blob: 5fc18097fcc5bde025b0c795143b91b00b7dfa3d [file] [log] [blame]
Joonsoo Kima2541292014-08-06 16:05:25 -07001/*
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
Stefan Strogin99e8ea62015-04-15 16:14:50 -070026#define CREATE_TRACE_POINTS
Joonsoo Kima2541292014-08-06 16:05:25 -070027
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>
Marek Szyprowskif7426b92014-10-09 15:26:47 -070036#include <linux/highmem.h>
Thierry Reding620951e2014-12-12 16:58:31 -080037#include <linux/io.h>
Liam Mark51934022015-10-23 12:14:11 -070038#include <linux/delay.h>
Prakash Guptaa0d60fa2017-08-02 12:30:55 +053039#include <linux/show_mem_notifier.h>
Stefan Strogin99e8ea62015-04-15 16:14:50 -070040#include <trace/events/cma.h>
Joonsoo Kima2541292014-08-06 16:05:25 -070041
Sasha Levin28b24c12015-04-14 15:44:57 -070042#include "cma.h"
Joonsoo Kima2541292014-08-06 16:05:25 -070043
Sasha Levin28b24c12015-04-14 15:44:57 -070044struct cma cma_areas[MAX_CMA_AREAS];
45unsigned cma_area_count;
Joonsoo Kima2541292014-08-06 16:05:25 -070046static DEFINE_MUTEX(cma_mutex);
47
Sasha Levinac173822015-04-14 15:47:04 -070048phys_addr_t cma_get_base(const struct cma *cma)
Joonsoo Kima2541292014-08-06 16:05:25 -070049{
50 return PFN_PHYS(cma->base_pfn);
51}
52
Sasha Levinac173822015-04-14 15:47:04 -070053unsigned long cma_get_size(const struct cma *cma)
Joonsoo Kima2541292014-08-06 16:05:25 -070054{
55 return cma->count << PAGE_SHIFT;
56}
57
Laura Abbott77dbb1d2017-04-18 11:27:03 -070058const char *cma_get_name(const struct cma *cma)
59{
60 return cma->name ? cma->name : "(undefined)";
61}
62
Sasha Levinac173822015-04-14 15:47:04 -070063static unsigned long cma_bitmap_aligned_mask(const struct cma *cma,
Doug Berger714c19e2017-07-10 15:49:44 -070064 unsigned int align_order)
Joonsoo Kima2541292014-08-06 16:05:25 -070065{
Weijie Yang68faed62014-10-13 15:51:03 -070066 if (align_order <= cma->order_per_bit)
67 return 0;
68 return (1UL << (align_order - cma->order_per_bit)) - 1;
Joonsoo Kima2541292014-08-06 16:05:25 -070069}
70
Danesh Petigara850fc432015-03-12 16:25:57 -070071/*
Doug Berger714c19e2017-07-10 15:49:44 -070072 * Find the offset of the base PFN from the specified align_order.
73 * The value returned is represented in order_per_bits.
