efirt.c revision 332028 
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: stable/11/sys/dev/efidev/efirt.c 332028 2018-04-04 13:58:18Z kevans $");
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
59static struct efi_systbl *efi_systbl;
60static struct efi_cfgtbl *efi_cfgtbl;
61static struct efi_rt *efi_runtime;
62
63static int efi_status2err[25] = {
64	0,		/* EFI_SUCCESS */
65	ENOEXEC,	/* EFI_LOAD_ERROR */
66	EINVAL,		/* EFI_INVALID_PARAMETER */
67	ENOSYS,		/* EFI_UNSUPPORTED */
68	EMSGSIZE, 	/* EFI_BAD_BUFFER_SIZE */
69	EOVERFLOW,	/* EFI_BUFFER_TOO_SMALL */
70	EBUSY,		/* EFI_NOT_READY */
71	EIO,		/* EFI_DEVICE_ERROR */
72	EROFS,		/* EFI_WRITE_PROTECTED */
73	EAGAIN,		/* EFI_OUT_OF_RESOURCES */
74	EIO,		/* EFI_VOLUME_CORRUPTED */
75	ENOSPC,		/* EFI_VOLUME_FULL */
76	ENXIO,		/* EFI_NO_MEDIA */
77	ESTALE,		/* EFI_MEDIA_CHANGED */
78	ENOENT,		/* EFI_NOT_FOUND */
79	EACCES,		/* EFI_ACCESS_DENIED */
80	ETIMEDOUT,	/* EFI_NO_RESPONSE */
81	EADDRNOTAVAIL,	/* EFI_NO_MAPPING */
82	ETIMEDOUT,	/* EFI_TIMEOUT */
83	EDOOFUS,	/* EFI_NOT_STARTED */
84	EALREADY,	/* EFI_ALREADY_STARTED */
85	ECANCELED,	/* EFI_ABORTED */
86	EPROTO,		/* EFI_ICMP_ERROR */
87	EPROTO,		/* EFI_TFTP_ERROR */
88	EPROTO		/* EFI_PROTOCOL_ERROR */
89};
90
91static int efi_enter(void);
92static void efi_leave(void);
93
94static int
95efi_status_to_errno(efi_status status)
96{
97	u_long code;
98
99	code = status & 0x3ffffffffffffffful;
100	return (code < nitems(efi_status2err) ? efi_status2err[code] : EDOOFUS);
101}
102
103static struct mtx efi_lock;
104
105static bool
106efi_is_in_map(struct efi_md *map, int ndesc, int descsz, vm_offset_t addr)
107{
108	struct efi_md *p;
109	int i;
110
111	for (i = 0, p = map; i < ndesc; i++, p = efi_next_descriptor(p,
112	    descsz)) {
113		if ((p->md_attr & EFI_MD_ATTR_RT) == 0)
114			continue;
115
116		if (addr >= (uintptr_t)p->md_virt &&
117		    addr < (uintptr_t)p->md_virt + p->md_pages * PAGE_SIZE)
118			return (true);
119	}
120
121	return (false);
122}
123
124static int
125efi_init(void)
126{
127	struct efi_map_header *efihdr;
128	struct efi_md *map;
129	caddr_t kmdp;
130	size_t efisz;
131
132	mtx_init(&efi_lock, "efi", NULL, MTX_DEF);
133
134	if (efi_systbl_phys == 0) {
135		if (bootverbose)
136			printf("EFI systbl not available\n");
137		return (0);
138	}
139	efi_systbl = (struct efi_systbl *)PHYS_TO_DMAP(efi_systbl_phys);
140	if (efi_systbl->st_hdr.th_sig != EFI_SYSTBL_SIG) {
141		efi_systbl = NULL;
142		if (bootverbose)
143			printf("EFI systbl signature invalid\n");
144		return (0);
145	}
146	efi_cfgtbl = (efi_systbl->st_cfgtbl == 0) ? NULL :
147	    (struct efi_cfgtbl *)efi_systbl->st_cfgtbl;
148	if (efi_cfgtbl == NULL) {
149		if (bootverbose)
150			printf("EFI config table is not present\n");
151	}
152
153	kmdp = preload_search_by_type("elf kernel");
154	if (kmdp == NULL)
155		kmdp = preload_search_by_type("elf64 kernel");
156	efihdr = (struct efi_map_header *)preload_search_info(kmdp,
157	    MODINFO_METADATA | MODINFOMD_EFI_MAP);
158	if (efihdr == NULL) {
159		if (bootverbose)
160			printf("EFI map is not present\n");
161		return (0);
162	}
163	efisz = (sizeof(struct efi_map_header) + 0xf) & ~0xf;
164	map = (struct efi_md *)((uint8_t *)efihdr + efisz);
165	if (efihdr->descriptor_size == 0)
166		return (ENOMEM);
167
168	if (!efi_create_1t1_map(map, efihdr->memory_size /
169	    efihdr->descriptor_size, efihdr->descriptor_size)) {
170		if (bootverbose)
171			printf("EFI cannot create runtime map\n");
