/* * 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. * * * Copyright (c) 2004-2006 Silicon Graphics, Inc. All Rights Reserved. * * This program is free software; you can redistribute it and/or modify it * under the terms of version 2 of the GNU General Public License * as published by the Free Software Foundation. * * This program is distributed in the hope that it would be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. * * Further, this software is distributed without any warranty that it is * free of the rightful claim of any third person regarding infringement * or the like. Any license provided herein, whether implied or * otherwise, applies only to this software file. Patent licenses, if * any, provided herein do not apply to combinations of this program with * other software, or any other product whatsoever. * * You should have received a copy of the GNU General Public * License along with this program; if not, write the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, USA. * * Contact information: Silicon Graphics, Inc., 1500 Crittenden Lane, * Mountain View, CA 94043, or: * * http://www.sgi.com * * For further information regarding this notice, see: * * http://oss.sgi.com/projects/GenInfo/NoticeExplan */ #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 <linux/delay.h> /* for mdelay */ #include <linux/miscdevice.h> #include <linux/serial_core.h> #include <asm/io.h> #include <asm/sn/simulator.h> #include <asm/sn/sn_sal.h> /* number of characters we can transmit to the SAL console at a time */ #define SN_SAL_MAX_CHARS 120 /* 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 /* sn_transmit_chars() calling args */ #define TRANSMIT_BUFFERED 0 #define TRANSMIT_RAW 1 /* To use dynamic numbers only and not use the assigned major and minor, * define the following.. */ /* #define USE_DYNAMIC_MINOR 1 *//* use dynamic minor number */ #define USE_DYNAMIC_MINOR 0 /* Don't rely on misc_register dynamic minor */ /* Device name we're using */ #define DEVICE_NAME "ttySG" #define DEVICE_NAME_DYNAMIC "ttySG0" /* need full name for misc_register */ /* The major/minor we are using, ignored for USE_DYNAMIC_MINOR */ #define DEVICE_MAJOR 204 #define DEVICE_MINOR 40 #ifdef CONFIG_MAGIC_SYSRQ static char sysrq_serial_str[] = "\eSYS"; static char *sysrq_serial_ptr = sysrq_serial_str; static unsigned long sysrq_requested; #endif /* CONFIG_MAGIC_SYSRQ */ /* * Port definition - this kinda drives it all */ struct sn_cons_port { struct timer_list sc_timer; struct uart_port sc_port; struct sn_sal_ops { int (*sal_puts_raw) (const char *s, int len); int (*sal_puts) (const char *s, int len); int (*sal_getc) (void); int (*sal_input_pending) (void); void (*sal_wakeup_transmit) (struct sn_cons_port *, int); } *sc_ops; unsigned long sc_interrupt_timeout; int sc_is_asynch; }; static struct sn_cons_port sal_console_port; static int sn_process_input; /* Only used if USE_DYNAMIC_MINOR is set to 1 */ static struct miscdevice misc; /* used with misc_register for dynamic */ extern void early_sn_setup(void); #undef DEBUG #ifdef DEBUG static int sn_debug_printf(const char *fmt, ...); #define DPRINTF(x...) sn_debug_printf(x) #else #define DPRINTF(x...) do { } while (0) #endif /* Prototypes */ static int snt_hw_puts_raw(const char *, int); static int snt_hw_puts_buffered(const char *, int); static int snt_poll_getc(void); static int snt_poll_input_pending(void); static int snt_intr_getc(void); static int snt_intr_input_pending(void); static void sn_transmit_chars(struct sn_cons_port *, int); /* A table for polling: */ static struct sn_sal_ops poll_ops = { .sal_puts_raw = snt_hw_puts_raw, .sal_puts = snt_hw_puts_raw, .sal_getc = snt_poll_getc, .sal_input_pending = snt_poll_input_pending }; /* A