Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

5 files changed, 2346 insertions, 0 deletions

diff --git a/drivers/misc/mic/vop/Makefile b/drivers/misc/mic/vop/Makefile
new file mode 100644
index 000000000..78819c899
--- /dev/null
+++ b/drivers/misc/mic/vop/Makefile
@@ -0,0 +1,9 @@
+#
+# Makefile - Intel MIC Linux driver.
+# Copyright(c) 2016, Intel Corporation.
+#
+obj-m := vop.o
+
+vop-objs += vop_main.o
+vop-objs += vop_debugfs.o
+vop-objs += vop_vringh.o
diff --git a/drivers/misc/mic/vop/vop_debugfs.c b/drivers/misc/mic/vop/vop_debugfs.c
new file mode 100644
index 000000000..ab43884e5
--- /dev/null
+++ b/drivers/misc/mic/vop/vop_debugfs.c
@@ -0,0 +1,232 @@
+/*
+ * Intel MIC Platform Software Stack (MPSS)
+ *
+ * Copyright(c) 2016 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * The full GNU General Public License is included in this distribution in
+ * the file called "COPYING".
+ *
+ * Intel Virtio Over PCIe (VOP) driver.
+ *
+ */
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+#include "vop_main.h"
+
+static int vop_dp_show(struct seq_file *s, void *pos)
+{
+	struct mic_device_desc *d;
+	struct mic_device_ctrl *dc;
+	struct mic_vqconfig *vqconfig;
+	__u32 *features;
+	__u8 *config;
+	struct vop_info *vi = s->private;
+	struct vop_device *vpdev = vi->vpdev;
+	struct mic_bootparam *bootparam = vpdev->hw_ops->get_dp(vpdev);
+	int j, k;
+
+	seq_printf(s, "Bootparam: magic 0x%x\n",
+		   bootparam->magic);
+	seq_printf(s, "Bootparam: h2c_config_db %d\n",
+		   bootparam->h2c_config_db);
+	seq_printf(s, "Bootparam: node_id %d\n",
+		   bootparam->node_id);
+	seq_printf(s, "Bootparam: c2h_scif_db %d\n",
+		   bootparam->c2h_scif_db);
+	seq_printf(s, "Bootparam: h2c_scif_db %d\n",
+		   bootparam->h2c_scif_db);
+	seq_printf(s, "Bootparam: scif_host_dma_addr 0x%llx\n",
+		   bootparam->scif_host_dma_addr);
+	seq_printf(s, "Bootparam: scif_card_dma_addr 0x%llx\n",
+		   bootparam->scif_card_dma_addr);
+
+	for (j = sizeof(*bootparam);
+		j < MIC_DP_SIZE; j += mic_total_desc_size(d)) {
+		d = (void *)bootparam + j;
+		dc = (void *)d + mic_aligned_desc_size(d);
+
+		/* end of list */
+		if (d->type == 0)
+			break;
+
+		if (d->type == -1)
+			continue;
+
+		seq_printf(s, "Type %d ", d->type);
+		seq_printf(s, "Num VQ %d ", d->num_vq);
+		seq_printf(s, "Feature Len %d\n", d->feature_len);
+		seq_printf(s, "Config Len %d ", d->config_len);
+		seq_printf(s, "Shutdown Status %d\n", d->status);
+
+		for (k = 0; k < d->num_vq; k++) {
+			vqconfig = mic_vq_config(d) + k;
+			seq_printf(s, "vqconfig[%d]: ", k);
+			seq_printf(s, "address 0x%llx ",
+				   vqconfig->address);
+			seq_printf(s, "num %d ", vqconfig->num);
+			seq_printf(s, "used address 0x%llx\n",
+				   vqconfig->used_address);
+		}
+
+		features = (__u32 *)mic_vq_features(d);
+		seq_printf(s, "Features: Host 0x%x ", features[0]);
+		seq_printf(s, "Guest 0x%x\n", features[1]);
+
+		config = mic_vq_configspace(d);
+		for (k = 0; k < d->config_len; k++)
+			seq_printf(s, "config[%d]=%d\n", k, config[k]);
+
+		seq_puts(s, "Device control:\n");
+		seq_printf(s, "Config Change %d ", dc->config_change);
+		seq_printf(s, "Vdev reset %d\n", dc->vdev_reset);
+		seq_printf(s, "Guest Ack %d ", dc->guest_ack);
+		seq_printf(s, "Host ack %d\n", dc->host_ack);
+		seq_printf(s, "Used address updated %d ",
+			   dc->used_address_updated);
+		seq_printf(s, "Vdev 0x%llx\n", dc->vdev);
+		seq_printf(s, "c2h doorbell %d ", dc->c2h_vdev_db);
+		seq_printf(s, "h2c doorbell %d\n", dc->h2c_vdev_db);
+	}
+	schedule_work(&vi->hotplug_work);
+	return 0;
+}
+
+static int vop_dp_debug_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, vop_dp_show, inode->i_private);
+}
+
+static int vop_dp_debug_release(struct inode *inode, struct file *file)
+{
+	return single_release(inode, file);
+}
+
+static const struct file_operations dp_ops = {
+	.owner   = THIS_MODULE,
+	.open    = vop_dp_debug_open,
+	.read    = seq_read,
+	.llseek  = seq_lseek,
+	.release = vop_dp_debug_release
+};
+
+static int vop_vdev_info_show(struct seq_file *s, void *unused)
+{
+	struct vop_info *vi = s->private;
+	struct list_head *pos, *tmp;
+	struct vop_vdev *vdev;
+	int i, j;
+
+	mutex_lock(&vi->vop_mutex);
+	list_for_each_safe(pos, tmp, &vi->vdev_list) {
+		vdev = list_entry(pos, struct vop_vdev, list);
+		seq_printf(s, "VDEV type %d state %s in %ld out %ld in_dma %ld out_dma %ld\n",
+			   vdev->virtio_id,
+			   vop_vdevup(vdev) ? "UP" : "DOWN",
+			   vdev->in_bytes,
+			   vdev->out_bytes,
+			   vdev->in_bytes_dma,
+			   vdev->out_bytes_dma);
+		for (i = 0; i < MIC_MAX_VRINGS; i++) {
+			struct vring_desc *desc;
+			struct vring_avail *avail;
+			struct vring_used *used;
+			struct vop_vringh *vvr = &vdev->vvr[i];
+			struct vringh *vrh = &vvr->vrh;
+			int num = vrh->vring.num;
+
+			if (!num)
+				continue;
+			desc = vrh->vring.desc;
+			seq_printf(s, "vring i %d avail_idx %d",
+				   i, vvr->vring.info->avail_idx & (num - 1));
+			seq_printf(s, " vring i %d avail_idx %d\n",
+				   i, vvr->vring.info->avail_idx);
+			seq_printf(s, "vrh i %d weak_barriers %d",
+				   i, vrh->weak_barriers);
+			seq_printf(s, " last_avail_idx %d last_used_idx %d",
+				   vrh->last_avail_idx, vrh->last_used_idx);
+			seq_printf(s, " completed %d\n", vrh->completed);
+			for (j = 0; j < num; j++) {
+				seq_printf(s, "desc[%d] addr 0x%llx len %d",
+					   j, desc->addr, desc->len);
+				seq_printf(s, " flags 0x%x next %d\n",
+					   desc->flags, desc->next);
+				desc++;
+			}
+			avail = vrh->vring.avail;
+			seq_printf(s, "avail flags 0x%x idx %d\n",
+				   vringh16_to_cpu(vrh, avail->flags),
+				   vringh16_to_cpu(vrh,
+						   avail->idx) & (num - 1));
+			seq_printf(s, "avail flags 0x%x idx %d\n",
+				   vringh16_to_cpu(vrh, avail->flags),
+				   vringh16_to_cpu(vrh, avail->idx));
+			for (j = 0; j < num; j++)
+				seq_printf(s, "avail ring[%d] %d\n",
+					   j, avail->ring[j]);
+			used = vrh->vring.used;
+			seq_printf(s, "used flags 0x%x idx %d\n",
+				   vringh16_to_cpu(vrh, used->flags),
+				   vringh16_to_cpu(vrh, used->idx) & (num - 1));
+			seq_printf(s, "used flags 0x%x idx %d\n",
+				   vringh16_to_cpu(vrh, used->flags),
+				   vringh16_to_cpu(vrh, used->idx));
+			for (j = 0; j < num; j++)
+				seq_printf(s, "used ring[%d] id %d len %d\n",
+					   j, vringh32_to_cpu(vrh,
+							      used->ring[j].id),
+					   vringh32_to_cpu(vrh,
+							   used->ring[j].len));
+		}
+	}
+	mutex_unlock(&vi->vop_mutex);
+
+	return 0;
+}
+
+static int vop_vdev_info_debug_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, vop_vdev_info_show, inode->i_private);
+}
+
+static int vop_vdev_info_debug_release(struct inode *inode, struct file *file)
+{
+	return single_release(inode, file);
+}
+
+static const struct file_operations vdev_info_ops = {
+	.owner   = THIS_MODULE,
+	.open    = vop_vdev_info_debug_open,
+	.read    = seq_read,
+	.llseek  = seq_lseek,
+	.release = vop_vdev_info_debug_release
+};
+
+void vop_init_debugfs(struct vop_info *vi)
+{
+	char name[16];
+
+	snprintf(name, sizeof(name), "%s%d", KBUILD_MODNAME, vi->vpdev->dnode);
+	vi->dbg = debugfs_create_dir(name, NULL);
+	if (!vi->dbg) {
+		pr_err("can't create debugfs dir vop\n");
+		return;
+	}
+	debugfs_create_file("dp", 0444, vi->dbg, vi, &dp_ops);
+	debugfs_create_file("vdev_info", 0444, vi->dbg, vi, &vdev_info_ops);
+}
+
+void vop_exit_debugfs(struct vop_info *vi)
+{
+	debugfs_remove_recursive(vi->dbg);
+}
diff --git a/drivers/misc/mic/vop/vop_main.c b/drivers/misc/mic/vop/vop_main.c
new file mode 100644
index 000000000..f4332a97c
--- /dev/null
+++ b/drivers/misc/mic/vop/vop_main.c
@@ -0,0 +1,766 @@
+/*
+ * Intel MIC Platform Software Stack (MPSS)
+ *
+ * Copyright(c) 2016 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * The full GNU General Public License is included in this distribution in
+ * the file called "COPYING".
+ *
+ * Adapted from:
+ *
+ * virtio for kvm on s390
+ *
+ * Copyright IBM Corp. 2008
+ *
+ * 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): Christian Borntraeger <borntraeger@de.ibm.com>
+ *
+ * Intel Virtio Over PCIe (VOP) driver.
+ *
+ */
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/dma-mapping.h>
+
+#include "vop_main.h"
+
+#define VOP_MAX_VRINGS 4
+
+/*
+ * _vop_vdev - Allocated per virtio device instance injected by the peer.
