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/design/pentium4/manuals/253668.htm
  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 #include <linux/platform_device.h>
  74 #include <linux/miscdevice.h>
  75 #include <linux/capability.h>
  76 #include <linux/smp_lock.h>
  77 #include <linux/kernel.h>
  78 #include <linux/module.h>
  79 #include <linux/mutex.h>
  80 #include <linux/cpu.h>
  81 #include <linux/fs.h>
  82 #include <linux/mm.h>
  83
  84 #include <asm/microcode.h>
  85 #include <asm/processor.h>
  86
  87 MODULE_DESCRIPTION("Microcode Update Driver");
  88 MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
  89 MODULE_LICENSE("GPL");
  90
  91 #define MICROCODE_VERSION       "2.00"
  92
  93 static struct microcode_ops     *microcode_ops;
  94
  95 /*
  96  * Synchronization.
  97  *
  98  * All non cpu-hotplug-callback call sites use:
  99  *
 100  * - microcode_mutex to synchronize with each other;
 101  * - get/put_online_cpus() to synchronize with
 102  *   the cpu-hotplug-callback call sites.
 103  *
 104  * We guarantee that only a single cpu is being
 105  * updated at any particular moment of time.
 106  */
 107 static DEFINE_MUTEX(microcode_mutex);
 108
 109 struct ucode_cpu_info           ucode_cpu_info[NR_CPUS];
 110 EXPORT_SYMBOL_GPL(ucode_cpu_info);
 111
 112 /*
 113  * Operations that are run on a target cpu:
 114  */
 115
 116 struct cpu_info_ctx {
 117         struct cpu_signature    *cpu_sig;
 118         int                     err;
 119 };
 120
 121 static void collect_cpu_info_local(void *arg)
 122 {
 123         struct cpu_info_ctx *ctx = arg;
 124
 125         ctx->err = microcode_ops->collect_cpu_info(smp_processor_id(),
 126                                                    ctx->cpu_sig);
 127 }
 128
 129 static int collect_cpu_info_on_target(int cpu, struct cpu_signature *cpu_sig)
 130 {
 131         struct cpu_info_ctx ctx = { .cpu_sig = cpu_sig, .err = 0 };
 132         int ret;
 133
 134         ret = smp_call_function_single(cpu, collect_cpu_info_local, &ctx, 1);
 135         if (!ret)
 136                 ret = ctx.err;
 137
 138         return ret;
 139 }
 140
 141 static int collect_cpu_info(int cpu)
 142 {
 143         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 144         int ret;
 145
 146         memset(uci, 0, sizeof(*uci));
 147
 148         ret = collect_cpu_info_on_target(cpu, &uci->cpu_sig);
 149         if (!ret)
 150                 uci->valid = 1;
 151
 152         return ret;
 153 }
 154
 155 struct apply_microcode_ctx {
 156         int err;
 157 };
 158
 159 static void apply_microcode_local(void *arg)
 160 {
 161         struct apply_microcode_ctx *ctx = arg;
 162
 163         ctx->err = microcode_ops->apply_microcode(smp_processor_id());
 164 }
 165
 166 static int apply_microcode_on_target(int cpu)
 167 {
 168         struct apply_microcode_ctx ctx = { .err = 0 };
 169         int ret;
 170
 171         ret = smp_call_function_single(cpu, apply_microcode_local, &ctx, 1);
 172         if (!ret)
 173                 ret = ctx.err;
 174
 175         return ret;
 176 }
 177
 178 #ifdef CONFIG_MICROCODE_OLD_INTERFACE
 179 static int do_microcode_update(const void __user *buf, size_t size)
 180 {
 181         int error = 0;
 182         int cpu;
 183
 184         for_each_online_cpu(cpu) {
 185                 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 186                 enum ucode_state ustate;
 187
 188                 if (!uci->valid)
 189                         continue;
 190
 191                 ustate = microcode_ops->request_microcode_user(cpu, buf, size);
 192                 if (ustate == UCODE_ERROR) {
 193                         error = -1;
 194                         break;
 195                 } else if (ustate == UCODE_OK)
 196                         apply_microcode_on_target(cpu);
 197         }
 198
