net/xdp/xsk_queue.h

18 	/* Hinder the adjacent cache prefetcher to prefetch the consumer
22 	u32 consumer ____cacheline_aligned_in_smp;
50  * ring, the kernel is the producer and user space is the consumer. For
51  * the Tx and fill rings, the kernel is the consumer and user space is
54  * producer                         consumer
56  * if (LOAD ->consumer) {           LOAD ->producer
60  *    STORE ->producer              STORE ->consumer
66  * the producer pointer. If this barrier was missing, the consumer
68  * before the producer has written the new data. The consumer would in
71  * (C) protects the consumer from speculatively loading the data before
77  * (A) is a control dependency that separates the load of ->consumer
78  * from the stores of $data. In case ->consumer indicates there is no
82  * store of the consumer pointer. If we did not have this memory
83  * barrier, the producer could observe the consumer pointer being set
84  * and overwrite the data with a new value before the consumer got the
85  * chance to read the old value. The consumer would thus miss reading
92  * producer                           consumer
100  * seen and read by the consumer.
102  * The consumer peeks into the ring to see if the producer has written
103  * any new entries. If so, the consumer can then read these entries
110 /* Functions that read and validate content from consumer rings. */
205 	WRITE_ONCE(q->ring->consumer, q->cached_cons);  in __xskq_cons_release()
263 	return READ_ONCE(q->ring->producer) - READ_ONCE(q->ring->consumer) ==  in xskq_cons_is_full()
270 	return READ_ONCE(q->ring->producer) - READ_ONCE(q->ring->consumer);  in xskq_cons_present_entries()
283 	q->cached_cons = READ_ONCE(q->ring->consumer);  in xskq_prod_is_full()
358 	return READ_ONCE(q->ring->consumer) == READ_ONCE(q->ring->producer);  in xskq_prod_is_empty()