1/*
2 * Copyright (C) 2015, 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 * $FreeBSD$
28 *
29 * netmap support for: ixl
30 *
31 * derived from ixgbe
32 * netmap support for a network driver.
33 * This file contains code but only static or inline functions used
34 * by a single driver. To avoid replication of code we just #include
35 * it near the beginning of the standard driver.
36 * For ixl the file is imported in two places, hence the conditional at the
37 * beginning.
38 */
39
40#include <net/netmap.h>
41#include <sys/selinfo.h>
42
43/*
44 * Some drivers may need the following headers. Others
45 * already include them by default
46
47#include <vm/vm.h>
48#include <vm/pmap.h>
49
50 */
51#include <dev/netmap/netmap_kern.h>
52
53int ixl_netmap_txsync(struct netmap_kring *kring, int flags);
54int ixl_netmap_rxsync(struct netmap_kring *kring, int flags);
55
56extern int ixl_rx_miss, ixl_rx_miss_bufs, ixl_crcstrip;
57
58#ifdef NETMAP_IXL_MAIN
59/*
60 * device-specific sysctl variables:
61 *
62 * ixl_crcstrip: 0: keep CRC in rx frames (default), 1: strip it.
63 *	During regular operations the CRC is stripped, but on some
64 *	hardware reception of frames not multiple of 64 is slower,
65 *	so using crcstrip=0 helps in benchmarks.
66 *
67 * ixl_rx_miss, ixl_rx_miss_bufs:
68 *	count packets that might be missed due to lost interrupts.
69 */
70SYSCTL_DECL(_dev_netmap);
71int ixl_rx_miss, ixl_rx_miss_bufs, ixl_crcstrip;
72SYSCTL_INT(_dev_netmap, OID_AUTO, ixl_crcstrip,
73    CTLFLAG_RW, &ixl_crcstrip, 0, "strip CRC on rx frames");
74SYSCTL_INT(_dev_netmap, OID_AUTO, ixl_rx_miss,
75    CTLFLAG_RW, &ixl_rx_miss, 0, "potentially missed rx intr");
76SYSCTL_INT(_dev_netmap, OID_AUTO, ixl_rx_miss_bufs,
77    CTLFLAG_RW, &ixl_rx_miss_bufs, 0, "potentially missed rx intr bufs");
78
79
80/*
81 * Register/unregister. We are already under netmap lock.
82 * Only called on the first register or the last unregister.
83 */
84static int
85ixl_netmap_reg(struct netmap_adapter *na, int onoff)
86{
87	struct ifnet *ifp = na->ifp;
88        struct ixl_vsi  *vsi = ifp->if_softc;
89        struct ixl_pf   *pf = (struct ixl_pf *)vsi->back;
90
91	IXL_PF_LOCK(pf);
92	ixl_disable_intr(vsi);
93
94	/* Tell the stack that the interface is no longer active */
95	ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
96
97	//set_crcstrip(&adapter->hw, onoff);
98	/* enable or disable flags and callbacks in na and ifp */
99	if (onoff) {
100		nm_set_native_flags(na);
101	} else {
102		nm_clear_native_flags(na);
103	}
104	ixl_init_locked(pf);	/* also enables intr */
105	//set_crcstrip(&adapter->hw, onoff); // XXX why twice ?
106	IXL_PF_UNLOCK(pf);
107	return (ifp->if_drv_flags & IFF_DRV_RUNNING ? 0 : 1);
108}
109
110
111/*
112 * The attach routine, called near the end of ixl_attach(),
113 * fills the parameters for netmap_attach() and calls it.
114 * It cannot fail, in the worst case (such as no memory)
115 * netmap mode will be disabled and the driver will only
116 * operate in standard mode.
117 */
118static void
119ixl_netmap_attach(struct ixl_vsi *vsi)
120{
121	struct netmap_adapter na;
122
123	bzero(&na, sizeof(na));
124
125	na.ifp = vsi->ifp;
126	na.na_flags = NAF_BDG_MAYSLEEP;
127	// XXX check that queues is set.
