virtio_ccw.c 30.6 KB
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/*
 * ccw based virtio transport
 *
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 * Copyright IBM Corp. 2012, 2014
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 *
 * 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>
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#include <linux/notifier.h>
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#include <asm/setup.h>
#include <asm/irq.h>
#include <asm/cio.h>
#include <asm/ccwdev.h>
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#include <asm/virtio-ccw.h>
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#include <asm/isc.h>
#include <asm/airq.h>
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/*
 * 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;
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	__u8 *status;
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	__u8 config[VIRTIO_CCW_CONFIG_SIZE];
	struct ccw_device *cdev;
	__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;
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	bool is_thinint;
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	bool going_away;
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	bool device_lost;
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	void *airq_info;
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};

struct vq_info_block {
	__u64 queue;
	__u32 align;
	__u16 index;
	__u16 num;
} __packed;

struct virtio_feature_desc {
	__u32 features;
	__u8 index;
} __packed;

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struct virtio_thinint_area {
	unsigned long summary_indicator;
	unsigned long indicator;
	u64 bit_nr;
	u8 isc;
} __packed;

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struct virtio_ccw_vq_info {
	struct virtqueue *vq;
	int num;
	void *queue;
	struct vq_info_block *info_block;
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	int bit_nr;
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	struct list_head node;
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	long cookie;
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};

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#define VIRTIO_AIRQ_ISC IO_SCH_ISC /* inherit from subchannel */

#define VIRTIO_IV_BITS (L1_CACHE_BYTES * 8)
#define MAX_AIRQ_AREAS 20

static int virtio_ccw_use_airq = 1;

struct airq_info {
	rwlock_t lock;
	u8 summary_indicator;
	struct airq_struct airq;
	struct airq_iv *aiv;
};
static struct airq_info *airq_areas[MAX_AIRQ_AREAS];

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#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
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#define CCW_CMD_SET_IND_ADAPTER 0x73
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#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
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#define VIRTIO_CCW_DOING_SET_IND_ADAPTER 0x08000000
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#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);
}

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static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info)
{
	unsigned long i, flags;

	write_lock_irqsave(&info->lock, flags);
	for (i = 0; i < airq_iv_end(info->aiv); i++) {
		if (vq == (void *)airq_iv_get_ptr(info->aiv, i)) {
			airq_iv_free_bit(info->aiv, i);
			airq_iv_set_ptr(info->aiv, i, 0);
			break;
		}
	}
	write_unlock_irqrestore(&info->lock, flags);
}

static void virtio_airq_handler(struct airq_struct *airq)
{
	struct airq_info *info = container_of(airq, struct airq_info, airq);
	unsigned long ai;

	inc_irq_stat(IRQIO_VAI);
	read_lock(&info->lock);
	/* Walk through indicators field, summary indicator active. */
	for (ai = 0;;) {
		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
		if (ai == -1UL)
			break;
		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
	}
	info->summary_indicator = 0;
	smp_wmb();
	/* Walk through indicators field, summary indicator not active. */
	for (ai = 0;;) {
		ai = airq_iv_scan(info->aiv, ai, airq_iv_end(info->aiv));
		if (ai == -1UL)
			break;
		vring_interrupt(0, (void *)airq_iv_get_ptr(info->aiv, ai));
	}
	read_unlock(&info->lock);
}

static struct airq_info *new_airq_info(void)
{
	struct airq_info *info;
	int rc;

	info = kzalloc(sizeof(*info), GFP_KERNEL);
	if (!info)
		return NULL;
	rwlock_init(&info->lock);
	info->aiv = airq_iv_create(VIRTIO_IV_BITS, AIRQ_IV_ALLOC | AIRQ_IV_PTR);
	if (!info->aiv) {
		kfree(info);
		return NULL;
	}
	info->airq.handler = virtio_airq_handler;
	info->airq.lsi_ptr = &info->summary_indicator;
	info->airq.lsi_mask = 0xff;
	info->airq.isc = VIRTIO_AIRQ_ISC;
	rc = register_adapter_interrupt(&info->airq);
	if (rc) {
		airq_iv_release(info->aiv);
		kfree(info);
		return NULL;
	}
	return info;
}

