| /****************************************************************************** |
| * 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-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) |
| { |
| struct vring_desc *desc; |
| struct vring_desc *vq_desc; /* Descriptor vring */ |
| struct vring_avail *vq_avail; /* "Available" vring */ |
| struct vring_used *vq_used; /* "Used" vring */ |
| |
| volatile uint16_t *current_used_idx; |
| uint16_t last_used_idx; |
| int id; |
| uint32_t vq_size, time; |
| |
| int vq = VIRTIO_SCSI_REQUEST_VQ; |
| |
| vq_size = virtio_get_qsize(dev, vq); |
| vq_desc = virtio_get_vring_desc(dev, vq); |
| vq_avail = virtio_get_vring_avail(dev, vq); |
| vq_used = virtio_get_vring_used(dev, vq); |
| |
| last_used_idx = vq_used->idx; |
| current_used_idx = &vq_used->idx; |
| |
| /* Determine descriptor index */ |
| id = (vq_avail->idx * 3) % vq_size; |
| |
| desc = &vq_desc[id]; |
| desc->addr = (uint64_t)req; |
| desc->len = sizeof(*req); |
| desc->flags = VRING_DESC_F_NEXT; |
| desc->next = (id + 1) % vq_size; |
| |
| /* Set up virtqueue descriptor for data */ |
| desc = &vq_desc[(id + 1) % vq_size]; |
| desc->addr = (uint64_t)resp; |
| desc->len = sizeof(*resp); |
| desc->flags = VRING_DESC_F_NEXT | VRING_DESC_F_WRITE; |
| desc->next = (id + 2) % vq_size; |
| |
| if (buf && buf_len) { |
| /* Set up virtqueue descriptor for status */ |
| desc = &vq_desc[(id + 2) % vq_size]; |
| desc->addr = (uint64_t)buf; |
| desc->len = buf_len; |
| desc->flags = is_read ? VRING_DESC_F_WRITE : 0; |
| desc->next = 0; |
| } else |
| desc->flags &= ~VRING_DESC_F_NEXT; |
| |
| vq_avail->ring[vq_avail->idx % vq_size] = id; |
| mb(); |
| vq_avail->idx += 1; |
| |
| /* Tell HV that the vq is ready */ |
| virtio_queue_notify(dev, 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; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * Initialize virtio-block device. |
| * @param dev pointer to virtio device information |
| */ |
| int virtioscsi_init(struct virtio_device *dev) |
| { |
| struct vring_avail *vq_avail; |
| unsigned int idx = 0; |
| int qsize = 0; |
| |
| /* 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, VIRTIO_STAT_ACKNOWLEDGE); |
| |
| /* Tell HV that we know how to drive the device. */ |
| virtio_set_status(dev, VIRTIO_STAT_ACKNOWLEDGE|VIRTIO_STAT_DRIVER); |
| |
| /* Device specific setup - we do not support special features right now */ |
| virtio_set_guest_features(dev, 0); |
| |
| while(1) { |
| qsize = virtio_get_qsize(dev, idx); |
| if (!qsize) |
| break; |
| virtio_vring_size(qsize); |
| |
| vq_avail = virtio_get_vring_avail(dev, 0); |
| vq_avail->flags = VRING_AVAIL_F_NO_INTERRUPT; |
| vq_avail->idx = 0; |
| idx++; |
| } |
| |
| /* Tell HV that setup succeeded */ |
| virtio_set_status(dev, VIRTIO_STAT_ACKNOWLEDGE|VIRTIO_STAT_DRIVER |
| |VIRTIO_STAT_DRIVER_OK); |
| |
| return 0; |
| } |
| |
| /** |
| * 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); |
| } |