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