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@@ -0,0 +1,63 @@
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+/* SPDX-License-Identifier: GPL-2.0 */
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+#ifndef _LINUX_DMA_MAPPING_H
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+#define _LINUX_DMA_MAPPING_H
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+
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+#include <linux/dma-direction.h>
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+#include <linux/types.h>
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+#include <asm/dma-mapping.h>
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+#include <cpu_func.h>
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+
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+#define dma_mapping_error(x, y) 0
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+
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+/**
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+ * Map a buffer to make it available to the DMA device
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+ *
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+ * Linux-like DMA API that is intended to be used from drivers. This hides the
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+ * underlying cache operation from drivers. Call this before starting the DMA
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+ * transfer. In most of architectures in U-Boot, the virtual address matches to
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+ * the physical address (but we have exceptions like sandbox). U-Boot does not
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+ * support iommu at the driver level, so it also matches to the DMA address.
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+ * Hence, this helper currently just performs the cache operation, then returns
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+ * straight-mapped dma_address, which is intended to be set to the register of
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+ * the DMA device.
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+ *
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+ * @vaddr: address of the buffer
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+ * @len: length of the buffer
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+ * @dir: the direction of DMA
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+ */
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+static inline dma_addr_t dma_map_single(void *vaddr, size_t len,
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+ enum dma_data_direction dir)
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+{
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+ unsigned long addr = (unsigned long)vaddr;
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+
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+ len = ALIGN(len, ARCH_DMA_MINALIGN);
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+
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+ if (dir == DMA_FROM_DEVICE)
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+ invalidate_dcache_range(addr, addr + len);
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+ else
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+ flush_dcache_range(addr, addr + len);
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+
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+ return addr;
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+}
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+
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+/**
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+ * Unmap a buffer to make it available to CPU
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+ *
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+ * Linux-like DMA API that is intended to be used from drivers. This hides the
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+ * underlying cache operation from drivers. Call this after finishin the DMA
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+ * transfer.
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+ *
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+ * @addr: DMA address
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+ * @len: length of the buffer
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+ * @dir: the direction of DMA
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+ */
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+static inline void dma_unmap_single(dma_addr_t addr, size_t len,
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+ enum dma_data_direction dir)
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+{
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+ len = ALIGN(len, ARCH_DMA_MINALIGN);
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+
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+ if (dir != DMA_TO_DEVICE)
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+ invalidate_dcache_range(addr, addr + len);
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+}
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+
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+#endif
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