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         int err = 0;
 280
 281         if (uci->valid) {
 282                 enum ucode_state ustate;
 283
 284                 ustate = microcode_ops->request_microcode_fw(cpu, &microcode_pdev->dev);
 285                 if (ustate == UCODE_OK)
 286                         apply_microcode_on_target(cpu);
 287                 else
 288                         if (ustate == UCODE_ERROR)
 289                                 err = -EINVAL;
 290         }
 291
 292         return err;
 293 }
 294
 295 static ssize_t reload_store(struct device *dev,
 296                             struct device_attribute *attr,
 297                             const char *buf, size_t size)
 298 {
 299         unsigned long val;
 300         int cpu;
 301         ssize_t ret = 0, tmp_ret;
 302
 303         ret = kstrtoul(buf, 0, &val);
 304         if (ret)
 305                 return ret;
 306
 307         if (val != 1)
 308                 return size;
 309
 310         get_online_cpus();
 311         mutex_lock(&microcode_mutex);
 312         for_each_online_cpu(cpu) {
 313                 tmp_ret = reload_for_cpu(cpu);
 314                 if (tmp_ret != 0)
 315                         pr_warn("Error reloading microcode on CPU %d\n", cpu);
 316
 317                 /* save retval of the first encountered reload error */
 318                 if (!ret)
 319                         ret = tmp_ret;
 320         }
 321         if (!ret)
 322                 perf_check_microcode();
 323         mutex_unlock(&microcode_mutex);
 324         put_online_cpus();
 325
 326         if (!ret)
 327                 ret = size;
 328
 329         return ret;
 330 }
 331
 332 static ssize_t version_show(struct device *dev,
 333                         struct device_attribute *attr, char *buf)
 334 {
 335         struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
 336
 337         return sprintf(buf, "0x%x\n", uci->cpu_sig.rev);
 338 }
 339
 340 static ssize_t pf_show(struct device *dev,
 341                         struct device_attribute *attr, char *buf)
 342 {
 343         struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
 344
 345         return sprintf(buf, "0x%x\n", uci->cpu_sig.pf);
 346 }
 347
 348 static DEVICE_ATTR(reload, 0200, NULL, reload_store);
 349 static DEVICE_ATTR(version, 0400, version_show, NULL);
 350 static DEVICE_ATTR(processor_flags, 0400, pf_show, NULL);
 351
 352 static struct attribute *mc_default_attrs[] = {
 353         &dev_attr_version.attr,
 354         &dev_attr_processor_flags.attr,
 355         NULL
 356 };
 357
 358 static struct attribute_group mc_attr_group = {
 359         .attrs                  = mc_default_attrs,
 360         .name                   = "microcode",
 361 };
 362
 363 static void microcode_fini_cpu(int cpu)
 364 {
 365         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 366
 367         microcode_ops->microcode_fini_cpu(cpu);
 368         uci->valid = 0;
 369 }
 370
 371 static enum ucode_state microcode_resume_cpu(int cpu)
 372 {
 373         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 374
 375         if (!uci->mc)
 376                 return UCODE_NFOUND;
 377
 378         pr_debug("CPU%d updated upon resume\n", cpu);
 379         apply_microcode_on_target(cpu);
 380
 381         return UCODE_OK;
 382 }
 383
 384 static enum ucode_state microcode_init_cpu(int cpu)
 385 {
 386         enum ucode_state ustate;
 387
 388         if (collect_cpu_info(cpu))
 389                 return UCODE_ERROR;
 390
 391         /* --dimm. Trigger a delayed update? */
 392         if (system_state != SYSTEM_RUNNING)
