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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 <trace/events/cma.h>
39
40#include "cma.h"
41
42struct cma cma_areas[MAX_CMA_AREAS];
43unsigned cma_area_count;
44static DEFINE_MUTEX(cma_mutex);
45
46phys_addr_t cma_get_base(const struct cma *cma)
47{
48 return PFN_PHYS(cma->base_pfn);
49}
50
51unsigned long cma_get_size(const struct cma *cma)
52{
53 return cma->count << PAGE_SHIFT;
54}
55
56static unsigned long cma_bitmap_aligned_mask(const struct cma *cma,
57 int align_order)
58{
59 if (align_order <= cma->order_per_bit)
60 return 0;
61 return (1UL << (align_order - cma->order_per_bit)) - 1;
62}
63
64/*
65 * Find a PFN aligned to the specified order and return an offset represented in
66 * order_per_bits.
67 */
68static unsigned long cma_bitmap_aligned_offset(const struct cma *cma,
69 int align_order)
70{
71 if (align_order <= cma->order_per_bit)
72 return 0;
73
74 return (ALIGN(cma->base_pfn, (1UL << align_order))
75 - cma->base_pfn) >> cma->order_per_bit;
76}
77
78static unsigned long cma_bitmap_pages_to_bits(const struct cma *cma,
79 unsigned long pages)
80{
81 return ALIGN(pages, 1UL << cma->order_per_bit) >> cma->order_per_bit;
82}
83
84static void cma_clear_bitmap(struct cma *cma, unsigned long pfn,
85 unsigned int count)
86{
87 unsigned long bitmap_no, bitmap_count;
88
89 bitmap_no = (pfn - cma->base_pfn) >> cma->order_per_bit;
90 bitmap_count = cma_bitmap_pages_to_bits(cma, count);
91
92 mutex_lock(&cma->lock);
93 bitmap_clear(cma->bitmap, bitmap_no, bitmap_count);
94 mutex_unlock(&cma->lock);
95}
96
97static int __init cma_activate_area(struct cma *cma)
98{
99 int bitmap_size = BITS_TO_LONGS(cma_bitmap_maxno(cma)) * sizeof(long);
100 unsigned long base_pfn = cma->base_pfn, pfn = base_pfn;
101 unsigned i = cma->count >> pageblock_order;
102 struct zone *zone;
103
104 cma->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
105
106 if (!cma->bitmap)
107 return -ENOMEM;
108
109 WARN_ON_ONCE(!pfn_valid(pfn));
110 zone = page_zone(pfn_to_page(pfn));
111
112 do {
113 unsigned j;
114
115 base_pfn = pfn;
116 for (j = pageblock_nr_pages; j; --j, pfn++) {
117 WARN_ON_ONCE(!pfn_valid(pfn));
118 /*
119 * alloc_contig_range requires the pfn range
120 * specified to be in the same zone. Make this
121 * simple by forcing the entire CMA resv range
122 * to be in the same zone.
123 */
124 if (page_zone(pfn_to_page(pfn)) != zone)
125 goto err;
126 }
127 init_cma_reserved_pageblock(pfn_to_page(base_pfn));
128 } while (--i);
129
130 mutex_init(&cma->lock);
131
132#ifdef CONFIG_CMA_DEBUGFS
133 INIT_HLIST_HEAD(&cma->mem_head);
134 spin_lock_init(&cma->mem_head_lock);
135#endif
136
137 return 0;
138
139err:
140 kfree(cma->bitmap);
141 cma->count = 0;
142 return -EINVAL;
143}
144
145static int __init cma_init_reserved_areas(void)
146{
147 int i;
148
149 for (i = 0; i < cma_area_count; i++) {
150 int ret = cma_activate_area(&cma_areas[i]);
151
152 if (ret)
153 return ret;
154 }
155
156 return 0;
157}
158core_initcall(cma_init_reserved_areas);
159
160/**
161 * cma_init_reserved_mem() - create custom contiguous area from reserved memory
162 * @base: Base address of the reserved area
163 * @size: Size of the reserved area (in bytes),
164 * @order_per_bit: Order of pages represented by one bit on bitmap.
165 * @res_cma: Pointer to store the created cma region.
166 *
167 * This function creates custom contiguous area from already reserved memory.
168 */
169int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
170 unsigned int order_per_bit,
171 struct cma **res_cma)
172{
173 struct cma *cma;
174 phys_addr_t alignment;
175
176 /* Sanity checks */
177 if (cma_area_count == ARRAY_SIZE(cma_areas)) {
178 pr_err("Not enough slots for CMA reserved regions!\n");
179 return -ENOSPC;
180 }
181
182 if (!size || !memblock_is_region_reserved(base, size))
183 return -EINVAL;
184
185 /* ensure minimal alignment required by mm core */
186 alignment = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order);
187
188 /* alignment should be aligned with order_per_bit */
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
195 /*
196 * Each reserved area must be initialised later, when more kernel
197 * subsystems (like slab allocator) are available.
