diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index 8437172..e0685a5 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -190,7 +190,6 @@
 	  To compile this driver as a module, choose M here: the module
 	  will be called 8250_boca.
 
-
 config SERIAL_8250_HUB6
 	tristate "Support Hub6 cards"
 	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
@@ -917,4 +916,12 @@
 		and wish to use the serial ports on this card, say Y.
 		Otherwise, say N.
 
+config SERIAL_SGI_IOC3
+	tristate "SGI Altix IOC3 serial support"
+	depends on (IA64_GENERIC || IA64_SGI_SN2) && SGI_IOC3
+	select SERIAL_CORE
+	help
+	  If you have an SGI Altix with an IOC3 serial card,
+	  say Y or M.  Otherwise, say N.
+
 endmenu
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 24a583e..eaf8e01 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -56,4 +56,5 @@
 obj-$(CONFIG_SERIAL_TXX9) += serial_txx9.o
 obj-$(CONFIG_SERIAL_VR41XX) += vr41xx_siu.o
 obj-$(CONFIG_SERIAL_SGI_IOC4) += ioc4_serial.o
+obj-$(CONFIG_SERIAL_SGI_IOC3) += ioc3_serial.o
 obj-$(CONFIG_SERIAL_AT91) += at91_serial.o
diff --git a/drivers/serial/ioc3_serial.c b/drivers/serial/ioc3_serial.c
new file mode 100644
index 0000000..8097cd9
--- /dev/null
+++ b/drivers/serial/ioc3_serial.c
@@ -0,0 +1,2197 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2005 Silicon Graphics, Inc.  All Rights Reserved.
+ */
+
+/*
+ * This file contains a module version of the ioc3 serial driver. This
+ * includes all the support functions needed (support functions, etc.)
+ * and the serial driver itself.
+ */
+#include <linux/errno.h>
+#include <linux/tty.h>
+#include <linux/serial.h>
+#include <linux/circ_buf.h>
+#include <linux/serial_reg.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/serial_core.h>
+#include <linux/ioc3.h>
+
+/*
+ * Interesting things about the ioc3
+ */
+
+#define LOGICAL_PORTS		2	/* rs232(0) and rs422(1) */
+#define PORTS_PER_CARD		2
+#define LOGICAL_PORTS_PER_CARD (PORTS_PER_CARD * LOGICAL_PORTS)
+#define MAX_CARDS		8
+#define MAX_LOGICAL_PORTS	(LOGICAL_PORTS_PER_CARD * MAX_CARDS)
+
+/* determine given the sio_ir what port it applies to */
+#define GET_PORT_FROM_SIO_IR(_x)	(_x & SIO_IR_SA) ? 0 : 1
+
+
+/*
+ * we have 2 logical ports (rs232, rs422) for each physical port
+ * evens are rs232, odds are rs422
+ */
+#define GET_PHYSICAL_PORT(_x)	((_x) >> 1)
+#define GET_LOGICAL_PORT(_x)	((_x) & 1)
+#define IS_PHYSICAL_PORT(_x)	!((_x) & 1)
+#define IS_RS232(_x)		!((_x) & 1)
+
+static unsigned int Num_of_ioc3_cards;
+static unsigned int Submodule_slot;
+
+/* defining this will get you LOTS of great debug info */
+//#define DEBUG_INTERRUPTS
+#define DPRINT_CONFIG(_x...)	;
+//#define DPRINT_CONFIG(_x...)  printk _x
+#define NOT_PROGRESS()	;
+//#define NOT_PROGRESS()	printk("%s : fails %d\n", __FUNCTION__, __LINE__)
+
+/* number of characters we want to transmit to the lower level at a time */
+#define MAX_CHARS		256
+#define FIFO_SIZE		(MAX_CHARS-1)	/* it's a uchar */
+
+/* Device name we're using */
+#define DEVICE_NAME		"ttySIOC"
+#define DEVICE_MAJOR		204
+#define DEVICE_MINOR		116
+
+/* flags for next_char_state */
+#define NCS_BREAK		0x1
+#define NCS_PARITY		0x2
+#define NCS_FRAMING		0x4
+#define NCS_OVERRUN		0x8
+
+/* cause we need SOME parameters ... */
+#define MIN_BAUD_SUPPORTED	1200
+#define MAX_BAUD_SUPPORTED	115200
+
+/* protocol types supported */
+#define PROTO_RS232		0
+#define PROTO_RS422		1
+
+/* Notification types */
+#define N_DATA_READY		0x01
+#define N_OUTPUT_LOWAT		0x02
+#define N_BREAK			0x04
+#define N_PARITY_ERROR		0x08
+#define N_FRAMING_ERROR		0x10
+#define N_OVERRUN_ERROR		0x20
+#define N_DDCD			0x40
+#define N_DCTS			0x80
+
+#define N_ALL_INPUT		(N_DATA_READY | N_BREAK			   \
+					| N_PARITY_ERROR | N_FRAMING_ERROR \
+					| N_OVERRUN_ERROR | N_DDCD | N_DCTS)
+
+#define N_ALL_OUTPUT		N_OUTPUT_LOWAT
+
+#define N_ALL_ERRORS		(N_PARITY_ERROR | N_FRAMING_ERROR \
+						| N_OVERRUN_ERROR)
+
+#define N_ALL			(N_DATA_READY | N_OUTPUT_LOWAT | N_BREAK    \
+					| N_PARITY_ERROR | N_FRAMING_ERROR  \
+					| N_OVERRUN_ERROR | N_DDCD | N_DCTS)
+
+#define SER_CLK_SPEED(prediv)	((22000000 << 1) / prediv)
+#define SER_DIVISOR(x, clk)	(((clk) + (x) * 8) / ((x) * 16))
+#define DIVISOR_TO_BAUD(div, clk) ((clk) / 16 / (div))
+
+/* Some masks */
+#define LCR_MASK_BITS_CHAR	(UART_LCR_WLEN5 | UART_LCR_WLEN6 \
+					| UART_LCR_WLEN7 | UART_LCR_WLEN8)
+#define LCR_MASK_STOP_BITS	(UART_LCR_STOP)
+
+#define PENDING(_a, _p)		(readl(&(_p)->vma->sio_ir) & (_a)->ic_enable)
+
+#define RING_BUF_SIZE		4096
+#define BUF_SIZE_BIT		SBBR_L_SIZE
+#define PROD_CONS_MASK		PROD_CONS_PTR_4K
+
+#define TOTAL_RING_BUF_SIZE	(RING_BUF_SIZE * 4)
+
+/* driver specific - one per card */
+struct ioc3_card {
+	struct {
+		/* uart ports are allocated here */
+		struct uart_port icp_uart_port[LOGICAL_PORTS];
+		/* the ioc3_port used for this port */
+		struct ioc3_port *icp_port;
+	} ic_port[PORTS_PER_CARD];
+	/* currently enabled interrupts */
+	uint32_t ic_enable;
+};
+
+/* Local port info for each IOC3 serial port */
+struct ioc3_port {
+	/* handy reference material */
+	struct uart_port *ip_port;
+	struct ioc3_card *ip_card;
+	struct ioc3_driver_data *ip_idd;
+	struct ioc3_submodule *ip_is;
+
+	/* pci mem addresses for this port */
+	struct ioc3_serialregs __iomem *ip_serial_regs;
+	struct ioc3_uartregs __iomem *ip_uart_regs;
+
+	/* Ring buffer page for this port */
+	dma_addr_t ip_dma_ringbuf;
+	/* vaddr of ring buffer */
+	struct ring_buffer *ip_cpu_ringbuf;
+
+	/* Rings for this port */
+	struct ring *ip_inring;
+	struct ring *ip_outring;
+
+	/* Hook to port specific values */
+	struct port_hooks *ip_hooks;
+
+	spinlock_t ip_lock;
+
+	/* Various rx/tx parameters */
+	int ip_baud;
+	int ip_tx_lowat;
+	int ip_rx_timeout;
+
+	/* Copy of notification bits */
+	int ip_notify;
+
+	/* Shadow copies of various registers so we don't need to PIO
+	 * read them constantly
+	 */
+	uint32_t ip_sscr;
+	uint32_t ip_tx_prod;
+	uint32_t ip_rx_cons;
+	unsigned char ip_flags;
+};
+
+/* tx low water mark.  We need to notify the driver whenever tx is getting
+ * close to empty so it can refill the tx buffer and keep things going.
+ * Let's assume that if we interrupt 1 ms before the tx goes idle, we'll
+ * have no trouble getting in more chars in time (I certainly hope so).
+ */
+#define TX_LOWAT_LATENCY      1000
+#define TX_LOWAT_HZ          (1000000 / TX_LOWAT_LATENCY)
+#define TX_LOWAT_CHARS(baud) (baud / 10 / TX_LOWAT_HZ)
+
+/* Flags per port */
+#define INPUT_HIGH		0x01
+	/* used to signify that we have turned off the rx_high
+	 * temporarily - we need to drain the fifo and don't
+	 * want to get blasted with interrupts.
+	 */
+#define DCD_ON			0x02
+	/* DCD state is on */
+#define LOWAT_WRITTEN		0x04
+#define READ_ABORTED		0x08
+	/* the read was aborted - used to avaoid infinate looping
+	 * in the interrupt handler
+	 */
+#define INPUT_ENABLE		0x10
+
+/* Since each port has different register offsets and bitmasks
+ * for everything, we'll store those that we need in tables so we
+ * don't have to be constantly checking the port we are dealing with.
+ */
+struct port_hooks {
+	uint32_t intr_delta_dcd;
+	uint32_t intr_delta_cts;
+	uint32_t intr_tx_mt;
+	uint32_t intr_rx_timer;
+	uint32_t intr_rx_high;
+	uint32_t intr_tx_explicit;
+	uint32_t intr_clear;
+	uint32_t intr_all;
+	char rs422_select_pin;
+};
+
+static struct port_hooks hooks_array[PORTS_PER_CARD] = {
+	/* values for port A */
+	{
+	.intr_delta_dcd = SIO_IR_SA_DELTA_DCD,
+	.intr_delta_cts = SIO_IR_SA_DELTA_CTS,
+	.intr_tx_mt = SIO_IR_SA_TX_MT,
+	.intr_rx_timer = SIO_IR_SA_RX_TIMER,
+	.intr_rx_high = SIO_IR_SA_RX_HIGH,
+	.intr_tx_explicit = SIO_IR_SA_TX_EXPLICIT,
+	.intr_clear = (SIO_IR_SA_TX_MT | SIO_IR_SA_RX_FULL
+				| SIO_IR_SA_RX_HIGH
+				| SIO_IR_SA_RX_TIMER
+				| SIO_IR_SA_DELTA_DCD
+				| SIO_IR_SA_DELTA_CTS
+				| SIO_IR_SA_INT
+				| SIO_IR_SA_TX_EXPLICIT
+				| SIO_IR_SA_MEMERR),
+	.intr_all =  SIO_IR_SA,
+	.rs422_select_pin = GPPR_UARTA_MODESEL_PIN,
+	 },
+
+	/* values for port B */
+	{
+	.intr_delta_dcd = SIO_IR_SB_DELTA_DCD,
+	.intr_delta_cts = SIO_IR_SB_DELTA_CTS,
+	.intr_tx_mt = SIO_IR_SB_TX_MT,
+	.intr_rx_timer = SIO_IR_SB_RX_TIMER,
+	.intr_rx_high = SIO_IR_SB_RX_HIGH,
+	.intr_tx_explicit = SIO_IR_SB_TX_EXPLICIT,
+	.intr_clear = (SIO_IR_SB_TX_MT | SIO_IR_SB_RX_FULL
+				| SIO_IR_SB_RX_HIGH
+				| SIO_IR_SB_RX_TIMER
+				| SIO_IR_SB_DELTA_DCD
+				| SIO_IR_SB_DELTA_CTS
+				| SIO_IR_SB_INT
+				| SIO_IR_SB_TX_EXPLICIT
+				| SIO_IR_SB_MEMERR),
+	.intr_all = SIO_IR_SB,
+	.rs422_select_pin = GPPR_UARTB_MODESEL_PIN,
+	 }
+};
+
+struct ring_entry {
+	union {
+		struct {
+			uint32_t alldata;
+			uint32_t allsc;
+		} all;
+		struct {
+			char data[4];	/* data bytes */
+			char sc[4];	/* status/control */
+		} s;
+	} u;
+};
+
+/* Test the valid bits in any of the 4 sc chars using "allsc" member */
+#define RING_ANY_VALID \
+	((uint32_t)(RXSB_MODEM_VALID | RXSB_DATA_VALID) * 0x01010101)
+
+#define ring_sc		u.s.sc
+#define ring_data	u.s.data
+#define ring_allsc	u.all.allsc
+
+/* Number of entries per ring buffer. */
+#define ENTRIES_PER_RING (RING_BUF_SIZE / (int) sizeof(struct ring_entry))
+
+/* An individual ring */
+struct ring {
+	struct ring_entry entries[ENTRIES_PER_RING];
+};
+
+/* The whole enchilada */
+struct ring_buffer {
+	struct ring TX_A;
+	struct ring RX_A;
+	struct ring TX_B;
+	struct ring RX_B;
+};
+
+/* Get a ring from a port struct */
+#define RING(_p, _wh)	&(((struct ring_buffer *)((_p)->ip_cpu_ringbuf))->_wh)
+
+/* for Infinite loop detection  */
+#define MAXITER		10000000
+
+
+/**
+ * set_baud - Baud rate setting code
+ * @port: port to set
+ * @baud: baud rate to use
+ */
+static int set_baud(struct ioc3_port *port, int baud)
+{
+	int divisor;
+	int actual_baud;
+	int diff;
+	int lcr, prediv;
+	struct ioc3_uartregs __iomem *uart;
+
+	for (prediv = 6; prediv < 64; prediv++) {
+		divisor = SER_DIVISOR(baud, SER_CLK_SPEED(prediv));
+		if (!divisor)
+			continue;	/* invalid divisor */
+		actual_baud = DIVISOR_TO_BAUD(divisor, SER_CLK_SPEED(prediv));
+
+		diff = actual_baud - baud;
+		if (diff < 0)
+			diff = -diff;
+
+		/* if we're within 1% we've found a match */
+		if (diff * 100 <= actual_baud)
+			break;
+	}
+
+	/* if the above loop completed, we didn't match
+	 * the baud rate.  give up.
