patch-2.4.21 linux-2.4.21/arch/ia64/sn/io/sn1/l1.c

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diff -urN linux-2.4.20/arch/ia64/sn/io/sn1/l1.c linux-2.4.21/arch/ia64/sn/io/sn1/l1.c
@@ -0,0 +1,3124 @@
+/* $Id: l1.c,v 1.2 2002/11/16 02:23:19 steiner Exp $
+ *
+ * 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) 1992-1997, 2000-2002 Silicon Graphics, Inc.  All rights reserved.
+ */
+
+/* In general, this file is organized in a hierarchy from lower-level
+ * to higher-level layers, as follows:
+ *
+ *	UART routines
+ *	Bedrock/L1 "PPP-like" protocol implementation
+ *	System controller "message" interface (allows multiplexing
+ *		of various kinds of requests and responses with
+ *		console I/O)
+ *	Console interface:
+ *	  "l1_cons", the glue that allows the L1 to act
+ *		as the system console for the stdio libraries
+ *
+ * Routines making use of the system controller "message"-style interface
+ * can be found in l1_command.c.
+ */
+
+
+#include <linux/types.h>
+#include <linux/config.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/delay.h>
+#include <asm/sn/sgi.h>
+#include <asm/sn/io.h>
+#include <asm/sn/iograph.h>
+#include <asm/sn/invent.h>
+#include <asm/sn/hcl.h>
+#include <asm/sn/hcl_util.h>
+#include <asm/sn/labelcl.h>
+#include <asm/sn/eeprom.h>
+#include <asm/sn/router.h>
+#include <asm/sn/module.h>
+#include <asm/sn/ksys/l1.h>
+#include <asm/sn/nodepda.h>
+#include <asm/sn/clksupport.h>
+#include <asm/sn/sn_sal.h>
+#include <asm/sn/sn_cpuid.h>
+#include <asm/sn/uart16550.h>
+#include <asm/sn/simulator.h>
+
+
+/* Make all console writes atomic */
+#define SYNC_CONSOLE_WRITE	1
+
+
+/*********************************************************************
+ * Hardware-level (UART) driver routines.
+ */
+
+/* macros for reading/writing registers */
+
+/* USLD and USSD are needed for SN2 - but since we moving this code out soon ... */
+#define LD(x)			(*(volatile uint64_t *)(x))
+#define USLD(x)			LD(x)			// (*(volatile ushort *)(x))
+#define SD(x, v)        	(LD(x) = (uint64_t) (v))
+#define USSD(x, v)        	SD(x,v)			// (USLD(x) = (ushort) (v))
+
+/* location of uart receive/xmit data register */
+#define L1_UART_BASE(n)		((ulong)REMOTE_HSPEC_ADDR((n), 0x00000080))
+#define LOCK_HUB		REMOTE_HUB_ADDR
+
+#define ADDR_L1_REG(n, r)	( L1_UART_BASE(n) | ( (r) << 3 ) )
+#define READ_L1_UART_REG(n, r)  ( LD(ADDR_L1_REG((n), (r))) )
+
+#define WRITE_L1_UART_REG(n, r, v) ( SD(ADDR_L1_REG((n), (r)), (v)) )
+
+/* upper layer interface calling methods */
+#define SERIAL_INTERRUPT_MODE	0
+#define SERIAL_POLLED_MODE	1
+
+
+/* UART-related #defines */
+
+#define UART_BAUD_RATE		57600
+#define UART_FIFO_DEPTH		16
+#define UART_DELAY_SPAN		10
+#define UART_PUTC_TIMEOUT	50000
+#define UART_INIT_TIMEOUT	100000
+
+/* error codes */
+#define UART_SUCCESS		  0
+#define UART_TIMEOUT		(-1)
+#define UART_LINK		(-2)
+#define UART_NO_CHAR		(-3)
+#define UART_VECTOR		(-4)
+
+#define UART_DELAY(x)		udelay(x)
+
+/* Some debug counters */
+#define L1C_INTERRUPTS		0
+#define L1C_OUR_R_INTERRUPTS	1
+#define L1C_OUR_X_INTERRUPTS	2
+#define L1C_SEND_CALLUPS	3
+#define L1C_RECEIVE_CALLUPS	4
+#define L1C_SET_BAUD		5
+#define L1C_ALREADY_LOCKED	L1C_SET_BAUD
+#define L1C_R_IRQ		6
+#define L1C_R_IRQ_RET		7
+#define L1C_LOCK_TIMEOUTS	8
+#define L1C_LOCK_COUNTER	9
+#define L1C_UNLOCK_COUNTER	10
+#define L1C_REC_STALLS		11
+#define L1C_CONNECT_CALLS	12
+#define L1C_SIZE		L1C_CONNECT_CALLS	/* Set to the last one */
+
+uint64_t L1_collectibles[L1C_SIZE + 1];
+
+
+/*
+ *	Some macros for handling Endian-ness
+ */
+
+#define COPY_INT_TO_BUFFER(_b, _i, _n)		\
+	{					\
+		_b[_i++] = (_n >> 24) & 0xff;	\
+		_b[_i++] = (_n >> 16) & 0xff;	\
+		_b[_i++] = (_n >>  8) & 0xff;	\
+		_b[_i++] =  _n        & 0xff;	\
+	}
+
+#define COPY_BUFFER_TO_INT(_b, _i, _n)		\
+	{					\
+		_n  = (_b[_i++] << 24) & 0xff;	\
+		_n |= (_b[_i++] << 16) & 0xff;	\
+		_n |= (_b[_i++] <<  8) & 0xff;	\
+		_n |=  _b[_i++]        & 0xff;	\
+	}
+
+#define COPY_BUFFER_TO_BUFFER(_b, _i, _bn)	\
+	{					\
+	    char *_xyz = (char *)_bn;		\
+	    _xyz[3] = _b[_i++];			\
+	    _xyz[2] = _b[_i++];			\
+	    _xyz[1] = _b[_i++];			\
+	    _xyz[0] = _b[_i++];			\
+	}
+
+void snia_kmem_free(void *where, int size);
+
+#define ALREADY_LOCKED		1
+#define NOT_LOCKED		0
+static int early_l1_serial_out(nasid_t, char *, int, int /* defines above*/ );
+
+#define BCOPY(x,y,z)	memcpy(y,x,z)
+
+uint8_t L1_interrupts_connected;		/* Non-zero when we are in interrupt mode */
+
+
+/*
+ * Console locking defines and functions.
+ *
+ */
+
+uint8_t L1_cons_is_inited = 0;			/* non-zero when console is init'd */
+nasid_t Master_console_nasid = (nasid_t)-1;
+extern nasid_t console_nasid;
+
+u64 ia64_sn_get_console_nasid(void);
+
+inline nasid_t
+get_master_nasid(void)
+{
+	nasid_t nasid = Master_console_nasid;
+
+	master_nasid = Master_console_nasid = nasid = 0;
+	if ( nasid == (nasid_t)-1 ) {
+		nasid = (nasid_t)ia64_sn_get_console_nasid();
+		if ( (nasid < 0) || (nasid >= MAX_NASIDS) ) {
+			/* Out of bounds, use local */
+			console_nasid = nasid = get_nasid();
+		}
+		else {
+			/* Got a valid nasid, set the console_nasid */
+			char xx[100];
+/* zzzzzz - force nasid to 0 for now */
+			sprintf(xx, "Master console is set to nasid %d (%d)\n", 0, (int)nasid);
+nasid = 0;
+/* end zzzzzz */
+			xx[99] = (char)0;
+			early_l1_serial_out(nasid, xx, strlen(xx), NOT_LOCKED);
+			Master_console_nasid = console_nasid = nasid;
+		}
+	}
+	return(nasid);
+}
+
+
+
+#define HUB_LOCK		16
+
+#define PRIMARY_LOCK_TIMEOUT    10000000
+#define HUB_LOCK_REG(n)         LOCK_HUB(n, MD_PERF_CNT0)
+
+#define SET_BITS(reg, bits)     SD(reg, LD(reg) |  (bits))
+#define CLR_BITS(reg, bits)     SD(reg, LD(reg) & ~(bits))
+#define TST_BITS(reg, bits)     ((LD(reg) & (bits)) != 0)
+
+#define HUB_TEST_AND_SET(n)	LD(LOCK_HUB(n,LB_SCRATCH_REG3_RZ))
+#define HUB_CLEAR(n)		SD(LOCK_HUB(n,LB_SCRATCH_REG3),0)
+
+#define RTC_TIME_MAX		((rtc_time_t) ~0ULL)
+
+/*
+ * primary_lock
+ *
+ *   Allows CPU's 0-3  to mutually exclude the hub from one another by
+ *   obtaining a blocking lock.  Does nothing if only one CPU is active.
+ *
+ *   This lock should be held just long enough to set or clear a global
+ *   lock bit.  After a relatively short timeout period, this routine
+ *   figures something is wrong, and steals the lock. It does not set
+ *   any other CPU to "dead".
+ */
+inline void
+primary_lock(nasid_t nasid)
+{
+	rtc_time_t          expire;
+
+	expire = rtc_time() + PRIMARY_LOCK_TIMEOUT;
+
+	while (HUB_TEST_AND_SET(nasid)) {
+		if (rtc_time() > expire) {
+			HUB_CLEAR(nasid);
+		}
+	}
+}
+
+/*
+ * primary_unlock (internal)
+ *
+ *   Counterpart to primary_lock
+ */
+
+inline void
+primary_unlock(nasid_t nasid)
+{
+	HUB_CLEAR(nasid);
+}
+
+/*
+ * hub_unlock
+ *
+ *   Counterpart to hub_lock_timeout and hub_lock
+ */
+
+inline void
+hub_unlock(nasid_t nasid, int level)
+{
+	uint64_t mask = 1ULL << level;
+
+	primary_lock(nasid);
+	CLR_BITS(HUB_LOCK_REG(nasid), mask);
+	primary_unlock(nasid);
+}
+
+/*
+ * hub_lock_timeout
+ *
+ *   Uses primary_lock to implement multiple lock levels.
+ *
+ *   There are 20 lock levels from 0 to 19 (limited by the number of bits
+ *   in HUB_LOCK_REG).  To prevent deadlock, multiple locks should be
+ *   obtained in order of increasingly higher level, and released in the
+ *   reverse order.
+ *
+ *   A timeout value of 0 may be used for no timeout.
+ *
+ *   Returns 0 if successful, -1 if lock times out.
