mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-30 22:26:55 +00:00
d4b6f1562a
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>
40 lines
975 B
C
40 lines
975 B
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
|
|
*/
|
|
#include <linux/init.h>
|
|
#include <linux/dma-direct.h>
|
|
#include <linux/dma-mapping.h>
|
|
#include <linux/dma-map-ops.h>
|
|
#include <linux/swiotlb.h>
|
|
|
|
#include <asm/bootinfo.h>
|
|
#include <asm/dma.h>
|
|
#include <asm/loongson.h>
|
|
|
|
/*
|
|
* We extract 4bit node id (bit 44~47) from Loongson-3's
|
|
* 48bit physical address space and embed it into 40bit.
|
|
*/
|
|
|
|
static int node_id_offset;
|
|
|
|
dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
|
|
{
|
|
long nid = (paddr >> 44) & 0xf;
|
|
|
|
return ((nid << 44) ^ paddr) | (nid << node_id_offset);
|
|
}
|
|
|
|
phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
|
|
{
|
|
long nid = (daddr >> node_id_offset) & 0xf;
|
|
|
|
return ((nid << node_id_offset) ^ daddr) | (nid << 44);
|
|
}
|
|
|
|
void __init plat_swiotlb_setup(void)
|
|
{
|
|
swiotlb_init(true, SWIOTLB_VERBOSE);
|
|
node_id_offset = ((readl(LS7A_DMA_CFG) & LS7A_DMA_NODE_MASK) >> LS7A_DMA_NODE_SHF) + 36;
|
|
}
|