xref: /freebsd/sys/dev/efidev/efirt.c (revision 88e852c0b5c872b1a3234515623104ae61b60773)
1 /*-
2  * Copyright (c) 2004 Marcel Moolenaar
3  * Copyright (c) 2001 Doug Rabson
4  * Copyright (c) 2016, 2018 The FreeBSD Foundation
5  * All rights reserved.
6  *
7  * Portions of this software were developed by Konstantin Belousov
8  * under sponsorship from the FreeBSD Foundation.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include <sys/param.h>
36 #include <sys/efi.h>
37 #include <sys/eventhandler.h>
38 #include <sys/kernel.h>
39 #include <sys/linker.h>
40 #include <sys/lock.h>
41 #include <sys/module.h>
42 #include <sys/mutex.h>
43 #include <sys/clock.h>
44 #include <sys/proc.h>
45 #include <sys/reboot.h>
46 #include <sys/rwlock.h>
47 #include <sys/sched.h>
48 #include <sys/sysctl.h>
49 #include <sys/systm.h>
50 #include <sys/vmmeter.h>
51 
52 #include <machine/fpu.h>
53 #include <machine/efi.h>
54 #include <machine/metadata.h>
55 #include <machine/vmparam.h>
56 
57 #include <vm/vm.h>
58 #include <vm/pmap.h>
59 #include <vm/vm_map.h>
60 
61 static struct efi_systbl *efi_systbl;
62 static eventhandler_tag efi_shutdown_tag;
63 /*
64  * The following pointers point to tables in the EFI runtime service data pages.
65  * Care should be taken to make sure that we've properly entered the EFI runtime
66  * environment (efi_enter()) before dereferencing them.
67  */
68 static struct efi_cfgtbl *efi_cfgtbl;
69 static struct efi_rt *efi_runtime;
70 
71 static int efi_status2err[25] = {
72 	0,		/* EFI_SUCCESS */
73 	ENOEXEC,	/* EFI_LOAD_ERROR */
74 	EINVAL,		/* EFI_INVALID_PARAMETER */
75 	ENOSYS,		/* EFI_UNSUPPORTED */
76 	EMSGSIZE, 	/* EFI_BAD_BUFFER_SIZE */
77 	EOVERFLOW,	/* EFI_BUFFER_TOO_SMALL */
78 	EBUSY,		/* EFI_NOT_READY */
79 	EIO,		/* EFI_DEVICE_ERROR */
80 	EROFS,		/* EFI_WRITE_PROTECTED */
81 	EAGAIN,		/* EFI_OUT_OF_RESOURCES */
82 	EIO,		/* EFI_VOLUME_CORRUPTED */
83 	ENOSPC,		/* EFI_VOLUME_FULL */
84 	ENXIO,		/* EFI_NO_MEDIA */
85 	ESTALE,		/* EFI_MEDIA_CHANGED */
86 	ENOENT,		/* EFI_NOT_FOUND */
87 	EACCES,		/* EFI_ACCESS_DENIED */
88 	ETIMEDOUT,	/* EFI_NO_RESPONSE */
89 	EADDRNOTAVAIL,	/* EFI_NO_MAPPING */
90 	ETIMEDOUT,	/* EFI_TIMEOUT */
91 	EDOOFUS,	/* EFI_NOT_STARTED */
92 	EALREADY,	/* EFI_ALREADY_STARTED */
93 	ECANCELED,	/* EFI_ABORTED */
94 	EPROTO,		/* EFI_ICMP_ERROR */
95 	EPROTO,		/* EFI_TFTP_ERROR */
96 	EPROTO		/* EFI_PROTOCOL_ERROR */
97 };
98 
99 static int efi_enter(void);
100 static void efi_leave(void);
101 
102 int
103 efi_status_to_errno(efi_status status)
104 {
105 	u_long code;
106 
107 	code = status & 0x3ffffffffffffffful;
108 	return (code < nitems(efi_status2err) ? efi_status2err[code] : EDOOFUS);
109 }
110 
111 static struct mtx efi_lock;
112 static SYSCTL_NODE(_hw, OID_AUTO, efi, CTLFLAG_RWTUN | CTLFLAG_MPSAFE, NULL,
113     "EFI");
114 static bool efi_poweroff = true;
115 SYSCTL_BOOL(_hw_efi, OID_AUTO, poweroff, CTLFLAG_RWTUN, &efi_poweroff, 0,
116     "If true, use EFI runtime services to power off in preference to ACPI");
117 
118 static bool
119 efi_is_in_map(struct efi_md *map, int ndesc, int descsz, vm_offset_t addr)
120 {
121 	struct efi_md *p;
122 	int i;
123 
124 	for (i = 0, p = map; i < ndesc; i++, p = efi_next_descriptor(p,
125 	    descsz)) {
126 		if ((p->md_attr & EFI_MD_ATTR_RT) == 0)
127 			continue;
128 
129 		if (addr >= (uintptr_t)p->md_virt &&
130 		    addr < (uintptr_t)p->md_virt + p->md_pages * PAGE_SIZE)
131 			return (true);
132 	}
133 
134 	return (false);
135 }
136 
137 static void
138 efi_shutdown_final(void *dummy __unused, int howto)
139 {
140 
141 	/*
142 	 * On some systems, ACPI S5 is missing or does not function properly.
