aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/net/enic/vnic_rq.h
blob: 37f08de2454ada35c39ae681b04e10a607d11633 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
/*
 * Copyright 2008-2010 Cisco Systems, Inc.  All rights reserved.
 * Copyright 2007 Nuova Systems, Inc.  All rights reserved.
 *
 * This program is free software; you may redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 */

#ifndef _VNIC_RQ_H_
#define _VNIC_RQ_H_

#include <linux/pci.h>

#include "vnic_dev.h"
#include "vnic_cq.h"

/* Receive queue control */
struct vnic_rq_ctrl {
	u64 ring_base;			/* 0x00 */
	u32 ring_size;			/* 0x08 */
	u32 pad0;
	u32 posted_index;		/* 0x10 */
	u32 pad1;
	u32 cq_index;			/* 0x18 */
	u32 pad2;
	u32 enable;			/* 0x20 */
	u32 pad3;
	u32 running;			/* 0x28 */
	u32 pad4;
	u32 fetch_index;		/* 0x30 */
	u32 pad5;
	u32 error_interrupt_enable;	/* 0x38 */
	u32 pad6;
	u32 error_interrupt_offset;	/* 0x40 */
	u32 pad7;
	u32 error_status;		/* 0x48 */
	u32 pad8;
	u32 dropped_packet_count;	/* 0x50 */
	u32 pad9;
	u32 dropped_packet_count_rc;	/* 0x58 */
	u32 pad10;
};

/* Break the vnic_rq_buf allocations into blocks of 32/64 entries */
#define VNIC_RQ_BUF_MIN_BLK_ENTRIES 32
#define VNIC_RQ_BUF_DFLT_BLK_ENTRIES 64
#define VNIC_RQ_BUF_BLK_ENTRIES(entries) \
	((unsigned int)((entries < VNIC_RQ_BUF_DFLT_BLK_ENTRIES) ? \
	VNIC_RQ_BUF_MIN_BLK_ENTRIES : VNIC_RQ_BUF_DFLT_BLK_ENTRIES))
#define VNIC_RQ_BUF_BLK_SZ(entries) \
	(VNIC_RQ_BUF_BLK_ENTRIES(entries) * sizeof(struct vnic_rq_buf))
#define VNIC_RQ_BUF_BLKS_NEEDED(entries) \
	DIV_ROUND_UP(entries, VNIC_RQ_BUF_BLK_ENTRIES(entries))
#define VNIC_RQ_BUF_BLKS_MAX VNIC_RQ_BUF_BLKS_NEEDED(4096)

struct vnic_rq_buf {
	struct vnic_rq_buf *next;
	dma_addr_t dma_addr;
	void *os_buf;
	unsigned int os_buf_index;
	unsigned int len;
	unsigned int index;
	void *desc;
};

struct vnic_rq {
	unsigned int index;
	struct vnic_dev *vdev;
	struct vnic_rq_ctrl __iomem *ctrl;              /* memory-mapped */
	struct vnic_dev_ring ring;
	struct vnic_rq_buf *bufs[VNIC_RQ_BUF_BLKS_MAX];
	struct vnic_rq_buf *to_use;
	struct vnic_rq_buf *to_clean;
	void *os_buf_head;
	unsigned int pkts_outstanding;
};

static inline unsigned int vnic_rq_desc_avail(struct vnic_rq *rq)
{
	/* how many does SW own? */
	return rq->ring.desc_avail;
}

static inline unsigned int vnic_rq_desc_used(struct vnic_rq *rq)
{
	/* how many does HW own? */
	return rq->ring.desc_count - rq->ring.desc_avail - 1;
}

static inline void *vnic_rq_next_desc(struct vnic_rq *rq)
{
	return rq->to_use->desc;
}

static inline unsigned int vnic_rq_next_index(struct vnic_rq *rq)
{
	return rq->to_use->index;
}

static inline void vnic_rq_post(struct vnic_rq *rq,
	void *os_buf, unsigned int os_buf_index,
	dma_addr_t dma_addr, unsigned int len)
{
	struct vnic_rq_buf *buf = rq->to_use;

	buf->os_buf = os_buf;
	buf->os_buf_index = os_buf_index;
	buf->dma_addr = dma_addr;
	buf->len = len;

	buf = buf->next;
	rq->to_use = buf;
	rq->ring.desc_avail--;

	/* Move the posted_index every nth descriptor
	 */

#ifndef VNIC_RQ_RETURN_RATE
#define VNIC_RQ_RETURN_RATE		0xf	/* keep 2^n - 1 */
#endif

	if ((buf->index & VNIC_RQ_RETURN_RATE) == 0) {
		/* Adding write memory barrier prevents compiler and/or CPU
		 * reordering, thus avoiding descriptor posting before
		 * descriptor is initialized. Otherwise, hardware can read
		 * stale descriptor fields.
		 */
		wmb();
		iowrite32(buf->index, &rq->ctrl->posted_index);
	}
}

static inline int vnic_rq_posting_soon(struct vnic_rq *rq)
{
	return (rq->to_use->index & VNIC_RQ_RETURN_RATE) == 0;
}

static inline void vnic_rq_return_descs(struct vnic_rq *rq, unsigned int count)
{
	rq->ring.desc_avail += count;
}

enum desc_return_options {
	VNIC_RQ_RETURN_DESC,
	VNIC_RQ_DEFER_RETURN_DESC,
};

static inline void vnic_rq_service(struct vnic_rq *rq,
	struct cq_desc *cq_desc, u16 completed_index,
	int desc_return, void (*buf_service)(struct vnic_rq *rq,
	struct cq_desc *cq_desc, struct vnic_rq_buf *buf,
	int skipped, void *opaque), void *opaque)
{
	struct vnic_rq_buf *buf;
	int skipped;

	buf = rq->to_clean;
	while (1) {

		skipped = (buf->index != completed_index);

		(*buf_service)(rq, cq_desc, buf, skipped, opaque);

		if (desc_return == VNIC_RQ_RETURN_DESC)
			rq->ring.desc_avail++;

		rq->to_clean = buf->next;

		if (!skipped)
			break;

		buf = rq->to_clean;
	}
}

static inline int vnic_rq_fill(struct vnic_rq *rq,
	int (*buf_fill)(struct vnic_rq *rq))
{
	int err;

	while (vnic_rq_desc_avail(rq) > 0) {

		err = (*buf_fill)(rq);
		if (err)
			return err;
	}

	return 0;
}

void vnic_rq_free(struct vnic_rq *rq);
int vnic_rq_alloc(struct vnic_dev *vdev, struct vnic_rq *rq, unsigned int index,
	unsigned int desc_count, unsigned int desc_size);
void vnic_rq_init(struct vnic_rq *rq, unsigned int cq_index,
	unsigned int error_interrupt_enable,
	unsigned int error_interrupt_offset);
unsigned int vnic_rq_error_status(struct vnic_rq *rq);
void vnic_rq_enable(struct vnic_rq *rq);
int vnic_rq_disable(struct vnic_rq *rq);
void vnic_rq_clean(struct vnic_rq *rq,
	void (*buf_clean)(struct vnic_rq *rq, struct vnic_rq_buf *buf));

#endif /* _VNIC_RQ_H_ */