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
  47 static bool dis_ucode_ldr;
  48
  49 static int __init disable_loader(char *str)
  50 {
  51         dis_ucode_ldr = true;
  52         return 1;
  53 }
  54 __setup("dis_ucode_ldr", disable_loader);
  55
  56 /*
  57  * Synchronization.
  58  *
  59  * All non cpu-hotplug-callback call sites use:
  60  *
  61  * - microcode_mutex to synchronize with each other;
  62  * - get/put_online_cpus() to synchronize with
  63  *   the cpu-hotplug-callback call sites.
  64  *
  65  * We guarantee that only a single cpu is being
  66  * updated at any particular moment of time.
  67  */
  68 static DEFINE_MUTEX(microcode_mutex);
  69
  70 struct ucode_cpu_info           ucode_cpu_info[NR_CPUS];
  71 EXPORT_SYMBOL_GPL(ucode_cpu_info);
  72
  73 /*
  74  * Operations that are run on a target cpu:
  75  */
  76
  77 struct cpu_info_ctx {
  78         struct cpu_signature    *cpu_sig;
  79         int                     err;
  80 };
  81
  82 static bool __init check_loader_disabled_bsp(void)
  83 {
  84 #ifdef CONFIG_X86_32
  85         const char *cmdline = (const char *)__pa_nodebug(boot_command_line);
  86         const char *opt     = "dis_ucode_ldr";
  87         const char *option  = (const char *)__pa_nodebug(opt);
  88         bool *res = (bool *)__pa_nodebug(&dis_ucode_ldr);
  89
  90 #else /* CONFIG_X86_64 */
  91         const char *cmdline = boot_command_line;
  92         const char *option  = "dis_ucode_ldr";
  93         bool *res = &dis_ucode_ldr;
  94 #endif
  95
  96         if (cmdline_find_option_bool(cmdline, option))
  97                 *res = true;
  98
  99         return *res;
 100 }
 101
 102 extern struct builtin_fw __start_builtin_fw[];
 103 extern struct builtin_fw __end_builtin_fw[];
 104
 105 bool get_builtin_firmware(struct cpio_data *cd, const char *name)
 106 {
 107 #ifdef CONFIG_FW_LOADER
 108         struct builtin_fw *b_fw;
 109
 110         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
 111                 if (!strcmp(name, b_fw->name)) {
 112                         cd->size = b_fw->size;
 113                         cd->data = b_fw->data;
 114                         return true;
 115                 }
 116         }
 117 #endif
 118         return false;
 119 }
 120
 121 void __init load_ucode_bsp(void)
 122 {
 123         int vendor;
 124         unsigned int family;
 125
 126         if (check_loader_disabled_bsp())
 127                 return;
 128
 129         if (!have_cpuid_p())
 130                 return;
 131
 132         vendor = x86_cpuid_vendor();
 133         family = x86_cpuid_family();
 134
 135         switch (vendor) {
 136         case X86_VENDOR_INTEL:
 137                 if (family >= 6)
 138                         load_ucode_intel_bsp();
 139                 break;
 140         case X86_VENDOR_AMD:
 141                 if (family >= 0x10)
 142                         load_ucode_amd_bsp(family);
 143                 break;
 144         default:
 145                 break;
 146         }
 147 }
 148
 149 static bool check_loader_disabled_ap(void)
 150 {
 151 #ifdef CONFIG_X86_32
 152         return *((bool *)__pa_nodebug(&dis_ucode_ldr));
 153 #else
 154         return dis_ucode_ldr;
 155 #endif
 156 }
 157
 158 void load_ucode_ap(void)
 159 {
 160         int vendor, family;
 161
 162         if (check_loader_disabled_ap())
 163                 return;
 164
 165         if (!have_cpuid_p())
 166                 return;
 167
 168         vendor = x86_cpuid_vendor();
 169         family = x86_cpuid_family();
 170
 171         switch (vendor) {
 172         case X86_VENDOR_INTEL:
 173                 if (family >= 6)
 174                         load_ucode_intel_ap();
 175                 break;
 176         case X86_VENDOR_AMD:
 177                 if (family >= 0x10)
 178                         load_ucode_amd_ap();
 179                 break;
 180         default:
 181                 break;
 182         }
 183 }
 184
 185 int __init save_microcode_in_initrd(void)
