[PATCH] i386: actively synchronize vmalloc area when registering certain callbacks
[linux-2.6] / 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/capability.h>
74 #include <linux/kernel.h>
75 #include <linux/init.h>
76 #include <linux/sched.h>
77 #include <linux/cpumask.h>
78 #include <linux/module.h>
79 #include <linux/slab.h>
80 #include <linux/vmalloc.h>
81 #include <linux/miscdevice.h>
82 #include <linux/spinlock.h>
83 #include <linux/mm.h>
84
85 #include <asm/msr.h>
86 #include <asm/uaccess.h>
87 #include <asm/processor.h>
88
89 MODULE_DESCRIPTION("Intel CPU (IA-32) Microcode Update Driver");
90 MODULE_AUTHOR("Tigran Aivazian <tigran@veritas.com>");
91 MODULE_LICENSE("GPL");
92
93 #define MICROCODE_VERSION       "1.14"
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
108 #define sigmatch(s1, s2, p1, p2) \
109         (((s1) == (s2)) && (((p1) & (p2)) || (((p1) == 0) && ((p2) == 0))))
110
111 #define exttable_size(et) ((et)->count * EXT_SIGNATURE_SIZE + EXT_HEADER_SIZE)
112
113 /* serialize access to the physical write to MSR 0x79 */
114 static DEFINE_SPINLOCK(microcode_update_lock);
115
116 /* no concurrent ->write()s are allowed on /dev/cpu/microcode */
117 static DECLARE_MUTEX(microcode_sem);
118
119 static void __user *user_buffer;        /* user area microcode data buffer */
120 static unsigned int user_buffer_size;   /* it's size */
121
122 typedef enum mc_error_code {
123         MC_SUCCESS      = 0,
124         MC_NOTFOUND     = 1,
125         MC_MARKED       = 2,
126         MC_ALLOCATED    = 3,
127 } mc_error_code_t;
128
129 static struct ucode_cpu_info {
130         unsigned int sig;
131         unsigned int pf;
132         unsigned int rev;
133         unsigned int cksum;
134         mc_error_code_t err;
135         microcode_t *mc;
136 } ucode_cpu_info[NR_CPUS];
137                                 
138 static int microcode_open (struct inode *unused1, struct file *unused2)
139 {
140         return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
141 }
142
143 static void collect_cpu_info (void *unused)
144 {
145         int cpu_num = smp_processor_id();
146         struct cpuinfo_x86 *c = cpu_data + cpu_num;
147         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
148         unsigned int val[2];
149
150         uci->sig = uci->pf = uci->rev = uci->cksum = 0;
151         uci->err = MC_NOTFOUND; 
152         uci->mc = NULL;
153
154         if (c->x86_vendor != X86_VENDOR_INTEL || c->x86 < 6 ||
155                 cpu_has(c, X86_FEATURE_IA64)) {
156                 printk(KERN_ERR "microcode: CPU%d not a capable Intel processor\n", cpu_num);
157                 return;
158         } else {
159                 uci->sig = cpuid_eax(0x00000001);
160
161                 if ((c->x86_model >= 5) || (c->x86 > 6)) {
162                         /* get processor flags from MSR 0x17 */
163                         rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
164                         uci->pf = 1 << ((val[1] >> 18) & 7);
165                 }
166         }
167
168         wrmsr(MSR_IA32_UCODE_REV, 0, 0);
169         /* see notes above for revision 1.07.  Apparent chip bug */
170         sync_core();
171         /* get the current revision from MSR 0x8B */
172         rdmsr(MSR_IA32_UCODE_REV, val[0], uci->rev);
173         pr_debug("microcode: collect_cpu_info : sig=0x%x, pf=0x%x, rev=0x%x\n",
174                         uci->sig, uci->pf, uci->rev);
175 }
176
177 static inline void mark_microcode_update (int cpu_num, microcode_header_t *mc_header, int sig, int pf, int cksum)
178 {
179         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
180
181         pr_debug("Microcode Found.\n");
182         pr_debug("   Header Revision 0x%x\n", mc_header->hdrver);
183         pr_debug("   Loader Revision 0x%x\n", mc_header->ldrver);
184         pr_debug("   Revision 0x%x \n", mc_header->rev);
185         pr_debug("   Date %x/%x/%x\n",
186                 ((mc_header->date >> 24 ) & 0xff),
187                 ((mc_header->date >> 16 ) & 0xff),
188                 (mc_header->date & 0xFFFF));
189         pr_debug("   Signature 0x%x\n", sig);
190         pr_debug("   Type 0x%x Family 0x%x Model 0x%x Stepping 0x%x\n",
191                 ((sig >> 12) & 0x3),
192                 ((sig >> 8) & 0xf),
193                 ((sig >> 4) & 0xf),
194                 ((sig & 0xf)));
195         pr_debug("   Processor Flags 0x%x\n", pf);
196         pr_debug("   Checksum 0x%x\n", cksum);
197
198         if (mc_header->rev < uci->rev) {
199                 printk(KERN_ERR "microcode: CPU%d not 'upgrading' to earlier revision"
200                        " 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
201                 goto out;
202         } else if (mc_header->rev == uci->rev) {
203                 /* notify the caller of success on this cpu */
