1 /* 2 * 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 * 2013-2016 Borislav Petkov <bp@alien8.de> 7 * 8 * X86 CPU microcode early update for Linux: 9 * 10 * Copyright (C) 2012 Fenghua Yu <fenghua.yu@intel.com> 11 * H Peter Anvin" <hpa@zytor.com> 12 * (C) 2015 Borislav Petkov <bp@alien8.de> 13 * 14 * This driver allows to upgrade microcode on x86 processors. 15 * 16 * This program is free software; you can redistribute it and/or 17 * modify it under the terms of the GNU General Public License 18 * as published by the Free Software Foundation; either version 19 * 2 of the License, or (at your option) any later version. 20 */ 21 22 #define pr_fmt(fmt) "microcode: " fmt 23 24 #include <linux/platform_device.h> 25 #include <linux/syscore_ops.h> 26 #include <linux/miscdevice.h> 27 #include <linux/capability.h> 28 #include <linux/firmware.h> 29 #include <linux/kernel.h> 30 #include <linux/mutex.h> 31 #include <linux/cpu.h> 32 #include <linux/fs.h> 33 #include <linux/mm.h> 34 35 #include <asm/microcode_intel.h> 36 #include <asm/cpu_device_id.h> 37 #include <asm/microcode_amd.h> 38 #include <asm/perf_event.h> 39 #include <asm/microcode.h> 40 #include <asm/processor.h> 41 #include <asm/cmdline.h> 42 #include <asm/setup.h> 43 44 #define DRIVER_VERSION "2.2" 45 46 static struct microcode_ops *microcode_ops; 47 static bool dis_ucode_ldr; 48 49 LIST_HEAD(microcode_cache); 50 51 /* 52 * Synchronization. 53 * 54 * All non cpu-hotplug-callback call sites use: 55 * 56 * - microcode_mutex to synchronize with each other; 57 * - get/put_online_cpus() to synchronize with 58 * the cpu-hotplug-callback call sites. 59 * 60 * We guarantee that only a single cpu is being 61 * updated at any particular moment of time. 62 */ 63 static DEFINE_MUTEX(microcode_mutex); 64 65 struct ucode_cpu_info ucode_cpu_info[NR_CPUS]; 66 67 /* 68 * Operations that are run on a target cpu: 69 */ 70 71 struct cpu_info_ctx { 72 struct cpu_signature *cpu_sig; 73 int err; 74 }; 75 76 static bool __init check_loader_disabled_bsp(void) 77 { 78 static const char *__dis_opt_str = "dis_ucode_ldr"; 79 80 #ifdef CONFIG_X86_32 81 const char *cmdline = (const char *)__pa_nodebug(boot_command_line); 82 const char *option = (const char *)__pa_nodebug(__dis_opt_str); 83 bool *res = (bool *)__pa_nodebug(&dis_ucode_ldr); 84 85 #else /* CONFIG_X86_64 */ 86 const char *cmdline = boot_command_line; 87 const char *option = __dis_opt_str; 88 bool *res = &dis_ucode_ldr; 89 #endif 90 91 if (cmdline_find_option_bool(cmdline, option)) 92 *res = true; 93 94 return *res; 95 } 96 97 extern struct builtin_fw __start_builtin_fw[]; 98 extern struct builtin_fw __end_builtin_fw[]; 99 100 bool get_builtin_firmware(struct cpio_data *cd, const char *name) 101 { 102 #ifdef CONFIG_FW_LOADER 103 struct builtin_fw *b_fw; 104 105 for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) { 106 if (!strcmp(name, b_fw->name)) { 107 cd->size = b_fw->size; 108 cd->data = b_fw->data; 109 return true; 110 } 111 } 112 #endif 113 return false; 114 } 115 116 void __init load_ucode_bsp(void) 117 { 118 int vendor; 119 unsigned int family; 120 121 if (check_loader_disabled_bsp()) 122 return; 123 124 if (!have_cpuid_p()) 125 return; 126 127 vendor = x86_cpuid_vendor(); 128 family = x86_cpuid_family(); 129 130 switch (vendor) { 131 case X86_VENDOR_INTEL: 132 if (family >= 6) 133 load_ucode_intel_bsp(); 134 break; 135 case X86_VENDOR_AMD: 136 if (family >= 0x10) 137 