aboutsummaryrefslogtreecommitdiff
path: root/lib/efi_loader/efi_memory.c
blob: 967c3f733e4c581e2e0adc13c7507d6cf74c71f5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
// SPDX-License-Identifier: GPL-2.0+
/*
 *  EFI application memory management
 *
 *  Copyright (c) 2016 Alexander Graf
 */

#include <common.h>
#include <efi_loader.h>
#include <inttypes.h>
#include <malloc.h>
#include <mapmem.h>
#include <watchdog.h>
#include <linux/list_sort.h>

DECLARE_GLOBAL_DATA_PTR;

efi_uintn_t efi_memory_map_key;

struct efi_mem_list {
	struct list_head link;
	struct efi_mem_desc desc;
};

#define EFI_CARVE_NO_OVERLAP		-1
#define EFI_CARVE_LOOP_AGAIN		-2
#define EFI_CARVE_OVERLAPS_NONRAM	-3

/* This list contains all memory map items */
LIST_HEAD(efi_mem);

#ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
void *efi_bounce_buffer;
#endif

/*
 * U-Boot services each EFI AllocatePool request as a separate
 * (multiple) page allocation.  We have to track the number of pages
 * to be able to free the correct amount later.
 * EFI requires 8 byte alignment for pool allocations, so we can
 * prepend each allocation with an 64 bit header tracking the
 * allocation size, and hand out the remainder to the caller.
 */
struct efi_pool_allocation {
	u64 num_pages;
	char data[] __aligned(ARCH_DMA_MINALIGN);
};

/*
 * Sorts the memory list from highest address to lowest address
 *
 * When allocating memory we should always start from the highest
 * address chunk, so sort the memory list such that the first list
 * iterator gets the highest address and goes lower from there.
 */
static int efi_mem_cmp(void *priv, struct list_head *a, struct list_head *b)
{
	struct efi_mem_list *mema = list_entry(a, struct efi_mem_list, link);
	struct efi_mem_list *memb = list_entry(b, struct efi_mem_list, link);

	if (mema->desc.physical_start == memb->desc.physical_start)
		return 0;
	else if (mema->desc.physical_start < memb->desc.physical_start)
		return 1;
	else
		return -1;
}

static void efi_mem_sort(void)
{
	list_sort(NULL, &efi_mem, efi_mem_cmp);
}

/** efi_mem_carve_out - unmap memory region
 *
 * @map:		memory map
 * @carve_desc:		memory region to unmap
 * @overlap_only_ram:	the carved out region may only overlap RAM
 * Return Value:	the number of overlapping pages which have been
 *			removed from the map,
 *			EFI_CARVE_NO_OVERLAP, if the regions don't overlap,
 *			EFI_CARVE_OVERLAPS_NONRAM, if the carve and map overlap,
 *			and the map contains anything but free ram
 *			(only when overlap_only_ram is true),
 *			EFI_CARVE_LOOP_AGAIN, if the mapping list should be
 *			traversed again, as it has been altered.
 *
 * Unmaps all memory occupied by the carve_desc region from the list entry
 * pointed to by map.
 *
 * In case of EFI_CARVE_OVERLAPS_NONRAM it is the callers responsibility
 * to re-add the already carved out pages to the mapping.
 */
static s64 efi_mem_carve_out(struct efi_mem_list *map,
			     struct efi_mem_desc *carve_desc,
			     bool overlap_only_ram)
{
	struct efi_mem_list *newmap;
	struct efi_mem_desc *map_desc = &map->desc;
	uint64_t map_start = map_desc->physical_start;
	uint64_t map_end = map_start + (map_desc->num_pages << EFI_PAGE_SHIFT);
	uint64_t carve_start = carve_desc->physical_start;
	uint64_t carve_end = carve_start +
			     (carve_desc->num_pages << EFI_PAGE_SHIFT);

	/* check whether we're overlapping */
	if ((carve_end <= map_start) || (carve_start >= map_end))
		return EFI_CARVE_NO_OVERLAP;

	/* We're overlapping with non-RAM, warn the caller if desired */
	if (overlap_only_ram && (map_desc->type != EFI_CONVENTIONAL_MEMORY))
		return EFI_CARVE_OVERLAPS_NONRAM;

	/* Sanitize carve_start and carve_end to lie within our bounds */
	carve_start = max(carve_start, map_start);
	carve_end = min(carve_end, map_end);