+ */
+
+inline int
+hub_lock_timeout(nasid_t nasid, int level, rtc_time_t timeout)
+{
+	uint64_t mask = 1ULL << level;
+	rtc_time_t expire = (timeout ?  rtc_time() + timeout : RTC_TIME_MAX);
+	int done    = 0;
+
+	while (! done) {
+		while (TST_BITS(HUB_LOCK_REG(nasid), mask)) {
+			if (rtc_time() > expire)
+				return -1;
+		}
+
+		primary_lock(nasid);
+
+		if (! TST_BITS(HUB_LOCK_REG(nasid), mask)) {
+			SET_BITS(HUB_LOCK_REG(nasid), mask);
+			done = 1;
+		}
+		primary_unlock(nasid);
+	}
+	return 0;
+}
+
+
+#define LOCK_TIMEOUT	(0x1500000 * 1) /* 0x1500000 is ~30 sec */
+
+void
+lock_console(nasid_t nasid)
+{
+	int ret;
+
+	/* If we already have it locked, just return */
+	L1_collectibles[L1C_LOCK_COUNTER]++;
+
+	ret = hub_lock_timeout(nasid, HUB_LOCK, (rtc_time_t)LOCK_TIMEOUT);
+	if ( ret != 0 ) {
+		L1_collectibles[L1C_LOCK_TIMEOUTS]++;
+		/* timeout */
+		hub_unlock(nasid, HUB_LOCK);
+		/* If the 2nd lock fails, just pile ahead.... */
+		hub_lock_timeout(nasid, HUB_LOCK, (rtc_time_t)LOCK_TIMEOUT);
+		L1_collectibles[L1C_LOCK_TIMEOUTS]++;
+	}
+}
+
+inline void
+unlock_console(nasid_t nasid)
+{
+	L1_collectibles[L1C_UNLOCK_COUNTER]++;
+	hub_unlock(nasid, HUB_LOCK);
+}
+
+
+int 
+get_L1_baud(void)
+{
+    return UART_BAUD_RATE;
+}
+
+
+/* uart driver functions */
+
+static inline void
+uart_delay( rtc_time_t delay_span )
+{
+    UART_DELAY( delay_span );
+}
+
+#define UART_PUTC_READY(n)      (READ_L1_UART_REG((n), REG_LSR) & LSR_XHRE)
+
+static int
+uart_putc( l1sc_t *sc ) 
+{
+    WRITE_L1_UART_REG( sc->nasid, REG_DAT, sc->send[sc->sent] );
+    return UART_SUCCESS;
+}
+
+
+static int
+uart_getc( l1sc_t *sc )
+{
+    u_char lsr_reg = 0;
+    nasid_t nasid = sc->nasid;
+
+    if( (lsr_reg = READ_L1_UART_REG( nasid, REG_LSR )) & 
+	(LSR_RCA | LSR_PARERR | LSR_FRMERR) ) 
+    {
+	if( lsr_reg & LSR_RCA ) 
+	    return( (u_char)READ_L1_UART_REG( nasid, REG_DAT ) );
+	else if( lsr_reg & (LSR_PARERR | LSR_FRMERR) ) {
+	    return UART_LINK;
+	}
+    }
+    return UART_NO_CHAR;
+}
+
+
+#define PROM_SER_CLK_SPEED	12000000
+#define PROM_SER_DIVISOR(x)	(PROM_SER_CLK_SPEED / ((x) * 16))
+
+static void
+uart_init( l1sc_t *sc, int baud )
+{
+#if !defined(USE_SAL_CONSOLE_IO)
+    rtc_time_t expire;
+    int clkdiv;
+    nasid_t nasid;
+
+    clkdiv = PROM_SER_DIVISOR(baud);
+    expire = rtc_time() + UART_INIT_TIMEOUT;
+    nasid = sc->nasid;
+    
+    /* make sure the transmit FIFO is empty */
+    while( !(READ_L1_UART_REG( nasid, REG_LSR ) & LSR_XSRE) ) {
+	uart_delay( UART_DELAY_SPAN );
+	if( rtc_time() > expire ) {
+	    break;
+	}
+    }
+
+    if ( sc->uart == BRL1_LOCALHUB_UART )
+	lock_console(nasid);
+
+    /* Setup for the proper baud rate */
+    WRITE_L1_UART_REG( nasid, REG_LCR, LCR_DLAB );
+	uart_delay( UART_DELAY_SPAN );
+    WRITE_L1_UART_REG( nasid, REG_DLH, (clkdiv >> 8) & 0xff );
+	uart_delay( UART_DELAY_SPAN );
+    WRITE_L1_UART_REG( nasid, REG_DLL, clkdiv & 0xff );
+	uart_delay( UART_DELAY_SPAN );
+
+    /* set operating parameters and set DLAB to 0 */
+
+    /* 8bit, one stop, clear request to send, auto flow control */
+    WRITE_L1_UART_REG( nasid, REG_LCR, LCR_BITS8 | LCR_STOP1 );
+	uart_delay( UART_DELAY_SPAN );
+    WRITE_L1_UART_REG( nasid, REG_MCR, MCR_RTS | MCR_AFE );
+	uart_delay( UART_DELAY_SPAN );
+
+    /* disable interrupts */
+    WRITE_L1_UART_REG( nasid, REG_ICR, 0x0 );
+	uart_delay( UART_DELAY_SPAN );
+
+    /* enable FIFO mode and reset both FIFOs, trigger on 1 */
+    WRITE_L1_UART_REG( nasid, REG_FCR, FCR_FIFOEN );
+	uart_delay( UART_DELAY_SPAN );
+    WRITE_L1_UART_REG( nasid, REG_FCR, FCR_FIFOEN | FCR_RxFIFO | FCR_TxFIFO | RxLVL0);
+
+    if ( sc->uart == BRL1_LOCALHUB_UART )
+	unlock_console(nasid);
+#endif	/* !USE_SAL_CONSOLE_IO */
+}
+
+/* This requires the console lock */
+
+
+static void
+uart_intr_enable( l1sc_t *sc, u_char mask )
+{
+    u_char lcr_reg, icr_reg;
+    nasid_t nasid = sc->nasid;
+
+    if ( sc->uart == BRL1_LOCALHUB_UART )
+	lock_console(nasid);
+
+    /* make sure that the DLAB bit in the LCR register is 0
+     */
+    lcr_reg = READ_L1_UART_REG( nasid, REG_LCR );
+    lcr_reg &= ~(LCR_DLAB);
+    WRITE_L1_UART_REG( nasid, REG_LCR, lcr_reg );
+
+    /* enable indicated interrupts
+     */
+    icr_reg = READ_L1_UART_REG( nasid, REG_ICR );
+    icr_reg |= mask;
+    WRITE_L1_UART_REG( nasid, REG_ICR, icr_reg /*(ICR_RIEN | ICR_TIEN)*/ );
+
+    if ( sc->uart == BRL1_LOCALHUB_UART )
+	unlock_console(nasid);
+}
+
+/* This requires the console lock */
+static void
+uart_intr_disable( l1sc_t *sc, u_char mask )
+{
+    u_char lcr_reg, icr_reg;
+    nasid_t nasid = sc->nasid;
+
+    if ( sc->uart == BRL1_LOCALHUB_UART )
+	lock_console(nasid);
+
+    /* make sure that the DLAB bit in the LCR register is 0
+     */
+    lcr_reg = READ_L1_UART_REG( nasid, REG_LCR );
+    lcr_reg &= ~(LCR_DLAB);
+    WRITE_L1_UART_REG( nasid, REG_LCR, lcr_reg );
+
+    /* enable indicated interrupts
+     */
+    icr_reg = READ_L1_UART_REG( nasid, REG_ICR );
+    icr_reg &= mask;
+    WRITE_L1_UART_REG( nasid, REG_ICR, icr_reg /*(ICR_RIEN | ICR_TIEN)*/ );
+
+    if ( sc->uart == BRL1_LOCALHUB_UART )
+	unlock_console(nasid);
+}
+
+#define uart_enable_xmit_intr(sc) \
+	uart_intr_enable((sc), ICR_TIEN)
+
+#define uart_disable_xmit_intr(sc) \
+        uart_intr_disable((sc), ~(ICR_TIEN))
+
+#define uart_enable_recv_intr(sc) \
+        uart_intr_enable((sc), ICR_RIEN)
+
+#define uart_disable_recv_intr(sc) \
+        uart_intr_disable((sc), ~(ICR_RIEN))
+
+
+/*********************************************************************
+ * Routines for accessing a remote (router) UART
+ */
+
+#define READ_RTR_L1_UART_REG(p, n, r, v)		\
+    {							\
+	if( vector_read_node( (p), (n), 0,		\
+			      RR_JBUS1(r), (v) ) ) {	\
+	    return UART_VECTOR;				\
+	}						\
+    }
+
+#define WRITE_RTR_L1_UART_REG(p, n, r, v)		\
+    {							\
+	if( vector_write_node( (p), (n), 0,		\
+			       RR_JBUS1(r), (v) ) ) {	\
+	    return UART_VECTOR;				\
+	}						\
+    }
+
+#define RTR_UART_PUTC_TIMEOUT	UART_PUTC_TIMEOUT*10
+#define RTR_UART_DELAY_SPAN	UART_DELAY_SPAN
+#define RTR_UART_INIT_TIMEOUT	UART_INIT_TIMEOUT*10
+
+static int
+rtr_uart_putc( l1sc_t *sc )
+{
+    uint64_t regval, c;
+    nasid_t nasid = sc->nasid;
+    net_vec_t path = sc->uart;
+    rtc_time_t expire = rtc_time() + RTR_UART_PUTC_TIMEOUT;
+
+    c = (sc->send[sc->sent] & 0xffULL);
+    
+    while( 1 ) 
+    {
+        /* Check for "tx hold reg empty" bit. */
+	READ_RTR_L1_UART_REG( path, nasid, REG_LSR, &regval );
+	if( regval & LSR_XHRE )
+	{
+	    WRITE_RTR_L1_UART_REG( path, nasid, REG_DAT, c );
+	    return UART_SUCCESS;
+	}
+
+	if( rtc_time() >= expire ) 
+	{
+	    return UART_TIMEOUT;
+	}
+	uart_delay( RTR_UART_DELAY_SPAN );
+    }
+}
+
+
+static int
+rtr_uart_getc( l1sc_t *sc )
+{
+    uint64_t regval;
+    nasid_t nasid = sc->nasid;
+    net_vec_t path = sc->uart;
+
+    READ_RTR_L1_UART_REG( path, nasid, REG_LSR, &regval );
+    if( regval & (LSR_RCA | LSR_PARERR | LSR_FRMERR) )
+    {
+	if( regval & LSR_RCA )
+	{
+	    READ_RTR_L1_UART_REG( path, nasid, REG_DAT, &regval );
+	    return( (int)regval );
+	}
+	else
+	{
+	    return UART_LINK;
+	}
+    }
+
+    return UART_NO_CHAR;
+}
+
+
+static int
+rtr_uart_init( l1sc_t *sc, int baud )
+{
+    rtc_time_t expire;
+    int clkdiv;
+    nasid_t nasid;
+    net_vec_t path;
+    uint64_t regval;
+
+    clkdiv = PROM_SER_DIVISOR(baud);
+    expire = rtc_time() + RTR_UART_INIT_TIMEOUT;
+    nasid = sc->nasid;
+    path = sc->uart;
+
+    /* make sure the transmit FIFO is empty */
+    while(1) {
+	READ_RTR_L1_UART_REG( path, nasid, REG_LSR, &regval );
+	if( regval & LSR_XSRE ) {
+	    break;
+	}
+	if( rtc_time() > expire ) {
+	    break;
+	}
+	uart_delay( RTR_UART_DELAY_SPAN );
+    }
+
+    WRITE_RTR_L1_UART_REG( path, nasid, REG_LCR, LCR_DLAB  );
+	uart_delay( UART_DELAY_SPAN );
+    WRITE_RTR_L1_UART_REG( path, nasid, REG_DLH, (clkdiv >> 8) & 0xff  );
+	uart_delay( UART_DELAY_SPAN );
+    WRITE_RTR_L1_UART_REG( path, nasid, REG_DLL, clkdiv & 0xff  );
+	uart_delay( UART_DELAY_SPAN );
+
+    /* set operating parameters and set DLAB to 0 */
+    WRITE_RTR_L1_UART_REG( path, nasid, REG_LCR, LCR_BITS8 | LCR_STOP1  );
+	uart_delay( UART_DELAY_SPAN );
+    WRITE_RTR_L1_UART_REG( path, nasid, REG_MCR, MCR_RTS | MCR_AFE  );
+	uart_delay( UART_DELAY_SPAN );
+
+    /* disable interrupts */
+    WRITE_RTR_L1_UART_REG( path, nasid, REG_ICR, 0x0  );
+	uart_delay( UART_DELAY_SPAN );
+
+    /* enable FIFO mode and reset both FIFOs */
+    WRITE_RTR_L1_UART_REG( path, nasid, REG_FCR, FCR_FIFOEN  );
+	uart_delay( UART_DELAY_SPAN );
+    WRITE_RTR_L1_UART_REG( path, nasid, REG_FCR,
+	FCR_FIFOEN | FCR_RxFIFO | FCR_TxFIFO );
+
+    return 0;
+}
+
+/*********************************************************************
+ * locking macros 
+ */
+
+#define L1SC_SEND_LOCK(l,p)   { if ((l)->uart == BRL1_LOCALHUB_UART) spin_lock_irqsave(&((l)->send_lock),p); }
+#define L1SC_SEND_UNLOCK(l,p) { if ((l)->uart == BRL1_LOCALHUB_UART) spin_unlock_irqrestore(&((l)->send_lock), p); }
+#define L1SC_RECV_LOCK(l,p)   { if ((l)->uart == BRL1_LOCALHUB_UART) spin_lock_irqsave(&((l)->recv_lock), p); } 
+#define L1SC_RECV_UNLOCK(l,p) { if ((l)->uart == BRL1_LOCALHUB_UART) spin_unlock_irqrestore(&((l)->recv_lock), p); }
+
+
+/*********************************************************************
+ * subchannel manipulation 
+ *
+ * The SUBCH_[UN]LOCK macros are used to arbitrate subchannel
+ * allocation.  SUBCH_DATA_[UN]LOCK control access to data structures
+ * associated with particular subchannels (e.g., receive queues).
+ *
+ */
+#define SUBCH_LOCK(sc, p)		spin_lock_irqsave( &((sc)->subch_lock), p )
+#define SUBCH_UNLOCK(sc, p)		spin_unlock_irqrestore( &((sc)->subch_lock), p )
+#define SUBCH_DATA_LOCK(sbch, p) 	spin_lock_irqsave( &((sbch)->data_lock), p )
+#define SUBCH_DATA_UNLOCK(sbch, p)	spin_unlock_irqrestore( &((sbch)->data_lock), p )
+
+
+/*
+ * set a function to be called for subchannel ch in the event of
+ * a transmission low-water interrupt from the uart
+ */
+void
+subch_set_tx_notify( l1sc_t *sc, int ch, brl1_notif_t func )
+{
+    unsigned long pl = 0;
+
+    L1SC_SEND_LOCK( sc, pl );
+#if	!defined(SYNC_CONSOLE_WRITE)
+    if ( func && !sc->send_in_use )
+	uart_enable_xmit_intr( sc );
+#endif
+    sc->subch[ch].tx_notify = func;
+    L1SC_SEND_UNLOCK(sc, pl );
+}
+
+/*
+ * set a function to be called for subchannel ch when data is received
+ */
+void
+subch_set_rx_notify( l1sc_t *sc, int ch, brl1_notif_t func )
+{
+    unsigned long pl = 0;
+    brl1_sch_t *subch = &(sc->subch[ch]);
+
+    SUBCH_DATA_LOCK( subch, pl );
+    sc->subch[ch].rx_notify = func;
+    SUBCH_DATA_UNLOCK( subch, pl );
+}
+
+/*********************************************************************
+ * Queue manipulation macros
+ *
+ *
+ */
+#define NEXT(p)         (((p) + 1) & (BRL1_QSIZE-1)) /* assume power of 2 */
+
+#define cq_init(q)      bzero((q), sizeof (*(q)))
+#define cq_empty(q)     ((q)->ipos == (q)->opos)
+#define cq_full(q)      (NEXT((q)->ipos) == (q)->opos)
+#define cq_used(q)      ((q)->opos <= (q)->ipos ?                       \
+                         (q)->ipos - (q)->opos :                        \
+                         BRL1_QSIZE + (q)->ipos - (q)->opos)
+#define cq_room(q)      ((q)->opos <= (q)->ipos ?                       \
+                         BRL1_QSIZE - 1 + (q)->opos - (q)->ipos :       \
+                         (q)->opos - (q)->ipos - 1)
+#define cq_add(q, c)    ((q)->buf[(q)->ipos] = (u_char) (c),            \
+                         (q)->ipos = NEXT((q)->ipos))
+#define cq_rem(q, c)    ((c) = (q)->buf[(q)->opos],                     \
+                         (q)->opos = NEXT((q)->opos))
+#define cq_discard(q)	((q)->opos = NEXT((q)->opos))
+
+#define cq_tent_full(q)	(NEXT((q)->tent_next) == (q)->opos)
+#define cq_tent_len(q)	((q)->ipos <= (q)->tent_next ?			\
+			 (q)->tent_next - (q)->ipos :			\
+			 BRL1_QSIZE + (q)->tent_next - (q)->ipos)
+#define cq_tent_add(q, c)						\
+			((q)->buf[(q)->tent_next] = (u_char) (c),	\
+			 (q)->tent_next = NEXT((q)->tent_next))
+#define cq_commit_tent(q)						\
+			((q)->ipos = (q)->tent_next)
+#define cq_discard_tent(q)						\
+			((q)->tent_next = (q)->ipos)
+
+
+
+
+/*********************************************************************
+ * CRC-16 (for checking bedrock/L1 packets).
