[PATCH] Altix system controller communication driver

drivers/char/Kconfig
    Make a config option for the SGI Altix system controller
    communication driver.

drivers/char/Makefile
    Add an object file target for the SGI Altix system controller
    communication driver.

drivers/char/snsc.c
    This file implements a driver that allows an application to
    communicate with the SGI Altix system controller network. Most of
    the heavy lifting is done in SAL in order to allow Linux run-time
    applications to share the system controller link(s) with SAL
    run-time services.

drivers/char/snsc.h
    Macros and data types for the Altix system controller driver
    (drivers/char/snsc.c).

drivers/serial/sn_console.c
    Modify the SGI Altix console driver to share an interupt with the
    system controller communication driver.

include/asm-ia64/sn/sn_sal.h
    Provide an interface to the SAL runtime services that allow the
    kernel or user applications to send/receive arbitary system
    controller data.
Signed-off-by: Greg Howard <ghoward@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/ia64/configs/generic_defconfig

@@ -575,6 +575,7 @@ CONFIG_SERIAL_NONSTANDARD=y
 # CONFIG_SYNCLINKMP is not set
 # CONFIG_N_HDLC is not set
 # CONFIG_STALDRV is not set
+CONFIG_SGI_SNSC=y
 
 #
 # Serial drivers

arch/ia64/configs/sn2_defconfig

@@ -527,6 +527,7 @@ CONFIG_SERIAL_NONSTANDARD=y
 # CONFIG_SYNCLINKMP is not set
 # CONFIG_N_HDLC is not set
 # CONFIG_STALDRV is not set
+CONFIG_SGI_SNSC=y
 
 #
 # Serial drivers

drivers/char/Kconfig

@@ -424,6 +424,14 @@ config A2232
 	  will also be built as a module. This has to be loaded before
 	  "ser_a2232". If you want to do this, answer M here.
 
+config SGI_SNSC
+	bool "SGI Altix system controller communication support"
+	depends on (IA64_SGI_SN2 || IA64_GENERIC)
+	help
+	  If you have an SGI Altix and you want to enable system
+	  controller communication from user space (you want this!),
+	  say Y.  Otherwise, say N.
+
 source "drivers/serial/Kconfig"
 
 config UNIX98_PTYS

drivers/char/Makefile

@@ -41,6 +41,7 @@ obj-$(CONFIG_SX)		+= sx.o generic_serial.o
 obj-$(CONFIG_RIO)		+= rio/ generic_serial.o
 obj-$(CONFIG_HVC_CONSOLE)	+= hvc_console.o hvsi.o
 obj-$(CONFIG_RAW_DRIVER)	+= raw.o
+obj-$(CONFIG_SGI_SNSC)		+= snsc.o
 obj-$(CONFIG_VIOCONS) += viocons.o
 obj-$(CONFIG_VIOTAPE)		+= viotape.o
 obj-$(CONFIG_HVCS)		+= hvcs.o

