xref: /freebsd/sys/dev/cpuctl/cpuctl.c (revision 0c54932d50a0cbffdd083bf6b2e8d587902f90c9)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2006-2008 Stanislav Sedov <stas@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/conf.h>
36 #include <sys/fcntl.h>
37 #include <sys/ioccom.h>
38 #include <sys/malloc.h>
39 #include <sys/module.h>
40 #include <sys/mutex.h>
41 #include <sys/priv.h>
42 #include <sys/proc.h>
43 #include <sys/queue.h>
44 #include <sys/sched.h>
45 #include <sys/kernel.h>
46 #include <sys/sysctl.h>
47 #include <sys/uio.h>
48 #include <sys/pcpu.h>
49 #include <sys/smp.h>
50 #include <sys/pmckern.h>
51 #include <sys/cpuctl.h>
52 
53 #include <vm/vm.h>
54 #include <vm/vm_param.h>
55 #include <vm/pmap.h>
56 
57 #include <machine/cpufunc.h>
58 #include <machine/md_var.h>
59 #include <machine/specialreg.h>
60 #include <x86/ucode.h>
61 
62 static d_open_t cpuctl_open;
63 static d_ioctl_t cpuctl_ioctl;
64 
65 #define	CPUCTL_VERSION 1
66 
67 #ifdef CPUCTL_DEBUG
68 # define	DPRINTF(format,...) printf(format, __VA_ARGS__);
69 #else
70 # define	DPRINTF(...)
71 #endif
72 
73 #define	UCODE_SIZE_MAX	(4 * 1024 * 1024)
74 
75 static int cpuctl_do_msr(int cpu, cpuctl_msr_args_t *data, u_long cmd,
76     struct thread *td);
77 static int cpuctl_do_cpuid(int cpu, cpuctl_cpuid_args_t *data,
78     struct thread *td);
79 static int cpuctl_do_cpuid_count(int cpu, cpuctl_cpuid_count_args_t *data,
80     struct thread *td);
81 static int cpuctl_do_eval_cpu_features(int cpu, struct thread *td);
82 static int cpuctl_do_update(int cpu, cpuctl_update_args_t *data,
83     struct thread *td);
84 static int update_intel(int cpu, cpuctl_update_args_t *args,
85     struct thread *td);
86 static int update_amd(int cpu, cpuctl_update_args_t *args, struct thread *td);
87 static int update_via(int cpu, cpuctl_update_args_t *args,
88     struct thread *td);
89 
90 static struct cdev **cpuctl_devs;
91 static MALLOC_DEFINE(M_CPUCTL, "cpuctl", "CPUCTL buffer");
92 
93 static struct cdevsw cpuctl_cdevsw = {
94         .d_version =    D_VERSION,
95         .d_open =       cpuctl_open,
96         .d_ioctl =      cpuctl_ioctl,
97         .d_name =       "cpuctl",
98 };
99 
100 /*
101  * This function checks if specified cpu enabled or not.
102  */
103 static int
104 cpu_enabled(int cpu)
105 {
106 
107 	return (pmc_cpu_is_disabled(cpu) == 0);
108 }
109 
110 /*
111  * Check if the current thread is bound to a specific cpu.
112  */
113 static int
114 cpu_sched_is_bound(struct thread *td)
115 {
116 	int ret;
117 
118 	thread_lock(td);
119 	ret = sched_is_bound(td);
120 	thread_unlock(td);
121 	return (ret);
122 }
123 
124 /*
125  * Switch to target cpu to run.
