1 /*
2 * Copyright (c) 2013-2015, Mellanox Technologies. All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses. You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below:
9 *
10 * Redistribution and use in source and binary forms, with or
11 * without modification, are permitted provided that the following
12 * conditions are met:
13 *
14 * - Redistributions of source code must retain the above
15 * copyright notice, this list of conditions and the following
16 * disclaimer.
17 *
18 * - Redistributions in binary form must reproduce the above
19 * copyright notice, this list of conditions and the following
20 * disclaimer in the documentation and/or other materials
21 * provided with the distribution.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * SOFTWARE.
31 */
32
33 #ifndef MLX5_DOORBELL_H
34 #define MLX5_DOORBELL_H
35
36 #define MLX5_BF_OFFSET 0x800
37 #define MLX5_CQ_DOORBELL 0x20
38
39 #if BITS_PER_LONG == 64
40 /* Assume that we can just write a 64-bit doorbell atomically. s390
41 * actually doesn't have writeq() but S/390 systems don't even have
42 * PCI so we won't worry about it.
43 */
44
45 #define MLX5_DECLARE_DOORBELL_LOCK(name)
46 #define MLX5_INIT_DOORBELL_LOCK(ptr) do { } while (0)
47 #define MLX5_GET_DOORBELL_LOCK(ptr) (NULL)
48
mlx5_write64(__be32 val[2],void __iomem * dest,spinlock_t * doorbell_lock)49 static inline void mlx5_write64(__be32 val[2], void __iomem *dest,
50 spinlock_t *doorbell_lock)
51 {
52 __raw_writeq(*(u64 *)val, dest);
53 }
54
55 #else
56
57 /* Just fall back to a spinlock to protect the doorbell if
58 * BITS_PER_LONG is 32 -- there's no portable way to do atomic 64-bit
59 * MMIO writes.
60 */
61
62 #define MLX5_DECLARE_DOORBELL_LOCK(name) spinlock_t name;
63 #define MLX5_INIT_DOORBELL_LOCK(ptr) spin_lock_init(ptr)
64 #define MLX5_GET_DOORBELL_LOCK(ptr) (ptr)
65
mlx5_write64(__be32 val[2],void __iomem * dest,spinlock_t * doorbell_lock)66 static inline void mlx5_write64(__be32 val[2], void __iomem *dest,
67 spinlock_t *doorbell_lock)
68 {
69 unsigned long flags;
70
71 if (doorbell_lock)
72 spin_lock_irqsave(doorbell_lock, flags);
73 __raw_writel((__force u32) val[0], dest);
74 __raw_writel((__force u32) val[1], dest + 4);
75 if (doorbell_lock)
76 spin_unlock_irqrestore(doorbell_lock, flags);
77 }
78
79 #endif
80
81 #endif /* MLX5_DOORBELL_H */
82