drivers/char/snsc.c

+/*
+ * SN Platform system controller communication support
+ *
+ * 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) 2004 Silicon Graphics, Inc. All rights reserved.
+ */
+
+/*
+ * System controller communication driver
+ *
+ * This driver allows a user process to communicate with the system
+ * controller (a.k.a. "IRouter") network in an SGI SN system.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <linux/device.h>
+#include <linux/poll.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <asm/sn/sn_sal.h>
+#include <asm/sn/nodepda.h>
+#include "snsc.h"
+
+#define SYSCTL_BASENAME	"snsc"
+
+#define SCDRV_BUFSZ	2048
+#define SCDRV_TIMEOUT	1000
+
+static irqreturn_t
+scdrv_interrupt(int irq, void *subch_data, struct pt_regs *regs)
+{
+	struct subch_data_s *sd = subch_data;
+	unsigned long flags;
+	int status;
+
+	spin_lock_irqsave(&sd->sd_rlock, flags);
+	spin_lock(&sd->sd_wlock);
+	status = ia64_sn_irtr_intr(sd->sd_nasid, sd->sd_subch);
+
+	if (status > 0) {
+		if (status & SAL_IROUTER_INTR_RECV) {
+			wake_up(&sd->sd_rq);
+		}
+		if (status & SAL_IROUTER_INTR_XMIT) {
+			ia64_sn_irtr_intr_disable
+			    (sd->sd_nasid, sd->sd_subch,
+			     SAL_IROUTER_INTR_XMIT);
+			wake_up(&sd->sd_wq);
+		}
+	}
+	spin_unlock(&sd->sd_wlock);
+	spin_unlock_irqrestore(&sd->sd_rlock, flags);
+	return IRQ_HANDLED;
+}
+
+/*
+ * scdrv_open
+ *
+ * Reserve a subchannel for system controller communication.
+ */
+
+static int
+scdrv_open(struct inode *inode, struct file *file)
+{
+	struct sysctl_data_s *scd;
+	struct subch_data_s *sd;
+	int rv;
+
+	/* look up device info for this device file */
+	scd = container_of(inode->i_cdev, struct sysctl_data_s, scd_cdev);
+
+	/* allocate memory for subchannel data */
+	sd = kmalloc(sizeof (struct subch_data_s), GFP_KERNEL);
+	if (sd == NULL) {
+		printk("%s: couldn't allocate subchannel data\n",
+		       __FUNCTION__);
+		return -ENOMEM;
+	}
+
+	/* initialize subch_data_s fields */
+	memset(sd, 0, sizeof (struct subch_data_s));
+	sd->sd_nasid = scd->scd_nasid;
+	sd->sd_subch = ia64_sn_irtr_open(scd->scd_nasid);
+
+	if (sd->sd_subch < 0) {
+		kfree(sd);
+		printk("%s: couldn't allocate subchannel\n", __FUNCTION__);
+		return -EBUSY;
+	}
+
+	spin_lock_init(&sd->sd_rlock);
+	spin_lock_init(&sd->sd_wlock);
+	init_waitqueue_head(&sd->sd_rq);
+	init_waitqueue_head(&sd->sd_wq);
+	sema_init(&sd->sd_rbs, 1);
+	sema_init(&sd->sd_wbs, 1);
+
+	file->private_data = sd;
+
+	/* hook this subchannel up to the system controller interrupt */
+	rv = request_irq(SGI_UART_VECTOR, scdrv_interrupt,
+			 SA_SHIRQ | SA_INTERRUPT,
+			 SYSCTL_BASENAME, sd);
+	if (rv) {
+		ia64_sn_irtr_close(sd->sd_nasid, sd->sd_subch);
+		kfree(sd);
+		printk("%s: irq request failed (%d)\n", __FUNCTION__, rv);
+		return -EBUSY;
+	}
+
+	return 0;
+}
+
+/*
+ * scdrv_release
+ *
+ * Release a previously-reserved subchannel.
+ */
+
+static int
+scdrv_release(struct inode *inode, struct file *file)
+{
+	struct subch_data_s *sd = (struct subch_data_s *) file->private_data;
+	int rv;
+
+	/* free the interrupt */
+	free_irq(SGI_UART_VECTOR, sd);
+
+	/* ask SAL to close the subchannel */
+	rv = ia64_sn_irtr_close(sd->sd_nasid, sd->sd_subch);
+
+	kfree(sd);
+	return rv;
+}
+
+/*
+ * scdrv_read
+ *
+ * Called to read bytes from the open IRouter pipe.
+ *
+ */
+
+static inline int
+read_status_check(struct subch_data_s *sd, int *len)
+{
+	return ia64_sn_irtr_recv(sd->sd_nasid, sd->sd_subch, sd->sd_rb, len);
+}
+
+static ssize_t
+scdrv_read(struct file *file, char __user *buf, size_t count, loff_t *f_pos)
+{
+	int status;
+	int len;
+	unsigned long flags;
+	struct subch_data_s *sd = (struct subch_data_s *) file->private_data;
+
+	/* try to get control of the read buffer */
