1/*
2 * Copyright (C) 2011-2014 Matteo Landi, Luigi Rizzo. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 */
25
26/*
27 * $FreeBSD: stable/11/sys/dev/netmap/if_em_netmap.h 343771 2019-02-05 10:33:22Z vmaffione $
28 *
29 * netmap support for: em.
30 *
31 * For more details on netmap support please see ixgbe_netmap.h
32 */
33
34
35#include <net/netmap.h>
36#include <sys/selinfo.h>
37#include <vm/vm.h>
38#include <vm/pmap.h>    /* vtophys ? */
39#include <dev/netmap/netmap_kern.h>
40
41
42// XXX do we need to block/unblock the tasks ?
43static void
44em_netmap_block_tasks(struct adapter *adapter)
45{
46	if (adapter->msix > 1) { /* MSIX */
47		int i;
48		struct tx_ring *txr = adapter->tx_rings;
49		struct rx_ring *rxr = adapter->rx_rings;
50
51		for (i = 0; i < adapter->num_queues; i++, txr++, rxr++) {
52			taskqueue_block(txr->tq);
53			taskqueue_drain(txr->tq, &txr->tx_task);
54			taskqueue_block(rxr->tq);
55			taskqueue_drain(rxr->tq, &rxr->rx_task);
56		}
57	} else {	/* legacy */
58		taskqueue_block(adapter->tq);
59		taskqueue_drain(adapter->tq, &adapter->link_task);
60		taskqueue_drain(adapter->tq, &adapter->que_task);
61	}
62}
63
64
65static void
66em_netmap_unblock_tasks(struct adapter *adapter)
67{
68	if (adapter->msix > 1) {
69		struct tx_ring *txr = adapter->tx_rings;
70		struct rx_ring *rxr = adapter->rx_rings;
71		int i;
72
73		for (i = 0; i < adapter->num_queues; i++, txr++, rxr++) {
74			taskqueue_unblock(txr->tq);
75			taskqueue_unblock(rxr->tq);
76		}
77	} else { /* legacy */
78		taskqueue_unblock(adapter->tq);
79	}
80}
81
82
83/*
84 * Register/unregister. We are already under netmap lock.
85 */
86static int
87em_netmap_reg(struct netmap_adapter *na, int onoff)
88{
89	struct ifnet *ifp = na->ifp;
90	struct adapter *adapter = ifp->if_softc;
91
92	EM_CORE_LOCK(adapter);
93	em_disable_intr(adapter);
94
95	/* Tell the stack that the interface is no longer active */
96	ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
97
98	em_netmap_block_tasks(adapter);
99	/* enable or disable flags and callbacks in na and ifp */
100	if (onoff) {
101		nm_set_native_flags(na);
102	} else {
103		nm_clear_native_flags(na);
104	}
105	em_init_locked(adapter);	/* also enable intr */
106	em_netmap_unblock_tasks(adapter);
107	EM_CORE_UNLOCK(adapter);
108	return (ifp->if_drv_flags & IFF_DRV_RUNNING ? 0 : 1);
109}
110
111
112/*
113 * Reconcile kernel and user view of the transmit ring.
114 */
115static int
116em_netmap_txsync(struct netmap_kring *kring, int flags)
117{
118	struct netmap_adapter *na = kring->na;
119	struct ifnet *ifp = na->ifp;
120	struct netmap_ring *ring = kring->ring;
121	u_int nm_i;	/* index into the netmap ring */
122	u_int nic_i;	/* index into the NIC ring */
123	u_int n;
124	u_int const lim = kring->nkr_num_slots - 1;
125	u_int const head = kring->rhead;
126	/* generate an interrupt approximately every half ring */
127	u_int report_frequency = kring->nkr_num_slots >> 1;
128
129	/* device-specific */
130	struct adapter *adapter = ifp->if_softc;
131	struct tx_ring *txr = &adapter->tx_rings[kring->ring_id];
132
133	bus_dmamap_sync(txr->txdma.dma_tag, txr->txdma.dma_map,
134			BUS_DMASYNC_POSTREAD);
135
136	/*
137	 * First part: process new packets to send.
