LXR linux/drivers/scsi/snic/vnic

   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 */
  26struct 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
  50struct 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
  74struct 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
  85static 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
  91static 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
  97static inline void *svnic_wq_next_desc(struct vnic_wq *wq)
  98{
  99        return wq->to_use->desc;
 100}
 101
 102static 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
 128static 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
 152void svnic_wq_free(struct vnic_wq *wq);
 153int svnic_wq_alloc(struct vnic_dev *vdev, struct vnic_wq *wq,
 154        unsigned int index, unsigned int desc_count, unsigned int desc_size);
 155int vnic_wq_devcmd2_alloc(struct vnic_dev *vdev, struct vnic_wq *wq,
 156                unsigned int desc_count, unsigned int desc_size);
 157void 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
 162void svnic_wq_init(struct vnic_wq *wq, unsigned int cq_index,
 163        unsigned int error_interrupt_enable,
 164        unsigned int error_interrupt_offset);
 165unsigned int svnic_wq_error_status(struct vnic_wq *wq);
 166void svnic_wq_enable(struct vnic_wq *wq);
 167int svnic_wq_disable(struct vnic_wq *wq);
 168void 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_ */
 171