blob: dbbd3816cc0bd9285daadb1890621f51137a390b [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
* Dynamic DMA mapping support.
* On cris there is no hardware dynamic DMA address translation,
* so consistent alloc/free are merely page allocation/freeing.
* The rest of the dynamic DMA mapping interface is implemented
* in asm/pci.h.
* Borrowed from i386.
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/pci.h>
#include <linux/gfp.h>
#include <asm/io.h>
static void *v32_dma_alloc(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
void *ret;
/* ignore region specifiers */
gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
if (dev == NULL || (dev->coherent_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;
static void v32_dma_free(struct device *dev, size_t size, void *vaddr,
dma_addr_t dma_handle, unsigned long attrs)
free_pages((unsigned long)vaddr, get_order(size));
static inline dma_addr_t v32_dma_map_page(struct device *dev,
struct page *page, unsigned long offset, size_t size,
enum dma_data_direction direction, unsigned long attrs)
return page_to_phys(page) + offset;
static inline int v32_dma_map_sg(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction direction,
unsigned long attrs)
printk("Map sg\n");
return nents;
static inline int v32_dma_supported(struct device *dev, u64 mask)
* we fall back to GFP_DMA when the mask isn't all 1s,
* so we can't guarantee allocations that must be
* within a tighter range than GFP_DMA..
if (mask < 0x00ffffff)
return 0;
return 1;
const struct dma_map_ops v32_dma_ops = {
.alloc = v32_dma_alloc,
.free = v32_dma_free,
.map_page = v32_dma_map_page,
.map_sg = v32_dma_map_sg,
.dma_supported = v32_dma_supported,