LXR linux/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
  55static 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
  73static 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 */
  87