arch/x86/kernel/cpu/microcode/intel.c

   1 /*
   2  * Intel CPU Microcode Update Driver for Linux
   3  *
   4  * Copyright (C) 2000-2006 Tigran Aivazian <aivazian.tigran@gmail.com>
   5  *               2006 Shaohua Li <shaohua.li@intel.com>
   6  *
   7  * Intel CPU microcode early update for Linux
   8  *
   9  * Copyright (C) 2012 Fenghua Yu <fenghua.yu@intel.com>
  10  *                    H Peter Anvin" <hpa@zytor.com>
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version
  15  * 2 of the License, or (at your option) any later version.
  16  */
  17
  18 /*
  19  * This needs to be before all headers so that pr_debug in printk.h doesn't turn
  20  * printk calls into no_printk().
  21  *
  22  *#define DEBUG
  23  */
  24 #define pr_fmt(fmt) "microcode: " fmt
  25
  26 #include <linux/earlycpio.h>
  27 #include <linux/firmware.h>
  28 #include <linux/uaccess.h>
  29 #include <linux/vmalloc.h>
  30 #include <linux/initrd.h>
  31 #include <linux/kernel.h>
  32 #include <linux/slab.h>
  33 #include <linux/cpu.h>
  34 #include <linux/mm.h>
  35
  36 #include <asm/microcode_intel.h>
  37 #include <asm/intel-family.h>
  38 #include <asm/processor.h>
  39 #include <asm/tlbflush.h>
  40 #include <asm/setup.h>
  41 #include <asm/msr.h>
  42
  43 static const char ucode_path[] = "kernel/x86/microcode/GenuineIntel.bin";
  44
  45 /* Current microcode patch used in early patching on the APs. */
  46 static struct microcode_intel *intel_ucode_patch;
  47
  48 static inline bool cpu_signatures_match(unsigned int s1, unsigned int p1,
  49                                         unsigned int s2, unsigned int p2)
  50 {
  51         if (s1 != s2)
  52                 return false;
  53
  54         /* Processor flags are either both 0 ... */
  55         if (!p1 && !p2)
  56                 return true;
  57
  58         /* ... or they intersect. */
  59         return p1 & p2;
  60 }
  61
  62 /*
  63  * Returns 1 if update has been found, 0 otherwise.
  64  */
  65 static int find_matching_signature(void *mc, unsigned int csig, int cpf)
  66 {
  67         struct microcode_header_intel *mc_hdr = mc;
  68         struct extended_sigtable *ext_hdr;
  69         struct extended_signature *ext_sig;
  70         int i;
  71
  72         if (cpu_signatures_match(csig, cpf, mc_hdr->sig, mc_hdr->pf))
  73                 return 1;
  74
  75         /* Look for ext. headers: */
  76         if (get_totalsize(mc_hdr) <= get_datasize(mc_hdr) + MC_HEADER_SIZE)
  77                 return 0;
  78
  79         ext_hdr = mc + get_datasize(mc_hdr) + MC_HEADER_SIZE;
  80         ext_sig = (void *)ext_hdr + EXT_HEADER_SIZE;
  81
  82         for (i = 0; i < ext_hdr->count; i++) {
  83                 if (cpu_signatures_match(csig, cpf, ext_sig->sig, ext_sig->pf))
  84                         return 1;
  85                 ext_sig++;
  86         }
  87         return 0;
  88 }
  89
  90 /*
  91  * Returns 1 if update has been found, 0 otherwise.
  92  */
  93 static int has_newer_microcode(void *mc, unsigned int csig, int cpf, int new_rev)
  94 {
  95         struct microcode_header_intel *mc_hdr = mc;
  96
  97         if (mc_hdr->rev <= new_rev)
  98                 return 0;
  99
 100         return find_matching_signature(mc, csig, cpf);
 101 }
 102
 103 /*
 104  * Given CPU signature and a microcode patch, this function finds if the
 105  * microcode patch has matching family and model with the CPU.
