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1/*
2 * Contiguous Memory Allocator
3 *
4 * Copyright (c) 2010-2011 by Samsung Electronics.
5 * Copyright IBM Corporation, 2013
6 * Copyright LG Electronics Inc., 2014
7 * Written by:
8 * Marek Szyprowski <m.szyprowski@samsung.com>
9 * Michal Nazarewicz <mina86@mina86.com>
10 * Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
11 * Joonsoo Kim <iamjoonsoo.kim@lge.com>
12 *
13 * This program is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU General Public License as
15 * published by the Free Software Foundation; either version 2 of the
16 * License or (at your optional) any later version of the license.
17 */
18
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 * Find the offset of the base PFN from the specified align_order.
72 * The value returned is represented in order_per_bits.
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 * alloc_contig_range requires the pfn range
123 * specified to be in the same zone. Make this
124 * simple by forcing the entire CMA resv range
125 * to be in the same zone.
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);
163
164/**
165 * cma_init_reserved_mem() - create custom contiguous area from reserved memory
166 * @base: Base address of the reserved area
167 * @size: Size of the reserved area (in bytes),
168 * @order_per_bit: Order of pages represented by one bit on bitmap.
169 * @name: The name of the area. If this parameter is NULL, the name of
170 * the area will be set to "cmaN", where N is a running counter of
171 * used areas.
172 * @res_cma: Pointer to store the created cma region.
173 *
174 * This function creates custom contiguous area from already reserved memory.
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 /* Sanity checks */
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 /* ensure minimal alignment required by mm core */
194 alignment = PAGE_SIZE <<
195 max_t(unsigned long, MAX_ORDER - 1, pageblock_order);
196
197 /* alignment should be aligned with order_per_bit */
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 * Each reserved area must be initialised later, when more kernel
206 * subsystems (like slab allocator) are available.
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}
225
226/**
227 * cma_declare_contiguous() - reserve custom contiguous area
228 * @base: Base address of the reserved area optional, use 0 for any
229 * @size: Size of the reserved area (in bytes),
230 * @limit: End address of the reserved memory (optional, 0 for any).
231 * @alignment: Alignment for the CMA area, should be power of 2 or zero
232 * @order_per_bit: Order of pages represented by one bit on bitmap.
233 * @fixed: hint about where to place the reserved area
234 * @name: The name of the area. See function cma_init_reserved_mem()
235 * @res_cma: Pointer to store the created cma region.
236 *
237 * This function reserves memory from early allocator. It should be
238 * called by arch specific code once the early allocator (memblock or bootmem)
239 * has been activated and all other subsystems have already allocated/reserved
240 * memory. This function allows to create custom reserved areas.
241 *
242 * If @fixed is true, reserve contiguous area at exactly @base. If false,
243 * reserve in range from @base to @limit.
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
254 /*
255 * We can't use __pa(high_memory) directly, since high_memory
256 * isn't a valid direct map VA, and DEBUG_VIRTUAL will (validly)
257 * complain. Find the boundary by adding one to the last valid
258 * address.
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
275 /*
276 * Sanitise input arguments.
277 * Pages both ends in CMA area could be merged into adjacent unmovable
278 * migratetype page by page allocator's buddy algorithm. In the case,
279 * you couldn't get a contiguous memory, which is not what we want.
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 /* size should be aligned with order_per_bit */
291 if (!IS_ALIGNED(size >> PAGE_SHIFT, 1 << order_per_bit))
292 return -EINVAL;
293
294 /*
295 * If allocating at a fixed base the request region must not cross the
296 * low/high memory boundary.
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
305 /*
306 * If the limit is unspecified or above the memblock end, its effective
307 * value will be the memblock end. Set it explicitly to simplify further
308 * checks.
309 */
310 if (limit == 0 || limit > memblock_end)
311 limit = memblock_end;
312
313 /* Reserve memory */
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
323 /*
324 * All pages in the reserved area must come from the same zone.
325 * If the requested region crosses the low/high memory boundary,
326 * try allocating from high memory first and fall back to low
327 * memory in case of failure.
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 * kmemleak scans/reads tracked objects for pointers to other
348 * objects but this address isn't mapped and accessible
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
393/**
394 * cma_alloc() - allocate pages from contiguous area
395 * @cma: Contiguous memory region for which the allocation is performed.
396 * @count: Requested number of pages.
397 * @align: Requested alignment of pages (in PAGE_SIZE order).