204                 uci->err = MC_SUCCESS;
205                 printk(KERN_ERR "microcode: CPU%d already at revision"
206                         " 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
207                 goto out;
208         }
209
210         pr_debug("microcode: CPU%d found a matching microcode update with "
211                 " revision 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
212         uci->cksum = cksum;
213         uci->pf = pf; /* keep the original mc pf for cksum calculation */
214         uci->err = MC_MARKED; /* found the match */
215 out:
216         return;
217 }
218
219 static int find_matching_ucodes (void) 
220 {
221         int cursor = 0;
222         int error = 0;
223
224         while (cursor + MC_HEADER_SIZE < user_buffer_size) {
225                 microcode_header_t mc_header;
226                 void *newmc = NULL;
227                 int i, sum, cpu_num, allocated_flag, total_size, data_size, ext_table_size;
228
229                 if (copy_from_user(&mc_header, user_buffer + cursor, MC_HEADER_SIZE)) {
230                         printk(KERN_ERR "microcode: error! Can not read user data\n");
231                         error = -EFAULT;
232                         goto out;
233                 }
234
235                 total_size = get_totalsize(&mc_header);
236                 if ((cursor + total_size > user_buffer_size) || (total_size < DEFAULT_UCODE_TOTALSIZE)) {
237                         printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
238                         error = -EINVAL;
239                         goto out;
240                 }
241
242                 data_size = get_datasize(&mc_header);
243                 if ((data_size + MC_HEADER_SIZE > total_size) || (data_size < DEFAULT_UCODE_DATASIZE)) {
244                         printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
245                         error = -EINVAL;
246                         goto out;
247                 }
248
249                 if (mc_header.ldrver != 1 || mc_header.hdrver != 1) {
250                         printk(KERN_ERR "microcode: error! Unknown microcode update format\n");
251                         error = -EINVAL;
252                         goto out;
253                 }
254
255                 for_each_online_cpu(cpu_num) {
256                         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
257                         if (uci->err != MC_NOTFOUND) /* already found a match or not an online cpu*/
258                                 continue;
259
260                         if (sigmatch(mc_header.sig, uci->sig, mc_header.pf, uci->pf))
261                                 mark_microcode_update(cpu_num, &mc_header, mc_header.sig, mc_header.pf, mc_header.cksum);
262                 }
263
264                 ext_table_size = total_size - (MC_HEADER_SIZE + data_size);
265                 if (ext_table_size) {
266                         struct extended_sigtable ext_header;
267                         struct extended_signature ext_sig;
268                         int ext_sigcount;
269
270                         if ((ext_table_size < EXT_HEADER_SIZE) 
271                                         || ((ext_table_size - EXT_HEADER_SIZE) % EXT_SIGNATURE_SIZE)) {
272                                 printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
273                                 error = -EINVAL;
274                                 goto out;
275                         }
276                         if (copy_from_user(&ext_header, user_buffer + cursor 
277                                         + MC_HEADER_SIZE + data_size, EXT_HEADER_SIZE)) {
278                                 printk(KERN_ERR "microcode: error! Can not read user data\n");
279                                 error = -EFAULT;
280                                 goto out;
281                         }
282                         if (ext_table_size != exttable_size(&ext_header)) {
283                                 printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
284                                 error = -EFAULT;
285                                 goto out;
286                         }
287
288                         ext_sigcount = ext_header.count;
289                         
290                         for (i = 0; i < ext_sigcount; i++) {
291                                 if (copy_from_user(&ext_sig, user_buffer + cursor + MC_HEADER_SIZE + data_size + EXT_HEADER_SIZE 
292                                                 + EXT_SIGNATURE_SIZE * i, EXT_SIGNATURE_SIZE)) {
293                                         printk(KERN_ERR "microcode: error! Can not read user data\n");
294                                         error = -EFAULT;
295                                         goto out;