+ *
+ * These are based on RFC 1662 ("PPP in HDLC-like framing").
+ */
+
+static unsigned short fcstab[256] = {
+      0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
+      0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
+      0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
+      0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
+      0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
+      0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
+      0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
+      0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
+      0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
+      0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
+      0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
+      0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
+      0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
+      0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
+      0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
+      0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
+      0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
+      0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
+      0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
+      0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
+      0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
+      0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
+      0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
+      0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
+      0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
+      0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
+      0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
+      0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
+      0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
+      0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
+      0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
+      0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
+};
+
+#define INIT_CRC	0xFFFF	/* initial CRC value	  */
+#define	GOOD_CRC	0xF0B8	/* "good" final CRC value */
+
+static unsigned short crc16_calc( unsigned short crc, u_char c )
+{
+    return( (crc >> 8) ^ fcstab[(crc ^ c) & 0xff] );
+}
+
+
+/***********************************************************************
+ * The following functions implement the PPP-like bedrock/L1 protocol
+ * layer.
+ *
+ */
+
+#define BRL1_FLAG_CH	0x7e
+#define BRL1_ESC_CH	0x7d
+#define BRL1_XOR_CH	0x20
+
+/* L1<->Bedrock packet types */
+#define BRL1_REQUEST    0x00
+#define BRL1_RESPONSE   0x20
+#define BRL1_EVENT      0x40
+
+#define BRL1_PKT_TYPE_MASK      0xE0
+#define BRL1_SUBCH_MASK         0x1F
+
+#define PKT_TYPE(tsb)   ((tsb) & BRL1_PKT_TYPE_MASK)
+#define SUBCH(tsb)	((tsb) & BRL1_SUBCH_MASK)
+
+/* timeouts */
+#define BRL1_INIT_TIMEOUT	500000
+
+/*
+ * brl1_discard_packet is a dummy "receive callback" used to get rid
+ * of packets we don't want
+ */
+void brl1_discard_packet( int dummy0, void *dummy1, struct pt_regs *dummy2, l1sc_t *sc, int ch )
+{
+    unsigned long pl = 0;
+    brl1_sch_t *subch = &sc->subch[ch];
+
+    sc_cq_t *q = subch->iqp;
+    SUBCH_DATA_LOCK( subch, pl );
+    q->opos = q->ipos;
+    atomic_set(&(subch->packet_arrived), 0);
+    SUBCH_DATA_UNLOCK( subch, pl );
+}
+
+
+/*
+ * brl1_send_chars sends the send buffer in the l1sc_t structure
+ * out through the uart.  Assumes that the caller has locked the
+ * UART (or send buffer in the kernel).
+ *
+ * This routine doesn't block-- if you want it to, call it in
+ * a loop.
+ */
+static int
+brl1_send_chars( l1sc_t *sc )
+{
+    /* We track the depth of the C brick's UART's
+     * fifo in software, and only check if the UART is accepting
+     * characters when our count indicates that the fifo should
+     * be full.
+     *
+     * For remote (router) UARTs, we check with the UART before sending every
+     * character.
+     */
+    if( sc->uart == BRL1_LOCALHUB_UART ) {
+	if( !(sc->fifo_space) && UART_PUTC_READY( sc->nasid ) )
+	    sc->fifo_space = UART_FIFO_DEPTH;
+	
+	while( (sc->sent < sc->send_len) && (sc->fifo_space) ) {
+	    uart_putc( sc );
+	    sc->fifo_space--;
+	    sc->sent++;
+	}
+    }
+    else {
+
+	/* remote (router) UARTs */
+
+	int result;
+	int tries = 0;
+
+	while( sc->sent < sc->send_len ) {
+	    result = sc->putc_f( sc );
+	    if( result >= 0 ) {
+		(sc->sent)++;
+		continue;
+	    }
+	    if( result == UART_TIMEOUT ) {
+		tries++;
+		/* send this character in TIMEOUT_RETRIES... */
+		if( tries < 30 /* TIMEOUT_RETRIES */ ) {
+		    continue;
+		}
+		/* ...or else... */
+		else {
+		    /* ...drop the packet. */
+		    sc->sent = sc->send_len;
+		    return sc->send_len;
+		}
+	    }
+	    if( result < 0 ) {
+		return result;
+	    }
+	}
+    }
+    return sc->sent;
+}
+
+
+/* brl1_send formats up a packet and (at least begins to) send it
+ * to the uart.  If the send buffer is in use when this routine obtains
+ * the lock, it will behave differently depending on the "wait" parameter.
+ * For wait == 0 (most I/O), it will return 0 (as in "zero bytes sent"),
+ * hopefully encouraging the caller to back off (unlock any high-level 
+ * spinlocks) and allow the buffer some time to drain.  For wait==1 (high-
+ * priority I/O along the lines of kernel error messages), we will flush
+ * the current contents of the send buffer and beat on the uart
+ * until our message has been completely transmitted.
+ */
+
+static int
+brl1_send( l1sc_t *sc, char *msg, int len, u_char type_and_subch, int wait )
+{
+    unsigned long pl = 0;
+    int index;
+    int pkt_len = 0;
+    unsigned short crc = INIT_CRC;
+    char *send_ptr = sc->send;
+
+
+    if( sc->send_in_use && !(wait) ) {
+	/* We are in the middle of sending, but can wait until done */
+	return 0;
+    }
+    else if( sc->send_in_use ) {
+	/* buffer's in use, but we're synchronous I/O, so we're going
+	 * to send whatever's in there right now and take the buffer
+	 */
+	int counter = 0;
+
+	if ( sc->uart == BRL1_LOCALHUB_UART )
+		lock_console(sc->nasid);
+	L1SC_SEND_LOCK(sc, pl);
+	while( sc->sent < sc->send_len ) {
+		brl1_send_chars( sc );
+		if ( counter++ > 0xfffff ) {
+			char *str = "Looping waiting for uart to clear (1)\n";
+			early_l1_serial_out(sc->nasid, str, strlen(str), ALREADY_LOCKED);
+			break;
+		}
+	}
+    }
+    else {
+	if ( sc->uart == BRL1_LOCALHUB_UART )
+		lock_console(sc->nasid);
+	L1SC_SEND_LOCK(sc, pl);
+	sc->send_in_use = 1;
+    }
+    *send_ptr++ = BRL1_FLAG_CH;
+    *send_ptr++ = type_and_subch;
+    pkt_len += 2;
+    crc = crc16_calc( crc, type_and_subch );
+
+    /* limit number of characters accepted to max payload size */
+    if( len > (BRL1_QSIZE - 1) )
+	len = (BRL1_QSIZE - 1);
+
+    /* copy in the message buffer (inserting PPP 
+     * framing info where necessary)
+     */
+    for( index = 0; index < len; index++ ) {
+
+	switch( *msg ) {
+	    
+	  case BRL1_FLAG_CH:
+	    *send_ptr++ = BRL1_ESC_CH;
+	    *send_ptr++ = (*msg) ^ BRL1_XOR_CH;
+	    pkt_len += 2;
+	    break;
+	    
+	  case BRL1_ESC_CH:
+	    *send_ptr++ = BRL1_ESC_CH;
+	    *send_ptr++ = (*msg) ^ BRL1_XOR_CH;
+	    pkt_len += 2;
+	    break;
+	    
+	  default:
+	    *send_ptr++ = *msg;
+	    pkt_len++;
+	}
+	crc = crc16_calc( crc, *msg );
+	msg++;
+    }
+    crc ^= 0xffff;
+
+    for( index = 0; index < sizeof(crc); index++ ) {
+	char crc_char = (char)(crc & 0x00FF);
+	if( (crc_char == BRL1_ESC_CH) || (crc_char == BRL1_FLAG_CH) ) {
+	    *send_ptr++ = BRL1_ESC_CH;
+	    pkt_len++;
+	    crc_char ^= BRL1_XOR_CH;
+	}
+	*send_ptr++ = crc_char;
+	pkt_len++;
+	crc >>= 8;
+    }
+    
+    *send_ptr++ = BRL1_FLAG_CH;
+    pkt_len++;
+
+    sc->send_len = pkt_len;
+    sc->sent = 0;
+
+    {
+	int counter = 0;
+	do {
+		brl1_send_chars( sc );
+		if ( counter++ > 0xfffff ) {
+			char *str = "Looping waiting for uart to clear (2)\n";
+			early_l1_serial_out(sc->nasid, str, strlen(str), ALREADY_LOCKED);
+			break;
+		}
+	} while( (sc->sent < sc->send_len) && wait );
+    }
+
+    if ( sc->uart == BRL1_LOCALHUB_UART )
+	unlock_console(sc->nasid);
+
+    if( sc->sent == sc->send_len ) {
+	/* success! release the send buffer and call the callup */
+#if	!defined(SYNC_CONSOLE_WRITE)
+	brl1_notif_t callup;
+#endif
+
+	sc->send_in_use = 0;
+	/* call any upper layer that's asked for notification */
+#if	defined(XX_SYNC_CONSOLE_WRITE)
+	/*
+	 * This is probably not a good idea - since the l1_ write func can be called multiple
+	 * time within the callup function.
+	 */
+	callup = subch->tx_notify;
+	if( callup && (SUBCH(type_and_subch) == SC_CONS_SYSTEM) ) {
+		L1_collectibles[L1C_SEND_CALLUPS]++;
+		(*callup)(sc->subch[SUBCH(type_and_subch)].irq_frame.bf_irq,
+				sc->subch[SUBCH(type_and_subch)].irq_frame.bf_dev_id,
+				sc->subch[SUBCH(type_and_subch)].irq_frame.bf_regs, sc, SUBCH(type_and_subch));
+	}
+#endif	/* SYNC_CONSOLE_WRITE */
+    }
+#if	!defined(SYNC_CONSOLE_WRITE)
+    else if ( !wait ) {
+	/* enable low-water interrupts so buffer will be drained */
+	uart_enable_xmit_intr(sc);
+    }
+#endif
+
+    L1SC_SEND_UNLOCK(sc, pl);
+
+    return len;
+}
+
+/* brl1_send_cont is intended to be called as an interrupt service
+ * routine.  It sends until the UART won't accept any more characters,
+ * or until an error is encountered (in which case we surrender the
+ * send buffer and give up trying to send the packet).  Once the
+ * last character in the packet has been sent, this routine releases
+ * the send buffer and calls any previously-registered "low-water"
+ * output routines.
+ */
+
+#if	!defined(SYNC_CONSOLE_WRITE)
+
+int
+brl1_send_cont( l1sc_t *sc )
+{
+    unsigned long pl = 0;
+    int done = 0;
+    brl1_notif_t callups[BRL1_NUM_SUBCHANS];
+    brl1_notif_t *callup;
+    brl1_sch_t *subch;
+    int index;
+
+    /*
+     * I'm not sure how I think this is to be handled - whether the lock is held
+     * over the interrupt - but it seems like it is a bad idea....
+     */
+
+    if ( sc->uart == BRL1_LOCALHUB_UART )
+	lock_console(sc->nasid);
+    L1SC_SEND_LOCK(sc, pl);
+    brl1_send_chars( sc );
+    done = (sc->sent == sc->send_len);
+    if( done ) {
+	sc->send_in_use = 0;
+#if	!defined(SYNC_CONSOLE_WRITE)
+	uart_disable_xmit_intr(sc);
+#endif
+    }
+    if ( sc->uart == BRL1_LOCALHUB_UART )
+	unlock_console(sc->nasid);
+    /* Release the lock */
+    L1SC_SEND_UNLOCK(sc, pl);
+
+    return 0;
+}
+#endif	/* SYNC_CONSOLE_WRITE */
+
+/* internal function -- used by brl1_receive to read a character 
+ * from the uart and check whether errors occurred in the process.
+ */
+static int
+read_uart( l1sc_t *sc, int *c, int *result )
+{
+    *c = sc->getc_f( sc );
+
+    /* no character is available */
+    if( *c == UART_NO_CHAR ) {
+	*result = BRL1_NO_MESSAGE;
+	return 0;
+    }
+
+    /* some error in UART */
+    if( *c < 0 ) {
+	*result = BRL1_LINK;
+	return 0;
+    }
+
+    /* everything's fine */
+    *result = BRL1_VALID;
+    return 1;
+}
+
+
+/*
+ * brl1_receive
+ *
+ * This function reads a Bedrock-L1 protocol packet into the l1sc_t
+ * response buffer.
+ *
+ * The operation of this function can be expressed as a finite state
+ * machine:
+ *
+
+START STATE			INPUT		TRANSITION
+==========================================================
+BRL1_IDLE (reset or error)	flag		BRL1_FLAG
+				other		BRL1_IDLE@
+
+BRL1_FLAG (saw a flag (0x7e))	flag		BRL1_FLAG
+				escape		BRL1_IDLE@
+				header byte	BRL1_HDR
+				other		BRL1_IDLE@
+
+BRL1_HDR (saw a type/subch byte)(see below)	BRL1_BODY
+						BRL1_HDR
+
+BRL1_BODY (reading packet body)	flag		BRL1_FLAG
+				escape		BRL1_ESC
+				other		BRL1_BODY
+
+BRL1_ESC (saw an escape (0x7d))	flag		BRL1_FLAG@
+				escape		BRL1_IDLE@
+				other		BRL1_BODY
+==========================================================
+
+"@" denotes an error transition.
+
+ * The BRL1_HDR state is a transient state which doesn't read input,
+ * but just provides a way in to code which decides to whom an
+ * incoming packet should be directed.
+ *
+ * brl1_receive can be used to poll for input from the L1, or as 
+ * an interrupt service routine.  It reads as much data as is
+ * ready from the junk bus UART and places into the appropriate
+ * input queues according to subchannel.  The header byte is
+ * stripped from console-type data, but is retained for message-
+ * type data (L1 responses).  A length byte will also be
+ * prepended to message-type packets.
+ *
+ * This routine is non-blocking; if the caller needs to block
+ * for input, it must call brl1_receive in a loop.
