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

   1 /*
   2  * CPU Microcode Update Driver for Linux
   3  *
   4  * Copyright (C) 2000-2006 Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
   5  *            2006      Shaohua Li <shaohua.li@intel.com>
   6  *            2013-2016 Borislav Petkov <bp@alien8.de>
   7  *
   8  * X86 CPU microcode early update for Linux:
   9  *
  10  *      Copyright (C) 2012 Fenghua Yu <fenghua.yu@intel.com>
  11  *                         H Peter Anvin" <hpa@zytor.com>
  12  *                (C) 2015 Borislav Petkov <bp@alien8.de>
  13  *
  14  * This driver allows to upgrade microcode on x86 processors.
  15  *
  16  * This program is free software; you can redistribute it and/or
  17  * modify it under the terms of the GNU General Public License
  18  * as published by the Free Software Foundation; either version
  19  * 2 of the License, or (at your option) any later version.
  20  */
  21
  22 #define pr_fmt(fmt) "microcode: " fmt
  23
  24 #include <linux/platform_device.h>
  25 #include <linux/syscore_ops.h>
  26 #include <linux/miscdevice.h>
  27 #include <linux/capability.h>
  28 #include <linux/firmware.h>
  29 #include <linux/kernel.h>
  30 #include <linux/mutex.h>
  31 #include <linux/cpu.h>
  32 #include <linux/fs.h>
  33 #include <linux/mm.h>
  34
  35 #include <asm/microcode_intel.h>
  36 #include <asm/cpu_device_id.h>
  37 #include <asm/microcode_amd.h>
  38 #include <asm/perf_event.h>
  39 #include <asm/microcode.h>
  40 #include <asm/processor.h>
  41 #include <asm/cmdline.h>
  42 #include <asm/setup.h>
  43
  44 #define DRIVER_VERSION  "2.2"
  45
  46 static struct microcode_ops     *microcode_ops;
  47 static bool dis_ucode_ldr;
  48
  49 LIST_HEAD(microcode_cache);
  50
  51 /*
  52  * Synchronization.
  53  *
  54  * All non cpu-hotplug-callback call sites use:
  55  *
  56  * - microcode_mutex to synchronize with each other;
  57  * - get/put_online_cpus() to synchronize with
  58  *   the cpu-hotplug-callback call sites.
  59  *
  60  * We guarantee that only a single cpu is being
  61  * updated at any particular moment of time.
  62  */
  63 static DEFINE_MUTEX(microcode_mutex);
  64
  65 struct ucode_cpu_info           ucode_cpu_info[NR_CPUS];
  66
  67 /*
  68  * Operations that are run on a target cpu:
  69  */
  70
  71 struct cpu_info_ctx {
  72         struct cpu_signature    *cpu_sig;
  73         int                     err;
  74 };
  75
  76 static bool __init check_loader_disabled_bsp(void)
  77 {
  78         static const char *__dis_opt_str = "dis_ucode_ldr";
  79
  80 #ifdef CONFIG_X86_32
  81         const char *cmdline = (const char *)__pa_nodebug(boot_command_line);
  82         const char *option  = (const char *)__pa_nodebug(__dis_opt_str);
  83         bool *res = (bool *)__pa_nodebug(&dis_ucode_ldr);
  84
  85 #else /* CONFIG_X86_64 */
  86         const char *cmdline = boot_command_line;
  87         const char *option  = __dis_opt_str;
  88         bool *res = &dis_ucode_ldr;
  89 #endif
  90
  91         if (cmdline_find_option_bool(cmdline, option))
  92                 *res = true;
  93
  94         return *res;
  95 }
  96
  97 extern struct builtin_fw __start_builtin_fw[];
  98 extern struct builtin_fw __end_builtin_fw[];
  99
 100 bool get_builtin_firmware(struct cpio_data *cd, const char *name)
 101 {
 102 #ifdef CONFIG_FW_LOADER
 103         struct builtin_fw *b_fw;
 104
 105         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
 106                 if (!strcmp(name, b_fw->name)) {
 107                         cd->size = b_fw->size;
 108                         cd->data = b_fw->data;
