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8607a965 1// SPDX-License-Identifier: GPL-2.0-or-later
a254129e
JK
2/*
3 * Contiguous Memory Allocator
4 *
5 * Copyright (c) 2010-2011 by Samsung Electronics.
6 * Copyright IBM Corporation, 2013
7 * Copyright LG Electronics Inc., 2014
8 * Written by:
9 * Marek Szyprowski <m.szyprowski@samsung.com>
10 * Michal Nazarewicz <mina86@mina86.com>
11 * Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
12 * Joonsoo Kim <iamjoonsoo.kim@lge.com>
a254129e
JK
13 */
14
15#define pr_fmt(fmt) "cma: " fmt
16
17#ifdef CONFIG_CMA_DEBUG
18#ifndef DEBUG
19# define DEBUG
20#endif
21#endif
99e8ea6c 22#define CREATE_TRACE_POINTS
a254129e
JK
23
24#include <linux/memblock.h>
25#include <linux/err.h>
26#include <linux/mm.h>
a254129e
JK
27#include <linux/sizes.h>
28#include <linux/slab.h>
29#include <linux/log2.h>
30#include <linux/cma.h>
f7426b98 31#include <linux/highmem.h>
620951e2 32#include <linux/io.h>
514c6032 33#include <linux/kmemleak.h>
99e8ea6c 34#include <trace/events/cma.h>
a254129e 35
28b24c1f
SL
36#include "cma.h"
37
38struct cma cma_areas[MAX_CMA_AREAS];
39unsigned cma_area_count;
a254129e 40
ac173824 41phys_addr_t cma_get_base(const struct cma *cma)
a254129e
JK
42{
43 return PFN_PHYS(cma->base_pfn);
44}
45
ac173824 46unsigned long cma_get_size(const struct cma *cma)
a254129e
JK
47{
48 return cma->count << PAGE_SHIFT;
49}
50
f318dd08
LA
51const char *cma_get_name(const struct cma *cma)
52{
18e98e56 53 return cma->name;
f318dd08
LA
54}
55
ac173824 56static unsigned long cma_bitmap_aligned_mask(const struct cma *cma,
e048cb32 57 unsigned int align_order)
a254129e 58{
68faed63
WY
59 if (align_order <= cma->order_per_bit)
60 return 0;
61 return (1UL << (align_order - cma->order_per_bit)) - 1;
a254129e
JK
62}
63
850fc430 64/*
e048cb32
DB
65 * Find the offset of the base PFN from the specified align_order.
66 * The value returned is represented in order_per_bits.
850fc430 67 */
ac173824 68static unsigned long cma_bitmap_aligned_offset(const struct cma *cma,
e048cb32 69 unsigned int align_order)
b5be83e3 70{
e048cb32
DB
71 return (cma->base_pfn & ((1UL << align_order) - 1))
72 >> cma->order_per_bit;
b5be83e3
GF
73}
74
ac173824
SL
75static unsigned long cma_bitmap_pages_to_bits(const struct cma *cma,
76 unsigned long pages)
a254129e
JK
77{
78 return ALIGN(pages, 1UL << cma->order_per_bit) >> cma->order_per_bit;
79}
80
ac173824 81static void cma_clear_bitmap(struct cma *cma, unsigned long pfn,
78fa5150 82 unsigned long count)
a254129e
JK
83{
84 unsigned long bitmap_no, bitmap_count;
0ef7dcac 85 unsigned long flags;
a254129e
JK
86
87 bitmap_no = (pfn - cma->base_pfn) >> cma->order_per_bit;
88 bitmap_count = cma_bitmap_pages_to_bits(cma, count);
89
0ef7dcac 90 spin_lock_irqsave(&cma->lock, flags);
a254129e 91 bitmap_clear(cma->bitmap, bitmap_no, bitmap_count);
0ef7dcac 92 spin_unlock_irqrestore(&cma->lock, flags);
a254129e
JK
93}
94
3a5139f1 95static void __init cma_activate_area(struct cma *cma)
a254129e 96{
072355c1 97 unsigned long base_pfn = cma->base_pfn, pfn;
a254129e
JK
98 struct zone *zone;
99
2184f992 100 cma->bitmap = bitmap_zalloc(cma_bitmap_maxno(cma), GFP_KERNEL);
3a5139f1
MK
101 if (!cma->bitmap)
102 goto out_error;
a254129e 103
072355c1
DH
104 /*
105 * alloc_contig_range() requires the pfn range specified to be in the
106 * same zone. Simplify by forcing the entire CMA resv range to be in the
107 * same zone.
