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