Merge with mainline to remove plat-omap/Kconfig conflict

Conflicts:
	arch/arm/plat-omap/Kconfig

18 files changed, 1585 insertions, 183 deletions

diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index e023682be2c..3141dd3b6e5 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -666,6 +666,14 @@ config VIRTIO_CONSOLE
 	help
 	  Virtio console for use with lguest and other hypervisors.
 
+	  Also serves as a general-purpose serial device for data
+	  transfer between the guest and host.  Character devices at
+	  /dev/vportNpn will be created when corresponding ports are
+	  found, where N is the device number and n is the port number
+	  within that device.  If specified by the host, a sysfs
+	  attribute called 'name' will be populated with a name for
+	  the port which can be used by udev scripts to create a
+	  symlink to the device.
 
 config HVCS
 	tristate "IBM Hypervisor Virtual Console Server support"
diff --git a/drivers/char/agp/intel-agp.c b/drivers/char/agp/intel-agp.c
index 3999a5f25f3..8a713f1e965 100644
--- a/drivers/char/agp/intel-agp.c
+++ b/drivers/char/agp/intel-agp.c
@@ -8,6 +8,7 @@
 #include <linux/kernel.h>
 #include <linux/pagemap.h>
 #include <linux/agp_backend.h>
+#include <asm/smp.h>
 #include "agp.h"
 
 /*
@@ -815,12 +816,6 @@ static void intel_i830_setup_flush(void)
 		intel_i830_fini_flush();
 }
 
-static void
-do_wbinvd(void *null)
-{
-	wbinvd();
-}
-
 /* The chipset_flush interface needs to get data that has already been
  * flushed out of the CPU all the way out to main memory, because the GPU
  * doesn't snoop those buffers.
@@ -837,12 +832,10 @@ static void intel_i830_chipset_flush(struct agp_bridge_data *bridge)
 
 	memset(pg, 0, 1024);
 
-	if (cpu_has_clflush) {
+	if (cpu_has_clflush)
 		clflush_cache_range(pg, 1024);
-	} else {
-		if (on_each_cpu(do_wbinvd, NULL, 1) != 0)
-			printk(KERN_ERR "Timed out waiting for cache flush.\n");
-	}
+	else if (wbinvd_on_all_cpus() != 0)
+		printk(KERN_ERR "Timed out waiting for cache flush.\n");
 }
 
 /* The intel i830 automatically initializes the agp aperture during POST.
diff --git a/drivers/char/hvc_beat.c b/drivers/char/hvc_beat.c
index 0afc8b82212..5fe4631e2a6 100644
--- a/drivers/char/hvc_beat.c
+++ b/drivers/char/hvc_beat.c
@@ -84,7 +84,7 @@ static int hvc_beat_put_chars(uint32_t vtermno, const char *buf, int cnt)
 	return cnt;
 }
 
-static struct hv_ops hvc_beat_get_put_ops = {
+static const struct hv_ops hvc_beat_get_put_ops = {
 	.get_chars = hvc_beat_get_chars,
 	.put_chars = hvc_beat_put_chars,
 };
@@ -99,7 +99,7 @@ static int hvc_beat_config(char *p)
 
 static int __init hvc_beat_console_init(void)
 {
-	if (hvc_beat_useit && machine_is_compatible("Beat")) {
+	if (hvc_beat_useit && of_machine_is_compatible("Beat")) {
 		hvc_instantiate(0, 0, &hvc_beat_get_put_ops);
 	}
 	return 0;
diff --git a/drivers/char/hvc_console.c b/drivers/char/hvc_console.c
index 416d3423150..4c3b59be286 100644
--- a/drivers/char/hvc_console.c
+++ b/drivers/char/hvc_console.c
@@ -125,7 +125,7 @@ static struct hvc_struct *hvc_get_by_index(int index)
  * console interfaces but can still be used as a tty device.  This has to be
  * static because kmalloc will not work during early console init.
  */
-static struct hv_ops *cons_ops[MAX_NR_HVC_CONSOLES];
+static const struct hv_ops *cons_ops[MAX_NR_HVC_CONSOLES];
 static uint32_t vtermnos[MAX_NR_HVC_CONSOLES] =
 	{[0 ... MAX_NR_HVC_CONSOLES - 1] = -1};
 
