summaryrefslogtreecommitdiffstats
path: root/mm/memblock.c
blob: e264e8c7089295f71651382e28674ce94f7fae03 (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
/*
 * Procedures for maintaining information about logical memory blocks.
 *
 * Peter Bergner, IBM Corp.	June 2001.
 * Copyright (C) 2001 Peter Bergner.
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <linux/memblock.h>

#define MEMBLOCK_ALLOC_ANYWHERE	0

struct memblock memblock;

static int memblock_debug;

static int __init early_memblock(char *p)
{
	if (p && strstr(p, "debug"))
		memblock_debug = 1;
	return 0;
}
early_param("memblock", early_memblock);

static void memblock_dump(struct memblock_type *region, char *name)
{
	unsigned long long base, size;
	int i;

	pr_info(" %s.cnt  = 0x%lx\n", name, region->cnt);

	for (i = 0; i < region->cnt; i++) {
		base = region->regions[i].base;
		size = region->regions[i].size;

		pr_info(" %s[0x%x]\t0x%016llx - 0x%016llx, 0x%llx bytes\n",
		    name, i, base, base + size - 1, size);
	}
}

void memblock_dump_all(void)
{
	if (!memblock_debug)
		return;

	pr_info("MEMBLOCK configuration:\n");
	pr_info(" rmo_size    = 0x%llx\n", (unsigned long long)memblock.rmo_size);
	pr_info(" memory.size = 0x%llx\n", (unsigned long long)memblock.memory.size);

	memblock_dump(&memblock.memory, "memory");
	memblock_dump(&memblock.reserved, "reserved");
}

static unsigned long memblock_addrs_overlap(u64 base1, u64 size1, u64 base2,
					u64 size2)
{
	return ((base1 < (base2 + size2)) && (base2 < (base1 + size1)));
}

static long memblock_addrs_adjacent(u64 base1, u64 size1, u64 base2, u64 size2)
{
	if (base2 == base1 + size1)
		return 1;
	else if (base1 == base2 + size2)
		return -1;

	return 0;
}

static long memblock_regions_adjacent(struct memblock_type *type,
		unsigned long r1, unsigned long r2)
{
	u64 base1 = type->regions[r1].base;
	u64 size1 = type->regions[r1].size;
	u64 base2 = type->regions[r2].base;
	u64 size2 = type->regions[r2].size;

	return memblock_addrs_adjacent(base1, size1, base2, size2);
}

static void memblock_remove_region(struct memblock_type *type, unsigned long r)
{
	unsigned long i;

	for (i = r; i < type->cnt - 1; i++) {
		type->regions[i].base = type->regions[i + 1].base;
		type->regions[i].size = type->regions[i + 1].size;
	}
	type->cnt--;
}

/* Assumption: base addr of region 1 < base addr of region 2 */
static void memblock_coalesce_regions(struct memblock_type *type,
		unsigned long r1, unsigned long r2)
{
	type->regions[r1].size += type->regions[r2].size;
	memblock_remove_region(type, r2);
}

void __init memblock_init(void)
{
	/* Create a dummy zero size MEMBLOCK which will get coalesced away later.
	 * This simplifies the memblock_add() code below...
	 */
	memblock.memory.regions[0].base = 0;
	memblock.memory.regions[0].size = 0;
	memblock.memory.cnt = 1;

	/* Ditto. */
	memblock.reserved.regions[0].base = 0;
	memblock.reserved.regions[0].size = 0;
	memblock.reserved.cnt = 1;
}

void __init memblock_analyze(void)
{
	int i;

	memblock.memory.size = 0;

	for (i = 0; i < memblock.memory.cnt; i++)
		memblock.memory.size += memblock.memory.regions[i].size;
}

static long memblock_add_region(struct memblock_type *type, u64 base, u64 size)
{
	unsigned long coalesced = 0;
	long adjacent, i;

	if ((type->cnt == 1) && (type->regions[0].size == 0)) {
		type->regions[0].base = base;
		type->regions[0].size = size;
		return 0;
	}

	/* First try and coalesce this MEMBLOCK with another. */
	for (i = 0; i < type->cnt; i++) {
		u64 rgnbase = type->regions[i].base;
		u64 rgnsize = type->regions[i].size;

		if ((rgnbase == base) && (rgnsize == size))
			/* Already have this region, so we're done */
			return 0;

		adjacent = memblock_addrs_adjacent(base, size, rgnbase, rgnsize);
		if (adjacent > 0) {
			type->regions[i].base -= size;
			type->regions[i].size += size;
			coalesced++;
			break;
		} else if (adjacent < 0) {
			type->regions[i].size += size;
			coalesced++;
			break;
		}
	}

	if ((i < type->cnt - 1) && memblock_regions_adjacent(type, i, i+1)) {
		memblock_coalesce_regions(type, i, i+1);
		coalesced++;
	}

	if (coalesced)
		return coalesced;
	if (type->cnt >= MAX_MEMBLOCK_REGIONS)
		return -1;