172		return (ENOMEM);
173	}
174
175	efi_runtime = (efi_systbl->st_rt == 0) ? NULL :
176	    (struct efi_rt *)efi_systbl->st_rt;
177	if (efi_runtime == NULL) {
178		if (bootverbose)
179			printf("EFI runtime services table is not present\n");
180		efi_destroy_1t1_map();
181		return (ENXIO);
182	}
183
184	/*
185	 * Some UEFI implementations have multiple implementations of the
186	 * RS->GetTime function. They switch from one we can only use early
187	 * in the boot process to one valid as a RunTime service only when we
188	 * call RS->SetVirtualAddressMap. As this is not always the case, e.g.
189	 * with an old loader.efi, check if the RS->GetTime function is within
190	 * the EFI map, and fail to attach if not.
191	 *
192	 * We need to enter into the EFI environment as efi_runtime may point
193	 * to an EFI address.
194	 */
195	efi_enter();
196	if (!efi_is_in_map(map, efihdr->memory_size / efihdr->descriptor_size,
197	    efihdr->descriptor_size, (vm_offset_t)efi_runtime->rt_gettime)) {
198		efi_leave();
199		if (bootverbose)
200			printf(
201			 "EFI runtime services table has an invalid pointer\n");
202		efi_runtime = NULL;
203		efi_destroy_1t1_map();
204		return (ENXIO);
205	}
206	efi_leave();
207
208	return (0);
209}
210
211static void
212efi_uninit(void)
213{
214
215	efi_destroy_1t1_map();
216
217	efi_systbl = NULL;
218	efi_cfgtbl = NULL;
219	efi_runtime = NULL;
220
221	mtx_destroy(&efi_lock);
222}
223
224int
225efi_rt_ok(void)
226{
227
228	if (efi_runtime == NULL)
229		return (ENXIO);
230	return (0);
231}
232
233static int
234efi_enter(void)
235{
236	struct thread *td;
237	pmap_t curpmap;
238	int error;
239
240	if (efi_runtime == NULL)
241		return (ENXIO);
242	td = curthread;
243	curpmap = &td->td_proc->p_vmspace->vm_pmap;
244	PMAP_LOCK(curpmap);
245	mtx_lock(&efi_lock);
246	error = fpu_kern_enter(td, NULL, FPU_KERN_NOCTX);
247	if (error != 0) {
248		PMAP_UNLOCK(curpmap);
249		return (error);
250	}
251
252	return (efi_arch_enter());
253}
254
255static void
256efi_leave(void)
257{
258	struct thread *td;
259	pmap_t curpmap;
260
261	efi_arch_leave();
262
263	curpmap = &curproc->p_vmspace->vm_pmap;
264	td = curthread;
265	fpu_kern_leave(td, NULL);
266	mtx_unlock(&efi_lock);
267	PMAP_UNLOCK(curpmap);
268}
269
270int
271efi_get_table(struct uuid *uuid, void **ptr)
272{
273	struct efi_cfgtbl *ct;
274	u_long count;
275
276	if (efi_cfgtbl == NULL || efi_systbl == NULL)
277		return (ENXIO);
278	count = efi_systbl->st_entries;
279	ct = efi_cfgtbl;
280	while (count--) {
281		if (!bcmp(&ct->ct_uuid, uuid, sizeof(*uuid))) {
282			*ptr = (void *)PHYS_TO_DMAP(ct->ct_data);
283			return (0);
284		}
285		ct++;
286	}
287	return (ENOENT);
288}
289
290static int
291efi_get_time_locked(struct efi_tm *tm, struct efi_tmcap *tmcap)
292{
293	efi_status status;
294	int error;
295
296	EFI_TIME_OWNED()
297	error = efi_enter();
298	if (error != 0)
299		return (error);
300	status = efi_runtime->rt_gettime(tm, tmcap);
301	efi_leave();
302	error = efi_status_to_errno(status);
303	return (error);
304}
305
306int
307efi_get_time(struct efi_tm *tm)
308{
309	struct efi_tmcap dummy;
310	int error;
311
312	if (efi_runtime == NULL)
313		return (ENXIO);
314	EFI_TIME_LOCK()
315	/*
316	 * UEFI spec states that the Capabilities argument to GetTime is
317	 * optional, but some UEFI implementations choke when passed a NULL
318	 * pointer. Pass a dummy efi_dmcap, even though we won't use it,
319	 * to workaround such implementations.
