release/src-rt-6.x/linux/linux-2.6/drivers/base/dma-mapping.c

   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
  12 /*
  13  * Managed DMA API
  14  */
  15 struct dma_devres {
  16         size_t          size;
  17         void            *vaddr;
  18         dma_addr_t      dma_handle;
  19 };
  20
  21 static void dmam_coherent_release(struct device *dev, void *res)
  22 {
  23         struct dma_devres *this = res;
  24
  25         dma_free_coherent(dev, this->size, this->vaddr, this->dma_handle);
  26 }
  27
  28 static void dmam_noncoherent_release(struct device *dev, void *res)
  29 {
  30         struct dma_devres *this = res;
  31
  32         dma_free_noncoherent(dev, this->size, this->vaddr, this->dma_handle);
  33 }
  34
  35 static int dmam_match(struct device *dev, void *res, void *match_data)
  36 {
  37         struct dma_devres *this = res, *match = match_data;
  38
  39         if (this->vaddr == match->vaddr) {
  40                 WARN_ON(this->size != match->size ||
  41                         this->dma_handle != match->dma_handle);
  42                 return 1;
  43         }
  44         return 0;
  45 }
  46
  47 /**
  48  * dmam_alloc_coherent - Managed dma_alloc_coherent()
  49  * @dev: Device to allocate coherent memory for
  50  * @size: Size of allocation
  51  * @dma_handle: Out argument for allocated DMA handle
  52  * @gfp: Allocation flags
  53  *
  54  * Managed dma_alloc_coherent().  Memory allocated using this function
  55  * will be automatically released on driver detach.
  56  *
  57  * RETURNS:
  58  * Pointer to allocated memory on success, NULL on failure.
  59  */
  60 void * dmam_alloc_coherent(struct device *dev, size_t size,
  61                            dma_addr_t *dma_handle, gfp_t gfp)
  62 {
  63         struct dma_devres *dr;
  64         void *vaddr;
  65
  66         dr = devres_alloc(dmam_coherent_release, sizeof(*dr), gfp);
  67         if (!dr)
  68                 return NULL;
  69
  70         vaddr = dma_alloc_coherent(dev, size, dma_handle, gfp);
  71         if (!vaddr) {
  72                 devres_free(dr);
  73                 return NULL;
  74         }
  75
  76         dr->vaddr = vaddr;
  77         dr->dma_handle = *dma_handle;
  78         dr->size = size;
  79
  80         devres_add(dev, dr);
  81
  82         return vaddr;
  83 }
  84 EXPORT_SYMBOL(dmam_alloc_coherent);
  85
  86 /**
  87  * dmam_free_coherent - Managed dma_free_coherent()
  88  * @dev: Device to free coherent memory for
  89  * @size: Size of allocation
  90  * @vaddr: Virtual address of the memory to free
  91  * @dma_handle: DMA handle of the memory to free
  92  *
  93  * Managed dma_free_coherent().
  94  */
  95 void dmam_free_coherent(struct device *dev, size_t size, void *vaddr,
  96                         dma_addr_t dma_handle)
  97 {
  98         struct dma_devres match_data = { size, vaddr, dma_handle };
  99
 100         dma_free_coherent(dev, size, vaddr, dma_handle);
 101         WARN_ON(devres_destroy(dev, dmam_coherent_release, dmam_match,
 102                                &match_data));
 103 }
 104 EXPORT_SYMBOL(dmam_free_coherent);
 105
 106 /**
 107  * dmam_alloc_non_coherent - Managed dma_alloc_non_coherent()
 108  * @dev: Device to allocate non_coherent memory for
 109  * @size: Size of allocation
 110  * @dma_handle: Out argument for allocated DMA handle
 111  * @gfp: Allocation flags
 112  *
 113  * Managed dma_alloc_non_coherent().  Memory allocated using this
 114  * function will be automatically released on driver detach.
 115  *
 116  * RETURNS:
 117  * Pointer to allocated memory on success, NULL on failure.
 118  */
 119 void *dmam_alloc_noncoherent(struct device *dev, size_t size,
 120                              dma_addr_t *dma_handle, gfp_t gfp)
 121 {
 122         struct dma_devres *dr;
 123         void *vaddr;
 124
 125         dr = devres_alloc(dmam_noncoherent_release, sizeof(*dr), gfp);
 126         if (!dr)
 127                 return NULL;
 128
 129         vaddr = dma_alloc_noncoherent(dev, size, dma_handle, gfp);
 130         if (!vaddr) {
 131                 devres_free(dr);
 132                 return NULL;
 133         }
 134
 135         dr->vaddr = vaddr;
 136         dr->dma_handle = *dma_handle;
 137         dr->size = size;
 138
 139         devres_add(dev, dr);
 140
 141         return vaddr;
 142 }
 143 EXPORT_SYMBOL(dmam_alloc_noncoherent);
 144
 145 /**
 146  * dmam_free_coherent - Managed dma_free_noncoherent()
 147  * @dev: Device to free noncoherent memory for
 148  * @size: Size of allocation
 149  * @vaddr: Virtual address of the memory to free
 150  * @dma_handle: DMA handle of the memory to free
 151  *
 152  * Managed dma_free_noncoherent().
 153  */
 154 void dmam_free_noncoherent(struct device *dev, size_t size, void *vaddr,
 155                            dma_addr_t dma_handle)
 156 {
 157         struct dma_devres match_data = { size, vaddr, dma_handle };
 158
 159         dma_free_noncoherent(dev, size, vaddr, dma_handle);
 160         WARN_ON(!devres_destroy(dev, dmam_noncoherent_release, dmam_match,
 161                                 &match_data));
 162 }
 163 EXPORT_SYMBOL(dmam_free_noncoherent);
 164
 165 #ifdef ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY
 166
 167 static void dmam_coherent_decl_release(struct device *dev, void *res)
 168 {
 169         dma_release_declared_memory(dev);
 170 }
 171
 172 /**
 173  * dmam_declare_coherent_memory - Managed dma_declare_coherent_memory()
 174  * @dev: Device to declare coherent memory for
 175  * @bus_addr: Bus address of coherent memory to be declared
 176  * @device_addr: Device address of coherent memory to be declared
 177  * @size: Size of coherent memory to be declared
 178  * @flags: Flags
 179  *
 180  * Managed dma_declare_coherent_memory().
 181  *
 182  * RETURNS:
 183  * 0 on success, -errno on failure.
 184  */
 185 int dmam_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
 186                                  dma_addr_t device_addr, size_t size, int flags)
 187 {
 188         void *res;
 189         int rc;
 190
 191         res = devres_alloc(dmam_coherent_decl_release, 0, GFP_KERNEL);
 192         if (!res)
 193                 return -ENOMEM;
 194
 195         rc = dma_declare_coherent_memory(dev, bus_addr, device_addr, size,
 196                                          flags);
 197         if (rc == 0)
 198                 devres_add(dev, res);
 199         else
 200                 devres_free(res);
 201
 202         return rc;
 203 }
 204 EXPORT_SYMBOL(dmam_declare_coherent_memory);
 205
 206 /**
 207  * dmam_release_declared_memory - Managed dma_release_declared_memory().
 208  * @dev: Device to release declared coherent memory for
 209  *
 210  * Managed dmam_release_declared_memory().
 211  */
 212 void dmam_release_declared_memory(struct device *dev)
 213 {
 214         WARN_ON(devres_destroy(dev, dmam_coherent_decl_release, NULL, NULL));
 215 }
 216 EXPORT_SYMBOL(dmam_release_declared_memory);
 217
 218 #endif