+	 */
+	if (prediv == 64) {
+		NOT_PROGRESS();
+		return 1;
+	}
+
+	uart = port->ip_uart_regs;
+	lcr = readb(&uart->iu_lcr);
+
+	writeb(lcr | UART_LCR_DLAB, &uart->iu_lcr);
+	writeb((unsigned char)divisor, &uart->iu_dll);
+	writeb((unsigned char)(divisor >> 8), &uart->iu_dlm);
+	writeb((unsigned char)prediv, &uart->iu_scr);
+	writeb((unsigned char)lcr, &uart->iu_lcr);
+
+	return 0;
+}
+
+/**
+ * get_ioc3_port - given a uart port, return the control structure
+ * @the_port: uart port to find
+ */
+static struct ioc3_port *get_ioc3_port(struct uart_port *the_port)
+{
+	struct ioc3_driver_data *idd = dev_get_drvdata(the_port->dev);
+	struct ioc3_card *card_ptr = idd->data[Submodule_slot];
+	int ii, jj;
+
+	if (!card_ptr) {
+		NOT_PROGRESS();
+		return NULL;
+	}
+	for (ii = 0; ii < PORTS_PER_CARD; ii++) {
+		for (jj = 0; jj < LOGICAL_PORTS; jj++) {
+			if (the_port == &card_ptr->ic_port[ii].icp_uart_port[jj])
+				return card_ptr->ic_port[ii].icp_port;
+		}
+	}
+	NOT_PROGRESS();
+	return NULL;
+}
+
+/**
+ * port_init - Initialize the sio and ioc3 hardware for a given port
+ *			called per port from attach...
+ * @port: port to initialize
+ */
+static int inline port_init(struct ioc3_port *port)
+{
+	uint32_t sio_cr;
+	struct port_hooks *hooks = port->ip_hooks;
+	struct ioc3_uartregs __iomem *uart;
+	int reset_loop_counter = 0xfffff;
+	struct ioc3_driver_data *idd = port->ip_idd;
+
+	/* Idle the IOC3 serial interface */
+	writel(SSCR_RESET, &port->ip_serial_regs->sscr);
+
+	/* Wait until any pending bus activity for this port has ceased */
+	do {
+		sio_cr = readl(&idd->vma->sio_cr);
+		if (reset_loop_counter-- <= 0) {
+			printk(KERN_WARNING
+			       "IOC3 unable to come out of reset"
+				" scr 0x%x\n", sio_cr);
+			return -1;
+		}
+	} while (!(sio_cr & SIO_CR_ARB_DIAG_IDLE) &&
+	       (((sio_cr &= SIO_CR_ARB_DIAG) == SIO_CR_ARB_DIAG_TXA)
+		|| sio_cr == SIO_CR_ARB_DIAG_TXB
+		|| sio_cr == SIO_CR_ARB_DIAG_RXA
+		|| sio_cr == SIO_CR_ARB_DIAG_RXB));
+
+	/* Finish reset sequence */
+	writel(0, &port->ip_serial_regs->sscr);
+
+	/* Once RESET is done, reload cached tx_prod and rx_cons values
+	 * and set rings to empty by making prod == cons
+	 */
+	port->ip_tx_prod = readl(&port->ip_serial_regs->stcir) & PROD_CONS_MASK;
+	writel(port->ip_tx_prod, &port->ip_serial_regs->stpir);
+	port->ip_rx_cons = readl(&port->ip_serial_regs->srpir) & PROD_CONS_MASK;
+	writel(port->ip_rx_cons | SRCIR_ARM, &port->ip_serial_regs->srcir);
+
+	/* Disable interrupts for this 16550 */
+	uart = port->ip_uart_regs;
+	writeb(0, &uart->iu_lcr);
+	writeb(0, &uart->iu_ier);
+
+	/* Set the default baud */
+	set_baud(port, port->ip_baud);
+
+	/* Set line control to 8 bits no parity */
+	writeb(UART_LCR_WLEN8 | 0, &uart->iu_lcr);
+	/* UART_LCR_STOP == 1 stop */
+
+	/* Enable the FIFOs */
+	writeb(UART_FCR_ENABLE_FIFO, &uart->iu_fcr);
+	/* then reset 16550 FIFOs */
+	writeb(UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT,
+	       &uart->iu_fcr);
+
+	/* Clear modem control register */
+	writeb(0, &uart->iu_mcr);
+
+	/* Clear deltas in modem status register */
+	writel(0, &port->ip_serial_regs->shadow);
+
+	/* Only do this once per port pair */
+	if (port->ip_hooks == &hooks_array[0]) {
+		unsigned long ring_pci_addr;
+		uint32_t __iomem *sbbr_l, *sbbr_h;
+
+		sbbr_l = &idd->vma->sbbr_l;
+		sbbr_h = &idd->vma->sbbr_h;
+		ring_pci_addr = (unsigned long __iomem)port->ip_dma_ringbuf;
+		DPRINT_CONFIG(("%s: ring_pci_addr 0x%p\n",
+			       __FUNCTION__, (void *)ring_pci_addr));
+
+		writel((unsigned int)((uint64_t) ring_pci_addr >> 32), sbbr_h);
+		writel((unsigned int)ring_pci_addr | BUF_SIZE_BIT, sbbr_l);
+	}
+
+	/* Set the receive timeout value to 10 msec */
+	writel(SRTR_HZ / 100, &port->ip_serial_regs->srtr);
+
+	/* Set rx threshold, enable DMA */
+	/* Set high water mark at 3/4 of full ring */
+	port->ip_sscr = (ENTRIES_PER_RING * 3 / 4);
+
+	/* uart experiences pauses at high baud rate reducing actual
+	 * throughput by 10% or so unless we enable high speed polling
+	 * XXX when this hardware bug is resolved we should revert to
+	 * normal polling speed
+	 */
+	port->ip_sscr |= SSCR_HIGH_SPD;
+
+	writel(port->ip_sscr, &port->ip_serial_regs->sscr);
+
+	/* Disable and clear all serial related interrupt bits */
+	port->ip_card->ic_enable &= ~hooks->intr_clear;
+	ioc3_disable(port->ip_is, idd, hooks->intr_clear);
+	ioc3_ack(port->ip_is, idd, hooks->intr_clear);
+	return 0;
+}
+
+/**
+ * enable_intrs - enable interrupts
+ * @port: port to enable
+ * @mask: mask to use
+ */
+static void enable_intrs(struct ioc3_port *port, uint32_t mask)
+{
+	if ((port->ip_card->ic_enable & mask) != mask) {
+		port->ip_card->ic_enable |= mask;
+		ioc3_enable(port->ip_is, port->ip_idd, mask);
+	}
+}
+
+/**
+ * local_open - local open a port
+ * @port: port to open
+ */
+static inline int local_open(struct ioc3_port *port)
+{
+	int spiniter = 0;
+
+	port->ip_flags = INPUT_ENABLE;
+
+	/* Pause the DMA interface if necessary */
+	if (port->ip_sscr & SSCR_DMA_EN) {
+		writel(port->ip_sscr | SSCR_DMA_PAUSE,
+		       &port->ip_serial_regs->sscr);
+		while ((readl(&port->ip_serial_regs->sscr)
+			& SSCR_PAUSE_STATE) == 0) {
+			spiniter++;
+			if (spiniter > MAXITER) {
+				NOT_PROGRESS();
+				return -1;
+			}
+		}
+	}
+
+	/* Reset the input fifo.  If the uart received chars while the port
+	 * was closed and DMA is not enabled, the uart may have a bunch of
+	 * chars hanging around in its rx fifo which will not be discarded
+	 * by rclr in the upper layer. We must get rid of them here.
+	 */
+	writeb(UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR,
+	       &port->ip_uart_regs->iu_fcr);
+
+	writeb(UART_LCR_WLEN8, &port->ip_uart_regs->iu_lcr);
+	/* UART_LCR_STOP == 1 stop */
+
+	/* Re-enable DMA, set default threshold to intr whenever there is
+	 * data available.
+	 */
+	port->ip_sscr &= ~SSCR_RX_THRESHOLD;
+	port->ip_sscr |= 1;	/* default threshold */
+
+	/* Plug in the new sscr.  This implicitly clears the DMA_PAUSE
+	 * flag if it was set above
+	 */
+	writel(port->ip_sscr, &port->ip_serial_regs->sscr);
+	port->ip_tx_lowat = 1;
+	return 0;
+}
+
+/**
+ * set_rx_timeout - Set rx timeout and threshold values.
+ * @port: port to use
+ * @timeout: timeout value in ticks
+ */
+static inline int set_rx_timeout(struct ioc3_port *port, int timeout)
+{
+	int threshold;
+
+	port->ip_rx_timeout = timeout;
+
+	/* Timeout is in ticks.  Let's figure out how many chars we
+	 * can receive at the current baud rate in that interval
+	 * and set the rx threshold to that amount.  There are 4 chars
+	 * per ring entry, so we'll divide the number of chars that will
+	 * arrive in timeout by 4.
+	 * So .... timeout * baud / 10 / HZ / 4, with HZ = 100.
+	 */
+	threshold = timeout * port->ip_baud / 4000;
+	if (threshold == 0)
+		threshold = 1;	/* otherwise we'll intr all the time! */
+
+	if ((unsigned)threshold > (unsigned)SSCR_RX_THRESHOLD)
+		return 1;
+
+	port->ip_sscr &= ~SSCR_RX_THRESHOLD;
+	port->ip_sscr |= threshold;
+	writel(port->ip_sscr, &port->ip_serial_regs->sscr);
+
+	/* Now set the rx timeout to the given value
+	 * again timeout * SRTR_HZ / HZ
+	 */
+	timeout = timeout * SRTR_HZ / 100;
+	if (timeout > SRTR_CNT)
+		timeout = SRTR_CNT;
+	writel(timeout, &port->ip_serial_regs->srtr);
+	return 0;
+}
+
+/**
+ * config_port - config the hardware
+ * @port: port to config
+ * @baud: baud rate for the port
+ * @byte_size: data size
+ * @stop_bits: number of stop bits
+ * @parenb: parity enable ?
+ * @parodd: odd parity ?
+ */
+static inline int
+config_port(struct ioc3_port *port,
+	    int baud, int byte_size, int stop_bits, int parenb, int parodd)
+{
+	char lcr, sizebits;
+	int spiniter = 0;
+
+	DPRINT_CONFIG(("%s: line %d baud %d byte_size %d stop %d parenb %d "
+			"parodd %d\n",
+		       __FUNCTION__, ((struct uart_port *)port->ip_port)->line,
+			baud, byte_size, stop_bits, parenb, parodd));
+
+	if (set_baud(port, baud))
+		return 1;
+
+	switch (byte_size) {
+	case 5:
+		sizebits = UART_LCR_WLEN5;
+		break;
+	case 6:
+		sizebits = UART_LCR_WLEN6;
+		break;
+	case 7:
+		sizebits = UART_LCR_WLEN7;
+		break;
+	case 8:
+		sizebits = UART_LCR_WLEN8;
+		break;
+	default:
+		return 1;
+	}
+
+	/* Pause the DMA interface if necessary */
+	if (port->ip_sscr & SSCR_DMA_EN) {
+		writel(port->ip_sscr | SSCR_DMA_PAUSE,
+		       &port->ip_serial_regs->sscr);
+		while ((readl(&port->ip_serial_regs->sscr)
+			& SSCR_PAUSE_STATE) == 0) {
+			spiniter++;
+			if (spiniter > MAXITER)
+				return -1;
+		}
+	}
+
+	/* Clear relevant fields in lcr */
+	lcr = readb(&port->ip_uart_regs->iu_lcr);
+	lcr &= ~(LCR_MASK_BITS_CHAR | UART_LCR_EPAR |
+		 UART_LCR_PARITY | LCR_MASK_STOP_BITS);
+
+	/* Set byte size in lcr */
+	lcr |= sizebits;
+
+	/* Set parity */
+	if (parenb) {
+		lcr |= UART_LCR_PARITY;
+		if (!parodd)
+			lcr |= UART_LCR_EPAR;
+	}
+
+	/* Set stop bits */
+	if (stop_bits)
+		lcr |= UART_LCR_STOP /* 2 stop bits */ ;
+
+	writeb(lcr, &port->ip_uart_regs->iu_lcr);
+
+	/* Re-enable the DMA interface if necessary */
+	if (port->ip_sscr & SSCR_DMA_EN) {
+		writel(port->ip_sscr, &port->ip_serial_regs->sscr);
+	}
+	port->ip_baud = baud;
+
+	/* When we get within this number of ring entries of filling the
+	 * entire ring on tx, place an EXPLICIT intr to generate a lowat
+	 * notification when output has drained.
+	 */
+	port->ip_tx_lowat = (TX_LOWAT_CHARS(baud) + 3) / 4;
+	if (port->ip_tx_lowat == 0)
+		port->ip_tx_lowat = 1;
+
+	set_rx_timeout(port, 2);
+	return 0;
+}
+
+/**
+ * do_write - Write bytes to the port.  Returns the number of bytes
+ *			actually written. Called from transmit_chars
+ * @port: port to use
+ * @buf: the stuff to write
+ * @len: how many bytes in 'buf'
+ */
+static inline int do_write(struct ioc3_port *port, char *buf, int len)
+{
+	int prod_ptr, cons_ptr, total = 0;
+	struct ring *outring;
+	struct ring_entry *entry;
+	struct port_hooks *hooks = port->ip_hooks;
+
+	BUG_ON(!(len >= 0));
+
+	prod_ptr = port->ip_tx_prod;
+	cons_ptr = readl(&port->ip_serial_regs->stcir) & PROD_CONS_MASK;
+	outring = port->ip_outring;
+
+	/* Maintain a 1-entry red-zone.  The ring buffer is full when
+	 * (cons - prod) % ring_size is 1.  Rather than do this subtraction
+	 * in the body of the loop, I'll do it now.
