Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

1 files changed, 1247 insertions, 0 deletions

diff --git a/drivers/ps3/ps3-vuart.c b/drivers/ps3/ps3-vuart.c
new file mode 100644
index 000000000..39ffa2366
--- /dev/null
+++ b/drivers/ps3/ps3-vuart.c
@@ -0,0 +1,1247 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  PS3 virtual uart
+ *
+ *  Copyright (C) 2006 Sony Computer Entertainment Inc.
+ *  Copyright 2006 Sony Corp.
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/workqueue.h>
+#include <linux/bitops.h>
+#include <asm/ps3.h>
+
+#include <asm/firmware.h>
+#include <asm/lv1call.h>
+
+#include "vuart.h"
+
+MODULE_AUTHOR("Sony Corporation");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("PS3 vuart");
+
+/**
+ * vuart - An inter-partition data link service.
+ *  port 0: PS3 AV Settings.
+ *  port 2: PS3 System Manager.
+ *
+ * The vuart provides a bi-directional byte stream data link between logical
+ * partitions.  Its primary role is as a communications link between the guest
+ * OS and the system policy module.  The current HV does not support any
+ * connections other than those listed.
+ */
+
+enum {PORT_COUNT = 3,};
+
+enum vuart_param {
+	PARAM_TX_TRIGGER = 0,
+	PARAM_RX_TRIGGER = 1,
+	PARAM_INTERRUPT_MASK = 2,
+	PARAM_RX_BUF_SIZE = 3, /* read only */
+	PARAM_RX_BYTES = 4, /* read only */
+	PARAM_TX_BUF_SIZE = 5, /* read only */
+	PARAM_TX_BYTES = 6, /* read only */
+	PARAM_INTERRUPT_STATUS = 7, /* read only */
+};
+
+enum vuart_interrupt_bit {
+	INTERRUPT_BIT_TX = 0,
+	INTERRUPT_BIT_RX = 1,
+	INTERRUPT_BIT_DISCONNECT = 2,
+};
+
+enum vuart_interrupt_mask {
+	INTERRUPT_MASK_TX = 1,
+	INTERRUPT_MASK_RX = 2,
+	INTERRUPT_MASK_DISCONNECT = 4,
+};
+
+/**
+ * struct ps3_vuart_port_priv - private vuart device data.
+ */
+
+struct ps3_vuart_port_priv {
+	u64 interrupt_mask;
+
+	struct {
+		spinlock_t lock;
+		struct list_head head;
+	} tx_list;
+	struct {
+		struct ps3_vuart_work work;
+		unsigned long bytes_held;
+		spinlock_t lock;
+		struct list_head head;
+	} rx_list;
+	struct ps3_vuart_stats stats;
+};
+
+static struct ps3_vuart_port_priv *to_port_priv(
+	struct ps3_system_bus_device *dev)
+{
+	BUG_ON(!dev);
+	BUG_ON(!dev->driver_priv);
+	return (struct ps3_vuart_port_priv *)dev->driver_priv;
+}
+
+/**
+ * struct ports_bmp - bitmap indicating ports needing service.
+ *
+ * A 256 bit read only bitmap indicating ports needing service.  Do not write
+ * to these bits.  Must not cross a page boundary.
+ */
+
+struct ports_bmp {
+	u64 status;
+	u64 unused[3];
+} __attribute__((aligned(32)));
+
+#define dump_ports_bmp(_b) _dump_ports_bmp(_b, __func__, __LINE__)
+static void __maybe_unused _dump_ports_bmp(
+	const struct ports_bmp *bmp, const char *func, int line)
+{
+	pr_debug("%s:%d: ports_bmp: %016llxh\n", func, line, bmp->status);
+}
+
+#define dump_port_params(_b) _dump_port_params(_b, __func__, __LINE__)
+static void __maybe_unused _dump_port_params(unsigned int port_number,
+	const char *func, int line)
+{
+#if defined(DEBUG)
+	static const char *strings[] = {
+		"tx_trigger      ",
+		"rx_trigger      ",
+		"interrupt_mask  ",
+		"rx_buf_size     ",
+		"rx_bytes        ",
+		"tx_buf_size     ",
+		"tx_bytes        ",
+		"interrupt_status",
+	};
+	int result;
+	unsigned int i;
+	u64 value;
+
+	for (i = 0; i < ARRAY_SIZE(strings); i++) {
+		result = lv1_get_virtual_uart_param(port_number, i, &value);
+
+		if (result) {
+			pr_debug("%s:%d: port_%u: %s failed: %s\n", func, line,
+				port_number, strings[i], ps3_result(result));
+			continue;
+		}
+		pr_debug("%s:%d: port_%u: %s = %lxh\n",
+			func, line, port_number, strings[i], value);
+	}
+#endif
+}
+
+int ps3_vuart_get_triggers(struct ps3_system_bus_device *dev,
+	struct vuart_triggers *trig)
+{
+	int result;
+	u64 size;
+	u64 val;
+	u64 tx;
+
+	result = lv1_get_virtual_uart_param(dev->port_number,
+		PARAM_TX_TRIGGER, &tx);
+	trig->tx = tx;
+
+	if (result) {
+		dev_dbg(&dev->core, "%s:%d: tx_trigger failed: %s\n",
+			__func__, __LINE__, ps3_result(result));
+		return result;
+	}
+
+	result = lv1_get_virtual_uart_param(dev->port_number,
+		PARAM_RX_BUF_SIZE, &size);
+
+	if (result) {
+		dev_dbg(&dev->core, "%s:%d: tx_buf_size failed: %s\n",
+			__func__, __LINE__, ps3_result(result));
+		return result;
+	}
+
+	result = lv1_get_virtual_uart_param(dev->port_number,
+		PARAM_RX_TRIGGER, &val);
+
+	if (result) {
+		dev_dbg(&dev->core, "%s:%d: rx_trigger failed: %s\n",
+			__func__, __LINE__, ps3_result(result));
+		return result;
+	}
+
+	trig->rx = size - val;
+
