Commit 7e64e059 authored by Cornelia Huck's avatar Cornelia Huck Committed by Gleb Natapov
Browse files

KVM: s390: Add a channel I/O based virtio transport driver. 



Add a driver for kvm guests that matches virtual ccw devices provided
by the host as virtio bridge devices.

These virtio-ccw devices use a special set of channel commands in order
to perform virtio functions.

Reviewed-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
Reviewed-by: default avatarAlexander Graf <agraf@suse.de>
Signed-off-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: default avatarGleb Natapov <gleb@redhat.com>
parent 0abbe448

arch/s390/include/asm/irq.h

+1 −0
Original line number Diff line number Diff line
@@ -35,6 +35,7 @@ enum interruption_class { 
	IOINT_CSC,

	IOINT_PCI,

	IOINT_MSI,

	IOINT_VIR,

	NMI_NMI,

	NR_IRQS,

};

arch/s390/kernel/irq.c

+1 −0
Original line number Diff line number Diff line
@@ -60,6 +60,7 @@ static const struct irq_class intrclass_names[] = { 
	[IOINT_CSC]  = {.name = "CSC", .desc = "[I/O] CHSC Subchannel"},

	[IOINT_PCI]  = {.name = "PCI", .desc = "[I/O] PCI Interrupt" },

	[IOINT_MSI] =  {.name = "MSI", .desc = "[I/O] MSI Interrupt" },

	[IOINT_VIR]  = {.name = "VIR", .desc = "[I/O] Virtual I/O Devices"},

	[NMI_NMI]    = {.name = "NMI", .desc = "[NMI] Machine Check"},

};

drivers/s390/kvm/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -6,4 +6,4 @@ 
# it under the terms of the GNU General Public License (version 2 only)

# as published by the Free Software Foundation.



obj-$(CONFIG_S390_GUEST) += kvm_virtio.o
 
obj-$(CONFIG_S390_GUEST) += kvm_virtio.o virtio_ccw.o

drivers/s390/kvm/virtio_ccw.c

0 → 100644
+853 −0
Original line number Diff line number Diff line 
/*

 * ccw based virtio transport

 *

 * Copyright IBM Corp. 2012

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License (version 2 only)

 * as published by the Free Software Foundation.

 *

 *    Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>

 */



#include <linux/kernel_stat.h>

#include <linux/init.h>

#include <linux/bootmem.h>

#include <linux/err.h>

#include <linux/virtio.h>

#include <linux/virtio_config.h>

#include <linux/slab.h>

#include <linux/interrupt.h>

#include <linux/virtio_ring.h>

#include <linux/pfn.h>

#include <linux/async.h>

#include <linux/wait.h>

#include <linux/list.h>

#include <linux/bitops.h>

#include <linux/module.h>

#include <linux/io.h>

#include <linux/kvm_para.h>

#include <asm/setup.h>

#include <asm/irq.h>

#include <asm/cio.h>

#include <asm/ccwdev.h>



/*

 * virtio related functions

 */



struct vq_config_block {

	__u16 index;

	__u16 num;

} __packed;



#define VIRTIO_CCW_CONFIG_SIZE 0x100

/* same as PCI config space size, should be enough for all drivers */



struct virtio_ccw_device {

	struct virtio_device vdev;

	__u8 status;

	__u8 config[VIRTIO_CCW_CONFIG_SIZE];

	struct ccw_device *cdev;

	struct ccw1 *ccw;

	__u32 area;

	__u32 curr_io;

	int err;

	wait_queue_head_t wait_q;

	spinlock_t lock;

	struct list_head virtqueues;

	unsigned long indicators;

	unsigned long indicators2;

	struct vq_config_block *config_block;

};



struct vq_info_block {

	__u64 queue;

	__u32 align;

	__u16 index;

	__u16 num;

} __packed;



struct virtio_feature_desc {

	__u32 features;

	__u8 index;

} __packed;



struct virtio_ccw_vq_info {

	struct virtqueue *vq;

	int num;

	void *queue;

	struct vq_info_block *info_block;

	struct list_head node;

};



