xref: /openbmc/u-boot/lib/efi_loader/efi_runtime.c (revision fbe502e9)
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 #ifdef CONFIG_SYS_CACHELINE_SIZE
33 #define EFI_CACHELINE_SIZE CONFIG_SYS_CACHELINE_SIZE
34 #else
35 /* Just use the greatest cache flush alignment requirement I'm aware of */
36 #define EFI_CACHELINE_SIZE 128
37 #endif
38 
39 #if defined(CONFIG_ARM64)
40 #define R_RELATIVE	1027
41 #define R_MASK		0xffffffffULL
42 #define IS_RELA		1
43 #elif defined(CONFIG_ARM)
44 #define R_RELATIVE	23
45 #define R_MASK		0xffULL
46 #elif defined(CONFIG_X86)
47 #include <asm/elf.h>
48 #define R_RELATIVE	R_386_RELATIVE
49 #define R_MASK		0xffULL
50 #else
51 #error Need to add relocation awareness
52 #endif
53 
54 struct elf_rel {
55 	ulong *offset;
56 	ulong info;
57 };
58 
59 struct elf_rela {
60 	ulong *offset;
61 	ulong info;
62 	long addend;
63 };
64 
65 /*
66  * EFI Runtime code lives in 2 stages. In the first stage, U-Boot and an EFI
67  * payload are running concurrently at the same time. In this mode, we can
68  * handle a good number of runtime callbacks
69  */
70 
71 static void EFIAPI efi_reset_system_boottime(
72 			enum efi_reset_type reset_type,
73 			efi_status_t reset_status,
74 			unsigned long data_size, void *reset_data)
75 {
76 	struct efi_event *evt;
77 
78 	EFI_ENTRY("%d %lx %lx %p", reset_type, reset_status, data_size,
79 		  reset_data);
80 
81 	/* Notify reset */
82 	list_for_each_entry(evt, &efi_events, link) {
83 		if (evt->group &&
84 		    !guidcmp(evt->group,
85 			     &efi_guid_event_group_reset_system)) {
86 			efi_signal_event(evt, false);
87 			break;
88 		}
89 	}
90 	switch (reset_type) {
91 	case EFI_RESET_COLD:
92 	case EFI_RESET_WARM:
93 	case EFI_RESET_PLATFORM_SPECIFIC:
94 		do_reset(NULL, 0, 0, NULL);
95 		break;
96 	case EFI_RESET_SHUTDOWN:
97 		/* We don't have anything to map this to */
98 		break;
99 	}
100 
101 	while (1) { }
102 }
103 
104 static efi_status_t EFIAPI efi_get_time_boottime(
105 			struct efi_time *time,
106 			struct efi_time_cap *capabilities)
107 {
108 #if defined(CONFIG_CMD_DATE) && defined(CONFIG_DM_RTC)
109 	struct rtc_time tm;
110 	int r;
111 	struct udevice *dev;
112 
113 	EFI_ENTRY("%p %p", time, capabilities);
114 
115 	r = uclass_get_device(UCLASS_RTC, 0, &dev);
116 	if (r)
117 		return EFI_EXIT(EFI_DEVICE_ERROR);
118 
119 	r = dm_rtc_get(dev, &tm);
120 	if (r)
121 		return EFI_EXIT(EFI_DEVICE_ERROR);
122 
123 	memset(time, 0, sizeof(*time));
124 	time->year = tm.tm_year;
125 	time->month = tm.tm_mon;
126 	time->day = tm.tm_mday;
127 	time->hour = tm.tm_hour;
128 	time->minute = tm.tm_min;
129 	time->daylight = tm.tm_isdst;
130 
131 	return EFI_EXIT(EFI_SUCCESS);
132 #else
133 	return EFI_DEVICE_ERROR;
134 #endif
135 }
136 
137 /* Boards may override the helpers below to implement RTS functionality */
138 
139 void __weak __efi_runtime EFIAPI efi_reset_system(
140 			enum efi_reset_type reset_type,
141 			efi_status_t reset_status,
142 			unsigned long data_size, void *reset_data)
143 {
144 	/* Nothing we can do */
145 	while (1) { }
146 }
147 
148 efi_status_t __weak efi_reset_system_init(void)
149 {
150 	return EFI_SUCCESS;
151 }
152 
153 efi_status_t __weak __efi_runtime EFIAPI efi_get_time(
154 			struct efi_time *time,