+ *
+ * @vdev: Virtio device
+ * @desc: Virtio device page descriptor
+ * @dc: Virtio device control
+ * @vpdev: VOP device which is the parent for this virtio device
+ * @vr: Buffer for accessing the VRING
+ * @used: Buffer for used
+ * @used_size: Size of the used buffer
+ * @reset_done: Track whether VOP reset is complete
+ * @virtio_cookie: Cookie returned upon requesting a interrupt
+ * @c2h_vdev_db: The doorbell used by the guest to interrupt the host
+ * @h2c_vdev_db: The doorbell used by the host to interrupt the guest
+ * @dnode: The destination node
+ */
+struct _vop_vdev {
+	struct virtio_device vdev;
+	struct mic_device_desc __iomem *desc;
+	struct mic_device_ctrl __iomem *dc;
+	struct vop_device *vpdev;
+	void __iomem *vr[VOP_MAX_VRINGS];
+	dma_addr_t used[VOP_MAX_VRINGS];
+	int used_size[VOP_MAX_VRINGS];
+	struct completion reset_done;
+	struct mic_irq *virtio_cookie;
+	int c2h_vdev_db;
+	int h2c_vdev_db;
+	int dnode;
+};
+
+#define to_vopvdev(vd) container_of(vd, struct _vop_vdev, vdev)
+
+#define _vop_aligned_desc_size(d) __mic_align(_vop_desc_size(d), 8)
+
+/* Helper API to obtain the parent of the virtio device */
+static inline struct device *_vop_dev(struct _vop_vdev *vdev)
+{
+	return vdev->vdev.dev.parent;
+}
+
+static inline unsigned _vop_desc_size(struct mic_device_desc __iomem *desc)
+{
+	return sizeof(*desc)
+		+ ioread8(&desc->num_vq) * sizeof(struct mic_vqconfig)
+		+ ioread8(&desc->feature_len) * 2
+		+ ioread8(&desc->config_len);
+}
+
+static inline struct mic_vqconfig __iomem *
+_vop_vq_config(struct mic_device_desc __iomem *desc)
+{
+	return (struct mic_vqconfig __iomem *)(desc + 1);
+}
+
+static inline u8 __iomem *
+_vop_vq_features(struct mic_device_desc __iomem *desc)
+{
+	return (u8 __iomem *)(_vop_vq_config(desc) + ioread8(&desc->num_vq));
+}
+
+static inline u8 __iomem *
+_vop_vq_configspace(struct mic_device_desc __iomem *desc)
+{
+	return _vop_vq_features(desc) + ioread8(&desc->feature_len) * 2;
+}
+
+static inline unsigned
+_vop_total_desc_size(struct mic_device_desc __iomem *desc)
+{
+	return _vop_aligned_desc_size(desc) + sizeof(struct mic_device_ctrl);
+}
+
+/* This gets the device's feature bits. */
+static u64 vop_get_features(struct virtio_device *vdev)
+{
+	unsigned int i, bits;
+	u32 features = 0;
+	struct mic_device_desc __iomem *desc = to_vopvdev(vdev)->desc;
+	u8 __iomem *in_features = _vop_vq_features(desc);
+	int feature_len = ioread8(&desc->feature_len);
+
+	bits = min_t(unsigned, feature_len, sizeof(vdev->features)) * 8;
+	for (i = 0; i < bits; i++)
+		if (ioread8(&in_features[i / 8]) & (BIT(i % 8)))
+			features |= BIT(i);
+
+	return features;
+}
+
+static int vop_finalize_features(struct virtio_device *vdev)
+{
+	unsigned int i, bits;
+	struct mic_device_desc __iomem *desc = to_vopvdev(vdev)->desc;
+	u8 feature_len = ioread8(&desc->feature_len);
+	/* Second half of bitmap is features we accept. */
+	u8 __iomem *out_features =
+		_vop_vq_features(desc) + feature_len;
+
+	/* Give virtio_ring a chance to accept features. */
+	vring_transport_features(vdev);
+
+	memset_io(out_features, 0, feature_len);
+	bits = min_t(unsigned, feature_len,
+		     sizeof(vdev->features)) * 8;
+	for (i = 0; i < bits; i++) {
+		if (__virtio_test_bit(vdev, i))
+			iowrite8(ioread8(&out_features[i / 8]) | (1 << (i % 8)),
+				 &out_features[i / 8]);
+	}
+	return 0;
+}
+
+/*
+ * Reading and writing elements in config space
+ */
+static void vop_get(struct virtio_device *vdev, unsigned int offset,
+		    void *buf, unsigned len)
+{
+	struct mic_device_desc __iomem *desc = to_vopvdev(vdev)->desc;
+
+	if (offset + len > ioread8(&desc->config_len))
+		return;
+	memcpy_fromio(buf, _vop_vq_configspace(desc) + offset, len);
+}
+
+static void vop_set(struct virtio_device *vdev, unsigned int offset,
+		    const void *buf, unsigned len)
+{
+	struct mic_device_desc __iomem *desc = to_vopvdev(vdev)->desc;
+
+	if (offset + len > ioread8(&desc->config_len))
+		return;
+	memcpy_toio(_vop_vq_configspace(desc) + offset, buf, len);
+}
+
+/*
+ * The operations to get and set the status word just access the status
+ * field of the device descriptor. set_status also interrupts the host
+ * to tell about status changes.
+ */
+static u8 vop_get_status(struct virtio_device *vdev)
+{
+	return ioread8(&to_vopvdev(vdev)->desc->status);
+}
+
+static void vop_set_status(struct virtio_device *dev, u8 status)
+{
+	struct _vop_vdev *vdev = to_vopvdev(dev);
+	struct vop_device *vpdev = vdev->vpdev;
+
+	if (!status)
+		return;
+	iowrite8(status, &vdev->desc->status);
+	vpdev->hw_ops->send_intr(vpdev, vdev->c2h_vdev_db);
+}
+
+/* Inform host on a virtio device reset and wait for ack from host */
+static void vop_reset_inform_host(struct virtio_device *dev)
+{
+	struct _vop_vdev *vdev = to_vopvdev(dev);
+	struct mic_device_ctrl __iomem *dc = vdev->dc;
+	struct vop_device *vpdev = vdev->vpdev;
+	int retry;
+
+	iowrite8(0, &dc->host_ack);
+	iowrite8(1, &dc->vdev_reset);
+	vpdev->hw_ops->send_intr(vpdev, vdev->c2h_vdev_db);
+
+	/* Wait till host completes all card accesses and acks the reset */
+	for (retry = 100; retry--;) {
+		if (ioread8(&dc->host_ack))
+			break;
+		msleep(100);
+	};
+
+	dev_dbg(_vop_dev(vdev), "%s: retry: %d\n", __func__, retry);
+
+	/* Reset status to 0 in case we timed out */
+	iowrite8(0, &vdev->desc->status);
+}
+
+static void vop_reset(struct virtio_device *dev)
+{
+	struct _vop_vdev *vdev = to_vopvdev(dev);
+
+	dev_dbg(_vop_dev(vdev), "%s: virtio id %d\n",
+		__func__, dev->id.device);
+
+	vop_reset_inform_host(dev);
+	complete_all(&vdev->reset_done);
+}
+
+/*
+ * The virtio_ring code calls this API when it wants to notify the Host.
+ */
+static bool vop_notify(struct virtqueue *vq)
+{
+	struct _vop_vdev *vdev = vq->priv;
+	struct vop_device *vpdev = vdev->vpdev;
+
+	vpdev->hw_ops->send_intr(vpdev, vdev->c2h_vdev_db);
+	return true;
+}
+
+static void vop_del_vq(struct virtqueue *vq, int n)
+{
+	struct _vop_vdev *vdev = to_vopvdev(vq->vdev);
+	struct vring *vr = (struct vring *)(vq + 1);
+	struct vop_device *vpdev = vdev->vpdev;
+
+	dma_unmap_single(&vpdev->dev, vdev->used[n],
+			 vdev->used_size[n], DMA_BIDIRECTIONAL);
+	free_pages((unsigned long)vr->used, get_order(vdev->used_size[n]));
+	vring_del_virtqueue(vq);
+	vpdev->hw_ops->iounmap(vpdev, vdev->vr[n]);
+	vdev->vr[n] = NULL;
+}
+
+static void vop_del_vqs(struct virtio_device *dev)
+{
+	struct _vop_vdev *vdev = to_vopvdev(dev);
+	struct virtqueue *vq, *n;
+	int idx = 0;
+
+	dev_dbg(_vop_dev(vdev), "%s\n", __func__);
+
+	list_for_each_entry_safe(vq, n, &dev->vqs, list)
+		vop_del_vq(vq, idx++);
+}
+
+/*
+ * This routine will assign vring's allocated in host/io memory. Code in
+ * virtio_ring.c however continues to access this io memory as if it were local
+ * memory without io accessors.
