[PATCH] Altix console driver
From: Patrick Gefre
Date: Tue Oct 21 2003 - 16:28:27 EST
2.6 Altix serial console driver add
# This is a BitKeeper generated patch for the following project:
# Project Name: Linux kernel tree
# This patch format is intended for GNU patch command version 2.5 or higher.
# This patch includes the following deltas:
# ChangeSet 1.1347 -> 1.1348
# drivers/char/Kconfig 1.24 -> 1.25
# MAINTAINERS 1.174 -> 1.175
# drivers/char/Makefile 1.60 -> 1.61
# (new) -> 1.1 drivers/char/sn_serial.c
#
# The following is the BitKeeper ChangeSet Log
# --------------------------------------------
# 03/10/21 pfg@xxxxxxxxxxxxxxxxxxxxxxx 1.1348
# Altix serial console patch
# --------------------------------------------
#
diff -Nru a/MAINTAINERS b/MAINTAINERS
--- a/MAINTAINERS Tue Oct 21 16:18:17 2003
+++ b/MAINTAINERS Tue Oct 21 16:18:17 2003
@@ -1753,6 +1753,12 @@
W: http://www.nsa.gov/selinux
S: Supported
+SGI SN-IA64 (Altix) SERIAL CONSOLE DRIVER
+P: Pat Gefre
+M: pfg@xxxxxxx
+L: linux-ia64@xxxxxxxxxxxxxxx
+S: Supported
+
SGI VISUAL WORKSTATION 320 AND 540
P: Andrey Panin
M: pazke@xxxxxxxxx
diff -Nru a/drivers/char/Kconfig b/drivers/char/Kconfig
--- a/drivers/char/Kconfig Tue Oct 21 16:18:17 2003
+++ b/drivers/char/Kconfig Tue Oct 21 16:18:17 2003
@@ -373,6 +373,22 @@
If you have an Alchemy AU1000 processor (MIPS based) and you want
to use serial ports, say Y. Otherwise, say N.
+config SGI_L1_SERIAL
+ bool "SGI Altix L1 serial support"
+ depends on SERIAL_NONSTANDARD && IA64
+ help
+ If you have an SGI Altix and you want to use the serial port
+ connected to the system controller (you want this!), say Y.
+ Otherwise, say N.
+
+config SGI_L1_SERIAL_CONSOLE
+ bool "SGI Altix L1 serial console support"
+ depends on SGI_L1_SERIAL
+ help
+ If you have an SGI Altix and you would like to use the system
+ controller serial port as your console (you want this!),
+ say Y. Otherwise, say N.
+
config AU1000_SERIAL_CONSOLE
bool "Enable Au1000 serial console"
depends on AU1000_UART
diff -Nru a/drivers/char/Makefile b/drivers/char/Makefile
--- a/drivers/char/Makefile Tue Oct 21 16:18:17 2003
+++ b/drivers/char/Makefile Tue Oct 21 16:18:17 2003
@@ -42,6 +42,7 @@
obj-$(CONFIG_SH_SCI) += sh-sci.o generic_serial.o
obj-$(CONFIG_HVC_CONSOLE) += hvc_console.o
obj-$(CONFIG_RAW_DRIVER) += raw.o
+obj-$(CONFIG_SGI_L1_SERIAL) += sn_serial.o
obj-$(CONFIG_PRINTER) += lp.o
obj-$(CONFIG_TIPAR) += tipar.o
diff -Nru a/drivers/char/sn_serial.c b/drivers/char/sn_serial.c
--- /dev/null Wed Dec 31 16:00:00 1969
+++ b/drivers/char/sn_serial.c Tue Oct 21 16:18:17 2003
@@ -0,0 +1,1000 @@
+/*
+ * C-Brick Serial Port (and console) driver for SGI Altix machines.
+ *
+ * This driver is NOT suitable for talking to the l1-controller for
+ * anything other than 'console activities' --- please use the l1
+ * driver for that.
+ *
+ * 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) 2003 Silicon Graphics, Inc. All rights reserved.
