dma-mapping.h revision 1124d6d21f80ec10cc962e2961c21a8dd1e0ca6a
1#ifndef ASMARM_DMA_MAPPING_H 2#define ASMARM_DMA_MAPPING_H 3 4#ifdef __KERNEL__ 5 6#include <linux/mm_types.h> 7#include <linux/scatterlist.h> 8 9#include <asm-generic/dma-coherent.h> 10#include <asm/memory.h> 11 12/* 13 * page_to_dma/dma_to_virt/virt_to_dma are architecture private functions 14 * used internally by the DMA-mapping API to provide DMA addresses. They 15 * must not be used by drivers. 16 */ 17#ifndef __arch_page_to_dma 18static inline dma_addr_t page_to_dma(struct device *dev, struct page *page) 19{ 20 return (dma_addr_t)__virt_to_bus((unsigned long)page_address(page)); 21} 22 23static inline void *dma_to_virt(struct device *dev, dma_addr_t addr) 24{ 25 return (void *)__bus_to_virt(addr); 26} 27 28static inline dma_addr_t virt_to_dma(struct device *dev, void *addr) 29{ 30 return (dma_addr_t)__virt_to_bus((unsigned long)(addr)); 31} 32#else 33static inline dma_addr_t page_to_dma(struct device *dev, struct page *page) 34{ 35 return __arch_page_to_dma(dev, page); 36} 37 38static inline void *dma_to_virt(struct device *dev, dma_addr_t addr) 39{ 40 return __arch_dma_to_virt(dev, addr); 41} 42 43static inline dma_addr_t virt_to_dma(struct device *dev, void *addr) 44{ 45 return __arch_virt_to_dma(dev, addr); 46} 47#endif 48 49/* 50 * DMA-consistent mapping functions. These allocate/free a region of 51 * uncached, unwrite-buffered mapped memory space for use with DMA 52 * devices. This is the "generic" version. The PCI specific version 53 * is in pci.h 54 * 55 * Note: Drivers should NOT use this function directly, as it will break 56 * platforms with CONFIG_DMABOUNCE. 57 * Use the driver DMA support - see dma-mapping.h (dma_sync_*) 58 */ 59extern void dma_cache_maint(const void *kaddr, size_t size, int rw); 60 61/* 62 * Return whether the given device DMA address mask can be supported 63 * properly. For example, if your device can only drive the low 24-bits 64 * during bus mastering, then you would pass 0x00ffffff as the mask 65 * to this function. 66 * 67 * FIXME: This should really be a platform specific issue - we should 68 * return false if GFP_DMA allocations may not satisfy the supplied 'mask'. 69 */ 70static inline int dma_supported(struct device *dev, u64 mask) 71{ 72 if (mask < ISA_DMA_THRESHOLD) 73 return 0; 74 return 1; 75} 76 77static inline int dma_set_mask(struct device *dev, u64 dma_mask) 78{ 79 if (!dev->dma_mask || !dma_supported(dev, dma_mask)) 80 return -EIO; 81 82 *dev->dma_mask = dma_mask; 83 84 return 0; 85} 86 87static inline int dma_get_cache_alignment(void) 88{ 89 return 32; 90} 91 92static inline int dma_is_consistent(struct device *dev, dma_addr_t handle) 93{ 94 return !!arch_is_coherent(); 95} 96 97/* 98 * DMA errors are defined by all-bits-set in the DMA address. 99 */ 100static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr) 101{ 102 return dma_addr == ~0; 103} 104 105/* 106 * Dummy noncoherent implementation. We don't provide a dma_cache_sync 107 * function so drivers using this API are highlighted with build warnings. 108 */ 109static inline void *dma_alloc_noncoherent(struct device *dev, size_t size, 110 dma_addr_t *handle, gfp_t gfp) 111{ 112 return NULL; 113} 114 115static inline void dma_free_noncoherent(struct device *dev, size_t size, 116 void *cpu_addr, dma_addr_t handle) 117{ 118} 119 120/** 121 * dma_alloc_coherent - allocate consistent memory for DMA 122 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices 123 * @size: required memory size 124 * @handle: bus-specific DMA address 125 * 126 * Allocate some uncached, unbuffered memory for a device for 127 * performing DMA. This function allocates pages, and will 128 * return the CPU-viewed address, and sets @handle to be the 129 * device-viewed address. 