static void destroy_airq_info(struct airq_info *info)
{
	if (!info)
		return;

	unregister_adapter_interrupt(&info->airq);
	airq_iv_release(info->aiv);
	kfree(info);
}

static unsigned long get_airq_indicator(struct virtqueue *vqs[], int nvqs,
					u64 *first, void **airq_info)
{
	int i, j;
	struct airq_info *info;
	unsigned long indicator_addr = 0;
	unsigned long bit, flags;

	for (i = 0; i < MAX_AIRQ_AREAS && !indicator_addr; i++) {
		if (!airq_areas[i])
			airq_areas[i] = new_airq_info();
		info = airq_areas[i];
		if (!info)
			return 0;
		write_lock_irqsave(&info->lock, flags);
		bit = airq_iv_alloc(info->aiv, nvqs);
		if (bit == -1UL) {
			/* Not enough vacancies. */
			write_unlock_irqrestore(&info->lock, flags);
			continue;
		}
		*first = bit;
		*airq_info = info;
		indicator_addr = (unsigned long)info->aiv->vector;
		for (j = 0; j < nvqs; j++) {
			airq_iv_set_ptr(info->aiv, bit + j,
					(unsigned long)vqs[j]);
		}
		write_unlock_irqrestore(&info->lock, flags);
	}
	return indicator_addr;
}

static void virtio_ccw_drop_indicators(struct virtio_ccw_device *vcdev)
{
	struct virtio_ccw_vq_info *info;

	list_for_each_entry(info, &vcdev->virtqueues, node)
		drop_airq_indicator(info->vq, vcdev->airq_info);
}

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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;
}

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static int ccw_io_helper(struct virtio_ccw_device *vcdev,
			 struct ccw1 *ccw, __u32 intparm)
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{
	int ret;
	unsigned long flags;
	int flag = intparm & VIRTIO_CCW_INTPARM_MASK;

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	do {
		spin_lock_irqsave(get_ccwdev_lock(vcdev->cdev), flags);
		ret = ccw_device_start(vcdev->cdev, ccw, intparm, 0, 0);
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		if (!ret) {
			if (!vcdev->curr_io)
				vcdev->err = 0;
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			vcdev->curr_io |= flag;
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		}
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		spin_unlock_irqrestore(get_ccwdev_lock(vcdev->cdev), flags);
		cpu_relax();
	} while (ret == -EBUSY);
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	wait_event(vcdev->wait_q, doing_io(vcdev, flag) == 0);
	return ret ? ret : vcdev->err;
}

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static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev,
				      struct ccw1 *ccw)
{
	int ret;
	unsigned long *indicatorp = NULL;
	struct virtio_thinint_area *thinint_area = NULL;
	struct airq_info *airq_info = vcdev->airq_info;

	if (vcdev->is_thinint) {
		thinint_area = kzalloc(sizeof(*thinint_area),
				       GFP_DMA | GFP_KERNEL);
		if (!thinint_area)
			return;
		thinint_area->summary_indicator =
			(unsigned long) &airq_info->summary_indicator;
		thinint_area->isc = VIRTIO_AIRQ_ISC;
		ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
		ccw->count = sizeof(*thinint_area);
		ccw->cda = (__u32)(unsigned long) thinint_area;
	} else {
		indicatorp = kmalloc(sizeof(&vcdev->indicators),
				     GFP_DMA | GFP_KERNEL);
		if (!indicatorp)
			return;
		*indicatorp = 0;
		ccw->cmd_code = CCW_CMD_SET_IND;
		ccw->count = sizeof(vcdev->indicators);
		ccw->cda = (__u32)(unsigned long) indicatorp;
	}
	/* Deregister indicators from host. */
	vcdev->indicators = 0;
	ccw->flags = 0;
	ret = ccw_io_helper(vcdev, ccw,
			    vcdev->is_thinint ?
			    VIRTIO_CCW_DOING_SET_IND_ADAPTER :
			    VIRTIO_CCW_DOING_SET_IND);
	if (ret && (ret != -ENODEV))
		dev_info(&vcdev->cdev->dev,
			 "Failed to deregister indicators (%d)\n", ret);
	else if (vcdev->is_thinint)
		virtio_ccw_drop_indicators(vcdev);
	kfree(indicatorp);
	kfree(thinint_area);
}

