xref: /freebsd/sys/dev/ice/ice_iflib_txrx.c (revision 3cbb4cc200f8a0ad7ed08233425ea54524a21f1c)
1 /* SPDX-License-Identifier: BSD-3-Clause */
2 /*  Copyright (c) 2020, Intel Corporation
3  *  All rights reserved.
4  *
5  *  Redistribution and use in source and binary forms, with or without
6  *  modification, are permitted provided that the following conditions are met:
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9  *      this list of conditions and the following disclaimer.
10  *
11  *   2. Redistributions in binary form must reproduce the above copyright
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13  *      documentation and/or other materials provided with the distribution.
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15  *   3. Neither the name of the Intel Corporation nor the names of its
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17  *      this software without specific prior written permission.
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29  *  POSSIBILITY OF SUCH DAMAGE.
30  */
31 /*$FreeBSD$*/
32 
33 /**
34  * @file ice_iflib_txrx.c
35  * @brief iflib Tx/Rx hotpath
36  *
37  * Main location for the iflib Tx/Rx hotpath implementation.
38  *
39  * Contains the implementation for the iflib function callbacks and the
40  * if_txrx ops structure.
41  */
42 
43 #include "ice_iflib.h"
44 
45 /* Tx/Rx hotpath utility functions */
46 #include "ice_common_txrx.h"
47 
48 /*
49  * iflib txrx method declarations
50  */
51 static int ice_ift_txd_encap(void *arg, if_pkt_info_t pi);
52 static int ice_ift_rxd_pkt_get(void *arg, if_rxd_info_t ri);
53 static void ice_ift_txd_flush(void *arg, uint16_t txqid, qidx_t pidx);
54 static int ice_ift_txd_credits_update(void *arg, uint16_t txqid, bool clear);
55 static int ice_ift_rxd_available(void *arg, uint16_t rxqid, qidx_t pidx, qidx_t budget);
56 static void ice_ift_rxd_flush(void *arg, uint16_t rxqid, uint8_t flidx, qidx_t pidx);
57 static void ice_ift_rxd_refill(void *arg, if_rxd_update_t iru);
58 
59 /* Macro to help extract the NIC mode flexible Rx descriptor fields from the
60  * advanced 32byte Rx descriptors.
61  */
62 #define RX_FLEX_NIC(desc, field) \
63 	(((struct ice_32b_rx_flex_desc_nic *)desc)->field)
64 
65 /**
66  * @var ice_txrx
67  * @brief Tx/Rx operations for the iflib stack
68  *
69  * Structure defining the Tx and Rx related operations that iflib can request
70  * the driver to perform. These are the main entry points for the hot path of
71  * the transmit and receive paths in the iflib driver.
72  */
73 struct if_txrx ice_txrx = {
74 	.ift_txd_encap = ice_ift_txd_encap,
75 	.ift_txd_flush = ice_ift_txd_flush,
76 	.ift_txd_credits_update = ice_ift_txd_credits_update,
77 	.ift_rxd_available = ice_ift_rxd_available,
78 	.ift_rxd_pkt_get = ice_ift_rxd_pkt_get,
79 	.ift_rxd_refill = ice_ift_rxd_refill,
80 	.ift_rxd_flush = ice_ift_rxd_flush,
81 };
82 
83 /**
84  * ice_ift_txd_encap - prepare Tx descriptors for a packet
85  * @arg: the iflib softc structure pointer
86  * @pi: packet info
87  *
88  * Prepares and encapsulates the given packet into into Tx descriptors, in
89  * preparation for sending to the transmit engine. Sets the necessary context
90  * descriptors for TSO and other offloads, and prepares the last descriptor
91  * for the writeback status.
92  *
93  * Return 0 on success, non-zero error code on failure.