128	printf("queues is %p\n", vsi->queues);
129	if (vsi->queues) {
130		na.num_tx_desc = vsi->queues[0].num_desc;
131		na.num_rx_desc = vsi->queues[0].num_desc;
132	}
133	na.nm_txsync = ixl_netmap_txsync;
134	na.nm_rxsync = ixl_netmap_rxsync;
135	na.nm_register = ixl_netmap_reg;
136	na.num_tx_rings = na.num_rx_rings = vsi->num_queues;
137	netmap_attach(&na);
138}
139
140
141#else /* !NETMAP_IXL_MAIN, code for ixl_txrx.c */
142
143/*
144 * Reconcile kernel and user view of the transmit ring.
145 *
146 * All information is in the kring.
147 * Userspace wants to send packets up to the one before kring->rhead,
148 * kernel knows kring->nr_hwcur is the first unsent packet.
149 *
150 * Here we push packets out (as many as possible), and possibly
151 * reclaim buffers from previously completed transmission.
152 *
153 * The caller (netmap) guarantees that there is only one instance
154 * running at any time. Any interference with other driver
155 * methods should be handled by the individual drivers.
156 */
157int
158ixl_netmap_txsync(struct netmap_kring *kring, int flags)
159{
160	struct netmap_adapter *na = kring->na;
161	struct ifnet *ifp = na->ifp;
162	struct netmap_ring *ring = kring->ring;
163	u_int nm_i;	/* index into the netmap ring */
164	u_int nic_i;	/* index into the NIC ring */
165	u_int n;
166	u_int const lim = kring->nkr_num_slots - 1;
167	u_int const head = kring->rhead;
168	/*
169	 * interrupts on every tx packet are expensive so request
170	 * them every half ring, or where NS_REPORT is set
171	 */
172	u_int report_frequency = kring->nkr_num_slots >> 1;
173
174	/* device-specific */
175	struct ixl_vsi *vsi = ifp->if_softc;
176	struct ixl_queue *que = &vsi->queues[kring->ring_id];
177	struct tx_ring *txr = &que->txr;
178
179	bus_dmamap_sync(txr->dma.tag, txr->dma.map,
180			BUS_DMASYNC_POSTREAD);
181
182	/*
183	 * First part: process new packets to send.
184	 * nm_i is the current index in the netmap ring,
185	 * nic_i is the corresponding index in the NIC ring.
186	 *
187	 * If we have packets to send (nm_i != head)
188	 * iterate over the netmap ring, fetch length and update
189	 * the corresponding slot in the NIC ring. Some drivers also
190	 * need to update the buffer's physical address in the NIC slot
191	 * even NS_BUF_CHANGED is not set (PNMB computes the addresses).
192	 *
193	 * The netmap_reload_map() calls is especially expensive,
194	 * even when (as in this case) the tag is 0, so do only
195	 * when the buffer has actually changed.
196	 *
197	 * If possible do not set the report/intr bit on all slots,
198	 * but only a few times per ring or when NS_REPORT is set.
199	 *
200	 * Finally, on 10G and faster drivers, it might be useful
201	 * to prefetch the next slot and txr entry.
202	 */
203
204	nm_i = kring->nr_hwcur;
205	if (nm_i != head) {	/* we have new packets to send */
206		nic_i = netmap_idx_k2n(kring, nm_i);
207
208		__builtin_prefetch(&ring->slot[nm_i]);
209		__builtin_prefetch(&txr->buffers[nic_i]);
210
211		for (n = 0; nm_i != head; n++) {
212			struct netmap_slot *slot = &ring->slot[nm_i];
213			u_int len = slot->len;
214			uint64_t paddr;
215			void *addr = PNMB(na, slot, &paddr);
216
217			/* device-specific */
218			struct i40e_tx_desc *curr = &txr->base[nic_i];
219			struct ixl_tx_buf *txbuf = &txr->buffers[nic_i];
220			u64 flags = (slot->flags & NS_REPORT ||
221				nic_i == 0 || nic_i == report_frequency) ?
