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