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/kernel.h>
  74 #include <linux/init.h>
  75 #include <linux/sched.h>
  76 #include <linux/module.h>
  77 #include <linux/slab.h>
  78 #include <linux/vmalloc.h>
  79 #include <linux/miscdevice.h>
  80 #include <linux/spinlock.h>
  81 #include <linux/mm.h>
  82
  83 #include <asm/msr.h>
  84 #include <asm/uaccess.h>
  85 #include <asm/processor.h>
  86
  87 MODULE_DESCRIPTION("Intel CPU (IA-32) Microcode Update Driver");
  88 MODULE_AUTHOR("Tigran Aivazian <tigran@veritas.com>");
  89 MODULE_LICENSE("GPL");
  90
  91 #define MICROCODE_VERSION       "1.14"
  92
  93 #define DEFAULT_UCODE_DATASIZE  (2000)    /* 2000 bytes */
  94 #define MC_HEADER_SIZE          (sizeof (microcode_header_t))     /* 48 bytes */
  95 #define DEFAULT_UCODE_TOTALSIZE (DEFAULT_UCODE_DATASIZE + MC_HEADER_SIZE) /* 2048 bytes */
  96 #define EXT_HEADER_SIZE         (sizeof (struct extended_sigtable)) /* 20 bytes */
  97 #define EXT_SIGNATURE_SIZE      (sizeof (struct extended_signature)) /* 12 bytes */
  98 #define DWSIZE                  (sizeof (u32))
  99 #define get_totalsize(mc) \
 100         (((microcode_t *)mc)->hdr.totalsize ? \
 101          ((microcode_t *)mc)->hdr.totalsize : DEFAULT_UCODE_TOTALSIZE)
 102 #define get_datasize(mc) \
 103         (((microcode_t *)mc)->hdr.datasize ? \
 104          ((microcode_t *)mc)->hdr.datasize : DEFAULT_UCODE_DATASIZE)
 105
 106 #define sigmatch(s1, s2, p1, p2) \
 107         (((s1) == (s2)) && (((p1) & (p2)) || (((p1) == 0) && ((p2) == 0))))
 108
 109 #define exttable_size(et) ((et)->count * EXT_SIGNATURE_SIZE + EXT_HEADER_SIZE)
 110
 111 /* serialize access to the physical write to MSR 0x79 */
 112 static DEFINE_SPINLOCK(microcode_update_lock);
 113
 114 /* no concurrent ->write()s are allowed on /dev/cpu/microcode */
 115 static DECLARE_MUTEX(microcode_sem);
 116
 117 static void __user *user_buffer;        /* user area microcode data buffer */
 118 static unsigned int user_buffer_size;   /* it's size */
 119
 120 typedef enum mc_error_code {
 121         MC_SUCCESS      = 0,
 122         MC_NOTFOUND     = 1,
 123         MC_MARKED       = 2,
 124         MC_ALLOCATED    = 3,
 125 } mc_error_code_t;
 126
 127 static struct ucode_cpu_info {
 128         unsigned int sig;
 129         unsigned int pf;
 130         unsigned int rev;
 131         unsigned int cksum;
 132         mc_error_code_t err;
 133         microcode_t *mc;
 134 } ucode_cpu_info[NR_CPUS];
 135
 136 static int microcode_open (struct inode *unused1, struct file *unused2)
 137 {
 138         return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
 139 }
 140
 141 static void collect_cpu_info (void *unused)
 142 {
 143         int cpu_num = smp_processor_id();
 144         struct cpuinfo_x86 *c = cpu_data + cpu_num;
 145         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 146         unsigned int val[2];
 147
 148         uci->sig = uci->pf = uci->rev = uci->cksum = 0;
 149         uci->err = MC_NOTFOUND;
 150         uci->mc = NULL;
 151
 152         if (c->x86_vendor != X86_VENDOR_INTEL || c->x86 < 6 ||
 153                 cpu_has(c, X86_FEATURE_IA64)) {
 154                 printk(KERN_ERR "microcode: CPU%d not a capable Intel processor\n", cpu_num);
 155                 return;
 156         } else {
 157                 uci->sig = cpuid_eax(0x00000001);
 158
 159                 if ((c->x86_model >= 5) || (c->x86 > 6)) {
 160                         /* get processor flags from MSR 0x17 */
 161                         rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
 162                         uci->pf = 1 << ((val[1] >> 18) & 7);
 163                 }
 164         }
 165
 166         wrmsr(MSR_IA32_UCODE_REV, 0, 0);
 167         __asm__ __volatile__ ("cpuid" : : : "ax", "bx", "cx", "dx");
 168         /* get the current revision from MSR 0x8B */
 169         rdmsr(MSR_IA32_UCODE_REV, val[0], uci->rev);
 170         pr_debug("microcode: collect_cpu_info : sig=0x%x, pf=0x%x, rev=0x%x\n",
 171                         uci->sig, uci->pf, uci->rev);
 172 }
 173
