arch/i386/kernel/microcode.c

   1 /*
   2  *      Intel CPU Microcode Update driver for Linux
   3  *
   4  *      Copyright (C) 2000 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  */
  68
  69
  70 #include <linux/init.h>
  71 #include <linux/sched.h>
  72 #include <linux/module.h>
  73 #include <linux/slab.h>
  74 #include <linux/vmalloc.h>
  75 #include <linux/miscdevice.h>
  76 #include <linux/spinlock.h>
  77 #include <linux/mm.h>
  78
  79 #include <asm/msr.h>
  80 #include <asm/uaccess.h>
  81 #include <asm/processor.h>
  82
  83 MODULE_DESCRIPTION("Intel CPU (IA-32) microcode update driver");
  84 MODULE_AUTHOR("Tigran Aivazian <tigran@veritas.com>");
  85 MODULE_LICENSE("GPL");
  86
  87 #define MICROCODE_VERSION       "1.13"
  88 #define MICRO_DEBUG             0
  89 #if MICRO_DEBUG
  90 #define dprintk(x...) printk(KERN_INFO x)
  91 #else
  92 #define dprintk(x...)
  93 #endif
  94
  95 #define DEFAULT_UCODE_DATASIZE  (2000)    /* 2000 bytes */
  96 #define MC_HEADER_SIZE          (sizeof (microcode_header_t))     /* 48 bytes */
  97 #define DEFAULT_UCODE_TOTALSIZE (DEFAULT_UCODE_DATASIZE + MC_HEADER_SIZE) /* 2048 bytes */
  98 #define EXT_HEADER_SIZE         (sizeof (struct extended_sigtable)) /* 20 bytes */
  99 #define EXT_SIGNATURE_SIZE      (sizeof (struct extended_signature)) /* 12 bytes */
 100 #define DWSIZE                  (sizeof (u32))
 101 #define get_totalsize(mc) \
 102         (((microcode_t *)mc)->hdr.totalsize ? \
 103          ((microcode_t *)mc)->hdr.totalsize : DEFAULT_UCODE_TOTALSIZE)
 104 #define get_datasize(mc) \
 105         (((microcode_t *)mc)->hdr.datasize ? \
 106          ((microcode_t *)mc)->hdr.datasize : DEFAULT_UCODE_DATASIZE)
 107 #define sigmatch(s1, s2, p1, p2) (((s1) == (s2)) && ((p1) & (p2)))
 108 #define exttable_size(et) ((et)->count * EXT_SIGNATURE_SIZE + EXT_HEADER_SIZE)
 109
 110 /* serialize access to the physical write to MSR 0x79 */
 111 static spinlock_t microcode_update_lock = SPIN_LOCK_UNLOCKED;
 112
 113 /* no concurrent ->write()s are allowed on /dev/cpu/microcode */
 114 static DECLARE_MUTEX(microcode_sem);
 115
 116 static void __user *user_buffer;        /* user area microcode data buffer */
 117 static unsigned int user_buffer_size;   /* it's size */
 118
 119 typedef enum mc_error_code {
 120         MC_SUCCESS      = 0,
 121         MC_NOTFOUND     = 1,
 122         MC_MARKED       = 2,
 123         MC_ALLOCATED    = 3,
 124 } mc_error_code_t;
 125
 126 static struct ucode_cpu_info {
 127         unsigned int sig;
 128         unsigned int pf;
 129         unsigned int rev;
 130         unsigned int cksum;
 131         mc_error_code_t err;
 132         microcode_t *mc;
 133 } ucode_cpu_info[NR_CPUS];
 134
 135 static int microcode_open (struct inode *unused1, struct file *unused2)
 136 {
 137         return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
 138 }
 139
 140 static void collect_cpu_info (void *unused)
 141 {
 142         int cpu_num = smp_processor_id();
 143         struct cpuinfo_x86 *c = cpu_data + cpu_num;
 144         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 145         unsigned int val[2];
 146
 147         uci->sig = uci->pf = uci->rev = uci->cksum = 0;
 148         uci->err = MC_NOTFOUND;
 149         uci->mc = NULL;
 150
 151         if (c->x86_vendor != X86_VENDOR_INTEL || c->x86 < 6 ||
 152                 cpu_has(c, X86_FEATURE_IA64)) {
 153                 printk(KERN_ERR "microcode: CPU%d not a capable Intel processor\n", cpu_num);
 154                 return;
 155         } else {
 156                 uci->sig = cpuid_eax(0x00000001);
 157
 158                 if ((c->x86_model >= 5) || (c->x86 > 6)) {
 159                         /* get processor flags from MSR 0x17 */
 160                         rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
 161                         uci->pf = 1 << ((val[1] >> 18) & 7);
 162                 }
 163         }
 164
 165         wrmsr(MSR_IA32_UCODE_REV, 0, 0);
 166         __asm__ __volatile__ ("cpuid" : : : "ax", "bx", "cx", "dx");
 167         /* get the current revision from MSR 0x8B */
 168         rdmsr(MSR_IA32_UCODE_REV, val[0], uci->rev);
