drivers/scsi/snic/vnic_wq.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /* Copyright 2014 Cisco Systems, Inc.  All rights reserved. */
   3
   4 #ifndef _VNIC_WQ_H_
   5 #define _VNIC_WQ_H_
   6
   7 #include <linux/pci.h>
   8 #include "vnic_dev.h"
   9 #include "vnic_cq.h"
  10
  11 /* Work queue control */
  12 struct vnic_wq_ctrl {
  13         u64 ring_base;                  /* 0x00 */
  14         u32 ring_size;                  /* 0x08 */
  15         u32 pad0;
  16         u32 posted_index;               /* 0x10 */
  17         u32 pad1;
  18         u32 cq_index;                   /* 0x18 */
  19         u32 pad2;
  20         u32 enable;                     /* 0x20 */
  21         u32 pad3;
  22         u32 running;                    /* 0x28 */
  23         u32 pad4;
  24         u32 fetch_index;                /* 0x30 */
  25         u32 pad5;
  26         u32 dca_value;                  /* 0x38 */
  27         u32 pad6;
  28         u32 error_interrupt_enable;     /* 0x40 */
  29         u32 pad7;
  30         u32 error_interrupt_offset;     /* 0x48 */
  31         u32 pad8;
  32         u32 error_status;               /* 0x50 */
  33         u32 pad9;
  34 };
  35
  36 struct vnic_wq_buf {
  37         struct vnic_wq_buf *next;
  38         dma_addr_t dma_addr;
  39         void *os_buf;
  40         unsigned int len;
  41         unsigned int index;
  42         int sop;
  43         void *desc;
  44 };
  45
  46 /* Break the vnic_wq_buf allocations into blocks of 64 entries */
  47 #define VNIC_WQ_BUF_MIN_BLK_ENTRIES 32
  48 #define VNIC_WQ_BUF_DFLT_BLK_ENTRIES 64
  49 #define VNIC_WQ_BUF_BLK_ENTRIES(entries) \
  50         ((unsigned int)(entries < VNIC_WQ_BUF_DFLT_BLK_ENTRIES) ? \
  51                 VNIC_WQ_BUF_MIN_BLK_ENTRIES : VNIC_WQ_BUF_DFLT_BLK_ENTRIES)
  52 #define VNIC_WQ_BUF_BLK_SZ \
  53         (VNIC_WQ_BUF_DFLT_BLK_ENTRIES * sizeof(struct vnic_wq_buf))
  54 #define VNIC_WQ_BUF_BLKS_NEEDED(entries) \
  55         DIV_ROUND_UP(entries, VNIC_WQ_BUF_DFLT_BLK_ENTRIES)
  56 #define VNIC_WQ_BUF_BLKS_NEEDED(entries) \
  57         DIV_ROUND_UP(entries, VNIC_WQ_BUF_DFLT_BLK_ENTRIES)
  58 #define VNIC_WQ_BUF_BLKS_MAX VNIC_WQ_BUF_BLKS_NEEDED(4096)
  59
  60 struct vnic_wq {
  61         unsigned int index;
  62         struct vnic_dev *vdev;
  63         struct vnic_wq_ctrl __iomem *ctrl;      /* memory-mapped */
  64         struct vnic_dev_ring ring;
  65         struct vnic_wq_buf *bufs[VNIC_WQ_BUF_BLKS_MAX];
  66         struct vnic_wq_buf *to_use;
  67         struct vnic_wq_buf *to_clean;
  68         unsigned int pkts_outstanding;
  69 };
  70
  71 static inline unsigned int svnic_wq_desc_avail(struct vnic_wq *wq)
  72 {
  73         /* how many does SW own? */
  74         return wq->ring.desc_avail;
  75 }
  76
  77 static inline unsigned int svnic_wq_desc_used(struct vnic_wq *wq)
  78 {
  79         /* how many does HW own? */
  80         return wq->ring.desc_count - wq->ring.desc_avail - 1;
  81 }
  82
  83 static inline void *svnic_wq_next_desc(struct vnic_wq *wq)
  84 {
  85         return wq->to_use->desc;
  86 }
  87
  88 static inline void svnic_wq_post(struct vnic_wq *wq,
  89         void *os_buf, dma_addr_t dma_addr,
  90         unsigned int len, int sop, int eop)
  91 {
  92         struct vnic_wq_buf *buf = wq->to_use;
  93
  94         buf->sop = sop;
  95         buf->os_buf = eop ? os_buf : NULL;
  96         buf->dma_addr = dma_addr;
  97         buf->len = len;
  98
  99         buf = buf->next;
 100         if (eop) {
 101                 /* Adding write memory barrier prevents compiler and/or CPU
 102                  * reordering, thus avoiding descriptor posting before
 103                  * descriptor is initialized. Otherwise, hardware can read
 104                  * stale descriptor fields.
 105                  */
 106                 wmb();
 107                 iowrite32(buf->index, &wq->ctrl->posted_index);
 108         }
 109         wq->to_use = buf;
 110
 111         wq->ring.desc_avail--;
 112 }
 113
 114 static inline void svnic_wq_service(struct vnic_wq *wq,
 115         struct cq_desc *cq_desc, u16 completed_index,
 116         void (*buf_service)(struct vnic_wq *wq,
 117         struct cq_desc *cq_desc, struct vnic_wq_buf *buf, void *opaque),
 118         void *opaque)
 119 {
 120         struct vnic_wq_buf *buf;
 121
 122         buf = wq->to_clean;
 123         while (1) {
 124
 125                 (*buf_service)(wq, cq_desc, buf, opaque);
 126
 127                 wq->ring.desc_avail++;
 128
 129                 wq->to_clean = buf->next;
 130
 131                 if (buf->index == completed_index)
 132                         break;
 133
 134                 buf = wq->to_clean;
 135         }
 136 }
 137
 138 void svnic_wq_free(struct vnic_wq *wq);
 139 int svnic_wq_alloc(struct vnic_dev *vdev, struct vnic_wq *wq,
 140         unsigned int index, unsigned int desc_count, unsigned int desc_size);
 141 int vnic_wq_devcmd2_alloc(struct vnic_dev *vdev, struct vnic_wq *wq,
 142                 unsigned int desc_count, unsigned int desc_size);
 143 void vnic_wq_init_start(struct vnic_wq *wq, unsigned int cq_index,
 144                 unsigned int fetch_index, unsigned int post_index,
 145                 unsigned int error_interrupt_enable,
 146                 unsigned int error_interrupt_offset);
 147
 148 void svnic_wq_init(struct vnic_wq *wq, unsigned int cq_index,
 149         unsigned int error_interrupt_enable,
 150         unsigned int error_interrupt_offset);
 151 unsigned int svnic_wq_error_status(struct vnic_wq *wq);
 152 void svnic_wq_enable(struct vnic_wq *wq);
 153 int svnic_wq_disable(struct vnic_wq *wq);
 154 void svnic_wq_clean(struct vnic_wq *wq,
 155         void (*buf_clean)(struct vnic_wq *wq, struct vnic_wq_buf *buf));
 156 #endif /* _VNIC_WQ_H_ */