+ *
+ * brl1_receive returns when there is no more input, the queue
+ * for the current incoming message is full, or there is an
+ * error (parity error, bad header, bad CRC, etc.).
+ */
+
+#define STATE_SET(l,s)		((l)->brl1_state = (s))
+#define STATE_GET(l)		((l)->brl1_state)
+
+#define LAST_HDR_SET(l,h)	((l)->brl1_last_hdr = (h))
+#define LAST_HDR_GET(l)		((l)->brl1_last_hdr)
+
+#define VALID_HDR(c)				\
+    ( SUBCH((c)) <= SC_CONS_SYSTEM		\
+	? PKT_TYPE((c)) == BRL1_REQUEST		\
+	: ( PKT_TYPE((c)) == BRL1_RESPONSE ||	\
+	    PKT_TYPE((c)) == BRL1_EVENT ) )
+
+#define IS_TTY_PKT(l)		( SUBCH(LAST_HDR_GET(l)) <= SC_CONS_SYSTEM ? 1 : 0 )
+
+
+int
+brl1_receive( l1sc_t *sc, int mode )
+{
+    int result;		/* value to be returned by brl1_receive */
+    int c;		/* most-recently-read character	     	*/
+    int done;		/* set done to break out of recv loop	*/
+    unsigned long pl = 0, cpl = 0;
+    sc_cq_t *q;		/* pointer to queue we're working with	*/
+
+    result = BRL1_NO_MESSAGE;
+
+    L1SC_RECV_LOCK(sc, cpl);
+
+    done = 0;
+    while( !done )
+    {
+	switch( STATE_GET(sc) )
+	{
+
+	  case BRL1_IDLE:
+	    /* Initial or error state.  Waiting for a flag character
+             * to resynchronize with the L1.
+             */
+
+	    if( !read_uart( sc, &c, &result ) ) {
+
+		/* error reading uart */
+		done = 1;
+		continue;
+	    }
+	    
+	    if( c == BRL1_FLAG_CH ) {
+		/* saw a flag character */
+		STATE_SET( sc, BRL1_FLAG );
+		continue;
+	    }
+	    break;
+	    
+	  case BRL1_FLAG:
+	    /* One or more flag characters have been read; look for
+	     * the beginning of a packet (header byte).
+	     */
+	    
+	    if( !read_uart( sc, &c, &result ) ) {
+
+		/* error reading uart */
+		if( c != UART_NO_CHAR )
+		    STATE_SET( sc, BRL1_IDLE );
+
+		done = 1;
+		continue;
+	    }
+	    
+	    if( c == BRL1_FLAG_CH ) {
+		/* multiple flags are OK */
+		continue;
+	    }
+
+	    if( !VALID_HDR( c ) ) {
+		/* if c isn't a flag it should have been
+		 * a valid header, so we have an error
+		 */
+		result = BRL1_PROTOCOL;
+		STATE_SET( sc, BRL1_IDLE );
+		done = 1;
+		continue;
+	    }
+
+	    /* we have a valid header byte */
+	    LAST_HDR_SET( sc, c );
+	    STATE_SET( sc, BRL1_HDR );
+
+	    break; 
+
+	  case BRL1_HDR:
+	    /* A header byte has been read. Do some bookkeeping. */
+	    q = sc->subch[ SUBCH( LAST_HDR_GET(sc) ) ].iqp;
+	    ASSERT(q);
+	    
+	    if( !IS_TTY_PKT(sc) ) {
+		/* if this is an event or command response rather
+		 * than console I/O, we need to reserve a couple
+		 * of extra spaces in the queue for the header
+		 * byte and a length byte; if we can't, stay in
+		 * the BRL1_HDR state.
+		 */
+		if( cq_room( q ) < 2 ) {
+		    result = BRL1_FULL_Q;
+		    done = 1;
+		    continue;
+		}
+		cq_tent_add( q, 0 );			/* reserve length byte */
+		cq_tent_add( q, LAST_HDR_GET( sc ) );	/* record header byte  */
+	    }
+	    STATE_SET( sc, BRL1_BODY );
+
+	    break;
+
+	  case BRL1_BODY:
+	    /* A header byte has been read.  We are now attempting
+	     * to receive the packet body.
+	     */
+
+	    q = sc->subch[ SUBCH( LAST_HDR_GET(sc) ) ].iqp;
+	    ASSERT(q);
+
+	    /* if the queue we want to write into is full, don't read from
+	     * the uart (this provides backpressure to the L1 side)
+	     */
+	    if( cq_tent_full( q ) ) {
+		result = BRL1_FULL_Q;
+		done = 1;
+		continue;
+	    }
+	    
+	    if( !read_uart( sc, &c, &result ) ) {
+
+		/* error reading uart */
+		if( c != UART_NO_CHAR )
+		    STATE_SET( sc, BRL1_IDLE );
+		done = 1;
+		continue;
+	    }
+
+	    if( c == BRL1_ESC_CH ) {
+		/* prepare to unescape the next character */
+		STATE_SET( sc, BRL1_ESC );
+		continue;
+	    }
+	    
+	    if( c == BRL1_FLAG_CH ) {
+		/* flag signifies the end of a packet */
+
+		unsigned short crc;	/* holds the crc as we calculate it */
+		int i;			/* index variable */
+		brl1_sch_t *subch;      /* subchannel for received packet */
+		brl1_notif_t callup;	/* "data ready" callup */
+
+		/* whatever else may happen, we've seen a flag and we're
+		 * starting a new packet
+		 */
+		STATE_SET( sc, BRL1_FLAG );
+
+		/* if the packet body has less than 2 characters,
+		 * it can't be a well-formed packet.  Discard it.
+		 */
+		if( cq_tent_len( q ) < /* 2 + possible length byte */
+		    (2 + (IS_TTY_PKT(sc) ? 0 : 1)) )
+		{
+		    result = BRL1_PROTOCOL;
+		    cq_discard_tent( q );
+		    STATE_SET( sc, BRL1_FLAG );
+		    done = 1;
+		    continue;
+		}
+		
+		/* check CRC */
+
+		/* accumulate CRC, starting with the header byte and
+		 * ending with the transmitted CRC.  This should
+		 * result in a known good value.
+		 */
+		crc = crc16_calc( INIT_CRC, LAST_HDR_GET(sc) );
+		for( i = (q->ipos + (IS_TTY_PKT(sc) ? 0 : 2)) % BRL1_QSIZE;
+		     i != q->tent_next;
+		     i = (i + 1) % BRL1_QSIZE )
+		{
+		    crc = crc16_calc( crc, q->buf[i] );
+		}
+
+		/* verify the caclulated crc against the "good" crc value;
+		 * if we fail, discard the bad packet and return an error.
+		 */
+		if( crc != (unsigned short)GOOD_CRC ) {
+		    result = BRL1_CRC;
+		    cq_discard_tent( q );
+		    STATE_SET( sc, BRL1_FLAG );
+		    done = 1;
+		    continue;
+		}
+		
+		/* so the crc check was ok.  Now we discard the CRC
+		 * from the end of the received bytes.
+		 */
+		q->tent_next += (BRL1_QSIZE - 2);
+		q->tent_next %= BRL1_QSIZE;
+
+		/* get the subchannel and lock it */
+		subch = &(sc->subch[SUBCH( LAST_HDR_GET(sc) )]);
+		SUBCH_DATA_LOCK( subch, pl );
+		
+		/* if this isn't a console packet, we need to record
+		 * a length byte
+		 */
+		if( !IS_TTY_PKT(sc) ) {
+		    q->buf[q->ipos] = cq_tent_len( q ) - 1;
+		}
+		
+		/* record packet for posterity */
+		cq_commit_tent( q );
+		result = BRL1_VALID;
+
+		/* notify subchannel owner that there's something
+		 * on the queue for them
+		 */
+		atomic_inc(&(subch->packet_arrived));
+		callup = subch->rx_notify;
+		SUBCH_DATA_UNLOCK( subch, pl );
+
+		if( callup && (mode == SERIAL_INTERRUPT_MODE) ) {
+		    L1SC_RECV_UNLOCK( sc, cpl );
+		    L1_collectibles[L1C_RECEIVE_CALLUPS]++;
+		    (*callup)( sc->subch[SUBCH(LAST_HDR_GET(sc))].irq_frame.bf_irq,
+				sc->subch[SUBCH(LAST_HDR_GET(sc))].irq_frame.bf_dev_id,
+				sc->subch[SUBCH(LAST_HDR_GET(sc))].irq_frame.bf_regs,
+				sc, SUBCH(LAST_HDR_GET(sc)) );
+		    L1SC_RECV_LOCK( sc, cpl );
+		}
+		continue;	/* go back for more! */
+	    }
+	    
+	    /* none of the special cases applied; we've got a normal
+	     * body character
+	     */
+	    cq_tent_add( q, c );
+
+	    break;
+
+	  case BRL1_ESC:
+	    /* saw an escape character.  The next character will need
+	     * to be unescaped.
+	     */
+
+	    q = sc->subch[ SUBCH( LAST_HDR_GET(sc) ) ].iqp;
+	    ASSERT(q);
+
+	    /* if the queue we want to write into is full, don't read from
+	     * the uart (this provides backpressure to the L1 side)
+	     */
+	    if( cq_tent_full( q ) ) {
+		result = BRL1_FULL_Q;
+		done = 1;
+		continue;
+	    }
+	    
+	    if( !read_uart( sc, &c, &result ) ) {
+
+		/* error reading uart */
+		if( c != UART_NO_CHAR ) {
+		    cq_discard_tent( q );
+		    STATE_SET( sc, BRL1_IDLE );
+		}
+		done = 1;
+		continue;
+	    }
+	    
+	    if( c == BRL1_FLAG_CH ) {
+		/* flag after escape is an error */
+		STATE_SET( sc, BRL1_FLAG );
+		cq_discard_tent( q );
+		result = BRL1_PROTOCOL;
+		done = 1;
+		continue;
+	    }
+
+	    if( c == BRL1_ESC_CH ) {
+		/* two consecutive escapes is an error */
+		STATE_SET( sc, BRL1_IDLE );
+		cq_discard_tent( q );
+		result = BRL1_PROTOCOL;
+		done = 1;
+		continue;
+	    }
+	    
+	    /* otherwise, we've got a character that needs
+	     * to be unescaped
+	     */
+	    cq_tent_add( q, (c ^ BRL1_XOR_CH) );
+	    STATE_SET( sc, BRL1_BODY );
+
+	    break;
+
+	} /* end of switch( STATE_GET(sc) ) */
+    } /* end of while(!done) */
+
+    L1SC_RECV_UNLOCK( sc, cpl );
+
+    return result;
+}	    
+
+
+/* brl1_init initializes the Bedrock/L1 protocol layer.  This includes
+ * zeroing out the send and receive state information.
+ */
+
+void
+brl1_init( l1sc_t *sc, nasid_t nasid, net_vec_t uart )
+{
+    int i;
+    brl1_sch_t *subch;
+
+    bzero( sc, sizeof( *sc ) );
+    sc->nasid = nasid;
+    sc->uart = uart;
+    sc->getc_f = (uart == BRL1_LOCALHUB_UART ? uart_getc : rtr_uart_getc);
+    sc->putc_f = (uart == BRL1_LOCALHUB_UART ? uart_putc : rtr_uart_putc);
+    sc->sol = 1;
+    subch = sc->subch;
+
+    /* initialize L1 subchannels
+     */
+
+    /* assign processor TTY channels */
+    for( i = 0; i < CPUS_PER_NODE; i++, subch++ ) {
+	subch->use = BRL1_SUBCH_RSVD;
+	subch->packet_arrived = ATOMIC_INIT(0);
+	spin_lock_init( &(subch->data_lock) );
+	sv_init( &(subch->arrive_sv), &(subch->data_lock), SV_MON_SPIN | SV_ORDER_FIFO /* | SV_INTS */ );
+	subch->tx_notify = NULL;
+	/* (for now, drop elscuart packets in the kernel) */
+	subch->rx_notify = brl1_discard_packet;
+	subch->iqp = &sc->garbage_q;
+    }
+
+    /* assign system TTY channel (first free subchannel after each
+     * processor's individual TTY channel has been assigned)
+     */
+    subch->use = BRL1_SUBCH_RSVD;
+    subch->packet_arrived = ATOMIC_INIT(0);
+    spin_lock_init( &(subch->data_lock) );
+    sv_init( &(subch->arrive_sv), &subch->data_lock, SV_MON_SPIN | SV_ORDER_FIFO /* | SV_INTS */ );
+    subch->tx_notify = NULL;
+    if( sc->uart == BRL1_LOCALHUB_UART ) {
+	subch->iqp = snia_kmem_zalloc_node( sizeof(sc_cq_t), KM_NOSLEEP, NASID_TO_COMPACT_NODEID(nasid) );
+	ASSERT( subch->iqp );
+	cq_init( subch->iqp );
+	subch->rx_notify = NULL;
+    }
+    else {
+	/* we shouldn't be getting console input from remote UARTs */
+	subch->iqp = &sc->garbage_q;
+	subch->rx_notify = brl1_discard_packet;
+    }
+    subch++; i++;
+
+    /* "reserved" subchannels (0x05-0x0F); for now, throw away
+     * incoming packets
+     */
+    for( ; i < 0x10; i++, subch++ ) {
+	subch->use = BRL1_SUBCH_FREE;
+	subch->packet_arrived = ATOMIC_INIT(0);
+	subch->tx_notify = NULL;
+	subch->rx_notify = brl1_discard_packet;
+	subch->iqp = &sc->garbage_q;
+    }
+
+    /* remaining subchannels are free */
+    for( ; i < BRL1_NUM_SUBCHANS; i++, subch++ ) {
+	subch->use = BRL1_SUBCH_FREE;
+	subch->packet_arrived = ATOMIC_INIT(0);
+	subch->tx_notify = NULL;
+	subch->rx_notify = brl1_discard_packet;
+	subch->iqp = &sc->garbage_q;
+    }
+
+    /* initialize synchronization structures
+     */
+    spin_lock_init( &(sc->subch_lock) );
+    spin_lock_init( &(sc->send_lock) );
+    spin_lock_init( &(sc->recv_lock) );
+
+    if( sc->uart == BRL1_LOCALHUB_UART ) {
+	uart_init( sc, UART_BAUD_RATE );
+    }
+    else {
+	rtr_uart_init( sc, UART_BAUD_RATE );
+    }
+
+    /* Set up remaining fields using L1 command functions-- elsc_module_get
+     * to read the module id, elsc_debug_get to see whether or not we're
+     * in verbose mode.
