1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * This only handles 32bit MTRR on 32bit hosts. This is strictly wrong 4 * because MTRRs can span up to 40 bits (36bits on most modern x86) 5 */ 6 7 #include <linux/export.h> 8 #include <linux/init.h> 9 #include <linux/io.h> 10 #include <linux/mm.h> 11 12 #include <asm/processor-flags.h> 13 #include <asm/cpufeature.h> 14 #include <asm/tlbflush.h> 15 #include <asm/mtrr.h> 16 #include <asm/msr.h> 17 #include <asm/memtype.h> 18 19 #include "mtrr.h" 20 21 struct fixed_range_block { 22 int base_msr; /* start address of an MTRR block */ 23 int ranges; /* number of MTRRs in this block */ 24 }; 25 26 static struct fixed_range_block fixed_range_blocks[] = { 27 { MSR_MTRRfix64K_00000, 1 }, /* one 64k MTRR */ 28 { MSR_MTRRfix16K_80000, 2 }, /* two 16k MTRRs */ 29 { MSR_MTRRfix4K_C0000, 8 }, /* eight 4k MTRRs */ 30 {} 31 }; 32 33 static unsigned long smp_changes_mask; 34 static int mtrr_state_set; 35 u64 mtrr_tom2; 36 37 struct mtrr_state_type mtrr_state; 38 EXPORT_SYMBOL_GPL(mtrr_state); 39 40 /* 41 * BIOS is expected to clear MtrrFixDramModEn bit, see for example 42 * "BIOS and Kernel Developer's Guide for the AMD Athlon 64 and AMD 43 * Opteron Processors" (26094 Rev. 3.30 February 2006), section 44 * "13.2.1.2 SYSCFG Register": "The MtrrFixDramModEn bit should be set 45 * to 1 during BIOS initialization of the fixed MTRRs, then cleared to 46 * 0 for operation." 47 */ 48 static inline void k8_check_syscfg_dram_mod_en(void) 49 { 50 u32 lo, hi; 51 52 if (!((boot_cpu_data.x86_vendor == X86_VENDOR_AMD) && 53 (boot_cpu_data.x86 >= 0x0f))) 54 return; 55 56 rdmsr(MSR_AMD64_SYSCFG, lo, hi); 57 if (lo & K8_MTRRFIXRANGE_DRAM_MODIFY) { 58 pr_err(FW_WARN "MTRR: CPU %u: SYSCFG[MtrrFixDramModEn]" 59 " not cleared by BIOS, clearing this bit\n", 60 smp_processor_id()); 61 lo &= ~K8_MTRRFIXRANGE_DRAM_MODIFY; 62 mtrr_wrmsr(MSR_AMD64_SYSCFG, lo, hi); 63 } 64 } 65 66 /* Get the size of contiguous MTRR range */ 67 static u64 get_mtrr_size(u64 mask) 68 { 69 u64 size; 70 71 mask >>= PAGE_SHIFT; 72 mask |= size_or_mask; 73 size = -mask; 74 size <<= PAGE_SHIFT; 75 return size; 76 } 77 78 /* 79 * Check and return the effective type for MTRR-MTRR type overlap. 80 * Returns 1 if the effective type is UNCACHEABLE, else returns 0 81 */ 82 static int check_type_overlap(u8 *prev, u8 *curr) 83 { 84 if (*prev == MTRR_TYPE_UNCACHABLE || *curr == MTRR_TYPE_UNCACHABLE) { 85 *prev = MTRR_TYPE_UNCACHABLE; 86 *curr = MTRR_TYPE_UNCACHABLE; 87 return 1; 88 } 89 90 if ((*prev == MTRR_TYPE_WRBACK && *curr == MTRR_TYPE_WRTHROUGH) || 91 (*prev == MTRR_TYPE_WRTHROUGH && *curr == MTRR_TYPE_WRBACK)) { 92 *prev = MTRR_TYPE_WRTHROUGH; 93 *curr = MTRR_TYPE_WRTHROUGH; 94 } 95 96 if (*prev != *curr) { 97 *prev = MTRR_TYPE_UNCACHABLE; 98 *curr = MTRR_TYPE_UNCACHABLE; 99 return 1; 100 } 101 102 return 0; 103 } 104 105 /** 106 * mtrr_type_lookup_fixed - look up memory type in MTRR fixed entries 107 * 108 * Return the MTRR fixed memory type of 'start'. 