1 /*
2 * Copyright 2008 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 #ifndef _VNIC_WQ_COPY_H_
19 #define _VNIC_WQ_COPY_H_
20
21 #include <linux/pci.h>
22 #include "vnic_wq.h"
23 #include "fcpio.h"
24
25 #define VNIC_WQ_COPY_MAX 1
26
27 struct vnic_wq_copy {
28 unsigned int index;
29 struct vnic_dev *vdev;
30 struct vnic_wq_ctrl __iomem *ctrl; /* memory-mapped */
31 struct vnic_dev_ring ring;
32 unsigned to_use_index;
33 unsigned to_clean_index;
34 };
35
vnic_wq_copy_desc_avail(struct vnic_wq_copy * wq)36 static inline unsigned int vnic_wq_copy_desc_avail(struct vnic_wq_copy *wq)
37 {
38 return wq->ring.desc_avail;
39 }
40
vnic_wq_copy_desc_in_use(struct vnic_wq_copy * wq)41 static inline unsigned int vnic_wq_copy_desc_in_use(struct vnic_wq_copy *wq)
42 {
43 return wq->ring.desc_count - 1 - wq->ring.desc_avail;
44 }
45
vnic_wq_copy_next_desc(struct vnic_wq_copy * wq)46 static inline void *vnic_wq_copy_next_desc(struct vnic_wq_copy *wq)
47 {
48 struct fcpio_host_req *desc = wq->ring.descs;
49 return &desc[wq->to_use_index];
50 }
51
vnic_wq_copy_post(struct vnic_wq_copy * wq)52 static inline void vnic_wq_copy_post(struct vnic_wq_copy *wq)
53 {
54
55 ((wq->to_use_index + 1) == wq->ring.desc_count) ?
56 (wq->to_use_index = 0) : (wq->to_use_index++);
57 wq->ring.desc_avail--;
58
59 /* Adding write memory barrier prevents compiler and/or CPU
60 * reordering, thus avoiding descriptor posting before
61 * descriptor is initialized. Otherwise, hardware can read
62 * stale descriptor fields.
63 */
64 wmb();
65
66 iowrite32(wq->to_use_index, &wq->ctrl->posted_index);
67 }
68
vnic_wq_copy_desc_process(struct vnic_wq_copy * wq,u16 index)69 static inline void vnic_wq_copy_desc_process(struct vnic_wq_copy *wq, u16 index)
70 {
71 unsigned int cnt;
72
73 if (wq->to_clean_index <= index)
74 cnt = (index - wq->to_clean_index) + 1;
75 else
76 cnt = wq->ring.desc_count - wq->to_clean_index + index + 1;
77
78 wq->to_clean_index = ((index + 1) % wq->ring.desc_count);
79 wq->ring.desc_avail += cnt;
80
81 }
82
vnic_wq_copy_service(struct vnic_wq_copy * wq,u16 completed_index,void (* q_service)(struct vnic_wq_copy * wq,struct fcpio_host_req * wq_desc))83 static inline void vnic_wq_copy_service(struct vnic_wq_copy *wq,
84 u16 completed_index,
85 void (*q_service)(struct vnic_wq_copy *wq,
86 struct fcpio_host_req *wq_desc))
87 {
88 struct fcpio_host_req *wq_desc = wq->ring.descs;
89 unsigned int curr_index;
90
91 while (1) {
92
93 if (q_service)
94 (*q_service)(wq, &wq_desc[wq->to_clean_index]);
95
96 wq->ring.desc_avail++;
97
98 curr_index = wq->to_clean_index;
99
100 /* increment the to-clean index so that we start
101 * with an unprocessed index next time we enter the loop
102 */
103 ((wq->to_clean_index + 1) == wq->ring.desc_count) ?
104 (wq->to_clean_index = 0) : (wq->to_clean_index++);
105
106 if (curr_index == completed_index)
107 break;
108
109 /* we have cleaned all the entries */
110 if ((completed_index == (u16)-1) &&
111 (wq->to_clean_index == wq->to_use_index))
112 break;
113 }
114 }
115
116 void vnic_wq_copy_enable(struct vnic_wq_copy *wq);
117 int vnic_wq_copy_disable(struct vnic_wq_copy *wq);
118 void vnic_wq_copy_free(struct vnic_wq_copy *wq);
119 int vnic_wq_copy_alloc(struct vnic_dev *vdev, struct vnic_wq_copy *wq,
120 unsigned int index, unsigned int desc_count, unsigned int desc_size);
121 void vnic_wq_copy_init(struct vnic_wq_copy *wq, unsigned int cq_index,
122 unsigned int error_interrupt_enable,
123 unsigned int error_interrupt_offset);
124 void vnic_wq_copy_clean(struct vnic_wq_copy *wq,
125 void (*q_clean)(struct vnic_wq_copy *wq,
126 struct fcpio_host_req *wq_desc));
127
128 #endif /* _VNIC_WQ_COPY_H_ */
129