arch/mips/loongson64/dma.c

   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 }