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19#define pr_fmt(fmt) "cma: " fmt
20
21#ifdef CONFIG_CMA_DEBUG
22#ifndef DEBUG
23# define DEBUG
24#endif
25#endif
26#define CREATE_TRACE_POINTS
27
28#include <linux/memblock.h>
29#include <linux/err.h>
30#include <linux/mm.h>
31#include <linux/mutex.h>
32#include <linux/sizes.h>
33#include <linux/slab.h>
34#include <linux/log2.h>
35#include <linux/cma.h>
36#include <linux/highmem.h>
37#include <linux/io.h>
38#include <linux/kmemleak.h>
39#include <trace/events/cma.h>
40
41#include "cma.h"
42
43struct cma cma_areas[MAX_CMA_AREAS];
44unsigned cma_area_count;
45static DEFINE_MUTEX(cma_mutex);
46
47phys_addr_t cma_get_base(const struct cma *cma)
48{
49 return PFN_PHYS(cma->base_pfn);
50}
51
52unsigned long cma_get_size(const struct cma *cma)
53{
54 return cma->count << PAGE_SHIFT;
55}
56
57const char *cma_get_name(const struct cma *cma)
58{
59 return cma->name ? cma->name : "(undefined)";
60}
61
62static unsigned long cma_bitmap_aligned_mask(const struct cma *cma,
63 unsigned int align_order)
64{
65 if (align_order <= cma->order_per_bit)
66 return 0;
67 return (1UL << (align_order - cma->order_per_bit)) - 1;
68}
69
70
71
72
73
74static unsigned long cma_bitmap_aligned_offset(const struct cma *cma,
75 unsigned int align_order)
76{
77 return (cma->base_pfn & ((1UL << align_order) - 1))
78 >> cma->order_per_bit;
79}
80
81static unsigned long cma_bitmap_pages_to_bits(const struct cma *cma,
82 unsigned long pages)
83{
84 return ALIGN(pages, 1UL << cma->order_per_bit) >> cma->order_per_bit;
85}
86
87static void cma_clear_bitmap(struct cma *cma, unsigned long pfn,
88 unsigned int count)
89{
90 unsigned long bitmap_no, bitmap_count;
91
92 bitmap_no = (pfn - cma->base_pfn) >> cma->order_per_bit;
93 bitmap_count = cma_bitmap_pages_to_bits(cma, count);
94
95 mutex_lock(&cma->lock);
96 bitmap_clear(cma->bitmap, bitmap_no, bitmap_count);
97 mutex_unlock(&cma->lock);
98}
99
100static int __init cma_activate_area(struct cma *cma)
101{
102 int bitmap_size = BITS_TO_LONGS(cma_bitmap_maxno(cma)) * sizeof(long);
103 unsigned long base_pfn = cma->base_pfn, pfn = base_pfn;
104 unsigned i = cma->count >> pageblock_order;
105 struct zone *zone;
106
107 cma->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
108
109 if (!cma->bitmap)
110 return -ENOMEM;
111
112 WARN_ON_ONCE(!pfn_valid(pfn));
113 zone = page_zone(pfn_to_page(pfn));
114
115 do {
116 unsigned j;
117
118 base_pfn = pfn;
119 for (j = pageblock_nr_pages; j; --j, pfn++) {
120 WARN_ON_ONCE(!pfn_valid(pfn));
121
122
123
124
125
126
127 if (page_zone(pfn_to_page(pfn)) != zone)
128 goto not_in_zone;
129 }
130 init_cma_reserved_pageblock(pfn_to_page(base_pfn));
131 } while (--i);
132
133 mutex_init(&cma->lock);
134
135#ifdef CONFIG_CMA_DEBUGFS
136 INIT_HLIST_HEAD(&cma->mem_head);
137 spin_lock_init(&cma->mem_head_lock);
138#endif
139
140 return 0;
141
142not_in_zone:
143 pr_err("CMA area %s could not be activated\n", cma->name);
144 kfree(cma->bitmap);
145 cma->count = 0;
146 return -EINVAL;
147}
148
149static int __init cma_init_reserved_areas(void)
150{
151 int i;
152
153 for (i = 0; i < cma_area_count; i++) {
154 int ret = cma_activate_area(&cma_areas[i]);
155
156 if (ret)
157 return ret;
158 }
159
160 return 0;
161}
162core_initcall(cma_init_reserved_areas);
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175
176int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
177 unsigned int order_per_bit,
178 const char *name,
179 struct cma **res_cma)
180{
181 struct cma *cma;
182 phys_addr_t alignment;
183
184
185 if (cma_area_count == ARRAY_SIZE(cma_areas)) {
