/* SPDX-License-Identifier: GPL-2.0-only */ /* * Copyright 2008 Cisco Systems, Inc. All rights reserved. * Copyright 2007 Nuova Systems, Inc. All rights reserved. */ #ifndef _CQ_DESC_H_ #define _CQ_DESC_H_ /* * Completion queue descriptor types */ enum cq_desc_types { CQ_DESC_TYPE_WQ_ENET = 0, CQ_DESC_TYPE_DESC_COPY = 1, CQ_DESC_TYPE_WQ_EXCH = 2, CQ_DESC_TYPE_RQ_ENET = 3, CQ_DESC_TYPE_RQ_FCP = 4, }; /* Completion queue descriptor: 16B * * All completion queues have this basic layout. The * type_specfic area is unique for each completion * queue type. */ struct cq_desc { __le16 completed_index; __le16 q_number; u8 type_specfic[11]; u8 type_color; }; #define CQ_DESC_TYPE_BITS 4 #define CQ_DESC_TYPE_MASK ((1 << CQ_DESC_TYPE_BITS) - 1) #define CQ_DESC_COLOR_MASK 1 #define CQ_DESC_COLOR_SHIFT 7 #define CQ_DESC_Q_NUM_BITS 10 #define CQ_DESC_Q_NUM_MASK ((1 << CQ_DESC_Q_NUM_BITS) - 1) #define CQ_DESC_COMP_NDX_BITS 12 #define CQ_DESC_COMP_NDX_MASK ((1 << CQ_DESC_COMP_NDX_BITS) - 1) static inline void cq_desc_dec(const struct cq_desc *desc_arg, u8 *type, u8 *color, u16 *q_number, u16 *completed_index) { const struct cq_desc *desc = desc_arg; const u8 type_color = desc->type_color; *color = (type_color >> CQ_DESC_COLOR_SHIFT) & CQ_DESC_COLOR_MASK; /* * Make sure color bit is read from desc *before* other fields * are read from desc. Hardware guarantees color bit is last * bit (byte) written. Adding the rmb() prevents the compiler * and/or CPU from reordering the reads which would potentially * result in reading stale values. */ rmb(); *type = type_color & CQ_DESC_TYPE_MASK; *q_number = le16_to_cpu(desc->q_number) & CQ_DESC_Q_NUM_MASK; *completed_index = le16_to_cpu(desc->completed_index) & CQ_DESC_COMP_NDX_MASK; } #endif /* _CQ_DESC_H_ */