cpuctl.c revision 301962
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: head/sys/dev/cpuctl/cpuctl.c 301962 2016-06-16 12:07:40Z kib $");
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
55static d_open_t cpuctl_open;
56static 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
68static int cpuctl_do_msr(int cpu, cpuctl_msr_args_t *data, u_long cmd,
69    struct thread *td);
70static int cpuctl_do_cpuid(int cpu, cpuctl_cpuid_args_t *data,
71    struct thread *td);
72static int cpuctl_do_cpuid_count(int cpu, cpuctl_cpuid_count_args_t *data,
73    struct thread *td);
74static int cpuctl_do_update(int cpu, cpuctl_update_args_t *data,
75    struct thread *td);
76static int update_intel(int cpu, cpuctl_update_args_t *args,
77    struct thread *td);
78static int update_amd(int cpu, cpuctl_update_args_t *args, struct thread *td);
79static int update_via(int cpu, cpuctl_update_args_t *args,
80    struct thread *td);
81
82static struct cdev **cpuctl_devs;
83static MALLOC_DEFINE(M_CPUCTL, "cpuctl", "CPUCTL buffer");
84
85static 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 */
95static int
96cpu_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 */
105static int
106cpu_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 */
119static void
120set_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 on cpu %d", __LINE__, cpu, td->td_oncpu));
130}
131
132static void
133restore_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
146int
147cpuctl_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		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	}
190fail:
191	return (ret);
192}
193
194/*
195 * Actually perform cpuid operation.
196 */
197static int
198cpuctl_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_ncpus,
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
223static int
224cpuctl_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 */
240static int
241cpuctl_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_ncpus,
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 */
290static int
291cpuctl_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_ncpus,
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
321static int
322update_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;
375fail:
376	free(ptr, M_CPUCTL);
377	return (ret);
378}
379
380static int
381update_amd(int cpu, cpuctl_update_args_t *args, struct thread *td)
382{
383	void *ptr = NULL;
384	uint32_t tmp[4];
385	int is_bound = 0;
386	int oldcpu;
387	int ret;
388
389	if (args->size == 0 || args->data == NULL) {
390		DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
391		return (EINVAL);
392	}
393	if (args->size > UCODE_SIZE_MAX) {
394		DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
395		return (EINVAL);
396	}
397	/*
398	 * XXX Might not require contignous address space - needs check
399	 */
400	ptr = contigmalloc(args->size, M_CPUCTL, 0, 0, 0xffffffff, 16, 0);
401	if (ptr == NULL) {
402		DPRINTF("[cpuctl,%d]: cannot allocate %zd bytes of memory",
403		    __LINE__, args->size);
404		return (ENOMEM);
405	}
406	if (copyin(args->data, ptr, args->size) != 0) {
407		DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
408		    __LINE__, args->data, ptr, args->size);
409		ret = EFAULT;
410		goto fail;
411	}
412	oldcpu = td->td_oncpu;
413	is_bound = cpu_sched_is_bound(td);
414	set_cpu(cpu, td);
415	critical_enter();
416
417	/*
418	 * Perform update.
419	 */
420	wrmsr_safe(MSR_K8_UCODE_UPDATE, (uintptr_t)ptr);
421
422	/*
423	 * Serialize instruction flow.
424	 */
425	do_cpuid(0, tmp);
426	critical_exit();
427	restore_cpu(oldcpu, is_bound, td);
428	ret = 0;
429fail:
430	if (ptr != NULL)
431		contigfree(ptr, args->size, M_CPUCTL);
432	return (ret);
433}
434
435static int
436update_via(int cpu, cpuctl_update_args_t *args, struct thread *td)
437{
438	void *ptr;
439	uint64_t rev0, rev1, res;
440	uint32_t tmp[4];
441	int is_bound;
442	int oldcpu;
443	int ret;
444
445	if (args->size == 0 || args->data == NULL) {
446		DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
447		return (EINVAL);
448	}
449	if (args->size > UCODE_SIZE_MAX) {
450		DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
451		return (EINVAL);
452	}
453
454	/*
455	 * 4 byte alignment required.
