mips/loongson64/dma.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 #include <linux/dma-direct.h>
0003 #include <linux/init.h>
0004 #include <linux/swiotlb.h>
0005 #include <boot_param.h>
0006
0007 dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
0008 {
0009     /* We extract 2bit node id (bit 44~47, only bit 44~45 used now) from
0010      * Loongson-3's 48bit address space and embed it into 40bit */
0011     long nid = (paddr >> 44) & 0x3;
0012
0013     return ((nid << 44) ^ paddr) | (nid << node_id_offset);
0014 }
0015
0016 phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
0017 {
0018     /* We extract 2bit node id (bit 44~47, only bit 44~45 used now) from
0019      * Loongson-3's 48bit address space and embed it into 40bit */
0020     long nid = (daddr >> node_id_offset) & 0x3;
0021
0022     return ((nid << node_id_offset) ^ daddr) | (nid << 44);
0023 }
0024
0025 void __init plat_swiotlb_setup(void)
0026 {
0027     swiotlb_init(true, SWIOTLB_VERBOSE);
0028 }