138	 */
139
140	nm_i = kring->nr_hwcur;
141	if (nm_i != head) {	/* we have new packets to send */
142		nic_i = netmap_idx_k2n(kring, nm_i);
143		for (n = 0; nm_i != head; n++) {
144			struct netmap_slot *slot = &ring->slot[nm_i];
145			u_int len = slot->len;
146			uint64_t paddr;
147			void *addr = PNMB(na, slot, &paddr);
148
149			/* device-specific */
150			struct e1000_tx_desc *curr = &txr->tx_base[nic_i];
151			struct em_txbuffer *txbuf = &txr->tx_buffers[nic_i];
152			int flags = (slot->flags & NS_REPORT ||
153				nic_i == 0 || nic_i == report_frequency) ?
154				E1000_TXD_CMD_RS : 0;
155
156			NM_CHECK_ADDR_LEN(na, addr, len);
157
158			if (slot->flags & NS_BUF_CHANGED) {
159				curr->buffer_addr = htole64(paddr);
160				/* buffer has changed, reload map */
161				netmap_reload_map(na, txr->txtag, txbuf->map, addr);
162			}
163			slot->flags &= ~(NS_REPORT | NS_BUF_CHANGED);
164
165			/* Fill the slot in the NIC ring. */
166			curr->upper.data = 0;
167			curr->lower.data = htole32(adapter->txd_cmd | len |
168				(E1000_TXD_CMD_EOP | flags) );
169			bus_dmamap_sync(txr->txtag, txbuf->map,
170				BUS_DMASYNC_PREWRITE);
171
172			nm_i = nm_next(nm_i, lim);
173			nic_i = nm_next(nic_i, lim);
174		}
175		kring->nr_hwcur = head;
176
177		/* synchronize the NIC ring */
178		bus_dmamap_sync(txr->txdma.dma_tag, txr->txdma.dma_map,
179			BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
180
181		/* (re)start the tx unit up to slot nic_i (excluded) */
182		E1000_WRITE_REG(&adapter->hw, E1000_TDT(txr->me), nic_i);
183	}
184
185	/*
186	 * Second part: reclaim buffers for completed transmissions.
187	 */
188	if (flags & NAF_FORCE_RECLAIM || nm_kr_txempty(kring)) {
189		/* record completed transmissions using TDH */
190		nic_i = E1000_READ_REG(&adapter->hw, E1000_TDH(kring->ring_id));
191		if (unlikely(nic_i >= kring->nkr_num_slots)) {
192			nm_prerr("TDH wrap at idx %d", nic_i);
193			nic_i -= kring->nkr_num_slots;
194		}
195		if (nic_i != txr->next_to_clean) {
196			txr->next_to_clean = nic_i;
197			kring->nr_hwtail = nm_prev(netmap_idx_n2k(kring, nic_i), lim);
198		}
199	}
200
201	return 0;
202}
203
204
205/*
206 * Reconcile kernel and user view of the receive ring.
207 */
208static int
209em_netmap_rxsync(struct netmap_kring *kring, int flags)
210{
211	struct netmap_adapter *na = kring->na;
212	struct ifnet *ifp = na->ifp;
213	struct netmap_ring *ring = kring->ring;
214	u_int nm_i;	/* index into the netmap ring */
215	u_int nic_i;	/* index into the NIC ring */
216	u_int n;
217	u_int const lim = kring->nkr_num_slots - 1;
218	u_int const head = kring->rhead;
219	int force_update = (flags & NAF_FORCE_READ) || kring->nr_kflags & NKR_PENDINTR;
220
221	/* device-specific */
222	struct adapter *adapter = ifp->if_softc;
223	struct rx_ring *rxr = &adapter->rx_rings[kring->ring_id];
224
225	if (head > lim)
226		return netmap_ring_reinit(kring);
227
228	/* XXX check sync modes */
229	bus_dmamap_sync(rxr->rxdma.dma_tag, rxr->rxdma.dma_map,
230			BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
231
232	/*
233	 * First part: import newly received packets.
