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 
mlx4_write64(__be32 val[2],void __iomem * dest,spinlock_t * doorbell_lock)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 
mlx4_write64(__be32 val[2],void __iomem * dest,spinlock_t * doorbell_lock)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 */
87