Danesh Petigara850fc432015-03-12 16:25:57 -070074 */
Sasha Levinac173822015-04-14 15:47:04 -070075static unsigned long cma_bitmap_aligned_offset(const struct cma *cma,
Doug Berger714c19e2017-07-10 15:49:44 -070076 unsigned int align_order)
Gregory Fongb5be83e2014-12-12 16:54:48 -080077{
Doug Berger714c19e2017-07-10 15:49:44 -070078 return (cma->base_pfn & ((1UL << align_order) - 1))
79 >> cma->order_per_bit;
Gregory Fongb5be83e2014-12-12 16:54:48 -080080}
81
Sasha Levinac173822015-04-14 15:47:04 -070082static unsigned long cma_bitmap_pages_to_bits(const struct cma *cma,
83 unsigned long pages)
Joonsoo Kima2541292014-08-06 16:05:25 -070084{
85 return ALIGN(pages, 1UL << cma->order_per_bit) >> cma->order_per_bit;
86}
87
Sasha Levinac173822015-04-14 15:47:04 -070088static void cma_clear_bitmap(struct cma *cma, unsigned long pfn,
89 unsigned int count)
Joonsoo Kima2541292014-08-06 16:05:25 -070090{
91 unsigned long bitmap_no, bitmap_count;
92
93 bitmap_no = (pfn - cma->base_pfn) >> cma->order_per_bit;
94 bitmap_count = cma_bitmap_pages_to_bits(cma, count);
95
96 mutex_lock(&cma->lock);
97 bitmap_clear(cma->bitmap, bitmap_no, bitmap_count);
98 mutex_unlock(&cma->lock);
99}
100
Prakash Guptaa0d60fa2017-08-02 12:30:55 +0530101static int cma_showmem_notifier(struct notifier_block *nb,
102 unsigned long action, void *data)
103{
104 int i;
105 unsigned long used;
106 struct cma *cma;
107
108 for (i = 0; i < cma_area_count; i++) {
109 cma = &cma_areas[i];
110 used = bitmap_weight(cma->bitmap,
111 (int)cma_bitmap_maxno(cma));
112 used <<= cma->order_per_bit;
113 pr_info("cma-%d pages: => %lu used of %lu total pages\n",
114 i, used, cma->count);
115 }
116
117 return 0;
118}
119
120static struct notifier_block cma_nb = {
121 .notifier_call = cma_showmem_notifier,
122};
123
Joonsoo Kima2541292014-08-06 16:05:25 -0700124static int __init cma_activate_area(struct cma *cma)
125{
126 int bitmap_size = BITS_TO_LONGS(cma_bitmap_maxno(cma)) * sizeof(long);
127 unsigned long base_pfn = cma->base_pfn, pfn = base_pfn;
128 unsigned i = cma->count >> pageblock_order;
129 struct zone *zone;
130
131 cma->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
132
133 if (!cma->bitmap)
134 return -ENOMEM;
135
136 WARN_ON_ONCE(!pfn_valid(pfn));
137 zone = page_zone(pfn_to_page(pfn));
138
139 do {
140 unsigned j;
141
142 base_pfn = pfn;
143 for (j = pageblock_nr_pages; j; --j, pfn++) {
144 WARN_ON_ONCE(!pfn_valid(pfn));
145 /*
146 * alloc_contig_range requires the pfn range
147 * specified to be in the same zone. Make this
148 * simple by forcing the entire CMA resv range
149 * to be in the same zone.
150 */
151 if (page_zone(pfn_to_page(pfn)) != zone)
152 goto err;
153 }
154 init_cma_reserved_pageblock(pfn_to_page(base_pfn));
155 } while (--i);
156
157 mutex_init(&cma->lock);
Sasha Levin26b02a12015-04-14 15:44:59 -0700158
159#ifdef CONFIG_CMA_DEBUGFS
160 INIT_HLIST_HEAD(&cma->mem_head);
161 spin_lock_init(&cma->mem_head_lock);
162#endif
163
Shiraz Hashima24e0232016-02-15 16:26:37 +0530164 if (!PageHighMem(pfn_to_page(cma->base_pfn)))
165 kmemleak_free_part(__va(cma->base_pfn << PAGE_SHIFT),
166 cma->count << PAGE_SHIFT);
167
Joonsoo Kima2541292014-08-06 16:05:25 -0700168 return 0;
169
170err:
171 kfree(cma->bitmap);
Laurent Pinchartf022d8c2014-10-24 13:18:39 +0300172 cma->count = 0;
Joonsoo Kima2541292014-08-06 16:05:25 -0700173 return -EINVAL;
174}
175
176static int __init cma_init_reserved_areas(void)
177{
178 int i;
179
180 for (i = 0; i < cma_area_count; i++) {
181 int ret = cma_activate_area(&cma_areas[i]);
182
183 if (ret)
184 return ret;
185 }
186
Prakash Guptaa0d60fa2017-08-02 12:30:55 +0530187 show_mem_notifier_register(&cma_nb);
188
Joonsoo Kima2541292014-08-06 16:05:25 -0700189 return 0;
190}
191core_initcall(cma_init_reserved_areas);
192
193/**
Marek Szyprowskide9e14e2014-10-13 15:51:09 -0700194 * cma_init_reserved_mem() - create custom contiguous area from reserved memory
195 * @base: Base address of the reserved area
196 * @size: Size of the reserved area (in bytes),
197 * @order_per_bit: Order of pages represented by one bit on bitmap.