 106  *
 107  * %true - if there's a match
 108  * %false - otherwise
 109  */
 110 static bool microcode_matches(struct microcode_header_intel *mc_header,
 111                               unsigned long sig)
 112 {
 113         unsigned long total_size = get_totalsize(mc_header);
 114         unsigned long data_size = get_datasize(mc_header);
 115         struct extended_sigtable *ext_header;
 116         unsigned int fam_ucode, model_ucode;
 117         struct extended_signature *ext_sig;
 118         unsigned int fam, model;
 119         int ext_sigcount, i;
 120
 121         fam   = x86_family(sig);
 122         model = x86_model(sig);
 123
 124         fam_ucode   = x86_family(mc_header->sig);
 125         model_ucode = x86_model(mc_header->sig);
 126
 127         if (fam == fam_ucode && model == model_ucode)
 128                 return true;
 129
 130         /* Look for ext. headers: */
 131         if (total_size <= data_size + MC_HEADER_SIZE)
 132                 return false;
 133
 134         ext_header   = (void *) mc_header + data_size + MC_HEADER_SIZE;
 135         ext_sig      = (void *)ext_header + EXT_HEADER_SIZE;
 136         ext_sigcount = ext_header->count;
 137
 138         for (i = 0; i < ext_sigcount; i++) {
 139                 fam_ucode   = x86_family(ext_sig->sig);
 140                 model_ucode = x86_model(ext_sig->sig);
 141
 142                 if (fam == fam_ucode && model == model_ucode)
 143                         return true;
 144
 145                 ext_sig++;
 146         }
 147         return false;
 148 }
 149
 150 static struct ucode_patch *memdup_patch(void *data, unsigned int size)
 151 {
 152         struct ucode_patch *p;
 153
 154         p = kzalloc(sizeof(struct ucode_patch), GFP_KERNEL);
 155         if (!p)
 156                 return NULL;
 157
 158         p->data = kmemdup(data, size, GFP_KERNEL);
 159         if (!p->data) {
 160                 kfree(p);
 161                 return NULL;
 162         }
 163
 164         return p;
 165 }
 166
 167 static void save_microcode_patch(void *data, unsigned int size)
 168 {
 169         struct microcode_header_intel *mc_hdr, *mc_saved_hdr;
 170         struct ucode_patch *iter, *tmp, *p = NULL;
 171         bool prev_found = false;
 172         unsigned int sig, pf;
 173
 174         mc_hdr = (struct microcode_header_intel *)data;
 175
 176         list_for_each_entry_safe(iter, tmp, &microcode_cache, plist) {
 177                 mc_saved_hdr = (struct microcode_header_intel *)iter->data;
 178                 sig          = mc_saved_hdr->sig;
 179                 pf           = mc_saved_hdr->pf;
 180
 181                 if (find_matching_signature(data, sig, pf)) {
 182                         prev_found = true;
 183
 184                         if (mc_hdr->rev <= mc_saved_hdr->rev)
 185                                 continue;
 186
 187                         p = memdup_patch(data, size);
 188                         if (!p)
 189                                 pr_err("Error allocating buffer %p\n", data);
 190                         else
 191                                 list_replace(&iter->plist, &p->plist);
 192                 }
 193         }
 194
 195         /*
 196          * There weren't any previous patches found in the list cache; save the
 197          * newly found.
 198          */
 199         if (!prev_found) {
 200                 p = memdup_patch(data, size);
 201                 if (!p)
 202                         pr_err("Error allocating buffer for %p\n", data);
 203                 else
 204                         list_add_tail(&p->plist, &microcode_cache);
 205         }
 206
 207         if (!p)
 208                 return;
 209
 210         /*
 211          * Save for early loading. On 32-bit, that needs to be a physical
 212          * address as the APs are running from physical addresses, before
 213          * paging has been enabled.
