android_kernel_xiaomi_sm8350/arch/sh/mm/consistent.c
Nick Piggin 8dfcc9ba27 [PATCH] mm: split highorder pages
Have an explicit mm call to split higher order pages into individual pages.
 Should help to avoid bugs and be more explicit about the code's intention.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-22 07:53:57 -08:00

85 lines
1.7 KiB
C

/*
* arch/sh/mm/consistent.c
*
* Copyright (C) 2004 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/io.h>
void *consistent_alloc(gfp_t gfp, size_t size, dma_addr_t *handle)
{
struct page *page, *end, *free;
void *ret;
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);
/*
* We must flush the cache before we pass it on to the device
*/
dma_cache_wback_inv(ret, size);
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 P2SEGADDR(ret);
}
void consistent_free(void *vaddr, size_t size)
{
unsigned long addr = P1SEGADDR((unsigned long)vaddr);
struct page *page=virt_to_page(addr);
int num_pages=(size+PAGE_SIZE-1) >> PAGE_SHIFT;
int i;
for(i=0;i<num_pages;i++) {
__free_page((page+i));
}
}
void consistent_sync(void *vaddr, size_t size, int direction)
{
void * p1addr = (void*) P1SEGADDR((unsigned long)vaddr);
switch (direction) {
case DMA_FROM_DEVICE: /* invalidate only */
dma_cache_inv(p1addr, size);
break;
case DMA_TO_DEVICE: /* writeback only */
dma_cache_wback(p1addr, size);
break;
case DMA_BIDIRECTIONAL: /* writeback and invalidate */
dma_cache_wback_inv(p1addr, size);
break;
default:
BUG();
}
}
EXPORT_SYMBOL(consistent_alloc);
EXPORT_SYMBOL(consistent_free);
EXPORT_SYMBOL(consistent_sync);