 199         return error;
 200 }
 201
 202 static int microcode_open(struct inode *unused1, struct file *unused2)
 203 {
 204         cycle_kernel_lock();
 205         return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
 206 }
 207
 208 static ssize_t microcode_write(struct file *file, const char __user *buf,
 209                                size_t len, loff_t *ppos)
 210 {
 211         ssize_t ret = -EINVAL;
 212
 213         if ((len >> PAGE_SHIFT) > num_physpages) {
 214                 pr_err("microcode: too much data (max %ld pages)\n", num_physpages);
 215                 return ret;
 216         }
 217
 218         get_online_cpus();
 219         mutex_lock(&microcode_mutex);
 220
 221         if (do_microcode_update(buf, len) == 0)
 222                 ret = (ssize_t)len;
 223
 224         mutex_unlock(&microcode_mutex);
 225         put_online_cpus();
 226
 227         return ret;
 228 }
 229
 230 static const struct file_operations microcode_fops = {
 231         .owner                  = THIS_MODULE,
 232         .write                  = microcode_write,
 233         .open                   = microcode_open,
 234 };
 235
 236 static struct miscdevice microcode_dev = {
 237         .minor                  = MICROCODE_MINOR,
 238         .name                   = "microcode",
 239         .devnode                = "cpu/microcode",
 240         .fops                   = &microcode_fops,
 241 };
 242
 243 static int __init microcode_dev_init(void)
 244 {
 245         int error;
 246
 247         error = misc_register(&microcode_dev);
 248         if (error) {
 249                 pr_err("microcode: can't misc_register on minor=%d\n", MICROCODE_MINOR);
 250                 return error;
 251         }
 252
 253         return 0;
 254 }
 255
 256 static void microcode_dev_exit(void)
 257 {
 258         misc_deregister(&microcode_dev);
 259 }
 260
 261 MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);
 262 #else
 263 #define microcode_dev_init()    0
 264 #define microcode_dev_exit()    do { } while (0)
 265 #endif
 266
 267 /* fake device for request_firmware */
 268 static struct platform_device   *microcode_pdev;
 269
 270 static int reload_for_cpu(int cpu)
 271 {
 272         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 273         int err = 0;
 274
 275         mutex_lock(&microcode_mutex);
 276         if (uci->valid) {
 277                 enum ucode_state ustate;
 278
 279                 ustate = microcode_ops->request_microcode_fw(cpu, &microcode_pdev->dev);
 280                 if (ustate == UCODE_OK)
 281                         apply_microcode_on_target(cpu);
 282                 else
 283                         if (ustate == UCODE_ERROR)
 284                                 err = -EINVAL;
 285         }
 286         mutex_unlock(&microcode_mutex);
 287
 288         return err;
 289 }
 290
 291 static ssize_t reload_store(struct sys_device *dev,
 292                             struct sysdev_attribute *attr,
 293                             const char *buf, size_t size)
 294 {
 295         unsigned long val;
 296         int cpu = dev->id;
 297         int ret = 0;
 298         char *end;
 299
 300         val = simple_strtoul(buf, &end, 0);
 301         if (end == buf)
 302                 return -EINVAL;
 303
 304         if (val == 1) {
 305                 get_online_cpus();
 306                 if (cpu_online(cpu))
 307                         ret = reload_for_cpu(cpu);
 308                 put_online_cpus();
 309         }
 310
 311         if (!ret)
 312                 ret = size;
 313
 314         return ret;
 315 }
 316
 317 static ssize_t version_show(struct sys_device *dev,
 318                         struct sysdev_attribute *attr, char *buf)
 319 {
 320         struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
 321
