1 /******************************************************************************
2 * Copyright (c) 2012 IBM Corporation
4 * This program and the accompanying materials
5 * are made available under the terms of the BSD License
6 * which accompanies this distribution, and is available at
7 * http://www.opensource.org/licenses/bsd-license.php
10 * IBM Corporation - initial implementation
11 *****************************************************************************/
18 #include "virtio-internal.h"
19 #include "virtio-scsi.h"
21 int virtioscsi_send(struct virtio_device *dev,
22 struct virtio_scsi_req_cmd *req,
23 struct virtio_scsi_resp_cmd *resp,
24 int is_read, void *buf, uint64_t buf_len)
26 struct vring_desc *vq_desc; /* Descriptor vring */
27 struct vring_avail *vq_avail; /* "Available" vring */
28 struct vring_used *vq_used; /* "Used" vring */
30 volatile uint16_t *current_used_idx;
31 uint16_t last_used_idx, avail_idx;
33 uint32_t vq_size, time;
35 int vq = VIRTIO_SCSI_REQUEST_VQ;
37 vq_size = virtio_get_qsize(dev, vq);
38 vq_desc = virtio_get_vring_desc(dev, vq);
39 vq_avail = virtio_get_vring_avail(dev, vq);
40 vq_used = virtio_get_vring_used(dev, vq);
42 avail_idx = virtio_modern16_to_cpu(dev, vq_avail->idx);
44 last_used_idx = vq_used->idx;
45 current_used_idx = &vq_used->idx;
47 /* Determine descriptor index */
48 id = (avail_idx * 3) % vq_size;
49 virtio_fill_desc(&vq_desc[id], dev->is_modern, (uint64_t)req, sizeof(*req), VRING_DESC_F_NEXT,
52 /* Set up virtqueue descriptor for data */
54 virtio_fill_desc(&vq_desc[(id + 1) % vq_size], dev->is_modern,
55 (uint64_t)resp, sizeof(*resp),
56 VRING_DESC_F_NEXT | VRING_DESC_F_WRITE,
58 /* Set up virtqueue descriptor for status */
59 virtio_fill_desc(&vq_desc[(id + 2) % vq_size], dev->is_modern,
60 (uint64_t)buf, buf_len,
61 (is_read ? VRING_DESC_F_WRITE : 0), 0);
63 virtio_fill_desc(&vq_desc[(id + 1) % vq_size], dev->is_modern,
64 (uint64_t)resp, sizeof(*resp),
65 VRING_DESC_F_WRITE, 0);
68 vq_avail->ring[avail_idx % vq_size] = virtio_cpu_to_modern16(dev, id);
70 vq_avail->idx = virtio_cpu_to_modern16(dev, avail_idx + 1);
72 /* Tell HV that the vq is ready */
73 virtio_queue_notify(dev, vq);
75 /* Wait for host to consume the descriptor */
76 time = SLOF_GetTimer() + VIRTIO_TIMEOUT;
77 while (*current_used_idx == last_used_idx) {
78 // do something better
80 if (time < SLOF_GetTimer())
88 * Initialize virtio-block device.
89 * @param dev pointer to virtio device information
91 int virtioscsi_init(struct virtio_device *dev)
93 struct vring_avail *vq_avail;
96 int status = VIRTIO_STAT_ACKNOWLEDGE;
99 // XXX That will clear the virtq base. We need to move
100 // initializing it to here anyway
102 // virtio_reset_device(dev);
104 /* Acknowledge device. */
105 virtio_set_status(dev, status);
107 /* Tell HV that we know how to drive the device. */
108 status |= VIRTIO_STAT_DRIVER;
109 virtio_set_status(dev, status);
111 /* Device specific setup - we do not support special features right now */
112 if (dev->is_modern) {
113 if (virtio_negotiate_guest_features(dev, VIRTIO_F_VERSION_1))
115 virtio_get_status(dev, &status);
117 virtio_set_guest_features(dev, 0);
121 qsize = virtio_get_qsize(dev, idx);
124 virtio_vring_size(qsize);
126 vq_avail = virtio_get_vring_avail(dev, idx);
127 vq_avail->flags = virtio_cpu_to_modern16(dev, VRING_AVAIL_F_NO_INTERRUPT);
132 /* Tell HV that setup succeeded */
133 status |= VIRTIO_STAT_DRIVER_OK;
134 virtio_set_status(dev, status);
138 printf("%s: failed\n", __func__);
139 status |= VIRTIO_STAT_FAILED;
140 virtio_set_status(dev, status);
145 * Shutdown the virtio-block device.
146 * @param dev pointer to virtio device information
148 void virtioscsi_shutdown(struct virtio_device *dev)
151 virtio_set_status(dev, VIRTIO_STAT_FAILED);
154 virtio_reset_device(dev);