+	 */
+	cons_ptr = (cons_ptr - (int)sizeof(struct ring_entry)) & PROD_CONS_MASK;
+
+	/* Stuff the bytes into the output */
+	while ((prod_ptr != cons_ptr) && (len > 0)) {
+		int xx;
+
+		/* Get 4 bytes (one ring entry) at a time */
+		entry = (struct ring_entry *)((caddr_t) outring + prod_ptr);
+
+		/* Invalidate all entries */
+		entry->ring_allsc = 0;
+
+		/* Copy in some bytes */
+		for (xx = 0; (xx < 4) && (len > 0); xx++) {
+			entry->ring_data[xx] = *buf++;
+			entry->ring_sc[xx] = TXCB_VALID;
+			len--;
+			total++;
+		}
+
+		/* If we are within some small threshold of filling up the
+		 * entire ring buffer, we must place an EXPLICIT intr here
+		 * to generate a lowat interrupt in case we subsequently
+		 * really do fill up the ring and the caller goes to sleep.
+		 * No need to place more than one though.
+		 */
+		if (!(port->ip_flags & LOWAT_WRITTEN) &&
+		    ((cons_ptr - prod_ptr) & PROD_CONS_MASK)
+		    <= port->ip_tx_lowat * (int)sizeof(struct ring_entry)) {
+			port->ip_flags |= LOWAT_WRITTEN;
+			entry->ring_sc[0] |= TXCB_INT_WHEN_DONE;
+		}
+
+		/* Go on to next entry */
+		prod_ptr += sizeof(struct ring_entry);
+		prod_ptr &= PROD_CONS_MASK;
+	}
+
+	/* If we sent something, start DMA if necessary */
+	if (total > 0 && !(port->ip_sscr & SSCR_DMA_EN)) {
+		port->ip_sscr |= SSCR_DMA_EN;
+		writel(port->ip_sscr, &port->ip_serial_regs->sscr);
+	}
+
+	/* Store the new producer pointer.  If tx is disabled, we stuff the
+	 * data into the ring buffer, but we don't actually start tx.
+	 */
+	if (!uart_tx_stopped(port->ip_port)) {
+		writel(prod_ptr, &port->ip_serial_regs->stpir);
+
+		/* If we are now transmitting, enable tx_mt interrupt so we
+		 * can disable DMA if necessary when the tx finishes.
+		 */
+		if (total > 0)
+			enable_intrs(port, hooks->intr_tx_mt);
+	}
+	port->ip_tx_prod = prod_ptr;
+
+	return total;
+}
+
+/**
+ * disable_intrs - disable interrupts
+ * @port: port to enable
+ * @mask: mask to use
+ */
+static inline void disable_intrs(struct ioc3_port *port, uint32_t mask)
+{
+	if (port->ip_card->ic_enable & mask) {
+		ioc3_disable(port->ip_is, port->ip_idd, mask);
+		port->ip_card->ic_enable &= ~mask;
+	}
+}
+
+/**
+ * set_notification - Modify event notification
+ * @port: port to use
+ * @mask: events mask
+ * @set_on: set ?
+ */
+static int set_notification(struct ioc3_port *port, int mask, int set_on)
+{
+	struct port_hooks *hooks = port->ip_hooks;
+	uint32_t intrbits, sscrbits;
+
+	BUG_ON(!mask);
+
+	intrbits = sscrbits = 0;
+
+	if (mask & N_DATA_READY)
+		intrbits |= (hooks->intr_rx_timer | hooks->intr_rx_high);
+	if (mask & N_OUTPUT_LOWAT)
+		intrbits |= hooks->intr_tx_explicit;
+	if (mask & N_DDCD) {
+		intrbits |= hooks->intr_delta_dcd;
+		sscrbits |= SSCR_RX_RING_DCD;
+	}
+	if (mask & N_DCTS)
+		intrbits |= hooks->intr_delta_cts;
+
+	if (set_on) {
+		enable_intrs(port, intrbits);
+		port->ip_notify |= mask;
+		port->ip_sscr |= sscrbits;
+	} else {
+		disable_intrs(port, intrbits);
+		port->ip_notify &= ~mask;
+		port->ip_sscr &= ~sscrbits;
+	}
+
+	/* We require DMA if either DATA_READY or DDCD notification is
+	 * currently requested. If neither of these is requested and
+	 * there is currently no tx in progress, DMA may be disabled.
+	 */
+	if (port->ip_notify & (N_DATA_READY | N_DDCD))
+		port->ip_sscr |= SSCR_DMA_EN;
+	else if (!(port->ip_card->ic_enable & hooks->intr_tx_mt))
+		port->ip_sscr &= ~SSCR_DMA_EN;
+
+	writel(port->ip_sscr, &port->ip_serial_regs->sscr);
+	return 0;
+}
+
+/**
+ * set_mcr - set the master control reg
+ * @the_port: port to use
+ * @mask1: mcr mask
+ * @mask2: shadow mask
+ */
+static inline int set_mcr(struct uart_port *the_port,
+			  int mask1, int mask2)
+{
+	struct ioc3_port *port = get_ioc3_port(the_port);
+	uint32_t shadow;
+	int spiniter = 0;
+	char mcr;
+
+	if (!port)
+		return -1;
+
+	/* Pause the DMA interface if necessary */
+	if (port->ip_sscr & SSCR_DMA_EN) {
+		writel(port->ip_sscr | SSCR_DMA_PAUSE,
+		       &port->ip_serial_regs->sscr);
+		while ((readl(&port->ip_serial_regs->sscr)
+			& SSCR_PAUSE_STATE) == 0) {
+			spiniter++;
+			if (spiniter > MAXITER)
+				return -1;
+		}
+	}
+	shadow = readl(&port->ip_serial_regs->shadow);
+	mcr = (shadow & 0xff000000) >> 24;
+
+	/* Set new value */
+	mcr |= mask1;
+	shadow |= mask2;
+	writeb(mcr, &port->ip_uart_regs->iu_mcr);
+	writel(shadow, &port->ip_serial_regs->shadow);
+
+	/* Re-enable the DMA interface if necessary */
+	if (port->ip_sscr & SSCR_DMA_EN) {
+		writel(port->ip_sscr, &port->ip_serial_regs->sscr);
+	}
+	return 0;
+}
+
+/**
+ * ioc3_set_proto - set the protocol for the port
+ * @port: port to use
+ * @proto: protocol to use
+ */
+static int ioc3_set_proto(struct ioc3_port *port, int proto)
+{
+	struct port_hooks *hooks = port->ip_hooks;
+
+	switch (proto) {
+	default:
+	case PROTO_RS232:
+		/* Clear the appropriate GIO pin */
+		DPRINT_CONFIG(("%s: rs232\n", __FUNCTION__));
+		writel(0, (&port->ip_idd->vma->gppr[0]
+					+ hooks->rs422_select_pin));
+		break;
+
+	case PROTO_RS422:
+		/* Set the appropriate GIO pin */
+		DPRINT_CONFIG(("%s: rs422\n", __FUNCTION__));
+		writel(1, (&port->ip_idd->vma->gppr[0]
+					+ hooks->rs422_select_pin));
+		break;
+	}
+	return 0;
+}
+
+/**
+ * transmit_chars - upper level write, called with the_port->lock
+ * @the_port: port to write
+ */
+static void transmit_chars(struct uart_port *the_port)
+{
+	int xmit_count, tail, head;
+	int result;
+	char *start;
+	struct tty_struct *tty;
+	struct ioc3_port *port = get_ioc3_port(the_port);
+	struct uart_info *info;
+
+	if (!the_port)
+		return;
+	if (!port)
+		return;
+
+	info = the_port->info;
+	tty = info->tty;
+
+	if (uart_circ_empty(&info->xmit) || uart_tx_stopped(the_port)) {
+		/* Nothing to do or hw stopped */
+		set_notification(port, N_ALL_OUTPUT, 0);
+		return;
+	}
+
+	head = info->xmit.head;
+	tail = info->xmit.tail;
+	start = (char *)&info->xmit.buf[tail];
+
+	/* write out all the data or until the end of the buffer */
+	xmit_count = (head < tail) ? (UART_XMIT_SIZE - tail) : (head - tail);
+	if (xmit_count > 0) {
+		result = do_write(port, start, xmit_count);
+		if (result > 0) {
+			/* booking */
+			xmit_count -= result;
+			the_port->icount.tx += result;
+			/* advance the pointers */
+			tail += result;
+			tail &= UART_XMIT_SIZE - 1;
+			info->xmit.tail = tail;
+			start = (char *)&info->xmit.buf[tail];
+		}
+	}
+	if (uart_circ_chars_pending(&info->xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(the_port);
+
+	if (uart_circ_empty(&info->xmit)) {
+		set_notification(port, N_OUTPUT_LOWAT, 0);
+	} else {
+		set_notification(port, N_OUTPUT_LOWAT, 1);
+	}
+}
+
+/**
+ * ioc3_change_speed - change the speed of the port
+ * @the_port: port to change
+ * @new_termios: new termios settings
+ * @old_termios: old termios settings
+ */
+static void
+ioc3_change_speed(struct uart_port *the_port,
+		  struct termios *new_termios, struct termios *old_termios)
+{
+	struct ioc3_port *port = get_ioc3_port(the_port);
+	unsigned int cflag;
+	int baud;
+	int new_parity = 0, new_parity_enable = 0, new_stop = 0, new_data = 8;
+	struct uart_info *info = the_port->info;
+
+	cflag = new_termios->c_cflag;
+
+	switch (cflag & CSIZE) {
+	case CS5:
+		new_data = 5;
+		break;
+	case CS6:
+		new_data = 6;
+		break;
+	case CS7:
+		new_data = 7;
+		break;
+	case CS8:
+		new_data = 8;
+		break;
+	default:
+		/* cuz we always need a default ... */
+		new_data = 5;
+		break;
+	}
+	if (cflag & CSTOPB) {
+		new_stop = 1;
+	}
+	if (cflag & PARENB) {
+		new_parity_enable = 1;
+		if (cflag & PARODD)
+			new_parity = 1;
+	}
+	baud = uart_get_baud_rate(the_port, new_termios, old_termios,
+				  MIN_BAUD_SUPPORTED, MAX_BAUD_SUPPORTED);
+	DPRINT_CONFIG(("%s: returned baud %d for line %d\n", __FUNCTION__, baud,
+				the_port->line));
+
+	if (!the_port->fifosize)
+		the_port->fifosize = FIFO_SIZE;
+	uart_update_timeout(the_port, cflag, baud);
+
+	the_port->ignore_status_mask = N_ALL_INPUT;
+
+	info->tty->low_latency = 1;
+
+	if (I_IGNPAR(info->tty))
+		the_port->ignore_status_mask &= ~(N_PARITY_ERROR
+						  | N_FRAMING_ERROR);
+	if (I_IGNBRK(info->tty)) {
+		the_port->ignore_status_mask &= ~N_BREAK;
+		if (I_IGNPAR(info->tty))
+			the_port->ignore_status_mask &= ~N_OVERRUN_ERROR;
+	}
+	if (!(cflag & CREAD)) {
+		/* ignore everything */
+		the_port->ignore_status_mask &= ~N_DATA_READY;
+	}
+
+	if (cflag & CRTSCTS) {
+		/* enable hardware flow control */
+		port->ip_sscr |= SSCR_HFC_EN;
+	}
+	else {
+		/* disable hardware flow control */
+		port->ip_sscr &= ~SSCR_HFC_EN;
+	}
+	writel(port->ip_sscr, &port->ip_serial_regs->sscr);
+
+	/* Set the configuration and proper notification call */
+	DPRINT_CONFIG(("%s : port 0x%p line %d cflag 0%o "
+		       "config_port(baud %d data %d stop %d penable %d "
+			" parity %d), notification 0x%x\n",
+		       __FUNCTION__, (void *)port, the_port->line, cflag, baud,
+		       new_data, new_stop, new_parity_enable, new_parity,
+		       the_port->ignore_status_mask));
+
+	if ((config_port(port, baud,	/* baud */
+			 new_data,	/* byte size */
+			 new_stop,	/* stop bits */
+			 new_parity_enable,	/* set parity */
+			 new_parity)) >= 0) {	/* parity 1==odd */
+		set_notification(port, the_port->ignore_status_mask, 1);
+	}
+}
+
+/**
+ * ic3_startup_local - Start up the serial port - returns >= 0 if no errors
+ * @the_port: Port to operate on
+ */
+static inline int ic3_startup_local(struct uart_port *the_port)
+{
+	struct ioc3_port *port;
+
+	if (!the_port) {
+		NOT_PROGRESS();
+		return -1;
+	}
+
+	port = get_ioc3_port(the_port);
+	if (!port) {
+		NOT_PROGRESS();
+		return -1;
+	}
+
+	local_open(port);
+
+	/* set the protocol */
+	ioc3_set_proto(port, IS_RS232(the_port->line) ? PROTO_RS232 :
+							PROTO_RS422);
+	return 0;
+}
+
+/*
+ * ioc3_cb_output_lowat - called when the output low water mark is hit
+ * @port: port to output
+ */
+static void ioc3_cb_output_lowat(struct ioc3_port *port)
+{
+	unsigned long pflags;
+
+	/* the_port->lock is set on the call here */
+	if (port->ip_port) {
+		spin_lock_irqsave(&port->ip_port->lock, pflags);
+		transmit_chars(port->ip_port);
+		spin_unlock_irqrestore(&port->ip_port->lock, pflags);
+	}
+}
+
+/*
+ * ioc3_cb_post_ncs - called for some basic errors
+ * @port: port to use
+ * @ncs: event
+ */
+static void ioc3_cb_post_ncs(struct uart_port *the_port, int ncs)
+{
+	struct uart_icount *icount;
+
+	icount = &the_port->icount;
+
+	if (ncs & NCS_BREAK)
+		icount->brk++;
+	if (ncs & NCS_FRAMING)
+		icount->frame++;
+	if (ncs & NCS_OVERRUN)
+		icount->overrun++;
+	if (ncs & NCS_PARITY)
+		icount->parity++;
+}
+
+/**
+ * do_read - Read in bytes from the port.  Return the number of bytes
+ *			actually read.
