xref: /freebsd/sys/dev/cpuctl/cpuctl.c (revision 884a2a699669ec61e2366e3e358342dbc94be24a)
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	(10 * 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 
78 static struct cdev **cpuctl_devs;
79 static MALLOC_DEFINE(M_CPUCTL, "cpuctl", "CPUCTL buffer");
80 
81 static 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  */
91 static int
92 cpu_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  */
101 static int
102 cpu_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  */
115 static void
116 set_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 
128 static void
129 restore_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 
142 int
143 cpuctl_ioctl(struct cdev *dev, u_long cmd, caddr_t data,
144 	int flags, struct thread *td)
145 {
146 	int ret;
147 	int cpu = dev2unit(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_MSRSBIT:
162 	case CPUCTL_MSRCBIT:
163 	case CPUCTL_WRMSR:
164 		ret = priv_check(td, PRIV_CPUCTL_WRMSR);
165 		if (ret != 0)
166 			goto fail;
167 		ret = cpuctl_do_msr(cpu, (cpuctl_msr_args_t *)data, cmd, td);
168 		break;
169 	case CPUCTL_CPUID:
170 		ret = cpuctl_do_cpuid(cpu, (cpuctl_cpuid_args_t *)data, td);
171 		break;
172 	case CPUCTL_UPDATE:
173 		ret = priv_check(td, PRIV_CPUCTL_UPDATE);
174 		if (ret != 0)
175 			goto fail;
176 		ret = cpuctl_do_update(cpu, (cpuctl_update_args_t *)data, td);
177 		break;
178 	default:
179 		ret = EINVAL;
180 		break;
181 	}
182 fail:
183 	return (ret);
184 }
185 
186 /*
187  * Actually perform cpuid operation.
188  */
189 static int
190 cpuctl_do_cpuid(int cpu, cpuctl_cpuid_args_t *data, struct thread *td)
191 {
192 	int is_bound = 0;
193 	int oldcpu;
194 
195 	KASSERT(cpu >= 0 && cpu < mp_ncpus,
196 	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
197 
198 	/* Explicitly clear cpuid data to avoid returning stale info. */
199 	bzero(data->data, sizeof(data->data));
200 	DPRINTF("[cpuctl,%d]: retriving cpuid level %#0x for %d cpu\n",
201 	    __LINE__, data->level, cpu);
202 	oldcpu = td->td_oncpu;
203 	is_bound = cpu_sched_is_bound(td);
204 	set_cpu(cpu, td);
205 	do_cpuid(data->level, data->data);
206 	restore_cpu(oldcpu, is_bound, td);
207 	return (0);
208 }
209 
210 /*
211  * Actually perform MSR operations.
212  */
213 static int
214 cpuctl_do_msr(int cpu, cpuctl_msr_args_t *data, u_long cmd, struct thread *td)
215 {
216 	uint64_t reg;
217 	int is_bound = 0;
218 	int oldcpu;
219 	int ret;
220 
221 	KASSERT(cpu >= 0 && cpu < mp_ncpus,
222 	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
223 
224 	/*
225 	 * Explicitly clear cpuid data to avoid returning stale
226 	 * info
227 	 */
228 	DPRINTF("[cpuctl,%d]: operating on MSR %#0x for %d cpu\n", __LINE__,
229 	    data->msr, cpu);
230 	oldcpu = td->td_oncpu;
231 	is_bound = cpu_sched_is_bound(td);
232 	set_cpu(cpu, td);
233 	if (cmd == CPUCTL_RDMSR) {
234 		data->data = 0;
235 		ret = rdmsr_safe(data->msr, &data->data);
236 	} else if (cmd == CPUCTL_WRMSR) {
237 		ret = wrmsr_safe(data->msr, data->data);
238 	} else if (cmd == CPUCTL_MSRSBIT) {
239 		critical_enter();
240 		ret = rdmsr_safe(data->msr, &reg);
241 		if (ret == 0)
242 			ret = wrmsr_safe(data->msr, reg | data->data);
243 		critical_exit();
244 	} else if (cmd == CPUCTL_MSRCBIT) {
245 		critical_enter();
246 		ret = rdmsr_safe(data->msr, &reg);
247 		if (ret == 0)
248 			ret = wrmsr_safe(data->msr, reg & ~data->data);
249 		critical_exit();
250 	} else
251 		panic("[cpuctl,%d]: unknown operation requested: %lu", __LINE__, cmd);
252 	restore_cpu(oldcpu, is_bound, td);
253 	return (ret);
254 }
255 
256 /*
257  * Actually perform microcode update.
