1 /* 2 * MTRR (Memory Type Range Register) cleanup 3 * 4 * Copyright (C) 2009 Yinghai Lu 5 * 6 * This library is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Library General Public 8 * License as published by the Free Software Foundation; either 9 * version 2 of the License, or (at your option) any later version. 10 * 11 * This library is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Library General Public License for more details. 15 * 16 * You should have received a copy of the GNU Library General Public 17 * License along with this library; if not, write to the Free 18 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 19 */ 20 #include <linux/init.h> 21 #include <linux/pci.h> 22 #include <linux/smp.h> 23 #include <linux/cpu.h> 24 #include <linux/mutex.h> 25 #include <linux/uaccess.h> 26 #include <linux/kvm_para.h> 27 #include <linux/range.h> 28 29 #include <asm/processor.h> 30 #include <asm/e820/api.h> 31 #include <asm/mtrr.h> 32 #include <asm/msr.h> 33 34 #include "mtrr.h" 35 36 struct var_mtrr_range_state { 37 unsigned long base_pfn; 38 unsigned long size_pfn; 39 mtrr_type type; 40 }; 41 42 struct var_mtrr_state { 43 unsigned long range_startk; 44 unsigned long range_sizek; 45 unsigned long chunk_sizek; 46 unsigned long gran_sizek; 47 unsigned int reg; 48 }; 49 50 /* Should be related to MTRR_VAR_RANGES nums */ 51 #define RANGE_NUM 256 52 53 static struct range __initdata range[RANGE_NUM]; 54 static int __initdata nr_range; 55 56 static struct var_mtrr_range_state __initdata range_state[RANGE_NUM]; 57 58 static int __initdata debug_print; 59 #define Dprintk(x...) do { if (debug_print) pr_debug(x); } while (0) 60 61 #define BIOS_BUG_MSG \ 62 "WARNING: BIOS bug: VAR MTRR %d contains strange UC entry under 1M, check with your system vendor!\n" 63 64 static int __init 65 x86_get_mtrr_mem_range(struct range *range, int nr_range, 66 unsigned long extra_remove_base, 67 unsigned long extra_remove_size) 68 { 69 unsigned long base, size; 70 mtrr_type type; 71 int i; 72 73 for (i = 0; i < num_var_ranges; i++) { 74 type = range_state[i].type; 75 if (type != MTRR_TYPE_WRBACK) 76 continue; 77 base = range_state[i].base_pfn; 78 size = range_state[i].size_pfn; 79 nr_range = add_range_with_merge(range, RANGE_NUM, nr_range, 80 base, base + size); 81 } 82 if (debug_print) { 83 pr_debug("After WB checking\n"); 84 for (i = 0; i < nr_range; i++) 85 pr_debug("MTRR MAP PFN: %016llx - %016llx\n", 86 range[i].start, range[i].end); 87 } 88 89 /* Take out UC ranges: */ 90 for (i = 0; i < num_var_ranges; i++) { 91 type = range_state[i].type; 92 if (type != MTRR_TYPE_UNCACHABLE && 93 type != MTRR_TYPE_WRPROT) 94 continue; 95 size = range_state[i].size_pfn; 96 if (!size) 97 continue; 98 base = range_state[i].base_pfn; 99 if (base < (1<<(20-PAGE_SHIFT)) && mtrr_state.have_fixed && 100 (mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED) && 101 (mtrr_state.enabled & MTRR_STATE_MTRR_FIXED_ENABLED)) { 102 /* Var MTRR contains UC entry below 1M? Skip it: */ 103 pr_warn(BIOS_BUG_MSG, i); 104 if (base + size <= (1<<(20-PAGE_SHIFT))) 105 continue; 106 size -= (1<<(20-PAGE_SHIFT)) - base; 107 base = 1<<(20-PAGE_SHIFT); 108 } 109 subtract_range(range, RANGE_NUM, base, base + size); 110 } 111 if (extra_remove_size) 112 subtract_range(range, RANGE_NUM, extra_remove_base, 113 extra_remove_base + extra_remove_size); 114 115 if (debug_print) { 116 pr_debug("After UC checking\n"); 117 for (i = 0; i < RANGE_NUM; i++) { 118 if (!range[i].end) 119 continue; 120 pr_debug("MTRR MAP PFN: %016llx - %016llx\n", 121 range[i].start, range[i].end); 122 } 123 } 124 125 /* sort the ranges */ 126 nr_range = clean_sort_range(range, RANGE_NUM); 127 if (debug_print) { 128 pr_debug("After sorting\n"); 129 for (i = 0; i < nr_range; i++) 130 pr_debug("MTRR MAP PFN: %016llx - %016llx\n", 131 range[i].start, range[i].end); 132 } 133 134 return nr_range; 135 } 136 137 #ifdef CONFIG_MTRR_SANITIZER 138 139 static unsigned long __init sum_ranges(struct range *range, int nr_range) 140 { 141 unsigned long sum = 0; 142 int i; 143 144 for (i = 0; i < nr_range; i++) 145 sum += range[i].end - range[i].start; 146 147 return sum; 148 } 149 150 static int enable_mtrr_cleanup __initdata = 151 CONFIG_MTRR_SANITIZER_ENABLE_DEFAULT; 152 153 static int __init disable_mtrr_cleanup_setup(char *str) 154 { 155 enable_mtrr_cleanup = 0; 156 return 0; 157 } 158 early_param("disable_mtrr_cleanup", disable_mtrr_cleanup_setup); 159 160 static int __init enable_mtrr_cleanup_setup(char *str) 161 { 162 enable_mtrr_cleanup = 1; 163 return 0; 164 } 165 early_param("enable_mtrr_cleanup", enable_mtrr_cleanup_setup); 166 167 static int __init mtrr_cleanup_debug_setup(char *str) 168 { 169 debug_print = 1; 170 return 0; 171 } 172 early_param("mtrr_cleanup_debug", mtrr_cleanup_debug_setup); 173 174 static void __init 175 set_var_mtrr(unsigned int reg, unsigned long basek, unsigned long sizek, 176 unsigned char type, unsigned int address_bits) 177 { 178 u32 base_lo, base_hi, mask_lo, mask_hi; 179 u64 base, mask; 180 181 if (!sizek) { 182 fill_mtrr_var_range(reg, 0, 0, 0, 0); 183 return; 184 } 185 186 mask = (1ULL << address_bits) - 1; 187 mask &= ~((((u64)sizek) << 10) - 1); 188 189 base = ((u64)basek) << 10; 190 191 base |= type; 192 mask |= 0x800; 193 194 base_lo = base & ((1ULL<<32) - 1); 195 base_hi = base >> 32; 196 197 mask_lo = mask & ((1ULL<<32) - 1); 198 mask_hi = mask >> 32; 199 200 fill_mtrr_var_range(reg, base_lo, base_hi, mask_lo, mask_hi); 201 } 202 203 static void __init 204 save_var_mtrr(unsigned int reg, unsigned long basek, unsigned long sizek, 205 unsigned char type) 206 { 207 range_state[reg].base_pfn = basek >> (PAGE_SHIFT - 10); 208 range_state[reg].size_pfn = sizek >> (PAGE_SHIFT - 10); 209 range_state[reg].type = type; 210 } 211 212 static void __init set_var_mtrr_all(unsigned int address_bits) 213 { 214 unsigned long basek, sizek; 215 unsigned char type; 216 unsigned int reg; 217 218 for (reg = 0; reg < num_var_ranges; reg++) { 219 basek = range_state[reg].base_pfn << (PAGE_SHIFT - 10); 220 sizek = range_state[reg].size_pfn << (PAGE_SHIFT - 10); 221 type = range_state[reg].type; 222 223 set_var_mtrr(reg, basek, sizek, type, address_bits); 224 } 225 } 226 227 static unsigned long to_size_factor(unsigned long sizek, char *factorp) 228 { 229 unsigned long base = sizek; 230 char factor; 231 232 if (base & ((1<<10) - 1)) { 233 /* Not MB-aligned: */ 234 factor = 'K'; 235 } else if (base & ((1<<20) - 1)) { 236 factor = 'M'; 237 base >>= 10; 238 } else { 239 factor = 'G'; 240 base >>= 20; 241 } 242 243 *factorp = factor; 244 245 return base; 246 } 247 248 static unsigned int __init 249 range_to_mtrr(unsigned int reg, unsigned long range_startk, 250 unsigned long range_sizek, unsigned char type) 251 { 252 if (!range_sizek || (reg >= num_var_ranges)) 253 return reg; 254 255 while (range_sizek) { 256 unsigned long max_align, align; 257 unsigned long sizek; 258 259 /* Compute