234	 */
235	if (netmap_no_pendintr || force_update) {
236		nic_i = rxr->next_to_check;
237		nm_i = netmap_idx_n2k(kring, nic_i);
238
239		for (n = 0; ; n++) { // XXX no need to count
240			union e1000_rx_desc_extended *curr = &rxr->rx_base[nic_i];
241			uint32_t staterr = le32toh(curr->wb.upper.status_error);
242
243			if ((staterr & E1000_RXD_STAT_DD) == 0)
244				break;
245			ring->slot[nm_i].len = le16toh(curr->wb.upper.length);
246			ring->slot[nm_i].flags = 0;
247			bus_dmamap_sync(rxr->rxtag, rxr->rx_buffers[nic_i].map,
248				BUS_DMASYNC_POSTREAD);
249			nm_i = nm_next(nm_i, lim);
250			/* make sure next_to_refresh follows next_to_check */
251			rxr->next_to_refresh = nic_i;	// XXX
252			nic_i = nm_next(nic_i, lim);
253		}
254		if (n) { /* update the state variables */
255			rxr->next_to_check = nic_i;
256			kring->nr_hwtail = nm_i;
257		}
258		kring->nr_kflags &= ~NKR_PENDINTR;
259	}
260
261	/*
262	 * Second part: skip past packets that userspace has released.
263	 */
264	nm_i = kring->nr_hwcur;
265	if (nm_i != head) {
266		nic_i = netmap_idx_k2n(kring, nm_i);
267		for (n = 0; nm_i != head; n++) {
268			struct netmap_slot *slot = &ring->slot[nm_i];
269			uint64_t paddr;
270			void *addr = PNMB(na, slot, &paddr);
271
272			union e1000_rx_desc_extended *curr = &rxr->rx_base[nic_i];
273			struct em_rxbuffer *rxbuf = &rxr->rx_buffers[nic_i];
274
275			if (addr == NETMAP_BUF_BASE(na)) /* bad buf */
276				goto ring_reset;
277
278			curr->read.buffer_addr = htole64(paddr);
279			if (slot->flags & NS_BUF_CHANGED) {
280				/* buffer has changed, reload map */
281				netmap_reload_map(na, rxr->rxtag, rxbuf->map, addr);
282				slot->flags &= ~NS_BUF_CHANGED;
283			}
284			curr->wb.upper.status_error = 0;
285			bus_dmamap_sync(rxr->rxtag, rxbuf->map,
286			    BUS_DMASYNC_PREREAD);
287			nm_i = nm_next(nm_i, lim);
288			nic_i = nm_next(nic_i, lim);
289		}
290		kring->nr_hwcur = head;
291
292		bus_dmamap_sync(rxr->rxdma.dma_tag, rxr->rxdma.dma_map,
293		    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
294		/*
295		 * IMPORTANT: we must leave one free slot in the ring,
296		 * so move nic_i back by one unit
297		 */
298		nic_i = nm_prev(nic_i, lim);
299		E1000_WRITE_REG(&adapter->hw, E1000_RDT(rxr->me), nic_i);
300	}
301
302	return 0;
303
304ring_reset:
305	return netmap_ring_reinit(kring);
306}
307
308
309static void
310em_netmap_attach(struct adapter *adapter)
311{
312	struct netmap_adapter na;
313
314	bzero(&na, sizeof(na));
315
316	na.ifp = adapter->ifp;
317	na.na_flags = NAF_BDG_MAYSLEEP;
318	na.num_tx_desc = adapter->num_tx_desc;
319	na.num_rx_desc = adapter->num_rx_desc;
320	na.nm_txsync = em_netmap_txsync;
321	na.nm_rxsync = em_netmap_rxsync;
322	na.nm_register = em_netmap_reg;
323	na.num_tx_rings = na.num_rx_rings = adapter->num_queues;
324	netmap_attach(&na);
325}
326
327/* end of file */
328