126  */
127 static void
128 set_cpu(int cpu, struct thread *td)
129 {
130 
131 	KASSERT(cpu >= 0 && cpu <= mp_maxid && cpu_enabled(cpu),
132 	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
133 	thread_lock(td);
134 	sched_bind(td, cpu);
135 	thread_unlock(td);
136 	KASSERT(td->td_oncpu == cpu,
137 	    ("[cpuctl,%d]: cannot bind to target cpu %d on cpu %d", __LINE__,
138 	    cpu, td->td_oncpu));
139 }
140 
141 static void
142 restore_cpu(int oldcpu, int is_bound, struct thread *td)
143 {
144 
145 	KASSERT(oldcpu >= 0 && oldcpu <= mp_maxid && cpu_enabled(oldcpu),
146 	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, oldcpu));
147 	thread_lock(td);
148 	if (is_bound == 0)
149 		sched_unbind(td);
150 	else
151 		sched_bind(td, oldcpu);
152 	thread_unlock(td);
153 }
154 
155 int
156 cpuctl_ioctl(struct cdev *dev, u_long cmd, caddr_t data,
157     int flags, struct thread *td)
158 {
159 	int cpu, ret;
160 
161 	cpu = dev2unit(dev);
162 	if (cpu > mp_maxid || !cpu_enabled(cpu)) {
163 		DPRINTF("[cpuctl,%d]: bad cpu number %d\n", __LINE__, cpu);
164 		return (ENXIO);
165 	}
166 	/* Require write flag for "write" requests. */
167 	if ((cmd == CPUCTL_MSRCBIT || cmd == CPUCTL_MSRSBIT ||
168 	    cmd == CPUCTL_UPDATE || cmd == CPUCTL_WRMSR ||
169 	    cmd == CPUCTL_EVAL_CPU_FEATURES) &&
170 	    (flags & FWRITE) == 0)
171 		return (EPERM);
172 	switch (cmd) {
173 	case CPUCTL_RDMSR:
174 		ret = cpuctl_do_msr(cpu, (cpuctl_msr_args_t *)data, cmd, td);
175 		break;
176 	case CPUCTL_MSRSBIT:
177 	case CPUCTL_MSRCBIT:
178 	case CPUCTL_WRMSR:
179 		ret = priv_check(td, PRIV_CPUCTL_WRMSR);
180 		if (ret != 0)
181 			goto fail;
182 		ret = cpuctl_do_msr(cpu, (cpuctl_msr_args_t *)data, cmd, td);
183 		break;
184 	case CPUCTL_CPUID:
185 		ret = cpuctl_do_cpuid(cpu, (cpuctl_cpuid_args_t *)data, td);
186 		break;
187 	case CPUCTL_UPDATE:
188 		ret = priv_check(td, PRIV_CPUCTL_UPDATE);
189 		if (ret != 0)
190 			goto fail;
191 		ret = cpuctl_do_update(cpu, (cpuctl_update_args_t *)data, td);
192 		break;
193 	case CPUCTL_CPUID_COUNT:
194 		ret = cpuctl_do_cpuid_count(cpu,
195 		    (cpuctl_cpuid_count_args_t *)data, td);
196 		break;
197 	case CPUCTL_EVAL_CPU_FEATURES:
198 		ret = cpuctl_do_eval_cpu_features(cpu, td);
199 		break;
200 	default:
201 		ret = EINVAL;
202 		break;
203 	}
204 fail:
205 	return (ret);
206 }
207 
208 /*
209  * Actually perform cpuid operation.
210  */
211 static int
212 cpuctl_do_cpuid_count(int cpu, cpuctl_cpuid_count_args_t *data,
213     struct thread *td)
214 {
215 	int is_bound = 0;
216 	int oldcpu;
217 
218 	KASSERT(cpu >= 0 && cpu <= mp_maxid,
219 	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
220 
221 	/* Explicitly clear cpuid data to avoid returning stale info. */
222 	bzero(data->data, sizeof(data->data));
223 	DPRINTF("[cpuctl,%d]: retrieving cpuid lev %#0x type %#0x for %d cpu\n",
224 	    __LINE__, data->level, data->level_type, cpu);
225 #ifdef __i386__
226 	if (cpu_id == 0)
227 		return (ENODEV);
228 #endif
229 	oldcpu = td->td_oncpu;
230 	is_bound = cpu_sched_is_bound(td);
231 	set_cpu(cpu, td);
232 	cpuid_count(data->level, data->level_type, data->data);
233 	restore_cpu(oldcpu, is_bound, td);
234 	return (0);
235 }
236 
237 static int
238 cpuctl_do_cpuid(int cpu, cpuctl_cpuid_args_t *data, struct thread *td)
239 {
240 	cpuctl_cpuid_count_args_t cdata;
241 	int error;
242 
243 	cdata.level = data->level;
244 	/* Override the level type. */
245 	cdata.level_type = 0;
246 	error = cpuctl_do_cpuid_count(cpu, &cdata, td);
247 	bcopy(cdata.data, data->data, sizeof(data->data)); /* Ignore error */
248 	return (error);
249 }
250 
251 /*
252  * Actually perform MSR operations.
