xref: /openbmc/u-boot/lib/efi_loader/efi_runtime.c (revision c3211708)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  *  EFI application runtime services
4  *
5  *  Copyright (c) 2016 Alexander Graf
6  */
7 
8 #include <common.h>
9 #include <command.h>
10 #include <dm.h>
11 #include <elf.h>
12 #include <efi_loader.h>
13 #include <rtc.h>
14 
15 /* For manual relocation support */
16 DECLARE_GLOBAL_DATA_PTR;
17 
18 struct efi_runtime_mmio_list {
19 	struct list_head link;
20 	void **ptr;
21 	u64 paddr;
22 	u64 len;
23 };
24 
25 /* This list contains all runtime available mmio regions */
26 LIST_HEAD(efi_runtime_mmio);
27 
28 static efi_status_t __efi_runtime EFIAPI efi_unimplemented(void);
29 static efi_status_t __efi_runtime EFIAPI efi_device_error(void);
30 static efi_status_t __efi_runtime EFIAPI efi_invalid_parameter(void);
31 
32 /*
33  * TODO(sjg@chromium.org): These defines and structs should come from the elf
34  * header for each arch (or a generic header) rather than being repeated here.
35  */
36 #if defined(__aarch64__)
37 #define R_RELATIVE	R_AARCH64_RELATIVE
38 #define R_MASK		0xffffffffULL
39 #define IS_RELA		1
40 #elif defined(__arm__)
41 #define R_RELATIVE	R_ARM_RELATIVE
42 #define R_MASK		0xffULL
43 #elif defined(__x86_64__) || defined(__i386__)
44 #define R_RELATIVE	R_386_RELATIVE
45 #define R_MASK		0xffULL
46 #elif defined(__riscv)
47 #define R_RELATIVE	R_RISCV_RELATIVE
48 #define R_MASK		0xffULL
49 #define IS_RELA		1
50 
51 struct dyn_sym {
52 	ulong foo1;
53 	ulong addr;
54 	u32 foo2;
55 	u32 foo3;
56 };
57 #if (__riscv_xlen == 32)
58 #define R_ABSOLUTE	R_RISCV_32
59 #define SYM_INDEX	8
60 #elif (__riscv_xlen == 64)
61 #define R_ABSOLUTE	R_RISCV_64
62 #define SYM_INDEX	32
63 #else
64 #error unknown riscv target
65 #endif
66 #else
67 #error Need to add relocation awareness
68 #endif
69 
70 struct elf_rel {
71 	ulong *offset;
72 	ulong info;
73 };
74 
75 struct elf_rela {
76 	ulong *offset;
77 	ulong info;
78 	long addend;
79 };
80 
81 /*
82  * EFI Runtime code lives in 2 stages. In the first stage, U-Boot and an EFI
83  * payload are running concurrently at the same time. In this mode, we can
84  * handle a good number of runtime callbacks
85  */
86 
87 static void EFIAPI efi_reset_system_boottime(
88 			enum efi_reset_type reset_type,
89 			efi_status_t reset_status,
90 			unsigned long data_size, void *reset_data)
91 {
92 	struct efi_event *evt;
93 
94 	EFI_ENTRY("%d %lx %lx %p", reset_type, reset_status, data_size,
95 		  reset_data);
96 
97 	/* Notify reset */
98 	list_for_each_entry(evt, &efi_events, link) {
99 		if (evt->group &&
100 		    !guidcmp(evt->group,
101 			     &efi_guid_event_group_reset_system)) {
102 			efi_signal_event(evt, false);
103 			break;
104 		}
105 	}
106 	switch (reset_type) {
107 	case EFI_RESET_COLD:
108 	case EFI_RESET_WARM:
109 	case EFI_RESET_PLATFORM_SPECIFIC:
110 		do_reset(NULL, 0, 0, NULL);
111 		break;
112 	case EFI_RESET_SHUTDOWN:
113 		/* We don't have anything to map this to */
114 		break;
115 	}
116 
117 	while (1) { }
118 }
119 
120 /**
121  * efi_get_time_boottime - get current time
122  *
123  * This function implements the GetTime runtime service.
124  * See the Unified Extensible Firmware Interface (UEFI) specification
125  * for details.
