Merge git://github.com/rustyrussell/linux

* git://github.com/rustyrussell/linux:
virtio-blk: use ida to allocate disk index
virtio: Add platform bus driver for memory mapped virtio device
virtio: Dont add "config" to list for !per_vq_vector
virtio: console: wait for first console port for early console output
virtio: console: add port stats for bytes received, sent and discarded
virtio: console: make discard_port_data() use get_inbuf()
virtio: console: rename variable
virtio: console: make get_inbuf() return port->inbuf if present
virtio: console: Fix return type for get_inbuf()
virtio: console: Use wait_event_freezable instead of _interruptible
virtio: console: Ignore port name update request if name already set
virtio: console: Fix indentation
virtio: modify vring_init and vring_size to take account of the layout containing *_event_idx
virtio.h: correct comment for struct virtio_driver
virtio-net: Use virtio_config_val() for retrieving config
virtio_config: Add virtio_config_val_len()
virtio-console: Use virtio_config_val() for retrieving config

Documentation/devicetree/bindings/virtio/mmio.txt

···
+* virtio memory mapped device
+
+See http://ozlabs.org/~rusty/virtio-spec/ for more details.
+
+Required properties:
+
+- compatible:	"virtio,mmio" compatibility string
+- reg:		control registers base address and size including configuration space
+- interrupts:	interrupt generated by the device
+
+Example:
+
+	virtio_block@3000 {
+		compatible = "virtio,mmio";
+		reg = <0x3000 0x100>;
+		interrupts = <41>;
+	}

drivers/block/virtio_blk.c

···
 #include <linux/scatterlist.h>
 #include <linux/string_helpers.h>
 #include <scsi/scsi_cmnd.h>
+#include <linux/idr.h>
 
 #define PART_BITS 4
 
-static int major, index;
+static int major;
+static DEFINE_IDA(vd_index_ida);
+
 struct workqueue_struct *virtblk_wq;
 
 struct virtio_blk
···
 
 	/* What host tells us, plus 2 for header & tailer. */
 	unsigned int sg_elems;
+
+	/* Ida index - used to track minor number allocations. */
+	int index;
 
 	/* Scatterlist: can be too big for stack. */
 	struct scatterlist sg[/*sg_elems*/];
···
 	return index << PART_BITS;
 }
 
+static int minor_to_index(int minor)
+{
+	return minor >> PART_BITS;
+}
+
 static ssize_t virtblk_serial_show(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
···
 {
 	struct virtio_blk *vblk;
 	struct request_queue *q;
-	int err;
+	int err, index;
 	u64 cap;
 	u32 v, blk_size, sg_elems, opt_io_size;
 	u16 min_io_size;
 	u8 physical_block_exp, alignment_offset;
 
-	if (index_to_minor(index) >= 1 << MINORBITS)
-		return -ENOSPC;
+	err = ida_simple_get(&vd_index_ida, 0, minor_to_index(1 << MINORBITS),
+			     GFP_KERNEL);
+	if (err < 0)
+		goto out;
+	index = err;
 
 	/* We need to know how many segments before we allocate. */
 	err = virtio_config_val(vdev, VIRTIO_BLK_F_SEG_MAX,
···
 				    sizeof(vblk->sg[0]) * sg_elems, GFP_KERNEL);
 	if (!vblk) {
 		err = -ENOMEM;
-		goto out;
+		goto out_free_index;
 	}
 
 	INIT_LIST_HEAD(&vblk->reqs);
···
 	vblk->disk->private_data = vblk;
 	vblk->disk->fops = &virtblk_fops;
 	vblk->disk->driverfs_dev = &vdev->dev;
-	index++;
+	vblk->index = index;
 
 	/* configure queue flush support */
 	if (virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH))
···
 	vdev->config->del_vqs(vdev);
 out_free_vblk:
 	kfree(vblk);
+out_free_index:
+	ida_simple_remove(&vd_index_ida, index);
 out:
 	return err;
 }
···
 static void __devexit virtblk_remove(struct virtio_device *vdev)
 {
 	struct virtio_blk *vblk = vdev->priv;
+	int index = vblk->index;
 
 	flush_work(&vblk->config_work);
 
···
 	mempool_destroy(vblk->pool);
 	vdev->config->del_vqs(vdev);
 	kfree(vblk);
+	ida_simple_remove(&vd_index_ida, index);
 }
 
 static const struct virtio_device_id id_table[] = {

drivers/char/virtio_console.c

···
  */
 #include <linux/cdev.h>
 #include <linux/debugfs.h>
+#include <linux/completion.h>
 #include <linux/device.h>
 #include <linux/err.h>
+#include <linux/freezer.h>
 #include <linux/fs.h>
 #include <linux/init.h>
 #include <linux/list.h>
···
 static struct ports_driver_data pdrvdata;
 