109 * 110 * MTRR fixed entries are divided into the following ways: 111 * 0x00000 - 0x7FFFF : This range is divided into eight 64KB sub-ranges 112 * 0x80000 - 0xBFFFF : This range is divided into sixteen 16KB sub-ranges 113 * 0xC0000 - 0xFFFFF : This range is divided into sixty-four 4KB sub-ranges 114 * 115 * Return Values: 116 * MTRR_TYPE_(type) - Matched memory type 117 * MTRR_TYPE_INVALID - Unmatched 118 */ 119 static u8 mtrr_type_lookup_fixed(u64 start, u64 end) 120 { 121 int idx; 122 123 if (start >= 0x100000) 124 return MTRR_TYPE_INVALID; 125 126 /* 0x0 - 0x7FFFF */ 127 if (start < 0x80000) { 128 idx = 0; 129 idx += (start >> 16); 130 return mtrr_state.fixed_ranges[idx]; 131 /* 0x80000 - 0xBFFFF */ 132 } else if (start < 0xC0000) { 133 idx = 1 * 8; 134 idx += ((start - 0x80000) >> 14); 135 return mtrr_state.fixed_ranges[idx]; 136 } 137 138 /* 0xC0000 - 0xFFFFF */ 139 idx = 3 * 8; 140 idx += ((start - 0xC0000) >> 12); 141 return mtrr_state.fixed_ranges[idx]; 142 } 143 144 /** 145 * mtrr_type_lookup_variable - look up memory type in MTRR variable entries 146 * 147 * Return Value: 148 * MTRR_TYPE_(type) - Matched memory type or default memory type (unmatched) 149 * 150 * Output Arguments: 151 * repeat - Set to 1 when [start:end] spanned across MTRR range and type 152 * returned corresponds only to [start:*partial_end]. Caller has 153 * to lookup again for [*partial_end:end]. 154 * 155 * uniform - Set to 1 when an MTRR covers the region uniformly, i.e. the 156 * region is fully covered by a single MTRR entry or the default 157 * type. 158 */ 159 static u8 mtrr_type_lookup_variable(u64 start, u64 end, u64 *partial_end, 160 int *repeat, u8 *uniform) 161 { 162 int i; 163 u64 base, mask; 164 u8 prev_match, curr_match; 165 166 *repeat = 0; 167 *uniform = 1; 168 169 prev_match = MTRR_TYPE_INVALID; 170 for (i = 0; i < num_var_ranges; ++i) { 171 unsigned short start_state, end_state, inclusive; 172 173 if (!(mtrr_state.var_ranges[i].mask_lo & (1 << 11))) 174 continue; 175 176 base = (((u64)mtrr_state.var_ranges[i].base_hi) << 32) + 177 (mtrr_state.var_ranges[i].base_lo & PAGE_MASK); 178 mask = (((u64)mtrr_state.var_ranges[i].mask_hi) << 32) + 179 (mtrr_state.var_ranges[i].mask_lo & PAGE_MASK); 180 181 start_state = ((start & mask) == (base & mask)); 182 end_state = ((end & mask) == (base & mask)); 183 inclusive = ((start < base) && (end > base)); 184 185 if ((start_state != end_state) || inclusive) { 186 /* 187 * We have start:end spanning across an MTRR. 188 * We split the region into either 189 * 190 * - start_state:1 191 * (start:mtrr_end)(mtrr_end:end) 192 * - end_state:1 193 * (start:mtrr_start)(mtrr_start:end) 194 * - inclusive:1 195 * (start:mtrr_start)(mtrr_start:mtrr_end)(mtrr_end:end) 196 * 197 * depending on kind of overlap. 198 * 199 * Return the type of the first region and a pointer 200 * to the start of next region so that caller will be 201 * advised to lookup again after having adjusted start 202 * and end. 203 * 204 * Note: This way we handle overlaps with multiple 205 * entries and the default type properly. 206 */ 207 if (start_state) 208 *partial_end = base + get_mtrr_size(mask); 209 else 210 *partial_end = base; 211 212 if (unlikely(*partial_end <= start)) { 213 WARN_ON(1); 214 *partial_end = start + PAGE_SIZE; 215 } 216 217 end = *partial_end - 1; /* end is inclusive */ 218 *repeat = 1; 219 *uniform = 0; 220 } 221 222 if ((start & mask) != (base & mask)) 223 continue; 224 225 curr_match = mtrr_state.var_ranges[i].base_lo & 0xff; 226 if (prev_match == MTRR_TYPE_INVALID) { 227 prev_match = curr_match; 228 continue; 229 } 230 231 *uniform = 0; 232 if (check_type_overlap(&prev_match, &curr_match)) 233 return curr_match; 234 } 235 236 if (prev_match != MTRR_TYPE_INVALID) 237 return prev_match; 238 239 return mtrr_state.def_type; 240 } 241 242 /** 243 * mtrr_type_lookup - look up memory type in MTRR 244 * 245 * Return Values: 246 * MTRR_TYPE_(type) - The effective MTRR type for the region 247 * MTRR_TYPE_INVALID - MTRR is disabled 248 * 249 * Output Argument: 250 * uniform - Set to 1 when an MTRR covers the region uniformly, i.e. the 251 * region is fully covered by a single MTRR entry or the default 252 * type. 253 */ 254 u8 mtrr_type_lookup(u64 start, u64 end, u8 *uniform) 255 { 256 u8 type, prev_type, is_uniform = 1, dummy; 257 int repeat; 258 u64 partial_end; 259 260 /* Make end inclusive instead of exclusive */ 261 end--; 262 263 if (!mtrr_state_set) 264 return MTRR_TYPE_INVALID; 265 266 if (!(mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED)) 267 return MTRR_TYPE_INVALID; 268 269 /* 270 * Look up the fixed ranges first, which take priority over 271 * the variable ranges. 272 */ 273 if ((start < 0x100000) && 274 (mtrr_state.have_fixed) && 275 (mtrr_state.enabled & MTRR_STATE_MTRR_FIXED_ENABLED)) { 276 is_uniform = 0; 277 type = mtrr_type_lookup_fixed(start, end); 278 goto out; 279 } 280 281 /* 282 * Look up the variable ranges. Look of multiple ranges matching 283 * this address and pick type as per MTRR precedence. 284 */ 285 type = mtrr_type_lookup_variable(start, end, &partial_end, 286 &repeat, &is_uniform); 287 288 /* 289 * Common path is with repeat = 0. 290 * However, we can have cases where [start:end] spans across some 291 * MTRR ranges and/or the default type. Do repeated lookups for 292 * that case here. 293 */ 294 while (repeat) { 295 prev_type = type; 296 start = partial_end; 297 is_uniform = 0; 298 type = mtrr_type_lookup_variable(start, end, &partial_end, 299 &repeat, &dummy); 300 301 if (check_type_overlap(&prev_type, &type)) 302 goto out; 303 } 304 305 if (mtrr_tom2 && (start >= (1ULL<<32)) && (end < mtrr_tom2)) 306 type = MTRR_TYPE_WRBACK; 307 308 out: 309 *uniform = is_uniform; 310 return type; 311 } 312 313 /* Get the MSR pair relating to a var range */ 314 static void 315 get_mtrr_var_range(unsigned int index, struct mtrr_var_range *vr) 316 { 317 rdmsr(MTRRphysBase_MSR(index), vr->base_lo, vr->base_hi); 318 rdmsr(MTRRphysMask_MSR(index), vr->mask_lo, vr->mask_hi); 319 } 320 321 /* Fill the MSR pair relating to a var range */ 322 void fill_mtrr_var_range(unsigned int index, 323 u32 base_lo, u32 base_hi, u32 mask_lo, u32 mask_hi) 324 { 325 struct mtrr_var_range *vr; 326 327 vr = mtrr_state.var_ranges; 328 329 vr[index].base_lo = base_lo; 330 vr[index].base_hi = base_hi; 331 vr[index].mask_lo = mask_lo; 332 vr[index].mask_hi = mask_hi; 333 } 334 335 static void get_fixed_ranges(mtrr_type *frs) 336 { 337 unsigned int *p = (unsigned int *)frs; 338 int i; 339 340 k8_check_syscfg_dram_mod_en(); 341 342 rdmsr(MSR_MTRRfix64K_00000, p[0], p[1]); 343 344 for (i = 0; i < 2; i++) 345 rdmsr(MSR_MTRRfix16K_80000 + i, p[2 + i * 2], p[3 + i * 2]); 346 for (i = 0; i < 8; i++) 347 rdmsr(MSR_MTRRfix4K_C0000 + i, p[6 + i * 2], p[7 + i * 2]); 348 } 349 350 void mtrr_save_fixed_ranges(void *info) 351 { 352 