108 */
109 WARN_ON_ONCE(!pfn_valid(base_pfn));
110 zone = page_zone(pfn_to_page(base_pfn));
111 for (pfn = base_pfn + 1; pfn < base_pfn + cma->count; pfn++) {
112 WARN_ON_ONCE(!pfn_valid(pfn));
113 if (page_zone(pfn_to_page(pfn)) != zone)
114 goto not_in_zone;
115 }
116
117 for (pfn = base_pfn; pfn < base_pfn + cma->count;
118 pfn += pageblock_nr_pages)
119 init_cma_reserved_pageblock(pfn_to_page(pfn));
a254129e 120
0ef7dcac 121 spin_lock_init(&cma->lock);
26b02a1f
SL
122
123#ifdef CONFIG_CMA_DEBUGFS
124 INIT_HLIST_HEAD(&cma->mem_head);
125 spin_lock_init(&cma->mem_head_lock);
126#endif
127
3a5139f1 128 return;
a254129e 129
d883c6cf 130not_in_zone:
2184f992 131 bitmap_free(cma->bitmap);
3a5139f1 132out_error:
072355c1
DH
133 /* Expose all pages to the buddy, they are useless for CMA. */
134 for (pfn = base_pfn; pfn < base_pfn + cma->count; pfn++)
135 free_reserved_page(pfn_to_page(pfn));
136 totalcma_pages -= cma->count;
f022d8cb 137 cma->count = 0;
3a5139f1
MK
138 pr_err("CMA area %s could not be activated\n", cma->name);
139 return;
a254129e
JK
140}
141
142static int __init cma_init_reserved_areas(void)
143{
144 int i;
145
3a5139f1
MK
146 for (i = 0; i < cma_area_count; i++)
147 cma_activate_area(&cma_areas[i]);
a254129e
JK
148
149 return 0;
150}
d883c6cf 151core_initcall(cma_init_reserved_areas);
a254129e 152
de9e14ee
MS
153/**
154 * cma_init_reserved_mem() - create custom contiguous area from reserved memory
155 * @base: Base address of the reserved area
156 * @size: Size of the reserved area (in bytes),
157 * @order_per_bit: Order of pages represented by one bit on bitmap.
e8b098fc
MR
158 * @name: The name of the area. If this parameter is NULL, the name of
159 * the area will be set to "cmaN", where N is a running counter of
160 * used areas.
de9e14ee
MS
161 * @res_cma: Pointer to store the created cma region.
162 *
163 * This function creates custom contiguous area from already reserved memory.
164 */
165int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
ac173824 166 unsigned int order_per_bit,
f318dd08 167 const char *name,
ac173824 168 struct cma **res_cma)
de9e14ee
MS
169{
170 struct cma *cma;
171 phys_addr_t alignment;
172
173 /* Sanity checks */
174 if (cma_area_count == ARRAY_SIZE(cma_areas)) {
175 pr_err("Not enough slots for CMA reserved regions!\n");
176 return -ENOSPC;
177 }
178
179 if (!size || !memblock_is_region_reserved(base, size))
180 return -EINVAL;
181
0f96ae29 182 /* ensure minimal alignment required by mm core */
badbda53
SR
183 alignment = PAGE_SIZE <<
184 max_t(unsigned long, MAX_ORDER - 1, pageblock_order);
de9e14ee
MS
185
186 /* alignment should be aligned with order_per_bit */
187 if (!IS_ALIGNED(alignment >> PAGE_SHIFT, 1 << order_per_bit))
188 return -EINVAL;
189
190 if (ALIGN(base, alignment) != base || ALIGN(size, alignment) != size)
191 return -EINVAL;
192
193 /*
194 * Each reserved area must be initialised later, when more kernel
195 * subsystems (like slab allocator) are available.