+	if (down_trylock(&sd->sd_rbs)) {
+		/* somebody else has it now;
+		 * if we're non-blocking, then exit...
+		 */
+		if (file->f_flags & O_NONBLOCK) {
+			return -EAGAIN;
+		}
+		/* ...or if we want to block, then do so here */
+		if (down_interruptible(&sd->sd_rbs)) {
+			/* something went wrong with wait */
+			return -ERESTARTSYS;
+		}
+	}
+
+	/* anything to read? */
+	len = CHUNKSIZE;
+	spin_lock_irqsave(&sd->sd_rlock, flags);
+	status = read_status_check(sd, &len);
+
+	/* if not, and we're blocking I/O, loop */
+	while (status < 0) {
+		DECLARE_WAITQUEUE(wait, current);
+
+		if (file->f_flags & O_NONBLOCK) {
+			spin_unlock_irqrestore(&sd->sd_rlock, flags);
+			up(&sd->sd_rbs);
+			return -EAGAIN;
+		}
+
+		len = CHUNKSIZE;
+		add_wait_queue(&sd->sd_rq, &wait);
+		set_current_state(TASK_INTERRUPTIBLE);
+		spin_unlock_irqrestore(&sd->sd_rlock, flags);
+
+		schedule_timeout(SCDRV_TIMEOUT);
+
+		remove_wait_queue(&sd->sd_rq, &wait);
+		if (signal_pending(current)) {
+			/* wait was interrupted */
+			up(&sd->sd_rbs);
+			return -ERESTARTSYS;
+		}
+
+		spin_lock_irqsave(&sd->sd_rlock, flags);
+		status = read_status_check(sd, &len);
+	}
+	spin_unlock_irqrestore(&sd->sd_rlock, flags);
+
+	if (len > 0) {
+		/* we read something in the last read_status_check(); copy
+		 * it out to user space
+		 */
+		if (count < len) {
+			pr_debug("%s: only accepting %d of %d bytes\n",
+				 __FUNCTION__, (int) count, len);
+		}
+		len = min((int) count, len);
+		if (copy_to_user(buf, sd->sd_rb, len))
+			len = -EFAULT;
+	}
+
+	/* release the read buffer and wake anyone who might be
+	 * waiting for it
+	 */
+	up(&sd->sd_rbs);
+
+	/* return the number of characters read in */
+	return len;
+}
+
+/*
+ * scdrv_write
+ *
+ * Writes a chunk of an IRouter packet (or other system controller data)
+ * to the system controller.
+ *
+ */
+static inline int
+write_status_check(struct subch_data_s *sd, int count)
+{
+	return ia64_sn_irtr_send(sd->sd_nasid, sd->sd_subch, sd->sd_wb, count);
+}
+
+static ssize_t
+scdrv_write(struct file *file, const char __user *buf,
+	    size_t count, loff_t *f_pos)
+{
+	unsigned long flags;
+	int status;
+	struct subch_data_s *sd = (struct subch_data_s *) file->private_data;
+
+	/* try to get control of the write buffer */
+	if (down_trylock(&sd->sd_wbs)) {
+		/* somebody else has it now;
+		 * if we're non-blocking, then exit...
+		 */
+		if (file->f_flags & O_NONBLOCK) {
+			return -EAGAIN;
+		}
+		/* ...or if we want to block, then do so here */
+		if (down_interruptible(&sd->sd_wbs)) {
+			/* something went wrong with wait */
+			return -ERESTARTSYS;
+		}
+	}
+
+	count = min((int) count, CHUNKSIZE);
+	if (copy_from_user(sd->sd_wb, buf, count)) {
+		up(&sd->sd_wbs);
+		return -EFAULT;
+	}
+
+	/* try to send the buffer */
+	spin_lock_irqsave(&sd->sd_wlock, flags);
+	status = write_status_check(sd, count);
+
+	/* if we failed, and we want to block, then loop */
+	while (status <= 0) {
+		DECLARE_WAITQUEUE(wait, current);
+
+		if (file->f_flags & O_NONBLOCK) {
+			spin_unlock(&sd->sd_wlock);
+			up(&sd->sd_wbs);
+			return -EAGAIN;
+		}
+
+		add_wait_queue(&sd->sd_wq, &wait);
+		set_current_state(TASK_INTERRUPTIBLE);
+		spin_unlock_irqrestore(&sd->sd_wlock, flags);
+
+		schedule_timeout(SCDRV_TIMEOUT);
+
+		remove_wait_queue(&sd->sd_wq, &wait);
+		if (signal_pending(current)) {
+			/* wait was interrupted */
+			up(&sd->sd_wbs);
+			return -ERESTARTSYS;
+		}
+
+		spin_lock_irqsave(&sd->sd_wlock, flags);
+		status = write_status_check(sd, count);
+	}
+	spin_unlock_irqrestore(&sd->sd_wlock, flags);
+
+	/* release the write buffer and wake anyone who's waiting for it */
+	up(&sd->sd_wbs);
+
+	/* return the number of characters accepted (should be the complete