143 	 * When present, shutdown via EFI Runtime Services instead, unless
144 	 * disabled.
145 	 */
146 	if ((howto & RB_POWEROFF) != 0 && efi_poweroff)
147 		(void)efi_reset_system(EFI_RESET_SHUTDOWN);
148 }
149 
150 static int
151 efi_init(void)
152 {
153 	struct efi_map_header *efihdr;
154 	struct efi_md *map;
155 	struct efi_rt *rtdm;
156 	caddr_t kmdp;
157 	size_t efisz;
158 	int ndesc, rt_disabled;
159 
160 	rt_disabled = 0;
161 	TUNABLE_INT_FETCH("efi.rt.disabled", &rt_disabled);
162 	if (rt_disabled == 1)
163 		return (0);
164 	mtx_init(&efi_lock, "efi", NULL, MTX_DEF);
165 
166 	if (efi_systbl_phys == 0) {
167 		if (bootverbose)
168 			printf("EFI systbl not available\n");
169 		return (0);
170 	}
171 
172 	efi_systbl = (struct efi_systbl *)efi_phys_to_kva(efi_systbl_phys);
173 	if (efi_systbl == NULL || efi_systbl->st_hdr.th_sig != EFI_SYSTBL_SIG) {
174 		efi_systbl = NULL;
175 		if (bootverbose)
176 			printf("EFI systbl signature invalid\n");
177 		return (0);
178 	}
179 	efi_cfgtbl = (efi_systbl->st_cfgtbl == 0) ? NULL :
180 	    (struct efi_cfgtbl *)efi_systbl->st_cfgtbl;
181 	if (efi_cfgtbl == NULL) {
182 		if (bootverbose)
183 			printf("EFI config table is not present\n");
184 	}
185 
186 	kmdp = preload_search_by_type("elf kernel");
187 	if (kmdp == NULL)
188 		kmdp = preload_search_by_type("elf64 kernel");
189 	efihdr = (struct efi_map_header *)preload_search_info(kmdp,
190 	    MODINFO_METADATA | MODINFOMD_EFI_MAP);
191 	if (efihdr == NULL) {
192 		if (bootverbose)
193 			printf("EFI map is not present\n");
194 		return (0);
195 	}
196 	efisz = (sizeof(struct efi_map_header) + 0xf) & ~0xf;
197 	map = (struct efi_md *)((uint8_t *)efihdr + efisz);
198 	if (efihdr->descriptor_size == 0)
199 		return (ENOMEM);
200 
201 	ndesc = efihdr->memory_size / efihdr->descriptor_size;
202 	if (!efi_create_1t1_map(map, ndesc, efihdr->descriptor_size)) {
203 		if (bootverbose)
204 			printf("EFI cannot create runtime map\n");
205 		return (ENOMEM);
206 	}
207 
208 	efi_runtime = (efi_systbl->st_rt == 0) ? NULL :
209 	    (struct efi_rt *)efi_systbl->st_rt;
210 	if (efi_runtime == NULL) {
211 		if (bootverbose)
212 			printf("EFI runtime services table is not present\n");
213 		efi_destroy_1t1_map();
214 		return (ENXIO);
215 	}
216 
217 #if defined(__aarch64__) || defined(__amd64__)
218 	/*
219 	 * Some UEFI implementations have multiple implementations of the
220 	 * RS->GetTime function. They switch from one we can only use early
221 	 * in the boot process to one valid as a RunTime service only when we
222 	 * call RS->SetVirtualAddressMap. As this is not always the case, e.g.
223 	 * with an old loader.efi, check if the RS->GetTime function is within
224 	 * the EFI map, and fail to attach if not.