@@ -247,7 +247,7 @@ static void destroy_hvc_struct(struct kref *kref)
  * vty adapters do NOT get an hvc_instantiate() callback since they
  * appear after early console init.
  */
-int hvc_instantiate(uint32_t vtermno, int index, struct hv_ops *ops)
+int hvc_instantiate(uint32_t vtermno, int index, const struct hv_ops *ops)
 {
 	struct hvc_struct *hp;
 
@@ -748,8 +748,9 @@ static const struct tty_operations hvc_ops = {
 	.chars_in_buffer = hvc_chars_in_buffer,
 };
 
-struct hvc_struct __devinit *hvc_alloc(uint32_t vtermno, int data,
-					struct hv_ops *ops, int outbuf_size)
+struct hvc_struct *hvc_alloc(uint32_t vtermno, int data,
+			     const struct hv_ops *ops,
+			     int outbuf_size)
 {
 	struct hvc_struct *hp;
 	int i;
diff --git a/drivers/char/hvc_console.h b/drivers/char/hvc_console.h
index 10950ca706d..54381eba4e4 100644
--- a/drivers/char/hvc_console.h
+++ b/drivers/char/hvc_console.h
@@ -55,7 +55,7 @@ struct hvc_struct {
 	int outbuf_size;
 	int n_outbuf;
 	uint32_t vtermno;
-	struct hv_ops *ops;
+	const struct hv_ops *ops;
 	int irq_requested;
 	int data;
 	struct winsize ws;
@@ -76,11 +76,12 @@ struct hv_ops {
 };
 
 /* Register a vterm and a slot index for use as a console (console_init) */
-extern int hvc_instantiate(uint32_t vtermno, int index, struct hv_ops *ops);
+extern int hvc_instantiate(uint32_t vtermno, int index,
+			   const struct hv_ops *ops);
 
 /* register a vterm for hvc tty operation (module_init or hotplug add) */
-extern struct hvc_struct * __devinit hvc_alloc(uint32_t vtermno, int data,
-				struct hv_ops *ops, int outbuf_size);
+extern struct hvc_struct * hvc_alloc(uint32_t vtermno, int data,
+				     const struct hv_ops *ops, int outbuf_size);
 /* remove a vterm from hvc tty operation (module_exit or hotplug remove) */
 extern int hvc_remove(struct hvc_struct *hp);
 
diff --git a/drivers/char/hvc_iseries.c b/drivers/char/hvc_iseries.c
index 936d05bf37f..fd0242676a2 100644
--- a/drivers/char/hvc_iseries.c
+++ b/drivers/char/hvc_iseries.c
@@ -197,7 +197,7 @@ done:
 	return sent;
 }
 
-static struct hv_ops hvc_get_put_ops = {
+static const struct hv_ops hvc_get_put_ops = {
 	.get_chars = get_chars,
 	.put_chars = put_chars,
 	.notifier_add = notifier_add_irq,
diff --git a/drivers/char/hvc_iucv.c b/drivers/char/hvc_iucv.c
index fe62bd0e17b..21681a81cc3 100644
--- a/drivers/char/hvc_iucv.c
+++ b/drivers/char/hvc_iucv.c
@@ -922,7 +922,7 @@ static int hvc_iucv_pm_restore_thaw(struct device *dev)
 
 
 /* HVC operations */
-static struct hv_ops hvc_iucv_ops = {
+static const struct hv_ops hvc_iucv_ops = {
 	.get_chars = hvc_iucv_get_chars,
 	.put_chars = hvc_iucv_put_chars,
 	.notifier_add = hvc_iucv_notifier_add,
diff --git a/drivers/char/hvc_rtas.c b/drivers/char/hvc_rtas.c
index 88590d04004..61c4a61558d 100644
--- a/drivers/char/hvc_rtas.c
+++ b/drivers/char/hvc_rtas.c
@@ -71,7 +71,7 @@ static int hvc_rtas_read_console(uint32_t vtermno, char *buf, int count)
 	return i;
 }
 
