xref: /freebsd/sys/dev/cpuctl/cpuctl.c (revision 3a92d97ff0f22d21608e1c19b83104c4937523b6)
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	(16 * 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_update(int cpu, cpuctl_update_args_t *data,
73     struct thread *td);
74 static int update_intel(int cpu, cpuctl_update_args_t *args,
75     struct thread *td);
76 static int update_amd(int cpu, cpuctl_update_args_t *args, struct thread *td);
77 static int update_via(int cpu, cpuctl_update_args_t *args,
78     struct thread *td);
79 
80 static struct cdev **cpuctl_devs;
81 static MALLOC_DEFINE(M_CPUCTL, "cpuctl", "CPUCTL buffer");
82 
83 static struct cdevsw cpuctl_cdevsw = {
84         .d_version =    D_VERSION,
85         .d_open =       cpuctl_open,
86         .d_ioctl =      cpuctl_ioctl,
87         .d_name =       "cpuctl",
88 };
89 
90 /*
91  * This function checks if specified cpu enabled or not.
92  */
93 static int
94 cpu_enabled(int cpu)
95 {
96 
97 	return (pmc_cpu_is_disabled(cpu) == 0);
98 }
99 
100 /*
101  * Check if the current thread is bound to a specific cpu.
102  */
103 static int
104 cpu_sched_is_bound(struct thread *td)
105 {
106 	int ret;
107 
108 	thread_lock(td);
109 	ret = sched_is_bound(td);
110 	thread_unlock(td);
111 	return (ret);
112 }
113 
114 /*
115  * Switch to target cpu to run.
116  */
117 static void
118 set_cpu(int cpu, struct thread *td)
119 {
120 
121 	KASSERT(cpu >= 0 && cpu < mp_ncpus && cpu_enabled(cpu),
122 	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
123 	thread_lock(td);
124 	sched_bind(td, cpu);
125 	thread_unlock(td);
126 	KASSERT(td->td_oncpu == cpu,
127 	    ("[cpuctl,%d]: cannot bind to target cpu %d", __LINE__, cpu));
128 }
129 
130 static void
131 restore_cpu(int oldcpu, int is_bound, struct thread *td)
132 {
133 
134 	KASSERT(oldcpu >= 0 && oldcpu < mp_ncpus && cpu_enabled(oldcpu),
135 	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, oldcpu));
136 	thread_lock(td);
137 	if (is_bound == 0)
138 		sched_unbind(td);
139 	else
140 		sched_bind(td, oldcpu);
141 	thread_unlock(td);
142 }
143 
144 int
145 cpuctl_ioctl(struct cdev *dev, u_long cmd, caddr_t data,
146 	int flags, struct thread *td)
147 {
148 	int ret;
149 	int cpu = dev2unit(dev);
150 
151 	if (cpu >= mp_ncpus || !cpu_enabled(cpu)) {
152 		DPRINTF("[cpuctl,%d]: bad cpu number %d\n", __LINE__, cpu);
153 		return (ENXIO);
154 	}
155 	/* Require write flag for "write" requests. */
156 	if ((cmd == CPUCTL_WRMSR || cmd == CPUCTL_UPDATE) &&
157 	    ((flags & FWRITE) == 0))
158 		return (EPERM);
159 	switch (cmd) {
160 	case CPUCTL_RDMSR:
161 		ret = cpuctl_do_msr(cpu, (cpuctl_msr_args_t *)data, cmd, td);
162 		break;
163 	case CPUCTL_MSRSBIT:
164 	case CPUCTL_MSRCBIT:
165 	case CPUCTL_WRMSR:
166 		ret = priv_check(td, PRIV_CPUCTL_WRMSR);
167 		if (ret != 0)
168 			goto fail;
169 		ret = cpuctl_do_msr(cpu, (cpuctl_msr_args_t *)data, cmd, td);
170 		break;
171 	case CPUCTL_CPUID:
172 		ret = cpuctl_do_cpuid(cpu, (cpuctl_cpuid_args_t *)data, td);
173 		break;
174 	case CPUCTL_UPDATE:
175 		ret = priv_check(td, PRIV_CPUCTL_UPDATE);
176 		if (ret != 0)
177 			goto fail;
178 		ret = cpuctl_do_update(cpu, (cpuctl_update_args_t *)data, td);
179 		break;
180 	default:
181 		ret = EINVAL;
182 		break;
183 	}
184 fail:
185 	return (ret);
186 }
187 
188 /*
189  * Actually perform cpuid operation.