+ */
+static struct virtqueue *vop_find_vq(struct virtio_device *dev,
+				     unsigned index,
+				     void (*callback)(struct virtqueue *vq),
+				     const char *name, bool ctx)
+{
+	struct _vop_vdev *vdev = to_vopvdev(dev);
+	struct vop_device *vpdev = vdev->vpdev;
+	struct mic_vqconfig __iomem *vqconfig;
+	struct mic_vqconfig config;
+	struct virtqueue *vq;
+	void __iomem *va;
+	struct _mic_vring_info __iomem *info;
+	void *used;
+	int vr_size, _vr_size, err, magic;
+	struct vring *vr;
+	u8 type = ioread8(&vdev->desc->type);
+
+	if (index >= ioread8(&vdev->desc->num_vq))
+		return ERR_PTR(-ENOENT);
+
+	if (!name)
+		return ERR_PTR(-ENOENT);
+
+	/* First assign the vring's allocated in host memory */
+	vqconfig = _vop_vq_config(vdev->desc) + index;
+	memcpy_fromio(&config, vqconfig, sizeof(config));
+	_vr_size = round_up(vring_size(le16_to_cpu(config.num), MIC_VIRTIO_RING_ALIGN), 4);
+	vr_size = PAGE_ALIGN(_vr_size + sizeof(struct _mic_vring_info));
+	va = vpdev->hw_ops->ioremap(vpdev, le64_to_cpu(config.address),
+			vr_size);
+	if (!va)
+		return ERR_PTR(-ENOMEM);
+	vdev->vr[index] = va;
+	memset_io(va, 0x0, _vr_size);
+	vq = vring_new_virtqueue(
+				index,
+				le16_to_cpu(config.num), MIC_VIRTIO_RING_ALIGN,
+				dev,
+				false,
+				ctx,
+				(void __force *)va, vop_notify, callback, name);
+	if (!vq) {
+		err = -ENOMEM;
+		goto unmap;
+	}
+	info = va + _vr_size;
+	magic = ioread32(&info->magic);
+
+	if (WARN(magic != MIC_MAGIC + type + index, "magic mismatch")) {
+		err = -EIO;
+		goto unmap;
+	}
+
+	/* Allocate and reassign used ring now */
+	vdev->used_size[index] = PAGE_ALIGN(sizeof(__u16) * 3 +
+					     sizeof(struct vring_used_elem) *
+					     le16_to_cpu(config.num));
+	used = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
+					get_order(vdev->used_size[index]));
+	if (!used) {
+		err = -ENOMEM;
+		dev_err(_vop_dev(vdev), "%s %d err %d\n",
+			__func__, __LINE__, err);
+		goto del_vq;
+	}
+	vdev->used[index] = dma_map_single(&vpdev->dev, used,
+					    vdev->used_size[index],
+					    DMA_BIDIRECTIONAL);
+	if (dma_mapping_error(&vpdev->dev, vdev->used[index])) {
+		err = -ENOMEM;
+		dev_err(_vop_dev(vdev), "%s %d err %d\n",
+			__func__, __LINE__, err);
+		goto free_used;
+	}
+	writeq(vdev->used[index], &vqconfig->used_address);
+	/*
+	 * To reassign the used ring here we are directly accessing
+	 * struct vring_virtqueue which is a private data structure
+	 * in virtio_ring.c. At the minimum, a BUILD_BUG_ON() in
+	 * vring_new_virtqueue() would ensure that
+	 *  (&vq->vring == (struct vring *) (&vq->vq + 1));
+	 */
+	vr = (struct vring *)(vq + 1);
+	vr->used = used;
+
+	vq->priv = vdev;
+	return vq;
+free_used:
+	free_pages((unsigned long)used,
+		   get_order(vdev->used_size[index]));
+del_vq:
+	vring_del_virtqueue(vq);
+unmap:
+	vpdev->hw_ops->iounmap(vpdev, vdev->vr[index]);
+	return ERR_PTR(err);
+}
+
+static int vop_find_vqs(struct virtio_device *dev, unsigned nvqs,
+			struct virtqueue *vqs[],
+			vq_callback_t *callbacks[],
+			const char * const names[], const bool *ctx,
+			struct irq_affinity *desc)
+{
+	struct _vop_vdev *vdev = to_vopvdev(dev);
+	struct vop_device *vpdev = vdev->vpdev;
+	struct mic_device_ctrl __iomem *dc = vdev->dc;
+	int i, err, retry;
+
+	/* We must have this many virtqueues. */
+	if (nvqs > ioread8(&vdev->desc->num_vq))
+		return -ENOENT;
+
+	for (i = 0; i < nvqs; ++i) {
+		dev_dbg(_vop_dev(vdev), "%s: %d: %s\n",
+			__func__, i, names[i]);
+		vqs[i] = vop_find_vq(dev, i, callbacks[i], names[i],
+				     ctx ? ctx[i] : false);
+		if (IS_ERR(vqs[i])) {
+			err = PTR_ERR(vqs[i]);
+			goto error;
+		}
+	}
+
+	iowrite8(1, &dc->used_address_updated);
+	/*
+	 * Send an interrupt to the host to inform it that used
+	 * rings have been re-assigned.
+	 */
+	vpdev->hw_ops->send_intr(vpdev, vdev->c2h_vdev_db);
+	for (retry = 100; --retry;) {
+		if (!ioread8(&dc->used_address_updated))
+			break;
+		msleep(100);
+	};
+
+	dev_dbg(_vop_dev(vdev), "%s: retry: %d\n", __func__, retry);
+	if (!retry) {
+		err = -ENODEV;
+		goto error;
+	}
+
+	return 0;
+error:
+	vop_del_vqs(dev);
+	return err;
+}
+
+/*
+ * The config ops structure as defined by virtio config
+ */
+static struct virtio_config_ops vop_vq_config_ops = {
+	.get_features = vop_get_features,
+	.finalize_features = vop_finalize_features,
+	.get = vop_get,
+	.set = vop_set,
+	.get_status = vop_get_status,
+	.set_status = vop_set_status,
+	.reset = vop_reset,
+	.find_vqs = vop_find_vqs,
+	.del_vqs = vop_del_vqs,
+};
+
+static irqreturn_t vop_virtio_intr_handler(int irq, void *data)
+{
+	struct _vop_vdev *vdev = data;
+	struct vop_device *vpdev = vdev->vpdev;
+	struct virtqueue *vq;
+
+	vpdev->hw_ops->ack_interrupt(vpdev, vdev->h2c_vdev_db);
+	list_for_each_entry(vq, &vdev->vdev.vqs, list)
+		vring_interrupt(0, vq);
+
+	return IRQ_HANDLED;
+}
+
+static void vop_virtio_release_dev(struct device *_d)
+{
+	struct virtio_device *vdev =
+			container_of(_d, struct virtio_device, dev);
+	struct _vop_vdev *vop_vdev =
+			container_of(vdev, struct _vop_vdev, vdev);
+
+	kfree(vop_vdev);
+}
+
+/*
+ * adds a new device and register it with virtio
+ * appropriate drivers are loaded by the device model
+ */
+static int _vop_add_device(struct mic_device_desc __iomem *d,
+			   unsigned int offset, struct vop_device *vpdev,
+			   int dnode)
+{
+	struct _vop_vdev *vdev, *reg_dev = NULL;
+	int ret;
+	u8 type = ioread8(&d->type);
+
+	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
+	if (!vdev)
+		return -ENOMEM;
+
+	vdev->vpdev = vpdev;
+	vdev->vdev.dev.parent = &vpdev->dev;
+	vdev->vdev.dev.release = vop_virtio_release_dev;
+	vdev->vdev.id.device = type;
+	vdev->vdev.config = &vop_vq_config_ops;
+	vdev->desc = d;
+	vdev->dc = (void __iomem *)d + _vop_aligned_desc_size(d);
+	vdev->dnode = dnode;
+	vdev->vdev.priv = (void *)(u64)dnode;
+	init_completion(&vdev->reset_done);
+
+	vdev->h2c_vdev_db = vpdev->hw_ops->next_db(vpdev);
+	vdev->virtio_cookie = vpdev->hw_ops->request_irq(vpdev,
+			vop_virtio_intr_handler, "virtio intr",
+			vdev, vdev->h2c_vdev_db);
+	if (IS_ERR(vdev->virtio_cookie)) {
+		ret = PTR_ERR(vdev->virtio_cookie);
+		goto kfree;
+	}
+	iowrite8((u8)vdev->h2c_vdev_db, &vdev->dc->h2c_vdev_db);
+	vdev->c2h_vdev_db = ioread8(&vdev->dc->c2h_vdev_db);
+
+	ret = register_virtio_device(&vdev->vdev);
+	reg_dev = vdev;
+	if (ret) {
+		dev_err(_vop_dev(vdev),
+			"Failed to register vop device %u type %u\n",
+			offset, type);
+		goto free_irq;
+	}
+	writeq((u64)vdev, &vdev->dc->vdev);
+	dev_dbg(_vop_dev(vdev), "%s: registered vop device %u type %u vdev %p\n",
+		__func__, offset, type, vdev);
+
+	return 0;
+
+free_irq:
+	vpdev->hw_ops->free_irq(vpdev, vdev->virtio_cookie, vdev);
+kfree:
+	if (reg_dev)
+		put_device(&vdev->vdev.dev);
+	else
+		kfree(vdev);
+	return ret;
+}
+
+/*
+ * match for a vop device with a specific desc pointer
+ */
+static int vop_match_desc(struct device *dev, void *data)
+{
+	struct virtio_device *_dev = dev_to_virtio(dev);
+	struct _vop_vdev *vdev = to_vopvdev(_dev);
+
+	return vdev->desc == (void __iomem *)data;
+}
+
+static void _vop_handle_config_change(struct mic_device_desc __iomem *d,
+				      unsigned int offset,
+				      struct vop_device *vpdev)
+{
+	struct mic_device_ctrl __iomem *dc
+		= (void __iomem *)d + _vop_aligned_desc_size(d);
+	struct _vop_vdev *vdev = (struct _vop_vdev *)readq(&dc->vdev);
+
+	if (ioread8(&dc->config_change) != MIC_VIRTIO_PARAM_CONFIG_CHANGED)
+		return;
+
+	dev_dbg(&vpdev->dev, "%s %d\n", __func__, __LINE__);
+	virtio_config_changed(&vdev->vdev);
+	iowrite8(1, &dc->guest_ack);
+}
+
+/*
+ * removes a virtio device if a hot remove event has been
+ * requested by the host.
+ */
+static int _vop_remove_device(struct mic_device_desc __iomem *d,
+			      unsigned int offset, struct vop_device *vpdev)
+{
+	struct mic_device_ctrl __iomem *dc
+		= (void __iomem *)d + _vop_aligned_desc_size(d);
+	struct _vop_vdev *vdev = (struct _vop_vdev *)readq(&dc->vdev);
+	u8 status;
+	int ret = -1;
+
+	if (ioread8(&dc->config_change) == MIC_VIRTIO_PARAM_DEV_REMOVE) {
+		struct device *dev = get_device(&vdev->vdev.dev);
+
+		dev_dbg(&vpdev->dev,
+			"%s %d config_change %d type %d vdev %p\n",
+			__func__, __LINE__,
+			ioread8(&dc->config_change), ioread8(&d->type), vdev);
+		status = ioread8(&d->status);
+		reinit_completion(&vdev->reset_done);
+		unregister_virtio_device(&vdev->vdev);
+		vpdev->hw_ops->free_irq(vpdev, vdev->virtio_cookie, vdev);
+		iowrite8(-1, &dc->h2c_vdev_db);
+		if (status & VIRTIO_CONFIG_S_DRIVER_OK)
+			wait_for_completion(&vdev->reset_done);
+		put_device(dev);
+		iowrite8(1, &dc->guest_ack);
+		dev_dbg(&vpdev->dev, "%s %d guest_ack %d\n",
+			__func__, __LINE__, ioread8(&dc->guest_ack));
+		iowrite8(-1, &d->type);
+		ret = 0;
+	}
+	return ret;
+}
+
+#define REMOVE_DEVICES true
+
+static void _vop_scan_devices(void __iomem *dp, struct vop_device *vpdev,
+			      bool remove, int dnode)
+{
+	s8 type;
+	unsigned int i;
+	struct mic_device_desc __iomem *d;
+	struct mic_device_ctrl __iomem *dc;
+	struct device *dev;
+	int ret;
+
+	for (i = sizeof(struct mic_bootparam);
+			i < MIC_DP_SIZE; i += _vop_total_desc_size(d)) {
+		d = dp + i;
+		dc = (void __iomem *)d + _vop_aligned_desc_size(d);
+		/*
+		 * This read barrier is paired with the corresponding write
+		 * barrier on the host which is inserted before adding or
+		 * removing a virtio device descriptor, by updating the type.