 169         dprintk("microcode: collect_cpu_info : sig=0x%x, pf=0x%x, rev=0x%x\n",
 170                         uci->sig, uci->pf, uci->rev);
 171 }
 172
 173 static inline void mark_microcode_update (int cpu_num, microcode_header_t *mc_header, int sig, int pf, int cksum)
 174 {
 175         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 176
 177         dprintk("Microcode Found.\n");
 178         dprintk("   Header Revision 0x%x\n", mc_header->hdrver);
 179         dprintk("   Loader Revision 0x%x\n", mc_header->ldrver);
 180         dprintk("   Revision 0x%x \n", mc_header->rev);
 181         dprintk("   Date %x/%x/%x\n",
 182                 ((mc_header->date >> 24 ) & 0xff),
 183                 ((mc_header->date >> 16 ) & 0xff),
 184                 (mc_header->date & 0xFFFF));
 185         dprintk("   Signature 0x%x\n", sig);
 186         dprintk("   Type 0x%x Family 0x%x Model 0x%x Stepping 0x%x\n",
 187                 ((sig >> 12) & 0x3),
 188                 ((sig >> 8) & 0xf),
 189                 ((sig >> 4) & 0xf),
 190                 ((sig & 0xf)));
 191         dprintk("   Processor Flags 0x%x\n", pf);
 192         dprintk("   Checksum 0x%x\n", cksum);
 193
 194         if (mc_header->rev < uci->rev) {
 195                 printk(KERN_ERR "microcode: CPU%d not 'upgrading' to earlier revision"
 196                        " 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
 197                 goto out;
 198         } else if (mc_header->rev == uci->rev) {
 199                 /* notify the caller of success on this cpu */
 200                 uci->err = MC_SUCCESS;
 201                 printk(KERN_ERR "microcode: CPU%d already at revision"
 202                         " 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
 203                 goto out;
 204         }
 205
 206         dprintk("microcode: CPU%d found a matching microcode update with "
 207                 " revision 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
 208         uci->cksum = cksum;
 209         uci->pf = pf; /* keep the original mc pf for cksum calculation */
 210         uci->err = MC_MARKED; /* found the match */
 211 out:
 212         return;
 213 }
 214
 215 static int find_matching_ucodes (void)
 216 {
 217         int cursor = 0;
 218         int error = 0;
 219
 220         while (cursor + MC_HEADER_SIZE < user_buffer_size) {
 221                 microcode_header_t mc_header;
 222                 void *newmc = NULL;
 223                 int i, sum, cpu_num, allocated_flag, total_size, data_size, ext_table_size;
 224
 225                 if (copy_from_user(&mc_header, user_buffer + cursor, MC_HEADER_SIZE)) {
 226                         printk(KERN_ERR "microcode: error! Can not read user data\n");
 227                         error = -EFAULT;
 228                         goto out;
 229                 }
 230
 231                 total_size = get_totalsize(&mc_header);
 232                 if ((cursor + total_size > user_buffer_size) || (total_size < DEFAULT_UCODE_TOTALSIZE)) {
 233                         printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
 234                         error = -EINVAL;
 235                         goto out;
 236                 }
 237
 238                 data_size = get_datasize(&mc_header);
 239                 if ((data_size + MC_HEADER_SIZE > total_size) || (data_size < DEFAULT_UCODE_DATASIZE)) {
 240                         printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
 241                         error = -EINVAL;
 242                         goto out;
 243                 }
 244
 245                 if (mc_header.ldrver != 1 || mc_header.hdrver != 1) {
 246                         printk(KERN_ERR "microcode: error! Unknown microcode update format\n");
 247                         error = -EINVAL;
 248                         goto out;
 249                 }
 250
 251                 for (cpu_num = 0; cpu_num < num_online_cpus(); cpu_num++) {
 252                         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 253                         if (uci->err != MC_NOTFOUND) /* already found a match or not an online cpu*/