+	 * "chunk" as requested)
+	 */
+	if ((status >= 0) && (status < count)) {
+		pr_debug("Didn't accept the full chunk; %d of %d\n",
+			 status, (int) count);
+	}
+	return status;
+}
+
+static unsigned int
+scdrv_poll(struct file *file, struct poll_table_struct *wait)
+{
+	unsigned int mask = 0;
+	int status = 0;
+	struct subch_data_s *sd = (struct subch_data_s *) file->private_data;
+	unsigned long flags;
+
+	poll_wait(file, &sd->sd_rq, wait);
+	poll_wait(file, &sd->sd_wq, wait);
+
+	spin_lock_irqsave(&sd->sd_rlock, flags);
+	spin_lock(&sd->sd_wlock);
+	status = ia64_sn_irtr_intr(sd->sd_nasid, sd->sd_subch);
+	spin_unlock(&sd->sd_wlock);
+	spin_unlock_irqrestore(&sd->sd_rlock, flags);
+
+	if (status > 0) {
+		if (status & SAL_IROUTER_INTR_RECV) {
+			mask |= POLLIN | POLLRDNORM;
+		}
+		if (status & SAL_IROUTER_INTR_XMIT) {
+			mask |= POLLOUT | POLLWRNORM;
+		}
+	}
+
+	return mask;
+}
+
+static struct file_operations scdrv_fops = {
+	.owner =	THIS_MODULE,
+	.read =		scdrv_read,
+	.write =	scdrv_write,
+	.poll =		scdrv_poll,
+	.open =		scdrv_open,
+	.release =	scdrv_release,
+};
+
+/*
+ * scdrv_init
+ *
+ * Called at boot time to initialize the system controller communication
+ * facility.
+ */
+int __init
+scdrv_init(void)
+{
+	geoid_t geoid;
+	cmoduleid_t cmod;
+	int i;
+	char devname[32];
+	char *devnamep;
+	module_t *m;
+	struct sysctl_data_s *scd;
+	void *salbuf;
+	struct class_simple *snsc_class;
+	dev_t first_dev, dev;
+
+	if (alloc_chrdev_region(&first_dev, 0, (MAX_SLABS*nummodules),
+				SYSCTL_BASENAME) < 0) {
+		printk("%s: failed to register SN system controller device\n",
+		       __FUNCTION__);
+		return -ENODEV;
+	}
+	snsc_class = class_simple_create(THIS_MODULE, SYSCTL_BASENAME);
+
+	for (cmod = 0; cmod < nummodules; cmod++) {
+		m = sn_modules[cmod];
+		for (i = 0; i <= MAX_SLABS; i++) {
+
+			if (m->nodes[i] == -1) {
+				/* node is not alive in module */
+				continue;
+			}
+
+			geoid = m->geoid[i];
+			devnamep = devname;
+			format_module_id(devnamep, geo_module(geoid),
+					 MODULE_FORMAT_BRIEF);
+			devnamep = devname + strlen(devname);
+			sprintf(devnamep, "#%d", geo_slab(geoid));
+
+			/* allocate sysctl device data */
+			scd = kmalloc(sizeof (struct sysctl_data_s),
+				      GFP_KERNEL);
+			if (!scd) {
+				printk("%s: failed to allocate device info"
+				       "for %s/%s\n", __FUNCTION__,
+				       SYSCTL_BASENAME, devname);
+				continue;
+			}
+			memset(scd, 0, sizeof (struct sysctl_data_s));
+
+			/* initialize sysctl device data fields */
+			scd->scd_nasid = cnodeid_to_nasid(m->nodes[i]);
+			if (!(salbuf = kmalloc(SCDRV_BUFSZ, GFP_KERNEL))) {
+				printk("%s: failed to allocate driver buffer"
+				       "(%s%s)\n", __FUNCTION__,
+				       SYSCTL_BASENAME, devname);
+				kfree(scd);
+				continue;
+			}
+
+			if (ia64_sn_irtr_init(scd->scd_nasid, salbuf,
+					      SCDRV_BUFSZ) < 0) {
+				printk
+				    ("%s: failed to initialize SAL for"
+				     " system controller communication"
+				     " (%s/%s): outdated PROM?\n",
+				     __FUNCTION__, SYSCTL_BASENAME, devname);
+				kfree(scd);
+				kfree(salbuf);
+				continue;
+			}
+
+			dev = first_dev + m->nodes[i];
+			cdev_init(&scd->scd_cdev, &scdrv_fops);
+			if (cdev_add(&scd->scd_cdev, dev, 1)) {
+				printk("%s: failed to register system"
+				       " controller device (%s%s)\n",
+				       __FUNCTION__, SYSCTL_BASENAME, devname);
+				kfree(scd);
+				kfree(salbuf);
+				continue;
+			}
+
+			class_simple_device_add(snsc_class, dev, NULL,
+						"%s", devname);
+
+			ia64_sn_irtr_intr_enable(scd->scd_nasid,
+						 0 /*ignored */ ,
+						 SAL_IROUTER_INTR_RECV);
+		}
+	}
+	return 0;
+}
+
+module_init(scdrv_init);

