cregit-Linux how code gets into the kernel

Release 4.10 crypto/async_tx/async_memcpy.c

Directory: crypto/async_tx
 * copy offload engine support
 * Copyright © 2006, Intel Corporation.
 *      Dan Williams <>
 *      with architecture considerations by:
 *      Neil Brown <>
 *      Jeff Garzik <>
 * 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_NOWAIT); 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; }


dan williamsdan williams33196.22%1071.43%
bartlomiej zolnierkiewiczbartlomiej zolnierkiewicz102.91%214.29%
peter zijlstrapeter zijlstra20.58%17.14%
neil brownneil brown10.29%17.14%

EXPORT_SYMBOL_GPL(async_memcpy); MODULE_AUTHOR("Intel Corporation"); MODULE_DESCRIPTION("asynchronous memcpy api"); MODULE_LICENSE("GPL");

Overall Contributors

dan williamsdan williams36895.83%1066.67%
bartlomiej zolnierkiewiczbartlomiej zolnierkiewicz102.60%213.33%
paul gortmakerpaul gortmaker30.78%16.67%
peter zijlstrapeter zijlstra20.52%16.67%
neil brownneil brown10.26%16.67%
Directory: crypto/async_tx
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