 254                                 continue;
 255
 256                         if (sigmatch(mc_header.sig, uci->sig, mc_header.pf, uci->pf))
 257                                 mark_microcode_update(cpu_num, &mc_header, mc_header.sig, mc_header.pf, mc_header.cksum);
 258                 }
 259
 260                 ext_table_size = total_size - (MC_HEADER_SIZE + data_size);
 261                 if (ext_table_size) {
 262                         struct extended_sigtable ext_header;
 263                         struct extended_signature ext_sig;
 264                         int ext_sigcount;
 265
 266                         if ((ext_table_size < EXT_HEADER_SIZE)
 267                                         || ((ext_table_size - EXT_HEADER_SIZE) % EXT_SIGNATURE_SIZE)) {
 268                                 printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
 269                                 error = -EINVAL;
 270                                 goto out;
 271                         }
 272                         if (copy_from_user(&ext_header, user_buffer + cursor
 273                                         + MC_HEADER_SIZE + data_size, EXT_HEADER_SIZE)) {
 274                                 printk(KERN_ERR "microcode: error! Can not read user data\n");
 275                                 error = -EFAULT;
 276                                 goto out;
 277                         }
 278                         if (ext_table_size != exttable_size(&ext_header)) {
 279                                 printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
 280                                 error = -EFAULT;
 281                                 goto out;
 282                         }
 283
 284                         ext_sigcount = ext_header.count;
 285
 286                         for (i = 0; i < ext_sigcount; i++) {
 287                                 if (copy_from_user(&ext_sig, user_buffer + cursor + MC_HEADER_SIZE + data_size + EXT_HEADER_SIZE
 288                                                 + EXT_SIGNATURE_SIZE * i, EXT_SIGNATURE_SIZE)) {
 289                                         printk(KERN_ERR "microcode: error! Can not read user data\n");
 290                                         error = -EFAULT;
 291                                         goto out;
 292                                 }
 293                                 for (cpu_num = 0; cpu_num < num_online_cpus(); cpu_num++) {
 294                                         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 295                                         if (uci->err != MC_NOTFOUND) /* already found a match or not an online cpu*/
 296                                                 continue;
 297                                         if (sigmatch(ext_sig.sig, uci->sig, ext_sig.pf, uci->pf)) {
 298                                                 mark_microcode_update(cpu_num, &mc_header, ext_sig.sig, ext_sig.pf, ext_sig.cksum);
 299                                         }
 300                                 }
 301                         }
 302                 }
 303                 /* now check if any cpu has matched */
 304                 for (cpu_num = 0, allocated_flag = 0, sum = 0; cpu_num < num_online_cpus(); cpu_num++) {
 305                         if (ucode_cpu_info[cpu_num].err == MC_MARKED) {
 306                                 struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 307                                 if (!allocated_flag) {
 308                                         allocated_flag = 1;
 309                                         newmc = vmalloc(total_size);
 310                                         if (!newmc) {
 311                                                 printk(KERN_ERR "microcode: error! Can not allocate memory\n");
 312                                                 error = -ENOMEM;
 313                                                 goto out;
 314                                         }
 315                                         if (copy_from_user(newmc + MC_HEADER_SIZE,
