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/module.h> 21 #include <linux/init.h> 22 #include <linux/pci.h> 23 #include <linux/smp.h> 24 #include <linux/cpu.h> 25 #include <linux/mutex.h> 26 #include <linux/uaccess.h> 27 #include <linux/kvm_para.h> 28 #include <linux/range.h> 29 30 #include <asm/processor.h> 31 #include <asm/e820.h> 32 #include <asm/mtrr.h> 33 #include <asm/msr.h> 34 35 #include "mtrr.h" 36 37 struct var_mtrr_range_state { 38 unsigned long base_pfn; 39 unsigned long size_pfn; 40 mtrr_type type; 41 }; 42 43 struct var_mtrr_state { 44 unsigned long range_startk; 45 unsigned long range_sizek; 46 unsigned long chunk_sizek; 47 unsigned long gran_sizek; 48 unsigned int reg; 49 }; 50 51 /* Should be related to MTRR_VAR_RANGES nums */ 52 #define RANGE_NUM 256 53 54 static struct range __initdata range[RANGE_NUM]; 55 static int __initdata nr_range; 56 57 static struct var_mtrr_range_state __initdata range_state[RANGE_NUM]; 58 59 static int __initdata debug_print; 60 #define Dprintk(x...) do { if (debug_print) printk(KERN_DEBUG x); } while (0) 61 62 #define BIOS_BUG_MSG KERN_WARNING \ 63 "WARNING: BIOS bug: VAR MTRR %d contains strange UC entry under 1M, check with your system vendor!\n" 64 65 static int __init 66 x86_get_mtrr_mem_range(struct range *range, int nr_range, 67 unsigned long extra_remove_base, 68 unsigned long extra_remove_size) 69 { 70 unsigned long base, size; 71 mtrr_type type; 72 int i; 73 74 for (i = 0; i < num_var_ranges; i++) { 75 type = range_state[i].type; 76 if (type != MTRR_TYPE_WRBACK) 77 continue; 78 base = range_state[i].base_pfn; 79 size = range_state[i].size_pfn; 80 nr_range = add_range_with_merge(range, RANGE_NUM, nr_range, 81 base, base + size); 82 } 83 if (debug_print) { 84 printk(KERN_DEBUG "After WB checking\n"); 85 for (i = 0; i < nr_range; i++) 86 printk(KERN_DEBUG "MTRR MAP PFN: %016llx - %016llx\n", 87 range[i].start, range[i].end); 88 } 89 90 /* Take out UC ranges: */ 91 for (i = 0; i < num_var_ranges; i++) { 92 type = range_state[i].type; 93 if (type != MTRR_TYPE_UNCACHABLE && 94 type != MTRR_TYPE_WRPROT) 95 continue; 96 size = range_state[i].size_pfn; 97 if (!size) 98 continue; 99 base = range_state[i].base_pfn; 100 if (base < (1<<(20-PAGE_SHIFT)) && mtrr_state.have_fixed && 101 (mtrr_state.enabled & 1)) { 102 /* Var MTRR contains UC entry below 1M? Skip it: */ 103 printk(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 printk(KERN_DEBUG "After UC checking\n"); 117 for (i = 0; i < RANGE_NUM; i++) { 118 if (!range[i].end) 119 continue; 120 printk(KERN_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 printk(KERN_DEBUG "After sorting\n"); 129 for (i = 0; i < nr_range; i++) 130 printk(KERN_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_basek, 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_basek = 0; 308 second_sizek = 0; 309 chunk_sizek = state->chunk_sizek; 310 gran_sizek = state->gran_sizek; 311 312 /* Align with gran size, prevent small block used up MTRRs: */ 313 range_basek = ALIGN(state->range_startk, gran_sizek); 314 if ((range_basek > basek) && basek) 315 return second_sizek; 316 317 state->range_sizek -= (range_basek - state->range_startk); 318 range_sizek = ALIGN(state->range_sizek, gran_sizek); 319 320 while (range_sizek > state->range_sizek) { 321 range_sizek -= gran_sizek; 322 if (!range_sizek) 323 return 0; 324 } 325 state->range_sizek = range_sizek; 326 327 /* Try to append some small hole: */ 328 range0_basek = state->range_startk; 329 range0_sizek = ALIGN(state->range_sizek, chunk_sizek); 330 331 /* No increase: */ 332 if (range0_sizek == state->range_sizek) { 333 Dprintk("rangeX: %016lx - %016lx\n", 334 range0_basek<<10, 335 (range0_basek + state->range_sizek)<<10); 336 state->reg = range_to_mtrr(state->reg, range0_basek, 337 state->range_sizek, MTRR_TYPE_WRBACK); 338 return 0; 339 } 340 341 /* Only cut back when it is not the last: */ 342 if (sizek) { 343 while (range0_basek + range0_sizek > (basek + sizek)) { 344 if (range0_sizek >= chunk_sizek) 345 range0_sizek -= chunk_sizek; 346 else 347 range0_sizek = 0; 348 349 if (!range0_sizek) 350 break; 351 } 352 } 353 354 second_try: 355 range_basek = range0_basek + range0_sizek; 356 357 /* One hole in the middle: */ 358 if (range_basek > basek && range_basek <= (basek + sizek)) 359 second_sizek = range_basek - basek; 360 361 if (range0_sizek > state->range_sizek) { 362 363 /* One hole in middle or at the end: */ 364 hole_sizek = range0_sizek - state->range_sizek - second_sizek; 365 366 /* Hole size should be less than half of range0 size: */ 367 if (hole_sizek >= (range0_sizek >> 1) && 368 range0_sizek >= chunk_sizek) { 369 range0_sizek -= chunk_sizek; 370 second_sizek = 0; 371 hole_sizek = 0; 372 373 goto second_try; 374 } 375 } 376 377 if (range0_sizek) { 378 Dprintk("range0: %016lx - %016lx\n", 379 range0_basek<<10, 380 (range0_basek + range0_sizek)<<10); 381 state->reg = range_to_mtrr(state->reg, range0_basek, 382 range0_sizek, MTRR_TYPE_WRBACK); 383 } 384 385 if (range0_sizek < state->range_sizek) { 386 /* Need to handle left over range: */ 387 range_sizek = state->range_sizek - range0_sizek; 388 389 Dprintk("range: %016lx - %016lx\n", 390 range_basek<<10, 391 (range_basek + range_sizek)<<10); 392 393 state->reg = range_to_mtrr(state->reg, range_basek, 394 range_sizek, MTRR_TYPE_WRBACK); 395 } 396 397 if (hole_sizek) { 398 hole_basek = range_basek - hole_sizek - second_sizek; 399 Dprintk("hole: %016lx - %016lx\n", 400 hole_basek<<10, 401 (hole_basek + hole_sizek)<<10); 402 state->reg = range_to_mtrr(state->reg, hole_basek, 403 hole_sizek, MTRR_TYPE_UNCACHABLE); 404 } 405 406 return second_sizek; 407 } 408 409 static void __init 410 set_var_mtrr_range(struct var_mtrr_state *state, unsigned long base_pfn, 411 unsigned long size_pfn) 412 { 413 unsigned long basek, sizek; 414 unsigned long second_sizek = 0; 415 416 if (state->reg >= num_var_ranges) 417 return; 418 419 basek = base_pfn << (PAGE_SHIFT - 10); 420 sizek = size_pfn << (PAGE_SHIFT - 10); 421 422 /* See if I can merge with the last range: */ 423 if ((basek <= 1024) || 424 (state->range_startk + state->range_sizek == basek)) { 425 unsigned long endk = basek + sizek; 426 state->range_sizek = endk - state->range_startk; 427 return; 428 } 429 /* Write the range mtrrs: */ 430 if (state->range_sizek != 0) 431 second_sizek = range_to_mtrr_with_hole(state, basek, sizek); 432 433 /* Allocate an msr: */ 434 state->range_startk = basek + second_sizek; 435 state->range_sizek = sizek - second_sizek; 436 } 437 438 /* Mininum size of mtrr block that can take hole: */ 439 static u64 mtrr_chunk_size __initdata = (256ULL<<20); 440 441 static int __init parse_mtrr_chunk_size_opt(char *p) 442 { 443 if (!p) 444 return -EINVAL; 445 mtrr_chunk_size = memparse(p, &p); 446 return 0; 447 } 448 early_param("mtrr_chunk_size", parse_mtrr_chunk_size_opt); 449 450 /* Granularity of mtrr of block: */ 451 static u64 mtrr_gran_size __initdata; 452 453 static int __init parse_mtrr_gran_size_opt(char *p) 454 { 455 if (!p) 456 return -EINVAL; 457 mtrr_gran_size = memparse(p, &p); 458 return 0; 459 } 460 early_param("mtrr_gran_size", parse_mtrr_gran_size_opt); 461 462 static unsigned long nr_mtrr_spare_reg __initdata = 463 CONFIG_MTRR_SANITIZER_SPARE_REG_NR_DEFAULT; 464 465 static int __init parse_mtrr_spare_reg(char *arg) 466 { 467 if (arg) 468 nr_mtrr_spare_reg = simple_strtoul(arg, NULL, 0); 469 return 0; 470 } 471 early_param("mtrr_spare_reg_nr", parse_mtrr_spare_reg); 472 473 static int __init 474 x86_setup_var_mtrrs(struct range *range, int nr_range, 475 u64 chunk_size, u64 gran_size) 476 { 477 struct var_mtrr_state var_state; 478 int num_reg; 479 int i; 480 481 var_state.range_startk = 0; 482 var_state.range_sizek = 0; 483 var_state.reg = 0; 484 var_state.chunk_sizek = chunk_size >> 10; 485 var_state.gran_sizek = gran_size >> 10; 486 487 memset(range_state, 0, sizeof(range_state)); 488 489 /* Write the range: */ 490 for (i = 0; i < nr_range; i++) { 491 set_var_mtrr_range(&var_state, range[i].start, 492 range[i].end - range[i].start); 493 } 494 495 /* Write the last range: */ 496 if (var_state.range_sizek != 0) 497 range_to_mtrr_with_hole(&var_state, 0, 0); 498 499 num_reg = var_state.reg; 500 /* Clear out the extra MTRR's: */ 501 while (var_state.reg < num_var_ranges) { 502 save_var_mtrr(var_state.reg, 0, 0, 0); 503 var_state.reg++; 504 } 505 506 return num_reg; 507 } 508 509 struct mtrr_cleanup_result { 510 unsigned long gran_sizek; 511 unsigned long chunk_sizek; 512 unsigned long lose_cover_sizek; 513 unsigned int num_reg; 514 int bad; 515 }; 516 517 /* 518 * gran_size: 64K, 128K, 256K, 512K, 1M, 2M, ..., 2G 519 * chunk size: gran_size, ..., 2G 520 * so we need (1+16)*8 521 */ 522 #define NUM_RESULT 136 523 #define PSHIFT (PAGE_SHIFT - 10) 524 525 static struct mtrr_cleanup_result __initdata result[NUM_RESULT]; 526 static unsigned long __initdata min_loss_pfn[RANGE_NUM]; 527 528 static void __init print_out_mtrr_range_state(void) 529 { 530 char start_factor = 'K', size_factor = 'K'; 531 unsigned long start_base, size_base; 532 mtrr_type type; 533 int i; 534 535 for (i = 0; i < num_var_ranges; i++) { 536 537 size_base = range_state[i].size_pfn << (PAGE_SHIFT - 10); 538 if (!size_base) 539 continue; 540 541 size_base = to_size_factor(size_base, &size_factor), 542 start_base = range_state[i].base_pfn << (PAGE_SHIFT - 10); 543 start_base = to_size_factor(start_base, &start_factor), 