[mirror_ubuntu-bionic-kernel.git] / drivers / s390 / cio / vfio_ccw_ops.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Physical device callbacks for vfio_ccw
 *
 * Copyright IBM Corp. 2017
 *
 * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
 *            Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
 */

#include <linux/vfio.h>
#include <linux/mdev.h>

#include "vfio_ccw_private.h"

static int vfio_ccw_mdev_reset(struct mdev_device *mdev)
{
	struct vfio_ccw_private *private;
	struct subchannel *sch;
	int ret;

	private = dev_get_drvdata(mdev_parent_dev(mdev));
	sch = private->sch;
	/*
	 * TODO:
	 * In the cureent stage, some things like "no I/O running" and "no
	 * interrupt pending" are clear, but we are not sure what other state
	 * we need to care about.
	 * There are still a lot more instructions need to be handled. We
	 * should come back here later.
	 */
	ret = vfio_ccw_sch_quiesce(sch);
	if (ret)
		return ret;

	ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch);
	if (!ret)
		private->state = VFIO_CCW_STATE_IDLE;

	return ret;
}

static int vfio_ccw_mdev_notifier(struct notifier_block *nb,
				  unsigned long action,
				  void *data)
{
	struct vfio_ccw_private *private =
		container_of(nb, struct vfio_ccw_private, nb);

	/*
	 * Vendor drivers MUST unpin pages in response to an
	 * invalidation.
	 */
	if (action == VFIO_IOMMU_NOTIFY_DMA_UNMAP) {
		struct vfio_iommu_type1_dma_unmap *unmap = data;

		if (!cp_iova_pinned(&private->cp, unmap->iova))
			return NOTIFY_OK;

		if (vfio_ccw_mdev_reset(private->mdev))
			return NOTIFY_BAD;

		cp_free(&private->cp);
		return NOTIFY_OK;
	}

	return NOTIFY_DONE;
}

static ssize_t name_show(struct kobject *kobj, struct device *dev, char *buf)
{
	return sprintf(buf, "I/O subchannel (Non-QDIO)\n");
}
static MDEV_TYPE_ATTR_RO(name);

static ssize_t device_api_show(struct kobject *kobj, struct device *dev,
			       char *buf)
{
	return sprintf(buf, "%s\n", VFIO_DEVICE_API_CCW_STRING);
}
static MDEV_TYPE_ATTR_RO(device_api);

static ssize_t available_instances_show(struct kobject *kobj,
					struct device *dev, char *buf)
{
	struct vfio_ccw_private *private = dev_get_drvdata(dev);

	return sprintf(buf, "%d\n", atomic_read(&private->avail));
}
static MDEV_TYPE_ATTR_RO(available_instances);

static struct attribute *mdev_types_attrs[] = {
	&mdev_type_attr_name.attr,
	&mdev_type_attr_device_api.attr,
	&mdev_type_attr_available_instances.attr,
	NULL,
};

static struct attribute_group mdev_type_group = {
	.name  = "io",
	.attrs = mdev_types_attrs,
};

static struct attribute_group *mdev_type_groups[] = {
	&mdev_type_group,
	NULL,
};

static int vfio_ccw_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
{
	struct vfio_ccw_private *private =
		dev_get_drvdata(mdev_parent_dev(mdev));

	if (private->state == VFIO_CCW_STATE_NOT_OPER)
		return -ENODEV;

	if (atomic_dec_if_positive(&private->avail) < 0)
		return -EPERM;

	private->mdev = mdev;
	private->state = VFIO_CCW_STATE_IDLE;

	return 0;
}

static int vfio_ccw_mdev_remove(struct mdev_device *mdev)
{
	struct vfio_ccw_private *private =
		dev_get_drvdata(mdev_parent_dev(mdev));

	if ((private->state != VFIO_CCW_STATE_NOT_OPER) &&
	    (private->state != VFIO_CCW_STATE_STANDBY)) {
		if (!vfio_ccw_mdev_reset(mdev))
			private->state = VFIO_CCW_STATE_STANDBY;
		/* The state will be NOT_OPER on error. */
	}