222				((u64)I40E_TX_DESC_CMD_RS << I40E_TXD_QW1_CMD_SHIFT) : 0;
223
224			/* prefetch for next round */
225			__builtin_prefetch(&ring->slot[nm_i + 1]);
226			__builtin_prefetch(&txr->buffers[nic_i + 1]);
227
228			NM_CHECK_ADDR_LEN(na, addr, len);
229
230			if (slot->flags & NS_BUF_CHANGED) {
231				/* buffer has changed, reload map */
232				netmap_reload_map(na, txr->dma.tag, txbuf->map, addr);
233			}
234			slot->flags &= ~(NS_REPORT | NS_BUF_CHANGED);
235
236			/* Fill the slot in the NIC ring. */
237			curr->buffer_addr = htole64(paddr);
238			curr->cmd_type_offset_bsz = htole64(
239			    ((u64)len << I40E_TXD_QW1_TX_BUF_SZ_SHIFT) |
240			    flags |
241			    ((u64)I40E_TX_DESC_CMD_EOP << I40E_TXD_QW1_CMD_SHIFT)
242			  ); // XXX more ?
243
244			/* make sure changes to the buffer are synced */
245			bus_dmamap_sync(txr->dma.tag, txbuf->map,
246				BUS_DMASYNC_PREWRITE);
247
248			nm_i = nm_next(nm_i, lim);
249			nic_i = nm_next(nic_i, lim);
250		}
251		kring->nr_hwcur = head;
252
253		/* synchronize the NIC ring */
254		bus_dmamap_sync(txr->dma.tag, txr->dma.map,
255			BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
256
257		/* (re)start the tx unit up to slot nic_i (excluded) */
258		wr32(vsi->hw, txr->tail, nic_i);
259	}
260
261	/*
262	 * Second part: reclaim buffers for completed transmissions.
263	 */
264	nic_i = LE32_TO_CPU(*(volatile __le32 *)&txr->base[que->num_desc]);
265	if (nic_i != txr->next_to_clean) {
266		/* some tx completed, increment avail */
267		txr->next_to_clean = nic_i;
268		kring->nr_hwtail = nm_prev(netmap_idx_n2k(kring, nic_i), lim);
269	}
270
271	nm_txsync_finalize(kring);
272
273	return 0;
274}
275
276
277/*
278 * Reconcile kernel and user view of the receive ring.
279 * Same as for the txsync, this routine must be efficient.
280 * The caller guarantees a single invocations, but races against
281 * the rest of the driver should be handled here.
282 *
283 * On call, kring->rhead is the first packet that userspace wants
284 * to keep, and kring->rcur is the wakeup point.
285 * The kernel has previously reported packets up to kring->rtail.
286 *
287 * If (flags & NAF_FORCE_READ) also check for incoming packets irrespective
288 * of whether or not we received an interrupt.
289 */
290int
291ixl_netmap_rxsync(struct netmap_kring *kring, int flags)
292{
293	struct netmap_adapter *na = kring->na;
294	struct ifnet *ifp = na->ifp;
295	struct netmap_ring *ring = kring->ring;
296	u_int nm_i;	/* index into the netmap ring */
297	u_int nic_i;	/* index into the NIC ring */
298	u_int n;
299	u_int const lim = kring->nkr_num_slots - 1;
300	u_int const head = nm_rxsync_prologue(kring);
301	int force_update = (flags & NAF_FORCE_READ) || kring->nr_kflags & NKR_PENDINTR;
302
303	/* device-specific */
304	struct ixl_vsi *vsi = ifp->if_softc;
305	struct ixl_queue *que = &vsi->queues[kring->ring_id];
306	struct rx_ring *rxr = &que->rxr;
307
308	if (head > lim)
309		return netmap_ring_reinit(kring);
310
311	/* XXX check sync modes */
312	bus_dmamap_sync(rxr->dma.tag, rxr->dma.map,
313			BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
314
315	/*
316	 * First part: import newly received packets.
