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 
phys_to_dma(struct device * dev,phys_addr_t paddr)21 dma_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 
dma_to_phys(struct device * dev,dma_addr_t dma_addr)30 phys_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 }
38