+ */
+
+#include <linux/config.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/serial.h>
+#include <linux/console.h>
+#include <linux/module.h>
+#include <linux/sysrq.h>
+#include <linux/circ_buf.h>
+#include <linux/serial_reg.h>
+#include <asm/sn/sn_sal.h>
+#include <asm/sn/pci/pciio.h> /* this is needed for get_console_nasid */
+#include <asm/sn/simulator.h>
+#include <asm/sn/sn2/sn_private.h>
+
+#if defined(CONFIG_SGI_L1_SERIAL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+static char sysrq_serial_str[] = "\eSYS";
+static char *sysrq_serial_ptr = sysrq_serial_str;
+static unsigned long sysrq_requested;
+#endif /* CONFIG_SGI_L1_SERIAL_CONSOLE && CONFIG_MAGIC_SYSRQ */
+
+/* minor device number */
+#define SN_SAL_MINOR 64
+
+/* number of characters left in xmit buffer before we ask for more */
+#define WAKEUP_CHARS 128
+
+/* number of characters we can transmit to the SAL console at a time */
+#define SN_SAL_MAX_CHARS 120
+
+#define SN_SAL_EVENT_WRITE_WAKEUP 0
+
+/* 64K, when we're asynch, it must be at least printk's LOG_BUF_LEN to
+ * avoid losing chars, (always has to be a power of 2) */
+#define SN_SAL_BUFFER_SIZE (64 * (1 << 10))
+
+#define SN_SAL_UART_FIFO_DEPTH 16
+#define SN_SAL_UART_FIFO_SPEED_CPS 9600/10
+
+/* we don't kmalloc/get_free_page these as we want them available
+ * before either of those are initialized */
+static char sn_xmit_buff_mem[SN_SAL_BUFFER_SIZE];
+
+struct volatile_circ_buf {
+ char *cb_buf;
+ int cb_head;
+ int cb_tail;
+};
+
+static struct volatile_circ_buf xmit = { .cb_buf = sn_xmit_buff_mem };
+static char sn_tmp_buffer[SN_SAL_BUFFER_SIZE];
+
+static struct tty_struct *sn_sal_tty;
+
+static struct timer_list sn_sal_timer;
+static int sn_sal_event; /* event type for task queue */
+
+static int sn_sal_is_asynch;
+static int sn_sal_irq;
+static spinlock_t sn_sal_lock = SPIN_LOCK_UNLOCKED;
+static int sn_total_tx_count;
+static int sn_total_rx_count;
+
+static void sn_sal_tasklet_action(unsigned long data);
+static DECLARE_TASKLET(sn_sal_tasklet, sn_sal_tasklet_action, 0);
+
+static unsigned long sn_interrupt_timeout;
+
+extern u64 master_node_bedrock_address;
+
+static int sn_debug_printf(const char *fmt, ...);
+
+#undef DEBUG
+#ifdef DEBUG
+#define DPRINTF(x...) sn_debug_printf(x)
+#else
+#define DPRINTF(x...) do { } while (0)
+#endif
+
+struct sn_sal_ops {
+ int (*sal_puts)(const char *s, int len);
+ int (*sal_getc)(void);
+ int (*sal_input_pending)(void);
+ void (*sal_wakeup_transmit)(void);
+};
+
+/* This is the pointer used. It is assigned to point to one of
+ * the tables below.
+ */
+static struct sn_sal_ops *sn_func;
+
+/* Prototypes */
+static void __init sn_sal_serial_console_init(void);
+static int snt_hw_puts(const char *, int);
+static int snt_poll_getc(void);
+static int snt_poll_input_pending(void);
+static int snt_sim_puts(const char *, int);
+static int snt_sim_getc(void);
+static int snt_sim_input_pending(void);
+static int snt_intr_getc(void);
+static int snt_intr_input_pending(void);
+static void sn_intr_transmit_chars(void);
+
+/* A table for polling */
+static struct sn_sal_ops poll_ops = {
+ .sal_puts = snt_hw_puts,
+ .sal_getc = snt_poll_getc,
+ .sal_input_pending = snt_poll_input_pending
+};
+
+/* A table for the simulator */
+static struct sn_sal_ops sim_ops = {
+ .sal_puts = snt_sim_puts,
+ .sal_getc = snt_sim_getc,
+ .sal_input_pending = snt_sim_input_pending
+};
+
+/* A table for interrupts enabled */
+static struct sn_sal_ops intr_ops = {
+ .sal_puts = snt_hw_puts,
+ .sal_getc = snt_intr_getc,
+ .sal_input_pending = snt_intr_input_pending,
+ .sal_wakeup_transmit = sn_intr_transmit_chars
+};
+
+
+/* the console does output in two distinctly different ways:
+ * synchronous and asynchronous (buffered). initally, early_printk
+ * does synchronous output. any data written goes directly to the SAL
+ * to be output (incidentally, it is internally buffered by the SAL)
+ * after interrupts and timers are initialized and available for use,
+ * the console init code switches to asynchronous output. this is
+ * also the earliest opportunity to begin polling for console input.
