linux_dsm_epyc7002/arch/mips/loongson64/loongson-3/dma.c
Christoph Hellwig d3bc81befc
MIPS: loongson: untangle dma implementations
Only loongson-3 is DMA coherent and uses swiotlb.  So move the dma
address translations stubs directly to the loongson-3 code, and remove
a few Kconfig indirections.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Patchwork: https://patchwork.linux-mips.org/patch/19539/
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Tom Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: iommu@lists.linux-foundation.org
Cc: linux-mips@linux-mips.org
2018-06-24 09:26:04 -07:00

26 lines
739 B
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/dma-direct.h>
#include <linux/init.h>
#include <linux/swiotlb.h>
dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
{
/* We extract 2bit node id (bit 44~47, only bit 44~45 used now) from
* Loongson-3's 48bit address space and embed it into 40bit */
long nid = (paddr >> 44) & 0x3;
return ((nid << 44) ^ paddr) | (nid << 37);
}
phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t daddr)
{
/* We extract 2bit node id (bit 44~47, only bit 44~45 used now) from
* Loongson-3's 48bit address space and embed it into 40bit */
long nid = (daddr >> 37) & 0x3;
return ((nid << 37) ^ daddr) | (nid << 44);
}
void __init plat_swiotlb_setup(void)
{
swiotlb_init(1);
}