1 /* 2 * CPU Microcode Update Driver for Linux 3 * 4 * Copyright (C) 2000-2006 Tigran Aivazian <aivazian.tigran@gmail.com> 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 = true; 48 49 bool initrd_gone; 50 51 LIST_HEAD(microcode_cache); 52 53 /* 54 * Synchronization. 55 * 56 * All non cpu-hotplug-callback call sites use: 57 * 58 * - microcode_mutex to synchronize with each other; 59 * - get/put_online_cpus() to synchronize with 60 * the cpu-hotplug-callback call sites. 61 * 62 * We guarantee that only a single cpu is being 63 * updated at any particular moment of time. 64 */ 65 static DEFINE_MUTEX(microcode_mutex); 66 67 struct ucode_cpu_info ucode_cpu_info[NR_CPUS]; 68 69 struct cpu_info_ctx { 70 struct cpu_signature *cpu_sig; 71 int err; 72 }; 73 74 /* 75 * Those patch levels cannot be updated to newer ones and thus should be final. 76 */ 77 static u32 final_levels[] = { 78 0x01000098, 79 0x0100009f, 80 0x010000af, 81 0, /* T-101 terminator */ 82 }; 83 84 /* 85 * Check the current patch level on this CPU. 86 * 87 * Returns: 88 * - true: if update should stop 89 * - false: otherwise 90 */ 91 static bool amd_check_current_patch_level(void) 92 { 93 u32 lvl, dummy, i; 94 u32 *levels; 95 96 native_rdmsr(MSR_AMD64_PATCH_LEVEL, lvl, dummy); 97 98 if (IS_ENABLED(CONFIG_X86_32)) 99 levels = (u32 *)__pa_nodebug(&final_levels); 100 else 101 levels = final_levels; 102 103 for (i = 0; levels[i]; i++) { 104 if (lvl == levels[i]) 105 return true; 106 } 107 return false; 108 } 109 110 static bool __init check_loader_disabled_bsp(void) 111 { 112 static const char *__dis_opt_str = "dis_ucode_ldr"; 113 114 #ifdef CONFIG_X86_32 115 const char *cmdline = (const char *)__pa_nodebug(boot_command_line); 116 const char *option = (const char *)__pa_nodebug(__dis_opt_str); 117 bool *res = (bool *)__pa_nodebug(&dis_ucode_ldr); 118 119 #else /* CONFIG_X86_64 */ 120 const char *cmdline = boot_command_line; 121 const char *option = __dis_opt_str; 122 bool *res = &dis_ucode_ldr; 123 #endif 124 125 if (!have_cpuid_p()) 126 return *res; 127 128 /* 129 * CPUID(1).ECX[31]: reserved for hypervisor use. This is still not 130 * completely accurate as xen pv guests don't see that CPUID bit set but 131 * that's good enough as they don't land on the BSP path anyway. 132 */ 133 if (native_cpuid_ecx(1) & BIT(31)) 134 return *res; 135 136 if (x86_cpuid_vendor() == X86_VENDOR_AMD) { 137 if (amd_check_current_patch_level()) 138 return *res; 139 } 140 141 if (cmdline_find_option_bool(cmdline, option) <= 0) 142 *res = false; 143 144 return *res; 145 } 146 147 extern struct builtin_fw __start_builtin_fw[]; 148 extern struct builtin_fw __end_builtin_fw[]; 149 150 bool get_builtin_firmware(struct cpio_data *cd, const char *name) 151 { 152 #ifdef CONFIG_FW_LOADER 153 struct builtin_fw *b_fw; 154 155 for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) { 156 if (!strcmp(name, b_fw->name)) { 157 cd->size = b_fw->size; 158 cd->data = b_fw->data; 159 return true; 160 } 161 } 162 #endif 163 return false; 164 } 165 166 void __init load_ucode_bsp(void) 167 { 168 unsigned int cpuid_1_eax; 169 170 if (check_loader_disabled_bsp()) 171 return; 172 173 cpuid_1_eax = native_cpuid_eax(1); 174 175 switch (x86_cpuid_vendor()) { 176 case X86_VENDOR_INTEL: 177 if (x86_family(cpuid_1_eax) >= 6) 178 load_ucode_intel_bsp(); 179 break; 180 case X86_VENDOR_AMD: 181 if (x86_family(cpuid_1_eax) >= 0x10) 182 load_ucode_amd_bsp(cpuid_1_eax); 183 break; 184 default: 185 break; 186 } 187 } 188 189 static bool check_loader_disabled_ap(void) 190 { 191 #ifdef