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c64be2bb MS |
1 | /* |
2 | * Contiguous Memory Allocator for DMA mapping framework | |
3 | * Copyright (c) 2010-2011 by Samsung Electronics. | |
4 | * Written by: | |
5 | * Marek Szyprowski <m.szyprowski@samsung.com> | |
6 | * Michal Nazarewicz <mina86@mina86.com> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU General Public License as | |
10 | * published by the Free Software Foundation; either version 2 of the | |
11 | * License or (at your optional) any later version of the license. | |
12 | */ | |
13 | ||
14 | #define pr_fmt(fmt) "cma: " fmt | |
15 | ||
16 | #ifdef CONFIG_CMA_DEBUG | |
17 | #ifndef DEBUG | |
18 | # define DEBUG | |
19 | #endif | |
20 | #endif | |
21 | ||
22 | #include <asm/page.h> | |
23 | #include <asm/dma-contiguous.h> | |
24 | ||
25 | #include <linux/memblock.h> | |
26 | #include <linux/err.h> | |
446c82fc | 27 | #include <linux/sizes.h> |
c64be2bb | 28 | #include <linux/dma-contiguous.h> |
a254129e | 29 | #include <linux/cma.h> |
c64be2bb MS |
30 | |
31 | #ifdef CONFIG_CMA_SIZE_MBYTES | |
32 | #define CMA_SIZE_MBYTES CONFIG_CMA_SIZE_MBYTES | |
33 | #else | |
34 | #define CMA_SIZE_MBYTES 0 | |
35 | #endif | |
36 | ||
a254129e JK |
37 | struct cma *dma_contiguous_default_area; |
38 | ||
c64be2bb MS |
39 | /* |
40 | * Default global CMA area size can be defined in kernel's .config. | |
73678804 | 41 | * This is useful mainly for distro maintainers to create a kernel |
c64be2bb MS |
42 | * that works correctly for most supported systems. |
43 | * The size can be set in bytes or as a percentage of the total memory | |
44 | * in the system. | |
45 | * | |
46 | * Users, who want to set the size of global CMA area for their system | |
47 | * should use cma= kernel parameter. | |
48 | */ | |
a785ce9c | 49 | static const phys_addr_t size_bytes = (phys_addr_t)CMA_SIZE_MBYTES * SZ_1M; |
4009793e | 50 | static phys_addr_t size_cmdline = -1; |
5ea3b1b2 AM |
51 | static phys_addr_t base_cmdline; |
52 | static phys_addr_t limit_cmdline; | |
c64be2bb MS |
53 | |
54 | static int __init early_cma(char *p) | |
55 | { | |
56 | pr_debug("%s(%s)\n", __func__, p); | |
57 | size_cmdline = memparse(p, &p); | |
5ea3b1b2 AM |
58 | if (*p != '@') |
59 | return 0; | |
60 | base_cmdline = memparse(p + 1, &p); | |
61 | if (*p != '-') { | |
62 | limit_cmdline = base_cmdline + size_cmdline; | |
63 | return 0; | |
64 | } | |
65 | limit_cmdline = memparse(p + 1, &p); | |
66 | ||
c64be2bb MS |
67 | return 0; |
68 | } | |
69 | early_param("cma", early_cma); | |
70 | ||
71 | #ifdef CONFIG_CMA_SIZE_PERCENTAGE | |
72 | ||
4009793e | 73 | static phys_addr_t __init __maybe_unused cma_early_percent_memory(void) |
c64be2bb MS |
74 | { |
75 | struct memblock_region *reg; | |
76 | unsigned long total_pages = 0; | |
77 | ||
78 | /* | |
79 | * We cannot use memblock_phys_mem_size() here, because | |
80 | * memblock_analyze() has not been called yet. | |
81 | */ | |
82 | for_each_memblock(memory, reg) | |
83 | total_pages += memblock_region_memory_end_pfn(reg) - | |
84 | memblock_region_memory_base_pfn(reg); | |
85 | ||
86 | return (total_pages * CONFIG_CMA_SIZE_PERCENTAGE / 100) << PAGE_SHIFT; | |
87 | } | |
88 | ||
89 | #else | |
90 | ||
4009793e | 91 | static inline __maybe_unused phys_addr_t cma_early_percent_memory(void) |
c64be2bb MS |
92 | { |
93 | return 0; | |
94 | } | |
95 | ||
96 | #endif | |
97 | ||
98 | /** | |
a2547380 | 99 | * dma_contiguous_reserve() - reserve area(s) for contiguous memory handling |
c64be2bb MS |
100 | * @limit: End address of the reserved memory (optional, 0 for any). |
101 | * | |
102 | * This function reserves memory from early allocator. It should be | |