196 */
197 cma = &cma_areas[cma_area_count];
18e98e56
BS
198
199 if (name)
200 snprintf(cma->name, CMA_MAX_NAME, name);
201 else
202 snprintf(cma->name, CMA_MAX_NAME, "cma%d\n", cma_area_count);
203
de9e14ee
MS
204 cma->base_pfn = PFN_DOWN(base);
205 cma->count = size >> PAGE_SHIFT;
206 cma->order_per_bit = order_per_bit;
207 *res_cma = cma;
208 cma_area_count++;
94737a85 209 totalcma_pages += (size / PAGE_SIZE);
de9e14ee
MS
210
211 return 0;
212}
213
a254129e 214/**
8676af1f 215 * cma_declare_contiguous_nid() - reserve custom contiguous area
a254129e 216 * @base: Base address of the reserved area optional, use 0 for any
c1f733aa 217 * @size: Size of the reserved area (in bytes),
a254129e
JK
218 * @limit: End address of the reserved memory (optional, 0 for any).
219 * @alignment: Alignment for the CMA area, should be power of 2 or zero
220 * @order_per_bit: Order of pages represented by one bit on bitmap.
a254129e 221 * @fixed: hint about where to place the reserved area
e8b098fc 222 * @name: The name of the area. See function cma_init_reserved_mem()
c1f733aa 223 * @res_cma: Pointer to store the created cma region.
8676af1f 224 * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
a254129e
JK
225 *
226 * This function reserves memory from early allocator. It should be
227 * called by arch specific code once the early allocator (memblock or bootmem)
228 * has been activated and all other subsystems have already allocated/reserved
229 * memory. This function allows to create custom reserved areas.
230 *
231 * If @fixed is true, reserve contiguous area at exactly @base. If false,
232 * reserve in range from @base to @limit.
233 */
8676af1f 234int __init cma_declare_contiguous_nid(phys_addr_t base,
c1f733aa 235 phys_addr_t size, phys_addr_t limit,
a254129e 236 phys_addr_t alignment, unsigned int order_per_bit,
8676af1f
AB
237 bool fixed, const char *name, struct cma **res_cma,
238 int nid)
a254129e 239{
f7426b98 240 phys_addr_t memblock_end = memblock_end_of_DRAM();
6b101e2a 241 phys_addr_t highmem_start;
a254129e
JK
242 int ret = 0;
243
6b101e2a 244 /*
2dece445
LA
245 * We can't use __pa(high_memory) directly, since high_memory
246 * isn't a valid direct map VA, and DEBUG_VIRTUAL will (validly)
247 * complain. Find the boundary by adding one to the last valid
248 * address.
6b101e2a 249 */
2dece445 250 highmem_start = __pa(high_memory - 1) + 1;
56fa4f60
LP
251 pr_debug("%s(size %pa, base %pa, limit %pa alignment %pa)\n",
252 __func__, &size, &base, &limit, &alignment);
a254129e
JK
253
254 if (cma_area_count == ARRAY_SIZE(cma_areas)) {
255 pr_err("Not enough slots for CMA reserved regions!\n");
256 return -ENOSPC;
257 }
258
259 if (!size)
260 return -EINVAL;
261
262 if (alignment && !is_power_of_2(alignment))
263 return -EINVAL;
264
265 /*
266 * Sanitise input arguments.
267 * Pages both ends in CMA area could be merged into adjacent unmovable
268 * migratetype page by page allocator's buddy algorithm. In the case,
269 * you couldn't get a contiguous memory, which is not what we want.