317	 *
318	 * nm_i is the index of the next free slot in the netmap ring,
319	 * nic_i is the index of the next received packet in the NIC ring,
320	 * and they may differ in case if_init() has been called while
321	 * in netmap mode. For the receive ring we have
322	 *
323	 *	nic_i = rxr->next_check;
324	 *	nm_i = kring->nr_hwtail (previous)
325	 * and
326	 *	nm_i == (nic_i + kring->nkr_hwofs) % ring_size
327	 *
328	 * rxr->next_check is set to 0 on a ring reinit
329	 */
330	if (netmap_no_pendintr || force_update) {
331		int crclen = ixl_crcstrip ? 0 : 4;
332		uint16_t slot_flags = kring->nkr_slot_flags;
333
334		nic_i = rxr->next_check; // or also k2n(kring->nr_hwtail)
335		nm_i = netmap_idx_n2k(kring, nic_i);
336
337		for (n = 0; ; n++) {
338			union i40e_32byte_rx_desc *curr = &rxr->base[nic_i];
339			uint64_t qword = le64toh(curr->wb.qword1.status_error_len);
340			uint32_t staterr = (qword & I40E_RXD_QW1_STATUS_MASK)
341				 >> I40E_RXD_QW1_STATUS_SHIFT;
342
343			if ((staterr & (1<<I40E_RX_DESC_STATUS_DD_SHIFT)) == 0)
344				break;
345			ring->slot[nm_i].len = ((qword & I40E_RXD_QW1_LENGTH_PBUF_MASK)
346			    >> I40E_RXD_QW1_LENGTH_PBUF_SHIFT) - crclen;
347			ring->slot[nm_i].flags = slot_flags;
348			bus_dmamap_sync(rxr->ptag,
349			    rxr->buffers[nic_i].pmap, BUS_DMASYNC_POSTREAD);
350			nm_i = nm_next(nm_i, lim);
351			nic_i = nm_next(nic_i, lim);
352		}
353		if (n) { /* update the state variables */
354			if (netmap_no_pendintr && !force_update) {
355				/* diagnostics */
356				ixl_rx_miss ++;
357				ixl_rx_miss_bufs += n;
358			}
359			rxr->next_check = nic_i;
360			kring->nr_hwtail = nm_i;
361		}
362		kring->nr_kflags &= ~NKR_PENDINTR;
363	}
364
365	/*
366	 * Second part: skip past packets that userspace has released.
367	 * (kring->nr_hwcur to head excluded),
368	 * and make the buffers available for reception.
369	 * As usual nm_i is the index in the netmap ring,
370	 * nic_i is the index in the NIC ring, and
371	 * nm_i == (nic_i + kring->nkr_hwofs) % ring_size
372	 */
373	nm_i = kring->nr_hwcur;
374	if (nm_i != head) {
375		nic_i = netmap_idx_k2n(kring, nm_i);
376		for (n = 0; nm_i != head; n++) {
377			struct netmap_slot *slot = &ring->slot[nm_i];
378			uint64_t paddr;
379			void *addr = PNMB(na, slot, &paddr);
380
381			union i40e_32byte_rx_desc *curr = &rxr->base[nic_i];
382			struct ixl_rx_buf *rxbuf = &rxr->buffers[nic_i];
383
384			if (addr == NETMAP_BUF_BASE(na)) /* bad buf */
385				goto ring_reset;
386
387			if (slot->flags & NS_BUF_CHANGED) {
388				/* buffer has changed, reload map */
389				netmap_reload_map(na, rxr->ptag, rxbuf->pmap, addr);
390				slot->flags &= ~NS_BUF_CHANGED;
391			}
392			curr->read.pkt_addr = htole64(paddr);
393			curr->read.hdr_addr = 0; // XXX needed
394			bus_dmamap_sync(rxr->ptag, rxbuf->pmap,
395			    BUS_DMASYNC_PREREAD);
396			nm_i = nm_next(nm_i, lim);
397			nic_i = nm_next(nic_i, lim);
398		}
399		kring->nr_hwcur = head;
400
401		bus_dmamap_sync(rxr->dma.tag, rxr->dma.map,
402		    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
403		/*
404		 * IMPORTANT: we must leave one free slot in the ring,
405		 * so move nic_i back by one unit
406		 */
407		nic_i = nm_prev(nic_i, lim);
408		wr32(vsi->hw, rxr->tail, nic_i);
409	}
410
411	/* tell userspace that there might be new packets */
412	nm_rxsync_finalize(kring);
413
414	return 0;
415
416ring_reset:
417	return netmap_ring_reinit(kring);
418}
419
420#endif /* !NETMAP_IXL_MAIN */
421
422/* end of file */
423