This commit was manufactured by cvs2svn to create branch 'vserver'.
[linux-2.6.git] / drivers / ps3 / vuart.c
diff --git a/drivers/ps3/vuart.c b/drivers/ps3/vuart.c
new file mode 100644 (file)
index 0000000..6974f65
--- /dev/null
@@ -0,0 +1,965 @@
+/*
+ *  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 <asm/ps3.h>
+
+#include <asm/lv1call.h>
+#include <asm/bitops.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 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)));
+
+/* redefine dev_dbg to do a syntax check */
+
+#if !defined(DEBUG)
+#undef dev_dbg
+static inline int __attribute__ ((format (printf, 2, 3))) dev_dbg(
+       const struct device *_dev, const char *fmt, ...) {return 0;}
+#endif
+
+#define dump_ports_bmp(_b) _dump_ports_bmp(_b, __func__, __LINE__)
+static void __attribute__ ((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);
+}
+
+static int ps3_vuart_match_id_to_port(enum ps3_match_id match_id,
+       unsigned int *port_number)
+{
+       switch(match_id) {
+       case PS3_MATCH_ID_AV_SETTINGS:
+               *port_number = 0;
+               return 0;
+       case PS3_MATCH_ID_SYSTEM_MANAGER:
+               *port_number = 2;
+               return 0;
+       default:
+               WARN_ON(1);
+               *port_number = UINT_MAX;
+               return -EINVAL;
+       };
+}
+
+#define dump_port_params(_b) _dump_port_params(_b, __func__, __LINE__)
+static void __attribute__ ((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_vuart_port_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_vuart_port_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_vuart_port_device *dev,
+       unsigned long *bytes_waiting)
+{
+       int 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;
+}
+
+static int ps3_vuart_set_interrupt_mask(struct ps3_vuart_port_device *dev,
+       unsigned long mask)
+{
+       int result;
+
+       dev_dbg(&dev->core, "%s:%d: %lxh\n", __func__, __LINE__, mask);
+
+       dev->interrupt_mask = mask;
+
+       result = lv1_set_virtual_uart_param(dev->port_number,
+               PARAM_INTERRUPT_MASK, dev->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_mask(struct ps3_vuart_port_device *dev,
+       unsigned long *status)
+{
+       int result = lv1_get_virtual_uart_param(dev->port_number,
+               PARAM_INTERRUPT_STATUS, status);
+
+       if (result)
+               dev_dbg(&dev->core, "%s:%d: interrupt_status failed: %s\n",
+                       __func__, __LINE__, ps3_result(result));
+
+       dev_dbg(&dev->core, "%s:%d: m %lxh, s %lxh, m&s %lxh\n",
+               __func__, __LINE__, dev->interrupt_mask, *status,
+               dev->interrupt_mask & *status);
+
+       return result;
+}
+
+int ps3_vuart_enable_interrupt_tx(struct ps3_vuart_port_device *dev)
+{
+       return (dev->interrupt_mask & INTERRUPT_MASK_TX) ? 0
+               : ps3_vuart_set_interrupt_mask(dev, dev->interrupt_mask
+               | INTERRUPT_MASK_TX);
+}
+
+int ps3_vuart_enable_interrupt_rx(struct ps3_vuart_port_device *dev)
+{
+       return (dev->interrupt_mask & INTERRUPT_MASK_RX) ? 0
+               : ps3_vuart_set_interrupt_mask(dev, dev->interrupt_mask
+               | INTERRUPT_MASK_RX);
+}
+
+int ps3_vuart_enable_interrupt_disconnect(struct ps3_vuart_port_device *dev)
+{
+       return (dev->interrupt_mask & INTERRUPT_MASK_DISCONNECT) ? 0
+               : ps3_vuart_set_interrupt_mask(dev, dev->interrupt_mask
+               | INTERRUPT_MASK_DISCONNECT);
+}
+
+int ps3_vuart_disable_interrupt_tx(struct ps3_vuart_port_device *dev)
+{
+       return (dev->interrupt_mask & INTERRUPT_MASK_TX)
+               ? ps3_vuart_set_interrupt_mask(dev, dev->interrupt_mask
+               & ~INTERRUPT_MASK_TX) : 0;
+}
+
+int ps3_vuart_disable_interrupt_rx(struct ps3_vuart_port_device *dev)
+{
+       return (dev->interrupt_mask & INTERRUPT_MASK_RX)
+               ? ps3_vuart_set_interrupt_mask(dev, dev->interrupt_mask
+               & ~INTERRUPT_MASK_RX) : 0;
+}
+
+int ps3_vuart_disable_interrupt_disconnect(struct ps3_vuart_port_device *dev)
+{
+       return (dev->interrupt_mask & INTERRUPT_MASK_DISCONNECT)
+               ? ps3_vuart_set_interrupt_mask(dev, dev->interrupt_mask
+               & ~INTERRUPT_MASK_DISCONNECT) : 0;
+}
+
+/**
+ * ps3_vuart_raw_write - Low level write helper.
