drivers/net/enic/vnic_rq.h

   1 /*
   2  * Copyright 2008 Cisco Systems, Inc.  All rights reserved.
   3  * Copyright 2007 Nuova Systems, Inc.  All rights reserved.
   4  *
   5  * This program is free software; you may redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; version 2 of the License.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  10  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  11  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  12  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  13  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  14  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  15  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  16  * SOFTWARE.
  17  *
  18  */
  19
  20 #ifndef _VNIC_RQ_H_
  21 #define _VNIC_RQ_H_
  22
  23 #include <linux/pci.h>
  24
  25 #include "vnic_dev.h"
  26 #include "vnic_cq.h"
  27
  28 /* Receive queue control */
  29 struct vnic_rq_ctrl {
  30         u64 ring_base;                  /* 0x00 */
  31         u32 ring_size;                  /* 0x08 */
  32         u32 pad0;
  33         u32 posted_index;               /* 0x10 */
  34         u32 pad1;
  35         u32 cq_index;                   /* 0x18 */
  36         u32 pad2;
  37         u32 enable;                     /* 0x20 */
  38         u32 pad3;
  39         u32 running;                    /* 0x28 */
  40         u32 pad4;
  41         u32 fetch_index;                /* 0x30 */
  42         u32 pad5;
  43         u32 error_interrupt_enable;     /* 0x38 */
  44         u32 pad6;
  45         u32 error_interrupt_offset;     /* 0x40 */
  46         u32 pad7;
  47         u32 error_status;               /* 0x48 */
  48         u32 pad8;
  49         u32 dropped_packet_count;       /* 0x50 */
  50         u32 pad9;
  51         u32 dropped_packet_count_rc;    /* 0x58 */
  52         u32 pad10;
  53 };
  54
  55 /* Break the vnic_rq_buf allocations into blocks of 64 entries */
  56 #define VNIC_RQ_BUF_BLK_ENTRIES 64
  57 #define VNIC_RQ_BUF_BLK_SZ \
  58         (VNIC_RQ_BUF_BLK_ENTRIES * sizeof(struct vnic_rq_buf))
  59 #define VNIC_RQ_BUF_BLKS_NEEDED(entries) \
  60         DIV_ROUND_UP(entries, VNIC_RQ_BUF_BLK_ENTRIES)
  61 #define VNIC_RQ_BUF_BLKS_MAX VNIC_RQ_BUF_BLKS_NEEDED(4096)
  62
  63 struct vnic_rq_buf {
  64         struct vnic_rq_buf *next;
  65         dma_addr_t dma_addr;
  66         void *os_buf;
  67         unsigned int os_buf_index;
  68         unsigned int len;
  69         unsigned int index;
  70         void *desc;
  71 };
  72
  73 struct vnic_rq {
  74         unsigned int index;
  75         struct vnic_dev *vdev;
  76         struct vnic_rq_ctrl __iomem *ctrl;              /* memory-mapped */
  77         struct vnic_dev_ring ring;
  78         struct vnic_rq_buf *bufs[VNIC_RQ_BUF_BLKS_MAX];
  79         struct vnic_rq_buf *to_use;
  80         struct vnic_rq_buf *to_clean;
  81         void *os_buf_head;
  82         unsigned int buf_index;
  83         unsigned int pkts_outstanding;
  84 };
  85
  86 static inline unsigned int vnic_rq_desc_avail(struct vnic_rq *rq)
  87 {
  88         /* how many does SW own? */
  89         return rq->ring.desc_avail;
  90 }
  91
  92 static inline unsigned int vnic_rq_desc_used(struct vnic_rq *rq)
  93 {
  94         /* how many does HW own? */
  95         return rq->ring.desc_count - rq->ring.desc_avail - 1;
  96 }
  97
  98 static inline void *vnic_rq_next_desc(struct vnic_rq *rq)
  99 {
 100         return rq->to_use->desc;
 101 }
 102
 103 static inline unsigned int vnic_rq_next_index(struct vnic_rq *rq)
