diff options
Diffstat (limited to 'Documentation/DMA-API.txt')
| -rw-r--r-- | Documentation/DMA-API.txt | 43 |
1 files changed, 15 insertions, 28 deletions
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index e133ccd60228..0076150fdccb 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -195,6 +195,14 @@ Requesting the required mask does not alter the current mask. If you wish to take advantage of it, you should issue a dma_set_mask() call to set the mask to the value returned. +:: + + size_t + dma_direct_max_mapping_size(struct device *dev); + +Returns the maximum size of a mapping for the device. The size parameter +of the mapping functions like dma_map_single(), dma_map_page() and +others should not be larger than the returned value. Part Id - Streaming DMA mappings -------------------------------- @@ -530,8 +538,8 @@ that simply cannot make consistent memory. dma_free_attrs(struct device *dev, size_t size, void *cpu_addr, dma_addr_t dma_handle, unsigned long attrs) -Free memory allocated by the dma_alloc_attrs(). All parameters common -parameters must identical to those otherwise passed to dma_fre_coherent, +Free memory allocated by the dma_alloc_attrs(). All common +parameters must be identical to those otherwise passed to dma_free_coherent, and the attrs argument must be identical to the attrs passed to dma_alloc_attrs(). @@ -566,8 +574,7 @@ boundaries when doing this. int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr, - dma_addr_t device_addr, size_t size, int - flags) + dma_addr_t device_addr, size_t size); Declare region of memory to be handed out by dma_alloc_coherent() when it's asked for coherent memory for this device. @@ -581,12 +588,6 @@ dma_addr_t in dma_alloc_coherent()). size is the size of the area (must be multiples of PAGE_SIZE). -flags can be ORed together and are: - -- DMA_MEMORY_EXCLUSIVE - only allocate memory from the declared regions. - Do not allow dma_alloc_coherent() to fall back to system memory when - it's out of memory in the declared region. - As a simplification for the platforms, only *one* such region of memory may be declared per device. @@ -605,23 +606,6 @@ unconditionally having removed all the required structures. It is the driver's job to ensure that no parts of this memory region are currently in use. -:: - - void * - dma_mark_declared_memory_occupied(struct device *dev, - dma_addr_t device_addr, size_t size) - -This is used to occupy specific regions of the declared space -(dma_alloc_coherent() will hand out the first free region it finds). - -device_addr is the *device* address of the region requested. - -size is the size (and should be a page-sized multiple). - -The return value will be either a pointer to the processor virtual -address of the memory, or an error (via PTR_ERR()) if any part of the -region is occupied. - Part III - Debug drivers use of the DMA-API ------------------------------------------- @@ -696,6 +680,9 @@ dma-api/disabled This read-only file contains the character 'Y' happen when it runs out of memory or if it was disabled at boot time +dma-api/dump This read-only file contains current DMA + mappings. + dma-api/error_count This file is read-only and shows the total numbers of errors found. @@ -717,7 +704,7 @@ dma-api/num_free_entries The current number of free dma_debug_entries dma-api/nr_total_entries The total number of dma_debug_entries in the allocator, both free and used. -dma-api/driver-filter You can write a name of a driver into this file +dma-api/driver_filter You can write a name of a driver into this file to limit the debug output to requests from that particular driver. Write an empty string to that file to disable the filter and see |