+ *
+ * Do not call ps3_vuart_raw_write directly, use ps3_vuart_write.
+ */
+
+static int ps3_vuart_raw_write(struct ps3_vuart_port_device *dev,
+       const void* buf, unsigned int bytes, unsigned long *bytes_written)
+{
+       int result;
+
+       dev_dbg(&dev->core, "%s:%d: %xh\n", __func__, __LINE__, bytes);
+
+       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;
+       }
+
+       dev->stats.bytes_written += *bytes_written;
+
+       dev_dbg(&dev->core, "%s:%d: wrote %lxh/%xh=>%lxh\n", __func__,
+               __LINE__, *bytes_written, bytes, dev->stats.bytes_written);
+
+       return result;
+}
+
+/**
+ * ps3_vuart_raw_read - Low level read helper.
+ *
+ * Do not call ps3_vuart_raw_read directly, use ps3_vuart_read.
+ */
+
+static int ps3_vuart_raw_read(struct ps3_vuart_port_device *dev, void* buf,
+       unsigned int bytes, unsigned long *bytes_read)
+{
+       int result;
+
+       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;
+       }
+
+       dev->stats.bytes_read += *bytes_read;
+
+       dev_dbg(&dev->core, "%s:%d: read %lxh/%xh=>%lxh\n", __func__, __LINE__,
+               *bytes_read, bytes, dev->stats.bytes_read);
+
+       return result;
+}
+
+/**
+ * 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
+ *
+ * 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_vuart_port_device *dev, const void* buf,
+       unsigned int bytes)
+{
+       static unsigned long dbg_number;
+       int result;
+       unsigned long flags;
+       struct list_buffer *lb;
+
+       dev_dbg(&dev->core, "%s:%d: %u(%xh) bytes\n", __func__, __LINE__,
+               bytes, bytes);
+
+       spin_lock_irqsave(&dev->tx_list.lock, flags);
+
+       if (list_empty(&dev->tx_list.head)) {
+               unsigned long bytes_written;
+
+               result = ps3_vuart_raw_write(dev, buf, bytes, &bytes_written);
+
+               spin_unlock_irqrestore(&dev->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(&dev->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(&dev->tx_list.lock, flags);
+       list_add_tail(&lb->link, &dev->tx_list.head);
+       ps3_vuart_enable_interrupt_tx(dev);
+       spin_unlock_irqrestore(&dev->tx_list.lock, flags);
+
+       dev_dbg(&dev->core, "%s:%d: queued buf_%lu, %xh bytes\n",
+               __func__, __LINE__, lb->dbg_number, bytes);
+
+       return 0;
+}
+
+/**
+ * ps3_vuart_read - the entry point for reading data from a port
+ *
+ * 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_vuart_port_device *dev, void* buf,
+       unsigned int bytes)
+{
+       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(&dev->rx_list.lock, flags);
+
+       if (dev->rx_list.bytes_held < bytes) {
+               spin_unlock_irqrestore(&dev->rx_list.lock, flags);
+               dev_dbg(&dev->core, "%s:%d: starved for %lxh bytes\n",
+                       __func__, __LINE__, bytes - dev->rx_list.bytes_held);
+               return -EAGAIN;
+       }
+
+       list_for_each_entry_safe(lb, n, &dev->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;
+               dev->rx_list.bytes_held -= bytes_read;
+
+               if (bytes_read < lb->tail - lb->head) {
+                       lb->head += bytes_read;
+                       spin_unlock_irqrestore(&dev->rx_list.lock, flags);
+
