xref: /freebsd/sys/dev/e1000/em_txrx.c (revision 9f23cbd6cae82fd77edfad7173432fa8dccd0a95)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2016 Nicole Graziano <nicole@nextbsd.org>
5  * Copyright (c) 2017 Matthew Macy <mmacy@mattmacy.io>
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 /* $FreeBSD$ */
31 #include "if_em.h"
32 
33 #ifdef RSS
34 #include <net/rss_config.h>
35 #include <netinet/in_rss.h>
36 #endif
37 
38 #ifdef VERBOSE_DEBUG
39 #define DPRINTF device_printf
40 #else
41 #define DPRINTF(...)
42 #endif
43 
44 /*********************************************************************
45  *  Local Function prototypes
46  *********************************************************************/
47 static int em_tso_setup(struct e1000_softc *sc, if_pkt_info_t pi,
48     uint32_t *txd_upper, uint32_t *txd_lower);
49 static int em_transmit_checksum_setup(struct e1000_softc *sc,
50     if_pkt_info_t pi, uint32_t *txd_upper, uint32_t *txd_lower);
51 static int em_isc_txd_encap(void *arg, if_pkt_info_t pi);
52 static void em_isc_txd_flush(void *arg, uint16_t txqid, qidx_t pidx);
53 static int em_isc_txd_credits_update(void *arg, uint16_t txqid, bool clear);
54 static void em_isc_rxd_refill(void *arg, if_rxd_update_t iru);
55 static void em_isc_rxd_flush(void *arg, uint16_t rxqid, uint8_t flid __unused,
56     qidx_t pidx);
57 static int em_isc_rxd_available(void *arg, uint16_t rxqid, qidx_t idx,
58     qidx_t budget);
59 static int em_isc_rxd_pkt_get(void *arg, if_rxd_info_t ri);
60 
61 static void lem_isc_rxd_refill(void *arg, if_rxd_update_t iru);
62 
63 static int lem_isc_rxd_available(void *arg, uint16_t rxqid, qidx_t idx,
64    qidx_t budget);
65 static int lem_isc_rxd_pkt_get(void *arg, if_rxd_info_t ri);
66 
67 static void em_receive_checksum(uint16_t, uint8_t, if_rxd_info_t);
68 static int em_determine_rsstype(uint32_t pkt_info);
69 extern int em_intr(void *arg);
70 
71 struct if_txrx em_txrx = {
72 	.ift_txd_encap = em_isc_txd_encap,
73 	.ift_txd_flush = em_isc_txd_flush,
74 	.ift_txd_credits_update = em_isc_txd_credits_update,
75 	.ift_rxd_available = em_isc_rxd_available,
76 	.ift_rxd_pkt_get = em_isc_rxd_pkt_get,
77 	.ift_rxd_refill = em_isc_rxd_refill,
78 	.ift_rxd_flush = em_isc_rxd_flush,
79 	.ift_legacy_intr = em_intr
80 };
81 
82 struct if_txrx lem_txrx = {
83 	.ift_txd_encap = em_isc_txd_encap,
84 	.ift_txd_flush = em_isc_txd_flush,
85 	.ift_txd_credits_update = em_isc_txd_credits_update,
86 	.ift_rxd_available = lem_isc_rxd_available,
87 	.ift_rxd_pkt_get = lem_isc_rxd_pkt_get,
88 	.ift_rxd_refill = lem_isc_rxd_refill,
89 	.ift_rxd_flush = em_isc_rxd_flush,
90 	.ift_legacy_intr = em_intr
91 };
92 
93 extern if_shared_ctx_t em_sctx;
94 
95 void
96 em_dump_rs(struct e1000_softc *sc)
97 {
98 	if_softc_ctx_t scctx = sc->shared;
99 	struct em_tx_queue *que;
100 	struct tx_ring *txr;
101 	qidx_t i, ntxd, qid, cur;
102 	int16_t rs_cidx;
103 	uint8_t status;
104 
105 	printf("\n");