190  */
191 static int
192 cpuctl_do_cpuid(int cpu, cpuctl_cpuid_args_t *data, struct thread *td)
193 {
194 	int is_bound = 0;
195 	int oldcpu;
196 
197 	KASSERT(cpu >= 0 && cpu < mp_ncpus,
198 	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
199 
200 	/* Explicitly clear cpuid data to avoid returning stale info. */
201 	bzero(data->data, sizeof(data->data));
202 	DPRINTF("[cpuctl,%d]: retriving cpuid level %#0x for %d cpu\n",
203 	    __LINE__, data->level, cpu);
204 	oldcpu = td->td_oncpu;
205 	is_bound = cpu_sched_is_bound(td);
206 	set_cpu(cpu, td);
207 	cpuid_count(data->level, 0, data->data);
208 	restore_cpu(oldcpu, is_bound, td);
209 	return (0);
210 }
211 
212 /*
213  * Actually perform MSR operations.
214  */
215 static int
216 cpuctl_do_msr(int cpu, cpuctl_msr_args_t *data, u_long cmd, struct thread *td)
217 {
218 	uint64_t reg;
219 	int is_bound = 0;
220 	int oldcpu;
221 	int ret;
222 
223 	KASSERT(cpu >= 0 && cpu < mp_ncpus,
224 	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
225 
226 	/*
227 	 * Explicitly clear cpuid data to avoid returning stale
228 	 * info
229 	 */
230 	DPRINTF("[cpuctl,%d]: operating on MSR %#0x for %d cpu\n", __LINE__,
231 	    data->msr, cpu);
232 	oldcpu = td->td_oncpu;
233 	is_bound = cpu_sched_is_bound(td);
234 	set_cpu(cpu, td);
235 	if (cmd == CPUCTL_RDMSR) {
236 		data->data = 0;
237 		ret = rdmsr_safe(data->msr, &data->data);
238 	} else if (cmd == CPUCTL_WRMSR) {
239 		ret = wrmsr_safe(data->msr, data->data);
240 	} else if (cmd == CPUCTL_MSRSBIT) {
241 		critical_enter();
242 		ret = rdmsr_safe(data->msr, &reg);
243 		if (ret == 0)
244 			ret = wrmsr_safe(data->msr, reg | data->data);
245 		critical_exit();
246 	} else if (cmd == CPUCTL_MSRCBIT) {
247 		critical_enter();
248 		ret = rdmsr_safe(data->msr, &reg);
249 		if (ret == 0)
250 			ret = wrmsr_safe(data->msr, reg & ~data->data);
251 		critical_exit();
252 	} else
253 		panic("[cpuctl,%d]: unknown operation requested: %lu", __LINE__, cmd);
254 	restore_cpu(oldcpu, is_bound, td);
255 	return (ret);
256 }
257 
258 /*
259  * Actually perform microcode update.
260  */
261 static int
262 cpuctl_do_update(int cpu, cpuctl_update_args_t *data, struct thread *td)
263 {
264 	cpuctl_cpuid_args_t args = {
265 		.level = 0,
266 	};
267 	char vendor[13];
268 	int ret;
269 
270 	KASSERT(cpu >= 0 && cpu < mp_ncpus,
271 	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
272 	DPRINTF("[cpuctl,%d]: XXX %d", __LINE__, cpu);
273 
274 	ret = cpuctl_do_cpuid(cpu, &args, td);
275 	if (ret != 0) {
276 		DPRINTF("[cpuctl,%d]: cannot retrive cpuid info for cpu %d",
277 		    __LINE__, cpu);
278 		return (ENXIO);
279 	}
280 	((uint32_t *)vendor)[0] = args.data[1];
281 	((uint32_t *)vendor)[1] = args.data[3];
282 	((uint32_t *)vendor)[2] = args.data[2];
283 	vendor[12] = '\0';
284 	if (strncmp(vendor, INTEL_VENDOR_ID, sizeof(INTEL_VENDOR_ID)) == 0)
285 		ret = update_intel(cpu, data, td);
286 	else if(strncmp(vendor, AMD_VENDOR_ID, sizeof(AMD_VENDOR_ID)) == 0)
287 		ret = update_amd(cpu, data, td);
288 	else if(strncmp(vendor, CENTAUR_VENDOR_ID, sizeof(CENTAUR_VENDOR_ID)) == 0)
289 		ret = update_via(cpu, data, td);
290 	else
291 		ret = ENXIO;
292 	return (ret);
293 }
294 
295 static int
296 update_intel(int cpu, cpuctl_update_args_t *args, struct thread *td)
297 {
298 	void *ptr;
299 	uint64_t rev0, rev1;
300 	uint32_t tmp[4];
301 	int is_bound;
302 	int oldcpu;
303 	int ret;
304 
305 	if (args->size == 0 || args->data == NULL) {
306 		DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
307 		return (EINVAL);
308 	}
309 	if (args->size > UCODE_SIZE_MAX) {
310 		DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
311 		return (EINVAL);
312 	}
313 
314 	/*
315 	 * 16 byte alignment required.  Rely on the fact that
316 	 * malloc(9) always returns the pointer aligned at least on
317 	 * the size of the allocation.
