arch/x86/kernel/microcode_core.c

   1 /*
   2  *      Intel 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  *
   7  *      This driver allows to upgrade microcode on Intel processors
   8  *      belonging to IA-32 family - PentiumPro, Pentium II,
   9  *      Pentium III, Xeon, Pentium 4, etc.
  10  *
  11  *      Reference: Section 8.11 of Volume 3a, IA-32 Intel? Architecture
  12  *      Software Developer's Manual
  13  *      Order Number 253668 or free download from:
  14  *
  15  *      http://developer.intel.com/Assets/PDF/manual/253668.pdf
  16  *
  17  *      For more information, go to http://www.urbanmyth.org/microcode
  18  *
  19  *      This program is free software; you can redistribute it and/or
  20  *      modify it under the terms of the GNU General Public License
  21  *      as published by the Free Software Foundation; either version
  22  *      2 of the License, or (at your option) any later version.
  23  *
  24  *      1.0     16 Feb 2000, Tigran Aivazian <tigran@sco.com>
  25  *              Initial release.
  26  *      1.01    18 Feb 2000, Tigran Aivazian <tigran@sco.com>
  27  *              Added read() support + cleanups.
  28  *      1.02    21 Feb 2000, Tigran Aivazian <tigran@sco.com>
  29  *              Added 'device trimming' support. open(O_WRONLY) zeroes
  30  *              and frees the saved copy of applied microcode.
  31  *      1.03    29 Feb 2000, Tigran Aivazian <tigran@sco.com>
  32  *              Made to use devfs (/dev/cpu/microcode) + cleanups.
  33  *      1.04    06 Jun 2000, Simon Trimmer <simon@veritas.com>
  34  *              Added misc device support (now uses both devfs and misc).
  35  *              Added MICROCODE_IOCFREE ioctl to clear memory.
  36  *      1.05    09 Jun 2000, Simon Trimmer <simon@veritas.com>
  37  *              Messages for error cases (non Intel & no suitable microcode).
  38  *      1.06    03 Aug 2000, Tigran Aivazian <tigran@veritas.com>
  39  *              Removed ->release(). Removed exclusive open and status bitmap.
  40  *              Added microcode_rwsem to serialize read()/write()/ioctl().
  41  *              Removed global kernel lock usage.
  42  *      1.07    07 Sep 2000, Tigran Aivazian <tigran@veritas.com>
  43  *              Write 0 to 0x8B msr and then cpuid before reading revision,
  44  *              so that it works even if there were no update done by the
  45  *              BIOS. Otherwise, reading from 0x8B gives junk (which happened
  46  *              to be 0 on my machine which is why it worked even when I
  47  *              disabled update by the BIOS)
  48  *              Thanks to Eric W. Biederman <ebiederman@lnxi.com> for the fix.
  49  *      1.08    11 Dec 2000, Richard Schaal <richard.schaal@intel.com> and
  50  *                           Tigran Aivazian <tigran@veritas.com>
  51  *              Intel Pentium 4 processor support and bugfixes.
  52  *      1.09    30 Oct 2001, Tigran Aivazian <tigran@veritas.com>
  53  *              Bugfix for HT (Hyper-Threading) enabled processors
  54  *              whereby processor resources are shared by all logical processors
  55  *              in a single CPU package.
  56  *      1.10    28 Feb 2002 Asit K Mallick <asit.k.mallick@intel.com> and
  57  *              Tigran Aivazian <tigran@veritas.com>,
  58  *              Serialize updates as required on HT processors due to
  59  *              speculative nature of implementation.
  60  *      1.11    22 Mar 2002 Tigran Aivazian <tigran@veritas.com>
  61  *              Fix the panic when writing zero-length microcode chunk.
  62  *      1.12    29 Sep 2003 Nitin Kamble <nitin.a.kamble@intel.com>,
  63  *              Jun Nakajima <jun.nakajima@intel.com>
  64  *              Support for the microcode updates in the new format.