106 	ntxd = scctx->isc_ntxd[0];
107 	for (qid = 0; qid < sc->tx_num_queues; qid++) {
108 		que = &sc->tx_queues[qid];
109 		txr =  &que->txr;
110 		rs_cidx = txr->tx_rs_cidx;
111 		if (rs_cidx != txr->tx_rs_pidx) {
112 			cur = txr->tx_rsq[rs_cidx];
113 			status = txr->tx_base[cur].upper.fields.status;
114 			if (!(status & E1000_TXD_STAT_DD))
115 				printf("qid[%d]->tx_rsq[%d]: %d clear ", qid, rs_cidx, cur);
116 		} else {
117 			rs_cidx = (rs_cidx-1)&(ntxd-1);
118 			cur = txr->tx_rsq[rs_cidx];
119 			printf("qid[%d]->tx_rsq[rs_cidx-1=%d]: %d  ", qid, rs_cidx, cur);
120 		}
121 		printf("cidx_prev=%d rs_pidx=%d ",txr->tx_cidx_processed,
122 		    txr->tx_rs_pidx);
123 		for (i = 0; i < ntxd; i++) {
124 			if (txr->tx_base[i].upper.fields.status & E1000_TXD_STAT_DD)
125 				printf("%d set ", i);
126 		}
127 		printf("\n");
128 	}
129 }
130 
131 /**********************************************************************
132  *
133  *  Setup work for hardware segmentation offload (TSO) on
134  *  adapters using advanced tx descriptors
135  *
136  **********************************************************************/
137 static int
138 em_tso_setup(struct e1000_softc *sc, if_pkt_info_t pi, uint32_t *txd_upper,
139     uint32_t *txd_lower)
140 {
141 	if_softc_ctx_t scctx = sc->shared;
142 	struct em_tx_queue *que = &sc->tx_queues[pi->ipi_qsidx];
143 	struct tx_ring *txr = &que->txr;
144 	struct e1000_hw *hw = &sc->hw;
145 	struct e1000_context_desc *TXD;
146 	int cur, hdr_len;
147 	uint32_t cmd_type_len;
148 
149 	hdr_len = pi->ipi_ehdrlen + pi->ipi_ip_hlen + pi->ipi_tcp_hlen;
150 	*txd_lower = (E1000_TXD_CMD_DEXT |	/* Extended descr type */
151 		      E1000_TXD_DTYP_D |	/* Data descr type */
152 		      E1000_TXD_CMD_TSE);	/* Do TSE on this packet */
153 
154 	/* IP and/or TCP header checksum calculation and insertion. */
155 	*txd_upper = (E1000_TXD_POPTS_IXSM | E1000_TXD_POPTS_TXSM) << 8;
156 
157 	cur = pi->ipi_pidx;
158 	TXD = (struct e1000_context_desc *)&txr->tx_base[cur];
159 
160 	/*
161 	 * Start offset for header checksum calculation.
162 	 * End offset for header checksum calculation.
163 	 * Offset of place put the checksum.
164 	 */
165 	TXD->lower_setup.ip_fields.ipcss = pi->ipi_ehdrlen;
166 	TXD->lower_setup.ip_fields.ipcse =
167 	    htole16(pi->ipi_ehdrlen + pi->ipi_ip_hlen - 1);
168 	TXD->lower_setup.ip_fields.ipcso =
169 	    pi->ipi_ehdrlen + offsetof(struct ip, ip_sum);
170 
171 	/*
172 	 * Start offset for payload checksum calculation.
173 	 * End offset for payload checksum calculation.
174 	 * Offset of place to put the checksum.
175 	 */
176 	TXD->upper_setup.tcp_fields.tucss = pi->ipi_ehdrlen + pi->ipi_ip_hlen;
177 	TXD->upper_setup.tcp_fields.tucse = 0;
178 	TXD->upper_setup.tcp_fields.tucso =
179 	    pi->ipi_ehdrlen + pi->ipi_ip_hlen + offsetof(struct tcphdr, th_sum);
180 
181 	/*
182 	 * Payload size per packet w/o any headers.
183 	 * Length of all headers up to payload.
