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: stable/11/sys/dev/netmap/if_ixl_netmap.h 359310 2020-03-25 23:06:04Z vmaffione $
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: NIC keeps CRC in rx frames, 1: NIC strips it (default).
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 */
70int ixl_rx_miss, ixl_rx_miss_bufs, ixl_crcstrip = 1;
71SYSCTL_DECL(_dev_netmap);
72/*
73 * The xl driver by default strips CRCs and we do not override it.
74 */
75#if 0
76SYSCTL_INT(_dev_netmap, OID_AUTO, ixl_crcstrip,
77    CTLFLAG_RW, &ixl_crcstrip, 1, "NIC strips CRC on rx frames");
78#endif
79SYSCTL_INT(_dev_netmap, OID_AUTO, ixl_rx_miss,
80    CTLFLAG_RW, &ixl_rx_miss, 0, "potentially missed rx intr");
81SYSCTL_INT(_dev_netmap, OID_AUTO, ixl_rx_miss_bufs,
82    CTLFLAG_RW, &ixl_rx_miss_bufs, 0, "potentially missed rx intr bufs");
83
84
85/*
86 * Register/unregister. We are already under netmap lock.
87 * Only called on the first register or the last unregister.
88 */
89static int
90ixl_netmap_reg(struct netmap_adapter *na, int onoff)
91{
92	struct ifnet *ifp = na->ifp;
93        struct ixl_vsi  *vsi = ifp->if_softc;
94        struct ixl_pf   *pf = (struct ixl_pf *)vsi->back;
95
96	IXL_PF_LOCK(pf);
97	ixl_disable_intr(vsi);
98
99	/* Tell the stack that the interface is no longer active */
100	ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
101
102	//set_crcstrip(&adapter->hw, onoff);
103	/* enable or disable flags and callbacks in na and ifp */
104	if (onoff) {
105		nm_set_native_flags(na);
106	} else {
107		nm_clear_native_flags(na);
108	}
109	ixl_init_locked(pf);	/* also enables intr */
110	//set_crcstrip(&adapter->hw, onoff); // XXX why twice ?
111	IXL_PF_UNLOCK(pf);
112	return (ifp->if_drv_flags & IFF_DRV_RUNNING ? 0 : 1);
113}
114
115
116/*
117 * The attach routine, called near the end of ixl_attach(),
118 * fills the parameters for netmap_attach() and calls it.
119 * It cannot fail, in the worst case (such as no memory)
120 * netmap mode will be disabled and the driver will only
121 * operate in standard mode.
122 */
123static void
124ixl_netmap_attach(struct ixl_vsi *vsi)
125{
126	struct netmap_adapter na;
127
128	bzero(&na, sizeof(na));
129
130	na.ifp = vsi->ifp;
131	na.na_flags = NAF_BDG_MAYSLEEP;
132	na.num_tx_desc = vsi->num_tx_desc;
133	na.num_rx_desc = vsi->num_rx_desc;
134	na.nm_txsync = ixl_netmap_txsync;
135	na.nm_rxsync = ixl_netmap_rxsync;
136	na.nm_register = ixl_netmap_reg;
137	na.num_tx_rings = na.num_rx_rings = vsi->num_queues;
138	netmap_attach(&na);
139}
140
141
142#else /* !NETMAP_IXL_MAIN, code for ixl_txrx.c */
143
144/*
145 * Reconcile kernel and user view of the transmit ring.
146 *
147 * All information is in the kring.
148 * Userspace wants to send packets up to the one before kring->rhead,
149 * kernel knows kring->nr_hwcur is the first unsent packet.
150 *
151 * Here we push packets out (as many as possible), and possibly
152 * reclaim buffers from previously completed transmission.
153 *
154 * The caller (netmap) guarantees that there is only one instance
155 * running at any time. Any interference with other driver
156 * methods should be handled by the individual drivers.
157 */
158int
159ixl_netmap_txsync(struct netmap_kring *kring, int flags)
160{
161	struct netmap_adapter *na = kring->na;
162	struct ifnet *ifp = na->ifp;
163	struct netmap_ring *ring = kring->ring;
164	u_int nm_i;	/* index into the netmap ring */
165	u_int nic_i;	/* index into the NIC ring */
166	u_int n;
167	u_int const lim = kring->nkr_num_slots - 1;
168	u_int const head = kring->rhead;
169	/*
170	 * interrupts on every tx packet are expensive so request
171	 * them every half ring, or where NS_REPORT is set
172	 */
173	u_int report_frequency = kring->nkr_num_slots >> 1;
174
175	/* device-specific */
176	struct ixl_vsi *vsi = ifp->if_softc;
177	struct ixl_queue *que = &vsi->queues[kring->ring_id];
178	struct tx_ring *txr = &que->txr;
179
180	bus_dmamap_sync(txr->dma.tag, txr->dma.map,
181			BUS_DMASYNC_POSTREAD);
182
183	/*
184	 * First part: process new packets to send.
185	 * nm_i is the current index in the netmap ring,
186	 * nic_i is the corresponding index in the NIC ring.