+ * after console initialization, console output and tty (serial port)
+ * output is buffered and sent to the SAL asynchronously (either by
+ * timer callback or by UART interrupt) */
+
+
+/* routines for running the console in polling mode */
+
+static int
+snt_hw_puts(const char *s, int len)
+{
+ /* looking at the PROM source code, putb calls the flush
+ * routine, so if we send characters in FIFO sized chunks, it
+ * should go out by the next time the timer gets called */
+ return ia64_sn_console_putb(s, len);
+}
+
+static int
+snt_poll_getc(void)
+{
+ int ch;
+ ia64_sn_console_getc(&ch);
+ return ch;
+}
+
+static int
+snt_poll_input_pending(void)
+{
+ int status, input;
+
+ status = ia64_sn_console_check(&input);
+ return !status && input;
+}
+
+
+/* routines for running the console on the simulator */
+
+static int
+snt_sim_puts(const char *str, int count)
+{
+ int counter = count;
+
+#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('[', master_node_bedrock_address + (UART_TX << 3));
+ writeb('+', master_node_bedrock_address + (UART_TX << 3));
+ writeb(']', master_node_bedrock_address + (UART_TX << 3));
+ writeb(' ', master_node_bedrock_address + (UART_TX << 3));
+#endif /* FLAG_DIRECT_CONSOLE_WRITES */
+ while (counter > 0) {
+ writeb(*str, master_node_bedrock_address + (UART_TX << 3));
+ counter--;
+ str++;
+ }
+
+ return count;
+}
+
+static int
+snt_sim_getc(void)
+{
+ return readb(master_node_bedrock_address + (UART_RX << 3));
+}
+
+static int
+snt_sim_input_pending(void)
+{
+ return readb(master_node_bedrock_address + (UART_LSR << 3)) & UART_LSR_DR;
+}
+
+
+/* routines for an interrupt driven console (normal) */
+
+static int
+snt_intr_getc(void)
+{
+ return ia64_sn_console_readc();
+}
+
+static int
+snt_intr_input_pending(void)
+{
+ return ia64_sn_console_intr_status() & SAL_CONSOLE_INTR_RECV;
+}
+
+/* The early printk (possible setup) and function call */
+
+void
+early_printk_sn_sal(const char *s, unsigned count)
+{
+ extern void early_sn_setup(void);
+
+ if (!sn_func) {
+ if (IS_RUNNING_ON_SIMULATOR())
+ sn_func = &sim_ops;
+ else
+ sn_func = &poll_ops;
+
+ early_sn_setup();
+ }
+ sn_func->sal_puts(s, count);
+}
+
+/* this is as "close to the metal" as we can get, used when the driver
+ * itself may be broken */
+static int
+sn_debug_printf(const char *fmt, ...)
+{
+ static char printk_buf[1024];
+ int printed_len;
+ va_list args;
+
+ va_start(args, fmt);
+ printed_len = vsnprintf(printk_buf, sizeof(printk_buf), fmt, args);
+ early_printk_sn_sal(printk_buf, printed_len);
+ va_end(args);
+ return printed_len;
+}
+
+/*
+ * Interrupt handling routines.
+ */
+
+static void
+sn_sal_sched_event(int event)
+{
+ sn_sal_event |= (1 << event);
+ tasklet_schedule(&sn_sal_tasklet);
+}
+
+/* sn_receive_chars can be called before sn_sal_tty is initialized. in
+ * that case, its only use is to trigger sysrq and kdb */
+static void
+sn_receive_chars(struct pt_regs *regs, unsigned long *flags)
+{
+ int ch;
+
+ while (sn_func->sal_input_pending()) {
+ ch = sn_func->sal_getc();
+ if (ch < 0) {
+ printk(KERN_ERR "sn_serial: An error occured while "
+ "obtaining data from the console (0x%0x)\n", ch);
+ break;
+ }
+#if defined(CONFIG_SGI_L1_SERIAL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+ if (sysrq_requested) {
+ unsigned long sysrq_timeout = sysrq_requested + HZ*5;
+
+ sysrq_requested = 0;
+ if (ch && time_before(jiffies, sysrq_timeout)) {
+ spin_unlock_irqrestore(&sn_sal_lock, *flags);
+ handle_sysrq(ch, regs, NULL);
+ spin_lock_irqsave(&sn_sal_lock, *flags);