186 pr_err("Not enough slots for CMA reserved regions!\n");
187 return -ENOSPC;
188 }
189
190 if (!size || !memblock_is_region_reserved(base, size))
191 return -EINVAL;
192
193
194 alignment = PAGE_SIZE <<
195 max_t(unsigned long, MAX_ORDER - 1, pageblock_order);
196
197
198 if (!IS_ALIGNED(alignment >> PAGE_SHIFT, 1 << order_per_bit))
199 return -EINVAL;
200
201 if (ALIGN(base, alignment) != base || ALIGN(size, alignment) != size)
202 return -EINVAL;
203
204
205
206
207
208 cma = &cma_areas[cma_area_count];
209 if (name) {
210 cma->name = name;
211 } else {
212 cma->name = kasprintf(GFP_KERNEL, "cma%d\n", cma_area_count);
213 if (!cma->name)
214 return -ENOMEM;
215 }
216 cma->base_pfn = PFN_DOWN(base);
217 cma->count = size >> PAGE_SHIFT;
218 cma->order_per_bit = order_per_bit;
219 *res_cma = cma;
220 cma_area_count++;
221 totalcma_pages += (size / PAGE_SIZE);
222
223 return 0;
224}
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244
245int __init cma_declare_contiguous(phys_addr_t base,
246 phys_addr_t size, phys_addr_t limit,
247 phys_addr_t alignment, unsigned int order_per_bit,
248 bool fixed, const char *name, struct cma **res_cma)
249{
250 phys_addr_t memblock_end = memblock_end_of_DRAM();
251 phys_addr_t highmem_start;
252 int ret = 0;
253
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259
260 highmem_start = __pa(high_memory - 1) + 1;
261 pr_debug("%s(size %pa, base %pa, limit %pa alignment %pa)\n",
262 __func__, &size, &base, &limit, &alignment);
263
264 if (cma_area_count == ARRAY_SIZE(cma_areas)) {
265 pr_err("Not enough slots for CMA reserved regions!\n");
266 return -ENOSPC;
267 }
268
269 if (!size)
270 return -EINVAL;
271
272 if (alignment && !is_power_of_2(alignment))
273 return -EINVAL;
274
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279
280
281 alignment = max(alignment, (phys_addr_t)PAGE_SIZE <<
282 max_t(unsigned long, MAX_ORDER - 1, pageblock_order));
283 base = ALIGN(base, alignment);
284 size = ALIGN(size, alignment);
285 limit &= ~(alignment - 1);
286
287 if (!base)
288 fixed = false;
289
290
291 if (!IS_ALIGNED(size >> PAGE_SHIFT, 1 << order_per_bit))
292 return -EINVAL;
293
294
295
296
297
298 if (fixed && base < highmem_start && base + size > highmem_start) {
299 ret = -EINVAL;
300 pr_err("Region at %pa defined on low/high memory boundary (%pa)\n",
301 &base, &highmem_start);
302 goto err;
303 }
304
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308
309
310 if (limit == 0 || limit > memblock_end)
311 limit = memblock_end;
312
313
314 if (fixed) {
315 if (memblock_is_region_reserved(base, size) ||
316 memblock_reserve(base, size) < 0) {
317 ret = -EBUSY;
318 goto err;
319 }
320 } else {
321 phys_addr_t addr = 0;
322
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327
328
329 if (base < highmem_start && limit > highmem_start) {
330 addr = memblock_alloc_range(size, alignment,
331 highmem_start, limit,
332 MEMBLOCK_NONE);
333 limit = highmem_start;
334 }
335
336 if (!addr) {
337 addr = memblock_alloc_range(size, alignment, base,
338 limit,
339 MEMBLOCK_NONE);
340 if (!addr) {
341 ret = -ENOMEM;
342 goto err;
343 }
344 }
345
346
347
348
349
350 kmemleak_ignore_phys(addr);
351 base = addr;
352 }
353
354 ret = cma_init_reserved_mem(base, size, order_per_bit, name, res_cma);
355 if (ret)
356 goto err;
357
358 pr_info("Reserved %ld MiB at %pa\n", (unsigned long)size / SZ_1M,
359 &base);
360 return 0;
361
362err:
363 pr_err("Failed to reserve %ld MiB\n", (unsigned long)size / SZ_1M);
364 return ret;
365}
366
367#ifdef CONFIG_CMA_DEBUG
368static void cma_debug_show_areas(struct cma *cma)