+ * @the_port: port to use
+ * @buf: place to put the stuff we read
+ * @len: how big 'buf' is
+ */
+
+static inline int do_read(struct uart_port *the_port, char *buf, int len)
+{
+	int prod_ptr, cons_ptr, total;
+	struct ioc3_port *port = get_ioc3_port(the_port);
+	struct ring *inring;
+	struct ring_entry *entry;
+	struct port_hooks *hooks = port->ip_hooks;
+	int byte_num;
+	char *sc;
+	int loop_counter;
+
+	BUG_ON(!(len >= 0));
+	BUG_ON(!port);
+
+	/* There is a nasty timing issue in the IOC3. When the rx_timer
+	 * expires or the rx_high condition arises, we take an interrupt.
+	 * At some point while servicing the interrupt, we read bytes from
+	 * the ring buffer and re-arm the rx_timer.  However the rx_timer is
+	 * not started until the first byte is received *after* it is armed,
+	 * and any bytes pending in the rx construction buffers are not drained
+	 * to memory until either there are 4 bytes available or the rx_timer
+	 * expires.  This leads to a potential situation where data is left
+	 * in the construction buffers forever - 1 to 3 bytes were received
+	 * after the interrupt was generated but before the rx_timer was
+	 * re-armed. At that point as long as no subsequent bytes are received
+	 * the timer will never be started and the bytes will remain in the
+	 * construction buffer forever.  The solution is to execute a DRAIN
+	 * command after rearming the timer.  This way any bytes received before
+	 * the DRAIN will be drained to memory, and any bytes received after
+	 * the DRAIN will start the TIMER and be drained when it expires.
+	 * Luckily, this only needs to be done when the DMA buffer is empty
+	 * since there is no requirement that this function return all
+	 * available data as long as it returns some.
+	 */
+	/* Re-arm the timer */
+
+	writel(port->ip_rx_cons | SRCIR_ARM, &port->ip_serial_regs->srcir);
+
+	prod_ptr = readl(&port->ip_serial_regs->srpir) & PROD_CONS_MASK;
+	cons_ptr = port->ip_rx_cons;
+
+	if (prod_ptr == cons_ptr) {
+		int reset_dma = 0;
+
+		/* Input buffer appears empty, do a flush. */
+
+		/* DMA must be enabled for this to work. */
+		if (!(port->ip_sscr & SSCR_DMA_EN)) {
+			port->ip_sscr |= SSCR_DMA_EN;
+			reset_dma = 1;
+		}
+
+		/* Potential race condition: we must reload the srpir after
+		 * issuing the drain command, otherwise we could think the rx
+		 * buffer is empty, then take a very long interrupt, and when
+		 * we come back it's full and we wait forever for the drain to
+		 * complete.
+		 */
+		writel(port->ip_sscr | SSCR_RX_DRAIN,
+		       &port->ip_serial_regs->sscr);
+		prod_ptr = readl(&port->ip_serial_regs->srpir) & PROD_CONS_MASK;
+
+		/* We must not wait for the DRAIN to complete unless there are
+		 * at least 8 bytes (2 ring entries) available to receive the
+		 * data otherwise the DRAIN will never complete and we'll
+		 * deadlock here.
+		 * In fact, to make things easier, I'll just ignore the flush if
+		 * there is any data at all now available.
+		 */
+		if (prod_ptr == cons_ptr) {
+			loop_counter = 0;
+			while (readl(&port->ip_serial_regs->sscr) &
+			       SSCR_RX_DRAIN) {
+				loop_counter++;
+				if (loop_counter > MAXITER)
+					return -1;
+			}
+
+			/* SIGH. We have to reload the prod_ptr *again* since
+			 * the drain may have caused it to change
+			 */
+			prod_ptr = readl(&port->ip_serial_regs->srpir)
+			    & PROD_CONS_MASK;
+		}
+		if (reset_dma) {
+			port->ip_sscr &= ~SSCR_DMA_EN;
+			writel(port->ip_sscr, &port->ip_serial_regs->sscr);
+		}
+	}
+	inring = port->ip_inring;
+	port->ip_flags &= ~READ_ABORTED;
+
+	total = 0;
+	loop_counter = 0xfffff;	/* to avoid hangs */
+
+	/* Grab bytes from the hardware */
+	while ((prod_ptr != cons_ptr) && (len > 0)) {
+		entry = (struct ring_entry *)((caddr_t) inring + cons_ptr);
+
+		if (loop_counter-- <= 0) {
+			printk(KERN_WARNING "IOC3 serial: "
+			       "possible hang condition/"
+			       "port stuck on read (line %d).\n",
+				the_port->line);
+			break;
+		}
+
+		/* According to the producer pointer, this ring entry
+		 * must contain some data.  But if the PIO happened faster
+		 * than the DMA, the data may not be available yet, so let's
+		 * wait until it arrives.
+		 */
+		if ((entry->ring_allsc & RING_ANY_VALID) == 0) {
+			/* Indicate the read is aborted so we don't disable
+			 * the interrupt thinking that the consumer is
+			 * congested.
+			 */
+			port->ip_flags |= READ_ABORTED;
+			len = 0;
+			break;
+		}
+
+		/* Load the bytes/status out of the ring entry */
+		for (byte_num = 0; byte_num < 4 && len > 0; byte_num++) {
+			sc = &(entry->ring_sc[byte_num]);
+
+			/* Check for change in modem state or overrun */
+			if ((*sc & RXSB_MODEM_VALID)
+			    && (port->ip_notify & N_DDCD)) {
+				/* Notify upper layer if DCD dropped */
+				if ((port->ip_flags & DCD_ON)
+				    && !(*sc & RXSB_DCD)) {
+					/* If we have already copied some data,
+					 * return it.  We'll pick up the carrier
+					 * drop on the next pass.  That way we
+					 * don't throw away the data that has
+					 * already been copied back to
+					 * the caller's buffer.
+					 */
+					if (total > 0) {
+						len = 0;
+						break;
+					}
+					port->ip_flags &= ~DCD_ON;
+
+					/* Turn off this notification so the
+					 * carrier drop protocol won't see it
+					 * again when it does a read.
+					 */
+					*sc &= ~RXSB_MODEM_VALID;
+
+					/* To keep things consistent, we need
+					 * to update the consumer pointer so
+					 * the next reader won't come in and
+					 * try to read the same ring entries
+					 * again. This must be done here before
+					 * the dcd change.
+					 */
+
+					if ((entry->ring_allsc & RING_ANY_VALID)
+					    == 0) {
+						cons_ptr += (int)sizeof
+						    (struct ring_entry);
+						cons_ptr &= PROD_CONS_MASK;
+					}
+					writel(cons_ptr,
+					       &port->ip_serial_regs->srcir);
+					port->ip_rx_cons = cons_ptr;
+
+					/* Notify upper layer of carrier drop */
+					if ((port->ip_notify & N_DDCD)
+					    && port->ip_port) {
+						uart_handle_dcd_change
+							(port->ip_port, 0);
+						wake_up_interruptible
+						    (&the_port->info->
+						     delta_msr_wait);
+					}
+
+					/* If we had any data to return, we
+					 * would have returned it above.
+					 */
+					return 0;
+				}
+			}
+			if (*sc & RXSB_MODEM_VALID) {
+				/* Notify that an input overrun occurred */
+				if ((*sc & RXSB_OVERRUN)
+				    && (port->ip_notify & N_OVERRUN_ERROR)) {
+					ioc3_cb_post_ncs(the_port, NCS_OVERRUN);
+				}
+				/* Don't look at this byte again */
+				*sc &= ~RXSB_MODEM_VALID;
+			}
+
+			/* Check for valid data or RX errors */
+			if ((*sc & RXSB_DATA_VALID) &&
+			    ((*sc & (RXSB_PAR_ERR
+				     | RXSB_FRAME_ERR | RXSB_BREAK))
+			     && (port->ip_notify & (N_PARITY_ERROR
+						    | N_FRAMING_ERROR
+						    | N_BREAK)))) {
+				/* There is an error condition on the next byte.
+				 * If we have already transferred some bytes,
+				 * we'll stop here. Otherwise if this is the
+				 * first byte to be read, we'll just transfer
+				 * it alone after notifying the
+				 * upper layer of its status.
+				 */
+				if (total > 0) {
+					len = 0;
+					break;
+				} else {
+					if ((*sc & RXSB_PAR_ERR) &&
+					    (port->
+					     ip_notify & N_PARITY_ERROR)) {
+						ioc3_cb_post_ncs(the_port,
+								 NCS_PARITY);
+					}
+					if ((*sc & RXSB_FRAME_ERR) &&
+					    (port->
+					     ip_notify & N_FRAMING_ERROR)) {
+						ioc3_cb_post_ncs(the_port,
+								 NCS_FRAMING);
+					}
+					if ((*sc & RXSB_BREAK)
+					    && (port->ip_notify & N_BREAK)) {
+						ioc3_cb_post_ncs
+						    (the_port, NCS_BREAK);
+					}
+					len = 1;
+				}
+			}
+			if (*sc & RXSB_DATA_VALID) {
+				*sc &= ~RXSB_DATA_VALID;
+				*buf = entry->ring_data[byte_num];
+				buf++;
+				len--;
+				total++;
+			}
+		}
+
+		/* If we used up this entry entirely, go on to the next one,
+		 * otherwise we must have run out of buffer space, so
+		 * leave the consumer pointer here for the next read in case
+		 * there are still unread bytes in this entry.
+		 */
+		if ((entry->ring_allsc & RING_ANY_VALID) == 0) {
+			cons_ptr += (int)sizeof(struct ring_entry);
+			cons_ptr &= PROD_CONS_MASK;
+		}
+	}
+
+	/* Update consumer pointer and re-arm rx timer interrupt */
+	writel(cons_ptr, &port->ip_serial_regs->srcir);
+	port->ip_rx_cons = cons_ptr;
+
+	/* If we have now dipped below the rx high water mark and we have
+	 * rx_high interrupt turned off, we can now turn it back on again.
+	 */
+	if ((port->ip_flags & INPUT_HIGH) && (((prod_ptr - cons_ptr)
+					       & PROD_CONS_MASK) <
+					      ((port->
+						ip_sscr &
+						SSCR_RX_THRESHOLD)
+					       << PROD_CONS_PTR_OFF))) {
+		port->ip_flags &= ~INPUT_HIGH;
+		enable_intrs(port, hooks->intr_rx_high);
+	}
+	return total;
+}
+
+/**
+ * receive_chars - upper level read.
+ * @the_port: port to read from
+ */
+static int receive_chars(struct uart_port *the_port)
+{
+	struct tty_struct *tty;
+	unsigned char ch[MAX_CHARS];
+	int read_count = 0, read_room, flip = 0;
+	struct uart_info *info = the_port->info;
+	struct ioc3_port *port = get_ioc3_port(the_port);
+	unsigned long pflags;
+
+	/* Make sure all the pointers are "good" ones */
+	if (!info)
+		return 0;
+	if (!info->tty)
+		return 0;
+
+	if (!(port->ip_flags & INPUT_ENABLE))
+		return 0;
+
+	spin_lock_irqsave(&the_port->lock, pflags);
+	tty = info->tty;
+
+	read_count = do_read(the_port, ch, MAX_CHARS);
+	if (read_count > 0) {
+		flip = 1;
+		read_room = tty_buffer_request_room(tty, read_count);
+		tty_insert_flip_string(tty, ch, read_room);
+		the_port->icount.rx += read_count;
+	}
+	spin_unlock_irqrestore(&the_port->lock, pflags);
+
+	if (flip)
+		tty_flip_buffer_push(tty);
+
+	return read_count;
+}
+
+/**
+ * ioc3uart_intr_one - lowest level (per port) interrupt handler.
+ * @is : submodule
+ * @idd: driver data
+ * @pending: interrupts to handle
+ * @regs: pt_regs
+ */
+
+static int inline
+ioc3uart_intr_one(struct ioc3_submodule *is,
+			struct ioc3_driver_data *idd,
+			unsigned int pending, struct pt_regs *regs)
+{
+	int port_num = GET_PORT_FROM_SIO_IR(pending);
+	struct port_hooks *hooks;
+	unsigned int rx_high_rd_aborted = 0;
+	unsigned long flags;
+	struct uart_port *the_port;
+	struct ioc3_port *port;
+	int loop_counter;
+	struct ioc3_card *card_ptr;
+	unsigned int sio_ir;
+
+	card_ptr = idd->data[is->id];
+	port = card_ptr->ic_port[port_num].icp_port;
+	hooks = port->ip_hooks;
+
+	/* Possible race condition here: The tx_mt interrupt bit may be
+	 * cleared without the intervention of the interrupt handler,
+	 * e.g. by a write.  If the top level interrupt handler reads a
+	 * tx_mt, then some other processor does a write, starting up
+	 * output, then we come in here, see the tx_mt and stop DMA, the
+	 * output started by the other processor will hang.  Thus we can
+	 * only rely on tx_mt being legitimate if it is read while the
+	 * port lock is held.  Therefore this bit must be ignored in the
+	 * passed in interrupt mask which was read by the top level
+	 * interrupt handler since the port lock was not held at the time
+	 * it was read.  We can only rely on this bit being accurate if it
+	 * is read while the port lock is held.  So we'll clear it for now,
+	 * and reload it later once we have the port lock.
