xref: /freebsd/sys/dev/cpuctl/cpuctl.c (revision a812392203d7c4c3f0db9d8a0f3391374c49c71f)
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 DEBUG
61 # define	DPRINTF(format,...) printf(format, __VA_ARGS__);
62 #else
63 # define	DPRINTF(...)
64 #endif
65 
66 #define	UCODE_SIZE_MAX	(32 * 1024)
67 
68 static int cpuctl_do_msr(int cpu, cpuctl_msr_args_t *data, u_long cmd,
69     struct thread *td);
70 static void cpuctl_do_cpuid(int cpu, cpuctl_cpuid_args_t *data,
71     struct thread *td);
72 static void 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_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
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
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_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 		cpuctl_do_cpuid(cpu, (cpuctl_cpuid_args_t *)data, td);
175 		ret = 0;
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 		cpuctl_do_cpuid_count(cpu, (cpuctl_cpuid_count_args_t *)data,
185 		    td);
186 		ret = 0;
187 		break;
188 	default:
189 		ret = EINVAL;
190 		break;
191 	}
192 fail:
193 	return (ret);
194 }
195 
196 /*
197  * Actually perform cpuid operation.
198  */
199 static void
200 cpuctl_do_cpuid_count(int cpu, cpuctl_cpuid_count_args_t *data,
201     struct thread *td)
202 {
203 	int is_bound = 0;
204 	int oldcpu;
205 
206 	KASSERT(cpu >= 0 && cpu < mp_ncpus,
207 	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
208 
209 	/* Explicitly clear cpuid data to avoid returning stale info. */
210 	bzero(data->data, sizeof(data->data));
211 	DPRINTF("[cpuctl,%d]: retrieving cpuid lev %#0x type %#0x for %d cpu\n",
212 	    __LINE__, data->level, data->level_type, cpu);
213 	oldcpu = td->td_oncpu;
214 	is_bound = cpu_sched_is_bound(td);
215 	set_cpu(cpu, td);
216 	cpuid_count(data->level, data->level_type, data->data);
217 	restore_cpu(oldcpu, is_bound, td);
218 }
219 
220 static void
221 cpuctl_do_cpuid(int cpu, cpuctl_cpuid_args_t *data, struct thread *td)
222 {
223 	cpuctl_cpuid_count_args_t cdata;
224 
225 	cdata.level = data->level;
226 	/* Override the level type. */
227 	cdata.level_type = 0;
228 	cpuctl_do_cpuid_count(cpu, &cdata, td);
229 	bcopy(cdata.data, data->data, sizeof(data->data)); /* Ignore error */
230 }
231 
232 /*
233  * Actually perform MSR operations.
234  */
235 static int
236 cpuctl_do_msr(int cpu, cpuctl_msr_args_t *data, u_long cmd, struct thread *td)
237 {
238 	uint64_t reg;
239 	int is_bound = 0;
240 	int oldcpu;
241 	int ret;
242 
243 	KASSERT(cpu >= 0 && cpu < mp_ncpus,
244 	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
245 
246 	/*
247 	 * Explicitly clear cpuid data to avoid returning stale
248 	 * info
249 	 */
250 	DPRINTF("[cpuctl,%d]: operating on MSR %#0x for %d cpu\n", __LINE__,
251 	    data->msr, cpu);
252 	oldcpu = td->td_oncpu;
253 	is_bound = cpu_sched_is_bound(td);
254 	set_cpu(cpu, td);
255 	if (cmd == CPUCTL_RDMSR) {
256 		data->data = 0;
257 		ret = rdmsr_safe(data->msr, &data->data);
258 	} else if (cmd == CPUCTL_WRMSR) {
259 		ret = wrmsr_safe(data->msr, data->data);
260 	} else if (cmd == CPUCTL_MSRSBIT) {
261 		critical_enter();
262 		ret = rdmsr_safe(data->msr, &reg);
263 		if (ret == 0)
264 			ret = wrmsr_safe(data->msr, reg | data->data);
265 		critical_exit();
266 	} else if (cmd == CPUCTL_MSRCBIT) {
267 		critical_enter();
268 		ret = rdmsr_safe(data->msr, &reg);
269 		if (ret == 0)
270 			ret = wrmsr_safe(data->msr, reg & ~data->data);
271 		critical_exit();
272 	} else
273 		panic("[cpuctl,%d]: unknown operation requested: %lu", __LINE__, cmd);
274 	restore_cpu(oldcpu, is_bound, td);
275 	return (ret);
276 }
277 
278 /*
279  * Actually perform microcode update.