 DEFINE_SPINLOCK(pdrvdata_lock);
+DECLARE_COMPLETION(early_console_added);
 
 /* This struct holds information that's relevant only for console ports */
 struct console {
···
 	int chr_major;
 };
 
+struct port_stats {
+	unsigned long bytes_sent, bytes_received, bytes_discarded;
+};
+
 /* This struct holds the per-port data */
 struct port {
 	/* Next port in the list, head is in the ports_device */
···
 
 	/* File in the debugfs directory that exposes this port's information */
 	struct dentry *debugfs_file;
+
+	/*
+	 * Keep count of the bytes sent, received and discarded for
+	 * this port for accounting and debugging purposes.  These
+	 * counts are not reset across port open / close events.
+	 */
+	struct port_stats stats;
 
 	/*
 	 * The entries in this struct will be valid if this port is
···
 }
 
 /* Callers should take appropriate locks */
-static void *get_inbuf(struct port *port)
+static struct port_buffer *get_inbuf(struct port *port)
 {
 	struct port_buffer *buf;
-	struct virtqueue *vq;
 	unsigned int len;
 
-	vq = port->in_vq;
-	buf = virtqueue_get_buf(vq, &len);
+	if (port->inbuf)
+		return port->inbuf;
+
+	buf = virtqueue_get_buf(port->in_vq, &len);
 	if (buf) {
 		buf->len = len;
 		buf->offset = 0;
+		port->stats.bytes_received += len;
 	}
 	return buf;
 }
···
 static void discard_port_data(struct port *port)
 {
 	struct port_buffer *buf;
-	struct virtqueue *vq;
-	unsigned int len;
-	int ret;
+	unsigned int err;
 
 	if (!port->portdev) {
 		/* Device has been unplugged.  vqs are already gone. */
 		return;
 	}
-	vq = port->in_vq;
-	if (port->inbuf)
-		buf = port->inbuf;
-	else
-		buf = virtqueue_get_buf(vq, &len);
+	buf = get_inbuf(port);
 
-	ret = 0;
+	err = 0;
 	while (buf) {
-		if (add_inbuf(vq, buf) < 0) {
-			ret++;
+		port->stats.bytes_discarded += buf->len - buf->offset;
+		if (add_inbuf(port->in_vq, buf) < 0) {
+			err++;
 			free_buf(buf);
 		}
-		buf = virtqueue_get_buf(vq, &len);
+		port->inbuf = NULL;
+		buf = get_inbuf(port);
 	}
-	port->inbuf = NULL;
-	if (ret)
+	if (err)
 		dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
-			 ret);
+			 err);
 }
 
 static bool port_has_data(struct port *port)
···
 	unsigned long flags;
 	bool ret;
 
-	spin_lock_irqsave(&port->inbuf_lock, flags);
-	if (port->inbuf) {
-		ret = true;
-		goto out;
-	}
-	port->inbuf = get_inbuf(port);
-	if (port->inbuf) {
-		ret = true;
-		goto out;
-	}
 	ret = false;
-out:
+	spin_lock_irqsave(&port->inbuf_lock, flags);
+	port->inbuf = get_inbuf(port);
+	if (port->inbuf)
+		ret = true;
+
 	spin_unlock_irqrestore(&port->inbuf_lock, flags);
 	return ret;
 }
···
 		cpu_relax();
 done:
 	spin_unlock_irqrestore(&port->outvq_lock, flags);
+
+	port->stats.bytes_sent += in_count;
 	/*
 	 * We're expected to return the amount of data we wrote -- all
 	 * of it
···
 		if (filp->f_flags & O_NONBLOCK)
 			return -EAGAIN;
 
-		ret = wait_event_interruptible(port->waitqueue,
-					       !will_read_block(port));
+		ret = wait_event_freezable(port->waitqueue,
+					   !will_read_block(port));
 		if (ret < 0)
 			return ret;
 	}
···
 		if (nonblock)
 			return -EAGAIN;
 
