diff options
Diffstat (limited to 'kernel/printk/internal.h')
| -rw-r--r-- | kernel/printk/internal.h | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/kernel/printk/internal.h b/kernel/printk/internal.h index ccb916688178..5d9deb56b582 100644 --- a/kernel/printk/internal.h +++ b/kernel/printk/internal.h @@ -84,6 +84,36 @@ void nbcon_seq_force(struct console *con, u64 seq); bool nbcon_alloc(struct console *con); void nbcon_free(struct console *con); +/* + * Check if the given console is currently capable and allowed to print + * records. + * + * Requires the console_srcu_read_lock. + */ +static inline bool console_is_usable(struct console *con) +{ + short flags = console_srcu_read_flags(con); + + if (!(flags & CON_ENABLED)) + return false; + + if ((flags & CON_SUSPENDED)) + return false; + + 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 #define PRINTK_PREFIX_MAX 0 @@ -104,6 +134,8 @@ static inline void nbcon_seq_force(struct console *con, u64 seq) { } static inline bool nbcon_alloc(struct console *con) { return false; } static inline void nbcon_free(struct console *con) { } +static inline bool console_is_usable(struct console *con) { return false; } + #endif /* CONFIG_PRINTK */ extern struct printk_buffers printk_shared_pbufs; |