+	dev_dbg(&dev->core, "%s:%d: tx %lxh, rx %lxh\n", __func__, __LINE__,
+		trig->tx, trig->rx);
+
+	return result;
+}
+
+int ps3_vuart_set_triggers(struct ps3_system_bus_device *dev, unsigned int tx,
+	unsigned int rx)
+{
+	int result;
+	u64 size;
+
+	result = lv1_set_virtual_uart_param(dev->port_number,
+		PARAM_TX_TRIGGER, tx);
+
+	if (result) {
+		dev_dbg(&dev->core, "%s:%d: tx_trigger failed: %s\n",
+			__func__, __LINE__, ps3_result(result));
+		return result;
+	}
+
+	result = lv1_get_virtual_uart_param(dev->port_number,
+		PARAM_RX_BUF_SIZE, &size);
+
+	if (result) {
+		dev_dbg(&dev->core, "%s:%d: tx_buf_size failed: %s\n",
+			__func__, __LINE__, ps3_result(result));
+		return result;
+	}
+
+	result = lv1_set_virtual_uart_param(dev->port_number,
+		PARAM_RX_TRIGGER, size - rx);
+
+	if (result) {
+		dev_dbg(&dev->core, "%s:%d: rx_trigger failed: %s\n",
+			__func__, __LINE__, ps3_result(result));
+		return result;
+	}
+
+	dev_dbg(&dev->core, "%s:%d: tx %xh, rx %xh\n", __func__, __LINE__,
+		tx, rx);
+
+	return result;
+}
+
+static int ps3_vuart_get_rx_bytes_waiting(struct ps3_system_bus_device *dev,
+	u64 *bytes_waiting)
+{
+	int result;
+
+	result = lv1_get_virtual_uart_param(dev->port_number,
+		PARAM_RX_BYTES, bytes_waiting);
+
+	if (result)
+		dev_dbg(&dev->core, "%s:%d: rx_bytes failed: %s\n",
+			__func__, __LINE__, ps3_result(result));
+
+	dev_dbg(&dev->core, "%s:%d: %llxh\n", __func__, __LINE__,
+		*bytes_waiting);
+	return result;
+}
+
+/**
+ * ps3_vuart_set_interrupt_mask - Enable/disable the port interrupt sources.
+ * @dev: The struct ps3_system_bus_device instance.
+ * @bmp: Logical OR of enum vuart_interrupt_mask values. A zero bit disables.
+ */
+
+static int ps3_vuart_set_interrupt_mask(struct ps3_system_bus_device *dev,
+	unsigned long mask)
+{
+	int result;
+	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
+
+	dev_dbg(&dev->core, "%s:%d: %lxh\n", __func__, __LINE__, mask);
+
+	priv->interrupt_mask = mask;
+
+	result = lv1_set_virtual_uart_param(dev->port_number,
+		PARAM_INTERRUPT_MASK, priv->interrupt_mask);
+
+	if (result)
+		dev_dbg(&dev->core, "%s:%d: interrupt_mask failed: %s\n",
+			__func__, __LINE__, ps3_result(result));
+
+	return result;
+}
+
+static int ps3_vuart_get_interrupt_status(struct ps3_system_bus_device *dev,
+	unsigned long *status)
+{
+	int result;
+	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
+	u64 tmp;
+
+	result = lv1_get_virtual_uart_param(dev->port_number,
+		PARAM_INTERRUPT_STATUS, &tmp);
+
+	if (result)
+		dev_dbg(&dev->core, "%s:%d: interrupt_status failed: %s\n",
+			__func__, __LINE__, ps3_result(result));
+
+	*status = tmp & priv->interrupt_mask;
+
+	dev_dbg(&dev->core, "%s:%d: m %llxh, s %llxh, m&s %lxh\n",
+		__func__, __LINE__, priv->interrupt_mask, tmp, *status);
+
+	return result;
+}
+
+int ps3_vuart_enable_interrupt_tx(struct ps3_system_bus_device *dev)
+{
+	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
+
+	return (priv->interrupt_mask & INTERRUPT_MASK_TX) ? 0
+		: ps3_vuart_set_interrupt_mask(dev, priv->interrupt_mask
+		| INTERRUPT_MASK_TX);
+}
+
+int ps3_vuart_enable_interrupt_rx(struct ps3_system_bus_device *dev)
+{
+	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
+
+	return (priv->interrupt_mask & INTERRUPT_MASK_RX) ? 0
+		: ps3_vuart_set_interrupt_mask(dev, priv->interrupt_mask
+		| INTERRUPT_MASK_RX);
+}
+
+int ps3_vuart_enable_interrupt_disconnect(struct ps3_system_bus_device *dev)
+{
+	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
+
+	return (priv->interrupt_mask & INTERRUPT_MASK_DISCONNECT) ? 0
+		: ps3_vuart_set_interrupt_mask(dev, priv->interrupt_mask
+		| INTERRUPT_MASK_DISCONNECT);
+}
+
+int ps3_vuart_disable_interrupt_tx(struct ps3_system_bus_device *dev)
+{
+	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
+
+	return (priv->interrupt_mask & INTERRUPT_MASK_TX)
+		? ps3_vuart_set_interrupt_mask(dev, priv->interrupt_mask
+		& ~INTERRUPT_MASK_TX) : 0;
+}
+
+int ps3_vuart_disable_interrupt_rx(struct ps3_system_bus_device *dev)
+{
+	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
+
+	return (priv->interrupt_mask & INTERRUPT_MASK_RX)
+		? ps3_vuart_set_interrupt_mask(dev, priv->interrupt_mask
+		& ~INTERRUPT_MASK_RX) : 0;
+}
+
+int ps3_vuart_disable_interrupt_disconnect(struct ps3_system_bus_device *dev)
+{
+	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
+
+	return (priv->interrupt_mask & INTERRUPT_MASK_DISCONNECT)
+		? ps3_vuart_set_interrupt_mask(dev, priv->interrupt_mask
+		& ~INTERRUPT_MASK_DISCONNECT) : 0;
+}
+
+/**
+ * ps3_vuart_raw_write - Low level write helper.