198 * @res_cma: Pointer to store the created cma region.
199 *
200 * This function creates custom contiguous area from already reserved memory.
201 */
202int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
Sasha Levinac173822015-04-14 15:47:04 -0700203 unsigned int order_per_bit,
Laura Abbott77dbb1d2017-04-18 11:27:03 -0700204 const char *name,
Sasha Levinac173822015-04-14 15:47:04 -0700205 struct cma **res_cma)
Marek Szyprowskide9e14e2014-10-13 15:51:09 -0700206{
207 struct cma *cma;
208 phys_addr_t alignment;
209
210 /* Sanity checks */
211 if (cma_area_count == ARRAY_SIZE(cma_areas)) {
212 pr_err("Not enough slots for CMA reserved regions!\n");
213 return -ENOSPC;
214 }
215
216 if (!size || !memblock_is_region_reserved(base, size))
217 return -EINVAL;
218
Shailendra Verma0f96ae22015-06-24 16:58:03 -0700219 /* ensure minimal alignment required by mm core */
Stephen Rothwellbadbda52016-05-27 14:27:41 -0700220 alignment = PAGE_SIZE <<
221 max_t(unsigned long, MAX_ORDER - 1, pageblock_order);
Marek Szyprowskide9e14e2014-10-13 15:51:09 -0700222
223 /* alignment should be aligned with order_per_bit */
224 if (!IS_ALIGNED(alignment >> PAGE_SHIFT, 1 << order_per_bit))
225 return -EINVAL;
226
227 if (ALIGN(base, alignment) != base || ALIGN(size, alignment) != size)
228 return -EINVAL;
229
230 /*
231 * Each reserved area must be initialised later, when more kernel
232 * subsystems (like slab allocator) are available.
233 */
234 cma = &cma_areas[cma_area_count];
Laura Abbott77dbb1d2017-04-18 11:27:03 -0700235 if (name) {
236 cma->name = name;
237 } else {
238 cma->name = kasprintf(GFP_KERNEL, "cma%d\n", cma_area_count);
239 if (!cma->name)
240 return -ENOMEM;
241 }
Marek Szyprowskide9e14e2014-10-13 15:51:09 -0700242 cma->base_pfn = PFN_DOWN(base);
243 cma->count = size >> PAGE_SHIFT;
244 cma->order_per_bit = order_per_bit;
245 *res_cma = cma;
246 cma_area_count++;
George G. Davis94737a82015-02-11 15:26:27 -0800247 totalcma_pages += (size / PAGE_SIZE);
Marek Szyprowskide9e14e2014-10-13 15:51:09 -0700248
249 return 0;
250}
251
252/**
Joonsoo Kima2541292014-08-06 16:05:25 -0700253 * cma_declare_contiguous() - reserve custom contiguous area
Joonsoo Kima2541292014-08-06 16:05:25 -0700254 * @base: Base address of the reserved area optional, use 0 for any
Joonsoo Kimc1f733a2014-08-06 16:05:32 -0700255 * @size: Size of the reserved area (in bytes),
Joonsoo Kima2541292014-08-06 16:05:25 -0700256 * @limit: End address of the reserved memory (optional, 0 for any).
257 * @alignment: Alignment for the CMA area, should be power of 2 or zero
258 * @order_per_bit: Order of pages represented by one bit on bitmap.
Joonsoo Kima2541292014-08-06 16:05:25 -0700259 * @fixed: hint about where to place the reserved area
Joonsoo Kimc1f733a2014-08-06 16:05:32 -0700260 * @res_cma: Pointer to store the created cma region.