+ /* don't record this char */
+ continue;
+ }
+ }
+ if (ch == *sysrq_serial_ptr) {
+ if (!(*++sysrq_serial_ptr)) {
+ sysrq_requested = jiffies;
+ sysrq_serial_ptr = sysrq_serial_str;
+ }
+ }
+ else
+ sysrq_serial_ptr = sysrq_serial_str;
+#endif /* CONFIG_SGI_L1_SERIAL_CONSOLE && CONFIG_MAGIC_SYSRQ */
+
+ /* record the character to pass up to the tty layer */
+ if (sn_sal_tty) {
+ *sn_sal_tty->flip.char_buf_ptr = ch;
+ sn_sal_tty->flip.char_buf_ptr++;
+ sn_sal_tty->flip.count++;
+ if (sn_sal_tty->flip.count == TTY_FLIPBUF_SIZE)
+ break;
+ }
+ sn_total_rx_count++;
+ }
+
+ if (sn_sal_tty)
+ tty_flip_buffer_push((struct tty_struct *)sn_sal_tty);
+}
+
+
+/* synch_flush_xmit must be called with sn_sal_lock */
+static void
+synch_flush_xmit(void)
+{
+ int xmit_count, tail, head, loops, ii;
+ int result;
+ char *start;
+
+ if (xmit.cb_head == xmit.cb_tail)
+ return; /* Nothing to do. */
+
+ head = xmit.cb_head;
+ tail = xmit.cb_tail;
+ start = &xmit.cb_buf[tail];
+
+ /* twice around gets the tail to the end of the buffer and
+ * then to the head, if needed */
+ loops = (head < tail) ? 2 : 1;
+
+ for (ii = 0; ii < loops; ii++) {
+ xmit_count = (head < tail) ? (SN_SAL_BUFFER_SIZE - tail) : (head - tail);
+
+ if (xmit_count > 0) {
+ result = sn_func->sal_puts((char *)start, xmit_count);
+ if (!result)
+ sn_debug_printf("\n*** synch_flush_xmit failed to flush\n");
+ if (result > 0) {
+ xmit_count -= result;
+ sn_total_tx_count += result;
+ tail += result;
+ tail &= SN_SAL_BUFFER_SIZE - 1;
+ xmit.cb_tail = tail;
+ start = (char *)&xmit.cb_buf[tail];
+ }
+ }
+ }
+}
+
+/* must be called with a lock protecting the circular buffer and
+ * sn_sal_tty */
+static void
+sn_poll_transmit_chars(void)
+{
+ int xmit_count, tail, head;
+ int result;
+ char *start;
+
+ BUG_ON(!sn_sal_is_asynch);
+
+ if (xmit.cb_head == xmit.cb_tail ||
+ (sn_sal_tty && (sn_sal_tty->stopped || sn_sal_tty->hw_stopped))) {
+ /* Nothing to do. */
+ return;
+ }
+
+ head = xmit.cb_head;
+ tail = xmit.cb_tail;
+ start = &xmit.cb_buf[tail];
+
+ xmit_count = (head < tail) ? (SN_SAL_BUFFER_SIZE - tail) : (head - tail);
+
+ if (xmit_count == 0)
+ sn_debug_printf("\n*** empty xmit_count\n");
+
+ /* use the ops, as we could be on the simulator */
+ result = sn_func->sal_puts((char *)start, xmit_count);
+ if (!result)
+ sn_debug_printf("\n*** error in synchronous sal_puts\n");
+ /* XXX chadt clean this up */
+ if (result > 0) {
+ xmit_count -= result;
+ sn_total_tx_count += result;
+ tail += result;
+ tail &= SN_SAL_BUFFER_SIZE - 1;
+ xmit.cb_tail = tail;
+ start = &xmit.cb_buf[tail];
+ }
+
+ /* if there's few enough characters left in the xmit buffer
+ * that we could stand for the upper layer to send us some
+ * more, ask for it. */
+ if (sn_sal_tty)
+ if (CIRC_CNT(xmit.cb_head, xmit.cb_tail, SN_SAL_BUFFER_SIZE) < WAKEUP_CHARS)
+ sn_sal_sched_event(SN_SAL_EVENT_WRITE_WAKEUP);
+}
+
+
+/* must be called with a lock protecting the circular buffer and
+ * sn_sal_tty */
+static void
+sn_intr_transmit_chars(void)
+{
+ int xmit_count, tail, head, loops, ii;
+ int result;
+ char *start;
+
+ BUG_ON(!sn_sal_is_asynch);
+
+ if (xmit.cb_head == xmit.cb_tail ||
+ (sn_sal_tty && (sn_sal_tty->stopped || sn_sal_tty->hw_stopped))) {
+ /* Nothing to do. */
+ return;
+ }
+
+ head = xmit.cb_head;
+ tail = xmit.cb_tail;
+ start = &xmit.cb_buf[tail];
+
+ /* twice around gets the tail to the end of the buffer and
+ * then to the head, if needed */
+ loops = (head < tail) ? 2 : 1;
+
+ for (ii = 0; ii < loops; ii++) {
+ xmit_count = (head < tail) ?