+ * @dev: The struct ps3_system_bus_device instance.
+ *
+ * Do not call ps3_vuart_raw_write directly, use ps3_vuart_write.
+ */
+
+static int ps3_vuart_raw_write(struct ps3_system_bus_device *dev,
+	const void *buf, unsigned int bytes, u64 *bytes_written)
+{
+	int result;
+	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
+
+	result = lv1_write_virtual_uart(dev->port_number,
+		ps3_mm_phys_to_lpar(__pa(buf)), bytes, bytes_written);
+
+	if (result) {
+		dev_warn(&dev->core, "%s:%d: lv1_write_virtual_uart failed: "
+			"%s\n", __func__, __LINE__, ps3_result(result));
+		return result;
+	}
+
+	priv->stats.bytes_written += *bytes_written;
+
+	dev_dbg(&dev->core, "%s:%d: wrote %llxh/%xh=>%lxh\n", __func__, __LINE__,
+		*bytes_written, bytes, priv->stats.bytes_written);
+
+	return result;
+}
+
+/**
+ * ps3_vuart_raw_read - Low level read helper.
+ * @dev: The struct ps3_system_bus_device instance.
+ *
+ * Do not call ps3_vuart_raw_read directly, use ps3_vuart_read.
+ */
+
+static int ps3_vuart_raw_read(struct ps3_system_bus_device *dev, void *buf,
+	unsigned int bytes, u64 *bytes_read)
+{
+	int result;
+	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
+
+	dev_dbg(&dev->core, "%s:%d: %xh\n", __func__, __LINE__, bytes);
+
+	result = lv1_read_virtual_uart(dev->port_number,
+		ps3_mm_phys_to_lpar(__pa(buf)), bytes, bytes_read);
+
+	if (result) {
+		dev_dbg(&dev->core, "%s:%d: lv1_read_virtual_uart failed: %s\n",
+			__func__, __LINE__, ps3_result(result));
+		return result;
+	}
+
+	priv->stats.bytes_read += *bytes_read;
+
+	dev_dbg(&dev->core, "%s:%d: read %llxh/%xh=>%lxh\n", __func__, __LINE__,
+		*bytes_read, bytes, priv->stats.bytes_read);
+
+	return result;
+}
+
+/**
+ * ps3_vuart_clear_rx_bytes - Discard bytes received.
+ * @dev: The struct ps3_system_bus_device instance.
+ * @bytes: Max byte count to discard, zero = all pending.
+ *
+ * Used to clear pending rx interrupt source.  Will not block.
+ */
+
+void ps3_vuart_clear_rx_bytes(struct ps3_system_bus_device *dev,
+	unsigned int bytes)
+{
+	int result;
+	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
+	u64 bytes_waiting;
+	void *tmp;
+
+	result = ps3_vuart_get_rx_bytes_waiting(dev, &bytes_waiting);
+
+	BUG_ON(result);
+
+	bytes = bytes ? min(bytes, (unsigned int)bytes_waiting) : bytes_waiting;
+
+	dev_dbg(&dev->core, "%s:%d: %u\n", __func__, __LINE__, bytes);
+
+	if (!bytes)
+		return;
+
+	/* Add some extra space for recently arrived data. */
+
+	bytes += 128;
+
+	tmp = kmalloc(bytes, GFP_KERNEL);
+
+	if (!tmp)
+		return;
+
+	ps3_vuart_raw_read(dev, tmp, bytes, &bytes_waiting);
+
+	kfree(tmp);
+
+	/* Don't include these bytes in the stats. */
+
+	priv->stats.bytes_read -= bytes_waiting;
+}
+EXPORT_SYMBOL_GPL(ps3_vuart_clear_rx_bytes);
+
+/**
+ * struct list_buffer - An element for a port device fifo buffer list.
+ */
+
+struct list_buffer {
+	struct list_head link;
+	const unsigned char *head;
+	const unsigned char *tail;
+	unsigned long dbg_number;
+	unsigned char data[];
+};
+
+/**
+ * ps3_vuart_write - the entry point for writing data to a port
+ * @dev: The struct ps3_system_bus_device instance.
