dma_pool_create (9) - Linux Manuals
dma_pool_create: Creates a pool of consistent memory blocks, for dma.
dma_pool_create - Creates a pool of consistent memory blocks, for dma.
struct dma_pool * dma_pool_create(const char
* name, struct device * dev, size_t size, size_t align, size_t boundary);
- name of pool, for diagnostics
- device that will be doing the DMA
- size of the blocks in this pool.
- alignment requirement for blocks; must be a power of two
- returned blocks won't cross this power of two boundary
Returns a dma allocation pool with the requested characteristics, or null if one can't be created. Given one of these pools, dma_pool_alloc may be used to allocate memory. Such memory will all have "consistent" DMA mappings, accessible by the device and its driver without using cache flushing primitives. The actual size of blocks allocated may be larger than requested because of alignment.
If boundary is nonzero, objects returned from dma_pool_alloc won't cross that size boundary. This is useful for devices which have addressing restrictions on individual DMA transfers, such as not crossing boundaries of 4KBytes.