	/* Carving at the beginning of our map? Just move it! */
	if (carve_start == map_start) {
		if (map_end == carve_end) {
			/* Full overlap, just remove map */
			list_del(&map->link);
			free(map);
		} else {
			map->desc.physical_start = carve_end;
			map->desc.num_pages = (map_end - carve_end)
					      >> EFI_PAGE_SHIFT;
		}

		return (carve_end - carve_start) >> EFI_PAGE_SHIFT;
	}

	/*
	 * Overlapping maps, just split the list map at carve_start,
	 * it will get moved or removed in the next iteration.
	 *
	 * [ map_desc |__carve_start__| newmap ]
	 */

	/* Create a new map from [ carve_start ... map_end ] */
	newmap = calloc(1, sizeof(*newmap));
	newmap->desc = map->desc;
	newmap->desc.physical_start = carve_start;
	newmap->desc.num_pages = (map_end - carve_start) >> EFI_PAGE_SHIFT;
	/* Insert before current entry (descending address order) */
	list_add_tail(&newmap->link, &map->link);

	/* Shrink the map to [ map_start ... carve_start ] */
	map_desc->num_pages = (carve_start - map_start) >> EFI_PAGE_SHIFT;

	return EFI_CARVE_LOOP_AGAIN;
}

uint64_t efi_add_memory_map(uint64_t start, uint64_t pages, int memory_type,
			    bool overlap_only_ram)
{
	struct list_head *lhandle;
	struct efi_mem_list *newlist;
	bool carve_again;
	uint64_t carved_pages = 0;

	debug("%s: 0x%" PRIx64 " 0x%" PRIx64 " %d %s\n", __func__,
	      start, pages, memory_type, overlap_only_ram ? "yes" : "no");

	if (memory_type >= EFI_MAX_MEMORY_TYPE)
		return EFI_INVALID_PARAMETER;

	if (!pages)
		return start;

	++efi_memory_map_key;
	newlist = calloc(1, sizeof(*newlist));
	newlist->desc.type = memory_type;
	newlist->desc.physical_start = start;
	newlist->desc.virtual_start = start;
	newlist->desc.num_pages = pages;

	switch (memory_type) {
	case EFI_RUNTIME_SERVICES_CODE:
	case EFI_RUNTIME_SERVICES_DATA:
		newlist->desc.attribute = (1 << EFI_MEMORY_WB_SHIFT) |
					  (1ULL << EFI_MEMORY_RUNTIME_SHIFT);
		break;
	case EFI_MMAP_IO:
		newlist->desc.attribute = 1ULL << EFI_MEMORY_RUNTIME_SHIFT;
		break;
	default:
		newlist->desc.attribute = 1 << EFI_MEMORY_WB_SHIFT;
		break;
	}

	/* Add our new map */
	do {
		carve_again = false;
		list_for_each(lhandle, &efi_mem) {
			struct efi_mem_list *lmem;
			s64 r;

			lmem = list_entry(lhandle, struct efi_mem_list, link);
			r = efi_mem_carve_out(lmem, &newlist->desc,
					      overlap_only_ram);
			switch (r) {
			case EFI_CARVE_OVERLAPS_NONRAM:
				/*
				 * The user requested to only have RAM overlaps,
				 * but we hit a non-RAM region. Error out.
				 */
				return 0;
			case EFI_CARVE_NO_OVERLAP:
				/* Just ignore this list entry */
				break;
			case EFI_CARVE_LOOP_AGAIN:
				/*
				 * We split an entry, but need to loop through
				 * the list again to actually carve it.
				 */
				carve_again = true;
				break;
			default:
				/* We carved a number of pages */
				carved_pages += r;
				carve_again = true;
				break;
			}

			if (carve_again) {
				/* The list changed, we need to start over */
				break;
			}
		}
	} while (carve_again);

	if (overlap_only_ram && (carved_pages != pages)) {
		/*
		 * The payload wanted to have RAM overlaps, but we overlapped
		 * with an unallocated region. Error out.
		 */
		return 0;
	}

	/* Add our new map */
        list_add_tail(&newlist->link, &efi_mem);

	/* And make sure memory is listed in descending order */
	efi_mem_sort();

	return start;
}

static uint64_t efi_find_free_memory(uint64_t len, uint64_t max_addr)
{
	struct list_head *lhandle;

	list_for_each(lhandle, &efi_mem) {
		struct efi_mem_list *lmem = list_entry(lhandle,
			struct efi_mem_list, link);
		struct efi_mem_desc *desc = &lmem->desc;
		uint64_t desc_len = desc->num_pages << EFI_PAGE_SHIFT;
		uint64_t desc_end = desc->physical_start + desc_len;
		uint64_t curmax = min(max_addr, desc_end);
		uint64_t ret = curmax - len;