544 type = range_state[i].type; 545 546 printk(KERN_DEBUG "reg %d, base: %ld%cB, range: %ld%cB, type %s\n", 547 i, start_base, start_factor, 548 size_base, size_factor, 549 (type == MTRR_TYPE_UNCACHABLE) ? "UC" : 550 ((type == MTRR_TYPE_WRPROT) ? "WP" : 551 ((type == MTRR_TYPE_WRBACK) ? "WB" : "Other")) 552 ); 553 } 554 } 555 556 static int __init mtrr_need_cleanup(void) 557 { 558 int i; 559 mtrr_type type; 560 unsigned long size; 561 /* Extra one for all 0: */ 562 int num[MTRR_NUM_TYPES + 1]; 563 564 /* Check entries number: */ 565 memset(num, 0, sizeof(num)); 566 for (i = 0; i < num_var_ranges; i++) { 567 type = range_state[i].type; 568 size = range_state[i].size_pfn; 569 if (type >= MTRR_NUM_TYPES) 570 continue; 571 if (!size) 572 type = MTRR_NUM_TYPES; 573 num[type]++; 574 } 575 576 /* Check if we got UC entries: */ 577 if (!num[MTRR_TYPE_UNCACHABLE]) 578 return 0; 579 580 /* Check if we only had WB and UC */ 581 if (num[MTRR_TYPE_WRBACK] + num[MTRR_TYPE_UNCACHABLE] != 582 num_var_ranges - num[MTRR_NUM_TYPES]) 583 return 0; 584 585 return 1; 586 } 587 588 static unsigned long __initdata range_sums; 589 590 static void __init 591 mtrr_calc_range_state(u64 chunk_size, u64 gran_size, 592 unsigned long x_remove_base, 593 unsigned long x_remove_size, int i) 594 { 595 static struct range range_new[RANGE_NUM]; 596 unsigned long range_sums_new; 597 static int nr_range_new; 598 int num_reg; 599 600 /* Convert ranges to var ranges state: */ 601 num_reg = x86_setup_var_mtrrs(range, nr_range, chunk_size, gran_size); 602 603 /* We got new setting in range_state, check it: */ 604 memset(range_new, 0, sizeof(range_new)); 605 nr_range_new = x86_get_mtrr_mem_range(range_new, 0, 606 x_remove_base, x_remove_size); 607 range_sums_new = sum_ranges(range_new, nr_range_new); 608 609 result[i].chunk_sizek = chunk_size >> 10; 610 result[i].gran_sizek = gran_size >> 10; 611 result[i].num_reg = num_reg; 612 613 if (range_sums < range_sums_new) { 614 result[i].lose_cover_sizek = (range_sums_new - range_sums) << PSHIFT; 615 result[i].bad = 1; 616 } else { 617 result[i].lose_cover_sizek = (range_sums - range_sums_new) << PSHIFT; 618 } 619 620 /* Double check it: */ 621 if (!result[i].bad && !result[i].lose_cover_sizek) { 622 if (nr_range_new != nr_range || memcmp(range, range_new, sizeof(range))) 623 result[i].bad = 1; 624 } 625 626 if (!result[i].bad && (range_sums - range_sums_new < min_loss_pfn[num_reg])) 627 min_loss_pfn[num_reg] = range_sums - range_sums_new; 628 } 629 630 static void __init mtrr_print_out_one_result(int i) 631 { 632 unsigned long gran_base, chunk_base, lose_base; 633 char gran_factor, chunk_factor, lose_factor; 634 635 gran_base = to_size_factor(result[i].gran_sizek, &gran_factor); 636 chunk_base = to_size_factor(result[i].chunk_sizek, &chunk_factor); 637 lose_base = to_size_factor(result[i].lose_cover_sizek, &lose_factor); 638 639 pr_info("%sgran_size: %ld%c \tchunk_size: %ld%c \t", 640 result[i].bad ? "*BAD*" : " ", 641 gran_base, gran_factor, chunk_base, chunk_factor); 642 pr_cont("num_reg: %d \tlose cover RAM: %s%ld%c\n", 643 result[i].num_reg, result[i].bad ? "-" : "", 644 