mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-28 07:04:00 +08:00
cf65a0f6f6
Currently the code is split over various files with dma- prefixes in the lib/ and drives/base directories, and the number of files keeps growing. Move them into a single directory to keep the code together and remove the file name prefixes. To match the irq infrastructure this directory is placed under the kernel/ directory. Signed-off-by: Christoph Hellwig <hch@lst.de>
60 lines
1.4 KiB
C
60 lines
1.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* DMA operations that map to virtual addresses without flushing memory.
|
|
*/
|
|
#include <linux/export.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/dma-mapping.h>
|
|
#include <linux/scatterlist.h>
|
|
|
|
static void *dma_virt_alloc(struct device *dev, size_t size,
|
|
dma_addr_t *dma_handle, gfp_t gfp,
|
|
unsigned long attrs)
|
|
{
|
|
void *ret;
|
|
|
|
ret = (void *)__get_free_pages(gfp, get_order(size));
|
|
if (ret)
|
|
*dma_handle = (uintptr_t)ret;
|
|
return ret;
|
|
}
|
|
|
|
static void dma_virt_free(struct device *dev, size_t size,
|
|
void *cpu_addr, dma_addr_t dma_addr,
|
|
unsigned long attrs)
|
|
{
|
|
free_pages((unsigned long)cpu_addr, get_order(size));
|
|
}
|
|
|
|
static dma_addr_t dma_virt_map_page(struct device *dev, struct page *page,
|
|
unsigned long offset, size_t size,
|
|
enum dma_data_direction dir,
|
|
unsigned long attrs)
|
|
{
|
|
return (uintptr_t)(page_address(page) + offset);
|
|
}
|
|
|
|
static int dma_virt_map_sg(struct device *dev, struct scatterlist *sgl,
|
|
int nents, enum dma_data_direction dir,
|
|
unsigned long attrs)
|
|
{
|
|
int i;
|
|
struct scatterlist *sg;
|
|
|
|
for_each_sg(sgl, sg, nents, i) {
|
|
BUG_ON(!sg_page(sg));
|
|
sg_dma_address(sg) = (uintptr_t)sg_virt(sg);
|
|
sg_dma_len(sg) = sg->length;
|
|
}
|
|
|
|
return nents;
|
|
}
|
|
|
|
const struct dma_map_ops dma_virt_ops = {
|
|
.alloc = dma_virt_alloc,
|
|
.free = dma_virt_free,
|
|
.map_page = dma_virt_map_page,
|
|
.map_sg = dma_virt_map_sg,
|
|
};
|
|
EXPORT_SYMBOL(dma_virt_ops);
|