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 89MODULE_DESCRIPTION("Microcode Update Driver"); 90MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>"); 91MODULE_LICENSE("GPL"); 92 93#define MICROCODE_VERSION "2.00" 94 95static 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 */ 109static DEFINE_MUTEX(microcode_mutex); 110 111struct ucode_cpu_info ucode_cpu_info[NR_CPUS]; 112EXPORT_SYMBOL_GPL(ucode_cpu_info); 113 114/* 115 * Operations that are run on a target cpu: 116 */ 117 118struct cpu_info_ctx { 119 struct cpu_signature *cpu_sig; 120 int err; 121}; 122 123static 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 131static 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 143static 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 157struct apply_microcode_ctx { 158 int err; 159}; 160 161static 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 168static 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 181static 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 204static int microcode_open(struct inode *inode, struct file *file) 205{ 206 return capable(CAP_SYS_RAWIO) ? nonseekable_open(inode, file) : -EPERM; 207} 208 209static 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(µcode_mutex); 221 222 if (do_microcode_update(buf, len) == 0) 223 ret = (ssize_t)len; 224 225 mutex_unlock(µcode_mutex); 226 put_online_cpus(); 227 228 return ret; 229} 230 231static const struct file_operations microcode_fops = { 232 .owner = THIS_MODULE, 233 .write = microcode_write, 234 .open = microcode_open, 235}; 236 237static struct miscdevice microcode_dev = { 238 .minor = MICROCODE_MINOR, 239 .name = "microcode", 240 .nodename = "cpu/microcode", 241 .fops = µcode_fops, 242}; 243 244static int __init microcode_dev_init(void) 245{ 246 int error; 247 248 error = misc_register(µcode_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 257static void microcode_dev_exit(void) 258{ 259 misc_deregister(µcode_dev); 260} 261 262MODULE_ALIAS_MISCDEV(MICROCODE_MINOR); 263MODULE_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 */ 270static struct platform_device *microcode_pdev; 271 272static 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(µcode_mutex); 278 if (uci->valid) { 279 enum ucode_state ustate; 280 281 ustate = microcode_ops->request_microcode_fw(cpu, µcode_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(µcode_mutex); 289 290 return err; 291} 292 293static 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 319static 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 327static 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 335static SYSDEV_ATTR(reload, 0200, NULL, reload_store); 336static SYSDEV_ATTR(version, 0400, version_show, NULL); 337static SYSDEV_ATTR(processor_flags, 0400, pf_show, NULL); 338 339static struct attribute *mc_default_attrs[] = { 340 &attr_reload.attr, 341 &attr_version.attr, 342 &attr_processor_flags.attr, 343 NULL 344}; 345 346static struct attribute_group mc_attr_group = { 347 .attrs = mc_default_attrs, 348 .name = "microcode", 349}; 350 351static 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 359static 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 372static 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, µcode_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 393static 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 406static 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 425static 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 438static 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 461static struct sysdev_driver mc_sysdev_driver = { 462 .add = mc_sysdev_add, 463 .remove = mc_sysdev_remove, 464 .resume = mc_sysdev_resume, 465}; 466 467static __cpuinit int 468mc_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 499static struct notifier_block __refdata mc_cpu_notifier = { 500 .notifier_call = mc_cpu_callback, 501}; 502 503static 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(µcode_mutex); 527 528 error = sysdev_driver_register(&cpu_sysdev_class, &mc_sysdev_driver); 529 530 mutex_unlock(µcode_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} 549module_init(microcode_init); 550 551static 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(µcode_mutex); 559 560 sysdev_driver_unregister(&cpu_sysdev_class, &mc_sysdev_driver); 561 562 mutex_unlock(µcode_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} 571module_exit(microcode_exit); 572