-static struct hv_ops hvc_rtas_get_put_ops = {
+static const struct hv_ops hvc_rtas_get_put_ops = {
 	.get_chars = hvc_rtas_read_console,
 	.put_chars = hvc_rtas_write_console,
 };
diff --git a/drivers/char/hvc_udbg.c b/drivers/char/hvc_udbg.c
index bd63ba878a5..b0957e61a7b 100644
--- a/drivers/char/hvc_udbg.c
+++ b/drivers/char/hvc_udbg.c
@@ -58,7 +58,7 @@ static int hvc_udbg_get(uint32_t vtermno, char *buf, int count)
 	return i;
 }
 
-static struct hv_ops hvc_udbg_ops = {
+static const struct hv_ops hvc_udbg_ops = {
 	.get_chars = hvc_udbg_get,
 	.put_chars = hvc_udbg_put,
 };
diff --git a/drivers/char/hvc_vio.c b/drivers/char/hvc_vio.c
index 10be343d6ae..27370e99c66 100644
--- a/drivers/char/hvc_vio.c
+++ b/drivers/char/hvc_vio.c
@@ -77,7 +77,7 @@ static int filtered_get_chars(uint32_t vtermno, char *buf, int count)
 	return got;
 }
 
-static struct hv_ops hvc_get_put_ops = {
+static const struct hv_ops hvc_get_put_ops = {
 	.get_chars = filtered_get_chars,
 	.put_chars = hvc_put_chars,
 	.notifier_add = notifier_add_irq,
diff --git a/drivers/char/hvc_xen.c b/drivers/char/hvc_xen.c
index b1a71638c77..60446f82a3f 100644
--- a/drivers/char/hvc_xen.c
+++ b/drivers/char/hvc_xen.c
@@ -122,7 +122,7 @@ static int read_console(uint32_t vtermno, char *buf, int len)
 	return recv;
 }
 
-static struct hv_ops hvc_ops = {
+static const struct hv_ops hvc_ops = {
 	.get_chars = read_console,
 	.put_chars = write_console,
 	.notifier_add = notifier_add_irq,
diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index c0df30faa66..d31483c5488 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -186,3 +186,15 @@ config HW_RANDOM_MXC_RNGA
 	  module will be called mxc-rnga.
 
