Merge tag 'compat-ioctl-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd...
[linux-2.6-block.git] / kernel / dma / contiguous.c
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989d42e8 1// SPDX-License-Identifier: GPL-2.0+
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2/*
3 * Contiguous Memory Allocator for DMA mapping framework
4 * Copyright (c) 2010-2011 by Samsung Electronics.
5 * Written by:
6 * Marek Szyprowski <m.szyprowski@samsung.com>
7 * Michal Nazarewicz <mina86@mina86.com>
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8 */
9
10#define pr_fmt(fmt) "cma: " fmt
11
12#ifdef CONFIG_CMA_DEBUG
13#ifndef DEBUG
14# define DEBUG
15#endif
16#endif
17
18#include <asm/page.h>
19#include <asm/dma-contiguous.h>
20
21#include <linux/memblock.h>
22#include <linux/err.h>
446c82fc 23#include <linux/sizes.h>
c64be2bb 24#include <linux/dma-contiguous.h>
a254129e 25#include <linux/cma.h>
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26
27#ifdef CONFIG_CMA_SIZE_MBYTES
28#define CMA_SIZE_MBYTES CONFIG_CMA_SIZE_MBYTES
29#else
30#define CMA_SIZE_MBYTES 0
31#endif
32
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33struct cma *dma_contiguous_default_area;
34
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35/*
36 * Default global CMA area size can be defined in kernel's .config.
73678804 37 * This is useful mainly for distro maintainers to create a kernel
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38 * that works correctly for most supported systems.
39 * The size can be set in bytes or as a percentage of the total memory
40 * in the system.
41 *
42 * Users, who want to set the size of global CMA area for their system
43 * should use cma= kernel parameter.
44 */
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45static const phys_addr_t size_bytes __initconst =
46 (phys_addr_t)CMA_SIZE_MBYTES * SZ_1M;
47static phys_addr_t size_cmdline __initdata = -1;
48static phys_addr_t base_cmdline __initdata;
49static phys_addr_t limit_cmdline __initdata;
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50
51static int __init early_cma(char *p)
52{
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53 if (!p) {
54 pr_err("Config string not provided\n");
55 return -EINVAL;
56 }
57
c64be2bb 58 size_cmdline = memparse(p, &p);
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59 if (*p != '@')
60 return 0;
61 base_cmdline = memparse(p + 1, &p);
62 if (*p != '-') {
63 limit_cmdline = base_cmdline + size_cmdline;
64 return 0;
65 }
66 limit_cmdline = memparse(p + 1, &p);
67
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68 return 0;
69}
70early_param("cma", early_cma);
71
72#ifdef CONFIG_CMA_SIZE_PERCENTAGE
73
4009793e 74static phys_addr_t __init __maybe_unused cma_early_percent_memory(void)
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75{
76 struct memblock_region *reg;
77 unsigned long total_pages = 0;
78
79 /*
80 * We cannot use memblock_phys_mem_size() here, because
81 * memblock_analyze() has not been called yet.
82 */
83 for_each_memblock(memory, reg)
84 total_pages += memblock_region_memory_end_pfn(reg) -
85 memblock_region_memory_base_pfn(reg);
86
87 return (total_pages * CONFIG_CMA_SIZE_PERCENTAGE / 100) << PAGE_SHIFT;
88}
89
90#else
91
4009793e 92static inline __maybe_unused phys_addr_t cma_early_percent_memory(void)
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93{
94 return 0;
95}
96
97#endif
98
99/**
a2547380 100 * dma_contiguous_reserve() - reserve area(s) for contiguous memory handling
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101 * @limit: End address of the reserved memory (optional, 0 for any).
102 *
103 * This function reserves memory from early allocator. It should be
104 * called by arch specific code once the early allocator (memblock or bootmem)
105 * has been activated and all other subsystems have already allocated/reserved
106 * memory.
