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