cpuctl.c revision 182628 
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 182628 2008-09-01 18:56:01Z ed $");
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	(10 * 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_update(int cpu, cpuctl_update_args_t *data,
73    struct thread *td);
74static int update_intel(int cpu, cpuctl_update_args_t *args,
75    struct thread *td);
76static int update_amd(int cpu, cpuctl_update_args_t *args, struct thread *td);
77
78static struct cdev **cpuctl_devs;
79static MALLOC_DEFINE(M_CPUCTL, "cpuctl", "CPUCTL buffer");
80
81static struct cdevsw cpuctl_cdevsw = {
82        .d_version =    D_VERSION,
83        .d_open =       cpuctl_open,
84        .d_ioctl =      cpuctl_ioctl,
85        .d_name =       "cpuctl",
86};
87
88/*
89 * This function checks if specified cpu enabled or not.
90 */
91static int
92cpu_enabled(int cpu)
93{
94
95	return (pmc_cpu_is_disabled(cpu) == 0);
96}
97
98/*
99 * Check if the current thread is bound to a specific cpu.
100 */
101static int
102cpu_sched_is_bound(struct thread *td)
103{
104	int ret;
105
106	thread_lock(td);
107	ret = sched_is_bound(td);
108	thread_unlock(td);
109	return (ret);
110}
111
112/*
113 * Switch to target cpu to run.
114 */
115static void
116set_cpu(int cpu, struct thread *td)
117{
118
119	KASSERT(cpu >= 0 && cpu < mp_ncpus && cpu_enabled(cpu),
120	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
121	thread_lock(td);
122	sched_bind(td, cpu);
123	thread_unlock(td);
124	KASSERT(td->td_oncpu == cpu,
125	    ("[cpuctl,%d]: cannot bind to target cpu %d", __LINE__, cpu));
126}
127
128static void
129restore_cpu(int oldcpu, int is_bound, struct thread *td)
130{
131
132	KASSERT(oldcpu >= 0 && oldcpu < mp_ncpus && cpu_enabled(oldcpu),
133	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, oldcpu));
134	thread_lock(td);
135	if (is_bound == 0)
136		sched_unbind(td);
137	else
138		sched_bind(td, oldcpu);
139	thread_unlock(td);
140}
141
142int
143cpuctl_ioctl(struct cdev *dev, u_long cmd, caddr_t data,
144	int flags, struct thread *td)
145{
146	int ret;
147	int cpu = minor(dev);
148
149	if (cpu >= mp_ncpus || !cpu_enabled(cpu)) {
150		DPRINTF("[cpuctl,%d]: bad cpu number %d\n", __LINE__, cpu);
151		return (ENXIO);
152	}
153	/* Require write flag for "write" requests. */
154	if ((cmd == CPUCTL_WRMSR || cmd == CPUCTL_UPDATE) &&
155	    ((flags & FWRITE) == 0))
156		return (EPERM);
157	switch (cmd) {
158	case CPUCTL_RDMSR:
159		ret = cpuctl_do_msr(cpu, (cpuctl_msr_args_t *)data, cmd, td);
160		break;
161	case CPUCTL_WRMSR:
162		ret = priv_check(td, PRIV_CPUCTL_WRMSR);
163		if (ret != 0)
164			goto fail;
165		ret = cpuctl_do_msr(cpu, (cpuctl_msr_args_t *)data, cmd, td);
166		break;
167	case CPUCTL_CPUID:
168		ret = cpuctl_do_cpuid(cpu, (cpuctl_cpuid_args_t *)data, td);
169		break;
170	case CPUCTL_UPDATE:
171		ret = priv_check(td, PRIV_CPUCTL_UPDATE);
172		if (ret != 0)
173			goto fail;
174		ret = cpuctl_do_update(cpu, (cpuctl_update_args_t *)data, td);
175		break;
176	default:
177		ret = EINVAL;
178		break;
179	}
180fail:
181	return (ret);
182}
183
184/*
185 * Actually perform cpuid operation.
186 */
187static int
188cpuctl_do_cpuid(int cpu, cpuctl_cpuid_args_t *data, struct thread *td)
189{
190	int is_bound = 0;
191	int oldcpu;
192
193	KASSERT(cpu >= 0 && cpu < mp_ncpus,
194	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
195
196	/* Explicitly clear cpuid data to avoid returning stale info. */
197	bzero(data->data, sizeof(data->data));
198	DPRINTF("[cpuctl,%d]: retriving cpuid level %#0x for %d cpu\n",
199	    __LINE__, data->level, cpu);
200	oldcpu = td->td_oncpu;
201	is_bound = cpu_sched_is_bound(td);
202	set_cpu(cpu, td);
203	do_cpuid(data->level, data->data);
204	restore_cpu(oldcpu, is_bound, td);
205	return (0);
206}
207
208/*
209 * Actually perform MSR operations.
