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   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 static int verbose;
  95 module_param(verbose, int, 0644);
  96
  97 #define MICROCODE_VERSION       "1.14a"
  98
  99 #define DEFAULT_UCODE_DATASIZE  (2000)    /* 2000 bytes */
 100 #define MC_HEADER_SIZE          (sizeof (microcode_header_t))     /* 48 bytes */
 101 #define DEFAULT_UCODE_TOTALSIZE (DEFAULT_UCODE_DATASIZE + MC_HEADER_SIZE) /* 2048 bytes */
 102 #define EXT_HEADER_SIZE         (sizeof (struct extended_sigtable)) /* 20 bytes */
 103 #define EXT_SIGNATURE_SIZE      (sizeof (struct extended_signature)) /* 12 bytes */
 104 #define DWSIZE                  (sizeof (u32))
 105 #define get_totalsize(mc) \
 106         (((microcode_t *)mc)->hdr.totalsize ? \
 107          ((microcode_t *)mc)->hdr.totalsize : DEFAULT_UCODE_TOTALSIZE)
 108 #define get_datasize(mc) \
 109         (((microcode_t *)mc)->hdr.datasize ? \
 110          ((microcode_t *)mc)->hdr.datasize : DEFAULT_UCODE_DATASIZE)
 111
 112 #define sigmatch(s1, s2, p1, p2) \
 113         (((s1) == (s2)) && (((p1) & (p2)) || (((p1) == 0) && ((p2) == 0))))
 114
 115 #define exttable_size(et) ((et)->count * EXT_SIGNATURE_SIZE + EXT_HEADER_SIZE)
 116
 117 /* serialize access to the physical write to MSR 0x79 */
 118 static DEFINE_SPINLOCK(microcode_update_lock);
 119
 120 /* no concurrent ->write()s are allowed on /dev/cpu/microcode */
 121 static DEFINE_MUTEX(microcode_mutex);
 122
 123 static void __user *user_buffer;        /* user area microcode data buffer */
 124 static unsigned int user_buffer_size;   /* it's size */
 125
 126 typedef enum mc_error_code {
 127         MC_SUCCESS      = 0,
 128         MC_IGNORED      = 1,
 129         MC_NOTFOUND     = 2,
 130         MC_MARKED       = 3,
 131         MC_ALLOCATED    = 4,
 132 } mc_error_code_t;
 133
 134 static struct ucode_cpu_info {
 135         unsigned int sig;
 136         unsigned int pf, orig_pf;
 137         unsigned int rev;
 138         unsigned int cksum;
 139         mc_error_code_t err;
 140         microcode_t *mc;
 141 } ucode_cpu_info[NR_CPUS];
 142
 143 static int microcode_open (struct inode *unused1, struct file *unused2)
 144 {
 145         return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
 146 }
 147
 148 static void collect_cpu_info (void *unused)
 149 {
 150         int cpu_num = smp_processor_id();
 151         struct cpuinfo_x86 *c = cpu_data + cpu_num;
 152         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 153         unsigned int val[2];
 154
 155         uci->sig = uci->pf = uci->rev = uci->cksum = 0;
 156         uci->err = MC_NOTFOUND;
 157         uci->mc = NULL;
 158
 159         if (c->x86_vendor != X86_VENDOR_INTEL || c->x86 < 6 ||
 160                 cpu_has(c, X86_FEATURE_IA64)) {
 161                 printk(KERN_ERR "microcode: CPU%d not a capable Intel processor\n", cpu_num);
 162                 return;
 163         } else {
 164                 uci->sig = cpuid_eax(0x00000001);
 165
 166                 if ((c->x86_model >= 5) || (c->x86 > 6)) {
 167                         /* get processor flags from MSR 0x17 */
 168                         rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
 169                         uci->pf = 1 << ((val[1] >> 18) & 7);
 170                 }
 171                 uci->orig_pf = uci->pf;
 172         }
 173
 174         wrmsr(MSR_IA32_UCODE_REV, 0, 0);
 175         /* see notes above for revision 1.07.  Apparent chip bug */
 176         sync_core();
 177         /* get the current revision from MSR 0x8B */
 178         rdmsr(MSR_IA32_UCODE_REV, val[0], uci->rev);
 179         pr_debug("microcode: collect_cpu_info : sig=0x%x, pf=0x%x, rev=0x%x\n",
 180                         uci->sig, uci->pf, uci->rev);
 181 }
 182
 183 static inline void mark_microcode_update (int cpu_num, microcode_header_t *mc_header, int sig, int pf, int cksum)
 184 {
 185         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 186
 187         pr_debug("Microcode Found.\n");
 188         pr_debug("   Header Revision 0x%x\n", mc_header->hdrver);
 189         pr_debug("   Loader Revision 0x%x\n", mc_header->ldrver);
 190         pr_debug("   Revision 0x%x \n", mc_header->rev);
 191         pr_debug("   Date %x/%x/%x\n",
 192                 ((mc_header->date >> 24 ) & 0xff),
 193                 ((mc_header->date >> 16 ) & 0xff),
 194                 (mc_header->date & 0xFFFF));
 195         pr_debug("   Signature 0x%x\n", sig);
 196         pr_debug("   Type 0x%x Family 0x%x Model 0x%x Stepping 0x%x\n",
 197                 ((sig >> 12) & 0x3),
 198                 ((sig >> 8) & 0xf),
 199                 ((sig >> 4) & 0xf),
 200                 ((sig & 0xf)));
 201         pr_debug("   Processor Flags 0x%x\n", pf);
 202         pr_debug("   Checksum 0x%x\n", cksum);
 203
 204         if (mc_header->rev < uci->rev) {
 205                 if (uci->err == MC_NOTFOUND) {
 206                         uci->err = MC_IGNORED;
 207                         uci->cksum = mc_header->rev;
 208                 } else if (uci->err == MC_IGNORED && uci->cksum < mc_header->rev)