94  */
95 static int
96 ice_ift_txd_encap(void *arg, if_pkt_info_t pi)
97 {
98 	struct ice_softc *sc = (struct ice_softc *)arg;
99 	struct ice_tx_queue *txq = &sc->pf_vsi.tx_queues[pi->ipi_qsidx];
100 	int nsegs = pi->ipi_nsegs;
101 	bus_dma_segment_t *segs = pi->ipi_segs;
102 	struct ice_tx_desc *txd = NULL;
103 	int i, j, mask, pidx_last;
104 	u32 cmd, off;
105 
106 	cmd = off = 0;
107 	i = pi->ipi_pidx;
108 
109 	/* Set up the TSO/CSUM offload */
110 	if (pi->ipi_csum_flags & ICE_CSUM_OFFLOAD) {
111 		/* Set up the TSO context descriptor if required */
112 		if (pi->ipi_csum_flags & CSUM_TSO) {
113 			if (ice_tso_detect_sparse(pi))
114 				return (EFBIG);
115 			i = ice_tso_setup(txq, pi);
116 		}
117 		ice_tx_setup_offload(txq, pi, &cmd, &off);
118 	}
119 	if (pi->ipi_mflags & M_VLANTAG)
120 		cmd |= ICE_TX_DESC_CMD_IL2TAG1;
121 
122 	mask = txq->desc_count - 1;
123 	for (j = 0; j < nsegs; j++) {
124 		bus_size_t seglen;
125 
126 		txd = &txq->tx_base[i];
127 		seglen = segs[j].ds_len;
128 
129 		txd->buf_addr = htole64(segs[j].ds_addr);
130 		txd->cmd_type_offset_bsz =
131 		    htole64(ICE_TX_DESC_DTYPE_DATA
132 		    | ((u64)cmd  << ICE_TXD_QW1_CMD_S)
133 		    | ((u64)off << ICE_TXD_QW1_OFFSET_S)
134 		    | ((u64)seglen  << ICE_TXD_QW1_TX_BUF_SZ_S)
135 		    | ((u64)htole16(pi->ipi_vtag) << ICE_TXD_QW1_L2TAG1_S));
136 
137 		txq->stats.tx_bytes += seglen;
138 		pidx_last = i;
139 		i = (i+1) & mask;
140 	}
141 
142 	/* Set the last descriptor for report */
143 #define ICE_TXD_CMD (ICE_TX_DESC_CMD_EOP | ICE_TX_DESC_CMD_RS)
144 	txd->cmd_type_offset_bsz |=
145 	    htole64(((u64)ICE_TXD_CMD << ICE_TXD_QW1_CMD_S));
146 
147 	/* Add to report status array */
148 	txq->tx_rsq[txq->tx_rs_pidx] = pidx_last;
149 	txq->tx_rs_pidx = (txq->tx_rs_pidx+1) & mask;
150 	MPASS(txq->tx_rs_pidx != txq->tx_rs_cidx);
151 
152 	pi->ipi_new_pidx = i;
153 
154 	++txq->stats.tx_packets;
155 	return (0);
156 }
157 
158 /**
159  * ice_ift_txd_flush - Flush Tx descriptors to hardware
160  * @arg: device specific softc pointer
161  * @txqid: the Tx queue to flush
162  * @pidx: descriptor index to advance tail to
163  *
164  * Advance the Transmit Descriptor Tail (TDT). This indicates to hardware that
165  * frames are available for transmit.
166  */
167 static void
168 ice_ift_txd_flush(void *arg, uint16_t txqid, qidx_t pidx)
169 {
170 	struct ice_softc *sc = (struct ice_softc *)arg;
171 	struct ice_tx_queue *txq = &sc->pf_vsi.tx_queues[txqid];
172 	struct ice_hw *hw = &sc->hw;
173 
174 	wr32(hw, txq->tail, pidx);
175 }
176 
177 /**
178  * ice_ift_txd_credits_update - cleanup Tx descriptors
179  * @arg: device private softc
180  * @txqid: the Tx queue to update
181  * @clear: if false, only report, do not actually clean
182  *
183  * If clear is false, iflib is asking if we *could* clean up any Tx
184  * descriptors.
185  *
186  * If clear is true, iflib is requesting to cleanup and reclaim used Tx
187  * descriptors.
