[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.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 */