+	 */
+
+	sio_ir = pending & ~(hooks->intr_tx_mt);
+	spin_lock_irqsave(&port->ip_lock, flags);
+
+	loop_counter = MAXITER;	/* to avoid hangs */
+
+	do {
+		uint32_t shadow;
+
+		if (loop_counter-- <= 0) {
+			printk(KERN_WARNING "IOC3 serial: "
+			       "possible hang condition/"
+			       "port stuck on interrupt (line %d).\n",
+				((struct uart_port *)port->ip_port)->line);
+			break;
+		}
+		/* Handle a DCD change */
+		if (sio_ir & hooks->intr_delta_dcd) {
+			ioc3_ack(is, idd, hooks->intr_delta_dcd);
+			shadow = readl(&port->ip_serial_regs->shadow);
+
+			if ((port->ip_notify & N_DDCD)
+			    && (shadow & SHADOW_DCD)
+			    && (port->ip_port)) {
+				the_port = port->ip_port;
+				uart_handle_dcd_change(the_port,
+						shadow & SHADOW_DCD);
+				wake_up_interruptible
+				    (&the_port->info->delta_msr_wait);
+			} else if ((port->ip_notify & N_DDCD)
+				   && !(shadow & SHADOW_DCD)) {
+				/* Flag delta DCD/no DCD */
+				uart_handle_dcd_change(port->ip_port,
+						shadow & SHADOW_DCD);
+				port->ip_flags |= DCD_ON;
+			}
+		}
+
+		/* Handle a CTS change */
+		if (sio_ir & hooks->intr_delta_cts) {
+			ioc3_ack(is, idd, hooks->intr_delta_cts);
+			shadow = readl(&port->ip_serial_regs->shadow);
+
+			if ((port->ip_notify & N_DCTS) && (port->ip_port)) {
+				the_port = port->ip_port;
+				uart_handle_cts_change(the_port, shadow
+						& SHADOW_CTS);
+				wake_up_interruptible
+				    (&the_port->info->delta_msr_wait);
+			}
+		}
+
+		/* rx timeout interrupt.  Must be some data available.  Put this
+		 * before the check for rx_high since servicing this condition
+		 * may cause that condition to clear.
+		 */
+		if (sio_ir & hooks->intr_rx_timer) {
+			ioc3_ack(is, idd, hooks->intr_rx_timer);
+			if ((port->ip_notify & N_DATA_READY)
+						&& (port->ip_port)) {
+				receive_chars(port->ip_port);
+			}
+		}
+
+		/* rx high interrupt. Must be after rx_timer.  */
+		else if (sio_ir & hooks->intr_rx_high) {
+			/* Data available, notify upper layer */
+			if ((port->ip_notify & N_DATA_READY) && port->ip_port) {
+				receive_chars(port->ip_port);
+			}
+
+			/* We can't ACK this interrupt.  If receive_chars didn't
+			 * cause the condition to clear, we'll have to disable
+			 * the interrupt until the data is drained.
+			 * If the read was aborted, don't disable the interrupt
+			 * as this may cause us to hang indefinitely.  An
+			 * aborted read generally means that this interrupt
+			 * hasn't been delivered to the cpu yet anyway, even
+			 * though we see it as asserted when we read the sio_ir.
+			 */
+			if ((sio_ir = PENDING(card_ptr, idd))
+					& hooks->intr_rx_high) {
+				if (port->ip_flags & READ_ABORTED) {
+					rx_high_rd_aborted++;
+				}
+				else {
+					card_ptr->ic_enable &= ~hooks->intr_rx_high;
+					port->ip_flags |= INPUT_HIGH;
+				}
+			}
+		}
+
+		/* We got a low water interrupt: notify upper layer to
+		 * send more data.  Must come before tx_mt since servicing
+		 * this condition may cause that condition to clear.
+		 */
+		if (sio_ir & hooks->intr_tx_explicit) {
+			port->ip_flags &= ~LOWAT_WRITTEN;
+			ioc3_ack(is, idd, hooks->intr_tx_explicit);
+			if (port->ip_notify & N_OUTPUT_LOWAT)
+				ioc3_cb_output_lowat(port);
+		}
+
+		/* Handle tx_mt.  Must come after tx_explicit.  */
+		else if (sio_ir & hooks->intr_tx_mt) {
+			/* If we are expecting a lowat notification
+			 * and we get to this point it probably means that for
+			 * some reason the tx_explicit didn't work as expected
+			 * (that can legitimately happen if the output buffer is
+			 * filled up in just the right way).
+			 * So send the notification now.
+			 */
+			if (port->ip_notify & N_OUTPUT_LOWAT) {
+				ioc3_cb_output_lowat(port);
+
+				/* We need to reload the sio_ir since the lowat
+				 * call may have caused another write to occur,
+				 * clearing the tx_mt condition.
+				 */
+				sio_ir = PENDING(card_ptr, idd);
+			}
+
+			/* If the tx_mt condition still persists even after the
+			 * lowat call, we've got some work to do.
+			 */
+			if (sio_ir & hooks->intr_tx_mt) {
+				/* If we are not currently expecting DMA input,
+				 * and the transmitter has just gone idle,
+				 * there is no longer any reason for DMA, so
+				 * disable it.
+				 */
+				if (!(port->ip_notify
+				      & (N_DATA_READY | N_DDCD))) {
+					BUG_ON(!(port->ip_sscr
+						 & SSCR_DMA_EN));
+					port->ip_sscr &= ~SSCR_DMA_EN;
+					writel(port->ip_sscr,
+					       &port->ip_serial_regs->sscr);
+				}
+				/* Prevent infinite tx_mt interrupt */
+				card_ptr->ic_enable &= ~hooks->intr_tx_mt;
+			}
+		}
+		sio_ir = PENDING(card_ptr, idd);
+
+		/* if the read was aborted and only hooks->intr_rx_high,
+		 * clear hooks->intr_rx_high, so we do not loop forever.
+		 */
+
+		if (rx_high_rd_aborted && (sio_ir == hooks->intr_rx_high)) {
+			sio_ir &= ~hooks->intr_rx_high;
+		}
+	} while (sio_ir & hooks->intr_all);
+
+	spin_unlock_irqrestore(&port->ip_lock, flags);
+	ioc3_enable(is, idd, card_ptr->ic_enable);
+	return 0;
+}
+
+/**
+ * ioc3uart_intr - field all serial interrupts
+ * @is : submodule
+ * @idd: driver data
+ * @pending: interrupts to handle
+ * @regs: pt_regs
+ *
+ */
+
+static int ioc3uart_intr(struct ioc3_submodule *is,
+			struct ioc3_driver_data *idd,
+			unsigned int pending, struct pt_regs *regs)
+{
+	int ret = 0;
+
+	/*
+	 * The upper level interrupt handler sends interrupts for both ports
+	 * here. So we need to call for each port with its interrupts.
+	 */
+
+	if (pending & SIO_IR_SA)
+		ret |= ioc3uart_intr_one(is, idd, pending & SIO_IR_SA, regs);
+	if (pending & SIO_IR_SB)
+		ret |= ioc3uart_intr_one(is, idd, pending & SIO_IR_SB, regs);
+
+	return ret;
+}
+
+/**
+ * ic3_type
+ * @port: Port to operate with (we ignore since we only have one port)
+ *
+ */
+static const char *ic3_type(struct uart_port *the_port)
+{
+	if (IS_RS232(the_port->line))
+		return "SGI IOC3 Serial [rs232]";
+	else
+		return "SGI IOC3 Serial [rs422]";
+}
+
+/**
+ * ic3_tx_empty - Is the transmitter empty?
+ * @port: Port to operate on
+ *
+ */
+static unsigned int ic3_tx_empty(struct uart_port *the_port)
+{
+	unsigned int ret = 0;
+	struct ioc3_port *port = get_ioc3_port(the_port);
+
+	if (readl(&port->ip_serial_regs->shadow) & SHADOW_TEMT)
+		ret = TIOCSER_TEMT;
+	return ret;
+}
+
+/**
+ * ic3_stop_tx - stop the transmitter
+ * @port: Port to operate on
+ *
+ */
+static void ic3_stop_tx(struct uart_port *the_port)
+{
+	struct ioc3_port *port = get_ioc3_port(the_port);
+
+	if (port)
+		set_notification(port, N_OUTPUT_LOWAT, 0);
+}
+
+/**
+ * ic3_stop_rx - stop the receiver
+ * @port: Port to operate on
+ *
+ */
+static void ic3_stop_rx(struct uart_port *the_port)
+{
+	struct ioc3_port *port = get_ioc3_port(the_port);
+
+	if (port)
+		port->ip_flags &= ~INPUT_ENABLE;
+}
+
+/**
+ * null_void_function
+ * @port: Port to operate on
+ *
+ */
+static void null_void_function(struct uart_port *the_port)
+{
+}
+
+/**
+ * ic3_shutdown - shut down the port - free irq and disable
+ * @port: port to shut down
+ *
+ */
+static void ic3_shutdown(struct uart_port *the_port)
+{
+	unsigned long port_flags;
+	struct ioc3_port *port;
+	struct uart_info *info;
+
+	port = get_ioc3_port(the_port);
+	if (!port)
+		return;
+
+	info = the_port->info;
+	wake_up_interruptible(&info->delta_msr_wait);
+
+	spin_lock_irqsave(&the_port->lock, port_flags);
+	set_notification(port, N_ALL, 0);
+	spin_unlock_irqrestore(&the_port->lock, port_flags);
+}
+
+/**
+ * ic3_set_mctrl - set control lines (dtr, rts, etc)
+ * @port: Port to operate on
+ * @mctrl: Lines to set/unset
+ *
+ */
+static void ic3_set_mctrl(struct uart_port *the_port, unsigned int mctrl)
+{
+	unsigned char mcr = 0;
+
+	if (mctrl & TIOCM_RTS)
+		mcr |= UART_MCR_RTS;
+	if (mctrl & TIOCM_DTR)
+		mcr |= UART_MCR_DTR;
+	if (mctrl & TIOCM_OUT1)
+		mcr |= UART_MCR_OUT1;
+	if (mctrl & TIOCM_OUT2)
+		mcr |= UART_MCR_OUT2;
+	if (mctrl & TIOCM_LOOP)
+		mcr |= UART_MCR_LOOP;
+
+	set_mcr(the_port, mcr, SHADOW_DTR);
+}
+
+/**
+ * ic3_get_mctrl - get control line info
+ * @port: port to operate on
+ *
+ */
+static unsigned int ic3_get_mctrl(struct uart_port *the_port)
+{
+	struct ioc3_port *port = get_ioc3_port(the_port);
+	uint32_t shadow;
+	unsigned int ret = 0;
+
+	if (!port)
+		return 0;
+
+	shadow = readl(&port->ip_serial_regs->shadow);
+	if (shadow & SHADOW_DCD)
+		ret |= TIOCM_CD;
+	if (shadow & SHADOW_DR)
+		ret |= TIOCM_DSR;
+	if (shadow & SHADOW_CTS)
+		ret |= TIOCM_CTS;
+	return ret;
+}
+
+/**
+ * ic3_start_tx - Start transmitter. Called with the_port->lock
+ * @port: Port to operate on
+ *
+ */
+static void ic3_start_tx(struct uart_port *the_port)
+{
+	struct ioc3_port *port = get_ioc3_port(the_port);
+
+	if (port) {
+		set_notification(port, N_OUTPUT_LOWAT, 1);
+		enable_intrs(port, port->ip_hooks->intr_tx_mt);
+	}
+}
+
+/**
+ * ic3_break_ctl - handle breaks
+ * @port: Port to operate on
+ * @break_state: Break state
+ *
+ */
+static void ic3_break_ctl(struct uart_port *the_port, int break_state)
+{
+}
+
+/**
+ * ic3_startup - Start up the serial port - always return 0 (We're always on)
+ * @port: Port to operate on
+ *
+ */
+static int ic3_startup(struct uart_port *the_port)
+{
+	int retval;
+	struct ioc3_port *port;
+	struct ioc3_card *card_ptr;
+	unsigned long port_flags;
+
+	if (!the_port) {
+		NOT_PROGRESS();
+		return -ENODEV;
+	}
+	port = get_ioc3_port(the_port);
+	if (!port) {
+		NOT_PROGRESS();
+		return -ENODEV;
+	}
+	card_ptr = port->ip_card;
+	port->ip_port = the_port;
+
+	if (!card_ptr) {
+		NOT_PROGRESS();
+		return -ENODEV;
+	}
+
+	/* Start up the serial port */
+	spin_lock_irqsave(&the_port->lock, port_flags);
+	retval = ic3_startup_local(the_port);
+	spin_unlock_irqrestore(&the_port->lock, port_flags);
+	return retval;
+}
+
+/**
+ * ic3_set_termios - set termios stuff
+ * @port: port to operate on
+ * @termios: New settings
+ * @termios: Old
+ *
+ */
+static void
+ic3_set_termios(struct uart_port *the_port,
+		struct termios *termios, struct termios *old_termios)
+{
+	unsigned long port_flags;
+
+	spin_lock_irqsave(&the_port->lock, port_flags);
+	ioc3_change_speed(the_port, termios, old_termios);
+	spin_unlock_irqrestore(&the_port->lock, port_flags);
+}
+
+/**
+ * ic3_request_port - allocate resources for port - no op....
+ * @port: port to operate on
+ *
+ */
+static int ic3_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+/* Associate the uart functions above - given to serial core */
+static struct uart_ops ioc3_ops = {
+	.tx_empty = ic3_tx_empty,
+	.set_mctrl = ic3_set_mctrl,
+	.get_mctrl = ic3_get_mctrl,
+	.stop_tx = ic3_stop_tx,
+	.start_tx = ic3_start_tx,
+	.stop_rx = ic3_stop_rx,
+	.enable_ms = null_void_function,
+	.break_ctl = ic3_break_ctl,
+	.startup = ic3_startup,
+	.shutdown = ic3_shutdown,
+	.set_termios = ic3_set_termios,
+	.type = ic3_type,
+	.release_port = null_void_function,
+	.request_port = ic3_request_port,
+};
+
+/*
+ * Boot-time initialization code
+ */
+
+static struct uart_driver ioc3_uart = {
+	.owner = THIS_MODULE,
+	.driver_name = "ioc3_serial",
+	.dev_name = DEVICE_NAME,
+	.major = DEVICE_MAJOR,
+	.minor = DEVICE_MINOR,
+	.nr = MAX_LOGICAL_PORTS
+};
+
+/**
+ * ioc3_serial_core_attach - register with serial core
+ *		This is done during pci probing
+ * @is: submodule struct for this
+ * @idd: handle for this card
+ */
+static inline int ioc3_serial_core_attach( struct ioc3_submodule *is,
+				struct ioc3_driver_data *idd)
+{
+	struct ioc3_port *port;
+	struct uart_port *the_port;
+	struct ioc3_card *card_ptr = idd->data[is->id];
+	int ii, phys_port;
+	struct pci_dev *pdev = idd->pdev;
+
+	DPRINT_CONFIG(("%s: attach pdev 0x%p - card_ptr 0x%p\n",
+		       __FUNCTION__, pdev, (void *)card_ptr));
+
+	if (!card_ptr)
+		return -ENODEV;
+
+	/* once around for each logical port on this card */
+	for (ii = 0; ii < LOGICAL_PORTS_PER_CARD; ii++) {
+		phys_port = GET_PHYSICAL_PORT(ii);
+		the_port = &card_ptr->ic_port[phys_port].
