xref: /openbmc/u-boot/lib/efi_loader/efi_runtime.c (revision 040b2583)
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 #include <asm/global_data.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 #if defined(CONFIG_ARM64)
33 #define R_RELATIVE	1027
34 #define R_MASK		0xffffffffULL
35 #define IS_RELA		1
36 #elif defined(CONFIG_ARM)
37 #define R_RELATIVE	23
38 #define R_MASK		0xffULL
39 #elif defined(CONFIG_X86)
40 #include <asm/elf.h>
41 #define R_RELATIVE	R_386_RELATIVE
42 #define R_MASK		0xffULL
43 #elif defined(CONFIG_RISCV)
44 #include <elf.h>
45 #define R_RELATIVE	R_RISCV_RELATIVE
46 #define R_MASK		0xffULL
47 #define IS_RELA		1
48 
49 struct dyn_sym {
50 	ulong foo1;
51 	ulong addr;
52 	u32 foo2;
53 	u32 foo3;
54 };
55 #ifdef CONFIG_CPU_RISCV_32
56 #define R_ABSOLUTE	R_RISCV_32
57 #define SYM_INDEX	8
58 #else
59 #define R_ABSOLUTE	R_RISCV_64
60 #define SYM_INDEX	32
61 #endif
62 #else
63 #error Need to add relocation awareness
64 #endif
65 
66 struct elf_rel {
67 	ulong *offset;
68 	ulong info;
69 };
70 
71 struct elf_rela {
72 	ulong *offset;
73 	ulong info;
74 	long addend;
75 };
76 
77 /*
78  * EFI Runtime code lives in 2 stages. In the first stage, U-Boot and an EFI
79  * payload are running concurrently at the same time. In this mode, we can
80  * handle a good number of runtime callbacks
81  */
82 
83 static void EFIAPI efi_reset_system_boottime(
84 			enum efi_reset_type reset_type,
85 			efi_status_t reset_status,
86 			unsigned long data_size, void *reset_data)
87 {
88 	struct efi_event *evt;
89 
90 	EFI_ENTRY("%d %lx %lx %p", reset_type, reset_status, data_size,
91 		  reset_data);
92 
93 	/* Notify reset */
94 	list_for_each_entry(evt, &efi_events, link) {
95 		if (evt->group &&
96 		    !guidcmp(evt->group,
97 			     &efi_guid_event_group_reset_system)) {
98 			efi_signal_event(evt, false);
99 			break;
100 		}
101 	}
102 	switch (reset_type) {
103 	case EFI_RESET_COLD:
104 	case EFI_RESET_WARM:
105 	case EFI_RESET_PLATFORM_SPECIFIC:
106 		do_reset(NULL, 0, 0, NULL);
107 		break;
108 	case EFI_RESET_SHUTDOWN:
109 		/* We don't have anything to map this to */
110 		break;
111 	}
112 
113 	while (1) { }
114 }
115 
116 static efi_status_t EFIAPI efi_get_time_boottime(
117 			struct efi_time *time,
118 			struct efi_time_cap *capabilities)
119 {
120 #if defined(CONFIG_CMD_DATE) && defined(CONFIG_DM_RTC)
121 	struct rtc_time tm;
122 	int r;
123 	struct udevice *dev;
124 
125 	EFI_ENTRY("%p %p", time, capabilities);
126 
127 	r = uclass_get_device(UCLASS_RTC, 0, &dev);
128 	if (r)
129 		return EFI_EXIT(EFI_DEVICE_ERROR);
130 
131 	r = dm_rtc_get(dev, &tm);
132 	if (r)
133 		return EFI_EXIT(EFI_DEVICE_ERROR);
134 
135 	memset(time, 0, sizeof(*time));
136 	time->year = tm.tm_year;
137 	time->month = tm.tm_mon;
138 	time->day = tm.tm_mday;
139 	time->hour = tm.tm_hour;
140 	time->minute = tm.tm_min;
141 	time->daylight = tm.tm_isdst;
142 
143 	return EFI_EXIT(EFI_SUCCESS);
144 #else
145 	return EFI_DEVICE_ERROR;
146 #endif
147 }
148 
149 /* Boards may override the helpers below to implement RTS functionality */
150 
151 void __weak __efi_runtime EFIAPI efi_reset_system(
152 			enum efi_reset_type reset_type,
153 			efi_status_t reset_status,
154 			unsigned long data_size, void *reset_data)
155 {
156 	/* Nothing we can do */
157 	while (1) { }
158 }
159 
160 efi_status_t __weak efi_reset_system_init(void)
161 {
162 	return EFI_SUCCESS;
163 }
164 
165 efi_status_t __weak __efi_runtime EFIAPI efi_get_time(
