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 #include <asm/perf_event.h> 91 92 MODULE_DESCRIPTION("Microcode Update Driver"); 93 MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>"); 94 MODULE_LICENSE("GPL"); 95 96 #define MICROCODE_VERSION "2.00" 97 98 static struct microcode_ops *microcode_ops; 99 100 bool dis_ucode_ldr; 101 module_param(dis_ucode_ldr, bool, 0); 102 103 /* 104 * Synchronization. 105 * 106 * All non cpu-hotplug-callback call sites use: 107 * 108 * - microcode_mutex to synchronize with each other; 109 * - get/put_online_cpus() to synchronize with 110 * the cpu-hotplug-callback call sites. 111 * 112 * We guarantee that only a single cpu is being 113 * updated at any particular moment of time. 114 */ 115 static DEFINE_MUTEX(microcode_mutex); 116 117 struct ucode_cpu_info ucode_cpu_info[NR_CPUS]; 118 EXPORT_SYMBOL_GPL(ucode_cpu_info); 119 120 /* 121 * Operations that are run on a target cpu: 122 */ 123 124 struct cpu_info_ctx { 125 struct cpu_signature *cpu_sig; 126 int err; 127 }; 128 129 static void collect_cpu_info_local(void *arg) 130 { 131 struct cpu_info_ctx *ctx = arg; 132 133 ctx->err = microcode_ops->collect_cpu_info(smp_processor_id(), 134 ctx->cpu_sig); 135 } 136 137 static int collect_cpu_info_on_target(int cpu, struct cpu_signature *cpu_sig) 138 { 139 struct cpu_info_ctx ctx = { .cpu_sig = cpu_sig, .err = 0 }; 140 int ret; 141 142 ret = smp_call_function_single(cpu, collect_cpu_info_local, &ctx, 1); 143 if (!ret) 144 ret = ctx.err; 145 146 return ret; 147 } 148 149 static int collect_cpu_info(int cpu) 150 { 151 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 152 int ret; 153 154 memset(uci, 0, sizeof(*uci)); 155 156 ret = collect_cpu_info_on_target(cpu, &uci->cpu_sig); 157 if (!ret) 158 uci->valid = 1; 159 160 return ret; 161 } 162 163 struct apply_microcode_ctx { 164 int err; 165 }; 166 167 static void apply_microcode_local(void *arg) 168 { 169 struct apply_microcode_ctx *ctx = arg; 170 171 ctx->err = microcode_ops->apply_microcode(smp_processor_id()); 172 } 173 174 static int apply_microcode_on_target(int cpu) 175 { 176 struct apply_microcode_ctx ctx = { .err = 0 }; 177 int ret; 178 179 ret = smp_call_function_single(cpu, apply_microcode_local, &ctx, 1); 180 if (!ret) 181 ret = ctx.err; 182 183 return ret; 184 } 185 186 #ifdef CONFIG_MICROCODE_OLD_INTERFACE 187 static int do_microcode_update(const void __user *buf, size_t size) 188 { 189 int error = 0; 190 int cpu; 191 192 for_each_online_cpu(cpu) { 193 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 194 enum ucode_state ustate; 195 196 if (!uci->valid) 197 continue; 198 199 ustate = microcode_ops->request_microcode_user(cpu, buf, size); 200 if (ustate == UCODE_ERROR) { 201 error = -1; 202 break; 203 } else if (ustate == UCODE_OK) 204 apply_microcode_on_target(cpu); 205 } 206 207 return error; 208 } 209 210 static int microcode_open(struct inode *inode, struct file *file) 211 { 212 return capable(CAP_SYS_RAWIO) ? nonseekable_open(inode, file) : -EPERM; 213 } 214 215 static ssize_t microcode_write(struct file *file, const char __user *buf, 216 size_t len, loff_t *ppos) 217 { 218 ssize_t ret = -EINVAL; 219 220 if ((len >> PAGE_SHIFT) > totalram_pages) { 221 pr_err("too much data (max %ld pages)\n", totalram_pages); 222 return ret; 223 } 224 225 get_online_cpus(); 226 mutex_lock(µcode_mutex); 227 228 if (do_microcode_update(buf, len) == 0) 229 ret = (ssize_t)len; 