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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> | |
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 | * @offset: offset in pages to start transaction | |
37 | * @len: length in bytes | |
38 | * @flags: ASYNC_TX_ASSUME_COHERENT, ASYNC_TX_ACK, ASYNC_TX_DEP_ACK, | |
39 | * ASYNC_TX_KMAP_SRC, ASYNC_TX_KMAP_DST | |
40 | * @depend_tx: memcpy depends on the result of this transaction | |
41 | * @cb_fn: function to call when the memcpy completes | |
42 | * @cb_param: parameter to pass to the callback routine | |
43 | */ | |
44 | struct dma_async_tx_descriptor * | |
45 | async_memcpy(struct page *dest, struct page *src, unsigned int dest_offset, | |
46 | unsigned int src_offset, size_t len, enum async_tx_flags flags, | |
47 | struct dma_async_tx_descriptor *depend_tx, | |
48 | dma_async_tx_callback cb_fn, void *cb_param) | |
49 | { | |
50 | struct dma_chan *chan = async_tx_find_channel(depend_tx, DMA_MEMCPY); | |
51 | struct dma_device *device = chan ? chan->device : NULL; | |
52 | int int_en = cb_fn ? 1 : 0; | |
53 | struct dma_async_tx_descriptor *tx = device ? | |
54 | device->device_prep_dma_memcpy(chan, len, | |
55 | int_en) : NULL; | |
56 | ||
57 | if (tx) { /* run the memcpy asynchronously */ | |
58 | dma_addr_t addr; | |
59 | enum dma_data_direction dir; | |
60 | ||
61 | pr_debug("%s: (async) len: %zu\n", __FUNCTION__, len); | |
62 | ||
63 | dir = (flags & ASYNC_TX_ASSUME_COHERENT) ? | |
64 | DMA_NONE : DMA_FROM_DEVICE; | |
65 | ||
66 | addr = dma_map_page(device->dev, dest, dest_offset, len, dir); | |
67 | tx->tx_set_dest(addr, tx, 0); | |
68 | ||
69 | dir = (flags & ASYNC_TX_ASSUME_COHERENT) ? | |
70 | DMA_NONE : DMA_TO_DEVICE; | |
71 | ||
72 | addr = dma_map_page(device->dev, src, src_offset, len, dir); | |
73 | tx->tx_set_src(addr, tx, 0); | |
74 | ||
75 | async_tx_submit(chan, tx, flags, depend_tx, cb_fn, cb_param); | |
76 | } else { /* run the memcpy synchronously */ | |
77 | void *dest_buf, *src_buf; | |
78 | pr_debug("%s: (sync) len: %zu\n", __FUNCTION__, len); | |
79 | ||
80 | /* wait for any prerequisite operations */ | |
81 | if (depend_tx) { | |
82 | /* if ack is already set then we cannot be sure | |
83 | * we are referring to the correct operation | |
84 | */ | |
85 | BUG_ON(depend_tx->ack); | |
86 | if (dma_wait_for_async_tx(depend_tx) == DMA_ERROR) | |
87 | panic("%s: DMA_ERROR waiting for depend_tx\n", | |
88 | __FUNCTION__); | |
89 | } | |
90 | ||
91 | if (flags & ASYNC_TX_KMAP_DST) | |
92 | dest_buf = kmap_atomic(dest, KM_USER0) + dest_offset; | |
93 | else | |
94 | dest_buf = page_address(dest) + dest_offset; | |
95 | ||
96 | if (flags & ASYNC_TX_KMAP_SRC) | |
97 | src_buf = kmap_atomic(src, KM_USER0) + src_offset; | |
98 | else | |
99 | src_buf = page_address(src) + src_offset; | |
100 | ||
101 | memcpy(dest_buf, src_buf, len); | |
102 | ||
103 | if (flags & ASYNC_TX_KMAP_DST) | |
104 | kunmap_atomic(dest_buf, KM_USER0); | |
105 | ||
106 | if (flags & ASYNC_TX_KMAP_SRC) | |
107 | kunmap_atomic(src_buf, KM_USER0); | |
108 | ||
109 | async_tx_sync_epilog(flags, depend_tx, cb_fn, cb_param); | |
110 | } | |
111 | ||
112 | return tx; | |
113 | } | |
114 | EXPORT_SYMBOL_GPL(async_memcpy); | |
115 | ||
116 | static int __init async_memcpy_init(void) | |
117 | { | |
118 | return 0; | |
119 | } | |
120 | ||
121 | static void __exit async_memcpy_exit(void) | |
122 | { | |
123 | do { } while (0); | |
124 | } | |
125 | ||
126 | module_init(async_memcpy_init); | |
127 | module_exit(async_memcpy_exit); | |
128 | ||
129 | MODULE_AUTHOR("Intel Corporation"); | |
130 | MODULE_DESCRIPTION("asynchronous memcpy api"); | |
131 | MODULE_LICENSE("GPL"); |