+		 */
+		rmb();
+		type = ioread8(&d->type);
+
+		/* end of list */
+		if (type == 0)
+			break;
+
+		if (type == -1)
+			continue;
+
+		/* device already exists */
+		dev = device_find_child(&vpdev->dev, (void __force *)d,
+					vop_match_desc);
+		if (dev) {
+			if (remove)
+				iowrite8(MIC_VIRTIO_PARAM_DEV_REMOVE,
+					 &dc->config_change);
+			put_device(dev);
+			_vop_handle_config_change(d, i, vpdev);
+			ret = _vop_remove_device(d, i, vpdev);
+			if (remove) {
+				iowrite8(0, &dc->config_change);
+				iowrite8(0, &dc->guest_ack);
+			}
+			continue;
+		}
+
+		/* new device */
+		dev_dbg(&vpdev->dev, "%s %d Adding new virtio device %p\n",
+			__func__, __LINE__, d);
+		if (!remove)
+			_vop_add_device(d, i, vpdev, dnode);
+	}
+}
+
+static void vop_scan_devices(struct vop_info *vi,
+			     struct vop_device *vpdev, bool remove)
+{
+	void __iomem *dp = vpdev->hw_ops->get_remote_dp(vpdev);
+
+	if (!dp)
+		return;
+	mutex_lock(&vi->vop_mutex);
+	_vop_scan_devices(dp, vpdev, remove, vpdev->dnode);
+	mutex_unlock(&vi->vop_mutex);
+}
+
+/*
+ * vop_hotplug_device tries to find changes in the device page.
+ */
+static void vop_hotplug_devices(struct work_struct *work)
+{
+	struct vop_info *vi = container_of(work, struct vop_info,
+					     hotplug_work);
+
+	vop_scan_devices(vi, vi->vpdev, !REMOVE_DEVICES);
+}
+
+/*
+ * Interrupt handler for hot plug/config changes etc.
+ */
+static irqreturn_t vop_extint_handler(int irq, void *data)
+{
+	struct vop_info *vi = data;
+	struct mic_bootparam __iomem *bp;
+	struct vop_device *vpdev = vi->vpdev;
+
+	bp = vpdev->hw_ops->get_remote_dp(vpdev);
+	dev_dbg(&vpdev->dev, "%s %d hotplug work\n",
+		__func__, __LINE__);
+	vpdev->hw_ops->ack_interrupt(vpdev, ioread8(&bp->h2c_config_db));
+	schedule_work(&vi->hotplug_work);
+	return IRQ_HANDLED;
+}
+
+static int vop_driver_probe(struct vop_device *vpdev)
+{
+	struct vop_info *vi;
+	int rc;
+
+	vi = kzalloc(sizeof(*vi), GFP_KERNEL);
+	if (!vi) {
+		rc = -ENOMEM;
+		goto exit;
+	}
+	dev_set_drvdata(&vpdev->dev, vi);
+	vi->vpdev = vpdev;
+
+	mutex_init(&vi->vop_mutex);
+	INIT_WORK(&vi->hotplug_work, vop_hotplug_devices);
+	if (vpdev->dnode) {
+		rc = vop_host_init(vi);
+		if (rc < 0)
+			goto free;
+	} else {
+		struct mic_bootparam __iomem *bootparam;
+
+		vop_scan_devices(vi, vpdev, !REMOVE_DEVICES);
+
+		vi->h2c_config_db = vpdev->hw_ops->next_db(vpdev);
+		vi->cookie = vpdev->hw_ops->request_irq(vpdev,
+							vop_extint_handler,
+							"virtio_config_intr",
+							vi, vi->h2c_config_db);
+		if (IS_ERR(vi->cookie)) {
+			rc = PTR_ERR(vi->cookie);
+			goto free;
+		}
+		bootparam = vpdev->hw_ops->get_remote_dp(vpdev);
+		iowrite8(vi->h2c_config_db, &bootparam->h2c_config_db);
+	}
+	vop_init_debugfs(vi);
+	return 0;
+free:
+	kfree(vi);
+exit:
+	return rc;
+}
+
+static void vop_driver_remove(struct vop_device *vpdev)
+{
+	struct vop_info *vi = dev_get_drvdata(&vpdev->dev);
+
+	if (vpdev->dnode) {
+		vop_host_uninit(vi);
+	} else {
+		struct mic_bootparam __iomem *bootparam =
+			vpdev->hw_ops->get_remote_dp(vpdev);
+		if (bootparam)
+			iowrite8(-1, &bootparam->h2c_config_db);
+		vpdev->hw_ops->free_irq(vpdev, vi->cookie, vi);
+		flush_work(&vi->hotplug_work);
+		vop_scan_devices(vi, vpdev, REMOVE_DEVICES);
+	}
+	vop_exit_debugfs(vi);
+	kfree(vi);
+}
+
+static struct vop_device_id id_table[] = {
+	{ VOP_DEV_TRNSP, VOP_DEV_ANY_ID },
+	{ 0 },
+};
+
+static struct vop_driver vop_driver = {
+	.driver.name =	KBUILD_MODNAME,
+	.driver.owner =	THIS_MODULE,
+	.id_table = id_table,
+	.probe = vop_driver_probe,
+	.remove = vop_driver_remove,
+};
+
+module_vop_driver(vop_driver);
+
+MODULE_DEVICE_TABLE(mbus, id_table);
+MODULE_AUTHOR("Intel Corporation");
+MODULE_DESCRIPTION("Intel(R) Virtio Over PCIe (VOP) driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/misc/mic/vop/vop_main.h b/drivers/misc/mic/vop/vop_main.h
new file mode 100644
index 000000000..ba47ec7a6
--- /dev/null
+++ b/drivers/misc/mic/vop/vop_main.h
@@ -0,0 +1,170 @@
+/*
+ * Intel MIC Platform Software Stack (MPSS)
+ *
+ * Copyright(c) 2016 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * The full GNU General Public License is included in this distribution in
+ * the file called "COPYING".
+ *
+ * Intel Virtio Over PCIe (VOP) driver.
+ *
+ */
+#ifndef _VOP_MAIN_H_
+#define _VOP_MAIN_H_
+
+#include <linux/vringh.h>
+#include <linux/virtio_config.h>
+#include <linux/virtio.h>
+#include <linux/miscdevice.h>
+
+#include <linux/mic_common.h>
+#include "../common/mic_dev.h"
+
+#include "../bus/vop_bus.h"
+
+/*
+ * Note on endianness.
+ * 1. Host can be both BE or LE
+ * 2. Guest/card is LE. Host uses le_to_cpu to access desc/avail
+ *    rings and ioreadXX/iowriteXX to access used ring.
+ * 3. Device page exposed by host to guest contains LE values. Guest
+ *    accesses these using ioreadXX/iowriteXX etc. This way in general we
+ *    obey the virtio spec according to which guest works with native
+ *    endianness and host is aware of guest endianness and does all
+ *    required endianness conversion.
+ * 4. Data provided from user space to guest (in ADD_DEVICE and
+ *    CONFIG_CHANGE ioctl's) is not interpreted by the driver and should be
+ *    in guest endianness.
+ */
+
+/*
+ * vop_info - Allocated per invocation of VOP probe
+ *
+ * @vpdev: VOP device
+ * @hotplug_work: Handle virtio device creation, deletion and configuration
+ * @cookie: Cookie received upon requesting a virtio configuration interrupt
+ * @h2c_config_db: The doorbell used by the peer to indicate a config change
+ * @vdev_list: List of "active" virtio devices injected in the peer node
+ * @vop_mutex: Synchronize access to the device page as well as serialize
+ *             creation/deletion of virtio devices on the peer node
+ * @dp: Peer device page information
+ * @dbg: Debugfs entry
+ * @dma_ch: The DMA channel used by this transport for data transfers.
+ * @name: Name for this transport used in misc device creation.
+ * @miscdev: The misc device registered.
+ */
+struct vop_info {
+	struct vop_device *vpdev;
+	struct work_struct hotplug_work;
+	struct mic_irq *cookie;
+	int h2c_config_db;
+	struct list_head vdev_list;
+	struct mutex vop_mutex;
+	void __iomem *dp;
+	struct dentry *dbg;
+	struct dma_chan *dma_ch;
+	char name[16];
+	struct miscdevice miscdev;
+};
+
+/**
+ * struct vop_vringh - Virtio ring host information.
+ *
+ * @vring: The VOP vring used for setting up user space mappings.
+ * @vrh: The host VRINGH used for accessing the card vrings.
+ * @riov: The VRINGH read kernel IOV.
+ * @wiov: The VRINGH write kernel IOV.
+ * @head: The VRINGH head index address passed to vringh_getdesc_kern(..).
+ * @vr_mutex: Mutex for synchronizing access to the VRING.
+ * @buf: Temporary kernel buffer used to copy in/out data
+ * from/to the card via DMA.
+ * @buf_da: dma address of buf.
+ * @vdev: Back pointer to VOP virtio device for vringh_notify(..).
+ */
+struct vop_vringh {
+	struct mic_vring vring;
+	struct vringh vrh;
+	struct vringh_kiov riov;
+	struct vringh_kiov wiov;
+	u16 head;
+	struct mutex vr_mutex;
+	void *buf;
+	dma_addr_t buf_da;
+	struct vop_vdev *vdev;
+};
+
+/**
+ * struct vop_vdev - Host information for a card Virtio device.
+ *
+ * @virtio_id - Virtio device id.
+ * @waitq - Waitqueue to allow ring3 apps to poll.
+ * @vpdev - pointer to VOP bus device.
+ * @poll_wake - Used for waking up threads blocked in poll.
+ * @out_bytes - Debug stats for number of bytes copied from host to card.
+ * @in_bytes - Debug stats for number of bytes copied from card to host.
+ * @out_bytes_dma - Debug stats for number of bytes copied from host to card
+ * using DMA.
+ * @in_bytes_dma - Debug stats for number of bytes copied from card to host
+ * using DMA.
+ * @tx_len_unaligned - Debug stats for number of bytes copied to the card where
+ * the transfer length did not have the required DMA alignment.
+ * @tx_dst_unaligned - Debug stats for number of bytes copied where the
+ * destination address on the card did not have the required DMA alignment.
+ * @vvr - Store per VRING data structures.
+ * @virtio_bh_work - Work struct used to schedule virtio bottom half handling.
+ * @dd - Virtio device descriptor.
+ * @dc - Virtio device control fields.
+ * @list - List of Virtio devices.
+ * @virtio_db - The doorbell used by the card to interrupt the host.
+ * @virtio_cookie - The cookie returned while requesting interrupts.
+ * @vi: Transport information.
+ * @vdev_mutex: Mutex synchronizing virtio device injection,
+ *              removal and data transfers.
+ * @destroy: Track if a virtio device is being destroyed.
+ * @deleted: The virtio device has been deleted.