  65  *      1.13    10 Oct 2003 Tigran Aivazian <tigran@veritas.com>
  66  *              Removed ->read() method and obsoleted MICROCODE_IOCFREE ioctl
  67  *              because we no longer hold a copy of applied microcode
  68  *              in kernel memory.
  69  *      1.14    25 Jun 2004 Tigran Aivazian <tigran@veritas.com>
  70  *              Fix sigmatch() macro to handle old CPUs with pf == 0.
  71  *              Thanks to Stuart Swales for pointing out this bug.
  72  */
  73
  74 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  75
  76 #include <linux/platform_device.h>
  77 #include <linux/miscdevice.h>
  78 #include <linux/capability.h>
  79 #include <linux/kernel.h>
  80 #include <linux/module.h>
  81 #include <linux/mutex.h>
  82 #include <linux/cpu.h>
  83 #include <linux/fs.h>
  84 #include <linux/mm.h>
  85 #include <linux/syscore_ops.h>
  86
  87 #include <asm/microcode.h>
  88 #include <asm/processor.h>
  89 #include <asm/cpu_device_id.h>
  90 #include <asm/perf_event.h>
  91
  92 MODULE_DESCRIPTION("Microcode Update Driver");
  93 MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
  94 MODULE_LICENSE("GPL");
  95
  96 #define MICROCODE_VERSION       "2.00"
  97
  98 static struct microcode_ops     *microcode_ops;
  99
 100 /*
 101  * Synchronization.
 102  *
 103  * All non cpu-hotplug-callback call sites use:
 104  *
 105  * - microcode_mutex to synchronize with each other;
 106  * - get/put_online_cpus() to synchronize with
 107  *   the cpu-hotplug-callback call sites.
 108  *
 109  * We guarantee that only a single cpu is being
 110  * updated at any particular moment of time.
 111  */
 112 static DEFINE_MUTEX(microcode_mutex);
 113
 114 struct ucode_cpu_info           ucode_cpu_info[NR_CPUS];
 115 EXPORT_SYMBOL_GPL(ucode_cpu_info);
 116
 117 /*
 118  * Operations that are run on a target cpu:
 119  */
 120
 121 struct cpu_info_ctx {
 122         struct cpu_signature    *cpu_sig;
 123         int                     err;
 124 };
 125
 126 static void collect_cpu_info_local(void *arg)
 127 {
 128         struct cpu_info_ctx *ctx = arg;
 129
 130         ctx->err = microcode_ops->collect_cpu_info(smp_processor_id(),
 131                                                    ctx->cpu_sig);
 132 }
 133
 134 static int collect_cpu_info_on_target(int cpu, struct cpu_signature *cpu_sig)
 135 {
 136         struct cpu_info_ctx ctx = { .cpu_sig = cpu_sig, .err = 0 };
 137         int ret;
 138
 139         ret = smp_call_function_single(cpu, collect_cpu_info_local, &ctx, 1);
 140         if (!ret)
 141                 ret = ctx.err;
 142
 143         return ret;
 144 }
 145
 146 static int collect_cpu_info(int cpu)
 147 {
 148         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 149         int ret;
 150
 151         memset(uci, 0, sizeof(*uci));
 152
 153         ret = collect_cpu_info_on_target(cpu, &uci->cpu_sig);
 154         if (!ret)
 155                 uci->valid = 1;
 156
 157         return ret;
 158 }
 159
 160 struct apply_microcode_ctx {
 161         int err;
 162 };
 163
 164 static void apply_microcode_local(void *arg)
 165 {
 166         struct apply_microcode_ctx *ctx = arg;
 167
 168         ctx->err = microcode_ops->apply_microcode(smp_processor_id());
 169 }
 170
 171 static int apply_microcode_on_target(int cpu)
 172 {
 173         struct apply_microcode_ctx ctx = { .err = 0 };
 174         int ret;
 175
 176         ret = smp_call_function_single(cpu, apply_microcode_local, &ctx, 1);