270 */
badbda53
SR
271 alignment = max(alignment, (phys_addr_t)PAGE_SIZE <<
272 max_t(unsigned long, MAX_ORDER - 1, pageblock_order));
c633324e
DB
273 if (fixed && base & (alignment - 1)) {
274 ret = -EINVAL;
275 pr_err("Region at %pa must be aligned to %pa bytes\n",
276 &base, &alignment);
277 goto err;
278 }
a254129e
JK
279 base = ALIGN(base, alignment);
280 size = ALIGN(size, alignment);
281 limit &= ~(alignment - 1);
282
800a85d3
LP
283 if (!base)
284 fixed = false;
285
a254129e
JK
286 /* size should be aligned with order_per_bit */
287 if (!IS_ALIGNED(size >> PAGE_SHIFT, 1 << order_per_bit))
288 return -EINVAL;
289
f7426b98 290 /*
16195ddd
LP
291 * If allocating at a fixed base the request region must not cross the
292 * low/high memory boundary.
f7426b98 293 */
16195ddd 294 if (fixed && base < highmem_start && base + size > highmem_start) {
f7426b98 295 ret = -EINVAL;
56fa4f60
LP
296 pr_err("Region at %pa defined on low/high memory boundary (%pa)\n",
297 &base, &highmem_start);
f7426b98
MS
298 goto err;
299 }
300
16195ddd
LP
301 /*
302 * If the limit is unspecified or above the memblock end, its effective
303 * value will be the memblock end. Set it explicitly to simplify further
304 * checks.
305 */
306 if (limit == 0 || limit > memblock_end)
307 limit = memblock_end;
308
c633324e
DB
309 if (base + size > limit) {
310 ret = -EINVAL;
311 pr_err("Size (%pa) of region at %pa exceeds limit (%pa)\n",
312 &size, &base, &limit);
313 goto err;
314 }
315
a254129e 316 /* Reserve memory */
800a85d3 317 if (fixed) {
a254129e
JK
318 if (memblock_is_region_reserved(base, size) ||
319 memblock_reserve(base, size) < 0) {
320 ret = -EBUSY;
321 goto err;
322 }
323 } else {
16195ddd
LP
324 phys_addr_t addr = 0;
325
326 /*
327 * All pages in the reserved area must come from the same zone.
328 * If the requested region crosses the low/high memory boundary,
329 * try allocating from high memory first and fall back to low
330 * memory in case of failure.
331 */
332 if (base < highmem_start && limit > highmem_start) {
8676af1f 333 addr = memblock_alloc_range_nid(size, alignment,
40366bd7 334 highmem_start, limit, nid, true);
16195ddd
LP
335 limit = highmem_start;
336 }
337
df2ff39e
RG
338 /*
339 * If there is enough memory, try a bottom-up allocation first.
340 * It will place the new cma area close to the start of the node
341 * and guarantee that the compaction is moving pages out of the
342 * cma area and not into it.
343 * Avoid using first 4GB to not interfere with constrained zones
344 * like DMA/DMA32.
345 */
346#ifdef CONFIG_PHYS_ADDR_T_64BIT
347 if (!memblock_bottom_up() && memblock_end >= SZ_4G + size) {
348 memblock_set_bottom_up(true);
349 addr = memblock_alloc_range_nid(size, alignment, SZ_4G,
350 limit, nid, true);
351 memblock_set_bottom_up(false);
352 }
353#endif
354
a254129e 355 if (!addr) {
8676af1f 356 addr = memblock_alloc_range_nid(size, alignment, base,
40366bd7 357 limit, nid, true);
16195ddd
LP
358 if (!addr) {
359 ret = -ENOMEM;
360 goto err;
361 }
a254129e 362 }
16195ddd 363
620951e2
TR
364 /*
365 * kmemleak scans/reads tracked objects for pointers to other
366 * objects but this address isn't mapped and accessible
367 */
9099daed 368 kmemleak_ignore_phys(addr);
16195ddd 369 base = addr;
a254129e
JK
370 }
371
f318dd08 372 ret = cma_init_reserved_mem(base, size, order_per_bit, name, res_cma);
de9e14ee 373 if (ret)
0d3bd18a 374 goto free_mem;
a254129e 375
56fa4f60
LP
