xref: /openbmc/u-boot/lib/efi_loader/efi_runtime.c (revision ae485b54)
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(CONFIG_ARM64)
36 #define R_RELATIVE	1027
37 #define R_MASK		0xffffffffULL
38 #define IS_RELA		1
39 #elif defined(CONFIG_ARM)
40 #define R_RELATIVE	23
41 #define R_MASK		0xffULL
42 #elif defined(CONFIG_X86)
43 #include <asm/elf.h>
44 #define R_RELATIVE	R_386_RELATIVE
45 #define R_MASK		0xffULL
46 #elif defined(CONFIG_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 #ifdef CONFIG_CPU_RISCV_32
59 #define R_ABSOLUTE	R_RISCV_32
60 #define SYM_INDEX	8
61 #else
62 #define R_ABSOLUTE	R_RISCV_64
63 #define SYM_INDEX	32
64 #endif
65 #else
66 #error Need to add relocation awareness
67 #endif
68 
69 struct elf_rel {
70 	ulong *offset;
71 	ulong info;
72 };
73 
74 struct elf_rela {
75 	ulong *offset;
76 	ulong info;
77 	long addend;
78 };
79 
80 /*
81  * EFI Runtime code lives in 2 stages. In the first stage, U-Boot and an EFI
82  * payload are running concurrently at the same time. In this mode, we can
83  * handle a good number of runtime callbacks
84  */
85 
86 static void EFIAPI efi_reset_system_boottime(
87 			enum efi_reset_type reset_type,
88 			efi_status_t reset_status,
89 			unsigned long data_size, void *reset_data)
90 {
91 	struct efi_event *evt;
92 
93 	EFI_ENTRY("%d %lx %lx %p", reset_type, reset_status, data_size,
94 		  reset_data);
95 
96 	/* Notify reset */
97 	list_for_each_entry(evt, &efi_events, link) {
98 		if (evt->group &&
99 		    !guidcmp(evt->group,
100 			     &efi_guid_event_group_reset_system)) {
101 			efi_signal_event(evt, false);
102 			break;
103 		}
104 	}
105 	switch (reset_type) {
106 	case EFI_RESET_COLD:
107 	case EFI_RESET_WARM:
108 	case EFI_RESET_PLATFORM_SPECIFIC:
109 		do_reset(NULL, 0, 0, NULL);
110 		break;
111 	case EFI_RESET_SHUTDOWN:
112 		/* We don't have anything to map this to */
113 		break;
114 	}
115 
116 	while (1) { }
117 }
118 
119 static efi_status_t EFIAPI efi_get_time_boottime(
120 			struct efi_time *time,
121 			struct efi_time_cap *capabilities)
122 {
123 #if defined(CONFIG_CMD_DATE) && defined(CONFIG_DM_RTC)
124 	struct rtc_time tm;
125 	int r;
126 	struct udevice *dev;
127 
128 	EFI_ENTRY("%p %p", time, capabilities);
129 
130 	r = uclass_get_device(UCLASS_RTC, 0, &dev);
131 	if (r)
132 		return EFI_EXIT(EFI_DEVICE_ERROR);
133 
134 	r = dm_rtc_get(dev, &tm);
135 	if (r)
136 		return EFI_EXIT(EFI_DEVICE_ERROR);
137 
138 	memset(time, 0, sizeof(*time));
139 	time->year = tm.tm_year;
140 	time->month = tm.tm_mon;
141 	time->day = tm.tm_mday;
142 	time->hour = tm.tm_hour;
143 	time->minute = tm.tm_min;
144 	time->daylight = tm.tm_isdst;
145 
146 	return EFI_EXIT(EFI_SUCCESS);
147 #else
148 	return EFI_DEVICE_ERROR;
149 #endif
150 }
151 
152 /* Boards may override the helpers below to implement RTS functionality */
153 
154 void __weak __efi_runtime EFIAPI efi_reset_system(
155 			enum efi_reset_type reset_type,
156 			efi_status_t reset_status,
157 			unsigned long data_size, void *reset_data)
158 {
159 	/* Nothing we can do */
160 	while (1) { }
161 }
162 
163 efi_status_t __weak efi_reset_system_init(void)
164 {
165 	return EFI_SUCCESS;
166 }
167 
168 efi_status_t __weak __efi_runtime EFIAPI efi_get_time(
169 			struct efi_time *time,
170 			struct efi_time_cap *capabilities)
171 {
172 	/* Nothing we can do */
173 	return EFI_DEVICE_ERROR;
174 }
175 