+ (SN_SAL_BUFFER_SIZE - tail) : (head - tail);
+
+ if (xmit_count > 0) {
+ result = ia64_sn_console_xmit_chars((char *)start, xmit_count);
+#ifdef DEBUG
+ if (!result)
+ sn_debug_printf("`");
+#endif
+ if (result > 0) {
+ xmit_count -= result;
+ sn_total_tx_count += result;
+ tail += result;
+ tail &= SN_SAL_BUFFER_SIZE - 1;
+ xmit.cb_tail = tail;
+ start = &xmit.cb_buf[tail];
+ }
+ }
+ }
+
+ /* if there's few enough characters left in the xmit buffer
+ * that we could stand for the upper layer to send us some
+ * more, ask for it. */
+ if (sn_sal_tty)
+ if (CIRC_CNT(xmit.cb_head, xmit.cb_tail, SN_SAL_BUFFER_SIZE) < WAKEUP_CHARS)
+ sn_sal_sched_event(SN_SAL_EVENT_WRITE_WAKEUP);
+}
+
+
+static irqreturn_t
+sn_sal_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+ /* this call is necessary to pass the interrupt back to the
+ * SAL, since it doesn't intercept the UART interrupts
+ * itself */
+ int status = ia64_sn_console_intr_status();
+ unsigned long flags;
+
+ spin_lock_irqsave(&sn_sal_lock, flags);
+ if (status & SAL_CONSOLE_INTR_RECV)
+ sn_receive_chars(regs, &flags);
+ if (status & SAL_CONSOLE_INTR_XMIT)
+ sn_intr_transmit_chars();
+ spin_unlock_irqrestore(&sn_sal_lock, flags);
+ return IRQ_HANDLED;
+}
+
+
+/* returns the console irq if interrupt is successfully registered,
+ * else 0 */
+static int
+sn_sal_connect_interrupt(void)
+{
+ cpuid_t intr_cpuid;
+ unsigned int intr_cpuloc;
+ nasid_t console_nasid;
+ unsigned int console_irq;
+ int result;
+
+ console_nasid = ia64_sn_get_console_nasid();
+ intr_cpuid = NODEPDA(NASID_TO_COMPACT_NODEID(console_nasid))->node_first_cpu;
+ intr_cpuloc = cpu_physical_id(intr_cpuid);
+ console_irq = CPU_VECTOR_TO_IRQ(intr_cpuloc, SGI_UART_VECTOR);
+
+ result = intr_connect_level(intr_cpuid, SGI_UART_VECTOR);
+ BUG_ON(result != SGI_UART_VECTOR);
+
+ result = request_irq(console_irq, sn_sal_interrupt, SA_INTERRUPT, "SAL console driver", &sn_sal_tty);
+ if (result >= 0)
+ return console_irq;
+
+ printk(KERN_INFO "sn_serial: console proceeding in polled mode\n");
+ return 0;
+}
+
+static void
+sn_sal_tasklet_action(unsigned long data)
+{
+ unsigned long flags;
+
+ if (sn_sal_tty) {
+ spin_lock_irqsave(&sn_sal_lock, flags);
+ if (sn_sal_tty) {
+ if (test_and_clear_bit(SN_SAL_EVENT_WRITE_WAKEUP, &sn_sal_event)) {
+ if ((sn_sal_tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) && sn_sal_tty->ldisc.write_wakeup)
+ (sn_sal_tty->ldisc.write_wakeup)((struct tty_struct *)sn_sal_tty);
+ wake_up_interruptible((wait_queue_head_t *)&sn_sal_tty->write_wait);
+ }
+ }
+ spin_unlock_irqrestore(&sn_sal_lock, flags);
+ }
+}
+
+
+/*
+ * This function handles polled mode.
+ */
+static void
+sn_sal_timer_poll(unsigned long dummy)
+{
+ unsigned long flags;
+
+ if (!sn_sal_irq) {
+ spin_lock_irqsave(&sn_sal_lock, flags);
+ sn_receive_chars(NULL, &flags);
+ sn_poll_transmit_chars();
+ spin_unlock_irqrestore(&sn_sal_lock, flags);
+ mod_timer(&sn_sal_timer, jiffies + sn_interrupt_timeout);
+ }
+}
+
+
+/*
+ * User-level console routines
+ */
+
+static int
+sn_sal_open(struct tty_struct *tty, struct file *filp)
+{
+ unsigned long flags;
+
+ DPRINTF("sn_sal_open: sn_sal_tty = %p, tty = %p, filp = %p\n",
+ sn_sal_tty, tty, filp);
+
+ spin_lock_irqsave(&sn_sal_lock, flags);
+ if (!sn_sal_tty)
+ sn_sal_tty = tty;
+ spin_unlock_irqrestore(&sn_sal_lock, flags);
+
+ return 0;
+}
+
+
+/* We're keeping all our resources. We're keeping interrupts turned
+ * on. Maybe just let the tty layer finish its stuff...? GMSH
+ */
+static void
+sn_sal_close(struct tty_struct *tty, struct file * filp)
+{
+ if (tty->count == 1) {
+ unsigned long flags;
+ tty->closing = 1;
+ if (tty->driver->flush_buffer)
+ tty->driver->flush_buffer(tty);
+ if (tty->ldisc.flush_buffer)
+ tty->ldisc.flush_buffer(tty);
+ tty->closing = 0;
+ spin_lock_irqsave(&sn_sal_lock, flags);
+ sn_sal_tty = NULL;
+ spin_unlock_irqrestore(&sn_sal_lock, flags);
+ }
+}
+
+
+static int
+sn_sal_write(struct tty_struct *tty, int from_user,
+ const unsigned char *buf, int count)
+{
+ int c, ret = 0;
+ unsigned long flags;
+
+ if (from_user) {
+ while (1) {
+ int c1;
+ c = CIRC_SPACE_TO_END(xmit.cb_head, xmit.cb_tail,
+ SN_SAL_BUFFER_SIZE);
+
+ if (count < c)
+ c = count;
+ if (c <= 0)
+ break;
+
+ c -= copy_from_user(sn_tmp_buffer, buf, c);
+ if (!c) {
+ if (!ret)
+ ret = -EFAULT;
+ break;
+ }
+
+ /* Turn off interrupts and see if the xmit buffer has
+ * moved since the last time we looked.
