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15#define pr_fmt(fmt) "cma: " fmt
16
17#ifdef CONFIG_CMA_DEBUG
18#ifndef DEBUG
19# define DEBUG
20#endif
21#endif
22#define CREATE_TRACE_POINTS
23
24#include <linux/memblock.h>
25#include <linux/err.h>
26#include <linux/mm.h>
27#include <linux/mutex.h>
28#include <linux/sizes.h>
29#include <linux/slab.h>
30#include <linux/log2.h>
31#include <linux/cma.h>
32#include <linux/highmem.h>
33#include <linux/io.h>
34#include <linux/kmemleak.h>
35#include <trace/events/cma.h>
36
37#include "cma.h"
38
39struct cma cma_areas[MAX_CMA_AREAS];
40unsigned cma_area_count;
41static DEFINE_MUTEX(cma_mutex);
42
43phys_addr_t cma_get_base(const struct cma *cma)
44{
45 return PFN_PHYS(cma->base_pfn);
46}
47
48unsigned long cma_get_size(const struct cma *cma)
49{
50 return cma->count << PAGE_SHIFT;
51}
52
53const char *cma_get_name(const struct cma *cma)
54{
55 return cma->name;
56}
57
58static unsigned long cma_bitmap_aligned_mask(const struct cma *cma,
59 unsigned int align_order)
60{
61 if (align_order <= cma->order_per_bit)
62 return 0;
63 return (1UL << (align_order - cma->order_per_bit)) - 1;
64}
65
66
67
68
69
70static unsigned long cma_bitmap_aligned_offset(const struct cma *cma,
71 unsigned int align_order)
72{
73 return (cma->base_pfn & ((1UL << align_order) - 1))
74 >> cma->order_per_bit;
75}
76
77static unsigned long cma_bitmap_pages_to_bits(const struct cma *cma,
78 unsigned long pages)
79{
80 return ALIGN(pages, 1UL << cma->order_per_bit) >> cma->order_per_bit;
81}
82
83static void cma_clear_bitmap(struct cma *cma, unsigned long pfn,
84 unsigned int count)
85{
86 unsigned long bitmap_no, bitmap_count;
87
88 bitmap_no = (pfn - cma->base_pfn) >> cma->order_per_bit;
89 bitmap_count = cma_bitmap_pages_to_bits(cma, count);
90
91 mutex_lock(&cma->lock);
92 bitmap_clear(cma->bitmap, bitmap_no, bitmap_count);
93 mutex_unlock(&cma->lock);
94}
95
96static void __init cma_activate_area(struct cma *cma)
97{
98 unsigned long base_pfn = cma->base_pfn, pfn = base_pfn;
99 unsigned i = cma->count >> pageblock_order;
100 struct zone *zone;
101
102 cma->bitmap = bitmap_zalloc(cma_bitmap_maxno(cma), GFP_KERNEL);
103 if (!cma->bitmap)
104 goto out_error;
105
106 WARN_ON_ONCE(!pfn_valid(pfn));
107 zone = page_zone(pfn_to_page(pfn));
108
109 do {
110 unsigned j;
111
112 base_pfn = pfn;
113 for (j = pageblock_nr_pages; j; --j, pfn++) {
114 WARN_ON_ONCE(!pfn_valid(pfn));
115
116
117
118
119
120
121 if (page_zone(pfn_to_page(pfn)) != zone)
122 goto not_in_zone;
123 }
124 init_cma_reserved_pageblock(pfn_to_page(base_pfn));
125 } while (--i);
126
127 mutex_init(&cma->lock);
128
129#ifdef CONFIG_CMA_DEBUGFS
130 INIT_HLIST_HEAD(&cma->mem_head);
131 spin_lock_init(&cma->mem_head_lock);
132#endif
133
134 return;
135
136not_in_zone:
137 bitmap_free(cma->bitmap);
138out_error:
139 cma->count = 0;
140 pr_err("CMA area %s could not be activated\n", cma->name);
141 return;
142}
143
144static int __init cma_init_reserved_areas(void)
145{
146 int i;
147
148 for (i = 0; i < cma_area_count; i++)
149 cma_activate_area(&cma_areas[i]);
150
151 return 0;
152}
153core_initcall(cma_init_reserved_areas);
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166
167int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
168 unsigned int order_per_bit,
169 const char *name,
170 struct cma **res_cma)
171{
172 struct cma *cma;
173 phys_addr_t alignment;
174
175
176 if (cma_area_count == ARRAY_SIZE(cma_areas)) {
177 pr_err("Not enough slots for CMA reserved regions!\n");
178 return -ENOSPC;
179 }
180
181 if (!size || !memblock_is_region_reserved(base, size))
182 return -EINVAL;
183
184
185 alignment = PAGE_SIZE <<
186 max_t(unsigned long, MAX_ORDER - 1, pageblock_order);
187
188
189 if (!IS_ALIGNED(alignment >> PAGE_SHIFT, 1 << order_per_bit))
