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/module.h>
  78 #include <linux/slab.h>
  79 #include <linux/vmalloc.h>
  80 #include <linux/miscdevice.h>
  81 #include <linux/spinlock.h>
  82 #include <linux/mm.h>
  83
  84 #include <asm/msr.h>
  85 #include <asm/uaccess.h>
  86 #include <asm/processor.h>
  87
  88 MODULE_DESCRIPTION("Intel CPU (IA-32) Microcode Update Driver");
  89 MODULE_AUTHOR("Tigran Aivazian <tigran@veritas.com>");
  90 MODULE_LICENSE("GPL");
  91
  92 #define MICROCODE_VERSION       "1.14"
  93
  94 #define DEFAULT_UCODE_DATASIZE  (2000)    /* 2000 bytes */
  95 #define MC_HEADER_SIZE          (sizeof (microcode_header_t))     /* 48 bytes */
  96 #define DEFAULT_UCODE_TOTALSIZE (DEFAULT_UCODE_DATASIZE + MC_HEADER_SIZE) /* 2048 bytes */
  97 #define EXT_HEADER_SIZE         (sizeof (struct extended_sigtable)) /* 20 bytes */
  98 #define EXT_SIGNATURE_SIZE      (sizeof (struct extended_signature)) /* 12 bytes */
  99 #define DWSIZE                  (sizeof (u32))
 100 #define get_totalsize(mc) \
 101         (((microcode_t *)mc)->hdr.totalsize ? \
 102          ((microcode_t *)mc)->hdr.totalsize : DEFAULT_UCODE_TOTALSIZE)
 103 #define get_datasize(mc) \
 104         (((microcode_t *)mc)->hdr.datasize ? \
 105          ((microcode_t *)mc)->hdr.datasize : DEFAULT_UCODE_DATASIZE)
 106
 107 #define sigmatch(s1, s2, p1, p2) \
 108         (((s1) == (s2)) && (((p1) & (p2)) || (((p1) == 0) && ((p2) == 0))))
 109
 110 #define exttable_size(et) ((et)->count * EXT_SIGNATURE_SIZE + EXT_HEADER_SIZE)
 111
 112 /* serialize access to the physical write to MSR 0x79 */
 113 static DEFINE_SPINLOCK(microcode_update_lock);
 114
 115 /* no concurrent ->write()s are allowed on /dev/cpu/microcode */
 116 static DECLARE_MUTEX(microcode_sem);
 117
 118 static void __user *user_buffer;        /* user area microcode data buffer */
 119 static unsigned int user_buffer_size;   /* it's size */
 120
 121 typedef enum mc_error_code {
 122         MC_SUCCESS      = 0,
 123         MC_NOTFOUND     = 1,
 124         MC_MARKED       = 2,
 125         MC_ALLOCATED    = 3,
 126 } mc_error_code_t;
 127
 128 static struct ucode_cpu_info {
 129         unsigned int sig;
 130         unsigned int pf;
 131         unsigned int rev;
 132         unsigned int cksum;
 133         mc_error_code_t err;
 134         microcode_t *mc;
 135 } ucode_cpu_info[NR_CPUS];
 136
 137 static int microcode_open (struct inode *unused1, struct file *unused2)
 138 {
 139         return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
 140 }
 141
 142 static void collect_cpu_info (void *unused)
 143 {
 144         int cpu_num = smp_processor_id();
 145         struct cpuinfo_x86 *c = cpu_data + cpu_num;
 146         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 147         unsigned int val[2];
 148
 149         uci->sig = uci->pf = uci->rev = uci->cksum = 0;
 150         uci->err = MC_NOTFOUND;
 151         uci->mc = NULL;
 152
 153         if (c->x86_vendor != X86_VENDOR_INTEL || c->x86 < 6 ||
 154                 cpu_has(c, X86_FEATURE_IA64)) {
 155                 printk(KERN_ERR "microcode: CPU%d not a capable Intel processor\n", cpu_num);
 156                 return;
 157         } else {
 158                 uci->sig = cpuid_eax(0x00000001);
 159
 160                 if ((c->x86_model >= 5) || (c->x86 > 6)) {
 161                         /* get processor flags from MSR 0x17 */
 162                         rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
 163                         uci->pf = 1 << ((val[1] >> 18) & 7);
 164                 }
 165         }
 166
 167         wrmsr(MSR_IA32_UCODE_REV, 0, 0);
 168         /* see notes above for revision 1.07.  Apparent chip bug */
 169         sync_core();
 170         /* get the current revision from MSR 0x8B */
 171         rdmsr(MSR_IA32_UCODE_REV, val[0], uci->rev);
 172         pr_debug("microcode: collect_cpu_info : sig=0x%x, pf=0x%x, rev=0x%x\n",
 173                         uci->sig, uci->pf, uci->rev);
 174 }
 175
 176 static inline void mark_microcode_update (int cpu_num, microcode_header_t *mc_header, int sig, int pf, int cksum)
 177 {
 178         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 179
 180         pr_debug("Microcode Found.\n");
 181         pr_debug("   Header Revision 0x%x\n", mc_header->hdrver);
 182         pr_debug("   Loader Revision 0x%x\n", mc_header->ldrver);
 183         pr_debug("   Revision 0x%x \n", mc_header->rev);
 184         pr_debug("   Date %x/%x/%x\n",
 185                 ((mc_header->date >> 24 ) & 0xff),
 186                 ((mc_header->date >> 16 ) & 0xff),
 187                 (mc_header->date & 0xFFFF));
 188         pr_debug("   Signature 0x%x\n", sig);
 189         pr_debug("   Type 0x%x Family 0x%x Model 0x%x Stepping 0x%x\n",
 190                 ((sig >> 12) & 0x3),
 191                 ((sig >> 8) & 0xf),
 192                 ((sig >> 4) & 0xf),
 193                 ((sig & 0xf)));
 194         pr_debug("   Processor Flags 0x%x\n", pf);
 195         pr_debug("   Checksum 0x%x\n", cksum);
 196
