xref: /freebsd/sys/dev/cpuctl/cpuctl.c (revision 685dc743dc3b5645e34836464128e1c0558b404b)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 #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 <vm/vm.h>
52 #include <vm/vm_param.h>
53 #include <vm/pmap.h>
54 
55 #include <machine/cpufunc.h>
56 #include <machine/md_var.h>
57 #include <machine/specialreg.h>
58 #include <x86/ucode.h>
59 
60 static d_open_t cpuctl_open;
61 static d_ioctl_t cpuctl_ioctl;
62 
63 #define	CPUCTL_VERSION 1
64 
65 #ifdef CPUCTL_DEBUG
66 # define	DPRINTF(format,...) printf(format, __VA_ARGS__);
67 #else
68 # define	DPRINTF(...)
69 #endif
70 
71 #define	UCODE_SIZE_MAX	(4 * 1024 * 1024)
72 
73 static int cpuctl_do_msr(int cpu, cpuctl_msr_args_t *data, u_long cmd,
74     struct thread *td);
75 static int cpuctl_do_cpuid(int cpu, cpuctl_cpuid_args_t *data,
76     struct thread *td);
77 static int cpuctl_do_cpuid_count(int cpu, cpuctl_cpuid_count_args_t *data,
78     struct thread *td);
79 static int cpuctl_do_eval_cpu_features(int cpu, struct thread *td);
80 static int cpuctl_do_update(int cpu, cpuctl_update_args_t *data,
81     struct thread *td);
82 static int update_intel(int cpu, cpuctl_update_args_t *args,
83     struct thread *td);
84 static int update_amd(int cpu, cpuctl_update_args_t *args, struct thread *td);
85 static int update_via(int cpu, cpuctl_update_args_t *args,
86     struct thread *td);
87 
88 static struct cdev **cpuctl_devs;
89 static MALLOC_DEFINE(M_CPUCTL, "cpuctl", "CPUCTL buffer");
90 
91 static struct cdevsw cpuctl_cdevsw = {
92         .d_version =    D_VERSION,
93         .d_open =       cpuctl_open,
94         .d_ioctl =      cpuctl_ioctl,
95         .d_name =       "cpuctl",
96 };
97 
98 /*
99  * This function checks if specified cpu enabled or not.
100  */
101 static int
102 cpu_enabled(int cpu)
103 {
104 
105 	return (pmc_cpu_is_disabled(cpu) == 0);
106 }
107 
108 /*
109  * Check if the current thread is bound to a specific cpu.
110  */
111 static int
112 cpu_sched_is_bound(struct thread *td)
113 {
114 	int ret;
115 
116 	thread_lock(td);
117 	ret = sched_is_bound(td);
118 	thread_unlock(td);
119 	return (ret);
120 }
121 
122 /*
123  * Switch to target cpu to run.
124  */
125 static void
126 set_cpu(int cpu, struct thread *td)
127 {
128 
129 	KASSERT(cpu >= 0 && cpu <= mp_maxid && cpu_enabled(cpu),
130 	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
131 	thread_lock(td);
132 	sched_bind(td, cpu);
133 	thread_unlock(td);
134 	KASSERT(td->td_oncpu == cpu,
135 	    ("[cpuctl,%d]: cannot bind to target cpu %d on cpu %d", __LINE__,
136 	    cpu, td->td_oncpu));
137 }
138 
139 static void
140 restore_cpu(int oldcpu, int is_bound, struct thread *td)
141 {
142 
143 	KASSERT(oldcpu >= 0 && oldcpu <= mp_maxid && cpu_enabled(oldcpu),
144 	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, oldcpu));
145 	thread_lock(td);
146 	if (is_bound == 0)
147 		sched_unbind(td);
148 	else
