xref: /openbmc/u-boot/lib/efi_loader/efi_runtime.c (revision dae73c4c)
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 <efi_loader.h>
12 #include <rtc.h>
13 
14 /* For manual relocation support */
15 DECLARE_GLOBAL_DATA_PTR;
16 
17 struct efi_runtime_mmio_list {
18 	struct list_head link;
19 	void **ptr;
20 	u64 paddr;
21 	u64 len;
22 };
23 
24 /* This list contains all runtime available mmio regions */
25 LIST_HEAD(efi_runtime_mmio);
26 
27 static efi_status_t __efi_runtime EFIAPI efi_unimplemented(void);
28 static efi_status_t __efi_runtime EFIAPI efi_device_error(void);
29 static efi_status_t __efi_runtime EFIAPI efi_invalid_parameter(void);
30 
31 /*
32  * TODO(sjg@chromium.org): These defines and structs should come from the elf
33  * header for each arch (or a generic header) rather than being repeated here.
34  */
35 #if defined(__aarch64__)
36 #define R_RELATIVE	1027
37 #define R_MASK		0xffffffffULL
38 #define IS_RELA		1
39 #elif defined(__arm__)
40 #define R_RELATIVE	23
41 #define R_MASK		0xffULL
42 #elif defined(__x86_64__) || defined(__i386__)
43 #include <asm/elf.h>
44 #define R_RELATIVE	R_386_RELATIVE
45 #define R_MASK		0xffULL
46 #elif defined(__riscv)
47 #include <elf.h>
48 #define R_RELATIVE	R_RISCV_RELATIVE
49 #define R_MASK		0xffULL
50 #define IS_RELA		1
51 
52 struct dyn_sym {
53 	ulong foo1;
54 	ulong addr;
55 	u32 foo2;
56 	u32 foo3;
57 };
58 #if (__riscv_xlen == 32)
59 #define R_ABSOLUTE	R_RISCV_32
60 #define SYM_INDEX	8
61 #elif (__riscv_xlen == 64)
62 #define R_ABSOLUTE	R_RISCV_64
63 #define SYM_INDEX	32
64 #else
65 #error unknown riscv target
66 #endif
67 #else
68 #error Need to add relocation awareness
69 #endif
70 
71 struct elf_rel {
72 	ulong *offset;
73 	ulong info;
74 };
75 
76 struct elf_rela {
77 	ulong *offset;
78 	ulong info;
79 	long addend;
80 };
81 
82 /*
83  * EFI Runtime code lives in 2 stages. In the first stage, U-Boot and an EFI
84  * payload are running concurrently at the same time. In this mode, we can
85  * handle a good number of runtime callbacks
86  */
87 
88 static void EFIAPI efi_reset_system_boottime(
89 			enum efi_reset_type reset_type,
90 			efi_status_t reset_status,
91 			unsigned long data_size, void *reset_data)
92 {
93 	struct efi_event *evt;
94 
95 	EFI_ENTRY("%d %lx %lx %p", reset_type, reset_status, data_size,
96 		  reset_data);
97 
98 	/* Notify reset */
99 	list_for_each_entry(evt, &efi_events, link) {
100 		if (evt->group &&
101 		    !guidcmp(evt->group,
102 			     &efi_guid_event_group_reset_system)) {
103 			efi_signal_event(evt, false);
104 			break;
105 		}
106 	}
107 	switch (reset_type) {
108 	case EFI_RESET_COLD:
109 	case EFI_RESET_WARM:
110 	case EFI_RESET_PLATFORM_SPECIFIC:
111 		do_reset(NULL, 0, 0, NULL);
112 		break;
113 	case EFI_RESET_SHUTDOWN:
114 		/* We don't have anything to map this to */
115 		break;
116 	}
117 
118 	while (1) { }
119 }
120 
121 static efi_status_t EFIAPI efi_get_time_boottime(
122 			struct efi_time *time,
123 			struct efi_time_cap *capabilities)
124 {
125 #if defined(CONFIG_CMD_DATE) && defined(CONFIG_DM_RTC)
126 	struct rtc_time tm;
127 	int r;
128 	struct udevice *dev;
129 
130 	EFI_ENTRY("%p %p", time, capabilities);
131 
132 	r = uclass_get_device(UCLASS_RTC, 0, &dev);
133 	if (r)
134 		return EFI_EXIT(EFI_DEVICE_ERROR);
135 
136 	r = dm_rtc_get(dev, &tm);
137 	if (r)
138 		return EFI_EXIT(EFI_DEVICE_ERROR);
139 
140 	memset(time, 0, sizeof(*time));
141 	time->year = tm.tm_year;
142 	time->month = tm.tm_mon;
143 	time->day = tm.tm_mday;
144 	time->hour = tm.tm_hour;
145 	time->minute = tm.tm_min;
146 	time->daylight = tm.tm_isdst;
147 
148 	return EFI_EXIT(EFI_SUCCESS);
149 #else
150 	return EFI_DEVICE_ERROR;
151 #endif
152 }
153 
