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. 4 */ 5 6 #ifndef _CQ_DESC_H_ 7 #define _CQ_DESC_H_ 8 9 /* 10 * Completion queue descriptor types 11 */ 12 enum cq_desc_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, 19 CQ_DESC_TYPE_SGL = 6, 20 CQ_DESC_TYPE_CLASSIFIER = 7, 21 CQ_DESC_TYPE_TEST = 127, 22 }; 23 24 /* Completion queue descriptor: 16B 25 * 26 * All completion queues have this basic layout. The 27 * type_specfic area is unique for each completion 28 * queue type. 29 */ 30 struct cq_desc { 31 __le16 completed_index; 32 __le16 q_number; 33 u8 type_specfic[11]; 34 u8 type_color; 35 }; 36 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_COLOR_MASK_NOSHIFT 0x80 42 #define CQ_DESC_Q_NUM_BITS 10 43 #define CQ_DESC_Q_NUM_MASK ((1 << CQ_DESC_Q_NUM_BITS) - 1) 44 #define CQ_DESC_COMP_NDX_BITS 12 45 #define CQ_DESC_COMP_NDX_MASK ((1 << CQ_DESC_COMP_NDX_BITS) - 1) 46 47 static inline void cq_color_enc(struct cq_desc *desc, const u8 color) 48 { 49 if (color) 50 desc->type_color |= (1 << CQ_DESC_COLOR_SHIFT); 51 else 52 desc->type_color &= ~(1 << CQ_DESC_COLOR_SHIFT); 53 } 54 55 static inline void cq_desc_enc(struct cq_desc *desc, 56 const u8 type, const u8 color, const u16 q_number, 57 const u16 completed_index) 58 { 59 desc->type_color = (type & CQ_DESC_TYPE_MASK) | 60 ((color & CQ_DESC_COLOR_MASK) << CQ_DESC_COLOR_SHIFT); 61 desc->q_number = cpu_to_le16(q_number & CQ_DESC_Q_NUM_MASK); 62 desc->completed_index = cpu_to_le16(completed_index & 63 CQ_DESC_COMP_NDX_MASK); 64 } 65 66 static inline void cq_desc_dec(const struct cq_desc *desc_arg, 67 u8 *type, u8 *color, u16 *q_number, u16 *completed_index) 68 { 69 const struct cq_desc *desc = desc_arg; 70 const u8 type_color = desc->type_color; 71 72 *color = (type_color >> CQ_DESC_COLOR_SHIFT) & CQ_DESC_COLOR_MASK; 73 74 /* 75 * Make sure color bit is read from desc *before* other fields 76 * are read from desc. Hardware guarantees color bit is last 77 * bit (byte) written. Adding the rmb() prevents the compiler 78 * and/or CPU from reordering the reads which would potentially 79 * result in reading stale values. 80 */ 81 82 rmb(); 83 84 *type = type_color & CQ_DESC_TYPE_MASK; 85 *q_number = le16_to_cpu(desc->q_number) & CQ_DESC_Q_NUM_MASK; 86 *completed_index = le16_to_cpu(desc->completed_index) & 87 CQ_DESC_COMP_NDX_MASK; 88 } 89 90 static inline void cq_color_dec(const struct cq_desc *desc_arg, u8 *color) 91 { 92 volatile const struct cq_desc *desc = desc_arg; 93 94 *color = (desc->type_color >> CQ_DESC_COLOR_SHIFT) & CQ_DESC_COLOR_MASK; 95 } 96 97 #endif /* _CQ_DESC_H_ */ 98