184 	 */
185 	TXD->tcp_seg_setup.fields.mss = htole16(pi->ipi_tso_segsz);
186 	TXD->tcp_seg_setup.fields.hdr_len = hdr_len;
187 
188 	/*
189 	 * 8254x SDM4.0 page 45, and PCIe GbE SDM2.5 page 63
190 	 * - Set up basic TUCMDs
191 	 * - Enable IP bit on 82544
192 	 * - For others IP bit on indicates IPv4, while off indicates IPv6
193 	*/
194 	cmd_type_len = sc->txd_cmd |
195 	    E1000_TXD_CMD_DEXT | /* Extended descr */
196 	    E1000_TXD_CMD_TSE |  /* TSE context */
197 	    E1000_TXD_CMD_TCP;   /* Do TCP checksum */
198 	if (hw->mac.type == e1000_82544)
199 		cmd_type_len |= E1000_TXD_CMD_IP;
200 	else if (pi->ipi_etype == ETHERTYPE_IP)
201 		cmd_type_len |= E1000_TXD_CMD_IP;
202 	TXD->cmd_and_length = htole32(cmd_type_len |
203 	    (pi->ipi_len - hdr_len)); /* Total len */
204 
205 	txr->tx_tso = true;
206 
207 	if (++cur == scctx->isc_ntxd[0]) {
208 		cur = 0;
209 	}
210 	DPRINTF(iflib_get_dev(sc->ctx), "%s: pidx: %d cur: %d\n", __FUNCTION__,
211 	    pi->ipi_pidx, cur);
212 	return (cur);
213 }
214 
215 #define TSO_WORKAROUND 4
216 #define DONT_FORCE_CTX 1
217 
218 
219 /*********************************************************************
220  *  The offload context is protocol specific (TCP/UDP) and thus
221  *  only needs to be set when the protocol changes. The occasion
222  *  of a context change can be a performance detriment, and
223  *  might be better just disabled. The reason arises in the way
224  *  in which the controller supports pipelined requests from the
225  *  Tx data DMA. Up to four requests can be pipelined, and they may
226  *  belong to the same packet or to multiple packets. However all
227  *  requests for one packet are issued before a request is issued
228  *  for a subsequent packet and if a request for the next packet
229  *  requires a context change, that request will be stalled
230  *  until the previous request completes. This means setting up
231  *  a new context effectively disables pipelined Tx data DMA which
232  *  in turn greatly slow down performance to send small sized
233  *  frames.
234  **********************************************************************/
235 
236 static int
237 em_transmit_checksum_setup(struct e1000_softc *sc, if_pkt_info_t pi,
238     uint32_t *txd_upper, uint32_t *txd_lower)
239 {
240 	struct e1000_context_desc *TXD = NULL;
241 	if_softc_ctx_t scctx = sc->shared;
242 	struct em_tx_queue *que = &sc->tx_queues[pi->ipi_qsidx];
243 	struct tx_ring *txr = &que->txr;
244 	int csum_flags = pi->ipi_csum_flags;
245 	int cur, hdr_len;
246 	uint32_t cmd;
247 
248 	cur = pi->ipi_pidx;
249 	hdr_len = pi->ipi_ehdrlen + pi->ipi_ip_hlen;
250 	cmd = sc->txd_cmd;
251 
252 	/*
253 	 * The 82574L can only remember the *last* context used
254 	 * regardless of queue that it was use for.  We cannot reuse
255 	 * contexts on this hardware platform and must generate a new
256 	 * context every time.  82574L hardware spec, section 7.2.6,
257 	 * second note.
258 	 */
259 	if (DONT_FORCE_CTX &&
260 	    sc->tx_num_queues == 1 &&
261 	    txr->csum_lhlen == pi->ipi_ehdrlen &&
262 	    txr->csum_iphlen == pi->ipi_ip_hlen &&
263 	    txr->csum_flags == csum_flags) {
264 		/*
265 		 * Same csum offload context as the previous packets;
266 		 * just return.
267 		 */
268 		*txd_upper = txr->csum_txd_upper;
269 		*txd_lower = txr->csum_txd_lower;
270 		return (cur);
271 	}
272 
273 	TXD = (struct e1000_context_desc *)&txr->tx_base[cur];
274 	if (csum_flags & CSUM_IP) {
275 		*txd_upper |= E1000_TXD_POPTS_IXSM << 8;
276 		/*
277 		 * Start offset for header checksum calculation.
278 		 * End offset for header checksum calculation.
279 		 * Offset of place to put the checksum.
