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  * $Id: mthca_doorbell.h 1349 2004-12-16 21:09:43Z roland $
35  */
36 
37 #include <linux/types.h>
38 
39 #define MTHCA_RD_DOORBELL      0x00
40 #define MTHCA_SEND_DOORBELL    0x10
41 #define MTHCA_RECEIVE_DOORBELL 0x18
42 #define MTHCA_CQ_DOORBELL      0x20
43 #define MTHCA_EQ_DOORBELL      0x28
44 
45 #if BITS_PER_LONG == 64
46 /*
47  * Assume that we can just write a 64-bit doorbell atomically.  s390
48  * actually doesn't have writeq() but S/390 systems don't even have
49  * PCI so we won't worry about it.
50  */
51 
52 #define MTHCA_DECLARE_DOORBELL_LOCK(name)
53 #define MTHCA_INIT_DOORBELL_LOCK(ptr)    do { } while (0)
54 #define MTHCA_GET_DOORBELL_LOCK(ptr)      (NULL)
55 
56 static inline void mthca_write64_raw(__be64 val, void __iomem *dest)
57 {
58 	__raw_writeq((__force u64) val, dest);
59 }
60 
61 static inline void mthca_write64(u32 hi, u32 lo, void __iomem *dest,
62 				 spinlock_t *doorbell_lock)
63 {
64 	__raw_writeq((__force u64) cpu_to_be64((u64) hi << 32 | lo), dest);
65 }
66 
67 static inline void mthca_write_db_rec(__be32 val[2], __be32 *db)
68 {
69 	*(u64 *) db = *(u64 *) val;
70 }
71 
72 #else
73 
74 /*
75  * Just fall back to a spinlock to protect the doorbell if
76  * BITS_PER_LONG is 32 -- there's no portable way to do atomic 64-bit
77  * MMIO writes.
78  */
79 
80 #define MTHCA_DECLARE_DOORBELL_LOCK(name) spinlock_t name;
81 #define MTHCA_INIT_DOORBELL_LOCK(ptr)     spin_lock_init(ptr)
82 #define MTHCA_GET_DOORBELL_LOCK(ptr)      (ptr)
83 
84 static inline void mthca_write64_raw(__be64 val, void __iomem *dest)
85 {
86 	__raw_writel(((__force u32 *) &val)[0], dest);
87 	__raw_writel(((__force u32 *) &val)[1], dest + 4);
88 }
89 
90 static inline void mthca_write64(u32 hi, u32 lo, void __iomem *dest,
91 				 spinlock_t *doorbell_lock)
92 {
93 	unsigned long flags;
94 
95 	hi = (__force u32) cpu_to_be32(hi);
96 	lo = (__force u32) cpu_to_be32(lo);
97 
98 	spin_lock_irqsave(doorbell_lock, flags);
99 	__raw_writel(hi, dest);
100 	__raw_writel(lo, dest + 4);
101 	spin_unlock_irqrestore(doorbell_lock, flags);
102 }
103 
104 static inline void mthca_write_db_rec(__be32 val[2], __be32 *db)
105 {
106 	db[0] = val[0];
107 	wmb();
108 	db[1] = val[1];
109 }
110 
111 #endif
112