 393                 return UCODE_NFOUND;
 394
 395         ustate = microcode_ops->request_microcode_fw(cpu, &microcode_pdev->dev);
 396
 397         if (ustate == UCODE_OK) {
 398                 pr_debug("CPU%d updated upon init\n", cpu);
 399                 apply_microcode_on_target(cpu);
 400         }
 401
 402         return ustate;
 403 }
 404
 405 static enum ucode_state microcode_update_cpu(int cpu)
 406 {
 407         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 408         enum ucode_state ustate;
 409
 410         if (uci->valid)
 411                 ustate = microcode_resume_cpu(cpu);
 412         else
 413                 ustate = microcode_init_cpu(cpu);
 414
 415         return ustate;
 416 }
 417
 418 static int mc_device_add(struct device *dev, struct subsys_interface *sif)
 419 {
 420         int err, cpu = dev->id;
 421
 422         if (!cpu_online(cpu))
 423                 return 0;
 424
 425         pr_debug("CPU%d added\n", cpu);
 426
 427         err = sysfs_create_group(&dev->kobj, &mc_attr_group);
 428         if (err)
 429                 return err;
 430
 431         if (microcode_init_cpu(cpu) == UCODE_ERROR)
 432                 return -EINVAL;
 433
 434         return err;
 435 }
 436
 437 static int mc_device_remove(struct device *dev, struct subsys_interface *sif)
 438 {
 439         int cpu = dev->id;
 440
 441         if (!cpu_online(cpu))
 442                 return 0;
 443
 444         pr_debug("CPU%d removed\n", cpu);
 445         microcode_fini_cpu(cpu);
 446         sysfs_remove_group(&dev->kobj, &mc_attr_group);
 447         return 0;
 448 }
 449
 450 static struct subsys_interface mc_cpu_interface = {
 451         .name                   = "microcode",
 452         .subsys                 = &cpu_subsys,
 453         .add_dev                = mc_device_add,
 454         .remove_dev             = mc_device_remove,
 455 };
 456
 457 /**
 458  * mc_bp_resume - Update boot CPU microcode during resume.
 459  */
 460 static void mc_bp_resume(void)
 461 {
 462         int cpu = smp_processor_id();
 463         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 464
 465         if (uci->valid && uci->mc)
 466                 microcode_ops->apply_microcode(cpu);
 467 }
 468
 469 static struct syscore_ops mc_syscore_ops = {
 470         .resume                 = mc_bp_resume,
 471 };
 472
 473 static __cpuinit int
 474 mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
 475 {
 476         unsigned int cpu = (unsigned long)hcpu;
 477         struct device *dev;
 478
 479         dev = get_cpu_device(cpu);
 480         switch (action) {
 481         case CPU_ONLINE:
 482         case CPU_ONLINE_FROZEN:
 483                 microcode_update_cpu(cpu);
 484         case CPU_DOWN_FAILED:
 485         case CPU_DOWN_FAILED_FROZEN:
 486                 pr_debug("CPU%d added\n", cpu);
 487                 if (sysfs_create_group(&dev->kobj, &mc_attr_group))
 488                         pr_err("Failed to create group for CPU%d\n", cpu);
 489                 break;
 490         case CPU_DOWN_PREPARE:
 491         case CPU_DOWN_PREPARE_FROZEN:
 492                 /* Suspend is in progress, only remove the interface */
 493                 sysfs_remove_group(&dev->kobj, &mc_attr_group);
 494                 pr_debug("CPU%d removed\n", cpu);
 495                 break;
 496
 497         /*
 498          * When a CPU goes offline, don't free up or invalidate the copy of
 499          * the microcode in kernel memory, so that we can reuse it when the
 500          * CPU comes back online without unnecessarily requesting the userspace
 501          * for it again.
