1 /*
2 * Copyright (c) 2004 Topspin Communications. All rights reserved.
3 * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
4 * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
5 *
6 * This software is available to you under a choice of one of two
7 * licenses. You may choose to be licensed under the terms of the GNU
8 * General Public License (GPL) Version 2, available from the file
9 * COPYING in the main directory of this source tree, or the
10 * OpenIB.org BSD license below:
11 *
12 * Redistribution and use in source and binary forms, with or
13 * without modification, are permitted provided that the following
14 * conditions are met:
15 *
16 * - Redistributions of source code must retain the above
17 * copyright notice, this list of conditions and the following
18 * disclaimer.
19 *
20 * - Redistributions in binary form must reproduce the above
21 * copyright notice, this list of conditions and the following
22 * disclaimer in the documentation and/or other materials
23 * provided with the distribution.
24 *
25 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
26 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
27 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
28 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
29 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
30 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
31 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
32 * SOFTWARE.
33 */
34
35 #ifndef MLX4_DOORBELL_H
36 #define MLX4_DOORBELL_H
37
38 #include <linux/types.h>
39 #include <linux/io.h>
40
41 #define MLX4_SEND_DOORBELL 0x14
42 #define MLX4_CQ_DOORBELL 0x20
43
44 #if BITS_PER_LONG == 64
45 /*
46 * Assume that we can just write a 64-bit doorbell atomically. s390
47 * actually doesn't have writeq() but S/390 systems don't even have
48 * PCI so we won't worry about it.
49 */
50
51 #define MLX4_DECLARE_DOORBELL_LOCK(name)
52 #define MLX4_INIT_DOORBELL_LOCK(ptr) do { } while (0)
53 #define MLX4_GET_DOORBELL_LOCK(ptr) (NULL)
54
55 static inline void mlx4_write64(__be32 val[2], void __iomem *dest,
56 spinlock_t *doorbell_lock)
57 {
58 __raw_writeq(*(u64 *) val, dest);
59 }
60
61 #else
62
63 /*
64 * Just fall back to a spinlock to protect the doorbell if
65 * BITS_PER_LONG is 32 -- there's no portable way to do atomic 64-bit
66 * MMIO writes.
67 */
68
69 #define MLX4_DECLARE_DOORBELL_LOCK(name) spinlock_t name;
70 #define MLX4_INIT_DOORBELL_LOCK(ptr) spin_lock_init(ptr)
71 #define MLX4_GET_DOORBELL_LOCK(ptr) (ptr)
72
73 static inline void mlx4_write64(__be32 val[2], void __iomem *dest,
74 spinlock_t *doorbell_lock)
75 {
76 unsigned long flags;
77
78 spin_lock_irqsave(doorbell_lock, flags);
79 __raw_writel((__force u32) val[0], dest);
80 __raw_writel((__force u32) val[1], dest + 4);
81 spin_unlock_irqrestore(doorbell_lock, flags);
82 }
83
84 #endif
85
86 #endif /* MLX4_DOORBELL_H */