1/*
2 * Procedures for maintaining information about logical memory blocks.
3 *
4 * Peter Bergner, IBM Corp.	June 2001.
5 * Copyright (C) 2001 Peter Bergner.
6 *
7 *      This program is free software; you can redistribute it and/or
8 *      modify it under the terms of the GNU General Public License
9 *      as published by the Free Software Foundation; either version
10 *      2 of the License, or (at your option) any later version.
11 */
12
13#include <linux/kernel.h>
14#include <linux/init.h>
15#include <linux/bitops.h>
16#include <linux/memblock.h>
17
18#define MEMBLOCK_ALLOC_ANYWHERE	0
19
20struct memblock memblock;
21
22static int memblock_debug;
23
24static int __init early_memblock(char *p)
25{
26	if (p && strstr(p, "debug"))
27		memblock_debug = 1;
28	return 0;
29}
30early_param("memblock", early_memblock);
31
32static void memblock_dump(struct memblock_region *region, char *name)
33{
34	unsigned long long base, size;
35	int i;
36
37	pr_info(" %s.cnt  = 0x%lx\n", name, region->cnt);
38
39	for (i = 0; i < region->cnt; i++) {
40		base = region->region[i].base;
41		size = region->region[i].size;
42
43		pr_info(" %s[0x%x]\t0x%016llx - 0x%016llx, 0x%llx bytes\n",
44		    name, i, base, base + size - 1, size);
45	}
46}
47
48void memblock_dump_all(void)
49{
50	if (!memblock_debug)
51		return;
52
53	pr_info("MEMBLOCK configuration:\n");
54	pr_info(" rmo_size    = 0x%llx\n", (unsigned long long)memblock.rmo_size);
55	pr_info(" memory.size = 0x%llx\n", (unsigned long long)memblock.memory.size);
56
57	memblock_dump(&memblock.memory, "memory");
58	memblock_dump(&memblock.reserved, "reserved");
59}
60
61static unsigned long memblock_addrs_overlap(u64 base1, u64 size1, u64 base2,
62					u64 size2)
63{
64	return ((base1 < (base2 + size2)) && (base2 < (base1 + size1)));
65}
66
67static long memblock_addrs_adjacent(u64 base1, u64 size1, u64 base2, u64 size2)
68{
69	if (base2 == base1 + size1)
70		return 1;
71	else if (base1 == base2 + size2)
72		return -1;
73
74	return 0;
75}
76
77static long memblock_regions_adjacent(struct memblock_region *rgn,
78		unsigned long r1, unsigned long r2)
79{
80	u64 base1 = rgn->region[r1].base;
81	u64 size1 = rgn->region[r1].size;
82	u64 base2 = rgn->region[r2].base;
83	u64 size2 = rgn->region[r2].size;
84
85	return memblock_addrs_adjacent(base1, size1, base2, size2);
86}
87
88static void memblock_remove_region(struct memblock_region *rgn, unsigned long r)
89{
90	unsigned long i;
91
92	for (i = r; i < rgn->cnt - 1; i++) {
93		rgn->region[i].base = rgn->region[i + 1].base;
94		rgn->region[i].size = rgn->region[i + 1].size;
95	}
96	rgn->cnt--;
97}
98
99/* Assumption: base addr of region 1 < base addr of region 2 */
100static void memblock_coalesce_regions(struct memblock_region *rgn,
101		unsigned long r1, unsigned long r2)
102{
103	rgn->region[r1].size += rgn->region[r2].size;
104	memblock_remove_region(rgn, r2);
105}
106
107void __init memblock_init(void)
108{
109	/* Create a dummy zero size MEMBLOCK which will get coalesced away later.
110	 * This simplifies the memblock_add() code below...
