1 /*
2  * Copyright 2008-2010 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  */
19 
20 #ifndef _VNIC_WQ_H_
21 #define _VNIC_WQ_H_
22 
23 #include <linux/pci.h>
24 
25 #include "vnic_dev.h"
26 #include "vnic_cq.h"
27 
28 /* Work queue control */
29 struct vnic_wq_ctrl {
30 	u64 ring_base;			/* 0x00 */
31 	u32 ring_size;			/* 0x08 */
32 	u32 pad0;
33 	u32 posted_index;		/* 0x10 */
34 	u32 pad1;
35 	u32 cq_index;			/* 0x18 */
36 	u32 pad2;
37 	u32 enable;			/* 0x20 */
38 	u32 pad3;
39 	u32 running;			/* 0x28 */
40 	u32 pad4;
41 	u32 fetch_index;		/* 0x30 */
42 	u32 pad5;
43 	u32 dca_value;			/* 0x38 */
44 	u32 pad6;
45 	u32 error_interrupt_enable;	/* 0x40 */
46 	u32 pad7;
47 	u32 error_interrupt_offset;	/* 0x48 */
48 	u32 pad8;
49 	u32 error_status;		/* 0x50 */
50 	u32 pad9;
51 };
52 
53 struct vnic_wq_buf {
54 	struct vnic_wq_buf *next;
55 	dma_addr_t dma_addr;
56 	void *os_buf;
57 	unsigned int len;
58 	unsigned int index;
59 	int sop;
60 	void *desc;
61 	uint64_t wr_id; /* Cookie */
62 	uint8_t cq_entry; /* Gets completion event from hw */
63 	uint8_t desc_skip_cnt; /* Num descs to occupy */
64 	uint8_t compressed_send; /* Both hdr and payload in one desc */
65 };
66 
67 /* Break the vnic_wq_buf allocations into blocks of 32/64 entries */
68 #define VNIC_WQ_BUF_MIN_BLK_ENTRIES 32
69 #define VNIC_WQ_BUF_DFLT_BLK_ENTRIES 64
70 #define VNIC_WQ_BUF_BLK_ENTRIES(entries) \
71 	((unsigned int)((entries < VNIC_WQ_BUF_DFLT_BLK_ENTRIES) ? \
72 	VNIC_WQ_BUF_MIN_BLK_ENTRIES : VNIC_WQ_BUF_DFLT_BLK_ENTRIES))
73 #define VNIC_WQ_BUF_BLK_SZ(entries) \
74 	(VNIC_WQ_BUF_BLK_ENTRIES(entries) * sizeof(struct vnic_wq_buf))
75 #define VNIC_WQ_BUF_BLKS_NEEDED(entries) \
76 	DIV_ROUND_UP(entries, VNIC_WQ_BUF_BLK_ENTRIES(entries))
77 #define VNIC_WQ_BUF_BLKS_MAX VNIC_WQ_BUF_BLKS_NEEDED(4096)
78 
79 struct vnic_wq {
80 	unsigned int index;
81 	struct vnic_dev *vdev;
82 	struct vnic_wq_ctrl __iomem *ctrl;              /* memory-mapped */
83 	struct vnic_dev_ring ring;
84 	struct vnic_wq_buf *bufs[VNIC_WQ_BUF_BLKS_MAX];
85 	struct vnic_wq_buf *to_use;
86 	struct vnic_wq_buf *to_clean;
87 	unsigned int pkts_outstanding;
88 };
89 
90 static inline unsigned int vnic_wq_desc_avail(struct vnic_wq *wq)
91 {
92 	/* how many does SW own? */
93 	return wq->ring.desc_avail;
94 }
95 
96 static inline unsigned int vnic_wq_desc_used(struct vnic_wq *wq)
97 {
98 	/* how many does HW own? */
99 	return wq->ring.desc_count - wq->ring.desc_avail - 1;
100 }
101 
102 static inline void *vnic_wq_next_desc(struct vnic_wq *wq)
103 {
104 	return wq->to_use->desc;
105 }
106 
107 static inline void vnic_wq_post(struct vnic_wq *wq,
108 	void *os_buf, dma_addr_t dma_addr,
109 	unsigned int len, int sop, int eop,
110 	uint8_t desc_skip_cnt, uint8_t cq_entry,
111 	uint8_t compressed_send, uint64_t wrid)
112 {
113 	struct vnic_wq_buf *buf = wq->to_use;
114 
115 	buf->sop = sop;
116 	buf->cq_entry = cq_entry;
117 	buf->compressed_send = compressed_send;
118 	buf->desc_skip_cnt = desc_skip_cnt;
119 	buf->os_buf = eop ? os_buf : NULL;
120 	buf->dma_addr = dma_addr;
121 	buf->len = len;
122 	buf->wr_id = wrid;
123 
124 	buf = buf->next;
125 	if (eop) {
126 		/* Adding write memory barrier prevents compiler and/or CPU
127 		 * reordering, thus avoiding descriptor posting before
128 		 * descriptor is initialized. Otherwise, hardware can read
129 		 * stale descriptor fields.
130 		 */
131 		wmb();
132 		iowrite32(buf->index, &wq->ctrl->posted_index);
133 	}
134 	wq->to_use = buf;
135 
136 	wq->ring.desc_avail -= desc_skip_cnt;
137 }
138 
139 static inline void vnic_wq_service(struct vnic_wq *wq,
140 	struct cq_desc *cq_desc, u16 completed_index,
141 	void (*buf_service)(struct vnic_wq *wq,
142 	struct cq_desc *cq_desc, struct vnic_wq_buf *buf, void *opaque),
143 	void *opaque)
144 {
145 	struct vnic_wq_buf *buf;
146 
147 	buf = wq->to_clean;
148 	while (1) {
149 
150 		(*buf_service)(wq, cq_desc, buf, opaque);
151 
152 		wq->ring.desc_avail++;
153 
154 		wq->to_clean = buf->next;
155 
156 		if (buf->index == completed_index)
157 			break;
158 
159 		buf = wq->to_clean;
160 	}
161 }
162 
163 void vnic_wq_free(struct vnic_wq *wq);
164 int vnic_wq_alloc(struct vnic_dev *vdev, struct vnic_wq *wq, unsigned int index,
165 	unsigned int desc_count, unsigned int desc_size);
166 void vnic_wq_init(struct vnic_wq *wq, unsigned int cq_index,
167 	unsigned int error_interrupt_enable,
168 	unsigned int error_interrupt_offset);
169 unsigned int vnic_wq_error_status(struct vnic_wq *wq);
170 void vnic_wq_enable(struct vnic_wq *wq);
171 int vnic_wq_disable(struct vnic_wq *wq);
172 void vnic_wq_clean(struct vnic_wq *wq,
173 	void (*buf_clean)(struct vnic_wq *wq, struct vnic_wq_buf *buf));
174 
175 #endif /* _VNIC_WQ_H_ */
176