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

   1 /*
   2  * Copyright 2008-2010 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_WQ_H_
  21 #define _VNIC_WQ_H_
  22
  23 #include <linux/pci.h>
  24
  25 #include "vnic_dev.h"
  26 #include "vnic_cq.h"
  27
  28 /* Work queue control */
  29 struct vnic_wq_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 dca_value;                  /* 0x38 */
  44         u32 pad6;
  45         u32 error_interrupt_enable;     /* 0x40 */
  46         u32 pad7;
  47         u32 error_interrupt_offset;     /* 0x48 */
  48         u32 pad8;
  49         u32 error_status;               /* 0x50 */
  50         u32 pad9;
  51 };
  52
  53 struct vnic_wq_buf {
  54         struct vnic_wq_buf *next;
  55         dma_addr_t dma_addr;
  56         void *os_buf;
  57         unsigned int len;
  58         unsigned int index;
  59         int sop;
  60         void *desc;
  61 };
  62
  63 /* Break the vnic_wq_buf allocations into blocks of 32/64 entries */
  64 #define VNIC_WQ_BUF_MIN_BLK_ENTRIES 32
  65 #define VNIC_WQ_BUF_DFLT_BLK_ENTRIES 64
  66 #define VNIC_WQ_BUF_BLK_ENTRIES(entries) \
  67         ((unsigned int)((entries < VNIC_WQ_BUF_DFLT_BLK_ENTRIES) ? \
  68         VNIC_WQ_BUF_MIN_BLK_ENTRIES : VNIC_WQ_BUF_DFLT_BLK_ENTRIES))
  69 #define VNIC_WQ_BUF_BLK_SZ(entries) \
  70         (VNIC_WQ_BUF_BLK_ENTRIES(entries) * sizeof(struct vnic_wq_buf))
  71 #define VNIC_WQ_BUF_BLKS_NEEDED(entries) \
  72         DIV_ROUND_UP(entries, VNIC_WQ_BUF_BLK_ENTRIES(entries))
  73 #define VNIC_WQ_BUF_BLKS_MAX VNIC_WQ_BUF_BLKS_NEEDED(4096)
  74
  75 struct vnic_wq {
  76         unsigned int index;
  77         struct vnic_dev *vdev;
  78         struct vnic_wq_ctrl __iomem *ctrl;              /* memory-mapped */
  79         struct vnic_dev_ring ring;
  80         struct vnic_wq_buf *bufs[VNIC_WQ_BUF_BLKS_MAX];
  81         struct vnic_wq_buf *to_use;
  82         struct vnic_wq_buf *to_clean;
  83         unsigned int pkts_outstanding;
  84 };
  85
  86 static inline unsigned int vnic_wq_desc_avail(struct vnic_wq *wq)
  87 {
  88         /* how many does SW own? */
  89         return wq->ring.desc_avail;
  90 }
  91
  92 static inline unsigned int vnic_wq_desc_used(struct vnic_wq *wq)
  93 {
  94         /* how many does HW own? */
  95         return wq->ring.desc_count - wq->ring.desc_avail - 1;
  96 }
  97
  98 static inline void *vnic_wq_next_desc(struct vnic_wq *wq)
  99 {
 100         return wq->to_use->desc;
 101 }
 102
 103 static inline void vnic_wq_post(struct vnic_wq *wq,
 104         void *os_buf, dma_addr_t dma_addr,
 105         unsigned int len, int sop, int eop)
 106 {
 107         struct vnic_wq_buf *buf = wq->to_use;
 108
 109         buf->sop = sop;
 110         buf->os_buf = eop ? os_buf : NULL;
 111         buf->dma_addr = dma_addr;
 112         buf->len = len;
 113
 114         buf = buf->next;
 115         if (eop) {
 116                 /* Adding write memory barrier prevents compiler and/or CPU
 117                  * reordering, thus avoiding descriptor posting before
 118                  * descriptor is initialized. Otherwise, hardware can read
 119                  * stale descriptor fields.
 120                  */
 121                 wmb();
 122                 iowrite32(buf->index, &wq->ctrl->posted_index);
 123         }
 124         wq->to_use = buf;
 125
 126         wq->ring.desc_avail--;
 127 }
 128
 129 static inline void vnic_wq_service(struct vnic_wq *wq,
 130         struct cq_desc *cq_desc, u16 completed_index,
 131         void (*buf_service)(struct vnic_wq *wq,
 132         struct cq_desc *cq_desc, struct vnic_wq_buf *buf, void *opaque),
 133         void *opaque)
 134 {
 135         struct vnic_wq_buf *buf;
 136
 137         buf = wq->to_clean;
 138         while (1) {
 139
 140                 (*buf_service)(wq, cq_desc, buf, opaque);
 141
 142                 wq->ring.desc_avail++;
 143
 144                 wq->to_clean = buf->next;
 145
 146                 if (buf->index == completed_index)
 147                         break;
 148
 149                 buf = wq->to_clean;
 150         }
 151 }
 152
 153 void vnic_wq_free(struct vnic_wq *wq);
 154 int vnic_wq_alloc(struct vnic_dev *vdev, struct vnic_wq *wq, unsigned int index,
 155         unsigned int desc_count, unsigned int desc_size);
 156 void vnic_wq_init(struct vnic_wq *wq, unsigned int cq_index,
 157         unsigned int error_interrupt_enable,
 158         unsigned int error_interrupt_offset);
 159 unsigned int vnic_wq_error_status(struct vnic_wq *wq);
 160 void vnic_wq_enable(struct vnic_wq *wq);
 161 int vnic_wq_disable(struct vnic_wq *wq);
 162 void vnic_wq_clean(struct vnic_wq *wq,
 163         void (*buf_clean)(struct vnic_wq *wq, struct vnic_wq_buf *buf));
 164
 165 #endif /* _VNIC_WQ_H_ */