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- /*
- * 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);
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