From: John Ogness Date: Tue, 26 Sep 2023 14:43:30 +0000 Subject: [PATCH 123/134] printk: nbcon: Add context to console_is_usable() Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6.7-rt18.tar.xz The nbcon consoles have two callbacks to be used for different contexts. In order to determine if an nbcon console is usable, console_is_usable() needs to know if it is a context that will use the write_atomic() callback or the write_thread() callback. Add an extra parameter @use_atomic to specify this. Signed-off-by: John Ogness Signed-off-by: Sebastian Andrzej Siewior --- kernel/printk/internal.h | 16 ++++++++++------ kernel/printk/nbcon.c | 6 +++--- kernel/printk/printk.c | 6 ++++-- 3 files changed, 17 insertions(+), 11 deletions(-) --- a/kernel/printk/internal.h +++ b/kernel/printk/internal.h @@ -100,7 +100,7 @@ void nbcon_kthread_create(struct console * 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) +static inline bool console_is_usable(struct console *con, short flags, bool use_atomic) { if (!(flags & CON_ENABLED)) return false; @@ -109,10 +109,13 @@ static inline bool console_is_usable(str return false; if (flags & CON_NBCON) { - if (!con->write_atomic) - return false; - if (!con->write_thread || !con->kthread) - return false; + if (use_atomic) { + if (!con->write_atomic) + return false; + } else { + if (!con->write_thread || !con->kthread) + return false; + } } else { if (!con->write) return false; @@ -178,7 +181,8 @@ static inline void nbcon_atomic_flush_al static inline bool nbcon_atomic_emit_next_record(struct console *con, bool *handover, int cookie) { return false; } -static inline bool console_is_usable(struct console *con, short flags) { return false; } +static inline bool console_is_usable(struct console *con, short flags, + bool use_atomic) { return false; } #endif /* CONFIG_PRINTK */ --- a/kernel/printk/nbcon.c +++ b/kernel/printk/nbcon.c @@ -963,7 +963,7 @@ static bool nbcon_kthread_should_wakeup( cookie = console_srcu_read_lock(); flags = console_srcu_read_flags(con); - is_usable = console_is_usable(con, flags); + is_usable = console_is_usable(con, flags, false); console_srcu_read_unlock(cookie); if (!is_usable) @@ -1022,7 +1022,7 @@ static int nbcon_kthread_func(void *__co con_flags = console_srcu_read_flags(con); - if (console_is_usable(con, con_flags)) { + if (console_is_usable(con, con_flags, false)) { con->driver_enter(con, &flags); /* @@ -1203,7 +1203,7 @@ static void __nbcon_atomic_flush_all(u64 if (!(flags & CON_NBCON)) continue; - if (!console_is_usable(con, flags)) + if (!console_is_usable(con, flags, true)) continue; if (nbcon_seq_read(con) >= stop_seq) --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -3040,7 +3040,7 @@ static bool console_flush_all(bool do_co if ((flags & CON_NBCON) && con->kthread) continue; - if (!console_is_usable(con, flags)) + if (!console_is_usable(con, flags, true)) continue; any_usable = true; @@ -3945,8 +3945,10 @@ static bool __pr_flush(struct console *c * that they make forward progress, so only increment * @diff for usable consoles. */ - if (!console_is_usable(c, flags)) + if (!console_is_usable(c, flags, true) && + !console_is_usable(c, flags, false)) { continue; + } if (flags & CON_NBCON) { printk_seq = nbcon_seq_read(c);