load_ucode_amd_bsp(family); 138 break; 139 default: 140 break; 141 } 142 } 143 144 static bool check_loader_disabled_ap(void) 145 { 146 #ifdef CONFIG_X86_32 147 return *((bool *)__pa_nodebug(&dis_ucode_ldr)); 148 #else 149 return dis_ucode_ldr; 150 #endif 151 } 152 153 void load_ucode_ap(void) 154 { 155 int vendor, family; 156 157 if (check_loader_disabled_ap()) 158 return; 159 160 if (!have_cpuid_p()) 161 return; 162 163 vendor = x86_cpuid_vendor(); 164 family = x86_cpuid_family(); 165 166 switch (vendor) { 167 case X86_VENDOR_INTEL: 168 if (family >= 6) 169 load_ucode_intel_ap(); 170 break; 171 case X86_VENDOR_AMD: 172 if (family >= 0x10) 173 load_ucode_amd_ap(family); 174 break; 175 default: 176 break; 177 } 178 } 179 180 static int __init save_microcode_in_initrd(void) 181 { 182 struct cpuinfo_x86 *c = &boot_cpu_data; 183 184 switch (c->x86_vendor) { 185 case X86_VENDOR_INTEL: 186 if (c->x86 >= 6) 187 return save_microcode_in_initrd_intel(); 188 break; 189 case X86_VENDOR_AMD: 190 if (c->x86 >= 0x10) 191 return save_microcode_in_initrd_amd(c->x86); 192 break; 193 default: 194 break; 195 } 196 197 return -EINVAL; 198 } 199 200 struct cpio_data find_microcode_in_initrd(const char *path, bool use_pa) 201 { 202 #ifdef CONFIG_BLK_DEV_INITRD 203 unsigned long start = 0; 204 size_t size; 205 206 #ifdef CONFIG_X86_32 207 struct boot_params *params; 208 209 if (use_pa) 210 params = (struct boot_params *)__pa_nodebug(&boot_params); 211 else 212 params = &boot_params; 213 214 size = params->hdr.ramdisk_size; 215 216 /* 217 * Set start only if we have an initrd image. We cannot use initrd_start 218 * because it is not set that early yet. 219 */ 220 if (size) 221 start = params->hdr.ramdisk_image; 222 223 # else /* CONFIG_X86_64 */ 224 size = (unsigned long)boot_params.ext_ramdisk_size << 32; 225 size |= boot_params.hdr.ramdisk_size; 226 227 if (size) { 228 start = (unsigned long)boot_params.ext_ramdisk_image << 32; 229 start |= boot_params.hdr.ramdisk_image; 230 231 start += PAGE_OFFSET; 232 } 233 # endif 234 235 /* 236 * Did we relocate the ramdisk? 237 * 238 * So we possibly relocate the ramdisk *after* applying microcode on the 239 * BSP so we rely on use_pa (use physical addresses) - even if it is not 240 * absolutely correct - to determine whether we've done the ramdisk 241 * relocation already. 242 */ 243 if (!use_pa && relocated_ramdisk) 244 start = initrd_start; 245 246 return find_cpio_data(path, (void *)start, size, NULL); 247 #else /* !CONFIG_BLK_DEV_INITRD */ 248 return (struct cpio_data){ NULL, 0, "" }; 249 #endif 250 } 251 252 void reload_early_microcode(void) 253 { 254 int vendor, family; 255 256 vendor = x86_cpuid_vendor(); 257 family = x86_cpuid_family(); 258 259 switch (vendor) { 260 case X86_VENDOR_INTEL: 261 if (family >= 6) 262 reload_ucode_intel(); 263 break; 264 case X86_VENDOR_AMD: 265 if (family >= 0x10) 266 reload_ucode_amd(); 267 break; 268 default: 269 break; 270 } 271 } 272 273 static void collect_cpu_info_local(void *arg) 274 { 275 struct cpu_info_ctx *ctx = arg; 276 277 ctx->err = microcode_ops->collect_cpu_info(smp_processor_id(), 278 ctx->cpu_sig); 279 } 280 281 static int collect_cpu_info_on_target(int cpu, struct cpu_signature *cpu_sig) 282 { 283 struct cpu_info_ctx ctx = { .cpu_sig = cpu_sig, .err = 0 }; 284 int ret; 285 286 ret = smp_call_function_single(cpu, collect_cpu_info_local, &ctx, 1); 287 if (!ret) 288 ret = ctx.err; 289 290 return ret; 291 } 