| /****************************************************************************** |
| * Copyright (c) 2012 IBM Corporation |
| * All rights reserved. |
| * This program and the accompanying materials |
| * are made available under the terms of the BSD License |
| * which accompanies this distribution, and is available at |
| * http://www.opensource.org/licenses/bsd-license.php |
| * |
| * Contributors: |
| * IBM Corporation - initial implementation |
| *****************************************************************************/ |
| |
| #include <stdio.h> |
| #include <string.h> |
| #include <cpu.h> |
| #include <helpers.h> |
| #include "virtio.h" |
| #include "virtio-internal.h" |
| #include "virtio-scsi.h" |
| |
| int virtioscsi_send(struct virtio_device *dev, |
| struct virtio_scsi_req_cmd *req, |
| struct virtio_scsi_resp_cmd *resp, |
| int is_read, void *buf, uint64_t buf_len) |
| { |
| |
| volatile uint16_t *current_used_idx; |
| uint16_t last_used_idx, avail_idx; |
| int id; |
| uint32_t time; |
| struct vqs *vq = &dev->vq[VIRTIO_SCSI_REQUEST_VQ]; |
| |
| avail_idx = virtio_modern16_to_cpu(dev, vq->avail->idx); |
| |
| last_used_idx = vq->used->idx; |
| current_used_idx = &vq->used->idx; |
| |
| /* Determine descriptor index */ |
| id = (avail_idx * 3) % vq->size; |
| virtio_fill_desc(vq, id, dev->features, (uint64_t)req, sizeof(*req), VRING_DESC_F_NEXT, |
| id + 1); |
| |
| if (buf == NULL || buf_len == 0) { |
| /* Set up descriptor for response information */ |
| virtio_fill_desc(vq, id + 1, dev->features, |
| (uint64_t)resp, sizeof(*resp), |
| VRING_DESC_F_WRITE, 0); |
| } else if (is_read) { |
| /* Set up descriptor for response information */ |
| virtio_fill_desc(vq, id + 1, dev->features, |
| (uint64_t)resp, sizeof(*resp), |
| VRING_DESC_F_NEXT | VRING_DESC_F_WRITE, |
| id + 2); |
| /* Set up virtqueue descriptor for data from device */ |
| virtio_fill_desc(vq, id + 2, dev->features, |
| (uint64_t)buf, buf_len, VRING_DESC_F_WRITE, 0); |
| } else { |
| /* Set up virtqueue descriptor for data to device */ |
| virtio_fill_desc(vq, id + 1, dev->features, |
| (uint64_t)buf, buf_len, VRING_DESC_F_NEXT, |
| id + 2); |
| /* Set up descriptor for response information */ |
| virtio_fill_desc(vq, id + 2, dev->features, |
| (uint64_t)resp, sizeof(*resp), |
| VRING_DESC_F_WRITE, 0); |
| } |
| |
| vq->avail->ring[avail_idx % vq->size] = virtio_cpu_to_modern16(dev, id); |
| mb(); |
| vq->avail->idx = virtio_cpu_to_modern16(dev, avail_idx + 1); |
| |
| /* Tell HV that the vq is ready */ |
| virtio_queue_notify(dev, VIRTIO_SCSI_REQUEST_VQ); |
| |
| /* Wait for host to consume the descriptor */ |
| time = SLOF_GetTimer() + VIRTIO_TIMEOUT; |
| while (*current_used_idx == last_used_idx) { |
| // do something better |
| mb(); |
| if (time < SLOF_GetTimer()) |
| break; |
| } |
| |
| virtio_free_desc(vq, id, dev->features); |
| virtio_free_desc(vq, id + 1, dev->features); |
| if (!(buf == NULL || buf_len == 0)) |
| virtio_free_desc(vq, id + 2, dev->features); |
| |
| return 0; |
| } |
| |
| /** |
| * Initialize virtio-block device. |
| * @param dev pointer to virtio device information |
| */ |
| int virtioscsi_init(struct virtio_device *dev) |
| { |
| struct vqs *vq_ctrl, *vq_event, *vq_request; |
| int status = VIRTIO_STAT_ACKNOWLEDGE; |
| |
| /* Reset device */ |
| // XXX That will clear the virtq base. We need to move |
| // initializing it to here anyway |
| // |
| // virtio_reset_device(dev); |
| |
| /* Acknowledge device. */ |
| virtio_set_status(dev, status); |
| |
| /* Tell HV that we know how to drive the device. */ |
| status |= VIRTIO_STAT_DRIVER; |
| virtio_set_status(dev, status); |
| |
| /* Device specific setup - we do not support special features right now */ |
| if (dev->features & VIRTIO_F_VERSION_1) { |
| if (virtio_negotiate_guest_features(dev, VIRTIO_F_VERSION_1)) |
| goto dev_error; |
| virtio_get_status(dev, &status); |
| } else { |
| virtio_set_guest_features(dev, 0); |
| } |
| |
| vq_ctrl = virtio_queue_init_vq(dev, VIRTIO_SCSI_CONTROL_VQ); |
| vq_event = virtio_queue_init_vq(dev, VIRTIO_SCSI_EVENT_VQ); |
| vq_request = virtio_queue_init_vq(dev, VIRTIO_SCSI_REQUEST_VQ); |
| if (!vq_ctrl || !vq_event || !vq_request) |
| goto dev_error; |
| |
| /* Tell HV that setup succeeded */ |
| status |= VIRTIO_STAT_DRIVER_OK; |
| virtio_set_status(dev, status); |
| |
| return 0; |
| dev_error: |
| printf("%s: failed\n", __func__); |
| status |= VIRTIO_STAT_FAILED; |
| virtio_set_status(dev, status); |
| return -1; |
| } |
| |
| /** |
| * Shutdown the virtio-block device. |
| * @param dev pointer to virtio device information |
| */ |
| void virtioscsi_shutdown(struct virtio_device *dev) |
| { |
| /* Quiesce device */ |
| virtio_set_status(dev, VIRTIO_STAT_FAILED); |
| |
| /* Reset device */ |
| virtio_reset_device(dev); |
| } |