xref: /freebsd/sys/dev/cpuctl/cpuctl.c (revision cdebaff820b2a4915a16cedfd511823d78aab171)
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("$FreeBSD$");
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
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
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
120 set_cpu(int cpu, struct thread *td)
121 {
122 
123 	KASSERT(cpu >= 0 && cpu <= mp_maxid && 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 on cpu %d", __LINE__, cpu, td->td_oncpu));
130 }
131 
132 static void
133 restore_cpu(int oldcpu, int is_bound, struct thread *td)
134 {
135 
136 	KASSERT(oldcpu >= 0 && oldcpu <= mp_maxid && 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
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_maxid || !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_WRMSR || cmd == CPUCTL_UPDATE) &&
159 	    ((flags & FWRITE) == 0))
160 		return (EPERM);
161 	switch (cmd) {
162 	case CPUCTL_RDMSR:
163 		ret = cpuctl_do_msr(cpu, (cpuctl_msr_args_t *)data, cmd, td);
164 		break;
165 	case CPUCTL_MSRSBIT:
166 	case CPUCTL_MSRCBIT:
167 	case CPUCTL_WRMSR:
168 		ret = priv_check(td, PRIV_CPUCTL_WRMSR);
169 		if (ret != 0)
170 			goto fail;
171 		ret = cpuctl_do_msr(cpu, (cpuctl_msr_args_t *)data, cmd, td);
172 		break;
173 	case CPUCTL_CPUID:
174 		ret = cpuctl_do_cpuid(cpu, (cpuctl_cpuid_args_t *)data, td);
175 		break;
176 	case CPUCTL_UPDATE:
177 		ret = priv_check(td, PRIV_CPUCTL_UPDATE);
178 		if (ret != 0)
179 			goto fail;
180 		ret = cpuctl_do_update(cpu, (cpuctl_update_args_t *)data, td);
181 		break;
182 	case CPUCTL_CPUID_COUNT:
183 		ret = cpuctl_do_cpuid_count(cpu,
184 		    (cpuctl_cpuid_count_args_t *)data, td);
185 		break;
186 	default:
187 		ret = EINVAL;
188 		break;
189 	}
190 fail:
191 	return (ret);
192 }
193 
194 /*
195  * Actually perform cpuid operation.
196  */
197 static int
198 cpuctl_do_cpuid_count(int cpu, cpuctl_cpuid_count_args_t *data,
199     struct thread *td)
200 {
201 	int is_bound = 0;
202 	int oldcpu;
203 
204 	KASSERT(cpu >= 0 && cpu <= mp_maxid,
205 	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
206 
207 	/* Explicitly clear cpuid data to avoid returning stale info. */
208 	bzero(data->data, sizeof(data->data));
209 	DPRINTF("[cpuctl,%d]: retrieving cpuid lev %#0x type %#0x for %d cpu\n",
210 	    __LINE__, data->level, data->level_type, cpu);
211 #ifdef __i386__
212 	if (cpu_id == 0)
213 		return (ENODEV);
214 #endif
215 	oldcpu = td->td_oncpu;
216 	is_bound = cpu_sched_is_bound(td);
217 	set_cpu(cpu, td);
218 	cpuid_count(data->level, data->level_type, data->data);
219 	restore_cpu(oldcpu, is_bound, td);
220 	return (0);
221 }
222 
223 static int
224 cpuctl_do_cpuid(int cpu, cpuctl_cpuid_args_t *data, struct thread *td)
225 {
226 	cpuctl_cpuid_count_args_t cdata;
227 	int error;
228 
229 	cdata.level = data->level;
230 	/* Override the level type. */
231 	cdata.level_type = 0;
232 	error = cpuctl_do_cpuid_count(cpu, &cdata, td);
233 	bcopy(cdata.data, data->data, sizeof(data->data)); /* Ignore error */
234 	return (error);
235 }
236 
237 /*
238  * Actually perform MSR operations.
