76 lines
1.8 KiB
C
76 lines
1.8 KiB
C
/*
|
|
* Dynamic DMA mapping support.
|
|
*
|
|
* We never have any address translations to worry about, so this
|
|
* is just alloc/free.
|
|
*/
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/gfp.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/device.h>
|
|
#include <linux/dma-mapping.h>
|
|
#include <linux/export.h>
|
|
#include <asm/cacheflush.h>
|
|
|
|
void *dma_alloc_coherent(struct device *dev, size_t size,
|
|
dma_addr_t *dma_handle, gfp_t gfp)
|
|
{
|
|
void *ret;
|
|
/* ignore region specifiers */
|
|
gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
|
|
|
|
if (dev == NULL || (*dev->dma_mask < 0xffffffff))
|
|
gfp |= GFP_DMA;
|
|
ret = (void *)__get_free_pages(gfp, get_order(size));
|
|
|
|
if (ret != NULL) {
|
|
memset(ret, 0, size);
|
|
*dma_handle = virt_to_phys(ret);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
void dma_free_coherent(struct device *dev, size_t size,
|
|
void *vaddr, dma_addr_t dma_handle)
|
|
{
|
|
free_pages((unsigned long)vaddr, get_order(size));
|
|
}
|
|
|
|
void dma_sync_single_for_device(struct device *dev, dma_addr_t handle,
|
|
size_t size, enum dma_data_direction dir)
|
|
{
|
|
switch (dir) {
|
|
case DMA_TO_DEVICE:
|
|
flush_dcache_range(handle, size);
|
|
break;
|
|
case DMA_FROM_DEVICE:
|
|
/* Should be clear already */
|
|
break;
|
|
default:
|
|
if (printk_ratelimit())
|
|
printk("dma_sync_single_for_device: unsupported dir %u\n", dir);
|
|
break;
|
|
}
|
|
}
|
|
|
|
EXPORT_SYMBOL(dma_sync_single_for_device);
|
|
dma_addr_t dma_map_single(struct device *dev, void *addr, size_t size,
|
|
enum dma_data_direction dir)
|
|
{
|
|
dma_addr_t handle = virt_to_phys(addr);
|
|
flush_dcache_range(handle, size);
|
|
return handle;
|
|
}
|
|
EXPORT_SYMBOL(dma_map_single);
|
|
|
|
dma_addr_t dma_map_page(struct device *dev, struct page *page,
|
|
unsigned long offset, size_t size,
|
|
enum dma_data_direction dir)
|
|
{
|
|
dma_addr_t handle = page_to_phys(page) + offset;
|
|
dma_sync_single_for_device(dev, handle, size, dir);
|
|
return handle;
|
|
}
|
|
EXPORT_SYMBOL(dma_map_page);
|