x86/mm/pat: Don't report PAT on CPUs that don't support it
[linux/fpc-iii.git] / drivers / base / dma-contiguous.c
blobb55804cac4c46ef1fd990a2d89a2eb1c917fc81f
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>
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.
14 #define pr_fmt(fmt) "cma: " fmt
16 #ifdef CONFIG_CMA_DEBUG
17 #ifndef DEBUG
18 # define DEBUG
19 #endif
20 #endif
22 #include <asm/page.h>
23 #include <asm/dma-contiguous.h>
25 #include <linux/memblock.h>
26 #include <linux/err.h>
27 #include <linux/sizes.h>
28 #include <linux/dma-contiguous.h>
29 #include <linux/cma.h>
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
37 struct cma *dma_contiguous_default_area;
40 * Default global CMA area size can be defined in kernel's .config.
41 * This is useful mainly for distro maintainers to create a kernel
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.
46 * Users, who want to set the size of global CMA area for their system
47 * should use cma= kernel parameter.
49 static const phys_addr_t size_bytes = (phys_addr_t)CMA_SIZE_MBYTES * SZ_1M;
50 static phys_addr_t size_cmdline = -1;
51 static phys_addr_t base_cmdline;
52 static phys_addr_t limit_cmdline;
54 static int __init early_cma(char *p)
56 pr_debug("%s(%s)\n", __func__, p);
57 size_cmdline = memparse(p, &p);
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;
65 limit_cmdline = memparse(p + 1, &p);
67 return 0;
69 early_param("cma", early_cma);
71 #ifdef CONFIG_CMA_SIZE_PERCENTAGE
73 static phys_addr_t __init __maybe_unused cma_early_percent_memory(void)
75 struct memblock_region *reg;
76 unsigned long total_pages = 0;
79 * We cannot use memblock_phys_mem_size() here, because
80 * memblock_analyze() has not been called yet.
82 for_each_memblock(memory, reg)
83 total_pages += memblock_region_memory_end_pfn(reg) -
84 memblock_region_memory_base_pfn(reg);
86 return (total_pages * CONFIG_CMA_SIZE_PERCENTAGE / 100) << PAGE_SHIFT;
89 #else
91 static inline __maybe_unused phys_addr_t cma_early_percent_memory(void)
93 return 0;
96 #endif
98 /**
99 * dma_contiguous_reserve() - reserve area(s) for contiguous memory handling
100 * @limit: End address of the reserved memory (optional, 0 for any).
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.
107 void __init dma_contiguous_reserve(phys_addr_t limit)
109 phys_addr_t selected_size = 0;
110 phys_addr_t selected_base = 0;
111 phys_addr_t selected_limit = limit;
112 bool fixed = false;
114 pr_debug("%s(limit %08lx)\n", __func__, (unsigned long)limit);
116 if (size_cmdline != -1) {
117 selected_size = size_cmdline;
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;
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
134 if (selected_size && !dma_contiguous_default_area) {
135 pr_debug("%s: reserving %ld MiB for global area\n", __func__,
136 (unsigned long)selected_size / SZ_1M);
138 dma_contiguous_reserve_area(selected_size, selected_base,
139 selected_limit,
140 &dma_contiguous_default_area,
141 fixed);
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
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.
159 * If @fixed is true, reserve contiguous area at exactly @base. If false,
160 * reserve in range from @base to @limit.
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)
166 int ret;
168 ret = cma_declare_contiguous(base, size, limit, 0, 0, fixed, res_cma);
169 if (ret)
170 return ret;
172 /* Architecture specific contiguous memory fixup. */
173 dma_contiguous_early_fixup(cma_get_base(*res_cma),
174 cma_get_size(*res_cma));
176 return 0;
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).
184 * @gfp_mask: GFP flags to use for this allocation.
186 * This function allocates memory buffer for specified device. It uses
187 * device specific contiguous memory area if available or the default
188 * global one. Requires architecture specific dev_get_cma_area() helper
189 * function.
191 struct page *dma_alloc_from_contiguous(struct device *dev, size_t count,
192 unsigned int align, gfp_t gfp_mask)
194 if (align > CONFIG_CMA_ALIGNMENT)
195 align = CONFIG_CMA_ALIGNMENT;
197 return cma_alloc(dev_get_cma_area(dev), count, align, gfp_mask);
201 * dma_release_from_contiguous() - release allocated pages
202 * @dev: Pointer to device for which the pages were allocated.
203 * @pages: Allocated pages.
204 * @count: Number of allocated pages.
206 * This function releases memory allocated by dma_alloc_from_contiguous().
207 * It returns false when provided pages do not belong to contiguous area and
208 * true otherwise.
210 bool dma_release_from_contiguous(struct device *dev, struct page *pages,
211 int count)
213 return cma_release(dev_get_cma_area(dev), pages, count);
217 * Support for reserved memory regions defined in device tree
219 #ifdef CONFIG_OF_RESERVED_MEM
220 #include <linux/of.h>
221 #include <linux/of_fdt.h>
222 #include <linux/of_reserved_mem.h>
224 #undef pr_fmt
225 #define pr_fmt(fmt) fmt
227 static int rmem_cma_device_init(struct reserved_mem *rmem, struct device *dev)
229 dev_set_cma_area(dev, rmem->priv);
230 return 0;
233 static void rmem_cma_device_release(struct reserved_mem *rmem,
234 struct device *dev)
236 dev_set_cma_area(dev, NULL);
239 static const struct reserved_mem_ops rmem_cma_ops = {
240 .device_init = rmem_cma_device_init,
241 .device_release = rmem_cma_device_release,
244 static int __init rmem_cma_setup(struct reserved_mem *rmem)
246 phys_addr_t align = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order);
247 phys_addr_t mask = align - 1;
248 unsigned long node = rmem->fdt_node;
249 struct cma *cma;
250 int err;
252 if (!of_get_flat_dt_prop(node, "reusable", NULL) ||
253 of_get_flat_dt_prop(node, "no-map", NULL))
254 return -EINVAL;
256 if ((rmem->base & mask) || (rmem->size & mask)) {
257 pr_err("Reserved memory: incorrect alignment of CMA region\n");
258 return -EINVAL;
261 err = cma_init_reserved_mem(rmem->base, rmem->size, 0, &cma);
262 if (err) {
263 pr_err("Reserved memory: unable to setup CMA region\n");
264 return err;
266 /* Architecture specific contiguous memory fixup. */
267 dma_contiguous_early_fixup(rmem->base, rmem->size);
269 if (of_get_flat_dt_prop(node, "linux,cma-default", NULL))
270 dma_contiguous_set_default(cma);
272 rmem->ops = &rmem_cma_ops;
273 rmem->priv = cma;
275 pr_info("Reserved memory: created CMA memory pool at %pa, size %ld MiB\n",
276 &rmem->base, (unsigned long)rmem->size / SZ_1M);
278 return 0;
280 RESERVEDMEM_OF_DECLARE(cma, "shared-dma-pool", rmem_cma_setup);
281 #endif