 	  If unsure, say Y.
+
+config HW_RANDOM_NOMADIK
+	tristate "ST-Ericsson Nomadik Random Number Generator support"
+	depends on HW_RANDOM && PLAT_NOMADIK
+	---help---
+	  This driver provides kernel-side support for the Random Number
+	  Generator hardware found on ST-Ericsson SoCs (8815 and 8500).
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called nomadik-rng.
+
+	  If unsure, say Y.
diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index 5eeb1303f0d..4273308aa1e 100644
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -18,3 +18,4 @@ obj-$(CONFIG_HW_RANDOM_VIRTIO) += virtio-rng.o
 obj-$(CONFIG_HW_RANDOM_TX4939) += tx4939-rng.o
 obj-$(CONFIG_HW_RANDOM_MXC_RNGA) += mxc-rnga.o
 obj-$(CONFIG_HW_RANDOM_OCTEON) += octeon-rng.o
+obj-$(CONFIG_HW_RANDOM_NOMADIK) += nomadik-rng.o
diff --git a/drivers/char/hw_random/nomadik-rng.c b/drivers/char/hw_random/nomadik-rng.c
new file mode 100644
index 00000000000..a8b4c401014
--- /dev/null
+++ b/drivers/char/hw_random/nomadik-rng.c
@@ -0,0 +1,103 @@
+/*
+ * Nomadik RNG support
+ *  Copyright 2009 Alessandro Rubini
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/amba/bus.h>
+#include <linux/hw_random.h>
+#include <linux/io.h>
+
+static int nmk_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
+{
+	void __iomem *base = (void __iomem *)rng->priv;
+
+	/*
+	 * The register is 32 bits and gives 16 random bits (low half).
+	 * A subsequent read will delay the core for 400ns, so we just read
+	 * once and accept the very unlikely very small delay, even if wait==0.
+	 */
+	*(u16 *)data = __raw_readl(base + 8) & 0xffff;
+	return 2;
+}
+
+/* we have at most one RNG per machine, granted */
+static struct hwrng nmk_rng = {
+	.name		= "nomadik",
+	.read		= nmk_rng_read,
+};
+
+static int nmk_rng_probe(struct amba_device *dev, struct amba_id *id)
+{
+	void __iomem *base;
+	int ret;
+
+	ret = amba_request_regions(dev, dev->dev.init_name);
+	if (ret)
+		return ret;
+	ret = -ENOMEM;
+	base = ioremap(dev->res.start, resource_size(&dev->res));
+	if (!base)
+		goto out_release;
+	nmk_rng.priv = (unsigned long)base;
+	ret = hwrng_register(&nmk_rng);
+	if (ret)
+		goto out_unmap;
+	return 0;
+
+out_unmap:
+	iounmap(base);
+out_release:
+	amba_release_regions(dev);
+	return ret;
+}
+
+static int nmk_rng_remove(struct amba_device *dev)
+{
+	void __iomem *base = (void __iomem *)nmk_rng.priv;
+	hwrng_unregister(&nmk_rng);
+	iounmap(base);
+	amba_release_regions(dev);
+	return 0;
+}
+
+static struct amba_id nmk_rng_ids[] = {
+	{
+		.id	= 0x000805e1,
+		.mask	= 0x000fffff, /* top bits are rev and cfg: accept all */
+	},
+	{0, 0},
+};
+
+static struct amba_driver nmk_rng_driver = {
+	.drv = {
+		.owner = THIS_MODULE,
+		.name = "rng",
+		},
+	.probe = nmk_rng_probe,
+	.remove = nmk_rng_remove,
+	.id_table = nmk_rng_ids,
+};
+
+static int __init nmk_rng_init(void)
+{
+	return amba_driver_register(&nmk_rng_driver);
+}
+
+static void __devexit nmk_rng_exit(void)
+{
+	amba_driver_unregister(&nmk_rng_driver);
+}
+
+module_init(nmk_rng_init);
+module_exit(nmk_rng_exit);
+
+MODULE_LICENSE("GPL");
diff --git a/drivers/char/nvram.c b/drivers/char/nvram.c
index fdbcc9fd6d3..5eb83c3ca20 100644
--- a/drivers/char/nvram.c
+++ b/drivers/char/nvram.c
@@ -336,14 +336,12 @@ static int nvram_ioctl(struct inode *inode, struct file *file,
 
 static int nvram_open(struct inode *inode, struct file *file)
 {
-	lock_kernel();
 	spin_lock(&nvram_state_lock);
 
 	if ((nvram_open_cnt && (file->f_flags & O_EXCL)) ||
 	    (nvram_open_mode & NVRAM_EXCL) ||
 	    ((file->f_mode & FMODE_WRITE) && (nvram_open_mode & NVRAM_WRITE))) {
 		spin_unlock(&nvram_state_lock);
-		unlock_kernel();
 		return -EBUSY;
 	}
 
@@ -354,7 +352,6 @@ static int nvram_open(struct inode *inode, struct file *file)
 	nvram_open_cnt++;
 
 	spin_unlock(&nvram_state_lock);
-	unlock_kernel();
 