 214          */
 215         if (IS_ENABLED(CONFIG_X86_32))
 216                 intel_ucode_patch = (struct microcode_intel *)__pa_nodebug(p->data);
 217         else
 218                 intel_ucode_patch = p->data;
 219 }
 220
 221 static int microcode_sanity_check(void *mc, int print_err)
 222 {
 223         unsigned long total_size, data_size, ext_table_size;
 224         struct microcode_header_intel *mc_header = mc;
 225         struct extended_sigtable *ext_header = NULL;
 226         u32 sum, orig_sum, ext_sigcount = 0, i;
 227         struct extended_signature *ext_sig;
 228
 229         total_size = get_totalsize(mc_header);
 230         data_size = get_datasize(mc_header);
 231
 232         if (data_size + MC_HEADER_SIZE > total_size) {
 233                 if (print_err)
 234                         pr_err("Error: bad microcode data file size.\n");
 235                 return -EINVAL;
 236         }
 237
 238         if (mc_header->ldrver != 1 || mc_header->hdrver != 1) {
 239                 if (print_err)
 240                         pr_err("Error: invalid/unknown microcode update format.\n");
 241                 return -EINVAL;
 242         }
 243
 244         ext_table_size = total_size - (MC_HEADER_SIZE + data_size);
 245         if (ext_table_size) {
 246                 u32 ext_table_sum = 0;
 247                 u32 *ext_tablep;
 248
 249                 if ((ext_table_size < EXT_HEADER_SIZE)
 250                  || ((ext_table_size - EXT_HEADER_SIZE) % EXT_SIGNATURE_SIZE)) {
 251                         if (print_err)
 252                                 pr_err("Error: truncated extended signature table.\n");
 253                         return -EINVAL;
 254                 }
 255
 256                 ext_header = mc + MC_HEADER_SIZE + data_size;
 257                 if (ext_table_size != exttable_size(ext_header)) {
 258                         if (print_err)
 259                                 pr_err("Error: extended signature table size mismatch.\n");
 260                         return -EFAULT;
 261                 }
 262
 263                 ext_sigcount = ext_header->count;
 264
 265                 /*
 266                  * Check extended table checksum: the sum of all dwords that
 267                  * comprise a valid table must be 0.
 268                  */
 269                 ext_tablep = (u32 *)ext_header;
 270
 271                 i = ext_table_size / sizeof(u32);
 272                 while (i--)
 273                         ext_table_sum += ext_tablep[i];
 274
 275                 if (ext_table_sum) {
 276                         if (print_err)
 277                                 pr_warn("Bad extended signature table checksum, aborting.\n");
 278                         return -EINVAL;
 279                 }
 280         }
 281
 282         /*
 283          * Calculate the checksum of update data and header. The checksum of
 284          * valid update data and header including the extended signature table
 285          * must be 0.
 286          */
 287         orig_sum = 0;
 288         i = (MC_HEADER_SIZE + data_size) / sizeof(u32);
 289         while (i--)
 290                 orig_sum += ((u32 *)mc)[i];
 291
 292         if (orig_sum) {
 293                 if (print_err)
 294                         pr_err("Bad microcode data checksum, aborting.\n");
 295                 return -EINVAL;
 296         }
 297
 298         if (!ext_table_size)
 299                 return 0;
 300
 301         /*
 302          * Check extended signature checksum: 0 => valid.
 303          */
 304         for (i = 0; i < ext_sigcount; i++) {
 305                 ext_sig = (void *)ext_header + EXT_HEADER_SIZE +
 306                           EXT_SIGNATURE_SIZE * i;
 307
 308                 sum = (mc_header->sig + mc_header->pf + mc_header->cksum) -
 309                       (ext_sig->sig + ext_sig->pf + ext_sig->cksum);
 310                 if (sum) {
 311                         if (print_err)
 312                                 pr_err("Bad extended signature checksum, aborting.\n");
 313                         return -EINVAL;
 314                 }
 315         }
 316         return 0;
 317 }
 318
 319 /*
 320  * Get microcode matching with BSP's model. Only CPUs with the same model as
 321  * BSP can stay in the platform.
