diff options
Diffstat (limited to 'crypto/async_tx/async_memcpy.c')
| -rw-r--r-- | crypto/async_tx/async_memcpy.c | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/crypto/async_tx/async_memcpy.c b/crypto/async_tx/async_memcpy.c new file mode 100644 index 000000000..f8c0b8dbe --- /dev/null +++ b/crypto/async_tx/async_memcpy.c @@ -0,0 +1,110 @@ +/* + * 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/module.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; + struct dmaengine_unmap_data *unmap = NULL; + + if (device) + unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOIO); + + if (unmap && is_dma_copy_aligned(device, src_offset, dest_offset, len)) { + unsigned long dma_prep_flags = 0; + + if (submit->cb_fn) + dma_prep_flags |= DMA_PREP_INTERRUPT; + if (submit->flags & ASYNC_TX_FENCE) + dma_prep_flags |= DMA_PREP_FENCE; + + unmap->to_cnt = 1; + unmap->addr[0] = dma_map_page(device->dev, src, src_offset, len, + DMA_TO_DEVICE); + unmap->from_cnt = 1; + unmap->addr[1] = dma_map_page(device->dev, dest, dest_offset, len, + DMA_FROM_DEVICE); + unmap->len = len; + + tx = device->device_prep_dma_memcpy(chan, unmap->addr[1], + unmap->addr[0], len, + dma_prep_flags); + } + + if (tx) { + pr_debug("%s: (async) len: %zu\n", __func__, len); + + dma_set_unmap(tx, unmap); + 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) + dest_offset; + src_buf = kmap_atomic(src) + src_offset; + + memcpy(dest_buf, src_buf, len); + + kunmap_atomic(src_buf); + kunmap_atomic(dest_buf); + + async_tx_sync_epilog(submit); + } + + dmaengine_unmap_put(unmap); + + return tx; +} +EXPORT_SYMBOL_GPL(async_memcpy); + +MODULE_AUTHOR("Intel Corporation"); +MODULE_DESCRIPTION("asynchronous memcpy api"); +MODULE_LICENSE("GPL"); |