	private->mdev = NULL;
	atomic_inc(&private->avail);

	return 0;
}

static int vfio_ccw_mdev_open(struct mdev_device *mdev)
{
	struct vfio_ccw_private *private =
		dev_get_drvdata(mdev_parent_dev(mdev));
	unsigned long events = VFIO_IOMMU_NOTIFY_DMA_UNMAP;

	private->nb.notifier_call = vfio_ccw_mdev_notifier;

	return vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
				      &events, &private->nb);
}

static void vfio_ccw_mdev_release(struct mdev_device *mdev)
{
	struct vfio_ccw_private *private =
		dev_get_drvdata(mdev_parent_dev(mdev));

	vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
				 &private->nb);
}

static ssize_t vfio_ccw_mdev_read(struct mdev_device *mdev,
				  char __user *buf,
				  size_t count,
				  loff_t *ppos)
{
	struct vfio_ccw_private *private;
	struct ccw_io_region *region;

	if (*ppos + count > sizeof(*region))
		return -EINVAL;

	private = dev_get_drvdata(mdev_parent_dev(mdev));
	region = &private->io_region;
	if (copy_to_user(buf, (void *)region + *ppos, count))
		return -EFAULT;

	return count;
}

static ssize_t vfio_ccw_mdev_write(struct mdev_device *mdev,
				   const char __user *buf,
				   size_t count,
				   loff_t *ppos)
{
	struct vfio_ccw_private *private;
	struct ccw_io_region *region;

	if (*ppos + count > sizeof(*region))
		return -EINVAL;

	private = dev_get_drvdata(mdev_parent_dev(mdev));
	if (private->state != VFIO_CCW_STATE_IDLE)
		return -EACCES;

	region = &private->io_region;
	if (copy_from_user((void *)region + *ppos, buf, count))
		return -EFAULT;

	vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_IO_REQ);
	if (region->ret_code != 0) {
		private->state = VFIO_CCW_STATE_IDLE;
		return region->ret_code;
	}

	return count;
}

static int vfio_ccw_mdev_get_device_info(struct vfio_device_info *info)
{
	info->flags = VFIO_DEVICE_FLAGS_CCW | VFIO_DEVICE_FLAGS_RESET;
	info->num_regions = VFIO_CCW_NUM_REGIONS;
	info->num_irqs = VFIO_CCW_NUM_IRQS;

	return 0;
}

static int vfio_ccw_mdev_get_region_info(struct vfio_region_info *info,
					 u16 *cap_type_id,
					 void **cap_type)
{
	switch (info->index) {
	case VFIO_CCW_CONFIG_REGION_INDEX:
		info->offset = 0;
		info->size = sizeof(struct ccw_io_region);
		info->flags = VFIO_REGION_INFO_FLAG_READ
			      | VFIO_REGION_INFO_FLAG_WRITE;
		return 0;
	default:
		return -EINVAL;
	}
}

static int vfio_ccw_mdev_get_irq_info(struct vfio_irq_info *info)
{
	if (info->index != VFIO_CCW_IO_IRQ_INDEX)
		return -EINVAL;

	info->count = 1;
	info->flags = VFIO_IRQ_INFO_EVENTFD;

	return 0;
}

static int vfio_ccw_mdev_set_irqs(struct mdev_device *mdev,
				  uint32_t flags,
				  void __user *data)
{
	struct vfio_ccw_private *private;
	struct eventfd_ctx **ctx;

	if (!(flags & VFIO_IRQ_SET_ACTION_TRIGGER))
		return -EINVAL;

	private = dev_get_drvdata(mdev_parent_dev(mdev));
	ctx = &private->io_trigger;

	switch (flags & VFIO_IRQ_SET_DATA_TYPE_MASK) {
	case VFIO_IRQ_SET_DATA_NONE:
	{
		if (*ctx)
			eventfd_signal(*ctx, 1);
		return 0;
	}
	case VFIO_IRQ_SET_DATA_BOOL:
	{
		uint8_t trigger;

		if (get_user(trigger, (uint8_t __user *)data))
			return -EFAULT;

		if (trigger && *ctx)
			eventfd_signal(*ctx, 1);
		return 0;
	}
	case VFIO_IRQ_SET_DATA_EVENTFD:
	{
		int32_t fd;

		if (get_user(fd, (int32_t __user *)data))
			return -EFAULT;

		if (fd == -1) {
			if (*ctx)
				eventfd_ctx_put(*ctx);
			*ctx = NULL;
		} else if (fd >= 0) {
			struct eventfd_ctx *efdctx;

			efdctx = eventfd_ctx_fdget(fd);
			if (IS_ERR(efdctx))
				return PTR_ERR(efdctx);

			if (*ctx)
				eventfd_ctx_put(*ctx);