292 293 static int collect_cpu_info(int cpu) 294 { 295 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 296 int ret; 297 298 memset(uci, 0, sizeof(*uci)); 299 300 ret = collect_cpu_info_on_target(cpu, &uci->cpu_sig); 301 if (!ret) 302 uci->valid = 1; 303 304 return ret; 305 } 306 307 struct apply_microcode_ctx { 308 int err; 309 }; 310 311 static void apply_microcode_local(void *arg) 312 { 313 struct apply_microcode_ctx *ctx = arg; 314 315 ctx->err = microcode_ops->apply_microcode(smp_processor_id()); 316 } 317 318 static int apply_microcode_on_target(int cpu) 319 { 320 struct apply_microcode_ctx ctx = { .err = 0 }; 321 int ret; 322 323 ret = smp_call_function_single(cpu, apply_microcode_local, &ctx, 1); 324 if (!ret) 325 ret = ctx.err; 326 327 return ret; 328 } 329 330 #ifdef CONFIG_MICROCODE_OLD_INTERFACE 331 static int do_microcode_update(const void __user *buf, size_t size) 332 { 333 int error = 0; 334 int cpu; 335 336 for_each_online_cpu(cpu) { 337 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 338 enum ucode_state ustate; 339 340 if (!uci->valid) 341 continue; 342 343 ustate = microcode_ops->request_microcode_user(cpu, buf, size); 344 if (ustate == UCODE_ERROR) { 345 error = -1; 346 break; 347 } else if (ustate == UCODE_OK) 348 apply_microcode_on_target(cpu); 349 } 350 351 return error; 352 } 353 354 static int microcode_open(struct inode *inode, struct file *file) 355 { 356 return capable(CAP_SYS_RAWIO) ? nonseekable_open(inode, file) : -EPERM; 357 } 358 359 static ssize_t microcode_write(struct file *file, const char __user *buf, 360 size_t len, loff_t *ppos) 361 { 362 ssize_t ret = -EINVAL; 363 364 if ((len >> PAGE_SHIFT) > totalram_pages) { 365 pr_err("too much data (max %ld pages)\n", totalram_pages); 366 return ret; 367 } 368 369 get_online_cpus(); 370 mutex_lock(µcode_mutex); 371 372 if (do_microcode_update(buf, len) == 0) 373 ret = (ssize_t)len; 374 375 if (ret > 0) 376 perf_check_microcode(); 377 378 mutex_unlock(µcode_mutex); 379 put_online_cpus(); 380 381 return ret; 382 } 383 384 static const struct file_operations microcode_fops = { 385 .owner = THIS_MODULE, 386 .write = microcode_write, 387 .open = microcode_open, 388 .llseek = no_llseek, 389 }; 390 391 static struct miscdevice microcode_dev = { 392 .minor = MICROCODE_MINOR, 393 .name = "microcode", 394 .nodename = "cpu/microcode", 395 .fops = µcode_fops, 396 }; 397 398 static int __init microcode_dev_init(void) 399 { 400 int error; 401 402 error = misc_register(µcode_dev); 403 if (error) { 404 pr_err("can't misc_register on minor=%d\n", MICROCODE_MINOR); 405 return error; 406 } 407 408 return 0; 409 } 410 411 static void __exit microcode_dev_exit(void) 412 { 413 misc_deregister(µcode_dev); 414 } 415 #else 416 #define microcode_dev_init() 0 417 #define microcode_dev_exit() do { } while (0) 418 #endif 419 420 /* fake device for request_firmware */ 421 static struct platform_device *microcode_pdev; 422 423 static int reload_for_cpu(int cpu) 424 { 425 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 426 enum ucode_state ustate; 427 int err = 0; 428 429 if (!uci->valid) 430 return err; 431 432 ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev, true); 433 if (ustate == UCODE_OK) 434 apply_microcode_on_target(cpu); 435 else 436 if (ustate == UCODE_ERROR) 437 err = -EINVAL; 438 return err; 439 } 440 441 static ssize_t reload_store(struct device *dev, 442 struct device_attribute *attr, 443 