 322  */
 323 static struct microcode_intel *
 324 scan_microcode(void *data, size_t size, struct ucode_cpu_info *uci, bool save)
 325 {
 326         struct microcode_header_intel *mc_header;
 327         struct microcode_intel *patch = NULL;
 328         unsigned int mc_size;
 329
 330         while (size) {
 331                 if (size < sizeof(struct microcode_header_intel))
 332                         break;
 333
 334                 mc_header = (struct microcode_header_intel *)data;
 335
 336                 mc_size = get_totalsize(mc_header);
 337                 if (!mc_size ||
 338                     mc_size > size ||
 339                     microcode_sanity_check(data, 0) < 0)
 340                         break;
 341
 342                 size -= mc_size;
 343
 344                 if (!microcode_matches(mc_header, uci->cpu_sig.sig)) {
 345                         data += mc_size;
 346                         continue;
 347                 }
 348
 349                 if (save) {
 350                         save_microcode_patch(data, mc_size);
 351                         goto next;
 352                 }
 353
 354
 355                 if (!patch) {
 356                         if (!has_newer_microcode(data,
 357                                                  uci->cpu_sig.sig,
 358                                                  uci->cpu_sig.pf,
 359                                                  uci->cpu_sig.rev))
 360                                 goto next;
 361
 362                 } else {
 363                         struct microcode_header_intel *phdr = &patch->hdr;
 364
 365                         if (!has_newer_microcode(data,
 366                                                  phdr->sig,
 367                                                  phdr->pf,
 368                                                  phdr->rev))
 369                                 goto next;
 370                 }
 371
 372                 /* We have a newer patch, save it. */
 373                 patch = data;
 374
 375 next:
 376                 data += mc_size;
 377         }
 378
 379         if (size)
 380                 return NULL;
 381
 382         return patch;
 383 }
 384
 385 static int collect_cpu_info_early(struct ucode_cpu_info *uci)
 386 {
 387         unsigned int val[2];
 388         unsigned int family, model;
 389         struct cpu_signature csig = { 0 };
 390         unsigned int eax, ebx, ecx, edx;
 391
 392         memset(uci, 0, sizeof(*uci));
 393
 394         eax = 0x00000001;
 395         ecx = 0;
 396         native_cpuid(&eax, &ebx, &ecx, &edx);
 397         csig.sig = eax;
 398
 399         family = x86_family(eax);
 400         model  = x86_model(eax);
 401
 402         if ((model >= 5) || (family > 6)) {
 403                 /* get processor flags from MSR 0x17 */
 404                 native_rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
 405                 csig.pf = 1 << ((val[1] >> 18) & 7);
 406         }
 407
 408         csig.rev = intel_get_microcode_revision();
 409
 410         uci->cpu_sig = csig;
 411         uci->valid = 1;
 412
 413         return 0;
 414 }
 415
 416 static void show_saved_mc(void)
 417 {
 418 #ifdef DEBUG
 419         int i = 0, j;
 420         unsigned int sig, pf, rev, total_size, data_size, date;
 421         struct ucode_cpu_info uci;
 422         struct ucode_patch *p;
 423
 424         if (list_empty(&microcode_cache)) {
 425                 pr_debug("no microcode data saved.\n");
 426                 return;
 427         }
 428
 429         collect_cpu_info_early(&uci);
 430
 431         sig     = uci.cpu_sig.sig;
 432         pf      = uci.cpu_sig.pf;
 433         rev     = uci.cpu_sig.rev;
 434         pr_debug("CPU: sig=0x%x, pf=0x%x, rev=0x%x\n", sig, pf, rev);
 435
 436         list_for_each_entry(p, &microcode_cache, plist) {
 437                 struct microcode_header_intel *mc_saved_header;
 438                 struct extended_sigtable *ext_header;
 439                 struct extended_signature *ext_sig;
 440                 int ext_sigcount;
 441
 442                 mc_saved_header = (struct microcode_header_intel *)p->data;
 443
 444                 sig     = mc_saved_header->sig;
 445                 pf      = mc_saved_header->pf;
 446                 rev     = mc_saved_header->rev;
 447                 date    = mc_saved_header->date;
 448
 449                 total_size      = get_totalsize(mc_saved_header);
 450                 data_size       = get_datasize(mc_saved_header);
 451
 452                 pr_debug("mc_saved[%d]: sig=0x%x, pf=0x%x, rev=0x%x, total size=0x%x, date = %04x-%02x-%02x\n",
 453                          i++, sig, pf, rev, total_size,
 454                          date & 0xffff,
 455                          date >> 24,
 456                          (date >> 16) & 0xff);
 457
 458                 /* Look for ext. headers: */
 459                 if (total_size <= data_size + MC_HEADER_SIZE)
 460                         continue;
 461
 462                 ext_header = (void *)mc_saved_header + data_size + MC_HEADER_SIZE;
 463                 ext_sigcount = ext_header->count;
 464                 ext_sig = (void *)ext_header + EXT_HEADER_SIZE;
 465
 466                 for (j = 0; j < ext_sigcount; j++) {
 467                         sig = ext_sig->sig;
 468                         pf = ext_sig->pf;
 469
 470                         pr_debug("\tExtended[%d]: sig=0x%x, pf=0x%x\n",
 471                                  j, sig, pf);
 472
 473                         ext_sig++;
 474                 }
 475         }
 476 #endif
 477 }
 478
 479 /*
 480  * Save this microcode patch. It will be loaded early when a CPU is
 481  * hot-added or resumes.