 177         if (!ret)
 178                 ret = ctx.err;
 179
 180         return ret;
 181 }
 182
 183 #ifdef CONFIG_MICROCODE_OLD_INTERFACE
 184 static int do_microcode_update(const void __user *buf, size_t size)
 185 {
 186         int error = 0;
 187         int cpu;
 188
 189         for_each_online_cpu(cpu) {
 190                 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 191                 enum ucode_state ustate;
 192
 193                 if (!uci->valid)
 194                         continue;
 195
 196                 ustate = microcode_ops->request_microcode_user(cpu, buf, size);
 197                 if (ustate == UCODE_ERROR) {
 198                         error = -1;
 199                         break;
 200                 } else if (ustate == UCODE_OK)
 201                         apply_microcode_on_target(cpu);
 202         }
 203
 204         return error;
 205 }
 206
 207 static int microcode_open(struct inode *inode, struct file *file)
 208 {
 209         return capable(CAP_SYS_RAWIO) ? nonseekable_open(inode, file) : -EPERM;
 210 }
 211
 212 static ssize_t microcode_write(struct file *file, const char __user *buf,
 213                                size_t len, loff_t *ppos)
 214 {
 215         ssize_t ret = -EINVAL;
 216
 217         if ((len >> PAGE_SHIFT) > totalram_pages) {
 218                 pr_err("too much data (max %ld pages)\n", totalram_pages);
 219                 return ret;
 220         }
 221
 222         get_online_cpus();
 223         mutex_lock(&microcode_mutex);
 224
 225         if (do_microcode_update(buf, len) == 0)
 226                 ret = (ssize_t)len;
 227
 228         mutex_unlock(&microcode_mutex);
 229         put_online_cpus();
 230
 231         return ret;
 232 }
 233
 234 static const struct file_operations microcode_fops = {
 235         .owner                  = THIS_MODULE,
 236         .write                  = microcode_write,
 237         .open                   = microcode_open,
 238         .llseek         = no_llseek,
 239 };
 240
 241 static struct miscdevice microcode_dev = {
 242         .minor                  = MICROCODE_MINOR,
 243         .name                   = "microcode",
 244         .nodename               = "cpu/microcode",
 245         .fops                   = &microcode_fops,
 246 };
 247
 248 static int __init microcode_dev_init(void)
 249 {
 250         int error;
 251
 252         error = misc_register(&microcode_dev);
 253         if (error) {
 254                 pr_err("can't misc_register on minor=%d\n", MICROCODE_MINOR);
 255                 return error;
 256         }
 257
 258         return 0;
 259 }
 260
 261 static void __exit microcode_dev_exit(void)
 262 {
 263         misc_deregister(&microcode_dev);
 264 }
 265
 266 MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);
 267 MODULE_ALIAS("devname:cpu/microcode");
 268 #else
 269 #define microcode_dev_init()    0
 270 #define microcode_dev_exit()    do { } while (0)
 271 #endif
 272
 273 /* fake device for request_firmware */
 274 static struct platform_device   *microcode_pdev;
 275
 276 static int reload_for_cpu(int cpu)
 277 {
 278         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 279         enum ucode_state ustate;
 280         int err = 0;
 281
 282         if (!uci->valid)
 283                 return err;
 284
 285         ustate = microcode_ops->request_microcode_fw(cpu, &microcode_pdev->dev);
 286         if (ustate == UCODE_OK)
