sunvdc.c

来自「linux 内核源代码」· C语言 代码 · 共 890 行 · 第 1/2 页

	return err;
}

static void do_vdc_request(struct request_queue *q)
{
	while (1) {
		struct request *req = elv_next_request(q);

		if (!req)
			break;

		blkdev_dequeue_request(req);
		if (__send_request(req) < 0)
			vdc_end_request(req, 0, req->hard_nr_sectors);
	}
}

static int generic_request(struct vdc_port *port, u8 op, void *buf, int len)
{
	struct vio_dring_state *dr;
	struct vio_completion comp;
	struct vio_disk_desc *desc;
	unsigned int map_perm;
	unsigned long flags;
	int op_len, err;
	void *req_buf;

	if (!(((u64)1 << ((u64)op - 1)) & port->operations))
		return -EOPNOTSUPP;

	switch (op) {
	case VD_OP_BREAD:
	case VD_OP_BWRITE:
	default:
		return -EINVAL;

	case VD_OP_FLUSH:
		op_len = 0;
		map_perm = 0;
		break;

	case VD_OP_GET_WCE:
		op_len = sizeof(u32);
		map_perm = LDC_MAP_W;
		break;

	case VD_OP_SET_WCE:
		op_len = sizeof(u32);
		map_perm = LDC_MAP_R;
		break;

	case VD_OP_GET_VTOC:
		op_len = sizeof(struct vio_disk_vtoc);
		map_perm = LDC_MAP_W;
		break;

	case VD_OP_SET_VTOC:
		op_len = sizeof(struct vio_disk_vtoc);
		map_perm = LDC_MAP_R;
		break;

	case VD_OP_GET_DISKGEOM:
		op_len = sizeof(struct vio_disk_geom);
		map_perm = LDC_MAP_W;
		break;

	case VD_OP_SET_DISKGEOM:
		op_len = sizeof(struct vio_disk_geom);
		map_perm = LDC_MAP_R;
		break;

	case VD_OP_SCSICMD:
		op_len = 16;
		map_perm = LDC_MAP_RW;
		break;

	case VD_OP_GET_DEVID:
		op_len = sizeof(struct vio_disk_devid);
		map_perm = LDC_MAP_W;
		break;

	case VD_OP_GET_EFI:
	case VD_OP_SET_EFI:
		return -EOPNOTSUPP;
		break;
	};

	map_perm |= LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;

	op_len = (op_len + 7) & ~7;
	req_buf = kzalloc(op_len, GFP_KERNEL);
	if (!req_buf)
		return -ENOMEM;

	if (len > op_len)
		len = op_len;

	if (map_perm & LDC_MAP_R)
		memcpy(req_buf, buf, len);

	spin_lock_irqsave(&port->vio.lock, flags);

	dr = &port->vio.drings[VIO_DRIVER_TX_RING];

	/* XXX If we want to use this code generically we have to
	 * XXX handle TX ring exhaustion etc.
	 */
	desc = vio_dring_cur(dr);

	err = ldc_map_single(port->vio.lp, req_buf, op_len,
			     desc->cookies, port->ring_cookies,
			     map_perm);
	if (err < 0) {
		spin_unlock_irqrestore(&port->vio.lock, flags);
		kfree(req_buf);
		return err;
	}

	init_completion(&comp.com);
	comp.waiting_for = WAITING_FOR_GEN_CMD;
	port->vio.cmp = &comp;

	desc->hdr.ack = VIO_ACK_ENABLE;
	desc->req_id = port->req_id;
	desc->operation = op;
	desc->slice = 0;
	desc->status = ~0;
	desc->offset = 0;
	desc->size = op_len;
	desc->ncookies = err;

