drivers/net/ethernet/cisco/enic/vnic_rq.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright 2008-2010 Cisco Systems, Inc.  All rights reserved.
   4  * Copyright 2007 Nuova Systems, Inc.  All rights reserved.
   5  */
   6
   7 #ifndef _VNIC_RQ_H_
   8 #define _VNIC_RQ_H_
   9
  10 #include <linux/pci.h>
  11 #include <linux/netdevice.h>
  12
  13 #include "vnic_dev.h"
  14 #include "vnic_cq.h"
  15
  16 /* Receive queue control */
  17 struct vnic_rq_ctrl {
  18         u64 ring_base;                  /* 0x00 */
  19         u32 ring_size;                  /* 0x08 */
  20         u32 pad0;
  21         u32 posted_index;               /* 0x10 */
  22         u32 pad1;
  23         u32 cq_index;                   /* 0x18 */
  24         u32 pad2;
  25         u32 enable;                     /* 0x20 */
  26         u32 pad3;
  27         u32 running;                    /* 0x28 */
  28         u32 pad4;
  29         u32 fetch_index;                /* 0x30 */
  30         u32 pad5;
  31         u32 error_interrupt_enable;     /* 0x38 */
  32         u32 pad6;
  33         u32 error_interrupt_offset;     /* 0x40 */
  34         u32 pad7;
  35         u32 error_status;               /* 0x48 */
  36         u32 pad8;
  37         u32 dropped_packet_count;       /* 0x50 */
  38         u32 pad9;
  39         u32 dropped_packet_count_rc;    /* 0x58 */
  40         u32 pad10;
  41 };
  42
  43 /* Break the vnic_rq_buf allocations into blocks of 32/64 entries */
  44 #define VNIC_RQ_BUF_MIN_BLK_ENTRIES 32
  45 #define VNIC_RQ_BUF_DFLT_BLK_ENTRIES 64
  46 #define VNIC_RQ_BUF_BLK_ENTRIES(entries) \
  47         ((unsigned int)((entries < VNIC_RQ_BUF_DFLT_BLK_ENTRIES) ? \
  48         VNIC_RQ_BUF_MIN_BLK_ENTRIES : VNIC_RQ_BUF_DFLT_BLK_ENTRIES))
  49 #define VNIC_RQ_BUF_BLK_SZ(entries) \
  50         (VNIC_RQ_BUF_BLK_ENTRIES(entries) * sizeof(struct vnic_rq_buf))
  51 #define VNIC_RQ_BUF_BLKS_NEEDED(entries) \
  52         DIV_ROUND_UP(entries, VNIC_RQ_BUF_BLK_ENTRIES(entries))
  53 #define VNIC_RQ_BUF_BLKS_MAX VNIC_RQ_BUF_BLKS_NEEDED(4096)
  54
  55 struct vnic_rq_buf {
  56         struct vnic_rq_buf *next;
  57         dma_addr_t dma_addr;
  58         void *os_buf;
  59         unsigned int os_buf_index;
  60         unsigned int len;
  61         unsigned int index;
  62         void *desc;
  63         uint64_t wr_id;
  64 };
  65
  66 enum enic_poll_state {
  67         ENIC_POLL_STATE_IDLE,
  68         ENIC_POLL_STATE_NAPI,
  69         ENIC_POLL_STATE_POLL
  70 };
  71
  72 struct vnic_rq {
  73         unsigned int index;
  74         struct vnic_dev *vdev;
  75         struct vnic_rq_ctrl __iomem *ctrl;              /* memory-mapped */
  76         struct vnic_dev_ring ring;
  77         struct vnic_rq_buf *bufs[VNIC_RQ_BUF_BLKS_MAX];
  78         struct vnic_rq_buf *to_use;
  79         struct vnic_rq_buf *to_clean;
  80         void *os_buf_head;
  81         unsigned int pkts_outstanding;
  82 };
  83
  84 static inline unsigned int vnic_rq_desc_avail(struct vnic_rq *rq)
  85 {
  86         /* how many does SW own? */
  87         return rq->ring.desc_avail;
  88 }
  89
  90 static inline unsigned int vnic_rq_desc_used(struct vnic_rq *rq)
  91 {
  92         /* how many does HW own? */
  93         return rq->ring.desc_count - rq->ring.desc_avail - 1;
  94 }
  95
  96 static inline void *vnic_rq_next_desc(struct vnic_rq *rq)
  97 {
  98         return rq->to_use->desc;
  99 }
 100
 101 static inline unsigned int vnic_rq_next_index(struct vnic_rq *rq)