+				icp_uart_port[GET_LOGICAL_PORT(ii)];
+		port = card_ptr->ic_port[phys_port].icp_port;
+		port->ip_port = the_port;
+
+		DPRINT_CONFIG(("%s: attach the_port 0x%p / port 0x%p [%d/%d]\n",
+			__FUNCTION__, (void *)the_port, (void *)port,
+				phys_port, ii));
+
+		/* membase, iobase and mapbase just need to be non-0 */
+		the_port->membase = (unsigned char __iomem *)1;
+		the_port->iobase = (pdev->bus->number << 16) |  ii;
+		the_port->line = (Num_of_ioc3_cards << 2) | ii;
+		the_port->mapbase = 1;
+		the_port->type = PORT_16550A;
+		the_port->fifosize = FIFO_SIZE;
+		the_port->ops = &ioc3_ops;
+		the_port->irq = idd->irq_io;
+		the_port->dev = &pdev->dev;
+
+		if (uart_add_one_port(&ioc3_uart, the_port) < 0) {
+			printk(KERN_WARNING
+		          "%s: unable to add port %d bus %d\n",
+			       __FUNCTION__, the_port->line, pdev->bus->number);
+		} else {
+			DPRINT_CONFIG(("IOC3 serial port %d irq %d bus %d\n",
+		          the_port->line, the_port->irq, pdev->bus->number));
+		}
+
+		/* all ports are rs232 for now */
+		if (IS_PHYSICAL_PORT(ii))
+			ioc3_set_proto(port, PROTO_RS232);
+	}
+	return 0;
+}
+
+/**
+ * ioc3uart_remove - register detach function
+ * @is: submodule struct for this submodule
+ * @idd: ioc3 driver data for this submodule
+ */
+
+static int ioc3uart_remove(struct ioc3_submodule *is,
+			struct ioc3_driver_data *idd)
+{
+	struct ioc3_card *card_ptr = idd->data[is->id];
+	struct uart_port *the_port;
+	struct ioc3_port *port;
+	int ii;
+
+	if (card_ptr) {
+		for (ii = 0; ii < LOGICAL_PORTS_PER_CARD; ii++) {
+			the_port = &card_ptr->ic_port[GET_PHYSICAL_PORT(ii)].
+					icp_uart_port[GET_LOGICAL_PORT(ii)];
+			if (the_port)
+				uart_remove_one_port(&ioc3_uart, the_port);
+			port = card_ptr->ic_port[GET_PHYSICAL_PORT(ii)].icp_port;
+			if (port && IS_PHYSICAL_PORT(ii)
+					&& (GET_PHYSICAL_PORT(ii) == 0)) {
+				pci_free_consistent(port->ip_idd->pdev,
+					TOTAL_RING_BUF_SIZE,
+					(void *)port->ip_cpu_ringbuf,
+					port->ip_dma_ringbuf);
+				kfree(port);
+				card_ptr->ic_port[GET_PHYSICAL_PORT(ii)].
+							icp_port = NULL;
+			}
+		}
+		kfree(card_ptr);
+		idd->data[is->id] = NULL;
+	}
+	return 0;
+}
+
+/**
+ * ioc3uart_probe - card probe function called from shim driver
+ * @is: submodule struct for this submodule
+ * @idd: ioc3 driver data for this card
+ */
+
+static int __devinit
+ioc3uart_probe(struct ioc3_submodule *is, struct ioc3_driver_data *idd)
+{
+	struct pci_dev *pdev = idd->pdev;
+	struct ioc3_card *card_ptr;
+	int ret = 0;
+	struct ioc3_port *port;
+	struct ioc3_port *ports[PORTS_PER_CARD];
+	int phys_port;
+
+	DPRINT_CONFIG(("%s (0x%p, 0x%p)\n", __FUNCTION__, is, idd));
+
+	card_ptr = kmalloc(sizeof(struct ioc3_card), GFP_KERNEL);
+	if (!card_ptr) {
+		printk(KERN_WARNING "ioc3_attach_one"
+		       ": unable to get memory for the IOC3\n");
+		return -ENOMEM;
+	}
+	memset(card_ptr, 0, sizeof(struct ioc3_card));
+	idd->data[is->id] = card_ptr;
+	Submodule_slot = is->id;
+
+	writel(((UARTA_BASE >> 3) << SIO_CR_SER_A_BASE_SHIFT) |
+		((UARTB_BASE >> 3) << SIO_CR_SER_B_BASE_SHIFT) |
+		(0xf << SIO_CR_CMD_PULSE_SHIFT), &idd->vma->sio_cr);
+
+	pci_write_config_dword(pdev, PCI_LAT, 0xff00);
+
+	/* Enable serial port mode select generic PIO pins as outputs */
+	ioc3_gpcr_set(idd, GPCR_UARTA_MODESEL | GPCR_UARTB_MODESEL);
+
+	/* Create port structures for each port */
+	for (phys_port = 0; phys_port < PORTS_PER_CARD; phys_port++) {
+		port = kmalloc(sizeof(struct ioc3_port), GFP_KERNEL);
+		if (!port) {
+			printk(KERN_WARNING
+			       "IOC3 serial memory not available for port\n");
+			goto out4;
+		}
+		memset(port, 0, sizeof(struct ioc3_port));
+		spin_lock_init(&port->ip_lock);
+
+		/* we need to remember the previous ones, to point back to
+		 * them farther down - setting up the ring buffers.
+		 */
+		ports[phys_port] = port;
+
+		/* init to something useful */
+		card_ptr->ic_port[phys_port].icp_port = port;
+		port->ip_is = is;
+		port->ip_idd = idd;
+		port->ip_baud = 9600;
+		port->ip_card = card_ptr;
+		port->ip_hooks = &hooks_array[phys_port];
+
+		/* Setup each port */
+		if (phys_port == 0) {
+			port->ip_serial_regs = &idd->vma->port_a;
+			port->ip_uart_regs = &idd->vma->sregs.uarta;
+
+			DPRINT_CONFIG(("%s : Port A ip_serial_regs 0x%p "
+				       "ip_uart_regs 0x%p\n",
+				       __FUNCTION__,
+				       (void *)port->ip_serial_regs,
+				       (void *)port->ip_uart_regs));
+
+			/* setup ring buffers */
+			port->ip_cpu_ringbuf = pci_alloc_consistent(pdev,
+				TOTAL_RING_BUF_SIZE, &port->ip_dma_ringbuf);
+
+			BUG_ON(!((((int64_t) port->ip_dma_ringbuf) &
+				  (TOTAL_RING_BUF_SIZE - 1)) == 0));
+			port->ip_inring = RING(port, RX_A);
+			port->ip_outring = RING(port, TX_A);
+			DPRINT_CONFIG(("%s : Port A ip_cpu_ringbuf 0x%p "
+				       "ip_dma_ringbuf 0x%p, ip_inring 0x%p "
+					"ip_outring 0x%p\n",
+				       __FUNCTION__,
+				       (void *)port->ip_cpu_ringbuf,
+				       (void *)port->ip_dma_ringbuf,
+				       (void *)port->ip_inring,
+				       (void *)port->ip_outring));
+		}
+		else {
+			port->ip_serial_regs = &idd->vma->port_b;
+			port->ip_uart_regs = &idd->vma->sregs.uartb;
+
+			DPRINT_CONFIG(("%s : Port B ip_serial_regs 0x%p "
+				       "ip_uart_regs 0x%p\n",
+				       __FUNCTION__,
+				       (void *)port->ip_serial_regs,
+				       (void *)port->ip_uart_regs));
+
+			/* share the ring buffers */
+			port->ip_dma_ringbuf =
+			    ports[phys_port - 1]->ip_dma_ringbuf;
+			port->ip_cpu_ringbuf =
+			    ports[phys_port - 1]->ip_cpu_ringbuf;
+			port->ip_inring = RING(port, RX_B);
+			port->ip_outring = RING(port, TX_B);
+			DPRINT_CONFIG(("%s : Port B ip_cpu_ringbuf 0x%p "
+				       "ip_dma_ringbuf 0x%p, ip_inring 0x%p "
+					"ip_outring 0x%p\n",
+				       __FUNCTION__,
+				       (void *)port->ip_cpu_ringbuf,
+				       (void *)port->ip_dma_ringbuf,
+				       (void *)port->ip_inring,
+				       (void *)port->ip_outring));
+		}
+
+		DPRINT_CONFIG(("%s : port %d [addr 0x%p] card_ptr 0x%p",
+			       __FUNCTION__,
+			       phys_port, (void *)port, (void *)card_ptr));
+		DPRINT_CONFIG((" ip_serial_regs 0x%p ip_uart_regs 0x%p\n",
+			       (void *)port->ip_serial_regs,
+			       (void *)port->ip_uart_regs));
+
+		/* Initialize the hardware for IOC3 */
+		port_init(port);
+
+		DPRINT_CONFIG(("%s: phys_port %d port 0x%p inring 0x%p "
+			       "outring 0x%p\n",
+			       __FUNCTION__,
+			       phys_port, (void *)port,
+			       (void *)port->ip_inring,
+			       (void *)port->ip_outring));
+
+	}
+
+	/* register port with the serial core */
+
+	if ((ret = ioc3_serial_core_attach(is, idd)))
+		goto out4;
+
+	Num_of_ioc3_cards++;
+
+	return ret;
+
+	/* error exits that give back resources */
+out4:
+	kfree(card_ptr);
+	return ret;
+}
+
+static struct ioc3_submodule ioc3uart_submodule = {
+	.name = "IOC3uart",
+	.probe = ioc3uart_probe,
+	.remove = ioc3uart_remove,
+	/* call .intr for both ports initially */
+	.irq_mask = SIO_IR_SA | SIO_IR_SB,
+	.intr = ioc3uart_intr,
+	.owner = THIS_MODULE,
+};
+
+/**
+ * ioc3_detect - module init called,
+ */
+static int __devinit ioc3uart_init(void)
+{
+	int ret;
+
+	/* register with serial core */
+	if ((ret = uart_register_driver(&ioc3_uart)) < 0) {
+		printk(KERN_WARNING
+		       "%s: Couldn't register IOC3 uart serial driver\n",
+		       __FUNCTION__);
+		return ret;
+	}
+	ret = ioc3_register_submodule(&ioc3uart_submodule);
+	if (ret)
+		uart_unregister_driver(&ioc3_uart);
+	return ret;
+}
+
+static void __devexit ioc3uart_exit(void)
+{
+	ioc3_unregister_submodule(&ioc3uart_submodule);
+	uart_unregister_driver(&ioc3_uart);
+}
+
+module_init(ioc3uart_init);
+module_exit(ioc3uart_exit);
+
+MODULE_AUTHOR("Pat Gefre - Silicon Graphics Inc. (SGI) <pfg@sgi.com>");
+MODULE_DESCRIPTION("Serial PCI driver module for SGI IOC3 card");
+MODULE_LICENSE("GPL");
diff --git a/drivers/sn/Kconfig b/drivers/sn/Kconfig
index 13b8d24..d95265b1 100644
--- a/drivers/sn/Kconfig
+++ b/drivers/sn/Kconfig
@@ -17,4 +17,18 @@
 	If you have an SGI Altix with an IOC4-based
 	I/O controller say Y.  Otherwise say N.
 
+config SGI_IOC3
+	tristate "SGI IOC3 Base IO support"
+	depends on (IA64_GENERIC || IA64_SGI_SN2)
+	default m
+	---help---
+	This option enables basic support for the SGI IOC3-based Base IO
+	controller card.  This option does not enable any specific
+	functions on such a card, but provides necessary infrastructure
+	for other drivers to utilize.
+
+	If you have an SGI Altix with an IOC3-based
+	I/O controller or a PCI IOC3 serial card say Y.
+	Otherwise say N.
