1 /* SPDX-License-Identifier: BSD-3-Clause
2 * Copyright 2008-2017 Cisco Systems, Inc. All rights reserved.
3 * Copyright 2007 Nuova Systems, Inc. All rights reserved.
10 * Completion queue descriptor types
13 CQ_DESC_TYPE_WQ_ENET = 0,
14 CQ_DESC_TYPE_DESC_COPY = 1,
15 CQ_DESC_TYPE_WQ_EXCH = 2,
16 CQ_DESC_TYPE_RQ_ENET = 3,
17 CQ_DESC_TYPE_RQ_FCP = 4,
18 CQ_DESC_TYPE_IOMMU_MISS = 5,
20 CQ_DESC_TYPE_CLASSIFIER = 7,
21 CQ_DESC_TYPE_TEST = 127,
24 /* Completion queue descriptor: 16B
26 * All completion queues have this basic layout. The
27 * type_specfic area is unique for each completion
31 __le16 completed_index;
37 #define CQ_DESC_TYPE_BITS 4
38 #define CQ_DESC_TYPE_MASK ((1 << CQ_DESC_TYPE_BITS) - 1)
39 #define CQ_DESC_COLOR_MASK 1
40 #define CQ_DESC_COLOR_SHIFT 7
41 #define CQ_DESC_Q_NUM_BITS 10
42 #define CQ_DESC_Q_NUM_MASK ((1 << CQ_DESC_Q_NUM_BITS) - 1)
43 #define CQ_DESC_COMP_NDX_BITS 12
44 #define CQ_DESC_COMP_NDX_MASK ((1 << CQ_DESC_COMP_NDX_BITS) - 1)
46 static inline void cq_color_enc(struct cq_desc *desc, const u8 color)
49 desc->type_color |= (1 << CQ_DESC_COLOR_SHIFT);
51 desc->type_color &= ~(1 << CQ_DESC_COLOR_SHIFT);
54 static inline void cq_desc_enc(struct cq_desc *desc,
55 const u8 type, const u8 color, const u16 q_number,
56 const u16 completed_index)
58 desc->type_color = (type & CQ_DESC_TYPE_MASK) |
59 ((color & CQ_DESC_COLOR_MASK) << CQ_DESC_COLOR_SHIFT);
60 desc->q_number = cpu_to_le16(q_number & CQ_DESC_Q_NUM_MASK);
61 desc->completed_index = cpu_to_le16(completed_index &
62 CQ_DESC_COMP_NDX_MASK);
65 static inline void cq_desc_dec(const struct cq_desc *desc_arg,
66 u8 *type, u8 *color, u16 *q_number, u16 *completed_index)
68 const struct cq_desc *desc = desc_arg;
69 const u8 type_color = desc->type_color;
71 *color = (type_color >> CQ_DESC_COLOR_SHIFT) & CQ_DESC_COLOR_MASK;
74 * Make sure color bit is read from desc *before* other fields
75 * are read from desc. Hardware guarantees color bit is last
76 * bit (byte) written. Adding the rmb() prevents the compiler
77 * and/or CPU from reordering the reads which would potentially
78 * result in reading stale values.
83 *type = type_color & CQ_DESC_TYPE_MASK;
84 *q_number = le16_to_cpu(desc->q_number) & CQ_DESC_Q_NUM_MASK;
85 *completed_index = le16_to_cpu(desc->completed_index) &
86 CQ_DESC_COMP_NDX_MASK;
89 static inline void cq_color_dec(const struct cq_desc *desc_arg, u8 *color)
91 volatile const struct cq_desc *desc = desc_arg;
93 *color = (desc->type_color >> CQ_DESC_COLOR_SHIFT) & CQ_DESC_COLOR_MASK;
96 #endif /* _CQ_DESC_H_ */