188  */
189 static int
190 ice_ift_txd_credits_update(void *arg, uint16_t txqid, bool clear)
191 {
192 	struct ice_softc *sc = (struct ice_softc *)arg;
193 	struct ice_tx_queue *txq = &sc->pf_vsi.tx_queues[txqid];
194 
195 	qidx_t processed = 0;
196 	qidx_t cur, prev, ntxd, rs_cidx;
197 	int32_t delta;
198 	bool is_done;
199 
200 	rs_cidx = txq->tx_rs_cidx;
201 	if (rs_cidx == txq->tx_rs_pidx)
202 		return (0);
203 	cur = txq->tx_rsq[rs_cidx];
204 	MPASS(cur != QIDX_INVALID);
205 	is_done = ice_is_tx_desc_done(&txq->tx_base[cur]);
206 
207 	if (!is_done)
208 		return (0);
209 	else if (clear == false)
210 		return (1);
211 
212 	prev = txq->tx_cidx_processed;
213 	ntxd = txq->desc_count;
214 	do {
215 		MPASS(prev != cur);
216 		delta = (int32_t)cur - (int32_t)prev;
217 		if (delta < 0)
218 			delta += ntxd;
219 		MPASS(delta > 0);
220 		processed += delta;
221 		prev = cur;
222 		rs_cidx = (rs_cidx + 1) & (ntxd-1);
223 		if (rs_cidx == txq->tx_rs_pidx)
224 			break;
225 		cur = txq->tx_rsq[rs_cidx];
226 		MPASS(cur != QIDX_INVALID);
227 		is_done = ice_is_tx_desc_done(&txq->tx_base[cur]);
228 	} while (is_done);
229 
230 	txq->tx_rs_cidx = rs_cidx;
231 	txq->tx_cidx_processed = prev;
232 
233 	return (processed);
234 }
235 
236 /**
237  * ice_ift_rxd_available - Return number of available Rx packets
238  * @arg: device private softc
239  * @rxqid: the Rx queue id
240  * @pidx: descriptor start point
241  * @budget: maximum Rx budget
242  *
243  * Determines how many Rx packets are available on the queue, up to a maximum
244  * of the given budget.
245  */
246 static int
247 ice_ift_rxd_available(void *arg, uint16_t rxqid, qidx_t pidx, qidx_t budget)
248 {
249 	struct ice_softc *sc = (struct ice_softc *)arg;
250 	struct ice_rx_queue *rxq = &sc->pf_vsi.rx_queues[rxqid];
251 	union ice_32b_rx_flex_desc *rxd;
252 	uint16_t status0;
253 	int cnt, i, nrxd;
254 
255 	nrxd = rxq->desc_count;
256 
257 	for (cnt = 0, i = pidx; cnt < nrxd - 1 && cnt < budget;) {
258 		rxd = &rxq->rx_base[i];
259 		status0 = le16toh(rxd->wb.status_error0);
260 
261 		if ((status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_DD_S)) == 0)
262 			break;
263 		if (++i == nrxd)
264 			i = 0;
265 		if (status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_EOF_S))
266 			cnt++;
267 	}
268 
269 	return (cnt);
270 }
271 
272 /**
273  * ice_ift_rxd_pkt_get - Called by iflib to send data to upper layer
274  * @arg: device specific softc
275  * @ri: receive packet info
276  *
277  * This function is called by iflib, and executes in ithread context. It is
278  * called by iflib to obtain data which has been DMA'ed into host memory.
279  * Returns zero on success, and an error code on failure.
280  */
281 static int
282 ice_ift_rxd_pkt_get(void *arg, if_rxd_info_t ri)
283 {
284 	struct ice_softc *sc = (struct ice_softc *)arg;
285 	struct ice_rx_queue *rxq = &sc->pf_vsi.rx_queues[ri->iri_qsidx];
286 	union ice_32b_rx_flex_desc *cur;
287 	u16 status0, plen, vtag, ptype;
288 	bool eop;
289 	size_t cidx;
290 	int i;
291 
292 	cidx = ri->iri_cidx;
293 	i = 0;
294 	do {
295 		/* 5 descriptor receive limit */
296 		MPASS(i < ICE_MAX_RX_SEGS);
297 
298 		cur = &rxq->rx_base[cidx];
299 		status0 = le16toh(cur->wb.status_error0);
300 		plen = le16toh(cur->wb.pkt_len) &
301 			ICE_RX_FLX_DESC_PKT_LEN_M;
302 		ptype = le16toh(cur->wb.ptype_flex_flags0) &
303 			ICE_RX_FLEX_DESC_PTYPE_M;
304 
305 		/* we should never be called without a valid descriptor */
306 		MPASS((status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_DD_S)) != 0);
307 
308 		ri->iri_len += plen;
309 
310 		cur->wb.status_error0 = 0;
311 		eop = (status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_EOF_S));
312 		if (status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_L2TAG1P_S))
313 			vtag = le16toh(cur->wb.l2tag1);
314 		else
315 			vtag = 0;
316 
317 		/*
318 		 * Make sure packets with bad L2 values are discarded.