lose_base, lose_factor); 645 } 646 647 static int __init mtrr_search_optimal_index(void) 648 { 649 int num_reg_good; 650 int index_good; 651 int i; 652 653 if (nr_mtrr_spare_reg >= num_var_ranges) 654 nr_mtrr_spare_reg = num_var_ranges - 1; 655 656 num_reg_good = -1; 657 for (i = num_var_ranges - nr_mtrr_spare_reg; i > 0; i--) { 658 if (!min_loss_pfn[i]) 659 num_reg_good = i; 660 } 661 662 index_good = -1; 663 if (num_reg_good != -1) { 664 for (i = 0; i < NUM_RESULT; i++) { 665 if (!result[i].bad && 666 result[i].num_reg == num_reg_good && 667 !result[i].lose_cover_sizek) { 668 index_good = i; 669 break; 670 } 671 } 672 } 673 674 return index_good; 675 } 676 677 int __init mtrr_cleanup(unsigned address_bits) 678 { 679 unsigned long x_remove_base, x_remove_size; 680 unsigned long base, size, def, dummy; 681 u64 chunk_size, gran_size; 682 mtrr_type type; 683 int index_good; 684 int i; 685 686 if (!is_cpu(INTEL) || enable_mtrr_cleanup < 1) 687 return 0; 688 689 rdmsr(MSR_MTRRdefType, def, dummy); 690 def &= 0xff; 691 if (def != MTRR_TYPE_UNCACHABLE) 692 return 0; 693 694 /* Get it and store it aside: */ 695 memset(range_state, 0, sizeof(range_state)); 696 for (i = 0; i < num_var_ranges; i++) { 697 mtrr_if->get(i, &base, &size, &type); 698 range_state[i].base_pfn = base; 699 range_state[i].size_pfn = size; 700 range_state[i].type = type; 701 } 702 703 /* Check if we need handle it and can handle it: */ 704 if (!mtrr_need_cleanup()) 705 return 0; 706 707 /* Print original var MTRRs at first, for debugging: */ 708 printk(KERN_DEBUG "original variable MTRRs\n"); 709 print_out_mtrr_range_state(); 710 711 memset(range, 0, sizeof(range)); 712 x_remove_size = 0; 713 x_remove_base = 1 << (32 - PAGE_SHIFT); 714 if (mtrr_tom2) 715 x_remove_size = (mtrr_tom2 >> PAGE_SHIFT) - x_remove_base; 716 717 /* 718 * [0, 1M) should always be covered by var mtrr with WB 719 * and fixed mtrrs should take effect before var mtrr for it: 720 */ 721 nr_range = add_range_with_merge(range, RANGE_NUM, 0, 0, 722 1ULL<<(20 - PAGE_SHIFT)); 723 /* add from var mtrr at last */ 724 nr_range = x86_get_mtrr_mem_range(range, nr_range, 725 x_remove_base, x_remove_size); 726 727 range_sums = sum_ranges(range, nr_range); 728 printk(KERN_INFO "total RAM covered: %ldM\n", 729 range_sums >> (20 - PAGE_SHIFT)); 730 731 if (mtrr_chunk_size && mtrr_gran_size) { 732 i = 0; 733 mtrr_calc_range_state(mtrr_chunk_size, mtrr_gran_size, 734 x_remove_base, x_remove_size, i); 735 736 mtrr_print_out_one_result(i); 737 738 if (!result[i].bad) { 739 set_var_mtrr_all(address_bits); 740 printk(KERN_DEBUG "New variable MTRRs\n"); 741 print_out_mtrr_range_state(); 742 return 1; 743 } 744 printk(KERN_INFO "invalid mtrr_gran_size or mtrr_chunk_size, " 745 "will find optimal one\n"); 746 } 747 748 i = 0; 749 memset(min_loss_pfn, 0xff, sizeof(min_loss_pfn)); 750 memset(result, 0, sizeof(result)); 751 for (gran_size = (1ULL<<16); gran_size < (1ULL<<32); gran_size <<= 1) { 752 753 for (chunk_size = gran_size; chunk_size < (1ULL<<32); 754 chunk_size <<= 1) { 755 756 if (i >= NUM_RESULT) 757 continue; 758 759 mtrr_calc_range_state(chunk_size, gran_size, 760 