+                       dev_dbg(&dev->core,
+                               "%s:%d: dequeued buf_%lu, %lxh bytes\n",
+                               __func__, __LINE__, lb->dbg_number, bytes_read);
+                       return 0;
+               }
+
+               dev_dbg(&dev->core, "%s:%d free buf_%lu\n", __func__, __LINE__,
+                       lb->dbg_number);
+
+               list_del(&lb->link);
+               kfree(lb);
+       }
+       spin_unlock_irqrestore(&dev->rx_list.lock, flags);
+
+       dev_dbg(&dev->core, "%s:%d: dequeued buf_%lu, %xh bytes\n",
+               __func__, __LINE__, lb->dbg_number, bytes);
+
+       return 0;
+}
+
+/**
+ * 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_vuart_port_device *dev)
+{
+       int result = 0;
+       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(&dev->tx_list.lock, flags);
+
+       list_for_each_entry_safe(lb, n, &dev->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(&dev->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_vuart_port_device *dev)
+{
+       static unsigned long dbg_number;
+       int result = 0;
+       unsigned long flags;
+       struct list_buffer *lb;
+       unsigned long bytes;
+
+       dev_dbg(&dev->core, "%s:%d\n", __func__, __LINE__);
+
+       result = ps3_vuart_get_rx_bytes_waiting(dev, &bytes);
+
+       if (result)
+               return -EIO;
+
+       BUG_ON(!bytes);
+
+       /* 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;
+
+       spin_lock_irqsave(&dev->rx_list.lock, flags);
+       list_add_tail(&lb->link, &dev->rx_list.head);
+       dev->rx_list.bytes_held += bytes;
+       spin_unlock_irqrestore(&dev->rx_list.lock, flags);
+
+       dev_dbg(&dev->core, "%s:%d: queued buf_%lu, %lxh bytes\n",
+               __func__, __LINE__, lb->dbg_number, bytes);
+
+       return 0;
+}
+
+static int ps3_vuart_handle_interrupt_disconnect(
+       struct ps3_vuart_port_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_vuart_port_device *dev)
+{
+       int result;
+       unsigned long status;
+
+       result = ps3_vuart_get_interrupt_mask(dev, &status);
+
+       if (result)
+               return result;
+
+       dev_dbg(&dev->core, "%s:%d: status: %lxh\n", __func__, __LINE__,
+               status);
+
+       if (status & INTERRUPT_MASK_DISCONNECT) {
+               dev->stats.disconnect_interrupts++;
+               result = ps3_vuart_handle_interrupt_disconnect(dev);
+               if (result)
+                       ps3_vuart_disable_interrupt_disconnect(dev);
+       }
+
+       if (status & INTERRUPT_MASK_TX) {
+               dev->stats.tx_interrupts++;
+               result = ps3_vuart_handle_interrupt_tx(dev);
+               if (result)
+                       ps3_vuart_disable_interrupt_tx(dev);
+       }
+
+       if (status & INTERRUPT_MASK_RX) {
+               dev->stats.rx_interrupts++;
+               result = ps3_vuart_handle_interrupt_rx(dev);
+               if (result)
+                       ps3_vuart_disable_interrupt_rx(dev);
+       }
+
+       return 0;
+}
+
+struct vuart_private {
+       unsigned int in_use;
+       unsigned int virq;
+       struct ps3_vuart_port_device *devices[PORT_COUNT];
+       const struct ports_bmp bmp;
+};
+
+/**
+ * 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_private *private;