 174 static inline void mark_microcode_update (int cpu_num, microcode_header_t *mc_header, int sig, int pf, int cksum)
 175 {
 176         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 177
 178         pr_debug("Microcode Found.\n");
 179         pr_debug("   Header Revision 0x%x\n", mc_header->hdrver);
 180         pr_debug("   Loader Revision 0x%x\n", mc_header->ldrver);
 181         pr_debug("   Revision 0x%x \n", mc_header->rev);
 182         pr_debug("   Date %x/%x/%x\n",
 183                 ((mc_header->date >> 24 ) & 0xff),
 184                 ((mc_header->date >> 16 ) & 0xff),
 185                 (mc_header->date & 0xFFFF));
 186         pr_debug("   Signature 0x%x\n", sig);
 187         pr_debug("   Type 0x%x Family 0x%x Model 0x%x Stepping 0x%x\n",
 188                 ((sig >> 12) & 0x3),
 189                 ((sig >> 8) & 0xf),
 190                 ((sig >> 4) & 0xf),
 191                 ((sig & 0xf)));
 192         pr_debug("   Processor Flags 0x%x\n", pf);
 193         pr_debug("   Checksum 0x%x\n", cksum);
 194
 195         if (mc_header->rev < uci->rev) {
 196                 printk(KERN_ERR "microcode: CPU%d not 'upgrading' to earlier revision"
 197                        " 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
 198                 goto out;
 199         } else if (mc_header->rev == uci->rev) {
 200                 /* notify the caller of success on this cpu */
 201                 uci->err = MC_SUCCESS;
 202                 printk(KERN_ERR "microcode: CPU%d already at revision"
 203                         " 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
 204                 goto out;
 205         }
 206
 207         pr_debug("microcode: CPU%d found a matching microcode update with "
 208                 " revision 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
 209         uci->cksum = cksum;
 210         uci->pf = pf; /* keep the original mc pf for cksum calculation */
 211         uci->err = MC_MARKED; /* found the match */
 212 out:
 213         return;
 214 }
 215
 216 static int find_matching_ucodes (void)
 217 {
 218         int cursor = 0;
 219         int error = 0;
 220
 221         while (cursor + MC_HEADER_SIZE < user_buffer_size) {
 222                 microcode_header_t mc_header;
 223                 void *newmc = NULL;
 224                 int i, sum, cpu_num, allocated_flag, total_size, data_size, ext_table_size;
 225
 226                 if (copy_from_user(&mc_header, user_buffer + cursor, MC_HEADER_SIZE)) {
 227                         printk(KERN_ERR "microcode: error! Can not read user data\n");
 228                         error = -EFAULT;
 229                         goto out;
 230                 }
 231
 232                 total_size = get_totalsize(&mc_header);
 233                 if ((cursor + total_size > user_buffer_size) || (total_size < DEFAULT_UCODE_TOTALSIZE)) {
 234                         printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
 235                         error = -EINVAL;
 236                         goto out;
 237                 }
 238
 239                 data_size = get_datasize(&mc_header);
 240                 if ((data_size + MC_HEADER_SIZE > total_size) || (data_size < DEFAULT_UCODE_DATASIZE)) {
 241                         printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
 242                         error = -EINVAL;
 243                         goto out;
 244                 }
 245
 246                 if (mc_header.ldrver != 1 || mc_header.hdrver != 1) {
 247                         printk(KERN_ERR "microcode: error! Unknown microcode update format\n");
 248                         error = -EINVAL;
 249                         goto out;
 250                 }
 251
 252                 for (cpu_num = 0; cpu_num < num_online_cpus(); cpu_num++) {
 253                         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 254                         if (uci->err != MC_NOTFOUND) /* already found a match or not an online cpu*/
 255                                 continue;
 256
 257                         if (sigmatch(mc_header.sig, uci->sig, mc_header.pf, uci->pf))
