Re: [PATCH 3/4] s390/kvm: Add a channel I/O based virtio transport driver.

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Cornelia Huck <cornelia.huck@xxxxxxxxxx> writes:

> 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.
>
> Signed-off-by: Cornelia Huck <cornelia.huck@xxxxxxxxxx>

Hi,

Have you written an appendix for the virtio specification for
virtio-ccw?  I think it would be good to include in this series for the
purposes of review.

Regards,

Anthony Liguori

> ---
>  arch/s390/include/asm/irq.h   |   1 +
>  arch/s390/kernel/irq.c        |   1 +
>  drivers/s390/kvm/Makefile     |   2 +-
>  drivers/s390/kvm/virtio_ccw.c | 761 ++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 764 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/s390/kvm/virtio_ccw.c
>
> diff --git a/arch/s390/include/asm/irq.h b/arch/s390/include/asm/irq.h
> index 2b9d418..b4bea53 100644
> --- a/arch/s390/include/asm/irq.h
> +++ b/arch/s390/include/asm/irq.h
> @@ -31,6 +31,7 @@ enum interruption_class {
>  	IOINT_CTC,
>  	IOINT_APB,
>  	IOINT_CSC,
> +	IOINT_VIR,
>  	NMI_NMI,
>  	NR_IRQS,
>  };
> diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c
> index dd7630d..2cc7eed 100644
> --- a/arch/s390/kernel/irq.c
> +++ b/arch/s390/kernel/irq.c
> @@ -56,6 +56,7 @@ static const struct irq_class intrclass_names[] = {
>  	{.name = "CTC", .desc = "[I/O] CTC" },
>  	{.name = "APB", .desc = "[I/O] AP Bus" },
>  	{.name = "CSC", .desc = "[I/O] CHSC Subchannel" },
> +	{.name = "VIR", .desc = "[I/O] Virtual I/O Devices" },
>  	{.name = "NMI", .desc = "[NMI] Machine Check" },
>  };
>  
> diff --git a/drivers/s390/kvm/Makefile b/drivers/s390/kvm/Makefile
> index 0815690..241891a 100644
> --- a/drivers/s390/kvm/Makefile
> +++ b/drivers/s390/kvm/Makefile
> @@ -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
> diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c
> new file mode 100644
> index 0000000..df0f994
> --- /dev/null
> +++ b/drivers/s390/kvm/virtio_ccw.c
> @@ -0,0 +1,761 @@
> +/*
> + * 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@xxxxxxxxxx>
> + */
> +
> +#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/virtio_console.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 <asm/io.h>
> +#include <asm/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;
> +} __attribute__ ((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; /* XXX - works because we're under 64 bit */
> +	struct vq_config_block *config_block;
> +};
> +
> +struct vq_info_block {
> +	__u64 queue;
> +	__u16 num;
> +} __attribute__ ((packed));
> +
> +struct virtio_ccw_vq_info {
> +	struct virtqueue *vq;
> +	int num;
> +	int queue_index;
> +	void *queue;
> +	struct vq_info_block *info_block;
> +	struct list_head node;
> +};
> +
> +#define KVM_VIRTIO_CCW_RING_ALIGN 4096
> +
> +#define CCW_CMD_SET_VQ 0x13
> +#define CCW_CMD_VDEV_RESET 0x33
> +#define CCW_CMD_SET_IND 0x43
> +#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_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 = vcdev->err;
> +	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 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;
> +	__u32 reg2;
> +
> +	vcdev = to_vc_device(info->vq->vdev);
> +	ccw_device_get_schid(vcdev->cdev, &schid);
> +	reg2 = *(__u32 *)&schid;
> +	kvm_hypercall2(3 /* CCW_NOTIFY */, reg2, info->queue_index);
> +}
> +
> +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;
> +
> +	/* 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->num = info->queue_index;
> +	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 | info->queue_index);
> +	if (ret)
> +		dev_warn(&vq->vdev->dev, "Error %x while deleting queue %d",
> +			 ret, info->queue_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->queue_index = i;
> +	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(info->num, KVM_VIRTIO_CCW_RING_ALIGN, vdev,
> +				 true, info->queue, virtio_ccw_kvm_notify,
> +				 callback, name);
> +	if (!vq) {
> +		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->num = info->queue_index;
> +	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 | info->queue_index);
> +	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);
> +	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;
> +		}
> +	}
> +	/* 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)(&vcdev->indicators);
> +	ret = ccw_io_helper(vcdev, VIRTIO_CCW_DOING_SET_IND);
> +	if (ret)
> +		goto out;
> +	return 0;
> +out:
> +	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);
> +
> +	/* 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);
> +	u32 features;
> +	int ret;
> +
> +	/* Read the feature bits from the host. */
> +	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);
> +}
> +
> +static void virtio_ccw_finalize_features(struct virtio_device *vdev)
> +{
> +	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
> +
> +	/* Give virtio_ring a chance to accept features. */
> +	vring_transport_features(vdev);
> +
> +	memcpy((void *)(unsigned long)vcdev->area, vdev->features,
> +	       sizeof(*vdev->features));
> +	/* Write the feature bits to the host. */
> +	vcdev->ccw.cmd_code = CCW_CMD_WRITE_FEAT;
> +	/* Sigh. The kernel's features may be longer than the host's. */
> +	vcdev->ccw.flags = CCW_FLAG_SLI;
> +	vcdev->ccw.count = sizeof(*vdev->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);
> +}
> +
> +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 (info->queue_index == 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;
> +
> +	/* 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_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)) {
> +		vq = virtio_ccw_vq_by_ind(vcdev, i);
> +		vring_interrupt(0, vq);
> +		clear_bit(i, &vcdev->indicators);
> +	}
> +}
> +
> +/*
> + * 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)
> +{
> +	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->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);
> +
> +	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);
> +	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);
> -- 
> 1.7.11.4
>
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