154 /* Boards may override the helpers below to implement RTS functionality */
155 
156 void __weak __efi_runtime EFIAPI efi_reset_system(
157 			enum efi_reset_type reset_type,
158 			efi_status_t reset_status,
159 			unsigned long data_size, void *reset_data)
160 {
161 	/* Nothing we can do */
162 	while (1) { }
163 }
164 
165 efi_status_t __weak efi_reset_system_init(void)
166 {
167 	return EFI_SUCCESS;
168 }
169 
170 efi_status_t __weak __efi_runtime EFIAPI efi_get_time(
171 			struct efi_time *time,
172 			struct efi_time_cap *capabilities)
173 {
174 	/* Nothing we can do */
175 	return EFI_DEVICE_ERROR;
176 }
177 
178 efi_status_t __weak efi_get_time_init(void)
179 {
180 	return EFI_SUCCESS;
181 }
182 
183 struct efi_runtime_detach_list_struct {
184 	void *ptr;
185 	void *patchto;
186 };
187 
188 static const struct efi_runtime_detach_list_struct efi_runtime_detach_list[] = {
189 	{
190 		/* do_reset is gone */
191 		.ptr = &efi_runtime_services.reset_system,
192 		.patchto = efi_reset_system,
193 	}, {
194 		/* invalidate_*cache_all are gone */
195 		.ptr = &efi_runtime_services.set_virtual_address_map,
196 		.patchto = &efi_invalid_parameter,
197 	}, {
198 		/* RTC accessors are gone */
199 		.ptr = &efi_runtime_services.get_time,
200 		.patchto = &efi_get_time,
201 	}, {
202 		/* Clean up system table */
203 		.ptr = &systab.con_in,
204 		.patchto = NULL,
205 	}, {
206 		/* Clean up system table */
207 		.ptr = &systab.con_out,
208 		.patchto = NULL,
209 	}, {
210 		/* Clean up system table */
211 		.ptr = &systab.std_err,
212 		.patchto = NULL,
213 	}, {
214 		/* Clean up system table */
215 		.ptr = &systab.boottime,
216 		.patchto = NULL,
217 	}, {
218 		.ptr = &efi_runtime_services.get_variable,
219 		.patchto = &efi_device_error,
220 	}, {
221 		.ptr = &efi_runtime_services.get_next_variable_name,
222 		.patchto = &efi_device_error,
223 	}, {
224 		.ptr = &efi_runtime_services.set_variable,
225 		.patchto = &efi_device_error,
226 	}
227 };
228 
229 static bool efi_runtime_tobedetached(void *p)
230 {
231 	int i;
232 
233 	for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++)
234 		if (efi_runtime_detach_list[i].ptr == p)
235 			return true;
236 
237 	return false;
238 }
239 
240 static void efi_runtime_detach(ulong offset)
241 {
242 	int i;
243 	ulong patchoff = offset - (ulong)gd->relocaddr;
244 
245 	for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++) {
246 		ulong patchto = (ulong)efi_runtime_detach_list[i].patchto;
247 		ulong *p = efi_runtime_detach_list[i].ptr;
248 		ulong newaddr = patchto ? (patchto + patchoff) : 0;
249 
250 		debug("%s: Setting %p to %lx\n", __func__, p, newaddr);
251 		*p = newaddr;
252 	}
253 }
254 
255 /* Relocate EFI runtime to uboot_reloc_base = offset */
256 void efi_runtime_relocate(ulong offset, struct efi_mem_desc *map)
257 {
258 #ifdef IS_RELA
259 	struct elf_rela *rel = (void*)&__efi_runtime_rel_start;
260 #else
261 	struct elf_rel *rel = (void*)&__efi_runtime_rel_start;
262 	static ulong lastoff = CONFIG_SYS_TEXT_BASE;
263 #endif
264 
265 	debug("%s: Relocating to offset=%lx\n", __func__, offset);
266 	for (; (ulong)rel < (ulong)&__efi_runtime_rel_stop; rel++) {
267 		ulong base = CONFIG_SYS_TEXT_BASE;
268 		ulong *p;
269 		ulong newaddr;
270 
271 		p = (void*)((ulong)rel->offset - base) + gd->relocaddr;
272 
273 		debug("%s: rel->info=%#lx *p=%#lx rel->offset=%p\n", __func__, rel->info, *p, rel->offset);
274 
275 		switch (rel->info & R_MASK) {
276 		case R_RELATIVE:
277 #ifdef IS_RELA
278 		newaddr = rel->addend + offset - CONFIG_SYS_TEXT_BASE;
279 #else
280 		newaddr = *p - lastoff + offset;
281 #endif
282 			break;
283 #ifdef R_ABSOLUTE
284 		case R_ABSOLUTE: {
