xref: /freebsd/sys/dev/efidev/efirt.c (revision 190cef3d)
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/kernel.h>
38 #include <sys/linker.h>
39 #include <sys/lock.h>
40 #include <sys/module.h>
41 #include <sys/mutex.h>
42 #include <sys/clock.h>
43 #include <sys/proc.h>
44 #include <sys/rwlock.h>
45 #include <sys/sched.h>
46 #include <sys/sysctl.h>
47 #include <sys/systm.h>
48 #include <sys/vmmeter.h>
49 
50 #include <machine/fpu.h>
51 #include <machine/efi.h>
52 #include <machine/metadata.h>
53 #include <machine/vmparam.h>
54 
55 #include <vm/vm.h>
56 #include <vm/pmap.h>
57 #include <vm/vm_map.h>
58 
59 static struct efi_systbl *efi_systbl;
60 /*
61  * The following pointers point to tables in the EFI runtime service data pages.
62  * Care should be taken to make sure that we've properly entered the EFI runtime
63  * environment (efi_enter()) before dereferencing them.
64  */
65 static struct efi_cfgtbl *efi_cfgtbl;
66 static struct efi_rt *efi_runtime;
67 
68 static int efi_status2err[25] = {
69 	0,		/* EFI_SUCCESS */
70 	ENOEXEC,	/* EFI_LOAD_ERROR */
71 	EINVAL,		/* EFI_INVALID_PARAMETER */
72 	ENOSYS,		/* EFI_UNSUPPORTED */
73 	EMSGSIZE, 	/* EFI_BAD_BUFFER_SIZE */
74 	EOVERFLOW,	/* EFI_BUFFER_TOO_SMALL */
75 	EBUSY,		/* EFI_NOT_READY */
76 	EIO,		/* EFI_DEVICE_ERROR */
77 	EROFS,		/* EFI_WRITE_PROTECTED */
78 	EAGAIN,		/* EFI_OUT_OF_RESOURCES */
79 	EIO,		/* EFI_VOLUME_CORRUPTED */
80 	ENOSPC,		/* EFI_VOLUME_FULL */
81 	ENXIO,		/* EFI_NO_MEDIA */
82 	ESTALE,		/* EFI_MEDIA_CHANGED */
83 	ENOENT,		/* EFI_NOT_FOUND */
84 	EACCES,		/* EFI_ACCESS_DENIED */
85 	ETIMEDOUT,	/* EFI_NO_RESPONSE */
86 	EADDRNOTAVAIL,	/* EFI_NO_MAPPING */
87 	ETIMEDOUT,	/* EFI_TIMEOUT */
88 	EDOOFUS,	/* EFI_NOT_STARTED */
89 	EALREADY,	/* EFI_ALREADY_STARTED */
90 	ECANCELED,	/* EFI_ABORTED */
91 	EPROTO,		/* EFI_ICMP_ERROR */
92 	EPROTO,		/* EFI_TFTP_ERROR */
93 	EPROTO		/* EFI_PROTOCOL_ERROR */
94 };
95 
96 static int efi_enter(void);
97 static void efi_leave(void);
98 
99 static int
100 efi_status_to_errno(efi_status status)
101 {
102 	u_long code;
103 
104 	code = status & 0x3ffffffffffffffful;
105 	return (code < nitems(efi_status2err) ? efi_status2err[code] : EDOOFUS);
106 }
107 
108 static struct mtx efi_lock;
109 
110 static bool
111 efi_is_in_map(struct efi_md *map, int ndesc, int descsz, vm_offset_t addr)
112 {
113 	struct efi_md *p;
114 	int i;
115 
116 	for (i = 0, p = map; i < ndesc; i++, p = efi_next_descriptor(p,
117 	    descsz)) {
118 		if ((p->md_attr & EFI_MD_ATTR_RT) == 0)
119 			continue;
120 
121 		if (addr >= (uintptr_t)p->md_virt &&
122 		    addr < (uintptr_t)p->md_virt + p->md_pages * PAGE_SIZE)