#define KVM_VIRTIO_CCW_RING_ALIGN 4096



#define KVM_S390_VIRTIO_CCW_NOTIFY 3



#define CCW_CMD_SET_VQ 0x13

#define CCW_CMD_VDEV_RESET 0x33

#define CCW_CMD_SET_IND 0x43

#define CCW_CMD_SET_CONF_IND 0x53

#define CCW_CMD_READ_FEAT 0x12

#define CCW_CMD_WRITE_FEAT 0x11

#define CCW_CMD_READ_CONF 0x22

#define CCW_CMD_WRITE_CONF 0x21

#define CCW_CMD_WRITE_STATUS 0x31

#define CCW_CMD_READ_VQ_CONF 0x32



#define VIRTIO_CCW_DOING_SET_VQ 0x00010000

#define VIRTIO_CCW_DOING_RESET 0x00040000

#define VIRTIO_CCW_DOING_READ_FEAT 0x00080000

#define VIRTIO_CCW_DOING_WRITE_FEAT 0x00100000

#define VIRTIO_CCW_DOING_READ_CONFIG 0x00200000

#define VIRTIO_CCW_DOING_WRITE_CONFIG 0x00400000

#define VIRTIO_CCW_DOING_WRITE_STATUS 0x00800000

#define VIRTIO_CCW_DOING_SET_IND 0x01000000

#define VIRTIO_CCW_DOING_READ_VQ_CONF 0x02000000

#define VIRTIO_CCW_DOING_SET_CONF_IND 0x04000000

#define VIRTIO_CCW_INTPARM_MASK 0xffff0000



static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev)

{

	return container_of(vdev, struct virtio_ccw_device, vdev);

}



static int doing_io(struct virtio_ccw_device *vcdev, __u32 flag)

{

	unsigned long flags;

	__u32 ret;



	spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);

	if (vcdev->err)

		ret = 0;

	else

		ret = vcdev->curr_io & flag;

	spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);

	return ret;

}



static int ccw_io_helper(struct virtio_ccw_device *vcdev, __u32 intparm)

{

	int ret;

	unsigned long flags;

	int flag = intparm & VIRTIO_CCW_INTPARM_MASK;



	spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);

	ret = ccw_device_start(vcdev->cdev, vcdev->ccw, intparm, 0, 0);

	if (!ret)

		vcdev->curr_io |= flag;

	spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);

	wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0);

	return ret ? ret : vcdev->err;

}



static inline long do_kvm_notify(struct subchannel_id schid,

				 unsigned long queue_index)

{

	register unsigned long __nr asm("1") = KVM_S390_VIRTIO_CCW_NOTIFY;

	register struct subchannel_id __schid asm("2") = schid;

	register unsigned long __index asm("3") = queue_index;

	register long __rc asm("2");



	asm volatile ("diag 2,4,0x500\n"

		      : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index)

		      : "memory", "cc");

	return __rc;

}



static void virtio_ccw_kvm_notify(struct virtqueue *vq)

{

	struct virtio_ccw_vq_info *info = vq->priv;

	struct virtio_ccw_device *vcdev;

	struct subchannel_id schid;



	vcdev = to_vc_device(info->vq->vdev);

	ccw_device_get_schid(vcdev->cdev, &schid);

	do_kvm_notify(schid, virtqueue_get_queue_index(vq));

}



static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev, int index)

{

	vcdev->config_block->index = index;

	vcdev->ccw->cmd_code = CCW_CMD_READ_VQ_CONF;

	vcdev->ccw->flags = 0;

	vcdev->ccw->count = sizeof(struct vq_config_block);

	vcdev->ccw->cda = (__u32)(unsigned long)(vcdev->config_block);

	ccw_io_helper(vcdev, VIRTIO_CCW_DOING_READ_VQ_CONF);

	return vcdev->config_block->num;

}



static void virtio_ccw_del_vq(struct virtqueue *vq)

{

	struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);

	struct virtio_ccw_vq_info *info = vq->priv;

	unsigned long flags;

	unsigned long size;

	int ret;

	unsigned int index = virtqueue_get_queue_index(vq);



	/* Remove from our list. */

	spin_lock_irqsave(&vcdev->lock, flags);

	list_del(&info->node);

	spin_unlock_irqrestore(&vcdev->lock, flags);



	/* Release from host. */

	info->info_block->queue = 0;

	info->info_block->align = 0;

	info->info_block->index = index;

	info->info_block->num = 0;

	vcdev->ccw->cmd_code = CCW_CMD_SET_VQ;

	vcdev->ccw->flags = 0;

	vcdev->ccw->count = sizeof(*info->info_block);

	vcdev->ccw->cda = (__u32)(unsigned long)(info->info_block);

	ret = ccw_io_helper(vcdev, VIRTIO_CCW_DOING_SET_VQ | index);

	/*

	 * -ENODEV isn't considered an error: The device is gone anyway.

