1 // SPDX-License-Identifier: GPL-2.0-only
2 /****************************************************************************
3  * Driver for Solarflare network controllers and boards
4  * Copyright 2022 Advanced Micro Devices, Inc.
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License version 2 as published
8  * by the Free Software Foundation, incorporated herein by reference.
9  */
10 
11 #include "tc_counters.h"
12 #include "mae_counter_format.h"
13 #include "mae.h"
14 #include "rx_common.h"
15 
16 /* Counter-management hashtables */
17 
18 static const struct rhashtable_params efx_tc_counter_id_ht_params = {
19 	.key_len	= offsetof(struct efx_tc_counter_index, linkage),
20 	.key_offset	= 0,
21 	.head_offset	= offsetof(struct efx_tc_counter_index, linkage),
22 };
23 
24 static const struct rhashtable_params efx_tc_counter_ht_params = {
25 	.key_len	= offsetof(struct efx_tc_counter, linkage),
26 	.key_offset	= 0,
27 	.head_offset	= offsetof(struct efx_tc_counter, linkage),
28 };
29 
30 static void efx_tc_counter_free(void *ptr, void *__unused)
31 {
32 	struct efx_tc_counter *cnt = ptr;
33 
34 	kfree(cnt);
35 }
36 
37 static void efx_tc_counter_id_free(void *ptr, void *__unused)
38 {
39 	struct efx_tc_counter_index *ctr = ptr;
40 
41 	WARN_ON(refcount_read(&ctr->ref));
42 	kfree(ctr);
43 }
44 
45 int efx_tc_init_counters(struct efx_nic *efx)
46 {
47 	int rc;
48 
49 	rc = rhashtable_init(&efx->tc->counter_id_ht, &efx_tc_counter_id_ht_params);
50 	if (rc < 0)
51 		goto fail_counter_id_ht;
52 	rc = rhashtable_init(&efx->tc->counter_ht, &efx_tc_counter_ht_params);
53 	if (rc < 0)
54 		goto fail_counter_ht;
55 	return 0;
56 fail_counter_ht:
57 	rhashtable_destroy(&efx->tc->counter_id_ht);
58 fail_counter_id_ht:
59 	return rc;
60 }
61 
62 /* Only call this in init failure teardown.
63  * Normal exit should fini instead as there may be entries in the table.
64  */
65 void efx_tc_destroy_counters(struct efx_nic *efx)
66 {
67 	rhashtable_destroy(&efx->tc->counter_ht);
68 	rhashtable_destroy(&efx->tc->counter_id_ht);
69 }
70 
71 void efx_tc_fini_counters(struct efx_nic *efx)
72 {
73 	rhashtable_free_and_destroy(&efx->tc->counter_id_ht, efx_tc_counter_id_free, NULL);
74 	rhashtable_free_and_destroy(&efx->tc->counter_ht, efx_tc_counter_free, NULL);
75 }
76 
77 /* Counter allocation */
78 
79 static struct efx_tc_counter *efx_tc_flower_allocate_counter(struct efx_nic *efx,
80 							     int type)
81 {
82 	struct efx_tc_counter *cnt;
83 	int rc, rc2;
84 
85 	cnt = kzalloc(sizeof(*cnt), GFP_USER);
86 	if (!cnt)
87 		return ERR_PTR(-ENOMEM);
88 
89 	spin_lock_init(&cnt->lock);
90 	cnt->touched = jiffies;
91 	cnt->type = type;
92 
93 	rc = efx_mae_allocate_counter(efx, cnt);
94 	if (rc)
95 		goto fail1;
96 	rc = rhashtable_insert_fast(&efx->tc->counter_ht, &cnt->linkage,
97 				    efx_tc_counter_ht_params);
98 	if (rc)
99 		goto fail2;
100 	return cnt;
101 fail2:
102 	/* If we get here, it implies that we couldn't insert into the table,
103 	 * which in turn probably means that the fw_id was already taken.
104 	 * In that case, it's unclear whether we really 'own' the fw_id; but
105 	 * the firmware seemed to think we did, so it's proper to free it.