280 		 */
281 		TXD->lower_setup.ip_fields.ipcss = pi->ipi_ehdrlen;
282 		TXD->lower_setup.ip_fields.ipcse = htole16(hdr_len);
283 		TXD->lower_setup.ip_fields.ipcso = pi->ipi_ehdrlen +
284 		    offsetof(struct ip, ip_sum);
285 		cmd |= E1000_TXD_CMD_IP;
286 	}
287 
288 	if (csum_flags & (CSUM_TCP|CSUM_UDP)) {
289 		uint8_t tucso;
290 
291 		*txd_upper |= E1000_TXD_POPTS_TXSM << 8;
292 		*txd_lower = E1000_TXD_CMD_DEXT | E1000_TXD_DTYP_D;
293 
294 		if (csum_flags & CSUM_TCP) {
295 			tucso = hdr_len + offsetof(struct tcphdr, th_sum);
296 			cmd |= E1000_TXD_CMD_TCP;
297 		} else
298 			tucso = hdr_len + offsetof(struct udphdr, uh_sum);
299 		TXD->upper_setup.tcp_fields.tucss = hdr_len;
300 		TXD->upper_setup.tcp_fields.tucse = htole16(0);
301 		TXD->upper_setup.tcp_fields.tucso = tucso;
302 	}
303 
304 	txr->csum_lhlen = pi->ipi_ehdrlen;
305 	txr->csum_iphlen = pi->ipi_ip_hlen;
306 	txr->csum_flags = csum_flags;
307 	txr->csum_txd_upper = *txd_upper;
308 	txr->csum_txd_lower = *txd_lower;
309 
310 	TXD->tcp_seg_setup.data = htole32(0);
311 	TXD->cmd_and_length =
312 		htole32(E1000_TXD_CMD_IFCS | E1000_TXD_CMD_DEXT | cmd);
313 
314 	if (++cur == scctx->isc_ntxd[0]) {
315 		cur = 0;
316 	}
317 	DPRINTF(iflib_get_dev(sc->ctx),
318 	    "checksum_setup csum_flags=%x txd_upper=%x txd_lower=%x hdr_len=%d cmd=%x\n",
319 	    csum_flags, *txd_upper, *txd_lower, hdr_len, cmd);
320 	return (cur);
321 }
322 
323 static int
324 em_isc_txd_encap(void *arg, if_pkt_info_t pi)
325 {
326 	struct e1000_softc *sc = arg;
327 	if_softc_ctx_t scctx = sc->shared;
328 	struct em_tx_queue *que = &sc->tx_queues[pi->ipi_qsidx];
329 	struct tx_ring *txr = &que->txr;
330 	bus_dma_segment_t *segs = pi->ipi_segs;
331 	int nsegs = pi->ipi_nsegs;
332 	int csum_flags = pi->ipi_csum_flags;
333 	int i, j, first, pidx_last;
334 	uint32_t txd_flags, txd_upper = 0, txd_lower = 0;
335 
336 	struct e1000_tx_desc *ctxd = NULL;
337 	bool do_tso, tso_desc;
338 	qidx_t ntxd;
339 
340 	txd_flags = pi->ipi_flags & IPI_TX_INTR ? E1000_TXD_CMD_RS : 0;
341 	i = first = pi->ipi_pidx;
342 	do_tso = (csum_flags & CSUM_TSO);
343 	tso_desc = false;
344 	ntxd = scctx->isc_ntxd[0];
345 	/*
346 	 * TSO Hardware workaround, if this packet is not
347 	 * TSO, and is only a single descriptor long, and
348 	 * it follows a TSO burst, then we need to add a
349 	 * sentinel descriptor to prevent premature writeback.
350 	 */
351 	if ((!do_tso) && (txr->tx_tso == true)) {
352 		if (nsegs == 1)
353 			tso_desc = true;
354 		txr->tx_tso = false;
355 	}
356 
357 	/* Do hardware assists */
358 	if (do_tso) {
359 		i = em_tso_setup(sc, pi, &txd_upper, &txd_lower);
360 		tso_desc = true;
361 	} else if (csum_flags & EM_CSUM_OFFLOAD) {
362 		i = em_transmit_checksum_setup(sc, pi, &txd_upper, &txd_lower);
363 	}
364 
365 	if (pi->ipi_mflags & M_VLANTAG) {
366 		/* Set the vlan id. */
367 		txd_upper |= htole16(pi->ipi_vtag) << 16;
368 		/* Tell hardware to add tag */
369 		txd_lower |= htole32(E1000_TXD_CMD_VLE);
370 	}
371 
372 	DPRINTF(iflib_get_dev(sc->ctx),
373 	    "encap: set up tx: nsegs=%d first=%d i=%d\n", nsegs, first, i);
374 	/* XXX sc->pcix_82544 -- lem_fill_descriptors */
375 
376 	/* Set up our transmit descriptors */
