arch/i386/kernel/microcode.c

   1 /*
   2  *      Intel CPU Microcode Update Driver for Linux
   3  *
   4  *      Copyright (C) 2000-2004 Tigran Aivazian
   5  *
   6  *      This driver allows to upgrade microcode on Intel processors
   7  *      belonging to IA-32 family - PentiumPro, Pentium II,
   8  *      Pentium III, Xeon, Pentium 4, etc.
   9  *
  10  *      Reference: Section 8.10 of Volume III, Intel Pentium 4 Manual,
  11  *      Order Number 245472 or free download from:
  12  *
  13  *      http://developer.intel.com/design/pentium4/manuals/245472.htm
  14  *
  15  *      For more information, go to http://www.urbanmyth.org/microcode
  16  *
  17  *      This program is free software; you can redistribute it and/or
  18  *      modify it under the terms of the GNU General Public License
  19  *      as published by the Free Software Foundation; either version
  20  *      2 of the License, or (at your option) any later version.
  21  *
  22  *      1.0     16 Feb 2000, Tigran Aivazian <tigran@sco.com>
  23  *              Initial release.
  24  *      1.01    18 Feb 2000, Tigran Aivazian <tigran@sco.com>
  25  *              Added read() support + cleanups.
  26  *      1.02    21 Feb 2000, Tigran Aivazian <tigran@sco.com>
  27  *              Added 'device trimming' support. open(O_WRONLY) zeroes
  28  *              and frees the saved copy of applied microcode.
  29  *      1.03    29 Feb 2000, Tigran Aivazian <tigran@sco.com>
  30  *              Made to use devfs (/dev/cpu/microcode) + cleanups.
  31  *      1.04    06 Jun 2000, Simon Trimmer <simon@veritas.com>
  32  *              Added misc device support (now uses both devfs and misc).
  33  *              Added MICROCODE_IOCFREE ioctl to clear memory.
  34  *      1.05    09 Jun 2000, Simon Trimmer <simon@veritas.com>
  35  *              Messages for error cases (non Intel & no suitable microcode).
  36  *      1.06    03 Aug 2000, Tigran Aivazian <tigran@veritas.com>
  37  *              Removed ->release(). Removed exclusive open and status bitmap.
  38  *              Added microcode_rwsem to serialize read()/write()/ioctl().
  39  *              Removed global kernel lock usage.
  40  *      1.07    07 Sep 2000, Tigran Aivazian <tigran@veritas.com>
  41  *              Write 0 to 0x8B msr and then cpuid before reading revision,
  42  *              so that it works even if there were no update done by the
  43  *              BIOS. Otherwise, reading from 0x8B gives junk (which happened
  44  *              to be 0 on my machine which is why it worked even when I
  45  *              disabled update by the BIOS)
  46  *              Thanks to Eric W. Biederman <ebiederman@lnxi.com> for the fix.
  47  *      1.08    11 Dec 2000, Richard Schaal <richard.schaal@intel.com> and
  48  *                           Tigran Aivazian <tigran@veritas.com>
  49  *              Intel Pentium 4 processor support and bugfixes.
  50  *      1.09    30 Oct 2001, Tigran Aivazian <tigran@veritas.com>
  51  *              Bugfix for HT (Hyper-Threading) enabled processors
  52  *              whereby processor resources are shared by all logical processors
  53  *              in a single CPU package.
  54  *      1.10    28 Feb 2002 Asit K Mallick <asit.k.mallick@intel.com> and
  55  *              Tigran Aivazian <tigran@veritas.com>,
  56  *              Serialize updates as required on HT processors due to speculative
  57  *              nature of implementation.
  58  *      1.11    22 Mar 2002 Tigran Aivazian <tigran@veritas.com>
  59  *              Fix the panic when writing zero-length microcode chunk.
  60  *      1.12    29 Sep 2003 Nitin Kamble <nitin.a.kamble@intel.com>,
  61  *              Jun Nakajima <jun.nakajima@intel.com>
  62  *              Support for the microcode updates in the new format.
  63  *      1.13    10 Oct 2003 Tigran Aivazian <tigran@veritas.com>
  64  *              Removed ->read() method and obsoleted MICROCODE_IOCFREE ioctl
  65  *              because we no longer hold a copy of applied microcode
  66  *              in kernel memory.
  67  *      1.14    25 Jun 2004 Tigran Aivazian <tigran@veritas.com>
  68  *              Fix sigmatch() macro to handle old CPUs with pf == 0.
  69  *              Thanks to Stuart Swales for pointing out this bug.