296                                 }
297                                 for_each_online_cpu(cpu_num) {
298                                         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
299                                         if (uci->err != MC_NOTFOUND) /* already found a match or not an online cpu*/
300                                                 continue;
301                                         if (sigmatch(ext_sig.sig, uci->sig, ext_sig.pf, uci->pf)) {
302                                                 mark_microcode_update(cpu_num, &mc_header, ext_sig.sig, ext_sig.pf, ext_sig.cksum);
303                                         }
304                                 }
305                         }
306                 }
307                 /* now check if any cpu has matched */
308                 allocated_flag = 0;
309                 sum = 0;
310                 for_each_online_cpu(cpu_num) {
311                         if (ucode_cpu_info[cpu_num].err == MC_MARKED) { 
312                                 struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
313                                 if (!allocated_flag) {
314                                         allocated_flag = 1;
315                                         newmc = vmalloc(total_size);
316                                         if (!newmc) {
317                                                 printk(KERN_ERR "microcode: error! Can not allocate memory\n");
318                                                 error = -ENOMEM;
319                                                 goto out;
320                                         }
321                                         if (copy_from_user(newmc + MC_HEADER_SIZE, 
322                                                                 user_buffer + cursor + MC_HEADER_SIZE, 
323                                                                 total_size - MC_HEADER_SIZE)) {
324                                                 printk(KERN_ERR "microcode: error! Can not read user data\n");
325                                                 vfree(newmc);
326                                                 error = -EFAULT;
327                                                 goto out;
328                                         }
329                                         memcpy(newmc, &mc_header, MC_HEADER_SIZE);
330                                         /* check extended table checksum */
331                                         if (ext_table_size) {
332                                                 int ext_table_sum = 0;
333                                                 int * ext_tablep = (((void *) newmc) + MC_HEADER_SIZE + data_size);
334                                                 i = ext_table_size / DWSIZE;
335                                                 while (i--) ext_table_sum += ext_tablep[i];
336                                                 if (ext_table_sum) {
337                                                         printk(KERN_WARNING "microcode: aborting, bad extended signature table checksum\n");
338                                                         vfree(newmc);
339                                                         error = -EINVAL;
340                                                         goto out;
341                                                 }
342                                         }
343
344                                         /* calculate the checksum */
345                                         i = (MC_HEADER_SIZE + data_size) / DWSIZE;
346                                         while (i--) sum += ((int *)newmc)[i];
347                                         sum -= (mc_header.sig + mc_header.pf + mc_header.cksum);
348                                 }
349                                 ucode_cpu_info[cpu_num].mc = newmc;
350                                 ucode_cpu_info[cpu_num].err = MC_ALLOCATED; /* mc updated */
351                                 if (sum + uci->sig + uci->pf + uci->cksum != 0) {
352                                         printk(KERN_ERR "microcode: CPU%d aborting, bad checksum\n", cpu_num);
353                                         error = -EINVAL;
354                                         goto out;
355                                 }
356                         }
357                 }
358                 cursor += total_size; /* goto the next update patch */
359         } /* end of while */
360 out:
361         return error;
362 }
363
364 static void do_update_one (void * unused)
365 {
366         unsigned long flags;
367         unsigned int val[2];
368         int cpu_num = smp_processor_id();
369         struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
370
371         if (uci->mc == NULL) {