376 pr_info("Reserved %ld MiB at %pa\n", (unsigned long)size / SZ_1M,
377 &base);
a254129e
JK
378 return 0;
379
0d3bd18a
PF
380free_mem:
381 memblock_free(base, size);
a254129e 382err:
0de9d2eb 383 pr_err("Failed to reserve %ld MiB\n", (unsigned long)size / SZ_1M);
a254129e
JK
384 return ret;
385}
386
dbe43d4d
JK
387#ifdef CONFIG_CMA_DEBUG
388static void cma_debug_show_areas(struct cma *cma)
389{
2b59e01a 390 unsigned long next_zero_bit, next_set_bit, nr_zero;
dbe43d4d 391 unsigned long start = 0;
2b59e01a
YH
392 unsigned long nr_part, nr_total = 0;
393 unsigned long nbits = cma_bitmap_maxno(cma);
dbe43d4d 394
0ef7dcac 395 spin_lock_irq(&cma->lock);
dbe43d4d
JK
396 pr_info("number of available pages: ");
397 for (;;) {
2b59e01a
YH
398 next_zero_bit = find_next_zero_bit(cma->bitmap, nbits, start);
399 if (next_zero_bit >= nbits)
dbe43d4d 400 break;
2b59e01a 401 next_set_bit = find_next_bit(cma->bitmap, nbits, next_zero_bit);
dbe43d4d 402 nr_zero = next_set_bit - next_zero_bit;
2b59e01a
YH
403 nr_part = nr_zero << cma->order_per_bit;
404 pr_cont("%s%lu@%lu", nr_total ? "+" : "", nr_part,
405 next_zero_bit);
406 nr_total += nr_part;
dbe43d4d
JK
407 start = next_zero_bit + nr_zero;
408 }
2b59e01a 409 pr_cont("=> %lu free of %lu total pages\n", nr_total, cma->count);
0ef7dcac 410 spin_unlock_irq(&cma->lock);
dbe43d4d
JK
411}
412#else
413static inline void cma_debug_show_areas(struct cma *cma) { }
414#endif
415
a254129e
JK
416/**
417 * cma_alloc() - allocate pages from contiguous area
418 * @cma: Contiguous memory region for which the allocation is performed.
419 * @count: Requested number of pages.
420 * @align: Requested alignment of pages (in PAGE_SIZE order).
65182029 421 * @no_warn: Avoid printing message about failed allocation
a254129e
JK
422 *
423 * This function allocates part of contiguous memory on specific
424 * contiguous memory area.
425 */
78fa5150
MK
426struct page *cma_alloc(struct cma *cma, unsigned long count,
427 unsigned int align, bool no_warn)
a254129e 428{
3acaea68
AM
429 unsigned long mask, offset;
430 unsigned long pfn = -1;
431 unsigned long start = 0;
a254129e 432 unsigned long bitmap_maxno, bitmap_no, bitmap_count;
78fa5150 433 unsigned long i;
a254129e 434 struct page *page = NULL;
dbe43d4d 435 int ret = -ENOMEM;
a254129e 436
835832ba 437 if (!cma || !cma->count || !cma->bitmap)
bbb26920 438 goto out;
a254129e 439
78fa5150 440 pr_debug("%s(cma %p, count %lu, align %d)\n", __func__, (void *)cma,
a254129e
JK
441 count, align);
442
443 if (!count)
bbb26920 444 goto out;
a254129e 445
7bc1aec5
LM
446 trace_cma_alloc_start(cma->name, count, align);
447
a254129e 448 mask = cma_bitmap_aligned_mask(cma, align);
b5be83e3 449 offset = cma_bitmap_aligned_offset(cma, align);
a254129e
JK
450 bitmap_maxno = cma_bitmap_maxno(cma);
451 bitmap_count = cma_bitmap_pages_to_bits(cma, count);
452
6b36ba59 453 if (bitmap_count > bitmap_maxno)
bbb26920 454 goto out;
6b36ba59 455
a254129e 456 for (;;) {
0ef7dcac 457 spin_lock_irq(&cma->lock);
b5be83e3
GF
458 bitmap_no = bitmap_find_next_zero_area_off(cma->bitmap,
459 bitmap_maxno, start, bitmap_count, mask,
460 offset);
a254129e 461 if (bitmap_no >= bitmap_maxno) {
0ef7dcac 462 spin_unlock_irq(&cma->lock);
a254129e
JK
463 break;
464 }
465 bitmap_set(cma->bitmap, bitmap_no, bitmap_count);
466 /*
467 * It's safe to drop the lock here. We've marked this region for
468 * our exclusive use. If the migration fails we will take the
469 * lock again and unmark it.
