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  *            2013-2015 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
  43 #define MICROCODE_VERSION       "2.01"
  44
  45 static struct microcode_ops     *microcode_ops;
  46 static bool dis_ucode_ldr;
  47
  48 /*
  49  * Synchronization.
  50  *
  51  * All non cpu-hotplug-callback call sites use:
  52  *
  53  * - microcode_mutex to synchronize with each other;
  54  * - get/put_online_cpus() to synchronize with
  55  *   the cpu-hotplug-callback call sites.
  56  *
  57  * We guarantee that only a single cpu is being
  58  * updated at any particular moment of time.
  59  */
  60 static DEFINE_MUTEX(microcode_mutex);
  61
  62 struct ucode_cpu_info           ucode_cpu_info[NR_CPUS];
  63
  64 /*
  65  * Operations that are run on a target cpu:
  66  */
  67
  68 struct cpu_info_ctx {
  69         struct cpu_signature    *cpu_sig;
  70         int                     err;
  71 };
  72
  73 static bool __init check_loader_disabled_bsp(void)
  74 {
  75         static const char *__dis_opt_str = "dis_ucode_ldr";
  76
  77 #ifdef CONFIG_X86_32
  78         const char *cmdline = (const char *)__pa_nodebug(boot_command_line);
  79         const char *option  = (const char *)__pa_nodebug(__dis_opt_str);
  80         bool *res = (bool *)__pa_nodebug(&dis_ucode_ldr);
  81
  82 #else /* CONFIG_X86_64 */
  83         const char *cmdline = boot_command_line;
  84         const char *option  = __dis_opt_str;
  85         bool *res = &dis_ucode_ldr;
  86 #endif
  87
  88         if (cmdline_find_option_bool(cmdline, option))
  89                 *res = true;
  90
  91         return *res;
  92 }
  93
  94 extern struct builtin_fw __start_builtin_fw[];
  95 extern struct builtin_fw __end_builtin_fw[];
  96
  97 bool get_builtin_firmware(struct cpio_data *cd, const char *name)
  98 {
  99 #ifdef CONFIG_FW_LOADER
 100         struct builtin_fw *b_fw;
 101
 102         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
 103                 if (!strcmp(name, b_fw->name)) {
 104                         cd->size = b_fw->size;
 105                         cd->data = b_fw->data;
 106                         return true;
 107                 }
 108         }
 109 #endif
 110         return false;
 111 }
 112
 113 void __init load_ucode_bsp(void)
 114 {
 115         int vendor;
 116         unsigned int family;
 117
 118         if (check_loader_disabled_bsp())
 119                 return;
 120
 121         if (!have_cpuid_p())
 122                 return;
 123
 124         vendor = x86_cpuid_vendor();
 125         family = x86_cpuid_family();
 126
 127         switch (vendor) {
 128         case X86_VENDOR_INTEL:
 129                 if (family >= 6)
 130                         load_ucode_intel_bsp();
 131                 break;
 132         case X86_VENDOR_AMD:
 133                 if (family >= 0x10)
 134                         load_ucode_amd_bsp(family);
 135                 break;
 136         default:
 137                 break;
 138         }
 139 }
 140
 141 static bool check_loader_disabled_ap(void)
 142 {
 143 #ifdef CONFIG_X86_32
 144         return *((bool *)__pa_nodebug(&dis_ucode_ldr));
 145 #else
 146         return dis_ucode_ldr;
 147 #endif
 148 }
 149
 150 void load_ucode_ap(void)
 151 {
 152         int vendor, family;
 153
 154         if (check_loader_disabled_ap())
 155                 return;
 156
 157         if (!have_cpuid_p())
 158                 return;
 159
 160         vendor = x86_cpuid_vendor();
 161         family = x86_cpuid_family();
 162
 163         switch (vendor) {
 164         case X86_VENDOR_INTEL:
 165                 if (family >= 6)
 166                         load_ucode_intel_ap();
 167                 break;
 168         case X86_VENDOR_AMD:
 169                 if (family >= 0x10)