the maximum size with which we can make a range: */ 260 if (range_startk) 261 max_align = __ffs(range_startk); 262 else 263 max_align = BITS_PER_LONG - 1; 264 265 align = __fls(range_sizek); 266 if (align > max_align) 267 align = max_align; 268 269 sizek = 1UL << align; 270 if (debug_print) { 271 char start_factor = 'K', size_factor = 'K'; 272 unsigned long start_base, size_base; 273 274 start_base = to_size_factor(range_startk, &start_factor); 275 size_base = to_size_factor(sizek, &size_factor); 276 277 Dprintk("Setting variable MTRR %d, " 278 "base: %ld%cB, range: %ld%cB, type %s\n", 279 reg, start_base, start_factor, 280 size_base, size_factor, 281 (type == MTRR_TYPE_UNCACHABLE) ? "UC" : 282 ((type == MTRR_TYPE_WRBACK) ? "WB" : "Other") 283 ); 284 } 285 save_var_mtrr(reg++, range_startk, sizek, type); 286 range_startk += sizek; 287 range_sizek -= sizek; 288 if (reg >= num_var_ranges) 289 break; 290 } 291 return reg; 292 } 293 294 static unsigned __init 295 range_to_mtrr_with_hole(struct var_mtrr_state *state, unsigned long basek, 296 unsigned long sizek) 297 { 298 unsigned long hole_basek, hole_sizek; 299 unsigned long second_sizek; 300 unsigned long range0_basek, range0_sizek; 301 unsigned long range_basek, range_sizek; 302 unsigned long chunk_sizek; 303 unsigned long gran_sizek; 304 305 hole_basek = 0; 306 hole_sizek = 0; 307 second_sizek = 0; 308 chunk_sizek = state->chunk_sizek; 309 gran_sizek = state->gran_sizek; 310 311 /* Align with gran size, prevent small block used up MTRRs: */ 312 range_basek = ALIGN(state->range_startk, gran_sizek); 313 if ((range_basek > basek) && basek) 314 return second_sizek; 315 316 state->range_sizek -= (range_basek - state->range_startk); 317 range_sizek = ALIGN(state->range_sizek, gran_sizek); 318 319 while (range_sizek > state->range_sizek) { 320 range_sizek -= gran_sizek; 321 if (!range_sizek) 322 return 0; 323 } 324 state->range_sizek = range_sizek; 325 326 /* Try to append some small hole: */ 327 range0_basek = state->range_startk; 328 range0_sizek = ALIGN(state->range_sizek, chunk_sizek); 329 330 /* No increase: */ 331 if (range0_sizek == state->range_sizek) { 332 Dprintk("rangeX: %016lx - %016lx\n", 333 range0_basek<<10, 334 (range0_basek + state->range_sizek)<<10); 335 state->reg = range_to_mtrr(state->reg, range0_basek, 336 state->range_sizek, MTRR_TYPE_WRBACK); 337 return 0; 338 } 339 340 /* Only cut back when it is not the last: */ 341 if (sizek) { 342 while (range0_basek + range0_sizek > (basek + sizek)) { 343 if (range0_sizek >= chunk_sizek) 344 range0_sizek -= chunk_sizek; 345 else 346 range0_sizek = 0; 347 348 if (!range0_sizek) 349 break; 350 } 351 } 352 353 second_try: 354 range_basek = range0_basek + range0_sizek; 355 356 /* One hole in the middle: */ 357 if (range_basek > basek && range_basek <= (basek + sizek)) 358 second_sizek = range_basek - basek; 359 360 if (range0_sizek > state->range_sizek) { 361 362 /* One hole in middle or at the end: */ 363 hole_sizek = range0_sizek - state->range_sizek - second_sizek; 364 365 /* Hole size should be less than half of range0 size: */ 366 if (hole_sizek >= (range0_sizek >> 1) && 367 range0_sizek >= chunk_sizek) { 368 range0_sizek -= chunk_sizek; 369 second_sizek = 0; 370 hole_sizek = 0; 371 372 goto second_try; 373 } 374 } 375 376 if (range0_sizek) { 377 Dprintk("range0: %016lx - %016lx\n", 378 range0_basek<<10, 379 (range0_basek + range0_sizek)<<10); 380 state->reg = range_to_mtrr(state->reg, range0_basek, 