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 <asm/bootinfo.h>
   6 #include <boot_param.h>
   7
   8 dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
   9 {
  10         /* We extract 2bit node id (bit 44~47, only bit 44~45 used now) from
  11          * Loongson-3's 48bit address space and embed it into 40bit */
  12         long nid = (paddr >> 44) & 0x3;
  13
  14         return ((nid << 44) ^ paddr) | (nid << node_id_offset);
  15 }
  16
  17 phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
  18 {
  19         /* We extract 2bit node id (bit 44~47, only bit 44~45 used now) from
  20          * Loongson-3's 48bit address space and embed it into 40bit */
  21         long nid = (daddr >> node_id_offset) & 0x3;
  22
  23         return ((nid << node_id_offset) ^ daddr) | (nid << 44);
  24 }
  25
  26 void __init plat_swiotlb_setup(void)
  27 {
  28         swiotlb_init(true, SWIOTLB_VERBOSE);
  29 }