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    23 Feb 2004 Tigran Aivazian <tigran@veritas.com>
  68  *              Restored devfs regular file entry point which was
  69  *              accidentally removed when back-porting changes from the 2.6
  70  *              version of the driver.
  71  */
  72
  73
  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/devfs_fs_kernel.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 #define MICRO_DEBUG             0
  94 #if MICRO_DEBUG
  95 #define dprintk(x...) printk(KERN_INFO x)
  96 #else
  97 #define dprintk(x...)
  98 #endif
  99
 100 #define DEFAULT_UCODE_DATASIZE  (2000)    /* 2000 bytes */
 101 #define MC_HEADER_SIZE          (sizeof (microcode_header_t))     /* 48 bytes */
 102 #define DEFAULT_UCODE_TOTALSIZE (DEFAULT_UCODE_DATASIZE + MC_HEADER_SIZE) /* 2048 bytes */
 103 #define EXT_HEADER_SIZE         (sizeof (struct extended_sigtable)) /* 20 bytes */
 104 #define EXT_SIGNATURE_SIZE      (sizeof (struct extended_signature)) /* 12 bytes */
 105 #define DWSIZE                  (sizeof (u32))
 106 #define get_totalsize(mc) \
 107         (((microcode_t *)mc)->hdr.totalsize ? \
 108          ((microcode_t *)mc)->hdr.totalsize : DEFAULT_UCODE_TOTALSIZE)
 109 #define get_datasize(mc) \
 110         (((microcode_t *)mc)->hdr.datasize ? \
 111          ((microcode_t *)mc)->hdr.datasize : DEFAULT_UCODE_DATASIZE)
 112
 113 #define sigmatch(s1, s2, p1, p2) \
 114         (((s1) == (s2)) && (((p1) & (p2)) || (((p1) == 0) && ((p2) == 0))))
 115
 116 #define exttable_size(et) ((et)->count * EXT_SIGNATURE_SIZE + EXT_HEADER_SIZE)
 117
 118 /* serialize access to the physical write to MSR 0x79 */
 119 static spinlock_t microcode_update_lock = SPIN_LOCK_UNLOCKED;
 120
 121 /* no concurrent ->write()s are allowed on /dev/cpu/microcode */
 122 static DECLARE_MUTEX(microcode_sem);
 123
 124 static void *user_buffer;               /* user area microcode data buffer */
 125 static unsigned int user_buffer_size;   /* it's size */
 126
 127 typedef enum mc_error_code {
 128         MC_SUCCESS      = 0,
 129         MC_NOTFOUND     = 1,
 130         MC_MARKED       = 2,
 131         MC_ALLOCATED    = 3,
 132 } mc_error_code_t;
 133
 134 static struct ucode_cpu_info {
 135         unsigned int sig;
 136         unsigned int 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         }
 172
 173         wrmsr(MSR_IA32_UCODE_REV, 0, 0);
 174         __asm__ __volatile__ ("cpuid" : : : "ax", "bx", "cx", "dx");
 175         /* get the current revision from MSR 0x8B */
 176         rdmsr(MSR_IA32_UCODE_REV, val[0], uci->rev);
 177         dprintk("microcode: collect_cpu_info : sig=0x%x, pf=0x%x, rev=0x%x\n",
 178                         uci->sig, uci->pf, uci->rev);
 179 }
 180
 181 static inline void mark_microcode_update (int cpu_num, microcode_header_t *mc_header, int sig, int pf, int cksum)
 182 {
 183         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 184
 185         dprintk("Microcode Found.\n");
 186         dprintk("   Header Revision 0x%x\n", mc_header->hdrver);
 187         dprintk("   Loader Revision 0x%x\n", mc_header->ldrver);
 188         dprintk("   Revision 0x%x \n", mc_header->rev);
 189         dprintk("   Date %x/%x/%x\n",
 190                 ((mc_header->date >> 24 ) & 0xff),
 191                 ((mc_header->date >> 16 ) & 0xff),
 192                 (mc_header->date & 0xFFFF));
 193         dprintk("   Signature 0x%x\n", sig);
 194         dprintk("   Type 0x%x Family 0x%x Model 0x%x Stepping 0x%x\n",
 195                 ((sig >> 12) & 0x3),
 196                 ((sig >> 8) & 0xf),
 197                 ((sig >> 4) & 0xf),
 198                 ((sig & 0xf)));
 199         dprintk("   Processor Flags 0x%x\n", pf);
 200         dprintk("   Checksum 0x%x\n", cksum);
 201
 202         if (mc_header->rev < uci->rev) {
 203                 printk(KERN_ERR "microcode: CPU%d not 'upgrading' to earlier revision"
 204                        " 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
 205                 goto out;
 206         } else if (mc_header->rev == uci->rev) {
 207                 /* notify the caller of success on this cpu */
 208                 uci->err = MC_SUCCESS;
 209                 printk(KERN_ERR "microcode: CPU%d already at revision"
 210                         " 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
 211                 goto out;
 212         }
 213
 214         dprintk("microcode: CPU%d found a matching microcode update with "
 215                 " revision 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
 216         uci->cksum = cksum;
 217         uci->pf = pf; /* keep the original mc pf for cksum calculation */
 218         uci->err = MC_MARKED; /* found the match */
 219 out:
 220         return;
 221 }
 222
 223 static int find_matching_ucodes (void)
 224 {
 225         int cursor = 0;
 226         int error = 0;
 227
 228         while (cursor + MC_HEADER_SIZE < user_buffer_size) {
 229                 microcode_header_t mc_header;
 230                 void *newmc = NULL;
 231                 int i, sum, cpu_num, allocated_flag, total_size, data_size, ext_table_size;
 232
 233                 if (copy_from_user(&mc_header, user_buffer + cursor, MC_HEADER_SIZE)) {
 234                         printk(KERN_ERR "microcode: error! Can not read user data\n");
 235                         error = -EFAULT;
 236                         goto out;
 237                 }
 238
 239                 total_size = get_totalsize(&mc_header);
 240                 if (cursor + total_size > user_buffer_size) {
 241                         printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
 242                         error = -EINVAL;
 243                         goto out;
 244                 }
 245
 246                 data_size = get_datasize(&mc_header);
 247                 if (data_size + MC_HEADER_SIZE > total_size) {
 248                         printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
 249                         error = -EINVAL;
 250                         goto out;
 251                 }
 252
 253                 if (mc_header.ldrver != 1 || mc_header.hdrver != 1) {
 254                         printk(KERN_ERR "microcode: error! Unknown microcode update format\n");
 255                         error = -EINVAL;
 256                         goto out;
 257                 }
 258
 259                 for (cpu_num = 0; cpu_num < smp_num_cpus; cpu_num++) {
 260                         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 261                         if (uci->err != MC_NOTFOUND) /* already found a match or not an online cpu*/
 262                                 continue;
 263
 264                         if (sigmatch(mc_header.sig, uci->sig, mc_header.pf, uci->pf))
 265                                 mark_microcode_update(cpu_num, &mc_header, mc_header.sig, mc_header.pf, mc_header.cksum);
 266                 }
 267
 268                 ext_table_size = total_size - (MC_HEADER_SIZE + data_size);
 269                 if (ext_table_size) {
 270                         struct extended_sigtable ext_header;
 271                         struct extended_signature ext_sig;
 272                         int ext_sigcount;
 273
 274                         if ((ext_table_size < EXT_HEADER_SIZE)
 275                                         || ((ext_table_size - EXT_HEADER_SIZE) % EXT_SIGNATURE_SIZE)) {
 276                                 printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
 277                                 error = -EINVAL;
 278                                 goto out;
 279                         }
 280                         if (copy_from_user(&ext_header, user_buffer + cursor
 281                                         + MC_HEADER_SIZE + data_size, EXT_HEADER_SIZE)) {
 282                                 printk(KERN_ERR "microcode: error! Can not read user data\n");
 283                                 error = -EFAULT;
 284                                 goto out;
 285                         }
 286                         if (ext_table_size != exttable_size(&ext_header)) {
 287                                 printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
 288                                 error = -EFAULT;
 289                                 goto out;
 290                         }
 291
 292                         ext_sigcount = ext_header.count;
 293
 294                         for (i = 0; i < ext_sigcount; i++) {
 295                                 if (copy_from_user(&ext_sig, user_buffer + cursor + MC_HEADER_SIZE + data_size + EXT_HEADER_SIZE
 296                                                 + EXT_SIGNATURE_SIZE * i, EXT_SIGNATURE_SIZE)) {
 297                                         printk(KERN_ERR "microcode: error! Can not read user data\n");
 298                                         error = -EFAULT;
 299                                         goto out;
 300                                 }
 301                                 for (cpu_num = 0; cpu_num < smp_num_cpus; cpu_num++) {
 302                                         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 303                                         if (uci->err != MC_NOTFOUND) /* already found a match or not an online cpu*/
 304                                                 continue;
 305                                         if (sigmatch(ext_sig.sig, uci->sig, ext_sig.pf, uci->pf)) {