+ *
+ * If the port is idle on entry as much of the incoming data is written to
+ * the port as the port will accept.  Otherwise a list buffer is created
+ * and any remaining incoming data is copied to that buffer.  The buffer is
+ * then enqueued for transmission via the transmit interrupt.
+ */
+
+int ps3_vuart_write(struct ps3_system_bus_device *dev, const void *buf,
+	unsigned int bytes)
+{
+	static unsigned long dbg_number;
+	int result;
+	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
+	unsigned long flags;
+	struct list_buffer *lb;
+
+	dev_dbg(&dev->core, "%s:%d: %u(%xh) bytes\n", __func__, __LINE__,
+		bytes, bytes);
+
+	spin_lock_irqsave(&priv->tx_list.lock, flags);
+
+	if (list_empty(&priv->tx_list.head)) {
+		u64 bytes_written;
+
+		result = ps3_vuart_raw_write(dev, buf, bytes, &bytes_written);
+
+		spin_unlock_irqrestore(&priv->tx_list.lock, flags);
+
+		if (result) {
+			dev_dbg(&dev->core,
+				"%s:%d: ps3_vuart_raw_write failed\n",
+				__func__, __LINE__);
+			return result;
+		}
+
+		if (bytes_written == bytes) {
+			dev_dbg(&dev->core, "%s:%d: wrote %xh bytes\n",
+				__func__, __LINE__, bytes);
+			return 0;
+		}
+
+		bytes -= bytes_written;
+		buf += bytes_written;
+	} else
+		spin_unlock_irqrestore(&priv->tx_list.lock, flags);
+
+	lb = kmalloc(sizeof(struct list_buffer) + bytes, GFP_KERNEL);
+
+	if (!lb)
+		return -ENOMEM;
+
+	memcpy(lb->data, buf, bytes);
+	lb->head = lb->data;
+	lb->tail = lb->data + bytes;
+	lb->dbg_number = ++dbg_number;
+
+	spin_lock_irqsave(&priv->tx_list.lock, flags);
+	list_add_tail(&lb->link, &priv->tx_list.head);
+	ps3_vuart_enable_interrupt_tx(dev);
+	spin_unlock_irqrestore(&priv->tx_list.lock, flags);
+
+	dev_dbg(&dev->core, "%s:%d: queued buf_%lu, %xh bytes\n",
+		__func__, __LINE__, lb->dbg_number, bytes);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ps3_vuart_write);
+
+/**
+ * ps3_vuart_queue_rx_bytes - Queue waiting bytes into the buffer list.
+ * @dev: The struct ps3_system_bus_device instance.
+ * @bytes_queued: Number of bytes queued to the buffer list.
+ *
+ * Must be called with priv->rx_list.lock held.
+ */
+
+static int ps3_vuart_queue_rx_bytes(struct ps3_system_bus_device *dev,
+	u64 *bytes_queued)
+{
+	static unsigned long dbg_number;
+	int result;
+	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
+	struct list_buffer *lb;
+	u64 bytes;
+
+	*bytes_queued = 0;
+
+	result = ps3_vuart_get_rx_bytes_waiting(dev, &bytes);
+	BUG_ON(result);
+
+	if (result)
+		return -EIO;
+
+	if (!bytes)
+		return 0;
+
+	/* Add some extra space for recently arrived data. */
+
+	bytes += 128;
+
+	lb = kmalloc(sizeof(struct list_buffer) + bytes, GFP_ATOMIC);
+
+	if (!lb)
+		return -ENOMEM;
+
+	ps3_vuart_raw_read(dev, lb->data, bytes, &bytes);
+
+	lb->head = lb->data;
+	lb->tail = lb->data + bytes;
+	lb->dbg_number = ++dbg_number;
+
+	list_add_tail(&lb->link, &priv->rx_list.head);
+	priv->rx_list.bytes_held += bytes;
+
+	dev_dbg(&dev->core, "%s:%d: buf_%lu: queued %llxh bytes\n",
+		__func__, __LINE__, lb->dbg_number, bytes);
+
+	*bytes_queued = bytes;
+
+	return 0;
+}
+
+/**
+ * ps3_vuart_read - The entry point for reading data from a port.
+ *
+ * Queue data waiting at the port, and if enough bytes to satisfy the request
+ * are held in the buffer list those bytes are dequeued and copied to the
+ * caller's buffer.  Emptied list buffers are retiered.  If the request cannot
+ * be statified by bytes held in the list buffers -EAGAIN is returned.