+
 endmenu
diff --git a/drivers/sn/Makefile b/drivers/sn/Makefile
index c2a2841..2cda011 100644
--- a/drivers/sn/Makefile
+++ b/drivers/sn/Makefile
@@ -4,3 +4,4 @@
 #
 
 obj-$(CONFIG_SGI_IOC4) += ioc4.o
+obj-$(CONFIG_SGI_IOC3) += ioc3.o
diff --git a/drivers/sn/ioc3.c b/drivers/sn/ioc3.c
new file mode 100644
index 0000000..aaa009f
--- /dev/null
+++ b/drivers/sn/ioc3.c
@@ -0,0 +1,851 @@
+/*
+ * SGI IOC3 master driver and IRQ demuxer
+ *
+ * Copyright (c) 2005 Stanislaw Skowronek <skylark@linux-mips.org>
+ * Heavily based on similar work by:
+ *   Brent Casavant <bcasavan@sgi.com> - IOC4 master driver
+ *   Pat Gefre <pfg@sgi.com> - IOC3 serial port IRQ demuxer
+ */
+
+#include <linux/config.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/delay.h>
+#include <linux/ioc3.h>
+#include <linux/rwsem.h>
+
+#define IOC3_PCI_SIZE 0x100000
+
+static LIST_HEAD(ioc3_devices);
+static int ioc3_counter;
+static DECLARE_RWSEM(ioc3_devices_rwsem);
+
+static struct ioc3_submodule *ioc3_submodules[IOC3_MAX_SUBMODULES];
+static struct ioc3_submodule *ioc3_ethernet;
+static rwlock_t ioc3_submodules_lock = RW_LOCK_UNLOCKED;
+
+/* NIC probing code */
+
+#define GPCR_MLAN_EN    0x00200000      /* enable MCR to pin 8 */
+
+static inline unsigned mcr_pack(unsigned pulse, unsigned sample)
+{
+	return (pulse << 10) | (sample << 2);
+}
+
+static int nic_wait(struct ioc3_driver_data *idd)
+{
+	volatile unsigned mcr;
+
+        do {
+                mcr = (volatile unsigned)idd->vma->mcr;
+        } while (!(mcr & 2));
+
+        return mcr & 1;
+}
+
+static int nic_reset(struct ioc3_driver_data *idd)
+{
+        int presence;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	idd->vma->mcr = mcr_pack(500, 65);
+	presence = nic_wait(idd);
+	local_irq_restore(flags);
+
+	udelay(500);
+
+        return presence;
+}
+
+static inline int nic_read_bit(struct ioc3_driver_data *idd)
+{
+	int result;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	idd->vma->mcr = mcr_pack(6, 13);
+	result = nic_wait(idd);
+	local_irq_restore(flags);
+
+	udelay(500);
+
+	return result;
+}
+
+static inline void nic_write_bit(struct ioc3_driver_data *idd, int bit)
+{
+	if (bit)
+		idd->vma->mcr = mcr_pack(6, 110);
+	else
+		idd->vma->mcr = mcr_pack(80, 30);
+
+	nic_wait(idd);
+}
+
+static unsigned nic_read_byte(struct ioc3_driver_data *idd)
+{
+	unsigned result = 0;
+	int i;
+
+	for (i = 0; i < 8; i++)
+		result = (result >> 1) | (nic_read_bit(idd) << 7);
+
+	return result;
+}
+
+static void nic_write_byte(struct ioc3_driver_data *idd, int byte)
+{
+	int i, bit;
+
+	for (i = 8; i; i--) {
+		bit = byte & 1;
+		byte >>= 1;
+
+		nic_write_bit(idd, bit);
+	}
+}
+
+static unsigned long
+nic_find(struct ioc3_driver_data *idd, int *last, unsigned long addr)
+{
+	int a, b, index, disc;
+
+	nic_reset(idd);
+
+	/* Search ROM.  */
+	nic_write_byte(idd, 0xF0);
+
+	/* Algorithm from ``Book of iButton Standards''.  */
+	for (index = 0, disc = 0; index < 64; index++) {
+		a = nic_read_bit(idd);
+		b = nic_read_bit(idd);
+
+		if (a && b) {
+			printk(KERN_WARNING "IOC3 NIC search failed.\n");
+			*last = 0;
+			return 0;
+		}
+
+		if (!a && !b) {
+			if (index == *last) {
+				addr |= 1UL << index;
+			} else if (index > *last) {
+				addr &= ~(1UL << index);
+				disc = index;
+			} else if ((addr & (1UL << index)) == 0)
+				disc = index;
+			nic_write_bit(idd, (addr>>index)&1);
+			continue;
+		} else {
+			if (a)
+				addr |= 1UL << index;
+			else
+				addr &= ~(1UL << index);
+			nic_write_bit(idd, a);
+			continue;
+		}
+	}
+	*last = disc;
+	return addr;
+}
+
+static void nic_addr(struct ioc3_driver_data *idd, unsigned long addr)
+{
+	int index;
+
+	nic_reset(idd);
+	nic_write_byte(idd, 0xF0);
+	for (index = 0; index < 64; index++) {
+		nic_read_bit(idd);
+		nic_read_bit(idd);
+		nic_write_bit(idd, (addr>>index)&1);
+	}
+}
+
+static void crc16_byte(unsigned int *crc, unsigned char db)
+{
+	int i;
+
+	for(i=0;i<8;i++) {
+		*crc <<= 1;
+		if((db^(*crc>>16)) & 1)
+			*crc ^= 0x8005;
+		db >>= 1;
+	}
+	*crc &= 0xFFFF;
+}
+
+static unsigned int crc16_area(unsigned char *dbs, int size, unsigned int crc)
+{
+	while(size--)
+		crc16_byte(&crc, *(dbs++));
+	return crc;
+}
+
+static void crc8_byte(unsigned int *crc, unsigned char db)
+{
+	int i,f;
+
+	for(i=0;i<8;i++) {
+		f = (*crc ^ db) & 1;
+		*crc >>= 1;
+		db >>= 1;
+		if(f)
+			*crc ^= 0x8c;
+	}
+	*crc &= 0xff;
+}
+
+static unsigned int crc8_addr(unsigned long addr)
+{
+	int i;
+	unsigned int crc = 0x00;
+
+	for(i=0;i<8;i++)
+		crc8_byte(&crc, addr>>(i<<3));
+	return crc;
+}
+
+static void
+read_redir_page(struct ioc3_driver_data *idd, unsigned long addr, int page,
+			unsigned char *redir, unsigned char *data)
+{
+	int loops = 16, i;
+
+	while(redir[page] != 0xFF) {
+		page = redir[page]^0xFF;
+		loops--;
+		if(loops<0) {
+			printk(KERN_ERR "IOC3: NIC circular redirection\n");
+			return;
+		}
+	}
+	loops = 3;
+	while(loops>0) {
+		nic_addr(idd, addr);
+		nic_write_byte(idd, 0xF0);
+		nic_write_byte(idd, (page << 5) & 0xE0);
+		nic_write_byte(idd, (page >> 3) & 0x1F);
+		for(i=0;i<0x20;i++)
+			data[i] = nic_read_byte(idd);
+		if(crc16_area(data, 0x20, 0x0000) == 0x800d)
+			return;
+		loops--;
+	}
+	printk(KERN_ERR "IOC3: CRC error in data page\n");
+	for(i=0;i<0x20;i++)
+		data[i] = 0x00;
+}
+
+static void
+read_redir_map(struct ioc3_driver_data *idd, unsigned long addr,
+					 unsigned char *redir)
+{
+	int i,j,loops = 3,crc_ok;
+	unsigned int crc;
+
+	while(loops>0) {
+		crc_ok = 1;
+		nic_addr(idd, addr);
+		nic_write_byte(idd, 0xAA);
+		nic_write_byte(idd, 0x00);
+		nic_write_byte(idd, 0x01);
+		for(i=0;i<64;i+=8) {
+			for(j=0;j<8;j++)
+				redir[i+j] = nic_read_byte(idd);
+			crc = crc16_area(redir+i, 8, (i==0)?0x8707:0x0000);
+			crc16_byte(&crc, nic_read_byte(idd));
+			crc16_byte(&crc, nic_read_byte(idd));
+			if(crc != 0x800d)
+				crc_ok = 0;
+		}
+		if(crc_ok)
+			return;
+		loops--;
+	}
+	printk(KERN_ERR "IOC3: CRC error in redirection page\n");
+	for(i=0;i<64;i++)
+		redir[i] = 0xFF;
+}
+
+static void read_nic(struct ioc3_driver_data *idd, unsigned long addr)
+{
+	unsigned char redir[64];
+	unsigned char data[64],part[32];
+	int i,j;
+
+	/* read redirections */
+	read_redir_map(idd, addr, redir);
+	/* read data pages */
+	read_redir_page(idd, addr, 0, redir, data);
+	read_redir_page(idd, addr, 1, redir, data+32);
+	/* assemble the part # */
+	j=0;
+	for(i=0;i<19;i++)
+		if(data[i+11] != ' ')
+			part[j++] = data[i+11];
+	for(i=0;i<6;i++)
+		if(data[i+32] != ' ')
+			part[j++] = data[i+32];
+	part[j] = 0;
+	/* skip Octane power supplies */
+	if(!strncmp(part, "060-0035-", 9))
+		return;
+	if(!strncmp(part, "060-0038-", 9))
+		return;
+	strcpy(idd->nic_part, part);
+	/* assemble the serial # */
+	j=0;
+	for(i=0;i<10;i++)
+		if(data[i+1] != ' ')
+			idd->nic_serial[j++] = data[i+1];
+	idd->nic_serial[j] = 0;
+}
+
+static void read_mac(struct ioc3_driver_data *idd, unsigned long addr)
+{
+	int i, loops = 3;
+	unsigned char data[13];
+
+	while(loops>0) {
+		nic_addr(idd, addr);
+		nic_write_byte(idd, 0xF0);
+		nic_write_byte(idd, 0x00);
+		nic_write_byte(idd, 0x00);
+		nic_read_byte(idd);
+		for(i=0;i<13;i++)
+			data[i] = nic_read_byte(idd);
+		if(crc16_area(data, 13, 0x0000) == 0x800d) {
+			for(i=10;i>4;i--)
+				idd->nic_mac[10-i] = data[i];
+			return;
+		}
+		loops--;
+	}
+	printk(KERN_ERR "IOC3: CRC error in MAC address\n");
+	for(i=0;i<6;i++)
+		idd->nic_mac[i] = 0x00;
+}
+
+static void probe_nic(struct ioc3_driver_data *idd)
+{
+        int save = 0, loops = 3;
+        unsigned long first, addr;
+
+        idd->vma->gpcr_s = GPCR_MLAN_EN;
+
+        while(loops>0) {
+                idd->nic_part[0] = 0;
+                idd->nic_serial[0] = 0;
+                addr = first = nic_find(idd, &save, 0);
+                if(!first)
+                        return;
+                while(1) {
+                        if(crc8_addr(addr))
+                                break;
+                        else {
+                                switch(addr & 0xFF) {
+                                case 0x0B:
+                                        read_nic(idd, addr);
+                                        break;
+                                case 0x09:
+                                case 0x89:
+                                case 0x91:
+                                        read_mac(idd, addr);
+                                        break;
+                                }
+                        }
+                        addr = nic_find(idd, &save, addr);
+                        if(addr == first)
+                                return;
+                }
+                loops--;
+        }
+        printk(KERN_ERR "IOC3: CRC error in NIC address\n");
+}
+
+/* Interrupts */
+
+static inline void
+write_ireg(struct ioc3_driver_data *idd, uint32_t val, int which)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&idd->ir_lock, flags);
+	switch (which) {
+	case IOC3_W_IES:
+		writel(val, &idd->vma->sio_ies);
+		break;
+	case IOC3_W_IEC:
+		writel(val, &idd->vma->sio_iec);
+		break;
+	}
+	spin_unlock_irqrestore(&idd->ir_lock, flags);
+}
+static inline uint32_t get_pending_intrs(struct ioc3_driver_data *idd)
+{
+	unsigned long flag;
+	uint32_t intrs = 0;
+
+	spin_lock_irqsave(&idd->ir_lock, flag);
+	intrs = readl(&idd->vma->sio_ir);
+	intrs &= readl(&idd->vma->sio_ies);
+	spin_unlock_irqrestore(&idd->ir_lock, flag);
+	return intrs;
+}
+
+static irqreturn_t ioc3_intr_io(int irq, void *arg, struct pt_regs *regs)
+{
+	unsigned long flags;
+	struct ioc3_driver_data *idd = (struct ioc3_driver_data *)arg;
+	int handled = 1, id;
+	unsigned int pending;
+
+	read_lock_irqsave(&ioc3_submodules_lock, flags);
+
+	if(idd->dual_irq && idd->vma->eisr) {
+		/* send Ethernet IRQ to the driver */
+		if(ioc3_ethernet && idd->active[ioc3_ethernet->id] &&
+						ioc3_ethernet->intr) {
+			handled = handled && !ioc3_ethernet->intr(ioc3_ethernet,
+							idd, 0, regs);
+		}
+	}
+	pending = get_pending_intrs(idd);	/* look at the IO IRQs */
+
+	for(id=0;id<IOC3_MAX_SUBMODULES;id++) {
+		if(idd->active[id] && ioc3_submodules[id]
+				&& (pending & ioc3_submodules[id]->irq_mask)
+				&& ioc3_submodules[id]->intr) {
+			write_ireg(idd, ioc3_submodules[id]->irq_mask,
+							IOC3_W_IEC);
+			if(!ioc3_submodules[id]->intr(ioc3_submodules[id],
+				   idd, pending & ioc3_submodules[id]->irq_mask,
+					regs))
+				pending &= ~ioc3_submodules[id]->irq_mask;
+			if (ioc3_submodules[id]->reset_mask)
+				write_ireg(idd, ioc3_submodules[id]->irq_mask,
+							IOC3_W_IES);
+		}
+	}
+	read_unlock_irqrestore(&ioc3_submodules_lock, flags);
+	if(pending) {
+		printk(KERN_WARNING
+		  "IOC3: Pending IRQs 0x%08x discarded and disabled\n",pending);
+		write_ireg(idd, pending, IOC3_W_IEC);
+		handled = 1;
+	}
+	return handled?IRQ_HANDLED:IRQ_NONE;
+}
+
+static irqreturn_t ioc3_intr_eth(int irq, void *arg, struct pt_regs *regs)
+{
+	unsigned long flags;