166 			struct efi_time *time,
167 			struct efi_time_cap *capabilities)
168 {
169 	/* Nothing we can do */
170 	return EFI_DEVICE_ERROR;
171 }
172 
173 efi_status_t __weak efi_get_time_init(void)
174 {
175 	return EFI_SUCCESS;
176 }
177 
178 struct efi_runtime_detach_list_struct {
179 	void *ptr;
180 	void *patchto;
181 };
182 
183 static const struct efi_runtime_detach_list_struct efi_runtime_detach_list[] = {
184 	{
185 		/* do_reset is gone */
186 		.ptr = &efi_runtime_services.reset_system,
187 		.patchto = efi_reset_system,
188 	}, {
189 		/* invalidate_*cache_all are gone */
190 		.ptr = &efi_runtime_services.set_virtual_address_map,
191 		.patchto = &efi_invalid_parameter,
192 	}, {
193 		/* RTC accessors are gone */
194 		.ptr = &efi_runtime_services.get_time,
195 		.patchto = &efi_get_time,
196 	}, {
197 		/* Clean up system table */
198 		.ptr = &systab.con_in,
199 		.patchto = NULL,
200 	}, {
201 		/* Clean up system table */
202 		.ptr = &systab.con_out,
203 		.patchto = NULL,
204 	}, {
205 		/* Clean up system table */
206 		.ptr = &systab.std_err,
207 		.patchto = NULL,
208 	}, {
209 		/* Clean up system table */
210 		.ptr = &systab.boottime,
211 		.patchto = NULL,
212 	}, {
213 		.ptr = &efi_runtime_services.get_variable,
214 		.patchto = &efi_device_error,
215 	}, {
216 		.ptr = &efi_runtime_services.get_next_variable,
217 		.patchto = &efi_device_error,
218 	}, {
219 		.ptr = &efi_runtime_services.set_variable,
220 		.patchto = &efi_device_error,
221 	}
222 };
223 
224 static bool efi_runtime_tobedetached(void *p)
225 {
226 	int i;
227 
228 	for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++)
229 		if (efi_runtime_detach_list[i].ptr == p)
230 			return true;
231 
232 	return false;
233 }
234 
235 static void efi_runtime_detach(ulong offset)
236 {
237 	int i;
238 	ulong patchoff = offset - (ulong)gd->relocaddr;
239 
240 	for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++) {
241 		ulong patchto = (ulong)efi_runtime_detach_list[i].patchto;
242 		ulong *p = efi_runtime_detach_list[i].ptr;
243 		ulong newaddr = patchto ? (patchto + patchoff) : 0;
244 
245 		debug("%s: Setting %p to %lx\n", __func__, p, newaddr);
246 		*p = newaddr;
247 	}
248 }
249 
250 /* Relocate EFI runtime to uboot_reloc_base = offset */
251 void efi_runtime_relocate(ulong offset, struct efi_mem_desc *map)
252 {
253 #ifdef IS_RELA
254 	struct elf_rela *rel = (void*)&__efi_runtime_rel_start;
255 #else
256 	struct elf_rel *rel = (void*)&__efi_runtime_rel_start;
257 	static ulong lastoff = CONFIG_SYS_TEXT_BASE;
258 #endif
259 
260 	debug("%s: Relocating to offset=%lx\n", __func__, offset);
261 	for (; (ulong)rel < (ulong)&__efi_runtime_rel_stop; rel++) {
262 		ulong base = CONFIG_SYS_TEXT_BASE;
263 		ulong *p;
264 		ulong newaddr;
265 
266 		p = (void*)((ulong)rel->offset - base) + gd->relocaddr;
267 
268 		debug("%s: rel->info=%#lx *p=%#lx rel->offset=%p\n", __func__, rel->info, *p, rel->offset);
269 
270 		switch (rel->info & R_MASK) {
271 		case R_RELATIVE:
272 #ifdef IS_RELA
273 		newaddr = rel->addend + offset - CONFIG_SYS_TEXT_BASE;
274 #else
275 		newaddr = *p - lastoff + offset;
276 #endif
277 			break;
278 #ifdef R_ABSOLUTE
279 		case R_ABSOLUTE: {
280 			ulong symidx = rel->info >> SYM_INDEX;
281 			extern struct dyn_sym __dyn_sym_start[];
282 			newaddr = __dyn_sym_start[symidx].addr + offset;
283 			break;
284 		}
285 #endif
286 		default:
287 			continue;
288 		}
289 
290 		/* Check if the relocation is inside bounds */