111	 */
112	memblock.memory.region[0].base = 0;
113	memblock.memory.region[0].size = 0;
114	memblock.memory.cnt = 1;
115
116	/* Ditto. */
117	memblock.reserved.region[0].base = 0;
118	memblock.reserved.region[0].size = 0;
119	memblock.reserved.cnt = 1;
120}
121
122void __init memblock_analyze(void)
123{
124	int i;
125
126	memblock.memory.size = 0;
127
128	for (i = 0; i < memblock.memory.cnt; i++)
129		memblock.memory.size += memblock.memory.region[i].size;
130}
131
132static long memblock_add_region(struct memblock_region *rgn, u64 base, u64 size)
133{
134	unsigned long coalesced = 0;
135	long adjacent, i;
136
137	if ((rgn->cnt == 1) && (rgn->region[0].size == 0)) {
138		rgn->region[0].base = base;
139		rgn->region[0].size = size;
140		return 0;
141	}
142
143	/* First try and coalesce this MEMBLOCK with another. */
144	for (i = 0; i < rgn->cnt; i++) {
145		u64 rgnbase = rgn->region[i].base;
146		u64 rgnsize = rgn->region[i].size;
147
148		if ((rgnbase == base) && (rgnsize == size))
149			/* Already have this region, so we're done */
150			return 0;
151
152		adjacent = memblock_addrs_adjacent(base, size, rgnbase, rgnsize);
153		if (adjacent > 0) {
154			rgn->region[i].base -= size;
155			rgn->region[i].size += size;
156			coalesced++;
157			break;
158		} else if (adjacent < 0) {
159			rgn->region[i].size += size;
160			coalesced++;
161			break;
162		}
163	}
164
165	if ((i < rgn->cnt - 1) && memblock_regions_adjacent(rgn, i, i+1)) {
166		memblock_coalesce_regions(rgn, i, i+1);
167		coalesced++;
168	}
169
170	if (coalesced)
171		return coalesced;
172	if (rgn->cnt >= MAX_MEMBLOCK_REGIONS)
173		return -1;
174
175	/* Couldn't coalesce the MEMBLOCK, so add it to the sorted table. */
176	for (i = rgn->cnt - 1; i >= 0; i--) {
177		if (base < rgn->region[i].base) {
178			rgn->region[i+1].base = rgn->region[i].base;
179			rgn->region[i+1].size = rgn->region[i].size;
180		} else {
181			rgn->region[i+1].base = base;
182			rgn->region[i+1].size = size;
183			break;
184		}
185	}
186
187	if (base < rgn->region[0].base) {
188		rgn->region[0].base = base;
189		rgn->region[0].size = size;
190	}
191	rgn->cnt++;
192
193	return 0;
194}
195
196long memblock_add(u64 base, u64 size)
197{
198	struct memblock_region *_rgn = &memblock.memory;
199
200	/* On pSeries LPAR systems, the first MEMBLOCK is our RMO region. */
201	if (base == 0)
202		memblock.rmo_size = size;
203
204	return memblock_add_region(_rgn, base, size);
205
206}
207
208static long __memblock_remove(struct memblock_region *rgn, u64 base, u64 size)
209{
210	u64 rgnbegin, rgnend;
211	u64 end = base + size;
212	int i;
213
214	rgnbegin = rgnend = 0; /* supress gcc warnings */
215
216	/* Find the region where (base, size) belongs to */
217	for (i=0; i < rgn->cnt; i++) {
218		rgnbegin = rgn->region[i].base;
219		rgnend = rgnbegin + rgn->region[i].size;
220
221		if ((rgnbegin <= base) && (end <= rgnend))
222			break;
223	}
224
225	/* Didn't find the region */
226	if (i == rgn->cnt)
227		return -1;
228
229	/* Check to see if we are removing entire region */
230	if ((rgnbegin == base) && (rgnend == end)) {
231		memblock_remove_region(rgn, i);
232		return 0;
233	}
234
235	/* Check to see if region is matching at the front */
236	if (rgnbegin == base) {
237		rgn->region[i].base = end;
238		rgn->region[i].size -= size;
239		return 0;
240	}
241
242	/* Check to see if the region is matching at the end */
243	if (rgnend == end) {
244		rgn->region[i].size -= size;
245		return 0;
246	}
247
248	/*
249	 * We need to split the entry -  adjust the current one to the
250	 * beginging of the hole and add the region after hole.
