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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * copy offload engine support
4 *
5 * Copyright © 2006, Intel Corporation.
6 *
7 * Dan Williams <dan.j.williams@intel.com>
8 *
9 * with architecture considerations by:
10 * Neil Brown <neilb@suse.de>
11 * Jeff Garzik <jeff@garzik.org>
12 */
13#include <linux/kernel.h>
14#include <linux/highmem.h>
15#include <linux/module.h>
16#include <linux/mm.h>
17#include <linux/dma-mapping.h>
18#include <linux/async_tx.h>
19
20/**
21 * async_memcpy - attempt to copy memory with a dma engine.
22 * @dest: destination page
23 * @src: src page
24 * @dest_offset: offset into 'dest' to start transaction
25 * @src_offset: offset into 'src' to start transaction
26 * @len: length in bytes
27 * @submit: submission / completion modifiers
28 *
29 * honored flags: ASYNC_TX_ACK
30 */
31struct dma_async_tx_descriptor *
32async_memcpy(struct page *dest, struct page *src, unsigned int dest_offset,
33 unsigned int src_offset, size_t len,
34 struct async_submit_ctl *submit)
35{
36 struct dma_chan *chan = async_tx_find_channel(submit, DMA_MEMCPY,
37 &dest, 1, &src, 1, len);
38 struct dma_device *device = chan ? chan->device : NULL;
39 struct dma_async_tx_descriptor *tx = NULL;
40 struct dmaengine_unmap_data *unmap = NULL;
41
42 if (device)
43 unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT);
44
45 if (unmap && is_dma_copy_aligned(device, src_offset, dest_offset, len)) {
46 unsigned long dma_prep_flags = 0;
47
48 if (submit->cb_fn)
49 dma_prep_flags |= DMA_PREP_INTERRUPT;
50 if (submit->flags & ASYNC_TX_FENCE)
51 dma_prep_flags |= DMA_PREP_FENCE;
52
53 unmap->to_cnt = 1;
54 unmap->addr[0] = dma_map_page(device->dev, src, src_offset, len,
55 DMA_TO_DEVICE);
56 unmap->from_cnt = 1;
57 unmap->addr[1] = dma_map_page(device->dev, dest, dest_offset, len,
58 DMA_FROM_DEVICE);
59 unmap->len = len;
60
61 tx = device->device_prep_dma_memcpy(chan, unmap->addr[1],
62 unmap->addr[0], len,
63 dma_prep_flags);
64 }
65
66 if (tx) {
67 pr_debug("%s: (async) len: %zu\n", __func__, len);
68
69 dma_set_unmap(tx, unmap);
70 async_tx_submit(chan, tx, submit);
71 } else {
72 void *dest_buf, *src_buf;
73 pr_debug("%s: (sync) len: %zu\n", __func__, len);
74
75 /* wait for any prerequisite operations */
76 async_tx_quiesce(&submit->depend_tx);
77
78 dest_buf = kmap_atomic(dest) + dest_offset;
79 src_buf = kmap_atomic(src) + src_offset;
80
81 memcpy(dest_buf, src_buf, len);
82
83 kunmap_atomic(src_buf);
84 kunmap_atomic(dest_buf);
85
86 async_tx_sync_epilog(submit);
87 }
88
89 dmaengine_unmap_put(unmap);
90
91 return tx;
92}
93EXPORT_SYMBOL_GPL(async_memcpy);
94
95MODULE_AUTHOR("Intel Corporation");
96MODULE_DESCRIPTION("asynchronous memcpy api");
97MODULE_LICENSE("GPL");
1/*
2 * copy offload engine support
3 *
4 * Copyright © 2006, Intel Corporation.
5 *
6 * Dan Williams <dan.j.williams@intel.com>
7 *
8 * with architecture considerations by:
9 * Neil Brown <neilb@suse.de>
10 * Jeff Garzik <jeff@garzik.org>
11 *
12 * This program is free software; you can redistribute it and/or modify it
13 * under the terms and conditions of the GNU General Public License,
14 * version 2, as published by the Free Software Foundation.
15 *
16 * This program is distributed in the hope it will be useful, but WITHOUT
17 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
18 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
19 * more details.
20 *
21 * You should have received a copy of the GNU General Public License along with
22 * this program; if not, write to the Free Software Foundation, Inc.,
23 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
24 *
25 */
26#include <linux/kernel.h>
27#include <linux/highmem.h>
28#include <linux/mm.h>
29#include <linux/dma-mapping.h>
30#include <linux/async_tx.h>
31
32/**
33 * async_memcpy - attempt to copy memory with a dma engine.
34 * @dest: destination page
35 * @src: src page
36 * @dest_offset: offset into 'dest' to start transaction
37 * @src_offset: offset into 'src' to start transaction
38 * @len: length in bytes
39 * @submit: submission / completion modifiers
40 *
41 * honored flags: ASYNC_TX_ACK
42 */
43struct dma_async_tx_descriptor *
44async_memcpy(struct page *dest, struct page *src, unsigned int dest_offset,
45 unsigned int src_offset, size_t len,
46 struct async_submit_ctl *submit)
47{
48 struct dma_chan *chan = async_tx_find_channel(submit, DMA_MEMCPY,
49 &dest, 1, &src, 1, len);
50 struct dma_device *device = chan ? chan->device : NULL;
51 struct dma_async_tx_descriptor *tx = NULL;
52
53 if (device && is_dma_copy_aligned(device, src_offset, dest_offset, len)) {
54 dma_addr_t dma_dest, dma_src;
55 unsigned long dma_prep_flags = 0;
56
57 if (submit->cb_fn)
58 dma_prep_flags |= DMA_PREP_INTERRUPT;
59 if (submit->flags & ASYNC_TX_FENCE)
60 dma_prep_flags |= DMA_PREP_FENCE;
61 dma_dest = dma_map_page(device->dev, dest, dest_offset, len,
62 DMA_FROM_DEVICE);
63
64 dma_src = dma_map_page(device->dev, src, src_offset, len,
65 DMA_TO_DEVICE);
66
67 tx = device->device_prep_dma_memcpy(chan, dma_dest, dma_src,
68 len, dma_prep_flags);
69 }
70
71 if (tx) {
72 pr_debug("%s: (async) len: %zu\n", __func__, len);
73 async_tx_submit(chan, tx, submit);
74 } else {
75 void *dest_buf, *src_buf;
76 pr_debug("%s: (sync) len: %zu\n", __func__, len);
77
78 /* wait for any prerequisite operations */
79 async_tx_quiesce(&submit->depend_tx);
80
81 dest_buf = kmap_atomic(dest, KM_USER0) + dest_offset;
82 src_buf = kmap_atomic(src, KM_USER1) + src_offset;
83
84 memcpy(dest_buf, src_buf, len);
85
86 kunmap_atomic(src_buf, KM_USER1);
87 kunmap_atomic(dest_buf, KM_USER0);
88
89 async_tx_sync_epilog(submit);
90 }
91
92 return tx;
93}
94EXPORT_SYMBOL_GPL(async_memcpy);
95
96MODULE_AUTHOR("Intel Corporation");
97MODULE_DESCRIPTION("asynchronous memcpy api");
98MODULE_LICENSE("GPL");