398 * @gfp_mask: GFP mask to use during compaction
399 *
400 * This function allocates part of contiguous memory on specific
401 * contiguous memory area.
402 */
403struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
404 gfp_t gfp_mask)
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 * It's safe to drop the lock here. We've marked this region for
442 * our exclusive use. If the migration fails we will take the
443 * lock again and unmark it.
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_mask);
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 /* try again with a bit different memory target */
464 start = bitmap_no + mask + 1;
465 }
466
467 trace_cma_alloc(pfn, page, count, align);
468
469 if (ret && !(gfp_mask & __GFP_NOWARN)) {
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
479/**
480 * cma_release() - release allocated pages
481 * @cma: Contiguous memory region for which the allocation is performed.
482 * @pages: Allocated pages.
483 * @count: Number of allocated pages.
484 *
485 * This function releases memory allocated by alloc_cma().
486 * It returns false when provided pages do not belong to contiguous area and
487 * true otherwise.
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}
1// SPDX-License-Identifier: GPL-2.0-or-later
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>
13 */
14
15#define pr_fmt(fmt) "cma: " fmt
16
17#define CREATE_TRACE_POINTS
18
19#include <linux/memblock.h>
20#include <linux/err.h>
21#include <linux/mm.h>
22#include <linux/sizes.h>
23#include <linux/slab.h>
24#include <linux/log2.h>
25#include <linux/cma.h>
26#include <linux/highmem.h>
27#include <linux/io.h>
28#include <linux/kmemleak.h>
29#include <trace/events/cma.h>
30
31#include "internal.h"
32#include "cma.h"
33
34struct cma cma_areas[MAX_CMA_AREAS];
35unsigned int cma_area_count;
36static DEFINE_MUTEX(cma_mutex);
37
38phys_addr_t cma_get_base(const struct cma *cma)
39{
40 return PFN_PHYS(cma->base_pfn);
41}
42
43unsigned long cma_get_size(const struct cma *cma)
44{
45 return cma->count << PAGE_SHIFT;
46}
47
48const char *cma_get_name(const struct cma *cma)
49{
50 return cma->name;
51}
52
53static unsigned long cma_bitmap_aligned_mask(const struct cma *cma,
54 unsigned int align_order)
55{
56 if (align_order <= cma->order_per_bit)
57 return 0;
58 return (1UL << (align_order - cma->order_per_bit)) - 1;
59}
60
61/*
62 * Find the offset of the base PFN from the specified align_order.
63 * The value returned is represented in order_per_bits.
64 */
65static unsigned long cma_bitmap_aligned_offset(const struct cma *cma,
66 unsigned int align_order)
67{
68 return (cma->base_pfn & ((1UL << align_order) - 1))
69 >> cma->order_per_bit;
70}
71
72static unsigned long cma_bitmap_pages_to_bits(const struct cma *cma,
73 unsigned long pages)
74{
75 return ALIGN(pages, 1UL << cma->order_per_bit) >> cma->order_per_bit;
76}
77
78static void cma_clear_bitmap(struct cma *cma, unsigned long pfn,
79 unsigned long count)
80{
81 unsigned long bitmap_no, bitmap_count;
82 unsigned long flags;
83
84 bitmap_no = (pfn - cma->base_pfn) >> cma->order_per_bit;
85 bitmap_count = cma_bitmap_pages_to_bits(cma, count);
86
87 spin_lock_irqsave(&cma->lock, flags);
88 bitmap_clear(cma->bitmap, bitmap_no, bitmap_count);
89 spin_unlock_irqrestore(&cma->lock, flags);
90}
91
92static void __init cma_activate_area(struct cma *cma)
93{
94 unsigned long base_pfn = cma->base_pfn, pfn;
95 struct zone *zone;
96
97 cma->bitmap = bitmap_zalloc(cma_bitmap_maxno(cma), GFP_KERNEL);
98 if (!cma->bitmap)
99 goto out_error;
100
101 /*
102 * alloc_contig_range() requires the pfn range specified to be in the
103 * same zone. Simplify by forcing the entire CMA resv range to be in the
104 * same zone.