123 			return (true);
124 	}
125 
126 	return (false);
127 }
128 
129 static int
130 efi_init(void)
131 {
132 	struct efi_map_header *efihdr;
133 	struct efi_md *map;
134 	struct efi_rt *rtdm;
135 	caddr_t kmdp;
136 	size_t efisz;
137 	int ndesc, rt_disabled;
138 
139 	rt_disabled = 0;
140 	TUNABLE_INT_FETCH("efi.rt.disabled", &rt_disabled);
141 	if (rt_disabled == 1)
142 		return (0);
143 	mtx_init(&efi_lock, "efi", NULL, MTX_DEF);
144 
145 	if (efi_systbl_phys == 0) {
146 		if (bootverbose)
147 			printf("EFI systbl not available\n");
148 		return (0);
149 	}
150 
151 	efi_systbl = (struct efi_systbl *)efi_phys_to_kva(efi_systbl_phys);
152 	if (efi_systbl == NULL || efi_systbl->st_hdr.th_sig != EFI_SYSTBL_SIG) {
153 		efi_systbl = NULL;
154 		if (bootverbose)
155 			printf("EFI systbl signature invalid\n");
156 		return (0);
157 	}
158 	efi_cfgtbl = (efi_systbl->st_cfgtbl == 0) ? NULL :
159 	    (struct efi_cfgtbl *)efi_systbl->st_cfgtbl;
160 	if (efi_cfgtbl == NULL) {
161 		if (bootverbose)
162 			printf("EFI config table is not present\n");
163 	}
164 
165 	kmdp = preload_search_by_type("elf kernel");
166 	if (kmdp == NULL)
167 		kmdp = preload_search_by_type("elf64 kernel");
168 	efihdr = (struct efi_map_header *)preload_search_info(kmdp,
169 	    MODINFO_METADATA | MODINFOMD_EFI_MAP);
170 	if (efihdr == NULL) {
171 		if (bootverbose)
172 			printf("EFI map is not present\n");
173 		return (0);
174 	}
175 	efisz = (sizeof(struct efi_map_header) + 0xf) & ~0xf;
176 	map = (struct efi_md *)((uint8_t *)efihdr + efisz);
177 	if (efihdr->descriptor_size == 0)
178 		return (ENOMEM);
179 
180 	ndesc = efihdr->memory_size / efihdr->descriptor_size;
181 	if (!efi_create_1t1_map(map, ndesc, efihdr->descriptor_size)) {
182 		if (bootverbose)
183 			printf("EFI cannot create runtime map\n");
184 		return (ENOMEM);
185 	}
186 
187 	efi_runtime = (efi_systbl->st_rt == 0) ? NULL :
188 	    (struct efi_rt *)efi_systbl->st_rt;
189 	if (efi_runtime == NULL) {
190 		if (bootverbose)
191 			printf("EFI runtime services table is not present\n");
192 		efi_destroy_1t1_map();
193 		return (ENXIO);
194 	}
195 
196 #if defined(__aarch64__) || defined(__amd64__)
197 	/*
198 	 * Some UEFI implementations have multiple implementations of the
199 	 * RS->GetTime function. They switch from one we can only use early
200 	 * in the boot process to one valid as a RunTime service only when we
201 	 * call RS->SetVirtualAddressMap. As this is not always the case, e.g.
202 	 * with an old loader.efi, check if the RS->GetTime function is within
203 	 * the EFI map, and fail to attach if not.
