 } 574 575 #endif /* CONFIG_SMP */ 576 577 #else /* !CONFIG_ARC_HAS_ICACHE */ 578 579 #define __ic_entire_inv() 580 #define __ic_line_inv_vaddr(pstart, vstart, sz) 581 582 #endif /* CONFIG_ARC_HAS_ICACHE */ 583 584 noinline void slc_op_rgn(phys_addr_t paddr, unsigned long sz, const int op) 585 { 586 #ifdef CONFIG_ISA_ARCV2 587 /* 588 * SLC is shared between all cores and concurrent aux operations from 589 * multiple cores need to be serialized using a spinlock 590 * A concurrent operation can be silently ignored and/or the old/new 591 * operation can remain incomplete forever (lockup in SLC_CTRL_BUSY loop 592 * below) 593 */ 594 static DEFINE_SPINLOCK(lock); 595 unsigned long flags; 596 unsigned int ctrl; 597 phys_addr_t end; 598 599 spin_lock_irqsave(&lock, flags); 600 601 /* 602 * The Region Flush operation is specified by CTRL.RGN_OP[11..9] 603 * - b'000 (default) is Flush, 604 * - b'001 is Invalidate if CTRL.IM == 0 605 * - b'001 is Flush-n-Invalidate if CTRL.IM == 1 606 */ 607 ctrl = read_aux_reg(ARC_REG_SLC_CTRL); 608 609 /* Don't rely on default value of IM bit */ 610 if (!(op & OP_FLUSH)) /* i.e. OP_INV */ 611 ctrl &= ~SLC_CTRL_IM; /* clear IM: Disable flush before Inv */ 612 else 613 ctrl |= SLC_CTRL_IM; 614 615 if (op & OP_INV) 616 ctrl |= SLC_CTRL_RGN_OP_INV; /* Inv or flush-n-inv */ 617 else 618 ctrl &= ~SLC_CTRL_RGN_OP_INV; 619 620 write_aux_reg(ARC_REG_SLC_CTRL, ctrl); 621 622 /* 623 * Lower bits are ignored, no need to clip 624 * END needs to be setup before START (latter triggers the operation) 625 * END can't be same as START, so add (l2_line_sz - 1) to sz 626 */ 627 end = paddr + sz + l2_line_sz - 1; 628 if (is_pae40_enabled()) 629 write_aux_reg(ARC_REG_SLC_RGN_END1, upper_32_bits(end)); 630 631 write_aux_reg(ARC_REG_SLC_RGN_END, lower_32_bits(end)); 632 633 if (is_pae40_enabled()) 634 write_aux_reg(ARC_REG_SLC_RGN_START1, upper_32_bits(paddr)); 635 636 write_aux_reg(ARC_REG_SLC_RGN_START, lower_32_bits(paddr)); 637 638 /* Make sure "busy" bit reports correct stataus, see STAR 9001165532 */ 639 read_aux_reg(ARC_REG_SLC_CTRL); 640 641 while (read_aux_reg(ARC_REG_SLC_CTRL) & SLC_CTRL_BUSY); 642 643 spin_unlock_irqrestore(&lock, flags); 644 #endif 645 } 646 647 noinline void slc_op_line(phys_addr_t paddr, unsigned long sz, const int op) 648 { 649 #ifdef CONFIG_ISA_ARCV2 650 /* 651 * SLC is shared between all cores and concurrent aux operations from 652 * multiple cores need to be serialized using a spinlock 653 * A concurrent operation can be silently ignored and/or the old/new 654 * operation can remain incomplete forever (lockup in SLC_CTRL_BUSY loop 655 * below) 656 */ 657 static DEFINE_SPINLOCK(lock); 658 659 const unsigned long SLC_LINE_MASK = ~(l2_line_sz - 1); 660 unsigned int ctrl, cmd; 661 unsigned long flags; 662 int num_lines; 663 664 spin_lock_irqsave(&lock, flags); 665 666 ctrl = read_aux_reg(ARC_REG_SLC_CTRL); 667 668 /* Don't rely on default value of IM bit */ 669 if (!