258  */
259 static int
260 cpuctl_do_update(int cpu, cpuctl_update_args_t *data, struct thread *td)
261 {
262 	cpuctl_cpuid_args_t args = {
263 		.level = 0,
264 	};
265 	char vendor[13];
266 	int ret;
267 
268 	KASSERT(cpu >= 0 && cpu < mp_ncpus,
269 	    ("[cpuctl,%d]: bad cpu number %d", __LINE__, cpu));
270 	DPRINTF("[cpuctl,%d]: XXX %d", __LINE__, cpu);
271 
272 	ret = cpuctl_do_cpuid(cpu, &args, td);
273 	if (ret != 0) {
274 		DPRINTF("[cpuctl,%d]: cannot retrive cpuid info for cpu %d",
275 		    __LINE__, cpu);
276 		return (ENXIO);
277 	}
278 	((uint32_t *)vendor)[0] = args.data[1];
279 	((uint32_t *)vendor)[1] = args.data[3];
280 	((uint32_t *)vendor)[2] = args.data[2];
281 	vendor[12] = '\0';
282 	if (strncmp(vendor, INTEL_VENDOR_ID, sizeof(INTEL_VENDOR_ID)) == 0)
283 		ret = update_intel(cpu, data, td);
284 	else if(strncmp(vendor, INTEL_VENDOR_ID, sizeof(AMD_VENDOR_ID)) == 0)
285 		ret = update_amd(cpu, data, td);
286 	else
287 		ret = ENXIO;
288 	return (ret);
289 }
290 
291 static int
292 update_intel(int cpu, cpuctl_update_args_t *args, struct thread *td)
293 {
294 	void *ptr = NULL;
295 	uint64_t rev0, rev1;
296 	uint32_t tmp[4];
297 	int is_bound = 0;
298 	int oldcpu;
299 	int ret;
300 
301 	if (args->size == 0 || args->data == NULL) {
302 		DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
303 		return (EINVAL);
304 	}
305 	if (args->size > UCODE_SIZE_MAX) {
306 		DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
307 		return (EINVAL);
308 	}
309 
310 	/*
311 	 * 16 byte alignment required.
312 	 */
313 	ptr = malloc(args->size + 16, M_CPUCTL, M_WAITOK);
314 	ptr = (void *)(16 + ((intptr_t)ptr & ~0xf));
315 	if (copyin(args->data, ptr, args->size) != 0) {
316 		DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
317 		    __LINE__, args->data, ptr, args->size);
318 		ret = EFAULT;
319 		goto fail;
320 	}
321 	oldcpu = td->td_oncpu;
322 	is_bound = cpu_sched_is_bound(td);
323 	set_cpu(cpu, td);
324 	critical_enter();
325 	rdmsr_safe(MSR_BIOS_SIGN, &rev0); /* Get current micorcode revision. */
326 
327 	/*
328 	 * Perform update.
329 	 */
330 	wrmsr_safe(MSR_BIOS_UPDT_TRIG, (uintptr_t)(ptr));
331 	wrmsr_safe(MSR_BIOS_SIGN, 0);
332 
333 	/*
334 	 * Serialize instruction flow.
