Root/mm/memblock.c

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

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