187	 *
188	 * If we have packets to send (nm_i != head)
189	 * iterate over the netmap ring, fetch length and update
190	 * the corresponding slot in the NIC ring. Some drivers also
191	 * need to update the buffer's physical address in the NIC slot
192	 * even NS_BUF_CHANGED is not set (PNMB computes the addresses).
193	 *
194	 * The netmap_reload_map() calls is especially expensive,
195	 * even when (as in this case) the tag is 0, so do only
196	 * when the buffer has actually changed.
197	 *
198	 * If possible do not set the report/intr bit on all slots,
199	 * but only a few times per ring or when NS_REPORT is set.
200	 *
201	 * Finally, on 10G and faster drivers, it might be useful
202	 * to prefetch the next slot and txr entry.
203	 */
204
205	nm_i = kring->nr_hwcur;
206	if (nm_i != head) {	/* we have new packets to send */
207		nic_i = netmap_idx_k2n(kring, nm_i);
208
209		__builtin_prefetch(&ring->slot[nm_i]);
210		__builtin_prefetch(&txr->buffers[nic_i]);
211
212		for (n = 0; nm_i != head; n++) {
213			struct netmap_slot *slot = &ring->slot[nm_i];
214			u_int len = slot->len;
215			uint64_t paddr;
216			void *addr = PNMB(na, slot, &paddr);
217
218			/* device-specific */
219			struct i40e_tx_desc *curr = &txr->base[nic_i];
220			struct ixl_tx_buf *txbuf = &txr->buffers[nic_i];
221			u64 flags = (slot->flags & NS_REPORT ||
222				nic_i == 0 || nic_i == report_frequency) ?
223				((u64)I40E_TX_DESC_CMD_RS << I40E_TXD_QW1_CMD_SHIFT) : 0;
224
225			/* prefetch for next round */
226			__builtin_prefetch(&ring->slot[nm_i + 1]);
227			__builtin_prefetch(&txr->buffers[nic_i + 1]);
228
229			NM_CHECK_ADDR_LEN(na, addr, len);
230
231			if (slot->flags & NS_BUF_CHANGED) {
232				/* buffer has changed, reload map */
233				netmap_reload_map(na, txr->dma.tag, txbuf->map, addr);
234			}
235			slot->flags &= ~(NS_REPORT | NS_BUF_CHANGED);
236
237			/* Fill the slot in the NIC ring. */
238			curr->buffer_addr = htole64(paddr);
239			curr->cmd_type_offset_bsz = htole64(
240			    ((u64)len << I40E_TXD_QW1_TX_BUF_SZ_SHIFT) |
241			    flags |
242			    ((u64)I40E_TX_DESC_CMD_EOP << I40E_TXD_QW1_CMD_SHIFT) |
243			    ((u64)I40E_TX_DESC_CMD_ICRC << I40E_TXD_QW1_CMD_SHIFT)
244			  ); // XXX more ?
245
246			/* make sure changes to the buffer are synced */
247			bus_dmamap_sync(txr->dma.tag, txbuf->map,
248				BUS_DMASYNC_PREWRITE);
249
250			nm_i = nm_next(nm_i, lim);
251			nic_i = nm_next(nic_i, lim);
252		}
253		kring->nr_hwcur = head;
254
255		/* synchronize the NIC ring */
256		bus_dmamap_sync(txr->dma.tag, txr->dma.map,
257			BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
258
259		/* (re)start the tx unit up to slot nic_i (excluded) */
260		wr32(vsi->hw, txr->tail, nic_i);
261	}
262
263	/*
264	 * Second part: reclaim buffers for completed transmissions.
265	 */
266	nic_i = LE32_TO_CPU(*(volatile __le32 *)&txr->base[que->num_tx_desc]);
267	if (unlikely(nic_i >= que->num_tx_desc)) {
268		nm_prerr("error: invalid value of hw head index %u", nic_i);
269	} else if (nic_i != txr->next_to_clean) {
270		/* some tx completed, increment avail */
271		txr->next_to_clean = nic_i;
272		kring->nr_hwtail = nm_prev(netmap_idx_n2k(kring, nic_i), lim);
273	}
274
275	return 0;
276}
277
278
279/*
280 * Reconcile kernel and user view of the receive ring.
281 * Same as for the txsync, this routine must be efficient.
282 * The caller guarantees a single invocations, but races against
283 * the rest of the driver should be handled here.
284 *
285 * On call, kring->rhead is the first packet that userspace wants
286 * to keep, and kring->rcur is the wakeup point.
287 * The kernel has previously reported packets up to kring->rtail.
288 *
289 * If (flags & NAF_FORCE_READ) also check for incoming packets irrespective
290 * of whether or not we received an interrupt.