			*ctx = efdctx;
		} else
			return -EINVAL;

		return 0;
	}
	default:
		return -EINVAL;
	}
}

static ssize_t vfio_ccw_mdev_ioctl(struct mdev_device *mdev,
				   unsigned int cmd,
				   unsigned long arg)
{
	int ret = 0;
	unsigned long minsz;

	switch (cmd) {
	case VFIO_DEVICE_GET_INFO:
	{
		struct vfio_device_info info;

		minsz = offsetofend(struct vfio_device_info, num_irqs);

		if (copy_from_user(&info, (void __user *)arg, minsz))
			return -EFAULT;

		if (info.argsz < minsz)
			return -EINVAL;

		ret = vfio_ccw_mdev_get_device_info(&info);
		if (ret)
			return ret;

		return copy_to_user((void __user *)arg, &info, minsz);
	}
	case VFIO_DEVICE_GET_REGION_INFO:
	{
		struct vfio_region_info info;
		u16 cap_type_id = 0;
		void *cap_type = NULL;

		minsz = offsetofend(struct vfio_region_info, offset);

		if (copy_from_user(&info, (void __user *)arg, minsz))
			return -EFAULT;

		if (info.argsz < minsz)
			return -EINVAL;

		ret = vfio_ccw_mdev_get_region_info(&info, &cap_type_id,
						    &cap_type);
		if (ret)
			return ret;

		return copy_to_user((void __user *)arg, &info, minsz);
	}
	case VFIO_DEVICE_GET_IRQ_INFO:
	{
		struct vfio_irq_info info;

		minsz = offsetofend(struct vfio_irq_info, count);

		if (copy_from_user(&info, (void __user *)arg, minsz))
			return -EFAULT;

		if (info.argsz < minsz || info.index >= VFIO_CCW_NUM_IRQS)
			return -EINVAL;

		ret = vfio_ccw_mdev_get_irq_info(&info);
		if (ret)
			return ret;

		if (info.count == -1)
			return -EINVAL;

		return copy_to_user((void __user *)arg, &info, minsz);
	}
	case VFIO_DEVICE_SET_IRQS:
	{
		struct vfio_irq_set hdr;
		size_t data_size;
		void __user *data;

		minsz = offsetofend(struct vfio_irq_set, count);

		if (copy_from_user(&hdr, (void __user *)arg, minsz))
			return -EFAULT;

		ret = vfio_set_irqs_validate_and_prepare(&hdr, 1,
							 VFIO_CCW_NUM_IRQS,
							 &data_size);
		if (ret)
			return ret;

		data = (void __user *)(arg + minsz);
		return vfio_ccw_mdev_set_irqs(mdev, hdr.flags, data);
	}
	case VFIO_DEVICE_RESET:
		return vfio_ccw_mdev_reset(mdev);
	default:
		return -ENOTTY;
	}
}

static const struct mdev_parent_ops vfio_ccw_mdev_ops = {
	.owner			= THIS_MODULE,
	.supported_type_groups  = mdev_type_groups,
	.create			= vfio_ccw_mdev_create,
	.remove			= vfio_ccw_mdev_remove,
	.open			= vfio_ccw_mdev_open,
	.release		= vfio_ccw_mdev_release,
	.read			= vfio_ccw_mdev_read,
	.write			= vfio_ccw_mdev_write,
	.ioctl			= vfio_ccw_mdev_ioctl,
};

int vfio_ccw_mdev_reg(struct subchannel *sch)
{
	return mdev_register_device(&sch->dev, &vfio_ccw_mdev_ops);
}