+	struct ioc3_driver_data *idd = (struct ioc3_driver_data *)arg;
+	int handled = 1;
+
+	if(!idd->dual_irq)
+		return IRQ_NONE;
+	read_lock_irqsave(&ioc3_submodules_lock, flags);
+	if(ioc3_ethernet && idd->active[ioc3_ethernet->id]
+				&& ioc3_ethernet->intr)
+		handled = handled && !ioc3_ethernet->intr(ioc3_ethernet, idd, 0,
+								regs);
+	read_unlock_irqrestore(&ioc3_submodules_lock, flags);
+	return handled?IRQ_HANDLED:IRQ_NONE;
+}
+
+void ioc3_enable(struct ioc3_submodule *is,
+				struct ioc3_driver_data *idd, unsigned int irqs)
+{
+	write_ireg(idd, irqs & is->irq_mask, IOC3_W_IES);
+}
+
+void ioc3_ack(struct ioc3_submodule *is, struct ioc3_driver_data *idd,
+				unsigned int irqs)
+{
+	writel(irqs & is->irq_mask, &idd->vma->sio_ir);
+}
+
+void ioc3_disable(struct ioc3_submodule *is,
+				struct ioc3_driver_data *idd, unsigned int irqs)
+{
+	write_ireg(idd, irqs & is->irq_mask, IOC3_W_IEC);
+}
+
+void ioc3_gpcr_set(struct ioc3_driver_data *idd, unsigned int val)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&idd->gpio_lock, flags);
+	writel(val, &idd->vma->gpcr_s);
+	spin_unlock_irqrestore(&idd->gpio_lock, flags);
+}
+
+/* Keep it simple, stupid! */
+static int find_slot(void **tab, int max)
+{
+	int i;
+	for(i=0;i<max;i++)
+		if(!(tab[i]))
+			return i;
+	return -1;
+}
+
+/* Register an IOC3 submodule */
+int ioc3_register_submodule(struct ioc3_submodule *is)
+{
+	struct ioc3_driver_data *idd;
+	int alloc_id;
+	unsigned long flags;
+
+	write_lock_irqsave(&ioc3_submodules_lock, flags);
+	alloc_id = find_slot((void **)ioc3_submodules, IOC3_MAX_SUBMODULES);
+	if(alloc_id != -1) {
+		ioc3_submodules[alloc_id] = is;
+		if(is->ethernet) {
+			if(ioc3_ethernet==NULL)
+				ioc3_ethernet=is;
+			else
+				printk(KERN_WARNING
+				  "IOC3 Ethernet module already registered!\n");
+		}
+	}
+	write_unlock_irqrestore(&ioc3_submodules_lock, flags);
+
+	if(alloc_id == -1) {
+		printk(KERN_WARNING "Increase IOC3_MAX_SUBMODULES!\n");
+		return -ENOMEM;
+	}
+
+	is->id=alloc_id;
+
+	/* Initialize submodule for each IOC3 */
+	if (!is->probe)
+		return 0;
+
+	down_read(&ioc3_devices_rwsem);
+	list_for_each_entry(idd, &ioc3_devices, list) {
+		/* set to 1 for IRQs in probe */
+		idd->active[alloc_id] = 1;
+		idd->active[alloc_id] = !is->probe(is, idd);
+	}
+	up_read(&ioc3_devices_rwsem);
+
+	return 0;
+}
+
+/* Unregister an IOC3 submodule */
+void ioc3_unregister_submodule(struct ioc3_submodule *is)
+{
+	struct ioc3_driver_data *idd;
+	unsigned long flags;
+
+	write_lock_irqsave(&ioc3_submodules_lock, flags);
+	if(ioc3_submodules[is->id]==is)
+		ioc3_submodules[is->id]=NULL;
+	else
+		printk(KERN_WARNING
+			"IOC3 submodule %s has wrong ID.\n",is->name);
+	if(ioc3_ethernet==is)
+		ioc3_ethernet = NULL;
+	write_unlock_irqrestore(&ioc3_submodules_lock, flags);
+
+	/* Remove submodule for each IOC3 */
+	down_read(&ioc3_devices_rwsem);
+	list_for_each_entry(idd, &ioc3_devices, list)
+		if(idd->active[is->id]) {
+			if(is->remove)
+				if(is->remove(is, idd))
+					printk(KERN_WARNING
+					       "%s: IOC3 submodule %s remove failed "
+					       "for pci_dev %s.\n",
+					       __FUNCTION__, module_name(is->owner),
+					       pci_name(idd->pdev));
+			idd->active[is->id] = 0;
+			if(is->irq_mask)
+				write_ireg(idd, is->irq_mask, IOC3_W_IEC);
+		}
+	up_read(&ioc3_devices_rwsem);
+}
+
+/*********************
+ * Device management *
+ *********************/
+
+static char *
+ioc3_class_names[]={"unknown", "IP27 BaseIO", "IP30 system", "MENET 1/2/3",
+			"MENET 4", "CADduo", "Altix Serial"};
+
+static int ioc3_class(struct ioc3_driver_data *idd)
+{
+	int res = IOC3_CLASS_NONE;
+	/* NIC-based logic */
+	if(!strncmp(idd->nic_part, "030-0891-", 9))
+		res = IOC3_CLASS_BASE_IP30;
+	if(!strncmp(idd->nic_part, "030-1155-", 9))
+		res = IOC3_CLASS_CADDUO;
+	if(!strncmp(idd->nic_part, "030-1657-", 9))
+		res = IOC3_CLASS_SERIAL;
+	if(!strncmp(idd->nic_part, "030-1664-", 9))
+		res = IOC3_CLASS_SERIAL;
+	/* total random heuristics */
+#ifdef CONFIG_SGI_IP27
+	if(!idd->nic_part[0])
+		res = IOC3_CLASS_BASE_IP27;
+#endif
+	/* print educational message */
+	printk(KERN_INFO "IOC3 part: [%s], serial: [%s] => class %s\n",
+			idd->nic_part, idd->nic_serial, ioc3_class_names[res]);
+	return res;
+}
+/* Adds a new instance of an IOC3 card */
+static int ioc3_probe(struct pci_dev *pdev, const struct pci_device_id *pci_id)
+{
+	struct ioc3_driver_data *idd;
+	uint32_t pcmd;
+	int ret, id;
+
+	/* Enable IOC3 and take ownership of it */
+	if ((ret = pci_enable_device(pdev))) {
+		printk(KERN_WARNING
+		       "%s: Failed to enable IOC3 device for pci_dev %s.\n",
+		       __FUNCTION__, pci_name(pdev));
+		goto out;
+	}
+	pci_set_master(pdev);
+
+#ifdef USE_64BIT_DMA
+        ret = pci_set_dma_mask(pdev, 0xffffffffffffffffULL);
+        if (!ret) {
+                ret = pci_set_consistent_dma_mask(pdev, 0xffffffffffffffffULL);
+                if (ret < 0) {
+                        printk(KERN_WARNING "%s: Unable to obtain 64 bit DMA "
+                               "for consistent allocations\n",
+				__FUNCTION__);
+                }
+	}
+#endif
+
+	/* Set up per-IOC3 data */
+	idd = kmalloc(sizeof(struct ioc3_driver_data), GFP_KERNEL);
+	if (!idd) {
+		printk(KERN_WARNING
+		       "%s: Failed to allocate IOC3 data for pci_dev %s.\n",
+		       __FUNCTION__, pci_name(pdev));
+		ret = -ENODEV;
+		goto out_idd;
+	}
+	memset(idd, 0, sizeof(struct ioc3_driver_data));
+	spin_lock_init(&idd->ir_lock);
+	spin_lock_init(&idd->gpio_lock);
+	idd->pdev = pdev;
+
+	/* Map all IOC3 registers.  These are shared between subdevices
+	 * so the main IOC3 module manages them.
+	 */
+	idd->pma = pci_resource_start(pdev, 0);
+	if (!idd->pma) {
+		printk(KERN_WARNING
+		       "%s: Unable to find IOC3 resource "
+		       "for pci_dev %s.\n",
+		       __FUNCTION__, pci_name(pdev));
+		ret = -ENODEV;
+		goto out_pci;
+	}
+	if (!request_region(idd->pma, IOC3_PCI_SIZE, "ioc3")) {
+		printk(KERN_WARNING
+		       "%s: Unable to request IOC3 region "
+		       "for pci_dev %s.\n",
+		       __FUNCTION__, pci_name(pdev));
+		ret = -ENODEV;
+		goto out_pci;
+	}
+	idd->vma = ioremap(idd->pma, IOC3_PCI_SIZE);
+	if (!idd->vma) {
+		printk(KERN_WARNING
+		       "%s: Unable to remap IOC3 region "
+		       "for pci_dev %s.\n",
+		       __FUNCTION__, pci_name(pdev));
+		ret = -ENODEV;
+		goto out_misc_region;
+	}
+
+	/* Track PCI-device specific data */
+	pci_set_drvdata(pdev, idd);
+	down_write(&ioc3_devices_rwsem);
+	list_add(&idd->list, &ioc3_devices);
+	idd->id = ioc3_counter++;
+	up_write(&ioc3_devices_rwsem);
+
+	idd->gpdr_shadow = idd->vma->gpdr;
+
+	/* Read IOC3 NIC contents */
+	probe_nic(idd);
+
+	/* Detect IOC3 class */
+	idd->class = ioc3_class(idd);
+
+	/* Initialize IOC3 */
+       pci_read_config_dword(pdev, PCI_COMMAND, &pcmd);
+       pci_write_config_dword(pdev, PCI_COMMAND,
+                               pcmd | PCI_COMMAND_MEMORY |
+                               PCI_COMMAND_PARITY | PCI_COMMAND_SERR |
+                               PCI_SCR_DROP_MODE_EN);
+
+	write_ireg(idd, ~0, IOC3_W_IEC);
+	writel(~0, &idd->vma->sio_ir);
+
+	/* Set up IRQs */
+	if(idd->class == IOC3_CLASS_BASE_IP30
+				|| idd->class == IOC3_CLASS_BASE_IP27) {
+		writel(0, &idd->vma->eier);
+		writel(~0, &idd->vma->eisr);
+
+		idd->dual_irq = 1;
+		if (!request_irq(pdev->irq, ioc3_intr_eth, SA_SHIRQ,
+				 "ioc3-eth", (void *)idd)) {
+			idd->irq_eth = pdev->irq;
+		} else {
+			printk(KERN_WARNING
+			       "%s : request_irq fails for IRQ 0x%x\n ",
+			       __FUNCTION__, pdev->irq);
+		}
+		if (!request_irq(pdev->irq+2, ioc3_intr_io, SA_SHIRQ,
+				 "ioc3-io", (void *)idd)) {
+			idd->irq_io = pdev->irq+2;
+		} else {
+			printk(KERN_WARNING
+			       "%s : request_irq fails for IRQ 0x%x\n ",
+			       __FUNCTION__, pdev->irq+2);
+		}
+	} else {
+		if (!request_irq(pdev->irq, ioc3_intr_io, SA_SHIRQ,
+				 "ioc3", (void *)idd)) {
+			idd->irq_io = pdev->irq;
+		} else {
+			printk(KERN_WARNING
+			       "%s : request_irq fails for IRQ 0x%x\n ",
+			       __FUNCTION__, pdev->irq);
+		}
+	}
+
+	/* Add this IOC3 to all submodules */
+	read_lock(&ioc3_submodules_lock);
+	for(id=0;id<IOC3_MAX_SUBMODULES;id++)
+		if(ioc3_submodules[id] && ioc3_submodules[id]->probe) {
+			idd->active[id] = 1;
+			idd->active[id] = !ioc3_submodules[id]->probe
+						(ioc3_submodules[id], idd);
+		}
+	read_unlock(&ioc3_submodules_lock);
+
+	printk(KERN_INFO "IOC3 Master Driver loaded for %s\n", pci_name(pdev));
+
+	return 0;
+
+out_misc_region:
+	release_region(idd->pma, IOC3_PCI_SIZE);
+out_pci:
+	kfree(idd);
+out_idd:
+	pci_disable_device(pdev);
+out:
+	return ret;
+}
+
+/* Removes a particular instance of an IOC3 card. */
+static void ioc3_remove(struct pci_dev *pdev)
+{
+	int id;
+	struct ioc3_driver_data *idd;
+
+	idd = pci_get_drvdata(pdev);
+
+	/* Remove this IOC3 from all submodules */
+	read_lock(&ioc3_submodules_lock);
+	for(id=0;id<IOC3_MAX_SUBMODULES;id++)
+		if(idd->active[id]) {
+			if(ioc3_submodules[id] && ioc3_submodules[id]->remove)
+				if(ioc3_submodules[id]->remove(ioc3_submodules[id],
+								idd))
+					printk(KERN_WARNING
+					       "%s: IOC3 submodule 0x%s remove failed "
+					       "for pci_dev %s.\n",
+					        __FUNCTION__,
+						module_name(ioc3_submodules[id]->owner),
+					        pci_name(pdev));
+			idd->active[id] = 0;
+		}
+	read_unlock(&ioc3_submodules_lock);
+
+	/* Clear and disable all IRQs */
+	write_ireg(idd, ~0, IOC3_W_IEC);
+	writel(~0, &idd->vma->sio_ir);
+
+	/* Release resources */
+	free_irq(idd->irq_io, (void *)idd);
+	if(idd->dual_irq)
+		free_irq(idd->irq_eth, (void *)idd);
+	iounmap(idd->vma);
+	release_region(idd->pma, IOC3_PCI_SIZE);
+
+	/* Disable IOC3 and relinquish */
+	pci_disable_device(pdev);
+
+	/* Remove and free driver data */
+	down_write(&ioc3_devices_rwsem);
+	list_del(&idd->list);
+	up_write(&ioc3_devices_rwsem);
+	kfree(idd);
+}
+
+static struct pci_device_id ioc3_id_table[] = {
+	{PCI_VENDOR_ID_SGI, PCI_DEVICE_ID_SGI_IOC3, PCI_ANY_ID, PCI_ANY_ID},
+	{0}
+};
+
+static struct pci_driver ioc3_driver = {
+	.name = "IOC3",
+	.id_table = ioc3_id_table,
+	.probe = ioc3_probe,
+	.remove = ioc3_remove,
+};
+
+MODULE_DEVICE_TABLE(pci, ioc3_id_table);
+
+/*********************
+ * Module management *
+ *********************/
+
+/* Module load */
+static int __devinit ioc3_init(void)
+{
+	if (ia64_platform_is("sn2"))
+		return pci_register_driver(&ioc3_driver);
+	return 0;
+}
+
+/* Module unload */
+static void __devexit ioc3_exit(void)
+{
+	pci_unregister_driver(&ioc3_driver);
+}
+
+module_init(ioc3_init);
+module_exit(ioc3_exit);
+
+MODULE_AUTHOR("Stanislaw Skowronek <skylark@linux-mips.org>");
+MODULE_DESCRIPTION("PCI driver for SGI IOC3");
+MODULE_LICENSE("GPL");
+
+EXPORT_SYMBOL(ioc3_register_submodule);
+EXPORT_SYMBOL(ioc3_unregister_submodule);
+EXPORT_SYMBOL(ioc3_ack);
+EXPORT_SYMBOL(ioc3_gpcr_set);
+EXPORT_SYMBOL(ioc3_disable);
+EXPORT_SYMBOL(ioc3_enable);