linux-stable-rt/arch/sh/mm/consistent.c

98 lines
2.0 KiB
C

/*
* arch/sh/mm/consistent.c
*
* Copyright (C) 2004 - 2007 Paul Mundt
*
* 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/mm.h>
#include <linux/dma-mapping.h>
#include <asm/cacheflush.h>
#include <asm/addrspace.h>
#include <asm/io.h>
void *consistent_alloc(gfp_t gfp, size_t size, dma_addr_t *handle)
{
struct page *page, *end, *free;
void *ret, *vp;
int order;
size = PAGE_ALIGN(size);
order = get_order(size);
page = alloc_pages(gfp, order);
if (!page)
return NULL;
split_page(page, order);
ret = page_address(page);
*handle = virt_to_phys(ret);
vp = ioremap_nocache(*handle, size);
if (!vp) {
free_pages((unsigned long)ret, order);
return NULL;
}
memset(vp, 0, size);
/*
* We must flush the cache before we pass it on to the device
*/
dma_cache_sync(NULL, ret, size, DMA_BIDIRECTIONAL);
page = virt_to_page(ret);
free = page + (size >> PAGE_SHIFT);
end = page + (1 << order);
while (++page < end) {
/* Free any unused pages */
if (page >= free) {
__free_page(page);
}
}
return vp;
}
EXPORT_SYMBOL(consistent_alloc);
void consistent_free(void *vaddr, size_t size, dma_addr_t dma_handle)
{
struct page *page;
unsigned long addr;
addr = (unsigned long)phys_to_virt((unsigned long)dma_handle);
page = virt_to_page(addr);
free_pages(addr, get_order(size));
iounmap(vaddr);
}
EXPORT_SYMBOL(consistent_free);
void consistent_sync(void *vaddr, size_t size, int direction)
{
#ifdef CONFIG_CPU_SH5
void *p1addr = vaddr;
#else
void *p1addr = (void*) P1SEGADDR((unsigned long)vaddr);
#endif
switch (direction) {
case DMA_FROM_DEVICE: /* invalidate only */
__flush_invalidate_region(p1addr, size);
break;
case DMA_TO_DEVICE: /* writeback only */
__flush_wback_region(p1addr, size);
break;
case DMA_BIDIRECTIONAL: /* writeback and invalidate */
__flush_purge_region(p1addr, size);
break;
default:
BUG();
}
}
EXPORT_SYMBOL(consistent_sync);