DMA Management Kernel Services
The operating system kernel provides several services for managing direct memory access (DMA) channels and performing DMA operations.
Understanding DMA Transfers provides additional kernel services information.
The services provided are:
| Item | Description |
|---|---|
| d_align | Provides needed information to align a buffer with a processor cache line. |
| d_cflush | Flushes the processor and I/O controller (IOCC) data caches when using the long term DMA_WRITE_ONLY mapping of DMA buffers approach to the bus device DMA. |
| d_map_clear | Deallocates resources previously allocated on a d_map_init call. |
| d_map_disable | Disables DMA for the specified handle. |
| d_map_enable | Enables DMA for the specified handle. |
| d_map_init | Allocates and initializes resources for performing DMA with PCI and ISA devices. |
| d_map_list | Performs platform-specific DMA mapping for a list of virtual addresses. |
| d_map_page | Performs platform-specific DMA mapping for a single page. |
| d_map_slave | Accepts a list of virtual addresses and sizes and sets up the slave DMA controller. |
| d_roundup | Rounds the value length up to a given number of cache lines. |
| d_unmap_list | Deallocates resources previously allocated on a d_map_list call. |
| d_unmap_page | Deallocates resources previously allocated on a d_map_page call. |
| d_unmap_slave | Deallocates resources previously allocated on a d_map_slave call. |