-		ret = wait_event_interruptible(port->waitqueue,
-					       !will_write_block(port));
+		ret = wait_event_freezable(port->waitqueue,
+					   !will_write_block(port));
 		if (ret < 0)
 			return ret;
 	}
···
 	out_offset += snprintf(buf + out_offset, out_count - out_offset,
 			       "outvq_full: %d\n", port->outvq_full);
 	out_offset += snprintf(buf + out_offset, out_count - out_offset,
+			       "bytes_sent: %lu\n", port->stats.bytes_sent);
+	out_offset += snprintf(buf + out_offset, out_count - out_offset,
+			       "bytes_received: %lu\n",
+			       port->stats.bytes_received);
+	out_offset += snprintf(buf + out_offset, out_count - out_offset,
+			       "bytes_discarded: %lu\n",
+			       port->stats.bytes_discarded);
+	out_offset += snprintf(buf + out_offset, out_count - out_offset,
 			       "is_console: %s\n",
 			       is_console_port(port) ? "yes" : "no");
 	out_offset += snprintf(buf + out_offset, out_count - out_offset,
···
 	port->cons.ws.ws_row = port->cons.ws.ws_col = 0;
 
 	port->host_connected = port->guest_connected = false;
+	port->stats = (struct port_stats) { 0 };
 
 	port->outvq_full = false;
 
···
 			break;
 
 		init_port_console(port);
+		complete(&early_console_added);
 		/*
 		 * Could remove the port here in case init fails - but
 		 * have to notify the host first.
···
 		send_sigio_to_port(port);
 		break;
 	case VIRTIO_CONSOLE_PORT_NAME:
+		/*
+		 * If we woke up after hibernation, we can get this
+		 * again.  Skip it in that case.
+		 */
+		if (port->name)
+			break;
+
 		/*
 		 * Skip the size of the header and the cpkt to get the size
 		 * of the name that was sent
···
 		return;
 
 	spin_lock_irqsave(&port->inbuf_lock, flags);
-	if (!port->inbuf)
-		port->inbuf = get_inbuf(port);
+	port->inbuf = get_inbuf(port);
 
 	/*
 	 * Don't queue up data when port is closed.  This condition
···
 	portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
 				   GFP_KERNEL);
 	if (!vqs || !io_callbacks || !io_names || !portdev->in_vqs ||
-			!portdev->out_vqs) {
+	    !portdev->out_vqs) {
 		err = -ENOMEM;
 		goto free;
 	}
···
 	struct ports_device *portdev;
 	int err;
 	bool multiport;
+	bool early = early_put_chars != NULL;
+
+	/* Ensure to read early_put_chars now */
+	barrier();
 
 	portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
 	if (!portdev) {
···
 
 	multiport = false;
 	portdev->config.max_nr_ports = 1;
-	if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT)) {
+	if (virtio_config_val(vdev, VIRTIO_CONSOLE_F_MULTIPORT,
+			      offsetof(struct virtio_console_config,
+				       max_nr_ports),
+			      &portdev->config.max_nr_ports) == 0)
 		multiport = true;
-		vdev->config->get(vdev, offsetof(struct virtio_console_config,
-						 max_nr_ports),
-				  &portdev->config.max_nr_ports,
-				  sizeof(portdev->config.max_nr_ports));
-	}
 
 	err = init_vqs(portdev);
 	if (err < 0) {
···
 
 	__send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
 			   VIRTIO_CONSOLE_DEVICE_READY, 1);
+
+	/*
+	 * If there was an early virtio console, assume that there are no
+	 * other consoles. We need to wait until the hvc_alloc matches the
+	 * hvc_instantiate, otherwise tty_open will complain, resulting in
+	 * a "Warning: unable to open an initial console" boot failure.
+	 * Without multiport this is done in add_port above. With multiport
+	 * this might take some host<->guest communication - thus we have to
+	 * wait.
+	 */
+	if (multiport && early)
+		wait_for_completion(&early_console_added);
+
 	return 0;
 
 free_vqs:

drivers/net/virtio_net.c

···
 {
 	u16 v;
 
-	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS))
-		return;
-
-	vi->vdev->config->get(vi->vdev,
+	if (virtio_config_val(vi->vdev, VIRTIO_NET_F_STATUS,
 			      offsetof(struct virtio_net_config, status),
-			      &v, sizeof(v));
+			      &v) < 0)
+		return;
 
 	/* Ignore unknown (future) status bits */
 	v &= VIRTIO_NET_S_LINK_UP;
···
 	}
 
 	/* Configuration may specify what MAC to use.  Otherwise random. */
-	if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
-		vdev->config->get(vdev,
+	if (virtio_config_val_len(vdev, VIRTIO_NET_F_MAC,
 				  offsetof(struct virtio_net_config, mac),
-				  dev->dev_addr, dev->addr_len);
-	} else
+				  dev->dev_addr, dev->addr_len) < 0)
 		random_ether_addr(dev->dev_addr);
 
 	/* Set up our device-specific information */

drivers/virtio/Kconfig

···
 
 	 If unsure, say M.
 