204 	 */
205 	rtdm = (struct efi_rt *)efi_phys_to_kva((uintptr_t)efi_runtime);
206 	if (rtdm == NULL || !efi_is_in_map(map, ndesc, efihdr->descriptor_size,
207 	    (vm_offset_t)rtdm->rt_gettime)) {
208 		if (bootverbose)
209 			printf(
210 			 "EFI runtime services table has an invalid pointer\n");
211 		efi_runtime = NULL;
212 		efi_destroy_1t1_map();
213 		return (ENXIO);
214 	}
215 #endif
216 
217 	return (0);
218 }
219 
220 static void
221 efi_uninit(void)
222 {
223 
224 	/* Most likely disabled by tunable */
225 	if (efi_runtime == NULL)
226 		return;
227 	efi_destroy_1t1_map();
228 
229 	efi_systbl = NULL;
230 	efi_cfgtbl = NULL;
231 	efi_runtime = NULL;
232 
233 	mtx_destroy(&efi_lock);
234 }
235 
236 int
237 efi_rt_ok(void)
238 {
239 
240 	if (efi_runtime == NULL)
241 		return (ENXIO);
242 	return (0);
243 }
244 
245 static int
246 efi_enter(void)
247 {
248 	struct thread *td;
249 	pmap_t curpmap;
250 
251 	if (efi_runtime == NULL)
252 		return (ENXIO);
253 	td = curthread;
254 	curpmap = &td->td_proc->p_vmspace->vm_pmap;
255 	PMAP_LOCK(curpmap);
256 	mtx_lock(&efi_lock);
257 	fpu_kern_enter(td, NULL, FPU_KERN_NOCTX);
258 	return (efi_arch_enter());
259 }
260 
261 static void
262 efi_leave(void)
263 {
264 	struct thread *td;
265 	pmap_t curpmap;
266 
267 	efi_arch_leave();
268 
269 	curpmap = &curproc->p_vmspace->vm_pmap;
270 	td = curthread;
271 	fpu_kern_leave(td, NULL);
272 	mtx_unlock(&efi_lock);
273 	PMAP_UNLOCK(curpmap);
274 }
275 
276 int
277 efi_get_table(struct uuid *uuid, void **ptr)
278 {
279 	struct efi_cfgtbl *ct;
280 	u_long count;
281 
282 	if (efi_cfgtbl == NULL || efi_systbl == NULL)
283 		return (ENXIO);
284 	count = efi_systbl->st_entries;
285 	ct = efi_cfgtbl;
286 	while (count--) {
287 		if (!bcmp(&ct->ct_uuid, uuid, sizeof(*uuid))) {
288 			*ptr = (void *)efi_phys_to_kva(ct->ct_data);
289 			return (0);
290 		}
291 		ct++;
292 	}
293 	return (ENOENT);
294 }
295 
296 static int efi_rt_handle_faults = EFI_RT_HANDLE_FAULTS_DEFAULT;
297 SYSCTL_INT(_machdep, OID_AUTO, efi_rt_handle_faults, CTLFLAG_RWTUN,
298     &efi_rt_handle_faults, 0,
299     "Call EFI RT methods with fault handler wrapper around");
300 
301 static int
302 efi_rt_arch_call_nofault(struct efirt_callinfo *ec)
303 {
304 
305 	switch (ec->ec_argcnt) {
306 	case 0:
307 		ec->ec_efi_status = ((register_t (*)(void))ec->ec_fptr)();
308 		break;
309 	case 1:
310 		ec->ec_efi_status = ((register_t (*)(register_t))ec->ec_fptr)
311 		    (ec->ec_arg1);
312 		break;
313 	case 2:
314 		ec->ec_efi_status = ((register_t (*)(register_t, register_t))
315 		    ec->ec_fptr)(ec->ec_arg1, ec->ec_arg2);
316 		break;
317 	case 3:
318 		ec->ec_efi_status = ((register_t (*)(register_t, register_t,
319 		    register_t))ec->ec_fptr)(ec->ec_arg1, ec->ec_arg2,
320 		    ec->ec_arg3);
321 		break;
322 	case 4:
323 		ec->ec_efi_status = ((register_t (*)(register_t, register_t,
324 		    register_t, register_t))ec->ec_fptr)(ec->ec_arg1,
325 		    ec->ec_arg2, ec->ec_arg3, ec->ec_arg4);
326 		break;
327 	case 5:
328 		ec->ec_efi_status = ((register_t (*)(register_t, register_t,
329 		    register_t, register_t, register_t))ec->ec_fptr)(
330 		    ec->ec_arg1, ec->ec_arg2, ec->ec_arg3, ec->ec_arg4,
331 		    ec->ec_arg5);
332 		break;
333 	default:
334 		panic("efi_rt_arch_call: %d args", (int)ec->ec_argcnt);
335 	}
336 
337 	return (0);
338 }
339 
340 static int
341 efi_call(struct efirt_callinfo *ecp)
342 {
343 	int error;
344 
345 	error = efi_enter();
346 	if (error != 0)
347 		return (error);
348 	error = efi_rt_handle_faults ? efi_rt_arch_call(ecp) :
349 	    efi_rt_arch_call_nofault(ecp);
350 	efi_leave();
351 	if (error == 0)
352 		error = efi_status_to_errno(ecp->ec_efi_status);
353 	else if (bootverbose)
354 		printf("EFI %s call faulted, error %d\n", ecp->ec_name, error);
355 	return (error);
356 }
357 
358 #define	EFI_RT_METHOD_PA(method)				\
359     ((uintptr_t)((struct efi_rt *)efi_phys_to_kva((uintptr_t)	\
360     efi_runtime))->method)
361 
362 static int
363 efi_get_time_locked(struct efi_tm *tm, struct efi_tmcap *tmcap)
364 {
365 	struct efirt_callinfo ec;
366 
367 	EFI_TIME_OWNED();
368 	if (efi_runtime == NULL)
369 		return (ENXIO);
370 	bzero(&ec, sizeof(ec));
371 	ec.ec_name = "rt_gettime";
372 	ec.ec_argcnt = 2;
373 	ec.ec_arg1 = (uintptr_t)tm;
374 	ec.ec_arg2 = (uintptr_t)tmcap;
375 	ec.ec_fptr = EFI_RT_METHOD_PA(rt_gettime);
376 	return (efi_call(&ec));
377 }
378 
379 int
380 efi_get_time(struct efi_tm *tm)
381 {
382 	struct efi_tmcap dummy;
383 	int error;
384 
385 	if (efi_runtime == NULL)
386 		return (ENXIO);
387 	EFI_TIME_LOCK();
388 	/*
389 	 * UEFI spec states that the Capabilities argument to GetTime is
390 	 * optional, but some UEFI implementations choke when passed a NULL
391 	 * pointer. Pass a dummy efi_tmcap, even though we won't use it,
392 	 * to workaround such implementations.
393 	 */
394 	error = efi_get_time_locked(tm, &dummy);
395 	EFI_TIME_UNLOCK();
396 	return (error);
397 }
398 
399 int
400 efi_get_time_capabilities(struct efi_tmcap *tmcap)
401 {
402 	struct efi_tm dummy;
403 	int error;
404 
405 	if (efi_runtime == NULL)
406 		return (ENXIO);
407 	EFI_TIME_LOCK();
408 	error = efi_get_time_locked(&dummy, tmcap);
409 	EFI_TIME_UNLOCK();
410 	return (error);
411 }
412 
413 int
414 efi_reset_system(void)
415 {
416 	struct efirt_callinfo ec;
417 
418 	if (efi_runtime == NULL)
419 		return (ENXIO);
420 	bzero(&ec, sizeof(ec));
421 	ec.ec_name = "rt_reset";
422 	ec.ec_argcnt = 4;
423 	ec.ec_arg1 = (uintptr_t)EFI_RESET_WARM;
424 	ec.ec_arg2 = (uintptr_t)0;
425 	ec.ec_arg3 = (uintptr_t)0;
426 	ec.ec_arg4 = (uintptr_t)NULL;
427 	ec.ec_fptr = EFI_RT_METHOD_PA(rt_reset);