Joonsoo Kima2541292014-08-06 16:05:25 -0700261 *
262 * This function reserves memory from early allocator. It should be
263 * called by arch specific code once the early allocator (memblock or bootmem)
264 * has been activated and all other subsystems have already allocated/reserved
265 * memory. This function allows to create custom reserved areas.
266 *
267 * If @fixed is true, reserve contiguous area at exactly @base. If false,
268 * reserve in range from @base to @limit.
269 */
Joonsoo Kimc1f733a2014-08-06 16:05:32 -0700270int __init cma_declare_contiguous(phys_addr_t base,
271 phys_addr_t size, phys_addr_t limit,
Joonsoo Kima2541292014-08-06 16:05:25 -0700272 phys_addr_t alignment, unsigned int order_per_bit,
Laura Abbott77dbb1d2017-04-18 11:27:03 -0700273 bool fixed, const char *name, struct cma **res_cma)
Joonsoo Kima2541292014-08-06 16:05:25 -0700274{
Marek Szyprowskif7426b92014-10-09 15:26:47 -0700275 phys_addr_t memblock_end = memblock_end_of_DRAM();
Joonsoo Kim6b101e22014-12-10 15:41:12 -0800276 phys_addr_t highmem_start;
Joonsoo Kima2541292014-08-06 16:05:25 -0700277 int ret = 0;
278
Joonsoo Kim6b101e22014-12-10 15:41:12 -0800279#ifdef CONFIG_X86
280 /*
281 * high_memory isn't direct mapped memory so retrieving its physical
282 * address isn't appropriate. But it would be useful to check the
Shailendra Verma0f96ae22015-06-24 16:58:03 -0700283 * physical address of the highmem boundary so it's justifiable to get
Joonsoo Kim6b101e22014-12-10 15:41:12 -0800284 * the physical address from it. On x86 there is a validation check for
285 * this case, so the following workaround is needed to avoid it.
286 */
287 highmem_start = __pa_nodebug(high_memory);
288#else
289 highmem_start = __pa(high_memory);
290#endif
Laurent Pinchart56fa4f62014-10-24 13:18:42 +0300291 pr_debug("%s(size %pa, base %pa, limit %pa alignment %pa)\n",
292 __func__, &size, &base, &limit, &alignment);
Joonsoo Kima2541292014-08-06 16:05:25 -0700293
294 if (cma_area_count == ARRAY_SIZE(cma_areas)) {
295 pr_err("Not enough slots for CMA reserved regions!\n");
296 return -ENOSPC;
297 }
298
299 if (!size)
300 return -EINVAL;
301
302 if (alignment && !is_power_of_2(alignment))
303 return -EINVAL;
304
305 /*
306 * Sanitise input arguments.
307 * Pages both ends in CMA area could be merged into adjacent unmovable
308 * migratetype page by page allocator's buddy algorithm. In the case,
309 * you couldn't get a contiguous memory, which is not what we want.
310 */
Stephen Rothwellbadbda52016-05-27 14:27:41 -0700311 alignment = max(alignment, (phys_addr_t)PAGE_SIZE <<
312 max_t(unsigned long, MAX_ORDER - 1, pageblock_order));
Joonsoo Kima2541292014-08-06 16:05:25 -0700313 base = ALIGN(base, alignment);
314 size = ALIGN(size, alignment);
315 limit &= ~(alignment - 1);
316
Laurent Pinchart800a85d2014-10-24 13:18:40 +0300317 if (!base)
318 fixed = false;
319
Joonsoo Kima2541292014-08-06 16:05:25 -0700320 /* size should be aligned with order_per_bit */
321 if (!IS_ALIGNED(size >> PAGE_SHIFT, 1 << order_per_bit))
322 return -EINVAL;
323
Marek Szyprowskif7426b92014-10-09 15:26:47 -0700324 /*
Laurent Pinchart16195dd2014-10-24 13:18:41 +0300325 * If allocating at a fixed base the request region must not cross the
326 * low/high memory boundary.
