1 /*-
2 * Copyright (c) 2006-2008 Stanislav Sedov <stas@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 */
27
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD: stable/10/sys/dev/cpuctl/cpuctl.c 315972 2017-03-26 01:10:59Z kib $");
30
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/conf.h>
34 #include <sys/fcntl.h>
35 #include <sys/ioccom.h>
36 #include <sys/malloc.h>
37 #include <sys/module.h>
38 #include <sys/mutex.h>
39 #include <sys/priv.h>
40 #include <sys/proc.h>
41 #include <sys/queue.h>
42 #include <sys/sched.h>
43 #include <sys/kernel.h>
44 #include <sys/sysctl.h>
45 #include <sys/uio.h>
46 #include <sys/pcpu.h>
47 #include <sys/smp.h>
48 #include <sys/pmckern.h>
49 #include <sys/cpuctl.h>
50
51 #include <machine/cpufunc.h>
52 #include <machine/md_var.h>
53 #include <machine/specialreg.h>
54
55 static d_open_t cpuctl_open;
56 static d_ioctl_t cpuctl_ioctl;
57
58 #define CPUCTL_VERSION 1
59
60 #ifdef CPUCTL_DEBUG
61 # define DPRINTF(format,...) printf(format, __VA_ARGS__);
62 #else
63 # define DPRINTF(...)
64 #endif
65
66 #define UCODE_SIZE_MAX (4 * 1024 * 1024)
67
68 static int cpuctl_do_msr(int cpu, cpuctl_msr_args_t *data, u_long cmd,
69 struct thread *td);
70 static int cpuctl_do_cpuid(int cpu, cpuctl_cpuid_args_t *data,
71 struct thread *td);
72 static int cpuctl_do_cpuid_count(int cpu, cpuctl_cpuid_count_args_t *data,
73 struct thread *td);
74 static int cpuctl_do_update(int cpu, cpuctl_update_args_t *data,
75 struct thread *td);
76 static int update_intel(int cpu, cpuctl_update_args_t *args,
77 struct thread *td);
78 static int update_amd(int cpu, cpuctl_update_args_t *args, struct thread *td);
79 static int update_via(int cpu, cpuctl_update_args_t *args,
80 struct thread *td);
81
82 static struct cdev **cpuctl_devs;
83 static MALLOC_DEFINE(M_CPUCTL, "cpuctl", "CPUCTL buffer");
84
85 static struct cdevsw cpuctl_cdevsw = {
86 .d_version = D_VERSION,
87 .d_open = cpuctl_open,
88 .d_ioctl = cpuctl_ioctl,
89 .d_name = "cpuctl",
90 };
91
92 /*
93 * This function checks if specified cpu enabled or not.
94 */
95 static int
cpu_enabled(int cpu)96 cpu_enabled(int cpu)
97 {
98
99 return (pmc_cpu_is_disabled(cpu) == 0);
100 }
101
102 /*
103 * Check if the current thread is bound to a specific cpu.
104 */
105 static int
cpu_sched_is_bound(struct thread * td)106 cpu_sched_is_bound(struct thread *td)
107 {
108 int ret;
109
110 thread_lock(td);
111 ret = sched_is_bound(td);
112 thread_unlock(td);
113 return (ret);
114 }
115
116 /*
117 * Switch to target cpu to run.