+ */
+
+int ps3_vuart_read(struct ps3_system_bus_device *dev, void *buf,
+	unsigned int bytes)
+{
+	int result;
+	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
+	unsigned long flags;
+	struct list_buffer *lb, *n;
+	unsigned long bytes_read;
+
+	dev_dbg(&dev->core, "%s:%d: %u(%xh) bytes\n", __func__, __LINE__,
+		bytes, bytes);
+
+	spin_lock_irqsave(&priv->rx_list.lock, flags);
+
+	/* Queue rx bytes here for polled reads. */
+
+	while (priv->rx_list.bytes_held < bytes) {
+		u64 tmp;
+
+		result = ps3_vuart_queue_rx_bytes(dev, &tmp);
+		if (result || !tmp) {
+			dev_dbg(&dev->core, "%s:%d: starved for %lxh bytes\n",
+				__func__, __LINE__,
+				bytes - priv->rx_list.bytes_held);
+			spin_unlock_irqrestore(&priv->rx_list.lock, flags);
+			return -EAGAIN;
+		}
+	}
+
+	list_for_each_entry_safe(lb, n, &priv->rx_list.head, link) {
+		bytes_read = min((unsigned int)(lb->tail - lb->head), bytes);
+
+		memcpy(buf, lb->head, bytes_read);
+		buf += bytes_read;
+		bytes -= bytes_read;
+		priv->rx_list.bytes_held -= bytes_read;
+
+		if (bytes_read < lb->tail - lb->head) {
+			lb->head += bytes_read;
+			dev_dbg(&dev->core, "%s:%d: buf_%lu: dequeued %lxh "
+				"bytes\n", __func__, __LINE__, lb->dbg_number,
+				bytes_read);
+			spin_unlock_irqrestore(&priv->rx_list.lock, flags);
+			return 0;
+		}
+
+		dev_dbg(&dev->core, "%s:%d: buf_%lu: free, dequeued %lxh "
+			"bytes\n", __func__, __LINE__, lb->dbg_number,
+			bytes_read);
+
+		list_del(&lb->link);
+		kfree(lb);
+	}
+
+	spin_unlock_irqrestore(&priv->rx_list.lock, flags);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ps3_vuart_read);
+
+/**
+ * ps3_vuart_work - Asynchronous read handler.
+ */
+
+static void ps3_vuart_work(struct work_struct *work)
+{
+	struct ps3_system_bus_device *dev =
+		ps3_vuart_work_to_system_bus_dev(work);
+	struct ps3_vuart_port_driver *drv =
+		ps3_system_bus_dev_to_vuart_drv(dev);
+
+	BUG_ON(!drv);
+	drv->work(dev);
+}
+
+int ps3_vuart_read_async(struct ps3_system_bus_device *dev, unsigned int bytes)
+{
+	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
+	unsigned long flags;
+
+	if (priv->rx_list.work.trigger) {
+		dev_dbg(&dev->core, "%s:%d: warning, multiple calls\n",
+			__func__, __LINE__);
+		return -EAGAIN;
+	}
+
+	BUG_ON(!bytes);
+
+	spin_lock_irqsave(&priv->rx_list.lock, flags);
+	if (priv->rx_list.bytes_held >= bytes) {
+		dev_dbg(&dev->core, "%s:%d: schedule_work %xh bytes\n",
+			__func__, __LINE__, bytes);
+		schedule_work(&priv->rx_list.work.work);
+		spin_unlock_irqrestore(&priv->rx_list.lock, flags);
+		return 0;
+	}
+
+	priv->rx_list.work.trigger = bytes;
+	spin_unlock_irqrestore(&priv->rx_list.lock, flags);
+
+	dev_dbg(&dev->core, "%s:%d: waiting for %u(%xh) bytes\n", __func__,
+		__LINE__, bytes, bytes);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ps3_vuart_read_async);
+
+void ps3_vuart_cancel_async(struct ps3_system_bus_device *dev)
+{
+	to_port_priv(dev)->rx_list.work.trigger = 0;
+}
+EXPORT_SYMBOL_GPL(ps3_vuart_cancel_async);
+
+/**
+ * ps3_vuart_handle_interrupt_tx - third stage transmit interrupt handler
+ *
+ * Services the transmit interrupt for the port.  Writes as much data from the
+ * buffer list as the port will accept.  Retires any emptied list buffers and
+ * adjusts the final list buffer state for a partial write.
+ */
+
+static int ps3_vuart_handle_interrupt_tx(struct ps3_system_bus_device *dev)
+{
+	int result = 0;
+	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
+	unsigned long flags;
+	struct list_buffer *lb, *n;
+	unsigned long bytes_total = 0;
+
+	dev_dbg(&dev->core, "%s:%d\n", __func__, __LINE__);
+
+	spin_lock_irqsave(&priv->tx_list.lock, flags);
+
+	list_for_each_entry_safe(lb, n, &priv->tx_list.head, link) {
+
+		u64 bytes_written;
+
+		result = ps3_vuart_raw_write(dev, lb->head, lb->tail - lb->head,
+			&bytes_written);
+
+		if (result) {
+			dev_dbg(&dev->core,
+				"%s:%d: ps3_vuart_raw_write failed\n",
+				__func__, __LINE__);
+			break;
+		}
+
+		bytes_total += bytes_written;
+
+		if (bytes_written < lb->tail - lb->head) {
+			lb->head += bytes_written;
+			dev_dbg(&dev->core,
+				"%s:%d cleared buf_%lu, %llxh bytes\n",
+				__func__, __LINE__, lb->dbg_number,
+				bytes_written);
+			goto port_full;
+		}
+
+		dev_dbg(&dev->core, "%s:%d free buf_%lu\n", __func__, __LINE__,
+			lb->dbg_number);
+
+		list_del(&lb->link);
+		kfree(lb);
+	}
+
+	ps3_vuart_disable_interrupt_tx(dev);
+port_full:
+	spin_unlock_irqrestore(&priv->tx_list.lock, flags);
+	dev_dbg(&dev->core, "%s:%d wrote %lxh bytes total\n",
+		__func__, __LINE__, bytes_total);
+	return result;
+}
+
+/**
+ * ps3_vuart_handle_interrupt_rx - third stage receive interrupt handler
+ *
+ * Services the receive interrupt for the port.  Creates a list buffer and
+ * copies all waiting port data to that buffer and enqueues the buffer in the
+ * buffer list.  Buffer list data is dequeued via ps3_vuart_read.