103 | * called by arch specific code once the early allocator (memblock or bootmem) | |
104 | * has been activated and all other subsystems have already allocated/reserved | |
105 | * memory. | |
106 | */ | |
107 | void __init dma_contiguous_reserve(phys_addr_t limit) | |
108 | { | |
4009793e | 109 | phys_addr_t selected_size = 0; |
5ea3b1b2 AM |
110 | phys_addr_t selected_base = 0; |
111 | phys_addr_t selected_limit = limit; | |
112 | bool fixed = false; | |
c64be2bb MS |
113 | |
114 | pr_debug("%s(limit %08lx)\n", __func__, (unsigned long)limit); | |
115 | ||
116 | if (size_cmdline != -1) { | |
117 | selected_size = size_cmdline; | |
5ea3b1b2 AM |
118 | selected_base = base_cmdline; |
119 | selected_limit = min_not_zero(limit_cmdline, limit); | |
120 | if (base_cmdline + size_cmdline == limit_cmdline) | |
121 | fixed = true; | |
c64be2bb MS |
122 | } else { |
123 | #ifdef CONFIG_CMA_SIZE_SEL_MBYTES | |
124 | selected_size = size_bytes; | |
125 | #elif defined(CONFIG_CMA_SIZE_SEL_PERCENTAGE) | |
126 | selected_size = cma_early_percent_memory(); | |
127 | #elif defined(CONFIG_CMA_SIZE_SEL_MIN) | |
128 | selected_size = min(size_bytes, cma_early_percent_memory()); | |
129 | #elif defined(CONFIG_CMA_SIZE_SEL_MAX) | |
130 | selected_size = max(size_bytes, cma_early_percent_memory()); | |
131 | #endif | |
132 | } | |
133 | ||
a2547380 | 134 | if (selected_size && !dma_contiguous_default_area) { |
c64be2bb | 135 | pr_debug("%s: reserving %ld MiB for global area\n", __func__, |
4009793e | 136 | (unsigned long)selected_size / SZ_1M); |
c64be2bb | 137 | |
5ea3b1b2 AM |
138 | dma_contiguous_reserve_area(selected_size, selected_base, |
139 | selected_limit, | |
140 | &dma_contiguous_default_area, | |
141 | fixed); | |
c64be2bb | 142 | } |
5ea3b1b2 | 143 | } |
c64be2bb | 144 | |
3162bbd7 JK |
145 | /** |
146 | * dma_contiguous_reserve_area() - reserve custom contiguous area | |
147 | * @size: Size of the reserved area (in bytes), | |
148 | * @base: Base address of the reserved area optional, use 0 for any | |
149 | * @limit: End address of the reserved memory (optional, 0 for any). | |
150 | * @res_cma: Pointer to store the created cma region. | |
151 | * @fixed: hint about where to place the reserved area | |
152 | * | |
153 | * This function reserves memory from early allocator. It should be | |
154 | * called by arch specific code once the early allocator (memblock or bootmem) | |
155 | * has been activated and all other subsystems have already allocated/reserved | |
156 | * memory. This function allows to create custom reserved areas for specific | |
157 | * devices. | |
158 | * | |
159 | * If @fixed is true, reserve contiguous area at exactly @base. If false, | |
160 | * reserve in range from @base to @limit. | |
161 | */ | |
162 | int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base, | |
163 | phys_addr_t limit, struct cma **res_cma, | |
164 | bool fixed) | |
165 | { | |
166 | int ret; | |
167 | ||
c1f733aa | 168 | ret = cma_declare_contiguous(base, size, limit, 0, 0, fixed, res_cma); |
3162bbd7 JK |
169 | if (ret) |
170 | return ret; | |
171 | ||
172 | /* Architecture specific contiguous memory fixup. */ | |
a254129e JK |
173 | dma_contiguous_early_fixup(cma_get_base(*res_cma), |
174 | cma_get_size(*res_cma)); | |
3162bbd7 JK |
175 | |
176 | return 0; | |
177 | } | |
178 | ||
c64be2bb | 179 | /** |
3162bbd7 JK |
180 | * dma_alloc_from_contiguous() - allocate pages from contiguous area |
181 | * @dev: Pointer to device for which the allocation is performed. | |
182 | * @count: Requested number of pages. | |
183 | * @align: Requested alignment of pages (in PAGE_SIZE order). | |
c64be2bb | 184 | * |
3162bbd7 JK |