253  */
254 static int
255 cpuctl_do_msr(int cpu, cpuctl_msr_args_t *data, u_long cmd, struct thread *td)
256 {
257 	uint64_t reg;
258 	int is_bound = 0;
259 	int oldcpu;
260 	int ret;
261 
262 	KASSERT(cpu >= 0 && cpu <= mp_maxid,
263 	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
264 
265 	/*
266 	 * Explicitly clear cpuid data to avoid returning stale
267 	 * info
268 	 */
269 	DPRINTF("[cpuctl,%d]: operating on MSR %#0x for %d cpu\n", __LINE__,
270 	    data->msr, cpu);
271 #ifdef __i386__
272 	if ((cpu_feature & CPUID_MSR) == 0)
273 		return (ENODEV);
274 #endif
275 	oldcpu = td->td_oncpu;
276 	is_bound = cpu_sched_is_bound(td);
277 	set_cpu(cpu, td);
278 	if (cmd == CPUCTL_RDMSR) {
279 		data->data = 0;
280 		ret = rdmsr_safe(data->msr, &data->data);
281 	} else if (cmd == CPUCTL_WRMSR) {
282 		ret = wrmsr_safe(data->msr, data->data);
283 	} else if (cmd == CPUCTL_MSRSBIT) {
284 		critical_enter();
285 		ret = rdmsr_safe(data->msr, &reg);
286 		if (ret == 0)
287 			ret = wrmsr_safe(data->msr, reg | data->data);
288 		critical_exit();
289 	} else if (cmd == CPUCTL_MSRCBIT) {
290 		critical_enter();
291 		ret = rdmsr_safe(data->msr, &reg);
292 		if (ret == 0)
293 			ret = wrmsr_safe(data->msr, reg & ~data->data);
294 		critical_exit();
295 	} else
296 		panic("[cpuctl,%d]: unknown operation requested: %lu",
297 		    __LINE__, cmd);
298 	restore_cpu(oldcpu, is_bound, td);
299 	return (ret);
300 }
301 
302 /*
303  * Actually perform microcode update.
304  */
305 static int
306 cpuctl_do_update(int cpu, cpuctl_update_args_t *data, struct thread *td)
307 {
308 	cpuctl_cpuid_args_t args = {
309 		.level = 0,
310 	};
311 	char vendor[13];
312 	int ret;
313 
314 	KASSERT(cpu >= 0 && cpu <= mp_maxid,
315 	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
316 	DPRINTF("[cpuctl,%d]: XXX %d", __LINE__, cpu);
317 
318 	ret = cpuctl_do_cpuid(cpu, &args, td);
319 	if (ret != 0)
320 		return (ret);
321 	((uint32_t *)vendor)[0] = args.data[1];
322 	((uint32_t *)vendor)[1] = args.data[3];
323 	((uint32_t *)vendor)[2] = args.data[2];
324 	vendor[12] = '\0';
325 	if (strncmp(vendor, INTEL_VENDOR_ID, sizeof(INTEL_VENDOR_ID)) == 0)
326 		ret = update_intel(cpu, data, td);
327 	else if(strncmp(vendor, AMD_VENDOR_ID, sizeof(AMD_VENDOR_ID)) == 0)
328 		ret = update_amd(cpu, data, td);
329 	else if(strncmp(vendor, CENTAUR_VENDOR_ID, sizeof(CENTAUR_VENDOR_ID))
330 	    == 0)
331 		ret = update_via(cpu, data, td);
332 	else
333 		ret = ENXIO;
334 	return (ret);
335 }
336 
337 struct ucode_update_data {
338 	void *ptr;
339 	int cpu;
340 	int ret;
341 };
342 
343 static void
344 ucode_intel_load_rv(void *arg)
345 {
346 	struct ucode_update_data *d;
347 
348 	d = arg;
349 	if (PCPU_GET(cpuid) == d->cpu)
350 		d->ret = ucode_intel_load(d->ptr, true, NULL, NULL);
351 }
352 
353 static int
354 update_intel(int cpu, cpuctl_update_args_t *args, struct thread *td)
355 {
356 	struct ucode_update_data d;
357 	void *ptr;
358 	int is_bound, oldcpu, ret;
359 
360 	if (args->size == 0 || args->data == NULL) {
361 		DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
362 		return (EINVAL);
363 	}
364 	if (args->size > UCODE_SIZE_MAX) {
365 		DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
366 		return (EINVAL);
367 	}
368 
369 	/*
370 	 * 16 byte alignment required.  Rely on the fact that
371 	 * malloc(9) always returns the pointer aligned at least on
372 	 * the size of the allocation.
