1 /* SPDX-License-Identifier: GPL-2.0-or-later */
3  * internal.h - printk internal definitions
5 #include <linux/console.h>
20 		(con->flags & CON_NBCON) ? "" : "legacy ",	\
21 		(con->flags & CON_BOOT) ? "boot" : "",		\
22 		con->name, con->index, ##__VA_ARGS__)
26  * true, all printing via console lock occurs within a dedicated
46  * the maximum size of a formatted record (i.e. with prefix added
51 /* the maximum size allowed to be reserved for a record */
56 	/* always show on console, ignore console_loglevel */
102 u64 nbcon_seq_read(struct console *con);
103 void nbcon_seq_force(struct console *con, u64 seq);
104 bool nbcon_alloc(struct console *con);
105 void nbcon_free(struct console *con);
108 bool nbcon_legacy_emit_next_record(struct console *con, bool *handover,
110 bool nbcon_kthread_create(struct console *con);
111 void nbcon_kthread_stop(struct console *con);
115  * Check if the given console is currently capable and allowed to print
120 static inline bool console_is_usable(struct console *con, short flags, bool use_atomic)  in console_is_usable()
130 		if (use_atomic && !con->write_atomic)  in console_is_usable()
140 		if (!con->write)  in console_is_usable()
145 	 * Console drivers may assume that per-cpu resources have been  in console_is_usable()
156  * nbcon_kthread_wake - Wake up a console printing thread
157  * @con:	Console to operate on
159 static inline void nbcon_kthread_wake(struct console *con)  in nbcon_kthread_wake()
172 	rcuwait_wake_up(&con->rcuwait); /* LMM(nbcon_kthread_wake:A) */  in nbcon_kthread_wake()
185  * semaphore and some of console functions (console_unlock()/etc.), so
186  * printk-safe must preserve the existing local IRQ guarantees.
194 static inline u64 nbcon_seq_read(struct console *con) { return 0; }  in nbcon_seq_read()
195 static inline void nbcon_seq_force(struct console *con, u64 seq) { }  in nbcon_seq_force()
196 static inline bool nbcon_alloc(struct console *con) { return false; }  in nbcon_alloc()
197 static inline void nbcon_free(struct console *con) { }  in nbcon_free()
200 static inline bool nbcon_legacy_emit_next_record(struct console *con, bool *handover,  in nbcon_legacy_emit_next_record()
202 static inline void nbcon_kthread_wake(struct console *con) { }  in nbcon_kthread_wake()
205 static inline bool console_is_usable(struct console *con, short flags,  in console_is_usable()
216  * struct console_flush_type - Define available console flush methods
232  * Identify which console flushing methods should be used in the context of
243 				ft->nbcon_offload = true;  in printk_get_console_flush_type()
245 				ft->nbcon_atomic = true;  in printk_get_console_flush_type()
251 				ft->legacy_direct = true;  in printk_get_console_flush_type()
253 				ft->legacy_offload = true;  in printk_get_console_flush_type()
259 			ft->nbcon_atomic = true;  in printk_get_console_flush_type()
264 				ft->legacy_direct = true;  in printk_get_console_flush_type()
266 				ft->legacy_offload = true;  in printk_get_console_flush_type()
276 			ft->nbcon_atomic = true;  in printk_get_console_flush_type()
287 				ft->legacy_direct = true;  in printk_get_console_flush_type()
294 			if (ft->nbcon_atomic && !legacy_allow_panic_sync)  in printk_get_console_flush_type()
295 				ft->legacy_direct = false;  in printk_get_console_flush_type()
308  * struct printk_buffers - Buffers to read/format/output printk messages.
310  * @scratchbuf:	Used as temporary ringbuffer reading and string-print space.
318  * struct printk_message - Container for a prepared printk message.
320  * @outbuf_len:	The length of prepared text in @pbufs->outbuf to output. This
323  * @seq:	The sequence number of the record used for @pbufs->outbuf.