X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=kernel%2Fprintk.c;h=8fb01c32aa3bb7eaf44f5b9e63e316628dd935c1;hb=de08341a0ef747d607542af3ae441b286f503e35;hp=9adc2a473e6e0f59bbc41350422d415e8f17a7ec;hpb=9446389ef612096704fdf18fa79bab423d4110f0;p=pandora-kernel.git diff --git a/kernel/printk.c b/kernel/printk.c index 9adc2a473e6e..8fb01c32aa3b 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -111,6 +111,9 @@ struct console_cmdline char name[8]; /* Name of the driver */ int index; /* Minor dev. to use */ char *options; /* Options for the driver */ +#ifdef CONFIG_A11Y_BRAILLE_CONSOLE + char *brl_options; /* Options for braille driver */ +#endif }; #define MAX_CMDLINECONSOLES 8 @@ -616,6 +619,53 @@ asmlinkage int printk(const char *fmt, ...) /* cpu currently holding logbuf_lock */ static volatile unsigned int printk_cpu = UINT_MAX; +/* + * Can we actually use the console at this time on this cpu? + * + * Console drivers may assume that per-cpu resources have + * been allocated. So unless they're explicitly marked as + * being able to cope (CON_ANYTIME) don't call them until + * this CPU is officially up. + */ +static inline int can_use_console(unsigned int cpu) +{ + return cpu_online(cpu) || have_callable_console(); +} + +/* + * Try to get console ownership to actually show the kernel + * messages from a 'printk'. Return true (and with the + * console_semaphore held, and 'console_locked' set) if it + * is successful, false otherwise. + * + * This gets called with the 'logbuf_lock' spinlock held and + * interrupts disabled. It should return with 'lockbuf_lock' + * released but interrupts still disabled. + */ +static int acquire_console_semaphore_for_printk(unsigned int cpu) +{ + int retval = 0; + + if (!try_acquire_console_sem()) { + retval = 1; + + /* + * If we can't use the console, we need to release + * the console semaphore by hand to avoid flushing + * the buffer. We need to hold the console semaphore + * in order to do this test safely. + */ + if (!can_use_console(cpu)) { + console_locked = 0; + up(&console_sem); + retval = 0; + } + } + printk_cpu = UINT_MAX; + spin_unlock(&logbuf_lock); + return retval; +} + const char printk_recursion_bug_msg [] = KERN_CRIT "BUG: recent printk recursion!\n"; static int printk_recursion_bug; @@ -725,43 +775,22 @@ asmlinkage int vprintk(const char *fmt, va_list args) log_level_unknown = 1; } - if (!down_trylock(&console_sem)) { - /* - * We own the drivers. We can drop the spinlock and - * let release_console_sem() print the text, maybe ... - */ - console_locked = 1; - printk_cpu = UINT_MAX; - spin_unlock(&logbuf_lock); + /* + * Try to acquire and then immediately release the + * console semaphore. The release will do all the + * actual magic (print out buffers, wake up klogd, + * etc). + * + * The acquire_console_semaphore_for_printk() function + * will release 'logbuf_lock' regardless of whether it + * actually gets the semaphore or not. + */ + if (acquire_console_semaphore_for_printk(this_cpu)) + release_console_sem(); - /* - * Console drivers may assume that per-cpu resources have - * been allocated. So unless they're explicitly marked as - * being able to cope (CON_ANYTIME) don't call them until - * this CPU is officially up. - */ - if (cpu_online(smp_processor_id()) || have_callable_console()) { - console_may_schedule = 0; - release_console_sem(); - } else { - /* Release by hand to avoid flushing the buffer. */ - console_locked = 0; - up(&console_sem); - } - lockdep_on(); - raw_local_irq_restore(flags); - } else { - /* - * Someone else owns the drivers. We drop the spinlock, which - * allows the semaphore holder to proceed and to call the - * console drivers with the output which we just produced. - */ - printk_cpu = UINT_MAX; - spin_unlock(&logbuf_lock); - lockdep_on(); + lockdep_on(); out_restore_irqs: - raw_local_irq_restore(flags); - } + raw_local_irq_restore(flags); preempt_enable(); return printed_len; @@ -782,15 +811,60 @@ static void call_console_drivers(unsigned start, unsigned end) #endif +static int __add_preferred_console(char *name, int idx, char *options, + char *brl_options) +{ + struct console_cmdline *c; + int i; + + /* + * See if this tty is not yet registered, and + * if we have a slot free. + */ + for (i = 0; i < MAX_CMDLINECONSOLES && console_cmdline[i].name[0]; i++) + if (strcmp(console_cmdline[i].name, name) == 0 && + console_cmdline[i].index == idx) { + if (!brl_options) + selected_console = i; + return 0; + } + if (i == MAX_CMDLINECONSOLES) + return -E2BIG; + if (!brl_options) + selected_console = i; + c = &console_cmdline[i]; + strlcpy(c->name, name, sizeof(c->name)); + c->options = options; +#ifdef CONFIG_A11Y_BRAILLE_CONSOLE + c->brl_options = brl_options; +#endif + c->index = idx; + return 0; +} /* * Set up a list of consoles. Called from init/main.c */ static int __init console_setup(char *str) { char buf[sizeof(console_cmdline[0].name) + 4]; /* 4 for index */ - char *s, *options; + char *s, *options, *brl_options = NULL; int idx; +#ifdef CONFIG_A11Y_BRAILLE_CONSOLE + if (!memcmp(str, "brl,", 4)) { + brl_options = ""; + str += 4; + } else if (!memcmp(str, "brl=", 4)) { + brl_options = str + 4; + str = strchr(brl_options, ','); + if (!str) { + printk(KERN_ERR "need port name after brl=\n"); + return 1; + } + *(str++) = 0; + } +#endif + /* * Decode str into name, index, options. */ @@ -815,7 +889,7 @@ static int __init console_setup(char *str) idx = simple_strtoul(s, NULL, 10); *s = 0; - add_preferred_console(buf, idx, options); + __add_preferred_console(buf, idx, options, brl_options); return 1; } __setup("console=", console_setup); @@ -835,28 +909,7 @@ __setup("console=", console_setup); */ int add_preferred_console(char *name, int idx, char *options) { - struct console_cmdline *c; - int i; - - /* - * See if this tty is not yet registered, and - * if we have a slot free. - */ - for (i = 0; i < MAX_CMDLINECONSOLES && console_cmdline[i].name[0]; i++) - if (strcmp(console_cmdline[i].name, name) == 0 && - console_cmdline[i].index == idx) { - selected_console = i; - return 0; - } - if (i == MAX_CMDLINECONSOLES) - return -E2BIG; - selected_console = i; - c = &console_cmdline[i]; - memcpy(c->name, name, sizeof(c->name)); - c->name[sizeof(c->name) - 1] = 0; - c->options = options; - c->index = idx; - return 0; + return __add_preferred_console(name, idx, options, NULL); } int update_console_cmdline(char *name, int idx, char *name_new, int idx_new, char *options) @@ -868,7 +921,7 @@ int update_console_cmdline(char *name, int idx, char *name_new, int idx_new, cha if (strcmp(console_cmdline[i].name, name) == 0 && console_cmdline[i].index == idx) { c = &console_cmdline[i]; - memcpy(c->name, name_new, sizeof(c->name)); + strlcpy(c->name, name_new, sizeof(c->name)); c->name[sizeof(c->name) - 1] = 0; c->options = options; c->index = idx_new; @@ -1137,6 +1190,16 @@ void register_console(struct console *console) continue; if (console->index < 0) console->index = console_cmdline[i].index; +#ifdef CONFIG_A11Y_BRAILLE_CONSOLE + if (console_cmdline[i].brl_options) { + console->flags |= CON_BRL; + braille_register_console(console, + console_cmdline[i].index, + console_cmdline[i].options, + console_cmdline[i].brl_options); + return; + } +#endif if (console->setup && console->setup(console, console_cmdline[i].options) != 0) break; @@ -1195,6 +1258,11 @@ int unregister_console(struct console *console) struct console *a, *b; int res = 1; +#ifdef CONFIG_A11Y_BRAILLE_CONSOLE + if (console->flags & CON_BRL) + return braille_unregister_console(console); +#endif + acquire_console_sem(); if (console_drivers == console) { console_drivers=console->next; @@ -1246,8 +1314,8 @@ late_initcall(disable_boot_consoles); */ void tty_write_message(struct tty_struct *tty, char *msg) { - if (tty && tty->driver->write) - tty->driver->write(tty, msg, strlen(msg)); + if (tty && tty->ops->write) + tty->ops->write(tty, msg, strlen(msg)); return; } @@ -1261,31 +1329,7 @@ void tty_write_message(struct tty_struct *tty, char *msg) */ int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst) { - static DEFINE_SPINLOCK(ratelimit_lock); - static unsigned toks = 10 * 5 * HZ; - static unsigned long last_msg; - static int missed; - unsigned long flags; - unsigned long now = jiffies; - - spin_lock_irqsave(&ratelimit_lock, flags); - toks += now - last_msg; - last_msg = now; - if (toks > (ratelimit_burst * ratelimit_jiffies)) - toks = ratelimit_burst * ratelimit_jiffies; - if (toks >= ratelimit_jiffies) { - int lost = missed; - - missed = 0; - toks -= ratelimit_jiffies; - spin_unlock_irqrestore(&ratelimit_lock, flags); - if (lost) - printk(KERN_WARNING "printk: %d messages suppressed.\n", lost); - return 1; - } - missed++; - spin_unlock_irqrestore(&ratelimit_lock, flags); - return 0; + return __ratelimit(ratelimit_jiffies, ratelimit_burst); } EXPORT_SYMBOL(__printk_ratelimit);