 316                                                                 user_buffer + cursor + MC_HEADER_SIZE,
 317                                                                 total_size - MC_HEADER_SIZE)) {
 318                                                 printk(KERN_ERR "microcode: error! Can not read user data\n");
 319                                                 vfree(newmc);
 320                                                 error = -EFAULT;
 321                                                 goto out;
 322                                         }
 323                                         memcpy(newmc, &mc_header, MC_HEADER_SIZE);
 324                                         /* check extended table checksum */
 325                                         if (ext_table_size) {
 326                                                 int ext_table_sum = 0;
 327                                                 int * ext_tablep = (((void *) newmc) + MC_HEADER_SIZE + data_size);
 328                                                 i = ext_table_size / DWSIZE;
 329                                                 while (i--) ext_table_sum += ext_tablep[i];
 330                                                 if (ext_table_sum) {
 331                                                         printk(KERN_WARNING "microcode: aborting, bad extended signature table checksum\n");
 332                                                         vfree(newmc);
 333                                                         error = -EINVAL;
 334                                                         goto out;
 335                                                 }
 336                                         }
 337
 338                                         /* calculate the checksum */
 339                                         i = (MC_HEADER_SIZE + data_size) / DWSIZE;
 340                                         while (i--) sum += ((int *)newmc)[i];
 341                                         sum -= (mc_header.sig + mc_header.pf + mc_header.cksum);
 342                                 }
 343                                 ucode_cpu_info[cpu_num].mc = newmc;
 344                                 ucode_cpu_info[cpu_num].err = MC_ALLOCATED; /* mc updated */
 345                                 if (sum + uci->sig + uci->pf + uci->cksum != 0) {
 346                                         printk(KERN_ERR "microcode: CPU%d aborting, bad checksum\n", cpu_num);
 347                                         error = -EINVAL;
 348                                         goto out;
 349                                 }
 350                         }
 351                 }
 352                 cursor += total_size; /* goto the next update patch */
 353         } /* end of while */
 354 out:
 355         return error;
 356 }
 357
 358 static void do_update_one (void * unused)
 359 {
 360         unsigned long flags;
 361         unsigned int val[2];
 362         int cpu_num = smp_processor_id();
 363         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 364
 365         if (uci->mc == NULL) {
 366                 printk(KERN_INFO "microcode: No suitable data for cpu %d\n", cpu_num);
 367                 return;
 368         }
 369
 370         /* serialize access to the physical write to MSR 0x79 */
 371         spin_lock_irqsave(&microcode_update_lock, flags);
 372
 373         /* write microcode via MSR 0x79 */
 374         wrmsr(MSR_IA32_UCODE_WRITE,
 375                 (unsigned long) uci->mc->bits,
 376                 (unsigned long) uci->mc->bits >> 16 >> 16);
 377         wrmsr(MSR_IA32_UCODE_REV, 0, 0);
 378
 379         __asm__ __volatile__ ("cpuid" : : : "ax", "bx", "cx", "dx");
 380         /* get the current revision from MSR 0x8B */
 381         rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
 382
 383         /* notify the caller of success on this cpu */
 384         uci->err = MC_SUCCESS;
 385         spin_unlock_irqrestore(&microcode_update_lock, flags);
 386         printk(KERN_INFO "microcode: CPU%d updated from revision "
 387                "0x%x to 0x%x, date = %08x \n",
 388                cpu_num, uci->rev, val[1], uci->mc->hdr.date);