377 	for (j = 0; j < nsegs; j++) {
378 		bus_size_t seg_len;
379 		bus_addr_t seg_addr;
380 		uint32_t cmd;
381 
382 		ctxd = &txr->tx_base[i];
383 		seg_addr = segs[j].ds_addr;
384 		seg_len = segs[j].ds_len;
385 		cmd = E1000_TXD_CMD_IFCS | sc->txd_cmd;
386 
387 		/*
388 		 * TSO Workaround:
389 		 * If this is the last descriptor, we want to
390 		 * split it so we have a small final sentinel
391 		 */
392 		if (tso_desc && (j == (nsegs - 1)) && (seg_len > 8)) {
393 			seg_len -= TSO_WORKAROUND;
394 			ctxd->buffer_addr = htole64(seg_addr);
395 			ctxd->lower.data = htole32(cmd | txd_lower | seg_len);
396 			ctxd->upper.data = htole32(txd_upper);
397 
398 			if (++i == scctx->isc_ntxd[0])
399 				i = 0;
400 
401 			/* Now make the sentinel */
402 			ctxd = &txr->tx_base[i];
403 			ctxd->buffer_addr = htole64(seg_addr + seg_len);
404 			ctxd->lower.data = htole32(cmd | txd_lower | TSO_WORKAROUND);
405 			ctxd->upper.data = htole32(txd_upper);
406 			pidx_last = i;
407 			if (++i == scctx->isc_ntxd[0])
408 				i = 0;
409 			DPRINTF(iflib_get_dev(sc->ctx),
410 			    "TSO path pidx_last=%d i=%d ntxd[0]=%d\n",
411 			    pidx_last, i, scctx->isc_ntxd[0]);
412 		} else {
413 			ctxd->buffer_addr = htole64(seg_addr);
414 			ctxd->lower.data = htole32(cmd | txd_lower | seg_len);
415 			ctxd->upper.data = htole32(txd_upper);
416 			pidx_last = i;
417 			if (++i == scctx->isc_ntxd[0])
418 				i = 0;
419 			DPRINTF(iflib_get_dev(sc->ctx), "pidx_last=%d i=%d ntxd[0]=%d\n",
420 			    pidx_last, i, scctx->isc_ntxd[0]);
421 		}
422 	}
423 
424 	/*
425 	 * Last Descriptor of Packet
426 	 * needs End Of Packet (EOP)
427 	 * and Report Status (RS)
428 	 */
429 	if (txd_flags && nsegs) {
430 		txr->tx_rsq[txr->tx_rs_pidx] = pidx_last;
431 		DPRINTF(iflib_get_dev(sc->ctx),
432 		    "setting to RS on %d rs_pidx %d first: %d\n",
433 		    pidx_last, txr->tx_rs_pidx, first);
434 		txr->tx_rs_pidx = (txr->tx_rs_pidx+1) & (ntxd-1);
435 		MPASS(txr->tx_rs_pidx != txr->tx_rs_cidx);
436 	}
437 	ctxd->lower.data |= htole32(E1000_TXD_CMD_EOP | txd_flags);
438 	DPRINTF(iflib_get_dev(sc->ctx),
439 	    "tx_buffers[%d]->eop = %d ipi_new_pidx=%d\n", first, pidx_last, i);
440 	pi->ipi_new_pidx = i;
441 
442 	return (0);
443 }
444 
445 static void
446 em_isc_txd_flush(void *arg, uint16_t txqid, qidx_t pidx)
447 {
448 	struct e1000_softc *sc = arg;
449 	struct em_tx_queue *que = &sc->tx_queues[txqid];
450 	struct tx_ring *txr = &que->txr;
451 
452 	E1000_WRITE_REG(&sc->hw, E1000_TDT(txr->me), pidx);
453 }
454 
455 static int
456 em_isc_txd_credits_update(void *arg, uint16_t txqid, bool clear)
457 {
458 	struct e1000_softc *sc = arg;
459 	if_softc_ctx_t scctx = sc->shared;
460 	struct em_tx_queue *que = &sc->tx_queues[txqid];
461 	struct tx_ring *txr = &que->txr;
462 
463 	qidx_t processed = 0;
464 	int updated;
465 	qidx_t cur, prev, ntxd, rs_cidx;
466 	int32_t delta;
467 	uint8_t status;
468 
469 	rs_cidx = txr->tx_rs_cidx;
470 	if (rs_cidx == txr->tx_rs_pidx)
471 		return (0);
472 	cur = txr->tx_rsq[rs_cidx];
473 	MPASS(cur != QIDX_INVALID);
474 	status = txr->tx_base[cur].upper.fields.status;
475 	updated = !!(status & E1000_TXD_STAT_DD);
476 
477 	if (!updated)