155 			struct efi_time_cap *capabilities)
156 {
157 	/* Nothing we can do */
158 	return EFI_DEVICE_ERROR;
159 }
160 
161 efi_status_t __weak efi_get_time_init(void)
162 {
163 	return EFI_SUCCESS;
164 }
165 
166 struct efi_runtime_detach_list_struct {
167 	void *ptr;
168 	void *patchto;
169 };
170 
171 static const struct efi_runtime_detach_list_struct efi_runtime_detach_list[] = {
172 	{
173 		/* do_reset is gone */
174 		.ptr = &efi_runtime_services.reset_system,
175 		.patchto = efi_reset_system,
176 	}, {
177 		/* invalidate_*cache_all are gone */
178 		.ptr = &efi_runtime_services.set_virtual_address_map,
179 		.patchto = &efi_invalid_parameter,
180 	}, {
181 		/* RTC accessors are gone */
182 		.ptr = &efi_runtime_services.get_time,
183 		.patchto = &efi_get_time,
184 	}, {
185 		/* Clean up system table */
186 		.ptr = &systab.con_in,
187 		.patchto = NULL,
188 	}, {
189 		/* Clean up system table */
190 		.ptr = &systab.con_out,
191 		.patchto = NULL,
192 	}, {
193 		/* Clean up system table */
194 		.ptr = &systab.std_err,
195 		.patchto = NULL,
196 	}, {
197 		/* Clean up system table */
198 		.ptr = &systab.boottime,
199 		.patchto = NULL,
200 	}, {
201 		.ptr = &efi_runtime_services.get_variable,
202 		.patchto = &efi_device_error,
203 	}, {
204 		.ptr = &efi_runtime_services.get_next_variable,
205 		.patchto = &efi_device_error,
206 	}, {
207 		.ptr = &efi_runtime_services.set_variable,
208 		.patchto = &efi_device_error,
209 	}
210 };
211 
212 static bool efi_runtime_tobedetached(void *p)
213 {
214 	int i;
215 
216 	for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++)
217 		if (efi_runtime_detach_list[i].ptr == p)
218 			return true;
219 
220 	return false;
221 }
222 
223 static void efi_runtime_detach(ulong offset)
224 {
225 	int i;
226 	ulong patchoff = offset - (ulong)gd->relocaddr;
227 
228 	for (i = 0; i < ARRAY_SIZE(efi_runtime_detach_list); i++) {
229 		ulong patchto = (ulong)efi_runtime_detach_list[i].patchto;
230 		ulong *p = efi_runtime_detach_list[i].ptr;
231 		ulong newaddr = patchto ? (patchto + patchoff) : 0;
232 
233 		debug("%s: Setting %p to %lx\n", __func__, p, newaddr);
234 		*p = newaddr;
235 	}
236 }
237 
238 /* Relocate EFI runtime to uboot_reloc_base = offset */
239 void efi_runtime_relocate(ulong offset, struct efi_mem_desc *map)
240 {
241 #ifdef IS_RELA
242 	struct elf_rela *rel = (void*)&__efi_runtime_rel_start;
243 #else
244 	struct elf_rel *rel = (void*)&__efi_runtime_rel_start;
245 	static ulong lastoff = CONFIG_SYS_TEXT_BASE;
246 #endif
247 
248 	debug("%s: Relocating to offset=%lx\n", __func__, offset);
249 	for (; (ulong)rel < (ulong)&__efi_runtime_rel_stop; rel++) {
250 		ulong base = CONFIG_SYS_TEXT_BASE;
251 		ulong *p;
252 		ulong newaddr;
253 
254 		p = (void*)((ulong)rel->offset - base) + gd->relocaddr;
255 
256 		if ((rel->info & R_MASK) != R_RELATIVE) {
257 			continue;
258 		}
259 
260 #ifdef IS_RELA
261 		newaddr = rel->addend + offset - CONFIG_SYS_TEXT_BASE;
262 #else
263 		newaddr = *p - lastoff + offset;
264 #endif
265 
266 		/* Check if the relocation is inside bounds */
267 		if (map && ((newaddr < map->virtual_start) ||
268 		    newaddr > (map->virtual_start +
269 			      (map->num_pages << EFI_PAGE_SHIFT)))) {
270 			if (!efi_runtime_tobedetached(p))
