x86: use a fallback dev for i386

We can use a fallback dev for cases of a NULL device being passed (mostly ISA)
This comes from x86_64 implementation.

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Glauber Costa 2008-04-08 13:21:04 -03:00 committed by Ingo Molnar
parent d1a0790290
commit 45a07e7749

View File

@ -14,6 +14,16 @@
#include <linux/module.h>
#include <asm/io.h>
/* Dummy device used for NULL arguments (normally ISA). Better would
be probably a smaller DMA mask, but this is bug-to-bug compatible
to i386. */
struct device fallback_dev = {
.bus_id = "fallback device",
.coherent_dma_mask = DMA_32BIT_MASK,
.dma_mask = &fallback_dev.coherent_dma_mask,
};
static int dma_alloc_from_coherent_mem(struct device *dev, ssize_t size,
dma_addr_t *dma_handle, void **ret)
{
@ -75,6 +85,9 @@ void *dma_alloc_coherent(struct device *dev, size_t size,
if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
gfp |= GFP_DMA;
if (!dev)
dev = &fallback_dev;
page = dma_alloc_pages(dev, gfp, order);
if (page == NULL)
return NULL;