 502          */
 503         case CPU_UP_CANCELED_FROZEN:
 504                 /* The CPU refused to come up during a system resume */
 505                 microcode_fini_cpu(cpu);
 506                 break;
 507         }
 508         return NOTIFY_OK;
 509 }
 510
 511 static struct notifier_block __refdata mc_cpu_notifier = {
 512         .notifier_call  = mc_cpu_callback,
 513 };
 514
 515 #ifdef MODULE
 516 /* Autoload on Intel and AMD systems */
 517 static const struct x86_cpu_id __initconst microcode_id[] = {
 518 #ifdef CONFIG_MICROCODE_INTEL
 519         { X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, },
 520 #endif
 521 #ifdef CONFIG_MICROCODE_AMD
 522         { X86_VENDOR_AMD, X86_FAMILY_ANY, X86_MODEL_ANY, },
 523 #endif
 524         {}
 525 };
 526 MODULE_DEVICE_TABLE(x86cpu, microcode_id);
 527 #endif
 528
 529 static struct attribute *cpu_root_microcode_attrs[] = {
 530         &dev_attr_reload.attr,
 531         NULL
 532 };
 533
 534 static struct attribute_group cpu_root_microcode_group = {
 535         .name  = "microcode",
 536         .attrs = cpu_root_microcode_attrs,
 537 };
 538
 539 static int __init microcode_init(void)
 540 {
 541         struct cpuinfo_x86 *c = &cpu_data(0);
 542         int error;
 543
 544         if (c->x86_vendor == X86_VENDOR_INTEL)
 545                 microcode_ops = init_intel_microcode();
 546         else if (c->x86_vendor == X86_VENDOR_AMD)
 547                 microcode_ops = init_amd_microcode();
 548         else
 549                 pr_err("no support for this CPU vendor\n");
 550
 551         if (!microcode_ops)
 552                 return -ENODEV;
 553
 554         microcode_pdev = platform_device_register_simple("microcode", -1,
 555                                                          NULL, 0);
 556         if (IS_ERR(microcode_pdev))
 557                 return PTR_ERR(microcode_pdev);
 558
 559         get_online_cpus();
 560         mutex_lock(&microcode_mutex);
 561
 562         error = subsys_interface_register(&mc_cpu_interface);
 563         if (!error)
 564                 perf_check_microcode();
 565         mutex_unlock(&microcode_mutex);
 566         put_online_cpus();
 567
 568         if (error)
 569                 goto out_pdev;
 570
 571         error = sysfs_create_group(&cpu_subsys.dev_root->kobj,
 572                                    &cpu_root_microcode_group);
 573
 574         if (error) {
 575                 pr_err("Error creating microcode group!\n");
 576                 goto out_driver;
 577         }
 578
 579         error = microcode_dev_init();
 580         if (error)
 581                 goto out_ucode_group;
 582
 583         register_syscore_ops(&mc_syscore_ops);
 584         register_hotcpu_notifier(&mc_cpu_notifier);
 585
 586         pr_info("Microcode Update Driver: v" MICROCODE_VERSION
 587                 " <tigran@aivazian.fsnet.co.uk>, Peter Oruba\n");
 588
 589         return 0;
 590
 591  out_ucode_group:
 592         sysfs_remove_group(&cpu_subsys.dev_root->kobj,
 593                            &cpu_root_microcode_group);
 594
 595  out_driver:
 596         get_online_cpus();
 597         mutex_lock(&microcode_mutex);
 598
 599         subsys_interface_unregister(&mc_cpu_interface);
 600
 601         mutex_unlock(&microcode_mutex);
 602         put_online_cpus();
 603
 604  out_pdev:
 605         platform_device_unregister(microcode_pdev);
 606         return error;
 607
 608 }
 609 module_init(microcode_init);
 610
 611 static void __exit microcode_exit(void)
 612 {
 613         struct cpuinfo_x86 *c = &cpu_data(0);
 614
 615         microcode_dev_exit();
 616
 617         unregister_hotcpu_notifier(&mc_cpu_notifier);
 618         unregister_syscore_ops(&mc_syscore_ops);
 619
 620         sysfs_remove_group(&cpu_subsys.dev_root->kobj,
 621                            &cpu_root_microcode_group);
 622
 623         get_online_cpus();
 624         mutex_lock(&microcode_mutex);
 625
 626         subsys_interface_unregister(&mc_cpu_interface);
 627
 628         mutex_unlock(&microcode_mutex);
 629         put_online_cpus();
 630
 631         platform_device_unregister(microcode_pdev);
 632
 633         microcode_ops = NULL;
 634
 635         if (c->x86_vendor == X86_VENDOR_AMD)
 636                 exit_amd_microcode();
 637
 638         pr_info("Microcode Update Driver: v" MICROCODE_VERSION " removed.\n");
 639 }
 640 module_exit(microcode_exit);