if (boot_cpu_has(X86_FEATURE_MTRR)) 353 get_fixed_ranges(mtrr_state.fixed_ranges); 354 } 355 356 static unsigned __initdata last_fixed_start; 357 static unsigned __initdata last_fixed_end; 358 static mtrr_type __initdata last_fixed_type; 359 360 static void __init print_fixed_last(void) 361 { 362 if (!last_fixed_end) 363 return; 364 365 pr_debug(" %05X-%05X %s\n", last_fixed_start, 366 last_fixed_end - 1, mtrr_attrib_to_str(last_fixed_type)); 367 368 last_fixed_end = 0; 369 } 370 371 static void __init update_fixed_last(unsigned base, unsigned end, 372 mtrr_type type) 373 { 374 last_fixed_start = base; 375 last_fixed_end = end; 376 last_fixed_type = type; 377 } 378 379 static void __init 380 print_fixed(unsigned base, unsigned step, const mtrr_type *types) 381 { 382 unsigned i; 383 384 for (i = 0; i < 8; ++i, ++types, base += step) { 385 if (last_fixed_end == 0) { 386 update_fixed_last(base, base + step, *types); 387 continue; 388 } 389 if (last_fixed_end == base && last_fixed_type == *types) { 390 last_fixed_end = base + step; 391 continue; 392 } 393 /* new segments: gap or different type */ 394 print_fixed_last(); 395 update_fixed_last(base, base + step, *types); 396 } 397 } 398 399 static void prepare_set(void); 400 static void post_set(void); 401 402 static void __init print_mtrr_state(void) 403 { 404 unsigned int i; 405 int high_width; 406 407 pr_debug("MTRR default type: %s\n", 408 mtrr_attrib_to_str(mtrr_state.def_type)); 409 if (mtrr_state.have_fixed) { 410 pr_debug("MTRR fixed ranges %sabled:\n", 411 ((mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED) && 412 (mtrr_state.enabled & MTRR_STATE_MTRR_FIXED_ENABLED)) ? 413 "en" : "dis"); 414 print_fixed(0x00000, 0x10000, mtrr_state.fixed_ranges + 0); 415 for (i = 0; i < 2; ++i) 416 print_fixed(0x80000 + i * 0x20000, 0x04000, 417 mtrr_state.fixed_ranges + (i + 1) * 8); 418 for (i = 0; i < 8; ++i) 419 print_fixed(0xC0000 + i * 0x08000, 0x01000, 420 mtrr_state.fixed_ranges + (i + 3) * 8); 421 422 /* tail */ 423 print_fixed_last(); 424 } 425 pr_debug("MTRR variable ranges %sabled:\n", 426 mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED ? "en" : "dis"); 427 high_width = (__ffs64(size_or_mask) - (32 - PAGE_SHIFT) + 3) / 4; 428 429 for (i = 0; i < num_var_ranges; ++i) { 430 if (mtrr_state.var_ranges[i].mask_lo & (1 << 11)) 431 pr_debug(" %u base %0*X%05X000 mask %0*X%05X000 %s\n", 432 i, 433 high_width, 434 mtrr_state.var_ranges[i].base_hi, 435 mtrr_state.var_ranges[i].base_lo >> 12, 436 high_width, 437 mtrr_state.var_ranges[i].mask_hi, 438 mtrr_state.var_ranges[i].mask_lo >> 12, 439 mtrr_attrib_to_str(mtrr_state.var_ranges[i].base_lo & 0xff)); 440 else 441 pr_debug(" %u disabled\n", i); 442 } 443 if (mtrr_tom2) 444 pr_debug("TOM2: %016llx aka %lldM\n", mtrr_tom2, mtrr_tom2>>20); 445 } 446 447 /* PAT setup for BP. We need to go through sync steps here */ 448 void __init mtrr_bp_pat_init(void) 449 { 450 unsigned long flags; 451 452 local_irq_save(flags); 453 prepare_set(); 454 455 pat_init(); 456 457 post_set(); 458 local_irq_restore(flags); 459 } 460 461 /* Grab all of the MTRR state for this CPU into *state */ 462 bool __init get_mtrr_state(void) 463 { 464 struct mtrr_var_range *vrs; 465 unsigned lo, dummy; 466 unsigned int i; 467 468 vrs = mtrr_state.var_ranges; 