From 03df8229a822ab2c262bf78b05a3ada686b885b9 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 15 Jun 2018 13:08:48 +0200 Subject: MIPS: IP32: use generic dma noncoherent ops Provide phys_to_dma/dma_to_phys helpers, everything else is generic. Signed-off-by: Christoph Hellwig Patchwork: https://patchwork.linux-mips.org/patch/19546/ Signed-off-by: Paul Burton Cc: Florian Fainelli Cc: David Daney Cc: Kevin Cernekee Cc: Jiaxun Yang Cc: Tom Bogendoerfer Cc: Huacai Chen Cc: iommu@lists.linux-foundation.org Cc: linux-mips@linux-mips.org --- arch/mips/sgi-ip32/Makefile | 2 +- arch/mips/sgi-ip32/ip32-dma.c | 37 +++++++++++++++++++++++++++++++++++++ 2 files changed, 38 insertions(+), 1 deletion(-) create mode 100644 arch/mips/sgi-ip32/ip32-dma.c (limited to 'arch/mips/sgi-ip32') diff --git a/arch/mips/sgi-ip32/Makefile b/arch/mips/sgi-ip32/Makefile index 60f0227425e7..4745cd94df11 100644 --- a/arch/mips/sgi-ip32/Makefile +++ b/arch/mips/sgi-ip32/Makefile @@ -4,4 +4,4 @@ # obj-y += ip32-berr.o ip32-irq.o ip32-platform.o ip32-setup.o ip32-reset.o \ - crime.o ip32-memory.o + crime.o ip32-memory.o ip32-dma.o 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 + */ +#include +#include + +/* + * 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; +} -- cgit v1.2.3