126  *
127  * @time:		pointer to structure to receive current time
128  * @capabilities:	pointer to structure to receive RTC properties
129  * Return Value:	status code
130  */
131 static efi_status_t EFIAPI efi_get_time_boottime(
132 			struct efi_time *time,
133 			struct efi_time_cap *capabilities)
134 {
135 #ifdef CONFIG_DM_RTC
136 	efi_status_t ret = EFI_SUCCESS;
137 	int r;
138 	struct rtc_time tm;
139 	struct udevice *dev;
140 
141 	EFI_ENTRY("%p %p", time, capabilities);
142 
143 	if (!time) {
144 		ret = EFI_INVALID_PARAMETER;
145 		goto out;
146 	}
147 
148 	r = uclass_get_device(UCLASS_RTC, 0, &dev);
149 	if (!r)
150 		r = dm_rtc_get(dev, &tm);
151 	if (r) {
152 		ret = EFI_DEVICE_ERROR;
153 		goto out;
154 	}
155 
156 	memset(time, 0, sizeof(*time));
157 	time->year = tm.tm_year;
158 	time->month = tm.tm_mon;
159 	time->day = tm.tm_mday;
160 	time->hour = tm.tm_hour;
161 	time->minute = tm.tm_min;
162 	time->second = tm.tm_sec;
163 	time->daylight = EFI_TIME_ADJUST_DAYLIGHT;
164 	if (tm.tm_isdst > 0)
165 		time->daylight |= EFI_TIME_IN_DAYLIGHT;
166 	time->timezone = EFI_UNSPECIFIED_TIMEZONE;
167 
168 	if (capabilities) {
169 		/* Set reasonable dummy values */
170 		capabilities->resolution = 1;		/* 1 Hz */
171 		capabilities->accuracy = 100000000;	/* 100 ppm */
172 		capabilities->sets_to_zero = false;
173 	}
174 out:
175 	return EFI_EXIT(ret);
176 #else
177 	EFI_ENTRY("%p %p", time, capabilities);
178 	return EFI_EXIT(EFI_DEVICE_ERROR);
179 #endif
180 }
181 
182 /* Boards may override the helpers below to implement RTS functionality */
183 
184 void __weak __efi_runtime EFIAPI efi_reset_system(
185 			enum efi_reset_type reset_type,
186 			efi_status_t reset_status,
187 			unsigned long data_size, void *reset_data)
188 {
189 	/* Nothing we can do */
190 	while (1) { }
191 }
192 
193 efi_status_t __weak efi_reset_system_init(void)
194 {
195 	return EFI_SUCCESS;
196 }
197 
198 efi_status_t __weak __efi_runtime EFIAPI efi_get_time(
199 			struct efi_time *time,
200 			struct efi_time_cap *capabilities)
201 {
202 	/* Nothing we can do */
203 	return EFI_DEVICE_ERROR;
204 }
205 
206 struct efi_runtime_detach_list_struct {
207 	void *ptr;
208 	void *patchto;
209 };
210 
211 static const struct efi_runtime_detach_list_struct efi_runtime_detach_list[] = {
212 	{
213 		/* do_reset is gone */
214 		.ptr = &efi_runtime_services.reset_system,
215 		.patchto = efi_reset_system,
216 	}, {
217 		/* invalidate_*cache_all are gone */
218 		.ptr = &efi_runtime_services.set_virtual_address_map,
219 		.patchto = &efi_invalid_parameter,
220 	}, {
221 		/* RTC accessors are gone */
222 		.ptr = &efi_runtime_services.get_time,
223 		.patchto = &efi_get_time,
224 	}, {
225 		/* Clean up system table */
226 		.ptr = &systab.con_in,
227 		.patchto = NULL,
228 	}, {
229 		/* Clean up system table */
230 		.ptr = &systab.con_out,
231 		.patchto = NULL,
232 	}, {
233 		/* Clean up system table */
234 		.ptr = &systab.std_err,
235 		.patchto = NULL,
236 	}, {
237 		/* Clean up system table */
238 		.ptr = &systab.boottime,
239 		.patchto = NULL,
240 	}, {
241 		.ptr = &efi_runtime_services.get_variable,
242 		.patchto = &efi_device_error,
243 	}, {
244 		.ptr = &efi_runtime_services.get_next_variable_name,
245 		.patchto = &efi_device_error,
246 	}, {
247 		.ptr = &efi_runtime_services.set_variable,
248 		.patchto = &efi_device_error,
249 	}
250 };
251 
252 static bool efi_runtime_tobedetached(void *p)
253 {
254 	int i;
255 
256 	for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++)
257 		if (efi_runtime_detach_list[i].ptr == p)
258 			return true;
259 
260 	return false;
261 }
262 
263 static void efi_runtime_detach(ulong offset)
264 {
265 	int i;
266 	ulong patchoff = offset - (ulong)gd->relocaddr;
267 
268 	for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++) {
