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/* SPDX-License-Identifier: BSD-3-Clause
* Copyright 2008-2017 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,
CQ_DESC_TYPE_IOMMU_MISS = 5,
CQ_DESC_TYPE_SGL = 6,
CQ_DESC_TYPE_CLASSIFIER = 7,
CQ_DESC_TYPE_TEST = 127,
};
/* 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_color_enc(struct cq_desc *desc, const u8 color)
{
if (color)
desc->type_color |= (1 << CQ_DESC_COLOR_SHIFT);
else
desc->type_color &= ~(1 << CQ_DESC_COLOR_SHIFT);
}
static inline void cq_desc_enc(struct cq_desc *desc,
const u8 type, const u8 color, const u16 q_number,
const u16 completed_index)
{
desc->type_color = (type & CQ_DESC_TYPE_MASK) |
((color & CQ_DESC_COLOR_MASK) << CQ_DESC_COLOR_SHIFT);
desc->q_number = cpu_to_le16(q_number & CQ_DESC_Q_NUM_MASK);
desc->completed_index = cpu_to_le16(completed_index &
CQ_DESC_COMP_NDX_MASK);
}
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;
}
static inline void cq_color_dec(const struct cq_desc *desc_arg, u8 *color)
{
volatile const struct cq_desc *desc = desc_arg;
*color = (desc->type_color >> CQ_DESC_COLOR_SHIFT) & CQ_DESC_COLOR_MASK;
}
#endif /* _CQ_DESC_H_ */
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