linux-stable/arch/mips/sgi-ip32/ip32-dma.c
Christoph Hellwig 5ceda74093 dma-direct: rename and cleanup __phys_to_dma
The __phys_to_dma vs phys_to_dma distinction isn't exactly obvious.  Try
to improve the situation by renaming __phys_to_dma to
phys_to_dma_unencryped, and not forcing architectures that want to
override phys_to_dma to actually provide __phys_to_dma.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
2020-09-11 09:14:43 +02:00

37 lines
949 B
C

// 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;
}