const char *buf, size_t size) 444 { 445 unsigned long val; 446 int cpu; 447 ssize_t ret = 0, tmp_ret; 448 449 ret = kstrtoul(buf, 0, &val); 450 if (ret) 451 return ret; 452 453 if (val != 1) 454 return size; 455 456 get_online_cpus(); 457 mutex_lock(µcode_mutex); 458 for_each_online_cpu(cpu) { 459 tmp_ret = reload_for_cpu(cpu); 460 if (tmp_ret != 0) 461 pr_warn("Error reloading microcode on CPU %d\n", cpu); 462 463 /* save retval of the first encountered reload error */ 464 if (!ret) 465 ret = tmp_ret; 466 } 467 if (!ret) 468 perf_check_microcode(); 469 mutex_unlock(µcode_mutex); 470 put_online_cpus(); 471 472 if (!ret) 473 ret = size; 474 475 return ret; 476 } 477 478 static ssize_t version_show(struct device *dev, 479 struct device_attribute *attr, char *buf) 480 { 481 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id; 482 483 return sprintf(buf, "0x%x\n", uci->cpu_sig.rev); 484 } 485 486 static ssize_t pf_show(struct device *dev, 487 struct device_attribute *attr, char *buf) 488 { 489 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id; 490 491 return sprintf(buf, "0x%x\n", uci->cpu_sig.pf); 492 } 493 494 static DEVICE_ATTR(reload, 0200, NULL, reload_store); 495 static DEVICE_ATTR(version, 0400, version_show, NULL); 496 static DEVICE_ATTR(processor_flags, 0400, pf_show, NULL); 497 498 static struct attribute *mc_default_attrs[] = { 499 &dev_attr_version.attr, 500 &dev_attr_processor_flags.attr, 501 NULL 502 }; 503 504 static struct attribute_group mc_attr_group = { 505 .attrs = mc_default_attrs, 506 .name = "microcode", 507 }; 508 509 static void microcode_fini_cpu(int cpu) 510 { 511 if (microcode_ops->microcode_fini_cpu) 512 microcode_ops->microcode_fini_cpu(cpu); 513 } 514 515 static enum ucode_state microcode_resume_cpu(int cpu) 516 { 517 if (apply_microcode_on_target(cpu)) 518 return UCODE_ERROR; 519 520 pr_debug("CPU%d updated upon resume\n", cpu); 521 522 return UCODE_OK; 523 } 524 525 static enum ucode_state microcode_init_cpu(int cpu, bool refresh_fw) 526 { 527 enum ucode_state ustate; 528 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 529 530 if (uci->valid) 531 return UCODE_OK; 532 533 if (collect_cpu_info(cpu)) 534 return UCODE_ERROR; 535 536 /* --dimm. Trigger a delayed update? */ 537 if (system_state != SYSTEM_RUNNING) 538 return UCODE_NFOUND; 539 540 ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev, 541 refresh_fw); 542 543 if (ustate == UCODE_OK) { 544 pr_debug("CPU%d updated upon init\n", cpu); 545 apply_microcode_on_target(cpu); 546 } 547 548 return ustate; 549 } 550 551 static enum ucode_state microcode_update_cpu(int cpu) 552 { 553 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 554 555 /* Refresh CPU microcode revision after resume. */ 556 collect_cpu_info(cpu); 557 558 if (uci->valid) 559 return microcode_resume_cpu(cpu); 560 561 return microcode_init_cpu(cpu, false); 562 } 563 564 static int mc_device_add(struct device *dev, struct subsys_interface *sif) 565 { 566 int err, cpu = dev->id; 567 568 if (!cpu_online(cpu)) 569 return 0; 570 571 pr_debug("CPU%d added\n", cpu); 572 573 err = sysfs_create_group(&dev->kobj, &mc_attr_group); 574 if (err) 575 return err; 576 577 if (microcode_init_cpu(cpu, true) == UCODE_ERROR) 578 return -EINVAL; 579 580 return err; 581 } 582 583 static void mc_device_remove(struct device *dev, struct subsys_interface *sif) 584 { 585 int cpu = dev->id; 586 587 if (!cpu_online(cpu)) 588 return; 589 590 pr_debug("CPU%d removed\n", cpu); 591 microcode_fini_cpu(cpu); 592 sysfs_remove_group(&dev->kobj, &mc_attr_group); 593 } 594 595 static struct subsys_interface mc_cpu_interface = { 596 .name = "microcode", 597 .subsys = &cpu_subsys, 598 .add_dev = mc_device_add, 599 .remove_dev = mc_device_remove, 600 }; 601 602 /** 603 * mc_bp_resume - Update boot CPU microcode during resume. 