 109                         return true;
 110                 }
 111         }
 112 #endif
 113         return false;
 114 }
 115
 116 void __init load_ucode_bsp(void)
 117 {
 118         int vendor;
 119         unsigned int family;
 120
 121         if (check_loader_disabled_bsp())
 122                 return;
 123
 124         if (!have_cpuid_p())
 125                 return;
 126
 127         vendor = x86_cpuid_vendor();
 128         family = x86_cpuid_family();
 129
 130         switch (vendor) {
 131         case X86_VENDOR_INTEL:
 132                 if (family >= 6)
 133                         load_ucode_intel_bsp();
 134                 break;
 135         case X86_VENDOR_AMD:
 136                 if (family >= 0x10)
 137                         load_ucode_amd_bsp(family);
 138                 break;
 139         default:
 140                 break;
 141         }
 142 }
 143
 144 static bool check_loader_disabled_ap(void)
 145 {
 146 #ifdef CONFIG_X86_32
 147         return *((bool *)__pa_nodebug(&dis_ucode_ldr));
 148 #else
 149         return dis_ucode_ldr;
 150 #endif
 151 }
 152
 153 void load_ucode_ap(void)
 154 {
 155         int vendor, family;
 156
 157         if (check_loader_disabled_ap())
 158                 return;
 159
 160         if (!have_cpuid_p())
 161                 return;
 162
 163         vendor = x86_cpuid_vendor();
 164         family = x86_cpuid_family();
 165
 166         switch (vendor) {
 167         case X86_VENDOR_INTEL:
 168                 if (family >= 6)
 169                         load_ucode_intel_ap();
 170                 break;
 171         case X86_VENDOR_AMD:
 172                 if (family >= 0x10)
 173                         load_ucode_amd_ap(family);
 174                 break;
 175         default:
 176                 break;
 177         }
 178 }
 179
 180 static int __init save_microcode_in_initrd(void)
 181 {
 182         struct cpuinfo_x86 *c = &boot_cpu_data;
 183
 184         switch (c->x86_vendor) {
 185         case X86_VENDOR_INTEL:
 186                 if (c->x86 >= 6)
 187                         return save_microcode_in_initrd_intel();
 188                 break;
 189         case X86_VENDOR_AMD:
 190                 if (c->x86 >= 0x10)
 191                         return save_microcode_in_initrd_amd(c->x86);
 192                 break;
 193         default:
 194                 break;
 195         }
 196
 197         return -EINVAL;
 198 }
 199
 200 struct cpio_data find_microcode_in_initrd(const char *path, bool use_pa)
 201 {
 202 #ifdef CONFIG_BLK_DEV_INITRD
 203         unsigned long start = 0;
 204         size_t size;
 205
 206 #ifdef CONFIG_X86_32
 207         struct boot_params *params;
 208
 209         if (use_pa)
 210                 params = (struct boot_params *)__pa_nodebug(&boot_params);
 211         else
 212                 params = &boot_params;
 213
 214         size = params->hdr.ramdisk_size;
 215
 216         /*
 217          * Set start only if we have an initrd image. We cannot use initrd_start
 218          * because it is not set that early yet.
 219          */
 220         if (size)
 221                 start = params->hdr.ramdisk_image;
 222
 223 # else /* CONFIG_X86_64 */
 224         size  = (unsigned long)boot_params.ext_ramdisk_size << 32;
 225         size |= boot_params.hdr.ramdisk_size;
 226
 227         if (size) {
 228                 start  = (unsigned long)boot_params.ext_ramdisk_image << 32;
 229                 start |= boot_params.hdr.ramdisk_image;
 230
 231                 start += PAGE_OFFSET;
 232         }
 233 # endif
 234
 235         /*
 236          * Did we relocate the ramdisk?