318 	 */
319 	ptr = malloc(args->size + 16, M_CPUCTL, M_WAITOK);
320 	if (copyin(args->data, ptr, args->size) != 0) {
321 		DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
322 		    __LINE__, args->data, ptr, args->size);
323 		ret = EFAULT;
324 		goto fail;
325 	}
326 	oldcpu = td->td_oncpu;
327 	is_bound = cpu_sched_is_bound(td);
328 	set_cpu(cpu, td);
329 	critical_enter();
330 	rdmsr_safe(MSR_BIOS_SIGN, &rev0); /* Get current microcode revision. */
331 
332 	/*
333 	 * Perform update.
334 	 */
335 	wrmsr_safe(MSR_BIOS_UPDT_TRIG, (uintptr_t)(ptr));
336 	wrmsr_safe(MSR_BIOS_SIGN, 0);
337 
338 	/*
339 	 * Serialize instruction flow.
340 	 */
341 	do_cpuid(0, tmp);
342 	critical_exit();
343 	rdmsr_safe(MSR_BIOS_SIGN, &rev1); /* Get new microcode revision. */
344 	restore_cpu(oldcpu, is_bound, td);
345 	if (rev1 > rev0)
346 		ret = 0;
347 	else
348 		ret = EEXIST;
349 fail:
350 	free(ptr, M_CPUCTL);
351 	return (ret);
352 }
353 
354 static int
355 update_amd(int cpu, cpuctl_update_args_t *args, struct thread *td)
356 {
357 	void *ptr = NULL;
358 	uint32_t tmp[4];
359 	int is_bound = 0;
360 	int oldcpu;
361 	int ret;
362 
363 	if (args->size == 0 || args->data == NULL) {
364 		DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
365 		return (EINVAL);
366 	}
367 	if (args->size > UCODE_SIZE_MAX) {
368 		DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
369 		return (EINVAL);
370 	}
371 	/*
372 	 * XXX Might not require contignous address space - needs check
373 	 */
374 	ptr = contigmalloc(args->size, M_CPUCTL, 0, 0, 0xffffffff, 16, 0);
375 	if (ptr == NULL) {
376 		DPRINTF("[cpuctl,%d]: cannot allocate %zd bytes of memory",
377 		    __LINE__, args->size);
378 		return (ENOMEM);
379 	}
380 	if (copyin(args->data, ptr, args->size) != 0) {
381 		DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
382 		    __LINE__, args->data, ptr, args->size);
383 		ret = EFAULT;
384 		goto fail;
385 	}
386 	oldcpu = td->td_oncpu;
387 	is_bound = cpu_sched_is_bound(td);
388 	set_cpu(cpu, td);
389 	critical_enter();
390 
391 	/*
392 	 * Perform update.
393 	 */
394 	wrmsr_safe(MSR_K8_UCODE_UPDATE, (uintptr_t)ptr);
395 
396 	/*
397 	 * Serialize instruction flow.
398 	 */
399 	do_cpuid(0, tmp);
400 	critical_exit();
401 	restore_cpu(oldcpu, is_bound, td);
402 	ret = 0;
403 fail:
404 	if (ptr != NULL)
405 		contigfree(ptr, args->size, M_CPUCTL);
406 	return (ret);
407 }
408 
409 static int
410 update_via(int cpu, cpuctl_update_args_t *args, struct thread *td)
411 {
412 	void *ptr;
413 	uint64_t rev0, rev1, res;
414 	uint32_t tmp[4];
415 	int is_bound;
416 	int oldcpu;
417 	int ret;
418 
419 	if (args->size == 0 || args->data == NULL) {
420 		DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
421 		return (EINVAL);
422 	}
423 	if (args->size > UCODE_SIZE_MAX) {
424 		DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
425 		return (EINVAL);
426 	}
427 
428 	/*
429 	 * 4 byte alignment required.