+ */
+ spin_lock_irqsave(&sn_sal_lock, flags);
+ c1 = CIRC_SPACE_TO_END(xmit.cb_head, xmit.cb_tail, SN_SAL_BUFFER_SIZE);
+
+ if (c1 < c)
+ c = c1;
+
+ memcpy(xmit.cb_buf + xmit.cb_head, sn_tmp_buffer, c);
+ xmit.cb_head = ((xmit.cb_head + c) & (SN_SAL_BUFFER_SIZE - 1));
+ spin_unlock_irqrestore(&sn_sal_lock, flags);
+
+ buf += c;
+ count -= c;
+ ret += c;
+ }
+ }
+ else {
+ /* The buffer passed in isn't coming from userland,
+ * so cut out the middleman (sn_tmp_buffer).
+ */
+ spin_lock_irqsave(&sn_sal_lock, flags);
+ while (1) {
+ c = CIRC_SPACE_TO_END(xmit.cb_head, xmit.cb_tail, SN_SAL_BUFFER_SIZE);
+
+ if (count < c)
+ c = count;
+ if (c <= 0) {
+ break;
+ }
+ memcpy(xmit.cb_buf + xmit.cb_head, buf, c);
+ xmit.cb_head = ((xmit.cb_head + c) & (SN_SAL_BUFFER_SIZE - 1));
+ buf += c;
+ count -= c;
+ ret += c;
+ }
+ spin_unlock_irqrestore(&sn_sal_lock, flags);
+ }
+
+ spin_lock_irqsave(&sn_sal_lock, flags);
+ if (xmit.cb_head != xmit.cb_tail && !(tty && (tty->stopped || tty->hw_stopped)))
+ if (sn_func->sal_wakeup_transmit)
+ sn_func->sal_wakeup_transmit();
+ spin_unlock_irqrestore(&sn_sal_lock, flags);
+
+ return ret;
+}
+
+
+static void
+sn_sal_put_char(struct tty_struct *tty, unsigned char ch)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&sn_sal_lock, flags);
+ if (CIRC_SPACE(xmit.cb_head, xmit.cb_tail, SN_SAL_BUFFER_SIZE) != 0) {
+ xmit.cb_buf[xmit.cb_head] = ch;
+ xmit.cb_head = (xmit.cb_head + 1) & (SN_SAL_BUFFER_SIZE-1);
+ if ( sn_func->sal_wakeup_transmit )
+ sn_func->sal_wakeup_transmit();
+ }
+ spin_unlock_irqrestore(&sn_sal_lock, flags);
+}
+
+
+static void
+sn_sal_flush_chars(struct tty_struct *tty)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&sn_sal_lock, flags);
+ if (CIRC_CNT(xmit.cb_head, xmit.cb_tail, SN_SAL_BUFFER_SIZE))
+ if (sn_func->sal_wakeup_transmit)
+ sn_func->sal_wakeup_transmit();
+ spin_unlock_irqrestore(&sn_sal_lock, flags);
+}
+
+
+static int
+sn_sal_write_room(struct tty_struct *tty)
+{
+ unsigned long flags;
+ int space;
+
+ spin_lock_irqsave(&sn_sal_lock, flags);
+ space = CIRC_SPACE(xmit.cb_head, xmit.cb_tail, SN_SAL_BUFFER_SIZE);
+ spin_unlock_irqrestore(&sn_sal_lock, flags);
+ return space;
+}
+
+
+static int
+sn_sal_chars_in_buffer(struct tty_struct *tty)
+{
+ unsigned long flags;
+ int space;
+
+ spin_lock_irqsave(&sn_sal_lock, flags);
+ space = CIRC_CNT(xmit.cb_head, xmit.cb_tail, SN_SAL_BUFFER_SIZE);
+ DPRINTF("<%d>", space);
+ spin_unlock_irqrestore(&sn_sal_lock, flags);
+ return space;
+}
+
+
+static void