381 range0_sizek, MTRR_TYPE_WRBACK); 382 } 383 384 if (range0_sizek < state->range_sizek) { 385 /* Need to handle left over range: */ 386 range_sizek = state->range_sizek - range0_sizek; 387 388 Dprintk("range: %016lx - %016lx\n", 389 range_basek<<10, 390 (range_basek + range_sizek)<<10); 391 392 state->reg = range_to_mtrr(state->reg, range_basek, 393 range_sizek, MTRR_TYPE_WRBACK); 394 } 395 396 if (hole_sizek) { 397 hole_basek = range_basek - hole_sizek - second_sizek; 398 Dprintk("hole: %016lx - %016lx\n", 399 hole_basek<<10, 400 (hole_basek + hole_sizek)<<10); 401 state->reg = range_to_mtrr(state->reg, hole_basek, 402 hole_sizek, MTRR_TYPE_UNCACHABLE); 403 } 404 405 return second_sizek; 406 } 407 408 static void __init 409 set_var_mtrr_range(struct var_mtrr_state *state, unsigned long base_pfn, 410 unsigned long size_pfn) 411 { 412 unsigned long basek, sizek; 413 unsigned long second_sizek = 0; 414 415 if (state->reg >= num_var_ranges) 416 return; 417 418 basek = base_pfn << (PAGE_SHIFT - 10); 419 sizek = size_pfn << (PAGE_SHIFT - 10); 420 421 /* See if I can merge with the last range: */ 422 if ((basek <= 1024) || 423 (state->range_startk + state->range_sizek == basek)) { 424 unsigned long endk = basek + sizek; 425 state->range_sizek = endk - state->range_startk; 426 return; 427 } 428 /* Write the range mtrrs: */ 429 if (state->range_sizek != 0) 430 second_sizek = range_to_mtrr_with_hole(state, basek, sizek); 431 432 /* Allocate an msr: */ 433 state->range_startk = basek + second_sizek; 434 state->range_sizek = sizek - second_sizek; 435 } 436 437 /* Mininum size of mtrr block that can take hole: */ 438 static u64 mtrr_chunk_size __initdata = (256ULL<<20); 439 440 static int __init parse_mtrr_chunk_size_opt(char *p) 441 { 442 if (!p) 443 return -EINVAL; 444 mtrr_chunk_size = memparse(p, &p); 445 return 0; 446 } 447 early_param("mtrr_chunk_size", parse_mtrr_chunk_size_opt); 448 449 /* Granularity of mtrr of block: */ 450 static u64 mtrr_gran_size __initdata; 451 452 static int __init parse_mtrr_gran_size_opt(char *p) 453 { 454 if (!p) 455 return -EINVAL; 456 mtrr_gran_size = memparse(p, &p); 457 return 0; 458 } 459 early_param("mtrr_gran_size", parse_mtrr_gran_size_opt); 460 461 static unsigned long nr_mtrr_spare_reg __initdata = 462 CONFIG_MTRR_SANITIZER_SPARE_REG_NR_DEFAULT; 463 464 static int __init parse_mtrr_spare_reg(char *arg) 465 { 466 if (arg) 467 nr_mtrr_spare_reg = simple_strtoul(arg, NULL, 0); 468 return 0; 469 } 470 early_param("mtrr_spare_reg_nr", parse_mtrr_spare_reg); 471 472 static int __init 473 x86_setup_var_mtrrs(struct range *range, int nr_range, 474 u64 chunk_size, u64 gran_size) 475 { 476 struct var_mtrr_state var_state; 477 int num_reg; 478 int i; 479 480 var_state.range_startk = 0; 481 var_state.range_sizek = 0; 482 var_state.reg = 0; 483 var_state.chunk_sizek = chunk_size >> 10; 484 var_state.gran_sizek = gran_size >> 10; 485 486 memset(range_state, 0, sizeof(range_state)); 487 488 /* Write the range: */ 489 for (i = 0; i < nr_range; i++) { 490 set_var_mtrr_range(&var_state, range[i].start, 491 range[i].end - range[i].start); 492 } 493 494 /* Write the last range: */ 495 if (var_state.range_sizek != 0) 496 range_to_mtrr_with_hole(&var_state, 0, 0); 497 498 num_reg = var_state.reg; 499 /* Clear out the extra MTRR's: */ 500 while (var_state.reg < num_var_ranges) { 501 save_var_mtrr(var_state.reg, 0, 0, 0); 502 var_state.reg++; 503 } 504 505 return num_reg; 506 } 507 508 struct