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linux/arch/loongarch/include/asm/dma-direct.h
Huacai Chen d4b6f1562a LoongArch: Add Non-Uniform Memory Access (NUMA) support
Add Non-Uniform Memory Access (NUMA) support for LoongArch. LoongArch
has 48-bit physical address, but the HyperTransport I/O bus only support
40-bit address, so we need a custom phys_to_dma() and dma_to_phys() to
extract the 4-bit node id (bit 44~47) from Loongson-3's 48-bit physical
address space and embed it into 40-bit. In the 40-bit dma address, node
id offset can be read from the LS7A_DMA_CFG register.

Reviewed-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-06-03 20:09:29 +08:00

11 lines
342 B
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
*/
#ifndef _LOONGARCH_DMA_DIRECT_H
#define _LOONGARCH_DMA_DIRECT_H
dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr);
phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr);
#endif /* _LOONGARCH_DMA_DIRECT_H */