+     */
+    {
+	extern int elsc_module_get(l1sc_t *);
+
+	sc->modid = elsc_module_get( sc );
+	sc->modid = (sc->modid < 0 ? INVALID_MODULE : sc->modid);
+	sc->verbose = 1;
+    }
+}
+
+/*********************************************************************
+ * These are interrupt-related functions used in the kernel to service
+ * the L1.
+ */
+
+/*
+ * brl1_intrd is the function which is called on a console interrupt.
+ */
+
+
+static void
+brl1_intrd(int irq, void *dev_id, struct pt_regs *stuff)
+{
+    u_char isr_reg;
+    l1sc_t *sc = get_elsc();
+    int ret;
+
+    L1_collectibles[L1C_INTERRUPTS]++;
+    isr_reg = READ_L1_UART_REG(sc->nasid, REG_ISR);
+
+    /* Save for callup args in console */
+    sc->subch[SC_CONS_SYSTEM].irq_frame.bf_irq = irq;
+    sc->subch[SC_CONS_SYSTEM].irq_frame.bf_dev_id = dev_id;
+    sc->subch[SC_CONS_SYSTEM].irq_frame.bf_regs = stuff;
+
+#if	defined(SYNC_CONSOLE_WRITE)
+    while( isr_reg & ISR_RxRDY )
+#else
+    while( isr_reg & (ISR_RxRDY | ISR_TxRDY) )
+#endif
+    {
+	if( isr_reg & ISR_RxRDY ) {
+	    L1_collectibles[L1C_OUR_R_INTERRUPTS]++;
+	    ret = brl1_receive(sc, SERIAL_INTERRUPT_MODE);
+	    if ( (ret != BRL1_VALID) && (ret != BRL1_NO_MESSAGE) && (ret != BRL1_PROTOCOL) && (ret != BRL1_CRC) )
+		L1_collectibles[L1C_REC_STALLS] = ret;
+	}
+#if	!defined(SYNC_CONSOLE_WRITE)
+	if( (isr_reg & ISR_TxRDY) || (sc->send_in_use && UART_PUTC_READY(sc->nasid)) ) {
+	    L1_collectibles[L1C_OUR_X_INTERRUPTS]++;
+	    brl1_send_cont(sc);
+	}
+#endif	/* SYNC_CONSOLE_WRITE */
+	isr_reg = READ_L1_UART_REG(sc->nasid, REG_ISR);
+    }
+}
+
+
+/*
+ * Install a callback function for the system console subchannel 
+ * to allow an upper layer to be notified when the send buffer 
+ * has been emptied.
+ */
+static inline void
+l1_tx_notif( brl1_notif_t func )
+{
+	subch_set_tx_notify( &NODEPDA(NASID_TO_COMPACT_NODEID(get_master_nasid()))->module->elsc,
+			SC_CONS_SYSTEM, func );
+}
+
+
+/*
+ * Install a callback function for the system console subchannel
+ * to allow an upper layer to be notified when a packet has been
+ * received.
+ */
+static inline void
+l1_rx_notif( brl1_notif_t func )
+{
+	subch_set_rx_notify( &NODEPDA(NASID_TO_COMPACT_NODEID(get_master_nasid()))->module->elsc,
+				SC_CONS_SYSTEM, func );
+}
+
+
+/* brl1_intr is called directly from the uart interrupt; after it runs, the
+ * interrupt "daemon" xthread is signalled to continue.
+ */
+void
+brl1_intr( void )
+{
+}
+
+#define BRL1_INTERRUPT_LEVEL	65	/* linux request_irq() value */
+
+/* Return the current interrupt level */
+
+//#define CONSOLE_POLLING_ALSO
+
+int
+l1_get_intr_value( void )
+{
+#if defined(USE_SAL_CONSOLE_IO)
+	return(0);
+#else
+#if defined(CONSOLE_POLLING_ALSO)
+	return(0);
+#else
+	return(BRL1_INTERRUPT_LEVEL);
+#endif /* CONSOLE_POLLING_ALSO */
+#endif /* USE_SAL_CONSOLE_IO */
+}
+
+/* Disconnect the callup functions - throw away interrupts */
+
+void
+l1_unconnect_intr(void)
+{
+#if !defined(USE_SAL_CONSOLE_IO)
+	/* UnRegister the upper-level callup functions */
+	l1_rx_notif((brl1_notif_t)NULL);
+	l1_tx_notif((brl1_notif_t)NULL);
+	/* We do NOT unregister the interrupts */
+#endif /* !USE_SAL_CONSOLE_IO */
+}
+
+/* Set up uart interrupt handling for this node's uart */
+
+void
+l1_connect_intr(void *rx_notify, void *tx_notify)
+{
+#if defined(USE_SAL_CONSOLE_IO)
+#if 0
+	// Will need code here for sn2 - something like this
+	console_nodepda = NODEPDA(NASID_TO_COMPACT_NODEID(get_master_nasid());
+	intr_connect_level(console_nodepda->node_first_cpu,
+                                SGI_UART_VECTOR, INTPEND0_MAXMASK,
+                                dummy_intr_func);
+	request_irq(SGI_UART_VECTOR | (console_nodepda->node_first_cpu << 8),
+                                intr_func, SA_INTERRUPT | SA_SHIRQ,
+                                "l1_protocol_driver", (void *)sc);
+#endif
+#else
+	l1sc_t *sc;
+	nasid_t nasid;
+	int tmp;
+	nodepda_t *console_nodepda;
+	int intr_connect_level(cpuid_t, int, ilvl_t, intr_func_t);
+
+	if ( L1_interrupts_connected ) {
+		/* Interrupts are connected, so just register the callups */
+		l1_rx_notif((brl1_notif_t)rx_notify);
+		l1_tx_notif((brl1_notif_t)tx_notify);
+
+		L1_collectibles[L1C_CONNECT_CALLS]++;
+		return;
+	}
+	else
+		L1_interrupts_connected = 1;
+
+	nasid = get_master_nasid();
+	console_nodepda = NODEPDA(NASID_TO_COMPACT_NODEID(nasid));
+	sc = &console_nodepda->module->elsc;
+	sc->intr_cpu = console_nodepda->node_first_cpu;
+
+	if ( intr_connect_level(sc->intr_cpu, UART_INTR, INTPEND0_MAXMASK, (intr_func_t)brl1_intr) ) {
+		L1_interrupts_connected = 0; /* FAILS !! */
+	}
+	else {
+		void synergy_intr_connect(int, int);
+
+		synergy_intr_connect(UART_INTR, sc->intr_cpu);
+		L1_collectibles[L1C_R_IRQ]++;
+		tmp = request_irq(BRL1_INTERRUPT_LEVEL, brl1_intrd, SA_INTERRUPT | SA_SHIRQ, "l1_protocol_driver", (void *)sc);
+		L1_collectibles[L1C_R_IRQ_RET] = (uint64_t)tmp;
+		if ( tmp ) {
+			L1_interrupts_connected = 0; /* FAILS !! */
+		}
+		else {
+			/* Register the upper-level callup functions */
+			l1_rx_notif((brl1_notif_t)rx_notify);
+			l1_tx_notif((brl1_notif_t)tx_notify);
+
+			/* Set the uarts the way we like it */
+			uart_enable_recv_intr( sc );
+			uart_disable_xmit_intr( sc );
+		}
+	}
+#endif	/* USE_SAL_CONSOLE_IO */
+}
+
+
+/* These are functions to use from serial_in/out when in protocol
+ * mode to send and receive uart control regs. These are external
+ * interfaces into the protocol driver.
+ */
+
+void
+l1_control_out(int offset, int value)
+{
+#if defined(USE_SAL_CONSOLE_IO)
+	/* quietly ignore unless simulator */
+	if ( IS_RUNNING_ON_SIMULATOR() ) {
+		extern u64 master_node_bedrock_address;
+		if ( master_node_bedrock_address != (u64)0 ) {
+			writeb(value, (unsigned long)master_node_bedrock_address +
+				(offset<< 3));
+		}
+		return;
+	}
+#else
+	nasid_t nasid = get_master_nasid();
+	WRITE_L1_UART_REG(nasid, offset, value); 
+#endif
+}
+
+/* Console input exported interface. Return a register value.  */
+
+int
+l1_control_in_polled(int offset)
+{
+	static int l1_control_in_local(int, int);
+
+	return(l1_control_in_local(offset, SERIAL_POLLED_MODE));
+}
+
+int
+l1_control_in(int offset)
+{
+	static int l1_control_in_local(int, int);
+
+	return(l1_control_in_local(offset, SERIAL_INTERRUPT_MODE));
+}
+
+static int
+l1_control_in_local(int offset, int mode)
+{
+#if defined(USE_SAL_CONSOLE_IO)
+	int sal_call_status = 0, input;
+	int ret = 0;
+
+	if ( offset == REG_LSR ) {
+		ret = (LSR_XHRE | LSR_XSRE);	/* can send anytime */
+		sal_call_status = ia64_sn_console_check(&input);
+		if ( !sal_call_status && input ) {
+			/* input pending */
+			ret |= LSR_RCA;
+		}
+	}
+
+	/* If the sal call failed, do it the old-fashioned way */
+	if ( sal_call_status ) {
+		if ( IS_RUNNING_ON_SIMULATOR() ) {
+			extern u64 master_node_bedrock_address;
+			ret = readb((unsigned long)master_node_bedrock_address +
+					(offset<< 3));
+		}		
+		else {
+#endif	/* USE_SAL_CONSOLE_IO */
+			nasid_t nasid;
+			int ret, input;
+			static int l1_poll(l1sc_t *, int);
+
+			nasid = get_master_nasid();
+			ret = READ_L1_UART_REG(nasid, offset); 
+
+			if ( offset == REG_LSR ) {
+				ret |= (LSR_XHRE | LSR_XSRE);	/* can send anytime */
+				if ( L1_cons_is_inited ) {
+					if ( NODEPDA(NASID_TO_COMPACT_NODEID(nasid))->module != (module_t *)0 ) {
+						input = l1_poll(&NODEPDA(NASID_TO_COMPACT_NODEID(nasid))->module->elsc, mode);
+						if ( input ) {
+							ret |= LSR_RCA;
+						}
+					}
+				}
+			}
+#if defined(USE_SAL_CONSOLE_IO)
+		}
+	}
+#endif
+	return(ret);
+}
+
+/*
+ * Console input exported interface. Return a character (if one is available)
+ */
+
+int
+l1_serial_in_polled(void)
+{
+	static int l1_serial_in_local(int mode);
+
+	return(l1_serial_in_local(SERIAL_POLLED_MODE));
+}
+
+int
+l1_serial_in(void)
+{
+	static int l1_serial_in_local(int mode);
+
+	return(l1_serial_in_local(SERIAL_INTERRUPT_MODE));
+}
+
+static int
+l1_serial_in_local(int mode)
+{
+#if defined(USE_SAL_CONSOLE_IO)
+	int sal_call_status;
+	int ch;
+
+	sal_call_status = ia64_sn_console_getc(&ch);
+	if ( !sal_call_status ) {
+		return(ch);
+	}
+	else {
+		/* If the sal called failed - do it the old-fashioned way */
+		if ( IS_RUNNING_ON_SIMULATOR() ) {
+			extern u64 master_node_bedrock_address;
+			return(readb((unsigned long)master_node_bedrock_address + (REG_DAT<< 3)));
+		}		
+		else {
+#endif	/* USE_SAL_CONSOLE_IO */
+			nasid_t nasid;
+			l1sc_t *sc;
+			int value;
+			static int l1_getc( l1sc_t *, int );
+			static inline l1sc_t *early_sc_init(nasid_t);
+
+			nasid = get_master_nasid();
+			sc = early_sc_init(nasid);
+			if ( L1_cons_is_inited ) {
+				if ( NODEPDA(NASID_TO_COMPACT_NODEID(nasid))->module != (module_t *)0 ) {
+					sc = &NODEPDA(NASID_TO_COMPACT_NODEID(nasid))->module->elsc;
+				}
+			}
+			value = l1_getc(sc, mode);
+			return(value);
+#if defined(USE_SAL_CONSOLE_IO)
+		}
+	}
+#endif
+}
+
+/* Console output exported interface. Write message to the console.  */
+
+int
+l1_serial_out( char *str, int len )
+{
+#if defined(USE_SAL_CONSOLE_IO)
+	void early_sn_setup(void);
+	int sal_call_status = 0;
+	int counter = len;
+
+#if defined(CONFIG_IA64_EARLY_PRINTK)
+	{
+		static int inited;
+		if(!inited) {
+			inited=1;
+			early_sn_setup();
+		}
+	}
+#endif
+
+	/* Attempt to write things out thru the sal */
+	sal_call_status = ia64_sn_console_putb(str, len);
+	if ( sal_call_status ) {
+		/* If the sal called failed - do it the old-fashioned way */
+		if ( IS_RUNNING_ON_SIMULATOR() ) {
+			extern u64 master_node_bedrock_address;
+                        if (!master_node_bedrock_address)
+                                early_sn_setup();
+			if ( master_node_bedrock_address != (u64)0 ) {
+#ifdef FLAG_DIRECT_CONSOLE_WRITES
+				/* This is an easy way to pre-pend the output to know whether the output
+				 * was done via sal or directly */
+				writeb('[', (unsigned long)master_node_bedrock_address + (REG_DAT<< 3));
+				writeb('+', (unsigned long)master_node_bedrock_address + (REG_DAT<< 3));
+				writeb(']', (unsigned long)master_node_bedrock_address + (REG_DAT<< 3));
+				writeb(' ', (unsigned long)master_node_bedrock_address + (REG_DAT<< 3));
+#endif	/* FLAG_DIRECT_CONSOLE_WRITES */
+				while ( counter > 0 ) {
+					writeb(*str, (unsigned long)master_node_bedrock_address + (REG_DAT<< 3));
+					counter--;
+					str++;
+				}
+			}
+		}
+		else {
+#endif	/* USE_SAL_CONSOLE_IO */
+			nasid_t nasid = get_master_nasid();
+			int l1_write(l1sc_t *, char *, int, int);
+
+			if ( L1_cons_is_inited ) {
+				if ( NODEPDA(NASID_TO_COMPACT_NODEID(nasid))->module != (module_t *)0 )
+					return(l1_write(&NODEPDA(NASID_TO_COMPACT_NODEID(nasid))->module->elsc, str, len,
+#if	defined(SYNC_CONSOLE_WRITE)
+							1
+#else
+							!L1_interrupts_connected
+#endif
+									));
+			}
+			return(early_l1_serial_out(nasid, str, len, NOT_LOCKED));
+#if defined(USE_SAL_CONSOLE_IO)
+		}
+	}
+	return((counter <= 0) ? 0 : (len - counter));
+#endif
+}
+
+
+/*
+ * These are the 'early' functions - when we need to do things before we have
+ * all the structs setup.