 237          *
 238          * So we possibly relocate the ramdisk *after* applying microcode on the
 239          * BSP so we rely on use_pa (use physical addresses) - even if it is not
 240          * absolutely correct - to determine whether we've done the ramdisk
 241          * relocation already.
 242          */
 243         if (!use_pa && relocated_ramdisk)
 244                 start = initrd_start;
 245
 246         return find_cpio_data(path, (void *)start, size, NULL);
 247 #else /* !CONFIG_BLK_DEV_INITRD */
 248         return (struct cpio_data){ NULL, 0, "" };
 249 #endif
 250 }
 251
 252 void reload_early_microcode(void)
 253 {
 254         int vendor, family;
 255
 256         vendor = x86_cpuid_vendor();
 257         family = x86_cpuid_family();
 258
 259         switch (vendor) {
 260         case X86_VENDOR_INTEL:
 261                 if (family >= 6)
 262                         reload_ucode_intel();
 263                 break;
 264         case X86_VENDOR_AMD:
 265                 if (family >= 0x10)
 266                         reload_ucode_amd();
 267                 break;
 268         default:
 269                 break;
 270         }
 271 }
 272
 273 static void collect_cpu_info_local(void *arg)
 274 {
 275         struct cpu_info_ctx *ctx = arg;
 276
 277         ctx->err = microcode_ops->collect_cpu_info(smp_processor_id(),
 278                                                    ctx->cpu_sig);
 279 }
 280
 281 static int collect_cpu_info_on_target(int cpu, struct cpu_signature *cpu_sig)
 282 {
 283         struct cpu_info_ctx ctx = { .cpu_sig = cpu_sig, .err = 0 };
 284         int ret;
 285
 286         ret = smp_call_function_single(cpu, collect_cpu_info_local, &ctx, 1);
 287         if (!ret)
 288                 ret = ctx.err;
 289
 290         return ret;
 291 }
 292
 293 static int collect_cpu_info(int cpu)
 294 {
 295         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 296         int ret;
 297
 298         memset(uci, 0, sizeof(*uci));
 299
 300         ret = collect_cpu_info_on_target(cpu, &uci->cpu_sig);
 301         if (!ret)
 302                 uci->valid = 1;
 303
 304         return ret;
 305 }
 306
 307 struct apply_microcode_ctx {
 308         int err;
 309 };
 310
 311 static void apply_microcode_local(void *arg)
 312 {
 313         struct apply_microcode_ctx *ctx = arg;
 314
 315         ctx->err = microcode_ops->apply_microcode(smp_processor_id());
 316 }
 317
 318 static int apply_microcode_on_target(int cpu)
 319 {
 320         struct apply_microcode_ctx ctx = { .err = 0 };
 321         int ret;
 322
 323         ret = smp_call_function_single(cpu, apply_microcode_local, &ctx, 1);
 324         if (!ret)
 325                 ret = ctx.err;
 326
 327         return ret;
 328 }
 329
 330 #ifdef CONFIG_MICROCODE_OLD_INTERFACE
 331 static int do_microcode_update(const void __user *buf, size_t size)
 332 {
 333         int error = 0;
 334         int cpu;
 335
 336         for_each_online_cpu(cpu) {
 337                 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 338                 enum ucode_state ustate;
 339
 340                 if (!uci->valid)
 341                         continue;
 342
 343                 ustate = microcode_ops->request_microcode_user(cpu, buf, size);
 344                 if (ustate == UCODE_ERROR) {
 345                         error = -1;
 346                         break;
 347                 } else if (ustate == UCODE_OK)
 348                         apply_microcode_on_target(cpu);
 349         }
 350
 351         return error;
 352 }
 353
 354 static int microcode_open(struct inode *inode, struct file *file)
 355 {
 356         return capable(CAP_SYS_RAWIO) ? nonseekable_open(inode, file) : -EPERM;
 357 }
 358
 359 static ssize_t microcode_write(struct file *file, const char __user *buf,