 322         return sprintf(buf, "0x%x\n", uci->cpu_sig.rev);
 323 }
 324
 325 static ssize_t pf_show(struct sys_device *dev,
 326                         struct sysdev_attribute *attr, char *buf)
 327 {
 328         struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
 329
 330         return sprintf(buf, "0x%x\n", uci->cpu_sig.pf);
 331 }
 332
 333 static SYSDEV_ATTR(reload, 0200, NULL, reload_store);
 334 static SYSDEV_ATTR(version, 0400, version_show, NULL);
 335 static SYSDEV_ATTR(processor_flags, 0400, pf_show, NULL);
 336
 337 static struct attribute *mc_default_attrs[] = {
 338         &attr_reload.attr,
 339         &attr_version.attr,
 340         &attr_processor_flags.attr,
 341         NULL
 342 };
 343
 344 static struct attribute_group mc_attr_group = {
 345         .attrs                  = mc_default_attrs,
 346         .name                   = "microcode",
 347 };
 348
 349 static void microcode_fini_cpu(int cpu)
 350 {
 351         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 352
 353         microcode_ops->microcode_fini_cpu(cpu);
 354         uci->valid = 0;
 355 }
 356
 357 static enum ucode_state microcode_resume_cpu(int cpu)
 358 {
 359         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 360
 361         if (!uci->mc)
 362                 return UCODE_NFOUND;
 363
 364         pr_debug("microcode: CPU%d updated upon resume\n", cpu);
 365         apply_microcode_on_target(cpu);
 366
 367         return UCODE_OK;
 368 }
 369
 370 static enum ucode_state microcode_init_cpu(int cpu)
 371 {
 372         enum ucode_state ustate;
 373
 374         if (collect_cpu_info(cpu))
 375                 return UCODE_ERROR;
 376
 377         /* --dimm. Trigger a delayed update? */
 378         if (system_state != SYSTEM_RUNNING)
 379                 return UCODE_NFOUND;
 380
 381         ustate = microcode_ops->request_microcode_fw(cpu, &microcode_pdev->dev);
 382
 383         if (ustate == UCODE_OK) {
 384                 pr_debug("microcode: CPU%d updated upon init\n", cpu);
 385                 apply_microcode_on_target(cpu);
 386         }
 387
 388         return ustate;
 389 }
 390
 391 static enum ucode_state microcode_update_cpu(int cpu)
 392 {
 393         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 394         enum ucode_state ustate;
 395
 396         if (uci->valid)
 397                 ustate = microcode_resume_cpu(cpu);
 398         else
 399                 ustate = microcode_init_cpu(cpu);
 400
 401         return ustate;
 402 }
 403
 404 static int mc_sysdev_add(struct sys_device *sys_dev)
 405 {
 406         int err, cpu = sys_dev->id;
 407
 408         if (!cpu_online(cpu))
 409                 return 0;
 410
 411         pr_debug("microcode: CPU%d added\n", cpu);
 412
 413         err = sysfs_create_group(&sys_dev->kobj, &mc_attr_group);
 414         if (err)
 415                 return err;
 416
 417         if (microcode_init_cpu(cpu) == UCODE_ERROR)
 418                 err = -EINVAL;
 419
 420         return err;
 421 }
 422
 423 static int mc_sysdev_remove(struct sys_device *sys_dev)
 424 {
 425         int cpu = sys_dev->id;
 426
 427         if (!cpu_online(cpu))
 428                 return 0;
 429
 430         pr_debug("microcode: CPU%d removed\n", cpu);
 431         microcode_fini_cpu(cpu);
 432         sysfs_remove_group(&sys_dev->kobj, &mc_attr_group);
 433         return 0;
 434 }
 435
 436 static int mc_sysdev_resume(struct sys_device *dev)
 437 {
 438         int cpu = dev->id;
 439         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 440
 441         if (!cpu_online(cpu))
 442                 return 0;
 443
 444         /*
 445          * All non-bootup cpus are still disabled,
 446          * so only CPU 0 will apply ucode here.
 447          *
 448          * Moreover, there can be no concurrent
 449          * updates from any other places at this point.