drivers/char/snsc.h

+/*
+ * SN Platform system controller communication support
+ *
+ * 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) 2004 Silicon Graphics, Inc. All rights reserved.
+ */
+
+/*
+ * This file contains macros and data types for communication with the
+ * system controllers in SGI SN systems.
+ */
+
+#ifndef _SN_SYSCTL_H_
+#define _SN_SYSCTL_H_
+
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/wait.h>
+#include <linux/kobject.h>
+#include <linux/fs.h>
+#include <linux/cdev.h>
+#include <asm/sn/types.h>
+#include <asm/semaphore.h>
+
+#define CHUNKSIZE 127
+
+/* This structure is used to track an open subchannel. */
+struct subch_data_s {
+	nasid_t sd_nasid;	/* node on which the subchannel was opened */
+	int sd_subch;		/* subchannel number */
+	spinlock_t sd_rlock;	/* monitor lock for rsv */
+	spinlock_t sd_wlock;	/* monitor lock for wsv */
+	wait_queue_head_t sd_rq;	/* wait queue for readers */
+	wait_queue_head_t sd_wq;	/* wait queue for writers */
+	struct semaphore sd_rbs;	/* semaphore for read buffer */
+	struct semaphore sd_wbs;	/* semaphore for write buffer */
+
+	char sd_rb[CHUNKSIZE];	/* read buffer */
+	char sd_wb[CHUNKSIZE];	/* write buffer */
+};
+
+struct sysctl_data_s {
+	struct cdev scd_cdev;	/* Character device info */
+	nasid_t scd_nasid;	/* Node on which subchannels are opened. */
+};
+
+#endif /* _SN_SYSCTL_H_ */