176 efi_status_t __weak efi_get_time_init(void)
177 {
178 	return EFI_SUCCESS;
179 }
180 
181 struct efi_runtime_detach_list_struct {
182 	void *ptr;
183 	void *patchto;
184 };
185 
186 static const struct efi_runtime_detach_list_struct efi_runtime_detach_list[] = {
187 	{
188 		/* do_reset is gone */
189 		.ptr = &efi_runtime_services.reset_system,
190 		.patchto = efi_reset_system,
191 	}, {
192 		/* invalidate_*cache_all are gone */
193 		.ptr = &efi_runtime_services.set_virtual_address_map,
194 		.patchto = &efi_invalid_parameter,
195 	}, {
196 		/* RTC accessors are gone */
197 		.ptr = &efi_runtime_services.get_time,
198 		.patchto = &efi_get_time,
199 	}, {
200 		/* Clean up system table */
201 		.ptr = &systab.con_in,
202 		.patchto = NULL,
203 	}, {
204 		/* Clean up system table */
205 		.ptr = &systab.con_out,
206 		.patchto = NULL,
207 	}, {
208 		/* Clean up system table */
209 		.ptr = &systab.std_err,
210 		.patchto = NULL,
211 	}, {
212 		/* Clean up system table */
213 		.ptr = &systab.boottime,
214 		.patchto = NULL,
215 	}, {
216 		.ptr = &efi_runtime_services.get_variable,
217 		.patchto = &efi_device_error,
218 	}, {
219 		.ptr = &efi_runtime_services.get_next_variable_name,
220 		.patchto = &efi_device_error,
221 	}, {
222 		.ptr = &efi_runtime_services.set_variable,
223 		.patchto = &efi_device_error,
224 	}
225 };
226 
227 static bool efi_runtime_tobedetached(void *p)
228 {
229 	int i;
230 
231 	for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++)
232 		if (efi_runtime_detach_list[i].ptr == p)
233 			return true;
234 
235 	return false;
236 }
237 
238 static void efi_runtime_detach(ulong offset)
239 {
240 	int i;
241 	ulong patchoff = offset - (ulong)gd->relocaddr;
242 
243 	for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++) {
244 		ulong patchto = (ulong)efi_runtime_detach_list[i].patchto;
245 		ulong *p = efi_runtime_detach_list[i].ptr;
246 		ulong newaddr = patchto ? (patchto + patchoff) : 0;
247 
248 		debug("%s: Setting %p to %lx\n", __func__, p, newaddr);
249 		*p = newaddr;
250 	}
251 }
252 
253 /* Relocate EFI runtime to uboot_reloc_base = offset */
254 void efi_runtime_relocate(ulong offset, struct efi_mem_desc *map)
255 {
256 #ifdef IS_RELA
257 	struct elf_rela *rel = (void*)&__efi_runtime_rel_start;
258 #else
259 	struct elf_rel *rel = (void*)&__efi_runtime_rel_start;
260 	static ulong lastoff = CONFIG_SYS_TEXT_BASE;
261 #endif
262 
263 	debug("%s: Relocating to offset=%lx\n", __func__, offset);
264 	for (; (ulong)rel < (ulong)&__efi_runtime_rel_stop; rel++) {
265 		ulong base = CONFIG_SYS_TEXT_BASE;
266 		ulong *p;
267 		ulong newaddr;
268 
269 		p = (void*)((ulong)rel->offset - base) + gd->relocaddr;
270 
271 		debug("%s: rel->info=%#lx *p=%#lx rel->offset=%p\n", __func__, rel->info, *p, rel->offset);
272 
273 		switch (rel->info & R_MASK) {
274 		case R_RELATIVE:
275 #ifdef IS_RELA
276 		newaddr = rel->addend + offset - CONFIG_SYS_TEXT_BASE;
277 #else
278 		newaddr = *p - lastoff + offset;
279 #endif
280 			break;
281 #ifdef R_ABSOLUTE
282 		case R_ABSOLUTE: {
283 			ulong symidx = rel->info >> SYM_INDEX;
284 			extern struct dyn_sym __dyn_sym_start[];
285 			newaddr = __dyn_sym_start[symidx].addr + offset;
286 			break;
287 		}
288 #endif
289 		default:
290 			continue;
291 		}
292 
293 		/* Check if the relocation is inside bounds */
294 		if (map && ((newaddr < map->virtual_start) ||