 482  */
 483 static void save_mc_for_early(u8 *mc, unsigned int size)
 484 {
 485 #ifdef CONFIG_HOTPLUG_CPU
 486         /* Synchronization during CPU hotplug. */
 487         static DEFINE_MUTEX(x86_cpu_microcode_mutex);
 488
 489         mutex_lock(&x86_cpu_microcode_mutex);
 490
 491         save_microcode_patch(mc, size);
 492         show_saved_mc();
 493
 494         mutex_unlock(&x86_cpu_microcode_mutex);
 495 #endif
 496 }
 497
 498 static bool load_builtin_intel_microcode(struct cpio_data *cp)
 499 {
 500         unsigned int eax = 1, ebx, ecx = 0, edx;
 501         char name[30];
 502
 503         if (IS_ENABLED(CONFIG_X86_32))
 504                 return false;
 505
 506         native_cpuid(&eax, &ebx, &ecx, &edx);
 507
 508         sprintf(name, "intel-ucode/%02x-%02x-%02x",
 509                       x86_family(eax), x86_model(eax), x86_stepping(eax));
 510
 511         return get_builtin_firmware(cp, name);
 512 }
 513
 514 /*
 515  * Print ucode update info.
 516  */
 517 static void
 518 print_ucode_info(struct ucode_cpu_info *uci, unsigned int date)
 519 {
 520         pr_info_once("microcode updated early to revision 0x%x, date = %04x-%02x-%02x\n",
 521                      uci->cpu_sig.rev,
 522                      date & 0xffff,
 523                      date >> 24,
 524                      (date >> 16) & 0xff);
 525 }
 526
 527 #ifdef CONFIG_X86_32
 528
 529 static int delay_ucode_info;
 530 static int current_mc_date;
 531
 532 /*
 533  * Print early updated ucode info after printk works. This is delayed info dump.
 534  */
 535 void show_ucode_info_early(void)
 536 {
 537         struct ucode_cpu_info uci;
 538
 539         if (delay_ucode_info) {
 540                 collect_cpu_info_early(&uci);
 541                 print_ucode_info(&uci, current_mc_date);
 542                 delay_ucode_info = 0;
 543         }
 544 }
 545
 546 /*
 547  * At this point, we can not call printk() yet. Delay printing microcode info in
 548  * show_ucode_info_early() until printk() works.
 549  */
 550 static void print_ucode(struct ucode_cpu_info *uci)
 551 {
 552         struct microcode_intel *mc;
 553         int *delay_ucode_info_p;
 554         int *current_mc_date_p;
 555
 556         mc = uci->mc;
 557         if (!mc)
 558                 return;
 559
 560         delay_ucode_info_p = (int *)__pa_nodebug(&delay_ucode_info);
 561         current_mc_date_p = (int *)__pa_nodebug(&current_mc_date);
 562
 563         *delay_ucode_info_p = 1;
 564         *current_mc_date_p = mc->hdr.date;
 565 }
 566 #else
 567
 568 static inline void print_ucode(struct ucode_cpu_info *uci)
 569 {
 570         struct microcode_intel *mc;
 571
 572         mc = uci->mc;
 573         if (!mc)
 574                 return;
 575
 576         print_ucode_info(uci, mc->hdr.date);
 577 }
 578 #endif
 579
 580 static int apply_microcode_early(struct ucode_cpu_info *uci, bool early)
 581 {
 582         struct microcode_intel *mc;
 583         u32 rev;
 584
 585         mc = uci->mc;
 586         if (!mc)
 587                 return 0;
 588
 589         /* write microcode via MSR 0x79 */
 590         native_wrmsrl(MSR_IA32_UCODE_WRITE, (unsigned long)mc->bits);
 591
 592         rev = intel_get_microcode_revision();
 593         if (rev != mc->hdr.rev)
 594                 return -1;
 595
 596         uci->cpu_sig.rev = rev;
 597
 598         if (early)
 599                 print_ucode(uci);
 600         else
 601                 print_ucode_info(uci, mc->hdr.date);
 602
 603         return 0;
 604 }
 605
 606 int __init save_microcode_in_initrd_intel(void)
 607 {
 608         struct ucode_cpu_info uci;
 609         struct cpio_data cp;
 610
 611         /*
 612          * initrd is going away, clear patch ptr. We will scan the microcode one
 613          * last time before jettisoning and save a patch, if found. Then we will
 614          * update that pointer too, with a stable patch address to use when
 615          * resuming the cores.