+ */
+
+static int ps3_vuart_handle_interrupt_rx(struct ps3_system_bus_device *dev)
+{
+	int result;
+	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
+	unsigned long flags;
+	u64 bytes;
+
+	dev_dbg(&dev->core, "%s:%d\n", __func__, __LINE__);
+
+	spin_lock_irqsave(&priv->rx_list.lock, flags);
+	result = ps3_vuart_queue_rx_bytes(dev, &bytes);
+
+	if (result) {
+		spin_unlock_irqrestore(&priv->rx_list.lock, flags);
+		return result;
+	}
+
+	if (priv->rx_list.work.trigger && priv->rx_list.bytes_held
+		>= priv->rx_list.work.trigger) {
+		dev_dbg(&dev->core, "%s:%d: schedule_work %lxh bytes\n",
+			__func__, __LINE__, priv->rx_list.work.trigger);
+		priv->rx_list.work.trigger = 0;
+		schedule_work(&priv->rx_list.work.work);
+	}
+
+	spin_unlock_irqrestore(&priv->rx_list.lock, flags);
+	return result;
+}
+
+static int ps3_vuart_handle_interrupt_disconnect(
+	struct ps3_system_bus_device *dev)
+{
+	dev_dbg(&dev->core, "%s:%d\n", __func__, __LINE__);
+	BUG_ON("no support");
+	return -1;
+}
+
+/**
+ * ps3_vuart_handle_port_interrupt - second stage interrupt handler
+ *
+ * Services any pending interrupt types for the port.  Passes control to the
+ * third stage type specific interrupt handler.  Returns control to the first
+ * stage handler after one iteration.
+ */
+
+static int ps3_vuart_handle_port_interrupt(struct ps3_system_bus_device *dev)
+{
+	int result;
+	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
+	unsigned long status;
+
+	result = ps3_vuart_get_interrupt_status(dev, &status);
+
+	if (result)
+		return result;
+
+	dev_dbg(&dev->core, "%s:%d: status: %lxh\n", __func__, __LINE__,
+		status);
+
+	if (status & INTERRUPT_MASK_DISCONNECT) {
+		priv->stats.disconnect_interrupts++;
+		result = ps3_vuart_handle_interrupt_disconnect(dev);
+		if (result)
+			ps3_vuart_disable_interrupt_disconnect(dev);
+	}
+
+	if (status & INTERRUPT_MASK_TX) {
+		priv->stats.tx_interrupts++;
+		result = ps3_vuart_handle_interrupt_tx(dev);
+		if (result)
+			ps3_vuart_disable_interrupt_tx(dev);
+	}
+
+	if (status & INTERRUPT_MASK_RX) {
+		priv->stats.rx_interrupts++;
+		result = ps3_vuart_handle_interrupt_rx(dev);
+		if (result)
+			ps3_vuart_disable_interrupt_rx(dev);
+	}
+
+	return 0;
+}
+
+static struct vuart_bus_priv {
+	struct ports_bmp *bmp;
+	unsigned int virq;
+	struct mutex probe_mutex;
+	int use_count;
+	struct ps3_system_bus_device *devices[PORT_COUNT];
+} vuart_bus_priv;
+
+/**
+ * ps3_vuart_irq_handler - first stage interrupt handler
+ *
+ * Loops finding any interrupting port and its associated instance data.
+ * Passes control to the second stage port specific interrupt handler.  Loops
+ * until all outstanding interrupts are serviced.
+ */
+
+static irqreturn_t ps3_vuart_irq_handler(int irq, void *_private)
+{
+	struct vuart_bus_priv *bus_priv = _private;
+
+	BUG_ON(!bus_priv);
+
+	while (1) {
+		unsigned int port;
+
+		dump_ports_bmp(bus_priv->bmp);
+
+		port = (BITS_PER_LONG - 1) - __ilog2(bus_priv->bmp->status);
+
+		if (port == BITS_PER_LONG)
+			break;
+
+		BUG_ON(port >= PORT_COUNT);
+		BUG_ON(!bus_priv->devices[port]);
+
+		ps3_vuart_handle_port_interrupt(bus_priv->devices[port]);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int ps3_vuart_bus_interrupt_get(void)
+{
+	int result;
+
+	pr_debug(" -> %s:%d\n", __func__, __LINE__);
+
+	vuart_bus_priv.use_count++;
+
+	BUG_ON(vuart_bus_priv.use_count > 2);
+
+	if (vuart_bus_priv.use_count != 1)
+		return 0;
+
+	BUG_ON(vuart_bus_priv.bmp);
+
+	vuart_bus_priv.bmp = kzalloc_obj(struct ports_bmp);
+
+	if (!vuart_bus_priv.bmp) {
+		result = -ENOMEM;
+		goto fail_bmp_malloc;
+	}
+
+	result = ps3_vuart_irq_setup(PS3_BINDING_CPU_ANY, vuart_bus_priv.bmp,
+		&vuart_bus_priv.virq);
+
+	if (result) {
+		pr_debug("%s:%d: ps3_vuart_irq_setup failed (%d)\n",
+			__func__, __LINE__, result);
+		result = -EPERM;
+		goto fail_alloc_irq;
+	}
+