x_remove_base, x_remove_size, i); 761 if (debug_print) { 762 mtrr_print_out_one_result(i); 763 printk(KERN_INFO "\n"); 764 } 765 766 i++; 767 } 768 } 769 770 /* Try to find the optimal index: */ 771 index_good = mtrr_search_optimal_index(); 772 773 if (index_good != -1) { 774 printk(KERN_INFO "Found optimal setting for mtrr clean up\n"); 775 i = index_good; 776 mtrr_print_out_one_result(i); 777 778 /* Convert ranges to var ranges state: */ 779 chunk_size = result[i].chunk_sizek; 780 chunk_size <<= 10; 781 gran_size = result[i].gran_sizek; 782 gran_size <<= 10; 783 x86_setup_var_mtrrs(range, nr_range, chunk_size, gran_size); 784 set_var_mtrr_all(address_bits); 785 printk(KERN_DEBUG "New variable MTRRs\n"); 786 print_out_mtrr_range_state(); 787 return 1; 788 } else { 789 /* print out all */ 790 for (i = 0; i < NUM_RESULT; i++) 791 mtrr_print_out_one_result(i); 792 } 793 794 printk(KERN_INFO "mtrr_cleanup: can not find optimal value\n"); 795 printk(KERN_INFO "please specify mtrr_gran_size/mtrr_chunk_size\n"); 796 797 return 0; 798 } 799 #else 800 int __init mtrr_cleanup(unsigned address_bits) 801 { 802 return 0; 803 } 804 #endif 805 806 static int disable_mtrr_trim; 807 808 static int __init disable_mtrr_trim_setup(char *str) 809 { 810 disable_mtrr_trim = 1; 811 return 0; 812 } 813 early_param("disable_mtrr_trim", disable_mtrr_trim_setup); 814 815 /* 816 * Newer AMD K8s and later CPUs have a special magic MSR way to force WB 817 * for memory >4GB. Check for that here. 818 * Note this won't check if the MTRRs < 4GB where the magic bit doesn't 819 * apply to are wrong, but so far we don't know of any such case in the wild. 820 */ 821 #define Tom2Enabled (1U << 21) 822 #define Tom2ForceMemTypeWB (1U << 22) 823 824 int __init amd_special_default_mtrr(void) 825 { 826 u32 l, h; 827 828 if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) 829 return 0; 830 if (boot_cpu_data.x86 < 0xf) 831 return 0; 832 /* In case some hypervisor doesn't pass SYSCFG through: */ 833 if (rdmsr_safe(MSR_K8_SYSCFG, &l, &h) < 0) 834 return 0; 835 /* 836 * Memory between 4GB and top of mem is forced WB by this magic bit. 837 * Reserved before K8RevF, but should be zero there. 838 */ 839 if ((l & (Tom2Enabled | Tom2ForceMemTypeWB)) == 840 (Tom2Enabled | Tom2ForceMemTypeWB)) 841 return 1; 842 return 0; 843 } 844 845 static u64 __init 846 real_trim_memory(unsigned long start_pfn, unsigned long limit_pfn) 847 { 848 u64 trim_start, trim_size; 849 850 trim_start = start_pfn; 851 trim_start <<= PAGE_SHIFT; 852 853 trim_size = limit_pfn; 854 trim_size <<= PAGE_SHIFT; 855 trim_size -= trim_start; 856 857 return e820_update_range(trim_start, trim_size, E820_RAM, E820_RESERVED); 858 } 859 860 /** 861 * mtrr_trim_uncached_memory - trim RAM not covered by MTRRs 862 * @end_pfn: ending page frame number 863 * 864 * Some buggy BIOSes don't setup the MTRRs properly for systems with certain 865 * memory configurations. This routine checks that the highest MTRR matches 866 * the end of memory, to make sure the MTRRs having a write back type cover 867 * all of the memory the kernel is intending to use. If not, it'll trim any 868 * memory off the end by adjusting end_pfn, removing it from the kernel's 869 * allocation pools, warning the user with an obnoxious message. 