 306                                                 mark_microcode_update(cpu_num, &mc_header, ext_sig.sig, ext_sig.pf, ext_sig.cksum);
 307                                         }
 308                                 }
 309                         }
 310                 }
 311                 /* now check if any cpu has matched */
 312                 for (cpu_num = 0, allocated_flag = 0, sum = 0; cpu_num < smp_num_cpus; cpu_num++) {
 313                         if (ucode_cpu_info[cpu_num].err == MC_MARKED) {
 314                                 struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 315                                 if (!allocated_flag) {
 316                                         allocated_flag = 1;
 317                                         newmc = vmalloc(total_size);
 318                                         if (!newmc) {
 319                                                 printk(KERN_ERR "microcode: error! Can not allocate memory\n");
 320                                                 error = -ENOMEM;
 321                                                 goto out;
 322                                         }
 323                                         if (copy_from_user(newmc + MC_HEADER_SIZE,
 324                                                                 user_buffer + cursor + MC_HEADER_SIZE,
 325                                                                 total_size - MC_HEADER_SIZE)) {
 326                                                 printk(KERN_ERR "microcode: error! Can not read user data\n");
 327                                                 vfree(newmc);
 328                                                 error = -EFAULT;
 329                                                 goto out;
 330                                         }
 331                                         memcpy(newmc, &mc_header, MC_HEADER_SIZE);
 332                                         /* check extended table checksum */
 333                                         if (ext_table_size) {
 334                                                 int * ext_tablep;
 335                                                 int ext_table_sum = 0;
 336                                                 i = ext_table_size / DWSIZE;
 337                                                 ext_tablep = (((void *) newmc) + MC_HEADER_SIZE + data_size);
 338                                                 while (i--) ext_table_sum += ext_tablep[i];
 339                                                 if (ext_table_sum) {
 340                                                         printk(KERN_WARNING "microcode: aborting, bad extended signature table checksum\n");
 341                                                         vfree(newmc);
 342                                                         error = -EINVAL;
 343                                                         goto out;
 344                                                 }
 345                                         }
 346
 347                                         /* calculate the checksum */
 348                                         i = (MC_HEADER_SIZE + data_size) / DWSIZE;
 349                                         while (i--) sum += ((int *)newmc)[i];
 350                                         sum -= (mc_header.sig + mc_header.pf + mc_header.cksum);
 351                                 }
 352                                 ucode_cpu_info[cpu_num].mc = newmc;
 353                                 ucode_cpu_info[cpu_num].err = MC_ALLOCATED; /* mc updated */
 354                                 if (sum + uci->sig + uci->pf + uci->cksum != 0) {
 355                                         printk(KERN_ERR "microcode: CPU%d aborting, bad checksum\n", cpu_num);
 356                                         error = -EINVAL;
 357                                         goto out;
 358                                 }
 359                         }
 360                 }
 361                 cursor += total_size; /* goto the next update patch */
 362         } /* end of while */
 363 out:
 364         return error;
 365 }
 366
 367 static void do_update_one (void * unused)
 368 {
 369         unsigned long flags;
 370         unsigned int val[2];
 371         int cpu_num = smp_processor_id();
 372         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
 373
 374         if (uci->mc == NULL) {
 375                 printk(KERN_INFO "microcode: No suitable data for cpu %d\n", cpu_num);
 376                 return;
 377         }
 378
 379         /* serialize access to the physical write to MSR 0x79 */
 380         spin_lock_irqsave(&microcode_update_lock, flags);
 381
 382         /* write microcode via MSR 0x79 */