604 */ 605 static void mc_bp_resume(void) 606 { 607 int cpu = smp_processor_id(); 608 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 609 610 if (uci->valid && uci->mc) 611 microcode_ops->apply_microcode(cpu); 612 else if (!uci->mc) 613 reload_early_microcode(); 614 } 615 616 static struct syscore_ops mc_syscore_ops = { 617 .resume = mc_bp_resume, 618 }; 619 620 static int mc_cpu_online(unsigned int cpu) 621 { 622 struct device *dev; 623 624 dev = get_cpu_device(cpu); 625 microcode_update_cpu(cpu); 626 pr_debug("CPU%d added\n", cpu); 627 628 if (sysfs_create_group(&dev->kobj, &mc_attr_group)) 629 pr_err("Failed to create group for CPU%d\n", cpu); 630 return 0; 631 } 632 633 static int mc_cpu_down_prep(unsigned int cpu) 634 { 635 struct device *dev; 636 637 dev = get_cpu_device(cpu); 638 /* Suspend is in progress, only remove the interface */ 639 sysfs_remove_group(&dev->kobj, &mc_attr_group); 640 pr_debug("CPU%d removed\n", cpu); 641 642 return 0; 643 } 644 645 static struct attribute *cpu_root_microcode_attrs[] = { 646 &dev_attr_reload.attr, 647 NULL 648 }; 649 650 static struct attribute_group cpu_root_microcode_group = { 651 .name = "microcode", 652 .attrs = cpu_root_microcode_attrs, 653 }; 654 655 int __init microcode_init(void) 656 { 657 struct cpuinfo_x86 *c = &boot_cpu_data; 658 int error; 659 660 if (dis_ucode_ldr) 661 return -EINVAL; 662 663 if (c->x86_vendor == X86_VENDOR_INTEL) 664 microcode_ops = init_intel_microcode(); 665 else if (c->x86_vendor == X86_VENDOR_AMD) 666 microcode_ops = init_amd_microcode(); 667 else 668 pr_err("no support for this CPU vendor\n"); 669 670 if (!microcode_ops) 671 return -ENODEV; 672 673 microcode_pdev = platform_device_register_simple("microcode", -1, 674 NULL, 0); 675 if (IS_ERR(microcode_pdev)) 676 return PTR_ERR(microcode_pdev); 677 678 get_online_cpus(); 679 mutex_lock(µcode_mutex); 680 681 error = subsys_interface_register(&mc_cpu_interface); 682 if (!error) 683 perf_check_microcode(); 684 mutex_unlock(µcode_mutex); 685 put_online_cpus(); 686 687 if (error) 688 goto out_pdev; 689 690 error = sysfs_create_group(&cpu_subsys.dev_root->kobj, 691 &cpu_root_microcode_group); 692 693 if (error) { 694 pr_err("Error creating microcode group!\n"); 695 goto out_driver; 696 } 697 698 error = microcode_dev_init(); 699 if (error) 700 goto out_ucode_group; 701 702 register_syscore_ops(&mc_syscore_ops); 703 cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "x86/microcode:online", 704 mc_cpu_online, mc_cpu_down_prep); 705 706 pr_info("Microcode Update Driver: v%s.", DRIVER_VERSION); 707 708 return 0; 709 710 out_ucode_group: 711 sysfs_remove_group(&cpu_subsys.dev_root->kobj, 712 &cpu_root_microcode_group); 713 714 out_driver: 715 get_online_cpus(); 716 mutex_lock(µcode_mutex); 717 718 subsys_interface_unregister(&mc_cpu_interface); 719 720 mutex_unlock(µcode_mutex); 721 put_online_cpus(); 722 723 out_pdev: 724 platform_device_unregister(microcode_pdev); 725 return error; 726 727 } 728 fs_initcall(save_microcode_in_initrd); 729 late_initcall(microcode_init); 730