/*
* Copyright (c) 2013, Mellanox Technologies inc. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/

#ifndef MLX5_DOORBELL_H
#define MLX5_DOORBELL_H

#define MLX5_BF_OFFSET 0x800
#define MLX5_CQ_DOORBELL 0x20

#if BITS_PER_LONG == 64
/* Assume that we can just write a 64-bit doorbell atomically. s390
* actually doesn't have writeq() but S/390 systems don't even have
* PCI so we won't worry about it.
*/

#define MLX5_DECLARE_DOORBELL_LOCK(name)
#define MLX5_INIT_DOORBELL_LOCK(ptr) do { } while (0)
#define MLX5_GET_DOORBELL_LOCK(ptr) (NULL)

static inline void mlx5_write64(__be32 val[2], void __iomem *dest,
spinlock_t *doorbell_lock)
{
__raw_writeq(*(u64 *)val, dest);
}

#else

/* Just fall back to a spinlock to protect the doorbell if
* BITS_PER_LONG is 32 -- there's no portable way to do atomic 64-bit
* MMIO writes.
*/

#define MLX5_DECLARE_DOORBELL_LOCK(name) spinlock_t name;
#define MLX5_INIT_DOORBELL_LOCK(ptr) spin_lock_init(ptr)
#define MLX5_GET_DOORBELL_LOCK(ptr) (ptr)

static inline void mlx5_write64(__be32 val[2], void __iomem *dest,
spinlock_t *doorbell_lock)
{
unsigned long flags;

spin_lock_irqsave(doorbell_lock, flags);
__raw_writel((__force u32) val[0], dest);
__raw_writel((__force u32) val[1], dest + 4);
spin_unlock_irqrestore(doorbell_lock, flags);
}

#endif

#endif /* MLX5_DOORBELL_H */