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