linux/drivers/base/dma-mapping.c
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   1/*
   2 * drivers/base/dma-mapping.c - arch-independent dma-mapping routines
   3 *
   4 * Copyright (c) 2006  SUSE Linux Products GmbH
   5 * Copyright (c) 2006  Tejun Heo <teheo@suse.de>
   6 *
   7 * This file is released under the GPLv2.
   8 */
   9
  10#include <linux/dma-mapping.h>
  11#include <linux/export.h>
  12#include <linux/gfp.h>
  13#include <asm-generic/dma-coherent.h>
  14
  15/*
  16 * Managed DMA API
  17 */
  18struct dma_devres {
  19        size_t          size;
  20        void            *vaddr;
  21        dma_addr_t      dma_handle;
  22};
  23
  24static void dmam_coherent_release(struct device *dev, void *res)
  25{
  26        struct dma_devres *this = res;
  27
  28        dma_free_coherent(dev, this->size, this->vaddr, this->dma_handle);
  29}
  30
  31static void dmam_noncoherent_release(struct device *dev, void *res)
  32{
  33        struct dma_devres *this = res;
  34
  35        dma_free_noncoherent(dev, this->size, this->vaddr, this->dma_handle);
  36}
  37
  38static int dmam_match(struct device *dev, void *res, void *match_data)
  39{
  40        struct dma_devres *this = res, *match = match_data;
  41
  42        if (this->vaddr == match->vaddr) {
  43                WARN_ON(this->size != match->size ||
  44                        this->dma_handle != match->dma_handle);
  45                return 1;
  46        }
  47        return 0;
  48}
  49
  50/**
  51 * dmam_alloc_coherent - Managed dma_alloc_coherent()
  52 * @dev: Device to allocate coherent memory for
  53 * @size: Size of allocation
  54 * @dma_handle: Out argument for allocated DMA handle
  55 * @gfp: Allocation flags
  56 *
  57 * Managed dma_alloc_coherent().  Memory allocated using this function
  58 * will be automatically released on driver detach.
  59 *
  60 * RETURNS:
  61 * Pointer to allocated memory on success, NULL on failure.
  62 */
  63void * dmam_alloc_coherent(struct device *dev, size_t size,
  64                           dma_addr_t *dma_handle, gfp_t gfp)
  65{
  66        struct dma_devres *dr;
  67        void *vaddr;
  68
  69        dr = devres_alloc(dmam_coherent_release, sizeof(*dr), gfp);
  70        if (!dr)
  71                return NULL;
  72
  73        vaddr = dma_alloc_coherent(dev, size, dma_handle, gfp);
  74        if (!vaddr) {
  75                devres_free(dr);
  76                return NULL;
  77        }
  78
  79        dr->vaddr = vaddr;
  80        dr->dma_handle = *dma_handle;
  81        dr->size = size;
  82
  83        devres_add(dev, dr);
  84
  85        return vaddr;
  86}
  87EXPORT_SYMBOL(dmam_alloc_coherent);
  88
  89/**
  90 * dmam_free_coherent - Managed dma_free_coherent()
  91 * @dev: Device to free coherent memory for
  92 * @size: Size of allocation
  93 * @vaddr: Virtual address of the memory to free
  94 * @dma_handle: DMA handle of the memory to free
  95 *
  96 * Managed dma_free_coherent().
  97 */
  98void dmam_free_coherent(struct device *dev, size_t size, void *vaddr,
  99                        dma_addr_t dma_handle)
 100{
 101        struct dma_devres match_data = { size, vaddr, dma_handle };
 102
 103        dma_free_coherent(dev, size, vaddr, dma_handle);
 104        WARN_ON(devres_destroy(dev, dmam_coherent_release, dmam_match,
 105                               &match_data));
 106}
 107EXPORT_SYMBOL(dmam_free_coherent);
 108
 109/**
 110 * dmam_alloc_non_coherent - Managed dma_alloc_non_coherent()
 111 * @dev: Device to allocate non_coherent memory for
 112 * @size: Size of allocation
 113 * @dma_handle: Out argument for allocated DMA handle
 114 * @gfp: Allocation flags
 115 *
 116 * Managed dma_alloc_non_coherent().  Memory allocated using this
 117 * function will be automatically released on driver detach.
 118 *
 119 * RETURNS:
 120 * Pointer to allocated memory on success, NULL on failure.