230 231 if (ret > 0) 232 perf_check_microcode(); 233 234 mutex_unlock(µcode_mutex); 235 put_online_cpus(); 236 237 return ret; 238 } 239 240 static const struct file_operations microcode_fops = { 241 .owner = THIS_MODULE, 242 .write = microcode_write, 243 .open = microcode_open, 244 .llseek = no_llseek, 245 }; 246 247 static struct miscdevice microcode_dev = { 248 .minor = MICROCODE_MINOR, 249 .name = "microcode", 250 .nodename = "cpu/microcode", 251 .fops = µcode_fops, 252 }; 253 254 static int __init microcode_dev_init(void) 255 { 256 int error; 257 258 error = misc_register(µcode_dev); 259 if (error) { 260 pr_err("can't misc_register on minor=%d\n", MICROCODE_MINOR); 261 return error; 262 } 263 264 return 0; 265 } 266 267 static void __exit microcode_dev_exit(void) 268 { 269 misc_deregister(µcode_dev); 270 } 271 272 MODULE_ALIAS_MISCDEV(MICROCODE_MINOR); 273 MODULE_ALIAS("devname:cpu/microcode"); 274 #else 275 #define microcode_dev_init() 0 276 #define microcode_dev_exit() do { } while (0) 277 #endif 278 279 /* fake device for request_firmware */ 280 static struct platform_device *microcode_pdev; 281 282 static int reload_for_cpu(int cpu) 283 { 284 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 285 enum ucode_state ustate; 286 int err = 0; 287 288 if (!uci->valid) 289 return err; 290 291 ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev, true); 292 if (ustate == UCODE_OK) 293 apply_microcode_on_target(cpu); 294 else 295 if (ustate == UCODE_ERROR) 296 err = -EINVAL; 297 return err; 298 } 299 300 static ssize_t reload_store(struct device *dev, 301 struct device_attribute *attr, 302 const char *buf, size_t size) 303 { 304 unsigned long val; 305 int cpu; 306 ssize_t ret = 0, tmp_ret; 307 308 ret = kstrtoul(buf, 0, &val); 309 if (ret) 310 return ret; 311 312 if (val != 1) 313 return size; 314 315 get_online_cpus(); 316 mutex_lock(µcode_mutex); 317 for_each_online_cpu(cpu) { 318 tmp_ret = reload_for_cpu(cpu); 319 if (tmp_ret != 0) 320 pr_warn("Error reloading microcode on CPU %d\n", cpu); 321 322 /* save retval of the first encountered reload error */ 323 if (!ret) 324 ret = tmp_ret; 325 } 326 if (!ret) 327 perf_check_microcode(); 328 mutex_unlock(µcode_mutex); 329 put_online_cpus(); 330 331 if (!ret) 332 ret = size; 333 334 return ret; 335 } 336 337 static ssize_t version_show(struct device *dev, 338 struct device_attribute *attr, char *buf) 339 { 340 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id; 341 342 return sprintf(buf, "0x%x\n", uci->cpu_sig.rev); 343 } 344 345 static ssize_t pf_show(struct device *dev, 346 struct device_attribute *attr, char *buf) 347 { 348 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id; 349 350 return sprintf(buf, "0x%x\n", uci->cpu_sig.pf); 351 } 352 353 static DEVICE_ATTR(reload, 0200, NULL, reload_store); 354 static DEVICE_ATTR(version, 0400, version_show, NULL); 355 static DEVICE_ATTR(processor_flags, 0400, pf_show, NULL); 356 357 static struct attribute *mc_default_attrs[] = { 358 &dev_attr_version.attr, 359 &dev_attr_processor_flags.attr, 360 NULL 361 }; 362 363 static struct attribute_group mc_attr_group = { 364 .attrs = mc_default_attrs, 365 .name = "microcode", 366 }; 367 368 static void microcode_fini_cpu(int cpu) 369 { 370 microcode_ops->microcode_fini_cpu(cpu); 371 } 372 373 static enum ucode_state microcode_resume_cpu(int cpu) 374 { 375 pr_debug("CPU%d updated upon resume\n", cpu); 376 377 