 	return 0;
 }
diff --git a/drivers/char/pcmcia/cm4000_cs.c b/drivers/char/pcmcia/cm4000_cs.c
index 2db4c0a29b0..c9bc896d68a 100644
--- a/drivers/char/pcmcia/cm4000_cs.c
+++ b/drivers/char/pcmcia/cm4000_cs.c
@@ -1047,7 +1047,7 @@ release_io:
 static ssize_t cmm_write(struct file *filp, const char __user *buf,
 			 size_t count, loff_t *ppos)
 {
-	struct cm4000_dev *dev = (struct cm4000_dev *) filp->private_data;
+	struct cm4000_dev *dev = filp->private_data;
 	unsigned int iobase = dev->p_dev->io.BasePort1;
 	unsigned short s;
 	unsigned char tmp;
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index a035ae39a35..213373b5f17 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -1,18 +1,6 @@
-/*D:300
- * The Guest console driver
- *
- * Writing console drivers is one of the few remaining Dark Arts in Linux.
- * Fortunately for us, the path of virtual consoles has been well-trodden by
- * the PowerPC folks, who wrote "hvc_console.c" to generically support any
- * virtual console.  We use that infrastructure which only requires us to write
- * the basic put_chars and get_chars functions and call the right register
- * functions.
- :*/
-
-/*M:002 The console can be flooded: while the Guest is processing input the
- * Host can send more.  Buffering in the Host could alleviate this, but it is a
- * difficult problem in general. :*/
-/* Copyright (C) 2006, 2007 Rusty Russell, IBM Corporation
+/*
+ * Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation
+ * Copyright (C) 2009, 2010 Red Hat, Inc.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -28,142 +16,694 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
+#include <linux/cdev.h>
+#include <linux/debugfs.h>
+#include <linux/device.h>
 #include <linux/err.h>
+#include <linux/fs.h>
 #include <linux/init.h>
+#include <linux/list.h>
+#include <linux/poll.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
 #include <linux/virtio.h>
 #include <linux/virtio_console.h>
+#include <linux/wait.h>
+#include <linux/workqueue.h>
 #include "hvc_console.h"
 