 186 {
 187         struct cpuinfo_x86 *c = &boot_cpu_data;
 188
 189         switch (c->x86_vendor) {
 190         case X86_VENDOR_INTEL:
 191                 if (c->x86 >= 6)
 192                         save_microcode_in_initrd_intel();
 193                 break;
 194         case X86_VENDOR_AMD:
 195                 if (c->x86 >= 0x10)
 196                         save_microcode_in_initrd_amd();
 197                 break;
 198         default:
 199                 break;
 200         }
 201
 202         return 0;
 203 }
 204
 205 void reload_early_microcode(void)
 206 {
 207         int vendor, family;
 208
 209         vendor = x86_cpuid_vendor();
 210         family = x86_cpuid_family();
 211
 212         switch (vendor) {
 213         case X86_VENDOR_INTEL:
 214                 if (family >= 6)
 215                         reload_ucode_intel();
 216                 break;
 217         case X86_VENDOR_AMD:
 218                 if (family >= 0x10)
 219                         reload_ucode_amd();
 220                 break;
 221         default:
 222                 break;
 223         }
 224 }
 225
 226 static void collect_cpu_info_local(void *arg)
 227 {
 228         struct cpu_info_ctx *ctx = arg;
 229
 230         ctx->err = microcode_ops->collect_cpu_info(smp_processor_id(),
 231                                                    ctx->cpu_sig);
 232 }
 233
 234 static int collect_cpu_info_on_target(int cpu, struct cpu_signature *cpu_sig)
 235 {
 236         struct cpu_info_ctx ctx = { .cpu_sig = cpu_sig, .err = 0 };
 237         int ret;
 238
 239         ret = smp_call_function_single(cpu, collect_cpu_info_local, &ctx, 1);
 240         if (!ret)
 241                 ret = ctx.err;
 242
 243         return ret;
 244 }
 245
 246 static int collect_cpu_info(int cpu)
 247 {
 248         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 249         int ret;
 250
 251         memset(uci, 0, sizeof(*uci));
 252
 253         ret = collect_cpu_info_on_target(cpu, &uci->cpu_sig);
 254         if (!ret)
 255                 uci->valid = 1;
 256
 257         return ret;
 258 }
 259
 260 struct apply_microcode_ctx {
 261         int err;
 262 };
 263
 264 static void apply_microcode_local(void *arg)
 265 {
 266         struct apply_microcode_ctx *ctx = arg;
 267
 268         ctx->err = microcode_ops->apply_microcode(smp_processor_id());
 269 }
 270
 271 static int apply_microcode_on_target(int cpu)
 272 {
 273         struct apply_microcode_ctx ctx = { .err = 0 };
 274         int ret;
 275
 276         ret = smp_call_function_single(cpu, apply_microcode_local, &ctx, 1);
 277         if (!ret)
 278                 ret = ctx.err;
 279
 280         return ret;
 281 }
 282
 283 #ifdef CONFIG_MICROCODE_OLD_INTERFACE
 284 static int do_microcode_update(const void __user *buf, size_t size)
 285 {
 286         int error = 0;
 287         int cpu;
 288
 289         for_each_online_cpu(cpu) {
 290                 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 291                 enum ucode_state ustate;
 292
 293                 if (!uci->valid)
 294                         continue;
 295
 296                 ustate = microcode_ops->request_microcode_user(cpu, buf, size);
 297                 if (ustate == UCODE_ERROR) {
 298                         error = -1;
 299                         break;
 300                 } else if (ustate == UCODE_OK)
 301                         apply_microcode_on_target(cpu);
 302         }
 303
 304         return error;
 305 }
 306
 307 static int microcode_open(struct inode *inode, struct file *file)
 308 {
 309         return capable(CAP_SYS_RAWIO) ? nonseekable_open(inode, file) : -EPERM;
 310 }
 311
 312 static ssize_t microcode_write(struct file *file, const char __user *buf,
 313                                size_t len, loff_t *ppos)
 314 {
 315         ssize_t ret = -EINVAL;
 316
 317         if ((len >> PAGE_SHIFT) > totalram_pages) {
 318                 pr_err("too much data (max %ld pages)\n", totalram_pages);
 319                 return ret;