105 */
106 WARN_ON_ONCE(!pfn_valid(base_pfn));
107 zone = page_zone(pfn_to_page(base_pfn));
108 for (pfn = base_pfn + 1; pfn < base_pfn + cma->count; pfn++) {
109 WARN_ON_ONCE(!pfn_valid(pfn));
110 if (page_zone(pfn_to_page(pfn)) != zone)
111 goto not_in_zone;
112 }
113
114 for (pfn = base_pfn; pfn < base_pfn + cma->count;
115 pfn += pageblock_nr_pages)
116 init_cma_reserved_pageblock(pfn_to_page(pfn));
117
118 spin_lock_init(&cma->lock);
119
120#ifdef CONFIG_CMA_DEBUGFS
121 INIT_HLIST_HEAD(&cma->mem_head);
122 spin_lock_init(&cma->mem_head_lock);
123#endif
124
125 return;
126
127not_in_zone:
128 bitmap_free(cma->bitmap);
129out_error:
130 /* Expose all pages to the buddy, they are useless for CMA. */
131 if (!cma->reserve_pages_on_error) {
132 for (pfn = base_pfn; pfn < base_pfn + cma->count; pfn++)
133 free_reserved_page(pfn_to_page(pfn));
134 }
135 totalcma_pages -= cma->count;
136 cma->count = 0;
137 pr_err("CMA area %s could not be activated\n", cma->name);
138}
139
140static int __init cma_init_reserved_areas(void)
141{
142 int i;
143
144 for (i = 0; i < cma_area_count; i++)
145 cma_activate_area(&cma_areas[i]);
146
147 return 0;
148}
149core_initcall(cma_init_reserved_areas);
150
151void __init cma_reserve_pages_on_error(struct cma *cma)
152{
153 cma->reserve_pages_on_error = true;
154}
155
156/**
157 * cma_init_reserved_mem() - create custom contiguous area from reserved memory
158 * @base: Base address of the reserved area
159 * @size: Size of the reserved area (in bytes),
160 * @order_per_bit: Order of pages represented by one bit on bitmap.
161 * @name: The name of the area. If this parameter is NULL, the name of
162 * the area will be set to "cmaN", where N is a running counter of
163 * used areas.
164 * @res_cma: Pointer to store the created cma region.
165 *
166 * This function creates custom contiguous area from already reserved memory.
167 */
168int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
169 unsigned int order_per_bit,
170 const char *name,
171 struct cma **res_cma)
172{
173 struct cma *cma;
174
175 /* Sanity checks */
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 * CMA uses CMA_MIN_ALIGNMENT_BYTES as alignment requirement which
186 * needs pageblock_order to be initialized. Let's enforce it.
187 */
188 if (!pageblock_order) {
189 pr_err("pageblock_order not yet initialized. Called during early boot?\n");
190 return -EINVAL;
191 }
192
193 /* ensure minimal alignment required by mm core */
194 if (!IS_ALIGNED(base | size, CMA_MIN_ALIGNMENT_BYTES))
195 return -EINVAL;
196
197 /*
198 * Each reserved area must be initialised later, when more kernel
199 * subsystems (like slab allocator) are available.
200 */
201 cma = &cma_areas[cma_area_count];
202
203 if (name)
204 snprintf(cma->name, CMA_MAX_NAME, name);
205 else
206 snprintf(cma->name, CMA_MAX_NAME, "cma%d\n", cma_area_count);
207
208 cma->base_pfn = PFN_DOWN(base);
209 cma->count = size >> PAGE_SHIFT;
210 cma->order_per_bit = order_per_bit;
211 *res_cma = cma;
212 cma_area_count++;
213 totalcma_pages += cma->count;
214
215 return 0;
216}
217
218/**
219 * cma_declare_contiguous_nid() - reserve custom contiguous area
220 * @base: Base address of the reserved area optional, use 0 for any
221 * @size: Size of the reserved area (in bytes),
222 * @limit: End address of the reserved memory (optional, 0 for any).
223 * @alignment: Alignment for the CMA area, should be power of 2 or zero
224 * @order_per_bit: Order of pages represented by one bit on bitmap.
225 * @fixed: hint about where to place the reserved area
226 * @name: The name of the area. See function cma_init_reserved_mem()
227 * @res_cma: Pointer to store the created cma region.
228 * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
229 *
230 * This function reserves memory from early allocator. It should be
231 * called by arch specific code once the early allocator (memblock or bootmem)
232 * has been activated and all other subsystems have already allocated/reserved
233 * memory. This function allows to create custom reserved areas.
234 *
235 * If @fixed is true, reserve contiguous area at exactly @base. If false,
236 * reserve in range from @base to @limit.
