drivers/infiniband/hw/mthca/mthca_doorbell.h

   1 /*
   2  * Copyright (c) 2004 Topspin Communications.  All rights reserved.
   3  *
   4  * This software is available to you under a choice of one of two
   5  * licenses.  You may choose to be licensed under the terms of the GNU
   6  * General Public License (GPL) Version 2, available from the file
   7  * COPYING in the main directory of this source tree, or the
   8  * OpenIB.org BSD license below:
   9  *
  10  *     Redistribution and use in source and binary forms, with or
  11  *     without modification, are permitted provided that the following
  12  *     conditions are met:
  13  *
  14  *      - Redistributions of source code must retain the above
  15  *        copyright notice, this list of conditions and the following
  16  *        disclaimer.
  17  *
  18  *      - Redistributions in binary form must reproduce the above
  19  *        copyright notice, this list of conditions and the following
  20  *        disclaimer in the documentation and/or other materials
  21  *        provided with the distribution.
  22  *
  23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30  * SOFTWARE.
  31  *
  32  * $Id: mthca_doorbell.h 1349 2004-12-16 21:09:43Z roland $
  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(u32 val[2], void __iomem *dest,
  55                                  spinlock_t *doorbell_lock)
  56 {
  57         __raw_writeq(*(u64 *) val, dest);
  58 }
  59
  60 static inline void mthca_write_db_rec(u32 val[2], u32 *db)
  61 {
  62         *(u64 *) db = *(u64 *) val;
  63 }
  64
  65 #else
  66
  67 /*
  68  * Just fall back to a spinlock to protect the doorbell if
  69  * BITS_PER_LONG is 32 -- there's no portable way to do atomic 64-bit
  70  * MMIO writes.
  71  */
  72
  73 #define MTHCA_DECLARE_DOORBELL_LOCK(name) spinlock_t name;
  74 #define MTHCA_INIT_DOORBELL_LOCK(ptr)     spin_lock_init(ptr)
  75 #define MTHCA_GET_DOORBELL_LOCK(ptr)      (ptr)
  76
  77 static inline void mthca_write64(u32 val[2], void __iomem *dest,
  78                                  spinlock_t *doorbell_lock)
  79 {
  80         unsigned long flags;
  81
  82         spin_lock_irqsave(doorbell_lock, flags);
  83         __raw_writel(val[0], dest);
  84         __raw_writel(val[1], dest + 4);
  85         spin_unlock_irqrestore(doorbell_lock, flags);
  86 }
  87
  88 static inline void mthca_write_db_rec(u32 val[2], u32 *db)
  89 {
  90         db[0] = val[0];
  91         wmb();
  92         db[1] = val[1];
  93 }
  94
  95 #endif