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 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 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