237 */
238int __init cma_declare_contiguous_nid(phys_addr_t base,
239 phys_addr_t size, phys_addr_t limit,
240 phys_addr_t alignment, unsigned int order_per_bit,
241 bool fixed, const char *name, struct cma **res_cma,
242 int nid)
243{
244 phys_addr_t memblock_end = memblock_end_of_DRAM();
245 phys_addr_t highmem_start;
246 int ret;
247
248 /*
249 * We can't use __pa(high_memory) directly, since high_memory
250 * isn't a valid direct map VA, and DEBUG_VIRTUAL will (validly)
251 * complain. Find the boundary by adding one to the last valid
252 * address.
253 */
254 highmem_start = __pa(high_memory - 1) + 1;
255 pr_debug("%s(size %pa, base %pa, limit %pa alignment %pa)\n",
256 __func__, &size, &base, &limit, &alignment);
257
258 if (cma_area_count == ARRAY_SIZE(cma_areas)) {
259 pr_err("Not enough slots for CMA reserved regions!\n");
260 return -ENOSPC;
261 }
262
263 if (!size)
264 return -EINVAL;
265
266 if (alignment && !is_power_of_2(alignment))
267 return -EINVAL;
268
269 if (!IS_ENABLED(CONFIG_NUMA))
270 nid = NUMA_NO_NODE;
271
272 /* Sanitise input arguments. */
273 alignment = max_t(phys_addr_t, alignment, CMA_MIN_ALIGNMENT_BYTES);
274 if (fixed && base & (alignment - 1)) {
275 ret = -EINVAL;
276 pr_err("Region at %pa must be aligned to %pa bytes\n",
277 &base, &alignment);
278 goto err;
279 }
280 base = ALIGN(base, alignment);
281 size = ALIGN(size, alignment);
282 limit &= ~(alignment - 1);
283
284 if (!base)
285 fixed = false;
286
287 /* size should be aligned with order_per_bit */
288 if (!IS_ALIGNED(size >> PAGE_SHIFT, 1 << order_per_bit))
289 return -EINVAL;
290
291 /*
292 * If allocating at a fixed base the request region must not cross the
293 * low/high memory boundary.
294 */
295 if (fixed && base < highmem_start && base + size > highmem_start) {
296 ret = -EINVAL;
297 pr_err("Region at %pa defined on low/high memory boundary (%pa)\n",
298 &base, &highmem_start);
299 goto err;
300 }
301
302 /*
303 * If the limit is unspecified or above the memblock end, its effective
304 * value will be the memblock end. Set it explicitly to simplify further
305 * checks.
306 */
307 if (limit == 0 || limit > memblock_end)
308 limit = memblock_end;
309
310 if (base + size > limit) {
311 ret = -EINVAL;
312 pr_err("Size (%pa) of region at %pa exceeds limit (%pa)\n",
313 &size, &base, &limit);
314 goto err;
315 }
316
317 /* Reserve memory */
318 if (fixed) {
319 if (memblock_is_region_reserved(base, size) ||
320 memblock_reserve(base, size) < 0) {
321 ret = -EBUSY;
322 goto err;
323 }
324 } else {
325 phys_addr_t addr = 0;
326
327 /*
328 * If there is enough memory, try a bottom-up allocation first.
329 * It will place the new cma area close to the start of the node
330 * and guarantee that the compaction is moving pages out of the
331 * cma area and not into it.
332 * Avoid using first 4GB to not interfere with constrained zones
333 * like DMA/DMA32.
334 */
335#ifdef CONFIG_PHYS_ADDR_T_64BIT
336 if (!memblock_bottom_up() && memblock_end >= SZ_4G + size) {
337 memblock_set_bottom_up(true);
338 addr = memblock_alloc_range_nid(size, alignment, SZ_4G,
339 limit, nid, true);
340 memblock_set_bottom_up(false);
341 }
342#endif
343
344 /*
345 * All pages in the reserved area must come from the same zone.
346 * If the requested region crosses the low/high memory boundary,
347 * try allocating from high memory first and fall back to low
348 * memory in case of failure.