291 		if (map && ((newaddr < map->virtual_start) ||
292 		    newaddr > (map->virtual_start +
293 			      (map->num_pages << EFI_PAGE_SHIFT)))) {
294 			if (!efi_runtime_tobedetached(p))
295 				printf("U-Boot EFI: Relocation at %p is out of "
296 				       "range (%lx)\n", p, newaddr);
297 			continue;
298 		}
299 
300 		debug("%s: Setting %p to %lx\n", __func__, p, newaddr);
301 		*p = newaddr;
302 		flush_dcache_range((ulong)p & ~(EFI_CACHELINE_SIZE - 1),
303 			ALIGN((ulong)&p[1], EFI_CACHELINE_SIZE));
304 	}
305 
306 #ifndef IS_RELA
307 	lastoff = offset;
308 #endif
309 
310         invalidate_icache_all();
311 }
312 
313 static efi_status_t EFIAPI efi_set_virtual_address_map(
314 			unsigned long memory_map_size,
315 			unsigned long descriptor_size,
316 			uint32_t descriptor_version,
317 			struct efi_mem_desc *virtmap)
318 {
319 	ulong runtime_start = (ulong)&__efi_runtime_start &
320 			      ~(ulong)EFI_PAGE_MASK;
321 	int n = memory_map_size / descriptor_size;
322 	int i;
323 
324 	EFI_ENTRY("%lx %lx %x %p", memory_map_size, descriptor_size,
325 		  descriptor_version, virtmap);
326 
327 	/* Rebind mmio pointers */
328 	for (i = 0; i < n; i++) {
329 		struct efi_mem_desc *map = (void*)virtmap +
330 					   (descriptor_size * i);
331 		struct list_head *lhandle;
332 		efi_physical_addr_t map_start = map->physical_start;
333 		efi_physical_addr_t map_len = map->num_pages << EFI_PAGE_SHIFT;
334 		efi_physical_addr_t map_end = map_start + map_len;
335 
336 		/* Adjust all mmio pointers in this region */
337 		list_for_each(lhandle, &efi_runtime_mmio) {
338 			struct efi_runtime_mmio_list *lmmio;
339 
340 			lmmio = list_entry(lhandle,
341 					   struct efi_runtime_mmio_list,
342 					   link);
343 			if ((map_start <= lmmio->paddr) &&
344 			    (map_end >= lmmio->paddr)) {
345 				u64 off = map->virtual_start - map_start;
346 				uintptr_t new_addr = lmmio->paddr + off;
347 				*lmmio->ptr = (void *)new_addr;
348 			}
349 		}
350 	}
351 
352 	/* Move the actual runtime code over */
353 	for (i = 0; i < n; i++) {
354 		struct efi_mem_desc *map;
355 
356 		map = (void*)virtmap + (descriptor_size * i);
357 		if (map->type == EFI_RUNTIME_SERVICES_CODE) {
358 			ulong new_offset = map->virtual_start -
359 					   (runtime_start - gd->relocaddr);
360 
361 			efi_runtime_relocate(new_offset, map);
362 			/* Once we're virtual, we can no longer handle
363 			   complex callbacks */
364 			efi_runtime_detach(new_offset);
365 			return EFI_EXIT(EFI_SUCCESS);
366 		}
367 	}
368 
369 	return EFI_EXIT(EFI_INVALID_PARAMETER);
370 }
371 
372 efi_status_t efi_add_runtime_mmio(void *mmio_ptr, u64 len)
373 {
374 	struct efi_runtime_mmio_list *newmmio;
375 	u64 pages = (len + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
376 	uint64_t addr = *(uintptr_t *)mmio_ptr;
377 	uint64_t retaddr;
378 
379 	retaddr = efi_add_memory_map(addr, pages, EFI_MMAP_IO, false);
380 	if (retaddr != addr)
381 		return EFI_OUT_OF_RESOURCES;
382 
383 	newmmio = calloc(1, sizeof(*newmmio));
384 	if (!newmmio)
385 		return EFI_OUT_OF_RESOURCES;
386 	newmmio->ptr = mmio_ptr;
387 	newmmio->paddr = *(uintptr_t *)mmio_ptr;
388 	newmmio->len = len;
389 	list_add_tail(&newmmio->link, &efi_runtime_mmio);
390 
391 	return EFI_SUCCESS;
392 }
393 
394 /*
395  * In the second stage, U-Boot has disappeared. To isolate our runtime code
396  * that at this point still exists from the rest, we put it into a special
397  * section.
