diff options
Diffstat (limited to 'kernel/dma/ops_helpers.c')
| -rw-r--r-- | kernel/dma/ops_helpers.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/kernel/dma/ops_helpers.c b/kernel/dma/ops_helpers.c index e443c69be429..5828e5e01b79 100644 --- a/kernel/dma/ops_helpers.c +++ b/kernel/dma/ops_helpers.c @@ -3,6 +3,7 @@ * Helpers for DMA ops implementations. These generally rely on the fact that * the allocated memory contains normal pages in the direct kernel mapping. */ +#include <linux/dma-contiguous.h> #include <linux/dma-noncoherent.h> /* @@ -49,3 +50,37 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, return -ENXIO; #endif /* CONFIG_MMU */ } + +struct page *dma_common_alloc_pages(struct device *dev, size_t size, + dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp) +{ + const struct dma_map_ops *ops = get_dma_ops(dev); + struct page *page; + + page = dma_alloc_contiguous(dev, size, gfp); + if (!page) + page = alloc_pages_node(dev_to_node(dev), gfp, get_order(size)); + if (!page) + return NULL; + + *dma_handle = ops->map_page(dev, page, 0, size, dir, + DMA_ATTR_SKIP_CPU_SYNC); + if (*dma_handle == DMA_MAPPING_ERROR) { + dma_free_contiguous(dev, page, size); + return NULL; + } + + memset(page_address(page), 0, size); + return page; +} + +void dma_common_free_pages(struct device *dev, size_t size, struct page *page, + dma_addr_t dma_handle, enum dma_data_direction dir) +{ + const struct dma_map_ops *ops = get_dma_ops(dev); + + if (ops->unmap_page) + ops->unmap_page(dev, dma_handle, size, dir, + DMA_ATTR_SKIP_CPU_SYNC); + dma_free_contiguous(dev, page, size); +} |