 320         }
 321
 322         get_online_cpus();
 323         mutex_lock(&microcode_mutex);
 324
 325         if (do_microcode_update(buf, len) == 0)
 326                 ret = (ssize_t)len;
 327
 328         if (ret > 0)
 329                 perf_check_microcode();
 330
 331         mutex_unlock(&microcode_mutex);
 332         put_online_cpus();
 333
 334         return ret;
 335 }
 336
 337 static const struct file_operations microcode_fops = {
 338         .owner                  = THIS_MODULE,
 339         .write                  = microcode_write,
 340         .open                   = microcode_open,
 341         .llseek         = no_llseek,
 342 };
 343
 344 static struct miscdevice microcode_dev = {
 345         .minor                  = MICROCODE_MINOR,
 346         .name                   = "microcode",
 347         .nodename               = "cpu/microcode",
 348         .fops                   = &microcode_fops,
 349 };
 350
 351 static int __init microcode_dev_init(void)
 352 {
 353         int error;
 354
 355         error = misc_register(&microcode_dev);
 356         if (error) {
 357                 pr_err("can't misc_register on minor=%d\n", MICROCODE_MINOR);
 358                 return error;
 359         }
 360
 361         return 0;
 362 }
 363
 364 static void __exit microcode_dev_exit(void)
 365 {
 366         misc_deregister(&microcode_dev);
 367 }
 368 #else
 369 #define microcode_dev_init()    0
 370 #define microcode_dev_exit()    do { } while (0)
 371 #endif
 372
 373 /* fake device for request_firmware */
 374 static struct platform_device   *microcode_pdev;
 375
 376 static int reload_for_cpu(int cpu)
 377 {
 378         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 379         enum ucode_state ustate;
 380         int err = 0;
 381
 382         if (!uci->valid)
 383                 return err;
 384
 385         ustate = microcode_ops->request_microcode_fw(cpu, &microcode_pdev->dev, true);
 386         if (ustate == UCODE_OK)
 387                 apply_microcode_on_target(cpu);
 388         else
 389                 if (ustate == UCODE_ERROR)
 390                         err = -EINVAL;
 391         return err;
 392 }
 393
 394 static ssize_t reload_store(struct device *dev,
 395                             struct device_attribute *attr,
 396                             const char *buf, size_t size)
 397 {
 398         unsigned long val;
 399         int cpu;
 400         ssize_t ret = 0, tmp_ret;
 401
 402         ret = kstrtoul(buf, 0, &val);
 403         if (ret)
 404                 return ret;
 405
 406         if (val != 1)
 407                 return size;
 408
 409         get_online_cpus();
 410         mutex_lock(&microcode_mutex);
 411         for_each_online_cpu(cpu) {
 412                 tmp_ret = reload_for_cpu(cpu);
 413                 if (tmp_ret != 0)
 414                         pr_warn("Error reloading microcode on CPU %d\n", cpu);
 415
 416                 /* save retval of the first encountered reload error */
 417                 if (!ret)
 418                         ret = tmp_ret;
 419         }
 420         if (!ret)
 421                 perf_check_microcode();
 422         mutex_unlock(&microcode_mutex);
 423         put_online_cpus();
 424
 425         if (!ret)
 426                 ret = size;
 427
 428         return ret;
 429 }
 430
 431 static ssize_t version_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.rev);
 437 }
 438
 439 static ssize_t pf_show(struct device *dev,
 440                         struct device_attribute *attr, char *buf)
 441 {
 442         struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
 443
 444         return sprintf(buf, "0x%x\n", uci->cpu_sig.pf);
 445 }
 446
 447 static DEVICE_ATTR(reload, 0200, NULL, reload_store);
 448 static DEVICE_ATTR(version, 0400, version_show, NULL);
 449 static DEVICE_ATTR(processor_flags, 0400, pf_show, NULL);
 450
 451 static struct attribute *mc_default_attrs[] = {
 452         &dev_attr_version.attr,
 453         &dev_attr_processor_flags.attr,