190 return -EINVAL;
191
192 if (ALIGN(base, alignment) != base || ALIGN(size, alignment) != size)
193 return -EINVAL;
194
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198
199 cma = &cma_areas[cma_area_count];
200
201 if (name)
202 snprintf(cma->name, CMA_MAX_NAME, name);
203 else
204 snprintf(cma->name, CMA_MAX_NAME, "cma%d\n", cma_area_count);
205
206 cma->base_pfn = PFN_DOWN(base);
207 cma->count = size >> PAGE_SHIFT;
208 cma->order_per_bit = order_per_bit;
209 *res_cma = cma;
210 cma_area_count++;
211 totalcma_pages += (size / PAGE_SIZE);
212
213 return 0;
214}
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236int __init cma_declare_contiguous_nid(phys_addr_t base,
237 phys_addr_t size, phys_addr_t limit,
238 phys_addr_t alignment, unsigned int order_per_bit,
239 bool fixed, const char *name, struct cma **res_cma,
240 int nid)
241{
242 phys_addr_t memblock_end = memblock_end_of_DRAM();
243 phys_addr_t highmem_start;
244 int ret = 0;
245
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251
252 highmem_start = __pa(high_memory - 1) + 1;
253 pr_debug("%s(size %pa, base %pa, limit %pa alignment %pa)\n",
254 __func__, &size, &base, &limit, &alignment);
255
256 if (cma_area_count == ARRAY_SIZE(cma_areas)) {
257 pr_err("Not enough slots for CMA reserved regions!\n");
258 return -ENOSPC;
259 }
260
261 if (!size)
262 return -EINVAL;
263
264 if (alignment && !is_power_of_2(alignment))
265 return -EINVAL;
266
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271
272
273 alignment = max(alignment, (phys_addr_t)PAGE_SIZE <<
274 max_t(unsigned long, MAX_ORDER - 1, pageblock_order));
275 if (fixed && base & (alignment - 1)) {
276 ret = -EINVAL;
277 pr_err("Region at %pa must be aligned to %pa bytes\n",
278 &base, &alignment);
279 goto err;
280 }
281 base = ALIGN(base, alignment);
282 size = ALIGN(size, alignment);
283 limit &= ~(alignment - 1);
284
285 if (!base)
286 fixed = false;
287
288
289 if (!IS_ALIGNED(size >> PAGE_SHIFT, 1 << order_per_bit))
290 return -EINVAL;
291
292
293
294
295
296 if (fixed && base < highmem_start && base + size > highmem_start) {
297 ret = -EINVAL;
298 pr_err("Region at %pa defined on low/high memory boundary (%pa)\n",
299 &base, &highmem_start);
300 goto err;
301 }
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307
308 if (limit == 0 || limit > memblock_end)
309 limit = memblock_end;
310
311 if (base + size > limit) {
312 ret = -EINVAL;
313 pr_err("Size (%pa) of region at %pa exceeds limit (%pa)\n",
314 &size, &base, &limit);
315 goto err;
316 }
317
318
319 if (fixed) {
320 if (memblock_is_region_reserved(base, size) ||
321 memblock_reserve(base, size) < 0) {
322 ret = -EBUSY;
323 goto err;
324 }
325 } else {
326 phys_addr_t addr = 0;
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334 if (base < highmem_start && limit > highmem_start) {
335 addr = memblock_alloc_range_nid(size, alignment,
336 highmem_start, limit, nid, true);
337 limit = highmem_start;
338 }
339
340 if (!addr) {
341 addr = memblock_alloc_range_nid(size, alignment, base,
342 limit, nid, true);
343 if (!addr) {
344 ret = -ENOMEM;
345 goto err;
346 }
347 }
348
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353 kmemleak_ignore_phys(addr);
354 base = addr;
355 }
356
357 ret = cma_init_reserved_mem(base, size, order_per_bit, name, res_cma);
358 if (ret)
359 goto free_mem;
360
361 pr_info("Reserved %ld MiB at %pa\n", (unsigned long)size / SZ_1M,
362 &base);
363 return 0;
364
365free_mem:
366 memblock_free(base, size);
367err:
368 pr_err("Failed to reserve %ld MiB\n", (unsigned long)size / SZ_1M);
369 return ret;
370}
371
372#ifdef CONFIG_CMA_DEBUG
373static void cma_debug_show_areas(struct cma *cma)
374{
375 unsigned long next_zero_bit, next_set_bit, nr_zero;