drivers/serial/sn_console.c

@@ -714,7 +714,8 @@ sn_sal_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 static int
 sn_sal_connect_interrupt(struct sn_cons_port *port)
 {
-	if (request_irq(SGI_UART_VECTOR, sn_sal_interrupt, SA_INTERRUPT,
+	if (request_irq(SGI_UART_VECTOR, sn_sal_interrupt,
+			SA_INTERRUPT | SA_SHIRQ,
 			"SAL console driver", port) >= 0) {
 		return SGI_UART_VECTOR;
 	}

include/asm-ia64/sn/sn_sal.h

@@ -8,7 +8,7 @@
  * License.  See the file "COPYING" in the main directory of this archive
  * for more details.
  *
- * Copyright (c) 2000-2003 Silicon Graphics, Inc.  All rights reserved.
+ * Copyright (c) 2000-2004 Silicon Graphics, Inc.  All rights reserved.
  */
 
 
@@ -60,6 +60,7 @@
 #define  SN_SAL_SYSCTL_FRU_CAPTURE		   0x0200003f
 
 #define  SN_SAL_SYSCTL_IOBRICK_PCI_OP		   0x02000042	// reentrant
+#define	 SN_SAL_IROUTER_OP			   0x02000043
 
 /*
  * Service-specific constants
@@ -85,6 +86,25 @@
 
 #endif	/* CONFIG_HOTPLUG_PCI_SGI */
 
+/*
+ * IRouter (i.e. generalized system controller) operations
+ */
+#define SAL_IROUTER_OPEN	0	/* open a subchannel */
+#define SAL_IROUTER_CLOSE	1	/* close a subchannel */
+#define SAL_IROUTER_SEND	2	/* send part of an IRouter packet */
+#define SAL_IROUTER_RECV	3	/* receive part of an IRouter packet */
+#define SAL_IROUTER_INTR_STATUS	4	/* check the interrupt status for
+					 * an open subchannel
+					 */
+#define SAL_IROUTER_INTR_ON	5	/* enable an interrupt */
+#define SAL_IROUTER_INTR_OFF	6	/* disable an interrupt */
+#define SAL_IROUTER_INIT	7	/* initialize IRouter driver */
+
+/* IRouter interrupt mask bits */
+#define SAL_IROUTER_INTR_XMIT	SAL_CONSOLE_INTR_XMIT
+#define SAL_IROUTER_INTR_RECV	SAL_CONSOLE_INTR_RECV
+
+
 /*
  * SN_SAL_GET_PARTITION_ADDR return constants
  */
@@ -704,4 +724,124 @@ ia64_sn_set_error_handling_features(const u64 *feature_bits)
 	return rv.status;
 }
 
