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/capability.h>
  74 #include <linux/kernel.h>
  75 #include <linux/init.h>
  76 #include <linux/sched.h>
  77 #include <linux/smp_lock.h>
  78 #include <linux/cpumask.h>
  79 #include <linux/module.h>
  80 #include <linux/slab.h>
  81 #include <linux/vmalloc.h>
  82 #include <linux/miscdevice.h>
  83 #include <linux/spinlock.h>
  84 #include <linux/mm.h>
  85 #include <linux/fs.h>
  86 #include <linux/mutex.h>
  87 #include <linux/cpu.h>
  88 #include <linux/firmware.h>
  89 #include <linux/platform_device.h>
  90
  91 #include <asm/msr.h>
  92 #include <asm/uaccess.h>
  93 #include <asm/processor.h>
  94 #include <asm/microcode.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 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 struct platform_device *microcode_pdev;
 207
 208 static ssize_t reload_store(struct sys_device *dev,
 209                             struct sysdev_attribute *attr,
 210                             const char *buf, size_t sz)
 211 {
 212         struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
 213         char *end;
 214         unsigned long val = simple_strtoul(buf, &end, 0);
 215         int err = 0;
 216         int cpu = dev->id;
 217
 218         if (end == buf)
 219                 return -EINVAL;
 220         if (val == 1) {
 221                 cpumask_t old = current->cpus_allowed;
 222
 223                 get_online_cpus();
 224                 if (cpu_online(cpu)) {
 225                         set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
 226                         mutex_lock(&microcode_mutex);
 227                         if (uci->valid) {
 228                                 err = microcode_ops->request_microcode_fw(cpu,
 229                                                 &microcode_pdev->dev);
 230                                 if (!err)
 231                                         microcode_ops->apply_microcode(cpu);
 232                         }
 233                         mutex_unlock(&microcode_mutex);
 234                         set_cpus_allowed_ptr(current, &old);
 235                 }
 236                 put_online_cpus();
 237         }
 238         if (err)
 239                 return err;
 240         return sz;
 241 }
 242
 243 static ssize_t version_show(struct sys_device *dev,
 244                         struct sysdev_attribute *attr, char *buf)
 245 {
 246         struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
 247
 248         return sprintf(buf, "0x%x\n", uci->cpu_sig.rev);
 249 }
 250
 251 static ssize_t pf_show(struct sys_device *dev,
 252                         struct sysdev_attribute *attr, char *buf)
 253 {
 254         struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
 255
 256         return sprintf(buf, "0x%x\n", uci->cpu_sig.pf);
 257 }
 258
 259 static SYSDEV_ATTR(reload, 0200, NULL, reload_store);
 260 static SYSDEV_ATTR(version, 0400, version_show, NULL);
 261 static SYSDEV_ATTR(processor_flags, 0400, pf_show, NULL);
 262
 263 static struct attribute *mc_default_attrs[] = {
 264         &attr_reload.attr,
 265         &attr_version.attr,
 266         &attr_processor_flags.attr,
 267         NULL
 268 };
 269
 270 static struct attribute_group mc_attr_group = {
 271         .attrs = mc_default_attrs,
 272         .name = "microcode",
 273 };
 274
 275 static void microcode_fini_cpu(int cpu)
 276 {
 277         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 278
 279         mutex_lock(&microcode_mutex);
 280         microcode_ops->microcode_fini_cpu(cpu);
 281         uci->valid = 0;
 282         mutex_unlock(&microcode_mutex);
 283 }
 284
 285 static void collect_cpu_info(int cpu)
 286 {
 287         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 288
 289         memset(uci, 0, sizeof(*uci));
 290         if (!microcode_ops->collect_cpu_info(cpu, &uci->cpu_sig))
 291                 uci->valid = 1;
 292 }
 293
 294 static int microcode_resume_cpu(int cpu)
 295 {
 296         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 297         struct cpu_signature nsig;
 298
 299         pr_debug("microcode: CPU%d resumed\n", cpu);
 300
 301         if (!uci->mc)
 302                 return 1;
 303
 304         /*
 305          * Let's verify that the 'cached' ucode does belong
 306          * to this cpu (a bit of paranoia):
 307          */
 308         if (microcode_ops->collect_cpu_info(cpu, &nsig)) {
 309                 microcode_fini_cpu(cpu);
 310                 return -1;
 311         }
 312
 313         if (memcmp(&nsig, &uci->cpu_sig, sizeof(nsig))) {
 314                 microcode_fini_cpu(cpu);
 315                 /* Should we look for a new ucode here? */
 316                 return 1;
 317         }
 318
 319         return 0;
 320 }
 321
 322 void microcode_update_cpu(int cpu)
 323 {
 324         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 325         int err = 0;
 326
 327         /*
 328          * Check if the system resume is in progress (uci->valid != NULL),
 329          * otherwise just request a firmware:
 330          */
 331         if (uci->valid) {
 332                 err = microcode_resume_cpu(cpu);
 333         } else {
 334                 collect_cpu_info(cpu);
 335                 if (uci->valid && system_state == SYSTEM_RUNNING)
 336                         err = microcode_ops->request_microcode_fw(cpu,
 337                                         &microcode_pdev->dev);
 338         }
 339         if (!err)
 340                 microcode_ops->apply_microcode(cpu);