	 * This may happen on device detach.

	 */

	if (ret && (ret != -ENODEV))

		dev_warn(&vq->vdev->dev, "Error %d while deleting queue %d",

			 ret, index);



	vring_del_virtqueue(vq);

	size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));

	free_pages_exact(info->queue, size);

	kfree(info->info_block);

	kfree(info);

}



static void virtio_ccw_del_vqs(struct virtio_device *vdev)

{

	struct virtqueue *vq, *n;



	list_for_each_entry_safe(vq, n, &vdev->vqs, list)

		virtio_ccw_del_vq(vq);

}



static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,

					     int i, vq_callback_t *callback,

					     const char *name)

{

	struct virtio_ccw_device *vcdev = to_vc_device(vdev);

	int err;

	struct virtqueue *vq;

	struct virtio_ccw_vq_info *info;

	unsigned long size;

	unsigned long flags;



	/* Allocate queue. */

	info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);

	if (!info) {

		dev_warn(&vcdev->cdev->dev, "no info\n");

		err = -ENOMEM;

		goto out_err;

	}

	info->info_block = kzalloc(sizeof(*info->info_block),

				   GFP_DMA | GFP_KERNEL);

	if (!info->info_block) {

		dev_warn(&vcdev->cdev->dev, "no info block\n");

		err = -ENOMEM;

		goto out_err;

	}

	info->num = virtio_ccw_read_vq_conf(vcdev, i);

	size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));

	info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);

	if (info->queue == NULL) {

		dev_warn(&vcdev->cdev->dev, "no queue\n");

		err = -ENOMEM;

		goto out_err;

	}



	vq = vring_new_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN, vdev,

				 true, info->queue, virtio_ccw_kvm_notify,

				 callback, name);

	if (!vq) {

		/* For now, we fail if we can't get the requested size. */

		dev_warn(&vcdev->cdev->dev, "no vq\n");

		err = -ENOMEM;

		free_pages_exact(info->queue, size);

		goto out_err;

	}

	info->vq = vq;

	vq->priv = info;



	/* Register it with the host. */

	info->info_block->queue = (__u64)info->queue;

	info->info_block->align = KVM_VIRTIO_CCW_RING_ALIGN;

	info->info_block->index = i;

	info->info_block->num = info->num;

	vcdev->ccw->cmd_code = CCW_CMD_SET_VQ;

	vcdev->ccw->flags = 0;

	vcdev->ccw->count = sizeof(*info->info_block);

	vcdev->ccw->cda = (__u32)(unsigned long)(info->info_block);

	err = ccw_io_helper(vcdev, VIRTIO_CCW_DOING_SET_VQ | i);

	if (err) {

		dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");

		free_pages_exact(info->queue, size);

		info->vq = NULL;

		vq->priv = NULL;

		goto out_err;

	}



	/* Save it to our list. */

	spin_lock_irqsave(&vcdev->lock, flags);

	list_add(&info->node, &vcdev->virtqueues);

	spin_unlock_irqrestore(&vcdev->lock, flags);



	return vq;



out_err:

	if (info)

		kfree(info->info_block);

	kfree(info);

	return ERR_PTR(err);

}



static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,

			       struct virtqueue *vqs[],

			       vq_callback_t *callbacks[],

			       const char *names[])

{

	struct virtio_ccw_device *vcdev = to_vc_device(vdev);

	unsigned long *indicatorp = NULL;

	int ret, i;



	for (i = 0; i < nvqs; ++i) {

		vqs[i] = virtio_ccw_setup_vq(vdev, i, callbacks[i], names[i]);

		if (IS_ERR(vqs[i])) {

			ret = PTR_ERR(vqs[i]);

			vqs[i] = NULL;

			goto out;

		}

	}

	ret = -ENOMEM;

	/* We need a data area under 2G to communicate. */

	indicatorp = kmalloc(sizeof(&vcdev->indicators), GFP_DMA | GFP_KERNEL);

	if (!indicatorp)

		goto out;

	*indicatorp = (unsigned long) &vcdev->indicators;