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static inline long do_kvm_notify(struct subchannel_id schid,
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				 unsigned long queue_index,
				 long cookie)
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{
	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");
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	register long __cookie asm("4") = cookie;
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	asm volatile ("diag 2,4,0x500\n"
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		      : "=d" (__rc) : "d" (__nr), "d" (__schid), "d" (__index),
		      "d"(__cookie)
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		      : "memory", "cc");
	return __rc;
}

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static bool virtio_ccw_kvm_notify(struct virtqueue *vq)
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{
	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);
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	info->cookie = do_kvm_notify(schid, vq->index, info->cookie);
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	if (info->cookie < 0)
		return false;
	return true;
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}

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static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,
				   struct ccw1 *ccw, int index)
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{
	vcdev->config_block->index = index;
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	ccw->cmd_code = CCW_CMD_READ_VQ_CONF;
	ccw->flags = 0;
	ccw->count = sizeof(struct vq_config_block);
	ccw->cda = (__u32)(unsigned long)(vcdev->config_block);
	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_VQ_CONF);
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	return vcdev->config_block->num;
}

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static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
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{
	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;
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	unsigned int index = vq->index;
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	/* 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;
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	ccw->cmd_code = CCW_CMD_SET_VQ;
	ccw->flags = 0;
	ccw->count = sizeof(*info->info_block);
	ccw->cda = (__u32)(unsigned long)(info->info_block);
	ret = ccw_io_helper(vcdev, ccw,
			    VIRTIO_CCW_DOING_SET_VQ | index);
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	/*
	 * -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;
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	struct ccw1 *ccw;
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	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
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	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
	if (!ccw)
		return;

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	virtio_ccw_drop_indicator(vcdev, ccw);
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	list_for_each_entry_safe(vq, n, &vdev->vqs, list)
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		virtio_ccw_del_vq(vq, ccw);

	kfree(ccw);
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}

static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
					     int i, vq_callback_t *callback,
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					     const char *name,
					     struct ccw1 *ccw)
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{
	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
	int err;
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	struct virtqueue *vq = NULL;
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	struct virtio_ccw_vq_info *info;
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	unsigned long size = 0; /* silence the compiler */
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	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;
	}
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	info->num = virtio_ccw_read_vq_conf(vcdev, ccw, i);
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	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;
		goto out_err;
	}

	/* 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;
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	ccw->cmd_code = CCW_CMD_SET_VQ;
	ccw->flags = 0;
	ccw->count = sizeof(*info->info_block);
	ccw->cda = (__u32)(unsigned long)(info->info_block);
	err = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_VQ | i);
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	if (err) {
		dev_warn(&vcdev->cdev->dev, "SET_VQ failed\n");
		goto out_err;
	}

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	info->vq = vq;
	vq->priv = info;

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	/* 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:
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	if (vq)
		vring_del_virtqueue(vq);
	if (info) {
		if (info->queue)
			free_pages_exact(info->queue, size);
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		kfree(info->info_block);
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	}
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	kfree(info);
	return ERR_PTR(err);
}

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static int virtio_ccw_register_adapter_ind(struct virtio_ccw_device *vcdev,
					   struct virtqueue *vqs[], int nvqs,
					   struct ccw1 *ccw)
{
	int ret;
	struct virtio_thinint_area *thinint_area = NULL;
	struct airq_info *info;