335 	 */
336 	do_cpuid(0, tmp);
337 	critical_exit();
338 	rdmsr_safe(MSR_BIOS_SIGN, &rev1); /* Get new micorcode revision. */
339 	restore_cpu(oldcpu, is_bound, td);
340 	if (rev1 > rev0)
341 		ret = 0;
342 	else
343 		ret = EEXIST;
344 fail:
345 	if (ptr != NULL)
346 		contigfree(ptr, args->size, M_CPUCTL);
347 	return (ret);
348 }
349 
350 static int
351 update_amd(int cpu, cpuctl_update_args_t *args, struct thread *td)
352 {
353 	void *ptr = NULL;
354 	uint32_t tmp[4];
355 	int is_bound = 0;
356 	int oldcpu;
357 	int ret;
358 
359 	if (args->size == 0 || args->data == NULL) {
360 		DPRINTF("[cpuctl,%d]: zero-sized firmware image", __LINE__);
361 		return (EINVAL);
362 	}
363 	if (args->size > UCODE_SIZE_MAX) {
364 		DPRINTF("[cpuctl,%d]: firmware image too large", __LINE__);
365 		return (EINVAL);
366 	}
367 	/*
368 	 * XXX Might not require contignous address space - needs check
369 	 */
370 	ptr = contigmalloc(args->size, M_CPUCTL, 0, 0, 0xffffffff, 16, 0);
371 	if (ptr == NULL) {
372 		DPRINTF("[cpuctl,%d]: cannot allocate %zd bytes of memory",
373 		    __LINE__, args->size);
374 		return (ENOMEM);
375 	}
376 	if (copyin(args->data, ptr, args->size) != 0) {
377 		DPRINTF("[cpuctl,%d]: copyin %p->%p of %zd bytes failed",
378 		    __LINE__, args->data, ptr, args->size);
379 		ret = EFAULT;
380 		goto fail;
381 	}
382 	oldcpu = td->td_oncpu;
383 	is_bound = cpu_sched_is_bound(td);
384 	set_cpu(cpu, td);
385 	critical_enter();
386 
387 	/*
388 	 * Perform update.
389 	 */
390 	wrmsr_safe(MSR_K8_UCODE_UPDATE, (uintptr_t)ptr);
391 
392 	/*
393 	 * Serialize instruction flow.
394 	 */
395 	do_cpuid(0, tmp);
396 	critical_exit();
397 	restore_cpu(oldcpu, is_bound, td);
398 	ret = 0;
399 fail:
400 	if (ptr != NULL)
401 		contigfree(ptr, args->size, M_CPUCTL);
402 	return (ret);
403 }
404 
405 int
406 cpuctl_open(struct cdev *dev, int flags, int fmt __unused, struct thread *td)
407 {
408 	int ret = 0;
409 	int cpu;
410 
411 	cpu = dev2unit(dev);
412 	if (cpu >= mp_ncpus || !cpu_enabled(cpu)) {
413 		DPRINTF("[cpuctl,%d]: incorrect cpu number %d\n", __LINE__,
414 		    cpu);
415 		return (ENXIO);
416 	}
417 	if (flags & FWRITE)
418 		ret = securelevel_gt(td->td_ucred, 0);
419 	return (ret);
420 }
421 
422 static int
423 cpuctl_modevent(module_t mod __unused, int type, void *data __unused)
424 {
425 	int cpu;
426 
427 	switch(type) {
428 	case MOD_LOAD:
429 		if ((cpu_feature & CPUID_MSR) == 0) {
430 			if (bootverbose)
431 				printf("cpuctl: not available.\n");
432 			return (ENODEV);
433 		}
434 		if (bootverbose)
435 			printf("cpuctl: access to MSR registers/cpuid info.\n");
436 		cpuctl_devs = (struct cdev **)malloc(sizeof(void *) * mp_ncpus,
437 		    M_CPUCTL, M_WAITOK | M_ZERO);
438 		if (cpuctl_devs == NULL) {
439 			DPRINTF("[cpuctl,%d]: cannot allocate memory\n",
440 			    __LINE__);
441 			return (ENOMEM);
442 		}
443 		for (cpu = 0; cpu < mp_ncpus; cpu++)
444 			if (cpu_enabled(cpu))
445 				cpuctl_devs[cpu] = make_dev(&cpuctl_cdevsw, cpu,
446 				    UID_ROOT, GID_KMEM, 0640, "cpuctl%d", cpu);
447 		break;
448 	case MOD_UNLOAD:
449 		for (cpu = 0; cpu < mp_ncpus; cpu++) {
450 			if (cpuctl_devs[cpu] != NULL)
451 				destroy_dev(cpuctl_devs[cpu]);
452 		}
453 		free(cpuctl_devs, M_CPUCTL);
454 		break;
455 	case MOD_SHUTDOWN:
456 		break;
457 	default:
458 		return (EOPNOTSUPP);
459         }
460 	return (0);
461 }
462 
463 DEV_MODULE(cpuctl, cpuctl_modevent, NULL);
464 MODULE_VERSION(cpuctl, CPUCTL_VERSION);
465