106 	 */
107 	rc2 = efx_mae_free_counter(efx, cnt);
108 	if (rc2)
109 		netif_warn(efx, hw, efx->net_dev,
110 			   "Failed to free MAE counter %u, rc %d\n",
111 			   cnt->fw_id, rc2);
112 fail1:
113 	kfree(cnt);
114 	return ERR_PTR(rc > 0 ? -EIO : rc);
115 }
116 
117 static void efx_tc_flower_release_counter(struct efx_nic *efx,
118 					  struct efx_tc_counter *cnt)
119 {
120 	int rc;
121 
122 	rhashtable_remove_fast(&efx->tc->counter_ht, &cnt->linkage,
123 			       efx_tc_counter_ht_params);
124 	rc = efx_mae_free_counter(efx, cnt);
125 	if (rc)
126 		netif_warn(efx, hw, efx->net_dev,
127 			   "Failed to free MAE counter %u, rc %d\n",
128 			   cnt->fw_id, rc);
129 	/* This doesn't protect counter updates coming in arbitrarily long
130 	 * after we deleted the counter.  The RCU just ensures that we won't
131 	 * free the counter while another thread has a pointer to it.
132 	 * Ensuring we don't update the wrong counter if the ID gets re-used
133 	 * is handled by the generation count.
134 	 */
135 	synchronize_rcu();
136 	EFX_WARN_ON_PARANOID(spin_is_locked(&cnt->lock));
137 	kfree(cnt);
138 }
139 
140 static struct efx_tc_counter *efx_tc_flower_find_counter_by_fw_id(
141 				struct efx_nic *efx, int type, u32 fw_id)
142 {
143 	struct efx_tc_counter key = {};
144 
145 	key.fw_id = fw_id;
146 	key.type = type;
147 
148 	return rhashtable_lookup_fast(&efx->tc->counter_ht, &key,
149 				      efx_tc_counter_ht_params);
150 }
151 
152 /* TC cookie to counter mapping */
153 
154 void efx_tc_flower_put_counter_index(struct efx_nic *efx,
155 				     struct efx_tc_counter_index *ctr)
156 {
157 	if (!refcount_dec_and_test(&ctr->ref))
158 		return; /* still in use */
159 	rhashtable_remove_fast(&efx->tc->counter_id_ht, &ctr->linkage,
160 			       efx_tc_counter_id_ht_params);
161 	efx_tc_flower_release_counter(efx, ctr->cnt);
162 	kfree(ctr);
163 }
164 
165 struct efx_tc_counter_index *efx_tc_flower_get_counter_index(
166 				struct efx_nic *efx, unsigned long cookie,
167 				enum efx_tc_counter_type type)
168 {
169 	struct efx_tc_counter_index *ctr, *old;
170 	struct efx_tc_counter *cnt;
171 
172 	ctr = kzalloc(sizeof(*ctr), GFP_USER);
173 	if (!ctr)
174 		return ERR_PTR(-ENOMEM);
175 	ctr->cookie = cookie;
176 	old = rhashtable_lookup_get_insert_fast(&efx->tc->counter_id_ht,
177 						&ctr->linkage,
178 						efx_tc_counter_id_ht_params);
179 	if (old) {
180 		/* don't need our new entry */
181 		kfree(ctr);
182 		if (!refcount_inc_not_zero(&old->ref))
183 			return ERR_PTR(-EAGAIN);
184 		/* existing entry found */
185 		ctr = old;
186 	} else {
187 		cnt = efx_tc_flower_allocate_counter(efx, type);
188 		if (IS_ERR(cnt)) {
189 			rhashtable_remove_fast(&efx->tc->counter_id_ht,
190 					       &ctr->linkage,
191 					       efx_tc_counter_id_ht_params);
192 			kfree(ctr);
193 			return (void *)cnt; /* it's an ERR_PTR */
194 		}
195 		ctr->cnt = cnt;
196 		refcount_set(&ctr->ref, 1);
197 	}
198 	return ctr;
199 }
200 
201 struct efx_tc_counter_index *efx_tc_flower_find_counter_index(
202 				struct efx_nic *efx, unsigned long cookie)