		/* We only take memory from free RAM */
		if (desc->type != EFI_CONVENTIONAL_MEMORY)
			continue;

		/* Out of bounds for max_addr */
		if ((ret + len) > max_addr)
			continue;

		/* Out of bounds for upper map limit */
		if ((ret + len) > desc_end)
			continue;

		/* Out of bounds for lower map limit */
		if (ret < desc->physical_start)
			continue;

		/* Return the highest address in this map within bounds */
		return ret;
	}

	return 0;
}

/*
 * Allocate memory pages.
 *
 * @type		type of allocation to be performed
 * @memory_type		usage type of the allocated memory
 * @pages		number of pages to be allocated
 * @memory		allocated memory
 * @return		status code
 */
efi_status_t efi_allocate_pages(int type, int memory_type,
				efi_uintn_t pages, uint64_t *memory)
{
	u64 len = pages << EFI_PAGE_SHIFT;
	efi_status_t r = EFI_SUCCESS;
	uint64_t addr;

	if (!memory)
		return EFI_INVALID_PARAMETER;

	switch (type) {
	case EFI_ALLOCATE_ANY_PAGES:
		/* Any page */
		addr = efi_find_free_memory(len, -1ULL);
		if (!addr) {
			r = EFI_NOT_FOUND;
			break;
		}
		break;
	case EFI_ALLOCATE_MAX_ADDRESS:
		/* Max address */
		addr = efi_find_free_memory(len, *memory);
		if (!addr) {
			r = EFI_NOT_FOUND;
			break;
		}
		break;
	case EFI_ALLOCATE_ADDRESS:
		/* Exact address, reserve it. The addr is already in *memory. */
		addr = *memory;
		break;
	default:
		/* UEFI doesn't specify other allocation types */
		r = EFI_INVALID_PARAMETER;
		break;
	}

	if (r == EFI_SUCCESS) {
		uint64_t ret;

		/* Reserve that map in our memory maps */
		ret = efi_add_memory_map(addr, pages, memory_type, true);
		if (ret == addr) {
			*memory = (uintptr_t)map_sysmem(addr, len);
		} else {
			/* Map would overlap, bail out */
			r = EFI_OUT_OF_RESOURCES;
		}
	}

	return r;
}

void *efi_alloc(uint64_t len, int memory_type)
{
	uint64_t ret = 0;
	uint64_t pages = (len + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
	efi_status_t r;

	r = efi_allocate_pages(EFI_ALLOCATE_ANY_PAGES, memory_type, pages,
			       &ret);
	if (r == EFI_SUCCESS)
		return (void*)(uintptr_t)ret;

	return NULL;
}

/*
 * Free memory pages.
 *
 * @memory	start of the memory area to be freed
 * @pages	number of pages to be freed
 * @return	status code
 */
efi_status_t efi_free_pages(uint64_t memory, efi_uintn_t pages)
{
	uint64_t r = 0;
	uint64_t addr = map_to_sysmem((void *)(uintptr_t)memory);

	r = efi_add_memory_map(addr, pages, EFI_CONVENTIONAL_MEMORY, false);
	/* Merging of adjacent free regions is missing */

	if (r == addr)
		return EFI_SUCCESS;

	return EFI_NOT_FOUND;
}

/*
 * Allocate memory from pool.
 *
 * @pool_type	type of the pool from which memory is to be allocated
 * @size	number of bytes to be allocated
 * @buffer	allocated memory
 * @return	status code
 */
efi_status_t efi_allocate_pool(int pool_type, efi_uintn_t size, void **buffer)
{
	efi_status_t r;
	struct efi_pool_allocation *alloc;
	u64 num_pages = (size + sizeof(struct efi_pool_allocation) +
			 EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;

	if (!buffer)
		return EFI_INVALID_PARAMETER;

	if (size == 0) {
		*buffer = NULL;
		return EFI_SUCCESS;
	}

	r = efi_allocate_pages(EFI_ALLOCATE_ANY_PAGES, pool_type, num_pages,
			       (uint64_t *)&alloc);

	if (r == EFI_SUCCESS) {
		alloc->num_pages = num_pages;
		*buffer = alloc->data;
	}

	return r;
}

/*
 * Free memory from pool.
 *
 * @buffer	start of memory to be freed
 * @return	status code
 */
efi_status_t efi_free_pool(void *buffer)
{
	efi_status_t r;
	struct efi_pool_allocation *alloc;

	if (buffer == NULL)
		return EFI_INVALID_PARAMETER;