mtrr_cleanup_result { 509 unsigned long gran_sizek; 510 unsigned long chunk_sizek; 511 unsigned long lose_cover_sizek; 512 unsigned int num_reg; 513 int bad; 514 }; 515 516 /* 517 * gran_size: 64K, 128K, 256K, 512K, 1M, 2M, ..., 2G 518 * chunk size: gran_size, ..., 2G 519 * so we need (1+16)*8 520 */ 521 #define NUM_RESULT 136 522 #define PSHIFT (PAGE_SHIFT - 10) 523 524 static struct mtrr_cleanup_result __initdata result[NUM_RESULT]; 525 static unsigned long __initdata min_loss_pfn[RANGE_NUM]; 526 527 static void __init print_out_mtrr_range_state(void) 528 { 529 char start_factor = 'K', size_factor = 'K'; 530 unsigned long start_base, size_base; 531 mtrr_type type; 532 int i; 533 534 for (i = 0; i < num_var_ranges; i++) { 535 536 size_base = range_state[i].size_pfn << (PAGE_SHIFT - 10); 537 if (!size_base) 538 continue; 539 540 size_base = to_size_factor(size_base, &size_factor); 541 start_base = range_state[i].base_pfn << (PAGE_SHIFT - 10); 542 start_base = to_size_factor(start_base, &start_factor); 543 type = range_state[i].type; 544 545 pr_debug("reg %d, base: %ld%cB, range: %ld%cB, type %s\n", 546 i, start_base, start_factor, 547 size_base, size_factor, 548 (type == MTRR_TYPE_UNCACHABLE) ? "UC" : 549 ((type == MTRR_TYPE_WRPROT) ? "WP" : 550 ((type == MTRR_TYPE_WRBACK) ? "WB" : "Other")) 551 ); 552 } 553 } 554 555 static int __init mtrr_need_cleanup(void) 556 { 557 int i; 558 mtrr_type type; 559 unsigned long size; 560 /* Extra one for all 0: */ 561 int num[MTRR_NUM_TYPES + 1]; 562 563 /* Check entries number: */ 564 memset(num, 0, sizeof(num)); 565 for (i = 0; i < num_var_ranges; i++) { 566 type = range_state[i].type; 567 size = range_state[i].size_pfn; 568 if (type >= MTRR_NUM_TYPES) 569 continue; 570 if (!size) 571 type = MTRR_NUM_TYPES; 572 num[type]++; 573 } 574 575 /* Check if we got UC entries: */ 576 if (!num[MTRR_TYPE_UNCACHABLE]) 577 return 0; 578 579 /* Check if we only had WB and UC */ 580 if (num[MTRR_TYPE_WRBACK] + num[MTRR_TYPE_UNCACHABLE] != 581 num_var_ranges - num[MTRR_NUM_TYPES]) 582 return 0; 583 584 return 1; 585 } 586 587 static unsigned long __initdata range_sums; 588 589 static void __init 590 mtrr_calc_range_state(u64 chunk_size, u64 gran_size, 591 unsigned long x_remove_base, 592 unsigned long x_remove_size, int i) 593 { 594 /* 595 * range_new should really be an automatic variable, but 596 * putting 4096 bytes on the stack is frowned upon, to put it 597 * mildly. It is safe to make it a static __initdata variable, 598 * since mtrr_calc_range_state is only called during init and 599 * there's no way it will call itself recursively. 600 */ 601 static struct range range_new[RANGE_NUM] __initdata; 602 unsigned long range_sums_new; 603 int nr_range_new; 604 int num_reg; 605 606 /* Convert ranges to var ranges state: */ 607 num_reg = x86_setup_var_mtrrs(range, nr_range, chunk_size, gran_size); 608 609 /* We got new setting in range_state, check it: */ 610 memset(range_new, 0, sizeof(range_new)); 611 nr_range_new = x86_get_mtrr_mem_range(range_new, 0, 612 x_remove_base, x_remove_size); 613 range_sums_new = sum_ranges(range_new, nr_range_new); 614 615 result[i].chunk_sizek = chunk_size >> 10; 616 result[i].gran_sizek = gran_size >> 10; 617 result[i].num_reg = num_reg; 618 619 if (range_sums < range_sums_new) { 620 result[i].lose_cover_sizek = (range_sums_new - range_sums) << PSHIFT; 621 result[i].bad = 1; 622 } else { 623 result[i].lose_cover_sizek = (range_sums - range_sums_new) << PSHIFT; 