/* pci-dma.c: Dynamic DMA mapping support for the FRV CPUs that have MMUs
*
* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/dma-mapping.h>
#include <linux/list.h>
#include <linux/pci.h>
#include <linux/highmem.h>
#include <asm/io.h>
void *dma_alloc_coherent(struct device *hwdev, size_t size, dma_addr_t *dma_handle, gfp_t gfp)
{
void *ret;
ret = consistent_alloc(gfp, size, dma_handle);
if (ret)
memset(ret, 0, size);
return ret;
}
void dma_free_coherent(struct device *hwdev, size_t size, void *vaddr, dma_addr_t dma_handle)
{
consistent_free(vaddr);
}
/*
* Map a single buffer of the indicated size for DMA in streaming mode.
* The 32-bit bus address to use is returned.
*
* Once the device is given the dma address, the device owns this memory
* until either pci_unmap_single or pci_dma_sync_single is performed.
*/
dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size,
enum dma_data_direction direction)
{
if (direction == DMA_NONE)
BUG();
frv_cache_wback_inv((unsigned long) ptr, (unsigned long) ptr + size);
return virt_to_bus(ptr);
}
/*
* Map a set of buffers described by scatterlist in streaming
* mode for DMA. This is the scather-gather version of the
* above pci_map_single interface. Here the scatter gather list
* elements are each tagged with the appropriate dma address
* and length. They are obtained via sg_dma_{address,length}(SG).
*
* NOTE: An implementation may be able to use a smaller number of
* DMA address/length pairs than there are SG table elements.
* (for example via virtual mapping capabilities)
* The routine returns the number of addr/length pairs actually
* used, at most nents.
*
* Device ownership issues as mentioned above for pci_map_single are
* the same here.
*/
int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction direction)
{
unsigned long dampr2;
void *vaddr;
int i;
if (direction == DMA_NONE)
BUG();
dampr2 = __get_DAMPR(2);
for (i = 0; i < nents; i++) {
vaddr = kmap_atomic(sg[i].page, __KM_CACHE);
frv_dcache_writeback((unsigned long) vaddr,
(unsigned long) vaddr + PAGE_SIZE);
}
kunmap_atomic(vaddr, __KM_CACHE);
if (dampr2) {
__set_DAMPR(2, dampr2);
__set_IAMPR(2, dampr2);
}
return nents;
}
dma_addr_t dma_map_page(struct device *dev, struct page *page, unsigned long offset,
size_t size, enum dma_data_direction direction)
{
BUG_ON(direction == DMA_NONE);
flush_dcache_page(page);
return (dma_addr_t) page_to_phys(page) + offset;
}