+ */
+struct vop_vdev {
+	int virtio_id;
+	wait_queue_head_t waitq;
+	struct vop_device *vpdev;
+	int poll_wake;
+	unsigned long out_bytes;
+	unsigned long in_bytes;
+	unsigned long out_bytes_dma;
+	unsigned long in_bytes_dma;
+	unsigned long tx_len_unaligned;
+	unsigned long tx_dst_unaligned;
+	unsigned long rx_dst_unaligned;
+	struct vop_vringh vvr[MIC_MAX_VRINGS];
+	struct work_struct virtio_bh_work;
+	struct mic_device_desc *dd;
+	struct mic_device_ctrl *dc;
+	struct list_head list;
+	int virtio_db;
+	struct mic_irq *virtio_cookie;
+	struct vop_info *vi;
+	struct mutex vdev_mutex;
+	struct completion destroy;
+	bool deleted;
+};
+
+/* Helper API to check if a virtio device is running */
+static inline bool vop_vdevup(struct vop_vdev *vdev)
+{
+	return !!vdev->dd->status;
+}
+
+void vop_init_debugfs(struct vop_info *vi);
+void vop_exit_debugfs(struct vop_info *vi);
+int vop_host_init(struct vop_info *vi);
+void vop_host_uninit(struct vop_info *vi);
+#endif
diff --git a/drivers/misc/mic/vop/vop_vringh.c b/drivers/misc/mic/vop/vop_vringh.c
new file mode 100644
index 000000000..a252c2199
--- /dev/null
+++ b/drivers/misc/mic/vop/vop_vringh.c
@@ -0,0 +1,1169 @@
+/*
+ * Intel MIC Platform Software Stack (MPSS)
+ *
+ * Copyright(c) 2016 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * The full GNU General Public License is included in this distribution in
+ * the file called "COPYING".
+ *
+ * Intel Virtio Over PCIe (VOP) driver.
+ *
+ */
+#include <linux/sched.h>
+#include <linux/poll.h>
+#include <linux/dma-mapping.h>
+
+#include <linux/mic_common.h>
+#include "../common/mic_dev.h"
+
+#include <linux/mic_ioctl.h>
+#include "vop_main.h"
+
+/* Helper API to obtain the VOP PCIe device */
+static inline struct device *vop_dev(struct vop_vdev *vdev)
+{
+	return vdev->vpdev->dev.parent;
+}
+
+/* Helper API to check if a virtio device is initialized */
+static inline int vop_vdev_inited(struct vop_vdev *vdev)
+{
+	if (!vdev)
+		return -EINVAL;
+	/* Device has not been created yet */
+	if (!vdev->dd || !vdev->dd->type) {
+		dev_err(vop_dev(vdev), "%s %d err %d\n",
+			__func__, __LINE__, -EINVAL);
+		return -EINVAL;
+	}
+	/* Device has been removed/deleted */
+	if (vdev->dd->type == -1) {
+		dev_dbg(vop_dev(vdev), "%s %d err %d\n",
+			__func__, __LINE__, -ENODEV);
+		return -ENODEV;
+	}
+	return 0;
+}
+
+static void _vop_notify(struct vringh *vrh)
+{
+	struct vop_vringh *vvrh = container_of(vrh, struct vop_vringh, vrh);
+	struct vop_vdev *vdev = vvrh->vdev;
+	struct vop_device *vpdev = vdev->vpdev;
+	s8 db = vdev->dc->h2c_vdev_db;
+
+	if (db != -1)
+		vpdev->hw_ops->send_intr(vpdev, db);
+}
+
+static void vop_virtio_init_post(struct vop_vdev *vdev)
+{
+	struct mic_vqconfig *vqconfig = mic_vq_config(vdev->dd);
+	struct vop_device *vpdev = vdev->vpdev;
+	int i, used_size;
+
+	for (i = 0; i < vdev->dd->num_vq; i++) {
+		used_size = PAGE_ALIGN(sizeof(u16) * 3 +
+				sizeof(struct vring_used_elem) *
+				le16_to_cpu(vqconfig->num));
+		if (!le64_to_cpu(vqconfig[i].used_address)) {
+			dev_warn(vop_dev(vdev), "used_address zero??\n");
+			continue;
+		}
+		vdev->vvr[i].vrh.vring.used =
+			(void __force *)vpdev->hw_ops->ioremap(
+			vpdev,
+			le64_to_cpu(vqconfig[i].used_address),
+			used_size);
+	}
+
+	vdev->dc->used_address_updated = 0;
+
+	dev_info(vop_dev(vdev), "%s: device type %d LINKUP\n",
+		 __func__, vdev->virtio_id);
+}
+
+static inline void vop_virtio_device_reset(struct vop_vdev *vdev)
+{
+	int i;
+
+	dev_dbg(vop_dev(vdev), "%s: status %d device type %d RESET\n",
+		__func__, vdev->dd->status, vdev->virtio_id);
+
+	for (i = 0; i < vdev->dd->num_vq; i++)
+		/*
+		 * Avoid lockdep false positive. The + 1 is for the vop
+		 * mutex which is held in the reset devices code path.
+		 */
+		mutex_lock_nested(&vdev->vvr[i].vr_mutex, i + 1);
+
+	/* 0 status means "reset" */
+	vdev->dd->status = 0;
+	vdev->dc->vdev_reset = 0;
+	vdev->dc->host_ack = 1;
+
+	for (i = 0; i < vdev->dd->num_vq; i++) {
+		struct vringh *vrh = &vdev->vvr[i].vrh;
+
+		vdev->vvr[i].vring.info->avail_idx = 0;
+		vrh->completed = 0;
+		vrh->last_avail_idx = 0;
+		vrh->last_used_idx = 0;
+	}
+
+	for (i = 0; i < vdev->dd->num_vq; i++)
+		mutex_unlock(&vdev->vvr[i].vr_mutex);
+}
+
+static void vop_virtio_reset_devices(struct vop_info *vi)
+{
+	struct list_head *pos, *tmp;
+	struct vop_vdev *vdev;
+
+	list_for_each_safe(pos, tmp, &vi->vdev_list) {
+		vdev = list_entry(pos, struct vop_vdev, list);
+		vop_virtio_device_reset(vdev);
+		vdev->poll_wake = 1;
+		wake_up(&vdev->waitq);
+	}
+}
+
+static void vop_bh_handler(struct work_struct *work)
+{
+	struct vop_vdev *vdev = container_of(work, struct vop_vdev,
+			virtio_bh_work);
+
+	if (vdev->dc->used_address_updated)
+		vop_virtio_init_post(vdev);
+
+	if (vdev->dc->vdev_reset)
+		vop_virtio_device_reset(vdev);
+
+	vdev->poll_wake = 1;
+	wake_up(&vdev->waitq);
+}
+
+static irqreturn_t _vop_virtio_intr_handler(int irq, void *data)
+{
+	struct vop_vdev *vdev = data;
+	struct vop_device *vpdev = vdev->vpdev;
+
+	vpdev->hw_ops->ack_interrupt(vpdev, vdev->virtio_db);
+	schedule_work(&vdev->virtio_bh_work);
+	return IRQ_HANDLED;
+}
+
+static int vop_virtio_config_change(struct vop_vdev *vdev, void *argp)
+{
+	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wake);
+	int ret = 0, retry, i;
+	struct vop_device *vpdev = vdev->vpdev;
+	struct vop_info *vi = dev_get_drvdata(&vpdev->dev);
+	struct mic_bootparam *bootparam = vpdev->hw_ops->get_dp(vpdev);
+	s8 db = bootparam->h2c_config_db;
+
+	mutex_lock(&vi->vop_mutex);
+	for (i = 0; i < vdev->dd->num_vq; i++)
+		mutex_lock_nested(&vdev->vvr[i].vr_mutex, i + 1);
+
+	if (db == -1 || vdev->dd->type == -1) {
+		ret = -EIO;
+		goto exit;
+	}
+
+	memcpy(mic_vq_configspace(vdev->dd), argp, vdev->dd->config_len);
+	vdev->dc->config_change = MIC_VIRTIO_PARAM_CONFIG_CHANGED;
+	vpdev->hw_ops->send_intr(vpdev, db);
+
+	for (retry = 100; retry--;) {
+		ret = wait_event_timeout(wake, vdev->dc->guest_ack,
+					 msecs_to_jiffies(100));
+		if (ret)
+			break;
+	}
+
+	dev_dbg(vop_dev(vdev),
+		"%s %d retry: %d\n", __func__, __LINE__, retry);
+	vdev->dc->config_change = 0;
+	vdev->dc->guest_ack = 0;
+exit:
+	for (i = 0; i < vdev->dd->num_vq; i++)
+		mutex_unlock(&vdev->vvr[i].vr_mutex);
+	mutex_unlock(&vi->vop_mutex);
+	return ret;
+}
+
+static int vop_copy_dp_entry(struct vop_vdev *vdev,
+			     struct mic_device_desc *argp, __u8 *type,
+			     struct mic_device_desc **devpage)
+{
+	struct vop_device *vpdev = vdev->vpdev;
+	struct mic_device_desc *devp;
+	struct mic_vqconfig *vqconfig;
+	int ret = 0, i;
+	bool slot_found = false;
+
+	vqconfig = mic_vq_config(argp);
+	for (i = 0; i < argp->num_vq; i++) {
+		if (le16_to_cpu(vqconfig[i].num) > MIC_MAX_VRING_ENTRIES) {
+			ret =  -EINVAL;
+			dev_err(vop_dev(vdev), "%s %d err %d\n",
+				__func__, __LINE__, ret);
+			goto exit;
+		}
+	}
+
+	/* Find the first free device page entry */
+	for (i = sizeof(struct mic_bootparam);
+		i < MIC_DP_SIZE - mic_total_desc_size(argp);
+		i += mic_total_desc_size(devp)) {
+		devp = vpdev->hw_ops->get_dp(vpdev) + i;
+		if (devp->type == 0 || devp->type == -1) {
+			slot_found = true;
+			break;
+		}
+	}
+	if (!slot_found) {
+		ret =  -EINVAL;
+		dev_err(vop_dev(vdev), "%s %d err %d\n",
+			__func__, __LINE__, ret);
+		goto exit;
+	}
+	/*
+	 * Save off the type before doing the memcpy. Type will be set in the
+	 * end after completing all initialization for the new device.