  70  */
  71
  72 //#define DEBUG /* pr_debug */
  73 #include <linux/capability.h>
  74 #include <linux/kernel.h>
  75 #include <linux/init.h>
  76 #include <linux/sched.h>
  77 #include <linux/cpumask.h>
  78 #include <linux/module.h>
  79 #include <linux/slab.h>
  80 #include <linux/vmalloc.h>
  81 #include <linux/miscdevice.h>
  82 #include <linux/spinlock.h>
  83 #include <linux/mm.h>
  84 #include <linux/mutex.h>
  85
  86 #include <asm/msr.h>
  87 #include <asm/uaccess.h>
  88 #include <asm/processor.h>
  89
  90 MODULE_DESCRIPTION("Intel CPU (IA-32) Microcode Update Driver");
  91 MODULE_AUTHOR("Tigran Aivazian <tigran@veritas.com>");
  92 MODULE_LICENSE("GPL");
  93
  94 #define MICROCODE_VERSION       "1.14"
  95
  96 #define DEFAULT_UCODE_DATASIZE  (2000)    /* 2000 bytes */
  97 #define MC_HEADER_SIZE          (sizeof (microcode_header_t))     /* 48 bytes */
  98 #define DEFAULT_UCODE_TOTALSIZE (DEFAULT_UCODE_DATASIZE + MC_HEADER_SIZE) /* 2048 bytes */
  99 #define EXT_HEADER_SIZE         (sizeof (struct extended_sigtable)) /* 20 bytes */
 100 #define EXT_SIGNATURE_SIZE      (sizeof (struct extended_signature)) /* 12 bytes */
 101 #define DWSIZE                  (sizeof (u32))
 102 #define get_totalsize(mc) \
 103         (((microcode_t *)mc)->hdr.totalsize ? \
 104          ((microcode_t *)mc)->hdr.totalsize : DEFAULT_UCODE_TOTALSIZE)
 105 #define get_datasize(mc) \
 106         (((microcode_t *)mc)->hdr.datasize ? \
 107          ((microcode_t *)mc)->hdr.datasize : DEFAULT_UCODE_DATASIZE)
 108
 109 #define sigmatch(s1, s2, p1, p2) \
 110         (((s1) == (s2)) && (((p1) & (p2)) || (((p1) == 0) && ((p2) == 0))))
 111
 112 #define exttable_size(et) ((et)->count * EXT_SIGNATURE_SIZE + EXT_HEADER_SIZE)
 113
 114 /* serialize access to the physical write to MSR 0x79 */
 115 static DEFINE_SPINLOCK(microcode_update_lock);
 116
 117 /* no concurrent ->write()s are allowed on /dev/cpu/microcode */
 118 static DEFINE_MUTEX(microcode_mutex);
 119
 120 static void __user *user_buffer;        /* user area microcode data buffer */
 121 static unsigned int user_buffer_size;   /* it's size */
 122
 123 typedef enum mc_error_code {
 124         MC_SUCCESS      = 0,
 125         MC_NOTFOUND     = 1,
 126         MC_MARKED       = 2,
 127         MC_ALLOCATED    = 3,
 128 } mc_error_code_t;
 129
 130 static struct ucode_cpu_info {
 131         unsigned int sig;
 132         unsigned int pf;
 133         unsigned int rev;
 134         unsigned int cksum;
 135         mc_error_code_t err;
 136         microcode_t *mc;
 137 } ucode_cpu_info[NR_CPUS];
 138
 139 static int microcode_open (struct inode *unused1, struct file *unused2)
 140 {
 141         return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
 142 }
 143
 144 static void collect_cpu_info (void *unused)
 145 {
 146         int cpu_num = smp_processor_id();
 147         struct cpuinfo_x86 *c = cpu_data + cpu_num;
 148         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 149         unsigned int val[2];
 150
 151         uci->sig = uci->pf = uci->rev = uci->cksum = 0;
 152         uci->err = MC_NOTFOUND;
 153         uci->mc = NULL;
 154
 155         if (c->x86_vendor != X86_VENDOR_INTEL || c->x86 < 6 ||
 156                 cpu_has(c, X86_FEATURE_IA64)) {
 157                 printk(KERN_ERR "microcode: CPU%d not a capable Intel processor\n", cpu_num);
 158                 return;
 159         } else {
 160                 uci->sig = cpuid_eax(0x00000001);
 161
 162                 if ((c->x86_model >= 5) || (c->x86 > 6)) {
 163                         /* get processor flags from MSR 0x17 */
 164                         rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
 165                         uci->pf = 1 << ((val[1] >> 18) & 7);
 166                 }
 167         }
 168
 169         wrmsr(MSR_IA32_UCODE_REV, 0, 0);
 170         /* see notes above for revision 1.07.  Apparent chip bug */
 171         sync_core();
 172         /* get the current revision from MSR 0x8B */
 173         rdmsr(MSR_IA32_UCODE_REV, val[0], uci->rev);
 174         pr_debug("microcode: collect_cpu_info : sig=0x%x, pf=0x%x, rev=0x%x\n",
 175                         uci->sig, uci->pf, uci->rev);
 176 }
 177
 178 static inline void mark_microcode_update (int cpu_num, microcode_header_t *mc_header, int sig, int pf, int cksum)
 179 {
 180         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 181
 182         pr_debug("Microcode Found.\n");
 183         pr_debug("   Header Revision 0x%x\n", mc_header->hdrver);
 184         pr_debug("   Loader Revision 0x%x\n", mc_header->ldrver);
 185         pr_debug("   Revision 0x%x \n", mc_header->rev);
 186         pr_debug("   Date %x/%x/%x\n",
 187                 ((mc_header->date >> 24 ) & 0xff),
 188                 ((mc_header->date >> 16 ) & 0xff),
 189                 (mc_header->date & 0xFFFF));
 190         pr_debug("   Signature 0x%x\n", sig);