 170                         load_ucode_amd_ap();
 171                 break;
 172         default:
 173                 break;
 174         }
 175 }
 176
 177 static int __init save_microcode_in_initrd(void)
 178 {
 179         struct cpuinfo_x86 *c = &boot_cpu_data;
 180
 181         switch (c->x86_vendor) {
 182         case X86_VENDOR_INTEL:
 183                 if (c->x86 >= 6)
 184                         return save_microcode_in_initrd_intel();
 185                 break;
 186         case X86_VENDOR_AMD:
 187                 if (c->x86 >= 0x10)
 188                         return save_microcode_in_initrd_amd();
 189                 break;
 190         default:
 191                 break;
 192         }
 193
 194         return -EINVAL;
 195 }
 196
 197 void reload_early_microcode(void)
 198 {
 199         int vendor, family;
 200
 201         vendor = x86_cpuid_vendor();
 202         family = x86_cpuid_family();
 203
 204         switch (vendor) {
 205         case X86_VENDOR_INTEL:
 206                 if (family >= 6)
 207                         reload_ucode_intel();
 208                 break;
 209         case X86_VENDOR_AMD:
 210                 if (family >= 0x10)
 211                         reload_ucode_amd();
 212                 break;
 213         default:
 214                 break;
 215         }
 216 }
 217
 218 static void collect_cpu_info_local(void *arg)
 219 {
 220         struct cpu_info_ctx *ctx = arg;
 221
 222         ctx->err = microcode_ops->collect_cpu_info(smp_processor_id(),
 223                                                    ctx->cpu_sig);
 224 }
 225
 226 static int collect_cpu_info_on_target(int cpu, struct cpu_signature *cpu_sig)
 227 {
 228         struct cpu_info_ctx ctx = { .cpu_sig = cpu_sig, .err = 0 };
 229         int ret;
 230
 231         ret = smp_call_function_single(cpu, collect_cpu_info_local, &ctx, 1);
 232         if (!ret)
 233                 ret = ctx.err;
 234
 235         return ret;
 236 }
 237
 238 static int collect_cpu_info(int cpu)
 239 {
 240         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 241         int ret;
 242
 243         memset(uci, 0, sizeof(*uci));
 244
 245         ret = collect_cpu_info_on_target(cpu, &uci->cpu_sig);
 246         if (!ret)
 247                 uci->valid = 1;
 248
 249         return ret;
 250 }
 251
 252 struct apply_microcode_ctx {
 253         int err;
 254 };
 255
 256 static void apply_microcode_local(void *arg)
 257 {
 258         struct apply_microcode_ctx *ctx = arg;
 259
 260         ctx->err = microcode_ops->apply_microcode(smp_processor_id());
 261 }
 262
 263 static int apply_microcode_on_target(int cpu)
 264 {
 265         struct apply_microcode_ctx ctx = { .err = 0 };
 266         int ret;
 267
 268         ret = smp_call_function_single(cpu, apply_microcode_local, &ctx, 1);
 269         if (!ret)
 270                 ret = ctx.err;
 271
 272         return ret;
 273 }
 274
 275 #ifdef CONFIG_MICROCODE_OLD_INTERFACE
 276 static int do_microcode_update(const void __user *buf, size_t size)
 277 {
 278         int error = 0;
 279         int cpu;
 280
 281         for_each_online_cpu(cpu) {
 282                 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 283                 enum ucode_state ustate;
 284
 285                 if (!uci->valid)
 286                         continue;
 287
 288                 ustate = microcode_ops->request_microcode_user(cpu, buf, size);
 289                 if (ustate == UCODE_ERROR) {
 290                         error = -1;
 291                         break;
 292                 } else if (ustate == UCODE_OK)
 293                         apply_microcode_on_target(cpu);
 294         }
 295
 296         return error;
 297 }
 298
 299 static int microcode_open(struct inode *inode, struct file *file)
 300 {
