2 * Copyright (c) 2013-2015, Mellanox Technologies, Ltd. All rights reserved.
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28 #ifndef MLX5_DOORBELL_H
29 #define MLX5_DOORBELL_H
31 #define MLX5_BF_OFFSET 0x800
32 #define MLX5_CQ_DOORBELL 0x20
34 #if BITS_PER_LONG == 64
35 /* Assume that we can just write a 64-bit doorbell atomically. s390
36 * actually doesn't have writeq() but S/390 systems don't even have
37 * PCI so we won't worry about it.
40 #define MLX5_DECLARE_DOORBELL_LOCK(name)
41 #define MLX5_INIT_DOORBELL_LOCK(ptr) do { } while (0)
42 #define MLX5_GET_DOORBELL_LOCK(ptr) (NULL)
44 static inline void mlx5_write64(__be32 val[2], void __iomem *dest,
45 spinlock_t *doorbell_lock)
47 __raw_writeq(*(u64 *)val, dest);
52 /* Just fall back to a spinlock to protect the doorbell if
53 * BITS_PER_LONG is 32 -- there's no portable way to do atomic 64-bit
57 #define MLX5_DECLARE_DOORBELL_LOCK(name) spinlock_t name;
58 #define MLX5_INIT_DOORBELL_LOCK(ptr) spin_lock_init(ptr)
59 #define MLX5_GET_DOORBELL_LOCK(ptr) (ptr)
61 static inline void mlx5_write64(__be32 val[2], void __iomem *dest,
62 spinlock_t *doorbell_lock)
66 spin_lock_irqsave(doorbell_lock, flags);
67 __raw_writel((__force u32) val[0], dest);
68 __raw_writel((__force u32) val[1], dest + 4);
69 spin_unlock_irqrestore(doorbell_lock, flags);
74 #endif /* MLX5_DOORBELL_H */