kernel/printk/printk_ringbuffer.c

568 static bool data_make_reusable(struct printk_ringbuffer *rb,
574 	struct prb_data_ring *data_ring = &rb->text_data_ring;
575 	struct prb_desc_ring *desc_ring = &rb->desc_ring;
636 static bool data_push_tail(struct printk_ringbuffer *rb, unsigned long lpos)
638 	struct prb_data_ring *data_ring = &rb->text_data_ring;
679 		if (!data_make_reusable(rb, tail_lpos, lpos, &next_lpos)) {
771 static bool desc_push_tail(struct printk_ringbuffer *rb,
774 	struct prb_desc_ring *desc_ring = &rb->desc_ring;
816 	if (!data_push_tail(rb, desc.text_blk_lpos.next))
879 static bool desc_reserve(struct printk_ringbuffer *rb, unsigned long *id_out)
881 	struct prb_desc_ring *desc_ring = &rb->desc_ring;
924 			if (!desc_push_tail(rb, id_prev_wrap))
1028 static char *data_alloc(struct printk_ringbuffer *rb, unsigned int size,
1031 	struct prb_data_ring *data_ring = &rb->text_data_ring;
1054 		if (!data_push_tail(rb, next_lpos - DATA_SIZE(data_ring))) {
1113 static char *data_realloc(struct printk_ringbuffer *rb, unsigned int size,
1116 	struct prb_data_ring *data_ring = &rb->text_data_ring;
1143 	if (!data_push_tail(rb, next_lpos - DATA_SIZE(data_ring)))
1329  * @rb:        The ringbuffer to re-reserve and extend data in.
1366 bool prb_reserve_in_last(struct prb_reserved_entry *e, struct printk_ringbuffer *rb,
1369 	struct prb_desc_ring *desc_ring = &rb->desc_ring;
1392 	e->rb = rb;
1410 		if (!data_check_size(&rb->text_data_ring, r->text_buf_size))
1416 		r->text_buf = data_alloc(rb, r->text_buf_size,
1419 		if (!get_data(&rb->text_data_ring, &d->text_blk_lpos, &data_size))
1434 		if (!data_check_size(&rb->text_data_ring, r->text_buf_size))
1440 		r->text_buf = data_realloc(rb, r->text_buf_size,
1448 	e->text_space = space_used(&rb->text_data_ring, &d->text_blk_lpos);
1477 static u64 desc_last_finalized_seq(struct printk_ringbuffer *rb)
1479 	struct prb_desc_ring *desc_ring = &rb->desc_ring;
1490 	return __ulseq_to_u64seq(rb, ulseq);
1493 static bool _prb_read_valid(struct printk_ringbuffer *rb, u64 *seq,
1501 static void desc_update_last_finalized(struct printk_ringbuffer *rb)
1503 	struct prb_desc_ring *desc_ring = &rb->desc_ring;
1504 	u64 old_seq = desc_last_finalized_seq(rb);
1515 	while (_prb_read_valid(rb, &try_seq, NULL, NULL)) {
1553 		old_seq = __ulseq_to_u64seq(rb, oldval);
1562 static void desc_make_final(struct printk_ringbuffer *rb, unsigned long id)
1564 	struct prb_desc_ring *desc_ring = &rb->desc_ring;
1570 		desc_update_last_finalized(rb);
1578  * @rb: The ringbuffer to reserve data in.
1599 bool prb_reserve(struct prb_reserved_entry *e, struct printk_ringbuffer *rb,
1602 	struct prb_desc_ring *desc_ring = &rb->desc_ring;
1608 	if (!data_check_size(&rb->text_data_ring, r->text_buf_size))
1619 	if (!desc_reserve(rb, &id)) {
1621 		atomic_long_inc(&rb->fail);
1641 	e->rb = rb;
1667 		desc_make_final(rb, DESC_ID(id - 1));
1669 	r->text_buf = data_alloc(rb, r->text_buf_size, &d->text_blk_lpos, id);
1680 	e->text_space = space_used(&rb->text_data_ring, &d->text_blk_lpos);
1692 	struct prb_desc_ring *desc_ring = &e->rb->desc_ring;
1748 	struct prb_desc_ring *desc_ring = &e->rb->desc_ring;
1760 		desc_make_final(e->rb, e->id);
1782 	desc_update_last_finalized(e->rb);
1907 static int prb_read(struct printk_ringbuffer *rb, u64 seq,
1910 	struct prb_desc_ring *desc_ring = &rb->desc_ring;
1936 	if (!copy_data(&rb->text_data_ring, &desc.text_blk_lpos, info->text_len,
1946 u64 prb_first_seq(struct printk_ringbuffer *rb)
1948 	struct prb_desc_ring *desc_ring = &rb->desc_ring;
1955 		id = atomic_long_read(&rb->desc_ring.tail_id); /* LMM(prb_first_seq:A) */
1993  * @rb:  The ringbuffer to get the sequence number from.
2005 u64 prb_next_reserve_seq(struct printk_ringbuffer *rb)
2007 	struct prb_desc_ring *desc_ring = &rb->desc_ring;
2024 	last_finalized_seq = desc_last_finalized_seq(rb);
2107 static bool _prb_read_valid(struct printk_ringbuffer *rb, u64 *seq,
2113 	while ((err = prb_read(rb, *seq, r, line_count))) {
2114 		tail_seq = prb_first_seq(rb);
2146 			if (this_cpu_in_panic() && ((*seq + 1) < prb_next_reserve_seq(rb)))
2160  * @rb:  The ringbuffer to read from.
2179 bool prb_read_valid(struct printk_ringbuffer *rb, u64 seq,
2182 	return _prb_read_valid(rb, &seq, r, NULL);
2189  * @rb:         The ringbuffer to read from.
2209 bool prb_read_valid_info(struct printk_ringbuffer *rb, u64 seq,
2216 	return _prb_read_valid(rb, &seq, &r, line_count);
2223  * @rb: The ringbuffer to get the sequence number from.
2234 u64 prb_first_valid_seq(struct printk_ringbuffer *rb)
2238 	if (!_prb_read_valid(rb, &seq, NULL, NULL))
2247  * @rb:  The ringbuffer to get the sequence number from.
2261 u64 prb_next_seq(struct printk_ringbuffer *rb)
2265 	seq = desc_last_finalized_seq(rb);
2281 	while (_prb_read_valid(rb, &seq, NULL, NULL))
2290  * @rb:       The ringbuffer to initialize.
2304 void prb_init(struct printk_ringbuffer *rb,
2312 	rb->desc_ring.count_bits = descbits;
2313 	rb->desc_ring.descs = descs;
2314 	rb->desc_ring.infos = infos;
2315 	atomic_long_set(&rb->desc_ring.head_id, DESC0_ID(descbits));
2316 	atomic_long_set(&rb->desc_ring.tail_id, DESC0_ID(descbits));
2317 	atomic_long_set(&rb->desc_ring.last_finalized_seq, 0);
2319 	rb->text_data_ring.size_bits = textbits;
2320 	rb->text_data_ring.data = text_buf;
2321 	atomic_long_set(&rb->text_data_ring.head_lpos, BLK0_LPOS(textbits));
2322 	atomic_long_set(&rb->text_data_ring.tail_lpos, BLK0_LPOS(textbits));
2324 	atomic_long_set(&rb->fail, 0);