624 } 625 626 /* Double check it: */ 627 if (!result[i].bad && !result[i].lose_cover_sizek) { 628 if (nr_range_new != nr_range || memcmp(range, range_new, sizeof(range))) 629 result[i].bad = 1; 630 } 631 632 if (!result[i].bad && (range_sums - range_sums_new < min_loss_pfn[num_reg])) 633 min_loss_pfn[num_reg] = range_sums - range_sums_new; 634 } 635 636 static void __init mtrr_print_out_one_result(int i) 637 { 638 unsigned long gran_base, chunk_base, lose_base; 639 char gran_factor, chunk_factor, lose_factor; 640 641 gran_base = to_size_factor(result[i].gran_sizek, &gran_factor); 642 chunk_base = to_size_factor(result[i].chunk_sizek, &chunk_factor); 643 lose_base = to_size_factor(result[i].lose_cover_sizek, &lose_factor); 644 645 pr_info("%sgran_size: %ld%c \tchunk_size: %ld%c \t", 646 result[i].bad ? "*BAD*" : " ", 647 gran_base, gran_factor, chunk_base, chunk_factor); 648 pr_cont("num_reg: %d \tlose cover RAM: %s%ld%c\n", 649 result[i].num_reg, result[i].bad ? "-" : "", 650 lose_base, lose_factor); 651 } 652 653 static int __init mtrr_search_optimal_index(void) 654 { 655 int num_reg_good; 656 int index_good; 657 int i; 658 659 if (nr_mtrr_spare_reg >= num_var_ranges) 660 nr_mtrr_spare_reg = num_var_ranges - 1; 661 662 num_reg_good = -1; 663 for (i = num_var_ranges - nr_mtrr_spare_reg; i > 0; i--) { 664 if (!min_loss_pfn[i]) 665 num_reg_good = i; 666 } 667 668 index_good = -1; 669 if (num_reg_good != -1) { 670 for (i = 0; i < NUM_RESULT; i++) { 671 if (!result[i].bad && 672 result[i].num_reg == num_reg_good && 673 !result[i].lose_cover_sizek) { 674 index_good = i; 675 break; 676 } 677 } 678 } 679 680 return index_good; 681 } 682 683 int __init mtrr_cleanup(unsigned address_bits) 684 { 685 unsigned long x_remove_base, x_remove_size; 686 unsigned long base, size, def, dummy; 687 u64 chunk_size, gran_size; 688 mtrr_type type; 689 int index_good; 690 int i; 691 692 if (!is_cpu(INTEL) || enable_mtrr_cleanup < 1) 693 return 0; 694 695 rdmsr(MSR_MTRRdefType, def, dummy); 696 def &= 0xff; 697 if (def != MTRR_TYPE_UNCACHABLE) 698 return 0; 699 700 /* Get it and store it aside: */ 701 memset(range_state, 0, sizeof(range_state)); 702 for (i = 0; i < num_var_ranges; i++) { 703 mtrr_if->get(i, &base, &size, &type); 704 range_state[i].base_pfn = base; 705 range_state[i].size_pfn = size; 706 range_state[i].type = type; 707 } 708 709 /* Check if we need handle it and can handle it: */ 710 if (!mtrr_need_cleanup()) 711 return 0; 712 713 /* Print original var MTRRs at first, for debugging: */ 714 pr_debug("original variable MTRRs\n"); 715 print_out_mtrr_range_state(); 716 717 memset(range, 0, sizeof(range)); 718 x_remove_size = 0; 719 x_remove_base = 1 << (32 - PAGE_SHIFT); 720 if (mtrr_tom2) 721 x_remove_size = (mtrr_tom2 >> PAGE_SHIFT) - x_remove_base; 722 723 /* 724 * [0, 1M) should always be covered by var mtrr with WB 725 * and fixed mtrrs should take effect before var mtrr for it: 726 */ 727 nr_range = add_range_with_merge(range, RANGE_NUM, 0, 0, 728 1ULL<<(20 - PAGE_SHIFT)); 729 /* add from var mtrr at last */ 730 nr_range = x86_get_mtrr_mem_range(range, nr_range, 731 x_remove_base, x_remove_size); 732 733 range_sums = sum_ranges(range, nr_range); 734 pr_info("total RAM covered: %ldM\n", 735 range_sums >> (20 - PAGE_SHIFT)); 736 737 if (mtrr_chunk_size && mtrr_gran_size) { 738 i = 0; 739 mtrr_calc_range_state(mtrr_chunk_size, mtrr_gran_size, 740 x_remove_base, x_remove_size, i); 741 742 mtrr_print_out_one_result(i); 