149 		sched_bind(td, oldcpu);
150 	thread_unlock(td);
151 }
152 
153 int
154 cpuctl_ioctl(struct cdev *dev, u_long cmd, caddr_t data,
155     int flags, struct thread *td)
156 {
157 	int cpu, ret;
158 
159 	cpu = dev2unit(dev);
160 	if (cpu > mp_maxid || !cpu_enabled(cpu)) {
161 		DPRINTF("[cpuctl,%d]: bad cpu number %d\n", __LINE__, cpu);
162 		return (ENXIO);
163 	}
164 	/* Require write flag for "write" requests. */
165 	if ((cmd == CPUCTL_MSRCBIT || cmd == CPUCTL_MSRSBIT ||
166 	    cmd == CPUCTL_UPDATE || cmd == CPUCTL_WRMSR ||
167 	    cmd == CPUCTL_EVAL_CPU_FEATURES) &&
168 	    (flags & FWRITE) == 0)
169 		return (EPERM);
170 	switch (cmd) {
171 	case CPUCTL_RDMSR:
172 		ret = cpuctl_do_msr(cpu, (cpuctl_msr_args_t *)data, cmd, td);
173 		break;
174 	case CPUCTL_MSRSBIT:
175 	case CPUCTL_MSRCBIT:
176 	case CPUCTL_WRMSR:
177 		ret = priv_check(td, PRIV_CPUCTL_WRMSR);
178 		if (ret != 0)
179 			goto fail;
180 		ret = cpuctl_do_msr(cpu, (cpuctl_msr_args_t *)data, cmd, td);
181 		break;
182 	case CPUCTL_CPUID:
183 		ret = cpuctl_do_cpuid(cpu, (cpuctl_cpuid_args_t *)data, td);
184 		break;
185 	case CPUCTL_UPDATE:
186 		ret = priv_check(td, PRIV_CPUCTL_UPDATE);
187 		if (ret != 0)
188 			goto fail;
189 		ret = cpuctl_do_update(cpu, (cpuctl_update_args_t *)data, td);
190 		break;
191 	case CPUCTL_CPUID_COUNT:
192 		ret = cpuctl_do_cpuid_count(cpu,
193 		    (cpuctl_cpuid_count_args_t *)data, td);
194 		break;
195 	case CPUCTL_EVAL_CPU_FEATURES:
196 		ret = cpuctl_do_eval_cpu_features(cpu, td);
197 		break;
198 	default:
199 		ret = EINVAL;
200 		break;
201 	}
202 fail:
203 	return (ret);
204 }
205 
206 /*
207  * Actually perform cpuid operation.
208  */
209 static int
210 cpuctl_do_cpuid_count(int cpu, cpuctl_cpuid_count_args_t *data,
211     struct thread *td)
212 {
213 	int is_bound = 0;
214 	int oldcpu;
215 
216 	KASSERT(cpu >= 0 && cpu <= mp_maxid,
217 	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
218 
219 	/* Explicitly clear cpuid data to avoid returning stale info. */
220 	bzero(data->data, sizeof(data->data));
221 	DPRINTF("[cpuctl,%d]: retrieving cpuid lev %#0x type %#0x for %d cpu\n",
222 	    __LINE__, data->level, data->level_type, cpu);
223 #ifdef __i386__
224 	if (cpu_id == 0)
225 		return (ENODEV);
226 #endif
227 	oldcpu = td->td_oncpu;
228 	is_bound = cpu_sched_is_bound(td);
229 	set_cpu(cpu, td);
230 	cpuid_count(data->level, data->level_type, data->data);
231 	restore_cpu(oldcpu, is_bound, td);
232 	return (0);
233 }
234 
235 static int
236 cpuctl_do_cpuid(int cpu, cpuctl_cpuid_args_t *data, struct thread *td)
237 {
238 	cpuctl_cpuid_count_args_t cdata;
239 	int error;
240 
241 	cdata.level = data->level;
242 	/* Override the level type. */
243 	cdata.level_type = 0;
244 	error = cpuctl_do_cpuid_count(cpu, &cdata, td);
245 	bcopy(cdata.data, data->data, sizeof(data->data)); /* Ignore error */
246 	return (error);
247 }
248 
249 /*
250  * Actually perform MSR operations.