-/*D:340 These represent our input and output console queues, and the virtio
- * operations for them. */
-static struct virtqueue *in_vq, *out_vq;
-static struct virtio_device *vdev;
+/*
+ * This is a global struct for storing common data for all the devices
+ * this driver handles.
+ *
+ * Mainly, it has a linked list for all the consoles in one place so
+ * that callbacks from hvc for get_chars(), put_chars() work properly
+ * across multiple devices and multiple ports per device.
+ */
+struct ports_driver_data {
+	/* Used for registering chardevs */
+	struct class *class;
+
+	/* Used for exporting per-port information to debugfs */
+	struct dentry *debugfs_dir;
+
+	/* Number of devices this driver is handling */
+	unsigned int index;
+
+	/*
+	 * This is used to keep track of the number of hvc consoles
+	 * spawned by this driver.  This number is given as the first
+	 * argument to hvc_alloc().  To correctly map an initial
+	 * console spawned via hvc_instantiate to the console being
+	 * hooked up via hvc_alloc, we need to pass the same vtermno.
+	 *
+	 * We also just assume the first console being initialised was
+	 * the first one that got used as the initial console.
+	 */
+	unsigned int next_vtermno;
+
+	/* All the console devices handled by this driver */
+	struct list_head consoles;
+};
+static struct ports_driver_data pdrvdata;
+
+DEFINE_SPINLOCK(pdrvdata_lock);
+
+/* This struct holds information that's relevant only for console ports */
+struct console {
+	/* We'll place all consoles in a list in the pdrvdata struct */
+	struct list_head list;
+
+	/* The hvc device associated with this console port */
+	struct hvc_struct *hvc;
+
+	/*
+	 * This number identifies the number that we used to register
+	 * with hvc in hvc_instantiate() and hvc_alloc(); this is the
+	 * number passed on by the hvc callbacks to us to
+	 * differentiate between the other console ports handled by
+	 * this driver
+	 */
+	u32 vtermno;
+};
+
+struct port_buffer {
+	char *buf;
+
+	/* size of the buffer in *buf above */
+	size_t size;
+
+	/* used length of the buffer */
+	size_t len;
+	/* offset in the buf from which to consume data */
+	size_t offset;
+};
+
+/*
+ * This is a per-device struct that stores data common to all the
+ * ports for that device (vdev->priv).
+ */
+struct ports_device {
+	/*
+	 * Workqueue handlers where we process deferred work after
+	 * notification
+	 */
+	struct work_struct control_work;
+	struct work_struct config_work;
+
+	struct list_head ports;
+
+	/* To protect the list of ports */
+	spinlock_t ports_lock;
+
+	/* To protect the vq operations for the control channel */
+	spinlock_t cvq_lock;
+
+	/* The current config space is stored here */
+	struct virtio_console_config config;
+
+	/* The virtio device we're associated with */
+	struct virtio_device *vdev;
+
+	/*
+	 * A couple of virtqueues for the control channel: one for
+	 * guest->host transfers, one for host->guest transfers
+	 */
+	struct virtqueue *c_ivq, *c_ovq;
+
+	/* Array of per-port IO virtqueues */
+	struct virtqueue **in_vqs, **out_vqs;
+
+	/* Used for numbering devices for sysfs and debugfs */
+	unsigned int drv_index;
+
+	/* Major number for this device.  Ports will be created as minors. */
+	int chr_major;
+};
+
+/* This struct holds the per-port data */
+struct port {
+	/* Next port in the list, head is in the ports_device */
+	struct list_head list;
+
+	/* Pointer to the parent virtio_console device */
+	struct ports_device *portdev;
+
+	/* The current buffer from which data has to be fed to readers */
+	struct port_buffer *inbuf;
+
+	/*
+	 * To protect the operations on the in_vq associated with this
+	 * port.  Has to be a spinlock because it can be called from
+	 * interrupt context (get_char()).
+	 */
+	spinlock_t inbuf_lock;
+
+	/* The IO vqs for this port */
+	struct virtqueue *in_vq, *out_vq;
+
+	/* File in the debugfs directory that exposes this port's information */
+	struct dentry *debugfs_file;
+
+	/*
+	 * The entries in this struct will be valid if this port is
+	 * hooked up to an hvc console
+	 */
+	struct console cons;
+
+	/* Each port associates with a separate char device */
+	struct cdev cdev;
+	struct device *dev;
+
+	/* A waitqueue for poll() or blocking read operations */
+	wait_queue_head_t waitqueue;
+
+	/* The 'name' of the port that we expose via sysfs properties */
+	char *name;
+
+	/* The 'id' to identify the port with the Host */
+	u32 id;
+
+	/* Is the host device open */
+	bool host_connected;
+
+	/* We should allow only one process to open a port */
+	bool guest_connected;
+};
+
+/* This is the very early arch-specified put chars function. */
+static int (*early_put_chars)(u32, const char *, int);
+
+static struct port *find_port_by_vtermno(u32 vtermno)
+{
+	struct port *port;
+	struct console *cons;
+	unsigned long flags;
+
+	spin_lock_irqsave(&pdrvdata_lock, flags);
+	list_for_each_entry(cons, &pdrvdata.consoles, list) {
+		if (cons->vtermno == vtermno) {
+			port = container_of(cons, struct port, cons);
+			goto out;
+		}
+	}
+	port = NULL;
+out:
+	spin_unlock_irqrestore(&pdrvdata_lock, flags);
+	return port;
+}
+
+static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
+{
+	struct port *port;
+	unsigned long flags;
+
+	spin_lock_irqsave(&portdev->ports_lock, flags);
+	list_for_each_entry(port, &portdev->ports, list)
+		if (port->id == id)
+			goto out;
+	port = NULL;
+out:
+	spin_unlock_irqrestore(&portdev->ports_lock, flags);
+
+	return port;
+}
+
+static struct port *find_port_by_vq(struct ports_device *portdev,
+				    struct virtqueue *vq)
+{
+	struct port *port;
+	unsigned long flags;
+
+	spin_lock_irqsave(&portdev->ports_lock, flags);
+	list_for_each_entry(port, &portdev->ports, list)
+		if (port->in_vq == vq || port->out_vq == vq)
+			goto out;
+	port = NULL;
+out:
+	spin_unlock_irqrestore(&portdev->ports_lock, flags);
+	return port;
+}
+
+static bool is_console_port(struct port *port)
+{
+	if (port->cons.hvc)
+		return true;
+	return false;
+}
+
+static inline bool use_multiport(struct ports_device *portdev)
+{
+	/*
+	 * This condition can be true when put_chars is called from
+	 * early_init
+	 */
+	if (!portdev->vdev)
+		return 0;
+	return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
+}
 