	/* Register queue indicators with host. */

	vcdev->indicators = 0;

	vcdev->ccw->cmd_code = CCW_CMD_SET_IND;

	vcdev->ccw->flags = 0;

	vcdev->ccw->count = sizeof(vcdev->indicators);

	vcdev->ccw->cda = (__u32)(unsigned long) indicatorp;

	ret = ccw_io_helper(vcdev, VIRTIO_CCW_DOING_SET_IND);

	if (ret)

		goto out;

	/* Register indicators2 with host for config changes */

	*indicatorp = (unsigned long) &vcdev->indicators2;

	vcdev->indicators2 = 0;

	vcdev->ccw->cmd_code = CCW_CMD_SET_CONF_IND;

	vcdev->ccw->flags = 0;

	vcdev->ccw->count = sizeof(vcdev->indicators2);

	vcdev->ccw->cda = (__u32)(unsigned long) indicatorp;

	ret = ccw_io_helper(vcdev, VIRTIO_CCW_DOING_SET_CONF_IND);

	if (ret)

		goto out;



	kfree(indicatorp);

	return 0;

out:

	kfree(indicatorp);

	virtio_ccw_del_vqs(vdev);

	return ret;

}



static void virtio_ccw_reset(struct virtio_device *vdev)

{

	struct virtio_ccw_device *vcdev = to_vc_device(vdev);



	/* Zero status bits. */

	vcdev->status = 0;



	/* Send a reset ccw on device. */

	vcdev->ccw->cmd_code = CCW_CMD_VDEV_RESET;

	vcdev->ccw->flags = 0;

	vcdev->ccw->count = 0;

	vcdev->ccw->cda = 0;

	ccw_io_helper(vcdev, VIRTIO_CCW_DOING_RESET);

}



static u32 virtio_ccw_get_features(struct virtio_device *vdev)

{

	struct virtio_ccw_device *vcdev = to_vc_device(vdev);

	struct virtio_feature_desc features;

	int ret;



	/* Read the feature bits from the host. */

	/* TODO: Features > 32 bits */

	features.index = 0;

	vcdev->ccw->cmd_code = CCW_CMD_READ_FEAT;

	vcdev->ccw->flags = 0;

	vcdev->ccw->count = sizeof(features);

	vcdev->ccw->cda = vcdev->area;

	ret = ccw_io_helper(vcdev, VIRTIO_CCW_DOING_READ_FEAT);

	if (ret)

		return 0;



	memcpy(&features, (void *)(unsigned long)vcdev->area,

	       sizeof(features));

	return le32_to_cpu(features.features);

}



static void virtio_ccw_finalize_features(struct virtio_device *vdev)

{

	struct virtio_ccw_device *vcdev = to_vc_device(vdev);

	struct virtio_feature_desc features;

	int i;



	/* Give virtio_ring a chance to accept features. */

	vring_transport_features(vdev);



	for (i = 0; i < sizeof(*vdev->features) / sizeof(features.features);

	     i++) {

		int highbits = i % 2 ? 32 : 0;

		features.index = i;

		features.features = cpu_to_le32(vdev->features[i / 2]

						>> highbits);

		memcpy((void *)(unsigned long)vcdev->area, &features,

		       sizeof(features));

		/* Write the feature bits to the host. */

		vcdev->ccw->cmd_code = CCW_CMD_WRITE_FEAT;

		vcdev->ccw->flags = 0;

		vcdev->ccw->count = sizeof(features);

		vcdev->ccw->cda = vcdev->area;

		ccw_io_helper(vcdev, VIRTIO_CCW_DOING_WRITE_FEAT);

	}

}



static void virtio_ccw_get_config(struct virtio_device *vdev,

				  unsigned int offset, void *buf, unsigned len)

{

	struct virtio_ccw_device *vcdev = to_vc_device(vdev);

	int ret;



	/* Read the config area from the host. */

	vcdev->ccw->cmd_code = CCW_CMD_READ_CONF;

	vcdev->ccw->flags = 0;

	vcdev->ccw->count = offset + len;

	vcdev->ccw->cda = vcdev->area;

	ret = ccw_io_helper(vcdev, VIRTIO_CCW_DOING_READ_CONFIG);

	if (ret)

		return;



	memcpy(vcdev->config, (void *)(unsigned long)vcdev->area,

	       sizeof(vcdev->config));

	memcpy(buf, &vcdev->config[offset], len);

