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 #include <linux/kernel.h>
21 #include <linux/errno.h>
22 #include <linux/types.h>
23 #include <linux/pci.h>
24 #include <linux/delay.h>
25 #include <linux/slab.h>
26 
27 #include "vnic_dev.h"
28 #include "vnic_rq.h"
29 
30 static int vnic_rq_alloc_bufs(struct vnic_rq *rq)
31 {
32 	struct vnic_rq_buf *buf;
33 	struct vnic_dev *vdev;
34 	unsigned int i, j, count = rq->ring.desc_count;
35 	unsigned int blks = VNIC_RQ_BUF_BLKS_NEEDED(count);
36 
37 	vdev = rq->vdev;
38 
39 	for (i = 0; i < blks; i++) {
40 		rq->bufs[i] = kzalloc(VNIC_RQ_BUF_BLK_SZ(count), GFP_ATOMIC);
41 		if (!rq->bufs[i])
42 			return -ENOMEM;
43 	}
44 
45 	for (i = 0; i < blks; i++) {
46 		buf = rq->bufs[i];
47 		for (j = 0; j < VNIC_RQ_BUF_BLK_ENTRIES(count); j++) {
48 			buf->index = i * VNIC_RQ_BUF_BLK_ENTRIES(count) + j;
49 			buf->desc = (u8 *)rq->ring.descs +
50 				rq->ring.desc_size * buf->index;
51 			if (buf->index + 1 == count) {
52 				buf->next = rq->bufs[0];
53 				break;
54 			} else if (j + 1 == VNIC_RQ_BUF_BLK_ENTRIES(count)) {
55 				buf->next = rq->bufs[i + 1];
56 			} else {
57 				buf->next = buf + 1;
58 				buf++;
59 			}
60 		}
61 	}
62 
63 	rq->to_use = rq->to_clean = rq->bufs[0];
64 
65 	return 0;
66 }
67 
68 void vnic_rq_free(struct vnic_rq *rq)
69 {
70 	struct vnic_dev *vdev;
71 	unsigned int i;
72 
73 	vdev = rq->vdev;
74 
75 	vnic_dev_free_desc_ring(vdev, &rq->ring);
76 
77 	for (i = 0; i < VNIC_RQ_BUF_BLKS_MAX; i++) {
78 		if (rq->bufs[i]) {
79 			kfree(rq->bufs[i]);
80 			rq->bufs[i] = NULL;
81 		}
82 	}
83 
84 	rq->ctrl = NULL;
85 }
86 
87 int vnic_rq_alloc(struct vnic_dev *vdev, struct vnic_rq *rq, unsigned int index,
88 	unsigned int desc_count, unsigned int desc_size)
89 {
90 	int err;
91 
92 	rq->index = index;
93 	rq->vdev = vdev;
94 
95 	rq->ctrl = vnic_dev_get_res(vdev, RES_TYPE_RQ, index);
96 	if (!rq->ctrl) {
97 		pr_err("Failed to hook RQ[%d] resource\n", index);
98 		return -EINVAL;
99 	}
100 
101 	vnic_rq_disable(rq);
102 
103 	err = vnic_dev_alloc_desc_ring(vdev, &rq->ring, desc_count, desc_size);
104 	if (err)
105 		return err;
106 
107 	err = vnic_rq_alloc_bufs(rq);
108 	if (err) {
109 		vnic_rq_free(rq);
110 		return err;
111 	}
112 
113 	return 0;
114 }
115 
116 static void vnic_rq_init_start(struct vnic_rq *rq, unsigned int cq_index,
117 	unsigned int fetch_index, unsigned int posted_index,
118 	unsigned int error_interrupt_enable,
119 	unsigned int error_interrupt_offset)
120 {
121 	u64 paddr;
122 	unsigned int count = rq->ring.desc_count;
123 
124 	paddr = (u64)rq->ring.base_addr | VNIC_PADDR_TARGET;
125 	writeq(paddr, &rq->ctrl->ring_base);
126 	iowrite32(count, &rq->ctrl->ring_size);