CONFIG_X86_32 192 return *((bool *)__pa_nodebug(&dis_ucode_ldr)); 193 #else 194 return dis_ucode_ldr; 195 #endif 196 } 197 198 void load_ucode_ap(void) 199 { 200 unsigned int cpuid_1_eax; 201 202 if (check_loader_disabled_ap()) 203 return; 204 205 cpuid_1_eax = native_cpuid_eax(1); 206 207 switch (x86_cpuid_vendor()) { 208 case X86_VENDOR_INTEL: 209 if (x86_family(cpuid_1_eax) >= 6) 210 load_ucode_intel_ap(); 211 break; 212 case X86_VENDOR_AMD: 213 if (x86_family(cpuid_1_eax) >= 0x10) 214 load_ucode_amd_ap(cpuid_1_eax); 215 break; 216 default: 217 break; 218 } 219 } 220 221 static int __init save_microcode_in_initrd(void) 222 { 223 struct cpuinfo_x86 *c = &boot_cpu_data; 224 int ret = -EINVAL; 225 226 switch (c->x86_vendor) { 227 case X86_VENDOR_INTEL: 228 if (c->x86 >= 6) 229 ret = save_microcode_in_initrd_intel(); 230 break; 231 case X86_VENDOR_AMD: 232 if (c->x86 >= 0x10) 233 return save_microcode_in_initrd_amd(cpuid_eax(1)); 234 break; 235 default: 236 break; 237 } 238 239 initrd_gone = true; 240 241 return ret; 242 } 243 244 struct cpio_data find_microcode_in_initrd(const char *path, bool use_pa) 245 { 246 #ifdef CONFIG_BLK_DEV_INITRD 247 unsigned long start = 0; 248 size_t size; 249 250 #ifdef CONFIG_X86_32 251 struct boot_params *params; 252 253 if (use_pa) 254 params = (struct boot_params *)__pa_nodebug(&boot_params); 255 else 256 params = &boot_params; 257 258 size = params->hdr.ramdisk_size; 259 260 /* 261 * Set start only if we have an initrd image. We cannot use initrd_start 262 * because it is not set that early yet. 263 */ 264 if (size) 265 start = params->hdr.ramdisk_image; 266 267 # else /* CONFIG_X86_64 */ 268 size = (unsigned long)boot_params.ext_ramdisk_size << 32; 269 size |= boot_params.hdr.ramdisk_size; 270 271 if (size) { 272 start = (unsigned long)boot_params.ext_ramdisk_image << 32; 273 start |= boot_params.hdr.ramdisk_image; 274 275 start += PAGE_OFFSET; 276 } 277 # endif 278 279 /* 280 * Fixup the start address: after reserve_initrd() runs, initrd_start 281 * has the virtual address of the beginning of the initrd. It also 282 * possibly relocates the ramdisk. In either case, initrd_start contains 283 * the updated address so use that instead. 284 * 285 * initrd_gone is for the hotplug case where we've thrown out initrd 286 * already. 287 */ 288 if (!use_pa) { 289 if (initrd_gone) 290 return (struct cpio_data){ NULL, 0, "" }; 291 if (initrd_start) 292 start = initrd_start; 293 } else { 294 /* 295 * The picture with physical addresses is a bit different: we 296 * need to get the *physical* address to which the ramdisk was 297 * relocated, i.e., relocated_ramdisk (not initrd_start) and 298 * since we're running from physical addresses, we need to access 299 * relocated_ramdisk through its *physical* address too. 300 */ 301 u64 *rr = (u64 *)__pa_nodebug(&relocated_ramdisk); 302 if (*rr) 303 start = *rr; 304 } 305 306 return find_cpio_data(path, (void *)start, size, NULL); 307 #else /* !CONFIG_BLK_DEV_INITRD */ 308 return (struct cpio_data){ NULL, 0, "" }; 309 #endif 310 } 311 312 void reload_early_microcode(void) 313 { 314 int vendor, family; 315 316 vendor = x86_cpuid_vendor(); 317 family = x86_cpuid_family(); 318 319 switch (vendor) { 320 case X86_VENDOR_INTEL: 321 if (family >= 6) 322 reload_ucode_intel(); 323 break; 324 case X86_VENDOR_AMD: 325 if (family >= 0x10) 326 reload_ucode_amd(); 327 break; 328 default: 329 break; 330 } 331 } 332 333 static void collect_cpu_info_local(void *arg) 334 { 335 struct cpu_info_ctx *ctx = arg; 336 337 ctx->err = microcode_ops->collect_cpu_info(smp_processor_id(), 338 ctx->cpu_sig); 339 } 340 341 static int collect_cpu_info_on_target(int cpu, struct cpu_signature *cpu_sig) 342 { 343 struct cpu_info_ctx ctx = { .cpu_sig = cpu_sig, .err = 0 }; 344 int ret; 345 346 ret = smp_call_function_single(cpu, collect_cpu_info_local, &ctx, 1); 347 if (!ret) 348 ret = ctx.err; 349 350 return ret; 351 } 352 353 static int collect_cpu_info(int cpu) 354 { 355 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 356 int ret; 357 358 memset(uci, 0, sizeof(*uci)); 359 360 ret = collect_cpu_info_on_target(cpu, &uci->cpu_sig); 361 if (!ret) 362 uci->valid = 1; 363 364 return ret; 365 } 366 367 struct apply_microcode_ctx { 368 int err; 369 }; 370 371 static void apply_microcode_local(void *arg) 372 { 373 struct apply_microcode_ctx *ctx = arg; 374 375 ctx->err = microcode_ops->apply_microcode(smp_processor_id()); 376 } 377 378 static int apply_microcode_on_target(int cpu) 379 { 380 struct apply_microcode_ctx ctx = { .err = 0 }; 381 int ret; 382 383 ret = smp_call_function_single(cpu, apply_microcode_local, &ctx, 1); 384 if (!ret) 385 ret = ctx.err; 386 387 return ret; 388 } 389 390 #ifdef CONFIG_MICROCODE_OLD_INTERFACE 391 static int do_microcode_update(const void __user *buf, size_t size) 392 { 393 int error = 0; 394 int cpu; 395 396 for_each_online_cpu(cpu) { 397 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 398 enum ucode_state ustate; 399 400 if (!uci->valid) 401 continue; 402 403 ustate = microcode_ops->request_microcode_user(cpu, buf, size); 404 if (ustate == UCODE_ERROR) { 405 error = -1; 406 break; 407 } else if (ustate == UCODE_OK) 408 apply_microcode_on_target(cpu); 409 } 410 411 return error; 412 } 413 414 static int microcode_open(struct inode *inode, struct file *file) 415 { 416 return capable(CAP_SYS_RAWIO) ? nonseekable_open(inode, file) : -EPERM; 417 } 418 419 static ssize_t microcode_write(struct file *file, const char __user *buf, 420 size_t len, loff_t *ppos) 421 { 422 ssize_t ret = -EINVAL; 423 424 if ((len >> PAGE_SHIFT) > totalram_pages) { 425 pr_err("too much data (max %ld pages)\n", totalram_pages); 426 return ret; 427 } 428 429 get_online_cpus(); 430 mutex_lock(µcode_mutex); 431 432 if (do_microcode_update(buf, len) == 0) 433 ret = (ssize_t)len; 434 435 if (ret > 0) 436 perf_check_microcode(); 437 438 mutex_unlock(µcode_mutex); 439 put_online_cpus(); 440 441 return ret; 442 } 443 444 static const struct file_operations microcode_fops = { 445 .owner = THIS_MODULE, 446 .write = microcode_write, 447 .open = microcode_open, 448 .llseek = no_llseek, 449 }; 450 451 static struct miscdevice microcode_dev = { 452 .minor = MICROCODE_MINOR, 453 .name = "microcode", 454 .nodename = "cpu/microcode", 455 .fops = µcode_fops, 456 }; 457 458 static int __init microcode_dev_init(void) 459 { 460 int error; 461 462 error = misc_register(µcode_dev); 463 if (error) { 464 pr_err("can't misc_register on minor=%d\n", MICROCODE_MINOR); 465 return error; 466 } 467 468 return 0; 469 } 470 471 static void __exit microcode_dev_exit(void) 472 { 473 misc_deregister(µcode_dev); 474 } 475 #else 476 #define microcode_dev_init() 0 477 #define microcode_dev_exit() do { } while (0) 478 #endif 479 480 /* fake device for request_firmware */ 481 static struct platform_device *microcode_pdev; 482 483 static int reload_for_cpu(int cpu) 484 { 485 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 486 enum ucode_state ustate; 487 int err = 0; 488 489 if (!uci->valid) 490 return err; 491 492 ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev, true); 