349 */
350 if (!addr && base < highmem_start && limit > highmem_start) {
351 addr = memblock_alloc_range_nid(size, alignment,
352 highmem_start, limit, nid, true);
353 limit = highmem_start;
354 }
355
356 if (!addr) {
357 addr = memblock_alloc_range_nid(size, alignment, base,
358 limit, nid, true);
359 if (!addr) {
360 ret = -ENOMEM;
361 goto err;
362 }
363 }
364
365 /*
366 * kmemleak scans/reads tracked objects for pointers to other
367 * objects but this address isn't mapped and accessible
368 */
369 kmemleak_ignore_phys(addr);
370 base = addr;
371 }
372
373 ret = cma_init_reserved_mem(base, size, order_per_bit, name, res_cma);
374 if (ret)
375 goto free_mem;
376
377 pr_info("Reserved %ld MiB at %pa on node %d\n", (unsigned long)size / SZ_1M,
378 &base, nid);
379 return 0;
380
381free_mem:
382 memblock_phys_free(base, size);
383err:
384 pr_err("Failed to reserve %ld MiB on node %d\n", (unsigned long)size / SZ_1M,
385 nid);
386 return ret;
387}
388
389static void cma_debug_show_areas(struct cma *cma)
390{
391 unsigned long next_zero_bit, next_set_bit, nr_zero;
392 unsigned long start = 0;
393 unsigned long nr_part, nr_total = 0;
394 unsigned long nbits = cma_bitmap_maxno(cma);
395
396 spin_lock_irq(&cma->lock);
397 pr_info("number of available pages: ");
398 for (;;) {
399 next_zero_bit = find_next_zero_bit(cma->bitmap, nbits, start);
400 if (next_zero_bit >= nbits)
401 break;
402 next_set_bit = find_next_bit(cma->bitmap, nbits, next_zero_bit);
403 nr_zero = next_set_bit - next_zero_bit;
404 nr_part = nr_zero << cma->order_per_bit;
405 pr_cont("%s%lu@%lu", nr_total ? "+" : "", nr_part,
406 next_zero_bit);
407 nr_total += nr_part;
408 start = next_zero_bit + nr_zero;
409 }
410 pr_cont("=> %lu free of %lu total pages\n", nr_total, cma->count);
411 spin_unlock_irq(&cma->lock);
412}
413
414static struct page *__cma_alloc(struct cma *cma, unsigned long count,
415 unsigned int align, gfp_t gfp)
416{
417 unsigned long mask, offset;
418 unsigned long pfn = -1;
419 unsigned long start = 0;
420 unsigned long bitmap_maxno, bitmap_no, bitmap_count;
421 unsigned long i;
422 struct page *page = NULL;
423 int ret = -ENOMEM;
424 const char *name = cma ? cma->name : NULL;
425
426 trace_cma_alloc_start(name, count, align);
427
428 if (!cma || !cma->count || !cma->bitmap)
429 return page;
430
431 pr_debug("%s(cma %p, name: %s, count %lu, align %d)\n", __func__,
432 (void *)cma, cma->name, count, align);
433
434 if (!count)
435 return page;
436
437 mask = cma_bitmap_aligned_mask(cma, align);
438 offset = cma_bitmap_aligned_offset(cma, align);
439 bitmap_maxno = cma_bitmap_maxno(cma);
440 bitmap_count = cma_bitmap_pages_to_bits(cma, count);
441
442 if (bitmap_count > bitmap_maxno)
443 return page;
444
445 for (;;) {
446 spin_lock_irq(&cma->lock);
447 bitmap_no = bitmap_find_next_zero_area_off(cma->bitmap,
448 bitmap_maxno, start, bitmap_count, mask,
449 offset);
450 if (bitmap_no >= bitmap_maxno) {
451 spin_unlock_irq(&cma->lock);
452 break;
453 }
454 bitmap_set(cma->bitmap, bitmap_no, bitmap_count);
455 /*
456 * It's safe to drop the lock here. We've marked this region for
457 * our exclusive use. If the migration fails we will take the
458 * lock again and unmark it.
459 */
460 spin_unlock_irq(&cma->lock);
461
462 pfn = cma->base_pfn + (bitmap_no << cma->order_per_bit);
463 mutex_lock(&cma_mutex);
464 ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA, gfp);
465 mutex_unlock(&cma_mutex);
466 if (ret == 0) {
467 page = pfn_to_page(pfn);
468 break;
469 }
470
471 cma_clear_bitmap(cma, pfn, count);
472 if (ret != -EBUSY)
473 break;
474
475 pr_debug("%s(): memory range at pfn 0x%lx %p is busy, retrying\n",
476 __func__, pfn, pfn_to_page(pfn));
477
478 trace_cma_alloc_busy_retry(cma->name, pfn, pfn_to_page(pfn),
479 count, align);
480 /* try again with a bit different memory target */
481 start = bitmap_no + mask + 1;
482 }
483
484 /*
485 * CMA can allocate multiple page blocks, which results in different
486 * blocks being marked with different tags. Reset the tags to ignore
487 * those page blocks.