+sn_sal_flush_buffer(struct tty_struct *tty)
+{
+ unsigned long flags;
+
+ /* drop everything */
+ spin_lock_irqsave(&sn_sal_lock, flags);
+ xmit.cb_head = xmit.cb_tail = 0;
+ spin_unlock_irqrestore(&sn_sal_lock, flags);
+
+ /* wake up tty level */
+ wake_up_interruptible(&tty->write_wait);
+ if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) && tty->ldisc.write_wakeup)
+ (tty->ldisc.write_wakeup)(tty);
+}
+
+
+static void
+sn_sal_hangup(struct tty_struct *tty)
+{
+ sn_sal_flush_buffer(tty);
+}
+
+
+static void
+sn_sal_wait_until_sent(struct tty_struct *tty, int timeout)
+{
+ /* this is SAL's problem */
+ DPRINTF("<sn_serial: should wait until sent>");
+}
+
+
+/*
+ * sn_sal_read_proc
+ *
+ * Console /proc interface
+ */
+
+static int
+sn_sal_read_proc(char *page, char **start, off_t off, int count,
+ int *eof, void *data)
+{
+ int len = 0;
+ off_t begin = 0;
+
+ len += sprintf(page, "sn_serial: nasid:%d irq:%d tx:%d rx:%d\n",
+ get_console_nasid(), sn_sal_irq,
+ sn_total_tx_count, sn_total_rx_count);
+ *eof = 1;
+
+ if (off >= len+begin)
+ return 0;
+ *start = page + (off-begin);
+
+ return count < begin+len-off ? count : begin+len-off;
+}
+
+
+static struct tty_operations sn_sal_driver_ops = {
+ .open = sn_sal_open,
+ .close = sn_sal_close,
+ .write = sn_sal_write,
+ .put_char = sn_sal_put_char,
+ .flush_chars = sn_sal_flush_chars,
+ .write_room = sn_sal_write_room,
+ .chars_in_buffer = sn_sal_chars_in_buffer,
+ .hangup = sn_sal_hangup,
+ .wait_until_sent = sn_sal_wait_until_sent,
+ .read_proc = sn_sal_read_proc,
+};
+static struct tty_driver *sn_sal_driver;
+
+/* sn_sal_init wishlist:
+ * - allocate sn_tmp_buffer
+ * - fix up the tty_driver struct
+ * - turn on receive interrupts
+ * - do any termios twiddling once and for all
+ */
+
+/*
+ * Boot-time initialization code
+ */
+
+static void __init
+sn_sal_switch_to_asynch(void)
+{
+ unsigned long flags;
+
+ sn_debug_printf("sn_serial: about to switch to asynchronous console\n");
+
+ /* without early_printk, we may be invoked late enough to race
+ * with other cpus doing console IO at this point, however
+ * console interrupts will never be enabled */
+ spin_lock_irqsave(&sn_sal_lock, flags);
+
+ /* early_printk invocation may have done this for us */
+ if (!sn_func) {
+ if (IS_RUNNING_ON_SIMULATOR())
+ sn_func = &sim_ops;
+ else
+ sn_func = &poll_ops;
+ }
+
+ /* we can't turn on the console interrupt (as request_irq
+ * calls kmalloc, which isn't set up yet), so we rely on a
+ * timer to poll for input and push data from the console
+ * buffer.