+
+       BUG_ON(!_private);
+       private = (struct vuart_private *)_private;
+
+       while (1) {
+               unsigned int port;
+
+               dump_ports_bmp(&private->bmp);
+
+               port = (BITS_PER_LONG - 1) - __ilog2(private->bmp.status);
+
+               if (port == BITS_PER_LONG)
+                       break;
+
+               BUG_ON(port >= PORT_COUNT);
+               BUG_ON(!private->devices[port]);
+
+               ps3_vuart_handle_port_interrupt(private->devices[port]);
+       }
+
+       return IRQ_HANDLED;
+}
+
+static int ps3_vuart_match(struct device *_dev, struct device_driver *_drv)
+{
+       int result;
+       struct ps3_vuart_port_driver *drv = to_ps3_vuart_port_driver(_drv);
+       struct ps3_vuart_port_device *dev = to_ps3_vuart_port_device(_dev);
+
+       result = dev->match_id == drv->match_id;
+
+       dev_info(&dev->core, "%s:%d: dev=%u(%s), drv=%u(%s): %s\n", __func__,
+               __LINE__, dev->match_id, dev->core.bus_id, drv->match_id,
+               drv->core.name, (result ? "match" : "miss"));
+
+       return result;
+}
+
+static struct vuart_private vuart_private;
+
+static int ps3_vuart_probe(struct device *_dev)
+{
+       int result;
+       unsigned long tmp;
+       struct ps3_vuart_port_device *dev = to_ps3_vuart_port_device(_dev);
+       struct ps3_vuart_port_driver *drv =
+               to_ps3_vuart_port_driver(_dev->driver);
+
+       dev_dbg(&dev->core, "%s:%d\n", __func__, __LINE__);
+
+       BUG_ON(!drv);
+
+       result = ps3_vuart_match_id_to_port(dev->match_id, &dev->port_number);
+
+       if (result) {
+               dev_dbg(&dev->core, "%s:%d: unknown match_id (%d)\n",
+                       __func__, __LINE__, dev->match_id);
+               result = -EINVAL;
+               goto fail_match;
+       }
+
+       if (vuart_private.devices[dev->port_number]) {
+               dev_dbg(&dev->core, "%s:%d: port busy (%d)\n", __func__,
+                       __LINE__, dev->port_number);
+               result = -EBUSY;
+               goto fail_match;
+       }
+
+       vuart_private.devices[dev->port_number] = dev;
+
+       INIT_LIST_HEAD(&dev->tx_list.head);
+       spin_lock_init(&dev->tx_list.lock);
+       INIT_LIST_HEAD(&dev->rx_list.head);
+       spin_lock_init(&dev->rx_list.lock);
+
+       vuart_private.in_use++;
+       if (vuart_private.in_use == 1) {
+               result = ps3_alloc_vuart_irq((void*)&vuart_private.bmp.status,
+                       &vuart_private.virq);
+
+               if (result) {
+                       dev_dbg(&dev->core,
+                               "%s:%d: ps3_alloc_vuart_irq failed (%d)\n",
+                               __func__, __LINE__, result);
+                       result = -EPERM;
+                       goto fail_alloc_irq;
+               }
+
+               result = request_irq(vuart_private.virq, ps3_vuart_irq_handler,
+                       IRQF_DISABLED, "vuart", &vuart_private);
+
+               if (result) {
+                       dev_info(&dev->core, "%s:%d: request_irq failed (%d)\n",
+                               __func__, __LINE__, result);
+                       goto fail_request_irq;
+               }
+       }
+
+       ps3_vuart_set_interrupt_mask(dev, INTERRUPT_MASK_RX);
+
