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author | Tony Lindgren | 2018-08-28 09:58:03 -0700 |
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committer | Tony Lindgren | 2018-08-28 09:58:03 -0700 |
commit | ea4d65f14f6aaa53e379b93c5544245ef081b3e7 (patch) | |
tree | a15485f4f1cf547a52b31fa8e16e14b9579b7200 /arch/mips/sgi-ip32/ip32-dma.c | |
parent | ce32d59ee2cd036f6e8a6ed17a06a0b0bec5c67c (diff) | |
parent | 496f3347d834aec91c38b45d6249ed00f58ad233 (diff) |
Merge branch 'perm-fix' into omap-for-v4.19/fixes-v2
Diffstat (limited to 'arch/mips/sgi-ip32/ip32-dma.c')
-rw-r--r-- | arch/mips/sgi-ip32/ip32-dma.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/arch/mips/sgi-ip32/ip32-dma.c b/arch/mips/sgi-ip32/ip32-dma.c new file mode 100644 index 000000000000..fa7b17cb5385 --- /dev/null +++ b/arch/mips/sgi-ip32/ip32-dma.c @@ -0,0 +1,37 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2006 Ralf Baechle <ralf@linux-mips.org> + */ +#include <linux/dma-direct.h> +#include <asm/ip32/crime.h> + +/* + * Few notes. + * 1. CPU sees memory as two chunks: 0-256M@0x0, and the rest @0x40000000+256M + * 2. PCI sees memory as one big chunk @0x0 (or we could use 0x40000000 for + * native-endian) + * 3. All other devices see memory as one big chunk at 0x40000000 + * 4. Non-PCI devices will pass NULL as struct device* + * + * Thus we translate differently, depending on device. + */ + +#define RAM_OFFSET_MASK 0x3fffffffUL + +dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr) +{ + dma_addr_t dma_addr = paddr & RAM_OFFSET_MASK; + + if (!dev) + dma_addr += CRIME_HI_MEM_BASE; + return dma_addr; +} + +phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dma_addr) +{ + phys_addr_t paddr = dma_addr & RAM_OFFSET_MASK; + + if (dma_addr >= 256*1024*1024) + paddr += CRIME_HI_MEM_BASE; + return paddr; +} |