xref: /openbmc/linux/drivers/scsi/fnic/vnic_rq.c (revision 842ed298)
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 
27 static 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 
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 		kfree(rq->bufs[i]);
76 		rq->bufs[i] = NULL;
77 	}
78 
79 	rq->ctrl = NULL;
80 }
81 
82 int 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 
111 void 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 
137 unsigned int vnic_rq_error_status(struct vnic_rq *rq)
138 {
139 	return ioread32(&rq->ctrl->error_status);
140 }
141 
142 void vnic_rq_enable(struct vnic_rq *rq)
143 {
144 	iowrite32(1, &rq->ctrl->enable);
145 }
146 
147 int 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 
165 void 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