	/* Couldn't coalesce the MEMBLOCK, so add it to the sorted table. */
	for (i = type->cnt - 1; i >= 0; i--) {
		if (base < type->regions[i].base) {
			type->regions[i+1].base = type->regions[i].base;
			type->regions[i+1].size = type->regions[i].size;
		} else {
			type->regions[i+1].base = base;
			type->regions[i+1].size = size;
			break;
		}
	}

	if (base < type->regions[0].base) {
		type->regions[0].base = base;
		type->regions[0].size = size;
	}
	type->cnt++;

	return 0;
}

long memblock_add(u64 base, u64 size)
{
	/* On pSeries LPAR systems, the first MEMBLOCK is our RMO region. */
	if (base == 0)
		memblock.rmo_size = size;

	return memblock_add_region(&memblock.memory, base, size);

}

static long __memblock_remove(struct memblock_type *type, u64 base, u64 size)
{
	u64 rgnbegin, rgnend;
	u64 end = base + size;
	int i;

	rgnbegin = rgnend = 0; /* supress gcc warnings */

	/* Find the region where (base, size) belongs to */
	for (i=0; i < type->cnt; i++) {
		rgnbegin = type->regions[i].base;
		rgnend = rgnbegin + type->regions[i].size;

		if ((rgnbegin <= base) && (end <= rgnend))
			break;
	}

	/* Didn't find the region */
	if (i == type->cnt)
		return -1;

	/* Check to see if we are removing entire region */
	if ((rgnbegin == base) && (rgnend == end)) {
		memblock_remove_region(type, i);
		return 0;
	}

	/* Check to see if region is matching at the front */
	if (rgnbegin == base) {
		type->regions[i].base = end;
		type->regions[i].size -= size;
		return 0;
	}

	/* Check to see if the region is matching at the end */
	if (rgnend == end) {
		type->regions[i].size -= size;
		return 0;
	}

	/*
	 * We need to split the entry -  adjust the current one to the
	 * beginging of the hole and add the region after hole.
	 */
	type->regions[i].size = base - type->regions[i].base;
	return memblock_add_region(type, end, rgnend - end);
}

long memblock_remove(u64 base, u64 size)
{
	return __memblock_remove(&memblock.memory, base, size);
}

long __init memblock_free(u64 base, u64 size)
{
	return __memblock_remove(&memblock.reserved, base, size);
}

long __init memblock_reserve(u64 base, u64 size)
{
	struct memblock_type *_rgn = &memblock.reserved;

	BUG_ON(0 == size);

	return memblock_add_region(_rgn, base, size);
}

long memblock_overlaps_region(struct memblock_type *type, u64 base, u64 size)
{
	unsigned long i;

	for (i = 0; i < type->cnt; i++) {
		u64 rgnbase = type->regions[i].base;
		u64 rgnsize = type->regions[i].size;
		if (memblock_addrs_overlap(base, size, rgnbase, rgnsize))
			break;
	}

	return (i < type->cnt) ? i : -1;
}

static u64 memblock_align_down(u64 addr, u64 size)
{
	return addr & ~(size - 1);
}

static u64 memblock_align_up(u64 addr, u64 size)
{
	return (addr + (size - 1)) & ~(size - 1);
}

static u64 __init memblock_alloc_region(u64 start, u64 end,
				   u64 size, u64 align)
{
	u64 base, res_base;
	long j;

	base = memblock_align_down((end - size), align);
	while (start <= base) {
		j = memblock_overlaps_region(&memblock.reserved, base, size);
		if (j < 0) {
			/* this area isn't reserved, take it */
			if (memblock_add_region(&memblock.reserved, base, size) < 0)
				base = ~(u64)0;
			return base;
		}
		res_base = memblock.reserved.regions[j].base;
		if (res_base < size)
			break;
		base = memblock_align_down(res_base - size, align);
	}

	return ~(u64)0;
}

u64 __weak __init memblock_nid_range(u64 start, u64 end, int *nid)
{
	*nid = 0;

	return end;
}

static u64 __init memblock_alloc_nid_region(struct memblock_region *mp,
				       u64 size, u64 align, int nid)
{
	u64 start, end;

	start = mp->base;
	end = start + mp->size;

	start = memblock_align_up(start, align);
	while (start < end) {
		u64 this_end;
		int this_nid;

		this_end = memblock_nid_range(start, end, &this_nid);
		if (this_nid == nid) {
			u64 ret = memblock_alloc_region(start, this_end, size, align);
			if (ret != ~(u64)0)
				return ret;
		}
		start = this_end;
	}

	return ~(u64)0;
}

u64 __init memblock_alloc_nid(u64 size, u64 align, int nid)
{
	struct memblock_type *mem = &memblock.memory;
	int i;

	BUG_ON(0 == size);

