5193a34646
counterparts to bus_dmamem_alloc() and bus_dmamem_free(). This allows the caller to specify the size of the allocation instead of it defaulting to the max_size field of the busdma tag. This is intended to aid in converting drivers to busdma. Lots of hardware cannot understand scatter/gather lists, which forces the driver to copy the i/o buffers to a single contiguous region before sending it to the hardware. Without these new methods, this would require a new busdma tag for each operation, or a complex internal allocator/cache for each driver. Allocations greater than PAGE_SIZE are rounded up to the next PAGE_SIZE by contigmalloc(), so this is not suitable for multiple static allocations that would be better served by a single fixed-length subdivided allocation. Reviewed by: jake (sparc64) |
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| linux | ||
| mcbus | ||
| osf1 | ||
| pci | ||
| tlsb | ||
| Makefile | ||