+ config VIRTIO_MMIO
+ 	tristate "Platform bus driver for memory mapped virtio devices (EXPERIMENTAL)"
+ 	depends on EXPERIMENTAL
+ 	select VIRTIO
+ 	select VIRTIO_RING
+ 	---help---
+ 	 This drivers provides support for memory mapped virtio
+	 platform device driver.
+
+ 	 If unsure, say N.
+
 endmenu

drivers/virtio/Makefile

···
 obj-$(CONFIG_VIRTIO) += virtio.o
 obj-$(CONFIG_VIRTIO_RING) += virtio_ring.o
+obj-$(CONFIG_VIRTIO_MMIO) += virtio_mmio.o
 obj-$(CONFIG_VIRTIO_PCI) += virtio_pci.o
 obj-$(CONFIG_VIRTIO_BALLOON) += virtio_balloon.o

drivers/virtio/virtio_mmio.c

···
+/*
+ * Virtio memory mapped device driver
+ *
+ * Copyright 2011, ARM Ltd.
+ *
+ * This module allows virtio devices to be used over a virtual, memory mapped
+ * platform device.
+ *
+ * Registers layout (all 32-bit wide):
+ *
+ * offset d. name             description
+ * ------ -- ---------------- -----------------
+ *
+ * 0x000  R  MagicValue       Magic value "virt"
+ * 0x004  R  Version          Device version (current max. 1)
+ * 0x008  R  DeviceID         Virtio device ID
+ * 0x00c  R  VendorID         Virtio vendor ID
+ *
+ * 0x010  R  HostFeatures     Features supported by the host
+ * 0x014  W  HostFeaturesSel  Set of host features to access via HostFeatures
+ *
+ * 0x020  W  GuestFeatures    Features activated by the guest
+ * 0x024  W  GuestFeaturesSel Set of activated features to set via GuestFeatures
+ * 0x028  W  GuestPageSize    Size of guest's memory page in bytes
+ *
+ * 0x030  W  QueueSel         Queue selector
+ * 0x034  R  QueueNumMax      Maximum size of the currently selected queue
+ * 0x038  W  QueueNum         Queue size for the currently selected queue
+ * 0x03c  W  QueueAlign       Used Ring alignment for the current queue
+ * 0x040  RW QueuePFN         PFN for the currently selected queue
+ *
+ * 0x050  W  QueueNotify      Queue notifier
+ * 0x060  R  InterruptStatus  Interrupt status register
+ * 0x060  W  InterruptACK     Interrupt acknowledge register
+ * 0x070  RW Status           Device status register
+ *
+ * 0x100+ RW                  Device-specific configuration space
+ *
+ * Based on Virtio PCI driver by Anthony Liguori, copyright IBM Corp. 2007
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include <linux/highmem.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/virtio.h>
+#include <linux/virtio_config.h>
+#include <linux/virtio_mmio.h>
+#include <linux/virtio_ring.h>
+
+
+
+/* The alignment to use between consumer and producer parts of vring.
+ * Currently hardcoded to the page size. */
+#define VIRTIO_MMIO_VRING_ALIGN		PAGE_SIZE
+
+
+
+#define to_virtio_mmio_device(_plat_dev) \
+	container_of(_plat_dev, struct virtio_mmio_device, vdev)
+
+struct virtio_mmio_device {
+	struct virtio_device vdev;
+	struct platform_device *pdev;
+
+	void __iomem *base;
+	unsigned long version;
+
+	/* a list of queues so we can dispatch IRQs */
+	spinlock_t lock;
+	struct list_head virtqueues;
+};
+
+struct virtio_mmio_vq_info {
+	/* the actual virtqueue */
+	struct virtqueue *vq;
+
+	/* the number of entries in the queue */
+	unsigned int num;
+
+	/* the index of the queue */
+	int queue_index;
+
+	/* the virtual address of the ring queue */
+	void *queue;
+
+	/* the list node for the virtqueues list */
+	struct list_head node;
+};
+
+
+
+/* Configuration interface */
+
+static u32 vm_get_features(struct virtio_device *vdev)
+{
+	struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+
+	/* TODO: Features > 32 bits */
+	writel(0, vm_dev->base + VIRTIO_MMIO_HOST_FEATURES_SEL);
+
+	return readl(vm_dev->base + VIRTIO_MMIO_HOST_FEATURES);
+}
+
+static void vm_finalize_features(struct virtio_device *vdev)
+{
+	struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+	int i;
+
+	/* Give virtio_ring a chance to accept features. */
+	vring_transport_features(vdev);
+
+	for (i = 0; i < ARRAY_SIZE(vdev->features); i++) {
+		writel(i, vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES_SET);
+		writel(vdev->features[i],
+				vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES);
+	}
+}
+
+static void vm_get(struct virtio_device *vdev, unsigned offset,
+		   void *buf, unsigned len)
+{
+	struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+	u8 *ptr = buf;
+	int i;
+
+	for (i = 0; i < len; i++)
+		ptr[i] = readb(vm_dev->base + VIRTIO_MMIO_CONFIG + offset + i);
+}
+
+static void vm_set(struct virtio_device *vdev, unsigned offset,
+		   const void *buf, unsigned len)
+{
