xref: /freebsd/sys/dev/efidev/efirt.c (revision 63a938566d524836885917d95bd491aa4400b181)
1 /*-
2  * Copyright (c) 2004 Marcel Moolenaar
3  * Copyright (c) 2001 Doug Rabson
4  * Copyright (c) 2016 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 	caddr_t kmdp;
135 	size_t efisz;
136 
137 	mtx_init(&efi_lock, "efi", NULL, MTX_DEF);
138 
139 	if (efi_systbl_phys == 0) {
140 		if (bootverbose)
141 			printf("EFI systbl not available\n");
142 		return (0);
143 	}
144 	if (!PMAP_HAS_DMAP) {
145 		if (bootverbose)
146 			printf("EFI systbl requires direct map\n");
147 		return (0);
148 	}
149 	efi_systbl = (struct efi_systbl *)PHYS_TO_DMAP(efi_systbl_phys);
150 	if (efi_systbl->st_hdr.th_sig != EFI_SYSTBL_SIG) {
151 		efi_systbl = NULL;
152 		if (bootverbose)
153 			printf("EFI systbl signature invalid\n");
154 		return (0);
155 	}
156 	efi_cfgtbl = (efi_systbl->st_cfgtbl == 0) ? NULL :
157 	    (struct efi_cfgtbl *)efi_systbl->st_cfgtbl;
158 	if (efi_cfgtbl == NULL) {
159 		if (bootverbose)
160 			printf("EFI config table is not present\n");
161 	}
162 
163 	kmdp = preload_search_by_type("elf kernel");
164 	if (kmdp == NULL)
165 		kmdp = preload_search_by_type("elf64 kernel");
166 	efihdr = (struct efi_map_header *)preload_search_info(kmdp,
167 	    MODINFO_METADATA | MODINFOMD_EFI_MAP);
168 	if (efihdr == NULL) {
169 		if (bootverbose)
170 			printf("EFI map is not present\n");
171 		return (0);
172 	}
173 	efisz = (sizeof(struct efi_map_header) + 0xf) & ~0xf;
174 	map = (struct efi_md *)((uint8_t *)efihdr + efisz);
175 	if (efihdr->descriptor_size == 0)
176 		return (ENOMEM);
177 
178 	if (!efi_create_1t1_map(map, efihdr->memory_size /
179 	    efihdr->descriptor_size, efihdr->descriptor_size)) {
180 		if (bootverbose)
181 			printf("EFI cannot create runtime map\n");
182 		return (ENOMEM);
183 	}
184 
185 	efi_runtime = (efi_systbl->st_rt == 0) ? NULL :
186 	    (struct efi_rt *)efi_systbl->st_rt;
187 	if (efi_runtime == NULL) {
188 		if (bootverbose)
189 			printf("EFI runtime services table is not present\n");
190 		efi_destroy_1t1_map();
191 		return (ENXIO);
192 	}
193 
194 	/*
195 	 * Some UEFI implementations have multiple implementations of the
196 	 * RS->GetTime function. They switch from one we can only use early
197 	 * in the boot process to one valid as a RunTime service only when we
198 	 * call RS->SetVirtualAddressMap. As this is not always the case, e.g.
199 	 * with an old loader.efi, check if the RS->GetTime function is within
200 	 * the EFI map, and fail to attach if not.
201 	 *
202 	 * We need to enter into the EFI environment as efi_runtime may point
203 	 * to an EFI address.
204 	 */
205 	efi_enter();
206 	if (!efi_is_in_map(map, efihdr->memory_size / efihdr->descriptor_size,
207 	    efihdr->descriptor_size, (vm_offset_t)efi_runtime->rt_gettime)) {
208 		efi_leave();
209 		if (bootverbose)
210 			printf(
211 			 "EFI runtime services table has an invalid pointer\n");
212 		efi_runtime = NULL;
213 		efi_destroy_1t1_map();
214 		return (ENXIO);
215 	}
216 	efi_leave();
217 
218 	return (0);
219 }
220 
221 static void
222 efi_uninit(void)
223 {
224 
225 	efi_destroy_1t1_map();
226 
227 	efi_systbl = NULL;
228 	efi_cfgtbl = NULL;
229 	efi_runtime = NULL;
230 
231 	mtx_destroy(&efi_lock);
232 }
233 
234 int
235 efi_rt_ok(void)
236 {
237 
238 	if (efi_runtime == NULL)
239 		return (ENXIO);
240 	return (0);
241 }
242 
243 static int
244 efi_enter(void)
245 {
246 	struct thread *td;
247 	pmap_t curpmap;
248 
249 	if (efi_runtime == NULL)
250 		return (ENXIO);
251 	td = curthread;
252 	curpmap = &td->td_proc->p_vmspace->vm_pmap;
253 	PMAP_LOCK(curpmap);
254 	mtx_lock(&efi_lock);
255 	fpu_kern_enter(td, NULL, FPU_KERN_NOCTX);
256 	return (efi_arch_enter());
257 }
258 
259 static void
260 efi_leave(void)
261 {
262 	struct thread *td;
263 	pmap_t curpmap;
264 
265 	efi_arch_leave();
266 
267 	curpmap = &curproc->p_vmspace->vm_pmap;
268 	td = curthread;
269 	fpu_kern_leave(td, NULL);
270 	mtx_unlock(&efi_lock);
271 	PMAP_UNLOCK(curpmap);
272 }
273 
274 int
275 efi_get_table(struct uuid *uuid, void **ptr)
276 {
277 	struct efi_cfgtbl *ct;
278 	u_long count;
279 
280 	if (efi_cfgtbl == NULL || efi_systbl == NULL)
281 		return (ENXIO);
282 	count = efi_systbl->st_entries;
283 	ct = efi_cfgtbl;
284 	while (count--) {
285 		if (!bcmp(&ct->ct_uuid, uuid, sizeof(*uuid))) {
286 			*ptr = (void *)PHYS_TO_DMAP(ct->ct_data);
287 			return (0);
288 		}
289 		ct++;
290 	}
291 	return (ENOENT);
292 }
293 
294 static int
295 efi_get_time_locked(struct efi_tm *tm, struct efi_tmcap *tmcap)
296 {
297 	efi_status status;
298 	int error;
299 
300 	EFI_TIME_OWNED()
301 	error = efi_enter();
302 	if (error != 0)
303 		return (error);
304 	status = efi_runtime->rt_gettime(tm, tmcap);
305 	efi_leave();
306 	error = efi_status_to_errno(status);
307 	return (error);
308 }
309 
310 int
311 efi_get_time(struct efi_tm *tm)
312 {
313 	struct efi_tmcap dummy;
314 	int error;
315 
316 	if (efi_runtime == NULL)
317 		return (ENXIO);
318 	EFI_TIME_LOCK()
319 	/*
320 	 * UEFI spec states that the Capabilities argument to GetTime is
321 	 * optional, but some UEFI implementations choke when passed a NULL
322 	 * pointer. Pass a dummy efi_tmcap, even though we won't use it,
323 	 * to workaround such implementations.