376 unsigned long start = 0;
377 unsigned long nr_part, nr_total = 0;
378 unsigned long nbits = cma_bitmap_maxno(cma);
379
380 mutex_lock(&cma->lock);
381 pr_info("number of available pages: ");
382 for (;;) {
383 next_zero_bit = find_next_zero_bit(cma->bitmap, nbits, start);
384 if (next_zero_bit >= nbits)
385 break;
386 next_set_bit = find_next_bit(cma->bitmap, nbits, next_zero_bit);
387 nr_zero = next_set_bit - next_zero_bit;
388 nr_part = nr_zero << cma->order_per_bit;
389 pr_cont("%s%lu@%lu", nr_total ? "+" : "", nr_part,
390 next_zero_bit);
391 nr_total += nr_part;
392 start = next_zero_bit + nr_zero;
393 }
394 pr_cont("=> %lu free of %lu total pages\n", nr_total, cma->count);
395 mutex_unlock(&cma->lock);
396}
397#else
398static inline void cma_debug_show_areas(struct cma *cma) { }
399#endif
400
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411struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
412 bool no_warn)
413{
414 unsigned long mask, offset;
415 unsigned long pfn = -1;
416 unsigned long start = 0;
417 unsigned long bitmap_maxno, bitmap_no, bitmap_count;
418 size_t i;
419 struct page *page = NULL;
420 int ret = -ENOMEM;
421
422 if (!cma || !cma->count || !cma->bitmap)
423 return NULL;
424
425 pr_debug("%s(cma %p, count %zu, align %d)\n", __func__, (void *)cma,
426 count, align);
427
428 if (!count)
429 return NULL;
430
431 mask = cma_bitmap_aligned_mask(cma, align);
432 offset = cma_bitmap_aligned_offset(cma, align);
433 bitmap_maxno = cma_bitmap_maxno(cma);
434 bitmap_count = cma_bitmap_pages_to_bits(cma, count);
435
436 if (bitmap_count > bitmap_maxno)
437 return NULL;
438
439 for (;;) {
440 mutex_lock(&cma->lock);
441 bitmap_no = bitmap_find_next_zero_area_off(cma->bitmap,
442 bitmap_maxno, start, bitmap_count, mask,
443 offset);
444 if (bitmap_no >= bitmap_maxno) {
445 mutex_unlock(&cma->lock);
446 break;
447 }
448 bitmap_set(cma->bitmap, bitmap_no, bitmap_count);
449
450
451
452
453
454 mutex_unlock(&cma->lock);
455
456 pfn = cma->base_pfn + (bitmap_no << cma->order_per_bit);
457 mutex_lock(&cma_mutex);
458 ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA,
459 GFP_KERNEL | (no_warn ? __GFP_NOWARN : 0));
460 mutex_unlock(&cma_mutex);
461 if (ret == 0) {
462 page = pfn_to_page(pfn);
463 break;
464 }
465
466 cma_clear_bitmap(cma, pfn, count);
467 if (ret != -EBUSY)
468 break;
469
470 pr_debug("%s(): memory range at %p is busy, retrying\n",
471 __func__, pfn_to_page(pfn));
472
473 start = bitmap_no + mask + 1;
474 }
475
476 trace_cma_alloc(pfn, page, count, align);
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482
483 if (page) {
484 for (i = 0; i < count; i++)
485 page_kasan_tag_reset(page + i);
486 }
487
488 if (ret && !no_warn) {
489 pr_err("%s: alloc failed, req-size: %zu pages, ret: %d\n",
490 __func__, count, ret);
491 cma_debug_show_areas(cma);
492 }
493
494 pr_debug("%s(): returned %p\n", __func__, page);
495 return page;
496}
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508bool cma_release(struct cma *cma, const struct page *pages, unsigned int count)
509{
510 unsigned long pfn;
511
512 if (!cma || !pages)
513 return false;
514
515 pr_debug("%s(page %p)\n", __func__, (void *)pages);
516
517 pfn = page_to_pfn(pages);
518
519 if (pfn < cma->base_pfn || pfn >= cma->base_pfn + cma->count)
520 return false;
521
522 VM_BUG_ON(pfn + count > cma->base_pfn + cma->count);
523
524 free_contig_range(pfn, count);
525 cma_clear_bitmap(cma, pfn, count);
526 trace_cma_release(pfn, pages, count);
527
528 return true;
529}
530
531int cma_for_each_area(int (*it)(struct cma *cma, void *data), void *data)
532{
533 int i;
534
535 for (i = 0; i < cma_area_count; i++) {
536 int ret = it(&cma_areas[i], data);
537
538 if (ret)
539 return ret;
540 }
541
542 return 0;
543}
544