dev/netmap/ixgbe_netmap.h

159  * All information is in the kring.
160  * Userspace wants to send packets up to the one before kring->rhead,
161  * kernel knows kring->nr_hwcur is the first unsent packet.
171 ixgbe_netmap_txsync(struct netmap_kring *kring, int flags)
173 	struct netmap_adapter *na = kring->na;
175 	struct netmap_ring *ring = kring->ring;
179 	u_int const lim = kring->nkr_num_slots - 1;
180 	u_int const head = kring->rhead;
185 	u_int report_frequency = kring->nkr_num_slots >> 1;
189 	struct tx_ring *txr = &adapter->tx_rings[kring->ring_id];
203 	 *		nm_i = kring->nr_hwcur
206 	 * 		nm_i == (nic_i + kring->nkr_hwofs) % ring_size
208 	 * In this driver kring->nkr_hwofs >= 0, but for other
213 	 * If we have packets to send (kring->nr_hwcur != kring->rhead)
230 	nm_i = kring->nr_hwcur;
232 		nic_i = netmap_idx_k2n(kring, nm_i);
276 		kring->nr_hwcur = head;
293 	} else if (!nm_kr_txempty(kring)) {
311 		nic_i = (nic_i < kring->nkr_num_slots / 4 ||
312 			 nic_i >= kring->nkr_num_slots*3/4) ?
328 				IXGBE_VFTDH(kring->ring_id) : IXGBE_TDH(kring->ring_id));
329 		if (unlikely(nic_i >= kring->nkr_num_slots)) {
331 			nic_i -= kring->nkr_num_slots;
336 			kring->nr_hwtail = nm_prev(netmap_idx_n2k(kring, nic_i), lim);
350  * On call, kring->rhead is the first packet that userspace wants
351  * to keep, and kring->rcur is the wakeup point.
352  * The kernel has previously reported packets up to kring->rtail.
358 ixgbe_netmap_rxsync(struct netmap_kring *kring, int flags)
360 	struct netmap_adapter *na = kring->na;
362 	struct netmap_ring *ring = kring->ring;
366 	u_int const lim = kring->nkr_num_slots - 1;
367 	u_int const head = kring->rhead;
368 	int force_update = (flags & NAF_FORCE_READ) || kring->nr_kflags & NKR_PENDINTR;
372 	struct rx_ring *rxr = &adapter->rx_rings[kring->ring_id];
375 		return netmap_ring_reinit(kring);
390 	 *	nm_i = kring->nr_hwtail (previous)
392 	 *	nm_i == (nic_i + kring->nkr_hwofs) % ring_size
399 		nic_i = rxr->next_to_check; // or also k2n(kring->nr_hwtail)
400 		nm_i = netmap_idx_n2k(kring, nic_i);
422 			kring->nr_hwtail = nm_i;
424 		kring->nr_kflags &= ~NKR_PENDINTR;
429 	 * (kring->nr_hwcur to kring->rhead excluded),
433 	 * nm_i == (nic_i + kring->nkr_hwofs) % ring_size
435 	nm_i = kring->nr_hwcur;
437 		nic_i = netmap_idx_k2n(kring, nm_i);
461 		kring->nr_hwcur = head;
476 	return netmap_ring_reinit(kring);