118 */
119 static void
set_cpu(int cpu,struct thread * td)120 set_cpu(int cpu, struct thread *td)
121 {
122
123 KASSERT(cpu >= 0 && cpu < mp_ncpus && cpu_enabled(cpu),
124 ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
125 thread_lock(td);
126 sched_bind(td, cpu);
127 thread_unlock(td);
128 KASSERT(td->td_oncpu == cpu,
129 ("[cpuctl,%d]: cannot bind to target cpu %d", __LINE__, cpu));
130 }
131
132 static void
restore_cpu(int oldcpu,int is_bound,struct thread * td)133 restore_cpu(int oldcpu, int is_bound, struct thread *td)
134 {
135
136 KASSERT(oldcpu >= 0 && oldcpu < mp_ncpus && cpu_enabled(oldcpu),
137 ("[cpuctl,%d]: bad cpu number %d", __LINE__, oldcpu));
138 thread_lock(td);
139 if (is_bound == 0)
140 sched_unbind(td);
141 else
142 sched_bind(td, oldcpu);
143 thread_unlock(td);
144 }
145
146 int
cpuctl_ioctl(struct cdev * dev,u_long cmd,caddr_t data,int flags,struct thread * td)147 cpuctl_ioctl(struct cdev *dev, u_long cmd, caddr_t data,
148 int flags, struct thread *td)
149 {
150 int ret;
151 int cpu = dev2unit(dev);
152
153 if (cpu >= mp_ncpus || !cpu_enabled(cpu)) {
154 DPRINTF("[cpuctl,%d]: bad cpu number %d\n", __LINE__, cpu);
155 return (ENXIO);
156 }
157 /* Require write flag for "write" requests. */
158 if ((cmd == CPUCTL_MSRCBIT || cmd == CPUCTL_MSRSBIT ||
159 cmd == CPUCTL_UPDATE || cmd == CPUCTL_WRMSR) &&
160 (flags & FWRITE) == 0)
161 return (EPERM);
162 switch (cmd) {
163 case CPUCTL_RDMSR:
164 ret = cpuctl_do_msr(cpu, (cpuctl_msr_args_t *)data, cmd, td);
165 break;
166 case CPUCTL_MSRSBIT:
167 case CPUCTL_MSRCBIT:
168 case CPUCTL_WRMSR:
169 ret = priv_check(td, PRIV_CPUCTL_WRMSR);
170 if (ret != 0)
171 goto fail;
172 ret = cpuctl_do_msr(cpu, (cpuctl_msr_args_t *)data, cmd, td);
173 break;
174 case CPUCTL_CPUID:
175 ret = cpuctl_do_cpuid(cpu, (cpuctl_cpuid_args_t *)data, td);
176 break;
177 case CPUCTL_UPDATE:
178 ret = priv_check(td, PRIV_CPUCTL_UPDATE);
179 if (ret != 0)
180 goto fail;
181 ret = cpuctl_do_update(cpu, (cpuctl_update_args_t *)data, td);
182 break;
183 case CPUCTL_CPUID_COUNT:
184 ret = cpuctl_do_cpuid_count(cpu,
185 (cpuctl_cpuid_count_args_t *)data, td);
186 break;
187 default:
188 ret = EINVAL;
189 break;
190 }
191 fail:
192 return (ret);
193 }
194
195 /*
196 * Actually perform cpuid operation.
197 */
198 static int
cpuctl_do_cpuid_count(int cpu,cpuctl_cpuid_count_args_t * data,struct thread * td)199 cpuctl_do_cpuid_count(int cpu, cpuctl_cpuid_count_args_t *data,
200 struct thread *td)
201 {
202 int is_bound = 0;
203 int oldcpu;
204
205 KASSERT(cpu >= 0 && cpu < mp_ncpus,
206 ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
207
208 /* Explicitly clear cpuid data to avoid returning stale info. */
209 bzero(data->data, sizeof(data->data));
210 DPRINTF("[cpuctl,%d]: retrieving cpuid lev %#0x type %#0x for %d cpu\n",
211 __LINE__, data->level, data->level_type, cpu);
212 #ifdef __i386__
213 if (cpu_id == 0)
214 return (ENODEV);
215 #endif
216 oldcpu = td->td_oncpu;
217 is_bound = cpu_sched_is_bound(td);
218 set_cpu(cpu, td);
219 cpuid_count(data->level, data->level_type, data->data);
220 restore_cpu(oldcpu, is_bound, td);
221 return (0);
222 }
223
224 static int
cpuctl_do_cpuid(int cpu,cpuctl_cpuid_args_t * data,struct thread * td)225 cpuctl_do_cpuid(int cpu, cpuctl_cpuid_args_t *data, struct thread *td)
226 {
227 cpuctl_cpuid_count_args_t cdata;
228 int error;
229
230 cdata.level = data->level;
231 /* Override the level type. */
232 cdata.level_type = 0;
233 error = cpuctl_do_cpuid_count(cpu, &cdata, td);
234 bcopy(cdata.data, data->data, sizeof(data->data)); /* Ignore error */
235 return (error);
236 }
237
238 /*
239 * Actually perform MSR operations.
