1 /* SPDX-License-Identifier: BSD-3-Clause */
2 /* Copyright (c) 2021, 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:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice,
9 * this list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * 3. Neither the name of the Intel Corporation nor the names of its
16 * contributors may be used to endorse or promote products derived from
17 * this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
20 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
23 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31 /*$FreeBSD$*/
32
33 /**
34 * @file ice_common_txrx.h
35 * @brief common Tx/Rx utility functions
36 *
37 * Contains common utility functions for the Tx/Rx hot path.
38 *
39 * The functions do depend on the if_pkt_info_t structure. A suitable
40 * implementation of this structure must be provided if these functions are to
41 * be used without the iflib networking stack.
42 */
43
44 #ifndef _ICE_COMMON_TXRX_H_
45 #define _ICE_COMMON_TXRX_H_
46
47 #include <netinet/udp.h>
48 #include <netinet/sctp.h>
49
50 /**
51 * ice_tso_detect_sparse - detect TSO packets with too many segments
52 * @pi: packet information
53 *
54 * Hardware only transmits packets with a maximum of 8 descriptors. For TSO
55 * packets, hardware needs to be able to build the split packets using 8 or
56 * fewer descriptors. Additionally, the header must be contained within at
57 * most 3 descriptors.
58 *
59 * To verify this, we walk the headers to find out how many descriptors the
60 * headers require (usually 1). Then we ensure that, for each TSO segment, its
61 * data plus the headers are contained within 8 or fewer descriptors.
62 */
63 static inline int
64 ice_tso_detect_sparse(if_pkt_info_t pi)
65 {
66 int count, curseg, i, hlen, segsz, seglen, tsolen, hdrs, maxsegs;
67 bus_dma_segment_t *segs = pi->ipi_segs;
68 int nsegs = pi->ipi_nsegs;
69
70 curseg = hdrs = 0;
71
72 hlen = pi->ipi_ehdrlen + pi->ipi_ip_hlen + pi->ipi_tcp_hlen;
73 tsolen = pi->ipi_len - hlen;
74
75 /* First, count the number of descriptors for the header.
76 * Additionally, make sure it does not span more than 3 segments.
77 */
78 i = 0;
79 curseg = segs[0].ds_len;
80 while (hlen > 0) {
81 hdrs++;
82 if (hdrs > ICE_MAX_TSO_HDR_SEGS)
83 return (1);
84 if (curseg == 0) {
85 i++;
86 if (__predict_false(i == nsegs))
87 return (1);
88
89 curseg = segs[i].ds_len;
90 }
91 seglen = min(curseg, hlen);
92 curseg -= seglen;
93 hlen -= seglen;
94 }
95
96 maxsegs = ICE_MAX_TX_SEGS - hdrs;
97
98 /* We must count the headers, in order to verify that they take up
99 * 3 or fewer descriptors. However, we don't need to check the data
100 * if the total segments is small.
101 */
102 if (nsegs <= maxsegs)
103 return (0);
104
105 count = 0;
106
107 /* Now check the data to make sure that each TSO segment is made up of
108 * no more than maxsegs descriptors. This ensures that hardware will
109 * be capable of performing TSO offload.
110 */
111 while (tsolen > 0) {
112 segsz = pi->ipi_tso_segsz;
113 while (segsz > 0 && tsolen != 0) {
114 count++;
115 if (count > maxsegs) {
116 return (1);
117 }
118 if (curseg == 0) {
119 i++;
120 if (__predict_false(i == nsegs)) {
121 return (1);
122 }
123 curseg = segs[i].ds_len;
124 }
125 seglen = min(curseg, segsz);
126 segsz -= seglen;
127 curseg -= seglen;
128 tsolen -= seglen;
129 }
130 count = 0;
131 }
132
133 return (0);
134 }
135
136 /**
137 * ice_tso_setup - Setup a context descriptor to prepare for a TSO packet
138 * @txq: the Tx queue to use
139 * @pi: the packet info to prepare for
140 *
141 * Setup a context descriptor in preparation for sending a Tx packet that
142 * requires the TSO offload. Returns the index of the descriptor to use when
143 * encapsulating the Tx packet data into descriptors.