 197         if (mc_header->rev < uci->rev) {
 198                 printk(KERN_ERR "microcode: CPU%d not 'upgrading' to earlier revision"
 199                        " 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
 200                 goto out;
 201         } else if (mc_header->rev == uci->rev) {
 202                 /* notify the caller of success on this cpu */
 203                 uci->err = MC_SUCCESS;
 204                 printk(KERN_ERR "microcode: CPU%d already at revision"
 205                         " 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
 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 (cpu_num = 0; cpu_num < num_online_cpus(); 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 (cpu_num = 0; cpu_num < num_online_cpus(); 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                 for (cpu_num = 0, allocated_flag = 0, sum = 0; cpu_num < num_online_cpus(); cpu_num++) {
 308                         if (ucode_cpu_info[cpu_num].err == MC_MARKED) {
 309                                 struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 310                                 if (!allocated_flag) {
 311                                         allocated_flag = 1;
 312                                         newmc = vmalloc(total_size);
 313                                         if (!newmc) {
 314                                                 printk(KERN_ERR "microcode: error! Can not allocate memory\n");
 315                                                 error = -ENOMEM;
 316                                                 goto out;
 317                                         }
 318                                         if (copy_from_user(newmc + MC_HEADER_SIZE,
 319                                                                 user_buffer + cursor + MC_HEADER_SIZE,
 320                                                                 total_size - MC_HEADER_SIZE)) {
 321                                                 printk(KERN_ERR "microcode: error! Can not read user data\n");
 322                                                 vfree(newmc);
 323                                                 error = -EFAULT;
 324                                                 goto out;
 325                                         }
 326                                         memcpy(newmc, &mc_header, MC_HEADER_SIZE);
 327                                         /* check extended table checksum */
 328                                         if (ext_table_size) {
 329                                                 int ext_table_sum = 0;
 330                                                 int * ext_tablep = (((void *) newmc) + MC_HEADER_SIZE + data_size);
 331                                                 i = ext_table_size / DWSIZE;
 332                                                 while (i--) ext_table_sum += ext_tablep[i];
 333                                                 if (ext_table_sum) {
 334                                                         printk(KERN_WARNING "microcode: aborting, bad extended signature table checksum\n");
 335                                                         vfree(newmc);
 336                                                         error = -EINVAL;
 337                                                         goto out;
 338                                                 }
 339                                         }
 340
 341                                         /* calculate the checksum */
 342                                         i = (MC_HEADER_SIZE + data_size) / DWSIZE;
 343                                         while (i--) sum += ((int *)newmc)[i];
 344                                         sum -= (mc_header.sig + mc_header.pf + mc_header.cksum);
 345                                 }
 346                                 ucode_cpu_info[cpu_num].mc = newmc;
 347                                 ucode_cpu_info[cpu_num].err = MC_ALLOCATED; /* mc updated */
 348                                 if (sum + uci->sig + uci->pf + uci->cksum != 0) {
 349                                         printk(KERN_ERR "microcode: CPU%d aborting, bad checksum\n", cpu_num);
 350                                         error = -EINVAL;
 351                                         goto out;
 352                                 }
 353                         }
 354                 }
 355                 cursor += total_size; /* goto the next update patch */
 356         } /* end of while */
 357 out:
 358         return error;
 359 }
 360
 361 static void do_update_one (void * unused)
 362 {
 363         unsigned long flags;
 364         unsigned int val[2];
 365         int cpu_num = smp_processor_id();
 366         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 367
 368         if (uci->mc == NULL) {
 369                 printk(KERN_INFO "microcode: No new microcode data for CPU%d\n", cpu_num);
 370                 return;
 371         }
 372
 373         /* serialize access to the physical write to MSR 0x79 */