 389         return;
 390 }
 391
 392 static int do_microcode_update (void)
 393 {
 394         int i, error;
 395
 396         if (on_each_cpu(collect_cpu_info, NULL, 1, 1) != 0) {
 397                 printk(KERN_ERR "microcode: Error! Could not run on all processors\n");
 398                 error = -EIO;
 399                 goto out;
 400         }
 401
 402         if ((error = find_matching_ucodes())) {
 403                 printk(KERN_ERR "microcode: Error in the microcode data\n");
 404                 goto out_free;
 405         }
 406
 407         if (on_each_cpu(do_update_one, NULL, 1, 1) != 0) {
 408                 printk(KERN_ERR "microcode: Error! Could not run on all processors\n");
 409                 error = -EIO;
 410         }
 411
 412 out_free:
 413         for (i = 0; i < num_online_cpus(); i++) {
 414                 if (ucode_cpu_info[i].mc) {
 415                         int j;
 416                         void *tmp = ucode_cpu_info[i].mc;
 417                         vfree(tmp);
 418                         for (j = i; j < num_online_cpus(); j++) {
 419                                 if (ucode_cpu_info[j].mc == tmp)
 420                                         ucode_cpu_info[j].mc = NULL;
 421                         }
 422                 }
 423         }
 424 out:
 425         return error;
 426 }
 427
 428 static ssize_t microcode_write (struct file *file, const char __user *buf, size_t len, loff_t *ppos)
 429 {
 430         ssize_t ret;
 431
 432         if (len < DEFAULT_UCODE_TOTALSIZE) {
 433                 printk(KERN_ERR "microcode: not enough data\n");
 434                 return -EINVAL;
 435         }
 436
 437         if ((len >> PAGE_SHIFT) > num_physpages) {
 438                 printk(KERN_ERR "microcode: too much data (max %ld pages)\n", num_physpages);
 439                 return -EINVAL;
 440         }
 441
 442         down(&microcode_sem);
 443
 444         user_buffer = (void __user *) buf;
 445         user_buffer_size = (int) len;
 446
 447         ret = do_microcode_update();
 448         if (!ret)
 449                 ret = (ssize_t)len;
 450
 451         up(&microcode_sem);
 452
 453         return ret;
 454 }
 455
 456 static int microcode_ioctl (struct inode *inode, struct file *file,
 457                 unsigned int cmd, unsigned long arg)
 458 {
 459         switch (cmd) {
 460                 /*
 461                  *  XXX: will be removed after microcode_ctl
 462                  *  is updated to ignore failure of this ioctl()
 463                  */
 464                 case MICROCODE_IOCFREE:
 465                         return 0;
 466                 default:
 467                         return -EINVAL;
 468         }
 469         return -EINVAL;
 470 }
 471
 472 static struct file_operations microcode_fops = {
 473         .owner          = THIS_MODULE,
 474         .write          = microcode_write,
 475         .ioctl          = microcode_ioctl,
 476         .open           = microcode_open,
 477 };
 478
 479 static struct miscdevice microcode_dev = {
 480         .minor          = MICROCODE_MINOR,
 481         .name           = "microcode",
 482         .fops           = &microcode_fops,
 483 };
 484
 485 static int __init microcode_init (void)
 486 {
 487         int error;
 488
 489         error = misc_register(&microcode_dev);
 490         if (error) {
 491                 printk(KERN_ERR
 492                         "microcode: can't misc_register on minor=%d\n",
 493                         MICROCODE_MINOR);
 494                 return error;
 495         }
 496
 497         printk(KERN_INFO
 498                 "IA-32 Microcode Update Driver: v%s <tigran@veritas.com>\n",
 499                 MICROCODE_VERSION);
 500         return 0;
 501 }
 502
 503 static void __exit microcode_exit (void)
 504 {
 505         misc_deregister(&microcode_dev);
 506         printk(KERN_INFO "IA-32 Microcode Update Driver v%s unregistered\n",
 507                         MICROCODE_VERSION);
 508 }
 509
 510 module_init(microcode_init)
 511 module_exit(microcode_exit)
 512 MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);