OpenCloudOS-Kernel/arch/loongarch/kernel/dma.c

58 lines
1.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
*/
#include <linux/acpi.h>
#include <linux/dma-direct.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 acpi_arch_dma_setup(struct device *dev)
{
int ret;
u64 mask, end = 0;
const struct bus_dma_region *map = NULL;
if (node_id_offset == 0) {
node_id_offset = ((readl(LS7A_DMA_CFG) & LS7A_DMA_NODE_MASK) >> LS7A_DMA_NODE_SHF);
node_id_offset += 36;
}
ret = acpi_dma_get_range(dev, &map);
if (!ret && map) {
const struct bus_dma_region *r = map;
for (end = 0; r->size; r++) {
if (r->dma_start + r->size - 1 > end)
end = r->dma_start + r->size - 1;
}
mask = DMA_BIT_MASK(ilog2(end) + 1);
dev->bus_dma_limit = end;
dev->dma_range_map = map;
dev->coherent_dma_mask = min(dev->coherent_dma_mask, mask);
*dev->dma_mask = min(*dev->dma_mask, mask);
}
}