144 */
145 static inline int
146 ice_tso_setup(struct ice_tx_queue *txq, if_pkt_info_t pi)
147 {
148 struct ice_tx_ctx_desc *txd;
149 u32 cmd, mss, type, tsolen;
150 int idx;
151 u64 type_cmd_tso_mss;
152
153 idx = pi->ipi_pidx;
154 txd = (struct ice_tx_ctx_desc *)&txq->tx_base[idx];
155 tsolen = pi->ipi_len - (pi->ipi_ehdrlen + pi->ipi_ip_hlen + pi->ipi_tcp_hlen);
156
157 type = ICE_TX_DESC_DTYPE_CTX;
158 cmd = ICE_TX_CTX_DESC_TSO;
159 /* TSO MSS must not be less than 64 */
160 if (pi->ipi_tso_segsz < ICE_MIN_TSO_MSS) {
161 txq->stats.mss_too_small++;
162 pi->ipi_tso_segsz = ICE_MIN_TSO_MSS;
163 }
164 mss = pi->ipi_tso_segsz;
165
166 type_cmd_tso_mss = ((u64)type << ICE_TXD_CTX_QW1_DTYPE_S) |
167 ((u64)cmd << ICE_TXD_CTX_QW1_CMD_S) |
168 ((u64)tsolen << ICE_TXD_CTX_QW1_TSO_LEN_S) |
169 ((u64)mss << ICE_TXD_CTX_QW1_MSS_S);
170 txd->qw1 = htole64(type_cmd_tso_mss);
171
172 txd->tunneling_params = htole32(0);
173 txq->tso++;
174
175 return ((idx + 1) & (txq->desc_count-1));
176 }
177
178 /**
179 * ice_tx_setup_offload - Setup register values for performing a Tx offload
180 * @txq: The Tx queue, used to track checksum offload stats
181 * @pi: the packet info to program for
182 * @cmd: the cmd register value to update
183 * @off: the off register value to update
184 *
185 * Based on the packet info provided, update the cmd and off values for
186 * enabling Tx offloads. This depends on the packet type and which offloads
187 * have been requested.
188 *
189 * We also track the total number of times that we've requested hardware
190 * offload a particular type of checksum for debugging purposes.
191 */
192 static inline void
193 ice_tx_setup_offload(struct ice_tx_queue *txq, if_pkt_info_t pi, u32 *cmd, u32 *off)
194 {
195 u32 remaining_csum_flags = pi->ipi_csum_flags;
196
197 switch (pi->ipi_etype) {
198 #ifdef INET
199 case ETHERTYPE_IP:
200 if (pi->ipi_csum_flags & ICE_CSUM_IP) {
201 *cmd |= ICE_TX_DESC_CMD_IIPT_IPV4_CSUM;
202 txq->stats.cso[ICE_CSO_STAT_TX_IP4]++;
203 remaining_csum_flags &= ~CSUM_IP;
204 } else
205 *cmd |= ICE_TX_DESC_CMD_IIPT_IPV4;
206 break;
207 #endif
208 #ifdef INET6
209 case ETHERTYPE_IPV6:
210 *cmd |= ICE_TX_DESC_CMD_IIPT_IPV6;
211 /*
212 * This indicates that the IIPT flag was set to the IPV6 value;
213 * there's no checksum for IPv6 packets.
