参照元†
- const void *start
- size_t size
- int direction
返り値†
/*
* Make an area consistent for devices.
* Note: Drivers should NOT use this function directly, as it will break
* platforms with CONFIG_DMABOUNCE.
* Use the driver DMA support - see dma-mapping.h (dma_sync_*)
*/
void dma_cache_maint(const void *start, size_t size, int direction)
{
void (*inner_op)(const void *, const void *);
void (*outer_op)(unsigned long, unsigned long);
BUG_ON(!virt_addr_valid(start) || !virt_addr_valid(start + size - 1));
switch (direction) {
case DMA_FROM_DEVICE: /* invalidate only */
inner_op = dmac_inv_range;
outer_op = outer_inv_range;
break;
case DMA_TO_DEVICE: /* writeback only */
inner_op = dmac_clean_range;
outer_op = outer_clean_range;
break;
case DMA_BIDIRECTIONAL: /* writeback and invalidate */
inner_op = dmac_flush_range;
outer_op = outer_flush_range;
break;
default:
BUG();
}
inner_op(start, start + size);
outer_op(__pa(start), __pa(start) + size);
}
EXPORT_SYMBOL(dma_cache_maint);
コメント†