239  */
240 static int
241 cpuctl_do_msr(int cpu, cpuctl_msr_args_t *data, u_long cmd, struct thread *td)
242 {
243 	uint64_t reg;
244 	int is_bound = 0;
245 	int oldcpu;
246 	int ret;
247 
248 	KASSERT(cpu >= 0 && cpu <= mp_maxid,
249 	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
250 
251 	/*
252 	 * Explicitly clear cpuid data to avoid returning stale
253 	 * info
254 	 */
255 	DPRINTF("[cpuctl,%d]: operating on MSR %#0x for %d cpu\n", __LINE__,
256 	    data->msr, cpu);
257 #ifdef __i386__
258 	if ((cpu_feature & CPUID_MSR) == 0)
259 		return (ENODEV);
260 #endif
261 	oldcpu = td->td_oncpu;
262 	is_bound = cpu_sched_is_bound(td);
263 	set_cpu(cpu, td);
264 	if (cmd == CPUCTL_RDMSR) {
265 		data->data = 0;
266 		ret = rdmsr_safe(data->msr, &data->data);
267 	} else if (cmd == CPUCTL_WRMSR) {
268 		ret = wrmsr_safe(data->msr, data->data);
269 	} else if (cmd == CPUCTL_MSRSBIT) {
270 		critical_enter();
271 		ret = rdmsr_safe(data->msr, &reg);
272 		if (ret == 0)
273 			ret = wrmsr_safe(data->msr, reg | data->data);
274 		critical_exit();
275 	} else if (cmd == CPUCTL_MSRCBIT) {
276 		critical_enter();
277 		ret = rdmsr_safe(data->msr, &reg);
278 		if (ret == 0)
279 			ret = wrmsr_safe(data->msr, reg & ~data->data);
280 		critical_exit();
281 	} else
282 		panic("[cpuctl,%d]: unknown operation requested: %lu", __LINE__, cmd);
283 	restore_cpu(oldcpu, is_bound, td);
284 	return (ret);
285 }
286 
287 /*
288  * Actually perform microcode update.
289  */
290 static int
291 cpuctl_do_update(int cpu, cpuctl_update_args_t *data, struct thread *td)
292 {
293 	cpuctl_cpuid_args_t args = {
294 		.level = 0,
295 	};
296 	char vendor[13];
297 	int ret;
298 
299 	KASSERT(cpu >= 0 && cpu <= mp_maxid,
300 	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
301 	DPRINTF("[cpuctl,%d]: XXX %d", __LINE__, cpu);
302 
303 	ret = cpuctl_do_cpuid(cpu, &args, td);
304 	if (ret != 0)
305 		return (ret);
306 	((uint32_t *)vendor)[0] = args.data[1];
307 	((uint32_t *)vendor)[1] = args.data[3];
308 	((uint32_t *)vendor)[2] = args.data[2];
309 	vendor[12] = '\0';
310 	if (strncmp(vendor, INTEL_VENDOR_ID, sizeof(INTEL_VENDOR_ID)) == 0)
311 		ret = update_intel(cpu, data, td);
312 	else if(strncmp(vendor, AMD_VENDOR_ID, sizeof(AMD_VENDOR_ID)) == 0)
313 		ret = update_amd(cpu, data, td);
314 	else if(strncmp(vendor, CENTAUR_VENDOR_ID, sizeof(CENTAUR_VENDOR_ID)) == 0)
315 		ret = update_via(cpu, data, td);
316 	else
317 		ret = ENXIO;
318 	return (ret);
319 }
320 
321 static int
322 update_intel(int cpu, cpuctl_update_args_t *args, struct thread *td)
323 {
324 	void *ptr;
325 	uint64_t rev0, rev1;
326 	uint32_t tmp[4];
327 	int is_bound;
328 	int oldcpu;
329 	int ret;
330 
331 	if (args->size == 0 || args->data == NULL) {
332 		DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
333 		return (EINVAL);
334 	}
335 	if (args->size > UCODE_SIZE_MAX) {
336 		DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
337 		return (EINVAL);
338 	}
339 
340 	/*
341 	 * 16 byte alignment required.  Rely on the fact that
342 	 * malloc(9) always returns the pointer aligned at least on
343 	 * the size of the allocation.
