Linux Kernel  3.7.1
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
async_memset.c
Go to the documentation of this file.
1 /*
2  * memory fill offload engine support
3  *
4  * Copyright © 2006, Intel Corporation.
5  *
6  * Dan Williams <[email protected]>
7  *
8  * with architecture considerations by:
9  * Neil Brown <[email protected]>
10  * Jeff Garzik <[email protected]>
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 
42 async_memset(struct page *dest, int val, unsigned int offset, size_t len,
43  struct async_submit_ctl *submit)
44 {
46  &dest, 1, NULL, 0, len);
47  struct dma_device *device = chan ? chan->device : NULL;
49 
50  if (device && is_dma_fill_aligned(device, offset, 0, len)) {
51  dma_addr_t dma_dest;
52  unsigned long dma_prep_flags = 0;
53 
54  if (submit->cb_fn)
55  dma_prep_flags |= DMA_PREP_INTERRUPT;
56  if (submit->flags & ASYNC_TX_FENCE)
57  dma_prep_flags |= DMA_PREP_FENCE;
58  dma_dest = dma_map_page(device->dev, dest, offset, len,
60 
61  tx = device->device_prep_dma_memset(chan, dma_dest, val, len,
62  dma_prep_flags);
63  }
64 
65  if (tx) {
66  pr_debug("%s: (async) len: %zu\n", __func__, len);
67  async_tx_submit(chan, tx, submit);
68  } else { /* run the memset synchronously */
69  void *dest_buf;
70  pr_debug("%s: (sync) len: %zu\n", __func__, len);
71 
72  dest_buf = page_address(dest) + offset;
73 
74  /* wait for any prerequisite operations */
75  async_tx_quiesce(&submit->depend_tx);
76 
77  memset(dest_buf, val, len);
78 
79  async_tx_sync_epilog(submit);
80  }
81 
82  return tx;
83 }
85 
86 MODULE_AUTHOR("Intel Corporation");
87 MODULE_DESCRIPTION("asynchronous memset api");
88 MODULE_LICENSE("GPL");