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/Assets/PDF/manual/253668.pdf 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#include <linux/syscore_ops.h> 86 87#include <asm/microcode.h> 88#include <asm/processor.h> 89#include <asm/cpu_device_id.h> 90 91MODULE_DESCRIPTION("Microcode Update Driver"); 92MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>"); 93MODULE_LICENSE("GPL"); 94 95#define MICROCODE_VERSION "2.00" 96 97static struct microcode_ops *microcode_ops; 98 99/* 100 * Synchronization. 101 * 102 * All non cpu-hotplug-callback call sites use: 103 * 104 * - microcode_mutex to synchronize with each other; 105 * - get/put_online_cpus() to synchronize with 106 * the cpu-hotplug-callback call sites. 107 * 108 * We guarantee that only a single cpu is being 109 * updated at any particular moment of time. 110 */ 111static DEFINE_MUTEX(microcode_mutex); 112 113struct ucode_cpu_info ucode_cpu_info[NR_CPUS]; 114EXPORT_SYMBOL_GPL(ucode_cpu_info); 115 116/* 117 * Operations that are run on a target cpu: 118 */ 119 120struct cpu_info_ctx { 121 struct cpu_signature *cpu_sig; 122 int err; 123}; 124 125static void collect_cpu_info_local(void *arg) 126{ 127 struct cpu_info_ctx *ctx = arg; 128 129 ctx->err = microcode_ops->collect_cpu_info(smp_processor_id(), 130 ctx->cpu_sig); 131} 132 133static int collect_cpu_info_on_target(int cpu, struct cpu_signature *cpu_sig) 134{ 135 struct cpu_info_ctx ctx = { .cpu_sig = cpu_sig, .err = 0 }; 136 int ret; 137 138 ret = smp_call_function_single(cpu, collect_cpu_info_local, &ctx, 1); 139 if (!ret) 140 ret = ctx.err; 141 142 return ret; 143} 144 145static int collect_cpu_info(int cpu) 146{ 147 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 148 int ret; 149 150 memset(uci, 0, sizeof(*uci)); 151 152 ret = collect_cpu_info_on_target(cpu, &uci->cpu_sig); 153 if (!ret) 154 uci->valid = 1; 155 156 return ret; 157} 158 159struct apply_microcode_ctx { 160 int err; 161}; 162 163static void apply_microcode_local(void *arg) 164{ 165 struct apply_microcode_ctx *ctx = arg; 166 167 ctx->err = microcode_ops->apply_microcode(smp_processor_id()); 168} 169 170static int apply_microcode_on_target(int cpu) 171{ 172 struct apply_microcode_ctx ctx = { .err = 0 }; 173 int ret; 174 175 ret = smp_call_function_single(cpu, apply_microcode_local, &ctx, 1); 176 if (!ret) 177 ret = ctx.err; 178 179 return ret; 180} 181 182#ifdef CONFIG_MICROCODE_OLD_INTERFACE 183static int do_microcode_update(const void __user *buf, size_t size) 184{ 185 int error = 0; 186 int cpu; 187 188 for_each_online_cpu(cpu) { 189 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 190 enum ucode_state ustate; 191 192 if (!uci->valid) 193 continue; 194 195 ustate = microcode_ops->request_microcode_user(cpu, buf, size); 196 if (ustate == UCODE_ERROR) { 197 error = -1; 198 break; 199 } else if (ustate == UCODE_OK) 200 apply_microcode_on_target(cpu); 201 } 202 203 return error; 204} 205 206static int microcode_open(struct inode *inode, struct file *file) 207{ 208 return capable(CAP_SYS_RAWIO) ? nonseekable_open(inode, file) : -EPERM; 209} 210 211static ssize_t microcode_write(struct file *file, const char __user *buf, 212 size_t len, loff_t *ppos) 213{ 214 ssize_t ret = -EINVAL; 215 216 if ((len >> PAGE_SHIFT) > totalram_pages) { 217 pr_err("too much data (max %ld pages)\n", totalram_pages); 218 return ret; 219 } 220 221 get_online_cpus(); 222 mutex_lock(µcode_mutex); 223 224 if (do_microcode_update(buf, len) == 0) 225 ret = (ssize_t)len; 226 227 mutex_unlock(µcode_mutex); 228 put_online_cpus(); 229 230 return ret; 231} 232 233static const struct file_operations microcode_fops = { 234 .owner = THIS_MODULE, 235 .write = microcode_write, 236 .open = microcode_open, 237 .llseek = no_llseek, 238}; 239 240static struct miscdevice microcode_dev = { 241 .minor = MICROCODE_MINOR, 242 .name = "microcode", 243 .nodename = "cpu/microcode", 244 .fops = µcode_fops, 245}; 246 247static int __init microcode_dev_init(void) 248{ 249 int error; 250 251 error = misc_register(µcode_dev); 252 if (error) { 253 pr_err("can't misc_register on minor=%d\n", MICROCODE_MINOR); 254 return error; 255 } 256 257 return 0; 258} 259 260static void __exit