 616          */
 617         intel_ucode_patch = NULL;
 618
 619         if (!load_builtin_intel_microcode(&cp))
 620                 cp = find_microcode_in_initrd(ucode_path, false);
 621
 622         if (!(cp.data && cp.size))
 623                 return 0;
 624
 625         collect_cpu_info_early(&uci);
 626
 627         scan_microcode(cp.data, cp.size, &uci, true);
 628
 629         show_saved_mc();
 630
 631         return 0;
 632 }
 633
 634 /*
 635  * @res_patch, output: a pointer to the patch we found.
 636  */
 637 static struct microcode_intel *__load_ucode_intel(struct ucode_cpu_info *uci)
 638 {
 639         static const char *path;
 640         struct cpio_data cp;
 641         bool use_pa;
 642
 643         if (IS_ENABLED(CONFIG_X86_32)) {
 644                 path      = (const char *)__pa_nodebug(ucode_path);
 645                 use_pa    = true;
 646         } else {
 647                 path      = ucode_path;
 648                 use_pa    = false;
 649         }
 650
 651         /* try built-in microcode first */
 652         if (!load_builtin_intel_microcode(&cp))
 653                 cp = find_microcode_in_initrd(path, use_pa);
 654
 655         if (!(cp.data && cp.size))
 656                 return NULL;
 657
 658         collect_cpu_info_early(uci);
 659
 660         return scan_microcode(cp.data, cp.size, uci, false);
 661 }
 662
 663 void __init load_ucode_intel_bsp(void)
 664 {
 665         struct microcode_intel *patch;
 666         struct ucode_cpu_info uci;
 667
 668         patch = __load_ucode_intel(&uci);
 669         if (!patch)
 670                 return;
 671
 672         uci.mc = patch;
 673
 674         apply_microcode_early(&uci, true);
 675 }
 676
 677 void load_ucode_intel_ap(void)
 678 {
 679         struct microcode_intel *patch, **iup;
 680         struct ucode_cpu_info uci;
 681
 682         if (IS_ENABLED(CONFIG_X86_32))
 683                 iup = (struct microcode_intel **) __pa_nodebug(&intel_ucode_patch);
 684         else
 685                 iup = &intel_ucode_patch;
 686
 687 reget:
 688         if (!*iup) {
 689                 patch = __load_ucode_intel(&uci);
 690                 if (!patch)
 691                         return;
 692
 693                 *iup = patch;
 694         }
 695
 696         uci.mc = *iup;
 697
 698         if (apply_microcode_early(&uci, true)) {
 699                 /* Mixed-silicon system? Try to refetch the proper patch: */
 700                 *iup = NULL;
 701
 702                 goto reget;
 703         }
 704 }
 705
 706 static struct microcode_intel *find_patch(struct ucode_cpu_info *uci)
 707 {
 708         struct microcode_header_intel *phdr;
 709         struct ucode_patch *iter, *tmp;
 710
 711         list_for_each_entry_safe(iter, tmp, &microcode_cache, plist) {
 712
 713                 phdr = (struct microcode_header_intel *)iter->data;
 714
 715                 if (phdr->rev <= uci->cpu_sig.rev)
 716                         continue;
 717
 718                 if (!find_matching_signature(phdr,
 719                                              uci->cpu_sig.sig,
 720                                              uci->cpu_sig.pf))
 721                         continue;
 722
 723                 return iter->data;
 724         }
 725         return NULL;
 726 }
 727
 728 void reload_ucode_intel(void)
 729 {
 730         struct microcode_intel *p;
 731         struct ucode_cpu_info uci;
 732
 733         collect_cpu_info_early(&uci);
 734
 735         p = find_patch(&uci);
 736         if (!p)
 737                 return;
 738
 739         uci.mc = p;
 740
 741         apply_microcode_early(&uci, false);
 742 }
 743
 744 static int collect_cpu_info(int cpu_num, struct cpu_signature *csig)
 745 {
 746         static struct cpu_signature prev;
 747         struct cpuinfo_x86 *c = &cpu_data(cpu_num);
 748         unsigned int val[2];
 749
 750         memset(csig, 0, sizeof(*csig));
 751
 752         csig->sig = cpuid_eax(0x00000001);
 753
 754         if ((c->x86_model >= 5) || (c->x86 > 6)) {
 755                 /* get processor flags from MSR 0x17 */
 756                 rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
 757                 csig->pf = 1 << ((val[1] >> 18) & 7);
 758         }
 759
 760         csig->rev = c->microcode;
 761
 762         /* No extra locking on prev, races are harmless. */
 763         if (csig->sig != prev.sig || csig->pf != prev.pf || csig->rev != prev.rev) {
 764                 pr_info("sig=0x%x, pf=0x%x, revision=0x%x\n",
 765                         csig->sig, csig->pf, csig->rev);