(op & OP_FLUSH)) /* i.e. OP_INV */ 670 ctrl &= ~SLC_CTRL_IM; /* clear IM: Disable flush before Inv */ 671 else 672 ctrl |= SLC_CTRL_IM; 673 674 write_aux_reg(ARC_REG_SLC_CTRL, ctrl); 675 676 cmd = op & OP_INV ? ARC_AUX_SLC_IVDL : ARC_AUX_SLC_FLDL; 677 678 sz += paddr & ~SLC_LINE_MASK; 679 paddr &= SLC_LINE_MASK; 680 681 num_lines = DIV_ROUND_UP(sz, l2_line_sz); 682 683 while (num_lines-- > 0) { 684 write_aux_reg(cmd, paddr); 685 paddr += l2_line_sz; 686 } 687 688 /* Make sure "busy" bit reports correct stataus, see STAR 9001165532 */ 689 read_aux_reg(ARC_REG_SLC_CTRL); 690 691 while (read_aux_reg(ARC_REG_SLC_CTRL) & SLC_CTRL_BUSY); 692 693 spin_unlock_irqrestore(&lock, flags); 694 #endif 695 } 696 697 #define slc_op(paddr, sz, op) slc_op_rgn(paddr, sz, op) 698 699 noinline static void slc_entire_op(const int op) 700 { 701 unsigned int ctrl, r = ARC_REG_SLC_CTRL; 702 703 ctrl = read_aux_reg(r); 704 705 if (!(op & OP_FLUSH)) /* i.e. OP_INV */ 706 ctrl &= ~SLC_CTRL_IM; /* clear IM: Disable flush before Inv */ 707 else 708 ctrl |= SLC_CTRL_IM; 709 710 write_aux_reg(r, ctrl); 711 712 if (op & OP_INV) /* Inv or flush-n-inv use same cmd reg */ 713 write_aux_reg(ARC_REG_SLC_INVALIDATE, 0x1); 714 else 715 write_aux_reg(ARC_REG_SLC_FLUSH, 0x1); 716 717 /* Make sure "busy" bit reports correct stataus, see STAR 9001165532 */ 718 read_aux_reg(r); 719 720 /* Important to wait for flush to complete */ 721 while (read_aux_reg(r) & SLC_CTRL_BUSY); 722 } 723 724 static inline void arc_slc_disable(void) 725 { 726 const int r = ARC_REG_SLC_CTRL; 727 728 slc_entire_op(OP_FLUSH_N_INV); 729 write_aux_reg(r, read_aux_reg(r) | SLC_CTRL_DIS); 730 } 731 732 static inline void arc_slc_enable(void) 733 { 734 const int r = ARC_REG_SLC_CTRL; 735 736 write_aux_reg(r, read_aux_reg(r) & ~SLC_CTRL_DIS); 737 } 738 739 /*********************************************************** 740 * Exported APIs 741 */ 742 743 /* 744 * Handle cache congruency of kernel and userspace mappings of page when kernel 745 * writes-to/reads-from 746 * 747 * The idea is to defer flushing of kernel mapping after a WRITE, possible if: 748 * -dcache is NOT aliasing, hence any U/K-mappings of page are congruent 749 * -U-mapping doesn't exist yet for page (finalised in update_mmu_cache) 750 * -In SMP, if hardware caches are coherent 751 * 752 * There's a corollary case, where kernel READs from a userspace mapped page. 753 * If the U-mapping is not congruent to to K-mapping, former needs flushing. 754 */ 755 void flush_dcache_page(struct page *page) 756 { 757 struct address_space *mapping; 758 759 if (!cache_is_vipt_aliasing()) { 760 clear_bit(PG_dc_clean, &page->flags); 761 return; 762 } 763 764 /* don't handle anon pages here */ 765 mapping = page_mapping_file(page); 766 if (!mapping) 767 return; 768 769 /* 770 * pagecache page, file not yet mapped to userspace 771 * Make a note that K-mapping is dirty 772 */ 773 if (!mapping_mapped(mapping)) { 774 clear_bit(PG_dc_clean, &page->flags); 775 } else if (page_mapcount(page)) { 776 777 /* kernel reading from page with U-mapping */ 778 phys_addr_t paddr = (unsigned long)page_address(page); 779 unsigned long vaddr = page->index << PAGE_SHIFT; 780 781 if (addr_not_cache_congruent(paddr, vaddr)) 782 __flush_dcache_page(paddr, vaddr); 783 } 784 } 785 EXPORT_SYMBOL(flush_dcache_page); 786 787 /* 788 * DMA ops for systems with L1 cache only 789 * Make memory coherent with L1 cache by flushing/invalidating L1 lines 790 */ 791 static void __dma_cache_wback_inv_l1(phys_addr_t start, unsigned long sz) 792 { 793 __dc_line_op_k(start, sz, OP_FLUSH_N_INV); 794 } 795 796 static void __dma_cache_inv_l1(phys_addr_t start, unsigned long sz) 797 { 798 __dc_line_op_k(start, sz, OP_INV); 799 } 800 801 static void __dma_cache_wback_l1(phys_addr_t start, unsigned long sz) 802 { 803 __dc_line_op_k(start, sz, OP_FLUSH); 804 } 805 806 /* 807 * DMA ops for systems with both L1 and L2 caches, but without IOC 808 * Both L1 and L2 lines need to be explicitly flushed/invalidated 809 */ 810 static void __dma_cache_wback_inv_slc(phys_addr_t start, unsigned long sz) 811 { 812 __dc_line_op_k(start, sz, OP_FLUSH_N_INV); 813 slc_op(start, sz, OP_FLUSH_N_INV); 814 } 815 816 static void __dma_cache_inv_slc(phys_addr_t start, unsigned long sz) 817 { 818 __dc_line_op_k(start, sz, OP_INV); 819 slc_op(start, sz, OP_INV); 820 } 821 822 static void __dma_cache_wback_slc(phys_addr_t start, unsigned long sz) 823 { 824 __dc_line_op_k(start, sz, OP_FLUSH); 825 slc_op(start, sz, OP_FLUSH); 826 } 827 828 /* 829 * Exported DMA API 830 */ 831 void dma_cache_wback_inv(phys_addr_t start, unsigned long sz) 832 { 833 __dma_cache_wback_inv(start, sz); 834 } 835 EXPORT_SYMBOL(dma_cache_wback_inv); 836 837 void dma_cache_inv(phys_addr_t start, unsigned long sz) 838 { 839 __dma_cache_inv(start, sz); 840 } 841 EXPORT_SYMBOL(dma_cache_inv); 842 843 void dma_cache_wback(phys_addr_t start, unsigned long sz) 844 { 845 __dma_cache_wback(start, sz); 846 } 847 EXPORT_SYMBOL(dma_cache_wback); 848 849 /* 850 * This is API for making I/D Caches consistent when modifying 851 * kernel code (loadable modules, kprobes, kgdb...) 852 * This is called on insmod, with kernel virtual address for CODE of 853 * the module. ARC cache maintenance ops require PHY address thus we 854 * need to convert vmalloc addr to PHY addr 855 */ 856 void flush_icache_range(unsigned long kstart, unsigned long kend) 857 { 858 unsigned int tot_sz; 859 860 WARN(kstart < TASK_SIZE, "%s() can't handle user vaddr", __func__); 861 862 /* Shortcut for bigger flush ranges. 863 * Here we don't care if this was kernel virtual or phy addr 864 */ 865 tot_sz = kend - kstart; 866 if (tot_sz > PAGE_SIZE) { 867 flush_cache_all(); 868 return; 869 } 870 871 /* Case: Kernel Phy addr (0x8000_0000 onwards) */ 872 if (likely(kstart > PAGE_OFFSET)) { 873 /* 874 * The 2nd arg despite being paddr will be used to index icache 875 * This is OK since no alternate virtual mappings will exist 876 * given the callers for this case: kprobe/kgdb in built-in 877 * kernel code only. 878 */ 879 __sync_icache_dcache(kstart, kstart, kend - kstart); 880 return; 881 } 882 883 /* 884 * Case: Kernel Vaddr (0x7000_0000 to 0x7fff_ffff) 885 * (1) ARC Cache Maintenance ops only take Phy addr, hence special 886 * handling of kernel vaddr. 