dma.c 817 B

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