198 */
199 cma = &cma_areas[cma_area_count];
200 cma->base_pfn = PFN_DOWN(base);
201 cma->count = size >> PAGE_SHIFT;
202 cma->order_per_bit = order_per_bit;
203 *res_cma = cma;
204 cma_area_count++;
205 totalcma_pages += (size / PAGE_SIZE);
206
207 return 0;
208}
209
210/**
211 * cma_declare_contiguous() - reserve custom contiguous area
212 * @base: Base address of the reserved area optional, use 0 for any
213 * @size: Size of the reserved area (in bytes),
214 * @limit: End address of the reserved memory (optional, 0 for any).
215 * @alignment: Alignment for the CMA area, should be power of 2 or zero
216 * @order_per_bit: Order of pages represented by one bit on bitmap.
217 * @fixed: hint about where to place the reserved area
218 * @res_cma: Pointer to store the created cma region.
219 *
220 * This function reserves memory from early allocator. It should be
221 * called by arch specific code once the early allocator (memblock or bootmem)
222 * has been activated and all other subsystems have already allocated/reserved
223 * memory. This function allows to create custom reserved areas.
224 *
225 * If @fixed is true, reserve contiguous area at exactly @base. If false,
226 * reserve in range from @base to @limit.
227 */
228int __init cma_declare_contiguous(phys_addr_t base,
229 phys_addr_t size, phys_addr_t limit,
230 phys_addr_t alignment, unsigned int order_per_bit,
231 bool fixed, struct cma **res_cma)
232{
233 phys_addr_t memblock_end = memblock_end_of_DRAM();
234 phys_addr_t highmem_start;
235 int ret = 0;
236
237#ifdef CONFIG_X86
238 /*
239 * high_memory isn't direct mapped memory so retrieving its physical
240 * address isn't appropriate. But it would be useful to check the
241 * physical address of the highmem boundary so it's justifiable to get
242 * the physical address from it. On x86 there is a validation check for
243 * this case, so the following workaround is needed to avoid it.
244 */
245 highmem_start = __pa_nodebug(high_memory);
246#else
247 highmem_start = __pa(high_memory);
248#endif
249 pr_debug("%s(size %pa, base %pa, limit %pa alignment %pa)\n",
250 __func__, &size, &base, &limit, &alignment);
251
252 if (cma_area_count == ARRAY_SIZE(cma_areas)) {
253 pr_err("Not enough slots for CMA reserved regions!\n");
254 return -ENOSPC;
255 }
256
257 if (!size)
258 return -EINVAL;
259
260 if (alignment && !is_power_of_2(alignment))
261 return -EINVAL;
262
263 /*
264 * Sanitise input arguments.
265 * Pages both ends in CMA area could be merged into adjacent unmovable
266 * migratetype page by page allocator's buddy algorithm. In the case,
267 * you couldn't get a contiguous memory, which is not what we want.
268 */
269 alignment = max(alignment,
270 (phys_addr_t)PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order));
271 base = ALIGN(base, alignment);
272 size = ALIGN(size, alignment);
273 limit &= ~(alignment - 1);
274
275 if (!base)
276 fixed = false;
277
278 /* size should be aligned with order_per_bit */
279 if (!IS_ALIGNED(size >> PAGE_SHIFT, 1 << order_per_bit))
280 return -EINVAL;
281
282 /*
283 * If allocating at a fixed base the request region must not cross the
284 * low/high memory boundary.
285 */
286 if (fixed && base < highmem_start && base + size > highmem_start) {
287 ret = -EINVAL;
288 pr_err("Region at %pa defined on low/high memory boundary (%pa)\n",
289 &base, &highmem_start);
290 goto err;
291 }
292
293 /*
294 * If the limit is unspecified or above the memblock end, its effective
295 * value will be the memblock end. Set it explicitly to simplify further
296 * checks.
297 */
298 if (limit == 0 || limit > memblock_end)
299 limit = memblock_end;
300
301 /* Reserve memory */
302 if (fixed) {
303 if (memblock_is_region_reserved(base, size) ||
304 memblock_reserve(base, size) < 0) {
305 ret = -EBUSY;
306 goto err;
307 }
308 } else {
309 phys_addr_t addr = 0;
310
311 /*
312 * All pages in the reserved area must come from the same zone.
313 * If the requested region crosses the low/high memory boundary,
314 * try allocating from high memory first and fall back to low
315 * memory in case of failure.
