Linux-2.6.12-rc2
[linux-2.6.git] / 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);