 766                 prev = *csig;
 767         }
 768
 769         return 0;
 770 }
 771
 772 static int apply_microcode_intel(int cpu)
 773 {
 774         struct microcode_intel *mc;
 775         struct ucode_cpu_info *uci;
 776         struct cpuinfo_x86 *c;
 777         static int prev_rev;
 778         u32 rev;
 779
 780         /* We should bind the task to the CPU */
 781         if (WARN_ON(raw_smp_processor_id() != cpu))
 782                 return -1;
 783
 784         uci = ucode_cpu_info + cpu;
 785         mc = uci->mc;
 786         if (!mc) {
 787                 /* Look for a newer patch in our cache: */
 788                 mc = find_patch(uci);
 789                 if (!mc)
 790                         return 0;
 791         }
 792
 793         /* write microcode via MSR 0x79 */
 794         wrmsrl(MSR_IA32_UCODE_WRITE, (unsigned long)mc->bits);
 795
 796         rev = intel_get_microcode_revision();
 797
 798         if (rev != mc->hdr.rev) {
 799                 pr_err("CPU%d update to revision 0x%x failed\n",
 800                        cpu, mc->hdr.rev);
 801                 return -1;
 802         }
 803
 804         if (rev != prev_rev) {
 805                 pr_info("updated to revision 0x%x, date = %04x-%02x-%02x\n",
 806                         rev,
 807                         mc->hdr.date & 0xffff,
 808                         mc->hdr.date >> 24,
 809                         (mc->hdr.date >> 16) & 0xff);
 810                 prev_rev = rev;
 811         }
 812
 813         c = &cpu_data(cpu);
 814
 815         uci->cpu_sig.rev = rev;
 816         c->microcode = rev;
 817
 818         return 0;
 819 }
 820
 821 static enum ucode_state generic_load_microcode(int cpu, void *data, size_t size,
 822                                 int (*get_ucode_data)(void *, const void *, size_t))
 823 {
 824         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 825         u8 *ucode_ptr = data, *new_mc = NULL, *mc = NULL;
 826         int new_rev = uci->cpu_sig.rev;
 827         unsigned int leftover = size;
 828         unsigned int curr_mc_size = 0, new_mc_size = 0;
 829         unsigned int csig, cpf;
 830
 831         while (leftover) {
 832                 struct microcode_header_intel mc_header;
 833                 unsigned int mc_size;
 834
 835                 if (leftover < sizeof(mc_header)) {
 836                         pr_err("error! Truncated header in microcode data file\n");
 837                         break;
 838                 }
 839
 840                 if (get_ucode_data(&mc_header, ucode_ptr, sizeof(mc_header)))
 841                         break;
 842
 843                 mc_size = get_totalsize(&mc_header);
 844                 if (!mc_size || mc_size > leftover) {
 845                         pr_err("error! Bad data in microcode data file\n");
 846                         break;
 847                 }
 848
 849                 /* For performance reasons, reuse mc area when possible */
 850                 if (!mc || mc_size > curr_mc_size) {
 851                         vfree(mc);
 852                         mc = vmalloc(mc_size);
 853                         if (!mc)
 854                                 break;
 855                         curr_mc_size = mc_size;
 856                 }
 857
 858                 if (get_ucode_data(mc, ucode_ptr, mc_size) ||
 859                     microcode_sanity_check(mc, 1) < 0) {
 860                         break;
 861                 }
 862
 863                 csig = uci->cpu_sig.sig;
 864                 cpf = uci->cpu_sig.pf;
 865                 if (has_newer_microcode(mc, csig, cpf, new_rev)) {
 866                         vfree(new_mc);
 867                         new_rev = mc_header.rev;
 868                         new_mc  = mc;
 869                         new_mc_size = mc_size;
 870                         mc = NULL;      /* trigger new vmalloc */
 871                 }
 872
 873                 ucode_ptr += mc_size;
 874                 leftover  -= mc_size;
 875         }
 876
 877         vfree(mc);
 878
 879         if (leftover) {
 880                 vfree(new_mc);
 881                 return UCODE_ERROR;
 882         }
 883
 884         if (!new_mc)
 885                 return UCODE_NFOUND;
 886
 887         vfree(uci->mc);
 888         uci->mc = (struct microcode_intel *)new_mc;
 889
 890         /*
 891          * If early loading microcode is supported, save this mc into
 892          * permanent memory. So it will be loaded early when a CPU is hot added
 893          * or resumes.