 258                                 mark_microcode_update(cpu_num, &mc_header, mc_header.sig, mc_header.pf, mc_header.cksum);
 259                 }
 260
 261                 ext_table_size = total_size - (MC_HEADER_SIZE + data_size);
 262                 if (ext_table_size) {
 263                         struct extended_sigtable ext_header;
 264                         struct extended_signature ext_sig;
 265                         int ext_sigcount;
 266
 267                         if ((ext_table_size < EXT_HEADER_SIZE)
 268                                         || ((ext_table_size - EXT_HEADER_SIZE) % EXT_SIGNATURE_SIZE)) {
 269                                 printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
 270                                 error = -EINVAL;
 271                                 goto out;
 272                         }
 273                         if (copy_from_user(&ext_header, user_buffer + cursor
 274                                         + MC_HEADER_SIZE + data_size, EXT_HEADER_SIZE)) {
 275                                 printk(KERN_ERR "microcode: error! Can not read user data\n");
 276                                 error = -EFAULT;
 277                                 goto out;
 278                         }
 279                         if (ext_table_size != exttable_size(&ext_header)) {
 280                                 printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
 281                                 error = -EFAULT;
 282                                 goto out;
 283                         }
 284
 285                         ext_sigcount = ext_header.count;
 286
 287                         for (i = 0; i < ext_sigcount; i++) {
 288                                 if (copy_from_user(&ext_sig, user_buffer + cursor + MC_HEADER_SIZE + data_size + EXT_HEADER_SIZE
 289                                                 + EXT_SIGNATURE_SIZE * i, EXT_SIGNATURE_SIZE)) {
 290                                         printk(KERN_ERR "microcode: error! Can not read user data\n");
 291                                         error = -EFAULT;
 292                                         goto out;
 293                                 }
 294                                 for (cpu_num = 0; cpu_num < num_online_cpus(); cpu_num++) {
 295                                         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 296                                         if (uci->err != MC_NOTFOUND) /* already found a match or not an online cpu*/
 297                                                 continue;
 298                                         if (sigmatch(ext_sig.sig, uci->sig, ext_sig.pf, uci->pf)) {
 299                                                 mark_microcode_update(cpu_num, &mc_header, ext_sig.sig, ext_sig.pf, ext_sig.cksum);
 300                                         }
 301                                 }
 302                         }
 303                 }
 304                 /* now check if any cpu has matched */
 305                 for (cpu_num = 0, allocated_flag = 0, sum = 0; cpu_num < num_online_cpus(); cpu_num++) {
 306                         if (ucode_cpu_info[cpu_num].err == MC_MARKED) {
 307                                 struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 308                                 if (!allocated_flag) {
 309                                         allocated_flag = 1;
 310                                         newmc = vmalloc(total_size);
 311                                         if (!newmc) {
 312                                                 printk(KERN_ERR "microcode: error! Can not allocate memory\n");
 313                                                 error = -ENOMEM;
 314                                                 goto out;
 315                                         }
 316                                         if (copy_from_user(newmc + MC_HEADER_SIZE,
 317                                                                 user_buffer + cursor + MC_HEADER_SIZE,
