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