469 470 rdmsr(MSR_MTRRcap, lo, dummy); 471 mtrr_state.have_fixed = (lo >> 8) & 1; 472 473 for (i = 0; i < num_var_ranges; i++) 474 get_mtrr_var_range(i, &vrs[i]); 475 if (mtrr_state.have_fixed) 476 get_fixed_ranges(mtrr_state.fixed_ranges); 477 478 rdmsr(MSR_MTRRdefType, lo, dummy); 479 mtrr_state.def_type = (lo & 0xff); 480 mtrr_state.enabled = (lo & 0xc00) >> 10; 481 482 if (amd_special_default_mtrr()) { 483 unsigned low, high; 484 485 /* TOP_MEM2 */ 486 rdmsr(MSR_K8_TOP_MEM2, low, high); 487 mtrr_tom2 = high; 488 mtrr_tom2 <<= 32; 489 mtrr_tom2 |= low; 490 mtrr_tom2 &= 0xffffff800000ULL; 491 } 492 493 print_mtrr_state(); 494 495 mtrr_state_set = 1; 496 497 return !!(mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED); 498 } 499 500 /* Some BIOS's are messed up and don't set all MTRRs the same! */ 501 void __init mtrr_state_warn(void) 502 { 503 unsigned long mask = smp_changes_mask; 504 505 if (!mask) 506 return; 507 if (mask & MTRR_CHANGE_MASK_FIXED) 508 pr_warn("mtrr: your CPUs had inconsistent fixed MTRR settings\n"); 509 if (mask & MTRR_CHANGE_MASK_VARIABLE) 510 pr_warn("mtrr: your CPUs had inconsistent variable MTRR settings\n"); 511 if (mask & MTRR_CHANGE_MASK_DEFTYPE) 512 pr_warn("mtrr: your CPUs had inconsistent MTRRdefType settings\n"); 513 514 pr_info("mtrr: probably your BIOS does not setup all CPUs.\n"); 515 pr_info("mtrr: corrected configuration.\n"); 516 } 517 518 /* 519 * Doesn't attempt to pass an error out to MTRR users 520 * because it's quite complicated in some cases and probably not 521 * worth it because the best error handling is to ignore it. 522 */ 523 void mtrr_wrmsr(unsigned msr, unsigned a, unsigned b) 524 { 525 if (wrmsr_safe(msr, a, b) < 0) { 526 pr_err("MTRR: CPU %u: Writing MSR %x to %x:%x failed\n", 527 smp_processor_id(), msr, a, b); 528 } 529 } 530 531 /** 532 * set_fixed_range - checks & updates a fixed-range MTRR if it 533 * differs from the value it should have 534 * @msr: MSR address of the MTTR which should be checked and updated 535 * @changed: pointer which indicates whether the MTRR needed to be changed 536 * @msrwords: pointer to the MSR values which the MSR should have 537 */ 538 static void set_fixed_range(int msr, bool *changed, unsigned int *msrwords) 539 { 540 unsigned lo, hi; 541 542 rdmsr(msr, lo, hi); 543 544 if (lo != msrwords[0] || hi != msrwords[1]) { 545 mtrr_wrmsr(msr, msrwords[0], msrwords[1]); 546 *changed = true; 547 } 548 } 549 550 /** 551 * generic_get_free_region - Get a free MTRR. 552 * @base: The starting (base) address of the region. 553 * @size: The size (in bytes) of the region. 554 * @replace_reg: mtrr index to be replaced; set to invalid value if none. 555 * 556 * Returns: The index of the region on success, else negative on error. 557 */ 558 int 559 generic_get_free_region(unsigned long base, unsigned long size, int replace_reg) 560 { 561 unsigned long lbase, lsize; 562 mtrr_type ltype; 563 int i, max; 564 565 max = num_var_ranges; 566 if (replace_reg >= 0 && replace_reg < max) 567 return replace_reg; 568 569 for (i = 0; i < max; ++i) { 570 mtrr_if->get(i, &lbase, &lsize, <ype); 571 if (lsize == 0) 572 return i; 573 } 574 575 return -ENOSPC; 576 } 577 578 static void generic_get_mtrr(unsigned int reg, unsigned long *base, 579 unsigned long *size, mtrr_type *type) 580 { 581 u32 mask_lo, mask_hi, base_lo, base_hi; 582 unsigned int hi; 583 u64 tmp, mask; 584 585 /* 586 * get_mtrr doesn't need to update mtrr_state, also it could be called 587 * from any cpu, so try to print it out directly. 