cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

dma.c (975B)

      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
     20static int node_id_offset;
     21
     22dma_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
     29phys_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
     36void __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}