251	 */
252	rgn->region[i].size = base - rgn->region[i].base;
253	return memblock_add_region(rgn, end, rgnend - end);
254}
255
256long memblock_remove(u64 base, u64 size)
257{
258	return __memblock_remove(&memblock.memory, base, size);
259}
260
261long __init memblock_free(u64 base, u64 size)
262{
263	return __memblock_remove(&memblock.reserved, base, size);
264}
265
266long __init memblock_reserve(u64 base, u64 size)
267{
268	struct memblock_region *_rgn = &memblock.reserved;
269
270	BUG_ON(0 == size);
271
272	return memblock_add_region(_rgn, base, size);
273}
274
275long memblock_overlaps_region(struct memblock_region *rgn, u64 base, u64 size)
276{
277	unsigned long i;
278
279	for (i = 0; i < rgn->cnt; i++) {
280		u64 rgnbase = rgn->region[i].base;
281		u64 rgnsize = rgn->region[i].size;
282		if (memblock_addrs_overlap(base, size, rgnbase, rgnsize))
283			break;
284	}
285
286	return (i < rgn->cnt) ? i : -1;
287}
288
289static u64 memblock_align_down(u64 addr, u64 size)
290{
291	return addr & ~(size - 1);
292}
293
294static u64 memblock_align_up(u64 addr, u64 size)
295{
296	return (addr + (size - 1)) & ~(size - 1);
297}
298
299static u64 __init memblock_alloc_nid_unreserved(u64 start, u64 end,
300					   u64 size, u64 align)
301{
302	u64 base, res_base;
303	long j;
304
305	base = memblock_align_down((end - size), align);
306	while (start <= base) {
307		j = memblock_overlaps_region(&memblock.reserved, base, size);
308		if (j < 0) {
309			/* this area isn't reserved, take it */
310			if (memblock_add_region(&memblock.reserved, base, size) < 0)
311				base = ~(u64)0;
312			return base;
313		}
314		res_base = memblock.reserved.region[j].base;
315		if (res_base < size)
316			break;
317		base = memblock_align_down(res_base - size, align);
318	}
319
320	return ~(u64)0;
321}
322
323static u64 __init memblock_alloc_nid_region(struct memblock_property *mp,
324				       u64 (*nid_range)(u64, u64, int *),
325				       u64 size, u64 align, int nid)
326{
327	u64 start, end;
328
329	start = mp->base;
330	end = start + mp->size;
331
332	start = memblock_align_up(start, align);
333	while (start < end) {
334		u64 this_end;
335		int this_nid;
336
337		this_end = nid_range(start, end, &this_nid);
338		if (this_nid == nid) {
339			u64 ret = memblock_alloc_nid_unreserved(start, this_end,
340							   size, align);
341			if (ret != ~(u64)0)
342				return ret;
343		}
344		start = this_end;
345	}
346
347	return ~(u64)0;
348}
349
350u64 __init memblock_alloc_nid(u64 size, u64 align, int nid,
351			 u64 (*nid_range)(u64 start, u64 end, int *nid))
352{
353	struct memblock_region *mem = &memblock.memory;
354	int i;
355
356	BUG_ON(0 == size);
357
358	size = memblock_align_up(size, align);
359
360	for (i = 0; i < mem->cnt; i++) {
361		u64 ret = memblock_alloc_nid_region(&mem->region[i],
362					       nid_range,
363					       size, align, nid);
364		if (ret != ~(u64)0)
365			return ret;
366	}
367
368	return memblock_alloc(size, align);
369}
370
371u64 __init memblock_alloc(u64 size, u64 align)
372{
373	return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ANYWHERE);
374}
375
376u64 __init memblock_alloc_base(u64 size, u64 align, u64 max_addr)
377{
378	u64 alloc;
379
380	alloc = __memblock_alloc_base(size, align, max_addr);
381
382	if (alloc == 0)
383		panic("ERROR: Failed to allocate 0x%llx bytes below 0x%llx.\n",
384		      (unsigned long long) size, (unsigned long long) max_addr);
385
386	return alloc;
387}
388
389u64 __init __memblock_alloc_base(u64 size, u64 align, u64 max_addr)
390{
391	long i, j;
392	u64 base = 0;
393	u64 res_base;
394
395	BUG_ON(0 == size);
396
397	size = memblock_align_up(size, align);
398
399	/* On some platforms, make sure we allocate lowmem */
400	/* Note that MEMBLOCK_REAL_LIMIT may be MEMBLOCK_ALLOC_ANYWHERE */
401	if (max_addr == MEMBLOCK_ALLOC_ANYWHERE)