588 */ 589 get_cpu(); 590 591 rdmsr(MTRRphysMask_MSR(reg), mask_lo, mask_hi); 592 593 if ((mask_lo & 0x800) == 0) { 594 /* Invalid (i.e. free) range */ 595 *base = 0; 596 *size = 0; 597 *type = 0; 598 goto out_put_cpu; 599 } 600 601 rdmsr(MTRRphysBase_MSR(reg), base_lo, base_hi); 602 603 /* Work out the shifted address mask: */ 604 tmp = (u64)mask_hi << (32 - PAGE_SHIFT) | mask_lo >> PAGE_SHIFT; 605 mask = size_or_mask | tmp; 606 607 /* Expand tmp with high bits to all 1s: */ 608 hi = fls64(tmp); 609 if (hi > 0) { 610 tmp |= ~((1ULL<<(hi - 1)) - 1); 611 612 if (tmp != mask) { 613 pr_warn("mtrr: your BIOS has configured an incorrect mask, fixing it.\n"); 614 add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK); 615 mask = tmp; 616 } 617 } 618 619 /* 620 * This works correctly if size is a power of two, i.e. a 621 * contiguous range: 622 */ 623 *size = -mask; 624 *base = (u64)base_hi << (32 - PAGE_SHIFT) | base_lo >> PAGE_SHIFT; 625 *type = base_lo & 0xff; 626 627 out_put_cpu: 628 put_cpu(); 629 } 630 631 /** 632 * set_fixed_ranges - checks & updates the fixed-range MTRRs if they 633 * differ from the saved set 634 * @frs: pointer to fixed-range MTRR values, saved by get_fixed_ranges() 635 */ 636 static int set_fixed_ranges(mtrr_type *frs) 637 { 638 unsigned long long *saved = (unsigned long long *)frs; 639 bool changed = false; 640 int block = -1, range; 641 642 k8_check_syscfg_dram_mod_en(); 643 644 while (fixed_range_blocks[++block].ranges) { 645 for (range = 0; range < fixed_range_blocks[block].ranges; range++) 646 set_fixed_range(fixed_range_blocks[block].base_msr + range, 647 &changed, (unsigned int *)saved++); 648 } 649 650 return changed; 651 } 652 653 /* 654 * Set the MSR pair relating to a var range. 655 * Returns true if changes are made. 656 */ 657 static bool set_mtrr_var_ranges(unsigned int index, struct mtrr_var_range *vr) 658 { 659 unsigned int lo, hi; 660 bool changed = false; 661 662 rdmsr(MTRRphysBase_MSR(index), lo, hi); 663 if ((vr->base_lo & 0xfffff0ffUL) != (lo & 0xfffff0ffUL) 664 || (vr->base_hi & (size_and_mask >> (32 - PAGE_SHIFT))) != 665 (hi & (size_and_mask >> (32 - PAGE_SHIFT)))) { 666 667 mtrr_wrmsr(MTRRphysBase_MSR(index), vr->base_lo, vr->base_hi); 668 changed = true; 669 } 670 671 rdmsr(MTRRphysMask_MSR(index), lo, hi); 672 673 if ((vr->mask_lo & 0xfffff800UL) != (lo & 0xfffff800UL) 674 || (vr->mask_hi & (size_and_mask >> (32 - PAGE_SHIFT))) != 675 (hi & (size_and_mask >> (32 - PAGE_SHIFT)))) { 676 mtrr_wrmsr(MTRRphysMask_MSR(index), vr->mask_lo, vr->mask_hi); 677 changed = true; 678 } 679 return changed; 680 } 681 682 static u32 deftype_lo, deftype_hi; 683 684 /** 685 * set_mtrr_state - Set the MTRR state for this CPU. 686 * 687 * NOTE: The CPU must already be in a safe state for MTRR changes. 688 * RETURNS: 0 if no changes made, else a mask indicating what was changed. 