285 			ulong symidx = rel->info >> SYM_INDEX;
286 			extern struct dyn_sym __dyn_sym_start[];
287 			newaddr = __dyn_sym_start[symidx].addr + offset;
288 			break;
289 		}
290 #endif
291 		default:
292 			continue;
293 		}
294 
295 		/* Check if the relocation is inside bounds */
296 		if (map && ((newaddr < map->virtual_start) ||
297 		    newaddr > (map->virtual_start +
298 			      (map->num_pages << EFI_PAGE_SHIFT)))) {
299 			if (!efi_runtime_tobedetached(p))
300 				printf("U-Boot EFI: Relocation at %p is out of "
301 				       "range (%lx)\n", p, newaddr);
302 			continue;
303 		}
304 
305 		debug("%s: Setting %p to %lx\n", __func__, p, newaddr);
306 		*p = newaddr;
307 		flush_dcache_range((ulong)p & ~(EFI_CACHELINE_SIZE - 1),
308 			ALIGN((ulong)&p[1], EFI_CACHELINE_SIZE));
309 	}
310 
311 #ifndef IS_RELA
312 	lastoff = offset;
313 #endif
314 
315         invalidate_icache_all();
316 }
317 
318 static efi_status_t EFIAPI efi_set_virtual_address_map(
319 			unsigned long memory_map_size,
320 			unsigned long descriptor_size,
321 			uint32_t descriptor_version,
322 			struct efi_mem_desc *virtmap)
323 {
324 	ulong runtime_start = (ulong)&__efi_runtime_start &
325 			      ~(ulong)EFI_PAGE_MASK;
326 	int n = memory_map_size / descriptor_size;
327 	int i;
328 
329 	EFI_ENTRY("%lx %lx %x %p", memory_map_size, descriptor_size,
330 		  descriptor_version, virtmap);
331 
332 	/* Rebind mmio pointers */
333 	for (i = 0; i < n; i++) {
334 		struct efi_mem_desc *map = (void*)virtmap +
335 					   (descriptor_size * i);
336 		struct list_head *lhandle;
337 		efi_physical_addr_t map_start = map->physical_start;
338 		efi_physical_addr_t map_len = map->num_pages << EFI_PAGE_SHIFT;
339 		efi_physical_addr_t map_end = map_start + map_len;
340 
341 		/* Adjust all mmio pointers in this region */
342 		list_for_each(lhandle, &efi_runtime_mmio) {
343 			struct efi_runtime_mmio_list *lmmio;
344 
345 			lmmio = list_entry(lhandle,
346 					   struct efi_runtime_mmio_list,
347 					   link);
348 			if ((map_start <= lmmio->paddr) &&
349 			    (map_end >= lmmio->paddr)) {
350 				u64 off = map->virtual_start - map_start;
351 				uintptr_t new_addr = lmmio->paddr + off;
352 				*lmmio->ptr = (void *)new_addr;
353 			}
354 		}
355 	}
356 
357 	/* Move the actual runtime code over */
358 	for (i = 0; i < n; i++) {
359 		struct efi_mem_desc *map;
360 
361 		map = (void*)virtmap + (descriptor_size * i);
362 		if (map->type == EFI_RUNTIME_SERVICES_CODE) {
363 			ulong new_offset = map->virtual_start -
364 					   (runtime_start - gd->relocaddr);
365 
366 			efi_runtime_relocate(new_offset, map);
367 			/* Once we're virtual, we can no longer handle
368 			   complex callbacks */
369 			efi_runtime_detach(new_offset);
370 			return EFI_EXIT(EFI_SUCCESS);
371 		}
372 	}
373 
374 	return EFI_EXIT(EFI_INVALID_PARAMETER);
375 }
376 
377 efi_status_t efi_add_runtime_mmio(void *mmio_ptr, u64 len)
378 {
379 	struct efi_runtime_mmio_list *newmmio;
380 	u64 pages = (len + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
381 	uint64_t addr = *(uintptr_t *)mmio_ptr;
382 	uint64_t retaddr;
383 
384 	retaddr = efi_add_memory_map(addr, pages, EFI_MMAP_IO, false);
385 	if (retaddr != addr)
386 		return EFI_OUT_OF_RESOURCES;
387 
388 	newmmio = calloc(1, sizeof(*newmmio));
389 	if (!newmmio)
390 		return EFI_OUT_OF_RESOURCES;
391 	newmmio->ptr = mmio_ptr;
392 	newmmio->paddr = *(uintptr_t *)mmio_ptr;
393 	newmmio->len = len;
394 	list_add_tail(&newmmio->link, &efi_runtime_mmio);
395 
396 	return EFI_SUCCESS;
397 }
398 
399 /*
400  * In the second stage, U-Boot has disappeared. To isolate our runtime code
401  * that at this point still exists from the rest, we put it into a special
402  * section.