+	struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+	const u8 *ptr = buf;
+	int i;
+
+	for (i = 0; i < len; i++)
+		writeb(ptr[i], vm_dev->base + VIRTIO_MMIO_CONFIG + offset + i);
+}
+
+static u8 vm_get_status(struct virtio_device *vdev)
+{
+	struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+
+	return readl(vm_dev->base + VIRTIO_MMIO_STATUS) & 0xff;
+}
+
+static void vm_set_status(struct virtio_device *vdev, u8 status)
+{
+	struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+
+	/* We should never be setting status to 0. */
+	BUG_ON(status == 0);
+
+	writel(status, vm_dev->base + VIRTIO_MMIO_STATUS);
+}
+
+static void vm_reset(struct virtio_device *vdev)
+{
+	struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+
+	/* 0 status means a reset. */
+	writel(0, vm_dev->base + VIRTIO_MMIO_STATUS);
+}
+
+
+
+/* Transport interface */
+
+/* the notify function used when creating a virt queue */
+static void vm_notify(struct virtqueue *vq)
+{
+	struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
+	struct virtio_mmio_vq_info *info = vq->priv;
+
+	/* We write the queue's selector into the notification register to
+	 * signal the other end */
+	writel(info->queue_index, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY);
+}
+
+/* Notify all virtqueues on an interrupt. */
+static irqreturn_t vm_interrupt(int irq, void *opaque)
+{
+	struct virtio_mmio_device *vm_dev = opaque;
+	struct virtio_mmio_vq_info *info;
+	struct virtio_driver *vdrv = container_of(vm_dev->vdev.dev.driver,
+			struct virtio_driver, driver);
+	unsigned long status;
+	unsigned long flags;
+	irqreturn_t ret = IRQ_NONE;
+
+	/* Read and acknowledge interrupts */
+	status = readl(vm_dev->base + VIRTIO_MMIO_INTERRUPT_STATUS);
+	writel(status, vm_dev->base + VIRTIO_MMIO_INTERRUPT_ACK);
+
+	if (unlikely(status & VIRTIO_MMIO_INT_CONFIG)
+			&& vdrv && vdrv->config_changed) {
+		vdrv->config_changed(&vm_dev->vdev);
+		ret = IRQ_HANDLED;
+	}
+
+	if (likely(status & VIRTIO_MMIO_INT_VRING)) {
+		spin_lock_irqsave(&vm_dev->lock, flags);
+		list_for_each_entry(info, &vm_dev->virtqueues, node)
+			ret |= vring_interrupt(irq, info->vq);
+		spin_unlock_irqrestore(&vm_dev->lock, flags);
+	}
+
+	return ret;
+}
+
+
+
+static void vm_del_vq(struct virtqueue *vq)
+{
+	struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
+	struct virtio_mmio_vq_info *info = vq->priv;
+	unsigned long flags, size;
+
+	spin_lock_irqsave(&vm_dev->lock, flags);
+	list_del(&info->node);
+	spin_unlock_irqrestore(&vm_dev->lock, flags);
+
+	vring_del_virtqueue(vq);
+
+	/* Select and deactivate the queue */
+	writel(info->queue_index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
+	writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
+
+	size = PAGE_ALIGN(vring_size(info->num, VIRTIO_MMIO_VRING_ALIGN));
+	free_pages_exact(info->queue, size);
+	kfree(info);
+}
+
+static void vm_del_vqs(struct virtio_device *vdev)
+{
+	struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+	struct virtqueue *vq, *n;
+
+	list_for_each_entry_safe(vq, n, &vdev->vqs, list)
+		vm_del_vq(vq);
+
+	free_irq(platform_get_irq(vm_dev->pdev, 0), vm_dev);
+}
+
+
+
+static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index,
+				  void (*callback)(struct virtqueue *vq),
+				  const char *name)
+{
+	struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+	struct virtio_mmio_vq_info *info;
+	struct virtqueue *vq;
+	unsigned long flags, size;
+	int err;
+
+	/* Select the queue we're interested in */
+	writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
+
+	/* Queue shouldn't already be set up. */
+	if (readl(vm_dev->base + VIRTIO_MMIO_QUEUE_PFN)) {
+		err = -ENOENT;
+		goto error_available;
+	}
+
+	/* Allocate and fill out our active queue description */
+	info = kmalloc(sizeof(*info), GFP_KERNEL);
+	if (!info) {
+		err = -ENOMEM;
+		goto error_kmalloc;
+	}
+	info->queue_index = index;
+
+	/* Allocate pages for the queue - start with a queue as big as
+	 * possible (limited by maximum size allowed by device), drop down
+	 * to a minimal size, just big enough to fit descriptor table
+	 * and two rings (which makes it "alignment_size * 2")
+	 */
+	info->num = readl(vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX);
+	while (1) {
+		size = PAGE_ALIGN(vring_size(info->num,
+				VIRTIO_MMIO_VRING_ALIGN));
+		/* Already smallest possible allocation? */
+		if (size <= VIRTIO_MMIO_VRING_ALIGN * 2) {
+			err = -ENOMEM;
+			goto error_alloc_pages;
+		}
+
