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