+
+/*
+ * Open a subchannel for sending arbitrary data to the system
+ * controller network via the system controller device associated with
+ * 'nasid'.  Return the subchannel number or a negative error code.
+ */
+static inline int
+ia64_sn_irtr_open(nasid_t nasid)
+{
+	struct ia64_sal_retval rv;
+	SAL_CALL_REENTRANT(rv, SN_SAL_IROUTER_OP, SAL_IROUTER_OPEN, nasid,
+			   0, 0, 0, 0, 0);
+	return (int) rv.v0;
+}
+
+/*
+ * Close system controller subchannel 'subch' previously opened on 'nasid'.
+ */
+static inline int
+ia64_sn_irtr_close(nasid_t nasid, int subch)
+{
+	struct ia64_sal_retval rv;
+	SAL_CALL_REENTRANT(rv, SN_SAL_IROUTER_OP, SAL_IROUTER_CLOSE,
+			   (u64) nasid, (u64) subch, 0, 0, 0, 0);
+	return (int) rv.status;
+}
+
+/*
+ * Read data from system controller associated with 'nasid' on
+ * subchannel 'subch'.  The buffer to be filled is pointed to by
+ * 'buf', and its capacity is in the integer pointed to by 'len'.  The
+ * referent of 'len' is set to the number of bytes read by the SAL
+ * call.  The return value is either SALRET_OK (for bytes read) or
+ * SALRET_ERROR (for error or "no data available").
+ */
+static inline int
+ia64_sn_irtr_recv(nasid_t nasid, int subch, char *buf, int *len)
+{
+	struct ia64_sal_retval rv;
+	SAL_CALL_REENTRANT(rv, SN_SAL_IROUTER_OP, SAL_IROUTER_RECV,
+			   (u64) nasid, (u64) subch, (u64) buf, (u64) len,
+			   0, 0);
+	return (int) rv.status;
+}
+
+/*
+ * Write data to the system controller network via the system
+ * controller associated with 'nasid' on suchannel 'subch'.  The
+ * buffer to be written out is pointed to by 'buf', and 'len' is the
+ * number of bytes to be written.  The return value is either the
+ * number of bytes written (which could be zero) or a negative error
+ * code.
+ */
+static inline int
+ia64_sn_irtr_send(nasid_t nasid, int subch, char *buf, int len)
+{
+	struct ia64_sal_retval rv;
+	SAL_CALL_REENTRANT(rv, SN_SAL_IROUTER_OP, SAL_IROUTER_SEND,
+			   (u64) nasid, (u64) subch, (u64) buf, (u64) len,
+			   0, 0);
+	return (int) rv.v0;
+}
+
+/*
+ * Check whether any interrupts are pending for the system controller
+ * associated with 'nasid' and its subchannel 'subch'.  The return
+ * value is a mask of pending interrupts (SAL_IROUTER_INTR_XMIT and/or
+ * SAL_IROUTER_INTR_RECV).
+ */
+static inline int
+ia64_sn_irtr_intr(nasid_t nasid, int subch)
+{
+	struct ia64_sal_retval rv;
+	SAL_CALL_REENTRANT(rv, SN_SAL_IROUTER_OP, SAL_IROUTER_INTR_STATUS,
+			   (u64) nasid, (u64) subch, 0, 0, 0, 0);
+	return (int) rv.v0;
+}
+
+/*
+ * Enable the interrupt indicated by the intr parameter (either
+ * SAL_IROUTER_INTR_XMIT or SAL_IROUTER_INTR_RECV).
+ */
+static inline int
+ia64_sn_irtr_intr_enable(nasid_t nasid, int subch, u64 intr)
+{
+	struct ia64_sal_retval rv;
+	SAL_CALL_REENTRANT(rv, SN_SAL_IROUTER_OP, SAL_IROUTER_INTR_ON,
+			   (u64) nasid, (u64) subch, intr, 0, 0, 0);
+	return (int) rv.v0;
+}
+
+/*
+ * Disable the interrupt indicated by the intr parameter (either
+ * SAL_IROUTER_INTR_XMIT or SAL_IROUTER_INTR_RECV).
+ */
+static inline int
+ia64_sn_irtr_intr_disable(nasid_t nasid, int subch, u64 intr)
+{
+	struct ia64_sal_retval rv;
+	SAL_CALL_REENTRANT(rv, SN_SAL_IROUTER_OP, SAL_IROUTER_INTR_OFF,
+			   (u64) nasid, (u64) subch, intr, 0, 0, 0);
+	return (int) rv.v0;
+}
+
+/*
+ * Initialize the SAL components of the system controller
+ * communication driver; specifically pass in a sizable buffer that
+ * can be used for allocation of subchannel queues as new subchannels
+ * are opened.  "buf" points to the buffer, and "len" specifies its
+ * length.
+ */
+static inline int
+ia64_sn_irtr_init(nasid_t nasid, void *buf, int len)
+{
+	struct ia64_sal_retval rv;
+	SAL_CALL_REENTRANT(rv, SN_SAL_IROUTER_OP, SAL_IROUTER_INIT,
+			   (u64) nasid, (u64) buf, (u64) len, 0, 0, 0);
+	return (int) rv.status;
+}
+
 #endif /* _ASM_IA64_SN_SN_SAL_H */