+       /* clear stale pending interrupts */
+       ps3_vuart_get_interrupt_mask(dev, &tmp);
+
+       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;
+       }
+
+       return result;
+
+fail_probe:
+fail_request_irq:
+       vuart_private.in_use--;
+       if (!vuart_private.in_use) {
+               ps3_free_vuart_irq(vuart_private.virq);
+               vuart_private.virq = NO_IRQ;
+       }
+fail_alloc_irq:
+fail_match:
+       dev_dbg(&dev->core, "%s:%d failed\n", __func__, __LINE__);
+       return result;
+}
+
+static int ps3_vuart_remove(struct device *_dev)
+{
+       struct ps3_vuart_port_device *dev = to_ps3_vuart_port_device(_dev);
+       struct ps3_vuart_port_driver *drv =
+               to_ps3_vuart_port_driver(_dev->driver);
+
+       dev_dbg(&dev->core, "%s:%d: %s\n", __func__, __LINE__,
+               dev->core.bus_id);
+
+       BUG_ON(vuart_private.in_use < 1);
+
+       if (drv->remove)
+               drv->remove(dev);
+       else
+               dev_dbg(&dev->core, "%s:%d: %s no remove method\n", __func__,
+                       __LINE__, dev->core.bus_id);
+
+       vuart_private.in_use--;
+
+       if (!vuart_private.in_use) {
+               free_irq(vuart_private.virq, &vuart_private);
+               ps3_free_vuart_irq(vuart_private.virq);
+               vuart_private.virq = NO_IRQ;
+       }
+       return 0;
+}
+
+/**
+ * ps3_vuart - The vuart instance.
+ *
+ * The vuart is managed as a bus that port devices connect to.
+ */
+
+struct bus_type ps3_vuart = {
+        .name = "ps3_vuart",
+       .match = ps3_vuart_match,
+       .probe = ps3_vuart_probe,
+       .remove = ps3_vuart_remove,
+};
+
+int __init ps3_vuart_init(void)
+{
+       int result;
+
+       pr_debug("%s:%d:\n", __func__, __LINE__);
+       result = bus_register(&ps3_vuart);
+       BUG_ON(result);
+       return result;
+}
+
+void __exit ps3_vuart_exit(void)
+{
+       pr_debug("%s:%d:\n", __func__, __LINE__);
+       bus_unregister(&ps3_vuart);
+}
+
+core_initcall(ps3_vuart_init);
+module_exit(ps3_vuart_exit);
+
+/**
+ * ps3_vuart_port_release_device - Remove a vuart port device.
+ */
+
+static void ps3_vuart_port_release_device(struct device *_dev)
+{
+       struct ps3_vuart_port_device *dev = to_ps3_vuart_port_device(_dev);
+#if defined(DEBUG)
+       memset(dev, 0xad, sizeof(struct ps3_vuart_port_device));
+#endif
+       kfree(dev);
+}
+
+/**
+ * ps3_vuart_port_device_register - Add a vuart port device.
+ */
+
+int ps3_vuart_port_device_register(struct ps3_vuart_port_device *dev)
+{
+       int result;
+       static unsigned int dev_count = 1;
+
+       dev->core.parent = NULL;
+       dev->core.bus = &ps3_vuart;
+       dev->core.release = ps3_vuart_port_release_device;
+
+       snprintf(dev->core.bus_id, sizeof(dev->core.bus_id), "vuart_%02x",
+               dev_count++);
+
+       dev_dbg(&dev->core, "%s:%d register\n", __func__, __LINE__);
+
+       result = device_register(&dev->core);
+
+       return result;
+}
+
+EXPORT_SYMBOL_GPL(ps3_vuart_port_device_register);
+
+/**
+ * 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.name);
+       drv->core.bus = &ps3_vuart;
+       result = 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)
+{
+       driver_unregister(&drv->core);
+}
+
+EXPORT_SYMBOL_GPL(ps3_vuart_port_driver_unregister);