 450          */
 451         WARN_ON(cpu != 0);
 452
 453         if (uci->valid && uci->mc)
 454                 microcode_ops->apply_microcode(cpu);
 455
 456         return 0;
 457 }
 458
 459 static struct sysdev_driver mc_sysdev_driver = {
 460         .add                    = mc_sysdev_add,
 461         .remove                 = mc_sysdev_remove,
 462         .resume                 = mc_sysdev_resume,
 463 };
 464
 465 static __cpuinit int
 466 mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
 467 {
 468         unsigned int cpu = (unsigned long)hcpu;
 469         struct sys_device *sys_dev;
 470
 471         sys_dev = get_cpu_sysdev(cpu);
 472         switch (action) {
 473         case CPU_ONLINE:
 474         case CPU_ONLINE_FROZEN:
 475                 microcode_update_cpu(cpu);
 476         case CPU_DOWN_FAILED:
 477         case CPU_DOWN_FAILED_FROZEN:
 478                 pr_debug("microcode: CPU%d added\n", cpu);
 479                 if (sysfs_create_group(&sys_dev->kobj, &mc_attr_group))
 480                         pr_err("microcode: Failed to create group for CPU%d\n", cpu);
 481                 break;
 482         case CPU_DOWN_PREPARE:
 483         case CPU_DOWN_PREPARE_FROZEN:
 484                 /* Suspend is in progress, only remove the interface */
 485                 sysfs_remove_group(&sys_dev->kobj, &mc_attr_group);
 486                 pr_debug("microcode: CPU%d removed\n", cpu);
 487                 break;
 488         case CPU_DEAD:
 489         case CPU_UP_CANCELED_FROZEN:
 490                 /* The CPU refused to come up during a system resume */
 491                 microcode_fini_cpu(cpu);
 492                 break;
 493         }
 494         return NOTIFY_OK;
 495 }
 496
 497 static struct notifier_block __refdata mc_cpu_notifier = {
 498         .notifier_call  = mc_cpu_callback,
 499 };
 500
 501 static int __init microcode_init(void)
 502 {
 503         struct cpuinfo_x86 *c = &cpu_data(0);
 504         int error;
 505
 506         if (c->x86_vendor == X86_VENDOR_INTEL)
 507                 microcode_ops = init_intel_microcode();
 508         else if (c->x86_vendor == X86_VENDOR_AMD)
 509                 microcode_ops = init_amd_microcode();
 510
 511         if (!microcode_ops) {
 512                 pr_err("microcode: no support for this CPU vendor\n");
 513                 return -ENODEV;
 514         }
 515
 516         microcode_pdev = platform_device_register_simple("microcode", -1,
 517                                                          NULL, 0);
 518         if (IS_ERR(microcode_pdev)) {
 519                 microcode_dev_exit();
 520                 return PTR_ERR(microcode_pdev);
 521         }
 522
 523         get_online_cpus();
 524         mutex_lock(&microcode_mutex);
 525
 526         error = sysdev_driver_register(&cpu_sysdev_class, &mc_sysdev_driver);
 527
 528         mutex_unlock(&microcode_mutex);
 529         put_online_cpus();
 530
 531         if (error) {
 532                 platform_device_unregister(microcode_pdev);
 533                 return error;
 534         }
 535
 536         error = microcode_dev_init();
 537         if (error)
 538                 return error;
 539
 540         register_hotcpu_notifier(&mc_cpu_notifier);
 541
 542         pr_info("Microcode Update Driver: v" MICROCODE_VERSION
 543                " <tigran@aivazian.fsnet.co.uk>,"
 544                " Peter Oruba\n");
 545
 546         return 0;
 547 }
 548 module_init(microcode_init);
 549
 550 static void __exit microcode_exit(void)
 551 {
 552         microcode_dev_exit();
 553
 554         unregister_hotcpu_notifier(&mc_cpu_notifier);
 555
 556         get_online_cpus();
 557         mutex_lock(&microcode_mutex);
 558
 559         sysdev_driver_unregister(&cpu_sysdev_class, &mc_sysdev_driver);
 560
 561         mutex_unlock(&microcode_mutex);
 562         put_online_cpus();
 563
 564         platform_device_unregister(microcode_pdev);
 565
 566         microcode_ops = NULL;
 567
 568         pr_info("Microcode Update Driver: v" MICROCODE_VERSION " removed.\n");
 569 }
 570 module_exit(microcode_exit);