xref: /openbmc/linux/drivers/scsi/snic/vnic_wq.h (revision d9fd5a71)
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 */
26 struct 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 
50 struct 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 
74 struct 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 
85 static 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 
91 static 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 
97 static inline void *svnic_wq_next_desc(struct vnic_wq *wq)
98 {
99 	return wq->to_use->desc;
100 }
101 
102 static 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 
128 static 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 
152 void svnic_wq_free(struct vnic_wq *wq);
153 int svnic_wq_alloc(struct vnic_dev *vdev, struct vnic_wq *wq,
154 	unsigned int index, unsigned int desc_count, unsigned int desc_size);
155 int vnic_wq_devcmd2_alloc(struct vnic_dev *vdev, struct vnic_wq *wq,
156 		unsigned int desc_count, unsigned int desc_size);
157 void 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 
162 void svnic_wq_init(struct vnic_wq *wq, unsigned int cq_index,
163 	unsigned int error_interrupt_enable,
164 	unsigned int error_interrupt_offset);
165 unsigned int svnic_wq_error_status(struct vnic_wq *wq);
166 void svnic_wq_enable(struct vnic_wq *wq);
167 int svnic_wq_disable(struct vnic_wq *wq);
168 void 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