493 if (ustate == UCODE_OK) 494 apply_microcode_on_target(cpu); 495 else 496 if (ustate == UCODE_ERROR) 497 err = -EINVAL; 498 return err; 499 } 500 501 static ssize_t reload_store(struct device *dev, 502 struct device_attribute *attr, 503 const char *buf, size_t size) 504 { 505 unsigned long val; 506 int cpu; 507 ssize_t ret = 0, tmp_ret; 508 509 ret = kstrtoul(buf, 0, &val); 510 if (ret) 511 return ret; 512 513 if (val != 1) 514 return size; 515 516 get_online_cpus(); 517 mutex_lock(µcode_mutex); 518 for_each_online_cpu(cpu) { 519 tmp_ret = reload_for_cpu(cpu); 520 if (tmp_ret != 0) 521 pr_warn("Error reloading microcode on CPU %d\n", cpu); 522 523 /* save retval of the first encountered reload error */ 524 if (!ret) 525 ret = tmp_ret; 526 } 527 if (!ret) 528 perf_check_microcode(); 529 mutex_unlock(µcode_mutex); 530 put_online_cpus(); 531 532 if (!ret) 533 ret = size; 534 535 return ret; 536 } 537 538 static ssize_t version_show(struct device *dev, 539 struct device_attribute *attr, char *buf) 540 { 541 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id; 542 543 return sprintf(buf, "0x%x\n", uci->cpu_sig.rev); 544 } 545 546 static ssize_t pf_show(struct device *dev, 547 struct device_attribute *attr, char *buf) 548 { 549 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id; 550 551 return sprintf(buf, "0x%x\n", uci->cpu_sig.pf); 552 } 553 554 static DEVICE_ATTR(reload, 0200, NULL, reload_store); 555 static DEVICE_ATTR(version, 0400, version_show, NULL); 556 static DEVICE_ATTR(processor_flags, 0400, pf_show, NULL); 557 558 static struct attribute *mc_default_attrs[] = { 559 &dev_attr_version.attr, 560 &dev_attr_processor_flags.attr, 561 NULL 562 }; 563 564 static struct attribute_group mc_attr_group = { 565 .attrs = mc_default_attrs, 566 .name = "microcode", 567 }; 568 569 static void microcode_fini_cpu(int cpu) 570 { 571 if (microcode_ops->microcode_fini_cpu) 572 microcode_ops->microcode_fini_cpu(cpu); 573 } 574 575 static enum ucode_state microcode_resume_cpu(int cpu) 576 { 577 if (apply_microcode_on_target(cpu)) 578 return UCODE_ERROR; 579 580 pr_debug("CPU%d updated upon resume\n", cpu); 581 582 return UCODE_OK; 583 } 584 585 static enum ucode_state microcode_init_cpu(int cpu, bool refresh_fw) 586 { 587 enum ucode_state ustate; 588 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 589 590 if (uci->valid) 591 return UCODE_OK; 592 593 if (collect_cpu_info(cpu)) 594 return UCODE_ERROR; 595 596 /* --dimm. Trigger a delayed update? */ 597 if (system_state != SYSTEM_RUNNING) 598 return UCODE_NFOUND; 599 600 ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev, 601 refresh_fw); 602 603 if (ustate == UCODE_OK) { 604 pr_debug("CPU%d updated upon init\n", cpu); 605 apply_microcode_on_target(cpu); 606 } 607 608 return ustate; 609 } 610 611 static enum ucode_state microcode_update_cpu(int cpu) 612 { 613 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 614 615 /* Refresh CPU microcode revision after resume. */ 616 collect_cpu_info(cpu); 617 618 if (uci->valid) 619 return microcode_resume_cpu(cpu); 620 621 return microcode_init_cpu(cpu, false); 622 } 623 624 static int mc_device_add(struct device *dev, struct subsys_interface *sif) 625 { 626 int err, cpu = dev->id; 627 628 if (!cpu_online(cpu)) 629 return 0; 630 631 pr_debug("CPU%d added\n", cpu); 632 633 err = sysfs_create_group(&dev->kobj, &mc_attr_group); 634 if (err) 635 return err; 636 637 if (microcode_init_cpu(cpu, true) == UCODE_ERROR) 638 return -EINVAL; 639 640 return err; 641 } 642 643 static void mc_device_remove(struct device *dev, struct subsys_interface *sif) 644 { 645 int cpu = dev->id; 646 647 if (!cpu_online(cpu)) 648 return; 649 650 pr_debug("CPU%d removed\n", cpu); 651 microcode_fini_cpu(cpu); 652 sysfs_remove_group(&dev->kobj, &mc_attr_group); 653 } 654 655 static struct subsys_interface mc_cpu_interface = { 656 .name = "microcode", 657 .subsys = &cpu_subsys, 658 .add_dev = mc_device_add, 659 .remove_dev = mc_device_remove, 660 }; 661 662 /** 663 * mc_bp_resume - Update boot CPU microcode during resume. 