402		max_addr = MEMBLOCK_REAL_LIMIT;
403
404	for (i = memblock.memory.cnt - 1; i >= 0; i--) {
405		u64 memblockbase = memblock.memory.region[i].base;
406		u64 memblocksize = memblock.memory.region[i].size;
407
408		if (memblocksize < size)
409			continue;
410		if (max_addr == MEMBLOCK_ALLOC_ANYWHERE)
411			base = memblock_align_down(memblockbase + memblocksize - size, align);
412		else if (memblockbase < max_addr) {
413			base = min(memblockbase + memblocksize, max_addr);
414			base = memblock_align_down(base - size, align);
415		} else
416			continue;
417
418		while (base && memblockbase <= base) {
419			j = memblock_overlaps_region(&memblock.reserved, base, size);
420			if (j < 0) {
421				/* this area isn't reserved, take it */
422				if (memblock_add_region(&memblock.reserved, base, size) < 0)
423					return 0;
424				return base;
425			}
426			res_base = memblock.reserved.region[j].base;
427			if (res_base < size)
428				break;
429			base = memblock_align_down(res_base - size, align);
430		}
431	}
432	return 0;
433}
434
435/* You must call memblock_analyze() before this. */
436u64 __init memblock_phys_mem_size(void)
437{
438	return memblock.memory.size;
439}
440
441u64 memblock_end_of_DRAM(void)
442{
443	int idx = memblock.memory.cnt - 1;
444
445	return (memblock.memory.region[idx].base + memblock.memory.region[idx].size);
446}
447
448/* You must call memblock_analyze() after this. */
449void __init memblock_enforce_memory_limit(u64 memory_limit)
450{
451	unsigned long i;
452	u64 limit;
453	struct memblock_property *p;
454
455	if (!memory_limit)
456		return;
457
458	/* Truncate the memblock regions to satisfy the memory limit. */
459	limit = memory_limit;
460	for (i = 0; i < memblock.memory.cnt; i++) {
461		if (limit > memblock.memory.region[i].size) {
462			limit -= memblock.memory.region[i].size;
463			continue;
464		}
465
466		memblock.memory.region[i].size = limit;
467		memblock.memory.cnt = i + 1;
468		break;
469	}
470
471	if (memblock.memory.region[0].size < memblock.rmo_size)
472		memblock.rmo_size = memblock.memory.region[0].size;
473
474	memory_limit = memblock_end_of_DRAM();
475
476	/* And truncate any reserves above the limit also. */
477	for (i = 0; i < memblock.reserved.cnt; i++) {
478		p = &memblock.reserved.region[i];
479
480		if (p->base > memory_limit)
481			p->size = 0;
482		else if ((p->base + p->size) > memory_limit)
483			p->size = memory_limit - p->base;
484
485		if (p->size == 0) {
486			memblock_remove_region(&memblock.reserved, i);
487			i--;
488		}
489	}
490}
491
492int __init memblock_is_reserved(u64 addr)
493{
494	int i;
495
496	for (i = 0; i < memblock.reserved.cnt; i++) {
497		u64 upper = memblock.reserved.region[i].base +
498			memblock.reserved.region[i].size - 1;
499		if ((addr >= memblock.reserved.region[i].base) && (addr <= upper))
500			return 1;
501	}
502	return 0;
503}
504
505int memblock_is_region_reserved(u64 base, u64 size)
506{
507	return memblock_overlaps_region(&memblock.reserved, base, size) >= 0;
508}
509
510/*
511 * Given a <base, len>, find which memory regions belong to this range.
512 * Adjust the request and return a contiguous chunk.
513 */
514int memblock_find(struct memblock_property *res)
515{
516	int i;
517	u64 rstart, rend;
518
519	rstart = res->base;
520	rend = rstart + res->size - 1;
521
522	for (i = 0; i < memblock.memory.cnt; i++) {
523		u64 start = memblock.memory.region[i].base;
524		u64 end = start + memblock.memory.region[i].size - 1;
525
526		if (start > rend)
527			return -1;
528
529		if ((end >= rstart) && (start < rend)) {
530			/* adjust the request */
531			if (rstart < start)
532				rstart = start;
533			if (rend > end)
534				rend = end;
535			res->base = rstart;
536			res->size = rend - rstart + 1;
537			return 0;
538		}
539	}
540	return -1;
541}
542