diff options
Diffstat (limited to 'qemu/roms/SLOF/lib/libvirtio/virtio-scsi.c')
| -rw-r--r-- | qemu/roms/SLOF/lib/libvirtio/virtio-scsi.c | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/qemu/roms/SLOF/lib/libvirtio/virtio-scsi.c b/qemu/roms/SLOF/lib/libvirtio/virtio-scsi.c new file mode 100644 index 000000000..48289289a --- /dev/null +++ b/qemu/roms/SLOF/lib/libvirtio/virtio-scsi.c @@ -0,0 +1,145 @@ +/****************************************************************************** + * 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); +} |