478 		return (0);
479 
480 	/* If clear is false just let caller know that there
481 	 * are descriptors to reclaim */
482 	if (!clear)
483 		return (1);
484 
485 	prev = txr->tx_cidx_processed;
486 	ntxd = scctx->isc_ntxd[0];
487 	do {
488 		MPASS(prev != cur);
489 		delta = (int32_t)cur - (int32_t)prev;
490 		if (delta < 0)
491 			delta += ntxd;
492 		MPASS(delta > 0);
493 		DPRINTF(iflib_get_dev(sc->ctx),
494 			      "%s: cidx_processed=%u cur=%u clear=%d delta=%d\n",
495 			      __FUNCTION__, prev, cur, clear, delta);
496 
497 		processed += delta;
498 		prev  = cur;
499 		rs_cidx = (rs_cidx + 1) & (ntxd-1);
500 		if (rs_cidx  == txr->tx_rs_pidx)
501 			break;
502 		cur = txr->tx_rsq[rs_cidx];
503 		MPASS(cur != QIDX_INVALID);
504 		status = txr->tx_base[cur].upper.fields.status;
505 	} while ((status & E1000_TXD_STAT_DD));
506 
507 	txr->tx_rs_cidx = rs_cidx;
508 	txr->tx_cidx_processed = prev;
509 	return(processed);
510 }
511 
512 static void
513 lem_isc_rxd_refill(void *arg, if_rxd_update_t iru)
514 {
515 	struct e1000_softc *sc = arg;
516 	if_softc_ctx_t scctx = sc->shared;
517 	struct em_rx_queue *que = &sc->rx_queues[iru->iru_qsidx];
518 	struct rx_ring *rxr = &que->rxr;
519 	struct e1000_rx_desc *rxd;
520 	uint64_t *paddrs;
521 	uint32_t next_pidx, pidx;
522 	uint16_t count;
523 	int i;
524 
525 	paddrs = iru->iru_paddrs;
526 	pidx = iru->iru_pidx;
527 	count = iru->iru_count;
528 
529 	for (i = 0, next_pidx = pidx; i < count; i++) {
530 		rxd = (struct e1000_rx_desc *)&rxr->rx_base[next_pidx];
531 		rxd->buffer_addr = htole64(paddrs[i]);
532 		/* status bits must be cleared */
533 		rxd->status = 0;
534 
535 		if (++next_pidx == scctx->isc_nrxd[0])
536 			next_pidx = 0;
537 	}
538 }
539 
540 static void
541 em_isc_rxd_refill(void *arg, if_rxd_update_t iru)
542 {
543 	struct e1000_softc *sc = arg;
544 	if_softc_ctx_t scctx = sc->shared;
545 	uint16_t rxqid = iru->iru_qsidx;
546 	struct em_rx_queue *que = &sc->rx_queues[rxqid];
547 	struct rx_ring *rxr = &que->rxr;
548 	union e1000_rx_desc_extended *rxd;
549 	uint64_t *paddrs;
550 	uint32_t next_pidx, pidx;
551 	uint16_t count;
552 	int i;
553 
554 	paddrs = iru->iru_paddrs;
555 	pidx = iru->iru_pidx;
556 	count = iru->iru_count;
557 
558 	for (i = 0, next_pidx = pidx; i < count; i++) {
559 		rxd = &rxr->rx_base[next_pidx];
560 		rxd->read.buffer_addr = htole64(paddrs[i]);
561 		/* DD bits must be cleared */
562 		rxd->wb.upper.status_error = 0;
563 
564 		if (++next_pidx == scctx->isc_nrxd[0])
565 			next_pidx = 0;
566 	}
567 }
568 
569 static void
570 em_isc_rxd_flush(void *arg, uint16_t rxqid, uint8_t flid __unused,
571     qidx_t pidx)
572 {
573 	struct e1000_softc *sc = arg;
574 	struct em_rx_queue *que = &sc->rx_queues[rxqid];
575 	struct rx_ring *rxr = &que->rxr;
576 
577 	E1000_WRITE_REG(&sc->hw, E1000_RDT(rxr->me), pidx);
578 }
579 
580 static int
581 lem_isc_rxd_available(void *arg, uint16_t rxqid, qidx_t idx, qidx_t budget)
582 {
583 	struct e1000_softc *sc = arg;
584 	if_softc_ctx_t scctx = sc->shared;
585 	struct em_rx_queue *que = &sc->rx_queues[rxqid];
586 	struct rx_ring *rxr = &que->rxr;
587 	struct e1000_rx_desc *rxd;
588 	uint32_t staterr = 0;
589 	int cnt, i;
590 
