linux/arch/nios2/mm/dma-mapping.c

92 lines
2.2 KiB
C

/*
* Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
* Copyright (C) 2009 Wind River Systems Inc
* Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
*
* Based on DMA code from MIPS.
*
* 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.
*/
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/dma-mapping.h>
#include <linux/io.h>
#include <linux/cache.h>
#include <asm/cacheflush.h>
void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,
size_t size, enum dma_data_direction dir)
{
void *vaddr = phys_to_virt(paddr);
switch (dir) {
case DMA_FROM_DEVICE:
invalidate_dcache_range((unsigned long)vaddr,
(unsigned long)(vaddr + size));
break;
case DMA_TO_DEVICE:
/*
* We just need to flush the caches here , but Nios2 flush
* instruction will do both writeback and invalidate.
*/
case DMA_BIDIRECTIONAL: /* flush and invalidate */
flush_dcache_range((unsigned long)vaddr,
(unsigned long)(vaddr + size));
break;
default:
BUG();
}
}
void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,
size_t size, enum dma_data_direction dir)
{
void *vaddr = phys_to_virt(paddr);
switch (dir) {
case DMA_BIDIRECTIONAL:
case DMA_FROM_DEVICE:
invalidate_dcache_range((unsigned long)vaddr,
(unsigned long)(vaddr + size));
break;
case DMA_TO_DEVICE:
break;
default:
BUG();
}
}
void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
gfp_t gfp, unsigned long attrs)
{
void *ret;
/* optimized page clearing */
gfp |= __GFP_ZERO;
if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
gfp |= GFP_DMA;
ret = (void *) __get_free_pages(gfp, get_order(size));
if (ret != NULL) {
*dma_handle = virt_to_phys(ret);
flush_dcache_range((unsigned long) ret,
(unsigned long) ret + size);
ret = UNCAC_ADDR(ret);
}
return ret;
}
void arch_dma_free(struct device *dev, size_t size, void *vaddr,
dma_addr_t dma_handle, unsigned long attrs)
{
unsigned long addr = (unsigned long) CAC_ADDR((unsigned long) vaddr);
free_pages(addr, get_order(size));
}