295 		    newaddr > (map->virtual_start +
296 			      (map->num_pages << EFI_PAGE_SHIFT)))) {
297 			if (!efi_runtime_tobedetached(p))
298 				printf("U-Boot EFI: Relocation at %p is out of "
299 				       "range (%lx)\n", p, newaddr);
300 			continue;
301 		}
302 
303 		debug("%s: Setting %p to %lx\n", __func__, p, newaddr);
304 		*p = newaddr;
305 		flush_dcache_range((ulong)p & ~(EFI_CACHELINE_SIZE - 1),
306 			ALIGN((ulong)&p[1], EFI_CACHELINE_SIZE));
307 	}
308 
309 #ifndef IS_RELA
310 	lastoff = offset;
311 #endif
312 
313         invalidate_icache_all();
314 }
315 
316 static efi_status_t EFIAPI efi_set_virtual_address_map(
317 			unsigned long memory_map_size,
318 			unsigned long descriptor_size,
319 			uint32_t descriptor_version,
320 			struct efi_mem_desc *virtmap)
321 {
322 	ulong runtime_start = (ulong)&__efi_runtime_start &
323 			      ~(ulong)EFI_PAGE_MASK;
324 	int n = memory_map_size / descriptor_size;
325 	int i;
326 
327 	EFI_ENTRY("%lx %lx %x %p", memory_map_size, descriptor_size,
328 		  descriptor_version, virtmap);
329 
330 	/* Rebind mmio pointers */
331 	for (i = 0; i < n; i++) {
332 		struct efi_mem_desc *map = (void*)virtmap +
333 					   (descriptor_size * i);
334 		struct list_head *lhandle;
335 		efi_physical_addr_t map_start = map->physical_start;
336 		efi_physical_addr_t map_len = map->num_pages << EFI_PAGE_SHIFT;
337 		efi_physical_addr_t map_end = map_start + map_len;
338 
339 		/* Adjust all mmio pointers in this region */
340 		list_for_each(lhandle, &efi_runtime_mmio) {
341 			struct efi_runtime_mmio_list *lmmio;
342 
343 			lmmio = list_entry(lhandle,
344 					   struct efi_runtime_mmio_list,
345 					   link);
346 			if ((map_start <= lmmio->paddr) &&
347 			    (map_end >= lmmio->paddr)) {
348 				u64 off = map->virtual_start - map_start;
349 				uintptr_t new_addr = lmmio->paddr + off;
350 				*lmmio->ptr = (void *)new_addr;
351 			}
352 		}
353 	}
354 
355 	/* Move the actual runtime code over */
356 	for (i = 0; i < n; i++) {
357 		struct efi_mem_desc *map;
358 
359 		map = (void*)virtmap + (descriptor_size * i);
360 		if (map->type == EFI_RUNTIME_SERVICES_CODE) {
361 			ulong new_offset = map->virtual_start -
362 					   (runtime_start - gd->relocaddr);
363 
364 			efi_runtime_relocate(new_offset, map);
365 			/* Once we're virtual, we can no longer handle
366 			   complex callbacks */
367 			efi_runtime_detach(new_offset);
368 			return EFI_EXIT(EFI_SUCCESS);
369 		}
370 	}
371 
372 	return EFI_EXIT(EFI_INVALID_PARAMETER);
373 }
374 
375 efi_status_t efi_add_runtime_mmio(void *mmio_ptr, u64 len)
376 {
377 	struct efi_runtime_mmio_list *newmmio;
378 	u64 pages = (len + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
379 	uint64_t addr = *(uintptr_t *)mmio_ptr;
380 	uint64_t retaddr;
381 
382 	retaddr = efi_add_memory_map(addr, pages, EFI_MMAP_IO, false);
383 	if (retaddr != addr)
384 		return EFI_OUT_OF_RESOURCES;
385 
386 	newmmio = calloc(1, sizeof(*newmmio));
387 	if (!newmmio)
388 		return EFI_OUT_OF_RESOURCES;
389 	newmmio->ptr = mmio_ptr;
390 	newmmio->paddr = *(uintptr_t *)mmio_ptr;
391 	newmmio->len = len;
392 	list_add_tail(&newmmio->link, &efi_runtime_mmio);
393 
394 	return EFI_SUCCESS;
395 }
396 
397 /*
398  * In the second stage, U-Boot has disappeared. To isolate our runtime code
399  * that at this point still exists from the rest, we put it into a special
400  * section.
