include/linux/mlx4/doorbell.h

   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 #ifndef MLX4_DOORBELL_H
  36 #define MLX4_DOORBELL_H
  37
  38 #include <linux/types.h>
  39 #include <linux/io.h>
  40
  41 #define MLX4_SEND_DOORBELL    0x14
  42 #define MLX4_CQ_DOORBELL      0x20
  43
  44 #if BITS_PER_LONG == 64
  45 /*
  46  * Assume that we can just write a 64-bit doorbell atomically.  s390
  47  * actually doesn't have writeq() but S/390 systems don't even have
  48  * PCI so we won't worry about it.
  49  */
  50
  51 #define MLX4_DECLARE_DOORBELL_LOCK(name)
  52 #define MLX4_INIT_DOORBELL_LOCK(ptr)    do { } while (0)
  53 #define MLX4_GET_DOORBELL_LOCK(ptr)      (NULL)
  54
  55 static inline void mlx4_write64(__be32 val[2], void __iomem *dest,
  56                                 spinlock_t *doorbell_lock)
  57 {
  58         __raw_writeq(*(u64 *) val, dest);
  59 }
  60
  61 #else
  62
  63 /*
  64  * Just fall back to a spinlock to protect the doorbell if
  65  * BITS_PER_LONG is 32 -- there's no portable way to do atomic 64-bit
  66  * MMIO writes.
  67  */
  68
  69 #define MLX4_DECLARE_DOORBELL_LOCK(name) spinlock_t name;
  70 #define MLX4_INIT_DOORBELL_LOCK(ptr)     spin_lock_init(ptr)
  71 #define MLX4_GET_DOORBELL_LOCK(ptr)      (ptr)
  72
  73 static inline void mlx4_write64(__be32 val[2], void __iomem *dest,
  74                                 spinlock_t *doorbell_lock)
  75 {
  76         unsigned long flags;
  77
  78         spin_lock_irqsave(doorbell_lock, flags);
  79         __raw_writel((__force u32) val[0], dest);
  80         __raw_writel((__force u32) val[1], dest + 4);
  81         spin_unlock_irqrestore(doorbell_lock, flags);
  82 }
  83
  84 #endif
  85
  86 #endif /* MLX4_DOORBELL_H */