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
  90 MODULE_DESCRIPTION("Microcode Update Driver");
  91 MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
  92 MODULE_LICENSE("GPL");
  93
  94 #define MICROCODE_VERSION       "2.00"
  95
  96 static struct microcode_ops     *microcode_ops;
  97
  98 /*
  99  * Synchronization.
 100  *
 101  * All non cpu-hotplug-callback call sites use:
 102  *
 103  * - microcode_mutex to synchronize with each other;
 104  * - get/put_online_cpus() to synchronize with
 105  *   the cpu-hotplug-callback call sites.
 106  *
 107  * We guarantee that only a single cpu is being
 108  * updated at any particular moment of time.
 109  */
 110 static DEFINE_MUTEX(microcode_mutex);
 111
 112 struct ucode_cpu_info           ucode_cpu_info[NR_CPUS];
 113 EXPORT_SYMBOL_GPL(ucode_cpu_info);
 114
 115 /*
 116  * Operations that are run on a target cpu:
 117  */
 118
 119 struct cpu_info_ctx {
 120         struct cpu_signature    *cpu_sig;
 121         int                     err;
 122 };
 123
 124 static void collect_cpu_info_local(void *arg)
 125 {
 126         struct cpu_info_ctx *ctx = arg;
 127
 128         ctx->err = microcode_ops->collect_cpu_info(smp_processor_id(),
 129                                                    ctx->cpu_sig);
 130 }
 131
 132 static int collect_cpu_info_on_target(int cpu, struct cpu_signature *cpu_sig)
 133 {
 134         struct cpu_info_ctx ctx = { .cpu_sig = cpu_sig, .err = 0 };
 135         int ret;
 136
 137         ret = smp_call_function_single(cpu, collect_cpu_info_local, &ctx, 1);
 138         if (!ret)
 139                 ret = ctx.err;
 140
 141         return ret;
 142 }
 143
 144 static int collect_cpu_info(int cpu)
 145 {
 146         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 147         int ret;
 148
 149         memset(uci, 0, sizeof(*uci));
 150
 151         ret = collect_cpu_info_on_target(cpu, &uci->cpu_sig);
 152         if (!ret)
 153                 uci->valid = 1;
 154
 155         return ret;
 156 }
 157
 158 struct apply_microcode_ctx {
 159         int err;
 160 };
 161
 162 static void apply_microcode_local(void *arg)
 163 {
 164         struct apply_microcode_ctx *ctx = arg;
 165
 166         ctx->err = microcode_ops->apply_microcode(smp_processor_id());
 167 }
 168
 169 static int apply_microcode_on_target(int cpu)
 170 {
 171         struct apply_microcode_ctx ctx = { .err = 0 };
 172         int ret;
 173
 174         ret = smp_call_function_single(cpu, apply_microcode_local, &ctx, 1);
 175         if (!ret)
 176                 ret = ctx.err;
 177
 178         return ret;
 179 }
 180
 181 #ifdef CONFIG_MICROCODE_OLD_INTERFACE
 182 static int do_microcode_update(const void __user *buf, size_t size)
 183 {
 184         int error = 0;
 185         int cpu;
 186
 187         for_each_online_cpu(cpu) {
 188                 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 189                 enum ucode_state ustate;
 190
 191                 if (!uci->valid)
 192                         continue;
 193
 194                 ustate = microcode_ops->request_microcode_user(cpu, buf, size);
 195                 if (ustate == UCODE_ERROR) {
 196                         error = -1;
 197                         break;
 198                 } else if (ustate == UCODE_OK)
 199                         apply_microcode_on_target(cpu);
 200         }
 201
 202         return error;
 203 }
 204
 205 static int microcode_open(struct inode *inode, struct file *file)
 206 {
 207         return capable(CAP_SYS_RAWIO) ? nonseekable_open(inode, file) : -EPERM;
 208 }
 209
 210 static ssize_t microcode_write(struct file *file, const char __user *buf,
 211                                size_t len, loff_t *ppos)
 212 {
 213         ssize_t ret = -EINVAL;
 214
 215         if ((len >> PAGE_SHIFT) > totalram_pages) {
 216                 pr_err("too much data (max %ld pages)\n", totalram_pages);
 217                 return ret;
 218         }
 219
 220         get_online_cpus();
 221         mutex_lock(&microcode_mutex);
 222
 223         if (do_microcode_update(buf, len) == 0)
 224                 ret = (ssize_t)len;