 102 {
 103         return rq->to_use->index;
 104 }
 105
 106 static inline void vnic_rq_post(struct vnic_rq *rq,
 107         void *os_buf, unsigned int os_buf_index,
 108         dma_addr_t dma_addr, unsigned int len,
 109         uint64_t wrid)
 110 {
 111         struct vnic_rq_buf *buf = rq->to_use;
 112
 113         buf->os_buf = os_buf;
 114         buf->os_buf_index = os_buf_index;
 115         buf->dma_addr = dma_addr;
 116         buf->len = len;
 117         buf->wr_id = wrid;
 118
 119         buf = buf->next;
 120         rq->to_use = buf;
 121         rq->ring.desc_avail--;
 122
 123         /* Move the posted_index every nth descriptor
 124          */
 125
 126 #ifndef VNIC_RQ_RETURN_RATE
 127 #define VNIC_RQ_RETURN_RATE             0xf     /* keep 2^n - 1 */
 128 #endif
 129
 130         if ((buf->index & VNIC_RQ_RETURN_RATE) == 0) {
 131                 /* Adding write memory barrier prevents compiler and/or CPU
 132                  * reordering, thus avoiding descriptor posting before
 133                  * descriptor is initialized. Otherwise, hardware can read
 134                  * stale descriptor fields.
 135                  */
 136                 wmb();
 137                 iowrite32(buf->index, &rq->ctrl->posted_index);
 138         }
 139 }
 140
 141 static inline void vnic_rq_return_descs(struct vnic_rq *rq, unsigned int count)
 142 {
 143         rq->ring.desc_avail += count;
 144 }
 145
 146 enum desc_return_options {
 147         VNIC_RQ_RETURN_DESC,
 148         VNIC_RQ_DEFER_RETURN_DESC,
 149 };
 150
 151 static inline void vnic_rq_service(struct vnic_rq *rq,
 152         struct cq_desc *cq_desc, u16 completed_index,
 153         int desc_return, void (*buf_service)(struct vnic_rq *rq,
 154         struct cq_desc *cq_desc, struct vnic_rq_buf *buf,
 155         int skipped, void *opaque), void *opaque)
 156 {
 157         struct vnic_rq_buf *buf;
 158         int skipped;
 159
 160         buf = rq->to_clean;
 161         while (1) {
 162
 163                 skipped = (buf->index != completed_index);
 164
 165                 (*buf_service)(rq, cq_desc, buf, skipped, opaque);
 166
 167                 if (desc_return == VNIC_RQ_RETURN_DESC)
 168                         rq->ring.desc_avail++;
 169
 170                 rq->to_clean = buf->next;
 171
 172                 if (!skipped)
 173                         break;
 174
 175                 buf = rq->to_clean;
 176         }
 177 }
 178
 179 static inline int vnic_rq_fill(struct vnic_rq *rq,
 180         int (*buf_fill)(struct vnic_rq *rq))
 181 {
 182         int err;
 183
 184         while (vnic_rq_desc_avail(rq) > 0) {
 185
 186                 err = (*buf_fill)(rq);
 187                 if (err)
 188                         return err;
 189         }
 190
 191         return 0;
 192 }
 193
 194 void vnic_rq_free(struct vnic_rq *rq);
 195 int vnic_rq_alloc(struct vnic_dev *vdev, struct vnic_rq *rq, unsigned int index,
 196         unsigned int desc_count, unsigned int desc_size);
 197 void vnic_rq_init(struct vnic_rq *rq, unsigned int cq_index,
 198         unsigned int error_interrupt_enable,
 199         unsigned int error_interrupt_offset);
 200 unsigned int vnic_rq_error_status(struct vnic_rq *rq);
 201 void vnic_rq_enable(struct vnic_rq *rq);
 202 int vnic_rq_disable(struct vnic_rq *rq);
 203 void vnic_rq_clean(struct vnic_rq *rq,
 204         void (*buf_clean)(struct vnic_rq *rq, struct vnic_rq_buf *buf));
 205
 206 #endif /* _VNIC_RQ_H_ */