drivers/infiniband/hw/mthca/mthca_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 #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