373 	 */
374 	ptr = malloc(args->size + 16, M_CPUCTL, M_WAITOK);
375 	if (copyin(args->data, ptr, args->size) != 0) {
376 		DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
377 		    __LINE__, args->data, ptr, args->size);
378 		ret = EFAULT;
379 		goto out;
380 	}
381 	oldcpu = td->td_oncpu;
382 	is_bound = cpu_sched_is_bound(td);
383 	set_cpu(cpu, td);
384 	d.ptr = ptr;
385 	d.cpu = cpu;
386 	smp_rendezvous(NULL, ucode_intel_load_rv, NULL, &d);
387 	restore_cpu(oldcpu, is_bound, td);
388 	ret = d.ret;
389 
390 	/*
391 	 * Replace any existing update.  This ensures that the new update
392 	 * will be reloaded automatically during ACPI resume.
393 	 */
394 	if (ret == 0)
395 		ptr = ucode_update(ptr);
396 
397 out:
398 	free(ptr, M_CPUCTL);
399 	return (ret);
400 }
401 
402 /*
403  * NB: MSR 0xc0010020, MSR_K8_UCODE_UPDATE, is not documented by AMD.
404  * Coreboot, illumos and Linux source code was used to understand
405  * its workings.
406  */
407 static void
408 amd_ucode_wrmsr(void *ucode_ptr)
409 {
410 	uint32_t tmp[4];
411 
412 	wrmsr_safe(MSR_K8_UCODE_UPDATE, (uintptr_t)ucode_ptr);
413 	do_cpuid(0, tmp);
414 }
415 
416 static int
417 update_amd(int cpu, cpuctl_update_args_t *args, struct thread *td)
418 {
419 	void *ptr;
420 	int ret;
421 
422 	if (args->size == 0 || args->data == NULL) {
423 		DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
424 		return (EINVAL);
425 	}
426 	if (args->size > UCODE_SIZE_MAX) {
427 		DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
428 		return (EINVAL);
429 	}
430 
431 	/*
432 	 * 16 byte alignment required.  Rely on the fact that
433 	 * malloc(9) always returns the pointer aligned at least on
434 	 * the size of the allocation.
435 	 */
436 	ptr = malloc(args->size + 16, M_CPUCTL, M_ZERO | M_WAITOK);
437 	if (copyin(args->data, ptr, args->size) != 0) {
438 		DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
439 		    __LINE__, args->data, ptr, args->size);
440 		ret = EFAULT;
441 		goto fail;
442 	}
443 	smp_rendezvous(NULL, amd_ucode_wrmsr, NULL, ptr);
444 	ret = 0;
445 fail:
446 	free(ptr, M_CPUCTL);
447 	return (ret);
448 }
449 
450 static int
451 update_via(int cpu, cpuctl_update_args_t *args, struct thread *td)
452 {
453 	void *ptr;
454 	uint64_t rev0, rev1, res;
455 	uint32_t tmp[4];
456 	int is_bound;
457 	int oldcpu;
458 	int ret;
459 
460 	if (args->size == 0 || args->data == NULL) {
461 		DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
462 		return (EINVAL);
463 	}
464 	if (args->size > UCODE_SIZE_MAX) {
465 		DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
466 		return (EINVAL);
467 	}
468 
469 	/*
470 	 * 4 byte alignment required.
471 	 */
472 	ptr = malloc(args->size, M_CPUCTL, M_WAITOK);
473 	if (copyin(args->data, ptr, args->size) != 0) {
474 		DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
475 		    __LINE__, args->data, ptr, args->size);
476 		ret = EFAULT;
477 		goto fail;
478 	}
479 	oldcpu = td->td_oncpu;
480 	is_bound = cpu_sched_is_bound(td);
481 	set_cpu(cpu, td);
482 	critical_enter();
483 	rdmsr_safe(MSR_BIOS_SIGN, &rev0); /* Get current microcode revision. */
484 
485 	/*
486 	 * Perform update.
487 	 */
488 	wrmsr_safe(MSR_BIOS_UPDT_TRIG, (uintptr_t)(ptr));
489 	do_cpuid(1, tmp);
490 
491 	/*
492 	 * Result are in low byte of MSR FCR5:
493 	 * 0x00: No update has been attempted since RESET.