107 */
108void __init dma_contiguous_reserve(phys_addr_t limit)
109{
4009793e 110 phys_addr_t selected_size = 0;
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111 phys_addr_t selected_base = 0;
112 phys_addr_t selected_limit = limit;
113 bool fixed = false;
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114
115 pr_debug("%s(limit %08lx)\n", __func__, (unsigned long)limit);
116
117 if (size_cmdline != -1) {
118 selected_size = size_cmdline;
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119 selected_base = base_cmdline;
120 selected_limit = min_not_zero(limit_cmdline, limit);
121 if (base_cmdline + size_cmdline == limit_cmdline)
122 fixed = true;
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123 } else {
124#ifdef CONFIG_CMA_SIZE_SEL_MBYTES
125 selected_size = size_bytes;
126#elif defined(CONFIG_CMA_SIZE_SEL_PERCENTAGE)
127 selected_size = cma_early_percent_memory();
128#elif defined(CONFIG_CMA_SIZE_SEL_MIN)
129 selected_size = min(size_bytes, cma_early_percent_memory());
130#elif defined(CONFIG_CMA_SIZE_SEL_MAX)
131 selected_size = max(size_bytes, cma_early_percent_memory());
132#endif
133 }
134
a2547380 135 if (selected_size && !dma_contiguous_default_area) {
c64be2bb 136 pr_debug("%s: reserving %ld MiB for global area\n", __func__,
4009793e 137 (unsigned long)selected_size / SZ_1M);
c64be2bb 138
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139 dma_contiguous_reserve_area(selected_size, selected_base,
140 selected_limit,
141 &dma_contiguous_default_area,
142 fixed);
c64be2bb 143 }
5ea3b1b2 144}
c64be2bb 145
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146/**
147 * dma_contiguous_reserve_area() - reserve custom contiguous area
148 * @size: Size of the reserved area (in bytes),
149 * @base: Base address of the reserved area optional, use 0 for any
150 * @limit: End address of the reserved memory (optional, 0 for any).
151 * @res_cma: Pointer to store the created cma region.
152 * @fixed: hint about where to place the reserved area
153 *
154 * This function reserves memory from early allocator. It should be
155 * called by arch specific code once the early allocator (memblock or bootmem)
156 * has been activated and all other subsystems have already allocated/reserved
157 * memory. This function allows to create custom reserved areas for specific
158 * devices.
159 *
160 * If @fixed is true, reserve contiguous area at exactly @base. If false,
161 * reserve in range from @base to @limit.
162 */
163int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base,
164 phys_addr_t limit, struct cma **res_cma,
165 bool fixed)
166{
167 int ret;
168
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169 ret = cma_declare_contiguous(base, size, limit, 0, 0, fixed,
170 "reserved", res_cma);
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171 if (ret)
172 return ret;
173
174 /* Architecture specific contiguous memory fixup. */
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175 dma_contiguous_early_fixup(cma_get_base(*res_cma),
176 cma_get_size(*res_cma));
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177
178 return 0;
179}
180
c64be2bb 181/**
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182 * dma_alloc_from_contiguous() - allocate pages from contiguous area
183 * @dev: Pointer to device for which the allocation is performed.
184 * @count: Requested number of pages.
185 * @align: Requested alignment of pages (in PAGE_SIZE order).
d834c5ab 186 * @no_warn: Avoid printing message about failed allocation.
c64be2bb 187 *
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188 * This function allocates memory buffer for specified device. It uses
189 * device specific contiguous memory area if available or the default
190 * global one. Requires architecture specific dev_get_cma_area() helper
191 * function.
c64be2bb 192 */
67a2e213 193struct page *dma_alloc_from_contiguous(struct device *dev, size_t count,
d834c5ab 194 unsigned int align, bool no_warn)
c64be2bb 195{
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196 if (align > CONFIG_CMA_ALIGNMENT)
197 align = CONFIG_CMA_ALIGNMENT;
198
d834c5ab 199 return cma_alloc(dev_get_cma_area(dev), count, align, no_warn);
c64be2bb 200}
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201
202/**
203 * dma_release_from_contiguous() - release allocated pages
204 * @dev: Pointer to device for which the pages were allocated.
205 * @pages: Allocated pages.
206 * @count: Number of allocated pages.
207 *
208 * This function releases memory allocated by dma_alloc_from_contiguous().
209 * It returns false when provided pages do not belong to contiguous area and
210 * true otherwise.
211 */
212bool dma_release_from_contiguous(struct device *dev, struct page *pages,
213 int count)
214{
a254129e 215 return cma_release(dev_get_cma_area(dev), pages, count);
3162bbd7 216}
de9e14ee 217
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218/**
219 * dma_alloc_contiguous() - allocate contiguous pages
220 * @dev: Pointer to device for which the allocation is performed.
221 * @size: Requested allocation size.
222 * @gfp: Allocation flags.
