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/* $Id: ip27-pci-dma.c,v 1.1 2000/02/16 21:22:00 ralf Exp $
*
* Dynamic DMA mapping support.
*
* On the Origin there is dynamic DMA address translation for all PCI DMA.
* However we don't use this facility yet but rely on the 2gb direct
* mapped DMA window for PCI64. So consistent alloc/free are merely page
* allocation/freeing. The rest of the dynamic DMA mapping interface is
* implemented in <asm/pci.h>. So this code will fail with more than
* 2gb of memory.
*/
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/pci.h>
#include <asm/io.h>
/* Pure 2^n version of get_order */
extern __inline__ int __get_order(unsigned long size)
{
int order;
size = (size-1) >> (PAGE_SHIFT-1);
order = -1;
do {
size >>= 1;
order++;
} while (size);
return order;
}
void *pci_alloc_consistent(struct pci_dev *hwdev, size_t size,
dma_addr_t *dma_handle)
{
void *ret;
int gfp = GFP_ATOMIC;
int order = __get_order(size);
if (hwdev == NULL || hwdev->dma_mask != 0xffffffff)
gfp |= GFP_DMA;
ret = (void *)__get_free_pages(gfp, order);
if (ret != NULL) {
memset(ret, 0, size);
*dma_handle = virt_to_bus(ret);
}
return ret;
}
void pci_free_consistent(struct pci_dev *hwdev, size_t size,
void *vaddr, dma_addr_t dma_handle)
{
free_pages((unsigned long)vaddr, __get_order(size));
}
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