743 744 if (!result[i].bad) { 745 set_var_mtrr_all(address_bits); 746 pr_debug("New variable MTRRs\n"); 747 print_out_mtrr_range_state(); 748 return 1; 749 } 750 pr_info("invalid mtrr_gran_size or mtrr_chunk_size, will find optimal one\n"); 751 } 752 753 i = 0; 754 memset(min_loss_pfn, 0xff, sizeof(min_loss_pfn)); 755 memset(result, 0, sizeof(result)); 756 for (gran_size = (1ULL<<16); gran_size < (1ULL<<32); gran_size <<= 1) { 757 758 for (chunk_size = gran_size; chunk_size < (1ULL<<32); 759 chunk_size <<= 1) { 760 761 if (i >= NUM_RESULT) 762 continue; 763 764 mtrr_calc_range_state(chunk_size, gran_size, 765 x_remove_base, x_remove_size, i); 766 if (debug_print) { 767 mtrr_print_out_one_result(i); 768 pr_info("\n"); 769 } 770 771 i++; 772 } 773 } 774 775 /* Try to find the optimal index: */ 776 index_good = mtrr_search_optimal_index(); 777 778 if (index_good != -1) { 779 pr_info("Found optimal setting for mtrr clean up\n"); 780 i = index_good; 781 mtrr_print_out_one_result(i); 782 783 /* Convert ranges to var ranges state: */ 784 chunk_size = result[i].chunk_sizek; 785 chunk_size <<= 10; 786 gran_size = result[i].gran_sizek; 787 gran_size <<= 10; 788 x86_setup_var_mtrrs(range, nr_range, chunk_size, gran_size); 789 set_var_mtrr_all(address_bits); 790 pr_debug("New variable MTRRs\n"); 791 print_out_mtrr_range_state(); 792 return 1; 793 } else { 794 /* print out all */ 795 for (i = 0; i < NUM_RESULT; i++) 796 mtrr_print_out_one_result(i); 797 } 798 799 pr_info("mtrr_cleanup: can not find optimal value\n"); 800 pr_info("please specify mtrr_gran_size/mtrr_chunk_size\n"); 801 802 return 0; 803 } 804 #else 805 int __init mtrr_cleanup(unsigned address_bits) 806 { 807 return 0; 808 } 809 #endif 810 811 static int disable_mtrr_trim; 812 813 static int __init disable_mtrr_trim_setup(char *str) 814 { 815 disable_mtrr_trim = 1; 816 return 0; 817 } 818 early_param("disable_mtrr_trim", disable_mtrr_trim_setup); 819 820 /* 821 * Newer AMD K8s and later CPUs have a special magic MSR way to force WB 822 * for memory >4GB. Check for that here. 823 * Note this won't check if the MTRRs < 4GB where the magic bit doesn't 824 * apply to are wrong, but so far we don't know of any such case in the wild. 825 */ 826 #define Tom2Enabled (1U << 21) 827 #define Tom2ForceMemTypeWB (1U << 22) 828 829 int __init amd_special_default_mtrr(void) 830 { 831 u32 l, h; 832 833 if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD && 834 boot_cpu_data.x86_vendor != X86_VENDOR_HYGON) 835 return 0; 836 if (boot_cpu_data.x86 < 0xf) 837 return 0; 838 /* In case some hypervisor doesn't pass SYSCFG through: */ 839 if (rdmsr_safe(MSR_K8_SYSCFG, &l, &h) < 0) 840 return 0; 841 /* 842 * Memory between 4GB and top of mem is forced WB by this magic bit. 843 * Reserved before K8RevF, but should be zero there. 844 */ 845 if ((l & (Tom2Enabled | Tom2ForceMemTypeWB)) == 846 (Tom2Enabled | Tom2ForceMemTypeWB)) 847 return 1; 848 return 0; 849 } 850 851 static u64 __init 852 real_trim_memory(unsigned long start_pfn, unsigned long limit_pfn) 853 { 854 u64 trim_start, trim_size; 855 856 trim_start = start_pfn; 857 trim_start <<= PAGE_SHIFT; 858 859 trim_size = limit_pfn; 860 trim_size <<= PAGE_SHIFT; 861 trim_size -= trim_start; 862 863 return e820__range_update(trim_start, trim_size, E820_TYPE_RAM, E820_TYPE_RESERVED); 864 } 865 866 /** 867 * mtrr_trim_uncached_memory - trim RAM not covered by MTRRs 868 * @end_pfn: ending page frame number 869 * 870 * Some buggy BIOSes don't setup the MTRRs properly for systems with certain 871 * memory configurations. This routine checks that the highest MTRR matches 872 * the end of memory, to make sure the MTRRs having a write back type cover 873 * all of the memory the kernel is intending to use. If not, it'll trim any 874 * memory off the end by adjusting end_pfn, removing it from the kernel's 875 * allocation pools, warning the user with an obnoxious message. 