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/export.h>
  12 #include <linux/gfp.h>
  13 #include <asm-generic/dma-coherent.h>
  14
  15 /*
  16  * Managed DMA API
  17  */
  18 struct dma_devres {
  19         size_t          size;
  20         void            *vaddr;
  21         dma_addr_t      dma_handle;
  22 };
  23
  24 static 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
  31 static 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
  38 static 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  */
  63 void * 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 }
  87 EXPORT_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  */
  98 void 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 }
 107 EXPORT_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  */
 122 void *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 }
 146 EXPORT_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  */
 157 void 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 }
 166 EXPORT_SYMBOL(dmam_free_noncoherent);
 167
 168 #ifdef ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY
 169
 170 static 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  */
 188 int 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 }
 207 EXPORT_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  */
 215 void dmam_release_declared_memory(struct device *dev)
 216 {
 217         WARN_ON(devres_destroy(dev, dmam_coherent_decl_release, NULL, NULL));
 218 }
 219 EXPORT_SYMBOL(dmam_release_declared_memory);
 220
 221 #endif
 222
 223 /*
 224  * Create scatter-list for the already allocated DMA buffer.
 225  */
 226 int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt,
 227                  void *cpu_addr, dma_addr_t handle, size_t size)
 228 {
 229         struct page *page = virt_to_page(cpu_addr);
 230         int ret;
 231
 232         ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
 233         if (unlikely(ret))
 234                 return ret;
 235
 236         sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
 237         return 0;
 238 }
 239 EXPORT_SYMBOL(dma_common_get_sgtable);
 240
 241 /*
 242  * Create userspace mapping for the DMA-coherent memory.
 243  */
 244 int 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 }
 269 EXPORT_SYMBOL(dma_common_mmap);