398  *
399  *        !!WARNING!!
400  *
401  * This means that we can not rely on any code outside of this file in any
402  * function or variable below this line.
403  *
404  * Please keep everything fully self-contained and annotated with
405  * __efi_runtime and __efi_runtime_data markers.
406  */
407 
408 /*
409  * Relocate the EFI runtime stub to a different place. We need to call this
410  * the first time we expose the runtime interface to a user and on set virtual
411  * address map calls.
412  */
413 
414 static efi_status_t __efi_runtime EFIAPI efi_unimplemented(void)
415 {
416 	return EFI_UNSUPPORTED;
417 }
418 
419 static efi_status_t __efi_runtime EFIAPI efi_device_error(void)
420 {
421 	return EFI_DEVICE_ERROR;
422 }
423 
424 static efi_status_t __efi_runtime EFIAPI efi_invalid_parameter(void)
425 {
426 	return EFI_INVALID_PARAMETER;
427 }
428 
429 efi_status_t __efi_runtime EFIAPI efi_update_capsule(
430 			struct efi_capsule_header **capsule_header_array,
431 			efi_uintn_t capsule_count,
432 			u64 scatter_gather_list)
433 {
434 	return EFI_UNSUPPORTED;
435 }
436 
437 efi_status_t __efi_runtime EFIAPI efi_query_capsule_caps(
438 			struct efi_capsule_header **capsule_header_array,
439 			efi_uintn_t capsule_count,
440 			u64 maximum_capsule_size,
441 			u32 reset_type)
442 {
443 	return EFI_UNSUPPORTED;
444 }
445 
446 efi_status_t __efi_runtime EFIAPI efi_query_variable_info(
447 			u32 attributes,
448 			u64 maximum_variable_storage_size,
449 			u64 remaining_variable_storage_size,
450 			u64 maximum_variable_size)
451 {
452 	return EFI_UNSUPPORTED;
453 }
454 
455 struct efi_runtime_services __efi_runtime_data efi_runtime_services = {
456 	.hdr = {
457 		.signature = EFI_RUNTIME_SERVICES_SIGNATURE,
458 		.revision = EFI_RUNTIME_SERVICES_REVISION,
459 		.headersize = sizeof(struct efi_table_hdr),
460 	},
461 	.get_time = &efi_get_time_boottime,
462 	.set_time = (void *)&efi_device_error,
463 	.get_wakeup_time = (void *)&efi_unimplemented,
464 	.set_wakeup_time = (void *)&efi_unimplemented,
465 	.set_virtual_address_map = &efi_set_virtual_address_map,
466 	.convert_pointer = (void *)&efi_invalid_parameter,
467 	.get_variable = efi_get_variable,
468 	.get_next_variable = efi_get_next_variable,
469 	.set_variable = efi_set_variable,
470 	.get_next_high_mono_count = (void *)&efi_device_error,
471 	.reset_system = &efi_reset_system_boottime,
472 	.update_capsule = efi_update_capsule,
473 	.query_capsule_caps = efi_query_capsule_caps,
474 	.query_variable_info = efi_query_variable_info,
475 };
476