-/* This is our input buffer, and how much data is left in it. */
-static unsigned int in_len;
-static char *in, *inbuf;
+static void free_buf(struct port_buffer *buf)
+{
+	kfree(buf->buf);
+	kfree(buf);
+}
+
+static struct port_buffer *alloc_buf(size_t buf_size)
+{
+	struct port_buffer *buf;
 
-/* The operations for our console. */
-static struct hv_ops virtio_cons;
+	buf = kmalloc(sizeof(*buf), GFP_KERNEL);
+	if (!buf)
+		goto fail;
+	buf->buf = kzalloc(buf_size, GFP_KERNEL);
+	if (!buf->buf)
+		goto free_buf;
+	buf->len = 0;
+	buf->offset = 0;
+	buf->size = buf_size;
+	return buf;
+
+free_buf:
+	kfree(buf);
+fail:
+	return NULL;
+}
+
+/* Callers should take appropriate locks */
+static void *get_inbuf(struct port *port)
+{
+	struct port_buffer *buf;
+	struct virtqueue *vq;
+	unsigned int len;
 
-/* The hvc device */
-static struct hvc_struct *hvc;
+	vq = port->in_vq;
+	buf = vq->vq_ops->get_buf(vq, &len);
+	if (buf) {
+		buf->len = len;
+		buf->offset = 0;
+	}
+	return buf;
+}
 
-/*D:310 The put_chars() callback is pretty straightforward.
+/*
+ * Create a scatter-gather list representing our input buffer and put
+ * it in the queue.
  *
- * We turn the characters into a scatter-gather list, add it to the output
- * queue and then kick the Host.  Then we sit here waiting for it to finish:
- * inefficient in theory, but in practice implementations will do it
- * immediately (lguest's Launcher does). */
-static int put_chars(u32 vtermno, const char *buf, int count)
+ * Callers should take appropriate locks.
+ */
+static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
 {
 	struct scatterlist sg[1];
+	int ret;
+
+	sg_init_one(sg, buf->buf, buf->size);
+
+	ret = vq->vq_ops->add_buf(vq, sg, 0, 1, buf);
+	vq->vq_ops->kick(vq);
+	return ret;
+}
+
+/* Discard any unread data this port has. Callers lockers. */
+static void discard_port_data(struct port *port)
+{
+	struct port_buffer *buf;
+	struct virtqueue *vq;
 	unsigned int len;
+	int ret;
 
-	/* This is a convenient routine to initialize a single-elem sg list */
-	sg_init_one(sg, buf, count);
+	vq = port->in_vq;
+	if (port->inbuf)
+		buf = port->inbuf;
+	else
+		buf = vq->vq_ops->get_buf(vq, &len);
 
-	/* add_buf wants a token to identify this buffer: we hand it any
-	 * non-NULL pointer, since there's only ever one buffer. */
-	if (out_vq->vq_ops->add_buf(out_vq, sg, 1, 0, (void *)1) >= 0) {
-		/* Tell Host to go! */
-		out_vq->vq_ops->kick(out_vq);
-		/* Chill out until it's done with the buffer. */
-		while (!out_vq->vq_ops->get_buf(out_vq, &len))
-			cpu_relax();
+	ret = 0;
+	while (buf) {
+		if (add_inbuf(vq, buf) < 0) {
+			ret++;
+			free_buf(buf);
+		}
+		buf = vq->vq_ops->get_buf(vq, &len);
 	}
+	port->inbuf = NULL;
+	if (ret)
+		dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
+			 ret);
+}
 
-	/* We're expected to return the amount of data we wrote: all of it. */
-	return count;
+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_unlock_irqrestore(&port->inbuf_lock, flags);
+	return ret;
 }
 