	/* This has to be a non-SMP write barrier because we are writing
	 * to memory which is shared with the peer LDOM.
	 */
	wmb();
	desc->hdr.state = VIO_DESC_READY;

	err = __vdc_tx_trigger(port);
	if (err >= 0) {
		port->req_id++;
		dr->prod = (dr->prod + 1) & (VDC_TX_RING_SIZE - 1);
		spin_unlock_irqrestore(&port->vio.lock, flags);

		wait_for_completion(&comp.com);
		err = comp.err;
	} else {
		port->vio.cmp = NULL;
		spin_unlock_irqrestore(&port->vio.lock, flags);
	}

	if (map_perm & LDC_MAP_W)
		memcpy(buf, req_buf, len);

	kfree(req_buf);

	return err;
}

static int __devinit vdc_alloc_tx_ring(struct vdc_port *port)
{
	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
	unsigned long len, entry_size;
	int ncookies;
	void *dring;

	entry_size = sizeof(struct vio_disk_desc) +
		(sizeof(struct ldc_trans_cookie) * port->ring_cookies);
	len = (VDC_TX_RING_SIZE * entry_size);

	ncookies = VIO_MAX_RING_COOKIES;
	dring = ldc_alloc_exp_dring(port->vio.lp, len,
				    dr->cookies, &ncookies,
				    (LDC_MAP_SHADOW |
				     LDC_MAP_DIRECT |
				     LDC_MAP_RW));
	if (IS_ERR(dring))
		return PTR_ERR(dring);

	dr->base = dring;
	dr->entry_size = entry_size;
	dr->num_entries = VDC_TX_RING_SIZE;
	dr->prod = dr->cons = 0;
	dr->pending = VDC_TX_RING_SIZE;
	dr->ncookies = ncookies;

	return 0;
}

static void vdc_free_tx_ring(struct vdc_port *port)
{
	struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];

	if (dr->base) {
		ldc_free_exp_dring(port->vio.lp, dr->base,
				   (dr->entry_size * dr->num_entries),
				   dr->cookies, dr->ncookies);
		dr->base = NULL;
		dr->entry_size = 0;
		dr->num_entries = 0;
		dr->pending = 0;
		dr->ncookies = 0;
	}
}

static int probe_disk(struct vdc_port *port)
{
	struct vio_completion comp;
	struct request_queue *q;
	struct gendisk *g;
	int err;

	init_completion(&comp.com);
	comp.err = 0;
	comp.waiting_for = WAITING_FOR_LINK_UP;
	port->vio.cmp = &comp;

	vio_port_up(&port->vio);

	wait_for_completion(&comp.com);
	if (comp.err)
		return comp.err;

	err = generic_request(port, VD_OP_GET_VTOC,
			      &port->label, sizeof(port->label));
	if (err < 0) {
		printk(KERN_ERR PFX "VD_OP_GET_VTOC returns error %d\n", err);
		return err;
	}

	err = generic_request(port, VD_OP_GET_DISKGEOM,
			      &port->geom, sizeof(port->geom));
	if (err < 0) {
		printk(KERN_ERR PFX "VD_OP_GET_DISKGEOM returns "
		       "error %d\n", err);
		return err;
	}

	port->vdisk_size = ((u64)port->geom.num_cyl *
			    (u64)port->geom.num_hd *
			    (u64)port->geom.num_sec);

	q = blk_init_queue(do_vdc_request, &port->vio.lock);
	if (!q) {
		printk(KERN_ERR PFX "%s: Could not allocate queue.\n",
		       port->vio.name);
		return -ENOMEM;
	}
	g = alloc_disk(1 << PARTITION_SHIFT);
	if (!g) {
		printk(KERN_ERR PFX "%s: Could not allocate gendisk.\n",
		       port->vio.name);
		blk_cleanup_queue(q);
		return -ENOMEM;
	}

	port->disk = g;

	blk_queue_max_hw_segments(q, port->ring_cookies);
	blk_queue_max_phys_segments(q, port->ring_cookies);
	blk_queue_max_sectors(q, port->max_xfer_size);
	g->major = vdc_major;
	g->first_minor = port->vio.vdev->dev_no << PARTITION_SHIFT;
	strcpy(g->disk_name, port->disk_name);

	g->fops = &vdc_fops;
	g->queue = q;
	g->private_data = port;
	g->driverfs_dev = &port->vio.vdev->dev;

	set_capacity(g, port->vdisk_size);

	printk(KERN_INFO PFX "%s: %u sectors (%u MB)\n",
	       g->disk_name,
	       port->vdisk_size, (port->vdisk_size >> (20 - 9)));

	add_disk(g);

	return 0;
}

static struct ldc_channel_config vdc_ldc_cfg = {
	.event		= vdc_event,
	.mtu		= 64,
	.mode		= LDC_MODE_UNRELIABLE,
};

