1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited 4 */ 5 #include <linux/init.h> 6 #include <linux/dma-direct.h> 7 #include <linux/dma-mapping.h> 8 #include <linux/dma-map-ops.h> 9 #include <linux/swiotlb.h> 10 11 #include <asm/bootinfo.h> 12 #include <asm/dma.h> 13 #include <asm/loongson.h> 14 15 /* 16 * We extract 4bit node id (bit 44~47) from Loongson-3's 17 * 48bit physical address space and embed it into 40bit. 18 */ 19 20 static int node_id_offset; 21 22 dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr) 23 { 24 long nid = (paddr >> 44) & 0xf; 25 26 return ((nid << 44) ^ paddr) | (nid << node_id_offset); 27 } 28 29 phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr) 30 { 31 long nid = (daddr >> node_id_offset) & 0xf; 32 33 return ((nid << node_id_offset) ^ daddr) | (nid << 44); 34 } 35 36 void __init plat_swiotlb_setup(void) 37 { 38 swiotlb_init(true, SWIOTLB_VERBOSE); 39 node_id_offset = ((readl(LS7A_DMA_CFG) & LS7A_DMA_NODE_MASK) >> LS7A_DMA_NODE_SHF) + 36; 40 } 41