Commit 4da42aaa authored by Marcos Paulo de Souza's avatar Marcos Paulo de Souza Committed by Petr Mladek
Browse files

printk: nbcon: Export console_is_usable 



The helper will be used on KDB code in the next commits.

Reviewed-by: default avatarPetr Mladek <pmladek@suse.com>
Reviewed-by: default avatarJohn Ogness <john.ogness@linutronix.de>
Signed-off-by: default avatarMarcos Paulo de Souza <mpdesouza@suse.com>
Link: https://patch.msgid.link/20251016-nbcon-kgdboc-v6-1-866aac60a80e@suse.com


Signed-off-by: default avatarPetr Mladek <pmladek@suse.com>
parent 48e3694a

include/linux/console.h

+45 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
#include <linux/irq_work.h>

#include <linux/rculist.h>

#include <linux/rcuwait.h>

#include <linux/smp.h>

#include <linux/types.h>

#include <linux/vesa.h>
@@ -605,6 +606,48 @@ extern bool nbcon_can_proceed(struct nbcon_write_context *wctxt); 
extern bool nbcon_enter_unsafe(struct nbcon_write_context *wctxt);

extern bool nbcon_exit_unsafe(struct nbcon_write_context *wctxt);

extern void nbcon_reacquire_nobuf(struct nbcon_write_context *wctxt);



/*

 * Check if the given console is currently capable and allowed to print

 * records. Note that this function does not consider the current context,

 * which can also play a role in deciding if @con can be used to print

 * records.

 */

static inline bool console_is_usable(struct console *con, short flags, bool use_atomic)

{

	if (!(flags & CON_ENABLED))

		return false;



	if ((flags & CON_SUSPENDED))

		return false;



	if (flags & CON_NBCON) {

		/* The write_atomic() callback is optional. */

		if (use_atomic && !con->write_atomic)

			return false;



		/*

		 * For the !use_atomic case, @printk_kthreads_running is not

		 * checked because the write_thread() callback is also used

		 * via the legacy loop when the printer threads are not

		 * available.

		 */

	} else {

		if (!con->write)

			return false;

	}



	/*

	 * 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(raw_smp_processor_id()) && !(flags & CON_ANYTIME))

		return false;



	return true;

}



#else

static inline void nbcon_cpu_emergency_enter(void) { }

static inline void nbcon_cpu_emergency_exit(void) { }
@@ -612,6 +655,8 @@ static inline bool nbcon_can_proceed(struct nbcon_write_context *wctxt) { return 
static inline bool nbcon_enter_unsafe(struct nbcon_write_context *wctxt) { return false; }

static inline bool nbcon_exit_unsafe(struct nbcon_write_context *wctxt) { return false; }

static inline void nbcon_reacquire_nobuf(struct nbcon_write_context *wctxt) { }

static inline bool console_is_usable(struct console *con, short flags,

				     bool use_atomic) { return false; }

#endif



extern int console_set_on_cmdline;

kernel/printk/internal.h

+0 −45
Original line number Diff line number Diff line
@@ -3,7 +3,6 @@ 
 * internal.h - printk internal definitions

 */

#include <linux/console.h>

#include <linux/percpu.h>

#include <linux/types.h>



#if defined(CONFIG_PRINTK) && defined(CONFIG_SYSCTL)
@@ -112,47 +111,6 @@ bool nbcon_kthread_create(struct console *con); 
void nbcon_kthread_stop(struct console *con);

void nbcon_kthreads_wake(void);



/*

 * Check if the given console is currently capable and allowed to print

 * records. Note that this function does not consider the current context,

 * which can also play a role in deciding if @con can be used to print

 * records.

 */

static inline bool console_is_usable(struct console *con, short flags, bool use_atomic)

{

	if (!(flags & CON_ENABLED))

		return false;



	if ((flags & CON_SUSPENDED))

		return false;



	if (flags & CON_NBCON) {

		/* The write_atomic() callback is optional. */

		if (use_atomic && !con->write_atomic)

			return false;



		/*

		 * For the !use_atomic case, @printk_kthreads_running is not

		 * checked because the write_thread() callback is also used

		 * via the legacy loop when the printer threads are not

		 * available.

		 */

	} else {

		if (!con->write)

			return false;

	}



	/*

	 * 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(raw_smp_processor_id()) && !(flags & CON_ANYTIME))

		return false;



	return true;

}



/**

 * nbcon_kthread_wake - Wake up a console printing thread

 * @con:	Console to operate on
@@ -204,9 +162,6 @@ static inline bool nbcon_legacy_emit_next_record(struct console *con, bool *hand 
static inline void nbcon_kthread_wake(struct console *con) { }

static inline void nbcon_kthreads_wake(void) { }



static inline bool console_is_usable(struct console *con, short flags,

				     bool use_atomic) { return false; }



#endif /* CONFIG_PRINTK */



extern bool have_boot_console;