table for interrupts enabled */ static struct sn_sal_ops intr_ops = { .sal_puts_raw = snt_hw_puts_raw, .sal_puts = snt_hw_puts_buffered, .sal_getc = snt_intr_getc, .sal_input_pending = snt_intr_input_pending, .sal_wakeup_transmit = sn_transmit_chars }; /* the console does output in two distinctly different ways: * synchronous (raw) 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 */ /** * snt_poll_getc - Get a character from the console in polling mode * */ static int snt_poll_getc(void) { int ch; ia64_sn_console_getc(&ch); return ch; } /** * snt_poll_input_pending - Check if any input is waiting - polling mode. * */ static int snt_poll_input_pending(void) { int status, input; status = ia64_sn_console_check(&input); return !status && input; } /* routines for an interrupt driven console (normal) */ /** * snt_intr_getc - Get a character from the console, interrupt mode * */ static int snt_intr_getc(void) { return ia64_sn_console_readc(); } /** * snt_intr_input_pending - Check if input is pending, interrupt mode * */ static int snt_intr_input_pending(void) { return ia64_sn_console_intr_status() & SAL_CONSOLE_INTR_RECV; } /* these functions are polled and interrupt */ /** * snt_hw_puts_raw - Send raw string to the console, polled or interrupt mode * @s: String * @len: Length * */ static int snt_hw_puts_raw(const char *s, int len) { /* this will call the PROM and not return until this is done */ return ia64_sn_console_putb(s, len); } /** * snt_hw_puts_buffered - Send string to console, polled or interrupt mode * @s: String * @len: Length * */ static int snt_hw_puts_buffered(const char *s, int len) { /* queue data to the PROM */ return ia64_sn_console_xmit_chars((char *)s, len); } /* uart interface structs * These functions are associated with the uart_port that the serial core * infrastructure calls. * * Note: Due to how the console works, many routines are no-ops. */ /** * snp_type - What type of console are we? * @port: Port to operate with (we ignore since we only have one port) * */ static const char *snp_type(struct uart_port *port) { return ("SGI SN L1"); } /** * snp_tx_empty - Is the transmitter empty? We pretend we're always empty * @port: Port to operate on (we ignore since we only have one port) * */ static unsigned int snp_tx_empty(struct uart_port *port) { return 1; } /** * snp_stop_tx - stop the transmitter - no-op for us * @port: Port to operat eon - we ignore - no-op function * */ static void snp_stop_tx(struct uart_port *port) { } /** * snp_release_port - Free i/o and resources for port - no-op for us * @port: Port to operate on - we ignore - no-op function * */ static void snp_release_port(struct uart_port *port) { } /** * snp_enable_ms - Force modem status interrupts on - no-op for us * @port: Port to operate on - we ignore - no-op function * */ static void snp_enable_ms(struct uart_port *port) { } /** * snp_shutdown - shut down the port - free irq and disable - no-op for us * @port: Port to shut down - we ignore * */ static void snp_shutdown(struct uart_port *port) { } /** * snp_set_mctrl - set control lines (dtr, rts, etc) - no-op for our console * @port: Port to operate on - we ignore * @mctrl: Lines to set/unset - we ignore * */ static void snp_set_mctrl(struct uart_port *port, unsigned int mctrl) { } /** * snp_get_mctrl - get contorl line info, we just return a static value * @port: port to operate on - we only have one port so we ignore this * */ static unsigned int snp_get_mctrl(struct uart_port *port) { return TIOCM_CAR | TIOCM_RNG | TIOCM_DSR | TIOCM_CTS; } /** * snp_stop_rx - Stop the receiver - we ignor ethis * @port: Port to operate on - we ignore * */ static void snp_stop_rx(struct uart_port *port) { } /** * snp_start_tx - Start transmitter * @port: Port to operate on * */ static void snp_start_tx(struct uart_port *port) { if (sal_console_port.sc_ops->sal_wakeup_transmit) sal_console_port.sc_ops->sal_wakeup_transmit(&sal_console_port, TRANSMIT_BUFFERED); } /** * snp_break_ctl - handle breaks - ignored by us * @port: Port to operate on * @break_state: Break state * */ static void snp_break_ctl(struct uart_port *port, int break_state) { } /** * snp_startup - Start up the serial port - always return 0 (We're always on) * @port: Port to operate on * */ static int snp_startup(struct uart_port *port) { return 0; } /** * snp_set_termios - set termios stuff - we ignore these * @port: port to operate on * @termios: New settings * @termios: Old * */ static void snp_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old) { } /** * snp_request_port - allocate resources for port - ignored by us * @port: port to operate on * */ static int snp_request_port(struct uart_port *port) { return 0; } /** * snp_config_port - allocate resources, set up - we ignore, we're always on * @port: Port to operate on * @flags: flags used for port setup * */ static void snp_config_port(struct uart_port *port, int flags) { } /* Associate the uart functions above - given to serial core */ static struct uart_ops sn_console_ops = { .tx_empty = snp_tx_empty, .set_mctrl = snp_set_mctrl, .get_mctrl = snp_get_mctrl, .stop_tx = snp_stop_tx, .start_tx = snp_start_tx, .stop_rx = snp_stop_rx, .enable_ms = snp_enable_ms, .break_ctl = snp_break_ctl, .startup = snp_startup, .shutdown = snp_shutdown, .set_termios = snp_set_termios, .pm = NULL, .type = snp_type, .release_port = snp_release_port, .request_port = snp_request_port, .config_port = snp_config_port, .verify_port = NULL, }; /* End of uart struct functions and defines */ #ifdef DEBUG /** * sn_debug_printf - close to hardware debugging printf * @fmt: printf format * * 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); if (!sal_console_port.sc_ops) { sal_console_port.sc_ops = &poll_ops; early_sn_setup(); } sal_console_port.sc_ops->sal_puts_raw(printk_buf, printed_len); va_end(args); return printed_len; } #endif /* DEBUG */ /* * Interrupt handling routines. */ /** * sn_receive_chars - Grab characters, pass them to tty layer * @port: Port to operate on * @flags: irq flags * * Note: If we're not registered with the serial core infrastructure yet, * we don't try to send characters to it... * */ static void sn_receive_chars(struct sn_cons_port *port, unsigned long flags) { int ch; struct tty_struct *tty; if (!port) { printk(KERN_ERR "sn_receive_chars - port NULL so can't receieve\n"); return; } if (!port->sc_ops) { printk(KERN_ERR "sn_receive_chars - port->sc_ops NULL so can't receieve\n"); return; } if (port->sc_port.info) { /* The serial_core stuffs are initilized, use them */ tty = port->sc_port.info->port.tty; } else { /* Not registered yet - can't pass to tty layer. */ tty = NULL; } while (port->sc_ops->sal_input_pending()) { ch = port->sc_ops->sal_getc(); if (ch < 0) { printk(KERN_ERR "sn_console: An error occured while " "obtaining data from the console (0x%0x)\n", ch); break; } #ifdef 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(&port->sc_port.lock, flags); handle_sysrq(ch, NULL); spin_lock_irqsave(&port->sc_port.lock, flags); /* ignore actual sysrq command char */ continue; } } if (ch == *sysrq_serial_ptr) { if (!