1 /*- 2 * Copyright (c) 2013-2017, Mellanox Technologies, Ltd. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS `AS IS' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 * SUCH DAMAGE. 24 */ 25 26 #ifndef MLX5_DOORBELL_H 27 #define MLX5_DOORBELL_H 28 29 #define MLX5_BF_OFFSET 0x800 30 #define MLX5_CQ_DOORBELL 0x20 31 32 #if BITS_PER_LONG == 64 33 /* Assume that we can just write a 64-bit doorbell atomically. s390 34 * actually doesn't have writeq() but S/390 systems don't even have 35 * PCI so we won't worry about it. 36 */ 37 38 #define MLX5_DECLARE_DOORBELL_LOCK(name) 39 #define MLX5_INIT_DOORBELL_LOCK(ptr) do { } while (0) 40 #define MLX5_GET_DOORBELL_LOCK(ptr) (NULL) 41 42 static inline void mlx5_write64(__be32 val[2], void __iomem *dest, 43 spinlock_t *doorbell_lock) 44 { 45 __raw_writeq(*(u64 *)val, dest); 46 } 47 48 #else 49 50 /* Just fall back to a spinlock to protect the doorbell if 51 * BITS_PER_LONG is 32 -- there's no portable way to do atomic 64-bit 52 * MMIO writes. 53 */ 54 55 #define MLX5_DECLARE_DOORBELL_LOCK(name) spinlock_t name; 56 #define MLX5_INIT_DOORBELL_LOCK(ptr) spin_lock_init(ptr) 57 #define MLX5_GET_DOORBELL_LOCK(ptr) (ptr) 58 59 static inline void mlx5_write64(__be32 val[2], void __iomem *dest, 60 spinlock_t *doorbell_lock) 61 { 62 unsigned long flags; 63 64 spin_lock_irqsave(doorbell_lock, flags); 65 __raw_writel((__force u32) val[0], dest); 66 __raw_writel((__force u32) val[1], dest + 4); 67 spin_unlock_irqrestore(doorbell_lock, flags); 68 } 69 70 #endif 71 72 #endif /* MLX5_DOORBELL_H */ 73