microcode_dev_exit(void) 261{ 262 misc_deregister(µcode_dev); 263} 264 265MODULE_ALIAS_MISCDEV(MICROCODE_MINOR); 266MODULE_ALIAS("devname:cpu/microcode"); 267#else 268#define microcode_dev_init() 0 269#define microcode_dev_exit() do { } while (0) 270#endif 271 272/* fake device for request_firmware */ 273static struct platform_device *microcode_pdev; 274 275static int reload_for_cpu(int cpu) 276{ 277 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 278 int err = 0; 279 280 mutex_lock(µcode_mutex); 281 if (uci->valid) { 282 enum ucode_state ustate; 283 284 ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev); 285 if (ustate == UCODE_OK) 286 apply_microcode_on_target(cpu); 287 else 288 if (ustate == UCODE_ERROR) 289 err = -EINVAL; 290 } 291 mutex_unlock(µcode_mutex); 292 293 return err; 294} 295 296static ssize_t reload_store(struct device *dev, 297 struct device_attribute *attr, 298 const char *buf, size_t size) 299{ 300 unsigned long val; 301 int cpu = dev->id; 302 int ret = 0; 303 char *end; 304 305 val = simple_strtoul(buf, &end, 0); 306 if (end == buf) 307 return -EINVAL; 308 309 if (val == 1) { 310 get_online_cpus(); 311 if (cpu_online(cpu)) 312 ret = reload_for_cpu(cpu); 313 put_online_cpus(); 314 } 315 316 if (!ret) 317 ret = size; 318 319 return ret; 320} 321 322static ssize_t version_show(struct device *dev, 323 struct device_attribute *attr, char *buf) 324{ 325 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id; 326 327 return sprintf(buf, "0x%x\n", uci->cpu_sig.rev); 328} 329 330static ssize_t pf_show(struct device *dev, 331 struct device_attribute *attr, char *buf) 332{ 333 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id; 334 335 return sprintf(buf, "0x%x\n", uci->cpu_sig.pf); 336} 337 338static DEVICE_ATTR(reload, 0200, NULL, reload_store); 339static DEVICE_ATTR(version, 0400, version_show, NULL); 340static DEVICE_ATTR(processor_flags, 0400, pf_show, NULL); 341 342static struct attribute *mc_default_attrs[] = { 343 &dev_attr_reload.attr, 344 &dev_attr_version.attr, 345 &dev_attr_processor_flags.attr, 346 NULL 347}; 348 349static struct attribute_group mc_attr_group = { 350 .attrs = mc_default_attrs, 351 .name = "microcode", 352}; 353 354static void microcode_fini_cpu(int cpu) 355{ 356 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 357 358 microcode_ops->microcode_fini_cpu(cpu); 359 uci->valid = 0; 360} 361 362static enum ucode_state microcode_resume_cpu(int cpu) 363{ 364 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 365 366 if (!uci->mc) 367 return UCODE_NFOUND; 368 369 pr_debug("CPU%d updated upon resume\n", cpu); 370 apply_microcode_on_target(cpu); 371 372 return UCODE_OK; 373} 374 375static enum ucode_state microcode_init_cpu(int cpu) 376{ 377 enum ucode_state ustate; 378 379 if (collect_cpu_info(cpu)) 380 return UCODE_ERROR; 381 382 /* --dimm. Trigger a delayed update? */ 383 if (system_state != SYSTEM_RUNNING) 384 return UCODE_NFOUND; 385 386 ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev); 387 388 if (ustate == UCODE_OK) { 389 pr_debug("CPU%d updated upon init\n", cpu); 390 apply_microcode_on_target(cpu); 391 } 392 393 return ustate; 394} 395 396static enum ucode_state microcode_update_cpu(int cpu) 397{ 398 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 399 enum ucode_state ustate; 400 401 if (uci->valid) 402 ustate = microcode_resume_cpu(cpu); 403 else 404 ustate = microcode_init_cpu(cpu); 405 406 return ustate; 407} 408 409static int mc_device_add(struct device *dev, struct subsys_interface *sif) 410{ 411 int err, cpu = dev->id; 412 413 if (!cpu_online(cpu)) 414 return 0; 415 416 pr_debug("CPU%d added\n", cpu); 417 418 err = sysfs_create_group(&dev->kobj, &mc_attr_group); 419 if (err) 420 return err; 421 422 if (microcode_init_cpu(cpu) == UCODE_ERROR) 423 return -EINVAL; 424 425 return err; 426} 427 428static int mc_device_remove(struct device *dev, struct subsys_interface *sif) 429{ 430 int cpu = dev->id; 431 432 if (!cpu_online(cpu)) 433 return 0; 434 435 pr_debug("CPU%d removed\n", cpu); 436 microcode_fini_cpu(cpu); 437 sysfs_remove_group(&dev->kobj, &mc_attr_group); 438 return 0; 439} 440 441static struct subsys_interface mc_cpu_interface = { 442 .name = "microcode", 443 .subsys = &cpu_subsys, 444 .add_dev = mc_device_add, 445 .remove_dev = mc_device_remove, 446}; 447 448/** 449 * mc_bp_resume - Update boot CPU microcode during resume. 