if (apply_microcode_on_target(cpu)) 378 return UCODE_ERROR; 379 380 return UCODE_OK; 381 } 382 383 static enum ucode_state microcode_init_cpu(int cpu, bool refresh_fw) 384 { 385 enum ucode_state ustate; 386 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 387 388 if (uci && uci->valid) 389 return UCODE_OK; 390 391 if (collect_cpu_info(cpu)) 392 return UCODE_ERROR; 393 394 /* --dimm. Trigger a delayed update? */ 395 if (system_state != SYSTEM_RUNNING) 396 return UCODE_NFOUND; 397 398 ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev, 399 refresh_fw); 400 401 if (ustate == UCODE_OK) { 402 pr_debug("CPU%d updated upon init\n", cpu); 403 apply_microcode_on_target(cpu); 404 } 405 406 return ustate; 407 } 408 409 static enum ucode_state microcode_update_cpu(int cpu) 410 { 411 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 412 413 if (uci->valid) 414 return microcode_resume_cpu(cpu); 415 416 return microcode_init_cpu(cpu, false); 417 } 418 419 static int mc_device_add(struct device *dev, struct subsys_interface *sif) 420 { 421 int err, cpu = dev->id; 422 423 if (!cpu_online(cpu)) 424 return 0; 425 426 pr_debug("CPU%d added\n", cpu); 427 428 err = sysfs_create_group(&dev->kobj, &mc_attr_group); 429 if (err) 430 return err; 431 432 if (microcode_init_cpu(cpu, true) == UCODE_ERROR) 433 return -EINVAL; 434 435 return err; 436 } 437 438 static int mc_device_remove(struct device *dev, struct subsys_interface *sif) 439 { 440 int cpu = dev->id; 441 442 if (!cpu_online(cpu)) 443 return 0; 444 445 pr_debug("CPU%d removed\n", cpu); 446 microcode_fini_cpu(cpu); 447 sysfs_remove_group(&dev->kobj, &mc_attr_group); 448 return 0; 449 } 450 451 static struct subsys_interface mc_cpu_interface = { 452 .name = "microcode", 453 .subsys = &cpu_subsys, 454 .add_dev = mc_device_add, 455 .remove_dev = mc_device_remove, 456 }; 457 458 /** 459 * mc_bp_resume - Update boot CPU microcode during resume. 460 */ 461 static void mc_bp_resume(void) 462 { 463 int cpu = smp_processor_id(); 464 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 465 466 if (uci->valid && uci->mc) 467 microcode_ops->apply_microcode(cpu); 468 else if (!uci->mc) 469 reload_early_microcode(); 470 } 471 472 static struct syscore_ops mc_syscore_ops = { 473 .resume = mc_bp_resume, 474 }; 475 476 static int 477 mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu) 478 { 479 unsigned int cpu = (unsigned long)hcpu; 480 struct device *dev; 481 482 dev = get_cpu_device(cpu); 483 484 switch (action & ~CPU_TASKS_FROZEN) { 485 case CPU_ONLINE: 486 microcode_update_cpu(cpu); 487 pr_debug("CPU%d added\n", cpu); 488 /* 489 * "break" is missing on purpose here because we want to fall 490 * through in order to create the sysfs group. 491 */ 492 493 case CPU_DOWN_FAILED: 494 if (sysfs_create_group(&dev->kobj, &mc_attr_group)) 495 pr_err("Failed to create group for CPU%d\n", cpu); 496 break; 497 498 case CPU_DOWN_PREPARE: 499 /* Suspend is in progress, only remove the interface */ 500 sysfs_remove_group(&dev->kobj, &mc_attr_group); 501 pr_debug("CPU%d removed\n", cpu); 502 break; 503 504 /* 505 * case CPU_DEAD: 506 * 507 * When a CPU goes offline, don't free up or invalidate the copy of 508 * the microcode in kernel memory, so that we can reuse it when the 509 * CPU comes back online without unnecessarily requesting the userspace 510 * for it again. 