203 {
204 	struct efx_tc_counter_index key = {};
205 
206 	key.cookie = cookie;
207 	return rhashtable_lookup_fast(&efx->tc->counter_id_ht, &key,
208 				      efx_tc_counter_id_ht_params);
209 }
210 
211 /* TC Channel.  Counter updates are delivered on this channel's RXQ. */
212 
213 static void efx_tc_handle_no_channel(struct efx_nic *efx)
214 {
215 	netif_warn(efx, drv, efx->net_dev,
216 		   "MAE counters require MSI-X and 1 additional interrupt vector.\n");
217 }
218 
219 static int efx_tc_probe_channel(struct efx_channel *channel)
220 {
221 	struct efx_rx_queue *rx_queue = &channel->rx_queue;
222 
223 	channel->irq_moderation_us = 0;
224 	rx_queue->core_index = 0;
225 
226 	INIT_WORK(&rx_queue->grant_work, efx_mae_counters_grant_credits);
227 
228 	return 0;
229 }
230 
231 static int efx_tc_start_channel(struct efx_channel *channel)
232 {
233 	struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
234 	struct efx_nic *efx = channel->efx;
235 
236 	return efx_mae_start_counters(efx, rx_queue);
237 }
238 
239 static void efx_tc_stop_channel(struct efx_channel *channel)
240 {
241 	struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
242 	struct efx_nic *efx = channel->efx;
243 	int rc;
244 
245 	rc = efx_mae_stop_counters(efx, rx_queue);
246 	if (rc)
247 		netif_warn(efx, drv, efx->net_dev,
248 			   "Failed to stop MAE counters streaming, rc=%d.\n",
249 			   rc);
250 	rx_queue->grant_credits = false;
251 	flush_work(&rx_queue->grant_work);
252 }
253 
254 static void efx_tc_remove_channel(struct efx_channel *channel)
255 {
256 }
257 
258 static void efx_tc_get_channel_name(struct efx_channel *channel,
259 				    char *buf, size_t len)
260 {
261 	snprintf(buf, len, "%s-mae", channel->efx->name);
262 }
263 
264 static void efx_tc_counter_update(struct efx_nic *efx,
265 				  enum efx_tc_counter_type counter_type,
266 				  u32 counter_idx, u64 packets, u64 bytes,
267 				  u32 mark)
268 {
269 	struct efx_tc_counter *cnt;
270 
271 	rcu_read_lock(); /* Protect against deletion of 'cnt' */
272 	cnt = efx_tc_flower_find_counter_by_fw_id(efx, counter_type, counter_idx);
273 	if (!cnt) {
274 		/* This can legitimately happen when a counter is removed,
275 		 * with updates for the counter still in-flight; however this
276 		 * should be an infrequent occurrence.
277 		 */
278 		if (net_ratelimit())
279 			netif_dbg(efx, drv, efx->net_dev,
280 				  "Got update for unwanted MAE counter %u type %u\n",
281 				  counter_idx, counter_type);
282 		goto out;
283 	}
284 
285 	spin_lock_bh(&cnt->lock);
286 	if ((s32)mark - (s32)cnt->gen < 0) {
287 		/* This counter update packet is from before the counter was
288 		 * allocated; thus it must be for a previous counter with
289 		 * the same ID that has since been freed, and it should be
290 		 * ignored.
291 		 */
292 	} else {
293 		/* Update latest seen generation count.  This ensures that
294 		 * even a long-lived counter won't start getting ignored if
295 		 * the generation count wraps around, unless it somehow
296 		 * manages to go 1<<31 generations without an update.