251  */
252 static int
253 cpuctl_do_msr(int cpu, cpuctl_msr_args_t *data, u_long cmd, struct thread *td)
254 {
255 	uint64_t reg;
256 	int is_bound = 0;
257 	int oldcpu;
258 	int ret;
259 
260 	KASSERT(cpu >= 0 && cpu <= mp_maxid,
261 	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
262 
263 	/*
264 	 * Explicitly clear cpuid data to avoid returning stale
265 	 * info
266 	 */
267 	DPRINTF("[cpuctl,%d]: operating on MSR %#0x for %d cpu\n", __LINE__,
268 	    data->msr, cpu);
269 #ifdef __i386__
270 	if ((cpu_feature & CPUID_MSR) == 0)
271 		return (ENODEV);
272 #endif
273 	oldcpu = td->td_oncpu;
274 	is_bound = cpu_sched_is_bound(td);
275 	set_cpu(cpu, td);
276 	if (cmd == CPUCTL_RDMSR) {
277 		data->data = 0;
278 		ret = rdmsr_safe(data->msr, &data->data);
279 	} else if (cmd == CPUCTL_WRMSR) {
280 		ret = wrmsr_safe(data->msr, data->data);
281 	} else if (cmd == CPUCTL_MSRSBIT) {
282 		critical_enter();
283 		ret = rdmsr_safe(data->msr, &reg);
284 		if (ret == 0)
285 			ret = wrmsr_safe(data->msr, reg | data->data);
286 		critical_exit();
287 	} else if (cmd == CPUCTL_MSRCBIT) {
288 		critical_enter();
289 		ret = rdmsr_safe(data->msr, &reg);
290 		if (ret == 0)
291 			ret = wrmsr_safe(data->msr, reg & ~data->data);
292 		critical_exit();
293 	} else
294 		panic("[cpuctl,%d]: unknown operation requested: %lu",
295 		    __LINE__, cmd);
296 	restore_cpu(oldcpu, is_bound, td);
297 	return (ret);
298 }
299 
300 /*
301  * Actually perform microcode update.
302  */
303 static int
304 cpuctl_do_update(int cpu, cpuctl_update_args_t *data, struct thread *td)
305 {
306 	cpuctl_cpuid_args_t args = {
307 		.level = 0,
308 	};
309 	char vendor[13];
310 	int ret;
311 
312 	KASSERT(cpu >= 0 && cpu <= mp_maxid,
313 	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
314 	DPRINTF("[cpuctl,%d]: XXX %d", __LINE__, cpu);
315 
316 	ret = cpuctl_do_cpuid(cpu, &args, td);
317 	if (ret != 0)
318 		return (ret);
319 	((uint32_t *)vendor)[0] = args.data[1];
320 	((uint32_t *)vendor)[1] = args.data[3];
321 	((uint32_t *)vendor)[2] = args.data[2];
322 	vendor[12] = '\0';
323 	if (strncmp(vendor, INTEL_VENDOR_ID, sizeof(INTEL_VENDOR_ID)) == 0)
324 		ret = update_intel(cpu, data, td);
325 	else if(strncmp(vendor, AMD_VENDOR_ID, sizeof(AMD_VENDOR_ID)) == 0)
326 		ret = update_amd(cpu, data, td);
327 	else if(strncmp(vendor, CENTAUR_VENDOR_ID, sizeof(CENTAUR_VENDOR_ID))
328 	    == 0)
329 		ret = update_via(cpu, data, td);
330 	else
331 		ret = ENXIO;
332 	return (ret);
333 }
334 
335 struct ucode_update_data {
336 	void *ptr;
337 	int cpu;
338 	int ret;
339 };
340 
341 static void
342 ucode_intel_load_rv(void *arg)
343 {
344 	struct ucode_update_data *d;
345 
346 	d = arg;
347 	if (PCPU_GET(cpuid) == d->cpu)
348 		d->ret = ucode_intel_load(d->ptr, true, NULL, NULL);
349 }
350 
351 static int
352 update_intel(int cpu, cpuctl_update_args_t *args, struct thread *td)
353 {
354 	struct ucode_update_data d;
355 	void *ptr;
356 	int is_bound, oldcpu, ret;
357 
358 	if (args->size == 0 || args->data == NULL) {
359 		DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
360 		return (EINVAL);
361 	}
362 	if (args->size > UCODE_SIZE_MAX) {
363 		DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
364 		return (EINVAL);
365 	}
366 
367 	/*
368 	 * 16 byte alignment required.  Rely on the fact that
369 	 * malloc(9) always returns the pointer aligned at least on
370 	 * the size of the allocation.