511 */ 512 } 513 514 /* The CPU refused to come up during a system resume */ 515 if (action == CPU_UP_CANCELED_FROZEN) 516 microcode_fini_cpu(cpu); 517 518 return NOTIFY_OK; 519 } 520 521 static struct notifier_block __refdata mc_cpu_notifier = { 522 .notifier_call = mc_cpu_callback, 523 }; 524 525 #ifdef MODULE 526 /* Autoload on Intel and AMD systems */ 527 static const struct x86_cpu_id __initconst microcode_id[] = { 528 #ifdef CONFIG_MICROCODE_INTEL 529 { X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, }, 530 #endif 531 #ifdef CONFIG_MICROCODE_AMD 532 { X86_VENDOR_AMD, X86_FAMILY_ANY, X86_MODEL_ANY, }, 533 #endif 534 {} 535 }; 536 MODULE_DEVICE_TABLE(x86cpu, microcode_id); 537 #endif 538 539 static struct attribute *cpu_root_microcode_attrs[] = { 540 &dev_attr_reload.attr, 541 NULL 542 }; 543 544 static struct attribute_group cpu_root_microcode_group = { 545 .name = "microcode", 546 .attrs = cpu_root_microcode_attrs, 547 }; 548 549 static int __init microcode_init(void) 550 { 551 struct cpuinfo_x86 *c = &cpu_data(0); 552 int error; 553 554 if (paravirt_enabled() || dis_ucode_ldr) 555 return 0; 556 557 if (c->x86_vendor == X86_VENDOR_INTEL) 558 microcode_ops = init_intel_microcode(); 559 else if (c->x86_vendor == X86_VENDOR_AMD) 560 microcode_ops = init_amd_microcode(); 561 else 562 pr_err("no support for this CPU vendor\n"); 563 564 if (!microcode_ops) 565 return -ENODEV; 566 567 microcode_pdev = platform_device_register_simple("microcode", -1, 568 NULL, 0); 569 if (IS_ERR(microcode_pdev)) 570 return PTR_ERR(microcode_pdev); 571 572 get_online_cpus(); 573 mutex_lock(µcode_mutex); 574 575 error = subsys_interface_register(&mc_cpu_interface); 576 if (!error) 577 perf_check_microcode(); 578 mutex_unlock(µcode_mutex); 579 put_online_cpus(); 580 581 if (error) 582 goto out_pdev; 583 584 error = sysfs_create_group(&cpu_subsys.dev_root->kobj, 585 &cpu_root_microcode_group); 586 587 if (error) { 588 pr_err("Error creating microcode group!\n"); 589 goto out_driver; 590 } 591 592 error = microcode_dev_init(); 593 if (error) 594 goto out_ucode_group; 595 596 register_syscore_ops(&mc_syscore_ops); 597 register_hotcpu_notifier(&mc_cpu_notifier); 598 599 pr_info("Microcode Update Driver: v" MICROCODE_VERSION 600 " <tigran@aivazian.fsnet.co.uk>, Peter Oruba\n"); 601 602 return 0; 603 604 out_ucode_group: 605 sysfs_remove_group(&cpu_subsys.dev_root->kobj, 606 &cpu_root_microcode_group); 607 608 out_driver: 609 get_online_cpus(); 610 mutex_lock(µcode_mutex); 611 612 subsys_interface_unregister(&mc_cpu_interface); 613 614 mutex_unlock(µcode_mutex); 615 put_online_cpus(); 616 617 out_pdev: 618 platform_device_unregister(microcode_pdev); 619 return error; 620 621 } 622 module_init(microcode_init); 623 624 static void __exit microcode_exit(void) 625 { 626 struct cpuinfo_x86 *c = &cpu_data(0); 627 628 microcode_dev_exit(); 629 630 unregister_hotcpu_notifier(&mc_cpu_notifier); 631 unregister_syscore_ops(&mc_syscore_ops); 632 633 sysfs_remove_group(&cpu_subsys.dev_root->kobj, 634 &cpu_root_microcode_group); 635 636 get_online_cpus(); 637 mutex_lock(µcode_mutex); 638 639 subsys_interface_unregister(&mc_cpu_interface); 640 641 mutex_unlock(µcode_mutex); 642 put_online_cpus(); 643 644 platform_device_unregister(microcode_pdev); 645 646 microcode_ops = NULL; 647 648 if (c->x86_vendor == X86_VENDOR_AMD) 649 exit_amd_microcode(); 650 651 pr_info("Microcode Update Driver: v" MICROCODE_VERSION " removed.\n"); 652 } 653 module_exit(microcode_exit); 654