240 */
241 static int
cpuctl_do_msr(int cpu,cpuctl_msr_args_t * data,u_long cmd,struct thread * td)242 cpuctl_do_msr(int cpu, cpuctl_msr_args_t *data, u_long cmd, struct thread *td)
243 {
244 uint64_t reg;
245 int is_bound = 0;
246 int oldcpu;
247 int ret;
248
249 KASSERT(cpu >= 0 && cpu < mp_ncpus,
250 ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
251
252 /*
253 * Explicitly clear cpuid data to avoid returning stale
254 * info
255 */
256 DPRINTF("[cpuctl,%d]: operating on MSR %#0x for %d cpu\n", __LINE__,
257 data->msr, cpu);
258 #ifdef __i386__
259 if ((cpu_feature & CPUID_MSR) == 0)
260 return (ENODEV);
261 #endif
262 oldcpu = td->td_oncpu;
263 is_bound = cpu_sched_is_bound(td);
264 set_cpu(cpu, td);
265 if (cmd == CPUCTL_RDMSR) {
266 data->data = 0;
267 ret = rdmsr_safe(data->msr, &data->data);
268 } else if (cmd == CPUCTL_WRMSR) {
269 ret = wrmsr_safe(data->msr, data->data);
270 } else if (cmd == CPUCTL_MSRSBIT) {
271 critical_enter();
272 ret = rdmsr_safe(data->msr, ®);
273 if (ret == 0)
274 ret = wrmsr_safe(data->msr, reg | data->data);
275 critical_exit();
276 } else if (cmd == CPUCTL_MSRCBIT) {
277 critical_enter();
278 ret = rdmsr_safe(data->msr, ®);
279 if (ret == 0)
280 ret = wrmsr_safe(data->msr, reg & ~data->data);
281 critical_exit();
282 } else
283 panic("[cpuctl,%d]: unknown operation requested: %lu", __LINE__, cmd);
284 restore_cpu(oldcpu, is_bound, td);
285 return (ret);
286 }
287
288 /*
289 * Actually perform microcode update.
290 */
291 static int
cpuctl_do_update(int cpu,cpuctl_update_args_t * data,struct thread * td)292 cpuctl_do_update(int cpu, cpuctl_update_args_t *data, struct thread *td)
293 {
294 cpuctl_cpuid_args_t args = {
295 .level = 0,
296 };
297 char vendor[13];
298 int ret;
299
300 KASSERT(cpu >= 0 && cpu < mp_ncpus,
301 ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
302 DPRINTF("[cpuctl,%d]: XXX %d", __LINE__, cpu);
303
304 ret = cpuctl_do_cpuid(cpu, &args, td);
305 if (ret != 0)
306 return (ret);
307 ((uint32_t *)vendor)[0] = args.data[1];
308 ((uint32_t *)vendor)[1] = args.data[3];
309 ((uint32_t *)vendor)[2] = args.data[2];
310 vendor[12] = '\0';
311 if (strncmp(vendor, INTEL_VENDOR_ID, sizeof(INTEL_VENDOR_ID)) == 0)
312 ret = update_intel(cpu, data, td);
313 else if(strncmp(vendor, AMD_VENDOR_ID, sizeof(AMD_VENDOR_ID)) == 0)
314 ret = update_amd(cpu, data, td);
315 else if(strncmp(vendor, CENTAUR_VENDOR_ID, sizeof(CENTAUR_VENDOR_ID)) == 0)
316 ret = update_via(cpu, data, td);
317 else
318 ret = ENXIO;
319 return (ret);
320 }
321
322 static int
update_intel(int cpu,cpuctl_update_args_t * args,struct thread * td)323 update_intel(int cpu, cpuctl_update_args_t *args, struct thread *td)
324 {
325 void *ptr;
326 uint64_t rev0, rev1;
327 uint32_t tmp[4];
328 int is_bound;
329 int oldcpu;
330 int ret;
331
332 if (args->size == 0 || args->data == NULL) {
333 DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
334 return (EINVAL);
335 }
336 if (args->size > UCODE_SIZE_MAX) {
337 DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
338 return (EINVAL);
339 }
340
341 /*
342 * 16 byte alignment required. Rely on the fact that
343 * malloc(9) always returns the pointer aligned at least on
344 * the size of the allocation.