 341 }
 342
 343 static void microcode_init_cpu(int cpu)
 344 {
 345         cpumask_t old = current->cpus_allowed;
 346
 347         set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
 348         /* We should bind the task to the CPU */
 349         BUG_ON(raw_smp_processor_id() != cpu);
 350
 351         mutex_lock(&microcode_mutex);
 352         microcode_update_cpu(cpu);
 353         mutex_unlock(&microcode_mutex);
 354
 355         set_cpus_allowed_ptr(current, &old);
 356 }
 357
 358 static int mc_sysdev_add(struct sys_device *sys_dev)
 359 {
 360         int err, cpu = sys_dev->id;
 361         struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 362
 363         if (!cpu_online(cpu))
 364                 return 0;
 365
 366         pr_debug("microcode: CPU%d added\n", cpu);
 367         memset(uci, 0, sizeof(*uci));
 368
 369         err = sysfs_create_group(&sys_dev->kobj, &mc_attr_group);
 370         if (err)
 371                 return err;
 372
 373         microcode_init_cpu(cpu);
 374         return 0;
 375 }
 376
 377 static int mc_sysdev_remove(struct sys_device *sys_dev)
 378 {
 379         int cpu = sys_dev->id;
 380
 381         if (!cpu_online(cpu))
 382                 return 0;
 383
 384         pr_debug("microcode: CPU%d removed\n", cpu);
 385         microcode_fini_cpu(cpu);
 386         sysfs_remove_group(&sys_dev->kobj, &mc_attr_group);
 387         return 0;
 388 }
 389
 390 static int mc_sysdev_resume(struct sys_device *dev)
 391 {
 392         int cpu = dev->id;
 393
 394         if (!cpu_online(cpu))
 395                 return 0;
 396
 397         /* only CPU 0 will apply ucode here */
 398         microcode_update_cpu(0);
 399         return 0;
 400 }
 401
 402 static struct sysdev_driver mc_sysdev_driver = {
 403         .add = mc_sysdev_add,
 404         .remove = mc_sysdev_remove,
 405         .resume = mc_sysdev_resume,
 406 };
 407
 408 static __cpuinit int
 409 mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
 410 {
 411         unsigned int cpu = (unsigned long)hcpu;
 412         struct sys_device *sys_dev;
 413
 414         sys_dev = get_cpu_sysdev(cpu);
 415         switch (action) {
 416         case CPU_ONLINE:
 417         case CPU_ONLINE_FROZEN:
 418                 microcode_init_cpu(cpu);
 419         case CPU_DOWN_FAILED:
 420         case CPU_DOWN_FAILED_FROZEN:
 421                 pr_debug("microcode: CPU%d added\n", cpu);
 422                 if (sysfs_create_group(&sys_dev->kobj, &mc_attr_group))
 423                         printk(KERN_ERR "microcode: Failed to create the sysfs "
 424                                 "group for CPU%d\n", cpu);
 425                 break;
 426         case CPU_DOWN_PREPARE:
 427         case CPU_DOWN_PREPARE_FROZEN:
 428                 /* Suspend is in progress, only remove the interface */
 429                 sysfs_remove_group(&sys_dev->kobj, &mc_attr_group);
 430                 pr_debug("microcode: CPU%d removed\n", cpu);
 431                 break;
 432         case CPU_DEAD:
 433         case CPU_UP_CANCELED_FROZEN:
 434                 /* The CPU refused to come up during a system resume */
 435                 microcode_fini_cpu(cpu);
 436                 break;
 437         }
 438         return NOTIFY_OK;
 439 }
 440
 441 static struct notifier_block __refdata mc_cpu_notifier = {
 442         .notifier_call = mc_cpu_callback,
 443 };
 444
 445 static int __init microcode_init(void)
 446 {
 447         struct cpuinfo_x86 *c = &cpu_data(0);
 448         int error;
 449
 450         if (c->x86_vendor == X86_VENDOR_INTEL)
 451                 microcode_ops = init_intel_microcode();
 452         else if (c->x86_vendor == X86_VENDOR_AMD)
 453                 microcode_ops = init_amd_microcode();
 454
 455         if (!microcode_ops) {
 456                 printk(KERN_ERR "microcode: no support for this CPU vendor\n");
 457                 return -ENODEV;
 458         }
 459
 460         error = microcode_dev_init();
 461         if (error)
 462                 return error;
 463         microcode_pdev = platform_device_register_simple("microcode", -1,
 464                                                          NULL, 0);
 465         if (IS_ERR(microcode_pdev)) {
 466                 microcode_dev_exit();
 467                 return PTR_ERR(microcode_pdev);
 468         }
 469
 470         get_online_cpus();
 471         error = sysdev_driver_register(&cpu_sysdev_class, &mc_sysdev_driver);
 472         put_online_cpus();
 473         if (error) {
 474                 microcode_dev_exit();
 475                 platform_device_unregister(microcode_pdev);
 476                 return error;
 477         }
 478
 479         register_hotcpu_notifier(&mc_cpu_notifier);
 480
 481         printk(KERN_INFO
 482                "Microcode Update Driver: v" MICROCODE_VERSION
 483                " <tigran@aivazian.fsnet.co.uk>,"
 484                " Peter Oruba\n");
 485
 486         return 0;
 487 }
 488
 489 static void __exit microcode_exit(void)
 490 {
 491         microcode_dev_exit();
 492
 493         unregister_hotcpu_notifier(&mc_cpu_notifier);
 494
 495         get_online_cpus();
 496         sysdev_driver_unregister(&cpu_sysdev_class, &mc_sysdev_driver);
 497         put_online_cpus();
 498
 499         platform_device_unregister(microcode_pdev);
 500
 501         microcode_ops = NULL;
 502
 503         printk(KERN_INFO
 504                "Microcode Update Driver: v" MICROCODE_VERSION " removed.\n");
 505 }
 506
 507 module_init(microcode_init);
 508 module_exit(microcode_exit);