+ */
+
+
+static l1sc_t Early_console;		/* fake l1sc_t */
+static int Early_console_inited = 0;
+
+static void
+early_brl1_init( l1sc_t *sc, nasid_t nasid, net_vec_t uart )
+{
+    int i;
+    brl1_sch_t *subch;
+
+    bzero( sc, sizeof( *sc ) );
+    sc->nasid = nasid;
+    sc->uart = uart;
+    sc->getc_f = (uart == BRL1_LOCALHUB_UART ? uart_getc : rtr_uart_getc);
+    sc->putc_f = (uart == BRL1_LOCALHUB_UART ? uart_putc : rtr_uart_putc);
+    sc->sol = 1;
+    subch = sc->subch;
+
+    /* initialize L1 subchannels
+     */
+
+    /* assign processor TTY channels */
+    for( i = 0; i < CPUS_PER_NODE; i++, subch++ ) {
+	subch->use = BRL1_SUBCH_RSVD;
+	subch->packet_arrived = ATOMIC_INIT(0);
+	subch->tx_notify = NULL;
+	subch->rx_notify = NULL;
+	subch->iqp = &sc->garbage_q;
+    }
+
+    /* assign system TTY channel (first free subchannel after each
+     * processor's individual TTY channel has been assigned)
+     */
+    subch->use = BRL1_SUBCH_RSVD;
+    subch->packet_arrived = ATOMIC_INIT(0);
+    subch->tx_notify = NULL;
+    subch->rx_notify = NULL;
+    if( sc->uart == BRL1_LOCALHUB_UART ) {
+	static sc_cq_t x_iqp;
+
+	subch->iqp = &x_iqp;
+	ASSERT( subch->iqp );
+	cq_init( subch->iqp );
+    }
+    else {
+	/* we shouldn't be getting console input from remote UARTs */
+	subch->iqp = &sc->garbage_q;
+    }
+    subch++; i++;
+
+    /* "reserved" subchannels (0x05-0x0F); for now, throw away
+     * incoming packets
+     */
+    for( ; i < 0x10; i++, subch++ ) {
+	subch->use = BRL1_SUBCH_FREE;
+	subch->packet_arrived = ATOMIC_INIT(0);
+	subch->tx_notify = NULL;
+	subch->rx_notify = NULL;
+	subch->iqp = &sc->garbage_q;
+    }
+
+    /* remaining subchannels are free */
+    for( ; i < BRL1_NUM_SUBCHANS; i++, subch++ ) {
+	subch->use = BRL1_SUBCH_FREE;
+	subch->packet_arrived = ATOMIC_INIT(0);
+	subch->tx_notify = NULL;
+	subch->rx_notify = NULL;
+	subch->iqp = &sc->garbage_q;
+    }
+}
+
+static inline l1sc_t *
+early_sc_init(nasid_t nasid)
+{
+	/* This is for early I/O */
+	if ( Early_console_inited == 0 ) {
+    		early_brl1_init(&Early_console, nasid,  BRL1_LOCALHUB_UART);
+		Early_console_inited = 1;
+	}
+	return(&Early_console);
+}
+
+#define PUTCHAR(ch) \
+    { \
+        while( (!(READ_L1_UART_REG( nasid, REG_LSR ) & LSR_XHRE)) || \
+                (!(READ_L1_UART_REG( nasid, REG_MSR ) & MSR_CTS)) ); \
+        WRITE_L1_UART_REG( nasid, REG_DAT, (ch) ); \
+    }
+
+static int
+early_l1_serial_out( nasid_t nasid, char *str, int len, int lock_state )
+{
+	int ret, sent = 0;
+	char *msg = str;
+	static int early_l1_send( nasid_t nasid, char *str, int len, int lock_state );
+
+	while ( sent < len ) {
+		ret = early_l1_send(nasid, msg, len - sent, lock_state);
+		sent += ret;
+		msg += ret;
+	}
+	return(len);
+}
+
+static inline int
+early_l1_send( nasid_t nasid, char *str, int len, int lock_state )
+{
+    int sent;
+    char crc_char;
+    unsigned short crc = INIT_CRC;
+
+    if( len > (BRL1_QSIZE - 1) )
+	len = (BRL1_QSIZE - 1);
+
+    sent = len;
+    if ( lock_state == NOT_LOCKED )
+    	lock_console(nasid);
+
+    PUTCHAR( BRL1_FLAG_CH );
+    PUTCHAR( BRL1_EVENT | SC_CONS_SYSTEM );
+    crc = crc16_calc( crc, (BRL1_EVENT | SC_CONS_SYSTEM) );
+
+    while( len ) {
+
+	if( (*str == BRL1_FLAG_CH) || (*str == BRL1_ESC_CH) ) {
+	    PUTCHAR( BRL1_ESC_CH );
+	    PUTCHAR( (*str) ^ BRL1_XOR_CH );
+	}
+	else {
+	    PUTCHAR( *str );
+	}
+	
+	crc = crc16_calc( crc, *str );
+
+	str++; len--;
+    }
+    
+    crc ^= 0xffff;
+    crc_char = crc & 0xff;
+    if( (crc_char == BRL1_ESC_CH) || (crc_char == BRL1_FLAG_CH) ) {
+	crc_char ^= BRL1_XOR_CH;
+	PUTCHAR( BRL1_ESC_CH );
+    }
+    PUTCHAR( crc_char );
+    crc_char = (crc >> 8) & 0xff;
+    if( (crc_char == BRL1_ESC_CH) || (crc_char == BRL1_FLAG_CH) ) {
+	crc_char ^= BRL1_XOR_CH;
+	PUTCHAR( BRL1_ESC_CH );
+    }
+    PUTCHAR( crc_char );
+    PUTCHAR( BRL1_FLAG_CH );
+
+    if ( lock_state == NOT_LOCKED )
+    	unlock_console(nasid);
+    return sent;
+}
+
+/*********************************************************************
+ * l1_cons functions
+ *
+ * These allow the L1 to act as the system console.  They're intended
+ * to abstract away most of the br/l1 internal details from the
+ * _L1_cons_* functions (in the prom-- see "l1_console.c") and
+ * l1_* functions (in the kernel-- see "sio_l1.c") that they support.
+ *
+ */
+
+static int
+l1_poll( l1sc_t *sc, int mode )
+{
+    int ret;
+
+    /* in case this gets called before the l1sc_t structure for the module_t
+     * struct for this node is initialized (i.e., if we're called with a
+     * zero l1sc_t pointer)...
+     */
+
+
+    if( !sc ) {
+	return 0;
+    }
+
+    if( atomic_read(&sc->subch[SC_CONS_SYSTEM].packet_arrived) ) {
+	return 1;
+    }
+
+    ret = brl1_receive( sc, mode );
+    if ( (ret != BRL1_VALID) && (ret != BRL1_NO_MESSAGE) && (ret != BRL1_PROTOCOL) && (ret != BRL1_CRC) )
+	L1_collectibles[L1C_REC_STALLS] = ret;
+
+    if( atomic_read(&sc->subch[SC_CONS_SYSTEM].packet_arrived) ) {
+	return 1;
+    }
+    return 0;
+}
+
+
+/* pull a character off of the system console queue (if one is available)
+ */
+static int
+l1_getc( l1sc_t *sc, int mode )
+{
+    unsigned long pl = 0;
+    int c;
+
+    brl1_sch_t *subch = &(sc->subch[SC_CONS_SYSTEM]);
+    sc_cq_t *q = subch->iqp;
+
+    if( !l1_poll( sc, mode ) ) {
+	return 0;
+    }
+
+    SUBCH_DATA_LOCK( subch, pl );
+    if( cq_empty( q ) ) {
+	atomic_set(&subch->packet_arrived, 0);
+	SUBCH_DATA_UNLOCK( subch, pl );
+	return 0;
+    }
+    cq_rem( q, c );
+    if( cq_empty( q ) )
+	atomic_set(&subch->packet_arrived, 0);
+    SUBCH_DATA_UNLOCK( subch, pl );
+
+    return c;
+}
+
+/*
+ * Write a message to the L1 on the system console subchannel.
+ *
+ * Danger: don't use a non-zero value for the wait parameter unless you're
+ * someone important (like a kernel error message).
+ */
+
+int
+l1_write( l1sc_t *sc, char *msg, int len, int wait )
+{
+	int sent = 0, ret = 0;
+
+	if ( wait ) {
+		while ( sent < len ) {
+			ret = brl1_send( sc, msg, len - sent, (SC_CONS_SYSTEM | BRL1_EVENT), wait );
+			sent += ret;
+			msg += ret;
+		}
+		ret = len;
+	}
+	else {
+		ret = brl1_send( sc, msg, len, (SC_CONS_SYSTEM | BRL1_EVENT), wait );
+	}
+	return(ret);
+}
+
+/* initialize the system console subchannel
+ */
+void
+l1_init(void)
+{
+	/* All we do now is remember that we have been called */
+	L1_cons_is_inited = 1;
+}
+
+
+/*********************************************************************
+ * The following functions and definitions implement the "message"-
+ * style interface to the L1 system controller.
+ *
+ * Note that throughout this file, "sc" generally stands for "system
+ * controller", while "subchannels" tend to be represented by
+ * variables with names like subch or ch.
+ *
+ */
+
+#ifdef L1_DEBUG
+#define L1_DBG_PRF(x) printf x
+#else
+#define L1_DBG_PRF(x)
+#endif
+
+/*
+ * sc_data_ready is called to signal threads that are blocked on l1 input.
+ */
+void
+sc_data_ready( int dummy0, void *dummy1, struct pt_regs *dummy2, l1sc_t *sc, int ch )
+{
+    unsigned long pl = 0;
+
+    brl1_sch_t *subch = &(sc->subch[ch]);
+    SUBCH_DATA_LOCK( subch, pl );
+    sv_signal( &(subch->arrive_sv) );
+    SUBCH_DATA_UNLOCK( subch, pl );
+}
+
+/* sc_open reserves a subchannel to send a request to the L1 (the
+ * L1's response will arrive on the same channel).  The number
+ * returned by sc_open is the system controller subchannel
+ * acquired.
+ */
+int
+sc_open( l1sc_t *sc, uint target )
+{
+    /* The kernel version implements a locking scheme to arbitrate
+     * subchannel assignment.
+     */
+    int ch;
+    unsigned long pl = 0;
+    brl1_sch_t *subch;
+
+    SUBCH_LOCK( sc, pl );
+
+    /* Look for a free subchannel. Subchannels 0-15 are reserved
+     * for other purposes.
+     */
+    for( subch = &(sc->subch[BRL1_CMD_SUBCH]), ch = BRL1_CMD_SUBCH; 
+			ch < BRL1_NUM_SUBCHANS; subch++, ch++ ) {
+        if( subch->use == BRL1_SUBCH_FREE )
+            break;
+    }
+
+    if( ch == BRL1_NUM_SUBCHANS ) {
+        /* there were no subchannels available! */
+        SUBCH_UNLOCK( sc, pl );
+        return SC_NSUBCH;
+    }
+
+    subch->use = BRL1_SUBCH_RSVD;
+    SUBCH_UNLOCK( sc, pl );
+
+    atomic_set(&subch->packet_arrived, 0);
+    subch->target = target;
+    spin_lock_init( &(subch->data_lock) );
+    sv_init( &(subch->arrive_sv), &(subch->data_lock), SV_MON_SPIN | SV_ORDER_FIFO /* | SV_INTS */);
+    subch->tx_notify = NULL;
+    subch->rx_notify = sc_data_ready;
+    subch->iqp = snia_kmem_zalloc_node( sizeof(sc_cq_t), KM_NOSLEEP,
+				   NASID_TO_COMPACT_NODEID(sc->nasid) );
+    ASSERT( subch->iqp );
+    cq_init( subch->iqp );
+
+    return ch;
+}
+
+
+/* sc_close frees a Bedrock<->L1 subchannel.
+ */
+int
+sc_close( l1sc_t *sc, int ch )
+{
+    unsigned long pl = 0;
+    brl1_sch_t *subch;
+
+    SUBCH_LOCK( sc, pl );
+    subch = &(sc->subch[ch]);
+    if( subch->use != BRL1_SUBCH_RSVD ) {
+        /* we're trying to close a subchannel that's not open */
+	SUBCH_UNLOCK( sc, pl );
+        return SC_NOPEN;
+    }
+
+    atomic_set(&subch->packet_arrived, 0);
+    subch->use = BRL1_SUBCH_FREE;
+
+    sv_broadcast( &(subch->arrive_sv) );
+    sv_destroy( &(subch->arrive_sv) );
+    spin_lock_destroy( &(subch->data_lock) );
+
+    ASSERT( subch->iqp && (subch->iqp != &sc->garbage_q) );
+    snia_kmem_free( subch->iqp, sizeof(sc_cq_t) );
+    subch->iqp = &sc->garbage_q;
+    subch->tx_notify = NULL;
+    subch->rx_notify = brl1_discard_packet;
+
+    SUBCH_UNLOCK( sc, pl );
+
+    return SC_SUCCESS;
+}
+
+
+/* sc_construct_msg builds a bedrock-to-L1 request in the supplied
+ * buffer.  Returns the length of the message.  The
+ * safest course when passing a buffer to be filled in is to use
+ * BRL1_QSIZE as the buffer size.
