drivers/scsi/fnic/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 #ifndef _VNIC_RQ_H_
  19 #define _VNIC_RQ_H_
  20
  21 #include <linux/pci.h>
  22 #include "vnic_dev.h"
  23 #include "vnic_cq.h"
  24
  25 /*
  26  * These defines avoid symbol clash between fnic and enic (Cisco 10G Eth
  27  * Driver) when both are built with CONFIG options =y
  28  */
  29 #define vnic_rq_desc_avail fnic_rq_desc_avail
  30 #define vnic_rq_desc_used fnic_rq_desc_used
  31 #define vnic_rq_next_desc fnic_rq_next_desc
  32 #define vnic_rq_next_index fnic_rq_next_index
  33 #define vnic_rq_next_buf_index fnic_rq_next_buf_index
  34 #define vnic_rq_post fnic_rq_post
  35 #define vnic_rq_posting_soon fnic_rq_posting_soon
  36 #define vnic_rq_return_descs fnic_rq_return_descs
  37 #define vnic_rq_service fnic_rq_service
  38 #define vnic_rq_fill fnic_rq_fill
  39 #define vnic_rq_free fnic_rq_free
  40 #define vnic_rq_alloc fnic_rq_alloc
  41 #define vnic_rq_init fnic_rq_init
  42 #define vnic_rq_error_status fnic_rq_error_status
  43 #define vnic_rq_enable fnic_rq_enable
  44 #define vnic_rq_disable fnic_rq_disable
  45 #define vnic_rq_clean fnic_rq_clean
  46
  47 /* Receive queue control */
  48 struct vnic_rq_ctrl {
  49         u64 ring_base;                  /* 0x00 */
  50         u32 ring_size;                  /* 0x08 */
  51         u32 pad0;
  52         u32 posted_index;               /* 0x10 */
  53         u32 pad1;
  54         u32 cq_index;                   /* 0x18 */
  55         u32 pad2;
  56         u32 enable;                     /* 0x20 */
  57         u32 pad3;
  58         u32 running;                    /* 0x28 */
  59         u32 pad4;
  60         u32 fetch_index;                /* 0x30 */
  61         u32 pad5;
  62         u32 error_interrupt_enable;     /* 0x38 */
  63         u32 pad6;
  64         u32 error_interrupt_offset;     /* 0x40 */
  65         u32 pad7;
  66         u32 error_status;               /* 0x48 */
  67         u32 pad8;
  68         u32 dropped_packet_count;       /* 0x50 */
  69         u32 pad9;
  70         u32 dropped_packet_count_rc;    /* 0x58 */
  71         u32 pad10;
  72 };
  73
  74 /* Break the vnic_rq_buf allocations into blocks of 64 entries */
  75 #define VNIC_RQ_BUF_BLK_ENTRIES 64
  76 #define VNIC_RQ_BUF_BLK_SZ \
  77         (VNIC_RQ_BUF_BLK_ENTRIES * sizeof(struct vnic_rq_buf))
  78 #define VNIC_RQ_BUF_BLKS_NEEDED(entries) \
  79         DIV_ROUND_UP(entries, VNIC_RQ_BUF_BLK_ENTRIES)
  80 #define VNIC_RQ_BUF_BLKS_MAX VNIC_RQ_BUF_BLKS_NEEDED(4096)
  81
  82 struct vnic_rq_buf {
  83         struct vnic_rq_buf *next;
  84         dma_addr_t dma_addr;
  85         void *os_buf;
  86         unsigned int os_buf_index;
  87         unsigned int len;
  88         unsigned int index;
  89         void *desc;
  90 };
  91
  92 struct vnic_rq {
  93         unsigned int index;
  94         struct vnic_dev *vdev;
  95         struct vnic_rq_ctrl __iomem *ctrl;      /* memory-mapped */
  96         struct vnic_dev_ring ring;
  97         struct vnic_rq_buf *bufs[VNIC_RQ_BUF_BLKS_MAX];
  98         struct vnic_rq_buf *to_use;
  99         struct vnic_rq_buf *to_clean;
 100         void *os_buf_head;
 101         unsigned int buf_index;
 102         unsigned int pkts_outstanding;
 103 };
 104
 105 static inline unsigned int vnic_rq_desc_avail(struct vnic_rq *rq)
 106 {
 107         /* how many does SW own? */
 108         return rq->ring.desc_avail;
 109 }
 110
 111 static inline unsigned int vnic_rq_desc_used(struct vnic_rq *rq)
 112 {
 113         /* how many does HW own? */
 114         return rq->ring.desc_count - rq->ring.desc_avail - 1;
 115 }
 116
 117 static inline void *vnic_rq_next_desc(struct vnic_rq *rq)
 118 {
 119         return rq->to_use->desc;
 120 }
 121