-/* Create a scatter-gather list representing our input buffer and put it in the
- * queue. */
-static void add_inbuf(void)
+static ssize_t send_control_msg(struct port *port, unsigned int event,
+				unsigned int value)
 {
 	struct scatterlist sg[1];
-	sg_init_one(sg, inbuf, PAGE_SIZE);
+	struct virtio_console_control cpkt;
+	struct virtqueue *vq;
+	int len;
+
+	if (!use_multiport(port->portdev))
+		return 0;
+
+	cpkt.id = port->id;
+	cpkt.event = event;
+	cpkt.value = value;
+
+	vq = port->portdev->c_ovq;
 
-	/* We should always be able to add one buffer to an empty queue. */
-	if (in_vq->vq_ops->add_buf(in_vq, sg, 0, 1, inbuf) < 0)
-		BUG();
-	in_vq->vq_ops->kick(in_vq);
+	sg_init_one(sg, &cpkt, sizeof(cpkt));
+	if (vq->vq_ops->add_buf(vq, sg, 1, 0, &cpkt) >= 0) {
+		vq->vq_ops->kick(vq);
+		while (!vq->vq_ops->get_buf(vq, &len))
+			cpu_relax();
+	}
+	return 0;
 }
 
-/*D:350 get_chars() is the callback from the hvc_console infrastructure when
- * an interrupt is received.
- *
- * Most of the code deals with the fact that the hvc_console() infrastructure
- * only asks us for 16 bytes at a time.  We keep in_offset and in_used fields
- * for partially-filled buffers. */
-static int get_chars(u32 vtermno, char *buf, int count)
+static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count)
 {
-	/* If we don't have an input queue yet, we can't get input. */
-	BUG_ON(!in_vq);
+	struct scatterlist sg[1];
+	struct virtqueue *out_vq;
+	ssize_t ret;
+	unsigned int len;
+
+	out_vq = port->out_vq;
+
+	sg_init_one(sg, in_buf, in_count);
+	ret = out_vq->vq_ops->add_buf(out_vq, sg, 1, 0, in_buf);
+
+	/* Tell Host to go! */
+	out_vq->vq_ops->kick(out_vq);
+
+	if (ret < 0) {
+		len = 0;
+		goto fail;
+	}
+
+	/*
+	 * Wait till the host acknowledges it pushed out the data we
+	 * sent. Also ensure we return to userspace the number of
+	 * bytes that were successfully consumed by the host.
+	 */
+	while (!out_vq->vq_ops->get_buf(out_vq, &len))
+		cpu_relax();
+fail:
+	/* We're expected to return the amount of data we wrote */
+	return len;
+}
+
+/*
+ * Give out the data that's requested from the buffer that we have
+ * queued up.
+ */
+static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count,
+			    bool to_user)
+{
+	struct port_buffer *buf;
+	unsigned long flags;
+
+	if (!out_count || !port_has_data(port))
+		return 0;
+
+	buf = port->inbuf;
+	out_count = min(out_count, buf->len - buf->offset);
+
+	if (to_user) {
+		ssize_t ret;
+
+		ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
+		if (ret)
+			return -EFAULT;
+	} else {
+		memcpy(out_buf, buf->buf + buf->offset, out_count);
+	}
+
+	buf->offset += out_count;
+
+	if (buf->offset == buf->len) {
+		/*
+		 * We're done using all the data in this buffer.
+		 * Re-queue so that the Host can send us more data.
+		 */
+		spin_lock_irqsave(&port->inbuf_lock, flags);
+		port->inbuf = NULL;
+
+		if (add_inbuf(port->in_vq, buf) < 0)
+			dev_warn(port->dev, "failed add_buf\n");
+
+		spin_unlock_irqrestore(&port->inbuf_lock, flags);
+	}
+	/* Return the number of bytes actually copied */
+	return out_count;
+}
 
-	/* No buffer?  Try to get one. */
-	if (!in_len) {
-		in = in_vq->vq_ops->get_buf(in_vq, &in_len);
-		if (!in)
+/* The condition that must be true for polling to end */
+static bool wait_