xref: /openbmc/linux/arch/mips/loongson64/dma.c (revision d9fd5a71)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/dma-direct.h>
3 #include <linux/init.h>
4 #include <linux/swiotlb.h>
5 #include <boot_param.h>
6 
7 dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
8 {
9 	/* We extract 2bit node id (bit 44~47, only bit 44~45 used now) from
10 	 * Loongson-3's 48bit address space and embed it into 40bit */
11 	long nid = (paddr >> 44) & 0x3;
12 
13 	return ((nid << 44) ^ paddr) | (nid << node_id_offset);
14 }
15 
16 phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
17 {
18 	/* We extract 2bit node id (bit 44~47, only bit 44~45 used now) from
19 	 * Loongson-3's 48bit address space and embed it into 40bit */
20 	long nid = (daddr >> node_id_offset) & 0x3;
21 
22 	return ((nid << node_id_offset) ^ daddr) | (nid << 44);
23 }
24 
25 void __init plat_swiotlb_setup(void)
26 {
27 	swiotlb_init(1);
28 }
29