 301         return capable(CAP_SYS_RAWIO) ? nonseekable_open(inode, file) : -EPERM;
 302 }
 303
 304 static ssize_t microcode_write(struct file *file, const char __user *buf,
 305                                size_t len, loff_t *ppos)
 306 {
 307         ssize_t ret = -EINVAL;
 308
 309         if ((len >> PAGE_SHIFT) > totalram_pages) {
 310                 pr_err("too much data (max %ld pages)\n", totalram_pages);
 311                 return ret;
 312         }
 313
 314         get_online_cpus();
 315         mutex_lock(&microcode_mutex);
 316
 317         if (do_microcode_update(buf, len) == 0)
 318                 ret = (ssize_t)len;
 319
 320         if (ret > 0)
 321                 perf_check_microcode();
 322
 323         mutex_unlock(&microcode_mutex);
 324         put_online_cpus();
 325
 326         return ret;
 327 }
 328
 329 static const struct file_operations microcode_fops = {
 330         .owner                  = THIS_MODULE,
 331         .write                  = microcode_write,
 332         .open                   = microcode_open,
 333         .llseek         = no_llseek,
 334 };
 335
 336 static struct miscdevice microcode_dev = {
 337         .minor                  = MICROCODE_MINOR,
 338         .name                   = "microcode",
 339         .nodename               = "cpu/microcode",
 340         .fops                   = &microcode_fops,
 341 };
 342
 343 static int __init microcode_dev_init(void)
 344 {
 345         int error;
 346
 347         error = misc_register(&microcode_dev);
 348         if (error) {
 349                 pr_err("can't misc_register on minor=%d\n", MICROCODE_MINOR);
 350                 return error;
 351         }
 352
 353         return 0;
 354 }
 355
 356 static void __exit microcode_dev_exit(void)
 357 {
 358         misc_deregister(&microcode_dev);
 359 }
 360 #else
 361 #define microcode_dev_init()    0
 362 #define microcode_dev_exit()    do { } while (0)
 363 #endif
 364
 365 /* fake device for request_firmware */
 366 static struct platform_device   *microcode_pdev;
 367
 368 static int reload_for_cpu(int cpu)
 369 {
 370         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 371         enum ucode_state ustate;
 372         int err = 0;
 373
 374         if (!uci->valid)
 375                 return err;
 376
 377         ustate = microcode_ops->request_microcode_fw(cpu, &microcode_pdev->dev, true);
 378         if (ustate == UCODE_OK)
 379                 apply_microcode_on_target(cpu);
 380         else
 381                 if (ustate == UCODE_ERROR)
 382                         err = -EINVAL;
 383         return err;
 384 }
 385
 386 static ssize_t reload_store(struct device *dev,
 387                             struct device_attribute *attr,
 388                             const char *buf, size_t size)
 389 {
 390         unsigned long val;
 391         int cpu;
 392         ssize_t ret = 0, tmp_ret;
 393
 394         ret = kstrtoul(buf, 0, &val);
 395         if (ret)
 396                 return ret;
 397
 398         if (val != 1)
 399                 return size;
 400
 401         get_online_cpus();
 402         mutex_lock(&microcode_mutex);
 403         for_each_online_cpu(cpu) {
 404                 tmp_ret = reload_for_cpu(cpu);
 405                 if (tmp_ret != 0)
 406                         pr_warn("Error reloading microcode on CPU %d\n", cpu);
 407
 408                 /* save retval of the first encountered reload error */
 409                 if (!ret)
 410                         ret = tmp_ret;
 411         }
 412         if (!ret)
 413                 perf_check_microcode();
 414         mutex_unlock(&microcode_mutex);
 415         put_online_cpus();
 416
 417         if (!ret)
 418                 ret = size;
 419
 420         return ret;
 421 }
 422