494 	 * 0x01: The last attempted update was successful.
495 	 * 0x02: The last attempted update was unsuccessful due to a bad
496 	 *       environment. No update was loaded and any preexisting
497 	 *       patches are still active.
498 	 * 0x03: The last attempted update was not applicable to this processor.
499 	 *       No update was loaded and any preexisting patches are still
500 	 *       active.
501 	 * 0x04: The last attempted update was not successful due to an invalid
502 	 *       update data block. No update was loaded and any preexisting
503 	 *       patches are still active
504 	 */
505 	rdmsr_safe(0x1205, &res);
506 	res &= 0xff;
507 	critical_exit();
508 	rdmsr_safe(MSR_BIOS_SIGN, &rev1); /* Get new microcode revision. */
509 	restore_cpu(oldcpu, is_bound, td);
510 
511 	DPRINTF("[cpu,%d]: rev0=%x rev1=%x res=%x\n", __LINE__,
512 	    (unsigned)(rev0 >> 32), (unsigned)(rev1 >> 32), (unsigned)res);
513 
514 	if (res != 0x01)
515 		ret = EINVAL;
516 	else
517 		ret = 0;
518 fail:
519 	free(ptr, M_CPUCTL);
520 	return (ret);
521 }
522 
523 static int
524 cpuctl_do_eval_cpu_features(int cpu, struct thread *td)
525 {
526 	int is_bound = 0;
527 	int oldcpu;
528 
529 	KASSERT(cpu >= 0 && cpu <= mp_maxid,
530 	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
531 
532 #ifdef __i386__
533 	if (cpu_id == 0)
534 		return (ENODEV);
535 #endif
536 	oldcpu = td->td_oncpu;
537 	is_bound = cpu_sched_is_bound(td);
538 	set_cpu(cpu, td);
539 	identify_cpu1();
540 	identify_cpu2();
541 	restore_cpu(oldcpu, is_bound, td);
542 	hw_ibrs_recalculate(true);
543 	hw_ssb_recalculate(true);
544 #ifdef __amd64__
545 	amd64_syscall_ret_flush_l1d_recalc();
546 	pmap_allow_2m_x_ept_recalculate();
547 #endif
548 	hw_mds_recalculate();
549 	x86_taa_recalculate();
550 	x86_rngds_mitg_recalculate(true);
551 	printcpuinfo();
552 	return (0);
553 }
554 
555 
556 int
557 cpuctl_open(struct cdev *dev, int flags, int fmt __unused, struct thread *td)
558 {
559 	int ret = 0;
560 	int cpu;
561 
562 	cpu = dev2unit(dev);
563 	if (cpu > mp_maxid || !cpu_enabled(cpu)) {
564 		DPRINTF("[cpuctl,%d]: incorrect cpu number %d\n", __LINE__,
565 		    cpu);
566 		return (ENXIO);
567 	}
568 	if (flags & FWRITE)
569 		ret = securelevel_gt(td->td_ucred, 0);
570 	return (ret);
571 }
572 
573 static int
574 cpuctl_modevent(module_t mod __unused, int type, void *data __unused)
575 {
576 	int cpu;
577 
578 	switch(type) {
579 	case MOD_LOAD:
580 		if (bootverbose)
581 			printf("cpuctl: access to MSR registers/cpuid info.\n");
582 		cpuctl_devs = malloc(sizeof(*cpuctl_devs) * (mp_maxid + 1), M_CPUCTL,
583 		    M_WAITOK | M_ZERO);
584 		CPU_FOREACH(cpu)
585 			if (cpu_enabled(cpu))
586 				cpuctl_devs[cpu] = make_dev(&cpuctl_cdevsw, cpu,
587 				    UID_ROOT, GID_KMEM, 0640, "cpuctl%d", cpu);
588 		break;
589 	case MOD_UNLOAD:
590 		CPU_FOREACH(cpu) {
591 			if (cpuctl_devs[cpu] != NULL)
592 				destroy_dev(cpuctl_devs[cpu]);
593 		}
594 		free(cpuctl_devs, M_CPUCTL);
595 		break;
596 	case MOD_SHUTDOWN:
597 		break;
598 	default:
599 		return (EOPNOTSUPP);
600         }
601 	return (0);
602 }
603 
604 DEV_MODULE(cpuctl, cpuctl_modevent, NULL);
605 MODULE_VERSION(cpuctl, CPUCTL_VERSION);
606