ubuntu-linux-kernel/arch/mips/include/asm/mach-ip32/dma-coherence.h

93 lines
2.1 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2006 Ralf Baechle <ralf@linux-mips.org>
*
*/
#ifndef __ASM_MACH_IP32_DMA_COHERENCE_H
#define __ASM_MACH_IP32_DMA_COHERENCE_H
#include <asm/ip32/crime.h>
struct device;
/*
* 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
static inline dma_addr_t plat_map_dma_mem(struct device *dev, void *addr,
size_t size)
{
dma_addr_t pa = virt_to_phys(addr) & RAM_OFFSET_MASK;
if (dev == NULL)
pa += CRIME_HI_MEM_BASE;
return pa;
}
static inline dma_addr_t plat_map_dma_mem_page(struct device *dev,
struct page *page)
{
dma_addr_t pa;
pa = page_to_phys(page) & RAM_OFFSET_MASK;
if (dev == NULL)
pa += CRIME_HI_MEM_BASE;
return pa;
}
/* This is almost certainly wrong but it's what dma-ip32.c used to use */
static inline unsigned long plat_dma_addr_to_phys(struct device *dev,
dma_addr_t dma_addr)
{
unsigned long addr = dma_addr & RAM_OFFSET_MASK;
if (dma_addr >= 256*1024*1024)
addr += CRIME_HI_MEM_BASE;
return addr;
}
static inline void plat_unmap_dma_mem(struct device *dev, dma_addr_t dma_addr,
size_t size, enum dma_data_direction direction)
{
}
static inline int plat_dma_supported(struct device *dev, u64 mask)
{
/*
* we fall back to GFP_DMA when the mask isn't all 1s,
* so we can't guarantee allocations that must be
* within a tighter range than GFP_DMA..
*/
if (mask < DMA_BIT_MASK(24))
return 0;
return 1;
}
static inline void plat_post_dma_flush(struct device *dev)
{
}
static inline int plat_device_is_coherent(struct device *dev)
{
return 0; /* IP32 is non-coherent */
}
#endif /* __ASM_MACH_IP32_DMA_COHERENCE_H */