 287                 apply_microcode_on_target(cpu);
 288         else
 289                 if (ustate == UCODE_ERROR)
 290                         err = -EINVAL;
 291         return err;
 292 }
 293
 294 static ssize_t reload_store(struct device *dev,
 295                             struct device_attribute *attr,
 296                             const char *buf, size_t size)
 297 {
 298         unsigned long val;
 299         int cpu;
 300         ssize_t ret = 0, tmp_ret;
 301
 302         ret = kstrtoul(buf, 0, &val);
 303         if (ret)
 304                 return ret;
 305
 306         if (val != 1)
 307                 return size;
 308
 309         get_online_cpus();
 310         mutex_lock(&microcode_mutex);
 311         for_each_online_cpu(cpu) {
 312                 tmp_ret = reload_for_cpu(cpu);
 313                 if (tmp_ret != 0)
 314                         pr_warn("Error reloading microcode on CPU %d\n", cpu);
 315
 316                 /* save retval of the first encountered reload error */
 317                 if (!ret)
 318                         ret = tmp_ret;
 319         }
 320         if (!ret)
 321                 perf_check_microcode();
 322         mutex_unlock(&microcode_mutex);
 323         put_online_cpus();
 324
 325         if (!ret)
 326                 ret = size;
 327
 328         return ret;
 329 }
 330
 331 static ssize_t version_show(struct device *dev,
 332                         struct device_attribute *attr, char *buf)
 333 {
 334         struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
 335
 336         return sprintf(buf, "0x%x\n", uci->cpu_sig.rev);
 337 }
 338
 339 static ssize_t pf_show(struct device *dev,
 340                         struct device_attribute *attr, char *buf)
 341 {
 342         struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
 343
 344         return sprintf(buf, "0x%x\n", uci->cpu_sig.pf);
 345 }
 346
 347 static DEVICE_ATTR(reload, 0200, NULL, reload_store);
 348 static DEVICE_ATTR(version, 0400, version_show, NULL);
 349 static DEVICE_ATTR(processor_flags, 0400, pf_show, NULL);
 350
 351 static struct attribute *mc_default_attrs[] = {
 352         &dev_attr_version.attr,
 353         &dev_attr_processor_flags.attr,
 354         NULL
 355 };
 356
 357 static struct attribute_group mc_attr_group = {
 358         .attrs                  = mc_default_attrs,
 359         .name                   = "microcode",
 360 };
 361
 362 static void microcode_fini_cpu(int cpu)
 363 {
 364         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 365
 366         microcode_ops->microcode_fini_cpu(cpu);
 367         uci->valid = 0;
 368 }
 369
 370 static enum ucode_state microcode_resume_cpu(int cpu)
 371 {
 372         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 373
 374         if (!uci->mc)
 375                 return UCODE_NFOUND;
 376
 377         pr_debug("CPU%d updated upon resume\n", cpu);
 378         apply_microcode_on_target(cpu);
 379
 380         return UCODE_OK;
 381 }
 382
 383 static enum ucode_state microcode_init_cpu(int cpu)
 384 {
 385         enum ucode_state ustate;
 386
 387         if (collect_cpu_info(cpu))
 388                 return UCODE_ERROR;
 389
 390         /* --dimm. Trigger a delayed update? */
 391         if (system_state != SYSTEM_RUNNING)
 392                 return UCODE_NFOUND;
 393
 394         ustate = microcode_ops->request_microcode_fw(cpu, &microcode_pdev->dev);
 395
 396         if (ustate == UCODE_OK) {
