diff options
Diffstat (limited to 'crypto/async_tx/async_memcpy.c')
| -rw-r--r-- | crypto/async_tx/async_memcpy.c | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/crypto/async_tx/async_memcpy.c b/crypto/async_tx/async_memcpy.c new file mode 100644 index 000000000000..a973f4ef897d --- /dev/null +++ b/crypto/async_tx/async_memcpy.c @@ -0,0 +1,131 @@ +/* + * 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, + * ASYNC_TX_KMAP_SRC, ASYNC_TX_KMAP_DST + * @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__); + } + + if (flags & ASYNC_TX_KMAP_DST) + dest_buf = kmap_atomic(dest, KM_USER0) + dest_offset; + else + dest_buf = page_address(dest) + dest_offset; + + if (flags & ASYNC_TX_KMAP_SRC) + src_buf = kmap_atomic(src, KM_USER0) + src_offset; + else + src_buf = page_address(src) + src_offset; + + memcpy(dest_buf, src_buf, len); + + if (flags & ASYNC_TX_KMAP_DST) + kunmap_atomic(dest_buf, KM_USER0); + + if (flags & ASYNC_TX_KMAP_SRC) + kunmap_atomic(src_buf, KM_USER0); + + 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"); |