 191         pr_debug("   Type 0x%x Family 0x%x Model 0x%x Stepping 0x%x\n",
 192                 ((sig >> 12) & 0x3),
 193                 ((sig >> 8) & 0xf),
 194                 ((sig >> 4) & 0xf),
 195                 ((sig & 0xf)));
 196         pr_debug("   Processor Flags 0x%x\n", pf);
 197         pr_debug("   Checksum 0x%x\n", cksum);
 198
 199         if (mc_header->rev < uci->rev) {
 200                 printk(KERN_ERR "microcode: CPU%d not 'upgrading' to earlier revision"
 201                        " 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
 202                 goto out;
 203         } else if (mc_header->rev == uci->rev) {
 204                 /* notify the caller of success on this cpu */
 205                 uci->err = MC_SUCCESS;
 206                 goto out;
 207         }
 208
 209         pr_debug("microcode: CPU%d found a matching microcode update with "
 210                 " revision 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
 211         uci->cksum = cksum;
 212         uci->pf = pf; /* keep the original mc pf for cksum calculation */
 213         uci->err = MC_MARKED; /* found the match */
 214 out:
 215         return;
 216 }
 217
 218 static int find_matching_ucodes (void)
 219 {
 220         int cursor = 0;
 221         int error = 0;
 222
 223         while (cursor + MC_HEADER_SIZE < user_buffer_size) {
 224                 microcode_header_t mc_header;
 225                 void *newmc = NULL;
 226                 int i, sum, cpu_num, allocated_flag, total_size, data_size, ext_table_size;
 227
 228                 if (copy_from_user(&mc_header, user_buffer + cursor, MC_HEADER_SIZE)) {
 229                         printk(KERN_ERR "microcode: error! Can not read user data\n");
 230                         error = -EFAULT;
 231                         goto out;
 232                 }
 233
 234                 total_size = get_totalsize(&mc_header);
 235                 if ((cursor + total_size > user_buffer_size) || (total_size < DEFAULT_UCODE_TOTALSIZE)) {
 236                         printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
 237                         error = -EINVAL;
 238                         goto out;
 239                 }
 240
 241                 data_size = get_datasize(&mc_header);
 242                 if ((data_size + MC_HEADER_SIZE > total_size) || (data_size < DEFAULT_UCODE_DATASIZE)) {
 243                         printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
 244                         error = -EINVAL;
 245                         goto out;
 246                 }
 247
 248                 if (mc_header.ldrver != 1 || mc_header.hdrver != 1) {
 249                         printk(KERN_ERR "microcode: error! Unknown microcode update format\n");
 250                         error = -EINVAL;
 251                         goto out;
 252                 }
 253
 254                 for_each_online_cpu(cpu_num) {
 255                         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 256                         if (uci->err != MC_NOTFOUND) /* already found a match or not an online cpu*/
 257                                 continue;
 258
 259                         if (sigmatch(mc_header.sig, uci->sig, mc_header.pf, uci->pf))
 260                                 mark_microcode_update(cpu_num, &mc_header, mc_header.sig, mc_header.pf, mc_header.cksum);
 261                 }
 262
 263                 ext_table_size = total_size - (MC_HEADER_SIZE + data_size);
 264                 if (ext_table_size) {
 265                         struct extended_sigtable ext_header;
 266                         struct extended_signature ext_sig;
 267                         int ext_sigcount;
 268
 269                         if ((ext_table_size < EXT_HEADER_SIZE)
 270                                         || ((ext_table_size - EXT_HEADER_SIZE) % EXT_SIGNATURE_SIZE)) {
 271                                 printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
 272                                 error = -EINVAL;
 273                                 goto out;
 274                         }
 275                         if (copy_from_user(&ext_header, user_buffer + cursor
 276                                         + MC_HEADER_SIZE + data_size, EXT_HEADER_SIZE)) {
 277                                 printk(KERN_ERR "microcode: error! Can not read user data\n");
 278                                 error = -EFAULT;
 279                                 goto out;
 280                         }
 281                         if (ext_table_size != exttable_size(&ext_header)) {
 282                                 printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
 283                                 error = -EFAULT;
 284                                 goto out;
 285                         }
 286
 287                         ext_sigcount = ext_header.count;
 288