+ *
+ * Command arguments are passed as type/argument pairs, i.e., to
+ * pass the number 5 as an argument to an L1 command, call
+ * sc_construct_msg as follows:
+ *
+ *    char msg[BRL1_QSIZE];
+ *    msg_len = sc_construct_msg( msg,
+ *				  BRL1_QSIZE,
+ *				  target_component,
+ *                                L1_ADDR_TASK_BOGUSTASK,
+ *                                L1_BOGUSTASK_REQ_BOGUSREQ,
+ *                                2,
+ *                                L1_ARG_INT, 5 );
+ *
+ * To pass an additional ASCII argument, you'd do the following:
+ *
+ *    char *str;
+ *    ... str points to a null-terminated ascii string ...
+ *    msg_len = sc_construct_msg( msg,
+ *                                BRL1_QSIZE,
+ *				  target_component,
+ *                                L1_ADDR_TASK_BOGUSTASK,
+ *                                L1_BOGUSTASK_REQ_BOGUSREQ,
+ *                                4,
+ *                                L1_ARG_INT, 5,
+ *                                L1_ARG_ASCII, str );
+ *
+ * Finally, arbitrary data of unknown type is passed using the argtype
+ * code L1_ARG_UNKNOWN, a data length, and a buffer pointer, e.g.
+ *
+ *    msg_len = sc_construct_msg( msg,
+ *                                BRL1_QSIZE,
+ *				  target_component,
+ *                                L1_ADDR_TASK_BOGUSTASK,
+ *                                L1_BOGUSTASK_REQ_BOGUSREQ,
+ *                                3,
+ *                                L1_ARG_UNKNOWN, 32, bufptr );
+ *
+ * ...passes 32 bytes of data starting at bufptr.  Note that no string or
+ * "unknown"-type argument should be long enough to overflow the message
+ * buffer.
+ *
+ * To construct a message for an L1 command that requires no arguments,
+ * you'd use the following:
+ *
+ *    msg_len = sc_construct_msg( msg,
+ *                                BRL1_QSIZE,
+ *				  target_component,
+ *                                L1_ADDR_TASK_BOGUSTASK,
+ *                                L1_BOGUSTASK_REQ_BOGUSREQ,
+ *                                0 );
+ *
+ * The final 0 means "no varargs".  Notice that this parameter is used to hold
+ * the number of additional arguments to sc_construct_msg, _not_ the actual
+ * number of arguments used by the L1 command (so 2 per L1_ARG_[INT,ASCII]
+ * type argument, and 3 per L1_ARG_UNKOWN type argument).  A call to construct
+ * an L1 command which required three integer arguments and two arguments of
+ * some arbitrary (unknown) type would pass 12 as the value for this parameter.
+ *
+ * ENDIANNESS WARNING: The following code does a lot of copying back-and-forth
+ * between byte arrays and four-byte big-endian integers.  Depending on the
+ * system controller connection and endianness of future architectures, some
+ * rewriting might be necessary.
+ */
+int
+sc_construct_msg( l1sc_t  *sc,		/* system controller struct */
+		  int	   ch,           /* subchannel for this message */
+		  char    *msg,          /* message buffer */
+		  int      msg_len,      /* size of message buffer */
+                  l1addr_t addr_task,    /* target system controller task */
+                  short    req_code,     /* 16-bit request code */
+                  int      req_nargs,    /* # of arguments (varargs) passed */
+                  ... )                 /* any additional parameters */
+{
+    uint32_t buf32;   /* 32-bit buffer used to bounce things around */
+    void *bufptr;       /* used to hold command argument addresses */
+    va_list al;         /* variable argument list */
+    int index;          /* current index into msg buffer */
+    int argno;          /* current position in varargs list */
+    int l1_argno;       /* running total of arguments to l1 */
+    int l1_arg_t;       /* argument type/length */
+    int l1_argno_byte;  /* offset of argument count byte */
+
+    index = argno = 0;
+
+    /* set up destination address */
+    if( (msg_len -= sizeof( buf32 )) < 0 )
+	return -1;
+    L1_ADDRESS_TO_TASK( &buf32, sc->subch[ch].target, addr_task );
+    COPY_INT_TO_BUFFER(msg, index, buf32);
+
+    /* copy request code */
+    if( (msg_len -= 2) < 0 )
+	return( -1 );
+    msg[index++] = ((req_code >> 8) & 0xff);
+    msg[index++] = (req_code & 0xff);
+
+    if( !req_nargs ) {
+        return index;
+    }
+
+    /* reserve a byte for the argument count */
+    if( (msg_len -= 1) < 0 )
+	return( -1 );
+    l1_argno_byte = index++;
+    l1_argno = 0;
+
+    /* copy additional arguments */
+    va_start( al, req_nargs );
+    while( argno < req_nargs ) {
+        l1_argno++;
+        l1_arg_t = va_arg( al, int ); argno++;
+        switch( l1_arg_t )
+        {
+          case L1_ARG_INT:
+	    if( (msg_len -= (sizeof( buf32 ) + 1)) < 0 )
+		return( -1 );
+            msg[index++] = L1_ARG_INT;
+            buf32 = (unsigned)va_arg( al, int ); argno++;
+	    COPY_INT_TO_BUFFER(msg, index, buf32);
+            break;
+
+          case L1_ARG_ASCII:
+            bufptr = va_arg( al, char* ); argno++;
+	    if( (msg_len -= (strlen( bufptr ) + 2)) < 0 )
+		return( -1 );
+            msg[index++] = L1_ARG_ASCII;
+            strcpy( (char *)&(msg[index]), (char *)bufptr );
+            index += (strlen( bufptr ) + 1); /* include terminating null */
+            break;
+
+	  case L1_ARG_UNKNOWN:
+              {
+                  int arglen;
+		  
+                  arglen = va_arg( al, int ); argno++;
+                  bufptr = va_arg( al, void* ); argno++;
+		  if( (msg_len -= (arglen + 1)) < 0 )
+		      return( -1 );
+                  msg[index++] = L1_ARG_UNKNOWN | arglen;
+                  BCOPY( bufptr, &(msg[index]), arglen  );
+                  index += arglen;
+		  break;
+              }
+	  
+	  default: /* unhandled argument type */
+	    return -1;
+        }
+    }
+
+    va_end( al );
+    msg[l1_argno_byte] = l1_argno;
+
+    return index;
+}
+
+
+
+/* sc_interpret_resp verifies an L1 response to a bedrock request, and
+ * breaks the response data up into the constituent parts.  If the
+ * response message indicates error, or if a mismatch is found in the
+ * expected number and type of arguments, an error is returned.  The
+ * arguments to this function work very much like the arguments to
+ * sc_construct_msg, above, except that L1_ARG_INTs must be followed
+ * by a _pointer_ to an integer that can be filled in by this function.
+ */
+int
+sc_interpret_resp( char *resp,          /* buffer received from L1 */
+                   int   resp_nargs,    /* number of _varargs_ passed in */
+                   ... )
+{
+    uint32_t buf32;   /* 32-bit buffer used to bounce things around */
+    void *bufptr;       /* used to hold response field addresses */
+    va_list al;         /* variable argument list */
+    int index;          /* current index into response buffer */
+    int argno;          /* current position in varargs list */
+    int l1_fldno;       /* number of resp fields received from l1 */
+    int l1_fld_t;       /* field type/length */
+
+    index = argno = 0;
+
+#if defined(L1_DEBUG)
+#define DUMP_RESP							  \
+    {									  \
+	int ix;								  \
+        char outbuf[512];						  \
+        sprintf( outbuf, "sc_interpret_resp error line %d: ", __LINE__ ); \
+	for( ix = 0; ix < 16; ix++ ) {					  \
+	    sprintf( &outbuf[strlen(outbuf)], "%x ", resp[ix] );	  \
+	}								  \
+	printk( "%s\n", outbuf );					  \
+    }
+#else
+#define DUMP_RESP
+#endif /* L1_DEBUG */
+
+    /* check response code */
+    COPY_BUFFER_TO_INT(resp, index, buf32);
+    if( buf32 != L1_RESP_OK ) {
+	DUMP_RESP;
+        return buf32;
+    }
+
+    /* get number of response fields */
+    l1_fldno = resp[index++];
+
+    va_start( al, resp_nargs );
+
+    /* copy out response fields */
+    while( argno < resp_nargs ) {
+        l1_fldno--;
+        l1_fld_t = va_arg( al, int ); argno++;
+        switch( l1_fld_t )
+        {
+          case L1_ARG_INT:
+            if( resp[index++] != L1_ARG_INT ) {
+                /* type mismatch */
+		va_end( al );
+		DUMP_RESP;
+		return -1;
+            }
+            bufptr = va_arg( al, int* ); argno++;
+	    COPY_BUFFER_TO_BUFFER(resp, index, bufptr);
+            break;
+
+          case L1_ARG_ASCII:
+            if( resp[index++] != L1_ARG_ASCII ) {
+                /* type mismatch */
+		va_end( al );
+		DUMP_RESP;
+                return -1;
+            }
+            bufptr = va_arg( al, char* ); argno++;
+            strcpy( (char *)bufptr, (char *)&(resp[index]) );
+            /* include terminating null */
+            index += (strlen( &(resp[index]) ) + 1);
+            break;
+
+          default:
+	    if( (l1_fld_t & L1_ARG_UNKNOWN) == L1_ARG_UNKNOWN )
+	    {
+		int *arglen;
+		
+		arglen = va_arg( al, int* ); argno++;
+		bufptr = va_arg( al, void* ); argno++;
+		*arglen = ((resp[index++] & ~L1_ARG_UNKNOWN) & 0xff);
+		BCOPY( &(resp[index]), bufptr, *arglen  );
+		index += (*arglen);
+	    }
+	    
+	    else {
+		/* unhandled type */
+		va_end( al );
+		DUMP_RESP;
+		return -1;
+	    }
+        }
+    }
+    va_end( al );
+  
+    if( (l1_fldno != 0) || (argno != resp_nargs) ) {
+        /* wrong number of arguments */
+	DUMP_RESP;
+        return -1;
+    }
+    return 0;
+}
+
+/* sc_send takes as arguments a system controller struct, a
+ * buffer which contains a Bedrock<->L1 "request" message,
+ * the message length, and the subchannel (presumably obtained
+ * from an earlier invocation of sc_open) over which the
+ * message is to be sent.  The final argument ("wait") indicates
+ * whether the send is to be performed synchronously or not.
+ *
+ * sc_send returns either zero or an error value.  Synchronous sends 
+ * (wait != 0) will not return until the data has actually been sent
+ * to the UART.  Synchronous sends generally receive privileged
+ * treatment.  The intent is that they be used sparingly, for such
+ * purposes as kernel printf's (the "ducons" routines).  Run-of-the-mill
+ * console output and L1 requests should NOT use a non-zero value
+ * for wait.
+ */
+int
+sc_send( l1sc_t *sc, int ch, char *msg, int len, int wait )
+{
+    char type_and_subch;
+    int result;
+
+    if( (ch < 0) || ( ch >= BRL1_NUM_SUBCHANS) ) {
+        return SC_BADSUBCH;
+    }
+
+    /* Verify that this is an open subchannel
+     */
+    if( sc->subch[ch].use == BRL1_SUBCH_FREE ) {
+        return SC_NOPEN;
+    }
+
+    type_and_subch = (BRL1_REQUEST | ((u_char)ch));
+    result = brl1_send( sc, msg, len, type_and_subch, wait );
+
+    /* If we sent as much as we asked to, return "ok". */
+    if( result == len )
+	return( SC_SUCCESS );
+
+    /* Or, if we sent less, than either the UART is busy or
+     * we're trying to send too large a packet anyway.
+     */
+    else if( result >= 0 && result < len )
+	return( SC_BUSY );
+
+    /* Or, if something else went wrong (result < 0), then
+     * return that error value.
+     */
+    else
+	return( result );
+}
+
+/* subch_pull_msg pulls a message off the receive queue for subch
+ * and places it the buffer pointed to by msg.  This routine should only
+ * be called when the caller already knows a message is available on the
+ * receive queue (and, in the kernel, only when the subchannel data lock
+ * is held by the caller).
+ */
+static void
+subch_pull_msg( brl1_sch_t *subch, char *msg, int *len )
+{
+    sc_cq_t *q;         /* receive queue */
+    int before_wrap,    /* packet may be split into two different       */
+        after_wrap;     /*   pieces to acommodate queue wraparound      */
+
+    /* pull message off the receive queue */
+    q = subch->iqp;
+
+    cq_rem( q, *len );   /* remove length byte and store */
+    cq_discard( q );     /* remove type/subch byte and discard */
+
+    if ( *len > 0 )
+	(*len)--;        /* don't count type/subch byte in length returned */
+
+    if( (q->opos + (*len)) > BRL1_QSIZE ) {
+        before_wrap = BRL1_QSIZE - q->opos;
+        after_wrap = (*len) - before_wrap;
+    }
+    else {
+        before_wrap = (*len);
+        after_wrap = 0;
+    }
+
+    BCOPY( q->buf + q->opos, msg, before_wrap  );
+    if( after_wrap ) {
+        BCOPY( q->buf, msg + before_wrap, after_wrap  );
+	q->opos = after_wrap;
+    }
+    else {
+	q->opos = ((q->opos + before_wrap) & (BRL1_QSIZE - 1));
+    }
+    atomic_dec(&(subch->packet_arrived));
+}
+
+
+/* sc_recv_poll can be called as a blocking or non-blocking function;
+ * it attempts to pull a message off of the subchannel specified
+ * in the argument list (ch).
+ *
+ * The "block" argument, if non-zero, is interpreted as a timeout
+ * delay (to avoid permanent waiting).