(*++sysrq_serial_ptr)) { sysrq_requested = jiffies; sysrq_serial_ptr = sysrq_serial_str; } /* * ignore the whole sysrq string except for the * leading escape */ if (ch != '\e') continue; } else sysrq_serial_ptr = sysrq_serial_str; #endif /* CONFIG_MAGIC_SYSRQ */ /* record the character to pass up to the tty layer */ if (tty) { if(tty_insert_flip_char(tty, ch, TTY_NORMAL) == 0) break; } port->sc_port.icount.rx++; } if (tty) tty_flip_buffer_push(tty); } /** * sn_transmit_chars - grab characters from serial core, send off * @port: Port to operate on * @raw: Transmit raw or buffered * * Note: If we're early, before we're registered with serial core, the * writes are going through sn_sal_console_write because that's how * register_console has been set up. We currently could have asynch * polls calling this function due to sn_sal_switch_to_asynch but we can * ignore them until we register with the serial core stuffs. * */ static void sn_transmit_chars(struct sn_cons_port *port, int raw) { int xmit_count, tail, head, loops, ii; int result; char *start; struct circ_buf *xmit; if (!port) return; BUG_ON(!port->sc_is_asynch); if (port->sc_port.info) { /* We're initilized, using serial core infrastructure */ xmit = &port->sc_port.info->xmit; } else { /* Probably sn_sal_switch_to_asynch has been run but serial core isn't * initilized yet. Just return. Writes are going through * sn_sal_console_write (due to register_console) at this time. */ return; } if (uart_circ_empty(xmit) || uart_tx_stopped(&port->sc_port)) { /* Nothing to do. */ ia64_sn_console_intr_disable(SAL_CONSOLE_INTR_XMIT); return; } head = xmit->head; tail = xmit->tail; start = &xmit->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) ? (UART_XMIT_SIZE - tail) : (head - tail); if (xmit_count > 0) { if (raw == TRANSMIT_RAW) result = port->sc_ops->sal_puts_raw(start, xmit_count); else result = port->sc_ops->sal_puts(start, xmit_count); #ifdef DEBUG if (!result) DPRINTF("`"); #endif if (result > 0) { xmit_count -= result; port->sc_port.icount.tx += result; tail += result; tail &= UART_XMIT_SIZE - 1; xmit->tail = tail; start = &xmit->buf[tail]; } } } if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(&port->sc_port); if (uart_circ_empty(xmit)) snp_stop_tx(&port->sc_port); /* no-op for us */ } /** * sn_sal_interrupt - Handle console interrupts * @irq: irq #, useful for debug statements * @dev_id: our pointer to our port (sn_cons_port which contains the uart port) * */ static irqreturn_t sn_sal_interrupt(int irq, void *dev_id) { struct sn_cons_port *port = (struct sn_cons_port *)dev_id; unsigned long flags; int status = ia64_sn_console_intr_status(); if (!port) return IRQ_NONE; spin_lock_irqsave(&port->sc_port.lock, flags); if (status & SAL_CONSOLE_INTR_RECV) { sn_receive_chars(port, flags); } if (status & SAL_CONSOLE_INTR_XMIT) { sn_transmit_chars(port, TRANSMIT_BUFFERED); } spin_unlock_irqrestore(&port->sc_port.lock, flags); return IRQ_HANDLED; } /** * sn_sal_timer_poll - this function handles polled console mode * @data: A pointer to our sn_cons_port (which contains the uart port) * * data is the pointer that init_timer will store for us. This function is * associated with init_timer to see if there is any console traffic. * Obviously not used in interrupt mode * */ static void sn_sal_timer_poll(unsigned long data) { struct sn_cons_port *port = (struct sn_cons_port *)data; unsigned long flags; if (!port) return; if (!port->sc_port.irq) { spin_lock_irqsave(&port->sc_port.lock, flags); if (sn_process_input) sn_receive_chars(port, flags); sn_transmit_chars(port, TRANSMIT_RAW); spin_unlock_irqrestore(&port->sc_port.lock, flags); mod_timer(&port->sc_timer, jiffies + port->sc_interrupt_timeout); } } /* * Boot-time initialization code */ /** * sn_sal_switch_to_asynch - Switch to async mode (as opposed to synch) * @port: Our sn_cons_port (which contains the uart port) * * So this is used by sn_sal_serial_console_init (early on, before we're * registered with serial core). It's also used by sn_sal_module_init * right after we've registered with serial core. The later only happens * if we didn't already come