	/* We do a bottom-up search for a region with the right
	 * nid since that's easier considering how memblock_nid_range()
	 * works
	 */
	size = memblock_align_up(size, align);

	for (i = 0; i < mem->cnt; i++) {
		u64 ret = memblock_alloc_nid_region(&mem->regions[i],
					       size, align, nid);
		if (ret != ~(u64)0)
			return ret;
	}

	return memblock_alloc(size, align);
}

u64 __init memblock_alloc(u64 size, u64 align)
{
	return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ANYWHERE);
}

u64 __init memblock_alloc_base(u64 size, u64 align, u64 max_addr)
{
	u64 alloc;

	alloc = __memblock_alloc_base(size, align, max_addr);

	if (alloc == 0)
		panic("ERROR: Failed to allocate 0x%llx bytes below 0x%llx.\n",
		      (unsigned long long) size, (unsigned long long) max_addr);

	return alloc;
}

u64 __init __memblock_alloc_base(u64 size, u64 align, u64 max_addr)
{
	long i;
	u64 base = 0;
	u64 res_base;

	BUG_ON(0 == size);

	size = memblock_align_up(size, align);

	/* On some platforms, make sure we allocate lowmem */
	/* Note that MEMBLOCK_REAL_LIMIT may be MEMBLOCK_ALLOC_ANYWHERE */
	if (max_addr == MEMBLOCK_ALLOC_ANYWHERE)
		max_addr = MEMBLOCK_REAL_LIMIT;

	/* Pump up max_addr */
	if (max_addr == MEMBLOCK_ALLOC_ANYWHERE)
		max_addr = ~(u64)0;

	/* We do a top-down search, this tends to limit memory
	 * fragmentation by keeping early boot allocs near the
	 * top of memory
	 */
	for (i = memblock.memory.cnt - 1; i >= 0; i--) {
		u64 memblockbase = memblock.memory.regions[i].base;
		u64 memblocksize = memblock.memory.regions[i].size;

		if (memblocksize < size)
			continue;
		base = min(memblockbase + memblocksize, max_addr);
		res_base = memblock_alloc_region(memblockbase, base, size, align);
		if (res_base != ~(u64)0)
			return res_base;
	}
	return 0;
}

/* You must call memblock_analyze() before this. */
u64 __init memblock_phys_mem_size(void)
{
	return memblock.memory.size;
}

u64 memblock_end_of_DRAM(void)
{
	int idx = memblock.memory.cnt - 1;

	return (memblock.memory.regions[idx].base + memblock.memory.regions[idx].size);
}

/* You must call memblock_analyze() after this. */
void __init memblock_enforce_memory_limit(u64 memory_limit)
{
	unsigned long i;
	u64 limit;
	struct memblock_region *p;

	if (!memory_limit)
		return;

	/* Truncate the memblock regions to satisfy the memory limit. */
	limit = memory_limit;
	for (i = 0; i < memblock.memory.cnt; i++) {
		if (limit > memblock.memory.regions[i].size) {
			limit -= memblock.memory.regions[i].size;
			continue;
		}

		memblock.memory.regions[i].size = limit;
		memblock.memory.cnt = i + 1;
		break;
	}

	if (memblock.memory.regions[0].size < memblock.rmo_size)
		memblock.rmo_size = memblock.memory.regions[0].size;

	memory_limit = memblock_end_of_DRAM();

	/* And truncate any reserves above the limit also. */
	for (i = 0; i < memblock.reserved.cnt; i++) {
		p = &memblock.reserved.regions[i];

		if (p->base > memory_limit)
			p->size = 0;
		else if ((p->base + p->size) > memory_limit)
			p->size = memory_limit - p->base;

		if (p->size == 0) {
			memblock_remove_region(&memblock.reserved, i);
			i--;
		}
	}
}

static int memblock_search(struct memblock_type *type, u64 addr)
{
	unsigned int left = 0, right = type->cnt;

	do {
		unsigned int mid = (right + left) / 2;

		if (addr < type->regions[mid].base)
			right = mid;
		else if (addr >= (type->regions[mid].base +
				  type->regions[mid].size))
			left = mid + 1;
		else
			return mid;
	} while (left < right);
	return -1;
}

int __init memblock_is_reserved(u64 addr)
{
	return memblock_search(&memblock.reserved, addr) != -1;
}

int memblock_is_memory(u64 addr)
{
	return memblock_search(&memblock.memory, addr) != -1;
}

int memblock_is_region_memory(u64 base, u64 size)
{
	int idx = memblock_search(&memblock.reserved, base);

	if (idx == -1)
		return 0;
	return memblock.reserved.regions[idx].base <= base &&
		(memblock.reserved.regions[idx].base +
		 memblock.reserved.regions[idx].size) >= (base + size);
}

int memblock_is_region_reserved(u64 base, u64 size)
{
	return memblock_overlaps_region(&memblock.reserved, base, size) >= 0;
}

OpenPOWER on IntegriCloud