Marek Szyprowskif7426b92014-10-09 15:26:47 -0700327 */
Laurent Pinchart16195dd2014-10-24 13:18:41 +0300328 if (fixed && base < highmem_start && base + size > highmem_start) {
Marek Szyprowskif7426b92014-10-09 15:26:47 -0700329 ret = -EINVAL;
Laurent Pinchart56fa4f62014-10-24 13:18:42 +0300330 pr_err("Region at %pa defined on low/high memory boundary (%pa)\n",
331 &base, &highmem_start);
Marek Szyprowskif7426b92014-10-09 15:26:47 -0700332 goto err;
333 }
334
Laurent Pinchart16195dd2014-10-24 13:18:41 +0300335 /*
336 * If the limit is unspecified or above the memblock end, its effective
337 * value will be the memblock end. Set it explicitly to simplify further
338 * checks.
339 */
340 if (limit == 0 || limit > memblock_end)
341 limit = memblock_end;
342
Joonsoo Kima2541292014-08-06 16:05:25 -0700343 /* Reserve memory */
Laurent Pinchart800a85d2014-10-24 13:18:40 +0300344 if (fixed) {
Joonsoo Kima2541292014-08-06 16:05:25 -0700345 if (memblock_is_region_reserved(base, size) ||
346 memblock_reserve(base, size) < 0) {
347 ret = -EBUSY;
348 goto err;
349 }
350 } else {
Laurent Pinchart16195dd2014-10-24 13:18:41 +0300351 phys_addr_t addr = 0;
352
353 /*
354 * All pages in the reserved area must come from the same zone.
355 * If the requested region crosses the low/high memory boundary,
356 * try allocating from high memory first and fall back to low
357 * memory in case of failure.
358 */
359 if (base < highmem_start && limit > highmem_start) {
360 addr = memblock_alloc_range(size, alignment,
Tony Luckfc6daaf2015-06-24 16:58:09 -0700361 highmem_start, limit,
362 MEMBLOCK_NONE);
Laurent Pinchart16195dd2014-10-24 13:18:41 +0300363 limit = highmem_start;
Joonsoo Kima2541292014-08-06 16:05:25 -0700364 }
Laurent Pinchart16195dd2014-10-24 13:18:41 +0300365
366 if (!addr) {
367 addr = memblock_alloc_range(size, alignment, base,
Tony Luckfc6daaf2015-06-24 16:58:09 -0700368 limit,
369 MEMBLOCK_NONE);
Laurent Pinchart16195dd2014-10-24 13:18:41 +0300370 if (!addr) {
371 ret = -ENOMEM;
372 goto err;
373 }
374 }
375
Thierry Reding620951e2014-12-12 16:58:31 -0800376 /*
377 * kmemleak scans/reads tracked objects for pointers to other
378 * objects but this address isn't mapped and accessible
379 */
Catalin Marinas9099dae2016-10-11 13:55:11 -0700380 kmemleak_ignore_phys(addr);
Laurent Pinchart16195dd2014-10-24 13:18:41 +0300381 base = addr;
Joonsoo Kima2541292014-08-06 16:05:25 -0700382 }
383
Laura Abbott77dbb1d2017-04-18 11:27:03 -0700384 ret = cma_init_reserved_mem(base, size, order_per_bit, name, res_cma);
Marek Szyprowskide9e14e2014-10-13 15:51:09 -0700385 if (ret)
386 goto err;
Joonsoo Kima2541292014-08-06 16:05:25 -0700387
Laurent Pinchart56fa4f62014-10-24 13:18:42 +0300388 pr_info("Reserved %ld MiB at %pa\n", (unsigned long)size / SZ_1M,
389 &base);
Joonsoo Kima2541292014-08-06 16:05:25 -0700390 return 0;
391
392err:
Joonsoo Kim0de9d2e2014-08-06 16:05:34 -0700393 pr_err("Failed to reserve %ld MiB\n", (unsigned long)size / SZ_1M);
Joonsoo Kima2541292014-08-06 16:05:25 -0700394 return ret;
395}
396
Jaewon Kimefb354d2017-02-24 14:58:50 -0800397#ifdef CONFIG_CMA_DEBUG