 360                                size_t len, loff_t *ppos)
 361 {
 362         ssize_t ret = -EINVAL;
 363
 364         if ((len >> PAGE_SHIFT) > totalram_pages) {
 365                 pr_err("too much data (max %ld pages)\n", totalram_pages);
 366                 return ret;
 367         }
 368
 369         get_online_cpus();
 370         mutex_lock(&microcode_mutex);
 371
 372         if (do_microcode_update(buf, len) == 0)
 373                 ret = (ssize_t)len;
 374
 375         if (ret > 0)
 376                 perf_check_microcode();
 377
 378         mutex_unlock(&microcode_mutex);
 379         put_online_cpus();
 380
 381         return ret;
 382 }
 383
 384 static const struct file_operations microcode_fops = {
 385         .owner                  = THIS_MODULE,
 386         .write                  = microcode_write,
 387         .open                   = microcode_open,
 388         .llseek         = no_llseek,
 389 };
 390
 391 static struct miscdevice microcode_dev = {
 392         .minor                  = MICROCODE_MINOR,
 393         .name                   = "microcode",
 394         .nodename               = "cpu/microcode",
 395         .fops                   = &microcode_fops,
 396 };
 397
 398 static int __init microcode_dev_init(void)
 399 {
 400         int error;
 401
 402         error = misc_register(&microcode_dev);
 403         if (error) {
 404                 pr_err("can't misc_register on minor=%d\n", MICROCODE_MINOR);
 405                 return error;
 406         }
 407
 408         return 0;
 409 }
 410
 411 static void __exit microcode_dev_exit(void)
 412 {
 413         misc_deregister(&microcode_dev);
 414 }
 415 #else
 416 #define microcode_dev_init()    0
 417 #define microcode_dev_exit()    do { } while (0)
 418 #endif
 419
 420 /* fake device for request_firmware */
 421 static struct platform_device   *microcode_pdev;
 422
 423 static int reload_for_cpu(int cpu)
 424 {
 425         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 426         enum ucode_state ustate;
 427         int err = 0;
 428
 429         if (!uci->valid)
 430                 return err;
 431
 432         ustate = microcode_ops->request_microcode_fw(cpu, &microcode_pdev->dev, true);
 433         if (ustate == UCODE_OK)
 434                 apply_microcode_on_target(cpu);
 435         else
 436                 if (ustate == UCODE_ERROR)
 437                         err = -EINVAL;
 438         return err;
 439 }
 440
 441 static ssize_t reload_store(struct device *dev,
 442                             struct device_attribute *attr,
 443                             const char *buf, size_t size)
 444 {
 445         unsigned long val;
 446         int cpu;
 447         ssize_t ret = 0, tmp_ret;
 448
 449         ret = kstrtoul(buf, 0, &val);
 450         if (ret)
 451                 return ret;
 452
 453         if (val != 1)
 454                 return size;
 455
 456         get_online_cpus();
 457         mutex_lock(&microcode_mutex);
 458         for_each_online_cpu(cpu) {
 459                 tmp_ret = reload_for_cpu(cpu);
 460                 if (tmp_ret != 0)
 461                         pr_warn("Error reloading microcode on CPU %d\n", cpu);
 462
 463                 /* save retval of the first encountered reload error */
 464                 if (!ret)
 465                         ret = tmp_ret;
 466         }
 467         if (!ret)
 468                 perf_check_microcode();
 469         mutex_unlock(&microcode_mutex);
 470         put_online_cpus();
 471
 472         if (!ret)
 473                 ret = size;
 474
 475         return ret;
 476 }
 477
 478 static ssize_t version_show(struct device *dev,
 479                         struct device_attribute *attr, char *buf)
 480 {
 481         struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