 122 static inline unsigned int vnic_rq_next_index(struct vnic_rq *rq)
 123 {
 124         return rq->to_use->index;
 125 }
 126
 127 static inline unsigned int vnic_rq_next_buf_index(struct vnic_rq *rq)
 128 {
 129         return rq->buf_index++;
 130 }
 131
 132 static inline void vnic_rq_post(struct vnic_rq *rq,
 133         void *os_buf, unsigned int os_buf_index,
 134         dma_addr_t dma_addr, unsigned int len)
 135 {
 136         struct vnic_rq_buf *buf = rq->to_use;
 137
 138         buf->os_buf = os_buf;
 139         buf->os_buf_index = os_buf_index;
 140         buf->dma_addr = dma_addr;
 141         buf->len = len;
 142
 143         buf = buf->next;
 144         rq->to_use = buf;
 145         rq->ring.desc_avail--;
 146
 147         /* Move the posted_index every nth descriptor
 148          */
 149
 150 #ifndef VNIC_RQ_RETURN_RATE
 151 #define VNIC_RQ_RETURN_RATE             0xf     /* keep 2^n - 1 */
 152 #endif
 153
 154         if ((buf->index & VNIC_RQ_RETURN_RATE) == 0) {
 155                 /* Adding write memory barrier prevents compiler and/or CPU
 156                  * reordering, thus avoiding descriptor posting before
 157                  * descriptor is initialized. Otherwise, hardware can read
 158                  * stale descriptor fields.
 159                  */
 160                 wmb();
 161                 iowrite32(buf->index, &rq->ctrl->posted_index);
 162         }
 163 }
 164
 165 static inline int vnic_rq_posting_soon(struct vnic_rq *rq)
 166 {
 167         return (rq->to_use->index & VNIC_RQ_RETURN_RATE) == 0;
 168 }
 169
 170 static inline void vnic_rq_return_descs(struct vnic_rq *rq, unsigned int count)
 171 {
 172         rq->ring.desc_avail += count;
 173 }
 174
 175 enum desc_return_options {
 176         VNIC_RQ_RETURN_DESC,
 177         VNIC_RQ_DEFER_RETURN_DESC,
 178 };
 179
 180 static inline void vnic_rq_service(struct vnic_rq *rq,
 181         struct cq_desc *cq_desc, u16 completed_index,
 182         int desc_return, void (*buf_service)(struct vnic_rq *rq,
 183         struct cq_desc *cq_desc, struct vnic_rq_buf *buf,
 184         int skipped, void *opaque), void *opaque)
 185 {
 186         struct vnic_rq_buf *buf;
 187         int skipped;
 188
 189         buf = rq->to_clean;
 190         while (1) {
 191
 192                 skipped = (buf->index != completed_index);
 193
 194                 (*buf_service)(rq, cq_desc, buf, skipped, opaque);
 195
 196                 if (desc_return == VNIC_RQ_RETURN_DESC)
 197                         rq->ring.desc_avail++;
 198
 199                 rq->to_clean = buf->next;
 200
 201                 if (!skipped)
 202                         break;
 203
 204                 buf = rq->to_clean;
 205         }
 206 }
 207
 208 static inline int vnic_rq_fill(struct vnic_rq *rq,
 209         int (*buf_fill)(struct vnic_rq *rq))
 210 {
 211         int err;
 212
 213         while (vnic_rq_desc_avail(rq) > 1) {
 214
 215                 err = (*buf_fill)(rq);
 216                 if (err)
 217                         return err;
 218         }
 219
 220         return 0;
 221 }
 222
 223 void vnic_rq_free(struct vnic_rq *rq);
 224 int vnic_rq_alloc(struct vnic_dev *vdev, struct vnic_rq *rq, unsigned int index,
 225         unsigned int desc_count, unsigned int desc_size);
 226 void vnic_rq_init(struct vnic_rq *rq, unsigned int cq_index,
 227         unsigned int error_interrupt_enable,
 228         unsigned int error_interrupt_offset);
 229 unsigned int vnic_rq_error_status(struct vnic_rq *rq);
 230 void vnic_rq_enable(struct vnic_rq *rq);
 231 int vnic_rq_disable(struct vnic_rq *rq);
 232 void vnic_rq_clean(struct vnic_rq *rq,
 233         void (*buf_clean)(struct vnic_rq *rq, struct vnic_rq_buf *buf));
 234
 235 #endif /* _VNIC_RQ_H_ */