291 */
292int
293ixl_netmap_rxsync(struct netmap_kring *kring, int flags)
294{
295	struct netmap_adapter *na = kring->na;
296	struct ifnet *ifp = na->ifp;
297	struct netmap_ring *ring = kring->ring;
298	u_int nm_i;	/* index into the netmap ring */
299	u_int nic_i;	/* index into the NIC ring */
300	u_int n;
301	u_int const lim = kring->nkr_num_slots - 1;
302	u_int const head = kring->rhead;
303	int force_update = (flags & NAF_FORCE_READ) || kring->nr_kflags & NKR_PENDINTR;
304
305	/* device-specific */
306	struct ixl_vsi *vsi = ifp->if_softc;
307	struct ixl_queue *que = &vsi->queues[kring->ring_id];
308	struct rx_ring *rxr = &que->rxr;
309
310	if (head > lim)
311		return netmap_ring_reinit(kring);
312
313	/* XXX check sync modes */
314	bus_dmamap_sync(rxr->dma.tag, rxr->dma.map,
315			BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
316
317	/*
318	 * First part: import newly received packets.
319	 *
320	 * nm_i is the index of the next free slot in the netmap ring,
321	 * nic_i is the index of the next received packet in the NIC ring,
322	 * and they may differ in case if_init() has been called while
323	 * in netmap mode. For the receive ring we have
324	 *
325	 *	nic_i = rxr->next_check;
326	 *	nm_i = kring->nr_hwtail (previous)
327	 * and
328	 *	nm_i == (nic_i + kring->nkr_hwofs) % ring_size
329	 *
330	 * rxr->next_check is set to 0 on a ring reinit
331	 */
332	if (netmap_no_pendintr || force_update) {
333		int crclen = ixl_crcstrip ? 0 : 4;
334
335		nic_i = rxr->next_check; // or also k2n(kring->nr_hwtail)
336		nm_i = netmap_idx_n2k(kring, nic_i);
337
338		for (n = 0; ; n++) {
339			union i40e_32byte_rx_desc *curr = &rxr->base[nic_i];
340			uint64_t qword = le64toh(curr->wb.qword1.status_error_len);
341			uint32_t staterr = (qword & I40E_RXD_QW1_STATUS_MASK)
342				 >> I40E_RXD_QW1_STATUS_SHIFT;
343
344			if ((staterr & (1<<I40E_RX_DESC_STATUS_DD_SHIFT)) == 0)
345				break;
346			ring->slot[nm_i].len = ((qword & I40E_RXD_QW1_LENGTH_PBUF_MASK)
347			    >> I40E_RXD_QW1_LENGTH_PBUF_SHIFT) - crclen;
348			ring->slot[nm_i].flags = 0;
349			bus_dmamap_sync(rxr->ptag,
350			    rxr->buffers[nic_i].pmap, BUS_DMASYNC_POSTREAD);
351			nm_i = nm_next(nm_i, lim);
352			nic_i = nm_next(nic_i, lim);
353		}
354		if (n) { /* update the state variables */
355			if (netmap_no_pendintr && !force_update) {
356				/* diagnostics */
357				ixl_rx_miss ++;
358				ixl_rx_miss_bufs += n;
359			}
360			rxr->next_check = nic_i;
361			kring->nr_hwtail = nm_i;
362		}
363		kring->nr_kflags &= ~NKR_PENDINTR;
364	}
365
366	/*
367	 * Second part: skip past packets that userspace has released.
368	 * (kring->nr_hwcur to head excluded),
369	 * and make the buffers available for reception.
370	 * As usual nm_i is the index in the netmap ring,
371	 * nic_i is the index in the NIC ring, and
372	 * nm_i == (nic_i + kring->nkr_hwofs) % ring_size
373	 */
374	nm_i = kring->nr_hwcur;
375	if (nm_i != head) {
376		nic_i = netmap_idx_k2n(kring, nm_i);
377		for (n = 0; nm_i != head; n++) {
378			struct netmap_slot *slot = &ring->slot[nm_i];
379			uint64_t paddr;
380			void *addr = PNMB(na, slot, &paddr);
381
382			union i40e_32byte_rx_desc *curr = &rxr->base[nic_i];
383			struct ixl_rx_buf *rxbuf = &rxr->buffers[nic_i];
384
385			if (addr == NETMAP_BUF_BASE(na)) /* bad buf */
386				goto ring_reset;
387
388			if (slot->flags & NS_BUF_CHANGED) {
389				/* buffer has changed, reload map */
390				netmap_reload_map(na, rxr->ptag, rxbuf->pmap, addr);
391				slot->flags &= ~NS_BUF_CHANGED;
392			}
393			curr->read.pkt_addr = htole64(paddr);
394			curr->read.hdr_addr = 0; // XXX needed
395			bus_dmamap_sync(rxr->ptag, rxbuf->pmap,
396			    BUS_DMASYNC_PREREAD);
397			nm_i = nm_next(nm_i, lim);
398			nic_i = nm_next(nic_i, lim);
399		}
400		kring->nr_hwcur = head;
401
402		bus_dmamap_sync(rxr->dma.tag, rxr->dma.map,
403		    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
404		/*
405		 * IMPORTANT: we must leave one free slot in the ring,
406		 * so move nic_i back by one unit
407		 */
408		nic_i = nm_prev(nic_i, lim);
409		wr32(vsi->hw, rxr->tail, nic_i);
410	}
411
412	return 0;
413
414ring_reset:
415	return netmap_ring_reinit(kring);
416}
417
418#endif /* !NETMAP_IXL_MAIN */
419
420/* end of file */
421