 423 static ssize_t version_show(struct device *dev,
 424                         struct device_attribute *attr, char *buf)
 425 {
 426         struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
 427
 428         return sprintf(buf, "0x%x\n", uci->cpu_sig.rev);
 429 }
 430
 431 static ssize_t pf_show(struct device *dev,
 432                         struct device_attribute *attr, char *buf)
 433 {
 434         struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
 435
 436         return sprintf(buf, "0x%x\n", uci->cpu_sig.pf);
 437 }
 438
 439 static DEVICE_ATTR(reload, 0200, NULL, reload_store);
 440 static DEVICE_ATTR(version, 0400, version_show, NULL);
 441 static DEVICE_ATTR(processor_flags, 0400, pf_show, NULL);
 442
 443 static struct attribute *mc_default_attrs[] = {
 444         &dev_attr_version.attr,
 445         &dev_attr_processor_flags.attr,
 446         NULL
 447 };
 448
 449 static struct attribute_group mc_attr_group = {
 450         .attrs                  = mc_default_attrs,
 451         .name                   = "microcode",
 452 };
 453
 454 static void microcode_fini_cpu(int cpu)
 455 {
 456         microcode_ops->microcode_fini_cpu(cpu);
 457 }
 458
 459 static enum ucode_state microcode_resume_cpu(int cpu)
 460 {
 461         pr_debug("CPU%d updated upon resume\n", cpu);
 462
 463         if (apply_microcode_on_target(cpu))
 464                 return UCODE_ERROR;
 465
 466         return UCODE_OK;
 467 }
 468
 469 static enum ucode_state microcode_init_cpu(int cpu, bool refresh_fw)
 470 {
 471         enum ucode_state ustate;
 472         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 473
 474         if (uci->valid)
 475                 return UCODE_OK;
 476
 477         if (collect_cpu_info(cpu))
 478                 return UCODE_ERROR;
 479
 480         /* --dimm. Trigger a delayed update? */
 481         if (system_state != SYSTEM_RUNNING)
 482                 return UCODE_NFOUND;
 483
 484         ustate = microcode_ops->request_microcode_fw(cpu, &microcode_pdev->dev,
 485                                                      refresh_fw);
 486
 487         if (ustate == UCODE_OK) {
 488                 pr_debug("CPU%d updated upon init\n", cpu);
 489                 apply_microcode_on_target(cpu);
 490         }
 491
 492         return ustate;
 493 }
 494
 495 static enum ucode_state microcode_update_cpu(int cpu)
 496 {
 497         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 498
 499         if (uci->valid)
 500                 return microcode_resume_cpu(cpu);
 501
 502         return microcode_init_cpu(cpu, false);
 503 }
 504
 505 static int mc_device_add(struct device *dev, struct subsys_interface *sif)
 506 {
 507         int err, cpu = dev->id;
 508
 509         if (!cpu_online(cpu))
 510                 return 0;
 511
 512         pr_debug("CPU%d added\n", cpu);
 513
 514         err = sysfs_create_group(&dev->kobj, &mc_attr_group);
 515         if (err)
 516                 return err;
 517
 518         if (microcode_init_cpu(cpu, true) == UCODE_ERROR)
 519                 return -EINVAL;
 520
 521         return err;
 522 }
 523
 524 static void mc_device_remove(struct device *dev, struct subsys_interface *sif)
 525 {
 526         int cpu = dev->id;
 527
 528         if (!cpu_online(cpu))
 529                 return;
 530
 531         pr_debug("CPU%d removed\n", cpu);
 532         microcode_fini_cpu(cpu);
 533         sysfs_remove_group(&dev->kobj, &mc_attr_group);
 534 }
 535
 536 static struct subsys_interface mc_cpu_interface = {
 537         .name                   = "microcode",
 538         .subsys                 = &cpu_subsys,
 539         .add_dev                = mc_device_add,
 540         .remove_dev             = mc_device_remove,
 541 };
 542
 543 /**
 544  * mc_bp_resume - Update boot CPU microcode during resume.
