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9bc89cd8 DW |
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> | |
4bb33cc8 | 28 | #include <linux/module.h> |
9bc89cd8 DW |
29 | #include <linux/mm.h> |
30 | #include <linux/dma-mapping.h> | |
31 | #include <linux/async_tx.h> | |
32 | ||
33 | /** | |
34 | * async_memcpy - attempt to copy memory with a dma engine. | |
35 | * @dest: destination page | |
36 | * @src: src page | |
a08abd8c DW |
37 | * @dest_offset: offset into 'dest' to start transaction |
38 | * @src_offset: offset into 'src' to start transaction | |
9bc89cd8 | 39 | * @len: length in bytes |
a08abd8c DW |
40 | * @submit: submission / completion modifiers |
41 | * | |
42 | * honored flags: ASYNC_TX_ACK | |
9bc89cd8 DW |
43 | */ |
44 | struct dma_async_tx_descriptor * | |
45 | async_memcpy(struct page *dest, struct page *src, unsigned int dest_offset, | |
a08abd8c DW |
46 | unsigned int src_offset, size_t len, |
47 | struct async_submit_ctl *submit) | |
9bc89cd8 | 48 | { |
a08abd8c | 49 | struct dma_chan *chan = async_tx_find_channel(submit, DMA_MEMCPY, |
47437b2c | 50 | &dest, 1, &src, 1, len); |
9bc89cd8 | 51 | struct dma_device *device = chan ? chan->device : NULL; |
0036731c | 52 | struct dma_async_tx_descriptor *tx = NULL; |
89716462 | 53 | struct dmaengine_unmap_data *unmap = NULL; |
9bc89cd8 | 54 | |
89716462 | 55 | if (device) |
b02bab6b | 56 | unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT); |
89716462 DW |
57 | |
58 | if (unmap && is_dma_copy_aligned(device, src_offset, dest_offset, len)) { | |
0776ae7b | 59 | unsigned long dma_prep_flags = 0; |
9bc89cd8 | 60 | |
0403e382 DW |
61 | if (submit->cb_fn) |
62 | dma_prep_flags |= DMA_PREP_INTERRUPT; | |
63 | if (submit->flags & ASYNC_TX_FENCE) | |
64 | dma_prep_flags |= DMA_PREP_FENCE; | |
89716462 DW |
65 | |
66 | unmap->to_cnt = 1; | |
67 | unmap->addr[0] = dma_map_page(device->dev, src, src_offset, len, | |
68 | DMA_TO_DEVICE); | |
69 | unmap->from_cnt = 1; | |
70 | unmap->addr[1] = dma_map_page(device->dev, dest, dest_offset, len, | |
71 | DMA_FROM_DEVICE); | |
72 | unmap->len = len; | |
73 | ||
74 | tx = device->device_prep_dma_memcpy(chan, unmap->addr[1], | |
75 | unmap->addr[0], len, | |
76 | dma_prep_flags); | |
0036731c | 77 | } |
9bc89cd8 | 78 | |
0036731c | 79 | if (tx) { |
3280ab3e | 80 | pr_debug("%s: (async) len: %zu\n", __func__, len); |
89716462 DW |
81 | |
82 | dma_set_unmap(tx, unmap); | |
a08abd8c | 83 | async_tx_submit(chan, tx, submit); |
0036731c | 84 | } else { |
9bc89cd8 | 85 | void *dest_buf, *src_buf; |
3280ab3e | 86 | pr_debug("%s: (sync) len: %zu\n", __func__, len); |
9bc89cd8 DW |
87 | |
88 | /* wait for any prerequisite operations */ | |
a08abd8c | 89 | async_tx_quiesce(&submit->depend_tx); |
9bc89cd8 | 90 | |
f0dfc0b0 CW |
91 | dest_buf = kmap_atomic(dest) + dest_offset; |
92 | src_buf = kmap_atomic(src) + src_offset; | |
9bc89cd8 DW |
93 | |
94 | memcpy(dest_buf, src_buf, len); | |
95 | ||
f0dfc0b0 CW |
96 | kunmap_atomic(src_buf); |
97 | kunmap_atomic(dest_buf); | |
9bc89cd8 | 98 | |
a08abd8c | 99 | async_tx_sync_epilog(submit); |
9bc89cd8 DW |
100 | } |
101 | ||
89716462 DW |
102 | dmaengine_unmap_put(unmap); |
103 | ||
9bc89cd8 DW |
104 | return tx; |
105 | } | |
106 | EXPORT_SYMBOL_GPL(async_memcpy); | |
107 | ||
9bc89cd8 DW |
108 | MODULE_AUTHOR("Intel Corporation"); |
109 | MODULE_DESCRIPTION("asynchronous memcpy api"); | |
110 | MODULE_LICENSE("GPL"); |