401  *
402  *        !!WARNING!!
403  *
404  * This means that we can not rely on any code outside of this file in any
405  * function or variable below this line.
406  *
407  * Please keep everything fully self-contained and annotated with
408  * __efi_runtime and __efi_runtime_data markers.
409  */
410 
411 /*
412  * Relocate the EFI runtime stub to a different place. We need to call this
413  * the first time we expose the runtime interface to a user and on set virtual
414  * address map calls.
415  */
416 
417 static efi_status_t __efi_runtime EFIAPI efi_unimplemented(void)
418 {
419 	return EFI_UNSUPPORTED;
420 }
421 
422 static efi_status_t __efi_runtime EFIAPI efi_device_error(void)
423 {
424 	return EFI_DEVICE_ERROR;
425 }
426 
427 static efi_status_t __efi_runtime EFIAPI efi_invalid_parameter(void)
428 {
429 	return EFI_INVALID_PARAMETER;
430 }
431 
432 efi_status_t __efi_runtime EFIAPI efi_update_capsule(
433 			struct efi_capsule_header **capsule_header_array,
434 			efi_uintn_t capsule_count,
435 			u64 scatter_gather_list)
436 {
437 	return EFI_UNSUPPORTED;
438 }
439 
440 efi_status_t __efi_runtime EFIAPI efi_query_capsule_caps(
441 			struct efi_capsule_header **capsule_header_array,
442 			efi_uintn_t capsule_count,
443 			u64 maximum_capsule_size,
444 			u32 reset_type)
445 {
446 	return EFI_UNSUPPORTED;
447 }
448 
449 efi_status_t __efi_runtime EFIAPI efi_query_variable_info(
450 			u32 attributes,
451 			u64 *maximum_variable_storage_size,
452 			u64 *remaining_variable_storage_size,
453 			u64 *maximum_variable_size)
454 {
455 	return EFI_UNSUPPORTED;
456 }
457 
458 struct efi_runtime_services __efi_runtime_data efi_runtime_services = {
459 	.hdr = {
460 		.signature = EFI_RUNTIME_SERVICES_SIGNATURE,
461 		.revision = EFI_RUNTIME_SERVICES_REVISION,
462 		.headersize = sizeof(struct efi_table_hdr),
463 	},
464 	.get_time = &efi_get_time_boottime,
465 	.set_time = (void *)&efi_device_error,
466 	.get_wakeup_time = (void *)&efi_unimplemented,
467 	.set_wakeup_time = (void *)&efi_unimplemented,
468 	.set_virtual_address_map = &efi_set_virtual_address_map,
469 	.convert_pointer = (void *)&efi_invalid_parameter,
470 	.get_variable = efi_get_variable,
471 	.get_next_variable_name = efi_get_next_variable_name,
472 	.set_variable = efi_set_variable,
473 	.get_next_high_mono_count = (void *)&efi_device_error,
474 	.reset_system = &efi_reset_system_boottime,
475 	.update_capsule = efi_update_capsule,
476 	.query_capsule_caps = efi_query_capsule_caps,
477 	.query_variable_info = efi_query_variable_info,
478 };
479