+ */
+
+int
+sc_recv_poll( l1sc_t *sc, int ch, char *msg, int *len, uint64_t block )
+{
+    int is_msg = 0;
+    unsigned long pl = 0;
+    brl1_sch_t *subch = &(sc->subch[ch]);
+
+    rtc_time_t exp_time = rtc_time() + block;
+
+    /* sanity check-- make sure this is an open subchannel */
+    if( subch->use == BRL1_SUBCH_FREE )
+	return( SC_NOPEN );
+
+    do {
+
+        /* kick the next lower layer and see if it pulls anything in
+         */
+	brl1_receive( sc, SERIAL_POLLED_MODE );
+	is_msg = atomic_read(&subch->packet_arrived);
+
+    } while( block && !is_msg && (rtc_time() < exp_time) );
+
+    if( !is_msg ) {
+	/* no message and we didn't care to wait for one */
+	return( SC_NMSG );
+    }
+
+    SUBCH_DATA_LOCK( subch, pl );
+    subch_pull_msg( subch, msg, len );
+    SUBCH_DATA_UNLOCK( subch, pl );
+
+    return( SC_SUCCESS );
+}
+    
+
+/* Like sc_recv_poll, sc_recv_intr can be called in either a blocking
+ * or non-blocking mode.  Rather than polling until an appointed timeout,
+ * however, sc_recv_intr sleeps on a syncrhonization variable until a
+ * signal from the lower layer tells us that a packet has arrived.
+ *
+ * sc_recv_intr can't be used with remote (router) L1s.
+ */
+int
+sc_recv_intr( l1sc_t *sc, int ch, char *msg, int *len, uint64_t block )
+{
+    int is_msg = 0;
+    unsigned long pl = 0;
+    brl1_sch_t *subch = &(sc->subch[ch]);
+
+    do {
+	SUBCH_DATA_LOCK(subch, pl);
+	is_msg = atomic_read(&subch->packet_arrived);
+	if( !is_msg && block ) {
+	    /* wake me when you've got something */
+	    subch->rx_notify = sc_data_ready;
+	    sv_wait( &(subch->arrive_sv), 0, 0);
+	    if( subch->use == BRL1_SUBCH_FREE ) {
+		/* oops-- somebody closed our subchannel while we were
+		 * sleeping!
+		 */
+
+		/* no need to unlock since the channel's closed anyhow */
+		return( SC_NOPEN );
+	    }
+	}
+    } while( !is_msg && block );
+
+    if( !is_msg ) {
+	/* no message and we didn't care to wait for one */
+	SUBCH_DATA_UNLOCK( subch, pl );
+	return( SC_NMSG );
+    }
+
+    subch_pull_msg( subch, msg, len );
+    SUBCH_DATA_UNLOCK( subch, pl );
+
+    return( SC_SUCCESS );
+}
+
+/* sc_command implements a (blocking) combination of sc_send and sc_recv.
+ * It is intended to be the SN1 equivalent of SN0's "elsc_command", which
+ * issued a system controller command and then waited for a response from
+ * the system controller before returning.
+ *
+ * cmd points to the outgoing command; resp points to the buffer in
+ * which the response is to be stored.  Both buffers are assumed to
+ * be the same length; if there is any doubt as to whether the
+ * response buffer is long enough to hold the L1's response, then
+ * make it BRL1_QSIZE bytes-- no Bedrock<->L1 message can be any
+ * bigger.
+ *
+ * Be careful using the same buffer for both cmd and resp; it could get
+ * hairy if there were ever an L1 command reqeuest that spanned multiple
+ * packets.  (On the other hand, that would require some additional
+ * rewriting of the L1 command interface anyway.)
+ */
+#define __RETRIES	50
+#define __WAIT_SEND	1	// ( sc->uart != BRL1_LOCALHUB_UART )
+#define __WAIT_RECV	10000000
+
+
+int
+sc_command( l1sc_t *sc, int ch, char *cmd, char *resp, int *len )
+{
+    int result;
+    int retries;
+
+    if ( IS_RUNNING_ON_SIMULATOR() )
+    	return SC_NMSG;
+
+    retries = __RETRIES;
+
+    while( (result = sc_send( sc, ch, cmd, *len, __WAIT_SEND )) < 0 ) {
+	if( result == SC_BUSY ) {
+	    retries--;
+	    if( retries <= 0 )
+		return result;
+	    uart_delay(500);
+	}
+	else {
+	    return result;
+	}
+    }
+    
+    /* block on sc_recv_* */
+    if( (sc->uart == BRL1_LOCALHUB_UART) && L1_interrupts_connected ) {
+	return( sc_recv_intr( sc, ch, resp, len, __WAIT_RECV ) );
+    }
+    else {
+	return( sc_recv_poll( sc, ch, resp, len, __WAIT_RECV ) );
+    }
+}
+
+/* sc_command_kern is a knuckle-dragging, no-patience version of sc_command
+ * used in situations where the kernel has a command that shouldn't be
+ * delayed until the send buffer clears.  sc_command should be used instead
+ * under most circumstances.
+ */
+
+int
+sc_command_kern( l1sc_t *sc, int ch, char *cmd, char *resp, int *len )
+{
+    int result;
+
+    if ( IS_RUNNING_ON_SIMULATOR() )
+    	return SC_NMSG;
+
+    if( (result = sc_send( sc, ch, cmd, *len, 1 )) < 0 ) {
+	return result;
+    }
+
+    return( sc_recv_poll( sc, ch, resp, len, __WAIT_RECV ) );
+}
+
+
+
+/* sc_poll checks the queue corresponding to the given
+ * subchannel to see if there's anything available.  If
+ * not, it kicks the brl1 layer and then checks again.
+ *
+ * Returns 1 if input is available on the given queue,
+ * 0 otherwise.
+ */
+
+int
+sc_poll( l1sc_t *sc, int ch )
+{
+    brl1_sch_t *subch = &(sc->subch[ch]);
+
+    if( atomic_read(&subch->packet_arrived) )
+	return 1;
+
+    brl1_receive( sc, SERIAL_POLLED_MODE );
+
+    if( atomic_read(&subch->packet_arrived) )
+	return 1;
+
+    return 0;
+}
+
+/* for now, sc_init just calls brl1_init */
+
+void
+sc_init( l1sc_t *sc, nasid_t nasid, net_vec_t uart )
+{
+    if ( !IS_RUNNING_ON_SIMULATOR() )
+    	brl1_init( sc, nasid, uart );
+}
+
+/* sc_dispatch_env_event handles events sent from the system control
+ * network's environmental monitor tasks.
+ */
+
+#if	defined(LINUX_KERNEL_THREADS)
+
+static void
+sc_dispatch_env_event( uint code, int argc, char *args, int maxlen )
+{
+    int j, i = 0;
+    uint32_t ESPcode;
+
+    switch( code ) {
+	/* for now, all codes do the same thing: grab two arguments
+	 * and print a cmn_err_tag message */
+      default:
+	/* check number of arguments */
+	if( argc != 2 ) {
+	    L1_DBG_PRF(( "sc_dispatch_env_event: "
+			 "expected 2 arguments, got %d\n", argc ));
+	    return;
+	}
+	
+	/* get ESP code (integer argument) */
+	if( args[i++] != L1_ARG_INT ) {
+	    L1_DBG_PRF(( "sc_dispatch_env_event: "
+			 "expected integer argument\n" ));
+	    return;
+	}
+	/* WARNING: highly endian */
+	COPY_BUFFER_TO_INT(args, i, ESPcode);
+
+	/* verify string argument */
+	if( args[i++] != L1_ARG_ASCII ) {
+	    L1_DBG_PRF(( "sc_dispatch_env_event: "
+			 "expected an ASCII string\n" ));
+	    return;
+	}
+	for( j = i; j < maxlen; j++ ) {
+	    if( args[j] == '\0' ) break; /* found string termination */
+	}
+	if( j == maxlen ) {
+	    j--;
+	    L1_DBG_PRF(( "sc_dispatch_env_event: "
+			 "message too long-- truncating\n" ));
+	}
+
+	/* strip out trailing cr/lf */
+	for( ; 
+	     j > 1 && ((args[j-1] == 0xd) || (args[j-1] == 0xa)); 
+	     j-- );
+	args[j] = '\0';
+	
+	/* strip out leading cr/lf */
+	for( ;
+	     i < j && ((args[i] == 0xd) || (args[i] == 0xa));
+	     i++ );
+    }
+}
+
+
+/* sc_event waits for events to arrive from the system controller, and
+ * prints appropriate messages to the syslog.
+ */
+
+static void
+sc_event( l1sc_t *sc, int ch )
+{
+    char event[BRL1_QSIZE];
+    int i;
+    int result;
+    int event_len;
+    uint32_t ev_src;
+    uint32_t ev_code;
+    int ev_argc;
+
+    while(1) {
+	
+	bzero( event, BRL1_QSIZE );
+
+	/*
+	 * wait for an event 
+	 */
+	result = sc_recv_intr( sc, ch, event, &event_len, 1 );
+	if( result != SC_SUCCESS ) {
+	    printk(KERN_WARNING  "Error receiving sysctl event on nasid %d\n",
+		     sc->nasid );
+	}
+	else {
+	    /*
+	     * an event arrived; break it down into useful pieces
+	     */
+#if defined(L1_DEBUG) && 0
+	    int ix;
+	    printf( "Event packet received:\n" );
+	    for (ix = 0; ix < 64; ix++) {
+		printf( "%x%x ", ((event[ix] >> 4) & ((uint64_t)0xf)),
+			(event[ix] & ((uint64_t)0xf)) );
+		if( (ix % 16) == 0xf ) printf( "\n" );
+	    }
+#endif /* L1_DEBUG */
+
+	    i = 0;
+
+	    /* get event source */
+	    COPY_BUFFER_TO_INT(event, i, ev_src);
+	    COPY_BUFFER_TO_INT(event, i, ev_code);
+
+	    /* get arg count */
+	    ev_argc = (event[i++] & 0xffUL);
+	    
+	    /* dispatch events by task */
+	    switch( (ev_src & L1_ADDR_TASK_MASK) >> L1_ADDR_TASK_SHFT )
+	    {
+	      case L1_ADDR_TASK_ENV: /* environmental monitor event */
+		sc_dispatch_env_event( ev_code, ev_argc, &(event[i]), 
+				       BRL1_QSIZE - i );
+		break;
+
+	      default: /* unhandled task type */
+		L1_DBG_PRF(( "Unhandled event type received from system "
+			     "controllers: source task %x\n",
+			     (ev_src & L1_ADDR_TASK_MASK) >> L1_ADDR_TASK_SHFT
+			   ));
+	    }
+	}
+	
+    }			
+}
+
+/* sc_listen sets up a service thread to listen for incoming events.
+ */
+
+void
+sc_listen( l1sc_t *sc )
+{
+    int result;
+    unsigned long pl = 0;
+    brl1_sch_t *subch;
+
+    char        msg[BRL1_QSIZE];
+    int         len;    /* length of message being sent */
+    int         ch;     /* system controller subchannel used */
+
+    extern int msc_shutdown_pri;
+
+    /* grab the designated "event subchannel" */
+    SUBCH_LOCK( sc, pl );
+    subch = &(sc->subch[BRL1_EVENT_SUBCH]);
+    if( subch->use != BRL1_SUBCH_FREE ) {
+	SUBCH_UNLOCK( sc, pl );
+	printk(KERN_WARNING  "sysctl event subchannel in use! "
+		 "Not monitoring sysctl events.\n" );
+	return;
+    }
+    subch->use = BRL1_SUBCH_RSVD;
+    SUBCH_UNLOCK( sc, pl );
+
+    atomic_set(&subch->packet_arrived, 0);
+    subch->target = BRL1_LOCALHUB_UART;
+    spin_lock_init( &(subch->data_lock) );
+    sv_init( &(subch->arrive_sv), &(subch->data_lock), SV_MON_SPIN | SV_ORDER_FIFO /* | SV_INTS */);
+    subch->tx_notify = NULL;
+    subch->rx_notify = sc_data_ready;
+    subch->iqp = snia_kmem_zalloc_node( sizeof(sc_cq_t), KM_NOSLEEP,
+				   NASID_TO_COMPACT_NODEID(sc->nasid) );
+    ASSERT( subch->iqp );
+    cq_init( subch->iqp );
+
+    /* set up a thread to listen for events */
+    sthread_create( "sysctl event handler", 0, 0, 0, msc_shutdown_pri,
+		    KT_PS, (st_func_t *) sc_event,
+		    (void *)sc, (void *)(uint64_t)BRL1_EVENT_SUBCH, 0, 0 );
+
+    /* signal the L1 to begin sending events */
+    bzero( msg, BRL1_QSIZE );
+    ch = sc_open( sc, L1_ADDR_LOCAL );
+
+    if( (len = sc_construct_msg( sc, ch, msg, BRL1_QSIZE,
+				 L1_ADDR_TASK_GENERAL,
+				 L1_REQ_EVENT_SUBCH, 2,
+				 L1_ARG_INT, BRL1_EVENT_SUBCH )) < 0 )
+    {
+	sc_close( sc, ch );
+	L1_DBG_PRF(( "Failure in sc_construct_msg (%d)\n", len ));
+	goto err_return;
+    }
+
+    result = sc_command_kern( sc, ch, msg, msg, &len );
+    if( result < 0 )
+    {
+	sc_close( sc, ch );
+	L1_DBG_PRF(( "Failure in sc_command_kern (%d)\n", result ));
+	goto err_return;
+    }
+
+    sc_close( sc, ch );
+
+    result = sc_interpret_resp( msg, 0 );
+    if( result < 0 )
+    {
+	L1_DBG_PRF(( "Failure in sc_interpret_resp (%d)\n", result ));
+	goto err_return;
+    }
+
+    /* everything went fine; just return */
+    return;
+	
+err_return:
+    /* there was a problem; complain */
+    printk(KERN_WARNING  "failed to set sysctl event-monitoring subchannel.  "
+	     "Sysctl events will not be monitored.\n" );
+}
+
+#endif	/* LINUX_KERNEL_THREADS */

FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)