| /****************************************************************************** |
| * Copyright (c) 2011 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 <cpu.h> |
| #include <helpers.h> |
| #include "virtio.h" |
| #include "virtio-blk.h" |
| |
| #define DEFAULT_SECTOR_SIZE 512 |
| |
| /** |
| * Initialize virtio-block device. |
| * @param dev pointer to virtio device information |
| */ |
| int |
| virtioblk_init(struct virtio_device *dev) |
| { |
| struct vring_avail *vq_avail; |
| int blk_size = DEFAULT_SECTOR_SIZE; |
| int features; |
| |
| /* 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 support F_BLK_SIZE */ |
| virtio_set_guest_features(dev, VIRTIO_BLK_F_BLK_SIZE); |
| |
| vq_avail = virtio_get_vring_avail(dev, 0); |
| vq_avail->flags = VRING_AVAIL_F_NO_INTERRUPT; |
| vq_avail->idx = 0; |
| |
| /* Tell HV that setup succeeded */ |
| virtio_set_status(dev, VIRTIO_STAT_ACKNOWLEDGE|VIRTIO_STAT_DRIVER |
| |VIRTIO_STAT_DRIVER_OK); |
| |
| virtio_get_host_features(dev, &features); |
| if (features & VIRTIO_BLK_F_BLK_SIZE) { |
| blk_size = virtio_get_config(dev, |
| offset_of(struct virtio_blk_cfg, blk_size), |
| sizeof(blk_size)); |
| } |
| |
| return blk_size; |
| } |
| |
| |
| /** |
| * Shutdown the virtio-block device. |
| * @param dev pointer to virtio device information |
| */ |
| void |
| virtioblk_shutdown(struct virtio_device *dev) |
| { |
| /* Quiesce device */ |
| virtio_set_status(dev, VIRTIO_STAT_FAILED); |
| |
| /* Reset device */ |
| virtio_reset_device(dev); |
| } |
| |
| |
| /** |
| * Read blocks |
| * @param reg pointer to "reg" property |
| * @param buf pointer to destination buffer |
| * @param blocknum block number of the first block that should be read |
| * @param cnt amount of blocks that should be read |
| * @return number of blocks that have been read successfully |
| */ |
| int |
| virtioblk_read(struct virtio_device *dev, char *buf, long blocknum, long cnt) |
| { |
| struct vring_desc *desc; |
| int id; |
| static struct virtio_blk_req blkhdr; |
| //struct virtio_blk_config *blkconf; |
| uint64_t capacity; |
| uint32_t vq_size, time; |
| struct vring_desc *vq_desc; /* Descriptor vring */ |
| struct vring_avail *vq_avail; /* "Available" vring */ |
| struct vring_used *vq_used; /* "Used" vring */ |
| volatile uint8_t status = -1; |
| volatile uint16_t *current_used_idx; |
| uint16_t last_used_idx; |
| int blk_size = DEFAULT_SECTOR_SIZE; |
| |
| //printf("virtioblk_read: dev=%p buf=%p blocknum=%li count=%li\n", |
| // dev, buf, blocknum, cnt); |
| |
| /* Check whether request is within disk capacity */ |
| capacity = virtio_get_config(dev, |
| offset_of(struct virtio_blk_cfg, capacity), |
| sizeof(capacity)); |
| if (blocknum + cnt - 1 > capacity) { |
| puts("virtioblk_read: Access beyond end of device!"); |
| return 0; |
| } |
| |
| blk_size = virtio_get_config(dev, |
| offset_of(struct virtio_blk_cfg, blk_size), |
| sizeof(blk_size)); |
| if (blk_size % DEFAULT_SECTOR_SIZE) { |
| fprintf(stderr, "virtio-blk: Unaligned sector read %d\n", blk_size); |
| return 0; |
| } |
| |
| vq_size = virtio_get_qsize(dev, 0); |
| vq_desc = virtio_get_vring_desc(dev, 0); |
| vq_avail = virtio_get_vring_avail(dev, 0); |
| vq_used = virtio_get_vring_used(dev, 0); |
| |
| last_used_idx = vq_used->idx; |
| current_used_idx = &vq_used->idx; |
| |
| /* Set up header */ |
| blkhdr.type = VIRTIO_BLK_T_IN | VIRTIO_BLK_T_BARRIER; |
| blkhdr.ioprio = 1; |
| blkhdr.sector = blocknum * blk_size / DEFAULT_SECTOR_SIZE; |
| |
| /* Determine descriptor index */ |
| id = (vq_avail->idx * 3) % vq_size; |
| |
| /* Set up virtqueue descriptor for header */ |
| desc = &vq_desc[id]; |
| desc->addr = (uint64_t)&blkhdr; |
| desc->len = sizeof(struct virtio_blk_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)buf; |
| desc->len = cnt * blk_size; |
| desc->flags = VRING_DESC_F_NEXT | VRING_DESC_F_WRITE; |
| desc->next = (id + 2) % vq_size; |
| |
| /* Set up virtqueue descriptor for status */ |
| desc = &vq_desc[(id + 2) % vq_size]; |
| desc->addr = (uint64_t)&status; |
| desc->len = 1; |
| desc->flags = VRING_DESC_F_WRITE; |
| desc->next = 0; |
| |
| vq_avail->ring[vq_avail->idx % vq_size] = id; |
| mb(); |
| vq_avail->idx += 1; |
| |
| /* Tell HV that the queue is ready */ |
| virtio_queue_notify(dev, 0); |
| |
| /* 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; |
| } |
| |
| if (status == 0) |
| return cnt; |
| |
| printf("virtioblk_read failed! status = %i\n", status); |
| |
| return 0; |
| } |