398static void cma_debug_show_areas(struct cma *cma)
399{
400 unsigned long next_zero_bit, next_set_bit;
401 unsigned long start = 0;
402 unsigned int nr_zero, nr_total = 0;
403
404 mutex_lock(&cma->lock);
405 pr_info("number of available pages: ");
406 for (;;) {
407 next_zero_bit = find_next_zero_bit(cma->bitmap, cma->count, start);
408 if (next_zero_bit >= cma->count)
409 break;
410 next_set_bit = find_next_bit(cma->bitmap, cma->count, next_zero_bit);
411 nr_zero = next_set_bit - next_zero_bit;
412 pr_cont("%s%u@%lu", nr_total ? "+" : "", nr_zero, next_zero_bit);
413 nr_total += nr_zero;
414 start = next_zero_bit + nr_zero;
415 }
416 pr_cont("=> %u free of %lu total pages\n", nr_total, cma->count);
417 mutex_unlock(&cma->lock);
418}
419#else
420static inline void cma_debug_show_areas(struct cma *cma) { }
421#endif
422
Joonsoo Kima2541292014-08-06 16:05:25 -0700423/**
424 * cma_alloc() - allocate pages from contiguous area
425 * @cma: Contiguous memory region for which the allocation is performed.
426 * @count: Requested number of pages.
427 * @align: Requested alignment of pages (in PAGE_SIZE order).
428 *
429 * This function allocates part of contiguous memory on specific
430 * contiguous memory area.
431 */
Rohit Vaswani67a2e2132015-10-22 13:32:11 -0700432struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align)
Joonsoo Kima2541292014-08-06 16:05:25 -0700433{
Andrew Morton3acaea62015-11-05 18:50:08 -0800434 unsigned long mask, offset;
435 unsigned long pfn = -1;
436 unsigned long start = 0;
Joonsoo Kima2541292014-08-06 16:05:25 -0700437 unsigned long bitmap_maxno, bitmap_no, bitmap_count;
438 struct page *page = NULL;
Liam Mark51934022015-10-23 12:14:11 -0700439 int retry_after_sleep = 0;
Jaewon Kimefb354d2017-02-24 14:58:50 -0800440 int ret = -ENOMEM;
Joonsoo Kima2541292014-08-06 16:05:25 -0700441
442 if (!cma || !cma->count)
443 return NULL;
444
Rohit Vaswani67a2e2132015-10-22 13:32:11 -0700445 pr_debug("%s(cma %p, count %zu, align %d)\n", __func__, (void *)cma,
Joonsoo Kima2541292014-08-06 16:05:25 -0700446 count, align);
447
448 if (!count)
449 return NULL;
450
Liam Mark9645c9e2015-11-25 14:37:54 -0800451 trace_cma_alloc_start(count, align);
452
Joonsoo Kima2541292014-08-06 16:05:25 -0700453 mask = cma_bitmap_aligned_mask(cma, align);
Gregory Fongb5be83e2014-12-12 16:54:48 -0800454 offset = cma_bitmap_aligned_offset(cma, align);
Joonsoo Kima2541292014-08-06 16:05:25 -0700455 bitmap_maxno = cma_bitmap_maxno(cma);
456 bitmap_count = cma_bitmap_pages_to_bits(cma, count);
457
Shiraz Hashim6b36ba52016-11-10 10:46:16 -0800458 if (bitmap_count > bitmap_maxno)
459 return NULL;
460
Joonsoo Kima2541292014-08-06 16:05:25 -0700461 for (;;) {
462 mutex_lock(&cma->lock);
Gregory Fongb5be83e2014-12-12 16:54:48 -0800463 bitmap_no = bitmap_find_next_zero_area_off(cma->bitmap,
464 bitmap_maxno, start, bitmap_count, mask,
465 offset);
Joonsoo Kima2541292014-08-06 16:05:25 -0700466 if (bitmap_no >= bitmap_maxno) {
Liam Mark51934022015-10-23 12:14:11 -0700467 if (retry_after_sleep < 2) {
468 start = 0;
469 /*
470 * Page may be momentarily pinned by some other
471 * process which has been scheduled out, eg.