through here via sn_sal_serial_console_init. * */ static void __init sn_sal_switch_to_asynch(struct sn_cons_port *port) { unsigned long flags; if (!port) return; DPRINTF("sn_console: 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(&port->sc_port.lock, flags); /* early_printk invocation may have done this for us */ if (!port->sc_ops) port->sc_ops = &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(&port->sc_timer); port->sc_timer.function = sn_sal_timer_poll; port->sc_timer.data = (unsigned long)port; if (IS_RUNNING_ON_SIMULATOR()) port->sc_interrupt_timeout = 6; else { /* 960cps / 16 char FIFO = 60HZ * HZ / (SN_SAL_FIFO_SPEED_CPS / SN_SAL_FIFO_DEPTH) */ port->sc_interrupt_timeout = HZ * SN_SAL_UART_FIFO_DEPTH / SN_SAL_UART_FIFO_SPEED_CPS; } mod_timer(&port->sc_timer, jiffies + port->sc_interrupt_timeout); port->sc_is_asynch = 1; spin_unlock_irqrestore(&port->sc_port.lock, flags); } /** * sn_sal_switch_to_interrupts - Switch to interrupt driven mode * @port: Our sn_cons_port (which contains the uart port) * * In sn_sal_module_init, after we're registered with serial core and * the port is added, this function is called to switch us to interrupt * mode. We were previously in asynch/polling mode (using init_timer). * * We attempt to switch to interrupt mode here by calling * request_irq. If that works out, we enable receive interrupts. */ static void __init sn_sal_switch_to_interrupts(struct sn_cons_port *port) { unsigned long flags; if (port) { DPRINTF("sn_console: switching to interrupt driven console\n"); if (request_irq(SGI_UART_VECTOR, sn_sal_interrupt, IRQF_DISABLED | IRQF_SHARED, "SAL console driver", port) >= 0) { spin_lock_irqsave(&port->sc_port.lock, flags); port->sc_port.irq = SGI_UART_VECTOR; port->sc_ops = &intr_ops; /* turn on receive interrupts */ ia64_sn_console_intr_enable(SAL_CONSOLE_INTR_RECV); spin_unlock_irqrestore(&port->sc_port.lock, flags); } else { printk(KERN_INFO "sn_console: console proceeding in polled mode\n"); } } } /* * Kernel console definitions */ static void sn_sal_console_write(struct console *, const char *, unsigned); static int sn_sal_console_setup(struct console *, char *); static struct uart_driver sal_console_uart; extern struct tty_driver *uart_console_device(struct console *, int *); static struct console sal_console = { .name = DEVICE_NAME, .write = sn_sal_console_write, .device = uart_console_device, .setup = sn_sal_console_setup, .index = -1, /* unspecified */ .data = &sal_console_uart, }; #define SAL_CONSOLE &sal_console static struct uart_driver sal_console_uart = { .owner = THIS_MODULE, .driver_name = "sn_console", .dev_name = DEVICE_NAME, .major = 0, /* major/minor set at registration time per USE_DYNAMIC_MINOR */ .minor = 0, .nr = 1, /* one port */ .cons = SAL_CONSOLE, }; /** * sn_sal_module_init - When the kernel loads us, get us rolling w/ serial core * * Before this is called, we've been printing kernel messages in a special * early mode not making use of the serial core infrastructure. When our * driver is loaded for real, we register the driver and port with serial * core and try to enable interrupt driven mode. * */ static int __init sn_sal_module_init(void) { int retval; if (!ia64_platform_is("sn2")) return 0; printk(KERN_INFO "sn_console: Console driver init\n"); if (USE_DYNAMIC_MINOR == 1) { misc.minor = MISC_DYNAMIC_MINOR; misc.name = DEVICE_NAME_DYNAMIC; retval = misc_register(&misc); if (retval != 0) { printk(KERN_WARNING "Failed to register console " "device using misc_register.