xref: /linux/drivers/scsi/snic/vnic_wq.h (revision 1a2ac6d7ecdcde74a4e16f31de64124160fc7237)
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_ */
157