	thinint_area = kzalloc(sizeof(*thinint_area), GFP_DMA | GFP_KERNEL);
	if (!thinint_area) {
		ret = -ENOMEM;
		goto out;
	}
	/* Try to get an indicator. */
	thinint_area->indicator = get_airq_indicator(vqs, nvqs,
						     &thinint_area->bit_nr,
						     &vcdev->airq_info);
	if (!thinint_area->indicator) {
		ret = -ENOSPC;
		goto out;
	}
	info = vcdev->airq_info;
	thinint_area->summary_indicator =
		(unsigned long) &info->summary_indicator;
	thinint_area->isc = VIRTIO_AIRQ_ISC;
	ccw->cmd_code = CCW_CMD_SET_IND_ADAPTER;
	ccw->flags = CCW_FLAG_SLI;
	ccw->count = sizeof(*thinint_area);
	ccw->cda = (__u32)(unsigned long)thinint_area;
	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND_ADAPTER);
	if (ret) {
		if (ret == -EOPNOTSUPP) {
			/*
			 * The host does not support adapter interrupts
			 * for virtio-ccw, stop trying.
			 */
			virtio_ccw_use_airq = 0;
			pr_info("Adapter interrupts unsupported on host\n");
		} else
			dev_warn(&vcdev->cdev->dev,
				 "enabling adapter interrupts = %d\n", ret);
		virtio_ccw_drop_indicators(vcdev);
	}
out:
	kfree(thinint_area);
	return ret;
}

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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;
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	struct ccw1 *ccw;

	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
	if (!ccw)
		return -ENOMEM;
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	for (i = 0; i < nvqs; ++i) {
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		vqs[i] = virtio_ccw_setup_vq(vdev, i, callbacks[i], names[i],
					     ccw);
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		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;
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	if (vcdev->is_thinint) {
		ret = virtio_ccw_register_adapter_ind(vcdev, vqs, nvqs, ccw);
		if (ret)
			/* no error, just fall back to legacy interrupts */
			vcdev->is_thinint = 0;
	}
	if (!vcdev->is_thinint) {
		/* Register queue indicators with host. */
		vcdev->indicators = 0;
		ccw->cmd_code = CCW_CMD_SET_IND;
		ccw->flags = 0;
		ccw->count = sizeof(vcdev->indicators);
		ccw->cda = (__u32)(unsigned long) indicatorp;
		ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_IND);
		if (ret)
			goto out;
	}
621 622 623
	/* Register indicators2 with host for config changes */
	*indicatorp = (unsigned long) &vcdev->indicators2;
	vcdev->indicators2 = 0;
624 625 626 627 628
	ccw->cmd_code = CCW_CMD_SET_CONF_IND;
	ccw->flags = 0;
	ccw->count = sizeof(vcdev->indicators2);
	ccw->cda = (__u32)(unsigned long) indicatorp;
	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_SET_CONF_IND);
629 630 631 632
	if (ret)
		goto out;

	kfree(indicatorp);
633
	kfree(ccw);
634 635 636
	return 0;
out:
	kfree(indicatorp);
637
	kfree(ccw);
638 639 640 641 642 643 644
	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);
645 646 647 648 649
	struct ccw1 *ccw;

	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
	if (!ccw)
		return;
650 651

	/* Zero status bits. */
652
	*vcdev->status = 0;
653 654

	/* Send a reset ccw on device. */
655 656 657 658 659 660
	ccw->cmd_code = CCW_CMD_VDEV_RESET;
	ccw->flags = 0;
	ccw->count = 0;
	ccw->cda = 0;
	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_RESET);
	kfree(ccw);
661 662 663 664 665
}

static u32 virtio_ccw_get_features(struct virtio_device *vdev)
{
	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
666 667 668
	struct virtio_feature_desc *features;
	int ret, rc;
	struct ccw1 *ccw;
669

670 671 672 673 674 675 676 677 678
	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
	if (!ccw)
		return 0;

	features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
	if (!features) {
		rc = 0;
		goto out_free;
	}
679 680
	/* Read the feature bits from the host. */
	/* TODO: Features > 32 bits */
681 682 683 684 685 686 687 688 689 690 691 692
	features->index = 0;
	ccw->cmd_code = CCW_CMD_READ_FEAT;
	ccw->flags = 0;
	ccw->count = sizeof(*features);
	ccw->cda = (__u32)(unsigned long)features;
	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_FEAT);
	if (ret) {
		rc = 0;
		goto out_free;
	}

	rc = le32_to_cpu(features->features);
693

694 695 696 697
out_free:
	kfree(features);
	kfree(ccw);
	return rc;
698 699 700 701 702
}

static void virtio_ccw_finalize_features(struct virtio_device *vdev)
{
	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
703
	struct virtio_feature_desc *features;
704
	int i;
705 706 707 708 709 710 711 712 713
	struct ccw1 *ccw;