+	result = request_irq(vuart_bus_priv.virq, ps3_vuart_irq_handler,
+		0, "vuart", &vuart_bus_priv);
+
+	if (result) {
+		pr_debug("%s:%d: request_irq failed (%d)\n",
+			__func__, __LINE__, result);
+		goto fail_request_irq;
+	}
+
+	pr_debug(" <- %s:%d: ok\n", __func__, __LINE__);
+	return result;
+
+fail_request_irq:
+	ps3_vuart_irq_destroy(vuart_bus_priv.virq);
+	vuart_bus_priv.virq = 0;
+fail_alloc_irq:
+	kfree(vuart_bus_priv.bmp);
+	vuart_bus_priv.bmp = NULL;
+fail_bmp_malloc:
+	vuart_bus_priv.use_count--;
+	pr_debug(" <- %s:%d: failed\n", __func__, __LINE__);
+	return result;
+}
+
+static int ps3_vuart_bus_interrupt_put(void)
+{
+	pr_debug(" -> %s:%d\n", __func__, __LINE__);
+
+	vuart_bus_priv.use_count--;
+
+	BUG_ON(vuart_bus_priv.use_count < 0);
+
+	if (vuart_bus_priv.use_count != 0)
+		return 0;
+
+	free_irq(vuart_bus_priv.virq, &vuart_bus_priv);
+
+	ps3_vuart_irq_destroy(vuart_bus_priv.virq);
+	vuart_bus_priv.virq = 0;
+
+	kfree(vuart_bus_priv.bmp);
+	vuart_bus_priv.bmp = NULL;
+
+	pr_debug(" <- %s:%d\n", __func__, __LINE__);
+	return 0;
+}
+
+static int ps3_vuart_probe(struct ps3_system_bus_device *dev)
+{
+	int result;
+	struct ps3_vuart_port_driver *drv;
+	struct ps3_vuart_port_priv *priv = NULL;
+
+	dev_dbg(&dev->core, "%s:%d\n", __func__, __LINE__);
+
+	drv = ps3_system_bus_dev_to_vuart_drv(dev);
+	BUG_ON(!drv);
+
+	dev_dbg(&dev->core, "%s:%d: (%s)\n", __func__, __LINE__,
+		drv->core.core.name);
+
+	if (dev->port_number >= PORT_COUNT) {
+		BUG();
+		return -EINVAL;
+	}
+
+	mutex_lock(&vuart_bus_priv.probe_mutex);
+
+	result = ps3_vuart_bus_interrupt_get();
+
+	if (result)
+		goto fail_setup_interrupt;
+
+	if (vuart_bus_priv.devices[dev->port_number]) {
+		dev_dbg(&dev->core, "%s:%d: port busy (%d)\n", __func__,
+			__LINE__, dev->port_number);
+		result = -EBUSY;
+		goto fail_busy;
+	}
+
+	vuart_bus_priv.devices[dev->port_number] = dev;
+
+	/* Setup dev->driver_priv. */
+
+	dev->driver_priv = kzalloc_obj(struct ps3_vuart_port_priv);
+
+	if (!dev->driver_priv) {
+		result = -ENOMEM;
+		goto fail_dev_malloc;
+	}
+
+	priv = to_port_priv(dev);
+
+	INIT_LIST_HEAD(&priv->tx_list.head);
+	spin_lock_init(&priv->tx_list.lock);
+
+	INIT_LIST_HEAD(&priv->rx_list.head);
+	spin_lock_init(&priv->rx_list.lock);
+
+	INIT_WORK(&priv->rx_list.work.work, ps3_vuart_work);
+	priv->rx_list.work.trigger = 0;
+	priv->rx_list.work.dev = dev;
+
+	/* clear stale pending interrupts */
+
+	ps3_vuart_clear_rx_bytes(dev, 0);
+
+	ps3_vuart_set_interrupt_mask(dev, INTERRUPT_MASK_RX);
+
+	ps3_vuart_set_triggers(dev, 1, 1);
+
+	if (drv->probe)
+		result = drv->probe(dev);
+	else {
+		result = 0;
+		dev_info(&dev->core, "%s:%d: no probe method\n", __func__,
+			__LINE__);
+	}
+
+	if (result) {
+		dev_dbg(&dev->core, "%s:%d: drv->probe failed\n",
+			__func__, __LINE__);
+		goto fail_probe;
+	}
+
+	mutex_unlock(&vuart_bus_priv.probe_mutex);
+
+	return result;
+
+fail_probe:
+	ps3_vuart_set_interrupt_mask(dev, 0);
+	kfree(dev->driver_priv);
+	dev->driver_priv = NULL;
+fail_dev_malloc:
+	vuart_bus_priv.devices[dev->port_number] = NULL;
+fail_busy:
+	ps3_vuart_bus_interrupt_put();
+fail_setup_interrupt:
+	mutex_unlock(&vuart_bus_priv.probe_mutex);
+	dev_dbg(&dev->core, "%s:%d: failed\n", __func__, __LINE__);
+	return result;
+}
+
+/**
+ * ps3_vuart_cleanup - common cleanup helper.
+ * @dev: The struct ps3_system_bus_device instance.
+ *
+ * Cleans interrupts and HV resources.  Must be called with
+ * vuart_bus_priv.probe_mutex held.  Used by ps3_vuart_remove and
+ * ps3_vuart_shutdown.  After this call, polled reading will still work.
+ */
+
+static int ps3_vuart_cleanup(struct ps3_system_bus_device *dev)
+{
+	dev_dbg(&dev->core, "%s:%d\n", __func__, __LINE__);
+
+	ps3_vuart_cancel_async(dev);
+	ps3_vuart_set_interrupt_mask(dev, 0);
+	ps3_vuart_bus_interrupt_put();
+	return 0;
+}
+
+/**
+ * ps3_vuart_remove - Completely clean the device instance.