689 */ 690 static unsigned long set_mtrr_state(void) 691 { 692 unsigned long change_mask = 0; 693 unsigned int i; 694 695 for (i = 0; i < num_var_ranges; i++) { 696 if (set_mtrr_var_ranges(i, &mtrr_state.var_ranges[i])) 697 change_mask |= MTRR_CHANGE_MASK_VARIABLE; 698 } 699 700 if (mtrr_state.have_fixed && set_fixed_ranges(mtrr_state.fixed_ranges)) 701 change_mask |= MTRR_CHANGE_MASK_FIXED; 702 703 /* 704 * Set_mtrr_restore restores the old value of MTRRdefType, 705 * so to set it we fiddle with the saved value: 706 */ 707 if ((deftype_lo & 0xff) != mtrr_state.def_type 708 || ((deftype_lo & 0xc00) >> 10) != mtrr_state.enabled) { 709 710 deftype_lo = (deftype_lo & ~0xcff) | mtrr_state.def_type | 711 (mtrr_state.enabled << 10); 712 change_mask |= MTRR_CHANGE_MASK_DEFTYPE; 713 } 714 715 return change_mask; 716 } 717 718 719 static unsigned long cr4; 720 static DEFINE_RAW_SPINLOCK(set_atomicity_lock); 721 722 /* 723 * Since we are disabling the cache don't allow any interrupts, 724 * they would run extremely slow and would only increase the pain. 725 * 726 * The caller must ensure that local interrupts are disabled and 727 * are reenabled after post_set() has been called. 728 */ 729 static void prepare_set(void) __acquires(set_atomicity_lock) 730 { 731 unsigned long cr0; 732 733 /* 734 * Note that this is not ideal 735 * since the cache is only flushed/disabled for this CPU while the 736 * MTRRs are changed, but changing this requires more invasive 737 * changes to the way the kernel boots 738 */ 739 740 raw_spin_lock(&set_atomicity_lock); 741 742 /* Enter the no-fill (CD=1, NW=0) cache mode and flush caches. */ 743 cr0 = read_cr0() | X86_CR0_CD; 744 write_cr0(cr0); 745 746 /* 747 * Cache flushing is the most time-consuming step when programming 748 * the MTRRs. Fortunately, as per the Intel Software Development 749 * Manual, we can skip it if the processor supports cache self- 750 * snooping. 751 */ 752 if (!static_cpu_has(X86_FEATURE_SELFSNOOP)) 753 wbinvd(); 754 755 /* Save value of CR4 and clear Page Global Enable (bit 7) */ 756 if (boot_cpu_has(X86_FEATURE_PGE)) { 757 cr4 = __read_cr4(); 758 __write_cr4(cr4 & ~X86_CR4_PGE); 759 } 760 761 /* Flush all TLBs via a mov %cr3, %reg; mov %reg, %cr3 */ 762 count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL); 763 flush_tlb_local(); 764 765 /* Save MTRR state */ 766 rdmsr(MSR_MTRRdefType, deftype_lo, deftype_hi); 767 768 /* Disable MTRRs, and set the default type to uncached */ 769 mtrr_wrmsr(MSR_MTRRdefType, deftype_lo & ~0xcff, deftype_hi); 770 771 /* Again, only flush caches if we have to. */ 772 if (!static_cpu_has(X86_FEATURE_SELFSNOOP)) 773 wbinvd(); 774 } 775 776 static void post_set(void) __releases(set_atomicity_lock) 777 { 778 /* Flush TLBs (no need to flush caches - they are disabled) */ 779 count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL); 780 flush_tlb_local(); 781 782 /* Intel (P6) standard MTRRs */ 783 mtrr_wrmsr(MSR_MTRRdefType, deftype_lo, deftype_hi); 784 785 /* Enable caches */ 786 write_cr0(read_cr0() & ~X86_CR0_CD); 787 788 /* Restore value of CR4 */ 789 if (boot_cpu_has(X86_FEATURE_PGE)) 790 __write_cr4(cr4); 791 raw_spin_unlock(&set_atomicity_lock); 792 } 793 794 static void generic_set_all(void) 795 { 796 unsigned long mask, count; 797 unsigned long flags; 798 799 local_irq_save(flags); 800 prepare_set(); 801 802 /* Actually set the state */ 803 mask = set_mtrr_state(); 804 805 /* also set PAT */ 806 pat_init(); 807 808 post_set(); 809 local_irq_restore(flags); 810 811 /* Use the atomic bitops to update the global mask */ 812 for (count = 0; count < sizeof(mask) * 8; ++count) { 813 if (mask & 0x01) 814 set_bit(count, &smp_changes_mask); 815 mask >>= 1; 816 } 817 818 } 819 820 /** 821 * generic_set_mtrr - set variable MTRR register on the local CPU. 822 * 823 * @reg: The register to set. 824 * @base: The base address of the region. 