1 files changed, 1270 insertions, 0 deletions

diff --git a/drivers/ps3/ps3-vuart.c b/drivers/ps3/ps3-vuart.c
new file mode 100644
index 000000000000..bb8d5b1eec90
--- /dev/null
+++ b/drivers/ps3/ps3-vuart.c
@@ -0,0 +1,1270 @@
+/*
+ *  PS3 virtual uart
+ *
+ *  Copyright (C) 2006 Sony Computer Entertainment Inc.
+ *  Copyright 2006 Sony Corp.
+ *
+ *  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; version 2 of the License.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  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/kernel.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: %016lxh\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
+}
+
+struct vuart_triggers {
+        unsigned long rx;
+        unsigned long tx;
+};
+
+int ps3_vuart_get_triggers(struct ps3_system_bus_device *dev,
+        struct vuart_triggers *trig)
+{
+        int result;
+        unsigned long size;
+        unsigned long val;
+
+        result = lv1_get_virtual_uart_param(dev->port_number,
+                PARAM_TX_TRIGGER, &trig->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;
+        unsigned long 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: %lxh\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 %lxh, s %lxh, 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, unsigned long *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_dbg(&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 %lxh/%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, unsigned long *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 %lxh/%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 remaning incoming data is copied to that buffer.  The buffer is
+ * then enqueued for transmision 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)) {
+                unsigned long 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 %lxh 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);
+
+        PREPARE_WORK(&priv->rx_list.work.work, ps3_vuart_work);
+
+        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) {
+
+                unsigned long 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, %lxh 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;
+}
+
+struct vuart_bus_priv {
+        struct ports_bmp *bmp;
+        unsigned int virq;
+        struct semaphore probe_mutex;
+        int use_count;
+        struct ps3_system_bus_device *devices[PORT_COUNT];
+} static 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(sizeof(struct ports_bmp), GFP_KERNEL);
+
+        if (!vuart_bus_priv.bmp) {
+                pr_debug("%s:%d: kzalloc failed.\n", __func__, __LINE__);
+                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,
+                IRQF_DISABLED, "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 = NO_IRQ;
+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 = NO_IRQ;
+
+        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);
+
+        dev_dbg(&dev->core, "%s:%d: (%s)\n", __func__, __LINE__,
+                drv->core.core.name);
+
+        BUG_ON(!drv);
+
+        if (dev->port_number >= PORT_COUNT) {
+                BUG();
+                return -EINVAL;
+        }
+
+        down(&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(sizeof(struct ps3_vuart_port_priv),
+                GFP_KERNEL);
+
+        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, NULL);
+        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;
+        }
+
+        up(&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:
+        up(&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 int 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);
+
+        down(&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__);
+                up(&vuart_bus_priv.probe_mutex);
+                return 0;
+        }
+
+        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__);
+        up(&vuart_bus_priv.probe_mutex);
+        return 0;
+}
+
+/**
+ * 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 int ps3_vuart_shutdown(struct ps3_system_bus_device *dev)
+{
+        struct ps3_vuart_port_driver *drv;
+
+        BUG_ON(!dev);
+
+        down(&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__);
+                up(&vuart_bus_priv.probe_mutex);
+                return 0;
+        }
+
+        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__);
+
+        up(&vuart_bus_priv.probe_mutex);
+        return 0;
+}
+
+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;
+
+        init_MUTEX(&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);