223 *
224 * This function allocates contiguous memory buffer for specified device. It
225 * first tries to use device specific contiguous memory area if available or
226 * the default global one, then tries a fallback allocation of normal pages.
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227 *
228 * Note that it byapss one-page size of allocations from the global area as
229 * the addresses within one page are always contiguous, so there is no need
230 * to waste CMA pages for that kind; it also helps reduce fragmentations.
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231 */
232struct page *dma_alloc_contiguous(struct device *dev, size_t size, gfp_t gfp)
233{
90ae409f 234 size_t count = size >> PAGE_SHIFT;
b1d2dc00 235 struct page *page = NULL;
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236 struct cma *cma = NULL;
237
238 if (dev && dev->cma_area)
239 cma = dev->cma_area;
240 else if (count > 1)
241 cma = dma_contiguous_default_area;
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242
243 /* CMA can be used only in the context which permits sleeping */
244 if (cma && gfpflags_allow_blocking(gfp)) {
90ae409f 245 size_t align = get_order(size);
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246 size_t cma_align = min_t(size_t, align, CONFIG_CMA_ALIGNMENT);
247
248 page = cma_alloc(cma, count, cma_align, gfp & __GFP_NOWARN);
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249 }
250
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251 return page;
252}
253
254/**
255 * dma_free_contiguous() - release allocated pages
256 * @dev: Pointer to device for which the pages were allocated.
257 * @page: Pointer to the allocated pages.
258 * @size: Size of allocated pages.
259 *
260 * This function releases memory allocated by dma_alloc_contiguous(). As the
261 * cma_release returns false when provided pages do not belong to contiguous
262 * area and true otherwise, this function then does a fallback __free_pages()
263 * upon a false-return.
264 */
265void dma_free_contiguous(struct device *dev, struct page *page, size_t size)
266{
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267 if (!cma_release(dev_get_cma_area(dev), page,
268 PAGE_ALIGN(size) >> PAGE_SHIFT))
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269 __free_pages(page, get_order(size));
270}
271
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272/*
273 * Support for reserved memory regions defined in device tree
274 */
275#ifdef CONFIG_OF_RESERVED_MEM
276#include <linux/of.h>
277#include <linux/of_fdt.h>
278#include <linux/of_reserved_mem.h>
279
280#undef pr_fmt
281#define pr_fmt(fmt) fmt
282
47f29df7 283static int rmem_cma_device_init(struct reserved_mem *rmem, struct device *dev)
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284{
285 dev_set_cma_area(dev, rmem->priv);
47f29df7 286 return 0;
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287}
288
289static void rmem_cma_device_release(struct reserved_mem *rmem,
290 struct device *dev)
291{
292 dev_set_cma_area(dev, NULL);
293}
294
295static const struct reserved_mem_ops rmem_cma_ops = {
296 .device_init = rmem_cma_device_init,
297 .device_release = rmem_cma_device_release,
298};
299
300static int __init rmem_cma_setup(struct reserved_mem *rmem)
301{
302 phys_addr_t align = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order);
303 phys_addr_t mask = align - 1;
304 unsigned long node = rmem->fdt_node;
305 struct cma *cma;
306 int err;
307
308 if (!of_get_flat_dt_prop(node, "reusable", NULL) ||
309 of_get_flat_dt_prop(node, "no-map", NULL))
310 return -EINVAL;
311
312 if ((rmem->base & mask) || (rmem->size & mask)) {
313 pr_err("Reserved memory: incorrect alignment of CMA region\n");
314 return -EINVAL;
315 }
316
f318dd08 317 err = cma_init_reserved_mem(rmem->base, rmem->size, 0, rmem->name, &cma);
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318 if (err) {
319 pr_err("Reserved memory: unable to setup CMA region\n");
320 return err;
321 }
322 /* Architecture specific contiguous memory fixup. */
323 dma_contiguous_early_fixup(rmem->base, rmem->size);
324
325 if (of_get_flat_dt_prop(node, "linux,cma-default", NULL))
326 dma_contiguous_set_default(cma);
327
328 rmem->ops = &rmem_cma_ops;
329 rmem->priv = cma;
330
331 pr_info("Reserved memory: created CMA memory pool at %pa, size %ld MiB\n",
332 &rmem->base, (unsigned long)rmem->size / SZ_1M);
333
334 return 0;
335}
336RESERVEDMEM_OF_DECLARE(cma, "shared-dma-pool", rmem_cma_setup);
337#endif