 121 */
 122void *dmam_alloc_noncoherent(struct device *dev, size_t size,
 123                             dma_addr_t *dma_handle, gfp_t gfp)
 124{
 125        struct dma_devres *dr;
 126        void *vaddr;
 127
 128        dr = devres_alloc(dmam_noncoherent_release, sizeof(*dr), gfp);
 129        if (!dr)
 130                return NULL;
 131
 132        vaddr = dma_alloc_noncoherent(dev, size, dma_handle, gfp);
 133        if (!vaddr) {
 134                devres_free(dr);
 135                return NULL;
 136        }
 137
 138        dr->vaddr = vaddr;
 139        dr->dma_handle = *dma_handle;
 140        dr->size = size;
 141
 142        devres_add(dev, dr);
 143
 144        return vaddr;
 145}
 146EXPORT_SYMBOL(dmam_alloc_noncoherent);
 147
 148/**
 149 * dmam_free_coherent - Managed dma_free_noncoherent()
 150 * @dev: Device to free noncoherent memory for
 151 * @size: Size of allocation
 152 * @vaddr: Virtual address of the memory to free
 153 * @dma_handle: DMA handle of the memory to free
 154 *
 155 * Managed dma_free_noncoherent().
 156 */
 157void dmam_free_noncoherent(struct device *dev, size_t size, void *vaddr,
 158                           dma_addr_t dma_handle)
 159{
 160        struct dma_devres match_data = { size, vaddr, dma_handle };
 161
 162        dma_free_noncoherent(dev, size, vaddr, dma_handle);
 163        WARN_ON(!devres_destroy(dev, dmam_noncoherent_release, dmam_match,
 164                                &match_data));
 165}
 166EXPORT_SYMBOL(dmam_free_noncoherent);
 167
 168#ifdef ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY
 169
 170static void dmam_coherent_decl_release(struct device *dev, void *res)
 171{
 172        dma_release_declared_memory(dev);
 173}
 174
 175/**
 176 * dmam_declare_coherent_memory - Managed dma_declare_coherent_memory()
 177 * @dev: Device to declare coherent memory for
 178 * @bus_addr: Bus address of coherent memory to be declared
 179 * @device_addr: Device address of coherent memory to be declared
 180 * @size: Size of coherent memory to be declared
 181 * @flags: Flags
 182 *
 183 * Managed dma_declare_coherent_memory().
 184 *
 185 * RETURNS:
 186 * 0 on success, -errno on failure.
 187 */
 188int dmam_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
 189                                 dma_addr_t device_addr, size_t size, int flags)
 190{
 191        void *res;
 192        int rc;
 193
 194        res = devres_alloc(dmam_coherent_decl_release, 0, GFP_KERNEL);
 195        if (!res)
 196                return -ENOMEM;
 197
 198        rc = dma_declare_coherent_memory(dev, bus_addr, device_addr, size,
 199                                         flags);
 200        if (rc == 0)
 201                devres_add(dev, res);
 202        else
 203                devres_free(res);
 204
 205        return rc;
 206}
 207EXPORT_SYMBOL(dmam_declare_coherent_memory);
 208
 209/**
 210 * dmam_release_declared_memory - Managed dma_release_declared_memory().
 211 * @dev: Device to release declared coherent memory for
 212 *
 213 * Managed dmam_release_declared_memory().
 214 */
 215void dmam_release_declared_memory(struct device *dev)
 216{
 217        WARN_ON(devres_destroy(dev, dmam_coherent_decl_release, NULL, NULL));
 218}
 219EXPORT_SYMBOL(dmam_release_declared_memory);
 220
 221/*
 222 * Create scatter-list for the already allocated DMA buffer.
 223 */
 224int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt,
 225                 void *cpu_addr, dma_addr_t handle, size_t size)
 226{
 227        struct page *page = virt_to_page(cpu_addr);
 228        int ret;
 229
 230        ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
 231        if (unlikely(ret))
 232                return ret;
 233
 234        sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
 235        return 0;
 236}
 237EXPORT_SYMBOL(dma_common_get_sgtable);
 238
 239#endif
 240
 241/*
 242 * Create userspace mapping for the DMA-coherent memory.
 243 */
 244int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
 245                    void *cpu_addr, dma_addr_t dma_addr, size_t size)
 246{
 247        int ret = -ENXIO;
 248#ifdef CONFIG_MMU
 249        unsigned long user_count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
 250        unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
 251        unsigned long pfn = page_to_pfn(virt_to_page(cpu_addr));
 252        unsigned long off = vma->vm_pgoff;
 253
 254        vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 255
 256        if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
 257                return ret;
 258
 259        if (off < count && user_count <= (count - off)) {
 260                ret = remap_pfn_range(vma, vma->vm_start,
 261                                      pfn + off,
 262                                      user_count << PAGE_SHIFT,
 263                                      vma->vm_page_prot);
 264        }
 265#endif  /* CONFIG_MMU */
 266
 267        return ret;
 268}
 269EXPORT_SYMBOL(dma_common_mmap);
 270
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