void vfio_ccw_mdev_unreg(struct subchannel *sch)
{
	mdev_unregister_device(&sch->dev);
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
84cd8fc4 DJS	2	/*
	3	* Physical device callbacks for vfio_ccw
	4	*
	5	* Copyright IBM Corp. 2017
	6	*
	7	* Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
	8	* Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
	9	*/
	10
	11	#include <linux/vfio.h>
	12	#include <linux/mdev.h>
	13
	14	#include "vfio_ccw_private.h"
	15
83d1193a DJS	16	static int vfio_ccw_mdev_reset(struct mdev_device *mdev)
	17	{
	18	struct vfio_ccw_private *private;
	19	struct subchannel *sch;
	20	int ret;
	21
	22	private = dev_get_drvdata(mdev_parent_dev(mdev));
83d1193a DJS	23	sch = private->sch;
	24	/*
	25	* TODO:
	26	* In the cureent stage, some things like "no I/O running" and "no
	27	* interrupt pending" are clear, but we are not sure what other state
	28	* we need to care about.
	29	* There are still a lot more instructions need to be handled. We
	30	* should come back here later.
	31	*/
	32	ret = vfio_ccw_sch_quiesce(sch);
	33	if (ret)
	34	return ret;
	35
bbe37e4c DJS	36	ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch);
	37	if (!ret)
	38	private->state = VFIO_CCW_STATE_IDLE;
	39
	40	return ret;
83d1193a DJS	41	}
83d1193a DJS	42
84cd8fc4 DJS	43	static int vfio_ccw_mdev_notifier(struct notifier_block *nb,
	44	unsigned long action,
	45	void *data)
	46	{
	47	struct vfio_ccw_private *private =
	48	container_of(nb, struct vfio_ccw_private, nb);
	49
84cd8fc4	50	/*
84cd8fc4 DJS	51	* Vendor drivers MUST unpin pages in response to an
	52	* invalidation.
	53	*/
4e149e43 DJS	54	if (action == VFIO_IOMMU_NOTIFY_DMA_UNMAP) {
4e149e43 DJS	55	struct vfio_iommu_type1_dma_unmap *unmap = data;
4e149e43 DJS	56
	57	if (!cp_iova_pinned(&private->cp, unmap->iova))
	58	return NOTIFY_OK;
	59
83d1193a	60	if (vfio_ccw_mdev_reset(private->mdev))
4e149e43 DJS	61	return NOTIFY_BAD;
	62
	63	cp_free(&private->cp);
	64	return NOTIFY_OK;
	65	}
84cd8fc4 DJS	66
	67	return NOTIFY_DONE;
	68	}
	69
	70	static ssize_t name_show(struct kobject kobj, struct device dev, char *buf)
	71	{
	72	return sprintf(buf, "I/O subchannel (Non-QDIO)\n");
	73	}
5bf18536	74	static MDEV_TYPE_ATTR_RO(name);
84cd8fc4 DJS	75
	76	static ssize_t device_api_show(struct kobject kobj, struct device dev,
	77	char *buf)
	78	{
	79	return sprintf(buf, "%s\n", VFIO_DEVICE_API_CCW_STRING);
	80	}
5bf18536	81	static MDEV_TYPE_ATTR_RO(device_api);
84cd8fc4 DJS	82
	83	static ssize_t available_instances_show(struct kobject *kobj,
	84	struct device dev, char buf)
	85	{
	86	struct vfio_ccw_private *private = dev_get_drvdata(dev);
	87
	88	return sprintf(buf, "%d\n", atomic_read(&private->avail));
	89	}
5bf18536	90	static MDEV_TYPE_ATTR_RO(available_instances);
84cd8fc4 DJS	91
	92	static struct attribute *mdev_types_attrs[] = {
	93	&mdev_type_attr_name.attr,
	94	&mdev_type_attr_device_api.attr,