 374         spin_lock_irqsave(&microcode_update_lock, flags);
 375
 376         /* write microcode via MSR 0x79 */
 377         wrmsr(MSR_IA32_UCODE_WRITE,
 378                 (unsigned long) uci->mc->bits,
 379                 (unsigned long) uci->mc->bits >> 16 >> 16);
 380         wrmsr(MSR_IA32_UCODE_REV, 0, 0);
 381
 382         /* see notes above for revision 1.07.  Apparent chip bug */
 383         sync_core();
 384
 385         /* get the current revision from MSR 0x8B */
 386         rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
 387
 388         /* notify the caller of success on this cpu */
 389         uci->err = MC_SUCCESS;
 390         spin_unlock_irqrestore(&microcode_update_lock, flags);
 391         printk(KERN_INFO "microcode: CPU%d updated from revision "
 392                "0x%x to 0x%x, date = %08x \n",
 393                cpu_num, uci->rev, val[1], uci->mc->hdr.date);
 394         return;
 395 }
 396
 397 static int do_microcode_update (void)
 398 {
 399         int i, error;
 400
 401         if (on_each_cpu(collect_cpu_info, NULL, 1, 1) != 0) {
 402                 printk(KERN_ERR "microcode: Error! Could not run on all processors\n");
 403                 error = -EIO;
 404                 goto out;
 405         }
 406
 407         if ((error = find_matching_ucodes())) {
 408                 printk(KERN_ERR "microcode: Error in the microcode data\n");
 409                 goto out_free;
 410         }
 411
 412         if (on_each_cpu(do_update_one, NULL, 1, 1) != 0) {
 413                 printk(KERN_ERR "microcode: Error! Could not run on all processors\n");
 414                 error = -EIO;
 415         }
 416
 417 out_free:
 418         for (i = 0; i < num_online_cpus(); i++) {
 419                 if (ucode_cpu_info[i].mc) {
 420                         int j;
 421                         void *tmp = ucode_cpu_info[i].mc;
 422                         vfree(tmp);
 423                         for (j = i; j < num_online_cpus(); j++) {
 424                                 if (ucode_cpu_info[j].mc == tmp)
 425                                         ucode_cpu_info[j].mc = NULL;
 426                         }
 427                 }
 428         }
 429 out:
 430         return error;
 431 }
 432
 433 static ssize_t microcode_write (struct file *file, const char __user *buf, size_t len, loff_t *ppos)
 434 {
 435         ssize_t ret;
 436
 437         if (len < DEFAULT_UCODE_TOTALSIZE) {
 438                 printk(KERN_ERR "microcode: not enough data\n");
 439                 return -EINVAL;
 440         }
 441
 442         if ((len >> PAGE_SHIFT) > num_physpages) {
 443                 printk(KERN_ERR "microcode: too much data (max %ld pages)\n", num_physpages);
 444                 return -EINVAL;
 445         }
 446
 447         down(&microcode_sem);
 448
 449         user_buffer = (void __user *) buf;
 450         user_buffer_size = (int) len;
 451
 452         ret = do_microcode_update();
 453         if (!ret)
 454                 ret = (ssize_t)len;
 455
 456         up(&microcode_sem);
 457
 458         return ret;
 459 }
 460
 461 static int microcode_ioctl (struct inode *inode, struct file *file,
 462                 unsigned int cmd, unsigned long arg)
 463 {
 464         switch (cmd) {
 465                 /*
 466                  *  XXX: will be removed after microcode_ctl
 467                  *  is updated to ignore failure of this ioctl()
 468                  */
 469                 case MICROCODE_IOCFREE:
 470                         return 0;
 471                 default:
 472                         return -EINVAL;
 473         }
 474         return -EINVAL;
 475 }
 476
 477 static struct file_operations microcode_fops = {
 478         .owner          = THIS_MODULE,
 479         .write          = microcode_write,
 480         .ioctl          = microcode_ioctl,
 481         .open           = microcode_open,
 482 };
 483
 484 static struct miscdevice microcode_dev = {
 485         .minor          = MICROCODE_MINOR,
 486         .name           = "microcode",
 487         .devfs_name     = "cpu/microcode",
 488         .fops           = &microcode_fops,
 489 };
 490
 491 static int __init microcode_init (void)
 492 {
 493         int error;
 494
 495         error = misc_register(&microcode_dev);
 496         if (error) {
 497                 printk(KERN_ERR
 498                         "microcode: can't misc_register on minor=%d\n",
 499                         MICROCODE_MINOR);
 500                 return error;
 501         }
 502
 503         printk(KERN_INFO
 504                 "IA-32 Microcode Update Driver: v" MICROCODE_VERSION " <tigran@veritas.com>\n");
 505         return 0;
 506 }
 507
 508 static void __exit microcode_exit (void)
 509 {
 510         misc_deregister(&microcode_dev);
 511         printk(KERN_INFO "IA-32 Microcode Update Driver v" MICROCODE_VERSION " unregistered\n");
 512 }
 513
 514 module_init(microcode_init)
 515 module_exit(microcode_exit)
 516 MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);