}



static void virtio_ccw_set_config(struct virtio_device *vdev,

				  unsigned int offset, const void *buf,

				  unsigned len)

{

	struct virtio_ccw_device *vcdev = to_vc_device(vdev);



	memcpy(&vcdev->config[offset], buf, len);

	/* Write the config area to the host. */

	memcpy((void *)(unsigned long)vcdev->area, vcdev->config,

	       sizeof(vcdev->config));

	vcdev->ccw->cmd_code = CCW_CMD_WRITE_CONF;

	vcdev->ccw->flags = 0;

	vcdev->ccw->count = offset + len;

	vcdev->ccw->cda = vcdev->area;

	ccw_io_helper(vcdev, VIRTIO_CCW_DOING_WRITE_CONFIG);

}



static u8 virtio_ccw_get_status(struct virtio_device *vdev)

{

	struct virtio_ccw_device *vcdev = to_vc_device(vdev);



	return vcdev->status;

}



static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)

{

	struct virtio_ccw_device *vcdev = to_vc_device(vdev);



	/* Write the status to the host. */

	vcdev->status = status;

	memcpy((void *)(unsigned long)vcdev->area, &status, sizeof(status));

	vcdev->ccw->cmd_code = CCW_CMD_WRITE_STATUS;

	vcdev->ccw->flags = 0;

	vcdev->ccw->count = sizeof(status);

	vcdev->ccw->cda = vcdev->area;

	ccw_io_helper(vcdev, VIRTIO_CCW_DOING_WRITE_STATUS);

}



static struct virtio_config_ops virtio_ccw_config_ops = {

	.get_features = virtio_ccw_get_features,

	.finalize_features = virtio_ccw_finalize_features,

	.get = virtio_ccw_get_config,

	.set = virtio_ccw_set_config,

	.get_status = virtio_ccw_get_status,

	.set_status = virtio_ccw_set_status,

	.reset = virtio_ccw_reset,

	.find_vqs = virtio_ccw_find_vqs,

	.del_vqs = virtio_ccw_del_vqs,

};





/*

 * ccw bus driver related functions

 */



static void virtio_ccw_release_dev(struct device *_d)

{

	struct virtio_device *dev = container_of(_d, struct virtio_device,

						 dev);

	struct virtio_ccw_device *vcdev = to_vc_device(dev);



	kfree((void *)(unsigned long)vcdev->area);

	kfree(vcdev->config_block);

	kfree(vcdev->ccw);

	kfree(vcdev);

}



static int irb_is_error(struct irb *irb)

{

	if (scsw_cstat(&irb->scsw) != 0)

		return 1;

	if (scsw_dstat(&irb->scsw) & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))

		return 1;

	if (scsw_cc(&irb->scsw) != 0)

		return 1;

	return 0;

}



static struct virtqueue *virtio_ccw_vq_by_ind(struct virtio_ccw_device *vcdev,

					      int index)

{

	struct virtio_ccw_vq_info *info;

	unsigned long flags;

	struct virtqueue *vq;



	vq = NULL;

	spin_lock_irqsave(&vcdev->lock, flags);

	list_for_each_entry(info, &vcdev->virtqueues, node) {

		if (virtqueue_get_queue_index(info->vq) == index) {

			vq = info->vq;

			break;

		}

	}

	spin_unlock_irqrestore(&vcdev->lock, flags);

	return vq;

}



static void virtio_ccw_int_handler(struct ccw_device *cdev,

				   unsigned long intparm,

				   struct irb *irb)

{

	__u32 activity = intparm & VIRTIO_CCW_INTPARM_MASK;

	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);

	int i;

	struct virtqueue *vq;

	struct virtio_driver *drv;



	/* Check if it's a notification from the host. */

	if ((intparm == 0) &&

	    (scsw_stctl(&irb->scsw) ==

	     (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND))) {

		/* OK */

	}

	if (irb_is_error(irb))

		vcdev->err = -EIO; /* XXX - use real error */

	if (vcdev->curr_io & activity) {

		switch (activity) {

		case VIRTIO_CCW_DOING_READ_FEAT:

		case VIRTIO_CCW_DOING_WRITE_FEAT:

		case VIRTIO_CCW_DOING_READ_CONFIG:

		case VIRTIO_CCW_DOING_WRITE_CONFIG:

		case VIRTIO_CCW_DOING_WRITE_STATUS:

		case VIRTIO_CCW_DOING_SET_VQ:

		case VIRTIO_CCW_DOING_SET_IND:

		case VIRTIO_CCW_DOING_SET_CONF_IND:

		case VIRTIO_CCW_DOING_RESET:

		case VIRTIO_CCW_DOING_READ_VQ_CONF:

			vcdev->curr_io &= ~activity;

			wake_up(&vcdev->wait_q);

			break;

		default:

			/* don't know what to do... */

			dev_warn(&cdev->dev, "Suspicious activity '%08x'\n",

				 activity);

			WARN_ON(1);

			break;

		}

	}

	for_each_set_bit(i, &vcdev->indicators,

			 sizeof(vcdev->indicators) * BITS_PER_BYTE) {

		/* The bit clear must happen before the vring kick. */

		clear_bit(i, &vcdev->indicators);

		barrier();

		vq = virtio_ccw_vq_by_ind(vcdev, i);

		vring_interrupt(0, vq);

	}

	if (test_bit(0, &vcdev->indicators2)) {

		drv = container_of(vcdev->vdev.dev.driver,

				   struct virtio_driver, driver);



		if (drv && drv->config_changed)

			drv->config_changed(&vcdev->vdev);

		clear_bit(0, &vcdev->indicators2);

	}

}



/*

 * We usually want to autoonline all devices, but give the admin

 * a way to exempt devices from this.

 */

#define __DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \

		     (8*sizeof(long)))

static unsigned long devs_no_auto[__MAX_SSID + 1][__DEV_WORDS];



static char *no_auto = "";



module_param(no_auto, charp, 0444);

MODULE_PARM_DESC(no_auto, "list of ccw bus id ranges not to be auto-onlined");



static int virtio_ccw_check_autoonline(struct ccw_device *cdev)

{

	struct ccw_dev_id id;



	ccw_device_get_id(cdev, &id);

	if (test_bit(id.devno, devs_no_auto[id.ssid]))

		return 0;

	return 1;

}



static void virtio_ccw_auto_online(void *data, async_cookie_t cookie)

{

	struct ccw_device *cdev = data;

	int ret;



	ret = ccw_device_set_online(cdev);

	if (ret)

		dev_warn(&cdev->dev, "Failed to set online: %d\n", ret);

}



static int virtio_ccw_probe(struct ccw_device *cdev)

{

	cdev->handler = virtio_ccw_int_handler;



	if (virtio_ccw_check_autoonline(cdev))

		async_schedule(virtio_ccw_auto_online, cdev);

	return 0;

}



static void virtio_ccw_remove(struct ccw_device *cdev)

{

	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);



	if (cdev->online) {

		unregister_virtio_device(&vcdev->vdev);

		dev_set_drvdata(&cdev->dev, NULL);

	}

	cdev->handler = NULL;

}



static int virtio_ccw_offline(struct ccw_device *cdev)

{

	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);



	unregister_virtio_device(&vcdev->vdev);

	dev_set_drvdata(&cdev->dev, NULL);

	return 0;

}





/* Area needs to be big enough to fit status, features or configuration. */

#define VIRTIO_AREA_SIZE VIRTIO_CCW_CONFIG_SIZE /* biggest possible use */



static int virtio_ccw_online(struct ccw_device *cdev)

{

	int ret;

	struct virtio_ccw_device *vcdev;



	vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);

	if (!vcdev) {

		dev_warn(&cdev->dev, "Could not get memory for virtio\n");

		ret = -ENOMEM;

		goto out_free;

	}

	vcdev->area = (__u32)(unsigned long)kzalloc(VIRTIO_AREA_SIZE,

						    GFP_DMA | GFP_KERNEL);

	if (!vcdev->area) {

		dev_warn(&cdev->dev, "Cound not get memory for virtio\n");

		ret = -ENOMEM;

		goto out_free;

	}

	vcdev->config_block = kzalloc(sizeof(*vcdev->config_block),

				   GFP_DMA | GFP_KERNEL);

	if (!vcdev->config_block) {

		ret = -ENOMEM;

		goto out_free;

	}

	vcdev->ccw = kzalloc(sizeof(*vcdev->ccw), GFP_DMA | GFP_KERNEL);

	if (!vcdev->ccw) {

		ret = -ENOMEM;

		goto out_free;