876 */ 877 int __init mtrr_trim_uncached_memory(unsigned long end_pfn) 878 { 879 unsigned long i, base, size, highest_pfn = 0, def, dummy; 880 mtrr_type type; 881 u64 total_trim_size; 882 /* extra one for all 0 */ 883 int num[MTRR_NUM_TYPES + 1]; 884 885 /* 886 * Make sure we only trim uncachable memory on machines that 887 * support the Intel MTRR architecture: 888 */ 889 if (!is_cpu(INTEL) || disable_mtrr_trim) 890 return 0; 891 892 rdmsr(MSR_MTRRdefType, def, dummy); 893 def &= 0xff; 894 if (def != MTRR_TYPE_UNCACHABLE) 895 return 0; 896 897 /* Get it and store it aside: */ 898 memset(range_state, 0, sizeof(range_state)); 899 for (i = 0; i < num_var_ranges; i++) { 900 mtrr_if->get(i, &base, &size, &type); 901 range_state[i].base_pfn = base; 902 range_state[i].size_pfn = size; 903 range_state[i].type = type; 904 } 905 906 /* Find highest cached pfn: */ 907 for (i = 0; i < num_var_ranges; i++) { 908 type = range_state[i].type; 909 if (type != MTRR_TYPE_WRBACK) 910 continue; 911 base = range_state[i].base_pfn; 912 size = range_state[i].size_pfn; 913 if (highest_pfn < base + size) 914 highest_pfn = base + size; 915 } 916 917 /* kvm/qemu doesn't have mtrr set right, don't trim them all: */ 918 if (!highest_pfn) { 919 pr_info("CPU MTRRs all blank - virtualized system.\n"); 920 return 0; 921 } 922 923 /* Check entries number: */ 924 memset(num, 0, sizeof(num)); 925 for (i = 0; i < num_var_ranges; i++) { 926 type = range_state[i].type; 927 if (type >= MTRR_NUM_TYPES) 928 continue; 929 size = range_state[i].size_pfn; 930 if (!size) 931 type = MTRR_NUM_TYPES; 932 num[type]++; 933 } 934 935 /* No entry for WB? */ 936 if (!num[MTRR_TYPE_WRBACK]) 937 return 0; 938 939 /* Check if we only had WB and UC: */ 940 if (num[MTRR_TYPE_WRBACK] + num[MTRR_TYPE_UNCACHABLE] != 941 num_var_ranges - num[MTRR_NUM_TYPES]) 942 return 0; 943 944 memset(range, 0, sizeof(range)); 945 nr_range = 0; 946 if (mtrr_tom2) { 947 range[nr_range].start = (1ULL<<(32 - PAGE_SHIFT)); 948 range[nr_range].end = mtrr_tom2 >> PAGE_SHIFT; 949 if (highest_pfn < range[nr_range].end) 950 highest_pfn = range[nr_range].end; 951 nr_range++; 952 } 953 nr_range = x86_get_mtrr_mem_range(range, nr_range, 0, 0); 954 955 /* Check the head: */ 956 total_trim_size = 0; 957 if (range[0].start) 958 total_trim_size += real_trim_memory(0, range[0].start); 959 960 /* Check the holes: */ 961 for (i = 0; i < nr_range - 1; i++) { 962 if (range[i].end < range[i+1].start) 963 total_trim_size += real_trim_memory(range[i].end, 964 range[i+1].start); 965 } 966 967 /* Check the top: */ 968 i = nr_range - 1; 969 if (range[i].end < end_pfn) 970 total_trim_size += real_trim_memory(range[i].end, 971 end_pfn); 972 973 if (total_trim_size) { 974 pr_warn("WARNING: BIOS bug: CPU MTRRs don't cover all of memory, losing %lluMB of RAM.\n", 975 total_trim_size >> 20); 976 977 if (!changed_by_mtrr_cleanup) 978 WARN_ON(1); 979 980 pr_info("update e820 for mtrr\n"); 981 e820__update_table_print(); 982 983 return 1; 984 } 985 986 return 0; 987 } 988