kernel/printk/nbcon.c

108  * @con:	Console to update
114 static inline void nbcon_state_set(struct console *con, struct nbcon_state *new)
116 	atomic_set(&ACCESS_PRIVATE(con, nbcon_state), new->atom);
121  * @con:	Console to read
124 static inline void nbcon_state_read(struct console *con, struct nbcon_state *state)
126 	state->atom = atomic_read(&ACCESS_PRIVATE(con, nbcon_state));
131  * @con:	Console to update
137 static inline bool nbcon_state_try_cmpxchg(struct console *con, struct nbcon_state *cur,
140 	return atomic_try_cmpxchg(&ACCESS_PRIVATE(con, nbcon_state), &cur->atom, new->atom);
145  * @con:	Console to read the sequence of
147  * Return:	Sequence number of the next record to print on @con.
149 u64 nbcon_seq_read(struct console *con)
151 	unsigned long nbcon_seq = atomic_long_read(&ACCESS_PRIVATE(con, nbcon_seq));
158  * @con:	Console to work on
164 void nbcon_seq_force(struct console *con, u64 seq)
174 	atomic_long_set(&ACCESS_PRIVATE(con, nbcon_seq), __u64seq_to_ulseq(valid_seq));
176 	/* Clear con->seq since nbcon consoles use con->nbcon_seq instead. */
177 	con->seq = 0;
186  * @ctxt->seq is updated to the new value of @con::nbcon_seq (expanded to
194 	struct console *con = ctxt->console;
196 	if (atomic_long_try_cmpxchg(&ACCESS_PRIVATE(con, nbcon_seq), &nbcon_seq,
200 		ctxt->seq = nbcon_seq_read(con);
230 	struct console *con = ctxt->console;
255 	} while (!nbcon_state_try_cmpxchg(con, cur, &new));
310 	struct console *con = ctxt->console;
340 	if (!nbcon_state_try_cmpxchg(con, cur, &new)) {
393 	struct console *con = ctxt->console;
426 	if (!nbcon_state_try_cmpxchg(con, cur, &new))
448 		nbcon_state_read(con, cur);
464 		if (nbcon_state_try_cmpxchg(con, cur, &new)) {
499 	struct console *con = ctxt->console;
523 	} while (!nbcon_state_try_cmpxchg(con, cur, &new));
545 	struct console *con = ctxt->console;
549 	nbcon_state_read(con, &cur);
572 		ctxt->pbufs = con->pbufs;
607 	struct console *con = ctxt->console;
611 	nbcon_state_read(con, &cur);
626 	} while (!nbcon_state_try_cmpxchg(con, &cur, &new));
728 	struct console *con = ctxt->console;
731 	nbcon_state_read(con, &cur);
741  * __nbcon_context_update_unsafe - Update the unsafe bit in @con->nbcon_state
761 	struct console *con = ctxt->console;
765 	nbcon_state_read(con, &cur);
780 	} while (!nbcon_state_try_cmpxchg(con, &cur, &new));
847 	struct console *con = ctxt->console;
848 	bool is_extended = console_srcu_read_flags(con) & CON_EXTENDED;
871 	 * @con->dropped is not protected in case of an unsafe hostile
875 	con_dropped = data_race(READ_ONCE(con->dropped));
884 	/* For skipped records just update seq/dropped in @con. */
891 	nbcon_state_read(con, &cur);
894 	if (con->write_atomic) {
895 		done = con->write_atomic(con, wctxt);
923 		WRITE_ONCE(con->dropped, dropped);
933  * @con:	Console to allocate buffers for
941 bool nbcon_alloc(struct console *con)
943 	if (con->flags & CON_BOOT) {
949 		con->pbufs = &printk_shared_pbufs;
951 		con->pbufs = kmalloc(sizeof(*con->pbufs), GFP_KERNEL);
952 		if (!con->pbufs) {
953 			con_printk(KERN_ERR, con, "failed to allocate printing buffer\n");
963  * @con:	Console to initialize
968  * This function expects that the legacy @con->seq has been set.
970 void nbcon_init(struct console *con)
975 	BUG_ON(!con->pbufs);
977 	nbcon_seq_force(con, con->seq);
978 	nbcon_state_set(con, &state);
983  * @con:	Console to free/cleanup nbcon data
985 void nbcon_free(struct console *con)
989 	nbcon_state_set(con, &state);
992 	if (!(con->flags & CON_BOOT))
993 		kfree(con->pbufs);
995 	con->pbufs = NULL;