271 				printf("U-Boot EFI: Relocation at %p is out of "
272 				       "range (%lx)\n", p, newaddr);
273 			continue;
274 		}
275 
276 		debug("%s: Setting %p to %lx\n", __func__, p, newaddr);
277 		*p = newaddr;
278 		flush_dcache_range((ulong)p & ~(EFI_CACHELINE_SIZE - 1),
279 			ALIGN((ulong)&p[1], EFI_CACHELINE_SIZE));
280 	}
281 
282 #ifndef IS_RELA
283 	lastoff = offset;
284 #endif
285 
286         invalidate_icache_all();
287 }
288 
289 static efi_status_t EFIAPI efi_set_virtual_address_map(
290 			unsigned long memory_map_size,
291 			unsigned long descriptor_size,
292 			uint32_t descriptor_version,
293 			struct efi_mem_desc *virtmap)
294 {
295 	ulong runtime_start = (ulong)&__efi_runtime_start &
296 			      ~(ulong)EFI_PAGE_MASK;
297 	int n = memory_map_size / descriptor_size;
298 	int i;
299 
300 	EFI_ENTRY("%lx %lx %x %p", memory_map_size, descriptor_size,
301 		  descriptor_version, virtmap);
302 
303 	/* Rebind mmio pointers */
304 	for (i = 0; i < n; i++) {
305 		struct efi_mem_desc *map = (void*)virtmap +
306 					   (descriptor_size * i);
307 		struct list_head *lhandle;
308 		efi_physical_addr_t map_start = map->physical_start;
309 		efi_physical_addr_t map_len = map->num_pages << EFI_PAGE_SHIFT;
310 		efi_physical_addr_t map_end = map_start + map_len;
311 
312 		/* Adjust all mmio pointers in this region */
313 		list_for_each(lhandle, &efi_runtime_mmio) {
314 			struct efi_runtime_mmio_list *lmmio;
315 
316 			lmmio = list_entry(lhandle,
317 					   struct efi_runtime_mmio_list,
318 					   link);
319 			if ((map_start <= lmmio->paddr) &&
320 			    (map_end >= lmmio->paddr)) {
321 				u64 off = map->virtual_start - map_start;
322 				uintptr_t new_addr = lmmio->paddr + off;
323 				*lmmio->ptr = (void *)new_addr;
324 			}
325 		}
326 	}
327 
328 	/* Move the actual runtime code over */
329 	for (i = 0; i < n; i++) {
330 		struct efi_mem_desc *map;
331 
332 		map = (void*)virtmap + (descriptor_size * i);
333 		if (map->type == EFI_RUNTIME_SERVICES_CODE) {
334 			ulong new_offset = map->virtual_start -
335 					   (runtime_start - gd->relocaddr);
336 
337 			efi_runtime_relocate(new_offset, map);
338 			/* Once we're virtual, we can no longer handle
339 			   complex callbacks */
340 			efi_runtime_detach(new_offset);
341 			return EFI_EXIT(EFI_SUCCESS);
342 		}
343 	}
344 
345 	return EFI_EXIT(EFI_INVALID_PARAMETER);
346 }
347 
348 efi_status_t efi_add_runtime_mmio(void *mmio_ptr, u64 len)
349 {
350 	struct efi_runtime_mmio_list *newmmio;
351 	u64 pages = (len + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
352 	uint64_t addr = *(uintptr_t *)mmio_ptr;
353 	uint64_t retaddr;
354 
355 	retaddr = efi_add_memory_map(addr, pages, EFI_MMAP_IO, false);
356 	if (retaddr != addr)
357 		return EFI_OUT_OF_RESOURCES;
358 
359 	newmmio = calloc(1, sizeof(*newmmio));
360 	if (!newmmio)
361 		return EFI_OUT_OF_RESOURCES;
362 	newmmio->ptr = mmio_ptr;
363 	newmmio->paddr = *(uintptr_t *)mmio_ptr;
364 	newmmio->len = len;
365 	list_add_tail(&newmmio->link, &efi_runtime_mmio);
366 
367 	return EFI_SUCCESS;
368 }
369 
370 /*
371  * In the second stage, U-Boot has disappeared. To isolate our runtime code
372  * that at this point still exists from the rest, we put it into a special
373  * section.