 454         NULL
 455 };
 456
 457 static struct attribute_group mc_attr_group = {
 458         .attrs                  = mc_default_attrs,
 459         .name                   = "microcode",
 460 };
 461
 462 static void microcode_fini_cpu(int cpu)
 463 {
 464         microcode_ops->microcode_fini_cpu(cpu);
 465 }
 466
 467 static enum ucode_state microcode_resume_cpu(int cpu)
 468 {
 469         pr_debug("CPU%d updated upon resume\n", cpu);
 470
 471         if (apply_microcode_on_target(cpu))
 472                 return UCODE_ERROR;
 473
 474         return UCODE_OK;
 475 }
 476
 477 static enum ucode_state microcode_init_cpu(int cpu, bool refresh_fw)
 478 {
 479         enum ucode_state ustate;
 480         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 481
 482         if (uci && uci->valid)
 483                 return UCODE_OK;
 484
 485         if (collect_cpu_info(cpu))
 486                 return UCODE_ERROR;
 487
 488         /* --dimm. Trigger a delayed update? */
 489         if (system_state != SYSTEM_RUNNING)
 490                 return UCODE_NFOUND;
 491
 492         ustate = microcode_ops->request_microcode_fw(cpu, &microcode_pdev->dev,
 493                                                      refresh_fw);
 494
 495         if (ustate == UCODE_OK) {
 496                 pr_debug("CPU%d updated upon init\n", cpu);
 497                 apply_microcode_on_target(cpu);
 498         }
 499
 500         return ustate;
 501 }
 502
 503 static enum ucode_state microcode_update_cpu(int cpu)
 504 {
 505         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 506
 507         if (uci->valid)
 508                 return microcode_resume_cpu(cpu);
 509
 510         return microcode_init_cpu(cpu, false);
 511 }
 512
 513 static int mc_device_add(struct device *dev, struct subsys_interface *sif)
 514 {
 515         int err, cpu = dev->id;
 516
 517         if (!cpu_online(cpu))
 518                 return 0;
 519
 520         pr_debug("CPU%d added\n", cpu);
 521
 522         err = sysfs_create_group(&dev->kobj, &mc_attr_group);
 523         if (err)
 524                 return err;
 525
 526         if (microcode_init_cpu(cpu, true) == UCODE_ERROR)
 527                 return -EINVAL;
 528
 529         return err;
 530 }
 531
 532 static void mc_device_remove(struct device *dev, struct subsys_interface *sif)
 533 {
 534         int cpu = dev->id;
 535
 536         if (!cpu_online(cpu))
 537                 return;
 538
 539         pr_debug("CPU%d removed\n", cpu);
 540         microcode_fini_cpu(cpu);
 541         sysfs_remove_group(&dev->kobj, &mc_attr_group);
 542 }
 543
 544 static struct subsys_interface mc_cpu_interface = {
 545         .name                   = "microcode",
 546         .subsys                 = &cpu_subsys,
 547         .add_dev                = mc_device_add,
 548         .remove_dev             = mc_device_remove,
 549 };
 550
 551 /**
 552  * mc_bp_resume - Update boot CPU microcode during resume.
 553  */
 554 static void mc_bp_resume(void)
 555 {
 556         int cpu = smp_processor_id();
 557         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 558
 559         if (uci->valid && uci->mc)
 560                 microcode_ops->apply_microcode(cpu);
 561         else if (!uci->mc)
 562                 reload_early_microcode();
 563 }
 564
 565 static struct syscore_ops mc_syscore_ops = {
 566         .resume                 = mc_bp_resume,
 567 };
 568
 569 static int
 570 mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
 571 {
 572         unsigned int cpu = (unsigned long)hcpu;
 573         struct device *dev;
 574
 575         dev = get_cpu_device(cpu);
 576
 577         switch (action & ~CPU_TASKS_FROZEN) {
 578         case CPU_ONLINE:
 579                 microcode_update_cpu(cpu);
 580                 pr_debug("CPU%d added\n", cpu);
 581                 /*
 582                  * "break" is missing on purpose here because we want to fall
 583                  * through in order to create the sysfs group.