185 | * This function allocates memory buffer for specified device. It uses |
186 | * device specific contiguous memory area if available or the default | |
187 | * global one. Requires architecture specific dev_get_cma_area() helper | |
188 | * function. | |
c64be2bb | 189 | */ |
67a2e213 | 190 | struct page *dma_alloc_from_contiguous(struct device *dev, size_t count, |
3162bbd7 | 191 | unsigned int align) |
c64be2bb | 192 | { |
3162bbd7 JK |
193 | if (align > CONFIG_CMA_ALIGNMENT) |
194 | align = CONFIG_CMA_ALIGNMENT; | |
195 | ||
a254129e | 196 | return cma_alloc(dev_get_cma_area(dev), count, align); |
c64be2bb | 197 | } |
3162bbd7 JK |
198 | |
199 | /** | |
200 | * dma_release_from_contiguous() - release allocated pages | |
201 | * @dev: Pointer to device for which the pages were allocated. | |
202 | * @pages: Allocated pages. | |
203 | * @count: Number of allocated pages. | |
204 | * | |
205 | * This function releases memory allocated by dma_alloc_from_contiguous(). | |
206 | * It returns false when provided pages do not belong to contiguous area and | |
207 | * true otherwise. | |
208 | */ | |
209 | bool dma_release_from_contiguous(struct device *dev, struct page *pages, | |
210 | int count) | |
211 | { | |
a254129e | 212 | return cma_release(dev_get_cma_area(dev), pages, count); |
3162bbd7 | 213 | } |
de9e14ee MS |
214 | |
215 | /* | |
216 | * Support for reserved memory regions defined in device tree | |
217 | */ | |
218 | #ifdef CONFIG_OF_RESERVED_MEM | |
219 | #include <linux/of.h> | |
220 | #include <linux/of_fdt.h> | |
221 | #include <linux/of_reserved_mem.h> | |
222 | ||
223 | #undef pr_fmt | |
224 | #define pr_fmt(fmt) fmt | |
225 | ||
47f29df7 | 226 | static int rmem_cma_device_init(struct reserved_mem *rmem, struct device *dev) |
de9e14ee MS |
227 | { |
228 | dev_set_cma_area(dev, rmem->priv); | |
47f29df7 | 229 | return 0; |
de9e14ee MS |
230 | } |
231 | ||
232 | static void rmem_cma_device_release(struct reserved_mem *rmem, | |
233 | struct device *dev) | |
234 | { | |
235 | dev_set_cma_area(dev, NULL); | |
236 | } | |
237 | ||
238 | static const struct reserved_mem_ops rmem_cma_ops = { | |
239 | .device_init = rmem_cma_device_init, | |
240 | .device_release = rmem_cma_device_release, | |
241 | }; | |
242 | ||
243 | static int __init rmem_cma_setup(struct reserved_mem *rmem) | |
244 | { | |
245 | phys_addr_t align = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order); | |
246 | phys_addr_t mask = align - 1; | |
247 | unsigned long node = rmem->fdt_node; | |
248 | struct cma *cma; | |
249 | int err; | |
250 | ||
251 | if (!of_get_flat_dt_prop(node, "reusable", NULL) || | |
252 | of_get_flat_dt_prop(node, "no-map", NULL)) | |
253 | return -EINVAL; | |
254 | ||
255 | if ((rmem->base & mask) || (rmem->size & mask)) { | |
256 | pr_err("Reserved memory: incorrect alignment of CMA region\n"); | |
257 | return -EINVAL; | |
258 | } | |
259 | ||
260 | err = cma_init_reserved_mem(rmem->base, rmem->size, 0, &cma); | |
261 | if (err) { | |
262 | pr_err("Reserved memory: unable to setup CMA region\n"); | |
263 | return err; | |
264 | } | |
265 | /* Architecture specific contiguous memory fixup. */ | |
266 | dma_contiguous_early_fixup(rmem->base, rmem->size); | |
267 | ||
268 | if (of_get_flat_dt_prop(node, "linux,cma-default", NULL)) | |
269 | dma_contiguous_set_default(cma); | |
270 | ||
271 | rmem->ops = &rmem_cma_ops; | |
272 | rmem->priv = cma; | |
273 | ||
274 | pr_info("Reserved memory: created CMA memory pool at %pa, size %ld MiB\n", | |
275 | &rmem->base, (unsigned long)rmem->size / SZ_1M); | |
276 | ||
277 | return 0; | |
278 | } | |
279 | RESERVEDMEM_OF_DECLARE(cma, "shared-dma-pool", rmem_cma_setup); | |
280 | #endif |