#include <linux/jiffies.h>
#include <linux/nmi.h>
#include <linux/module.h>
-#include <linux/moduleparam.h>
#include <linux/interrupt.h> /* For in_interrupt() */
+#include <linux/config.h>
#include <linux/delay.h>
#include <linux/smp.h>
#include <linux/security.h>
DEFAULT_CONSOLE_LOGLEVEL, /* default_console_loglevel */
};
-EXPORT_UNUSED_SYMBOL(console_printk); /* June 2006 */
+EXPORT_SYMBOL(console_printk);
/*
* Low lever drivers may need that to know if they can schedule in
* path in the console code where we end up in places I want
* locked without the console sempahore held
*/
-static int console_locked, console_suspended;
+static int console_locked;
+int console_suspended;
/*
* logbuf_lock protects log_buf, log_start, log_end, con_start and logged_chars
struct console *con;
for (con = console_drivers; con; con = con->next) {
- if ((con->flags & CON_ENABLED) && con->write &&
- (cpu_online(smp_processor_id()) ||
- (con->flags & CON_ANYTIME)))
+ if ((con->flags & CON_ENABLED) && con->write)
con->write(con, &LOG_BUF(start), end - start);
}
}
#else
static int printk_time = 0;
#endif
-module_param(printk_time, int, S_IRUGO | S_IWUSR);
static int __init printk_time_setup(char *str)
{
return sched_clock();
}
-/* Check if we have any console registered that can be called early in boot. */
-static int have_callable_console(void)
-{
- struct console *con;
-
- for (con = console_drivers; con; con = con->next)
- if (con->flags & CON_ANYTIME)
- return 1;
-
- return 0;
-}
-
/**
* printk - print a kernel message
* @fmt: format string
zap_locks();
/* This stops the holder of console_sem just where we want him */
- local_irq_save(flags);
- lockdep_off();
- spin_lock(&logbuf_lock);
+ spin_lock_irqsave(&logbuf_lock, flags);
printk_cpu = smp_processor_id();
/* Emit the output into the temporary buffer */
log_level_unknown = 1;
}
- if (!down_trylock(&console_sem)) {
+ if (!cpu_online(smp_processor_id())) {
/*
- * We own the drivers. We can drop the spinlock and
- * let release_console_sem() print the text, maybe ...
+ * Some console drivers may assume that per-cpu resources have
+ * been allocated. So don't allow them to be called by this
+ * CPU until it is officially up. We shouldn't be calling into
+ * random console drivers on a CPU which doesn't exist yet..
*/
- console_locked = 1;
printk_cpu = UINT_MAX;
- spin_unlock(&logbuf_lock);
-
+ spin_unlock_irqrestore(&logbuf_lock, flags);
+ goto out;
+ }
+ if (!down_trylock(&console_sem)) {
+ console_locked = 1;
/*
- * 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.
+ * We own the drivers. We can drop the spinlock and let
+ * release_console_sem() print the text
*/
- 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();
- local_irq_restore(flags);
+ printk_cpu = UINT_MAX;
+ spin_unlock_irqrestore(&logbuf_lock, flags);
+ console_may_schedule = 0;
+ release_console_sem();
} else {
/*
* Someone else owns the drivers. We drop the spinlock, which
* console drivers with the output which we just produced.
*/
printk_cpu = UINT_MAX;
- spin_unlock(&logbuf_lock);
- lockdep_on();
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&logbuf_lock, flags);
}
-
+out:
preempt_enable();
return printed_len;
}
return 0;
}
-/**
- * suspend_console - suspend the console subsystem
- *
- * This disables printk() while we go into suspend states
- */
-void suspend_console(void)
-{
- acquire_console_sem();
- console_suspended = 1;
-}
-
-void resume_console(void)
-{
- console_suspended = 0;
- release_console_sem();
-}
-
/**
* acquire_console_sem - lock the console system for exclusive use.
*
*/
void acquire_console_sem(void)
{
- BUG_ON(in_interrupt());
if (console_suspended) {
down(&secondary_console_sem);
return;
}
+
+ BUG_ON(in_interrupt());
down(&console_sem);
console_locked = 1;
console_may_schedule = 1;
{
return console_locked;
}
-EXPORT_UNUSED_SYMBOL(is_console_locked); /* June 2006 */
+EXPORT_SYMBOL(is_console_locked);
/**
* release_console_sem - unlock the console system
return;
}
- console_may_schedule = 0;
-
for ( ; ; ) {
spin_lock_irqsave(&logbuf_lock, flags);
wake_klogd |= log_start - log_end;
local_irq_restore(flags);
}
console_locked = 0;
+ console_may_schedule = 0;
up(&console_sem);
spin_unlock_irqrestore(&logbuf_lock, flags);
- if (wake_klogd && !oops_in_progress && waitqueue_active(&log_wait)) {
- /*
- * If we printk from within the lock dependency code,
- * from within the scheduler code, then do not lock
- * up due to self-recursion:
- */
- if (!lockdep_internal())
- wake_up_interruptible(&log_wait);
- }
+ if (wake_klogd && !oops_in_progress && waitqueue_active(&log_wait))
+ wake_up_interruptible(&log_wait);
}
EXPORT_SYMBOL(release_console_sem);
git://git.onelab.eu / linux-2.6.git / blobdiff