344 	 */
345 	ptr = malloc(args->size + 16, M_CPUCTL, M_WAITOK);
346 	if (copyin(args->data, ptr, args->size) != 0) {
347 		DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
348 		    __LINE__, args->data, ptr, args->size);
349 		ret = EFAULT;
350 		goto fail;
351 	}
352 	oldcpu = td->td_oncpu;
353 	is_bound = cpu_sched_is_bound(td);
354 	set_cpu(cpu, td);
355 	critical_enter();
356 	rdmsr_safe(MSR_BIOS_SIGN, &rev0); /* Get current microcode revision. */
357 
358 	/*
359 	 * Perform update.
360 	 */
361 	wrmsr_safe(MSR_BIOS_UPDT_TRIG, (uintptr_t)(ptr));
362 	wrmsr_safe(MSR_BIOS_SIGN, 0);
363 
364 	/*
365 	 * Serialize instruction flow.
366 	 */
367 	do_cpuid(0, tmp);
368 	critical_exit();
369 	rdmsr_safe(MSR_BIOS_SIGN, &rev1); /* Get new microcode revision. */
370 	restore_cpu(oldcpu, is_bound, td);
371 	if (rev1 > rev0)
372 		ret = 0;
373 	else
374 		ret = EEXIST;
375 fail:
376 	free(ptr, M_CPUCTL);
377 	return (ret);
378 }
379 
380 /*
381  * NB: MSR 0xc0010020, MSR_K8_UCODE_UPDATE, is not documented by AMD.
382  * Coreboot, illumos and Linux source code was used to understand
383  * its workings.
384  */
385 static void
386 amd_ucode_wrmsr(void *ucode_ptr)
387 {
388 	uint32_t tmp[4];
389 
390 	wrmsr_safe(MSR_K8_UCODE_UPDATE, (uintptr_t)ucode_ptr);
391 	do_cpuid(0, tmp);
392 }
393 
394 static int
395 update_amd(int cpu, cpuctl_update_args_t *args, struct thread *td)
396 {
397 	void *ptr;
398 	int ret;
399 
400 	if (args->size == 0 || args->data == NULL) {
401 		DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
402 		return (EINVAL);
403 	}
404 	if (args->size > UCODE_SIZE_MAX) {
405 		DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
406 		return (EINVAL);
407 	}
408 
409 	/*
410 	 * 16 byte alignment required.  Rely on the fact that
411 	 * malloc(9) always returns the pointer aligned at least on
412 	 * the size of the allocation.
413 	 */
414 	ptr = malloc(args->size + 16, M_CPUCTL, M_ZERO | M_WAITOK);
415 	if (copyin(args->data, ptr, args->size) != 0) {
416 		DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
417 		    __LINE__, args->data, ptr, args->size);
418 		ret = EFAULT;
419 		goto fail;
420 	}
421 	smp_rendezvous(NULL, amd_ucode_wrmsr, NULL, ptr);
422 	ret = 0;
423 fail:
424 	free(ptr, M_CPUCTL);
425 	return (ret);
426 }
427 
428 static int
429 update_via(int cpu, cpuctl_update_args_t *args, struct thread *td)
430 {
431 	void *ptr;
432 	uint64_t rev0, rev1, res;
433 	uint32_t tmp[4];
434 	int is_bound;
435 	int oldcpu;
436 	int ret;
437 
438 	if (args->size == 0 || args->data == NULL) {
439 		DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
440 		return (EINVAL);
441 	}
442 	if (args->size > UCODE_SIZE_MAX) {
443 		DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
444 		return (EINVAL);
445 	}
446 
447 	/*
448 	 * 4 byte alignment required.