130 */ 131extern void *dma_alloc_coherent(struct device *, size_t, dma_addr_t *, gfp_t); 132 133/** 134 * dma_free_coherent - free memory allocated by dma_alloc_coherent 135 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices 136 * @size: size of memory originally requested in dma_alloc_coherent 137 * @cpu_addr: CPU-view address returned from dma_alloc_coherent 138 * @handle: device-view address returned from dma_alloc_coherent 139 * 140 * Free (and unmap) a DMA buffer previously allocated by 141 * dma_alloc_coherent(). 142 * 143 * References to memory and mappings associated with cpu_addr/handle 144 * during and after this call executing are illegal. 145 */ 146extern void dma_free_coherent(struct device *, size_t, void *, dma_addr_t); 147 148/** 149 * dma_mmap_coherent - map a coherent DMA allocation into user space 150 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices 151 * @vma: vm_area_struct describing requested user mapping 152 * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent 153 * @handle: device-view address returned from dma_alloc_coherent 154 * @size: size of memory originally requested in dma_alloc_coherent 155 * 156 * Map a coherent DMA buffer previously allocated by dma_alloc_coherent 157 * into user space. The coherent DMA buffer must not be freed by the 158 * driver until the user space mapping has been released. 159 */ 160int dma_mmap_coherent(struct device *, struct vm_area_struct *, 161 void *, dma_addr_t, size_t); 162 163 164/** 165 * dma_alloc_writecombine - allocate writecombining memory for DMA 166 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices 167 * @size: required memory size 168 * @handle: bus-specific DMA address 169 * 170 * Allocate some uncached, buffered memory for a device for 171 * performing DMA. This function allocates pages, and will 172 * return the CPU-viewed address, and sets @handle to be the 173 * device-viewed address. 174 */ 175extern void *dma_alloc_writecombine(struct device *, size_t, dma_addr_t *, 176 gfp_t); 177 178#define dma_free_writecombine(dev,size,cpu_addr,handle) \ 179 dma_free_coherent(dev,size,cpu_addr,handle) 180 181int dma_mmap_writecombine(struct device *, struct vm_area_struct *, 182 void *, dma_addr_t, size_t); 183 184 185#ifdef CONFIG_DMABOUNCE 186/* 187 * For SA-1111, IXP425, and ADI systems the dma-mapping functions are "magic" 188 * and utilize bounce buffers as needed to work around limited DMA windows. 189 * 190 * On the SA-1111, a bug limits DMA to only certain regions of RAM. 191 * On the IXP425, the PCI inbound window is 64MB (256MB total RAM) 192 * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM) 193 * 194 * The following are helper functions used by the dmabounce subystem 195 * 196 */ 197 198/** 199 * dmabounce_register_dev 200 * 201 * @dev: valid struct device pointer 202 * @small_buf_size: size of buffers to use with small buffer pool 203 * @large_buf_size: size of buffers to use with large buffer pool (can be 0) 204 * 205 * This function should be called by low-level platform code to register 206 * a device as requireing DMA buffer bouncing. The function will allocate 207 * appropriate DMA pools for the device. 208 * 209 */ 210extern int dmabounce_register_dev(struct device *, unsigned long, 211 unsigned long); 212 213/** 214 * dmabounce_unregister_dev 215 * 216 * @dev: valid struct device pointer 217 * 218 * This function should be called by low-level platform code when device 219 * that was previously registered with dmabounce_register_dev is removed 220 * from the system. 