664 */ 665 static void mc_bp_resume(void) 666 { 667 int cpu = smp_processor_id(); 668 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 669 670 if (uci->valid && uci->mc) 671 microcode_ops->apply_microcode(cpu); 672 else if (!uci->mc) 673 reload_early_microcode(); 674 } 675 676 static struct syscore_ops mc_syscore_ops = { 677 .resume = mc_bp_resume, 678 }; 679 680 static int mc_cpu_online(unsigned int cpu) 681 { 682 struct device *dev; 683 684 dev = get_cpu_device(cpu); 685 microcode_update_cpu(cpu); 686 pr_debug("CPU%d added\n", cpu); 687 688 if (sysfs_create_group(&dev->kobj, &mc_attr_group)) 689 pr_err("Failed to create group for CPU%d\n", cpu); 690 return 0; 691 } 692 693 static int mc_cpu_down_prep(unsigned int cpu) 694 { 695 struct device *dev; 696 697 dev = get_cpu_device(cpu); 698 /* Suspend is in progress, only remove the interface */ 699 sysfs_remove_group(&dev->kobj, &mc_attr_group); 700 pr_debug("CPU%d removed\n", cpu); 701 702 return 0; 703 } 704 705 static struct attribute *cpu_root_microcode_attrs[] = { 706 &dev_attr_reload.attr, 707 NULL 708 }; 709 710 static struct attribute_group cpu_root_microcode_group = { 711 .name = "microcode", 712 .attrs = cpu_root_microcode_attrs, 713 }; 714 715 int __init microcode_init(void) 716 { 717 struct cpuinfo_x86 *c = &boot_cpu_data; 718 int error; 719 720 if (dis_ucode_ldr) 721 return -EINVAL; 722 723 if (c->x86_vendor == X86_VENDOR_INTEL) 724 microcode_ops = init_intel_microcode(); 725 else if (c->x86_vendor == X86_VENDOR_AMD) 726 microcode_ops = init_amd_microcode(); 727 else 728 pr_err("no support for this CPU vendor\n"); 729 730 if (!microcode_ops) 731 return -ENODEV; 732 733 microcode_pdev = platform_device_register_simple("microcode", -1, 734 NULL, 0); 735 if (IS_ERR(microcode_pdev)) 736 return PTR_ERR(microcode_pdev); 737 738 get_online_cpus(); 739 mutex_lock(µcode_mutex); 740 741 error = subsys_interface_register(&mc_cpu_interface); 742 if (!error) 743 perf_check_microcode(); 744 mutex_unlock(µcode_mutex); 745 put_online_cpus(); 746 747 if (error) 748 goto out_pdev; 749 750 error = sysfs_create_group(&cpu_subsys.dev_root->kobj, 751 &cpu_root_microcode_group); 752 753 if (error) { 754 pr_err("Error creating microcode group!\n"); 755 goto out_driver; 756 } 757 758 error = microcode_dev_init(); 759 if (error) 760 goto out_ucode_group; 761 762 register_syscore_ops(&mc_syscore_ops); 763 cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "x86/microcode:online", 764 mc_cpu_online, mc_cpu_down_prep); 765 766 pr_info("Microcode Update Driver: v%s.", DRIVER_VERSION); 767 768 return 0; 769 770 out_ucode_group: 771 sysfs_remove_group(&cpu_subsys.dev_root->kobj, 772 &cpu_root_microcode_group); 773 774 out_driver: 775 get_online_cpus(); 776 mutex_lock(µcode_mutex); 777 778 subsys_interface_unregister(&mc_cpu_interface); 779 780 mutex_unlock(µcode_mutex); 781 put_online_cpus(); 782 783 out_pdev: 784 platform_device_unregister(microcode_pdev); 785 return error; 786 787 } 788 fs_initcall(save_microcode_in_initrd); 789 late_initcall(microcode_init); 790