371 	 */
372 	ptr = malloc(args->size + 16, M_CPUCTL, M_WAITOK);
373 	if (copyin(args->data, ptr, args->size) != 0) {
374 		DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
375 		    __LINE__, args->data, ptr, args->size);
376 		ret = EFAULT;
377 		goto out;
378 	}
379 	oldcpu = td->td_oncpu;
380 	is_bound = cpu_sched_is_bound(td);
381 	set_cpu(cpu, td);
382 	d.ptr = ptr;
383 	d.cpu = cpu;
384 	smp_rendezvous(NULL, ucode_intel_load_rv, NULL, &d);
385 	restore_cpu(oldcpu, is_bound, td);
386 	ret = d.ret;
387 
388 	/*
389 	 * Replace any existing update.  This ensures that the new update
390 	 * will be reloaded automatically during ACPI resume.
391 	 */
392 	if (ret == 0)
393 		ptr = ucode_update(ptr);
394 
395 out:
396 	free(ptr, M_CPUCTL);
397 	return (ret);
398 }
399 
400 /*
401  * NB: MSR 0xc0010020, MSR_K8_UCODE_UPDATE, is not documented by AMD.
402  * Coreboot, illumos and Linux source code was used to understand
403  * its workings.
404  */
405 static void
406 amd_ucode_wrmsr(void *ucode_ptr)
407 {
408 	uint32_t tmp[4];
409 
410 	wrmsr_safe(MSR_K8_UCODE_UPDATE, (uintptr_t)ucode_ptr);
411 	do_cpuid(0, tmp);
412 }
413 
414 static int
415 update_amd(int cpu, cpuctl_update_args_t *args, struct thread *td)
416 {
417 	void *ptr;
418 	int ret;
419 
420 	if (args->size == 0 || args->data == NULL) {
421 		DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
422 		return (EINVAL);
423 	}
424 	if (args->size > UCODE_SIZE_MAX) {
425 		DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
426 		return (EINVAL);
427 	}
428 
429 	/*
430 	 * 16 byte alignment required.  Rely on the fact that
431 	 * malloc(9) always returns the pointer aligned at least on
432 	 * the size of the allocation.
433 	 */
434 	ptr = malloc(args->size + 16, M_CPUCTL, M_ZERO | M_WAITOK);
435 	if (copyin(args->data, ptr, args->size) != 0) {
436 		DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
437 		    __LINE__, args->data, ptr, args->size);
438 		ret = EFAULT;
439 		goto fail;
440 	}
441 	smp_rendezvous(NULL, amd_ucode_wrmsr, NULL, ptr);
442 	ret = 0;
443 fail:
444 	free(ptr, M_CPUCTL);
445 	return (ret);
446 }
447 
448 static int
449 update_via(int cpu, cpuctl_update_args_t *args, struct thread *td)
450 {
451 	void *ptr;
452 	uint64_t rev0, rev1, res;
453 	uint32_t tmp[4];
454 	int is_bound;
455 	int oldcpu;
456 	int ret;
457 
458 	if (args->size == 0 || args->data == NULL) {
459 		DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
460 		return (EINVAL);
461 	}
462 	if (args->size > UCODE_SIZE_MAX) {
463 		DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
464 		return (EINVAL);
465 	}
466 
467 	/*
468 	 * 4 byte alignment required.
469 	 */
470 	ptr = malloc(args->size, M_CPUCTL, M_WAITOK);
471 	if (copyin(args->data, ptr, args->size) != 0) {
472 		DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
473 		    __LINE__, args->data, ptr, args->size);
474 		ret = EFAULT;
475 		goto fail;
476 	}
477 	oldcpu = td->td_oncpu;
478 	is_bound = cpu_sched_is_bound(td);
479 	set_cpu(cpu, td);
480 	critical_enter();
481 	rdmsr_safe(MSR_BIOS_SIGN, &rev0); /* Get current microcode revision. */
482 
483 	/*
484 	 * Perform update.
485 	 */
486 	wrmsr_safe(MSR_BIOS_UPDT_TRIG, (uintptr_t)(ptr));
487 	do_cpuid(1, tmp);
488 
489 	/*
490 	 * Result are in low byte of MSR FCR5:
491 	 * 0x00: No update has been attempted since RESET.
492 	 * 0x01: The last attempted update was successful.
493 	 * 0x02: The last attempted update was unsuccessful due to a bad
494 	 *       environment. No update was loaded and any preexisting
495 	 *       patches are still active.
