From: John Ogness Date: Tue, 20 Aug 2024 08:35:28 +0206 Subject: [PATCH 02/54] printk: nbcon: Consolidate alloc() and init() Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.11/older/patches-6.11-rt7.tar.xz Rather than splitting the nbcon allocation and initialization into two pieces, perform all initialization in nbcon_alloc(). Later, the initial sequence is calculated and can be explicitly set using nbcon_seq_force(). This removes the need for the strong rules of nbcon_init() that even included a BUG_ON(). Signed-off-by: John Ogness Reviewed-by: Petr Mladek Link: https://lore.kernel.org/r/20240820063001.36405-3-john.ogness@linutronix.de Signed-off-by: Petr Mladek Signed-off-by: Sebastian Andrzej Siewior --- kernel/printk/internal.h | 2 -- kernel/printk/nbcon.c | 37 +++++++++++-------------------------- kernel/printk/printk.c | 2 +- 3 files changed, 12 insertions(+), 29 deletions(-) --- a/kernel/printk/internal.h +++ b/kernel/printk/internal.h @@ -75,7 +75,6 @@ u16 printk_parse_prefix(const char *text u64 nbcon_seq_read(struct console *con); void nbcon_seq_force(struct console *con, u64 seq); bool nbcon_alloc(struct console *con); -void nbcon_init(struct console *con); void nbcon_free(struct console *con); #else @@ -96,7 +95,6 @@ static inline bool printk_percpu_data_re static inline u64 nbcon_seq_read(struct console *con) { return 0; } 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_init(struct console *con) { } static inline void nbcon_free(struct console *con) { } #endif /* CONFIG_PRINTK */ --- a/kernel/printk/nbcon.c +++ b/kernel/printk/nbcon.c @@ -929,17 +929,22 @@ static bool nbcon_emit_next_record(struc } /** - * nbcon_alloc - Allocate buffers needed by the nbcon console - * @con: Console to allocate buffers for + * nbcon_alloc - Allocate and init the nbcon console specific data + * @con: Console to initialize * - * Return: True on success. False otherwise and the console cannot - * be used. + * Return: True if the console was fully allocated and initialized. + * Otherwise @con must not be registered. * - * This is not part of nbcon_init() because buffer allocation must - * be performed earlier in the console registration process. + * When allocation and init was successful, the console must be properly + * freed using nbcon_free() once it is no longer needed. */ bool nbcon_alloc(struct console *con) { + struct nbcon_state state = { }; + + nbcon_state_set(con, &state); + atomic_long_set(&ACCESS_PRIVATE(con, nbcon_seq), 0); + if (con->flags & CON_BOOT) { /* * Boot console printing is synchronized with legacy console @@ -959,26 +964,6 @@ bool nbcon_alloc(struct console *con) } /** - * nbcon_init - Initialize the nbcon console specific data - * @con: Console to initialize - * - * nbcon_alloc() *must* be called and succeed before this function - * is called. - * - * This function expects that the legacy @con->seq has been set. - */ -void nbcon_init(struct console *con) -{ - struct nbcon_state state = { }; - - /* nbcon_alloc() must have been called and successful! */ - BUG_ON(!con->pbufs); - - nbcon_seq_force(con, con->seq); - nbcon_state_set(con, &state); -} - -/** * nbcon_free - Free and cleanup the nbcon console specific data * @con: Console to free/cleanup nbcon data */ --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -3619,7 +3619,7 @@ void register_console(struct console *ne console_init_seq(newcon, bootcon_registered); if (newcon->flags & CON_NBCON) - nbcon_init(newcon); + nbcon_seq_force(newcon, newcon->seq); /* * Put this console in the list - keep the