591 	for (cnt = 0, i = idx; cnt < scctx->isc_nrxd[0] && cnt <= budget;) {
592 		rxd = (struct e1000_rx_desc *)&rxr->rx_base[i];
593 		staterr = rxd->status;
594 
595 		if ((staterr & E1000_RXD_STAT_DD) == 0)
596 			break;
597 		if (++i == scctx->isc_nrxd[0])
598 			i = 0;
599 		if (staterr & E1000_RXD_STAT_EOP)
600 			cnt++;
601 	}
602 	return (cnt);
603 }
604 
605 static int
606 em_isc_rxd_available(void *arg, uint16_t rxqid, qidx_t idx, qidx_t budget)
607 {
608 	struct e1000_softc *sc = arg;
609 	if_softc_ctx_t scctx = sc->shared;
610 	struct em_rx_queue *que = &sc->rx_queues[rxqid];
611 	struct rx_ring *rxr = &que->rxr;
612 	union e1000_rx_desc_extended *rxd;
613 	uint32_t staterr = 0;
614 	int cnt, i;
615 
616 	for (cnt = 0, i = idx; cnt < scctx->isc_nrxd[0] && cnt <= budget;) {
617 		rxd = &rxr->rx_base[i];
618 		staterr = le32toh(rxd->wb.upper.status_error);
619 
620 		if ((staterr & E1000_RXD_STAT_DD) == 0)
621 			break;
622 		if (++i == scctx->isc_nrxd[0])
623 			i = 0;
624 		if (staterr & E1000_RXD_STAT_EOP)
625 			cnt++;
626 	}
627 	return (cnt);
628 }
629 
630 static int
631 lem_isc_rxd_pkt_get(void *arg, if_rxd_info_t ri)
632 {
633 	struct e1000_softc *sc = arg;
634 	if_softc_ctx_t scctx = sc->shared;
635 	struct em_rx_queue *que = &sc->rx_queues[ri->iri_qsidx];
636 	struct rx_ring *rxr = &que->rxr;
637 	struct e1000_rx_desc *rxd;
638 	uint16_t len;
639 	uint32_t status, errors;
640 	bool eop;
641 	int i, cidx;
642 
643 	status = errors = i = 0;
644 	cidx = ri->iri_cidx;
645 
646 	do {
647 		rxd = (struct e1000_rx_desc *)&rxr->rx_base[cidx];
648 		status = rxd->status;
649 		errors = rxd->errors;
650 
651 		/* Error Checking then decrement count */
652 		MPASS ((status & E1000_RXD_STAT_DD) != 0);
653 
654 		len = le16toh(rxd->length);
655 		ri->iri_len += len;
656 
657 		eop = (status & E1000_RXD_STAT_EOP) != 0;
658 
659 		/* Make sure bad packets are discarded */
660 		if (errors & E1000_RXD_ERR_FRAME_ERR_MASK) {
661 			sc->dropped_pkts++;
662 			/* XXX fixup if common */
663 			return (EBADMSG);
664 		}
665 
666 		ri->iri_frags[i].irf_flid = 0;
667 		ri->iri_frags[i].irf_idx = cidx;
668 		ri->iri_frags[i].irf_len = len;
669 		/* Zero out the receive descriptors status. */
670 		rxd->status = 0;
671 
672 		if (++cidx == scctx->isc_nrxd[0])
673 			cidx = 0;
674 		i++;
675 	} while (!eop);
676 
677 	if (scctx->isc_capenable & IFCAP_RXCSUM)
678 		em_receive_checksum(status, errors, ri);
679 
680 	if (scctx->isc_capenable & IFCAP_VLAN_HWTAGGING &&
681 	    status & E1000_RXD_STAT_VP) {
682 		ri->iri_vtag = le16toh(rxd->special & E1000_RXD_SPC_VLAN_MASK);
683 		ri->iri_flags |= M_VLANTAG;
684 	}
685 
686 	ri->iri_nfrags = i;
687 
688 	return (0);
689 }
690 
691 static int
692 em_isc_rxd_pkt_get(void *arg, if_rxd_info_t ri)
693 {
694 	struct e1000_softc *sc = arg;
695 	if_softc_ctx_t scctx = sc->shared;
696 	struct em_rx_queue *que = &sc->rx_queues[ri->iri_qsidx];
697 	struct rx_ring *rxr = &que->rxr;
698 	union e1000_rx_desc_extended *rxd;
699 
700 	uint16_t len;
701 	uint32_t pkt_info;
702 	uint32_t staterr;
703 	bool eop;
704 	int i, cidx;
705 
706 	staterr = i = 0;
707 	cidx = ri->iri_cidx;
708 
709 	do {
710 		rxd = &rxr->rx_base[cidx];