	}



	vcdev->vdev.dev.parent = &cdev->dev;

	vcdev->vdev.dev.release = virtio_ccw_release_dev;

	vcdev->vdev.config = &virtio_ccw_config_ops;

	vcdev->cdev = cdev;

	init_waitqueue_head(&vcdev->wait_q);

	INIT_LIST_HEAD(&vcdev->virtqueues);

	spin_lock_init(&vcdev->lock);



	dev_set_drvdata(&cdev->dev, vcdev);

	vcdev->vdev.id.vendor = cdev->id.cu_type;

	vcdev->vdev.id.device = cdev->id.cu_model;

	ret = register_virtio_device(&vcdev->vdev);

	if (ret) {

		dev_warn(&cdev->dev, "Failed to register virtio device: %d\n",

			 ret);

		goto out_put;

	}

	return 0;

out_put:

	dev_set_drvdata(&cdev->dev, NULL);

	put_device(&vcdev->vdev.dev);

	return ret;

out_free:

	if (vcdev) {

		kfree((void *)(unsigned long)vcdev->area);

		kfree(vcdev->config_block);

		kfree(vcdev->ccw);

	}

	kfree(vcdev);

	return ret;

}



static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)

{

	/* TODO: Check whether we need special handling here. */

	return 0;

}



static struct ccw_device_id virtio_ids[] = {

	{ CCW_DEVICE(0x3832, 0) },

	{},

};

MODULE_DEVICE_TABLE(ccw, virtio_ids);



static struct ccw_driver virtio_ccw_driver = {

	.driver = {

		.owner = THIS_MODULE,

		.name = "virtio_ccw",

	},

	.ids = virtio_ids,

	.probe = virtio_ccw_probe,

	.remove = virtio_ccw_remove,

	.set_offline = virtio_ccw_offline,

	.set_online = virtio_ccw_online,

	.notify = virtio_ccw_cio_notify,

	.int_class = IOINT_VIR,

};



static int __init pure_hex(char **cp, unsigned int *val, int min_digit,

			   int max_digit, int max_val)

{

	int diff;



	diff = 0;

	*val = 0;



	while (diff <= max_digit) {

		int value = hex_to_bin(**cp);



		if (value < 0)

			break;

		*val = *val * 16 + value;

		(*cp)++;

		diff++;

	}



	if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))

		return 1;



	return 0;

}



static int __init parse_busid(char *str, unsigned int *cssid,

			      unsigned int *ssid, unsigned int *devno)

{

	char *str_work;

	int rc, ret;



	rc = 1;



	if (*str == '\0')

		goto out;



	str_work = str;

	ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);

	if (ret || (str_work[0] != '.'))

		goto out;

	str_work++;

	ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);

	if (ret || (str_work[0] != '.'))

		goto out;

	str_work++;

	ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);

	if (ret || (str_work[0] != '\0'))

		goto out;



	rc = 0;

out:

	return rc;

}



static void __init no_auto_parse(void)

{

	unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;

	char *parm, *str;

	int rc;



	str = no_auto;

	while ((parm = strsep(&str, ","))) {

		rc = parse_busid(strsep(&parm, "-"), &from_cssid,

				 &from_ssid, &from);

		if (rc)

			continue;

		if (parm != NULL) {

			rc = parse_busid(parm, &to_cssid,

					 &to_ssid, &to);

			if ((from_ssid > to_ssid) ||

			    ((from_ssid == to_ssid) && (from > to)))

				rc = -EINVAL;

		} else {

			to_cssid = from_cssid;

			to_ssid = from_ssid;

			to = from;

		}

		if (rc)

			continue;

		while ((from_ssid < to_ssid) ||

		       ((from_ssid == to_ssid) && (from <= to))) {

			set_bit(from, devs_no_auto[from_ssid]);

			from++;

			if (from > __MAX_SUBCHANNEL) {

				from_ssid++;

				from = 0;

			}

		}

	}

}



static int __init virtio_ccw_init(void)

{

	/* parse no_auto string before we do anything further */

	no_auto_parse();

	return ccw_driver_register(&virtio_ccw_driver);

}

module_init(virtio_ccw_init);



static void __exit virtio_ccw_exit(void)

{

	ccw_driver_unregister(&virtio_ccw_driver);

}

module_exit(virtio_ccw_exit);