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