345 */
346 ptr = malloc(args->size + 16, M_CPUCTL, M_WAITOK);
347 if (copyin(args->data, ptr, args->size) != 0) {
348 DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
349 __LINE__, args->data, ptr, args->size);
350 ret = EFAULT;
351 goto fail;
352 }
353 oldcpu = td->td_oncpu;
354 is_bound = cpu_sched_is_bound(td);
355 set_cpu(cpu, td);
356 critical_enter();
357 rdmsr_safe(MSR_BIOS_SIGN, &rev0); /* Get current microcode revision. */
358
359 /*
360 * Perform update.
361 */
362 wrmsr_safe(MSR_BIOS_UPDT_TRIG, (uintptr_t)(ptr));
363 wrmsr_safe(MSR_BIOS_SIGN, 0);
364
365 /*
366 * Serialize instruction flow.
367 */
368 do_cpuid(0, tmp);
369 critical_exit();
370 rdmsr_safe(MSR_BIOS_SIGN, &rev1); /* Get new microcode revision. */
371 restore_cpu(oldcpu, is_bound, td);
372 if (rev1 > rev0)
373 ret = 0;
374 else
375 ret = EEXIST;
376 fail:
377 free(ptr, M_CPUCTL);
378 return (ret);
379 }
380
381 /*
382 * NB: MSR 0xc0010020, MSR_K8_UCODE_UPDATE, is not documented by AMD.
383 * Coreboot, illumos and Linux source code was used to understand
384 * its workings.
385 */
386 static void
amd_ucode_wrmsr(void * ucode_ptr)387 amd_ucode_wrmsr(void *ucode_ptr)
388 {
389 uint32_t tmp[4];
390
391 wrmsr_safe(MSR_K8_UCODE_UPDATE, (uintptr_t)ucode_ptr);
392 do_cpuid(0, tmp);
393 }
394
395 static int
update_amd(int cpu,cpuctl_update_args_t * args,struct thread * td)396 update_amd(int cpu, cpuctl_update_args_t *args, struct thread *td)
397 {
398 void *ptr;
399 int ret;
400
401 if (args->size == 0 || args->data == NULL) {
402 DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
403 return (EINVAL);
404 }
405 if (args->size > UCODE_SIZE_MAX) {
406 DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
407 return (EINVAL);
408 }
409
410 /*
411 * 16 byte alignment required. Rely on the fact that
412 * malloc(9) always returns the pointer aligned at least on
413 * the size of the allocation.
414 */
415 ptr = malloc(args->size + 16, M_CPUCTL, M_ZERO | M_WAITOK);
416 if (copyin(args->data, ptr, args->size) != 0) {
417 DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
418 __LINE__, args->data, ptr, args->size);
419 ret = EFAULT;
420 goto fail;
421 }
422 smp_rendezvous(NULL, amd_ucode_wrmsr, NULL, ptr);
423 ret = 0;
424 fail:
425 free(ptr, M_CPUCTL);
426 return (ret);
427 }
428
429 static int
update_via(int cpu,cpuctl_update_args_t * args,struct thread * td)430 update_via(int cpu, cpuctl_update_args_t *args, struct thread *td)
431 {
432 void *ptr;
433 uint64_t rev0, rev1, res;
434 uint32_t tmp[4];
435 int is_bound;
436 int oldcpu;
437 int ret;
438
439 if (args->size == 0 || args->data == NULL) {
440 DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
441 return (EINVAL);
442 }
443 if (args->size > UCODE_SIZE_MAX) {
444 DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
445 return (EINVAL);
446 }
447
448 /*
449 * 4 byte alignment required.