+	 */
+	*type = argp->type;
+	argp->type = 0;
+	memcpy(devp, argp, mic_desc_size(argp));
+
+	*devpage = devp;
+exit:
+	return ret;
+}
+
+static void vop_init_device_ctrl(struct vop_vdev *vdev,
+				 struct mic_device_desc *devpage)
+{
+	struct mic_device_ctrl *dc;
+
+	dc = (void *)devpage + mic_aligned_desc_size(devpage);
+
+	dc->config_change = 0;
+	dc->guest_ack = 0;
+	dc->vdev_reset = 0;
+	dc->host_ack = 0;
+	dc->used_address_updated = 0;
+	dc->c2h_vdev_db = -1;
+	dc->h2c_vdev_db = -1;
+	vdev->dc = dc;
+}
+
+static int vop_virtio_add_device(struct vop_vdev *vdev,
+				 struct mic_device_desc *argp)
+{
+	struct vop_info *vi = vdev->vi;
+	struct vop_device *vpdev = vi->vpdev;
+	struct mic_device_desc *dd = NULL;
+	struct mic_vqconfig *vqconfig;
+	int vr_size, i, j, ret;
+	u8 type = 0;
+	s8 db = -1;
+	char irqname[16];
+	struct mic_bootparam *bootparam;
+	u16 num;
+	dma_addr_t vr_addr;
+
+	bootparam = vpdev->hw_ops->get_dp(vpdev);
+	init_waitqueue_head(&vdev->waitq);
+	INIT_LIST_HEAD(&vdev->list);
+	vdev->vpdev = vpdev;
+
+	ret = vop_copy_dp_entry(vdev, argp, &type, &dd);
+	if (ret) {
+		dev_err(vop_dev(vdev), "%s %d err %d\n",
+			__func__, __LINE__, ret);
+		return ret;
+	}
+
+	vop_init_device_ctrl(vdev, dd);
+
+	vdev->dd = dd;
+	vdev->virtio_id = type;
+	vqconfig = mic_vq_config(dd);
+	INIT_WORK(&vdev->virtio_bh_work, vop_bh_handler);
+
+	for (i = 0; i < dd->num_vq; i++) {
+		struct vop_vringh *vvr = &vdev->vvr[i];
+		struct mic_vring *vr = &vdev->vvr[i].vring;
+
+		num = le16_to_cpu(vqconfig[i].num);
+		mutex_init(&vvr->vr_mutex);
+		vr_size = PAGE_ALIGN(round_up(vring_size(num, MIC_VIRTIO_RING_ALIGN), 4) +
+			sizeof(struct _mic_vring_info));
+		vr->va = (void *)
+			__get_free_pages(GFP_KERNEL | __GFP_ZERO,
+					 get_order(vr_size));
+		if (!vr->va) {
+			ret = -ENOMEM;
+			dev_err(vop_dev(vdev), "%s %d err %d\n",
+				__func__, __LINE__, ret);
+			goto err;
+		}
+		vr->len = vr_size;
+		vr->info = vr->va + round_up(vring_size(num, MIC_VIRTIO_RING_ALIGN), 4);
+		vr->info->magic = cpu_to_le32(MIC_MAGIC + vdev->virtio_id + i);
+		vr_addr = dma_map_single(&vpdev->dev, vr->va, vr_size,
+					 DMA_BIDIRECTIONAL);
+		if (dma_mapping_error(&vpdev->dev, vr_addr)) {
+			free_pages((unsigned long)vr->va, get_order(vr_size));
+			ret = -ENOMEM;
+			dev_err(vop_dev(vdev), "%s %d err %d\n",
+				__func__, __LINE__, ret);
+			goto err;
+		}
+		vqconfig[i].address = cpu_to_le64(vr_addr);
+
+		vring_init(&vr->vr, num, vr->va, MIC_VIRTIO_RING_ALIGN);
+		ret = vringh_init_kern(&vvr->vrh,
+				       *(u32 *)mic_vq_features(vdev->dd),
+				       num, false, vr->vr.desc, vr->vr.avail,
+				       vr->vr.used);
+		if (ret) {
+			dev_err(vop_dev(vdev), "%s %d err %d\n",
+				__func__, __LINE__, ret);
+			goto err;
+		}
+		vringh_kiov_init(&vvr->riov, NULL, 0);
+		vringh_kiov_init(&vvr->wiov, NULL, 0);
+		vvr->head = USHRT_MAX;
+		vvr->vdev = vdev;
+		vvr->vrh.notify = _vop_notify;
+		dev_dbg(&vpdev->dev,
+			"%s %d index %d va %p info %p vr_size 0x%x\n",
+			__func__, __LINE__, i, vr->va, vr->info, vr_size);
+		vvr->buf = (void *)__get_free_pages(GFP_KERNEL,
+					get_order(VOP_INT_DMA_BUF_SIZE));
+		vvr->buf_da = dma_map_single(&vpdev->dev,
+					  vvr->buf, VOP_INT_DMA_BUF_SIZE,
+					  DMA_BIDIRECTIONAL);
+	}
+
+	snprintf(irqname, sizeof(irqname), "vop%dvirtio%d", vpdev->index,
+		 vdev->virtio_id);
+	vdev->virtio_db = vpdev->hw_ops->next_db(vpdev);
+	vdev->virtio_cookie = vpdev->hw_ops->request_irq(vpdev,
+			_vop_virtio_intr_handler, irqname, vdev,
+			vdev->virtio_db);
+	if (IS_ERR(vdev->virtio_cookie)) {
+		ret = PTR_ERR(vdev->virtio_cookie);
+		dev_dbg(&vpdev->dev, "request irq failed\n");
+		goto err;
+	}
+
+	vdev->dc->c2h_vdev_db = vdev->virtio_db;
+
+	/*
+	 * Order the type update with previous stores. This write barrier
+	 * is paired with the corresponding read barrier before the uncached
+	 * system memory read of the type, on the card while scanning the
+	 * device page.
+	 */
+	smp_wmb();
+	dd->type = type;
+	argp->type = type;
+
+	if (bootparam) {
+		db = bootparam->h2c_config_db;
+		if (db != -1)
+			vpdev->hw_ops->send_intr(vpdev, db);
+	}
+	dev_dbg(&vpdev->dev, "Added virtio id %d db %d\n", dd->type, db);
+	return 0;
+err:
+	vqconfig = mic_vq_config(dd);
+	for (j = 0; j < i; j++) {
+		struct vop_vringh *vvr = &vdev->vvr[j];
+
+		dma_unmap_single(&vpdev->dev, le64_to_cpu(vqconfig[j].address),
+				 vvr->vring.len, DMA_BIDIRECTIONAL);
+		free_pages((unsigned long)vvr->vring.va,
+			   get_order(vvr->vring.len));
+	}
+	return ret;
+}
+
+static void vop_dev_remove(struct vop_info *pvi, struct mic_device_ctrl *devp,
+			   struct vop_device *vpdev)
+{
+	struct mic_bootparam *bootparam = vpdev->hw_ops->get_dp(vpdev);
+	s8 db;
+	int ret, retry;
+	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wake);
+
+	devp->config_change = MIC_VIRTIO_PARAM_DEV_REMOVE;
+	db = bootparam->h2c_config_db;
+	if (db != -1)
+		vpdev->hw_ops->send_intr(vpdev, db);
+	else
+		goto done;
+	for (retry = 15; retry--;) {
+		ret = wait_event_timeout(wake, devp->guest_ack,
+					 msecs_to_jiffies(1000));
+		if (ret)
+			break;
+	}
+done:
+	devp->config_change = 0;
+	devp->guest_ack = 0;
+}
+
+static void vop_virtio_del_device(struct vop_vdev *vdev)
+{
+	struct vop_info *vi = vdev->vi;
+	struct vop_device *vpdev = vdev->vpdev;
+	int i;
+	struct mic_vqconfig *vqconfig;
+	struct mic_bootparam *bootparam = vpdev->hw_ops->get_dp(vpdev);
+
+	if (!bootparam)
+		goto skip_hot_remove;
+	vop_dev_remove(vi, vdev->dc, vpdev);
+skip_hot_remove:
+	vpdev->hw_ops->free_irq(vpdev, vdev->virtio_cookie, vdev);
+	flush_work(&vdev->virtio_bh_work);
+	vqconfig = mic_vq_config(vdev->dd);
+	for (i = 0; i < vdev->dd->num_vq; i++) {
+		struct vop_vringh *vvr = &vdev->vvr[i];
+
+		dma_unmap_single(&vpdev->dev,
+				 vvr->buf_da, VOP_INT_DMA_BUF_SIZE,
+				 DMA_BIDIRECTIONAL);
+		free_pages((unsigned long)vvr->buf,
+			   get_order(VOP_INT_DMA_BUF_SIZE));
+		vringh_kiov_cleanup(&vvr->riov);
+		vringh_kiov_cleanup(&vvr->wiov);
+		dma_unmap_single(&vpdev->dev, le64_to_cpu(vqconfig[i].address),
+				 vvr->vring.len, DMA_BIDIRECTIONAL);
+		free_pages((unsigned long)vvr->vring.va,
+			   get_order(vvr->vring.len));
+	}
+	/*
+	 * Order the type update with previous stores. This write barrier
+	 * is paired with the corresponding read barrier before the uncached
+	 * system memory read of the type, on the card while scanning the
+	 * device page.
+	 */
+	smp_wmb();
+	vdev->dd->type = -1;
+}
+
+/*
+ * vop_sync_dma - Wrapper for synchronous DMAs.
+ *
+ * @dev - The address of the pointer to the device instance used
+ * for DMA registration.
+ * @dst - destination DMA address.
+ * @src - source DMA address.
+ * @len - size of the transfer.
+ *
+ * Return DMA_SUCCESS on success
+ */
+static int vop_sync_dma(struct vop_vdev *vdev, dma_addr_t dst, dma_addr_t src,
+			size_t len)
+{
+	int err = 0;
+	struct dma_device *ddev;
+	struct dma_async_tx_descriptor *tx;
+	struct vop_info *vi = dev_get_drvdata(&vdev->vpdev->dev);
+	struct dma_chan *vop_ch = vi->dma_ch;
+
+	if (!vop_ch) {
+		err = -EBUSY;
+		goto error;
+	}
+	ddev = vop_ch->device;
+	tx = ddev->device_prep_dma_memcpy(vop_ch, dst, src, len,
+		DMA_PREP_FENCE);
+	if (!tx) {
+		err = -ENOMEM;
+		goto error;
+	} else {
+		dma_cookie_t cookie;
+
+		cookie = tx->tx_submit(tx);
+		if (dma_submit_error(cookie)) {
+			err = -ENOMEM;
+			goto error;
+		}
+		dma_async_issue_pending(vop_ch);
+		err = dma_sync_wait(vop_ch, cookie);
+	}
+error:
+	if (err)
+		dev_err(&vi->vpdev->dev, "%s %d err %d\n",
+			__func__, __LINE__, err);
+	return err;
+}
+
+#define VOP_USE_DMA true
+
+/*
+ * Initiates the copies across the PCIe bus from card memory to a user
+ * space buffer. When transfers are done using DMA, source/destination
+ * addresses and transfer length must follow the alignment requirements of
+ * the MIC DMA engine.
+ */
+static int vop_virtio_copy_to_user(struct vop_vdev *vdev, void __user *ubuf,
+				   size_t len, u64 daddr, size_t dlen,
+				   int vr_idx)
+{
+	struct vop_device *vpdev = vdev->vpdev;
+	void __iomem *dbuf = vpdev->hw_ops->ioremap(vpdev, daddr, len);
+	struct vop_vringh *vvr = &vdev->vvr[vr_idx];
+	struct vop_info *vi = dev_get_drvdata(&vpdev->dev);
+	size_t dma_alignment = 1 << vi->dma_ch->device->copy_align;
+	bool x200 = is_dma_copy_aligned(vi->dma_ch->device, 1, 1, 1);
+	size_t dma_offset, partlen;
+	int err;
+
+	if (!VOP_USE_DMA) {
+		if (copy_to_user(ubuf, (void __force *)dbuf, len)) {
+			err = -EFAULT;
+			dev_err(vop_dev(vdev), "%s %d err %d\n",
+				__func__, __LINE__, err);
+			goto err;
+		}
+		vdev->in_bytes += len;
+		err = 0;
+		goto err;
+	}
+
+	dma_offset = daddr - round_down(daddr, dma_alignment);
+	daddr -= dma_offset;
+	len += dma_offset;
+	/*
+	 * X100 uses DMA addresses as seen by the card so adding
+	 * the aperture base is not required for DMA. However x200
+	 * requires DMA addresses to be an offset into the bar so
+	 * add the aperture base for x200.
