1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright 2008 Cisco Systems, Inc. All rights reserved.
4 * Copyright 2007 Nuova Systems, Inc. All rights reserved.
5 */
6#ifndef _VNIC_WQ_COPY_H_
7#define _VNIC_WQ_COPY_H_
8
9#include <linux/pci.h>
10#include "vnic_wq.h"
11#include "fcpio.h"
12
13#define VNIC_WQ_COPY_MAX 1
14
15struct vnic_wq_copy {
16 unsigned int index;
17 struct vnic_dev *vdev;
18 struct vnic_wq_ctrl __iomem *ctrl; /* memory-mapped */
19 struct vnic_dev_ring ring;
20 unsigned to_use_index;
21 unsigned to_clean_index;
22};
23
24static inline unsigned int vnic_wq_copy_desc_avail(struct vnic_wq_copy *wq)
25{
26 return wq->ring.desc_avail;
27}
28
29static inline unsigned int vnic_wq_copy_desc_in_use(struct vnic_wq_copy *wq)
30{
31 return wq->ring.desc_count - 1 - wq->ring.desc_avail;
32}
33
34static inline void *vnic_wq_copy_next_desc(struct vnic_wq_copy *wq)
35{
36 struct fcpio_host_req *desc = wq->ring.descs;
37 return &desc[wq->to_use_index];
38}
39
40static inline void vnic_wq_copy_post(struct vnic_wq_copy *wq)
41{
42
43 ((wq->to_use_index + 1) == wq->ring.desc_count) ?
44 (wq->to_use_index = 0) : (wq->to_use_index++);
45 wq->ring.desc_avail--;
46
47 /* Adding write memory barrier prevents compiler and/or CPU
48 * reordering, thus avoiding descriptor posting before
49 * descriptor is initialized. Otherwise, hardware can read
50 * stale descriptor fields.
51 */
52 wmb();
53
54 iowrite32(wq->to_use_index, &wq->ctrl->posted_index);
55}
56
57static inline void vnic_wq_copy_desc_process(struct vnic_wq_copy *wq, u16 index)
58{
59 unsigned int cnt;
60
61 if (wq->to_clean_index <= index)
62 cnt = (index - wq->to_clean_index) + 1;
63 else
64 cnt = wq->ring.desc_count - wq->to_clean_index + index + 1;
65
66 wq->to_clean_index = ((index + 1) % wq->ring.desc_count);
67 wq->ring.desc_avail += cnt;
68
69}
70
71static inline void vnic_wq_copy_service(struct vnic_wq_copy *wq,
72 u16 completed_index,
73 void (*q_service)(struct vnic_wq_copy *wq,
74 struct fcpio_host_req *wq_desc))
75{
76 struct fcpio_host_req *wq_desc = wq->ring.descs;
77 unsigned int curr_index;
78
79 while (1) {
80
81 if (q_service)
82 (*q_service)(wq, &wq_desc[wq->to_clean_index]);
83
84 wq->ring.desc_avail++;
85
86 curr_index = wq->to_clean_index;
87
88 /* increment the to-clean index so that we start
89 * with an unprocessed index next time we enter the loop
90 */
91 ((wq->to_clean_index + 1) == wq->ring.desc_count) ?
92 (wq->to_clean_index = 0) : (wq->to_clean_index++);
93
94 if (curr_index == completed_index)
95 break;
96
97 /* we have cleaned all the entries */
98 if ((completed_index == (u16)-1) &&
99 (wq->to_clean_index == wq->to_use_index))
100 break;
101 }
102}
103
104void vnic_wq_copy_enable(struct vnic_wq_copy *wq);
105int vnic_wq_copy_disable(struct vnic_wq_copy *wq);
106void vnic_wq_copy_free(struct vnic_wq_copy *wq);
107int vnic_wq_copy_alloc(struct vnic_dev *vdev, struct vnic_wq_copy *wq,
108 unsigned int index, unsigned int desc_count, unsigned int desc_size);
109void vnic_wq_copy_init(struct vnic_wq_copy *wq, unsigned int cq_index,
110 unsigned int error_interrupt_enable,
111 unsigned int error_interrupt_offset);
112void vnic_wq_copy_clean(struct vnic_wq_copy *wq,
113 void (*q_clean)(struct vnic_wq_copy *wq,
114 struct fcpio_host_req *wq_desc));
115
116#endif /* _VNIC_WQ_COPY_H_ */
117

source code of linux/drivers/scsi/fnic/vnic_wq_copy.h