280  */
281 static int
282 cpuctl_do_update(int cpu, cpuctl_update_args_t *data, struct thread *td)
283 {
284 	cpuctl_cpuid_args_t args = {
285 		.level = 0,
286 	};
287 	char vendor[13];
288 	int ret;
289 
290 	KASSERT(cpu >= 0 && cpu < mp_ncpus,
291 	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
292 	DPRINTF("[cpuctl,%d]: XXX %d", __LINE__, cpu);
293 
294 	cpuctl_do_cpuid(cpu, &args, td);
295 	((uint32_t *)vendor)[0] = args.data[1];
296 	((uint32_t *)vendor)[1] = args.data[3];
297 	((uint32_t *)vendor)[2] = args.data[2];
298 	vendor[12] = '\0';
299 	if (strncmp(vendor, INTEL_VENDOR_ID, sizeof(INTEL_VENDOR_ID)) == 0)
300 		ret = update_intel(cpu, data, td);
301 	else if(strncmp(vendor, AMD_VENDOR_ID, sizeof(AMD_VENDOR_ID)) == 0)
302 		ret = update_amd(cpu, data, td);
303 	else if(strncmp(vendor, CENTAUR_VENDOR_ID, sizeof(CENTAUR_VENDOR_ID)) == 0)
304 		ret = update_via(cpu, data, td);
305 	else
306 		ret = ENXIO;
307 	return (ret);
308 }
309 
310 static int
311 update_intel(int cpu, cpuctl_update_args_t *args, struct thread *td)
312 {
313 	void *ptr;
314 	uint64_t rev0, rev1;
315 	uint32_t tmp[4];
316 	int is_bound;
317 	int oldcpu;
318 	int ret;
319 
320 	if (args->size == 0 || args->data == NULL) {
321 		DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
322 		return (EINVAL);
323 	}
324 	if (args->size > UCODE_SIZE_MAX) {
325 		DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
326 		return (EINVAL);
327 	}
328 
329 	/*
330 	 * 16 byte alignment required.  Rely on the fact that
331 	 * malloc(9) always returns the pointer aligned at least on
332 	 * the size of the allocation.
333 	 */
334 	ptr = malloc(args->size + 16, M_CPUCTL, M_WAITOK);
335 	if (copyin(args->data, ptr, args->size) != 0) {
336 		DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
337 		    __LINE__, args->data, ptr, args->size);
338 		ret = EFAULT;
339 		goto fail;
340 	}
341 	oldcpu = td->td_oncpu;
342 	is_bound = cpu_sched_is_bound(td);
343 	set_cpu(cpu, td);
344 	critical_enter();
345 	rdmsr_safe(MSR_BIOS_SIGN, &rev0); /* Get current microcode revision. */
346 
347 	/*
348 	 * Perform update.
349 	 */
350 	wrmsr_safe(MSR_BIOS_UPDT_TRIG, (uintptr_t)(ptr));
351 	wrmsr_safe(MSR_BIOS_SIGN, 0);
352 
353 	/*
354 	 * Serialize instruction flow.
355 	 */
356 	do_cpuid(0, tmp);
357 	critical_exit();
358 	rdmsr_safe(MSR_BIOS_SIGN, &rev1); /* Get new microcode revision. */
359 	restore_cpu(oldcpu, is_bound, td);
360 	if (rev1 > rev0)
361 		ret = 0;
362 	else
363 		ret = EEXIST;
364 fail:
365 	free(ptr, M_CPUCTL);
366 	return (ret);
367 }
368 
369 static int
370 update_amd(int cpu, cpuctl_update_args_t *args, struct thread *td)
371 {
372 	void *ptr = NULL;
373 	uint32_t tmp[4];
374 	int is_bound = 0;
375 	int oldcpu;
376 	int ret;
377 
378 	if (args->size == 0 || args->data == NULL) {
379 		DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
380 		return (EINVAL);
381 	}
382 	if (args->size > UCODE_SIZE_MAX) {
383 		DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
384 		return (EINVAL);
385 	}
386 	/*
387 	 * XXX Might not require contignous address space - needs check
388 	 */
389 	ptr = contigmalloc(args->size, M_CPUCTL, 0, 0, 0xffffffff, 16, 0);
390 	if (ptr == NULL) {
391 		DPRINTF("[cpuctl,%d]: cannot allocate %zd bytes of memory",
392 		    __LINE__, args->size);
393 		return (ENOMEM);
394 	}
395 	if (copyin(args->data, ptr, args->size) != 0) {
396 		DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
397 		    __LINE__, args->data, ptr, args->size);
398 		ret = EFAULT;
399 		goto fail;
400 	}
401 	oldcpu = td->td_oncpu;
402 	is_bound = cpu_sched_is_bound(td);
403 	set_cpu(cpu, td);
404 	critical_enter();
405 
406 	/*
407 	 * Perform update.
