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
55static 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
73static 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 */
87