1 /* 2 * Copyright (c) 2013-2015, Mellanox Technologies. 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 33 #ifndef MLX5_DOORBELL_H 34 #define MLX5_DOORBELL_H 35 36 #define MLX5_BF_OFFSET 0x800 37 #define MLX5_CQ_DOORBELL 0x20 38 39 #if BITS_PER_LONG == 64 40 /* Assume that we can just write a 64-bit doorbell atomically. s390 41 * actually doesn't have writeq() but S/390 systems don't even have 42 * PCI so we won't worry about it. 43 */ 44 45 static inline void mlx5_write64(__be32 val[2], void __iomem *dest, 46 spinlock_t *doorbell_lock) 47 { 48 __raw_writeq(*(u64 *)val, dest); 49 } 50 51 #else 52 53 /* Just fall back to a spinlock to protect the doorbell if 54 * BITS_PER_LONG is 32 -- there's no portable way to do atomic 64-bit 55 * MMIO writes. 56 */ 57 58 static inline void mlx5_write64(__be32 val[2], void __iomem *dest, 59 spinlock_t *doorbell_lock) 60 { 61 unsigned long flags; 62 63 if (doorbell_lock) 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 if (doorbell_lock) 68 spin_unlock_irqrestore(doorbell_lock, flags); 69 } 70 71 #endif 72 73 #endif /* MLX5_DOORBELL_H */ 74