 318                                                                 total_size - MC_HEADER_SIZE)) {
 319                                                 printk(KERN_ERR "microcode: error! Can not read user data\n");
 320                                                 vfree(newmc);
 321                                                 error = -EFAULT;
 322                                                 goto out;
 323                                         }
 324                                         memcpy(newmc, &mc_header, MC_HEADER_SIZE);
 325                                         /* check extended table checksum */
 326                                         if (ext_table_size) {
 327                                                 int ext_table_sum = 0;
 328                                                 int * ext_tablep = (((void *) newmc) + MC_HEADER_SIZE + data_size);
 329                                                 i = ext_table_size / DWSIZE;
 330                                                 while (i--) ext_table_sum += ext_tablep[i];
 331                                                 if (ext_table_sum) {
 332                                                         printk(KERN_WARNING "microcode: aborting, bad extended signature table checksum\n");
 333                                                         vfree(newmc);
 334                                                         error = -EINVAL;
 335                                                         goto out;
 336                                                 }
 337                                         }
 338
 339                                         /* calculate the checksum */
 340                                         i = (MC_HEADER_SIZE + data_size) / DWSIZE;
 341                                         while (i--) sum += ((int *)newmc)[i];
 342                                         sum -= (mc_header.sig + mc_header.pf + mc_header.cksum);
 343                                 }
 344                                 ucode_cpu_info[cpu_num].mc = newmc;
 345                                 ucode_cpu_info[cpu_num].err = MC_ALLOCATED; /* mc updated */
 346                                 if (sum + uci->sig + uci->pf + uci->cksum != 0) {
 347                                         printk(KERN_ERR "microcode: CPU%d aborting, bad checksum\n", cpu_num);
 348                                         error = -EINVAL;
 349                                         goto out;
 350                                 }
 351                         }
 352                 }
 353                 cursor += total_size; /* goto the next update patch */
 354         } /* end of while */
 355 out:
 356         return error;
 357 }
 358
 359 static void do_update_one (void * unused)
 360 {
 361         unsigned long flags;
 362         unsigned int val[2];
 363         int cpu_num = smp_processor_id();
 364         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 365
 366         if (uci->mc == NULL) {
 367                 printk(KERN_INFO "microcode: No new microcode data for CPU%d\n", cpu_num);
 368                 return;
 369         }
 370
 371         /* serialize access to the physical write to MSR 0x79 */
 372         spin_lock_irqsave(&microcode_update_lock, flags);
 373
 374         /* write microcode via MSR 0x79 */
 375         wrmsr(MSR_IA32_UCODE_WRITE,
 376                 (unsigned long) uci->mc->bits,
 377                 (unsigned long) uci->mc->bits >> 16 >> 16);
 378         wrmsr(MSR_IA32_UCODE_REV, 0, 0);
 379
 380         __asm__ __volatile__ ("cpuid" : : : "ax", "bx", "cx", "dx");
 381         /* get the current revision from MSR 0x8B */
 382         rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
 383
 384         /* notify the caller of success on this cpu */
 385         uci->err = MC_SUCCESS;
 386         spin_unlock_irqrestore(&microcode_update_lock, flags);
 387         printk(KERN_INFO "microcode: CPU%d updated from revision "
 388                "0x%x to 0x%x, date = %08x \n",
 389                cpu_num, uci->rev, val[1], uci->mc->hdr.date);
 390         return;
 391 }
 392