+ * @dev: The struct ps3_system_bus_device instance.
+ *
+ * Cleans all memory, interrupts and HV resources.  After this call the
+ * device can no longer be used.
+ */
+
+static void ps3_vuart_remove(struct ps3_system_bus_device *dev)
+{
+	struct ps3_vuart_port_priv *priv = to_port_priv(dev);
+	struct ps3_vuart_port_driver *drv;
+
+	BUG_ON(!dev);
+
+	mutex_lock(&vuart_bus_priv.probe_mutex);
+
+	dev_dbg(&dev->core, " -> %s:%d: match_id %d\n", __func__, __LINE__,
+		dev->match_id);
+
+	if (!dev->core.driver) {
+		dev_dbg(&dev->core, "%s:%d: no driver bound\n", __func__,
+			__LINE__);
+		mutex_unlock(&vuart_bus_priv.probe_mutex);
+		return;
+	}
+
+	drv = ps3_system_bus_dev_to_vuart_drv(dev);
+
+	BUG_ON(!drv);
+
+	if (drv->remove) {
+		drv->remove(dev);
+	} else {
+		dev_dbg(&dev->core, "%s:%d: no remove method\n", __func__,
+		__LINE__);
+		BUG();
+	}
+
+	ps3_vuart_cleanup(dev);
+
+	vuart_bus_priv.devices[dev->port_number] = NULL;
+	kfree(priv);
+	priv = NULL;
+
+	dev_dbg(&dev->core, " <- %s:%d\n", __func__, __LINE__);
+	mutex_unlock(&vuart_bus_priv.probe_mutex);
+}
+
+/**
+ * ps3_vuart_shutdown - Cleans interrupts and HV resources.
+ * @dev: The struct ps3_system_bus_device instance.
+ *
+ * Cleans interrupts and HV resources.  After this call the
+ * device can still be used in polling mode.  This behavior required
+ * by sys-manager to be able to complete the device power operation
+ * sequence.
+ */
+
+static void ps3_vuart_shutdown(struct ps3_system_bus_device *dev)
+{
+	struct ps3_vuart_port_driver *drv;
+
+	BUG_ON(!dev);
+
+	mutex_lock(&vuart_bus_priv.probe_mutex);
+
+	dev_dbg(&dev->core, " -> %s:%d: match_id %d\n", __func__, __LINE__,
+		dev->match_id);
+
+	if (!dev->core.driver) {
+		dev_dbg(&dev->core, "%s:%d: no driver bound\n", __func__,
+			__LINE__);
+		mutex_unlock(&vuart_bus_priv.probe_mutex);
+		return;
+	}
+
+	drv = ps3_system_bus_dev_to_vuart_drv(dev);
+
+	BUG_ON(!drv);
+
+	if (drv->shutdown)
+		drv->shutdown(dev);
+	else if (drv->remove) {
+		dev_dbg(&dev->core, "%s:%d: no shutdown, calling remove\n",
+			__func__, __LINE__);
+		drv->remove(dev);
+	} else {
+		dev_dbg(&dev->core, "%s:%d: no shutdown method\n", __func__,
+			__LINE__);
+		BUG();
+	}
+
+	ps3_vuart_cleanup(dev);
+
+	dev_dbg(&dev->core, " <- %s:%d\n", __func__, __LINE__);
+
+	mutex_unlock(&vuart_bus_priv.probe_mutex);
+}
+
+static int __init ps3_vuart_bus_init(void)
+{
+	pr_debug("%s:%d:\n", __func__, __LINE__);
+
+	if (!firmware_has_feature(FW_FEATURE_PS3_LV1))
+		return -ENODEV;
+
+	mutex_init(&vuart_bus_priv.probe_mutex);
+
+	return 0;
+}
+
+static void __exit ps3_vuart_bus_exit(void)
+{
+	pr_debug("%s:%d:\n", __func__, __LINE__);
+}
+
+core_initcall(ps3_vuart_bus_init);
+module_exit(ps3_vuart_bus_exit);
+
+/**
+ * ps3_vuart_port_driver_register - Add a vuart port device driver.
+ */
+
+int ps3_vuart_port_driver_register(struct ps3_vuart_port_driver *drv)
+{
+	int result;
+
+	pr_debug("%s:%d: (%s)\n", __func__, __LINE__, drv->core.core.name);
+
+	BUG_ON(!drv->core.match_id);
+	BUG_ON(!drv->core.core.name);
+
+	drv->core.probe = ps3_vuart_probe;
+	drv->core.remove = ps3_vuart_remove;
+	drv->core.shutdown = ps3_vuart_shutdown;
+
+	result = ps3_system_bus_driver_register(&drv->core);
+	return result;
+}
+EXPORT_SYMBOL_GPL(ps3_vuart_port_driver_register);
+
+/**
+ * ps3_vuart_port_driver_unregister - Remove a vuart port device driver.
+ */
+
+void ps3_vuart_port_driver_unregister(struct ps3_vuart_port_driver *drv)
+{
+	pr_debug("%s:%d: (%s)\n", __func__, __LINE__, drv->core.core.name);
+	ps3_system_bus_driver_unregister(&drv->core);
+}
+EXPORT_SYMBOL_GPL(ps3_vuart_port_driver_unregister);