127 	iowrite32(cq_index, &rq->ctrl->cq_index);
128 	iowrite32(error_interrupt_enable, &rq->ctrl->error_interrupt_enable);
129 	iowrite32(error_interrupt_offset, &rq->ctrl->error_interrupt_offset);
130 	iowrite32(0, &rq->ctrl->dropped_packet_count);
131 	iowrite32(0, &rq->ctrl->error_status);
132 	iowrite32(fetch_index, &rq->ctrl->fetch_index);
133 	iowrite32(posted_index, &rq->ctrl->posted_index);
134 
135 	rq->to_use = rq->to_clean =
136 		&rq->bufs[fetch_index / VNIC_RQ_BUF_BLK_ENTRIES(count)]
137 			[fetch_index % VNIC_RQ_BUF_BLK_ENTRIES(count)];
138 }
139 
140 void vnic_rq_init(struct vnic_rq *rq, unsigned int cq_index,
141 	unsigned int error_interrupt_enable,
142 	unsigned int error_interrupt_offset)
143 {
144 	u32 fetch_index;
145 
146 	/* Use current fetch_index as the ring starting point */
147 	fetch_index = ioread32(&rq->ctrl->fetch_index);
148 
149 	if (fetch_index == 0xFFFFFFFF) { /* check for hardware gone  */
150 		/* Hardware surprise removal: reset fetch_index */
151 		fetch_index = 0;
152 	}
153 
154 	vnic_rq_init_start(rq, cq_index,
155 		fetch_index, fetch_index,
156 		error_interrupt_enable,
157 		error_interrupt_offset);
158 }
159 
160 unsigned int vnic_rq_error_status(struct vnic_rq *rq)
161 {
162 	return ioread32(&rq->ctrl->error_status);
163 }
164 
165 void vnic_rq_enable(struct vnic_rq *rq)
166 {
167 	iowrite32(1, &rq->ctrl->enable);
168 }
169 
170 int vnic_rq_disable(struct vnic_rq *rq)
171 {
172 	unsigned int wait;
173 
174 	iowrite32(0, &rq->ctrl->enable);
175 
176 	/* Wait for HW to ACK disable request */
177 	for (wait = 0; wait < 1000; wait++) {
178 		if (!(ioread32(&rq->ctrl->running)))
179 			return 0;
180 		udelay(10);
181 	}
182 
183 	pr_err("Failed to disable RQ[%d]\n", rq->index);
184 
185 	return -ETIMEDOUT;
186 }
187 
188 void vnic_rq_clean(struct vnic_rq *rq,
189 	void (*buf_clean)(struct vnic_rq *rq, struct vnic_rq_buf *buf))
190 {
191 	struct vnic_rq_buf *buf;
192 	u32 fetch_index;
193 	unsigned int count = rq->ring.desc_count;
194 
195 	buf = rq->to_clean;
196 
197 	while (vnic_rq_desc_used(rq) > 0) {
198 
199 		(*buf_clean)(rq, buf);
200 
201 		buf = rq->to_clean = buf->next;
202 		rq->ring.desc_avail++;
203 	}
204 
205 	/* Use current fetch_index as the ring starting point */
206 	fetch_index = ioread32(&rq->ctrl->fetch_index);
207 
208 	if (fetch_index == 0xFFFFFFFF) { /* check for hardware gone  */
209 		/* Hardware surprise removal: reset fetch_index */
210 		fetch_index = 0;
211 	}
212 	rq->to_use = rq->to_clean =
213 		&rq->bufs[fetch_index / VNIC_RQ_BUF_BLK_ENTRIES(count)]
214 			[fetch_index % VNIC_RQ_BUF_BLK_ENTRIES(count)];
215 	iowrite32(fetch_index, &rq->ctrl->posted_index);
216 
217 	vnic_dev_clear_desc_ring(&rq->ring);
218 }
219 
220