225 	 */
226 	rtdm = (struct efi_rt *)efi_phys_to_kva((uintptr_t)efi_runtime);
227 	if (rtdm == NULL || !efi_is_in_map(map, ndesc, efihdr->descriptor_size,
228 	    (vm_offset_t)rtdm->rt_gettime)) {
229 		if (bootverbose)
230 			printf(
231 			 "EFI runtime services table has an invalid pointer\n");
232 		efi_runtime = NULL;
233 		efi_destroy_1t1_map();
234 		return (ENXIO);
235 	}
236 #endif
237 
238 	/*
239 	 * We use SHUTDOWN_PRI_LAST - 1 to trigger after IPMI, but before ACPI.
240 	 */
241 	efi_shutdown_tag = EVENTHANDLER_REGISTER(shutdown_final,
242 	    efi_shutdown_final, NULL, SHUTDOWN_PRI_LAST - 1);
243 
244 	return (0);
245 }
246 
247 static void
248 efi_uninit(void)
249 {
250 
251 	/* Most likely disabled by tunable */
252 	if (efi_runtime == NULL)
253 		return;
254 	if (efi_shutdown_tag != NULL)
255 		EVENTHANDLER_DEREGISTER(shutdown_final, efi_shutdown_tag);
256 	efi_destroy_1t1_map();
257 
258 	efi_systbl = NULL;
259 	efi_cfgtbl = NULL;
260 	efi_runtime = NULL;
261 
262 	mtx_destroy(&efi_lock);
263 }
264 
265 static int
266 rt_ok(void)
267 {
268 
269 	if (efi_runtime == NULL)
270 		return (ENXIO);
271 	return (0);
272 }
273 
274 static int
275 efi_enter(void)
276 {
277 	struct thread *td;
278 	pmap_t curpmap;
279 	int error;
280 
281 	if (efi_runtime == NULL)
282 		return (ENXIO);
283 	td = curthread;
284 	curpmap = &td->td_proc->p_vmspace->vm_pmap;
285 	PMAP_LOCK(curpmap);
286 	mtx_lock(&efi_lock);
287 	fpu_kern_enter(td, NULL, FPU_KERN_NOCTX);
288 	error = efi_arch_enter();
289 	if (error != 0) {
290 		fpu_kern_leave(td, NULL);
291 		mtx_unlock(&efi_lock);
292 		PMAP_UNLOCK(curpmap);
293 	}
294 	return (error);
295 }
296 
297 static void
298 efi_leave(void)
299 {
300 	struct thread *td;
301 	pmap_t curpmap;
302 
303 	efi_arch_leave();
304 
305 	curpmap = &curproc->p_vmspace->vm_pmap;
306 	td = curthread;
307 	fpu_kern_leave(td, NULL);
308 	mtx_unlock(&efi_lock);
309 	PMAP_UNLOCK(curpmap);
310 }
311 
312 static int
313 get_table(struct uuid *uuid, void **ptr)
314 {
315 	struct efi_cfgtbl *ct;
316 	u_long count;
317 	int error;
318 
319 	if (efi_cfgtbl == NULL || efi_systbl == NULL)
320 		return (ENXIO);
321 	error = efi_enter();
322 	if (error != 0)
323 		return (error);
324 	count = efi_systbl->st_entries;
325 	ct = efi_cfgtbl;
326 	while (count--) {
327 		if (!bcmp(&ct->ct_uuid, uuid, sizeof(*uuid))) {
328 			*ptr = ct->ct_data;
329 			efi_leave();
330 			return (0);
331 		}
332 		ct++;
333 	}
334 
335 	efi_leave();
336 	return (ENOENT);
337 }
338 
339 static int efi_rt_handle_faults = EFI_RT_HANDLE_FAULTS_DEFAULT;
340 SYSCTL_INT(_machdep, OID_AUTO, efi_rt_handle_faults, CTLFLAG_RWTUN,
341     &efi_rt_handle_faults, 0,
342     "Call EFI RT methods with fault handler wrapper around");
343 
344 static int
345 efi_rt_arch_call_nofault(struct efirt_callinfo *ec)
346 {
347 
348 	switch (ec->ec_argcnt) {
349 	case 0:
350 		ec->ec_efi_status = ((register_t (*)(void))ec->ec_fptr)();
351 		break;
352 	case 1:
353 		ec->ec_efi_status = ((register_t (*)(register_t))ec->ec_fptr)
354 		    (ec->ec_arg1);
355 		break;
356 	case 2:
357 		ec->ec_efi_status = ((register_t (*)(register_t, register_t))
358 		    ec->ec_fptr)(ec->ec_arg1, ec->ec_arg2);
359 		break;
360 	case 3:
361 		ec->ec_efi_status = ((register_t (*)(register_t, register_t,
362 		    register_t))ec->ec_fptr)(ec->ec_arg1, ec->ec_arg2,
363 		    ec->ec_arg3);
364 		break;
365 	case 4:
366 		ec->ec_efi_status = ((register_t (*)(register_t, register_t,
367 		    register_t, register_t))ec->ec_fptr)(ec->ec_arg1,
368 		    ec->ec_arg2, ec->ec_arg3, ec->ec_arg4);
369 		break;
370 	case 5:
371 		ec->ec_efi_status = ((register_t (*)(register_t, register_t,
372 		    register_t, register_t, register_t))ec->ec_fptr)(
373 		    ec->ec_arg1, ec->ec_arg2, ec->ec_arg3, ec->ec_arg4,
374 		    ec->ec_arg5);
375 		break;
376 	default:
377 		panic("efi_rt_arch_call: %d args", (int)ec->ec_argcnt);
378 	}
379 
380 	return (0);
381 }
382 
383 static int
384 efi_call(struct efirt_callinfo *ecp)
385 {
386 	int error;
387 
388 	error = efi_enter();
389 	if (error != 0)
390 		return (error);
391 	error = efi_rt_handle_faults ? efi_rt_arch_call(ecp) :
392 	    efi_rt_arch_call_nofault(ecp);
393 	efi_leave();
394 	if (error == 0)
395 		error = efi_status_to_errno(ecp->ec_efi_status);
396 	else if (bootverbose)
397 		printf("EFI %s call faulted, error %d\n", ecp->ec_name, error);
398 	return (error);
399 }
400 
401 #define	EFI_RT_METHOD_PA(method)				\
402     ((uintptr_t)((struct efi_rt *)efi_phys_to_kva((uintptr_t)	\
403     efi_runtime))->method)
404 
405 static int
406 efi_get_time_locked(struct efi_tm *tm, struct efi_tmcap *tmcap)
407 {
408 	struct efirt_callinfo ec;
409 
410 	EFI_TIME_OWNED();
411 	if (efi_runtime == NULL)
412 		return (ENXIO);
413 	bzero(&ec, sizeof(ec));
414 	ec.ec_name = "rt_gettime";
415 	ec.ec_argcnt = 2;
416 	ec.ec_arg1 = (uintptr_t)tm;
417 	ec.ec_arg2 = (uintptr_t)tmcap;
418 	ec.ec_fptr = EFI_RT_METHOD_PA(rt_gettime);
419 	return (efi_call(&ec));
420 }
421 
422 static int
423 get_time(struct efi_tm *tm)
424 {
425 	struct efi_tmcap dummy;
426 	int error;
427 
428 	if (efi_runtime == NULL)
429 		return (ENXIO);
430 	EFI_TIME_LOCK();
431 	/*
432 	 * UEFI spec states that the Capabilities argument to GetTime is
433 	 * optional, but some UEFI implementations choke when passed a NULL
434 	 * pointer. Pass a dummy efi_tmcap, even though we won't use it,
435 	 * to workaround such implementations.
436 	 */
437 	error = efi_get_time_locked(tm, &dummy);
438 	EFI_TIME_UNLOCK();
439 	return (error);
440 }
441 
442 static int
443 get_time_capabilities(struct efi_tmcap *tmcap)
444 {
445 	struct efi_tm dummy;
446 	int error;
447 
448 	if (efi_runtime == NULL)
449 		return (ENXIO);
450 	EFI_TIME_LOCK();
451 	error = efi_get_time_locked(&dummy, tmcap);
452 	EFI_TIME_UNLOCK();
453 	return (error);
454 }
455 
456 static int
457 reset_system(enum efi_reset type)
458 {
459 	struct efirt_callinfo ec;
460 
461 	switch (type) {
462 	case EFI_RESET_COLD:
463 	case EFI_RESET_WARM:
464 	case EFI_RESET_SHUTDOWN:
465 		break;
466 	default:
467 		return (EINVAL);
468 	}
469 	if (efi_runtime == NULL)
470 		return (ENXIO);
471 	bzero(&ec, sizeof(ec));
472 	ec.ec_name = "rt_reset";
473 	ec.ec_argcnt = 4;
474 	ec.ec_arg1 = (uintptr_t)type;
475 	ec.ec_arg2 = (uintptr_t)0;
476 	ec.ec_arg3 = (uintptr_t)0;
477 	ec.ec_arg4 = (uintptr_t)NULL;
478 	ec.ec_fptr = EFI_RT_METHOD_PA(rt_reset);
479 	return (efi_call(&ec));