 209                         uci->cksum = mc_header->rev;
 210         } else if (mc_header->rev == uci->rev) {
 211                 if (uci->err < MC_MARKED) {
 212                         /* notify the caller of success on this cpu */
 213                         uci->err = MC_SUCCESS;
 214                 }
 215         } else if (uci->err != MC_ALLOCATED || mc_header->rev > uci->mc->hdr.rev) {
 216                 pr_debug("microcode: CPU%d found a matching microcode update with "
 217                         " revision 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
 218                 uci->cksum = cksum;
 219                 uci->pf = pf; /* keep the original mc pf for cksum calculation */
 220                 uci->err = MC_MARKED; /* found the match */
 221                 for_each_online_cpu(cpu_num) {
 222                         if (ucode_cpu_info + cpu_num != uci
 223                             && ucode_cpu_info[cpu_num].mc == uci->mc) {
 224                                 uci->mc = NULL;
 225                                 break;
 226                         }
 227                 }
 228                 if (uci->mc != NULL) {
 229                         vfree(uci->mc);
 230                         uci->mc = NULL;
 231                 }
 232         }
 233         return;
 234 }
 235
 236 static int find_matching_ucodes (void)
 237 {
 238         int cursor = 0;
 239         int error = 0;
 240
 241         while (cursor + MC_HEADER_SIZE < user_buffer_size) {
 242                 microcode_header_t mc_header;
 243                 void *newmc = NULL;
 244                 int i, sum, cpu_num, allocated_flag, total_size, data_size, ext_table_size;
 245
 246                 if (copy_from_user(&mc_header, user_buffer + cursor, MC_HEADER_SIZE)) {
 247                         printk(KERN_ERR "microcode: error! Can not read user data\n");
 248                         error = -EFAULT;
 249                         goto out;
 250                 }
 251
 252                 total_size = get_totalsize(&mc_header);
 253                 if ((cursor + total_size > user_buffer_size) || (total_size < DEFAULT_UCODE_TOTALSIZE)) {
 254                         printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
 255                         error = -EINVAL;
 256                         goto out;
 257                 }
 258
 259                 data_size = get_datasize(&mc_header);
 260                 if ((data_size + MC_HEADER_SIZE > total_size) || (data_size < DEFAULT_UCODE_DATASIZE)) {
 261                         printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
 262                         error = -EINVAL;
 263                         goto out;
 264                 }
 265
 266                 if (mc_header.ldrver != 1 || mc_header.hdrver != 1) {
 267                         printk(KERN_ERR "microcode: error! Unknown microcode update format\n");
 268                         error = -EINVAL;
 269                         goto out;
 270                 }
 271
 272                 for_each_online_cpu(cpu_num) {
 273                         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 274
 275                         if (sigmatch(mc_header.sig, uci->sig, mc_header.pf, uci->orig_pf))
 276                                 mark_microcode_update(cpu_num, &mc_header, mc_header.sig, mc_header.pf, mc_header.cksum);
 277                 }
 278
 279                 ext_table_size = total_size - (MC_HEADER_SIZE + data_size);
 280                 if (ext_table_size) {
 281                         struct extended_sigtable ext_header;
 282                         struct extended_signature ext_sig;
 283                         int ext_sigcount;
 284
 285                         if ((ext_table_size < EXT_HEADER_SIZE)
 286                                         || ((ext_table_size - EXT_HEADER_SIZE) % EXT_SIGNATURE_SIZE)) {
 287                                 printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
 288                                 error = -EINVAL;
 289                                 goto out;
 290                         }
 291                         if (copy_from_user(&ext_header, user_buffer + cursor
 292                                         + MC_HEADER_SIZE + data_size, EXT_HEADER_SIZE)) {
 293                                 printk(KERN_ERR "microcode: error! Can not read user data\n");
 294                                 error = -EFAULT;
 295                                 goto out;
 296                         }
 297                         if (ext_table_size != exttable_size(&ext_header)) {
 298                                 printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
 299                                 error = -EFAULT;
 300                                 goto out;
 301                         }
 302
 303                         ext_sigcount = ext_header.count;
 304
 305                         for (i = 0; i < ext_sigcount; i++) {
 306                                 if (copy_from_user(&ext_sig, user_buffer + cursor + MC_HEADER_SIZE + data_size + EXT_HEADER_SIZE