496 	 * 0x03: The last attempted update was not applicable to this processor.
497 	 *       No update was loaded and any preexisting patches are still
498 	 *       active.
499 	 * 0x04: The last attempted update was not successful due to an invalid
500 	 *       update data block. No update was loaded and any preexisting
501 	 *       patches are still active
502 	 */
503 	rdmsr_safe(0x1205, &res);
504 	res &= 0xff;
505 	critical_exit();
506 	rdmsr_safe(MSR_BIOS_SIGN, &rev1); /* Get new microcode revision. */
507 	restore_cpu(oldcpu, is_bound, td);
508 
509 	DPRINTF("[cpu,%d]: rev0=%x rev1=%x res=%x\n", __LINE__,
510 	    (unsigned)(rev0 >> 32), (unsigned)(rev1 >> 32), (unsigned)res);
511 
512 	if (res != 0x01)
513 		ret = EINVAL;
514 	else
515 		ret = 0;
516 fail:
517 	free(ptr, M_CPUCTL);
518 	return (ret);
519 }
520 
521 static int
522 cpuctl_do_eval_cpu_features(int cpu, struct thread *td)
523 {
524 	int is_bound = 0;
525 	int oldcpu;
526 
527 	KASSERT(cpu >= 0 && cpu <= mp_maxid,
528 	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
529 
530 #ifdef __i386__
531 	if (cpu_id == 0)
532 		return (ENODEV);
533 #endif
534 	oldcpu = td->td_oncpu;
535 	is_bound = cpu_sched_is_bound(td);
536 	set_cpu(cpu, td);
537 	identify_cpu1();
538 	identify_cpu2();
539 	restore_cpu(oldcpu, is_bound, td);
540 	hw_ibrs_recalculate(true);
541 	hw_ssb_recalculate(true);
542 #ifdef __amd64__
543 	amd64_syscall_ret_flush_l1d_recalc();
544 	pmap_allow_2m_x_ept_recalculate();
545 #endif
546 	hw_mds_recalculate();
547 	x86_taa_recalculate();
548 	x86_rngds_mitg_recalculate(true);
549 	printcpuinfo();
550 	return (0);
551 }
552 
553 int
554 cpuctl_open(struct cdev *dev, int flags, int fmt __unused, struct thread *td)
555 {
556 	int ret = 0;
557 	int cpu;
558 
559 	cpu = dev2unit(dev);
560 	if (cpu > mp_maxid || !cpu_enabled(cpu)) {
561 		DPRINTF("[cpuctl,%d]: incorrect cpu number %d\n", __LINE__,
562 		    cpu);
563 		return (ENXIO);
564 	}
565 	if (flags & FWRITE)
566 		ret = securelevel_gt(td->td_ucred, 0);
567 	return (ret);
568 }
569 
570 static int
571 cpuctl_modevent(module_t mod __unused, int type, void *data __unused)
572 {
573 	int cpu;
574 
575 	switch(type) {
576 	case MOD_LOAD:
577 		if (bootverbose)
578 			printf("cpuctl: access to MSR registers/cpuid info.\n");
579 		cpuctl_devs = malloc(sizeof(*cpuctl_devs) * (mp_maxid + 1), M_CPUCTL,
580 		    M_WAITOK | M_ZERO);
581 		CPU_FOREACH(cpu)
582 			if (cpu_enabled(cpu))
583 				cpuctl_devs[cpu] = make_dev(&cpuctl_cdevsw, cpu,
584 				    UID_ROOT, GID_KMEM, 0640, "cpuctl%d", cpu);
585 		break;
586 	case MOD_UNLOAD:
587 		CPU_FOREACH(cpu) {
588 			if (cpuctl_devs[cpu] != NULL)
589 				destroy_dev(cpuctl_devs[cpu]);
590 		}
591 		free(cpuctl_devs, M_CPUCTL);
592 		break;
593 	case MOD_SHUTDOWN:
594 		break;
595 	default:
596 		return (EOPNOTSUPP);
597         }
598 	return (0);
599 }
600 
601 DEV_MODULE(cpuctl, cpuctl_modevent, NULL);
602 MODULE_VERSION(cpuctl, CPUCTL_VERSION);
603