+ */
+ init_timer(&sn_sal_timer);
+ sn_sal_timer.function = sn_sal_timer_poll;
+
+ if (IS_RUNNING_ON_SIMULATOR())
+ sn_interrupt_timeout = 6;
+ else {
+ /* 960cps / 16 char FIFO = 60HZ
+ * HZ / (SN_SAL_FIFO_SPEED_CPS / SN_SAL_FIFO_DEPTH) */
+ sn_interrupt_timeout = HZ * SN_SAL_UART_FIFO_DEPTH / SN_SAL_UART_FIFO_SPEED_CPS;
+ }
+ mod_timer(&sn_sal_timer, jiffies + sn_interrupt_timeout);
+
+ sn_sal_is_asynch = 1;
+ spin_unlock_irqrestore(&sn_sal_lock, flags);
+}
+
+static void __init
+sn_sal_switch_to_interrupts(void)
+{
+ int irq;
+
+ sn_debug_printf("sn_serial: switching to interrupt driven console\n");
+
+ irq = sn_sal_connect_interrupt();
+ if (irq) {
+ unsigned long flags;
+ spin_lock_irqsave(&sn_sal_lock, flags);
+
+ /* sn_sal_irq is a global variable. When it's set to
+ * a non-zero value, we stop polling for input (since
+ * interrupts should now be enabled). */
+ sn_sal_irq = irq;
+ sn_func = &intr_ops;
+
+ /* turn on receive interrupts */
+ ia64_sn_console_intr_enable(SAL_CONSOLE_INTR_RECV);
+ spin_unlock_irqrestore(&sn_sal_lock, flags);
+ }
+}
+
+static int __init
+sn_sal_module_init(void)
+{
+ int retval;
+
+ printk("sn_serial: sn_sal_module_init\n");
+
+ if (!ia64_platform_is("sn2"))
+ return -ENODEV;
+
+ sn_sal_driver = alloc_tty_driver(1);
+ if ( !sn_sal_driver )
+ return -ENOMEM;
+
+ sn_sal_driver->owner = THIS_MODULE;
+ sn_sal_driver->driver_name = "sn_serial";
+ sn_sal_driver->name = "ttyS";
+ sn_sal_driver->major = TTY_MAJOR;
+ sn_sal_driver->minor_start = SN_SAL_MINOR;
+ sn_sal_driver->type = TTY_DRIVER_TYPE_SERIAL;
+ sn_sal_driver->subtype = SERIAL_TYPE_NORMAL;
+ sn_sal_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_NO_DEVFS;
+
+ tty_set_operations(sn_sal_driver, &sn_sal_driver_ops);
+
+ /* when this driver is compiled in, the console initialization
+ * will have already switched us into asynchronous operation
+ * before we get here through the module initcalls */
+ if (!sn_sal_is_asynch)
+ sn_sal_switch_to_asynch();
+
+ /* at this point (module_init) we can try to turn on interrupts */
+ if (!IS_RUNNING_ON_SIMULATOR())
+ sn_sal_switch_to_interrupts();
+
+ sn_sal_driver->init_termios = tty_std_termios;
+ sn_sal_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
+
+ if ((retval = tty_register_driver(sn_sal_driver))) {
+ printk(KERN_ERR "sn_serial: Unable to register tty driver\n");
+ return retval;
+ }
+#ifdef CONFIG_SGI_L1_SERIAL_CONSOLE
+ sn_sal_serial_console_init();
+#endif /* CONFIG_SGI_L1_SERIAL_CONSOLE */
+ return 0;
+}
+
+
+static void __exit
+sn_sal_module_exit(void)
+{
+ del_timer_sync(&sn_sal_timer);
+ tty_unregister_driver(sn_sal_driver);
+ put_tty_driver(sn_sal_driver);
+}
+
+module_init(sn_sal_module_init);
+module_exit(sn_sal_module_exit);
+
+/*
+ * Kernel console definitions
+ */
+
+#ifdef CONFIG_SGI_L1_SERIAL_CONSOLE
+/*
+ * Print a string to the SAL console. The console_lock must be held
+ * when we get here.
+ */
+static void
+sn_sal_console_write(struct console *co, const char *s, unsigned count)
+{
+ unsigned long flags;
+
+ BUG_ON(!sn_sal_is_asynch);
+
+ /* somebody really wants this output, might be an
+ * oops, kdb, panic, etc. make sure they get it. */
+ if (spin_is_locked(&sn_sal_lock)) {
+ synch_flush_xmit();
+ sn_func->sal_puts(s, count);
+ }
+ else if (in_interrupt()) {
+ spin_lock_irqsave(&sn_sal_lock, flags);
+ synch_flush_xmit();
+ spin_unlock_irqrestore(&sn_sal_lock, flags);
+ sn_func->sal_puts(s, count);
+ }
+ else
+ sn_sal_write(NULL, 0, s, count);
+}
+
+static struct tty_driver *
+sn_sal_console_device(struct console *c, int *index)
+{
+ *index = c->index;
+ return sn_sal_driver;
+}
+
+static int __init
+sn_sal_console_setup(struct console *co, char *options)
+{
+ return 0;
+}
+
+
+static struct console sal_console = {
+ .name = "ttyS",
+ .write = sn_sal_console_write,
+ .device = sn_sal_console_device,
+ .setup = sn_sal_console_setup,
+ .index = -1
+};
+
+static void __init
+sn_sal_serial_console_init(void)
+{
+ if (ia64_platform_is("sn2")) {
+ sn_sal_switch_to_asynch();
+ sn_debug_printf("sn_sal_serial_console_init : register console\n");
+ register_console(&sal_console);
+ }
+}
+
+#endif /* CONFIG_SGI_L1_SERIAL_CONSOLE */