 545  */
 546 static void mc_bp_resume(void)
 547 {
 548         int cpu = smp_processor_id();
 549         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 550
 551         if (uci->valid && uci->mc)
 552                 microcode_ops->apply_microcode(cpu);
 553         else if (!uci->mc)
 554                 reload_early_microcode();
 555 }
 556
 557 static struct syscore_ops mc_syscore_ops = {
 558         .resume                 = mc_bp_resume,
 559 };
 560
 561 static int mc_cpu_online(unsigned int cpu)
 562 {
 563         struct device *dev;
 564
 565         dev = get_cpu_device(cpu);
 566         microcode_update_cpu(cpu);
 567         pr_debug("CPU%d added\n", cpu);
 568
 569         if (sysfs_create_group(&dev->kobj, &mc_attr_group))
 570                 pr_err("Failed to create group for CPU%d\n", cpu);
 571         return 0;
 572 }
 573
 574 static int mc_cpu_down_prep(unsigned int cpu)
 575 {
 576         struct device *dev;
 577
 578         dev = get_cpu_device(cpu);
 579         /* Suspend is in progress, only remove the interface */
 580         sysfs_remove_group(&dev->kobj, &mc_attr_group);
 581         pr_debug("CPU%d removed\n", cpu);
 582         /*
 583          * When a CPU goes offline, don't free up or invalidate the copy of
 584          * the microcode in kernel memory, so that we can reuse it when the
 585          * CPU comes back online without unnecessarily requesting the userspace
 586          * for it again.
 587          */
 588         return 0;
 589 }
 590
 591 static struct attribute *cpu_root_microcode_attrs[] = {
 592         &dev_attr_reload.attr,
 593         NULL
 594 };
 595
 596 static struct attribute_group cpu_root_microcode_group = {
 597         .name  = "microcode",
 598         .attrs = cpu_root_microcode_attrs,
 599 };
 600
 601 int __init microcode_init(void)
 602 {
 603         struct cpuinfo_x86 *c = &boot_cpu_data;
 604         int error;
 605
 606         if (dis_ucode_ldr)
 607                 return -EINVAL;
 608
 609         if (c->x86_vendor == X86_VENDOR_INTEL)
 610                 microcode_ops = init_intel_microcode();
 611         else if (c->x86_vendor == X86_VENDOR_AMD)
 612                 microcode_ops = init_amd_microcode();
 613         else
 614                 pr_err("no support for this CPU vendor\n");
 615
 616         if (!microcode_ops)
 617                 return -ENODEV;
 618
 619         microcode_pdev = platform_device_register_simple("microcode", -1,
 620                                                          NULL, 0);
 621         if (IS_ERR(microcode_pdev))
 622                 return PTR_ERR(microcode_pdev);
 623
 624         get_online_cpus();
 625         mutex_lock(&microcode_mutex);
 626
 627         error = subsys_interface_register(&mc_cpu_interface);
 628         if (!error)
 629                 perf_check_microcode();
 630         mutex_unlock(&microcode_mutex);
 631         put_online_cpus();
 632
 633         if (error)
 634                 goto out_pdev;
 635
 636         error = sysfs_create_group(&cpu_subsys.dev_root->kobj,
 637                                    &cpu_root_microcode_group);
 638
 639         if (error) {
 640                 pr_err("Error creating microcode group!\n");
 641                 goto out_driver;
 642         }
 643
 644         error = microcode_dev_init();
 645         if (error)
 646                 goto out_ucode_group;
 647
 648         register_syscore_ops(&mc_syscore_ops);
 649         cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "x86/microcode:online",
 650                                   mc_cpu_online, mc_cpu_down_prep);
 651
 652         pr_info("Microcode Update Driver: v%s.", MICROCODE_VERSION);
 653
 654         return 0;
 655
 656  out_ucode_group:
 657         sysfs_remove_group(&cpu_subsys.dev_root->kobj,
 658                            &cpu_root_microcode_group);
 659
 660  out_driver:
 661         get_online_cpus();
 662         mutex_lock(&microcode_mutex);
 663
 664         subsys_interface_unregister(&mc_cpu_interface);
 665
 666         mutex_unlock(&microcode_mutex);
 667         put_online_cpus();
 668
 669  out_pdev:
 670         platform_device_unregister(microcode_pdev);
 671         return error;
 672
 673 }
 674 fs_initcall(save_microcode_in_initrd);
 675 late_initcall(microcode_init);