320	 */
321	error = efi_get_time_locked(tm, &dummy);
322	EFI_TIME_UNLOCK()
323	return (error);
324}
325
326int
327efi_get_time_capabilities(struct efi_tmcap *tmcap)
328{
329	struct efi_tm dummy;
330	int error;
331
332	if (efi_runtime == NULL)
333		return (ENXIO);
334	EFI_TIME_LOCK()
335	error = efi_get_time_locked(&dummy, tmcap);
336	EFI_TIME_UNLOCK()
337	return (error);
338}
339
340int
341efi_reset_system(void)
342{
343	int error;
344
345	error = efi_enter();
346	if (error != 0)
347		return (error);
348	efi_runtime->rt_reset(EFI_RESET_WARM, 0, 0, NULL);
349	efi_leave();
350	return (EIO);
351}
352
353static int
354efi_set_time_locked(struct efi_tm *tm)
355{
356	efi_status status;
357	int error;
358
359	EFI_TIME_OWNED();
360	error = efi_enter();
361	if (error != 0)
362		return (error);
363	status = efi_runtime->rt_settime(tm);
364	efi_leave();
365	error = efi_status_to_errno(status);
366	return (error);
367}
368
369int
370efi_set_time(struct efi_tm *tm)
371{
372	int error;
373
374	if (efi_runtime == NULL)
375		return (ENXIO);
376	EFI_TIME_LOCK()
377	error = efi_set_time_locked(tm);
378	EFI_TIME_UNLOCK()
379	return (error);
380}
381
382int
383efi_var_get(efi_char *name, struct uuid *vendor, uint32_t *attrib,
384    size_t *datasize, void *data)
385{
386	efi_status status;
387	int error;
388
389	error = efi_enter();
390	if (error != 0)
391		return (error);
392	status = efi_runtime->rt_getvar(name, vendor, attrib, datasize, data);
393	efi_leave();
394	error = efi_status_to_errno(status);
395	return (error);
396}
397
398int
399efi_var_nextname(size_t *namesize, efi_char *name, struct uuid *vendor)
400{
401	efi_status status;
402	int error;
403
404	error = efi_enter();
405	if (error != 0)
406		return (error);
407	status = efi_runtime->rt_scanvar(namesize, name, vendor);
408	efi_leave();
409	error = efi_status_to_errno(status);
410	return (error);
411}
412
413int
414efi_var_set(efi_char *name, struct uuid *vendor, uint32_t attrib,
415    size_t datasize, void *data)
416{
417	efi_status status;
418	int error;
419
420	error = efi_enter();
421	if (error != 0)
422		return (error);
423	status = efi_runtime->rt_setvar(name, vendor, attrib, datasize, data);
424	efi_leave();
425	error = efi_status_to_errno(status);
426	return (error);
427}
428
429static int
430efirt_modevents(module_t m, int event, void *arg __unused)
431{
432
433	switch (event) {
434	case MOD_LOAD:
435		return (efi_init());
436
437	case MOD_UNLOAD:
438		efi_uninit();
439		return (0);
440
441	case MOD_SHUTDOWN:
442		return (0);
443
444	default:
445		return (EOPNOTSUPP);
446	}
447}
448
449static moduledata_t efirt_moddata = {
450	.name = "efirt",
451	.evhand = efirt_modevents,
452	.priv = NULL,
453};
454/* After fpuinitstate, before efidev */
455DECLARE_MODULE(efirt, efirt_moddata, SI_SUB_DRIVERS, SI_ORDER_SECOND);
456MODULE_VERSION(efirt, 1);
457