https://github.com/torvalds/linux
Tip revision: 523d939ef98fd712632d93a5a2b588e477a7565e authored by Linus Torvalds on 24 July 2016, 19:23:50 UTC
Linux 4.7
Linux 4.7
Tip revision: 523d939
pci-dma.c
/* 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/dma-mapping.h>
#include <linux/list.h>
#include <linux/pci.h>
#include <linux/export.h>
#include <linux/highmem.h>
#include <linux/scatterlist.h>
#include <asm/io.h>
static void *frv_dma_alloc(struct device *hwdev, size_t size,
dma_addr_t *dma_handle, gfp_t gfp,
struct dma_attrs *attrs)
{
void *ret;
ret = consistent_alloc(gfp, size, dma_handle);
if (ret)
memset(ret, 0, size);
return ret;
}
static void frv_dma_free(struct device *hwdev, size_t size, void *vaddr,
dma_addr_t dma_handle, struct dma_attrs *attrs)
{
consistent_free(vaddr);
}
static int frv_dma_map_sg(struct device *dev, struct scatterlist *sglist,
int nents, enum dma_data_direction direction,
struct dma_attrs *attrs)
{
unsigned long dampr2;
void *vaddr;
int i;
struct scatterlist *sg;
BUG_ON(direction == DMA_NONE);
dampr2 = __get_DAMPR(2);
for_each_sg(sglist, sg, nents, i) {
vaddr = kmap_atomic_primary(sg_page(sg));
frv_dcache_writeback((unsigned long) vaddr,
(unsigned long) vaddr + PAGE_SIZE);
}
kunmap_atomic_primary(vaddr);
if (dampr2) {
__set_DAMPR(2, dampr2);
__set_IAMPR(2, dampr2);
}
return nents;
}
static dma_addr_t frv_dma_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction direction, struct dma_attrs *attrs)
{
flush_dcache_page(page);
return (dma_addr_t) page_to_phys(page) + offset;
}
static void frv_dma_sync_single_for_device(struct device *dev,
dma_addr_t dma_handle, size_t size,
enum dma_data_direction direction)
{
flush_write_buffers();
}
static void frv_dma_sync_sg_for_device(struct device *dev,
struct scatterlist *sg, int nelems,
enum dma_data_direction direction)
{
flush_write_buffers();
}
static int frv_dma_supported(struct device *dev, u64 mask)
{
/*
* we fall back to GFP_DMA when the mask isn't all 1s,
* so we can't guarantee allocations that must be
* within a tighter range than GFP_DMA..
*/
if (mask < 0x00ffffff)
return 0;
return 1;
}
struct dma_map_ops frv_dma_ops = {
.alloc = frv_dma_alloc,
.free = frv_dma_free,
.map_page = frv_dma_map_page,
.map_sg = frv_dma_map_sg,
.sync_single_for_device = frv_dma_sync_single_for_device,
.sync_sg_for_device = frv_dma_sync_sg_for_device,
.dma_supported = frv_dma_supported,
};
EXPORT_SYMBOL(frv_dma_ops);