470 */
0ef7dcac 471 spin_unlock_irq(&cma->lock);
a254129e
JK
472
473 pfn = cma->base_pfn + (bitmap_no << cma->order_per_bit);
ca96b625 474 ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA,
65182029 475 GFP_KERNEL | (no_warn ? __GFP_NOWARN : 0));
a4efc174 476
a254129e
JK
477 if (ret == 0) {
478 page = pfn_to_page(pfn);
479 break;
a254129e 480 }
b7155e76 481
a254129e 482 cma_clear_bitmap(cma, pfn, count);
b7155e76
JK
483 if (ret != -EBUSY)
484 break;
485
a254129e
JK
486 pr_debug("%s(): memory range at %p is busy, retrying\n",
487 __func__, pfn_to_page(pfn));
7bc1aec5 488
3aab8ae7
MK
489 trace_cma_alloc_busy_retry(cma->name, pfn, pfn_to_page(pfn),
490 count, align);
a254129e
JK
491 /* try again with a bit different memory target */
492 start = bitmap_no + mask + 1;
493 }
494
3aab8ae7 495 trace_cma_alloc_finish(cma->name, pfn, page, count, align);
99e8ea6c 496
2813b9c0
AK
497 /*
498 * CMA can allocate multiple page blocks, which results in different
499 * blocks being marked with different tags. Reset the tags to ignore
500 * those page blocks.
501 */
502 if (page) {
503 for (i = 0; i < count; i++)
504 page_kasan_tag_reset(page + i);
505 }
506
65182029 507 if (ret && !no_warn) {
78fa5150 508 pr_err_ratelimited("%s: %s: alloc failed, req-size: %lu pages, ret: %d\n",
63f83b31 509 __func__, cma->name, count, ret);
dbe43d4d
JK
510 cma_debug_show_areas(cma);
511 }
512
a254129e 513 pr_debug("%s(): returned %p\n", __func__, page);
bbb26920 514out:
43ca106f 515 if (page) {
bbb26920 516 count_vm_event(CMA_ALLOC_SUCCESS);
43ca106f
MK
517 cma_sysfs_account_success_pages(cma, count);
518 } else {
bbb26920 519 count_vm_event(CMA_ALLOC_FAIL);
43ca106f
MK
520 if (cma)
521 cma_sysfs_account_fail_pages(cma, count);
522 }
bbb26920 523
a254129e
JK
524 return page;
525}
526
527/**
528 * cma_release() - release allocated pages
529 * @cma: Contiguous memory region for which the allocation is performed.
530 * @pages: Allocated pages.
531 * @count: Number of allocated pages.
532 *
929f92f7 533 * This function releases memory allocated by cma_alloc().
a254129e
JK
534 * It returns false when provided pages do not belong to contiguous area and
535 * true otherwise.
536 */
78fa5150
MK
537bool cma_release(struct cma *cma, const struct page *pages,
538 unsigned long count)
a254129e
JK
539{
540 unsigned long pfn;
541
542 if (!cma || !pages)
543 return false;
544
78fa5150 545 pr_debug("%s(page %p, count %lu)\n", __func__, (void *)pages, count);
a254129e
JK
546
547 pfn = page_to_pfn(pages);
548
549 if (pfn < cma->base_pfn || pfn >= cma->base_pfn + cma->count)
550 return false;
551
552 VM_BUG_ON(pfn + count > cma->base_pfn + cma->count);
553
554 free_contig_range(pfn, count);
555 cma_clear_bitmap(cma, pfn, count);
3aab8ae7 556 trace_cma_release(cma->name, pfn, pages, count);
a254129e
JK
557
558 return true;
559}
e4231bcd
LA
560
561int cma_for_each_area(int (*it)(struct cma *cma, void *data), void *data)
562{
563 int i;
564
565 for (i = 0; i < cma_area_count; i++) {
566 int ret = it(&cma_areas[i], data);
567
568 if (ret)
569 return ret;
570 }
571
572 return 0;
573}