Commit | Line | Data |
---|---|---|
9bc89cd8 DW |
1 | /* |
2 | * memory fill 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/interrupt.h> | |
28 | #include <linux/mm.h> | |
29 | #include <linux/dma-mapping.h> | |
30 | #include <linux/async_tx.h> | |
31 | ||
32 | /** | |
33 | * async_memset - attempt to fill memory with a dma engine. | |
34 | * @dest: destination page | |
35 | * @val: fill value | |
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 | * @depend_tx: memset depends on the result of this transaction | |
40 | * @cb_fn: function to call when the memcpy completes | |
41 | * @cb_param: parameter to pass to the callback routine | |
42 | */ | |
43 | struct dma_async_tx_descriptor * | |
44 | async_memset(struct page *dest, int val, unsigned int offset, | |
45 | size_t len, enum async_tx_flags flags, | |
46 | struct dma_async_tx_descriptor *depend_tx, | |
47 | dma_async_tx_callback cb_fn, void *cb_param) | |
48 | { | |
49 | struct dma_chan *chan = async_tx_find_channel(depend_tx, DMA_MEMSET); | |
50 | struct dma_device *device = chan ? chan->device : NULL; | |
51 | int int_en = cb_fn ? 1 : 0; | |
52 | struct dma_async_tx_descriptor *tx = device ? | |
53 | device->device_prep_dma_memset(chan, val, len, | |
54 | int_en) : NULL; | |
55 | ||
56 | if (tx) { /* run the memset asynchronously */ | |
57 | dma_addr_t dma_addr; | |
58 | enum dma_data_direction dir; | |
59 | ||
60 | pr_debug("%s: (async) len: %zu\n", __FUNCTION__, len); | |
61 | dir = (flags & ASYNC_TX_ASSUME_COHERENT) ? | |
62 | DMA_NONE : DMA_FROM_DEVICE; | |
63 | ||
64 | dma_addr = dma_map_page(device->dev, dest, offset, len, dir); | |
65 | tx->tx_set_dest(dma_addr, tx, 0); | |
66 | ||
67 | async_tx_submit(chan, tx, flags, depend_tx, cb_fn, cb_param); | |
68 | } else { /* run the memset synchronously */ | |
69 | void *dest_buf; | |
70 | pr_debug("%s: (sync) len: %zu\n", __FUNCTION__, len); | |
71 | ||
72 | dest_buf = (void *) (((char *) page_address(dest)) + offset); | |
73 | ||
74 | /* wait for any prerequisite operations */ | |
75 | if (depend_tx) { | |
76 | /* if ack is already set then we cannot be sure | |
77 | * we are referring to the correct operation | |
78 | */ | |
79 | BUG_ON(depend_tx->ack); | |
80 | if (dma_wait_for_async_tx(depend_tx) == DMA_ERROR) | |
81 | panic("%s: DMA_ERROR waiting for depend_tx\n", | |
82 | __FUNCTION__); | |
83 | } | |
84 | ||
85 | memset(dest_buf, val, len); | |
86 | ||
87 | async_tx_sync_epilog(flags, depend_tx, cb_fn, cb_param); | |
88 | } | |
89 | ||
90 | return tx; | |
91 | } | |
92 | EXPORT_SYMBOL_GPL(async_memset); | |
93 | ||
94 | static int __init async_memset_init(void) | |
95 | { | |
96 | return 0; | |
97 | } | |
98 | ||
99 | static void __exit async_memset_exit(void) | |
100 | { | |
101 | do { } while (0); | |
102 | } | |
103 | ||
104 | module_init(async_memset_init); | |
105 | module_exit(async_memset_exit); | |
106 | ||
107 | MODULE_AUTHOR("Intel Corporation"); | |
108 | MODULE_DESCRIPTION("asynchronous memset api"); | |
109 | MODULE_LICENSE("GPL"); |