825 * @size: The size of the region. If this is 0 the region is disabled. 826 * @type: The type of the region. 827 * 828 * Returns nothing. 829 */ 830 static void generic_set_mtrr(unsigned int reg, unsigned long base, 831 unsigned long size, mtrr_type type) 832 { 833 unsigned long flags; 834 struct mtrr_var_range *vr; 835 836 vr = &mtrr_state.var_ranges[reg]; 837 838 local_irq_save(flags); 839 prepare_set(); 840 841 if (size == 0) { 842 /* 843 * The invalid bit is kept in the mask, so we simply 844 * clear the relevant mask register to disable a range. 845 */ 846 mtrr_wrmsr(MTRRphysMask_MSR(reg), 0, 0); 847 memset(vr, 0, sizeof(struct mtrr_var_range)); 848 } else { 849 vr->base_lo = base << PAGE_SHIFT | type; 850 vr->base_hi = (base & size_and_mask) >> (32 - PAGE_SHIFT); 851 vr->mask_lo = -size << PAGE_SHIFT | 0x800; 852 vr->mask_hi = (-size & size_and_mask) >> (32 - PAGE_SHIFT); 853 854 mtrr_wrmsr(MTRRphysBase_MSR(reg), vr->base_lo, vr->base_hi); 855 mtrr_wrmsr(MTRRphysMask_MSR(reg), vr->mask_lo, vr->mask_hi); 856 } 857 858 post_set(); 859 local_irq_restore(flags); 860 } 861 862 int generic_validate_add_page(unsigned long base, unsigned long size, 863 unsigned int type) 864 { 865 unsigned long lbase, last; 866 867 /* 868 * For Intel PPro stepping <= 7 869 * must be 4 MiB aligned and not touch 0x70000000 -> 0x7003FFFF 870 */ 871 if (is_cpu(INTEL) && boot_cpu_data.x86 == 6 && 872 boot_cpu_data.x86_model == 1 && 873 boot_cpu_data.x86_stepping <= 7) { 874 if (base & ((1 << (22 - PAGE_SHIFT)) - 1)) { 875 pr_warn("mtrr: base(0x%lx000) is not 4 MiB aligned\n", base); 876 return -EINVAL; 877 } 878 if (!(base + size < 0x70000 || base > 0x7003F) && 879 (type == MTRR_TYPE_WRCOMB 880 || type == MTRR_TYPE_WRBACK)) { 881 pr_warn("mtrr: writable mtrr between 0x70000000 and 0x7003FFFF may hang the CPU.\n"); 882 return -EINVAL; 883 } 884 } 885 886 /* 887 * Check upper bits of base and last are equal and lower bits are 0 888 * for base and 1 for last 889 */ 890 last = base + size - 1; 891 for (lbase = base; !(lbase & 1) && (last & 1); 892 lbase = lbase >> 1, last = last >> 1) 893 ; 894 if (lbase != last) { 895 pr_warn("mtrr: base(0x%lx000) is not aligned on a size(0x%lx000) boundary\n", base, size); 896 return -EINVAL; 897 } 898 return 0; 899 } 900 901 static int generic_have_wrcomb(void) 902 { 903 unsigned long config, dummy; 904 rdmsr(MSR_MTRRcap, config, dummy); 905 return config & (1 << 10); 906 } 907 908 int positive_have_wrcomb(void) 909 { 910 return 1; 911 } 912 913 /* 914 * Generic structure... 915 */ 916 const struct mtrr_ops generic_mtrr_ops = { 917 .use_intel_if = 1, 918 .set_all = generic_set_all, 919 .get = generic_get_mtrr, 920 .get_free_region = generic_get_free_region, 921 .set = generic_set_mtrr, 922 .validate_add_page = generic_validate_add_page, 923 .have_wrcomb = generic_have_wrcomb, 924 }; 925