214 */
215 txq->stats.cso[ICE_CSO_STAT_TX_IP6]++;
216 break;
217 #endif
218 default:
219 txq->stats.cso[ICE_CSO_STAT_TX_L3_ERR]++;
220 break;
221 }
222
223 *off |= (pi->ipi_ehdrlen >> 1) << ICE_TX_DESC_LEN_MACLEN_S;
224 *off |= (pi->ipi_ip_hlen >> 2) << ICE_TX_DESC_LEN_IPLEN_S;
225
226 if (!(remaining_csum_flags & ~ICE_RX_CSUM_FLAGS))
227 return;
228
229 switch (pi->ipi_ipproto) {
230 case IPPROTO_TCP:
231 if (pi->ipi_csum_flags & ICE_CSUM_TCP) {
232 *cmd |= ICE_TX_DESC_CMD_L4T_EOFT_TCP;
233 *off |= (pi->ipi_tcp_hlen >> 2) <<
234 ICE_TX_DESC_LEN_L4_LEN_S;
235 txq->stats.cso[ICE_CSO_STAT_TX_TCP]++;
236 }
237 break;
238 case IPPROTO_UDP:
239 if (pi->ipi_csum_flags & ICE_CSUM_UDP) {
240 *cmd |= ICE_TX_DESC_CMD_L4T_EOFT_UDP;
241 *off |= (sizeof(struct udphdr) >> 2) <<
242 ICE_TX_DESC_LEN_L4_LEN_S;
243 txq->stats.cso[ICE_CSO_STAT_TX_UDP]++;
244 }
245 break;
246 case IPPROTO_SCTP:
247 if (pi->ipi_csum_flags & ICE_CSUM_SCTP) {
248 *cmd |= ICE_TX_DESC_CMD_L4T_EOFT_SCTP;
249 *off |= (sizeof(struct sctphdr) >> 2) <<
250 ICE_TX_DESC_LEN_L4_LEN_S;
251 txq->stats.cso[ICE_CSO_STAT_TX_SCTP]++;
252 }
253 break;
254 default:
255 txq->stats.cso[ICE_CSO_STAT_TX_L4_ERR]++;
256 break;
257 }
258 }
259
260 /**
261 * ice_rx_checksum - verify hardware checksum is valid or not
262 * @rxq: the Rx queue structure
263 * @flags: checksum flags to update
264 * @data: checksum data to update
265 * @status0: descriptor status data
266 * @ptype: packet type
267 *
268 * Determine whether the hardware indicated that the Rx checksum is valid. If
269 * so, update the checksum flags and data, informing the stack of the status
270 * of the checksum so that it does not spend time verifying it manually.
271 */
272 static void
273 ice_rx_checksum(struct ice_rx_queue *rxq, uint32_t *flags, uint32_t *data,
274 u16 status0, u16 ptype)
275 {
276 const u16 l3_error = (BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_IPE_S) |
277 BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_EIPE_S));
278 const u16 l4_error = (BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_L4E_S) |
279 BIT(ICE_RX_FLEX_DESC_STATUS0_XSUM_EUDPE_S));
280 const u16 xsum_errors = (l3_error | l4_error |
281 BIT(ICE_RX_FLEX_DESC_STATUS0_IPV6EXADD_S));
282 struct ice_rx_ptype_decoded decoded;
283 bool is_ipv4, is_ipv6;
284
285 /* No L3 or L4 checksum was calculated */
286 if (!(status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_L3L4P_S))) {
287 return;
288 }
289
290 decoded = ice_decode_rx_desc_ptype(ptype);
291 *flags = 0;
292
293 if (!(decoded.known && decoded.outer_ip))
294 return;
295
296 is_ipv4 = (decoded.outer_ip == ICE_RX_PTYPE_OUTER_IP) &&
297 (decoded.outer_ip_ver == ICE_RX_PTYPE_OUTER_IPV4);
298 is_ipv6 = (decoded.outer_ip == ICE_RX_PTYPE_OUTER_IP) &&
299 (decoded.outer_ip_ver == ICE_RX_PTYPE_OUTER_IPV6);
300
301 /* No checksum errors were reported */
302 if (!(status0 & xsum_errors)) {
303 if (is_ipv4)
304 *flags |= CSUM_L3_CALC | CSUM_L3_VALID;
305
306 switch (decoded.inner_prot) {
307 case ICE_RX_PTYPE_INNER_PROT_TCP:
308 case ICE_RX_PTYPE_INNER_PROT_UDP:
309 case ICE_RX_PTYPE_INNER_PROT_SCTP:
310 *flags |= CSUM_L4_CALC | CSUM_L4_VALID;
311 *data |= htons(0xffff);
312 break;
313 default:
314 break;
315 }
316
317 return;
318 }
319
320 /*
321 * Certain IPv6 extension headers impact the validity of L4 checksums.
322 * If one of these headers exist, hardware will set the IPV6EXADD bit
323 * in the descriptor. If the bit is set then pretend like hardware
324 * didn't checksum this packet.