369{
370 unsigned long next_zero_bit, next_set_bit;
371 unsigned long start = 0;
372 unsigned int nr_zero, nr_total = 0;
373
374 mutex_lock(&cma->lock);
375 pr_info("number of available pages: ");
376 for (;;) {
377 next_zero_bit = find_next_zero_bit(cma->bitmap, cma->count, start);
378 if (next_zero_bit >= cma->count)
379 break;
380 next_set_bit = find_next_bit(cma->bitmap, cma->count, next_zero_bit);
381 nr_zero = next_set_bit - next_zero_bit;
382 pr_cont("%s%u@%lu", nr_total ? "+" : "", nr_zero, next_zero_bit);
383 nr_total += nr_zero;
384 start = next_zero_bit + nr_zero;
385 }
386 pr_cont("=> %u free of %lu total pages\n", nr_total, cma->count);
387 mutex_unlock(&cma->lock);
388}
389#else
390static inline void cma_debug_show_areas(struct cma *cma) { }
391#endif
392
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401
402
403struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
404 bool no_warn)
405{
406 unsigned long mask, offset;
407 unsigned long pfn = -1;
408 unsigned long start = 0;
409 unsigned long bitmap_maxno, bitmap_no, bitmap_count;
410 struct page *page = NULL;
411 int ret = -ENOMEM;
412
413 if (!cma || !cma->count)
414 return NULL;
415
416 pr_debug("%s(cma %p, count %zu, align %d)\n", __func__, (void *)cma,
417 count, align);
418
419 if (!count)
420 return NULL;
421
422 mask = cma_bitmap_aligned_mask(cma, align);
423 offset = cma_bitmap_aligned_offset(cma, align);
424 bitmap_maxno = cma_bitmap_maxno(cma);
425 bitmap_count = cma_bitmap_pages_to_bits(cma, count);
426
427 if (bitmap_count > bitmap_maxno)
428 return NULL;
429
430 for (;;) {
431 mutex_lock(&cma->lock);
432 bitmap_no = bitmap_find_next_zero_area_off(cma->bitmap,
433 bitmap_maxno, start, bitmap_count, mask,
434 offset);
435 if (bitmap_no >= bitmap_maxno) {
436 mutex_unlock(&cma->lock);
437 break;
438 }
439 bitmap_set(cma->bitmap, bitmap_no, bitmap_count);
440
441
442
443
444
445 mutex_unlock(&cma->lock);
446
447 pfn = cma->base_pfn + (bitmap_no << cma->order_per_bit);
448 mutex_lock(&cma_mutex);
449 ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA,
450 GFP_KERNEL | (no_warn ? __GFP_NOWARN : 0));
451 mutex_unlock(&cma_mutex);
452 if (ret == 0) {
453 page = pfn_to_page(pfn);
454 break;
455 }
456
457 cma_clear_bitmap(cma, pfn, count);
458 if (ret != -EBUSY)
459 break;
460
461 pr_debug("%s(): memory range at %p is busy, retrying\n",
462 __func__, pfn_to_page(pfn));
463
464 start = bitmap_no + mask + 1;
465 }
466
467 trace_cma_alloc(pfn, page, count, align);
468
469 if (ret && !no_warn) {
470 pr_err("%s: alloc failed, req-size: %zu pages, ret: %d\n",
471 __func__, count, ret);
472 cma_debug_show_areas(cma);
473 }
474
475 pr_debug("%s(): returned %p\n", __func__, page);
476 return page;
477}
478
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487
488
489bool cma_release(struct cma *cma, const struct page *pages, unsigned int count)
490{
491 unsigned long pfn;
492
493 if (!cma || !pages)
494 return false;
495
496 pr_debug("%s(page %p)\n", __func__, (void *)pages);
497
498 pfn = page_to_pfn(pages);
499
500 if (pfn < cma->base_pfn || pfn >= cma->base_pfn + cma->count)
501 return false;
502
503 VM_BUG_ON(pfn + count > cma->base_pfn + cma->count);
504
505 free_contig_range(pfn, count);
506 cma_clear_bitmap(cma, pfn, count);
507 trace_cma_release(pfn, pages, count);
508
509 return true;
510}
511
512int cma_for_each_area(int (*it)(struct cma *cma, void *data), void *data)
513{
514 int i;
515
516 for (i = 0; i < cma_area_count; i++) {
517 int ret = it(&cma_areas[i], data);
518
519 if (ret)
520 return ret;
521 }
522
523 return 0;
524}
525