488 */
489 if (page) {
490 for (i = 0; i < count; i++)
491 page_kasan_tag_reset(nth_page(page, i));
492 }
493
494 if (ret && !(gfp & __GFP_NOWARN)) {
495 pr_err_ratelimited("%s: %s: alloc failed, req-size: %lu pages, ret: %d\n",
496 __func__, cma->name, count, ret);
497 cma_debug_show_areas(cma);
498 }
499
500 pr_debug("%s(): returned %p\n", __func__, page);
501 trace_cma_alloc_finish(name, pfn, page, count, align, ret);
502 if (page) {
503 count_vm_event(CMA_ALLOC_SUCCESS);
504 cma_sysfs_account_success_pages(cma, count);
505 } else {
506 count_vm_event(CMA_ALLOC_FAIL);
507 cma_sysfs_account_fail_pages(cma, count);
508 }
509
510 return page;
511}
512
513/**
514 * cma_alloc() - allocate pages from contiguous area
515 * @cma: Contiguous memory region for which the allocation is performed.
516 * @count: Requested number of pages.
517 * @align: Requested alignment of pages (in PAGE_SIZE order).
518 * @no_warn: Avoid printing message about failed allocation
519 *
520 * This function allocates part of contiguous memory on specific
521 * contiguous memory area.
522 */
523struct page *cma_alloc(struct cma *cma, unsigned long count,
524 unsigned int align, bool no_warn)
525{
526 return __cma_alloc(cma, count, align, GFP_KERNEL | (no_warn ? __GFP_NOWARN : 0));
527}
528
529struct folio *cma_alloc_folio(struct cma *cma, int order, gfp_t gfp)
530{
531 struct page *page;
532
533 if (WARN_ON(!order || !(gfp & __GFP_COMP)))
534 return NULL;
535
536 page = __cma_alloc(cma, 1 << order, order, gfp);
537
538 return page ? page_folio(page) : NULL;
539}
540
541bool cma_pages_valid(struct cma *cma, const struct page *pages,
542 unsigned long count)
543{
544 unsigned long pfn;
545
546 if (!cma || !pages)
547 return false;
548
549 pfn = page_to_pfn(pages);
550
551 if (pfn < cma->base_pfn || pfn >= cma->base_pfn + cma->count) {
552 pr_debug("%s(page %p, count %lu)\n", __func__,
553 (void *)pages, count);
554 return false;
555 }
556
557 return true;
558}
559
560/**
561 * cma_release() - release allocated pages
562 * @cma: Contiguous memory region for which the allocation is performed.
563 * @pages: Allocated pages.
564 * @count: Number of allocated pages.
565 *
566 * This function releases memory allocated by cma_alloc().
567 * It returns false when provided pages do not belong to contiguous area and
568 * true otherwise.
569 */
570bool cma_release(struct cma *cma, const struct page *pages,
571 unsigned long count)
572{
573 unsigned long pfn;
574
575 if (!cma_pages_valid(cma, pages, count))
576 return false;
577
578 pr_debug("%s(page %p, count %lu)\n", __func__, (void *)pages, count);
579
580 pfn = page_to_pfn(pages);
581
582 VM_BUG_ON(pfn + count > cma->base_pfn + cma->count);
583
584 free_contig_range(pfn, count);
585 cma_clear_bitmap(cma, pfn, count);
586 cma_sysfs_account_release_pages(cma, count);
587 trace_cma_release(cma->name, pfn, pages, count);
588
589 return true;
590}
591
592bool cma_free_folio(struct cma *cma, const struct folio *folio)
593{
594 if (WARN_ON(!folio_test_large(folio)))
595 return false;
596
597 return cma_release(cma, &folio->page, folio_nr_pages(folio));
598}
599
600int cma_for_each_area(int (*it)(struct cma *cma, void *data), void *data)
601{
602 int i;
603
604 for (i = 0; i < cma_area_count; i++) {
605 int ret = it(&cma_areas[i], data);
606
607 if (ret)
608 return ret;
609 }
610
611 return 0;
612}