drivers/scsi/snic/vnic_wq.h

   1 /*
   2  * Copyright 2014 Cisco Systems, Inc.  All rights reserved.
   3  *
   4  * This program is free software; you may redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; version 2 of the License.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   9  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  10  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  11  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  12  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  13  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  14  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  15  * SOFTWARE.
  16  */
  17
  18 #ifndef _VNIC_WQ_H_
  19 #define _VNIC_WQ_H_
  20
  21 #include <linux/pci.h>
  22 #include "vnic_dev.h"
  23 #include "vnic_cq.h"
  24
  25 /* Work queue control */
  26 struct vnic_wq_ctrl {
  27         u64 ring_base;                  /* 0x00 */
  28         u32 ring_size;                  /* 0x08 */
  29         u32 pad0;
  30         u32 posted_index;               /* 0x10 */
  31         u32 pad1;
  32         u32 cq_index;                   /* 0x18 */
  33         u32 pad2;
  34         u32 enable;                     /* 0x20 */
  35         u32 pad3;
  36         u32 running;                    /* 0x28 */
  37         u32 pad4;
  38         u32 fetch_index;                /* 0x30 */
  39         u32 pad5;
  40         u32 dca_value;                  /* 0x38 */
  41         u32 pad6;
  42         u32 error_interrupt_enable;     /* 0x40 */
  43         u32 pad7;
  44         u32 error_interrupt_offset;     /* 0x48 */
  45         u32 pad8;
  46         u32 error_status;               /* 0x50 */
  47         u32 pad9;
  48 };
  49
  50 struct vnic_wq_buf {
  51         struct vnic_wq_buf *next;
  52         dma_addr_t dma_addr;
  53         void *os_buf;
  54         unsigned int len;
  55         unsigned int index;
  56         int sop;
  57         void *desc;
  58 };
  59
  60 /* Break the vnic_wq_buf allocations into blocks of 64 entries */
  61 #define VNIC_WQ_BUF_MIN_BLK_ENTRIES 32
  62 #define VNIC_WQ_BUF_DFLT_BLK_ENTRIES 64
  63 #define VNIC_WQ_BUF_BLK_ENTRIES(entries) \
  64         ((unsigned int)(entries < VNIC_WQ_BUF_DFLT_BLK_ENTRIES) ? \
  65                 VNIC_WQ_BUF_MIN_BLK_ENTRIES : VNIC_WQ_BUF_DFLT_BLK_ENTRIES)
  66 #define VNIC_WQ_BUF_BLK_SZ \
  67         (VNIC_WQ_BUF_DFLT_BLK_ENTRIES * sizeof(struct vnic_wq_buf))
  68 #define VNIC_WQ_BUF_BLKS_NEEDED(entries) \
  69         DIV_ROUND_UP(entries, VNIC_WQ_BUF_DFLT_BLK_ENTRIES)
  70 #define VNIC_WQ_BUF_BLKS_NEEDED(entries) \
  71         DIV_ROUND_UP(entries, VNIC_WQ_BUF_DFLT_BLK_ENTRIES)
  72 #define VNIC_WQ_BUF_BLKS_MAX VNIC_WQ_BUF_BLKS_NEEDED(4096)
  73
  74 struct vnic_wq {
  75         unsigned int index;
  76         struct vnic_dev *vdev;
  77         struct vnic_wq_ctrl __iomem *ctrl;      /* memory-mapped */
  78         struct vnic_dev_ring ring;
  79         struct vnic_wq_buf *bufs[VNIC_WQ_BUF_BLKS_MAX];
  80         struct vnic_wq_buf *to_use;
  81         struct vnic_wq_buf *to_clean;
  82         unsigned int pkts_outstanding;
  83 };
  84
  85 static inline unsigned int svnic_wq_desc_avail(struct vnic_wq *wq)
  86 {
  87         /* how many does SW own? */
  88         return wq->ring.desc_avail;
  89 }
  90
  91 static inline unsigned int svnic_wq_desc_used(struct vnic_wq *wq)
  92 {
  93         /* how many does HW own? */
  94         return wq->ring.desc_count - wq->ring.desc_avail - 1;
  95 }
  96
  97 static inline void *svnic_wq_next_desc(struct vnic_wq *wq)
  98 {
  99         return wq->to_use->desc;
 100 }
 101
 102 static inline void svnic_wq_post(struct vnic_wq *wq,
 103         void *os_buf, dma_addr_t dma_addr,
 104         unsigned int len, int sop, int eop)
 105 {
 106         struct vnic_wq_buf *buf = wq->to_use;
 107
 108         buf->sop = sop;
 109         buf->os_buf = eop ? os_buf : NULL;
 110         buf->dma_addr = dma_addr;
 111         buf->len = len;
 112
 113         buf = buf->next;
 114         if (eop) {
 115                 /* Adding write memory barrier prevents compiler and/or CPU
 116                  * reordering, thus avoiding descriptor posting before
 117                  * descriptor is initialized. Otherwise, hardware can read
 118                  * stale descriptor fields.
 119                  */
 120                 wmb();
 121                 iowrite32(buf->index, &wq->ctrl->posted_index);
 122         }
 123         wq->to_use = buf;
 124
 125         wq->ring.desc_avail--;
 126 }
 127
 128 static inline void svnic_wq_service(struct vnic_wq *wq,
 129         struct cq_desc *cq_desc, u16 completed_index,
 130         void (*buf_service)(struct vnic_wq *wq,
 131         struct cq_desc *cq_desc, struct vnic_wq_buf *buf, void *opaque),
 132         void *opaque)
 133 {
 134         struct vnic_wq_buf *buf;
 135
 136         buf = wq->to_clean;
 137         while (1) {
 138
 139                 (*buf_service)(wq, cq_desc, buf, opaque);
 140
 141                 wq->ring.desc_avail++;
 142
 143                 wq->to_clean = buf->next;
 144
 145                 if (buf->index == completed_index)
 146                         break;
 147
 148                 buf = wq->to_clean;
 149         }
 150 }
 151
 152 void svnic_wq_free(struct vnic_wq *wq);
 153 int svnic_wq_alloc(struct vnic_dev *vdev, struct vnic_wq *wq,
 154         unsigned int index, unsigned int desc_count, unsigned int desc_size);
 155 int vnic_wq_devcmd2_alloc(struct vnic_dev *vdev, struct vnic_wq *wq,
 156                 unsigned int desc_count, unsigned int desc_size);
 157 void vnic_wq_init_start(struct vnic_wq *wq, unsigned int cq_index,
 158                 unsigned int fetch_index, unsigned int post_index,
 159                 unsigned int error_interrupt_enable,
 160                 unsigned int error_interrupt_offset);
 161
 162 void svnic_wq_init(struct vnic_wq *wq, unsigned int cq_index,
 163         unsigned int error_interrupt_enable,
 164         unsigned int error_interrupt_offset);
 165 unsigned int svnic_wq_error_status(struct vnic_wq *wq);
 166 void svnic_wq_enable(struct vnic_wq *wq);
 167 int svnic_wq_disable(struct vnic_wq *wq);
 168 void svnic_wq_clean(struct vnic_wq *wq,
 169         void (*buf_clean)(struct vnic_wq *wq, struct vnic_wq_buf *buf));
 170 #endif /* _VNIC_WQ_H_ */