 104 {
 105         return rq->to_use->index;
 106 }
 107
 108 static inline unsigned int vnic_rq_next_buf_index(struct vnic_rq *rq)
 109 {
 110         return rq->buf_index++;
 111 }
 112
 113 static inline void vnic_rq_post(struct vnic_rq *rq,
 114         void *os_buf, unsigned int os_buf_index,
 115         dma_addr_t dma_addr, unsigned int len)
 116 {
 117         struct vnic_rq_buf *buf = rq->to_use;
 118
 119         buf->os_buf = os_buf;
 120         buf->os_buf_index = os_buf_index;
 121         buf->dma_addr = dma_addr;
 122         buf->len = len;
 123
 124         buf = buf->next;
 125         rq->to_use = buf;
 126         rq->ring.desc_avail--;
 127
 128         /* Move the posted_index every nth descriptor
 129          */
 130
 131 #ifndef VNIC_RQ_RETURN_RATE
 132 #define VNIC_RQ_RETURN_RATE             0xf     /* keep 2^n - 1 */
 133 #endif
 134
 135         if ((buf->index & VNIC_RQ_RETURN_RATE) == 0) {
 136                 /* Adding write memory barrier prevents compiler and/or CPU
 137                  * reordering, thus avoiding descriptor posting before
 138                  * descriptor is initialized. Otherwise, hardware can read
 139                  * stale descriptor fields.
 140                  */
 141                 wmb();
 142                 iowrite32(buf->index, &rq->ctrl->posted_index);
 143         }
 144 }
 145
 146 static inline void vnic_rq_return_descs(struct vnic_rq *rq, unsigned int count)
 147 {
 148         rq->ring.desc_avail += count;
 149 }
 150
 151 enum desc_return_options {
 152         VNIC_RQ_RETURN_DESC,
 153         VNIC_RQ_DEFER_RETURN_DESC,
 154 };
 155
 156 static inline void vnic_rq_service(struct vnic_rq *rq,
 157         struct cq_desc *cq_desc, u16 completed_index,
 158         int desc_return, void (*buf_service)(struct vnic_rq *rq,
 159         struct cq_desc *cq_desc, struct vnic_rq_buf *buf,
 160         int skipped, void *opaque), void *opaque)
 161 {
 162         struct vnic_rq_buf *buf;
 163         int skipped;
 164
 165         buf = rq->to_clean;
 166         while (1) {
 167
 168                 skipped = (buf->index != completed_index);
 169
 170                 (*buf_service)(rq, cq_desc, buf, skipped, opaque);
 171
 172                 if (desc_return == VNIC_RQ_RETURN_DESC)
 173                         rq->ring.desc_avail++;
 174
 175                 rq->to_clean = buf->next;
 176
 177                 if (!skipped)
 178                         break;
 179
 180                 buf = rq->to_clean;
 181         }
 182 }
 183
 184 static inline int vnic_rq_fill(struct vnic_rq *rq,
 185         int (*buf_fill)(struct vnic_rq *rq))
 186 {
 187         int err;
 188
 189         while (vnic_rq_desc_avail(rq) > 1) {
 190
 191                 err = (*buf_fill)(rq);
 192                 if (err)
 193                         return err;
 194         }
 195
 196         return 0;
 197 }
 198
 199 void vnic_rq_free(struct vnic_rq *rq);
 200 int vnic_rq_alloc(struct vnic_dev *vdev, struct vnic_rq *rq, unsigned int index,
 201         unsigned int desc_count, unsigned int desc_size);
 202 void vnic_rq_init(struct vnic_rq *rq, unsigned int cq_index,
 203         unsigned int error_interrupt_enable,
 204         unsigned int error_interrupt_offset);
 205 unsigned int vnic_rq_error_status(struct vnic_rq *rq);
 206 void vnic_rq_enable(struct vnic_rq *rq);
 207 int vnic_rq_disable(struct vnic_rq *rq);
 208 void vnic_rq_clean(struct vnic_rq *rq,
 209         void (*buf_clean)(struct vnic_rq *rq, struct vnic_rq_buf *buf));
 210
 211 #endif /* _VNIC_RQ_H_ */