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author | 2023-10-10 14:33:42 +0000 | |
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committer | 2023-10-10 14:33:42 +0000 | |
commit | af1a266670d040d2f4083ff309d732d648afba2a (patch) | |
tree | 2fc46203448ddcc6f81546d379abfaeb323575e9 /roms/u-boot/include/linux/dma-mapping.h | |
parent | e02cda008591317b1625707ff8e115a4841aa889 (diff) |
Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec
Diffstat (limited to 'roms/u-boot/include/linux/dma-mapping.h')
-rw-r--r-- | roms/u-boot/include/linux/dma-mapping.h | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/roms/u-boot/include/linux/dma-mapping.h b/roms/u-boot/include/linux/dma-mapping.h new file mode 100644 index 000000000..6a107d52e --- /dev/null +++ b/roms/u-boot/include/linux/dma-mapping.h @@ -0,0 +1,64 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_DMA_MAPPING_H +#define _LINUX_DMA_MAPPING_H + +#include <asm/cache.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 |