	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
	if (!ccw)
		return;

	features = kzalloc(sizeof(*features), GFP_DMA | GFP_KERNEL);
	if (!features)
		goto out_free;
714 715 716 717

	/* Give virtio_ring a chance to accept features. */
	vring_transport_features(vdev);

718
	for (i = 0; i < sizeof(*vdev->features) / sizeof(features->features);
719 720
	     i++) {
		int highbits = i % 2 ? 32 : 0;
721 722 723
		features->index = i;
		features->features = cpu_to_le32(vdev->features[i / 2]
						 >> highbits);
724
		/* Write the feature bits to the host. */
725 726 727 728 729
		ccw->cmd_code = CCW_CMD_WRITE_FEAT;
		ccw->flags = 0;
		ccw->count = sizeof(*features);
		ccw->cda = (__u32)(unsigned long)features;
		ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
730
	}
731 732 733
out_free:
	kfree(features);
	kfree(ccw);
734 735 736 737 738 739 740
}

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;
741 742 743 744 745 746 747 748 749 750
	struct ccw1 *ccw;
	void *config_area;

	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
	if (!ccw)
		return;

	config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
	if (!config_area)
		goto out_free;
751 752

	/* Read the config area from the host. */
753 754 755 756 757
	ccw->cmd_code = CCW_CMD_READ_CONF;
	ccw->flags = 0;
	ccw->count = offset + len;
	ccw->cda = (__u32)(unsigned long)config_area;
	ret = ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_READ_CONFIG);
758
	if (ret)
759
		goto out_free;
760

761
	memcpy(vcdev->config, config_area, sizeof(vcdev->config));
762
	memcpy(buf, &vcdev->config[offset], len);
763 764 765 766

out_free:
	kfree(config_area);
	kfree(ccw);
767 768 769 770 771 772 773
}

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);
774 775 776 777 778 779 780 781 782 783
	struct ccw1 *ccw;
	void *config_area;

	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
	if (!ccw)
		return;

	config_area = kzalloc(VIRTIO_CCW_CONFIG_SIZE, GFP_DMA | GFP_KERNEL);
	if (!config_area)
		goto out_free;
784 785 786

	memcpy(&vcdev->config[offset], buf, len);
	/* Write the config area to the host. */
787 788 789 790 791 792 793 794 795 796
	memcpy(config_area, vcdev->config, sizeof(vcdev->config));
	ccw->cmd_code = CCW_CMD_WRITE_CONF;
	ccw->flags = 0;
	ccw->count = offset + len;
	ccw->cda = (__u32)(unsigned long)config_area;
	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_CONFIG);

out_free:
	kfree(config_area);
	kfree(ccw);
797 798 799 800 801 802
}

static u8 virtio_ccw_get_status(struct virtio_device *vdev)
{
	struct virtio_ccw_device *vcdev = to_vc_device(vdev);

803
	return *vcdev->status;
804 805 806 807 808
}

static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
{
	struct virtio_ccw_device *vcdev = to_vc_device(vdev);
809 810 811 812 813
	struct ccw1 *ccw;

	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
	if (!ccw)
		return;
814 815

	/* Write the status to the host. */
816 817 818 819 820 821 822
	*vcdev->status = status;
	ccw->cmd_code = CCW_CMD_WRITE_STATUS;
	ccw->flags = 0;
	ccw->count = sizeof(status);
	ccw->cda = (__u32)(unsigned long)vcdev->status;
	ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS);
	kfree(ccw);
823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847
}

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);

848
	kfree(vcdev->status);
849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873
	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) {
874
		if (info->vq->index == index) {
875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891
			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;

892 893
	if (!vcdev)
		return;
894 895 896 897 898 899
	/* 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 */
	}
900 901 902 903 904 905 906 907 908
	if (irb_is_error(irb)) {
		/* Command reject? */
		if ((scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
		    (irb->ecw[0] & SNS0_CMD_REJECT))
			vcdev->err = -EOPNOTSUPP;
		else
			/* Map everything else to -EIO. */
			vcdev->err = -EIO;
	}
909 910 911 912 913 914 915 916 917 918 919 920
	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:
921
		case VIRTIO_CCW_DOING_SET_IND_ADAPTER:
922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941
			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)) {
942
		virtio_config_changed(&vcdev->vdev);
943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988
		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;
}