887 * 888 * (2) Despite @tot_sz being < PAGE_SIZE (bigger cases handled already), 889 * it still needs to handle a 2 page scenario, where the range 890 * straddles across 2 virtual pages and hence need for loop 891 */ 892 while (tot_sz > 0) { 893 unsigned int off, sz; 894 unsigned long phy, pfn; 895 896 off = kstart % PAGE_SIZE; 897 pfn = vmalloc_to_pfn((void *)kstart); 898 phy = (pfn << PAGE_SHIFT) + off; 899 sz = min_t(unsigned int, tot_sz, PAGE_SIZE - off); 900 __sync_icache_dcache(phy, kstart, sz); 901 kstart += sz; 902 tot_sz -= sz; 903 } 904 } 905 EXPORT_SYMBOL(flush_icache_range); 906 907 /* 908 * General purpose helper to make I and D cache lines consistent. 909 * @paddr is phy addr of region 910 * @vaddr is typically user vaddr (breakpoint) or kernel vaddr (vmalloc) 911 * However in one instance, when called by kprobe (for a breakpt in 912 * builtin kernel code) @vaddr will be paddr only, meaning CDU operation will 913 * use a paddr to index the cache (despite VIPT). This is fine since since a 914 * builtin kernel page will not have any virtual mappings. 915 * kprobe on loadable module will be kernel vaddr. 916 */ 917 void __sync_icache_dcache(phys_addr_t paddr, unsigned long vaddr, int len) 918 { 919 __dc_line_op(paddr, vaddr, len, OP_FLUSH_N_INV); 920 __ic_line_inv_vaddr(paddr, vaddr, len); 921 } 922 923 /* wrapper to compile time eliminate alignment checks in flush loop */ 924 void __inv_icache_page(phys_addr_t paddr, unsigned long vaddr) 925 { 926 __ic_line_inv_vaddr(paddr, vaddr, PAGE_SIZE); 927 } 928 929 /* 930 * wrapper to clearout kernel or userspace mappings of a page 931 * For kernel mappings @vaddr == @paddr 932 */ 933 void __flush_dcache_page(phys_addr_t paddr, unsigned long vaddr) 934 { 935 __dc_line_op(paddr, vaddr & PAGE_MASK, PAGE_SIZE, OP_FLUSH_N_INV); 936 } 937 938 noinline void flush_cache_all(void) 939 { 940 unsigned long flags; 941 942 local_irq_save(flags); 943 944 __ic_entire_inv(); 945 __dc_entire_op(OP_FLUSH_N_INV); 946 947 local_irq_restore(flags); 948 949 } 950 951 #ifdef CONFIG_ARC_CACHE_VIPT_ALIASING 952 953 void flush_cache_mm(struct mm_struct *mm) 954 { 955 flush_cache_all(); 956 } 957 958 void flush_cache_page(struct vm_area_struct *vma, unsigned long u_vaddr, 959 unsigned long pfn) 960 { 961 phys_addr_t paddr = pfn << PAGE_SHIFT; 962 963 u_vaddr &= PAGE_MASK; 964 965 __flush_dcache_page(paddr, u_vaddr); 966 967 if (vma->vm_flags & VM_EXEC) 968 __inv_icache_page(paddr, u_vaddr); 969 } 970 971 void flush_cache_range(struct vm_area_struct *vma, unsigned long start, 972 unsigned long end) 973 { 974 flush_cache_all(); 975 } 976 977 void flush_anon_page(struct vm_area_struct *vma, struct page *page, 978 unsigned long u_vaddr) 979 { 980 /* TBD: do we really need to clear the kernel mapping */ 981 __flush_dcache_page((phys_addr_t)page_address(page), u_vaddr); 982 __flush_dcache_page((phys_addr_t)page_address(page), 983 (phys_addr_t)page_address(page)); 984 985 } 986 987 #endif 988 