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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /arch/mips/sgi-ip32/ip32-dma.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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 0000000000..20c6da9d76 --- /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; +} |