 393 static int do_microcode_update (void)
 394 {
 395         int i, error;
 396
 397         if (on_each_cpu(collect_cpu_info, NULL, 1, 1) != 0) {
 398                 printk(KERN_ERR "microcode: Error! Could not run on all processors\n");
 399                 error = -EIO;
 400                 goto out;
 401         }
 402
 403         if ((error = find_matching_ucodes())) {
 404                 printk(KERN_ERR "microcode: Error in the microcode data\n");
 405                 goto out_free;
 406         }
 407
 408         if (on_each_cpu(do_update_one, NULL, 1, 1) != 0) {
 409                 printk(KERN_ERR "microcode: Error! Could not run on all processors\n");
 410                 error = -EIO;
 411         }
 412
 413 out_free:
 414         for (i = 0; i < num_online_cpus(); i++) {
 415                 if (ucode_cpu_info[i].mc) {
 416                         int j;
 417                         void *tmp = ucode_cpu_info[i].mc;
 418                         vfree(tmp);
 419                         for (j = i; j < num_online_cpus(); j++) {
 420                                 if (ucode_cpu_info[j].mc == tmp)
 421                                         ucode_cpu_info[j].mc = NULL;
 422                         }
 423                 }
 424         }
 425 out:
 426         return error;
 427 }
 428
 429 static ssize_t microcode_write (struct file *file, const char __user *buf, size_t len, loff_t *ppos)
 430 {
 431         ssize_t ret;
 432
 433         if (len < DEFAULT_UCODE_TOTALSIZE) {
 434                 printk(KERN_ERR "microcode: not enough data\n");
 435                 return -EINVAL;
 436         }
 437
 438         if ((len >> PAGE_SHIFT) > num_physpages) {
 439                 printk(KERN_ERR "microcode: too much data (max %ld pages)\n", num_physpages);
 440                 return -EINVAL;
 441         }
 442
 443         down(&microcode_sem);
 444
 445         user_buffer = (void __user *) buf;
 446         user_buffer_size = (int) len;
 447
 448         ret = do_microcode_update();
 449         if (!ret)
 450                 ret = (ssize_t)len;
 451
 452         up(&microcode_sem);
 453
 454         return ret;
 455 }
 456
 457 static int microcode_ioctl (struct inode *inode, struct file *file,
 458                 unsigned int cmd, unsigned long arg)
 459 {
 460         switch (cmd) {
 461                 /*
 462                  *  XXX: will be removed after microcode_ctl
 463                  *  is updated to ignore failure of this ioctl()
 464                  */
 465                 case MICROCODE_IOCFREE:
 466                         return 0;
 467                 default:
 468                         return -EINVAL;
 469         }
 470         return -EINVAL;
 471 }
 472
 473 static struct file_operations microcode_fops = {
 474         .owner          = THIS_MODULE,
 475         .write          = microcode_write,
 476         .ioctl          = microcode_ioctl,
 477         .open           = microcode_open,
 478 };
 479
 480 static struct miscdevice microcode_dev = {
 481         .minor          = MICROCODE_MINOR,
 482         .name           = "microcode",
 483         .devfs_name     = "cpu/microcode",
 484         .fops           = &microcode_fops,
 485 };
 486
 487 static int __init microcode_init (void)
 488 {
 489         int error;
 490
 491         error = misc_register(&microcode_dev);
 492         if (error) {
 493                 printk(KERN_ERR
 494                         "microcode: can't misc_register on minor=%d\n",
 495                         MICROCODE_MINOR);
 496                 return error;
 497         }
 498
 499         printk(KERN_INFO
 500                 "IA-32 Microcode Update Driver: v" MICROCODE_VERSION " <tigran@veritas.com>\n");
 501         return 0;
 502 }
 503
 504 static void __exit microcode_exit (void)
 505 {
 506         misc_deregister(&microcode_dev);
 507         printk(KERN_INFO "IA-32 Microcode Update Driver v" MICROCODE_VERSION " unregistered\n");
 508 }
 509
 510 module_init(microcode_init)
 511 module_exit(microcode_exit)
 512 MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);