210 */
211static int
212cpuctl_do_msr(int cpu, cpuctl_msr_args_t *data, u_long cmd, struct thread *td)
213{
214	int is_bound = 0;
215	int oldcpu;
216	int ret;
217
218	KASSERT(cpu >= 0 && cpu < mp_ncpus,
219	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
220
221	/*
222	 * Explicitly clear cpuid data to avoid returning stale
223	 * info
224	 */
225	data->data = 0;
226	DPRINTF("[cpuctl,%d]: operating on MSR %#0x for %d cpu\n", __LINE__,
227	    data->msr, cpu);
228	oldcpu = td->td_oncpu;
229	is_bound = cpu_sched_is_bound(td);
230	set_cpu(cpu, td);
231	ret = cmd == CPUCTL_RDMSR ? rdmsr_safe(data->msr, &data->data) :
232	    wrmsr_safe(data->msr, data->data);
233	restore_cpu(oldcpu, is_bound, td);
234	return (ret);
235}
236
237/*
238 * Actually perform microcode update.
239 */
240static int
241cpuctl_do_update(int cpu, cpuctl_update_args_t *data, struct thread *td)
242{
243	cpuctl_cpuid_args_t args = {
244		.level = 0,
245	};
246	char vendor[13];
247	int ret;
248
249	KASSERT(cpu >= 0 && cpu < mp_ncpus,
250	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
251	DPRINTF("[cpuctl,%d]: XXX %d", __LINE__, cpu);
252
253	ret = cpuctl_do_cpuid(cpu, &args, td);
254	if (ret != 0) {
255		DPRINTF("[cpuctl,%d]: cannot retrive cpuid info for cpu %d",
256		    __LINE__, cpu);
257		return (ENXIO);
258	}
259	((uint32_t *)vendor)[0] = args.data[1];
260	((uint32_t *)vendor)[1] = args.data[3];
261	((uint32_t *)vendor)[2] = args.data[2];
262	vendor[12] = '\0';
263	if (strncmp(vendor, INTEL_VENDOR_ID, sizeof(INTEL_VENDOR_ID)) == 0)
264		ret = update_intel(cpu, data, td);
265	else if(strncmp(vendor, INTEL_VENDOR_ID, sizeof(AMD_VENDOR_ID)) == 0)
266		ret = update_amd(cpu, data, td);
267	else
268		ret = ENXIO;
269	return (ret);
270}
271
272static int
273update_intel(int cpu, cpuctl_update_args_t *args, struct thread *td)
274{
275	void *ptr = NULL;
276	uint64_t rev0, rev1;
277	uint32_t tmp[4];
278	int is_bound = 0;
279	int oldcpu;
280	int ret;
281
282	if (args->size == 0 || args->data == NULL) {
283		DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
284		return (EINVAL);
285	}
286	if (args->size > UCODE_SIZE_MAX) {
287		DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
288		return (EINVAL);
289	}
290
291	/*
292	 * 16 byte alignment required.
293	 */
294	ptr = malloc(args->size + 16, M_CPUCTL, M_WAITOK);
295	ptr = (void *)(16 + ((intptr_t)ptr & ~0xf));
296	if (copyin(args->data, ptr, args->size) != 0) {
297		DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
298		    __LINE__, args->data, ptr, args->size);
299		ret = EFAULT;
300		goto fail;
301	}
302	oldcpu = td->td_oncpu;
303	is_bound = cpu_sched_is_bound(td);
304	set_cpu(cpu, td);
305	critical_enter();
306	rdmsr_safe(MSR_BIOS_SIGN, &rev0); /* Get current micorcode revision. */
307
308	/*
309	 * Perform update.
310	 */
311	wrmsr_safe(MSR_BIOS_UPDT_TRIG, (uintptr_t)(ptr));
312	wrmsr_safe(MSR_BIOS_SIGN, 0);
313
314	/*
315	 * Serialize instruction flow.
