57 lines
1.5 KiB
C
57 lines
1.5 KiB
C
|
/* MN10300 Dynamic DMA mapping support
|
||
|
|
*
|
||
|
|
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
|
||
|
|
* Written by David Howells (dhowells@redhat.com)
|
||
|
|
* 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;
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL(dma_alloc_coherent);
|
||
|
|
|
||
|
|
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));
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL(dma_free_coherent);
|