 225
 226         mutex_unlock(&microcode_mutex);
 227         put_online_cpus();
 228
 229         return ret;
 230 }
 231
 232 static const struct file_operations microcode_fops = {
 233         .owner                  = THIS_MODULE,
 234         .write                  = microcode_write,
 235         .open                   = microcode_open,
 236         .llseek         = no_llseek,
 237 };
 238
 239 static struct miscdevice microcode_dev = {
 240         .minor                  = MICROCODE_MINOR,
 241         .name                   = "microcode",
 242         .nodename               = "cpu/microcode",
 243         .fops                   = &microcode_fops,
 244 };
 245
 246 static int __init microcode_dev_init(void)
 247 {
 248         int error;
 249
 250         error = misc_register(&microcode_dev);
 251         if (error) {
 252                 pr_err("can't misc_register on minor=%d\n", MICROCODE_MINOR);
 253                 return error;
 254         }
 255
 256         return 0;
 257 }
 258
 259 static void __exit microcode_dev_exit(void)
 260 {
 261         misc_deregister(&microcode_dev);
 262 }
 263
 264 MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);
 265 MODULE_ALIAS("devname:cpu/microcode");
 266 #else
 267 #define microcode_dev_init()    0
 268 #define microcode_dev_exit()    do { } while (0)
 269 #endif
 270
 271 /* fake device for request_firmware */
 272 static struct platform_device   *microcode_pdev;
 273
 274 static int reload_for_cpu(int cpu)
 275 {
 276         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 277         int err = 0;
 278
 279         mutex_lock(&microcode_mutex);
 280         if (uci->valid) {
 281                 enum ucode_state ustate;
 282
 283                 ustate = microcode_ops->request_microcode_fw(cpu, &microcode_pdev->dev);
 284                 if (ustate == UCODE_OK)
 285                         apply_microcode_on_target(cpu);
 286                 else
 287                         if (ustate == UCODE_ERROR)
 288                                 err = -EINVAL;
 289         }
 290         mutex_unlock(&microcode_mutex);
 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 = dev->id;
 301         int ret = 0;
 302         char *end;
 303
 304         val = simple_strtoul(buf, &end, 0);
 305         if (end == buf)
 306                 return -EINVAL;
 307
 308         if (val == 1) {
 309                 get_online_cpus();
 310                 if (cpu_online(cpu))
 311                         ret = reload_for_cpu(cpu);
 312                 put_online_cpus();
 313         }
 314
 315         if (!ret)
 316                 ret = size;
 317
 318         return ret;
 319 }
 320
 321 static ssize_t version_show(struct device *dev,
 322                         struct device_attribute *attr, char *buf)
 323 {
 324         struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
 325
 326         return sprintf(buf, "0x%x\n", uci->cpu_sig.rev);
 327 }
 328
 329 static ssize_t pf_show(struct device *dev,
 330                         struct device_attribute *attr, char *buf)
 331 {
 332         struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
 333
 334         return sprintf(buf, "0x%x\n", uci->cpu_sig.pf);
 335 }
 336
 337 static DEVICE_ATTR(reload, 0200, NULL, reload_store);
 338 static DEVICE_ATTR(version, 0400, version_show, NULL);
 339 static DEVICE_ATTR(processor_flags, 0400, pf_show, NULL);
 340
 341 static struct attribute *mc_default_attrs[] = {
 342         &dev_attr_reload.attr,
 343         &dev_attr_version.attr,
 344         &dev_attr_processor_flags.attr,
 345         NULL
 346 };
 347
 348 static struct attribute_group mc_attr_group = {
 349         .attrs                  = mc_default_attrs,
 350         .name                   = "microcode",
 351 };
 352
 353 static void microcode_fini_cpu(int cpu)
 354 {
 355         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 356
 357         microcode_ops->microcode_fini_cpu(cpu);
 358         uci->valid = 0;
 359 }
 360
 361 static enum ucode_state microcode_resume_cpu(int cpu)
 362 {
 363         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 364