 307                                                 + EXT_SIGNATURE_SIZE * i, EXT_SIGNATURE_SIZE)) {
 308                                         printk(KERN_ERR "microcode: error! Can not read user data\n");
 309                                         error = -EFAULT;
 310                                         goto out;
 311                                 }
 312                                 for_each_online_cpu(cpu_num) {
 313                                         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 314
 315                                         if (sigmatch(ext_sig.sig, uci->sig, ext_sig.pf, uci->orig_pf)) {
 316                                                 mark_microcode_update(cpu_num, &mc_header, ext_sig.sig, ext_sig.pf, ext_sig.cksum);
 317                                         }
 318                                 }
 319                         }
 320                 }
 321                 /* now check if any cpu has matched */
 322                 allocated_flag = 0;
 323                 sum = 0;
 324                 for_each_online_cpu(cpu_num) {
 325                         if (ucode_cpu_info[cpu_num].err == MC_MARKED) {
 326                                 struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 327                                 if (!allocated_flag) {
 328                                         allocated_flag = 1;
 329                                         newmc = vmalloc(total_size);
 330                                         if (!newmc) {
 331                                                 printk(KERN_ERR "microcode: error! Can not allocate memory\n");
 332                                                 error = -ENOMEM;
 333                                                 goto out;
 334                                         }
 335                                         if (copy_from_user(newmc + MC_HEADER_SIZE,
 336                                                                 user_buffer + cursor + MC_HEADER_SIZE,
 337                                                                 total_size - MC_HEADER_SIZE)) {
 338                                                 printk(KERN_ERR "microcode: error! Can not read user data\n");
 339                                                 vfree(newmc);
 340                                                 error = -EFAULT;
 341                                                 goto out;
 342                                         }
 343                                         memcpy(newmc, &mc_header, MC_HEADER_SIZE);
 344                                         /* check extended table checksum */
 345                                         if (ext_table_size) {
 346                                                 int ext_table_sum = 0;
 347                                                 int * ext_tablep = (((void *) newmc) + MC_HEADER_SIZE + data_size);
 348                                                 i = ext_table_size / DWSIZE;
 349                                                 while (i--) ext_table_sum += ext_tablep[i];
 350                                                 if (ext_table_sum) {
 351                                                         printk(KERN_WARNING "microcode: aborting, bad extended signature table checksum\n");
 352                                                         vfree(newmc);
 353                                                         error = -EINVAL;
 354                                                         goto out;
 355                                                 }
 356                                         }
 357
 358                                         /* calculate the checksum */
 359                                         i = (MC_HEADER_SIZE + data_size) / DWSIZE;
 360                                         while (i--) sum += ((int *)newmc)[i];
 361                                         sum -= (mc_header.sig + mc_header.pf + mc_header.cksum);
 362                                 }
 363                                 ucode_cpu_info[cpu_num].mc = newmc;
 364                                 ucode_cpu_info[cpu_num].err = MC_ALLOCATED; /* mc updated */
 365                                 if (sum + uci->sig + uci->pf + uci->cksum != 0) {
 366                                         printk(KERN_ERR "microcode: CPU%d aborting, bad checksum\n", cpu_num);
 367                                         error = -EINVAL;
 368                                         goto out;
 369                                 }
 370                         }
 371                 }
 372                 cursor += total_size; /* goto the next update patch */
 373         } /* end of while */
 374 out:
 375         return error;
 376 }
 377
 378 static void do_update_one (void * unused)
 379 {
 380         unsigned long flags;
 381         unsigned int val[2];
 382         int cpu_num = smp_processor_id();
 383         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 384
 385         if (uci->mc == NULL) {