456	 */
457	ptr = malloc(args->size, M_CPUCTL, M_WAITOK);
458	if (copyin(args->data, ptr, args->size) != 0) {
459		DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
460		    __LINE__, args->data, ptr, args->size);
461		ret = EFAULT;
462		goto fail;
463	}
464	oldcpu = td->td_oncpu;
465	is_bound = cpu_sched_is_bound(td);
466	set_cpu(cpu, td);
467	critical_enter();
468	rdmsr_safe(MSR_BIOS_SIGN, &rev0); /* Get current microcode revision. */
469
470	/*
471	 * Perform update.
472	 */
473	wrmsr_safe(MSR_BIOS_UPDT_TRIG, (uintptr_t)(ptr));
474	do_cpuid(1, tmp);
475
476	/*
477	 * Result are in low byte of MSR FCR5:
478	 * 0x00: No update has been attempted since RESET.
479	 * 0x01: The last attempted update was successful.
480	 * 0x02: The last attempted update was unsuccessful due to a bad
481	 *       environment. No update was loaded and any preexisting
482	 *       patches are still active.
483	 * 0x03: The last attempted update was not applicable to this processor.
484	 *       No update was loaded and any preexisting patches are still
485	 *       active.
486	 * 0x04: The last attempted update was not successful due to an invalid
487	 *       update data block. No update was loaded and any preexisting
488	 *       patches are still active
489	 */
490	rdmsr_safe(0x1205, &res);
491	res &= 0xff;
492	critical_exit();
493	rdmsr_safe(MSR_BIOS_SIGN, &rev1); /* Get new microcode revision. */
494	restore_cpu(oldcpu, is_bound, td);
495
496	DPRINTF("[cpu,%d]: rev0=%x rev1=%x res=%x\n", __LINE__,
497	    (unsigned)(rev0 >> 32), (unsigned)(rev1 >> 32), (unsigned)res);
498
499	if (res != 0x01)
500		ret = EINVAL;
501	else
502		ret = 0;
503fail:
504	free(ptr, M_CPUCTL);
505	return (ret);
506}
507
508int
509cpuctl_open(struct cdev *dev, int flags, int fmt __unused, struct thread *td)
510{
511	int ret = 0;
512	int cpu;
513
514	cpu = dev2unit(dev);
515	if (cpu >= mp_ncpus || !cpu_enabled(cpu)) {
516		DPRINTF("[cpuctl,%d]: incorrect cpu number %d\n", __LINE__,
517		    cpu);
518		return (ENXIO);
519	}
520	if (flags & FWRITE)
521		ret = securelevel_gt(td->td_ucred, 0);
522	return (ret);
523}
524
525static int
526cpuctl_modevent(module_t mod __unused, int type, void *data __unused)
527{
528	int cpu;
529
530	switch(type) {
531	case MOD_LOAD:
532		if (bootverbose)
533			printf("cpuctl: access to MSR registers/cpuid info.\n");
534		cpuctl_devs = malloc(sizeof(*cpuctl_devs) * mp_ncpus, M_CPUCTL,
535		    M_WAITOK | M_ZERO);
536		for (cpu = 0; cpu < mp_ncpus; cpu++)
537			if (cpu_enabled(cpu))
538				cpuctl_devs[cpu] = make_dev(&cpuctl_cdevsw, cpu,
539				    UID_ROOT, GID_KMEM, 0640, "cpuctl%d", cpu);
540		break;
541	case MOD_UNLOAD:
542		for (cpu = 0; cpu < mp_ncpus; cpu++) {
543			if (cpuctl_devs[cpu] != NULL)
544				destroy_dev(cpuctl_devs[cpu]);
545		}
546		free(cpuctl_devs, M_CPUCTL);
547		break;
548	case MOD_SHUTDOWN:
549		break;
550	default:
551		return (EOPNOTSUPP);
552        }
553	return (0);
554}
555
556DEV_MODULE(cpuctl, cpuctl_modevent, NULL);
557MODULE_VERSION(cpuctl, CPUCTL_VERSION);
558