1/*
2 * Copyright 2008 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#include <linux/errno.h>
20#include <linux/types.h>
21#include <linux/pci.h>
22#include <linux/delay.h>
23#include <linux/slab.h>
24#include "vnic_dev.h"
25#include "vnic_rq.h"
26
27static int vnic_rq_alloc_bufs(struct vnic_rq *rq)
28{
29	struct vnic_rq_buf *buf;
30	unsigned int i, j, count = rq->ring.desc_count;
31	unsigned int blks = VNIC_RQ_BUF_BLKS_NEEDED(count);
32
33	for (i = 0; i < blks; i++) {
34		rq->bufs[i] = kzalloc(VNIC_RQ_BUF_BLK_SZ, GFP_ATOMIC);
35		if (!rq->bufs[i]) {
36			printk(KERN_ERR "Failed to alloc rq_bufs\n");
37			return -ENOMEM;
38		}
39	}
40
41	for (i = 0; i < blks; i++) {
42		buf = rq->bufs[i];
43		for (j = 0; j < VNIC_RQ_BUF_BLK_ENTRIES; j++) {
44			buf->index = i * VNIC_RQ_BUF_BLK_ENTRIES + j;
45			buf->desc = (u8 *)rq->ring.descs +
46				rq->ring.desc_size * buf->index;
47			if (buf->index + 1 == count) {
48				buf->next = rq->bufs[0];
49				break;
50			} else if (j + 1 == VNIC_RQ_BUF_BLK_ENTRIES) {
51				buf->next = rq->bufs[i + 1];
52			} else {
53				buf->next = buf + 1;
54				buf++;
55			}
56		}
57	}
58
59	rq->to_use = rq->to_clean = rq->bufs[0];
60	rq->buf_index = 0;
61
62	return 0;
63}
64
65void vnic_rq_free(struct vnic_rq *rq)
66{
67	struct vnic_dev *vdev;
68	unsigned int i;
69
70	vdev = rq->vdev;
71
72	vnic_dev_free_desc_ring(vdev, &rq->ring);
73
74	for (i = 0; i < VNIC_RQ_BUF_BLKS_MAX; i++) {
75		kfree(rq->bufs[i]);
76		rq->bufs[i] = NULL;
77	}
78
79	rq->ctrl = NULL;
80}
81
82int vnic_rq_alloc(struct vnic_dev *vdev, struct vnic_rq *rq, unsigned int index,
83	unsigned int desc_count, unsigned int desc_size)
84{
85	int err;
86
87	rq->index = index;
88	rq->vdev = vdev;
89
90	rq->ctrl = vnic_dev_get_res(vdev, RES_TYPE_RQ, index);
91	if (!rq->ctrl) {
92		printk(KERN_ERR "Failed to hook RQ[%d] resource\n", index);
93		return -EINVAL;
94	}
95
96	vnic_rq_disable(rq);
97
98	err = vnic_dev_alloc_desc_ring(vdev, &rq->ring, desc_count, desc_size);
99	if (err)
100		return err;
101
102	err = vnic_rq_alloc_bufs(rq);
103	if (err) {
104		vnic_rq_free(rq);
105		return err;
106	}
107
108	return 0;
109}
110
111void vnic_rq_init(struct vnic_rq *rq, unsigned int cq_index,
112	unsigned int error_interrupt_enable,
113	unsigned int error_interrupt_offset)
114{
115	u64 paddr;
116	u32 fetch_index;
117
118	paddr = (u64)rq->ring.base_addr | VNIC_PADDR_TARGET;
119	writeq(paddr, &rq->ctrl->ring_base);
120	iowrite32(rq->ring.desc_count, &rq->ctrl->ring_size);
121	iowrite32(cq_index, &rq->ctrl->cq_index);
122	iowrite32(error_interrupt_enable, &rq->ctrl->error_interrupt_enable);
123	iowrite32(error_interrupt_offset, &rq->ctrl->error_interrupt_offset);
124	iowrite32(0, &rq->ctrl->dropped_packet_count);
125	iowrite32(0, &rq->ctrl->error_status);
126
127	/* Use current fetch_index as the ring starting point */
128	fetch_index = ioread32(&rq->ctrl->fetch_index);
129	rq->to_use = rq->to_clean =
130		&rq->bufs[fetch_index / VNIC_RQ_BUF_BLK_ENTRIES]
131			[fetch_index % VNIC_RQ_BUF_BLK_ENTRIES];
132	iowrite32(fetch_index, &rq->ctrl->posted_index);
133
134	rq->buf_index = 0;
135}
136
137unsigned int vnic_rq_error_status(struct vnic_rq *rq)
138{
139	return ioread32(&rq->ctrl->error_status);
140}
141
142void vnic_rq_enable(struct vnic_rq *rq)
143{
144	iowrite32(1, &rq->ctrl->enable);
145}
146
147int vnic_rq_disable(struct vnic_rq *rq)
148{
149	unsigned int wait;
150
151	iowrite32(0, &rq->ctrl->enable);
152
153	/* Wait for HW to ACK disable request */
154	for (wait = 0; wait < 100; wait++) {
155		if (!(ioread32(&rq->ctrl->running)))
156			return 0;
157		udelay(1);
158	}
159
160	printk(KERN_ERR "Failed to disable RQ[%d]\n", rq->index);
161
162	return -ETIMEDOUT;
163}
164
165void vnic_rq_clean(struct vnic_rq *rq,
166	void (*buf_clean)(struct vnic_rq *rq, struct vnic_rq_buf *buf))
167{
168	struct vnic_rq_buf *buf;
169	u32 fetch_index;
170
171	WARN_ON(ioread32(&rq->ctrl->enable));
172
173	buf = rq->to_clean;
174
175	while (vnic_rq_desc_used(rq) > 0) {
176
177		(*buf_clean)(rq, buf);
178
179		buf = rq->to_clean = buf->next;
180		rq->ring.desc_avail++;
181	}
182
183	/* Use current fetch_index as the ring starting point */
184	fetch_index = ioread32(&rq->ctrl->fetch_index);
185	rq->to_use = rq->to_clean =
186		&rq->bufs[fetch_index / VNIC_RQ_BUF_BLK_ENTRIES]
187			[fetch_index % VNIC_RQ_BUF_BLK_ENTRIES];
188	iowrite32(fetch_index, &rq->ctrl->posted_index);
189
190	rq->buf_index = 0;
191
192	vnic_dev_clear_desc_ring(&rq->ring);
193}
194
195