110 lines
3.3 KiB
C
110 lines
3.3 KiB
C
![]() |
/*
|
||
|
* memory fill 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/interrupt.h>
|
||
|
#include <linux/mm.h>
|
||
|
#include <linux/dma-mapping.h>
|
||
|
#include <linux/async_tx.h>
|
||
|
|
||
|
/**
|
||
|
* async_memset - attempt to fill memory with a dma engine.
|
||
|
* @dest: destination page
|
||
|
* @val: fill value
|
||
|
* @offset: offset in pages to start transaction
|
||
|
* @len: length in bytes
|
||
|
* @flags: ASYNC_TX_ASSUME_COHERENT, ASYNC_TX_ACK, ASYNC_TX_DEP_ACK
|
||
|
* @depend_tx: memset depends on the result of this transaction
|
||
|
* @cb_fn: function to call when the memcpy completes
|
||
|
* @cb_param: parameter to pass to the callback routine
|
||
|
*/
|
||
|
struct dma_async_tx_descriptor *
|
||
|
async_memset(struct page *dest, int val, unsigned int offset,
|
||
|
size_t len, enum async_tx_flags flags,
|
||
|
struct dma_async_tx_descriptor *depend_tx,
|
||
|
dma_async_tx_callback cb_fn, void *cb_param)
|
||
|
{
|
||
|
struct dma_chan *chan = async_tx_find_channel(depend_tx, DMA_MEMSET);
|
||
|
struct dma_device *device = chan ? chan->device : NULL;
|
||
|
int int_en = cb_fn ? 1 : 0;
|
||
|
struct dma_async_tx_descriptor *tx = device ?
|
||
|
device->device_prep_dma_memset(chan, val, len,
|
||
|
int_en) : NULL;
|
||
|
|
||
|
if (tx) { /* run the memset asynchronously */
|
||
|
dma_addr_t dma_addr;
|
||
|
enum dma_data_direction dir;
|
||
|
|
||
|
pr_debug("%s: (async) len: %zu\n", __FUNCTION__, len);
|
||
|
dir = (flags & ASYNC_TX_ASSUME_COHERENT) ?
|
||
|
DMA_NONE : DMA_FROM_DEVICE;
|
||
|
|
||
|
dma_addr = dma_map_page(device->dev, dest, offset, len, dir);
|
||
|
tx->tx_set_dest(dma_addr, tx, 0);
|
||
|
|
||
|
async_tx_submit(chan, tx, flags, depend_tx, cb_fn, cb_param);
|
||
|
} else { /* run the memset synchronously */
|
||
|
void *dest_buf;
|
||
|
pr_debug("%s: (sync) len: %zu\n", __FUNCTION__, len);
|
||
|
|
||
|
dest_buf = (void *) (((char *) page_address(dest)) + offset);
|
||
|
|
||
|
/* wait for any prerequisite operations */
|
||
|
if (depend_tx) {
|
||
|
/* if ack is already set then we cannot be sure
|
||
|
* we are referring to the correct operation
|
||
|
*/
|
||
|
BUG_ON(depend_tx->ack);
|
||
|
if (dma_wait_for_async_tx(depend_tx) == DMA_ERROR)
|
||
|
panic("%s: DMA_ERROR waiting for depend_tx\n",
|
||
|
__FUNCTION__);
|
||
|
}
|
||
|
|
||
|
memset(dest_buf, val, len);
|
||
|
|
||
|
async_tx_sync_epilog(flags, depend_tx, cb_fn, cb_param);
|
||
|
}
|
||
|
|
||
|
return tx;
|
||
|
}
|
||
|
EXPORT_SYMBOL_GPL(async_memset);
|
||
|
|
||
|
static int __init async_memset_init(void)
|
||
|
{
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
static void __exit async_memset_exit(void)
|
||
|
{
|
||
|
do { } while (0);
|
||
|
}
|
||
|
|
||
|
module_init(async_memset_init);
|
||
|
module_exit(async_memset_exit);
|
||
|
|
||
|
MODULE_AUTHOR("Intel Corporation");
|
||
|
MODULE_DESCRIPTION("asynchronous memset api");
|
||
|
MODULE_LICENSE("GPL");
|