408 	 */
409 	wrmsr_safe(MSR_K8_UCODE_UPDATE, (uintptr_t)ptr);
410 
411 	/*
412 	 * Serialize instruction flow.
413 	 */
414 	do_cpuid(0, tmp);
415 	critical_exit();
416 	restore_cpu(oldcpu, is_bound, td);
417 	ret = 0;
418 fail:
419 	if (ptr != NULL)
420 		contigfree(ptr, args->size, M_CPUCTL);
421 	return (ret);
422 }
423 
424 static int
425 update_via(int cpu, cpuctl_update_args_t *args, struct thread *td)
426 {
427 	void *ptr;
428 	uint64_t rev0, rev1, res;
429 	uint32_t tmp[4];
430 	int is_bound;
431 	int oldcpu;
432 	int ret;
433 
434 	if (args->size == 0 || args->data == NULL) {
435 		DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
436 		return (EINVAL);
437 	}
438 	if (args->size > UCODE_SIZE_MAX) {
439 		DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
440 		return (EINVAL);
441 	}
442 
443 	/*
444 	 * 4 byte alignment required.
445 	 */
446 	ptr = malloc(args->size, M_CPUCTL, M_WAITOK);
447 	if (copyin(args->data, ptr, args->size) != 0) {
448 		DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
449 		    __LINE__, args->data, ptr, args->size);
450 		ret = EFAULT;
451 		goto fail;
452 	}
453 	oldcpu = td->td_oncpu;
454 	is_bound = cpu_sched_is_bound(td);
455 	set_cpu(cpu, td);
456 	critical_enter();
457 	rdmsr_safe(MSR_BIOS_SIGN, &rev0); /* Get current microcode revision. */
458 
459 	/*
460 	 * Perform update.
461 	 */
462 	wrmsr_safe(MSR_BIOS_UPDT_TRIG, (uintptr_t)(ptr));
463 	do_cpuid(1, tmp);
464 
465 	/*
466 	 * Result are in low byte of MSR FCR5:
467 	 * 0x00: No update has been attempted since RESET.
468 	 * 0x01: The last attempted update was successful.
469 	 * 0x02: The last attempted update was unsuccessful due to a bad
470 	 *       environment. No update was loaded and any preexisting
471 	 *       patches are still active.
472 	 * 0x03: The last attempted update was not applicable to this processor.
473 	 *       No update was loaded and any preexisting patches are still
474 	 *       active.
475 	 * 0x04: The last attempted update was not successful due to an invalid
476 	 *       update data block. No update was loaded and any preexisting
477 	 *       patches are still active
478 	 */
479 	rdmsr_safe(0x1205, &res);
480 	res &= 0xff;
481 	critical_exit();
482 	rdmsr_safe(MSR_BIOS_SIGN, &rev1); /* Get new microcode revision. */
483 	restore_cpu(oldcpu, is_bound, td);
484 
485 	DPRINTF("[cpu,%d]: rev0=%x rev1=%x res=%x\n", __LINE__,
486 	    (unsigned)(rev0 >> 32), (unsigned)(rev1 >> 32), (unsigned)res);
487 
488 	if (res != 0x01)
489 		ret = EINVAL;
490 	else
491 		ret = 0;
492 fail:
493 	free(ptr, M_CPUCTL);
494 	return (ret);
495 }
496 
497 int
498 cpuctl_open(struct cdev *dev, int flags, int fmt __unused, struct thread *td)
499 {
500 	int ret = 0;
501 	int cpu;
502 
503 	cpu = dev2unit(dev);
504 	if (cpu >= mp_ncpus || !cpu_enabled(cpu)) {
505 		DPRINTF("[cpuctl,%d]: incorrect cpu number %d\n", __LINE__,
506 		    cpu);
507 		return (ENXIO);
508 	}
509 	if (flags & FWRITE)
510 		ret = securelevel_gt(td->td_ucred, 0);
511 	return (ret);
512 }
513 
514 static int
515 cpuctl_modevent(module_t mod __unused, int type, void *data __unused)
516 {
517 	int cpu;
518 
519 	switch(type) {
520 	case MOD_LOAD:
521 		if ((cpu_feature & CPUID_MSR) == 0) {
522 			if (bootverbose)
523 				printf("cpuctl: not available.\n");
524 			return (ENODEV);
525 		}
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