drivers/net/enic/base/cq_desc.h

   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 #include <rte_byteorder.h>
   9
  10 /*
  11  * Completion queue descriptor types
  12  */
  13 enum cq_desc_types {
  14         CQ_DESC_TYPE_WQ_ENET = 0,
  15         CQ_DESC_TYPE_DESC_COPY = 1,
  16         CQ_DESC_TYPE_WQ_EXCH = 2,
  17         CQ_DESC_TYPE_RQ_ENET = 3,
  18         CQ_DESC_TYPE_RQ_FCP = 4,
  19         CQ_DESC_TYPE_IOMMU_MISS = 5,
  20         CQ_DESC_TYPE_SGL = 6,
  21         CQ_DESC_TYPE_CLASSIFIER = 7,
  22         CQ_DESC_TYPE_TEST = 127,
  23 };
  24
  25 /* Completion queue descriptor: 16B
  26  *
  27  * All completion queues have this basic layout.  The
  28  * type_specfic area is unique for each completion
  29  * queue type.
  30  */
  31 struct cq_desc {
  32         __le16 completed_index;
  33         __le16 q_number;
  34         u8 type_specfic[11];
  35         u8 type_color;
  36 };
  37
  38 #define CQ_DESC_TYPE_BITS        4
  39 #define CQ_DESC_TYPE_MASK        ((1 << CQ_DESC_TYPE_BITS) - 1)
  40 #define CQ_DESC_COLOR_MASK       1
  41 #define CQ_DESC_COLOR_SHIFT      7
  42 #define CQ_DESC_COLOR_MASK_NOSHIFT 0x80
  43 #define CQ_DESC_Q_NUM_BITS       10
  44 #define CQ_DESC_Q_NUM_MASK       ((1 << CQ_DESC_Q_NUM_BITS) - 1)
  45 #define CQ_DESC_COMP_NDX_BITS    12
  46 #define CQ_DESC_COMP_NDX_MASK    ((1 << CQ_DESC_COMP_NDX_BITS) - 1)
  47
  48 static inline void cq_color_enc(struct cq_desc *desc, const u8 color)
  49 {
  50         if (color)
  51                 desc->type_color |=  (1 << CQ_DESC_COLOR_SHIFT);
  52         else
  53                 desc->type_color &= ~(1 << CQ_DESC_COLOR_SHIFT);
  54 }
  55
  56 static inline void cq_desc_enc(struct cq_desc *desc,
  57         const u8 type, const u8 color, const u16 q_number,
  58         const u16 completed_index)
  59 {
  60         desc->type_color = (type & CQ_DESC_TYPE_MASK) |
  61                 ((color & CQ_DESC_COLOR_MASK) << CQ_DESC_COLOR_SHIFT);
  62         desc->q_number = rte_cpu_to_le_16(q_number & CQ_DESC_Q_NUM_MASK);
  63         desc->completed_index = rte_cpu_to_le_16(completed_index &
  64                 CQ_DESC_COMP_NDX_MASK);
  65 }
  66
  67 static inline void cq_desc_dec(const struct cq_desc *desc_arg,
  68         u8 *type, u8 *color, u16 *q_number, u16 *completed_index)
  69 {
  70         const struct cq_desc *desc = desc_arg;
  71         const u8 type_color = desc->type_color;
  72
  73         *color = (type_color >> CQ_DESC_COLOR_SHIFT) & CQ_DESC_COLOR_MASK;
  74
  75         /*
  76          * Make sure color bit is read from desc *before* other fields
  77          * are read from desc.  Hardware guarantees color bit is last
  78          * bit (byte) written.  Adding the rmb() prevents the compiler
  79          * and/or CPU from reordering the reads which would potentially
  80          * result in reading stale values.
  81          */
  82
  83         rmb();
  84
  85         *type = type_color & CQ_DESC_TYPE_MASK;
  86         *q_number = rte_le_to_cpu_16(desc->q_number) & CQ_DESC_Q_NUM_MASK;
  87         *completed_index = rte_le_to_cpu_16(desc->completed_index) &
  88                 CQ_DESC_COMP_NDX_MASK;
  89 }
  90
  91 static inline void cq_color_dec(const struct cq_desc *desc_arg, u8 *color)
  92 {
  93         volatile const struct cq_desc *desc = desc_arg;
  94
  95         *color = (desc->type_color >> CQ_DESC_COLOR_SHIFT) & CQ_DESC_COLOR_MASK;
  96 }
  97
  98 #endif /* _CQ_DESC_H_ */