 289                         for (i = 0; i < ext_sigcount; i++) {
 290                                 if (copy_from_user(&ext_sig, user_buffer + cursor + MC_HEADER_SIZE + data_size + EXT_HEADER_SIZE
 291                                                 + EXT_SIGNATURE_SIZE * i, EXT_SIGNATURE_SIZE)) {
 292                                         printk(KERN_ERR "microcode: error! Can not read user data\n");
 293                                         error = -EFAULT;
 294                                         goto out;
 295                                 }
 296                                 for_each_online_cpu(cpu_num) {
 297                                         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 298                                         if (uci->err != MC_NOTFOUND) /* already found a match or not an online cpu*/
 299                                                 continue;
 300                                         if (sigmatch(ext_sig.sig, uci->sig, ext_sig.pf, uci->pf)) {
 301                                                 mark_microcode_update(cpu_num, &mc_header, ext_sig.sig, ext_sig.pf, ext_sig.cksum);
 302                                         }
 303                                 }
 304                         }
 305                 }
 306                 /* now check if any cpu has matched */
 307                 allocated_flag = 0;
 308                 sum = 0;
 309                 for_each_online_cpu(cpu_num) {
 310                         if (ucode_cpu_info[cpu_num].err == MC_MARKED) {
 311                                 struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 312                                 if (!allocated_flag) {
 313                                         allocated_flag = 1;
 314                                         newmc = vmalloc(total_size);
 315                                         if (!newmc) {
 316                                                 printk(KERN_ERR "microcode: error! Can not allocate memory\n");
 317                                                 error = -ENOMEM;
 318                                                 goto out;
 319                                         }
 320                                         if (copy_from_user(newmc + MC_HEADER_SIZE,
 321                                                                 user_buffer + cursor + MC_HEADER_SIZE,
 322                                                                 total_size - MC_HEADER_SIZE)) {
 323                                                 printk(KERN_ERR "microcode: error! Can not read user data\n");
 324                                                 vfree(newmc);
 325                                                 error = -EFAULT;
 326                                                 goto out;
 327                                         }
 328                                         memcpy(newmc, &mc_header, MC_HEADER_SIZE);
 329                                         /* check extended table checksum */
 330                                         if (ext_table_size) {
 331                                                 int ext_table_sum = 0;
 332                                                 int * ext_tablep = (((void *) newmc) + MC_HEADER_SIZE + data_size);
 333                                                 i = ext_table_size / DWSIZE;
 334                                                 while (i--) ext_table_sum += ext_tablep[i];
 335                                                 if (ext_table_sum) {
 336                                                         printk(KERN_WARNING "microcode: aborting, bad extended signature table checksum\n");
 337                                                         vfree(newmc);
 338                                                         error = -EINVAL;
 339                                                         goto out;
 340                                                 }
 341                                         }
 342
 343                                         /* calculate the checksum */
 344                                         i = (MC_HEADER_SIZE + data_size) / DWSIZE;
 345                                         while (i--) sum += ((int *)newmc)[i];
 346                                         sum -= (mc_header.sig + mc_header.pf + mc_header.cksum);
 347                                 }
 348                                 ucode_cpu_info[cpu_num].mc = newmc;
 349                                 ucode_cpu_info[cpu_num].err = MC_ALLOCATED; /* mc updated */
 350                                 if (sum + uci->sig + uci->pf + uci->cksum != 0) {
 351                                         printk(KERN_ERR "microcode: CPU%d aborting, bad checksum\n", cpu_num);
 352                                         error = -EINVAL;
 353                                         goto out;
 354                                 }