480 }
481 
482 static int
483 efi_set_time_locked(struct efi_tm *tm)
484 {
485 	struct efirt_callinfo ec;
486 
487 	EFI_TIME_OWNED();
488 	if (efi_runtime == NULL)
489 		return (ENXIO);
490 	bzero(&ec, sizeof(ec));
491 	ec.ec_name = "rt_settime";
492 	ec.ec_argcnt = 1;
493 	ec.ec_arg1 = (uintptr_t)tm;
494 	ec.ec_fptr = EFI_RT_METHOD_PA(rt_settime);
495 	return (efi_call(&ec));
496 }
497 
498 static int
499 set_time(struct efi_tm *tm)
500 {
501 	int error;
502 
503 	if (efi_runtime == NULL)
504 		return (ENXIO);
505 	EFI_TIME_LOCK();
506 	error = efi_set_time_locked(tm);
507 	EFI_TIME_UNLOCK();
508 	return (error);
509 }
510 
511 static int
512 var_get(efi_char *name, struct uuid *vendor, uint32_t *attrib,
513     size_t *datasize, void *data)
514 {
515 	struct efirt_callinfo ec;
516 
517 	if (efi_runtime == NULL)
518 		return (ENXIO);
519 	bzero(&ec, sizeof(ec));
520 	ec.ec_argcnt = 5;
521 	ec.ec_name = "rt_getvar";
522 	ec.ec_arg1 = (uintptr_t)name;
523 	ec.ec_arg2 = (uintptr_t)vendor;
524 	ec.ec_arg3 = (uintptr_t)attrib;
525 	ec.ec_arg4 = (uintptr_t)datasize;
526 	ec.ec_arg5 = (uintptr_t)data;
527 	ec.ec_fptr = EFI_RT_METHOD_PA(rt_getvar);
528 	return (efi_call(&ec));
529 }
530 
531 static int
532 var_nextname(size_t *namesize, efi_char *name, struct uuid *vendor)
533 {
534 	struct efirt_callinfo ec;
535 
536 	if (efi_runtime == NULL)
537 		return (ENXIO);
538 	bzero(&ec, sizeof(ec));
539 	ec.ec_argcnt = 3;
540 	ec.ec_name = "rt_scanvar";
541 	ec.ec_arg1 = (uintptr_t)namesize;
542 	ec.ec_arg2 = (uintptr_t)name;
543 	ec.ec_arg3 = (uintptr_t)vendor;
544 	ec.ec_fptr = EFI_RT_METHOD_PA(rt_scanvar);
545 	return (efi_call(&ec));
546 }
547 
548 static int
549 var_set(efi_char *name, struct uuid *vendor, uint32_t attrib,
550     size_t datasize, void *data)
551 {
552 	struct efirt_callinfo ec;
553 
554 	if (efi_runtime == NULL)
555 		return (ENXIO);
556 	bzero(&ec, sizeof(ec));
557 	ec.ec_argcnt = 5;
558 	ec.ec_name = "rt_setvar";
559 	ec.ec_arg1 = (uintptr_t)name;
560 	ec.ec_arg2 = (uintptr_t)vendor;
561 	ec.ec_arg3 = (uintptr_t)attrib;
562 	ec.ec_arg4 = (uintptr_t)datasize;
563 	ec.ec_arg5 = (uintptr_t)data;
564 	ec.ec_fptr = EFI_RT_METHOD_PA(rt_setvar);
565 	return (efi_call(&ec));
566 }
567 
568 const static struct efi_ops efi_ops = {
569 	.rt_ok = rt_ok,
570 	.get_table = get_table,
571 	.get_time = get_time,
572 	.get_time_capabilities = get_time_capabilities,
573 	.reset_system = reset_system,
574 	.set_time = set_time,
575 	.var_get = var_get,
576 	.var_nextname = var_nextname,
577 	.var_set = var_set,
578 };
579 const struct efi_ops *active_efi_ops = &efi_ops;
580 
581 static int
582 efirt_modevents(module_t m, int event, void *arg __unused)
583 {
584 
585 	switch (event) {
586 	case MOD_LOAD:
587 		return (efi_init());
588 
589 	case MOD_UNLOAD:
590 		efi_uninit();
591 		return (0);
592 
593 	case MOD_SHUTDOWN:
594 		return (0);
595 
596 	default:
597 		return (EOPNOTSUPP);
598 	}
599 }
600 
601 static moduledata_t efirt_moddata = {
602 	.name = "efirt",
603 	.evhand = efirt_modevents,
604 	.priv = NULL,
605 };
606 /* After fpuinitstate, before efidev */
607 DECLARE_MODULE(efirt, efirt_moddata, SI_SUB_DRIVERS, SI_ORDER_SECOND);
608 MODULE_VERSION(efirt, 1);
609