Files
Linux_Drivers/linux_5.10/arch/mips/sgi-ip32/ip32-dma.c
sam.xiang 5c7dd7acc3 [linux] create linux_5.10.4 from T-head official:
repo: https://github.com/T-head-Semi/linux
	commit: b1313fe517ca3703119dcc99ef3bbf75ab42bcfb

Change-Id: I6cbb35294024ea3a66140e311f4bb705fd7fd626
2023-03-10 20:32:41 +08:00

38 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;
}