 397                 pr_debug("CPU%d updated upon init\n", cpu);
 398                 apply_microcode_on_target(cpu);
 399         }
 400
 401         return ustate;
 402 }
 403
 404 static enum ucode_state microcode_update_cpu(int cpu)
 405 {
 406         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 407         enum ucode_state ustate;
 408
 409         if (uci->valid)
 410                 ustate = microcode_resume_cpu(cpu);
 411         else
 412                 ustate = microcode_init_cpu(cpu);
 413
 414         return ustate;
 415 }
 416
 417 static int mc_device_add(struct device *dev, struct subsys_interface *sif)
 418 {
 419         int err, cpu = dev->id;
 420
 421         if (!cpu_online(cpu))
 422                 return 0;
 423
 424         pr_debug("CPU%d added\n", cpu);
 425
 426         err = sysfs_create_group(&dev->kobj, &mc_attr_group);
 427         if (err)
 428                 return err;
 429
 430         if (microcode_init_cpu(cpu) == UCODE_ERROR)
 431                 return -EINVAL;
 432
 433         return err;
 434 }
 435
 436 static int mc_device_remove(struct device *dev, struct subsys_interface *sif)
 437 {
 438         int cpu = dev->id;
 439
 440         if (!cpu_online(cpu))
 441                 return 0;
 442
 443         pr_debug("CPU%d removed\n", cpu);
 444         microcode_fini_cpu(cpu);
 445         sysfs_remove_group(&dev->kobj, &mc_attr_group);
 446         return 0;
 447 }
 448
 449 static struct subsys_interface mc_cpu_interface = {
 450         .name                   = "microcode",
 451         .subsys                 = &cpu_subsys,
 452         .add_dev                = mc_device_add,
 453         .remove_dev             = mc_device_remove,
 454 };
 455
 456 /**
 457  * mc_bp_resume - Update boot CPU microcode during resume.
 458  */
 459 static void mc_bp_resume(void)
 460 {
 461         int cpu = smp_processor_id();
 462         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 463
 464         if (uci->valid && uci->mc)
 465                 microcode_ops->apply_microcode(cpu);
 466 }
 467
 468 static struct syscore_ops mc_syscore_ops = {
 469         .resume                 = mc_bp_resume,
 470 };
 471
 472 static __cpuinit int
 473 mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
 474 {
 475         unsigned int cpu = (unsigned long)hcpu;
 476         struct device *dev;
 477
 478         dev = get_cpu_device(cpu);
 479         switch (action) {
 480         case CPU_ONLINE:
 481         case CPU_ONLINE_FROZEN:
 482                 microcode_update_cpu(cpu);
 483         case CPU_DOWN_FAILED:
 484         case CPU_DOWN_FAILED_FROZEN:
 485                 pr_debug("CPU%d added\n", cpu);
 486                 if (sysfs_create_group(&dev->kobj, &mc_attr_group))
 487                         pr_err("Failed to create group for CPU%d\n", cpu);
 488                 break;
 489         case CPU_DOWN_PREPARE:
 490         case CPU_DOWN_PREPARE_FROZEN:
 491                 /* Suspend is in progress, only remove the interface */
 492                 sysfs_remove_group(&dev->kobj, &mc_attr_group);
 493                 pr_debug("CPU%d removed\n", cpu);
 494                 break;
 495
 496         /*
 497          * When a CPU goes offline, don't free up or invalidate the copy of
 498          * the microcode in kernel memory, so that we can reuse it when the
 499          * CPU comes back online without unnecessarily requesting the userspace
 500          * for it again.