374  *
375  *        !!WARNING!!
376  *
377  * This means that we can not rely on any code outside of this file in any
378  * function or variable below this line.
379  *
380  * Please keep everything fully self-contained and annotated with
381  * __efi_runtime and __efi_runtime_data markers.
382  */
383 
384 /*
385  * Relocate the EFI runtime stub to a different place. We need to call this
386  * the first time we expose the runtime interface to a user and on set virtual
387  * address map calls.
388  */
389 
390 static efi_status_t __efi_runtime EFIAPI efi_unimplemented(void)
391 {
392 	return EFI_UNSUPPORTED;
393 }
394 
395 static efi_status_t __efi_runtime EFIAPI efi_device_error(void)
396 {
397 	return EFI_DEVICE_ERROR;
398 }
399 
400 static efi_status_t __efi_runtime EFIAPI efi_invalid_parameter(void)
401 {
402 	return EFI_INVALID_PARAMETER;
403 }
404 
405 efi_status_t __efi_runtime EFIAPI efi_update_capsule(
406 			struct efi_capsule_header **capsule_header_array,
407 			efi_uintn_t capsule_count,
408 			u64 scatter_gather_list)
409 {
410 	return EFI_UNSUPPORTED;
411 }
412 
413 efi_status_t __efi_runtime EFIAPI efi_query_capsule_caps(
414 			struct efi_capsule_header **capsule_header_array,
415 			efi_uintn_t capsule_count,
416 			u64 maximum_capsule_size,
417 			u32 reset_type)
418 {
419 	return EFI_UNSUPPORTED;
420 }
421 
422 efi_status_t __efi_runtime EFIAPI efi_query_variable_info(
423 			u32 attributes,
424 			u64 maximum_variable_storage_size,
425 			u64 remaining_variable_storage_size,
426 			u64 maximum_variable_size)
427 {
428 	return EFI_UNSUPPORTED;
429 }
430 
431 struct efi_runtime_services __efi_runtime_data efi_runtime_services = {
432 	.hdr = {
433 		.signature = EFI_RUNTIME_SERVICES_SIGNATURE,
434 		.revision = EFI_RUNTIME_SERVICES_REVISION,
435 		.headersize = sizeof(struct efi_table_hdr),
436 	},
437 	.get_time = &efi_get_time_boottime,
438 	.set_time = (void *)&efi_device_error,
439 	.get_wakeup_time = (void *)&efi_unimplemented,
440 	.set_wakeup_time = (void *)&efi_unimplemented,
441 	.set_virtual_address_map = &efi_set_virtual_address_map,
442 	.convert_pointer = (void *)&efi_invalid_parameter,
443 	.get_variable = efi_get_variable,
444 	.get_next_variable = efi_get_next_variable,
445 	.set_variable = efi_set_variable,
446 	.get_next_high_mono_count = (void *)&efi_device_error,
447 	.reset_system = &efi_reset_system_boottime,
448 	.update_capsule = efi_update_capsule,
449 	.query_capsule_caps = efi_query_capsule_caps,
450 	.query_variable_info = efi_query_variable_info,
451 };
452