android_kernel_samsung_msm8976/crypto/async_tx/async_memcpy.c
Dan Williams a08abd8ca8 async_tx: structify submission arguments, add scribble
Prepare the api for the arrival of a new parameter, 'scribble'.  This
will allow callers to identify scratchpad memory for dma address or page
address conversions.  As this adds yet another parameter, take this
opportunity to convert the common submission parameters (flags,
dependency, callback, and callback argument) into an object that is
passed by reference.

Also, take this opportunity to fix up the kerneldoc and add notes about
the relevant ASYNC_TX_* flags for each routine.

[ Impact: moves api pass-by-value parameters to a pass-by-reference struct ]

Signed-off-by: Andre Noll <maan@systemlinux.org>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-06-03 14:07:35 -07:00

109 lines
3 KiB
C

/*
* copy offload engine support
*
* Copyright © 2006, Intel Corporation.
*
* Dan Williams <dan.j.williams@intel.com>
*
* with architecture considerations by:
* Neil Brown <neilb@suse.de>
* Jeff Garzik <jeff@garzik.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*
*/
#include <linux/kernel.h>
#include <linux/highmem.h>
#include <linux/mm.h>
#include <linux/dma-mapping.h>
#include <linux/async_tx.h>
/**
* async_memcpy - attempt to copy memory with a dma engine.
* @dest: destination page
* @src: src page
* @dest_offset: offset into 'dest' to start transaction
* @src_offset: offset into 'src' to start transaction
* @len: length in bytes
* @submit: submission / completion modifiers
*
* honored flags: ASYNC_TX_ACK
*/
struct dma_async_tx_descriptor *
async_memcpy(struct page *dest, struct page *src, unsigned int dest_offset,
unsigned int src_offset, size_t len,
struct async_submit_ctl *submit)
{
struct dma_chan *chan = async_tx_find_channel(submit, DMA_MEMCPY,
&dest, 1, &src, 1, len);
struct dma_device *device = chan ? chan->device : NULL;
struct dma_async_tx_descriptor *tx = NULL;
if (device) {
dma_addr_t dma_dest, dma_src;
unsigned long dma_prep_flags;
dma_prep_flags = submit->cb_fn ? DMA_PREP_INTERRUPT : 0;
dma_dest = dma_map_page(device->dev, dest, dest_offset, len,
DMA_FROM_DEVICE);
dma_src = dma_map_page(device->dev, src, src_offset, len,
DMA_TO_DEVICE);
tx = device->device_prep_dma_memcpy(chan, dma_dest, dma_src,
len, dma_prep_flags);
}
if (tx) {
pr_debug("%s: (async) len: %zu\n", __func__, len);
async_tx_submit(chan, tx, submit);
} else {
void *dest_buf, *src_buf;
pr_debug("%s: (sync) len: %zu\n", __func__, len);
/* wait for any prerequisite operations */
async_tx_quiesce(&submit->depend_tx);
dest_buf = kmap_atomic(dest, KM_USER0) + dest_offset;
src_buf = kmap_atomic(src, KM_USER1) + src_offset;
memcpy(dest_buf, src_buf, len);
kunmap_atomic(dest_buf, KM_USER0);
kunmap_atomic(src_buf, KM_USER1);
async_tx_sync_epilog(submit);
}
return tx;
}
EXPORT_SYMBOL_GPL(async_memcpy);
static int __init async_memcpy_init(void)
{
return 0;
}
static void __exit async_memcpy_exit(void)
{
do { } while (0);
}
module_init(async_memcpy_init);
module_exit(async_memcpy_exit);
MODULE_AUTHOR("Intel Corporation");
MODULE_DESCRIPTION("asynchronous memcpy api");
MODULE_LICENSE("GPL");