324 	 */
325 	error = efi_get_time_locked(tm, &dummy);
326 	EFI_TIME_UNLOCK()
327 	return (error);
328 }
329 
330 int
331 efi_get_time_capabilities(struct efi_tmcap *tmcap)
332 {
333 	struct efi_tm dummy;
334 	int error;
335 
336 	if (efi_runtime == NULL)
337 		return (ENXIO);
338 	EFI_TIME_LOCK()
339 	error = efi_get_time_locked(&dummy, tmcap);
340 	EFI_TIME_UNLOCK()
341 	return (error);
342 }
343 
344 int
345 efi_reset_system(void)
346 {
347 	int error;
348 
349 	error = efi_enter();
350 	if (error != 0)
351 		return (error);
352 	efi_runtime->rt_reset(EFI_RESET_WARM, 0, 0, NULL);
353 	efi_leave();
354 	return (EIO);
355 }
356 
357 static int
358 efi_set_time_locked(struct efi_tm *tm)
359 {
360 	efi_status status;
361 	int error;
362 
363 	EFI_TIME_OWNED();
364 	error = efi_enter();
365 	if (error != 0)
366 		return (error);
367 	status = efi_runtime->rt_settime(tm);
368 	efi_leave();
369 	error = efi_status_to_errno(status);
370 	return (error);
371 }
372 
373 int
374 efi_set_time(struct efi_tm *tm)
375 {
376 	int error;
377 
378 	if (efi_runtime == NULL)
379 		return (ENXIO);
380 	EFI_TIME_LOCK()
381 	error = efi_set_time_locked(tm);
382 	EFI_TIME_UNLOCK()
383 	return (error);
384 }
385 
386 int
387 efi_var_get(efi_char *name, struct uuid *vendor, uint32_t *attrib,
388     size_t *datasize, void *data)
389 {
390 	efi_status status;
391 	int error;
392 
393 	error = efi_enter();
394 	if (error != 0)
395 		return (error);
396 	status = efi_runtime->rt_getvar(name, vendor, attrib, datasize, data);
397 	efi_leave();
398 	error = efi_status_to_errno(status);
399 	return (error);
400 }
401 
402 int
403 efi_var_nextname(size_t *namesize, efi_char *name, struct uuid *vendor)
404 {
405 	efi_status status;
406 	int error;
407 
408 	error = efi_enter();
409 	if (error != 0)
410 		return (error);
411 	status = efi_runtime->rt_scanvar(namesize, name, vendor);
412 	efi_leave();
413 	error = efi_status_to_errno(status);
414 	return (error);
415 }
416 
417 int
418 efi_var_set(efi_char *name, struct uuid *vendor, uint32_t attrib,
419     size_t datasize, void *data)
420 {
421 	efi_status status;
422 	int error;
423 
424 	error = efi_enter();
425 	if (error != 0)
426 		return (error);
427 	status = efi_runtime->rt_setvar(name, vendor, attrib, datasize, data);
428 	efi_leave();
429 	error = efi_status_to_errno(status);
430 	return (error);
431 }
432 
433 static int
434 efirt_modevents(module_t m, int event, void *arg __unused)
435 {
436 
437 	switch (event) {
438 	case MOD_LOAD:
439 		return (efi_init());
440 
441 	case MOD_UNLOAD:
442 		efi_uninit();
443 		return (0);
444 
445 	case MOD_SHUTDOWN:
446 		return (0);
447 
448 	default:
449 		return (EOPNOTSUPP);
450 	}
451 }
452 
453 static moduledata_t efirt_moddata = {
454 	.name = "efirt",
455 	.evhand = efirt_modevents,
456 	.priv = NULL,
457 };
458 /* After fpuinitstate, before efidev */
459 DECLARE_MODULE(efirt, efirt_moddata, SI_SUB_DRIVERS, SI_ORDER_SECOND);
460 MODULE_VERSION(efirt, 1);
461