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Diffstat (limited to 'include/linux/mlx5/doorbell.h')
-rw-r--r-- | include/linux/mlx5/doorbell.h | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/include/linux/mlx5/doorbell.h b/include/linux/mlx5/doorbell.h new file mode 100644 index 000000000..5c267707e --- /dev/null +++ b/include/linux/mlx5/doorbell.h @@ -0,0 +1,60 @@ +/* + * Copyright (c) 2013-2015, Mellanox Technologies. 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 + +/* 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. + * + * Note that the write is not atomic on 32-bit systems! In contrast to 64-bit + * ones, it requires proper locking. mlx5_write64 doesn't do any locking, so use + * it at your own discretion, protected by some kind of lock on 32 bits. + * + * TODO: use write{q,l}_relaxed() + */ + +static inline void mlx5_write64(__be32 val[2], void __iomem *dest) +{ +#if BITS_PER_LONG == 64 + __raw_writeq(*(u64 *)val, dest); +#else + __raw_writel((__force u32) val[0], dest); + __raw_writel((__force u32) val[1], dest + 4); +#endif +} + +#endif /* MLX5_DOORBELL_H */ |