319 		 * NOTE: Only the EOP descriptor has valid error results.
320 		 */
321 		if (eop && (status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_RXE_S))) {
322 			rxq->stats.desc_errs++;
323 			return (EBADMSG);
324 		}
325 		ri->iri_frags[i].irf_flid = 0;
326 		ri->iri_frags[i].irf_idx = cidx;
327 		ri->iri_frags[i].irf_len = plen;
328 		if (++cidx == rxq->desc_count)
329 			cidx = 0;
330 		i++;
331 	} while (!eop);
332 
333 	/* capture soft statistics for this Rx queue */
334 	rxq->stats.rx_packets++;
335 	rxq->stats.rx_bytes += ri->iri_len;
336 
337 	if ((iflib_get_ifp(sc->ctx)->if_capenable & IFCAP_RXCSUM) != 0)
338 		ice_rx_checksum(rxq, &ri->iri_csum_flags,
339 				&ri->iri_csum_data, status0, ptype);
340 	ri->iri_flowid = le32toh(RX_FLEX_NIC(&cur->wb, rss_hash));
341 	ri->iri_rsstype = ice_ptype_to_hash(ptype);
342 	ri->iri_vtag = vtag;
343 	ri->iri_nfrags = i;
344 	if (vtag)
345 		ri->iri_flags |= M_VLANTAG;
346 	return (0);
347 }
348 
349 /**
350  * ice_ift_rxd_refill - Prepare Rx descriptors for re-use by hardware
351  * @arg: device specific softc structure
352  * @iru: the Rx descriptor update structure
353  *
354  * Update the Rx descriptor indices for a given queue, assigning new physical
355  * addresses to the descriptors, preparing them for re-use by the hardware.
356  */
357 static void
358 ice_ift_rxd_refill(void *arg, if_rxd_update_t iru)
359 {
360 	struct ice_softc *sc = (struct ice_softc *)arg;
361 	struct ice_rx_queue *rxq;
362 	uint32_t next_pidx;
363 	int i;
364 	uint64_t *paddrs;
365 	uint32_t pidx;
366 	uint16_t qsidx, count;
367 
368 	paddrs = iru->iru_paddrs;
369 	pidx = iru->iru_pidx;
370 	qsidx = iru->iru_qsidx;
371 	count = iru->iru_count;
372 
373 	rxq = &(sc->pf_vsi.rx_queues[qsidx]);
374 
375 	for (i = 0, next_pidx = pidx; i < count; i++) {
376 		rxq->rx_base[next_pidx].read.pkt_addr = htole64(paddrs[i]);
377 		if (++next_pidx == (uint32_t)rxq->desc_count)
378 			next_pidx = 0;
379 	}
380 }
381 
382 /**
383  * ice_ift_rxd_flush - Flush Rx descriptors to hardware
384  * @arg: device specific softc pointer
385  * @rxqid: the Rx queue to flush
386  * @flidx: unused parameter
387  * @pidx: descriptor index to advance tail to
388  *
389  * Advance the Receive Descriptor Tail (RDT). This indicates to hardware that
390  * software is done with the descriptor and it can be recycled.
391  */
392 static void
393 ice_ift_rxd_flush(void *arg, uint16_t rxqid, uint8_t flidx __unused,
394 		  qidx_t pidx)
395 {
396 	struct ice_softc *sc = (struct ice_softc *)arg;
397 	struct ice_rx_queue *rxq = &sc->pf_vsi.rx_queues[rxqid];
398 	struct ice_hw *hw = &sc->hw;
399 
400 	wr32(hw, rxq->tail, pidx);
401 }
402