	95	&mdev_type_attr_available_instances.attr,
	96	NULL,
	97	};
	98
	99	static struct attribute_group mdev_type_group = {
	100	.name = "io",
	101	.attrs = mdev_types_attrs,
	102	};
	103
5bf18536	104	static struct attribute_group *mdev_type_groups[] = {
84cd8fc4 DJS	105	&mdev_type_group,
	106	NULL,
	107	};
	108
	109	static int vfio_ccw_mdev_create(struct kobject kobj, struct mdev_device mdev)
	110	{
	111	struct vfio_ccw_private *private =
	112	dev_get_drvdata(mdev_parent_dev(mdev));
	113
bbe37e4c DJS	114	if (private->state == VFIO_CCW_STATE_NOT_OPER)
	115	return -ENODEV;
	116
84cd8fc4 DJS	117	if (atomic_dec_if_positive(&private->avail) < 0)
	118	return -EPERM;
	119
	120	private->mdev = mdev;
bbe37e4c	121	private->state = VFIO_CCW_STATE_IDLE;
84cd8fc4 DJS	122
	123	return 0;
	124	}
	125
	126	static int vfio_ccw_mdev_remove(struct mdev_device *mdev)
	127	{
83d1193a DJS	128	struct vfio_ccw_private *private =
83d1193a DJS	129	dev_get_drvdata(mdev_parent_dev(mdev));
84cd8fc4	130
129cc19a DJS	131	if ((private->state != VFIO_CCW_STATE_NOT_OPER) &&
	132	(private->state != VFIO_CCW_STATE_STANDBY)) {
	133	if (!vfio_ccw_mdev_reset(mdev))
	134	private->state = VFIO_CCW_STATE_STANDBY;
	135	/* The state will be NOT_OPER on error. */
	136	}
bbe37e4c	137
84cd8fc4 DJS	138	private->mdev = NULL;
	139	atomic_inc(&private->avail);
	140
	141	return 0;
	142	}
	143
	144	static int vfio_ccw_mdev_open(struct mdev_device *mdev)
	145	{
	146	struct vfio_ccw_private *private =
	147	dev_get_drvdata(mdev_parent_dev(mdev));
	148	unsigned long events = VFIO_IOMMU_NOTIFY_DMA_UNMAP;
	149
	150	private->nb.notifier_call = vfio_ccw_mdev_notifier;
	151
	152	return vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
	153	&events, &private->nb);
	154	}
	155
5bf18536	156	static void vfio_ccw_mdev_release(struct mdev_device *mdev)
84cd8fc4 DJS	157	{
	158	struct vfio_ccw_private *private =
	159	dev_get_drvdata(mdev_parent_dev(mdev));
	160
	161	vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
	162	&private->nb);
	163	}
	164
060d2b5a DJS	165	static ssize_t vfio_ccw_mdev_read(struct mdev_device *mdev,
	166	char __user *buf,
	167	size_t count,
	168	loff_t *ppos)
	169	{
	170	struct vfio_ccw_private *private;
	171	struct ccw_io_region *region;
	172
	173	if (ppos + count > sizeof(region))
	174	return -EINVAL;
	175
	176	private = dev_get_drvdata(mdev_parent_dev(mdev));
060d2b5a DJS	177	region = &private->io_region;
	178	if (copy_to_user(buf, (void )region + ppos, count))
	179	return -EFAULT;
	180
	181	return count;
	182	}
	183
	184	static ssize_t vfio_ccw_mdev_write(struct mdev_device *mdev,
	185	const char __user *buf,
	186	size_t count,
	187	loff_t *ppos)
	188	{
	189	struct vfio_ccw_private *private;
	190	struct ccw_io_region *region;
	191
	192	if (ppos + count > sizeof(region))
	193	return -EINVAL;
	194
	195	private = dev_get_drvdata(mdev_parent_dev(mdev));
bbe37e4c DJS	196	if (private->state != VFIO_CCW_STATE_IDLE)