+		info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
+		if (info->queue)
+			break;
+
+		info->num /= 2;
+	}
+
+	/* Activate the queue */
+	writel(info->num, vm_dev->base + VIRTIO_MMIO_QUEUE_NUM);
+	writel(VIRTIO_MMIO_VRING_ALIGN,
+			vm_dev->base + VIRTIO_MMIO_QUEUE_ALIGN);
+	writel(virt_to_phys(info->queue) >> PAGE_SHIFT,
+			vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
+
+	/* Create the vring */
+	vq = vring_new_virtqueue(info->num, VIRTIO_MMIO_VRING_ALIGN,
+				 vdev, info->queue, vm_notify, callback, name);
+	if (!vq) {
+		err = -ENOMEM;
+		goto error_new_virtqueue;
+	}
+
+	vq->priv = info;
+	info->vq = vq;
+
+	spin_lock_irqsave(&vm_dev->lock, flags);
+	list_add(&info->node, &vm_dev->virtqueues);
+	spin_unlock_irqrestore(&vm_dev->lock, flags);
+
+	return vq;
+
+error_new_virtqueue:
+	writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
+	free_pages_exact(info->queue, size);
+error_alloc_pages:
+	kfree(info);
+error_kmalloc:
+error_available:
+	return ERR_PTR(err);
+}
+
+static int vm_find_vqs(struct virtio_device *vdev, unsigned nvqs,
+		       struct virtqueue *vqs[],
+		       vq_callback_t *callbacks[],
+		       const char *names[])
+{
+	struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+	unsigned int irq = platform_get_irq(vm_dev->pdev, 0);
+	int i, err;
+
+	err = request_irq(irq, vm_interrupt, IRQF_SHARED,
+			dev_name(&vdev->dev), vm_dev);
+	if (err)
+		return err;
+
+	for (i = 0; i < nvqs; ++i) {
+		vqs[i] = vm_setup_vq(vdev, i, callbacks[i], names[i]);
+		if (IS_ERR(vqs[i])) {
+			vm_del_vqs(vdev);
+			return PTR_ERR(vqs[i]);
+		}
+	}
+
+	return 0;
+}
+
+
+
+static struct virtio_config_ops virtio_mmio_config_ops = {
+	.get		= vm_get,
+	.set		= vm_set,
+	.get_status	= vm_get_status,
+	.set_status	= vm_set_status,
+	.reset		= vm_reset,
+	.find_vqs	= vm_find_vqs,
+	.del_vqs	= vm_del_vqs,
+	.get_features	= vm_get_features,
+	.finalize_features = vm_finalize_features,
+};
+
+
+
+/* Platform device */
+
+static int __devinit virtio_mmio_probe(struct platform_device *pdev)
+{
+	struct virtio_mmio_device *vm_dev;
+	struct resource *mem;
+	unsigned long magic;
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!mem)
+		return -EINVAL;
+
+	if (!devm_request_mem_region(&pdev->dev, mem->start,
+			resource_size(mem), pdev->name))
+		return -EBUSY;
+
+	vm_dev = devm_kzalloc(&pdev->dev, sizeof(*vm_dev), GFP_KERNEL);
+	if (!vm_dev)
+		return  -ENOMEM;
+
+	vm_dev->vdev.dev.parent = &pdev->dev;
+	vm_dev->vdev.config = &virtio_mmio_config_ops;
+	vm_dev->pdev = pdev;
+	INIT_LIST_HEAD(&vm_dev->virtqueues);
+	spin_lock_init(&vm_dev->lock);
+
+	vm_dev->base = devm_ioremap(&pdev->dev, mem->start, resource_size(mem));
+	if (vm_dev->base == NULL)
+		return -EFAULT;
+
+	/* Check magic value */
+	magic = readl(vm_dev->base + VIRTIO_MMIO_MAGIC_VALUE);
+	if (memcmp(&magic, "virt", 4) != 0) {
+		dev_warn(&pdev->dev, "Wrong magic value 0x%08lx!\n", magic);
+		return -ENODEV;
+	}
+
+	/* Check device version */
+	vm_dev->version = readl(vm_dev->base + VIRTIO_MMIO_VERSION);
+	if (vm_dev->version != 1) {
+		dev_err(&pdev->dev, "Version %ld not supported!\n",
+				vm_dev->version);
+		return -ENXIO;
+	}
+
+	vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID);
+	vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID);
+
+	writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE);
+
+	platform_set_drvdata(pdev, vm_dev);
+
+	return register_virtio_device(&vm_dev->vdev);
+}
+
+static int __devexit virtio_mmio_remove(struct platform_device *pdev)
+{
+	struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev);
+
+	unregister_virtio_device(&vm_dev->vdev);
+
+	return 0;
+}
+
+
+
+/* Platform driver */
+
+static struct of_device_id virtio_mmio_match[] = {
+	{ .compatible = "virtio,mmio", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, virtio_mmio_match);
+
+static struct platform_driver virtio_mmio_driver = {
+	.probe		= virtio_mmio_probe,
+	.remove		= __devexit_p(virtio_mmio_remove),
+	.driver		= {
+		.name	= "virtio-mmio",
+		.owner	= THIS_MODULE,
+		.of_match_table	= virtio_mmio_match,
+	},
+};
+
+static int __init virtio_mmio_init(void)
+{
+	return platform_driver_register(&virtio_mmio_driver);
+}
+
+static void __exit virtio_mmio_exit(void)
+{
+	platform_driver_unregister(&virtio_mmio_driver);
+}
+
+module_init(virtio_mmio_init);
+module_exit(virtio_mmio_exit);
+
+MODULE_AUTHOR("Pawel Moll <[e-mail]>");
+MODULE_DESCRIPTION("Platform bus driver for memory mapped virtio devices");
+MODULE_LICENSE("GPL");