269 		ulong patchto = (ulong)efi_runtime_detach_list[i].patchto;
270 		ulong *p = efi_runtime_detach_list[i].ptr;
271 		ulong newaddr = patchto ? (patchto + patchoff) : 0;
272 
273 		debug("%s: Setting %p to %lx\n", __func__, p, newaddr);
274 		*p = newaddr;
275 	}
276 }
277 
278 /* Relocate EFI runtime to uboot_reloc_base = offset */
279 void efi_runtime_relocate(ulong offset, struct efi_mem_desc *map)
280 {
281 #ifdef IS_RELA
282 	struct elf_rela *rel = (void*)&__efi_runtime_rel_start;
283 #else
284 	struct elf_rel *rel = (void*)&__efi_runtime_rel_start;
285 	static ulong lastoff = CONFIG_SYS_TEXT_BASE;
286 #endif
287 
288 	debug("%s: Relocating to offset=%lx\n", __func__, offset);
289 	for (; (ulong)rel < (ulong)&__efi_runtime_rel_stop; rel++) {
290 		ulong base = CONFIG_SYS_TEXT_BASE;
291 		ulong *p;
292 		ulong newaddr;
293 
294 		p = (void*)((ulong)rel->offset - base) + gd->relocaddr;
295 
296 		debug("%s: rel->info=%#lx *p=%#lx rel->offset=%p\n", __func__, rel->info, *p, rel->offset);
297 
298 		switch (rel->info & R_MASK) {
299 		case R_RELATIVE:
300 #ifdef IS_RELA
301 		newaddr = rel->addend + offset - CONFIG_SYS_TEXT_BASE;
302 #else
303 		newaddr = *p - lastoff + offset;
304 #endif
305 			break;
306 #ifdef R_ABSOLUTE
307 		case R_ABSOLUTE: {
308 			ulong symidx = rel->info >> SYM_INDEX;
309 			extern struct dyn_sym __dyn_sym_start[];
310 			newaddr = __dyn_sym_start[symidx].addr + offset;
311 			break;
312 		}
313 #endif
314 		default:
315 			continue;
316 		}
317 
318 		/* Check if the relocation is inside bounds */
319 		if (map && ((newaddr < map->virtual_start) ||
320 		    newaddr > (map->virtual_start +
321 			      (map->num_pages << EFI_PAGE_SHIFT)))) {
322 			if (!efi_runtime_tobedetached(p))
323 				printf("U-Boot EFI: Relocation at %p is out of "
324 				       "range (%lx)\n", p, newaddr);
325 			continue;
326 		}
327 
328 		debug("%s: Setting %p to %lx\n", __func__, p, newaddr);
329 		*p = newaddr;
330 		flush_dcache_range((ulong)p & ~(EFI_CACHELINE_SIZE - 1),
331 			ALIGN((ulong)&p[1], EFI_CACHELINE_SIZE));
332 	}
333 
334 #ifndef IS_RELA
335 	lastoff = offset;
336 #endif
337 
338         invalidate_icache_all();
339 }
340 
341 static efi_status_t EFIAPI efi_set_virtual_address_map(
342 			unsigned long memory_map_size,
343 			unsigned long descriptor_size,
344 			uint32_t descriptor_version,
345 			struct efi_mem_desc *virtmap)
346 {
347 	ulong runtime_start = (ulong)&__efi_runtime_start &
348 			      ~(ulong)EFI_PAGE_MASK;
349 	int n = memory_map_size / descriptor_size;
350 	int i;
351 
352 	EFI_ENTRY("%lx %lx %x %p", memory_map_size, descriptor_size,
353 		  descriptor_version, virtmap);
354 
355 	/* Rebind mmio pointers */
356 	for (i = 0; i < n; i++) {
357 		struct efi_mem_desc *map = (void*)virtmap +
358 					   (descriptor_size * i);
359 		struct list_head *lhandle;
360 		efi_physical_addr_t map_start = map->physical_start;
361 		efi_physical_addr_t map_len = map->num_pages << EFI_PAGE_SHIFT;
362 		efi_physical_addr_t map_end = map_start + map_len;
363 
364 		/* Adjust all mmio pointers in this region */
365 		list_for_each(lhandle, &efi_runtime_mmio) {
366 			struct efi_runtime_mmio_list *lmmio;
367 
368 			lmmio = list_entry(lhandle,
369 					   struct efi_runtime_mmio_list,
370 					   link);
371 			if ((map_start <= lmmio->paddr) &&
372 			    (map_end >= lmmio->paddr)) {
373 				u64 off = map->virtual_start - map_start;
374 				uintptr_t new_addr = lmmio->paddr + off;
375 				*lmmio->ptr = (void *)new_addr;
376 			}
377 		}
378 	}
379 
380 	/* Move the actual runtime code over */
381 	for (i = 0; i < n; i++) {
382 		struct efi_mem_desc *map;
383 
384 		map = (void*)virtmap + (descriptor_size * i);
385 		if (map->type == EFI_RUNTIME_SERVICES_CODE) {