 584                  */
 585
 586         case CPU_DOWN_FAILED:
 587                 if (sysfs_create_group(&dev->kobj, &mc_attr_group))
 588                         pr_err("Failed to create group for CPU%d\n", cpu);
 589                 break;
 590
 591         case CPU_DOWN_PREPARE:
 592                 /* Suspend is in progress, only remove the interface */
 593                 sysfs_remove_group(&dev->kobj, &mc_attr_group);
 594                 pr_debug("CPU%d removed\n", cpu);
 595                 break;
 596
 597         /*
 598          * case CPU_DEAD:
 599          *
 600          * When a CPU goes offline, don't free up or invalidate the copy of
 601          * the microcode in kernel memory, so that we can reuse it when the
 602          * CPU comes back online without unnecessarily requesting the userspace
 603          * for it again.
 604          */
 605         }
 606
 607         /* The CPU refused to come up during a system resume */
 608         if (action == CPU_UP_CANCELED_FROZEN)
 609                 microcode_fini_cpu(cpu);
 610
 611         return NOTIFY_OK;
 612 }
 613
 614 static struct notifier_block mc_cpu_notifier = {
 615         .notifier_call  = mc_cpu_callback,
 616 };
 617
 618 static struct attribute *cpu_root_microcode_attrs[] = {
 619         &dev_attr_reload.attr,
 620         NULL
 621 };
 622
 623 static struct attribute_group cpu_root_microcode_group = {
 624         .name  = "microcode",
 625         .attrs = cpu_root_microcode_attrs,
 626 };
 627
 628 int __init microcode_init(void)
 629 {
 630         struct cpuinfo_x86 *c = &boot_cpu_data;
 631         int error;
 632
 633         if (paravirt_enabled() || dis_ucode_ldr)
 634                 return -EINVAL;
 635
 636         if (c->x86_vendor == X86_VENDOR_INTEL)
 637                 microcode_ops = init_intel_microcode();
 638         else if (c->x86_vendor == X86_VENDOR_AMD)
 639                 microcode_ops = init_amd_microcode();
 640         else
 641                 pr_err("no support for this CPU vendor\n");
 642
 643         if (!microcode_ops)
 644                 return -ENODEV;
 645
 646         microcode_pdev = platform_device_register_simple("microcode", -1,
 647                                                          NULL, 0);
 648         if (IS_ERR(microcode_pdev))
 649                 return PTR_ERR(microcode_pdev);
 650
 651         get_online_cpus();
 652         mutex_lock(&microcode_mutex);
 653
 654         error = subsys_interface_register(&mc_cpu_interface);
 655         if (!error)
 656                 perf_check_microcode();
 657         mutex_unlock(&microcode_mutex);
 658         put_online_cpus();
 659
 660         if (error)
 661                 goto out_pdev;
 662
 663         error = sysfs_create_group(&cpu_subsys.dev_root->kobj,
 664                                    &cpu_root_microcode_group);
 665
 666         if (error) {
 667                 pr_err("Error creating microcode group!\n");
 668                 goto out_driver;
 669         }
 670
 671         error = microcode_dev_init();
 672         if (error)
 673                 goto out_ucode_group;
 674
 675         register_syscore_ops(&mc_syscore_ops);
 676         register_hotcpu_notifier(&mc_cpu_notifier);
 677
 678         pr_info("Microcode Update Driver: v" MICROCODE_VERSION
 679                 " <tigran@aivazian.fsnet.co.uk>, Peter Oruba\n");
 680
 681         return 0;
 682
 683  out_ucode_group:
 684         sysfs_remove_group(&cpu_subsys.dev_root->kobj,
 685                            &cpu_root_microcode_group);
 686
 687  out_driver:
 688         get_online_cpus();
 689         mutex_lock(&microcode_mutex);
 690
 691         subsys_interface_unregister(&mc_cpu_interface);
 692
 693         mutex_unlock(&microcode_mutex);
 694         put_online_cpus();
 695
 696  out_pdev:
 697         platform_device_unregister(microcode_pdev);
 698         return error;
 699
 700 }
 701 late_initcall(microcode_init);