drivers/virtio/virtio_pci.c

···
 		}
 	}
 
-	spin_lock_irqsave(&vp_dev->lock, flags);
-	list_add(&info->node, &vp_dev->virtqueues);
-	spin_unlock_irqrestore(&vp_dev->lock, flags);
+	if (callback) {
+		spin_lock_irqsave(&vp_dev->lock, flags);
+		list_add(&info->node, &vp_dev->virtqueues);
+		spin_unlock_irqrestore(&vp_dev->lock, flags);
+	} else {
+		INIT_LIST_HEAD(&info->node);
+	}
 
 	return vq;
 

include/linux/virtio.h

···
  * virtio_driver - operations for a virtio I/O driver
  * @driver: underlying device driver (populate name and owner).
  * @id_table: the ids serviced by this driver.
- * @feature_table: an array of feature numbers supported by this device.
+ * @feature_table: an array of feature numbers supported by this driver.
  * @feature_table_size: number of entries in the feature table array.
  * @probe: the function to call when a device is found.  Returns 0 or -errno.
- * @remove: the function when a device is removed.
+ * @remove: the function to call when a device is removed.
  * @config_changed: optional function to call when the device configuration
  *    changes; may be called in interrupt context.
  */

include/linux/virtio_config.h

···
 #define virtio_config_val(vdev, fbit, offset, v) \
 	virtio_config_buf((vdev), (fbit), (offset), (v), sizeof(*v))
 