450 */
451 ptr = malloc(args->size, M_CPUCTL, M_WAITOK);
452 if (copyin(args->data, ptr, args->size) != 0) {
453 DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
454 __LINE__, args->data, ptr, args->size);
455 ret = EFAULT;
456 goto fail;
457 }
458 oldcpu = td->td_oncpu;
459 is_bound = cpu_sched_is_bound(td);
460 set_cpu(cpu, td);
461 critical_enter();
462 rdmsr_safe(MSR_BIOS_SIGN, &rev0); /* Get current microcode revision. */
463
464 /*
465 * Perform update.
466 */
467 wrmsr_safe(MSR_BIOS_UPDT_TRIG, (uintptr_t)(ptr));
468 do_cpuid(1, tmp);
469
470 /*
471 * Result are in low byte of MSR FCR5:
472 * 0x00: No update has been attempted since RESET.
473 * 0x01: The last attempted update was successful.
474 * 0x02: The last attempted update was unsuccessful due to a bad
475 * environment. No update was loaded and any preexisting
476 * patches are still active.
477 * 0x03: The last attempted update was not applicable to this processor.
478 * No update was loaded and any preexisting patches are still
479 * active.
480 * 0x04: The last attempted update was not successful due to an invalid
481 * update data block. No update was loaded and any preexisting
482 * patches are still active
483 */
484 rdmsr_safe(0x1205, &res);
485 res &= 0xff;
486 critical_exit();
487 rdmsr_safe(MSR_BIOS_SIGN, &rev1); /* Get new microcode revision. */
488 restore_cpu(oldcpu, is_bound, td);
489
490 DPRINTF("[cpu,%d]: rev0=%x rev1=%x res=%x\n", __LINE__,
491 (unsigned)(rev0 >> 32), (unsigned)(rev1 >> 32), (unsigned)res);
492
493 if (res != 0x01)
494 ret = EINVAL;
495 else
496 ret = 0;
497 fail:
498 free(ptr, M_CPUCTL);
499 return (ret);
500 }
501
502 int
cpuctl_open(struct cdev * dev,int flags,int fmt __unused,struct thread * td)503 cpuctl_open(struct cdev *dev, int flags, int fmt __unused, struct thread *td)
504 {
505 int ret = 0;
506 int cpu;
507
508 cpu = dev2unit(dev);
509 if (cpu >= mp_ncpus || !cpu_enabled(cpu)) {
510 DPRINTF("[cpuctl,%d]: incorrect cpu number %d\n", __LINE__,
511 cpu);
512 return (ENXIO);
513 }
514 if (flags & FWRITE)
515 ret = securelevel_gt(td->td_ucred, 0);
516 return (ret);
517 }
518
519 static int
cpuctl_modevent(module_t mod __unused,int type,void * data __unused)520 cpuctl_modevent(module_t mod __unused, int type, void *data __unused)
521 {
522 int cpu;
523
524 switch(type) {
525 case MOD_LOAD:
526 if (bootverbose)
527 printf("cpuctl: access to MSR registers/cpuid info.\n");
528 cpuctl_devs = malloc(sizeof(*cpuctl_devs) * mp_ncpus, M_CPUCTL,
529 M_WAITOK | M_ZERO);
530 for (cpu = 0; cpu < mp_ncpus; cpu++)
531 if (cpu_enabled(cpu))
532 cpuctl_devs[cpu] = make_dev(&cpuctl_cdevsw, cpu,
533 UID_ROOT, GID_KMEM, 0640, "cpuctl%d", cpu);
534 break;
535 case MOD_UNLOAD:
536 for (cpu = 0; cpu < mp_ncpus; cpu++) {
537 if (cpuctl_devs[cpu] != NULL)
538 destroy_dev(cpuctl_devs[cpu]);
539 }
540 free(cpuctl_devs, M_CPUCTL);
541 break;
542 case MOD_SHUTDOWN:
543 break;
544 default:
545 return (EOPNOTSUPP);
546 }
547 return (0);
548 }
549
550 DEV_MODULE(cpuctl, cpuctl_modevent, NULL);
551 MODULE_VERSION(cpuctl, CPUCTL_VERSION);
552