403  *
404  *        !!WARNING!!
405  *
406  * This means that we can not rely on any code outside of this file in any
407  * function or variable below this line.
408  *
409  * Please keep everything fully self-contained and annotated with
410  * __efi_runtime and __efi_runtime_data markers.
411  */
412 
413 /*
414  * Relocate the EFI runtime stub to a different place. We need to call this
415  * the first time we expose the runtime interface to a user and on set virtual
416  * address map calls.
417  */
418 
419 static efi_status_t __efi_runtime EFIAPI efi_unimplemented(void)
420 {
421 	return EFI_UNSUPPORTED;
422 }
423 
424 static efi_status_t __efi_runtime EFIAPI efi_device_error(void)
425 {
426 	return EFI_DEVICE_ERROR;
427 }
428 
429 static efi_status_t __efi_runtime EFIAPI efi_invalid_parameter(void)
430 {
431 	return EFI_INVALID_PARAMETER;
432 }
433 
434 efi_status_t __efi_runtime EFIAPI efi_update_capsule(
435 			struct efi_capsule_header **capsule_header_array,
436 			efi_uintn_t capsule_count,
437 			u64 scatter_gather_list)
438 {
439 	return EFI_UNSUPPORTED;
440 }
441 
442 efi_status_t __efi_runtime EFIAPI efi_query_capsule_caps(
443 			struct efi_capsule_header **capsule_header_array,
444 			efi_uintn_t capsule_count,
445 			u64 maximum_capsule_size,
446 			u32 reset_type)
447 {
448 	return EFI_UNSUPPORTED;
449 }
450 
451 efi_status_t __efi_runtime EFIAPI efi_query_variable_info(
452 			u32 attributes,
453 			u64 *maximum_variable_storage_size,
454 			u64 *remaining_variable_storage_size,
455 			u64 *maximum_variable_size)
456 {
457 	return EFI_UNSUPPORTED;
458 }
459 
460 struct efi_runtime_services __efi_runtime_data efi_runtime_services = {
461 	.hdr = {
462 		.signature = EFI_RUNTIME_SERVICES_SIGNATURE,
463 		.revision = EFI_RUNTIME_SERVICES_REVISION,
464 		.headersize = sizeof(struct efi_table_hdr),
465 	},
466 	.get_time = &efi_get_time_boottime,
467 	.set_time = (void *)&efi_device_error,
468 	.get_wakeup_time = (void *)&efi_unimplemented,
469 	.set_wakeup_time = (void *)&efi_unimplemented,
470 	.set_virtual_address_map = &efi_set_virtual_address_map,
471 	.convert_pointer = (void *)&efi_invalid_parameter,
472 	.get_variable = efi_get_variable,
473 	.get_next_variable_name = efi_get_next_variable_name,
474 	.set_variable = efi_set_variable,
475 	.get_next_high_mono_count = (void *)&efi_device_error,
476 	.reset_system = &efi_reset_system_boottime,
477 	.update_capsule = efi_update_capsule,
478 	.query_capsule_caps = efi_query_capsule_caps,
479 	.query_variable_info = efi_query_variable_info,
480 };
481