bbe37e4c DJS	197	return -EACCES;
060d2b5a DJS	198
	199	region = &private->io_region;
	200	if (copy_from_user((void )region + ppos, buf, count))
	201	return -EFAULT;
4e149e43	202
bbe37e4c DJS	203	vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_IO_REQ);
	204	if (region->ret_code != 0) {
	205	private->state = VFIO_CCW_STATE_IDLE;
4e149e43	206	return region->ret_code;
bbe37e4c	207	}
060d2b5a DJS	208
	209	return count;
	210	}
	211
e01bcdd6 DJS	212	static int vfio_ccw_mdev_get_device_info(struct vfio_device_info *info)
e01bcdd6 DJS	213	{
83d1193a	214	info->flags = VFIO_DEVICE_FLAGS_CCW \| VFIO_DEVICE_FLAGS_RESET;
e01bcdd6	215	info->num_regions = VFIO_CCW_NUM_REGIONS;
120e214e	216	info->num_irqs = VFIO_CCW_NUM_IRQS;
e01bcdd6 DJS	217
	218	return 0;
	219	}
	220
	221	static int vfio_ccw_mdev_get_region_info(struct vfio_region_info *info,
	222	u16 *cap_type_id,
	223	void **cap_type)
	224	{
	225	switch (info->index) {
	226	case VFIO_CCW_CONFIG_REGION_INDEX:
	227	info->offset = 0;
	228	info->size = sizeof(struct ccw_io_region);
	229	info->flags = VFIO_REGION_INFO_FLAG_READ
	230	\| VFIO_REGION_INFO_FLAG_WRITE;
	231	return 0;
	232	default:
	233	return -EINVAL;
	234	}
	235	}
	236
5bf18536	237	static int vfio_ccw_mdev_get_irq_info(struct vfio_irq_info *info)
120e214e DJS	238	{
	239	if (info->index != VFIO_CCW_IO_IRQ_INDEX)
	240	return -EINVAL;
	241
	242	info->count = 1;
	243	info->flags = VFIO_IRQ_INFO_EVENTFD;
	244
	245	return 0;
	246	}
	247
	248	static int vfio_ccw_mdev_set_irqs(struct mdev_device *mdev,
	249	uint32_t flags,
	250	void __user *data)
	251	{
	252	struct vfio_ccw_private *private;
	253	struct eventfd_ctx **ctx;
	254
	255	if (!(flags & VFIO_IRQ_SET_ACTION_TRIGGER))
	256	return -EINVAL;
	257
	258	private = dev_get_drvdata(mdev_parent_dev(mdev));
120e214e DJS	259	ctx = &private->io_trigger;
	260
	261	switch (flags & VFIO_IRQ_SET_DATA_TYPE_MASK) {
	262	case VFIO_IRQ_SET_DATA_NONE:
	263	{
	264	if (*ctx)
	265	eventfd_signal(*ctx, 1);
	266	return 0;
	267	}
	268	case VFIO_IRQ_SET_DATA_BOOL:
	269	{
	270	uint8_t trigger;
	271
	272	if (get_user(trigger, (uint8_t __user *)data))
	273	return -EFAULT;
	274
	275	if (trigger && *ctx)
	276	eventfd_signal(*ctx, 1);
	277	return 0;
	278	}
	279	case VFIO_IRQ_SET_DATA_EVENTFD:
	280	{
	281	int32_t fd;
	282
	283	if (get_user(fd, (int32_t __user *)data))
	284	return -EFAULT;
	285
	286	if (fd == -1) {
	287	if (*ctx)
	288	eventfd_ctx_put(*ctx);
	289	*ctx = NULL;
	290	} else if (fd >= 0) {
	291	struct eventfd_ctx *efdctx;
	292
	293	efdctx = eventfd_ctx_fdget(fd);
	294	if (IS_ERR(efdctx))
	295	return PTR_ERR(efdctx);
	296
	297	if (*ctx)
	298	eventfd_ctx_put(*ctx);
	299
	300	*ctx = efdctx;
	301	} else
	302	return -EINVAL;
	303
	304	return 0;
	305	}
	306	default:
	307	return -EINVAL;
	308	}
	309	}
	310
e01bcdd6 DJS	311	static ssize_t vfio_ccw_mdev_ioctl(struct mdev_device *mdev,
	312	unsigned int cmd,
	313	unsigned long arg)
	314	{
	315	int ret = 0;