870 */ 871 int __init mtrr_trim_uncached_memory(unsigned long end_pfn) 872 { 873 unsigned long i, base, size, highest_pfn = 0, def, dummy; 874 mtrr_type type; 875 u64 total_trim_size; 876 /* extra one for all 0 */ 877 int num[MTRR_NUM_TYPES + 1]; 878 879 /* 880 * Make sure we only trim uncachable memory on machines that 881 * support the Intel MTRR architecture: 882 */ 883 if (!is_cpu(INTEL) || disable_mtrr_trim) 884 return 0; 885 886 rdmsr(MSR_MTRRdefType, def, dummy); 887 def &= 0xff; 888 if (def != MTRR_TYPE_UNCACHABLE) 889 return 0; 890 891 /* Get it and store it aside: */ 892 memset(range_state, 0, sizeof(range_state)); 893 for (i = 0; i < num_var_ranges; i++) { 894 mtrr_if->get(i, &base, &size, &type); 895 range_state[i].base_pfn = base; 896 range_state[i].size_pfn = size; 897 range_state[i].type = type; 898 } 899 900 /* Find highest cached pfn: */ 901 for (i = 0; i < num_var_ranges; i++) { 902 type = range_state[i].type; 903 if (type != MTRR_TYPE_WRBACK) 904 continue; 905 base = range_state[i].base_pfn; 906 size = range_state[i].size_pfn; 907 if (highest_pfn < base + size) 908 highest_pfn = base + size; 909 } 910 911 /* kvm/qemu doesn't have mtrr set right, don't trim them all: */ 912 if (!highest_pfn) { 913 printk(KERN_INFO "CPU MTRRs all blank - virtualized system.\n"); 914 return 0; 915 } 916 917 /* Check entries number: */ 918 memset(num, 0, sizeof(num)); 919 for (i = 0; i < num_var_ranges; i++) { 920 type = range_state[i].type; 921 if (type >= MTRR_NUM_TYPES) 922 continue; 923 size = range_state[i].size_pfn; 924 if (!size) 925 type = MTRR_NUM_TYPES; 926 num[type]++; 927 } 928 929 /* No entry for WB? */ 930 if (!num[MTRR_TYPE_WRBACK]) 931 return 0; 932 933 /* Check if we only had WB and UC: */ 934 if (num[MTRR_TYPE_WRBACK] + num[MTRR_TYPE_UNCACHABLE] != 935 num_var_ranges - num[MTRR_NUM_TYPES]) 936 return 0; 937 938 memset(range, 0, sizeof(range)); 939 nr_range = 0; 940 if (mtrr_tom2) { 941 range[nr_range].start = (1ULL<<(32 - PAGE_SHIFT)); 942 range[nr_range].end = mtrr_tom2 >> PAGE_SHIFT; 943 if (highest_pfn < range[nr_range].end) 944 highest_pfn = range[nr_range].end; 945 nr_range++; 946 } 947 nr_range = x86_get_mtrr_mem_range(range, nr_range, 0, 0); 948 949 /* Check the head: */ 950 total_trim_size = 0; 951 if (range[0].start) 952 total_trim_size += real_trim_memory(0, range[0].start); 953 954 /* Check the holes: */ 955 for (i = 0; i < nr_range - 1; i++) { 956 if (range[i].end < range[i+1].start) 957 total_trim_size += real_trim_memory(range[i].end, 958 range[i+1].start); 959 } 960 961 /* Check the top: */ 962 i = nr_range - 1; 963 if (range[i].end < end_pfn) 964 total_trim_size += real_trim_memory(range[i].end, 965 end_pfn); 966 967 if (total_trim_size) { 968 pr_warning("WARNING: BIOS bug: CPU MTRRs don't cover all of memory, losing %lluMB of RAM.\n", total_trim_size >> 20); 969 970 if (!changed_by_mtrr_cleanup) 971 WARN_ON(1); 972 973 pr_info("update e820 for mtrr\n"); 974 update_e820(); 975 976 return 1; 977 } 978 979 return 0; 980 } 981