 365         if (!uci->mc)
 366                 return UCODE_NFOUND;
 367
 368         pr_debug("CPU%d updated upon resume\n", cpu);
 369         apply_microcode_on_target(cpu);
 370
 371         return UCODE_OK;
 372 }
 373
 374 static enum ucode_state microcode_init_cpu(int cpu)
 375 {
 376         enum ucode_state ustate;
 377
 378         if (collect_cpu_info(cpu))
 379                 return UCODE_ERROR;
 380
 381         /* --dimm. Trigger a delayed update? */
 382         if (system_state != SYSTEM_RUNNING)
 383                 return UCODE_NFOUND;
 384
 385         ustate = microcode_ops->request_microcode_fw(cpu, &microcode_pdev->dev);
 386
 387         if (ustate == UCODE_OK) {
 388                 pr_debug("CPU%d updated upon init\n", cpu);
 389                 apply_microcode_on_target(cpu);
 390         }
 391
 392         return ustate;
 393 }
 394
 395 static enum ucode_state microcode_update_cpu(int cpu)
 396 {
 397         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 398         enum ucode_state ustate;
 399
 400         if (uci->valid)
 401                 ustate = microcode_resume_cpu(cpu);
 402         else
 403                 ustate = microcode_init_cpu(cpu);
 404
 405         return ustate;
 406 }
 407
 408 static int mc_device_add(struct device *dev, struct subsys_interface *sif)
 409 {
 410         int err, cpu = dev->id;
 411
 412         if (!cpu_online(cpu))
 413                 return 0;
 414
 415         pr_debug("CPU%d added\n", cpu);
 416
 417         err = sysfs_create_group(&dev->kobj, &mc_attr_group);
 418         if (err)
 419                 return err;
 420
 421         if (microcode_init_cpu(cpu) == UCODE_ERROR)
 422                 return -EINVAL;
 423
 424         return err;
 425 }
 426
 427 static int mc_device_remove(struct device *dev, struct subsys_interface *sif)
 428 {
 429         int cpu = dev->id;
 430
 431         if (!cpu_online(cpu))
 432                 return 0;
 433
 434         pr_debug("CPU%d removed\n", cpu);
 435         microcode_fini_cpu(cpu);
 436         sysfs_remove_group(&dev->kobj, &mc_attr_group);
 437         return 0;
 438 }
 439
 440 static struct subsys_interface mc_cpu_interface = {
 441         .name                   = "microcode",
 442         .subsys                 = &cpu_subsys,
 443         .add_dev                = mc_device_add,
 444         .remove_dev             = mc_device_remove,
 445 };
 446
 447 /**
 448  * mc_bp_resume - Update boot CPU microcode during resume.
 449  */
 450 static void mc_bp_resume(void)
 451 {
 452         int cpu = smp_processor_id();
 453         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 454
 455         if (uci->valid && uci->mc)
 456                 microcode_ops->apply_microcode(cpu);
 457 }
 458
 459 static struct syscore_ops mc_syscore_ops = {
 460         .resume                 = mc_bp_resume,
 461 };
 462
 463 static __cpuinit int
 464 mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
 465 {
 466         unsigned int cpu = (unsigned long)hcpu;
 467         struct device *dev;
 468
 469         dev = get_cpu_device(cpu);
 470         switch (action) {
 471         case CPU_ONLINE:
 472         case CPU_ONLINE_FROZEN:
 473                 microcode_update_cpu(cpu);
 474         case CPU_DOWN_FAILED:
 475         case CPU_DOWN_FAILED_FROZEN:
 476                 pr_debug("CPU%d added\n", cpu);
 477                 if (sysfs_create_group(&dev->kobj, &mc_attr_group))
 478                         pr_err("Failed to create group for CPU%d\n", cpu);
 479                 break;
 480         case CPU_DOWN_PREPARE:
 481         case CPU_DOWN_PREPARE_FROZEN:
 482                 /* Suspend is in progress, only remove the interface */
 483                 sysfs_remove_group(&dev->kobj, &mc_attr_group);
 484                 pr_debug("CPU%d removed\n", cpu);
 485                 break;
 486
 487         /*
 488          * When a CPU goes offline, don't free up or invalidate the copy of
 489          * the microcode in kernel memory, so that we can reuse it when the
 490          * CPU comes back online without unnecessarily requesting the userspace
 491          * for it again.