472 * in exit path, during unmap call, or process
473 * fork and so cannot be freed there. Sleep
474 * for 100ms and retry twice to see if it has
475 * been freed later.
476 */
477 mutex_unlock(&cma->lock);
478 msleep(100);
479 retry_after_sleep++;
480 continue;
481 } else {
482 mutex_unlock(&cma->lock);
483 break;
484 }
Joonsoo Kima2541292014-08-06 16:05:25 -0700485 }
486 bitmap_set(cma->bitmap, bitmap_no, bitmap_count);
487 /*
488 * It's safe to drop the lock here. We've marked this region for
489 * our exclusive use. If the migration fails we will take the
490 * lock again and unmark it.
491 */
492 mutex_unlock(&cma->lock);
493
494 pfn = cma->base_pfn + (bitmap_no << cma->order_per_bit);
495 mutex_lock(&cma_mutex);
496 ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA);
497 mutex_unlock(&cma_mutex);
498 if (ret == 0) {
499 page = pfn_to_page(pfn);
500 break;
Joonsoo Kima2541292014-08-06 16:05:25 -0700501 }
Joonsoo Kimb7155e72014-08-06 16:05:30 -0700502
Joonsoo Kima2541292014-08-06 16:05:25 -0700503 cma_clear_bitmap(cma, pfn, count);
Joonsoo Kimb7155e72014-08-06 16:05:30 -0700504 if (ret != -EBUSY)
505 break;
506
Joonsoo Kima2541292014-08-06 16:05:25 -0700507 pr_debug("%s(): memory range at %p is busy, retrying\n",
508 __func__, pfn_to_page(pfn));
Liam Mark9645c9e2015-11-25 14:37:54 -0800509
510 trace_cma_alloc_busy_retry(pfn, pfn_to_page(pfn), count, align);
Joonsoo Kima2541292014-08-06 16:05:25 -0700511 /* try again with a bit different memory target */
512 start = bitmap_no + mask + 1;
513 }
514
Andrew Morton3acaea62015-11-05 18:50:08 -0800515 trace_cma_alloc(pfn, page, count, align);
Stefan Strogin99e8ea62015-04-15 16:14:50 -0700516
Jaewon Kimefb354d2017-02-24 14:58:50 -0800517 if (ret) {
518 pr_info("%s: alloc failed, req-size: %zu pages, ret: %d\n",
519 __func__, count, ret);
520 cma_debug_show_areas(cma);
521 }
522
Joonsoo Kima2541292014-08-06 16:05:25 -0700523 pr_debug("%s(): returned %p\n", __func__, page);
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 *
533 * This function releases memory allocated by alloc_cma().
534 * It returns false when provided pages do not belong to contiguous area and
535 * true otherwise.
536 */
Sasha Levinac173822015-04-14 15:47:04 -0700537bool cma_release(struct cma *cma, const struct page *pages, unsigned int count)
Joonsoo Kima2541292014-08-06 16:05:25 -0700538{
539 unsigned long pfn;
540
541 if (!cma || !pages)
542 return false;
543
544 pr_debug("%s(page %p)\n", __func__, (void *)pages);
545
546 pfn = page_to_pfn(pages);
547
548 if (pfn < cma->base_pfn || pfn >= cma->base_pfn + cma->count)
549 return false;
550
551 VM_BUG_ON(pfn + count > cma->base_pfn + cma->count);
552
553 free_contig_range(pfn, count);
554 cma_clear_bitmap(cma, pfn, count);
Stefan Strogin99e8ea62015-04-15 16:14:50 -0700555 trace_cma_release(pfn, pages, count);
Joonsoo Kima2541292014-08-06 16:05:25 -0700556
557 return true;
558}