46  * - NAK received (this is equivalent to issuing re-submit for all pending
49  * - cancel (non-pending and pending)
54  * containing all packets scheduled for transmission, and the set of pending
61  * - the pending set,
71  * sets-up the timeout and adds the packet to the pending set before starting
79  * reference to the packet from the pending set. The receiver thread will then
82  * On receival of a NAK, the receiver thread re-submits all currently pending
87  * checking all currently pending packets if their timeout has expired. If the
99  * packet cannot be added to the queue, the pending set, and the timeout, or
102  * references from the data structures (queue, pending) have to be removed.
125  *   may not be queued, dequeued, or removed or added to the pending set. Note
139  * - pending
140  *   Indicates if a packet is present in the set of pending packets or not.
141  *   This flag must only be modified with the pending lock held, and must be
142  *   coherent to the presence of the packet in the pending set.
167  * - To avoid deadlocks, if both queue and pending locks are required, the
168  *   pending lock must be acquired before the queue lock.
172  * - The packet timestamp must be accessed only while holding the pending
212  * SSH_PTL_MAX_PENDING - Maximum number of pending packets.
710 	 * less limited via the maximum number of pending packets). Thus, when  in __ssh_ptl_queue_find_entrypoint()
804 	spin_lock(&ptl->pending.lock);  in ssh_ptl_pending_push()
808 		spin_unlock(&ptl->pending.lock);  in ssh_ptl_pending_push()
813 	 * On re-submission, the packet has already been added the pending  in ssh_ptl_pending_push()
819 	/* In case it is already pending (e.g. re-submission), do not add it. */  in ssh_ptl_pending_push()
821 		atomic_inc(&ptl->pending.count);  in ssh_ptl_pending_push()
822 		list_add_tail(&ssh_packet_get(p)->pending_node, &ptl->pending.head);  in ssh_ptl_pending_push()
825 	spin_unlock(&ptl->pending.lock);  in ssh_ptl_pending_push()
835 	spin_lock(&ptl->pending.lock);  in ssh_ptl_pending_remove()
838 		spin_unlock(&ptl->pending.lock);  in ssh_ptl_pending_remove()
843 	atomic_dec(&ptl->pending.count);  in ssh_ptl_pending_remove()
845 	spin_unlock(&ptl->pending.lock);  in ssh_ptl_pending_remove()
888 		return !atomic_read(&ptl->pending.count);  in ssh_ptl_tx_can_process()
899 	return atomic_read(&ptl->pending.count) < SSH_PTL_MAX_PENDING;  in ssh_ptl_tx_can_process()
1198 	spin_lock(&ptl->pending.lock);  in ssh_ptl_ack_pop()
1199 	list_for_each_entry_safe(p, n, &ptl->pending.head, pending_node) {  in ssh_ptl_ack_pop()
1202 		 * to be added to pending is first to be sent, is first to be  in ssh_ptl_ack_pop()
1218 		 * Mark the packet as ACKed and remove it from pending by  in ssh_ptl_ack_pop()
1219 		 * removing its node and decrementing the pending counter.  in ssh_ptl_ack_pop()
1226 		atomic_dec(&ptl->pending.count);  in ssh_ptl_ack_pop()
1232 	spin_unlock(&ptl->pending.lock);  in ssh_ptl_ack_pop()
1252 			 * The packet has not been found in the set of pending  in ssh_ptl_acknowledge()
1255 			ptl_warn(ptl, "ptl: received ACK for non-pending packet\n");  in ssh_ptl_acknowledge()
1258 			 * The packet is pending, but we are not allowed to take  in ssh_ptl_acknowledge()
1295 	if (atomic_read(&ptl->pending.count) < SSH_PTL_MAX_PENDING)  in ssh_ptl_acknowledge()
1345 	    (atomic_read(&ptl->pending.count) < SSH_PTL_MAX_PENDING))  in ssh_ptl_submit()
1357  * with the pending lock held.
1368 	lockdep_assert_held(&packet->ptl->pending.lock);  in __ssh_ptl_resubmit()
1414 	spin_lock(&ptl->pending.lock);  in ssh_ptl_resubmit_pending()
1416 	/* Re-queue all pending packets. */  in ssh_ptl_resubmit_pending()
1417 	list_for_each_entry(p, &ptl->pending.head, pending_node) {  in ssh_ptl_resubmit_pending()
1427 	spin_unlock(&ptl->pending.lock);  in ssh_ptl_resubmit_pending()
1481 		if (atomic_read(&p->ptl->pending.count) < SSH_PTL_MAX_PENDING)  in ssh_ptl_cancel()
1489 /* Must be called with pending lock held */
1492 	lockdep_assert_held(&p->ptl->pending.lock);  in ssh_packet_get_expiration()
1511 	trace_ssam_ptl_timeout_reap(atomic_read(&ptl->pending.count));  in ssh_ptl_timeout_reap()
1514 	 * Mark reaper as "not pending". This is done before checking any  in ssh_ptl_timeout_reap()
1521 	spin_lock(&ptl->pending.lock);  in ssh_ptl_timeout_reap()
1523 	list_for_each_entry_safe(p, n, &ptl->pending.head, pending_node) {  in ssh_ptl_timeout_reap()
1562 		 * added to the pending list again after we've removed it here.  in ssh_ptl_timeout_reap()
1569 		atomic_dec(&ptl->pending.count);  in ssh_ptl_timeout_reap()
1573 	spin_unlock(&ptl->pending.lock);  in ssh_ptl_timeout_reap()
1584 		 * the pending set.  in ssh_ptl_timeout_reap()
1909  * and pending packets. Packets canceled by this operation will be completed
1949 	 * and pending set.  in ssh_ptl_shutdown()
1955 	 * packet as locked an then remove it from the queue (or pending set  in ssh_ptl_shutdown()
1978 	/* Mark pending packets as locked and move them to complete_p. */  in ssh_ptl_shutdown()
1979 	spin_lock(&ptl->pending.lock);  in ssh_ptl_shutdown()
1980 	list_for_each_entry_safe(p, n, &ptl->pending.head, pending_node) {  in ssh_ptl_shutdown()
1988 	atomic_set(&ptl->pending.count, 0);  in ssh_ptl_shutdown()
1989 	spin_unlock(&ptl->pending.lock);  in ssh_ptl_shutdown()
2037 	spin_lock_init(&ptl->pending.lock);  in ssh_ptl_init()
2038 	INIT_LIST_HEAD(&ptl->pending.head);  in ssh_ptl_init()
2039 	atomic_set_release(&ptl->pending.count, 0);  in ssh_ptl_init()