1 /* 1 /*
2 * Copyright (c) 2013-2015, Mellanox Technolog 2 * Copyright (c) 2013-2015, Mellanox Technologies. All rights reserved.
3 * 3 *
4 * This software is available to you under a c 4 * This software is available to you under a choice of one of two
5 * licenses. You may choose to be licensed un 5 * licenses. You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, ava 6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this sourc 7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below: 8 * OpenIB.org BSD license below:
9 * 9 *
10 * Redistribution and use in source and bi 10 * Redistribution and use in source and binary forms, with or
11 * without modification, are permitted pro 11 * without modification, are permitted provided that the following
12 * conditions are met: 12 * conditions are met:
13 * 13 *
14 * - Redistributions of source code must 14 * - Redistributions of source code must retain the above
15 * copyright notice, this list of condi 15 * copyright notice, this list of conditions and the following
16 * disclaimer. 16 * disclaimer.
17 * 17 *
18 * - Redistributions in binary form must 18 * - Redistributions in binary form must reproduce the above
19 * copyright notice, this list of condi 19 * copyright notice, this list of conditions and the following
20 * disclaimer in the documentation and/ 20 * disclaimer in the documentation and/or other materials
21 * provided with the distribution. 21 * provided with the distribution.
22 * 22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT W 23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMIT 24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR P 25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTH 26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER L 27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARIS 28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR 29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * SOFTWARE. 30 * SOFTWARE.
31 */ 31 */
32 32
33 #ifndef MLX5_DOORBELL_H 33 #ifndef MLX5_DOORBELL_H
34 #define MLX5_DOORBELL_H 34 #define MLX5_DOORBELL_H
35 35
36 #define MLX5_BF_OFFSET 0x800 36 #define MLX5_BF_OFFSET 0x800
37 #define MLX5_CQ_DOORBELL 0x20 37 #define MLX5_CQ_DOORBELL 0x20
38 38
>> 39 #if BITS_PER_LONG == 64
39 /* Assume that we can just write a 64-bit door 40 /* Assume that we can just write a 64-bit doorbell atomically. s390
40 * actually doesn't have writeq() but S/390 sy 41 * actually doesn't have writeq() but S/390 systems don't even have
41 * PCI so we won't worry about it. 42 * PCI so we won't worry about it.
42 * <<
43 * Note that the write is not atomic on 32-bit <<
44 * ones, it requires proper locking. mlx5_writ <<
45 * it at your own discretion, protected by som <<
46 * <<
47 * TODO: use write{q,l}_relaxed() <<
48 */ 43 */
49 44
50 static inline void mlx5_write64(__be32 val[2], !! 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
>> 49 static inline void mlx5_write64(__be32 val[2], void __iomem *dest,
>> 50 spinlock_t *doorbell_lock)
51 { 51 {
52 #if BITS_PER_LONG == 64 <<
53 __raw_writeq(*(u64 *)val, dest); 52 __raw_writeq(*(u64 *)val, dest);
>> 53 }
>> 54
54 #else 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
>> 66 static inline void mlx5_write64(__be32 val[2], void __iomem *dest,
>> 67 spinlock_t *doorbell_lock)
>> 68 {
>> 69 unsigned long flags;
>> 70
>> 71 spin_lock_irqsave(doorbell_lock, flags);
55 __raw_writel((__force u32) val[0], des 72 __raw_writel((__force u32) val[0], dest);
56 __raw_writel((__force u32) val[1], des 73 __raw_writel((__force u32) val[1], dest + 4);
57 #endif !! 74 spin_unlock_irqrestore(doorbell_lock, flags);
58 } 75 }
>> 76
>> 77 #endif
59 78
60 #endif /* MLX5_DOORBELL_H */ 79 #endif /* MLX5_DOORBELL_H */
61 80
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