+	 */
+	if (x200)
+		daddr += vpdev->aper->pa;
+	while (len) {
+		partlen = min_t(size_t, len, VOP_INT_DMA_BUF_SIZE);
+		err = vop_sync_dma(vdev, vvr->buf_da, daddr,
+				   ALIGN(partlen, dma_alignment));
+		if (err) {
+			dev_err(vop_dev(vdev), "%s %d err %d\n",
+				__func__, __LINE__, err);
+			goto err;
+		}
+		if (copy_to_user(ubuf, vvr->buf + dma_offset,
+				 partlen - dma_offset)) {
+			err = -EFAULT;
+			dev_err(vop_dev(vdev), "%s %d err %d\n",
+				__func__, __LINE__, err);
+			goto err;
+		}
+		daddr += partlen;
+		ubuf += partlen;
+		dbuf += partlen;
+		vdev->in_bytes_dma += partlen;
+		vdev->in_bytes += partlen;
+		len -= partlen;
+		dma_offset = 0;
+	}
+	err = 0;
+err:
+	vpdev->hw_ops->iounmap(vpdev, dbuf);
+	dev_dbg(vop_dev(vdev),
+		"%s: ubuf %p dbuf %p len 0x%lx vr_idx 0x%x\n",
+		__func__, ubuf, dbuf, len, vr_idx);
+	return err;
+}
+
+/*
+ * Initiates copies across the PCIe bus from a user space buffer to card
+ * memory. When transfers are done using DMA, source/destination addresses
+ * and transfer length must follow the alignment requirements of the MIC
+ * DMA engine.
+ */
+static int vop_virtio_copy_from_user(struct vop_vdev *vdev, void __user *ubuf,
+				     size_t len, u64 daddr, size_t dlen,
+				     int vr_idx)
+{
+	struct vop_device *vpdev = vdev->vpdev;
+	void __iomem *dbuf = vpdev->hw_ops->ioremap(vpdev, daddr, len);
+	struct vop_vringh *vvr = &vdev->vvr[vr_idx];
+	struct vop_info *vi = dev_get_drvdata(&vdev->vpdev->dev);
+	size_t dma_alignment = 1 << vi->dma_ch->device->copy_align;
+	bool x200 = is_dma_copy_aligned(vi->dma_ch->device, 1, 1, 1);
+	size_t partlen;
+	bool dma = VOP_USE_DMA;
+	int err = 0;
+	size_t offset = 0;
+
+	if (daddr & (dma_alignment - 1)) {
+		vdev->tx_dst_unaligned += len;
+		dma = false;
+	} else if (ALIGN(len, dma_alignment) > dlen) {
+		vdev->tx_len_unaligned += len;
+		dma = false;
+	}
+
+	if (!dma)
+		goto memcpy;
+
+	/*
+	 * X100 uses DMA addresses as seen by the card so adding
+	 * the aperture base is not required for DMA. However x200
+	 * requires DMA addresses to be an offset into the bar so
+	 * add the aperture base for x200.
+	 */
+	if (x200)
+		daddr += vpdev->aper->pa;
+	while (len) {
+		partlen = min_t(size_t, len, VOP_INT_DMA_BUF_SIZE);
+
+		if (copy_from_user(vvr->buf, ubuf, partlen)) {
+			err = -EFAULT;
+			dev_err(vop_dev(vdev), "%s %d err %d\n",
+				__func__, __LINE__, err);
+			goto err;
+		}
+		err = vop_sync_dma(vdev, daddr, vvr->buf_da,
+				   ALIGN(partlen, dma_alignment));
+		if (err) {
+			dev_err(vop_dev(vdev), "%s %d err %d\n",
+				__func__, __LINE__, err);
+			goto err;
+		}
+		daddr += partlen;
+		ubuf += partlen;
+		dbuf += partlen;
+		vdev->out_bytes_dma += partlen;
+		vdev->out_bytes += partlen;
+		len -= partlen;
+	}
+memcpy:
+	/*
+	 * We are copying to IO below and should ideally use something
+	 * like copy_from_user_toio(..) if it existed.
+	 */
+	while (len) {
+		partlen = min_t(size_t, len, VOP_INT_DMA_BUF_SIZE);
+
+		if (copy_from_user(vvr->buf, ubuf + offset, partlen)) {
+			err = -EFAULT;
+			dev_err(vop_dev(vdev), "%s %d err %d\n",
+				__func__, __LINE__, err);
+			goto err;
+		}
+		memcpy_toio(dbuf + offset, vvr->buf, partlen);
+		offset += partlen;
+		vdev->out_bytes += partlen;
+		len -= partlen;
+	}
+	err = 0;
+err:
+	vpdev->hw_ops->iounmap(vpdev, dbuf);
+	dev_dbg(vop_dev(vdev),
+		"%s: ubuf %p dbuf %p len 0x%lx vr_idx 0x%x\n",
+		__func__, ubuf, dbuf, len, vr_idx);
+	return err;
+}
+
+#define MIC_VRINGH_READ true
+
+/* Determine the total number of bytes consumed in a VRINGH KIOV */
+static inline u32 vop_vringh_iov_consumed(struct vringh_kiov *iov)
+{
+	int i;
+	u32 total = iov->consumed;
+
+	for (i = 0; i < iov->i; i++)
+		total += iov->iov[i].iov_len;
+	return total;
+}
+
+/*
+ * Traverse the VRINGH KIOV and issue the APIs to trigger the copies.
+ * This API is heavily based on the vringh_iov_xfer(..) implementation
+ * in vringh.c. The reason we cannot reuse vringh_iov_pull_kern(..)
+ * and vringh_iov_push_kern(..) directly is because there is no
+ * way to override the VRINGH xfer(..) routines as of v3.10.
+ */
+static int vop_vringh_copy(struct vop_vdev *vdev, struct vringh_kiov *iov,
+			   void __user *ubuf, size_t len, bool read, int vr_idx,
+			   size_t *out_len)
+{
+	int ret = 0;
+	size_t partlen, tot_len = 0;
+
+	while (len && iov->i < iov->used) {
+		struct kvec *kiov = &iov->iov[iov->i];
+
+		partlen = min(kiov->iov_len, len);
+		if (read)
+			ret = vop_virtio_copy_to_user(vdev, ubuf, partlen,
+						      (u64)kiov->iov_base,
+						      kiov->iov_len,
+						      vr_idx);
+		else
+			ret = vop_virtio_copy_from_user(vdev, ubuf, partlen,
+							(u64)kiov->iov_base,
+							kiov->iov_len,
+							vr_idx);
+		if (ret) {
+			dev_err(vop_dev(vdev), "%s %d err %d\n",
+				__func__, __LINE__, ret);
+			break;
+		}
+		len -= partlen;
+		ubuf += partlen;
+		tot_len += partlen;
+		iov->consumed += partlen;
+		kiov->iov_len -= partlen;
+		kiov->iov_base += partlen;
+		if (!kiov->iov_len) {
+			/* Fix up old iov element then increment. */
+			kiov->iov_len = iov->consumed;
+			kiov->iov_base -= iov->consumed;
+
+			iov->consumed = 0;
+			iov->i++;
+		}
+	}
+	*out_len = tot_len;
+	return ret;
+}
+
+/*
+ * Use the standard VRINGH infrastructure in the kernel to fetch new
+ * descriptors, initiate the copies and update the used ring.
+ */
+static int _vop_virtio_copy(struct vop_vdev *vdev, struct mic_copy_desc *copy)
+{
+	int ret = 0;
+	u32 iovcnt = copy->iovcnt;
+	struct iovec iov;
+	struct iovec __user *u_iov = copy->iov;
+	void __user *ubuf = NULL;
+	struct vop_vringh *vvr = &vdev->vvr[copy->vr_idx];
+	struct vringh_kiov *riov = &vvr->riov;
+	struct vringh_kiov *wiov = &vvr->wiov;
+	struct vringh *vrh = &vvr->vrh;
+	u16 *head = &vvr->head;
+	struct mic_vring *vr = &vvr->vring;
+	size_t len = 0, out_len;
+
+	copy->out_len = 0;
+	/* Fetch a new IOVEC if all previous elements have been processed */
+	if (riov->i == riov->used && wiov->i == wiov->used) {
+		ret = vringh_getdesc_kern(vrh, riov, wiov,
+					  head, GFP_KERNEL);
+		/* Check if there are available descriptors */
+		if (ret <= 0)
+			return ret;
+	}
+	while (iovcnt) {
+		if (!len) {
+			/* Copy over a new iovec from user space. */
+			ret = copy_from_user(&iov, u_iov, sizeof(*u_iov));
+			if (ret) {
+				ret = -EINVAL;
+				dev_err(vop_dev(vdev), "%s %d err %d\n",
+					__func__, __LINE__, ret);
+				break;
+			}
+			len = iov.iov_len;
+			ubuf = iov.iov_base;
+		}
+		/* Issue all the read descriptors first */
+		ret = vop_vringh_copy(vdev, riov, ubuf, len,
+				      MIC_VRINGH_READ, copy->vr_idx, &out_len);
+		if (ret) {
+			dev_err(vop_dev(vdev), "%s %d err %d\n",
+				__func__, __LINE__, ret);
+			break;
+		}
+		len -= out_len;
+		ubuf += out_len;
+		copy->out_len += out_len;
+		/* Issue the write descriptors next */
+		ret = vop_vringh_copy(vdev, wiov, ubuf, len,
+				      !MIC_VRINGH_READ, copy->vr_idx, &out_len);
+		if (ret) {
+			dev_err(vop_dev(vdev), "%s %d err %d\n",
+				__func__, __LINE__, ret);
+			break;
+		}
+		len -= out_len;
+		ubuf += out_len;
+		copy->out_len += out_len;
+		if (!len) {
+			/* One user space iovec is now completed */
+			iovcnt--;
+			u_iov++;
+		}
+		/* Exit loop if all elements in KIOVs have been processed. */
+		if (riov->i == riov->used && wiov->i == wiov->used)
+			break;
+	}
+	/*
+	 * Update the used ring if a descriptor was available and some data was
+	 * copied in/out and the user asked for a used ring update.