989 990 991 992 993 994 995
static struct virtio_ccw_device *virtio_grab_drvdata(struct ccw_device *cdev)
{
	unsigned long flags;
	struct virtio_ccw_device *vcdev;

	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
	vcdev = dev_get_drvdata(&cdev->dev);
996
	if (!vcdev || vcdev->going_away) {
997 998 999
		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
		return NULL;
	}
1000
	vcdev->going_away = true;
1001 1002 1003 1004
	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
	return vcdev;
}

1005 1006
static void virtio_ccw_remove(struct ccw_device *cdev)
{
1007
	unsigned long flags;
1008
	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1009

1010 1011 1012
	if (vcdev && cdev->online) {
		if (vcdev->device_lost)
			virtio_break_device(&vcdev->vdev);
1013
		unregister_virtio_device(&vcdev->vdev);
1014 1015 1016 1017
		spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
		dev_set_drvdata(&cdev->dev, NULL);
		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
	}
1018 1019 1020 1021 1022
	cdev->handler = NULL;
}

static int virtio_ccw_offline(struct ccw_device *cdev)
{
1023
	unsigned long flags;
1024
	struct virtio_ccw_device *vcdev = virtio_grab_drvdata(cdev);
1025

1026 1027 1028 1029 1030 1031 1032 1033
	if (!vcdev)
		return 0;
	if (vcdev->device_lost)
		virtio_break_device(&vcdev->vdev);
	unregister_virtio_device(&vcdev->vdev);
	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
	dev_set_drvdata(&cdev->dev, NULL);
	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1034 1035 1036 1037 1038 1039 1040 1041
	return 0;
}


static int virtio_ccw_online(struct ccw_device *cdev)
{
	int ret;
	struct virtio_ccw_device *vcdev;
1042
	unsigned long flags;
1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055

	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->config_block = kzalloc(sizeof(*vcdev->config_block),
				   GFP_DMA | GFP_KERNEL);
	if (!vcdev->config_block) {
		ret = -ENOMEM;
		goto out_free;
	}
1056 1057
	vcdev->status = kzalloc(sizeof(*vcdev->status), GFP_DMA | GFP_KERNEL);
	if (!vcdev->status) {
1058 1059 1060 1061
		ret = -ENOMEM;
		goto out_free;
	}

1062 1063
	vcdev->is_thinint = virtio_ccw_use_airq; /* at least try */

1064 1065 1066 1067 1068 1069 1070 1071
	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);

1072
	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1073
	dev_set_drvdata(&cdev->dev, vcdev);
1074
	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1075 1076 1077 1078 1079 1080 1081 1082 1083 1084
	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:
1085
	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
1086
	dev_set_drvdata(&cdev->dev, NULL);
1087
	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
1088 1089 1090 1091
	put_device(&vcdev->vdev.dev);
	return ret;
out_free:
	if (vcdev) {
1092
		kfree(vcdev->status);
1093 1094 1095 1096 1097 1098 1099 1100
		kfree(vcdev->config_block);
	}
	kfree(vcdev);
	return ret;
}

static int virtio_ccw_cio_notify(struct ccw_device *cdev, int event)
{
1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120
	int rc;
	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);

	/*
	 * Make sure vcdev is set
	 * i.e. set_offline/remove callback not already running
	 */
	if (!vcdev)
		return NOTIFY_DONE;

	switch (event) {
	case CIO_GONE:
		vcdev->device_lost = true;
		rc = NOTIFY_DONE;
		break;
	default:
		rc = NOTIFY_DONE;
		break;
	}
	return rc;
1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139
}

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,
1140
	.int_class = IRQIO_VIR,
1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242
};

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)
{
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	int i;

1245
	ccw_driver_unregister(&virtio_ccw_driver);
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	for (i = 0; i < MAX_AIRQ_AREAS; i++)
		destroy_airq_info(airq_areas[i]);
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}
module_exit(virtio_ccw_exit);