386 			ulong new_offset = map->virtual_start -
387 					   (runtime_start - gd->relocaddr);
388 
389 			efi_runtime_relocate(new_offset, map);
390 			/* Once we're virtual, we can no longer handle
391 			   complex callbacks */
392 			efi_runtime_detach(new_offset);
393 			return EFI_EXIT(EFI_SUCCESS);
394 		}
395 	}
396 
397 	return EFI_EXIT(EFI_INVALID_PARAMETER);
398 }
399 
400 efi_status_t efi_add_runtime_mmio(void *mmio_ptr, u64 len)
401 {
402 	struct efi_runtime_mmio_list *newmmio;
403 	u64 pages = (len + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
404 	uint64_t addr = *(uintptr_t *)mmio_ptr;
405 	uint64_t retaddr;
406 
407 	retaddr = efi_add_memory_map(addr, pages, EFI_MMAP_IO, false);
408 	if (retaddr != addr)
409 		return EFI_OUT_OF_RESOURCES;
410 
411 	newmmio = calloc(1, sizeof(*newmmio));
412 	if (!newmmio)
413 		return EFI_OUT_OF_RESOURCES;
414 	newmmio->ptr = mmio_ptr;
415 	newmmio->paddr = *(uintptr_t *)mmio_ptr;
416 	newmmio->len = len;
417 	list_add_tail(&newmmio->link, &efi_runtime_mmio);
418 
419 	return EFI_SUCCESS;
420 }
421 
422 /*
423  * In the second stage, U-Boot has disappeared. To isolate our runtime code
424  * that at this point still exists from the rest, we put it into a special
425  * section.
426  *
427  *        !!WARNING!!
428  *
429  * This means that we can not rely on any code outside of this file in any
430  * function or variable below this line.
431  *
432  * Please keep everything fully self-contained and annotated with
433  * __efi_runtime and __efi_runtime_data markers.
434  */
435 
436 /*
437  * Relocate the EFI runtime stub to a different place. We need to call this
438  * the first time we expose the runtime interface to a user and on set virtual
439  * address map calls.
440  */
441 
442 static efi_status_t __efi_runtime EFIAPI efi_unimplemented(void)
443 {
444 	return EFI_UNSUPPORTED;
445 }
446 
447 static efi_status_t __efi_runtime EFIAPI efi_device_error(void)
448 {
449 	return EFI_DEVICE_ERROR;
450 }
451 
452 static efi_status_t __efi_runtime EFIAPI efi_invalid_parameter(void)
453 {
454 	return EFI_INVALID_PARAMETER;
455 }
456 
457 efi_status_t __efi_runtime EFIAPI efi_update_capsule(
458 			struct efi_capsule_header **capsule_header_array,
459 			efi_uintn_t capsule_count,
460 			u64 scatter_gather_list)
461 {
462 	return EFI_UNSUPPORTED;
463 }
464 
465 efi_status_t __efi_runtime EFIAPI efi_query_capsule_caps(
466 			struct efi_capsule_header **capsule_header_array,
467 			efi_uintn_t capsule_count,
468 			u64 maximum_capsule_size,
469 			u32 reset_type)
470 {
471 	return EFI_UNSUPPORTED;
472 }
473 
474 efi_status_t __efi_runtime EFIAPI efi_query_variable_info(
475 			u32 attributes,
476 			u64 *maximum_variable_storage_size,
477 			u64 *remaining_variable_storage_size,
478 			u64 *maximum_variable_size)
479 {
480 	return EFI_UNSUPPORTED;
481 }
482 
483 struct efi_runtime_services __efi_runtime_data efi_runtime_services = {
484 	.hdr = {
485 		.signature = EFI_RUNTIME_SERVICES_SIGNATURE,
486 		.revision = EFI_SPECIFICATION_VERSION,
487 		.headersize = sizeof(struct efi_runtime_services),
488 	},
489 	.get_time = &efi_get_time_boottime,
490 	.set_time = (void *)&efi_device_error,
491 	.get_wakeup_time = (void *)&efi_unimplemented,
492 	.set_wakeup_time = (void *)&efi_unimplemented,
493 	.set_virtual_address_map = &efi_set_virtual_address_map,
494 	.convert_pointer = (void *)&efi_invalid_parameter,
495 	.get_variable = efi_get_variable,
496 	.get_next_variable_name = efi_get_next_variable_name,
497 	.set_variable = efi_set_variable,
498 	.get_next_high_mono_count = (void *)&efi_device_error,
499 	.reset_system = &efi_reset_system_boottime,
500 	.update_capsule = efi_update_capsule,
501 	.query_capsule_caps = efi_query_capsule_caps,
502 	.query_variable_info = efi_query_variable_info,
503 };
504