 482
 483         return sprintf(buf, "0x%x\n", uci->cpu_sig.rev);
 484 }
 485
 486 static ssize_t pf_show(struct device *dev,
 487                         struct device_attribute *attr, char *buf)
 488 {
 489         struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
 490
 491         return sprintf(buf, "0x%x\n", uci->cpu_sig.pf);
 492 }
 493
 494 static DEVICE_ATTR(reload, 0200, NULL, reload_store);
 495 static DEVICE_ATTR(version, 0400, version_show, NULL);
 496 static DEVICE_ATTR(processor_flags, 0400, pf_show, NULL);
 497
 498 static struct attribute *mc_default_attrs[] = {
 499         &dev_attr_version.attr,
 500         &dev_attr_processor_flags.attr,
 501         NULL
 502 };
 503
 504 static struct attribute_group mc_attr_group = {
 505         .attrs                  = mc_default_attrs,
 506         .name                   = "microcode",
 507 };
 508
 509 static void microcode_fini_cpu(int cpu)
 510 {
 511         if (microcode_ops->microcode_fini_cpu)
 512                 microcode_ops->microcode_fini_cpu(cpu);
 513 }
 514
 515 static enum ucode_state microcode_resume_cpu(int cpu)
 516 {
 517         if (apply_microcode_on_target(cpu))
 518                 return UCODE_ERROR;
 519
 520         pr_debug("CPU%d updated upon resume\n", cpu);
 521
 522         return UCODE_OK;
 523 }
 524
 525 static enum ucode_state microcode_init_cpu(int cpu, bool refresh_fw)
 526 {
 527         enum ucode_state ustate;
 528         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 529
 530         if (uci->valid)
 531                 return UCODE_OK;
 532
 533         if (collect_cpu_info(cpu))
 534                 return UCODE_ERROR;
 535
 536         /* --dimm. Trigger a delayed update? */
 537         if (system_state != SYSTEM_RUNNING)
 538                 return UCODE_NFOUND;
 539
 540         ustate = microcode_ops->request_microcode_fw(cpu, &microcode_pdev->dev,
 541                                                      refresh_fw);
 542
 543         if (ustate == UCODE_OK) {
 544                 pr_debug("CPU%d updated upon init\n", cpu);
 545                 apply_microcode_on_target(cpu);
 546         }
 547
 548         return ustate;
 549 }
 550
 551 static enum ucode_state microcode_update_cpu(int cpu)
 552 {
 553         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 554
 555         /* Refresh CPU microcode revision after resume. */
 556         collect_cpu_info(cpu);
 557
 558         if (uci->valid)
 559                 return microcode_resume_cpu(cpu);
 560
 561         return microcode_init_cpu(cpu, false);
 562 }
 563
 564 static int mc_device_add(struct device *dev, struct subsys_interface *sif)
 565 {
 566         int err, cpu = dev->id;
 567
 568         if (!cpu_online(cpu))
 569                 return 0;
 570
 571         pr_debug("CPU%d added\n", cpu);
 572
 573         err = sysfs_create_group(&dev->kobj, &mc_attr_group);
 574         if (err)
 575                 return err;
 576
 577         if (microcode_init_cpu(cpu, true) == UCODE_ERROR)
 578                 return -EINVAL;
 579
 580         return err;
 581 }
 582
 583 static void mc_device_remove(struct device *dev, struct subsys_interface *sif)
 584 {
 585         int cpu = dev->id;
 586
 587         if (!cpu_online(cpu))
 588                 return;
 589
 590         pr_debug("CPU%d removed\n", cpu);
 591         microcode_fini_cpu(cpu);
 592         sysfs_remove_group(&dev->kobj, &mc_attr_group);
 593 }
 594
 595 static struct subsys_interface mc_cpu_interface = {
 596         .name                   = "microcode",
 597         .subsys                 = &cpu_subsys,
 598         .add_dev                = mc_device_add,
 599         .remove_dev             = mc_device_remove,
 600 };
 601
 602 /**
 603  * mc_bp_resume - Update boot CPU microcode during resume.