 492          */
 493         case CPU_UP_CANCELED_FROZEN:
 494                 /* The CPU refused to come up during a system resume */
 495                 microcode_fini_cpu(cpu);
 496                 break;
 497         }
 498         return NOTIFY_OK;
 499 }
 500
 501 static struct notifier_block __refdata mc_cpu_notifier = {
 502         .notifier_call  = mc_cpu_callback,
 503 };
 504
 505 static int __init microcode_init(void)
 506 {
 507         struct cpuinfo_x86 *c = &cpu_data(0);
 508         int error;
 509
 510         if (c->x86_vendor == X86_VENDOR_INTEL)
 511                 microcode_ops = init_intel_microcode();
 512         else if (c->x86_vendor == X86_VENDOR_AMD)
 513                 microcode_ops = init_amd_microcode();
 514         else
 515                 pr_err("no support for this CPU vendor\n");
 516
 517         if (!microcode_ops)
 518                 return -ENODEV;
 519
 520         microcode_pdev = platform_device_register_simple("microcode", -1,
 521                                                          NULL, 0);
 522         if (IS_ERR(microcode_pdev))
 523                 return PTR_ERR(microcode_pdev);
 524
 525         get_online_cpus();
 526         mutex_lock(&microcode_mutex);
 527
 528         error = subsys_interface_register(&mc_cpu_interface);
 529
 530         mutex_unlock(&microcode_mutex);
 531         put_online_cpus();
 532
 533         if (error)
 534                 goto out_pdev;
 535
 536         error = microcode_dev_init();
 537         if (error)
 538                 goto out_driver;
 539
 540         register_syscore_ops(&mc_syscore_ops);
 541         register_hotcpu_notifier(&mc_cpu_notifier);
 542
 543         pr_info("Microcode Update Driver: v" MICROCODE_VERSION
 544                 " <tigran@aivazian.fsnet.co.uk>, Peter Oruba\n");
 545
 546         return 0;
 547
 548 out_driver:
 549         get_online_cpus();
 550         mutex_lock(&microcode_mutex);
 551
 552         subsys_interface_unregister(&mc_cpu_interface);
 553
 554         mutex_unlock(&microcode_mutex);
 555         put_online_cpus();
 556
 557 out_pdev:
 558         platform_device_unregister(microcode_pdev);
 559         return error;
 560
 561 }
 562 module_init(microcode_init);
 563
 564 static void __exit microcode_exit(void)
 565 {
 566         struct cpuinfo_x86 *c = &cpu_data(0);
 567
 568         microcode_dev_exit();
 569
 570         unregister_hotcpu_notifier(&mc_cpu_notifier);
 571         unregister_syscore_ops(&mc_syscore_ops);
 572
 573         get_online_cpus();
 574         mutex_lock(&microcode_mutex);
 575
 576         subsys_interface_unregister(&mc_cpu_interface);
 577
 578         mutex_unlock(&microcode_mutex);
 579         put_online_cpus();
 580
 581         platform_device_unregister(microcode_pdev);
 582
 583         microcode_ops = NULL;
 584
 585         if (c->x86_vendor == X86_VENDOR_AMD)
 586                 exit_amd_microcode();
 587
 588         pr_info("Microcode Update Driver: v" MICROCODE_VERSION " removed.\n");
 589 }
 590 module_exit(microcode_exit);