mirror of
https://github.com/torvalds/linux.git
synced 2024-11-15 16:41:58 +00:00
eb0645a8b1
Andrew Morton: [async_memcpy] is very wrong if both ASYNC_TX_KMAP_DST and ASYNC_TX_KMAP_SRC can ever be set. We'll end up using the same kmap slot for both src add dest and we get either corrupted data or a BUG. Evgeniy Polyakov: Btw, shouldn't it always be kmap_atomic() even if flag is not set. That pages are usual one returned by alloc_page(). So fix the usage of kmap_atomic and kill the ASYNC_TX_KMAP_DST and ASYNC_TX_KMAP_SRC flags. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
121 lines
3.6 KiB
C
121 lines
3.6 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
|
|
* @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: memcpy 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_memcpy(struct page *dest, struct page *src, unsigned int dest_offset,
|
|
unsigned int src_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_MEMCPY);
|
|
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_memcpy(chan, len,
|
|
int_en) : NULL;
|
|
|
|
if (tx) { /* run the memcpy asynchronously */
|
|
dma_addr_t 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;
|
|
|
|
addr = dma_map_page(device->dev, dest, dest_offset, len, dir);
|
|
tx->tx_set_dest(addr, tx, 0);
|
|
|
|
dir = (flags & ASYNC_TX_ASSUME_COHERENT) ?
|
|
DMA_NONE : DMA_TO_DEVICE;
|
|
|
|
addr = dma_map_page(device->dev, src, src_offset, len, dir);
|
|
tx->tx_set_src(addr, tx, 0);
|
|
|
|
async_tx_submit(chan, tx, flags, depend_tx, cb_fn, cb_param);
|
|
} else { /* run the memcpy synchronously */
|
|
void *dest_buf, *src_buf;
|
|
pr_debug("%s: (sync) len: %zu\n", __FUNCTION__, len);
|
|
|
|
/* 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__);
|
|
}
|
|
|
|
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(flags, depend_tx, cb_fn, cb_param);
|
|
}
|
|
|
|
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");
|