 386                 if (verbose) {
 387                         if (uci->err == MC_SUCCESS)
 388                                 printk(KERN_INFO "microcode: CPU%d already at revision 0x%x\n",
 389                                         cpu_num, uci->rev);
 390                         else
 391                                 printk(KERN_INFO "microcode: No new microcode data for CPU%d\n", cpu_num);
 392                 }
 393                 return;
 394         }
 395
 396         /* serialize access to the physical write to MSR 0x79 */
 397         spin_lock_irqsave(&microcode_update_lock, flags);
 398
 399         /* write microcode via MSR 0x79 */
 400         wrmsr(MSR_IA32_UCODE_WRITE,
 401                 (unsigned long) uci->mc->bits,
 402                 (unsigned long) uci->mc->bits >> 16 >> 16);
 403         wrmsr(MSR_IA32_UCODE_REV, 0, 0);
 404
 405         /* see notes above for revision 1.07.  Apparent chip bug */
 406         sync_core();
 407
 408         /* get the current revision from MSR 0x8B */
 409         rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
 410
 411         /* notify the caller of success on this cpu */
 412         uci->err = MC_SUCCESS;
 413         spin_unlock_irqrestore(&microcode_update_lock, flags);
 414         printk(KERN_INFO "microcode: CPU%d updated from revision "
 415                "0x%x to 0x%x, date = %08x \n",
 416                cpu_num, uci->rev, val[1], uci->mc->hdr.date);
 417         return;
 418 }
 419
 420 static int do_microcode_update (void)
 421 {
 422         int i, error;
 423
 424         if (on_each_cpu(collect_cpu_info, NULL, 1, 1) != 0) {
 425                 printk(KERN_ERR "microcode: Error! Could not run on all processors\n");
 426                 error = -EIO;
 427                 goto out;
 428         }
 429
 430         if ((error = find_matching_ucodes())) {
 431                 printk(KERN_ERR "microcode: Error in the microcode data\n");
 432                 goto out_free;
 433         }
 434
 435         if (on_each_cpu(do_update_one, NULL, 1, 1) != 0) {
 436                 printk(KERN_ERR "microcode: Error! Could not run on all processors\n");
 437                 error = -EIO;
 438         }
 439
 440 out_free:
 441         for_each_online_cpu(i) {
 442                 if (ucode_cpu_info[i].mc) {
 443                         int j;
 444                         void *tmp = ucode_cpu_info[i].mc;
 445                         vfree(tmp);
 446                         for_each_online_cpu(j) {
 447                                 if (ucode_cpu_info[j].mc == tmp)
 448                                         ucode_cpu_info[j].mc = NULL;
 449                         }
 450                 }
 451                 if (ucode_cpu_info[i].err == MC_IGNORED && verbose)
 452                         printk(KERN_WARNING "microcode: CPU%d not 'upgrading' to earlier revision"
 453                                " 0x%x (current=0x%x)\n", i, ucode_cpu_info[i].cksum, ucode_cpu_info[i].rev);
 454         }
 455 out:
 456         return error;
 457 }
 458
 459 static ssize_t microcode_write (struct file *file, const char __user *buf, size_t len, loff_t *ppos)
 460 {
 461         ssize_t ret;
 462
 463         if (len < DEFAULT_UCODE_TOTALSIZE) {
 464                 printk(KERN_ERR "microcode: not enough data\n");
 465                 return -EINVAL;
 466         }
 467
 468         if ((len >> PAGE_SHIFT) > num_physpages) {
 469                 printk(KERN_ERR "microcode: too much data (max %ld pages)\n", num_physpages);
 470                 return -EINVAL;
 471         }
 472
 473         mutex_lock(&microcode_mutex);
 474
 475         user_buffer = (void __user *) buf;
 476         user_buffer_size = (int) len;
 477
 478         ret = do_microcode_update();
 479         if (!ret)
 480                 ret = (ssize_t)len;
 481
 482         mutex_unlock(&microcode_mutex);
 483
 484         return ret;
 485 }
 486
 487 static struct file_operations microcode_fops = {
 488         .owner          = THIS_MODULE,
 489         .write          = microcode_write,
 490         .open           = microcode_open,
 491 };
 492
 493 static struct miscdevice microcode_dev = {
 494         .minor          = MICROCODE_MINOR,
 495         .name           = "microcode",
 496         .fops           = &microcode_fops,
 497 };
 498
 499 static int __init microcode_init (void)
 500 {
 501         int error;
 502
 503         error = misc_register(&microcode_dev);
 504         if (error) {
 505                 printk(KERN_ERR
 506                         "microcode: can't misc_register on minor=%d\n",
 507                         MICROCODE_MINOR);
 508                 return error;
 509         }
 510
 511         printk(KERN_INFO
 512                 "IA-32 Microcode Update Driver: v" MICROCODE_VERSION " <tigran@veritas.com>\n");
 513         return 0;
 514 }
 515
 516 static void __exit microcode_exit (void)
 517 {
 518         misc_deregister(&microcode_dev);
 519 }
 520
 521 module_init(microcode_init)
 522 module_exit(microcode_exit)
 523 MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);