221 * 222 */ 223extern void dmabounce_unregister_dev(struct device *); 224 225/** 226 * dma_needs_bounce 227 * 228 * @dev: valid struct device pointer 229 * @dma_handle: dma_handle of unbounced buffer 230 * @size: size of region being mapped 231 * 232 * Platforms that utilize the dmabounce mechanism must implement 233 * this function. 234 * 235 * The dmabounce routines call this function whenever a dma-mapping 236 * is requested to determine whether a given buffer needs to be bounced 237 * or not. The function must return 0 if the buffer is OK for 238 * DMA access and 1 if the buffer needs to be bounced. 239 * 240 */ 241extern int dma_needs_bounce(struct device*, dma_addr_t, size_t); 242 243/* 244 * The DMA API, implemented by dmabounce.c. See below for descriptions. 245 */ 246extern dma_addr_t dma_map_single(struct device *, void *, size_t, 247 enum dma_data_direction); 248extern dma_addr_t dma_map_page(struct device *, struct page *, 249 unsigned long, size_t, enum dma_data_direction); 250extern void dma_unmap_single(struct device *, dma_addr_t, size_t, 251 enum dma_data_direction); 252 253/* 254 * Private functions 255 */ 256int dmabounce_sync_for_cpu(struct device *, dma_addr_t, unsigned long, 257 size_t, enum dma_data_direction); 258int dmabounce_sync_for_device(struct device *, dma_addr_t, unsigned long, 259 size_t, enum dma_data_direction); 260#else 261static inline int dmabounce_sync_for_cpu(struct device *d, dma_addr_t addr, 262 unsigned long offset, size_t size, enum dma_data_direction dir) 263{ 264 return 1; 265} 266 267static inline int dmabounce_sync_for_device(struct device *d, dma_addr_t addr, 268 unsigned long offset, size_t size, enum dma_data_direction dir) 269{ 270 return 1; 271} 272 273 274/** 275 * dma_map_single - map a single buffer for streaming DMA 276 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices 277 * @cpu_addr: CPU direct mapped address of buffer 278 * @size: size of buffer to map 279 * @dir: DMA transfer direction 280 * 281 * Ensure that any data held in the cache is appropriately discarded 282 * or written back. 283 * 284 * The device owns this memory once this call has completed. The CPU 285 * can regain ownership by calling dma_unmap_single() or 286 * dma_sync_single_for_cpu(). 287 */ 288static inline dma_addr_t dma_map_single(struct device *dev, void *cpu_addr, 289 size_t size, enum dma_data_direction dir) 290{ 291 BUG_ON(!valid_dma_direction(dir)); 292 293 if (!arch_is_coherent()) 294 dma_cache_maint(cpu_addr, size, dir); 295 296 return virt_to_dma(dev, cpu_addr); 297} 298 299/** 300 * dma_map_page - map a portion of a page for streaming DMA 301 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices 302 * @page: page that buffer resides in 303 * @offset: offset into page for start of buffer 304 * @size: size of buffer to map 305 * @dir: DMA transfer direction 306 * 307 * Ensure that any data held in the cache is appropriately discarded 308 * or written back. 309 * 310 * The device owns this memory once this call has completed. The CPU 311 * can regain ownership by calling dma_unmap_page(). 312 */ 313static inline dma_addr_t dma_map_page(struct device *dev, struct page *page, 314 unsigned long offset, size_t size, enum dma_data_direction dir) 315{ 316 BUG_ON(!valid_dma_direction(dir)); 317 318 if (!arch_is_coherent()) 319 dma_cache_maint(page_address(page) + offset, size, dir); 320 321 return page_to_dma(dev, page) + offset; 322} 323 324/** 325 * dma_unmap_single - unmap a single buffer previously mapped 326 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices 327 * @handle: DMA address of buffer 328 * @size: size of buffer (same as passed to dma_map_single) 329 * @dir: DMA transfer direction (same as passed to dma_map_single) 330 * 331 * Unmap a single streaming mode DMA translation. The handle and size 332 * must match what was provided in the previous dma_map_single() call. 333 * All other usages are undefined. 