989 void copy_user_highpage(struct page *to, struct page *from, 990 unsigned long u_vaddr, struct vm_area_struct *vma) 991 { 992 void *kfrom = kmap_atomic(from); 993 void *kto = kmap_atomic(to); 994 int clean_src_k_mappings = 0; 995 996 /* 997 * If SRC page was already mapped in userspace AND it's U-mapping is 998 * not congruent with K-mapping, sync former to physical page so that 999 * K-mapping in memcpy below, sees the right data 1000 * 1001 * Note that while @u_vaddr refers to DST page's userspace vaddr, it is 1002 * equally valid for SRC page as well 1003 * 1004 * For !VIPT cache, all of this gets compiled out as 1005 * addr_not_cache_congruent() is 0 1006 */ 1007 if (page_mapcount(from) && addr_not_cache_congruent(kfrom, u_vaddr)) { 1008 __flush_dcache_page((unsigned long)kfrom, u_vaddr); 1009 clean_src_k_mappings = 1; 1010 } 1011 1012 copy_page(kto, kfrom); 1013 1014 /* 1015 * Mark DST page K-mapping as dirty for a later finalization by 1016 * update_mmu_cache(). Although the finalization could have been done 1017 * here as well (given that both vaddr/paddr are available). 1018 * But update_mmu_cache() already has code to do that for other 1019 * non copied user pages (e.g. read faults which wire in pagecache page 1020 * directly). 1021 */ 1022 clear_bit(PG_dc_clean, &to->flags); 1023 1024 /* 1025 * if SRC was already usermapped and non-congruent to kernel mapping 1026 * sync the kernel mapping back to physical page 1027 */ 1028 if (clean_src_k_mappings) { 1029 __flush_dcache_page((unsigned long)kfrom, (unsigned long)kfrom); 1030 set_bit(PG_dc_clean, &from->flags); 1031 } else { 1032 clear_bit(PG_dc_clean, &from->flags); 1033 } 1034 1035 kunmap_atomic(kto); 1036 kunmap_atomic(kfrom); 1037 } 1038 1039 void clear_user_page(void *to, unsigned long u_vaddr, struct page *page) 1040 { 1041 clear_page(to); 1042 clear_bit(PG_dc_clean, &page->flags); 1043 } 1044 EXPORT_SYMBOL(clear_user_page); 1045 1046 /********************************************************************** 1047 * Explicit Cache flush request from user space via syscall 1048 * Needed for JITs which generate code on the fly 1049 */ 1050 SYSCALL_DEFINE3(cacheflush, uint32_t, start, uint32_t, sz, uint32_t, flags) 1051 { 1052 /* TBD: optimize this */ 1053 flush_cache_all(); 1054 return 0; 1055 } 1056 1057 /* 1058 * IO-Coherency (IOC) setup rules: 1059 * 1060 * 1. Needs to be at system level, so only once by Master core 1061 * Non-Masters need not be accessing caches at that time 1062 * - They are either HALT_ON_RESET and kick started much later or 1063 * - if run on reset, need to ensure that arc_platform_smp_wait_to_boot() 1064 * doesn't perturb caches or coherency unit 1065 * 1066 * 2. caches (L1 and SLC) need to be purged (flush+inv) before setting up IOC, 1067 * otherwise any straggler data might behave strangely post IOC enabling 1068 * 1069 * 3. All Caches need to be disabled when setting up IOC to elide any in-flight 1070 * Coherency transactions 1071 */ 1072 noinline void __init arc_ioc_setup(void) 1073 { 1074 unsigned int ioc_base, mem_sz; 1075 1076 /* 1077 * If IOC was already enabled (due to bootloader) it technically needs to 1078 * be reconfigured with aperture base,size corresponding to Linux memory map 1079 * which will certainly be different than uboot's. But disabling and 1080 * reenabling IOC when DMA might be potentially active is tricky business. 