 604  */
 605 static void mc_bp_resume(void)
 606 {
 607         int cpu = smp_processor_id();
 608         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 609
 610         if (uci->valid && uci->mc)
 611                 microcode_ops->apply_microcode(cpu);
 612         else if (!uci->mc)
 613                 reload_early_microcode();
 614 }
 615
 616 static struct syscore_ops mc_syscore_ops = {
 617         .resume                 = mc_bp_resume,
 618 };
 619
 620 static int mc_cpu_online(unsigned int cpu)
 621 {
 622         struct device *dev;
 623
 624         dev = get_cpu_device(cpu);
 625         microcode_update_cpu(cpu);
 626         pr_debug("CPU%d added\n", cpu);
 627
 628         if (sysfs_create_group(&dev->kobj, &mc_attr_group))
 629                 pr_err("Failed to create group for CPU%d\n", cpu);
 630         return 0;
 631 }
 632
 633 static int mc_cpu_down_prep(unsigned int cpu)
 634 {
 635         struct device *dev;
 636
 637         dev = get_cpu_device(cpu);
 638         /* Suspend is in progress, only remove the interface */
 639         sysfs_remove_group(&dev->kobj, &mc_attr_group);
 640         pr_debug("CPU%d removed\n", cpu);
 641
 642         return 0;
 643 }
 644
 645 static struct attribute *cpu_root_microcode_attrs[] = {
 646         &dev_attr_reload.attr,
 647         NULL
 648 };
 649
 650 static struct attribute_group cpu_root_microcode_group = {
 651         .name  = "microcode",
 652         .attrs = cpu_root_microcode_attrs,
 653 };
 654
 655 int __init microcode_init(void)
 656 {
 657         struct cpuinfo_x86 *c = &boot_cpu_data;
 658         int error;
 659
 660         if (dis_ucode_ldr)
 661                 return -EINVAL;
 662
 663         if (c->x86_vendor == X86_VENDOR_INTEL)
 664                 microcode_ops = init_intel_microcode();
 665         else if (c->x86_vendor == X86_VENDOR_AMD)
 666                 microcode_ops = init_amd_microcode();
 667         else
 668                 pr_err("no support for this CPU vendor\n");
 669
 670         if (!microcode_ops)
 671                 return -ENODEV;
 672
 673         microcode_pdev = platform_device_register_simple("microcode", -1,
 674                                                          NULL, 0);
 675         if (IS_ERR(microcode_pdev))
 676                 return PTR_ERR(microcode_pdev);
 677
 678         get_online_cpus();
 679         mutex_lock(&microcode_mutex);
 680
 681         error = subsys_interface_register(&mc_cpu_interface);
 682         if (!error)
 683                 perf_check_microcode();
 684         mutex_unlock(&microcode_mutex);
 685         put_online_cpus();
 686
 687         if (error)
 688                 goto out_pdev;
 689
 690         error = sysfs_create_group(&cpu_subsys.dev_root->kobj,
 691                                    &cpu_root_microcode_group);
 692
 693         if (error) {
 694                 pr_err("Error creating microcode group!\n");
 695                 goto out_driver;
 696         }
 697
 698         error = microcode_dev_init();
 699         if (error)
 700                 goto out_ucode_group;
 701
 702         register_syscore_ops(&mc_syscore_ops);
 703         cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "x86/microcode:online",
 704                                   mc_cpu_online, mc_cpu_down_prep);
 705
 706         pr_info("Microcode Update Driver: v%s.", DRIVER_VERSION);
 707
 708         return 0;
 709
 710  out_ucode_group:
 711         sysfs_remove_group(&cpu_subsys.dev_root->kobj,
 712                            &cpu_root_microcode_group);
 713
 714  out_driver:
 715         get_online_cpus();
 716         mutex_lock(&microcode_mutex);
 717
 718         subsys_interface_unregister(&mc_cpu_interface);
 719
 720         mutex_unlock(&microcode_mutex);
 721         put_online_cpus();
 722
 723  out_pdev:
 724         platform_device_unregister(microcode_pdev);
 725         return error;
 726
 727 }
 728 fs_initcall(save_microcode_in_initrd);
 729 late_initcall(microcode_init);