linux/mlx4/doorbell.h

0001 /*
0002  * Copyright (c) 2004 Topspin Communications.  All rights reserved.
0003  * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
0004  * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
0005  *
0006  * This software is available to you under a choice of one of two
0007  * licenses.  You may choose to be licensed under the terms of the GNU
0008  * General Public License (GPL) Version 2, available from the file
0009  * COPYING in the main directory of this source tree, or the
0010  * OpenIB.org BSD license below:
0011  *
0012  *     Redistribution and use in source and binary forms, with or
0013  *     without modification, are permitted provided that the following
0014  *     conditions are met:
0015  *
0016  *      - Redistributions of source code must retain the above
0017  *        copyright notice, this list of conditions and the following
0018  *        disclaimer.
0019  *
0020  *      - Redistributions in binary form must reproduce the above
0021  *        copyright notice, this list of conditions and the following
0022  *        disclaimer in the documentation and/or other materials
0023  *        provided with the distribution.
0024  *
0025  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
0026  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
0027  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
0028  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
0029  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
0030  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
0031  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
0032  * SOFTWARE.
0033  */
0034
0035 #ifndef MLX4_DOORBELL_H
0036 #define MLX4_DOORBELL_H
0037
0038 #include <linux/types.h>
0039 #include <linux/io.h>
0040
0041 #define MLX4_SEND_DOORBELL    0x14
0042 #define MLX4_CQ_DOORBELL      0x20
0043
0044 #if BITS_PER_LONG == 64
0045 /*
0046  * Assume that we can just write a 64-bit doorbell atomically.  s390
0047  * actually doesn't have writeq() but S/390 systems don't even have
0048  * PCI so we won't worry about it.
0049  */
0050
0051 #define MLX4_DECLARE_DOORBELL_LOCK(name)
0052 #define MLX4_INIT_DOORBELL_LOCK(ptr)    do { } while (0)
0053 #define MLX4_GET_DOORBELL_LOCK(ptr)      (NULL)
0054
0055 static inline void mlx4_write64(__be32 val[2], void __iomem *dest,
0056                 spinlock_t *doorbell_lock)
0057 {
0058     __raw_writeq(*(u64 *) val, dest);
0059 }
0060
0061 #else
0062
0063 /*
0064  * Just fall back to a spinlock to protect the doorbell if
0065  * BITS_PER_LONG is 32 -- there's no portable way to do atomic 64-bit
0066  * MMIO writes.
0067  */
0068
0069 #define MLX4_DECLARE_DOORBELL_LOCK(name) spinlock_t name;
0070 #define MLX4_INIT_DOORBELL_LOCK(ptr)     spin_lock_init(ptr)
0071 #define MLX4_GET_DOORBELL_LOCK(ptr)      (ptr)
0072
0073 static inline void mlx4_write64(__be32 val[2], void __iomem *dest,
0074                 spinlock_t *doorbell_lock)
0075 {
0076     unsigned long flags;
0077
0078     spin_lock_irqsave(doorbell_lock, flags);
0079     __raw_writel((__force u32) val[0], dest);
0080     __raw_writel((__force u32) val[1], dest + 4);
0081     spin_unlock_irqrestore(doorbell_lock, flags);
0082 }
0083
0084 #endif
0085
0086 #endif /* MLX4_DOORBELL_H */