372                 printk(KERN_INFO "microcode: No new microcode data for CPU%d\n", cpu_num);
373                 return;
374         }
375
376         /* serialize access to the physical write to MSR 0x79 */
377         spin_lock_irqsave(&microcode_update_lock, flags);          
378
379         /* write microcode via MSR 0x79 */
380         wrmsr(MSR_IA32_UCODE_WRITE,
381                 (unsigned long) uci->mc->bits, 
382                 (unsigned long) uci->mc->bits >> 16 >> 16);
383         wrmsr(MSR_IA32_UCODE_REV, 0, 0);
384
385         /* see notes above for revision 1.07.  Apparent chip bug */
386         sync_core();
387
388         /* get the current revision from MSR 0x8B */
389         rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
390
391         /* notify the caller of success on this cpu */
392         uci->err = MC_SUCCESS;
393         spin_unlock_irqrestore(&microcode_update_lock, flags);
394         printk(KERN_INFO "microcode: CPU%d updated from revision "
395                "0x%x to 0x%x, date = %08x \n", 
396                cpu_num, uci->rev, val[1], uci->mc->hdr.date);
397         return;
398 }
399
400 static int do_microcode_update (void)
401 {
402         int i, error;
403
404         if (on_each_cpu(collect_cpu_info, NULL, 1, 1) != 0) {
405                 printk(KERN_ERR "microcode: Error! Could not run on all processors\n");
406                 error = -EIO;
407                 goto out;
408         }
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 (on_each_cpu(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
420 out_free:
421         for_each_online_cpu(i) {
422                 if (ucode_cpu_info[i].mc) {
423                         int j;
424                         void *tmp = ucode_cpu_info[i].mc;
425                         vfree(tmp);
426                         for_each_online_cpu(j) {
427                                 if (ucode_cpu_info[j].mc == tmp)
428                                         ucode_cpu_info[j].mc = NULL;
429                         }
430                 }
431         }
432 out:
433         return error;
434 }
435
436 static ssize_t microcode_write (struct file *file, const char __user *buf, size_t len, loff_t *ppos)
437 {
438         ssize_t ret;
439
440         if (len < DEFAULT_UCODE_TOTALSIZE) {
441                 printk(KERN_ERR "microcode: not enough data\n"); 
442                 return -EINVAL;
443         }
444
445         if ((len >> PAGE_SHIFT) > num_physpages) {
446                 printk(KERN_ERR "microcode: too much data (max %ld pages)\n", num_physpages);
447                 return -EINVAL;
448         }
449
450         down(&microcode_sem);
451
452         user_buffer = (void __user *) buf;
453         user_buffer_size = (int) len;
454
455         ret = do_microcode_update();
456         if (!ret)
457                 ret = (ssize_t)len;
458
459         up(&microcode_sem);
460
461         return ret;
462 }
463
464 static int microcode_ioctl (struct inode *inode, struct file *file, 
465                 unsigned int cmd, unsigned long arg)
466 {
467         switch (cmd) {
468                 /* 
469                  *  XXX: will be removed after microcode_ctl 
470                  *  is updated to ignore failure of this ioctl()
471                  */
472                 case MICROCODE_IOCFREE:
473                         return 0;
474                 default:
475                         return -EINVAL;
476         }
477         return -EINVAL;
478 }
479
480 static struct file_operations microcode_fops = {
481         .owner          = THIS_MODULE,
482         .write          = microcode_write,
483         .ioctl          = microcode_ioctl,
484         .open           = microcode_open,
485 };
486
487 static struct miscdevice microcode_dev = {
488         .minor          = MICROCODE_MINOR,
489         .name           = "microcode",
490         .devfs_name     = "cpu/microcode",
491         .fops           = &microcode_fops,
492 };
493
494 static int __init microcode_init (void)
495 {
496         int error;
497
498         error = misc_register(&microcode_dev);
499         if (error) {
500                 printk(KERN_ERR
501                         "microcode: can't misc_register on minor=%d\n",
502                         MICROCODE_MINOR);
503                 return error;
504         }
505
506         printk(KERN_INFO 
507                 "IA-32 Microcode Update Driver: v" MICROCODE_VERSION " <tigran@veritas.com>\n");
508         return 0;
509 }
510
511 static void __exit microcode_exit (void)
512 {
513         misc_deregister(&microcode_dev);
514         printk(KERN_INFO "IA-32 Microcode Update Driver v" MICROCODE_VERSION " unregistered\n");
515 }
516
517 module_init(microcode_init)
518 module_exit(microcode_exit)
519 MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);