	316	unsigned long minsz;
	317
	318	switch (cmd) {
	319	case VFIO_DEVICE_GET_INFO:
	320	{
	321	struct vfio_device_info info;
	322
	323	minsz = offsetofend(struct vfio_device_info, num_irqs);
	324
	325	if (copy_from_user(&info, (void __user *)arg, minsz))
	326	return -EFAULT;
	327
	328	if (info.argsz < minsz)
	329	return -EINVAL;
	330
	331	ret = vfio_ccw_mdev_get_device_info(&info);
	332	if (ret)
	333	return ret;
	334
	335	return copy_to_user((void __user *)arg, &info, minsz);
	336	}
	337	case VFIO_DEVICE_GET_REGION_INFO:
	338	{
	339	struct vfio_region_info info;
	340	u16 cap_type_id = 0;
	341	void *cap_type = NULL;
	342
	343	minsz = offsetofend(struct vfio_region_info, offset);
	344
	345	if (copy_from_user(&info, (void __user *)arg, minsz))
	346	return -EFAULT;
	347
	348	if (info.argsz < minsz)
	349	return -EINVAL;
	350
	351	ret = vfio_ccw_mdev_get_region_info(&info, &cap_type_id,
	352	&cap_type);
	353	if (ret)
	354	return ret;
	355
	356	return copy_to_user((void __user *)arg, &info, minsz);
	357	}
120e214e DJS	358	case VFIO_DEVICE_GET_IRQ_INFO:
	359	{
	360	struct vfio_irq_info info;
	361
	362	minsz = offsetofend(struct vfio_irq_info, count);
	363
	364	if (copy_from_user(&info, (void __user *)arg, minsz))
	365	return -EFAULT;
	366
	367	if (info.argsz < minsz \|\| info.index >= VFIO_CCW_NUM_IRQS)
	368	return -EINVAL;
	369
	370	ret = vfio_ccw_mdev_get_irq_info(&info);
	371	if (ret)
	372	return ret;
	373
	374	if (info.count == -1)
	375	return -EINVAL;
	376
	377	return copy_to_user((void __user *)arg, &info, minsz);
	378	}
	379	case VFIO_DEVICE_SET_IRQS:
	380	{
	381	struct vfio_irq_set hdr;
	382	size_t data_size;
	383	void __user *data;
	384
	385	minsz = offsetofend(struct vfio_irq_set, count);
	386
	387	if (copy_from_user(&hdr, (void __user *)arg, minsz))
	388	return -EFAULT;
	389
	390	ret = vfio_set_irqs_validate_and_prepare(&hdr, 1,
	391	VFIO_CCW_NUM_IRQS,
	392	&data_size);
	393	if (ret)
	394	return ret;
	395
	396	data = (void __user *)(arg + minsz);
	397	return vfio_ccw_mdev_set_irqs(mdev, hdr.flags, data);
	398	}
83d1193a DJS	399	case VFIO_DEVICE_RESET:
83d1193a DJS	400	return vfio_ccw_mdev_reset(mdev);
e01bcdd6 DJS	401	default:
	402	return -ENOTTY;
	403	}
	404	}
	405
84cd8fc4 DJS	406	static const struct mdev_parent_ops vfio_ccw_mdev_ops = {
	407	.owner = THIS_MODULE,
	408	.supported_type_groups = mdev_type_groups,
	409	.create = vfio_ccw_mdev_create,
	410	.remove = vfio_ccw_mdev_remove,
	411	.open = vfio_ccw_mdev_open,
	412	.release = vfio_ccw_mdev_release,
060d2b5a DJS	413	.read = vfio_ccw_mdev_read,
060d2b5a DJS	414	.write = vfio_ccw_mdev_write,
e01bcdd6	415	.ioctl = vfio_ccw_mdev_ioctl,
84cd8fc4 DJS	416	};
	417
	418	int vfio_ccw_mdev_reg(struct subchannel *sch)
	419	{
	420	return mdev_register_device(&sch->dev, &vfio_ccw_mdev_ops);
	421	}
	422
	423	void vfio_ccw_mdev_unreg(struct subchannel *sch)
	424	{
	425	mdev_unregister_device(&sch->dev);
	426	}