static struct vio_driver_ops vdc_vio_ops = {
	.send_attr		= vdc_send_attr,
	.handle_attr		= vdc_handle_attr,
	.handshake_complete	= vdc_handshake_complete,
};

static void print_version(void)
{
	static int version_printed;

	if (version_printed++ == 0)
		printk(KERN_INFO "%s", version);
}

static int __devinit vdc_port_probe(struct vio_dev *vdev,
				    const struct vio_device_id *id)
{
	struct mdesc_handle *hp;
	struct vdc_port *port;
	int err;

	print_version();

	hp = mdesc_grab();

	err = -ENODEV;
	if ((vdev->dev_no << PARTITION_SHIFT) & ~(u64)MINORMASK) {
		printk(KERN_ERR PFX "Port id [%lu] too large.\n",
		       vdev->dev_no);
		goto err_out_release_mdesc;
	}

	port = kzalloc(sizeof(*port), GFP_KERNEL);
	err = -ENOMEM;
	if (!port) {
		printk(KERN_ERR PFX "Cannot allocate vdc_port.\n");
		goto err_out_release_mdesc;
	}

	if (vdev->dev_no >= 26)
		snprintf(port->disk_name, sizeof(port->disk_name),
			 VDCBLK_NAME "%c%c",
			 'a' + ((int)vdev->dev_no / 26) - 1,
			 'a' + ((int)vdev->dev_no % 26));
	else
		snprintf(port->disk_name, sizeof(port->disk_name),
			 VDCBLK_NAME "%c", 'a' + ((int)vdev->dev_no % 26));

	err = vio_driver_init(&port->vio, vdev, VDEV_DISK,
			      vdc_versions, ARRAY_SIZE(vdc_versions),
			      &vdc_vio_ops, port->disk_name);
	if (err)
		goto err_out_free_port;

	port->vdisk_block_size = 512;
	port->max_xfer_size = ((128 * 1024) / port->vdisk_block_size);
	port->ring_cookies = ((port->max_xfer_size *
			       port->vdisk_block_size) / PAGE_SIZE) + 2;

	err = vio_ldc_alloc(&port->vio, &vdc_ldc_cfg, port);
	if (err)
		goto err_out_free_port;

	err = vdc_alloc_tx_ring(port);
	if (err)
		goto err_out_free_ldc;

	err = probe_disk(port);
	if (err)
		goto err_out_free_tx_ring;

	dev_set_drvdata(&vdev->dev, port);

	mdesc_release(hp);

	return 0;

err_out_free_tx_ring:
	vdc_free_tx_ring(port);

err_out_free_ldc:
	vio_ldc_free(&port->vio);

err_out_free_port:
	kfree(port);

err_out_release_mdesc:
	mdesc_release(hp);
	return err;
}

static int vdc_port_remove(struct vio_dev *vdev)
{
	struct vdc_port *port = dev_get_drvdata(&vdev->dev);

	if (port) {
		del_timer_sync(&port->vio.timer);

		vdc_free_tx_ring(port);
		vio_ldc_free(&port->vio);

		dev_set_drvdata(&vdev->dev, NULL);

		kfree(port);
	}
	return 0;
}

static struct vio_device_id vdc_port_match[] = {
	{
		.type = "vdc-port",
	},
	{},
};
MODULE_DEVICE_TABLE(vio, vdc_port_match);

static struct vio_driver vdc_port_driver = {
	.id_table	= vdc_port_match,
	.probe		= vdc_port_probe,
	.remove		= vdc_port_remove,
	.driver		= {
		.name	= "vdc_port",
		.owner	= THIS_MODULE,
	}
};

static int __init vdc_init(void)
{
	int err;

	err = register_blkdev(0, VDCBLK_NAME);
	if (err < 0)
		goto out_err;

	vdc_major = err;

	err = vio_register_driver(&vdc_port_driver);
	if (err)
		goto out_unregister_blkdev;

	return 0;

out_unregister_blkdev:
	unregister_blkdev(vdc_major, VDCBLK_NAME);
	vdc_major = 0;

out_err:
	return err;
}

static void __exit vdc_exit(void)
{
	vio_unregister_driver(&vdc_port_driver);
	unregister_blkdev(vdc_major, VDCBLK_NAME);
}

module_init(vdc_init);
module_exit(vdc_exit);