	alloc = container_of(buffer, struct efi_pool_allocation, data);
	/* Sanity check, was the supplied address returned by allocate_pool */
	assert(((uintptr_t)alloc & EFI_PAGE_MASK) == 0);

	r = efi_free_pages((uintptr_t)alloc, alloc->num_pages);

	return r;
}

/*
 * Get map describing memory usage.
 *
 * @memory_map_size	on entry the size, in bytes, of the memory map buffer,
 *			on exit the size of the copied memory map
 * @memory_map		buffer to which the memory map is written
 * @map_key		key for the memory map
 * @descriptor_size	size of an individual memory descriptor
 * @descriptor_version	version number of the memory descriptor structure
 * @return		status code
 */
efi_status_t efi_get_memory_map(efi_uintn_t *memory_map_size,
				struct efi_mem_desc *memory_map,
				efi_uintn_t *map_key,
				efi_uintn_t *descriptor_size,
				uint32_t *descriptor_version)
{
	efi_uintn_t map_size = 0;
	int map_entries = 0;
	struct list_head *lhandle;
	efi_uintn_t provided_map_size = *memory_map_size;

	if (!memory_map_size)
		return EFI_INVALID_PARAMETER;

	list_for_each(lhandle, &efi_mem)
		map_entries++;

	map_size = map_entries * sizeof(struct efi_mem_desc);

	*memory_map_size = map_size;

	if (provided_map_size < map_size)
		return EFI_BUFFER_TOO_SMALL;

	if (!memory_map)
		return EFI_INVALID_PARAMETER;

	if (descriptor_size)
		*descriptor_size = sizeof(struct efi_mem_desc);

	if (descriptor_version)
		*descriptor_version = EFI_MEMORY_DESCRIPTOR_VERSION;

	/* Copy list into array */
	/* Return the list in ascending order */
	memory_map = &memory_map[map_entries - 1];
	list_for_each(lhandle, &efi_mem) {
		struct efi_mem_list *lmem;

		lmem = list_entry(lhandle, struct efi_mem_list, link);
		*memory_map = lmem->desc;
		memory_map--;
	}

	if (map_key)
		*map_key = efi_memory_map_key;

	return EFI_SUCCESS;
}

__weak void efi_add_known_memory(void)
{
	int i;

	/* Add RAM */
	for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
		u64 ram_start = gd->bd->bi_dram[i].start;
		u64 ram_size = gd->bd->bi_dram[i].size;
		u64 start = (ram_start + EFI_PAGE_MASK) & ~EFI_PAGE_MASK;
		u64 pages = (ram_size + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;

		efi_add_memory_map(start, pages, EFI_CONVENTIONAL_MEMORY,
				   false);
	}
}

/* Add memory regions for U-Boot's memory and for the runtime services code */
static void add_u_boot_and_runtime(void)
{
	unsigned long runtime_start, runtime_end, runtime_pages;
	unsigned long uboot_start, uboot_pages;
	unsigned long uboot_stack_size = 16 * 1024 * 1024;

	/* Add U-Boot */
	uboot_start = (gd->start_addr_sp - uboot_stack_size) & ~EFI_PAGE_MASK;
	uboot_pages = (gd->ram_top - uboot_start) >> EFI_PAGE_SHIFT;
	efi_add_memory_map(uboot_start, uboot_pages, EFI_LOADER_DATA, false);

	/* Add Runtime Services */
	runtime_start = (ulong)&__efi_runtime_start & ~EFI_PAGE_MASK;
	runtime_end = (ulong)&__efi_runtime_stop;
	runtime_end = (runtime_end + EFI_PAGE_MASK) & ~EFI_PAGE_MASK;
	runtime_pages = (runtime_end - runtime_start) >> EFI_PAGE_SHIFT;
	efi_add_memory_map(runtime_start, runtime_pages,
			   EFI_RUNTIME_SERVICES_CODE, false);
}

int efi_memory_init(void)
{
	efi_add_known_memory();

	if (!IS_ENABLED(CONFIG_SANDBOX))
		add_u_boot_and_runtime();

#ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
	/* Request a 32bit 64MB bounce buffer region */
	uint64_t efi_bounce_buffer_addr = 0xffffffff;

	if (efi_allocate_pages(EFI_ALLOCATE_MAX_ADDRESS, EFI_LOADER_DATA,
			       (64 * 1024 * 1024) >> EFI_PAGE_SHIFT,
			       &efi_bounce_buffer_addr) != EFI_SUCCESS)
		return -1;

	efi_bounce_buffer = (void*)(uintptr_t)efi_bounce_buffer_addr;
#endif

	return 0;
}