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 * Did we relocate the ramdisk? 247 * 248 * So we possibly relocate the ramdisk *after* applying microcode on the 249 * BSP so we rely on use_pa (use physical addresses) - even if it is not 250 * absolutely correct - to determine whether we've done the ramdisk 251 * relocation already. 252 */ 253 if (!use_pa && relocated_ramdisk) 254 start = initrd_start; 255 256 return find_cpio_data(path, (void *)start, size, NULL); 257 #else /* !CONFIG_BLK_DEV_INITRD */ 258 return (struct cpio_data){ NULL, 0, "" }; 259 #endif 260 } 261 262 void reload_early_microcode(void) 263 { 264 int vendor, family; 265 266 vendor = x86_cpuid_vendor(); 267 family = x86_cpuid_family(); 268 269 switch (vendor) { 270 case X86_VENDOR_INTEL: 271 if (family >= 6) 272 reload_ucode_intel(); 273 break; 274 case X86_VENDOR_AMD: 275 if (family >= 0x10) 276 reload_ucode_amd(); 277 break; 278 default: 279 break; 280 } 281 } 282 283 static void collect_cpu_info_local(void *arg) 284 { 285 struct cpu_info_ctx *ctx = arg; 286 287 ctx->err = microcode_ops->collect_cpu_info(smp_processor_id(), 288 ctx->cpu_sig); 289 } 290 291 static int collect_cpu_info_on_target(int cpu, struct cpu_signature *cpu_sig) 292 { 293 struct cpu_info_ctx ctx = { .cpu_sig = cpu_sig, .err = 0 }; 294 int ret; 295 296 ret = smp_call_function_single(cpu, collect_cpu_info_local, &ctx, 1); 297 if (!ret) 298 ret = ctx.err; 299 300 return ret; 301 } 302 303 static int collect_cpu_info(int cpu) 304 { 305 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 306 int ret; 307 308 memset(uci, 0, sizeof(*uci)); 309 310 ret = collect_cpu_info_on_target(cpu, &uci->cpu_sig); 311 if (!ret) 312 uci->valid = 1; 313 314 return ret; 315 } 316 317 struct apply_microcode_ctx { 318 int err; 319 }; 320 321 static void apply_microcode_local(void *arg) 322 { 323 struct apply_microcode_ctx *ctx = arg; 324 325 ctx->err = microcode_ops->apply_microcode(smp_processor_id()); 326 } 327 328 static int apply_microcode_on_target(int cpu) 329 { 330 struct apply_microcode_ctx ctx = { .err = 0 }; 331 int ret; 332 333 ret = smp_call_function_single(cpu, apply_microcode_local, &ctx, 1); 334 if (!ret) 335 ret = ctx.err; 336 337 return ret; 338 } 339 340 #ifdef CONFIG_MICROCODE_OLD_INTERFACE 341 static int do_microcode_update(const void __user *buf, size_t size) 342 { 343 int error = 0; 344 int cpu; 345 346 for_each_online_cpu(cpu) { 347 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 348 enum ucode_state ustate; 349 350 if (!uci->valid) 351 continue; 352 353 ustate = microcode_ops->request_microcode_user(cpu, buf, size); 354 if (ustate == UCODE_ERROR) { 355 error = -1; 356 break; 357 } else if (ustate == UCODE_OK) 358 apply_microcode_on_target(cpu); 359 } 360 361 return error; 362 } 363 364 static int microcode_open(struct inode *inode, struct file *file) 365 { 366 return capable(CAP_SYS_RAWIO) ? nonseekable_open(inode, file) : -EPERM; 367 } 368 369 static ssize_t microcode_write(struct file *file, const char __user *buf, 370 size_t len, loff_t *ppos) 371 { 372 ssize_t ret = -EINVAL; 373 374 if ((len >> PAGE_SHIFT) > totalram_pages) { 375 pr_err("too much data (max %ld pages)\n", totalram_pages); 376 return ret; 377 } 378 379 get_online_cpus(); 380 mutex_lock(µcode_mutex); 381 382 if (do_microcode_update(buf, len) == 0) 383 ret = (ssize_t)len; 384 385 if (ret > 0) 386 perf_check_microcode(); 387 388 mutex_unlock(µcode_mutex); 389 put_online_cpus(); 390 391 return ret; 392 } 393 394 static const struct file_operations microcode_fops = { 395 .owner = THIS_MODULE, 396 .write = microcode_write, 397 .open = microcode_open, 398 .llseek = no_llseek, 399 }; 400 401 static struct miscdevice microcode_dev = { 402 .minor = MICROCODE_MINOR, 403 .name = "microcode", 404 .nodename = "cpu/microcode", 405 .fops = µcode_fops, 406 }; 407 408 static int __init microcode_dev_init(void) 409 { 410 int error; 411 412 error = misc_register(µcode_dev); 413 if (error) { 414 pr_err("can't misc_register on minor=%d\n", MICROCODE_MINOR); 415 return error; 416 } 417 418 return 0; 419 } 420 421 static void __exit microcode_dev_exit(void) 422 { 423 misc_deregister(µcode_dev); 424 } 425 #else 426 #define microcode_dev_init() 0 427 #define microcode_dev_exit() do { } while (0) 428 #endif 429 430 /* fake device for request_firmware */ 431 static struct platform_device *microcode_pdev; 432 433 static int reload_for_cpu(int cpu) 434 { 435 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 436 enum ucode_state ustate; 437 int err = 0; 438 439 if (!uci->valid) 440 return err; 441 442 ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev, true); 443 if (ustate == UCODE_OK) 444 apply_microcode_on_target(cpu); 445 else 446 if (ustate == UCODE_ERROR) 447 err = -EINVAL; 448 return err; 449 } 450 451 static ssize_t reload_store(struct device *dev, 452 struct device_attribute *attr, 453 const char *buf, size_t size) 454 { 455 unsigned long val; 456 int cpu; 457 ssize_t ret = 0, tmp_ret; 458 459 ret = kstrtoul(buf, 0, &val); 460 if (ret) 461 return ret; 462 463 if (val != 1) 464 return size; 465 466 get_online_cpus(); 467 mutex_lock(µcode_mutex); 468 for_each_online_cpu(cpu) { 469 tmp_ret = reload_for_cpu(cpu); 470 if (tmp_ret != 0) 471 pr_warn("Error reloading microcode on CPU %d\n", cpu); 472 473 /* save retval of the first encountered reload error */ 474 if (!ret) 475 ret = tmp_ret; 476 } 477 if (!ret) 478 perf_check_microcode(); 479 mutex_unlock(µcode_mutex); 480 put_online_cpus(); 481 482 if (!ret) 483 ret = size; 484 485 return ret; 486 } 487 488 static ssize_t version_show(struct device *dev, 489 struct device_attribute *attr, char *buf) 490 { 491 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id; 492 493 return sprintf(buf, "0x%x\n", uci->cpu_sig.rev); 494 } 495 496 static ssize_t pf_show(struct device *dev, 497 struct device_attribute *attr, char *buf) 498 { 499 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id; 500 501 return sprintf(buf, "0x%x\n", uci->cpu_sig.pf); 502 } 503 504 static DEVICE_ATTR(reload, 0200, NULL, reload_store); 505 static DEVICE_ATTR(version, 0400, version_show, NULL); 506 static DEVICE_ATTR(processor_flags, 0400, pf_show, NULL); 507 508 static struct attribute *mc_default_attrs[] = { 509 &dev_attr_version.attr, 510 &dev_attr_processor_flags.attr, 511 NULL 512 }; 513 514 static struct attribute_group mc_attr_group = { 515 .attrs = mc_default_attrs, 516 .name = "microcode", 517 }; 518 519 static void microcode_fini_cpu(int cpu) 520 { 521 if (microcode_ops->microcode_fini_cpu) 522 microcode_ops->microcode_fini_cpu(cpu); 523 } 524 525 static enum ucode_state microcode_resume_cpu(int cpu) 526 { 527 if (apply_microcode_on_target(cpu)) 528 return UCODE_ERROR; 529 530 pr_debug("CPU%d updated upon resume\n", cpu); 531 532 return UCODE_OK; 533 } 534 535 static enum ucode_state microcode_init_cpu(int cpu, bool refresh_fw) 536 { 537 enum ucode_state ustate; 538 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 539 540 if (uci->valid) 541 return UCODE_OK; 542 543 if (collect_cpu_info(cpu)) 544 return UCODE_ERROR; 545 546 /* --dimm. Trigger a delayed update? */ 547 if (system_state != SYSTEM_RUNNING) 548 return UCODE_NFOUND; 549 550 ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev, 551 refresh_fw); 552 553 if (ustate == UCODE_OK) { 554 pr_debug("CPU%d updated upon init\n", cpu); 555 apply_microcode_on_target(cpu); 556 } 557 558 return ustate; 559 } 560 561 static enum ucode_state microcode_update_cpu(int cpu) 562 { 563 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 564 565 /* Refresh CPU microcode revision after resume. */ 566 collect_cpu_info(cpu); 567 568 if (uci->valid) 569 return microcode_resume_cpu(cpu); 570 571 return microcode_init_cpu(cpu, false); 572 } 573 574 static int mc_device_add(struct device *dev, struct subsys_interface *sif) 575 { 576 int err, cpu = dev->id; 577 578 if (!cpu_online(cpu)) 579 return 0; 580 581 pr_debug("CPU%d added\n", cpu); 582 583 err = sysfs_create_group(&dev->kobj, &mc_attr_group); 584 if (err) 585 return err; 586 587 if (microcode_init_cpu(cpu, true) == UCODE_ERROR) 588 return -EINVAL; 589 590 return err; 591 } 592 593 static void mc_device_remove(struct device *dev, struct subsys_interface *sif) 594 { 595 int cpu = dev->id; 596 597 if (!cpu_online(cpu)) 598 return; 599 600 pr_debug("CPU%d removed\n", cpu); 601 microcode_fini_cpu(cpu); 602 sysfs_remove_group(&dev->kobj, &mc_attr_group); 603 } 604 605 static struct subsys_interface mc_cpu_interface = { 606 .name = "microcode", 607 .subsys = &cpu_subsys, 608 .add_dev = mc_device_add, 609 .remove_dev = mc_device_remove, 610 }; 611 612 /** 613 * mc_bp_resume - Update boot CPU microcode during resume. 614 */ 615 static void mc_bp_resume(void) 616 { 617 int cpu = smp_processor_id(); 618 struct ucode_cpu_info *uci = ucode_cpu_info + cpu; 619 620 if (uci->valid && uci->mc) 621 microcode_ops->apply_microcode(cpu); 622 else if (!uci->mc) 623 reload_early_microcode(); 624 } 625 626 static struct syscore_ops mc_syscore_ops = { 627 .resume = mc_bp_resume, 628 }; 629 630 static int mc_cpu_online(unsigned int cpu) 631 { 632 struct device *dev; 633 634 dev = get_cpu_device(cpu); 635 microcode_update_cpu(cpu); 636 pr_debug("CPU%d added\n", cpu); 637 638 if (sysfs_create_group(&dev->kobj, &mc_attr_group)) 639 pr_err("Failed to create group for CPU%d\n", cpu); 640 return 0; 641 } 642 643 static int mc_cpu_down_prep(unsigned int cpu) 644 { 645 struct device *dev; 646 647 dev = get_cpu_device(cpu); 648 /* Suspend is in progress, only remove the interface */ 649 sysfs_remove_group(&dev->kobj, &mc_attr_group); 650 pr_debug("CPU%d removed\n", cpu); 651 652 return 0; 653 } 654 655 static struct attribute *cpu_root_microcode_attrs[] = { 656 &dev_attr_reload.attr, 657 NULL 658 }; 659 660 static struct attribute_group cpu_root_microcode_group = { 661 .name = "microcode", 662 .attrs = cpu_root_microcode_attrs, 663 }; 664 665 int __init microcode_init(void) 666 { 667 struct cpuinfo_x86 *c = &boot_cpu_data; 668 int error; 669 670 if (dis_ucode_ldr) 671 return -EINVAL; 672 673 if (c->x86_vendor == X86_VENDOR_INTEL) 674 microcode_ops = init_intel_microcode(); 675 else if (c->x86_vendor == X86_VENDOR_AMD) 676 microcode_ops = init_amd_microcode(); 677 else 678 pr_err("no support for this CPU vendor\n"); 679 680 if (!microcode_ops) 681 return -ENODEV; 682 683 microcode_pdev = platform_device_register_simple("microcode", -1, 684 NULL, 0); 685 if (IS_ERR(microcode_pdev)) 686 return PTR_ERR(microcode_pdev); 687 688 get_online_cpus(); 689 mutex_lock(µcode_mutex); 690 691 error = subsys_interface_register(&mc_cpu_interface); 692 if (!error) 693 perf_check_microcode(); 694 mutex_unlock(µcode_mutex); 695 put_online_cpus(); 696 697 if (error) 698 goto out_pdev; 699 700 error = sysfs_create_group(&cpu_subsys.dev_root->kobj, 701 &cpu_root_microcode_group); 702 703 if (error) { 704 pr_err("Error creating microcode group!\n"); 705 goto out_driver; 706 } 707 708 error = microcode_dev_init(); 709 if (error) 710 goto out_ucode_group; 711 712 register_syscore_ops(&mc_syscore_ops); 713 cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "x86/microcode:online", 714 mc_cpu_online, mc_cpu_down_prep); 715 716 pr_info("Microcode Update Driver: v%s.", DRIVER_VERSION); 717 718 return 0; 719 720 out_ucode_group: 721 sysfs_remove_group(&cpu_subsys.dev_root->kobj, 722 &cpu_root_microcode_group); 723 724 out_driver: 725 get_online_cpus(); 726 mutex_lock(µcode_mutex); 727 728 subsys_interface_unregister(&mc_cpu_interface); 729 730 mutex_unlock(µcode_mutex); 731 put_online_cpus(); 732 733 out_pdev: 734 platform_device_unregister(microcode_pdev); 735 return error; 736 737 } 738 fs_initcall(save_microcode_in_initrd); 739 late_initcall(microcode_init); 740