334 * 335 * After this call, reads by the CPU to the buffer are guaranteed to see 336 * whatever the device wrote there. 337 */ 338static inline void dma_unmap_single(struct device *dev, dma_addr_t handle, 339 size_t size, enum dma_data_direction dir) 340{ 341 /* nothing to do */ 342} 343#endif /* CONFIG_DMABOUNCE */ 344 345/** 346 * dma_unmap_page - unmap a buffer previously mapped through dma_map_page() 347 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices 348 * @handle: DMA address of buffer 349 * @size: size of buffer (same as passed to dma_map_page) 350 * @dir: DMA transfer direction (same as passed to dma_map_page) 351 * 352 * Unmap a page streaming mode DMA translation. The handle and size 353 * must match what was provided in the previous dma_map_page() call. 354 * All other usages are undefined. 355 * 356 * After this call, reads by the CPU to the buffer are guaranteed to see 357 * whatever the device wrote there. 358 */ 359static inline void dma_unmap_page(struct device *dev, dma_addr_t handle, 360 size_t size, enum dma_data_direction dir) 361{ 362 dma_unmap_single(dev, handle, size, dir); 363} 364 365/** 366 * dma_sync_single_range_for_cpu 367 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices 368 * @handle: DMA address of buffer 369 * @offset: offset of region to start sync 370 * @size: size of region to sync 371 * @dir: DMA transfer direction (same as passed to dma_map_single) 372 * 373 * Make physical memory consistent for a single streaming mode DMA 374 * translation after a transfer. 375 * 376 * If you perform a dma_map_single() but wish to interrogate the 377 * buffer using the cpu, yet do not wish to teardown the PCI dma 378 * mapping, you must call this function before doing so. At the 379 * next point you give the PCI dma address back to the card, you 380 * must first the perform a dma_sync_for_device, and then the 381 * device again owns the buffer. 382 */ 383static inline void dma_sync_single_range_for_cpu(struct device *dev, 384 dma_addr_t handle, unsigned long offset, size_t size, 385 enum dma_data_direction dir) 386{ 387 BUG_ON(!valid_dma_direction(dir)); 388 389 dmabounce_sync_for_cpu(dev, handle, offset, size, dir); 390} 391 392static inline void dma_sync_single_range_for_device(struct device *dev, 393 dma_addr_t handle, unsigned long offset, size_t size, 394 enum dma_data_direction dir) 395{ 396 BUG_ON(!valid_dma_direction(dir)); 397 398 if (!dmabounce_sync_for_device(dev, handle, offset, size, dir)) 399 return; 400 401 if (!arch_is_coherent()) 402 dma_cache_maint(dma_to_virt(dev, handle) + offset, size, dir); 403} 404 405static inline void dma_sync_single_for_cpu(struct device *dev, 406 dma_addr_t handle, size_t size, enum dma_data_direction dir) 407{ 408 dma_sync_single_range_for_cpu(dev, handle, 0, size, dir); 409} 410 411static inline void dma_sync_single_for_device(struct device *dev, 412 dma_addr_t handle, size_t size, enum dma_data_direction dir) 413{ 414 dma_sync_single_range_for_device(dev, handle, 0, size, dir); 415} 416 417/* 418 * The scatter list versions of the above methods. 419 */ 420extern int dma_map_sg(struct device *, struct scatterlist *, int, 421 enum dma_data_direction); 422extern void dma_unmap_sg(struct device *, struct scatterlist *, int, 423 enum dma_data_direction); 424extern void dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int, 425 enum dma_data_direction); 426extern void dma_sync_sg_for_device(struct device *, struct scatterlist *, int, 427 enum dma_data_direction); 428 429 430#endif /* __KERNEL__ */ 431#endif 432