Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
printk: nbcon: Export console_is_usable
The helper will be used on KDB code in the next commits.
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Link: https://patch.msgid.link/20251016-nbcon-kgdboc-v6-1-866aac60a80e@suse.com
Signed-off-by: Petr Mladek <pmladek@suse.com>
authored by
Marcos Paulo de Souza
and committed by
Petr Mladek
4da42aaa
48e3694a
+45
-45
+45
include/linux/console.h
+45
include/linux/console.h
···
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#include <linux/irq_work.h>
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#include <linux/rculist.h>
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#include <linux/rcuwait.h>
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#include <linux/smp.h>
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#include <linux/types.h>
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#include <linux/vesa.h>
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···
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extern bool nbcon_enter_unsafe(struct nbcon_write_context *wctxt);
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extern bool nbcon_exit_unsafe(struct nbcon_write_context *wctxt);
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extern void nbcon_reacquire_nobuf(struct nbcon_write_context *wctxt);
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/*
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* Check if the given console is currently capable and allowed to print
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* records. Note that this function does not consider the current context,
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* which can also play a role in deciding if @con can be used to print
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* records.
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*/
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static inline bool console_is_usable(struct console *con, short flags, bool use_atomic)
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{
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if (!(flags & CON_ENABLED))
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return false;
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if ((flags & CON_SUSPENDED))
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return false;
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if (flags & CON_NBCON) {
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/* The write_atomic() callback is optional. */
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if (use_atomic && !con->write_atomic)
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return false;
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/*
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* For the !use_atomic case, @printk_kthreads_running is not
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* checked because the write_thread() callback is also used
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* via the legacy loop when the printer threads are not
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* available.
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*/
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} else {
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if (!con->write)
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return false;
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}
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/*
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* Console drivers may assume that per-cpu resources have been
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* allocated. So unless they're explicitly marked as being able to
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* cope (CON_ANYTIME) don't call them until this CPU is officially up.
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*/
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if (!cpu_online(raw_smp_processor_id()) && !(flags & CON_ANYTIME))
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return false;
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return true;
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}
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#else
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static inline void nbcon_cpu_emergency_enter(void) { }
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static inline void nbcon_cpu_emergency_exit(void) { }
···
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static inline bool nbcon_enter_unsafe(struct nbcon_write_context *wctxt) { return false; }
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static inline bool nbcon_exit_unsafe(struct nbcon_write_context *wctxt) { return false; }
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static inline void nbcon_reacquire_nobuf(struct nbcon_write_context *wctxt) { }
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static inline bool console_is_usable(struct console *con, short flags,
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bool use_atomic) { return false; }
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#endif
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extern int console_set_on_cmdline;
-45
kernel/printk/internal.h
-45
kernel/printk/internal.h
···
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* internal.h - printk internal definitions
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*/
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#include <linux/console.h>
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#include <linux/percpu.h>
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#include <linux/types.h>
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#if defined(CONFIG_PRINTK) && defined(CONFIG_SYSCTL)
···
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void nbcon_kthread_stop(struct console *con);
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void nbcon_kthreads_wake(void);
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/*
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* Check if the given console is currently capable and allowed to print
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* records. Note that this function does not consider the current context,
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* which can also play a role in deciding if @con can be used to print
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* records.
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*/
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static inline bool console_is_usable(struct console *con, short flags, bool use_atomic)
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{
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if (!(flags & CON_ENABLED))
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return false;
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if ((flags & CON_SUSPENDED))
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return false;
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if (flags & CON_NBCON) {
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/* The write_atomic() callback is optional. */
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if (use_atomic && !con->write_atomic)
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return false;
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/*
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* For the !use_atomic case, @printk_kthreads_running is not
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* checked because the write_thread() callback is also used
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* via the legacy loop when the printer threads are not
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* available.
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*/
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} else {
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if (!con->write)
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return false;
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}
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/*
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* Console drivers may assume that per-cpu resources have been
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* allocated. So unless they're explicitly marked as being able to
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* cope (CON_ANYTIME) don't call them until this CPU is officially up.
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*/
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if (!cpu_online(raw_smp_processor_id()) && !(flags & CON_ANYTIME))
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return false;
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return true;
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}
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/**
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* nbcon_kthread_wake - Wake up a console printing thread
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* @con: Console to operate on
···
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int cookie, bool use_atomic) { return false; }
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static inline void nbcon_kthread_wake(struct console *con) { }
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static inline void nbcon_kthreads_wake(void) { }
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static inline bool console_is_usable(struct console *con, short flags,
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bool use_atomic) { return false; }
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#endif /* CONFIG_PRINTK */
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