430 	 */
431 	ptr = malloc(args->size, M_CPUCTL, M_WAITOK);
432 	if (copyin(args->data, ptr, args->size) != 0) {
433 		DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
434 		    __LINE__, args->data, ptr, args->size);
435 		ret = EFAULT;
436 		goto fail;
437 	}
438 	oldcpu = td->td_oncpu;
439 	is_bound = cpu_sched_is_bound(td);
440 	set_cpu(cpu, td);
441 	critical_enter();
442 	rdmsr_safe(MSR_BIOS_SIGN, &rev0); /* Get current microcode revision. */
443 
444 	/*
445 	 * Perform update.
446 	 */
447 	wrmsr_safe(MSR_BIOS_UPDT_TRIG, (uintptr_t)(ptr));
448 	do_cpuid(1, tmp);
449 
450 	/*
451 	 * Result are in low byte of MSR FCR5:
452 	 * 0x00: No update has been attempted since RESET.
453 	 * 0x01: The last attempted update was successful.
454 	 * 0x02: The last attempted update was unsuccessful due to a bad
455 	 *       environment. No update was loaded and any preexisting
456 	 *       patches are still active.
457 	 * 0x03: The last attempted update was not applicable to this processor.
458 	 *       No update was loaded and any preexisting patches are still
459 	 *       active.
460 	 * 0x04: The last attempted update was not successful due to an invalid
461 	 *       update data block. No update was loaded and any preexisting
462 	 *       patches are still active
463 	 */
464 	rdmsr_safe(0x1205, &res);
465 	res &= 0xff;
466 	critical_exit();
467 	rdmsr_safe(MSR_BIOS_SIGN, &rev1); /* Get new microcode revision. */
468 	restore_cpu(oldcpu, is_bound, td);
469 
470 	DPRINTF("[cpu,%d]: rev0=%x rev1=%x res=%x\n", __LINE__,
471 	    (unsigned)(rev0 >> 32), (unsigned)(rev1 >> 32), (unsigned)res);
472 
473 	if (res != 0x01)
474 		ret = EINVAL;
475 	else
476 		ret = 0;
477 fail:
478 	free(ptr, M_CPUCTL);
479 	return (ret);
480 }
481 
482 int
483 cpuctl_open(struct cdev *dev, int flags, int fmt __unused, struct thread *td)
484 {
485 	int ret = 0;
486 	int cpu;
487 
488 	cpu = dev2unit(dev);
489 	if (cpu >= mp_ncpus || !cpu_enabled(cpu)) {
490 		DPRINTF("[cpuctl,%d]: incorrect cpu number %d\n", __LINE__,
491 		    cpu);
492 		return (ENXIO);
493 	}
494 	if (flags & FWRITE)
495 		ret = securelevel_gt(td->td_ucred, 0);
496 	return (ret);
497 }
498 
499 static int
500 cpuctl_modevent(module_t mod __unused, int type, void *data __unused)
501 {
502 	int cpu;
503 
504 	switch(type) {
505 	case MOD_LOAD:
506 		if ((cpu_feature & CPUID_MSR) == 0) {
507 			if (bootverbose)
508 				printf("cpuctl: not available.\n");
509 			return (ENODEV);
510 		}
511 		if (bootverbose)
512 			printf("cpuctl: access to MSR registers/cpuid info.\n");
513 		cpuctl_devs = malloc(sizeof(*cpuctl_devs) * mp_ncpus, M_CPUCTL,
514 		    M_WAITOK | M_ZERO);
515 		for (cpu = 0; cpu < mp_ncpus; cpu++)
516 			if (cpu_enabled(cpu))
517 				cpuctl_devs[cpu] = make_dev(&cpuctl_cdevsw, cpu,
518 				    UID_ROOT, GID_KMEM, 0640, "cpuctl%d", cpu);
519 		break;
520 	case MOD_UNLOAD:
521 		for (cpu = 0; cpu < mp_ncpus; cpu++) {
522 			if (cpuctl_devs[cpu] != NULL)
523 				destroy_dev(cpuctl_devs[cpu]);
524 		}
525 		free(cpuctl_devs, M_CPUCTL);
526 		break;
527 	case MOD_SHUTDOWN:
528 		break;
529 	default:
530 		return (EOPNOTSUPP);
531         }
532 	return (0);
533 }
534 
535 DEV_MODULE(cpuctl, cpuctl_modevent, NULL);
536 MODULE_VERSION(cpuctl, CPUCTL_VERSION);
537