+#define virtio_config_val_len(vdev, fbit, offset, v, len) \
+	virtio_config_buf((vdev), (fbit), (offset), (v), (len))
+
 static inline int virtio_config_buf(struct virtio_device *vdev,
 				    unsigned int fbit,
 				    unsigned int offset,

include/linux/virtio_mmio.h

···
+/*
+ * Virtio platform device driver
+ *
+ * Copyright 2011, ARM Ltd.
+ *
+ * Based on Virtio PCI driver by Anthony Liguori, copyright IBM Corp. 2007
+ *
+ * This header is BSD licensed so anyone can use the definitions to implement
+ * compatible drivers/servers.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of IBM nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef _LINUX_VIRTIO_MMIO_H
+#define _LINUX_VIRTIO_MMIO_H
+
+/*
+ * Control registers
+ */
+
+/* Magic value ("virt" string) - Read Only */
+#define VIRTIO_MMIO_MAGIC_VALUE		0x000
+
+/* Virtio device version - Read Only */
+#define VIRTIO_MMIO_VERSION		0x004
+
+/* Virtio device ID - Read Only */
+#define VIRTIO_MMIO_DEVICE_ID		0x008
+
+/* Virtio vendor ID - Read Only */
+#define VIRTIO_MMIO_VENDOR_ID		0x00c
+
+/* Bitmask of the features supported by the host
+ * (32 bits per set) - Read Only */
+#define VIRTIO_MMIO_HOST_FEATURES	0x010
+
+/* Host features set selector - Write Only */
+#define VIRTIO_MMIO_HOST_FEATURES_SEL	0x014
+
+/* Bitmask of features activated by the guest
+ * (32 bits per set) - Write Only */
+#define VIRTIO_MMIO_GUEST_FEATURES	0x020
+
+/* Activated features set selector - Write Only */
+#define VIRTIO_MMIO_GUEST_FEATURES_SET	0x024
+
+/* Guest's memory page size in bytes - Write Only */
+#define VIRTIO_MMIO_GUEST_PAGE_SIZE	0x028
+
+/* Queue selector - Write Only */
+#define VIRTIO_MMIO_QUEUE_SEL		0x030
+
+/* Maximum size of the currently selected queue - Read Only */
+#define VIRTIO_MMIO_QUEUE_NUM_MAX	0x034
+
+/* Queue size for the currently selected queue - Write Only */
+#define VIRTIO_MMIO_QUEUE_NUM		0x038
+
+/* Used Ring alignment for the currently selected queue - Write Only */
+#define VIRTIO_MMIO_QUEUE_ALIGN		0x03c
+
+/* Guest's PFN for the currently selected queue - Read Write */
+#define VIRTIO_MMIO_QUEUE_PFN		0x040
+
+/* Queue notifier - Write Only */
+#define VIRTIO_MMIO_QUEUE_NOTIFY	0x050
+
+/* Interrupt status - Read Only */
+#define VIRTIO_MMIO_INTERRUPT_STATUS	0x060
+
+/* Interrupt acknowledge - Write Only */
+#define VIRTIO_MMIO_INTERRUPT_ACK	0x064
+
+/* Device status register - Read Write */
+#define VIRTIO_MMIO_STATUS		0x070
+
+/* The config space is defined by each driver as
+ * the per-driver configuration space - Read Write */
+#define VIRTIO_MMIO_CONFIG		0x100
+
+
+
+/*
+ * Interrupt flags (re: interrupt status & acknowledge registers)
+ */
+
+#define VIRTIO_MMIO_INT_VRING		(1 << 0)
+#define VIRTIO_MMIO_INT_CONFIG		(1 << 1)
+
+#endif

include/linux/virtio_ring.h

···
 	vr->num = num;
 	vr->desc = p;
 	vr->avail = p + num*sizeof(struct vring_desc);
-	vr->used = (void *)(((unsigned long)&vr->avail->ring[num] + align-1)
-			    & ~(align - 1));
+	vr->used = (void *)(((unsigned long)&vr->avail->ring[num] + sizeof(__u16)
+		+ align-1) & ~(align - 1));
 }
 
 static inline unsigned vring_size(unsigned int num, unsigned long align)
 {
-	return ((sizeof(struct vring_desc) * num + sizeof(__u16) * (2 + num)
+	return ((sizeof(struct vring_desc) * num + sizeof(__u16) * (3 + num)
 		 + align - 1) & ~(align - 1))
 		+ sizeof(__u16) * 3 + sizeof(struct vring_used_elem) * num;
 }