1081 * To avoid random memory issues later, just panic here and ask user to 1082 * upgrade bootloader to one which doesn't enable IOC 1083 */ 1084 if (read_aux_reg(ARC_REG_IO_COH_ENABLE) & ARC_IO_COH_ENABLE_BIT) 1085 panic("IOC already enabled, please upgrade bootloader!\n"); 1086 1087 if (!ioc_enable) 1088 return; 1089 1090 /* Flush + invalidate + disable L1 dcache */ 1091 __dc_disable(); 1092 1093 /* Flush + invalidate SLC */ 1094 if (read_aux_reg(ARC_REG_SLC_BCR)) 1095 slc_entire_op(OP_FLUSH_N_INV); 1096 1097 /* 1098 * currently IOC Aperture covers entire DDR 1099 * TBD: fix for PGU + 1GB of low mem 1100 * TBD: fix for PAE 1101 */ 1102 mem_sz = arc_get_mem_sz(); 1103 1104 if (!is_power_of_2(mem_sz) || mem_sz < 4096) 1105 panic("IOC Aperture size must be power of 2 larger than 4KB"); 1106 1107 /* 1108 * IOC Aperture size decoded as 2 ^ (SIZE + 2) KB, 1109 * so setting 0x11 implies 512MB, 0x12 implies 1GB... 1110 */ 1111 write_aux_reg(ARC_REG_IO_COH_AP0_SIZE, order_base_2(mem_sz >> 10) - 2); 1112 1113 /* for now assume kernel base is start of IOC aperture */ 1114 ioc_base = CONFIG_LINUX_RAM_BASE; 1115 1116 if (ioc_base % mem_sz != 0) 1117 panic("IOC Aperture start must be aligned to the size of the aperture"); 1118 1119 write_aux_reg(ARC_REG_IO_COH_AP0_BASE, ioc_base >> 12); 1120 write_aux_reg(ARC_REG_IO_COH_PARTIAL, ARC_IO_COH_PARTIAL_BIT); 1121 write_aux_reg(ARC_REG_IO_COH_ENABLE, ARC_IO_COH_ENABLE_BIT); 1122 1123 /* Re-enable L1 dcache */ 1124 __dc_enable(); 1125 } 1126 1127 /* 1128 * Cache related boot time checks/setups only needed on master CPU: 1129 * - Geometry checks (kernel build and hardware agree: e.g. L1_CACHE_BYTES) 1130 * Assume SMP only, so all cores will have same cache config. A check on 1131 * one core suffices for all 1132 * - IOC setup / dma callbacks only need to be done once 1133 */ 1134 void __init arc_cache_init_master(void) 1135 { 1136 unsigned int __maybe_unused cpu = smp_processor_id(); 1137 1138 if (IS_ENABLED(CONFIG_ARC_HAS_ICACHE)) { 1139 struct cpuinfo_arc_cache *ic = &cpuinfo_arc700[cpu].icache; 1140 1141 if (!ic->line_len) 1142 panic("cache support enabled but non-existent cache\n"); 1143 1144 if (ic->line_len != L1_CACHE_BYTES) 1145 panic("ICache line [%d] != kernel Config [%d]", 1146 ic->line_len, L1_CACHE_BYTES); 1147 1148 /* 1149 * In MMU v4 (HS38x) the aliasing icache config uses IVIL/PTAG 1150 * pair to provide vaddr/paddr respectively, just as in MMU v3 1151 */ 1152 if (is_isa_arcv2() && ic->alias) 1153 _cache_line_loop_ic_fn = __cache_line_loop_v3; 1154 else 1155 _cache_line_loop_ic_fn = __cache_line_loop; 1156 } 1157 1158 if (IS_ENABLED(CONFIG_ARC_HAS_DCACHE)) { 1159 struct cpuinfo_arc_cache *dc = &cpuinfo_arc700[cpu].dcache; 