450 */ 451static void mc_bp_resume(void) 452{ 453 int cpu = smp_processor_id(); 454 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 455 456 if (uci->valid && uci->mc) 457 microcode_ops->apply_microcode(cpu); 458} 459 460static struct syscore_ops mc_syscore_ops = { 461 .resume = mc_bp_resume, 462}; 463 464static __cpuinit int 465mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu) 466{ 467 unsigned int cpu = (unsigned long)hcpu; 468 struct device *dev; 469 470 dev = get_cpu_device(cpu); 471 switch (action) { 472 case CPU_ONLINE: 473 case CPU_ONLINE_FROZEN: 474 microcode_update_cpu(cpu); 475 case CPU_DOWN_FAILED: 476 case CPU_DOWN_FAILED_FROZEN: 477 pr_debug("CPU%d added\n", cpu); 478 if (sysfs_create_group(&dev->kobj, &mc_attr_group)) 479 pr_err("Failed to create group for CPU%d\n", cpu); 480 break; 481 case CPU_DOWN_PREPARE: 482 case CPU_DOWN_PREPARE_FROZEN: 483 /* Suspend is in progress, only remove the interface */ 484 sysfs_remove_group(&dev->kobj, &mc_attr_group); 485 pr_debug("CPU%d removed\n", cpu); 486 break; 487 488 /* 489 * When a CPU goes offline, don't free up or invalidate the copy of 490 * the microcode in kernel memory, so that we can reuse it when the 491 * CPU comes back online without unnecessarily requesting the userspace 492 * for it again. 493 */ 494 case CPU_UP_CANCELED_FROZEN: 495 /* The CPU refused to come up during a system resume */ 496 microcode_fini_cpu(cpu); 497 break; 498 } 499 return NOTIFY_OK; 500} 501 502static struct notifier_block __refdata mc_cpu_notifier = { 503 .notifier_call = mc_cpu_callback, 504}; 505 506#ifdef MODULE 507/* Autoload on Intel and AMD systems */ 508static const struct x86_cpu_id microcode_id[] = { 509#ifdef CONFIG_MICROCODE_INTEL 510 { X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, }, 511#endif 512#ifdef CONFIG_MICROCODE_AMD 513 { X86_VENDOR_AMD, X86_FAMILY_ANY, X86_MODEL_ANY, }, 514#endif 515 {} 516}; 517MODULE_DEVICE_TABLE(x86cpu, microcode_id); 518#endif 519 520static int __init microcode_init(void) 521{ 522 struct cpuinfo_x86 *c = &cpu_data(0); 523 int error; 524 525 if (c->x86_vendor == X86_VENDOR_INTEL) 526 microcode_ops = init_intel_microcode(); 527 else if (c->x86_vendor == X86_VENDOR_AMD) 528 microcode_ops = init_amd_microcode(); 529 else 530 pr_err("no support for this CPU vendor\n"); 531 532 if (!microcode_ops) 533 return -ENODEV; 534 535 microcode_pdev = platform_device_register_simple("microcode", -1, 536 NULL, 0); 537 if (IS_ERR(microcode_pdev)) 538 return PTR_ERR(microcode_pdev); 539 540 get_online_cpus(); 541 mutex_lock(µcode_mutex); 542 543 error = subsys_interface_register(&mc_cpu_interface); 544 545 mutex_unlock(µcode_mutex); 546 put_online_cpus(); 547 548 if (error) 549 goto out_pdev; 550 551 error = microcode_dev_init(); 552 if (error) 553 goto out_driver; 554 555 register_syscore_ops(&mc_syscore_ops); 556 register_hotcpu_notifier(&mc_cpu_notifier); 557 558 pr_info("Microcode Update Driver: v" MICROCODE_VERSION 559 " <tigran@aivazian.fsnet.co.uk>, Peter Oruba\n"); 560 561 return 0; 562 563out_driver: 564 get_online_cpus(); 565 mutex_lock(µcode_mutex); 566 567 subsys_interface_unregister(&mc_cpu_interface); 568 569 mutex_unlock(µcode_mutex); 570 put_online_cpus(); 571 572out_pdev: 573 platform_device_unregister(microcode_pdev); 574 return error; 575 576} 577module_init(microcode_init); 578 579static void __exit microcode_exit(void) 580{ 581 struct cpuinfo_x86 *c = &cpu_data(0); 582 583 microcode_dev_exit(); 584 585 unregister_hotcpu_notifier(&mc_cpu_notifier); 586 unregister_syscore_ops(&mc_syscore_ops); 587 588 get_online_cpus(); 589 mutex_lock(µcode_mutex); 590 591 subsys_interface_unregister(&mc_cpu_interface); 592 593 mutex_unlock(µcode_mutex); 594 put_online_cpus(); 595 596 platform_device_unregister(microcode_pdev); 597 598 microcode_ops = NULL; 599 600 if (c->x86_vendor == X86_VENDOR_AMD) 601 exit_amd_microcode(); 602 603 pr_info("Microcode Update Driver: v" MICROCODE_VERSION " removed.\n"); 604} 605module_exit(microcode_exit); 606