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- /* SPDX-License-Identifier: GPL-2.0 */
- #ifndef _LINUX_DMA_MAPPING_H
- #define _LINUX_DMA_MAPPING_H
- #include <linux/dma-direction.h>
- #include <linux/types.h>
- #include <asm/dma-mapping.h>
- #include <cpu_func.h>
- #define dma_mapping_error(x, y) 0
- /**
- * Map a buffer to make it available to the DMA device
- *
- * Linux-like DMA API that is intended to be used from drivers. This hides the
- * underlying cache operation from drivers. Call this before starting the DMA
- * transfer. In most of architectures in U-Boot, the virtual address matches to
- * the physical address (but we have exceptions like sandbox). U-Boot does not
- * support iommu at the driver level, so it also matches to the DMA address.
- * Hence, this helper currently just performs the cache operation, then returns
- * straight-mapped dma_address, which is intended to be set to the register of
- * the DMA device.
- *
- * @vaddr: address of the buffer
- * @len: length of the buffer
- * @dir: the direction of DMA
- */
- static inline dma_addr_t dma_map_single(void *vaddr, size_t len,
- enum dma_data_direction dir)
- {
- unsigned long addr = (unsigned long)vaddr;
- len = ALIGN(len, ARCH_DMA_MINALIGN);
- if (dir == DMA_FROM_DEVICE)
- invalidate_dcache_range(addr, addr + len);
- else
- flush_dcache_range(addr, addr + len);
- return addr;
- }
- /**
- * Unmap a buffer to make it available to CPU
- *
- * Linux-like DMA API that is intended to be used from drivers. This hides the
- * underlying cache operation from drivers. Call this after finishin the DMA
- * transfer.
- *
- * @addr: DMA address
- * @len: length of the buffer
- * @dir: the direction of DMA
- */
- static inline void dma_unmap_single(dma_addr_t addr, size_t len,
- enum dma_data_direction dir)
- {
- len = ALIGN(len, ARCH_DMA_MINALIGN);
- if (dir != DMA_TO_DEVICE)
- invalidate_dcache_range(addr, addr + len);
- }
- #endif
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