1160 1161 if (!dc->line_len) 1162 panic("cache support enabled but non-existent cache\n"); 1163 1164 if (dc->line_len != L1_CACHE_BYTES) 1165 panic("DCache line [%d] != kernel Config [%d]", 1166 dc->line_len, L1_CACHE_BYTES); 1167 1168 /* check for D-Cache aliasing on ARCompact: ARCv2 has PIPT */ 1169 if (is_isa_arcompact()) { 1170 int handled = IS_ENABLED(CONFIG_ARC_CACHE_VIPT_ALIASING); 1171 int num_colors = dc->sz_k/dc->assoc/TO_KB(PAGE_SIZE); 1172 1173 if (dc->alias) { 1174 if (!handled) 1175 panic("Enable CONFIG_ARC_CACHE_VIPT_ALIASING\n"); 1176 if (CACHE_COLORS_NUM != num_colors) 1177 panic("CACHE_COLORS_NUM not optimized for config\n"); 1178 } else if (!dc->alias && handled) { 1179 panic("Disable CONFIG_ARC_CACHE_VIPT_ALIASING\n"); 1180 } 1181 } 1182 } 1183 1184 /* 1185 * Check that SMP_CACHE_BYTES (and hence ARCH_DMA_MINALIGN) is larger 1186 * or equal to any cache line length. 1187 */ 1188 BUILD_BUG_ON_MSG(L1_CACHE_BYTES > SMP_CACHE_BYTES, 1189 "SMP_CACHE_BYTES must be >= any cache line length"); 1190 if (is_isa_arcv2() && (l2_line_sz > SMP_CACHE_BYTES)) 1191 panic("L2 Cache line [%d] > kernel Config [%d]\n", 1192 l2_line_sz, SMP_CACHE_BYTES); 1193 1194 /* Note that SLC disable not formally supported till HS 3.0 */ 1195 if (is_isa_arcv2() && l2_line_sz && !slc_enable) 1196 arc_slc_disable(); 1197 1198 if (is_isa_arcv2() && ioc_exists) 1199 arc_ioc_setup(); 1200 1201 if (is_isa_arcv2() && l2_line_sz && slc_enable) { 1202 __dma_cache_wback_inv = __dma_cache_wback_inv_slc; 1203 __dma_cache_inv = __dma_cache_inv_slc; 1204 __dma_cache_wback = __dma_cache_wback_slc; 1205 } else { 1206 __dma_cache_wback_inv = __dma_cache_wback_inv_l1; 1207 __dma_cache_inv = __dma_cache_inv_l1; 1208 __dma_cache_wback = __dma_cache_wback_l1; 1209 } 1210 /* 1211 * In case of IOC (say IOC+SLC case), pointers above could still be set 1212 * but end up not being relevant as the first function in chain is not 1213 * called at all for devices using coherent DMA. 1214 * arch_sync_dma_for_cpu() -> dma_cache_*() -> __dma_cache_*() 1215 */ 1216 } 1217 1218 void __ref arc_cache_init(void) 1219 { 1220 unsigned int __maybe_unused cpu = smp_processor_id(); 1221 char str[256]; 1222 1223 pr_info("%s", arc_cache_mumbojumbo(0, str, sizeof(str))); 1224 1225 if (!cpu) 1226 arc_cache_init_master(); 1227 1228 /* 1229 * In PAE regime, TLB and cache maintenance ops take wider addresses 1230 * And even if PAE is not enabled in kernel, the upper 32-bits still need 1231 * to be zeroed to keep the ops sane. 1232 * As an optimization for more common !PAE enabled case, zero them out 1233 * once at init, rather than checking/setting to 0 for every runtime op 1234 */ 1235 if (is_isa_arcv2() && pae40_exist_but_not_enab()) { 1236 1237 if (IS_ENABLED(CONFIG_ARC_HAS_ICACHE)) 1238 write_aux_reg(ARC_REG_IC_PTAG_HI, 0); 1239 1240 if (IS_ENABLED(CONFIG_ARC_HAS_DCACHE)) 1241 write_aux_reg(ARC_REG_DC_PTAG_HI, 0); 1242 1243 if (l2_line_sz) { 1244 write_aux_reg(ARC_REG_SLC_RGN_END1, 0); 1245 write_aux_reg(ARC_REG_SLC_RGN_START1, 0); 1246 } 1247 } 1248 } 1249