325 */
326 if (is_ipv6 && (status0 & BIT(ICE_RX_FLEX_DESC_STATUS0_IPV6EXADD_S))) {
327 rxq->stats.cso[ICE_CSO_STAT_RX_IP6_ERR]++;
328 return;
329 }
330
331 /*
332 * At this point, status0 must have at least one of the l3_error or
333 * l4_error bits set.
334 */
335
336 if (status0 & l3_error) {
337 if (is_ipv4) {
338 rxq->stats.cso[ICE_CSO_STAT_RX_IP4_ERR]++;
339 *flags |= CSUM_L3_CALC;
340 } else {
341 /* Hardware indicated L3 error but this isn't IPv4? */
342 rxq->stats.cso[ICE_CSO_STAT_RX_L3_ERR]++;
343 }
344 /* don't bother reporting L4 errors if we got an L3 error */
345 return;
346 } else if (is_ipv4) {
347 *flags |= CSUM_L3_CALC | CSUM_L3_VALID;
348 }
349
350 if (status0 & l4_error) {
351 switch (decoded.inner_prot) {
352 case ICE_RX_PTYPE_INNER_PROT_TCP:
353 rxq->stats.cso[ICE_CSO_STAT_RX_TCP_ERR]++;
354 *flags |= CSUM_L4_CALC;
355 break;
356 case ICE_RX_PTYPE_INNER_PROT_UDP:
357 rxq->stats.cso[ICE_CSO_STAT_RX_UDP_ERR]++;
358 *flags |= CSUM_L4_CALC;
359 break;
360 case ICE_RX_PTYPE_INNER_PROT_SCTP:
361 rxq->stats.cso[ICE_CSO_STAT_RX_SCTP_ERR]++;
362 *flags |= CSUM_L4_CALC;
363 break;
364 default:
365 /*
366 * Hardware indicated L4 error, but this isn't one of
367 * the expected protocols.
368 */
369 rxq->stats.cso[ICE_CSO_STAT_RX_L4_ERR]++;
370 }
371 }
372 }
373
374 /**
375 * ice_ptype_to_hash - Convert packet type to a hash value
376 * @ptype: the packet type to convert
377 *
378 * Given the packet type, convert to a suitable hashtype to report to the
379 * upper stack via the iri_rsstype value of the if_rxd_info_t structure.
380 *
381 * If the hash type is unknown we'll report M_HASHTYPE_OPAQUE.
382 */
383 static inline int
384 ice_ptype_to_hash(u16 ptype)
385 {
386 struct ice_rx_ptype_decoded decoded;
387
388 if (ptype >= ARRAY_SIZE(ice_ptype_lkup))
389 return M_HASHTYPE_OPAQUE;
390
391 decoded = ice_decode_rx_desc_ptype(ptype);
392
393 if (!decoded.known)
394 return M_HASHTYPE_OPAQUE;
395
396 if (decoded.outer_ip == ICE_RX_PTYPE_OUTER_L2)
397 return M_HASHTYPE_OPAQUE;
398
399 /* Note: anything that gets to this point is IP */
400 if (decoded.outer_ip_ver == ICE_RX_PTYPE_OUTER_IPV6) {
401 switch (decoded.inner_prot) {
402 case ICE_RX_PTYPE_INNER_PROT_TCP:
403 return M_HASHTYPE_RSS_TCP_IPV6;
404 case ICE_RX_PTYPE_INNER_PROT_UDP:
405 return M_HASHTYPE_RSS_UDP_IPV6;
406 default:
407 return M_HASHTYPE_RSS_IPV6;
408 }
409 }
410 if (decoded.outer_ip_ver == ICE_RX_PTYPE_OUTER_IPV4) {
411 switch (decoded.inner_prot) {
412 case ICE_RX_PTYPE_INNER_PROT_TCP:
413 return M_HASHTYPE_RSS_TCP_IPV4;
414 case ICE_RX_PTYPE_INNER_PROT_UDP:
415 return M_HASHTYPE_RSS_UDP_IPV4;
416 default:
417 return M_HASHTYPE_RSS_IPV4;
418 }
419 }
420
421 /* We should never get here!! */
422 return M_HASHTYPE_OPAQUE;
423 }
424 #endif
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