+	 */
+	if (*head != USHRT_MAX && copy->out_len && copy->update_used) {
+		u32 total = 0;
+
+		/* Determine the total data consumed */
+		total += vop_vringh_iov_consumed(riov);
+		total += vop_vringh_iov_consumed(wiov);
+		vringh_complete_kern(vrh, *head, total);
+		*head = USHRT_MAX;
+		if (vringh_need_notify_kern(vrh) > 0)
+			vringh_notify(vrh);
+		vringh_kiov_cleanup(riov);
+		vringh_kiov_cleanup(wiov);
+		/* Update avail idx for user space */
+		vr->info->avail_idx = vrh->last_avail_idx;
+	}
+	return ret;
+}
+
+static inline int vop_verify_copy_args(struct vop_vdev *vdev,
+				       struct mic_copy_desc *copy)
+{
+	if (!vdev || copy->vr_idx >= vdev->dd->num_vq)
+		return -EINVAL;
+	return 0;
+}
+
+/* Copy a specified number of virtio descriptors in a chain */
+static int vop_virtio_copy_desc(struct vop_vdev *vdev,
+				struct mic_copy_desc *copy)
+{
+	int err;
+	struct vop_vringh *vvr;
+
+	err = vop_verify_copy_args(vdev, copy);
+	if (err)
+		return err;
+
+	vvr = &vdev->vvr[copy->vr_idx];
+	mutex_lock(&vvr->vr_mutex);
+	if (!vop_vdevup(vdev)) {
+		err = -ENODEV;
+		dev_err(vop_dev(vdev), "%s %d err %d\n",
+			__func__, __LINE__, err);
+		goto err;
+	}
+	err = _vop_virtio_copy(vdev, copy);
+	if (err) {
+		dev_err(vop_dev(vdev), "%s %d err %d\n",
+			__func__, __LINE__, err);
+	}
+err:
+	mutex_unlock(&vvr->vr_mutex);
+	return err;
+}
+
+static int vop_open(struct inode *inode, struct file *f)
+{
+	struct vop_vdev *vdev;
+	struct vop_info *vi = container_of(f->private_data,
+		struct vop_info, miscdev);
+
+	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
+	if (!vdev)
+		return -ENOMEM;
+	vdev->vi = vi;
+	mutex_init(&vdev->vdev_mutex);
+	f->private_data = vdev;
+	init_completion(&vdev->destroy);
+	complete(&vdev->destroy);
+	return 0;
+}
+
+static int vop_release(struct inode *inode, struct file *f)
+{
+	struct vop_vdev *vdev = f->private_data, *vdev_tmp;
+	struct vop_info *vi = vdev->vi;
+	struct list_head *pos, *tmp;
+	bool found = false;
+
+	mutex_lock(&vdev->vdev_mutex);
+	if (vdev->deleted)
+		goto unlock;
+	mutex_lock(&vi->vop_mutex);
+	list_for_each_safe(pos, tmp, &vi->vdev_list) {
+		vdev_tmp = list_entry(pos, struct vop_vdev, list);
+		if (vdev == vdev_tmp) {
+			vop_virtio_del_device(vdev);
+			list_del(pos);
+			found = true;
+			break;
+		}
+	}
+	mutex_unlock(&vi->vop_mutex);
+unlock:
+	mutex_unlock(&vdev->vdev_mutex);
+	if (!found)
+		wait_for_completion(&vdev->destroy);
+	f->private_data = NULL;
+	kfree(vdev);
+	return 0;
+}
+
+static long vop_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
+{
+	struct vop_vdev *vdev = f->private_data;
+	struct vop_info *vi = vdev->vi;
+	void __user *argp = (void __user *)arg;
+	int ret;
+
+	switch (cmd) {
+	case MIC_VIRTIO_ADD_DEVICE:
+	{
+		struct mic_device_desc dd, *dd_config;
+
+		if (copy_from_user(&dd, argp, sizeof(dd)))
+			return -EFAULT;
+
+		if (mic_aligned_desc_size(&dd) > MIC_MAX_DESC_BLK_SIZE ||
+		    dd.num_vq > MIC_MAX_VRINGS)
+			return -EINVAL;
+
+		dd_config = memdup_user(argp, mic_desc_size(&dd));
+		if (IS_ERR(dd_config))
+			return PTR_ERR(dd_config);
+
+		/* Ensure desc has not changed between the two reads */
+		if (memcmp(&dd, dd_config, sizeof(dd))) {
+			ret = -EINVAL;
+			goto free_ret;
+		}
+		mutex_lock(&vdev->vdev_mutex);
+		mutex_lock(&vi->vop_mutex);
+		ret = vop_virtio_add_device(vdev, dd_config);
+		if (ret)
+			goto unlock_ret;
+		list_add_tail(&vdev->list, &vi->vdev_list);
+unlock_ret:
+		mutex_unlock(&vi->vop_mutex);
+		mutex_unlock(&vdev->vdev_mutex);
+free_ret:
+		kfree(dd_config);
+		return ret;
+	}
+	case MIC_VIRTIO_COPY_DESC:
+	{
+		struct mic_copy_desc copy;
+
+		mutex_lock(&vdev->vdev_mutex);
+		ret = vop_vdev_inited(vdev);
+		if (ret)
+			goto _unlock_ret;
+
+		if (copy_from_user(&copy, argp, sizeof(copy))) {
+			ret = -EFAULT;
+			goto _unlock_ret;
+		}
+
+		ret = vop_virtio_copy_desc(vdev, &copy);
+		if (ret < 0)
+			goto _unlock_ret;
+		if (copy_to_user(
+			&((struct mic_copy_desc __user *)argp)->out_len,
+			&copy.out_len, sizeof(copy.out_len)))
+			ret = -EFAULT;
+_unlock_ret:
+		mutex_unlock(&vdev->vdev_mutex);
+		return ret;
+	}
+	case MIC_VIRTIO_CONFIG_CHANGE:
+	{
+		void *buf;
+
+		mutex_lock(&vdev->vdev_mutex);
+		ret = vop_vdev_inited(vdev);
+		if (ret)
+			goto __unlock_ret;
+		buf = memdup_user(argp, vdev->dd->config_len);
+		if (IS_ERR(buf)) {
+			ret = PTR_ERR(buf);
+			goto __unlock_ret;
+		}
+		ret = vop_virtio_config_change(vdev, buf);
+		kfree(buf);
+__unlock_ret:
+		mutex_unlock(&vdev->vdev_mutex);
+		return ret;
+	}
+	default:
+		return -ENOIOCTLCMD;
+	};
+	return 0;
+}
+
+/*
+ * We return EPOLLIN | EPOLLOUT from poll when new buffers are enqueued, and
+ * not when previously enqueued buffers may be available. This means that
+ * in the card->host (TX) path, when userspace is unblocked by poll it
+ * must drain all available descriptors or it can stall.
+ */
+static __poll_t vop_poll(struct file *f, poll_table *wait)
+{
+	struct vop_vdev *vdev = f->private_data;
+	__poll_t mask = 0;
+
+	mutex_lock(&vdev->vdev_mutex);
+	if (vop_vdev_inited(vdev)) {
+		mask = EPOLLERR;
+		goto done;
+	}
+	poll_wait(f, &vdev->waitq, wait);
+	if (vop_vdev_inited(vdev)) {
+		mask = EPOLLERR;
+	} else if (vdev->poll_wake) {
+		vdev->poll_wake = 0;
+		mask = EPOLLIN | EPOLLOUT;
+	}
+done:
+	mutex_unlock(&vdev->vdev_mutex);
+	return mask;
+}
+
+static inline int
+vop_query_offset(struct vop_vdev *vdev, unsigned long offset,
+		 unsigned long *size, unsigned long *pa)
+{
+	struct vop_device *vpdev = vdev->vpdev;
+	unsigned long start = MIC_DP_SIZE;
+	int i;
+
+	/*
+	 * MMAP interface is as follows:
+	 * offset				region
+	 * 0x0					virtio device_page
+	 * 0x1000				first vring
+	 * 0x1000 + size of 1st vring		second vring
+	 * ....
+	 */
+	if (!offset) {
+		*pa = virt_to_phys(vpdev->hw_ops->get_dp(vpdev));
+		*size = MIC_DP_SIZE;
+		return 0;
+	}
+
+	for (i = 0; i < vdev->dd->num_vq; i++) {
+		struct vop_vringh *vvr = &vdev->vvr[i];
+
+		if (offset == start) {
+			*pa = virt_to_phys(vvr->vring.va);
+			*size = vvr->vring.len;
+			return 0;
+		}
+		start += vvr->vring.len;
+	}
+	return -1;
+}
+
+/*
+ * Maps the device page and virtio rings to user space for readonly access.
+ */
+static int vop_mmap(struct file *f, struct vm_area_struct *vma)
+{
+	struct vop_vdev *vdev = f->private_data;
+	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
+	unsigned long pa, size = vma->vm_end - vma->vm_start, size_rem = size;
+	int i, err;
+
+	err = vop_vdev_inited(vdev);
+	if (err)
+		goto ret;
+	if (vma->vm_flags & VM_WRITE) {
+		err = -EACCES;
+		goto ret;
+	}
+	while (size_rem) {
+		i = vop_query_offset(vdev, offset, &size, &pa);
+		if (i < 0) {
+			err = -EINVAL;
+			goto ret;
+		}
+		err = remap_pfn_range(vma, vma->vm_start + offset,
+				      pa >> PAGE_SHIFT, size,
+				      vma->vm_page_prot);
+		if (err)
+			goto ret;
+		size_rem -= size;
+		offset += size;
+	}
+ret:
+	return err;
+}
+
+static const struct file_operations vop_fops = {
+	.open = vop_open,
+	.release = vop_release,
+	.unlocked_ioctl = vop_ioctl,
+	.poll = vop_poll,
+	.mmap = vop_mmap,
+	.owner = THIS_MODULE,
+};
+
+int vop_host_init(struct vop_info *vi)
+{
+	int rc;
+	struct miscdevice *mdev;
+	struct vop_device *vpdev = vi->vpdev;
+
+	INIT_LIST_HEAD(&vi->vdev_list);
+	vi->dma_ch = vpdev->dma_ch;
+	mdev = &vi->miscdev;
+	mdev->minor = MISC_DYNAMIC_MINOR;
+	snprintf(vi->name, sizeof(vi->name), "vop_virtio%d", vpdev->index);
+	mdev->name = vi->name;
+	mdev->fops = &vop_fops;
+	mdev->parent = &vpdev->dev;
+
+	rc = misc_register(mdev);
+	if (rc)
+		dev_err(&vpdev->dev, "%s failed rc %d\n", __func__, rc);
+	return rc;
+}
+
+void vop_host_uninit(struct vop_info *vi)
+{
+	struct list_head *pos, *tmp;
+	struct vop_vdev *vdev;
+
+	mutex_lock(&vi->vop_mutex);
+	vop_virtio_reset_devices(vi);
+	list_for_each_safe(pos, tmp, &vi->vdev_list) {
+		vdev = list_entry(pos, struct vop_vdev, list);
+		list_del(pos);
+		reinit_completion(&vdev->destroy);
+		mutex_unlock(&vi->vop_mutex);
+		mutex_lock(&vdev->vdev_mutex);
+		vop_virtio_del_device(vdev);
+		vdev->deleted = true;
+		mutex_unlock(&vdev->vdev_mutex);
+		complete(&vdev->destroy);
+		mutex_lock(&vi->vop_mutex);
+	}
+	mutex_unlock(&vi->vop_mutex);
+	misc_deregister(&vi->miscdev);
+}