xref: /OK3568_Linux_fs/kernel/include/linux/mlx4/doorbell.h (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun  * Copyright (c) 2004 Topspin Communications.  All rights reserved.
3*4882a593Smuzhiyun  * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
4*4882a593Smuzhiyun  * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
5*4882a593Smuzhiyun  *
6*4882a593Smuzhiyun  * This software is available to you under a choice of one of two
7*4882a593Smuzhiyun  * licenses.  You may choose to be licensed under the terms of the GNU
8*4882a593Smuzhiyun  * General Public License (GPL) Version 2, available from the file
9*4882a593Smuzhiyun  * COPYING in the main directory of this source tree, or the
10*4882a593Smuzhiyun  * OpenIB.org BSD license below:
11*4882a593Smuzhiyun  *
12*4882a593Smuzhiyun  *     Redistribution and use in source and binary forms, with or
13*4882a593Smuzhiyun  *     without modification, are permitted provided that the following
14*4882a593Smuzhiyun  *     conditions are met:
15*4882a593Smuzhiyun  *
16*4882a593Smuzhiyun  *      - Redistributions of source code must retain the above
17*4882a593Smuzhiyun  *        copyright notice, this list of conditions and the following
18*4882a593Smuzhiyun  *        disclaimer.
19*4882a593Smuzhiyun  *
20*4882a593Smuzhiyun  *      - Redistributions in binary form must reproduce the above
21*4882a593Smuzhiyun  *        copyright notice, this list of conditions and the following
22*4882a593Smuzhiyun  *        disclaimer in the documentation and/or other materials
23*4882a593Smuzhiyun  *        provided with the distribution.
24*4882a593Smuzhiyun  *
25*4882a593Smuzhiyun  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
26*4882a593Smuzhiyun  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
27*4882a593Smuzhiyun  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
28*4882a593Smuzhiyun  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
29*4882a593Smuzhiyun  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
30*4882a593Smuzhiyun  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
31*4882a593Smuzhiyun  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
32*4882a593Smuzhiyun  * SOFTWARE.
33*4882a593Smuzhiyun  */
34*4882a593Smuzhiyun 
35*4882a593Smuzhiyun #ifndef MLX4_DOORBELL_H
36*4882a593Smuzhiyun #define MLX4_DOORBELL_H
37*4882a593Smuzhiyun 
38*4882a593Smuzhiyun #include <linux/types.h>
39*4882a593Smuzhiyun #include <linux/io.h>
40*4882a593Smuzhiyun 
41*4882a593Smuzhiyun #define MLX4_SEND_DOORBELL    0x14
42*4882a593Smuzhiyun #define MLX4_CQ_DOORBELL      0x20
43*4882a593Smuzhiyun 
44*4882a593Smuzhiyun #if BITS_PER_LONG == 64
45*4882a593Smuzhiyun /*
46*4882a593Smuzhiyun  * Assume that we can just write a 64-bit doorbell atomically.  s390
47*4882a593Smuzhiyun  * actually doesn't have writeq() but S/390 systems don't even have
48*4882a593Smuzhiyun  * PCI so we won't worry about it.
49*4882a593Smuzhiyun  */
50*4882a593Smuzhiyun 
51*4882a593Smuzhiyun #define MLX4_DECLARE_DOORBELL_LOCK(name)
52*4882a593Smuzhiyun #define MLX4_INIT_DOORBELL_LOCK(ptr)    do { } while (0)
53*4882a593Smuzhiyun #define MLX4_GET_DOORBELL_LOCK(ptr)      (NULL)
54*4882a593Smuzhiyun 
mlx4_write64(__be32 val[2],void __iomem * dest,spinlock_t * doorbell_lock)55*4882a593Smuzhiyun static inline void mlx4_write64(__be32 val[2], void __iomem *dest,
56*4882a593Smuzhiyun 				spinlock_t *doorbell_lock)
57*4882a593Smuzhiyun {
58*4882a593Smuzhiyun 	__raw_writeq(*(u64 *) val, dest);
59*4882a593Smuzhiyun }
60*4882a593Smuzhiyun 
61*4882a593Smuzhiyun #else
62*4882a593Smuzhiyun 
63*4882a593Smuzhiyun /*
64*4882a593Smuzhiyun  * Just fall back to a spinlock to protect the doorbell if
65*4882a593Smuzhiyun  * BITS_PER_LONG is 32 -- there's no portable way to do atomic 64-bit
66*4882a593Smuzhiyun  * MMIO writes.
67*4882a593Smuzhiyun  */
68*4882a593Smuzhiyun 
69*4882a593Smuzhiyun #define MLX4_DECLARE_DOORBELL_LOCK(name) spinlock_t name;
70*4882a593Smuzhiyun #define MLX4_INIT_DOORBELL_LOCK(ptr)     spin_lock_init(ptr)
71*4882a593Smuzhiyun #define MLX4_GET_DOORBELL_LOCK(ptr)      (ptr)
72*4882a593Smuzhiyun 
mlx4_write64(__be32 val[2],void __iomem * dest,spinlock_t * doorbell_lock)73*4882a593Smuzhiyun static inline void mlx4_write64(__be32 val[2], void __iomem *dest,
74*4882a593Smuzhiyun 				spinlock_t *doorbell_lock)
75*4882a593Smuzhiyun {
76*4882a593Smuzhiyun 	unsigned long flags;
77*4882a593Smuzhiyun 
78*4882a593Smuzhiyun 	spin_lock_irqsave(doorbell_lock, flags);
79*4882a593Smuzhiyun 	__raw_writel((__force u32) val[0], dest);
80*4882a593Smuzhiyun 	__raw_writel((__force u32) val[1], dest + 4);
81*4882a593Smuzhiyun 	spin_unlock_irqrestore(doorbell_lock, flags);
82*4882a593Smuzhiyun }
83*4882a593Smuzhiyun 
84*4882a593Smuzhiyun #endif
85*4882a593Smuzhiyun 
86*4882a593Smuzhiyun #endif /* MLX4_DOORBELL_H */
87