 383         wrmsr(MSR_IA32_UCODE_WRITE, (unsigned int)(uci->mc->bits), 0);
 384         wrmsr(MSR_IA32_UCODE_REV, 0, 0);
 385
 386         __asm__ __volatile__ ("cpuid" : : : "ax", "bx", "cx", "dx");
 387         /* get the current revision from MSR 0x8B */
 388         rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
 389
 390         /* notify the caller of success on this cpu */
 391         uci->err = MC_SUCCESS;
 392         spin_unlock_irqrestore(&microcode_update_lock, flags);
 393         printk(KERN_INFO "microcode: CPU%d updated from revision "
 394                "0x%x to 0x%x, date = %08x \n",
 395                cpu_num, uci->rev, val[1], uci->mc->hdr.date);
 396         return;
 397 }
 398
 399 static int do_microcode_update (void)
 400 {
 401         int i, error;
 402
 403         if (smp_call_function(collect_cpu_info, NULL, 1, 1) != 0) {
 404                 printk(KERN_ERR "microcode: Error! Could not run on all processors\n");
 405                 error = -EIO;
 406                 goto out;
 407         }
 408         collect_cpu_info(NULL);
 409
 410         if ((error = find_matching_ucodes())) {
 411                 printk(KERN_ERR "microcode: Error in the microcode data\n");
 412                 goto out_free;
 413         }
 414
 415         if (smp_call_function(do_update_one, NULL, 1, 1) != 0) {
 416                 printk(KERN_ERR "microcode: Error! Could not run on all processors\n");
 417                 error = -EIO;
 418         }
 419         do_update_one(NULL);
 420
 421 out_free:
 422         for (i = 0; i < smp_num_cpus; i++) {
 423                 if (ucode_cpu_info[i].mc) {
 424                         int j;
 425                         void *tmp = ucode_cpu_info[i].mc;
 426                         vfree(tmp);
 427                         for (j = i; j < smp_num_cpus; j++) {
 428                                 if (ucode_cpu_info[j].mc == tmp)
 429                                         ucode_cpu_info[j].mc = NULL;
 430                         }
 431                 }
 432         }
 433 out:
 434         return error;
 435 }
 436
 437 static ssize_t microcode_write (struct file *file, const char *buf, size_t len, loff_t *ppos)
 438 {
 439         ssize_t ret;
 440
 441         if ((len >> PAGE_SHIFT) > num_physpages) {
 442                 printk(KERN_ERR "microcode: too much data (max %ld pages)\n", num_physpages);
 443                 return -EINVAL;
 444         }
 445
 446         down(&microcode_sem);
 447
 448         user_buffer = (void *) buf;
 449         user_buffer_size = (int) len;
 450
 451         ret = do_microcode_update();
 452         if (!ret)
 453                 ret = (ssize_t)len;
 454
 455         up(&microcode_sem);
 456
 457         return ret;
 458 }
 459
 460 static int microcode_ioctl (struct inode *inode, struct file *file,
 461                 unsigned int cmd, unsigned long arg)
 462 {
 463         switch (cmd) {
 464                 /*
 465                  *  XXX: will be removed after microcode_ctl
 466                  *  is updated to ignore failure of this ioctl()
 467                  */
 468                 case MICROCODE_IOCFREE:
 469                         return 0;
 470                 default:
 471                         return -EINVAL;
 472         }
 473         return -EINVAL;
 474 }
 475
 476 /* shared between misc device and devfs regular file */
 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         .fops           = &microcode_fops,
 488 };
 489
 490 static devfs_handle_t devfs_handle;
 491
 492 static int __init microcode_init (void)
 493 {
 494         int error;
 495
 496         error = misc_register(&microcode_dev);
 497         if (error)
 498                 printk(KERN_ERR
 499                         "microcode: can't misc_register on minor=%d\n",
 500                         MICROCODE_MINOR);
 501         devfs_handle = devfs_register(NULL, "cpu/microcode",
 502                         DEVFS_FL_DEFAULT, 0, 0, S_IFREG | S_IRUSR | S_IWUSR,
 503                         &microcode_fops, NULL);
 504         if (devfs_handle == NULL && error) {
 505                 printk(KERN_ERR "microcode: failed to devfs_register()\n");
 506                 goto out;
 507         }
 508         error = 0;
 509         printk(KERN_INFO
 510                 "IA-32 Microcode Update Driver: v"
 511                 MICROCODE_VERSION " <tigran@veritas.com>\n");
 512 out:
 513         return error;
 514 }
 515
 516 static void __exit microcode_exit (void)
 517 {
 518         misc_deregister(&microcode_dev);
 519         devfs_unregister(devfs_handle);
 520         printk(KERN_INFO "IA-32 Microcode Update Driver v"
 521                 MICROCODE_VERSION " unregistered\n");
 522 }
 523
 524 module_init(microcode_init)
 525 module_exit(microcode_exit)