\n"); return -ENODEV; } sal_console_uart.major = MISC_MAJOR; sal_console_uart.minor = misc.minor; } else { sal_console_uart.major = DEVICE_MAJOR; sal_console_uart.minor = DEVICE_MINOR; } /* We register the driver and the port before switching to interrupts * or async above so the proper uart structures are populated */ if (uart_register_driver(&sal_console_uart) < 0) { printk ("ERROR sn_sal_module_init failed uart_register_driver, line %d\n", __LINE__); return -ENODEV; } spin_lock_init(&sal_console_port.sc_port.lock); /* Setup the port struct with the minimum needed */ sal_console_port.sc_port.membase = (char *)1; /* just needs to be non-zero */ sal_console_port.sc_port.type = PORT_16550A; sal_console_port.sc_port.fifosize = SN_SAL_MAX_CHARS; sal_console_port.sc_port.ops = &sn_console_ops; sal_console_port.sc_port.line = 0; if (uart_add_one_port(&sal_console_uart, &sal_console_port.sc_port) < 0) { /* error - not sure what I'd do - so I'll do nothing */ printk(KERN_ERR "%s: unable to add port\n", __func__); } /* 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 (!sal_console_port.sc_is_asynch) { sn_sal_switch_to_asynch(&sal_console_port); } /* at this point (module_init) we can try to turn on interrupts */ if (!IS_RUNNING_ON_SIMULATOR()) { sn_sal_switch_to_interrupts(&sal_console_port); } sn_process_input = 1; return 0; } /** * sn_sal_module_exit - When we're unloaded, remove the driver/port * */ static void __exit sn_sal_module_exit(void) { del_timer_sync(&sal_console_port.sc_timer); uart_remove_one_port(&sal_console_uart, &sal_console_port.sc_port); uart_unregister_driver(&sal_console_uart); misc_deregister(&misc); } module_init(sn_sal_module_init); module_exit(sn_sal_module_exit); /** * puts_raw_fixed - sn_sal_console_write helper for adding \r's as required * @puts_raw : puts function to do the writing * @s: input string * @count: length * * We need a \r ahead of every \n for direct writes through * ia64_sn_console_putb (what sal_puts_raw below actually does). * */ static void puts_raw_fixed(int (*puts_raw) (const char *s, int len), const char *s, int count) { const char *s1; /* Output '\r' before each '\n' */ while ((s1 = memchr(s, '\n', count)) != NULL) { puts_raw(s, s1 - s); puts_raw("\r\n", 2); count -= s1 + 1 - s; s = s1 + 1; } puts_raw(s, count); } /** * sn_sal_console_write - Print statements before serial core available * @console: Console to operate on - we ignore since we have just one * @s: String to send * @count: length * * This is referenced in the console struct. It is used for early * console printing before we register with serial core and for things * such as kdb. The console_lock must be held when we get here. * * This function has some code for trying to print output even if the lock * is held. We try to cover the case where a lock holder could have died. * We don't use this special case code if we're not registered with serial * core yet. After we're registered with serial core, the only time this * function would be used is for high level kernel output like magic sys req, * kdb, and printk's. */ static void sn_sal_console_write(struct console *co, const char *s, unsigned count) { unsigned long flags = 0; struct sn_cons_port *port = &sal_console_port; static int stole_lock = 0; BUG_ON(!port->sc_is_asynch); /* We can't look at the xmit buffer if we're not registered with serial core * yet. So only do the fancy recovery after registering */ if (!port->sc_port.info) { /* Not yet registered with serial core - simple case */ puts_raw_fixed(port->sc_ops->sal_puts_raw, s, count); return; } /* somebody really wants this output, might be an * oops, kdb, panic, etc. make sure they get it. */ if (spin_is_locked(&port->sc_port.lock)) { int lhead = port->sc_port.info->xmit.head; int ltail = port->sc_port.info->xmit.tail; int counter, got_lock = 0; /* * We attempt to determine if someone has died with the * lock. We wait ~20 secs after the head and tail ptrs * stop moving and assume the lock holder