449 	 */
450 	ptr = malloc(args->size, M_CPUCTL, M_WAITOK);
451 	if (copyin(args->data, ptr, args->size) != 0) {
452 		DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
453 		    __LINE__, args->data, ptr, args->size);
454 		ret = EFAULT;
455 		goto fail;
456 	}
457 	oldcpu = td->td_oncpu;
458 	is_bound = cpu_sched_is_bound(td);
459 	set_cpu(cpu, td);
460 	critical_enter();
461 	rdmsr_safe(MSR_BIOS_SIGN, &rev0); /* Get current microcode revision. */
462 
463 	/*
464 	 * Perform update.
465 	 */
466 	wrmsr_safe(MSR_BIOS_UPDT_TRIG, (uintptr_t)(ptr));
467 	do_cpuid(1, tmp);
468 
469 	/*
470 	 * Result are in low byte of MSR FCR5:
471 	 * 0x00: No update has been attempted since RESET.
472 	 * 0x01: The last attempted update was successful.
473 	 * 0x02: The last attempted update was unsuccessful due to a bad
474 	 *       environment. No update was loaded and any preexisting
475 	 *       patches are still active.
476 	 * 0x03: The last attempted update was not applicable to this processor.
477 	 *       No update was loaded and any preexisting patches are still
478 	 *       active.
479 	 * 0x04: The last attempted update was not successful due to an invalid
480 	 *       update data block. No update was loaded and any preexisting
481 	 *       patches are still active
482 	 */
483 	rdmsr_safe(0x1205, &res);
484 	res &= 0xff;
485 	critical_exit();
486 	rdmsr_safe(MSR_BIOS_SIGN, &rev1); /* Get new microcode revision. */
487 	restore_cpu(oldcpu, is_bound, td);
488 
489 	DPRINTF("[cpu,%d]: rev0=%x rev1=%x res=%x\n", __LINE__,
490 	    (unsigned)(rev0 >> 32), (unsigned)(rev1 >> 32), (unsigned)res);
491 
492 	if (res != 0x01)
493 		ret = EINVAL;
494 	else
495 		ret = 0;
496 fail:
497 	free(ptr, M_CPUCTL);
498 	return (ret);
499 }
500 
501 int
502 cpuctl_open(struct cdev *dev, int flags, int fmt __unused, struct thread *td)
503 {
504 	int ret = 0;
505 	int cpu;
506 
507 	cpu = dev2unit(dev);
508 	if (cpu > mp_maxid || !cpu_enabled(cpu)) {
509 		DPRINTF("[cpuctl,%d]: incorrect cpu number %d\n", __LINE__,
510 		    cpu);
511 		return (ENXIO);
512 	}
513 	if (flags & FWRITE)
514 		ret = securelevel_gt(td->td_ucred, 0);
515 	return (ret);
516 }
517 
518 static int
519 cpuctl_modevent(module_t mod __unused, int type, void *data __unused)
520 {
521 	int cpu;
522 
523 	switch(type) {
524 	case MOD_LOAD:
525 		if (bootverbose)
526 			printf("cpuctl: access to MSR registers/cpuid info.\n");
527 		cpuctl_devs = malloc(sizeof(*cpuctl_devs) * (mp_maxid + 1), M_CPUCTL,
528 		    M_WAITOK | M_ZERO);
529 		CPU_FOREACH(cpu)
530 			if (cpu_enabled(cpu))
531 				cpuctl_devs[cpu] = make_dev(&cpuctl_cdevsw, cpu,
532 				    UID_ROOT, GID_KMEM, 0640, "cpuctl%d", cpu);
533 		break;
534 	case MOD_UNLOAD:
535 		CPU_FOREACH(cpu) {
536 			if (cpuctl_devs[cpu] != NULL)
537 				destroy_dev(cpuctl_devs[cpu]);
538 		}
539 		free(cpuctl_devs, M_CPUCTL);
540 		break;
541 	case MOD_SHUTDOWN:
542 		break;
543 	default:
544 		return (EOPNOTSUPP);
545         }
546 	return (0);
547 }
548 
549 DEV_MODULE(cpuctl, cpuctl_modevent, NULL);
550 MODULE_VERSION(cpuctl, CPUCTL_VERSION);
551