 894          */
 895         save_mc_for_early(new_mc, new_mc_size);
 896
 897         pr_debug("CPU%d found a matching microcode update with version 0x%x (current=0x%x)\n",
 898                  cpu, new_rev, uci->cpu_sig.rev);
 899
 900         return UCODE_OK;
 901 }
 902
 903 static int get_ucode_fw(void *to, const void *from, size_t n)
 904 {
 905         memcpy(to, from, n);
 906         return 0;
 907 }
 908
 909 static bool is_blacklisted(unsigned int cpu)
 910 {
 911         struct cpuinfo_x86 *c = &cpu_data(cpu);
 912
 913         if (c->x86 == 6 && c->x86_model == INTEL_FAM6_BROADWELL_X) {
 914                 pr_err_once("late loading on model 79 is disabled.\n");
 915                 return true;
 916         }
 917
 918         return false;
 919 }
 920
 921 static enum ucode_state request_microcode_fw(int cpu, struct device *device,
 922                                              bool refresh_fw)
 923 {
 924         char name[30];
 925         struct cpuinfo_x86 *c = &cpu_data(cpu);
 926         const struct firmware *firmware;
 927         enum ucode_state ret;
 928
 929         if (is_blacklisted(cpu))
 930                 return UCODE_NFOUND;
 931
 932         sprintf(name, "intel-ucode/%02x-%02x-%02x",
 933                 c->x86, c->x86_model, c->x86_mask);
 934
 935         if (request_firmware_direct(&firmware, name, device)) {
 936                 pr_debug("data file %s load failed\n", name);
 937                 return UCODE_NFOUND;
 938         }
 939
 940         ret = generic_load_microcode(cpu, (void *)firmware->data,
 941                                      firmware->size, &get_ucode_fw);
 942
 943         release_firmware(firmware);
 944
 945         return ret;
 946 }
 947
 948 static int get_ucode_user(void *to, const void *from, size_t n)
 949 {
 950         return copy_from_user(to, from, n);
 951 }
 952
 953 static enum ucode_state
 954 request_microcode_user(int cpu, const void __user *buf, size_t size)
 955 {
 956         if (is_blacklisted(cpu))
 957                 return UCODE_NFOUND;
 958
 959         return generic_load_microcode(cpu, (void *)buf, size, &get_ucode_user);
 960 }
 961
 962 static struct microcode_ops microcode_intel_ops = {
 963         .request_microcode_user           = request_microcode_user,
 964         .request_microcode_fw             = request_microcode_fw,
 965         .collect_cpu_info                 = collect_cpu_info,
 966         .apply_microcode                  = apply_microcode_intel,
 967 };
 968
 969 struct microcode_ops * __init init_intel_microcode(void)
 970 {
 971         struct cpuinfo_x86 *c = &boot_cpu_data;
 972
 973         if (c->x86_vendor != X86_VENDOR_INTEL || c->x86 < 6 ||
 974             cpu_has(c, X86_FEATURE_IA64)) {
 975                 pr_err("Intel CPU family 0x%x not supported\n", c->x86);
 976                 return NULL;
 977         }
 978
 979         return &microcode_intel_ops;
 980 }