is not functional * and plow ahead. If the lock is freed within the time out * period we re-get the lock and go ahead normally. We also * remember if we have plowed ahead so that we don't have * to wait out the time out period again - the asumption * is that we will time out again. */ for (counter = 0; counter < 150; mdelay(125), counter++) { if (!spin_is_locked(&port->sc_port.lock) || stole_lock) { if (!stole_lock) { spin_lock_irqsave(&port->sc_port.lock, flags); got_lock = 1; } break; } else { /* still locked */ if ((lhead != port->sc_port.info->xmit.head) || (ltail != port->sc_port.info->xmit.tail)) { lhead = port->sc_port.info->xmit.head; ltail = port->sc_port.info->xmit.tail; counter = 0; } } } /* flush anything in the serial core xmit buffer, raw */ sn_transmit_chars(port, 1); if (got_lock) { spin_unlock_irqrestore(&port->sc_port.lock, flags); stole_lock = 0; } else { /* fell thru */ stole_lock = 1; } puts_raw_fixed(port->sc_ops->sal_puts_raw, s, count); } else { stole_lock = 0; spin_lock_irqsave(&port->sc_port.lock, flags); sn_transmit_chars(port, 1); spin_unlock_irqrestore(&port->sc_port.lock, flags); puts_raw_fixed(port->sc_ops->sal_puts_raw, s, count); } } /** * sn_sal_console_setup - Set up console for early printing * @co: Console to work with * @options: Options to set * * Altix console doesn't do anything with baud rates, etc, anyway. * * This isn't required since not providing the setup function in the * console struct is ok. However, other patches like KDB plop something * here so providing it is easier. * */ static int sn_sal_console_setup(struct console *co, char *options) { return 0; } /** * sn_sal_console_write_early - simple early output routine * @co - console struct * @s - string to print * @count - count * * Simple function to provide early output, before even * sn_sal_serial_console_init is called. Referenced in the * console struct registerd in sn_serial_console_early_setup. * */ static void __init sn_sal_console_write_early(struct console *co, const char *s, unsigned count) { puts_raw_fixed(sal_console_port.sc_ops->sal_puts_raw, s, count); } /* Used for very early console printing - again, before * sn_sal_serial_console_init is run */ static struct console sal_console_early __initdata = { .name = "sn_sal", .write = sn_sal_console_write_early, .flags = CON_PRINTBUFFER, .index = -1, }; /** * sn_serial_console_early_setup - Sets up early console output support * * Register a console early on... This is for output before even * sn_sal_serial_cosnole_init is called. This function is called from * setup.c. This allows us to do really early polled writes. When * sn_sal_serial_console_init is called, this console is unregistered * and a new one registered. */ int __init sn_serial_console_early_setup(void) { if (!ia64_platform_is("sn2")) return -1; sal_console_port.sc_ops = &poll_ops; spin_lock_init(&sal_console_port.sc_port.lock); early_sn_setup(); /* Find SAL entry points */ register_console(&sal_console_early); return 0; } /** * sn_sal_serial_console_init - Early console output - set up for register * * This function is called when regular console init happens. Because we * support even earlier console output with sn_serial_console_early_setup * (called from setup.c directly), this function unregisters the really * early console. * * Note: Even if setup.c doesn't register sal_console_early, unregistering * it here doesn't hurt anything. * */ static int __init sn_sal_serial_console_init(void) { if (ia64_platform_is("sn2")) { sn_sal_switch_to_asynch(&sal_console_port); DPRINTF("sn_sal_serial_console_init : register console\n"); register_console(&sal_console); unregister_console(&sal_console_early); } return 0; } console_initcall(sn_sal_serial_console_init);