428 	return (efi_call(&ec));
429 }
430 
431 static int
432 efi_set_time_locked(struct efi_tm *tm)
433 {
434 	struct efirt_callinfo ec;
435 
436 	EFI_TIME_OWNED();
437 	if (efi_runtime == NULL)
438 		return (ENXIO);
439 	bzero(&ec, sizeof(ec));
440 	ec.ec_name = "rt_settime";
441 	ec.ec_argcnt = 1;
442 	ec.ec_arg1 = (uintptr_t)tm;
443 	ec.ec_fptr = EFI_RT_METHOD_PA(rt_settime);
444 	return (efi_call(&ec));
445 }
446 
447 int
448 efi_set_time(struct efi_tm *tm)
449 {
450 	int error;
451 
452 	if (efi_runtime == NULL)
453 		return (ENXIO);
454 	EFI_TIME_LOCK();
455 	error = efi_set_time_locked(tm);
456 	EFI_TIME_UNLOCK();
457 	return (error);
458 }
459 
460 int
461 efi_var_get(efi_char *name, struct uuid *vendor, uint32_t *attrib,
462     size_t *datasize, void *data)
463 {
464 	struct efirt_callinfo ec;
465 
466 	if (efi_runtime == NULL)
467 		return (ENXIO);
468 	bzero(&ec, sizeof(ec));
469 	ec.ec_argcnt = 5;
470 	ec.ec_name = "rt_getvar";
471 	ec.ec_arg1 = (uintptr_t)name;
472 	ec.ec_arg2 = (uintptr_t)vendor;
473 	ec.ec_arg3 = (uintptr_t)attrib;
474 	ec.ec_arg4 = (uintptr_t)datasize;
475 	ec.ec_arg5 = (uintptr_t)data;
476 	ec.ec_fptr = EFI_RT_METHOD_PA(rt_getvar);
477 	return (efi_call(&ec));
478 }
479 
480 int
481 efi_var_nextname(size_t *namesize, efi_char *name, struct uuid *vendor)
482 {
483 	struct efirt_callinfo ec;
484 
485 	if (efi_runtime == NULL)
486 		return (ENXIO);
487 	bzero(&ec, sizeof(ec));
488 	ec.ec_argcnt = 3;
489 	ec.ec_name = "rt_scanvar";
490 	ec.ec_arg1 = (uintptr_t)namesize;
491 	ec.ec_arg2 = (uintptr_t)name;
492 	ec.ec_arg3 = (uintptr_t)vendor;
493 	ec.ec_fptr = EFI_RT_METHOD_PA(rt_scanvar);
494 	return (efi_call(&ec));
495 }
496 
497 int
498 efi_var_set(efi_char *name, struct uuid *vendor, uint32_t attrib,
499     size_t datasize, void *data)
500 {
501 	struct efirt_callinfo ec;
502 
503 	if (efi_runtime == NULL)
504 		return (ENXIO);
505 	bzero(&ec, sizeof(ec));
506 	ec.ec_argcnt = 5;
507 	ec.ec_name = "rt_setvar";
508 	ec.ec_arg1 = (uintptr_t)name;
509 	ec.ec_arg2 = (uintptr_t)vendor;
510 	ec.ec_arg3 = (uintptr_t)attrib;
511 	ec.ec_arg4 = (uintptr_t)datasize;
512 	ec.ec_arg5 = (uintptr_t)data;
513 	ec.ec_fptr = EFI_RT_METHOD_PA(rt_setvar);
514 	return (efi_call(&ec));
515 }
516 
517 static int
518 efirt_modevents(module_t m, int event, void *arg __unused)
519 {
520 
521 	switch (event) {
522 	case MOD_LOAD:
523 		return (efi_init());
524 
525 	case MOD_UNLOAD:
526 		efi_uninit();
527 		return (0);
528 
529 	case MOD_SHUTDOWN:
530 		return (0);
531 
532 	default:
533 		return (EOPNOTSUPP);
534 	}
535 }
536 
537 static moduledata_t efirt_moddata = {
538 	.name = "efirt",
539 	.evhand = efirt_modevents,
540 	.priv = NULL,
541 };
542 /* After fpuinitstate, before efidev */
543 DECLARE_MODULE(efirt, efirt_moddata, SI_SUB_DRIVERS, SI_ORDER_SECOND);
544 MODULE_VERSION(efirt, 1);
545