 355                         }
 356                 }
 357                 cursor += total_size; /* goto the next update patch */
 358         } /* end of while */
 359 out:
 360         return error;
 361 }
 362
 363 static void do_update_one (void * unused)
 364 {
 365         unsigned long flags;
 366         unsigned int val[2];
 367         int cpu_num = smp_processor_id();
 368         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 369
 370         if (uci->mc == NULL) {
 371                 return;
 372         }
 373
 374         /* serialize access to the physical write to MSR 0x79 */
 375         spin_lock_irqsave(&microcode_update_lock, flags);
 376
 377         /* write microcode via MSR 0x79 */
 378         wrmsr(MSR_IA32_UCODE_WRITE,
 379                 (unsigned long) uci->mc->bits,
 380                 (unsigned long) uci->mc->bits >> 16 >> 16);
 381         wrmsr(MSR_IA32_UCODE_REV, 0, 0);
 382
 383         /* see notes above for revision 1.07.  Apparent chip bug */
 384         sync_core();
 385
 386         /* get the current revision from MSR 0x8B */
 387         rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
 388
 389         /* notify the caller of success on this cpu */
 390         uci->err = MC_SUCCESS;
 391         spin_unlock_irqrestore(&microcode_update_lock, flags);
 392         printk(KERN_INFO "microcode: CPU%d updated from revision "
 393                "0x%x to 0x%x, date = %08x \n",
 394                cpu_num, uci->rev, val[1], uci->mc->hdr.date);
 395         return;
 396 }
 397
 398 static int do_microcode_update (void)
 399 {
 400         int i, error;
 401
 402         if (on_each_cpu(collect_cpu_info, NULL, 1, 1) != 0) {
 403                 printk(KERN_ERR "microcode: Error! Could not run on all processors\n");
 404                 error = -EIO;
 405                 goto out;
 406         }
 407
 408         if ((error = find_matching_ucodes())) {
 409                 printk(KERN_ERR "microcode: Error in the microcode data\n");
 410                 goto out_free;
 411         }
 412
 413         if (on_each_cpu(do_update_one, NULL, 1, 1) != 0) {
 414                 printk(KERN_ERR "microcode: Error! Could not run on all processors\n");
 415                 error = -EIO;
 416         }
 417
 418 out_free:
 419         for_each_online_cpu(i) {
 420                 if (ucode_cpu_info[i].mc) {
 421                         int j;
 422                         void *tmp = ucode_cpu_info[i].mc;
 423                         vfree(tmp);
 424                         for_each_online_cpu(j) {
 425                                 if (ucode_cpu_info[j].mc == tmp)
 426                                         ucode_cpu_info[j].mc = NULL;
 427                         }
 428                 }
 429         }
 430 out:
 431         return error;
 432 }
 433
 434 static ssize_t microcode_write (struct file *file, const char __user *buf, size_t len, loff_t *ppos)
 435 {
 436         ssize_t ret;
 437
 438         if (len < DEFAULT_UCODE_TOTALSIZE) {
 439                 printk(KERN_ERR "microcode: not enough data\n");
 440                 return -EINVAL;
 441         }
 442
 443         if ((len >> PAGE_SHIFT) > num_physpages) {
 444                 printk(KERN_ERR "microcode: too much data (max %ld pages)\n", num_physpages);
 445                 return -EINVAL;
 446         }
 447
 448         mutex_lock(&microcode_mutex);
 449
 450         user_buffer = (void __user *) buf;
 451         user_buffer_size = (int) len;
 452
 453         ret = do_microcode_update();
 454         if (!ret)
 455                 ret = (ssize_t)len;
 456
 457         mutex_unlock(&microcode_mutex);
 458
 459         return ret;
 460 }
 461
 462 static struct file_operations microcode_fops = {
 463         .owner          = THIS_MODULE,
 464         .write          = microcode_write,
 465         .open           = microcode_open,
 466 };
 467
 468 static struct miscdevice microcode_dev = {
 469         .minor          = MICROCODE_MINOR,
 470         .name           = "microcode",
 471         .devfs_name     = "cpu/microcode",
 472         .fops           = &microcode_fops,
 473 };
 474
 475 static int __init microcode_init (void)
 476 {
 477         int error;
 478
 479         error = misc_register(&microcode_dev);
 480         if (error) {
 481                 printk(KERN_ERR
 482                         "microcode: can't misc_register on minor=%d\n",
 483                         MICROCODE_MINOR);
 484                 return error;
 485         }
 486
 487         printk(KERN_INFO
 488                 "IA-32 Microcode Update Driver: v" MICROCODE_VERSION " <tigran@veritas.com>\n");
 489         return 0;
 490 }
 491
 492 static void __exit microcode_exit (void)
 493 {
 494         misc_deregister(&microcode_dev);
 495 }
 496
 497 module_init(microcode_init)
 498 module_exit(microcode_exit)
 499 MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);