blob: f3649d8f50e363b701de98092455aa63a0e6917c [file] [log] [blame]
/* MN10300 Dynamic DMA mapping support
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (
* Derived from: arch/i386/kernel/pci-dma.c
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/pci.h>
#include <asm/io.h>
void *dma_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, int gfp)
unsigned long addr;
void *ret;
/* ignore region specifiers */
gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
if (dev == NULL || dev->coherent_dma_mask < 0xffffffff)
gfp |= GFP_DMA;
addr = __get_free_pages(gfp, get_order(size));
if (!addr)
return NULL;
/* map the coherent memory through the uncached memory window */
ret = (void *) (addr | 0x20000000);
/* fill the memory with obvious rubbish */
memset((void *) addr, 0xfb, size);
/* write back and evict all cache lines covering this region */
mn10300_dcache_flush_inv_range2(virt_to_phys((void *) addr), PAGE_SIZE);
*dma_handle = virt_to_bus((void *) addr);
return ret;
void dma_free_coherent(struct device *dev, size_t size, void *vaddr,
dma_addr_t dma_handle)
unsigned long addr = (unsigned long) vaddr & ~0x20000000;
free_pages(addr, get_order(size));