 501          */
 502         case CPU_UP_CANCELED_FROZEN:
 503                 /* The CPU refused to come up during a system resume */
 504                 microcode_fini_cpu(cpu);
 505                 break;
 506         }
 507         return NOTIFY_OK;
 508 }
 509
 510 static struct notifier_block __refdata mc_cpu_notifier = {
 511         .notifier_call  = mc_cpu_callback,
 512 };
 513
 514 #ifdef MODULE
 515 /* Autoload on Intel and AMD systems */
 516 static const struct x86_cpu_id __initconst microcode_id[] = {
 517 #ifdef CONFIG_MICROCODE_INTEL
 518         { X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, },
 519 #endif
 520 #ifdef CONFIG_MICROCODE_AMD
 521         { X86_VENDOR_AMD, X86_FAMILY_ANY, X86_MODEL_ANY, },
 522 #endif
 523         {}
 524 };
 525 MODULE_DEVICE_TABLE(x86cpu, microcode_id);
 526 #endif
 527
 528 static struct attribute *cpu_root_microcode_attrs[] = {
 529         &dev_attr_reload.attr,
 530         NULL
 531 };
 532
 533 static struct attribute_group cpu_root_microcode_group = {
 534         .name  = "microcode",
 535         .attrs = cpu_root_microcode_attrs,
 536 };
 537
 538 static int __init microcode_init(void)
 539 {
 540         struct cpuinfo_x86 *c = &cpu_data(0);
 541         int error;
 542
 543         if (c->x86_vendor == X86_VENDOR_INTEL)
 544                 microcode_ops = init_intel_microcode();
 545         else if (c->x86_vendor == X86_VENDOR_AMD)
 546                 microcode_ops = init_amd_microcode();
 547         else
 548                 pr_err("no support for this CPU vendor\n");
 549
 550         if (!microcode_ops)
 551                 return -ENODEV;
 552
 553         microcode_pdev = platform_device_register_simple("microcode", -1,
 554                                                          NULL, 0);
 555         if (IS_ERR(microcode_pdev))
 556                 return PTR_ERR(microcode_pdev);
 557
 558         get_online_cpus();
 559         mutex_lock(&microcode_mutex);
 560
 561         error = subsys_interface_register(&mc_cpu_interface);
 562         if (!error)
 563                 perf_check_microcode();
 564         mutex_unlock(&microcode_mutex);
 565         put_online_cpus();
 566
 567         if (error)
 568                 goto out_pdev;
 569
 570         error = sysfs_create_group(&cpu_subsys.dev_root->kobj,
 571                                    &cpu_root_microcode_group);
 572
 573         if (error) {
 574                 pr_err("Error creating microcode group!\n");
 575                 goto out_driver;
 576         }
 577
 578         error = microcode_dev_init();
 579         if (error)
 580                 goto out_ucode_group;
 581
 582         register_syscore_ops(&mc_syscore_ops);
 583         register_hotcpu_notifier(&mc_cpu_notifier);
 584
 585         pr_info("Microcode Update Driver: v" MICROCODE_VERSION
 586                 " <tigran@aivazian.fsnet.co.uk>, Peter Oruba\n");
 587
 588         return 0;
 589
 590  out_ucode_group:
 591         sysfs_remove_group(&cpu_subsys.dev_root->kobj,
 592                            &cpu_root_microcode_group);
 593
 594  out_driver:
 595         get_online_cpus();
 596         mutex_lock(&microcode_mutex);
 597
 598         subsys_interface_unregister(&mc_cpu_interface);
 599
 600         mutex_unlock(&microcode_mutex);
 601         put_online_cpus();
 602
 603  out_pdev:
 604         platform_device_unregister(microcode_pdev);
 605         return error;
 606
 607 }
 608 module_init(microcode_init);
 609
 610 static void __exit microcode_exit(void)
 611 {
 612         struct cpuinfo_x86 *c = &cpu_data(0);
 613
 614         microcode_dev_exit();
 615
 616         unregister_hotcpu_notifier(&mc_cpu_notifier);
 617         unregister_syscore_ops(&mc_syscore_ops);
 618
 619         sysfs_remove_group(&cpu_subsys.dev_root->kobj,
 620                            &cpu_root_microcode_group);
 621
 622         get_online_cpus();
 623         mutex_lock(&microcode_mutex);
 624
 625         subsys_interface_unregister(&mc_cpu_interface);
 626
 627         mutex_unlock(&microcode_mutex);
 628         put_online_cpus();
 629
 630         platform_device_unregister(microcode_pdev);
 631
 632         microcode_ops = NULL;
 633
 634         if (c->x86_vendor == X86_VENDOR_AMD)
 635                 exit_amd_microcode();
 636
 637         pr_info("Microcode Update Driver: v" MICROCODE_VERSION " removed.\n");
 638 }
 639 module_exit(microcode_exit);