316	 */
317	do_cpuid(0, tmp);
318	critical_exit();
319	rdmsr_safe(MSR_BIOS_SIGN, &rev1); /* Get new micorcode revision. */
320	restore_cpu(oldcpu, is_bound, td);
321	if (rev1 > rev0)
322		ret = 0;
323	else
324		ret = EEXIST;
325fail:
326	if (ptr != NULL)
327		contigfree(ptr, args->size, M_CPUCTL);
328	return (ret);
329}
330
331static int
332update_amd(int cpu, cpuctl_update_args_t *args, struct thread *td)
333{
334	void *ptr = NULL;
335	uint32_t tmp[4];
336	int is_bound = 0;
337	int oldcpu;
338	int ret;
339
340	if (args->size == 0 || args->data == NULL) {
341		DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
342		return (EINVAL);
343	}
344	if (args->size > UCODE_SIZE_MAX) {
345		DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
346		return (EINVAL);
347	}
348	/*
349	 * XXX Might not require contignous address space - needs check
350	 */
351	ptr = contigmalloc(args->size, M_CPUCTL, 0, 0, 0xffffffff, 16, 0);
352	if (ptr == NULL) {
353		DPRINTF("[cpuctl,%d]: cannot allocate %zd bytes of memory",
354		    __LINE__, args->size);
355		return (ENOMEM);
356	}
357	if (copyin(args->data, ptr, args->size) != 0) {
358		DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
359		    __LINE__, args->data, ptr, args->size);
360		ret = EFAULT;
361		goto fail;
362	}
363	oldcpu = td->td_oncpu;
364	is_bound = cpu_sched_is_bound(td);
365	set_cpu(cpu, td);
366	critical_enter();
367
368	/*
369	 * Perform update.
370	 */
371	wrmsr_safe(MSR_K8_UCODE_UPDATE, (uintptr_t)args->data);
372
373	/*
374	 * Serialize instruction flow.
375	 */
376	do_cpuid(0, tmp);
377	critical_exit();
378	restore_cpu(oldcpu, is_bound, td);
379	ret = 0;
380fail:
381	if (ptr != NULL)
382		contigfree(ptr, args->size, M_CPUCTL);
383	return (ret);
384}
385
386int
387cpuctl_open(struct cdev *dev, int flags, int fmt __unused, struct thread *td)
388{
389	int ret = 0;
390	int cpu;
391
392	cpu = minor(dev);
393	if (cpu >= mp_ncpus || !cpu_enabled(cpu)) {
394		DPRINTF("[cpuctl,%d]: incorrect cpu number %d\n", __LINE__,
395		    cpu);
396		return (ENXIO);
397	}
398	if (flags & FWRITE)
399		ret = securelevel_gt(td->td_ucred, 0);
400	return (ret);
401}
402
403static int
404cpuctl_modevent(module_t mod __unused, int type, void *data __unused)
405{
406	int cpu;
407
408	switch(type) {
409	case MOD_LOAD:
410		if ((cpu_feature & CPUID_MSR) == 0) {
411			if (bootverbose)
412				printf("cpuctl: not available.\n");
413			return (ENODEV);
414		}
415		if (bootverbose)
416			printf("cpuctl: access to MSR registers/cpuid info.\n");
417		cpuctl_devs = (struct cdev **)malloc(sizeof(void *) * mp_ncpus,
418		    M_CPUCTL, M_WAITOK | M_ZERO);
419		if (cpuctl_devs == NULL) {
420			DPRINTF("[cpuctl,%d]: cannot allocate memory\n",
421			    __LINE__);
422			return (ENOMEM);
423		}
424		for (cpu = 0; cpu < mp_ncpus; cpu++)
425			if (cpu_enabled(cpu))
426				cpuctl_devs[cpu] = make_dev(&cpuctl_cdevsw, cpu,
427				    UID_ROOT, GID_KMEM, 0640, "cpuctl%d", cpu);
428		break;
429	case MOD_UNLOAD:
430		for (cpu = 0; cpu < mp_ncpus; cpu++) {
431			if (cpuctl_devs[cpu] != NULL)
432				destroy_dev(cpuctl_devs[cpu]);
433		}
434		free(cpuctl_devs, M_CPUCTL);
435		break;
436	case MOD_SHUTDOWN:
437		break;
438	default:
439		return (EOPNOTSUPP);
440        }
441	return (0);
442}
443
444DEV_MODULE(cpuctl, cpuctl_modevent, NULL);
445MODULE_VERSION(cpuctl, CPUCTL_VERSION);
446