711 		staterr = le32toh(rxd->wb.upper.status_error);
712 		pkt_info = le32toh(rxd->wb.lower.mrq);
713 
714 		/* Error Checking then decrement count */
715 		MPASS ((staterr & E1000_RXD_STAT_DD) != 0);
716 
717 		len = le16toh(rxd->wb.upper.length);
718 		ri->iri_len += len;
719 
720 		eop = (staterr & E1000_RXD_STAT_EOP) != 0;
721 
722 		/* Make sure bad packets are discarded */
723 		if (staterr & E1000_RXDEXT_ERR_FRAME_ERR_MASK) {
724 			sc->dropped_pkts++;
725 			return EBADMSG;
726 		}
727 
728 		ri->iri_frags[i].irf_flid = 0;
729 		ri->iri_frags[i].irf_idx = cidx;
730 		ri->iri_frags[i].irf_len = len;
731 		/* Zero out the receive descriptors status. */
732 		rxd->wb.upper.status_error &= htole32(~0xFF);
733 
734 		if (++cidx == scctx->isc_nrxd[0])
735 			cidx = 0;
736 		i++;
737 	} while (!eop);
738 
739 	if (scctx->isc_capenable & IFCAP_RXCSUM)
740 		em_receive_checksum(staterr, staterr >> 24, ri);
741 
742 	if (scctx->isc_capenable & IFCAP_VLAN_HWTAGGING &&
743 	    staterr & E1000_RXD_STAT_VP) {
744 		ri->iri_vtag = le16toh(rxd->wb.upper.vlan);
745 		ri->iri_flags |= M_VLANTAG;
746 	}
747 
748 	ri->iri_flowid = le32toh(rxd->wb.lower.hi_dword.rss);
749 	ri->iri_rsstype = em_determine_rsstype(pkt_info);
750 
751 	ri->iri_nfrags = i;
752 	return (0);
753 }
754 
755 /*********************************************************************
756  *
757  *  Verify that the hardware indicated that the checksum is valid.
758  *  Inform the stack about the status of checksum so that stack
759  *  doesn't spend time verifying the checksum.
760  *
761  *********************************************************************/
762 static void
763 em_receive_checksum(uint16_t status, uint8_t errors, if_rxd_info_t ri)
764 {
765 	if (__predict_false(status & E1000_RXD_STAT_IXSM))
766 		return;
767 
768 	/* If there is a layer 3 or 4 error we are done */
769 	if (__predict_false(errors & (E1000_RXD_ERR_IPE | E1000_RXD_ERR_TCPE)))
770 		return;
771 
772 	/* IP Checksum Good */
773 	if (status & E1000_RXD_STAT_IPCS)
774 		ri->iri_csum_flags = (CSUM_IP_CHECKED | CSUM_IP_VALID);
775 
776 	/* Valid L4E checksum */
777 	if (__predict_true(status &
778 	    (E1000_RXD_STAT_TCPCS | E1000_RXD_STAT_UDPCS))) {
779 		ri->iri_csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
780 		ri->iri_csum_data = htons(0xffff);
781 	}
782 }
783 
784 /********************************************************************
785  *
786  *  Parse the packet type to determine the appropriate hash
787  *
788  ******************************************************************/
789 static int
790 em_determine_rsstype(uint32_t pkt_info)
791 {
792 	switch (pkt_info & E1000_RXDADV_RSSTYPE_MASK) {
793 	case E1000_RXDADV_RSSTYPE_IPV4_TCP:
794 		return M_HASHTYPE_RSS_TCP_IPV4;
795 	case E1000_RXDADV_RSSTYPE_IPV4:
796 		return M_HASHTYPE_RSS_IPV4;
797 	case E1000_RXDADV_RSSTYPE_IPV6_TCP:
798 		return M_HASHTYPE_RSS_TCP_IPV6;
799 	case E1000_RXDADV_RSSTYPE_IPV6_EX:
800 		return M_HASHTYPE_RSS_IPV6_EX;
801 	case E1000_RXDADV_RSSTYPE_IPV6:
802 		return M_HASHTYPE_RSS_IPV6;
803 	case E1000_RXDADV_RSSTYPE_IPV6_TCP_EX:
804 		return M_HASHTYPE_RSS_TCP_IPV6_EX;
805 	default:
806 		return M_HASHTYPE_OPAQUE;
807 	}
808 }
809