1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * Copyright (C) 2006  Ralf Baechle <ralf@linux-mips.org>
 4 */
 5#include <linux/dma-direct.h>
 6#include <asm/ip32/crime.h>
 7
 8/*
 9 * Few notes.
10 * 1. CPU sees memory as two chunks: 0-256M@0x0, and the rest @0x40000000+256M
11 * 2. PCI sees memory as one big chunk @0x0 (or we could use 0x40000000 for
12 *    native-endian)
13 * 3. All other devices see memory as one big chunk at 0x40000000
14 * 4. Non-PCI devices will pass NULL as struct device*
15 *
16 * Thus we translate differently, depending on device.
17 */
18
19#define RAM_OFFSET_MASK 0x3fffffffUL
20
21dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
22{
23	dma_addr_t dma_addr = paddr & RAM_OFFSET_MASK;
24
25	if (!dev)
26		dma_addr += CRIME_HI_MEM_BASE;
27	return dma_addr;
28}
29
30phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr)
31{
32	phys_addr_t paddr = dma_addr & RAM_OFFSET_MASK;
33
34	if (dma_addr >= 256*1024*1024)
35		paddr += CRIME_HI_MEM_BASE;
36	return paddr;
37}