316 */
317 if (base < highmem_start && limit > highmem_start) {
318 addr = memblock_alloc_range(size, alignment,
319 highmem_start, limit,
320 MEMBLOCK_NONE);
321 limit = highmem_start;
322 }
323
324 if (!addr) {
325 addr = memblock_alloc_range(size, alignment, base,
326 limit,
327 MEMBLOCK_NONE);
328 if (!addr) {
329 ret = -ENOMEM;
330 goto err;
331 }
332 }
333
334 /*
335 * kmemleak scans/reads tracked objects for pointers to other
336 * objects but this address isn't mapped and accessible
337 */
338 kmemleak_ignore(phys_to_virt(addr));
339 base = addr;
340 }
341
342 ret = cma_init_reserved_mem(base, size, order_per_bit, res_cma);
343 if (ret)
344 goto err;
345
346 pr_info("Reserved %ld MiB at %pa\n", (unsigned long)size / SZ_1M,
347 &base);
348 return 0;
349
350err:
351 pr_err("Failed to reserve %ld MiB\n", (unsigned long)size / SZ_1M);
352 return ret;
353}
354
355/**
356 * cma_alloc() - allocate pages from contiguous area
357 * @cma: Contiguous memory region for which the allocation is performed.
358 * @count: Requested number of pages.
359 * @align: Requested alignment of pages (in PAGE_SIZE order).
360 *
361 * This function allocates part of contiguous memory on specific
362 * contiguous memory area.
363 */
364struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align)
365{
366 unsigned long mask, offset;
367 unsigned long pfn = -1;
368 unsigned long start = 0;
369 unsigned long bitmap_maxno, bitmap_no, bitmap_count;
370 struct page *page = NULL;
371 int ret;
372
373 if (!cma || !cma->count)
374 return NULL;
375
376 pr_debug("%s(cma %p, count %zu, align %d)\n", __func__, (void *)cma,
377 count, align);
378
379 if (!count)
380 return NULL;
381
382 mask = cma_bitmap_aligned_mask(cma, align);
383 offset = cma_bitmap_aligned_offset(cma, align);
384 bitmap_maxno = cma_bitmap_maxno(cma);
385 bitmap_count = cma_bitmap_pages_to_bits(cma, count);
386
387 for (;;) {
388 mutex_lock(&cma->lock);
389 bitmap_no = bitmap_find_next_zero_area_off(cma->bitmap,
390 bitmap_maxno, start, bitmap_count, mask,
391 offset);
392 if (bitmap_no >= bitmap_maxno) {
393 mutex_unlock(&cma->lock);
394 break;
395 }
396 bitmap_set(cma->bitmap, bitmap_no, bitmap_count);
397 /*
398 * It's safe to drop the lock here. We've marked this region for
399 * our exclusive use. If the migration fails we will take the
400 * lock again and unmark it.
401 */
402 mutex_unlock(&cma->lock);
403
404 pfn = cma->base_pfn + (bitmap_no << cma->order_per_bit);
405 mutex_lock(&cma_mutex);
406 ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA);
407 mutex_unlock(&cma_mutex);
408 if (ret == 0) {
409 page = pfn_to_page(pfn);
410 break;
411 }
412
413 cma_clear_bitmap(cma, pfn, count);
414 if (ret != -EBUSY)
415 break;
416
417 pr_debug("%s(): memory range at %p is busy, retrying\n",
418 __func__, pfn_to_page(pfn));
419 /* try again with a bit different memory target */
420 start = bitmap_no + mask + 1;
421 }
422
423 trace_cma_alloc(pfn, page, count, align);
424
425 pr_debug("%s(): returned %p\n", __func__, page);
426 return page;
427}
428
429/**
430 * cma_release() - release allocated pages
431 * @cma: Contiguous memory region for which the allocation is performed.
432 * @pages: Allocated pages.
433 * @count: Number of allocated pages.
434 *
435 * This function releases memory allocated by alloc_cma().
436 * It returns false when provided pages do not belong to contiguous area and
437 * true otherwise.
438 */
439bool cma_release(struct cma *cma, const struct page *pages, unsigned int count)
440{
441 unsigned long pfn;
442
443 if (!cma || !pages)
444 return false;
445
446 pr_debug("%s(page %p)\n", __func__, (void *)pages);
447
448 pfn = page_to_pfn(pages);
449
450 if (pfn < cma->base_pfn || pfn >= cma->base_pfn + cma->count)
451 return false;
452
453 VM_BUG_ON(pfn + count > cma->base_pfn + cma->count);
454
455 free_contig_range(pfn, count);
456 cma_clear_bitmap(cma, pfn, count);
457 trace_cma_release(pfn, pages, count);
458
459 return true;
460}
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}