297 		 */
298 		cnt->gen = mark;
299 		/* update counter values */
300 		cnt->packets += packets;
301 		cnt->bytes += bytes;
302 		cnt->touched = jiffies;
303 	}
304 	spin_unlock_bh(&cnt->lock);
305 out:
306 	rcu_read_unlock();
307 }
308 
309 static void efx_tc_rx_version_1(struct efx_nic *efx, const u8 *data, u32 mark)
310 {
311 	u16 n_counters, i;
312 
313 	/* Header format:
314 	 * + |   0    |   1    |   2    |   3    |
315 	 * 0 |version |         reserved         |
316 	 * 4 |    seq_index    |   n_counters    |
317 	 */
318 
319 	n_counters = le16_to_cpu(*(const __le16 *)(data + 6));
320 
321 	/* Counter update entry format:
322 	 * | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | a | b | c | d | e | f |
323 	 * |  counter_idx  |     packet_count      |      byte_count       |
324 	 */
325 	for (i = 0; i < n_counters; i++) {
326 		const void *entry = data + 8 + 16 * i;
327 		u64 packet_count, byte_count;
328 		u32 counter_idx;
329 
330 		counter_idx = le32_to_cpu(*(const __le32 *)entry);
331 		packet_count = le32_to_cpu(*(const __le32 *)(entry + 4)) |
332 			       ((u64)le16_to_cpu(*(const __le16 *)(entry + 8)) << 32);
333 		byte_count = le16_to_cpu(*(const __le16 *)(entry + 10)) |
334 			     ((u64)le32_to_cpu(*(const __le32 *)(entry + 12)) << 16);
335 		efx_tc_counter_update(efx, EFX_TC_COUNTER_TYPE_AR, counter_idx,
336 				      packet_count, byte_count, mark);
337 	}
338 }
339 
340 #define TCV2_HDR_PTR(pkt, field)						\
341 	((void)BUILD_BUG_ON_ZERO(ERF_SC_PACKETISER_HEADER_##field##_LBN & 7),	\
342 	 (pkt) + ERF_SC_PACKETISER_HEADER_##field##_LBN / 8)
343 #define TCV2_HDR_BYTE(pkt, field)						\
344 	((void)BUILD_BUG_ON_ZERO(ERF_SC_PACKETISER_HEADER_##field##_WIDTH != 8),\
345 	 *TCV2_HDR_PTR(pkt, field))
346 #define TCV2_HDR_WORD(pkt, field)						\
347 	((void)BUILD_BUG_ON_ZERO(ERF_SC_PACKETISER_HEADER_##field##_WIDTH != 16),\
348 	 (void)BUILD_BUG_ON_ZERO(ERF_SC_PACKETISER_HEADER_##field##_LBN & 15),	\
349 	 *(__force const __le16 *)TCV2_HDR_PTR(pkt, field))
350 #define TCV2_PKT_PTR(pkt, poff, i, field)					\
351 	((void)BUILD_BUG_ON_ZERO(ERF_SC_PACKETISER_PAYLOAD_##field##_LBN & 7),	\
352 	 (pkt) + ERF_SC_PACKETISER_PAYLOAD_##field##_LBN/8 + poff +		\
353 	 i * ER_RX_SL_PACKETISER_PAYLOAD_WORD_SIZE)
354 
355 /* Read a little-endian 48-bit field with 16-bit alignment */
356 static u64 efx_tc_read48(const __le16 *field)
357 {
358 	u64 out = 0;
359 	int i;
360 
361 	for (i = 0; i < 3; i++)
362 		out |= (u64)le16_to_cpu(field[i]) << (i * 16);
363 	return out;
364 }
365 
366 static enum efx_tc_counter_type efx_tc_rx_version_2(struct efx_nic *efx,
367 						    const u8 *data, u32 mark)
368 {
369 	u8 payload_offset, header_offset, ident;
370 	enum efx_tc_counter_type type;
371 	u16 n_counters, i;
372 
373 	ident = TCV2_HDR_BYTE(data, IDENTIFIER);
374 	switch (ident) {
375 	case ERF_SC_PACKETISER_HEADER_IDENTIFIER_AR:
376 		type = EFX_TC_COUNTER_TYPE_AR;
377 		break;
378 	case ERF_SC_PACKETISER_HEADER_IDENTIFIER_CT:
379 		type = EFX_TC_COUNTER_TYPE_CT;
380 		break;
381 	case ERF_SC_PACKETISER_HEADER_IDENTIFIER_OR:
382 		type = EFX_TC_COUNTER_TYPE_OR;
383 		break;
384 	default:
385 		if (net_ratelimit())
386 			netif_err(efx, drv, efx->net_dev,
387 				  "ignored v2 MAE counter packet (bad identifier %u"
388 				  "), counters may be inaccurate\n", ident);
389 		return EFX_TC_COUNTER_TYPE_MAX;
390 	}
391 	header_offset = TCV2_HDR_BYTE(data, HEADER_OFFSET);
392 	/* mae_counter_format.h implies that this offset is fixed, since it
393 	 * carries on with SOP-based LBNs for the fields in this header
394 	 */
395 	if (header_offset != ERF_SC_PACKETISER_HEADER_HEADER_OFFSET_DEFAULT) {
396 		if (net_ratelimit())
397 			netif_err(efx, drv, efx->net_dev,
398 				  "choked on v2 MAE counter packet (bad header_offset %u"
399 				  "), counters may be inaccurate\n", header_offset);
400 		return EFX_TC_COUNTER_TYPE_MAX;
401 	}
402 	payload_offset = TCV2_HDR_BYTE(data, PAYLOAD_OFFSET);
403 	n_counters = le16_to_cpu(TCV2_HDR_WORD(data, COUNT));
404 
405 	for (i = 0; i < n_counters; i++) {
406 		const void *counter_idx_p, *packet_count_p, *byte_count_p;
407 		u64 packet_count, byte_count;
408 		u32 counter_idx;
409 
410 		/* 24-bit field with 32-bit alignment */
411 		counter_idx_p = TCV2_PKT_PTR(data, payload_offset, i, COUNTER_INDEX);
412 		BUILD_BUG_ON(ERF_SC_PACKETISER_PAYLOAD_COUNTER_INDEX_WIDTH != 24);
413 		BUILD_BUG_ON(ERF_SC_PACKETISER_PAYLOAD_COUNTER_INDEX_LBN & 31);
414 		counter_idx = le32_to_cpu(*(const __le32 *)counter_idx_p) & 0xffffff;
415 		/* 48-bit field with 16-bit alignment */
416 		packet_count_p = TCV2_PKT_PTR(data, payload_offset, i, PACKET_COUNT);
417 		BUILD_BUG_ON(ERF_SC_PACKETISER_PAYLOAD_PACKET_COUNT_WIDTH != 48);
418 		BUILD_BUG_ON(ERF_SC_PACKETISER_PAYLOAD_PACKET_COUNT_LBN & 15);
419 		packet_count = efx_tc_read48((const __le16 *)packet_count_p);
420 		/* 48-bit field with 16-bit alignment */
421 		byte_count_p = TCV2_PKT_PTR(data, payload_offset, i, BYTE_COUNT);
422 		BUILD_BUG_ON(ERF_SC_PACKETISER_PAYLOAD_BYTE_COUNT_WIDTH != 48);
423 		BUILD_BUG_ON(ERF_SC_PACKETISER_PAYLOAD_BYTE_COUNT_LBN & 15);
424 		byte_count = efx_tc_read48((const __le16 *)byte_count_p);
425 
426 		if (type == EFX_TC_COUNTER_TYPE_CT) {
427 			/* CT counters are 1-bit saturating counters to update
428 			 * the lastuse time in CT stats. A received CT counter
429 			 * should have packet counter to 0 and only LSB bit on
430 			 * in byte counter.
431 			 */
432 			if (packet_count || byte_count != 1)
433 				netdev_warn_once(efx->net_dev,
434 						 "CT counter with inconsistent state (%llu, %llu)\n",
435 						 packet_count, byte_count);
436 			/* Do not increment the driver's byte counter */
437 			byte_count = 0;
438 		}
439 
440 		efx_tc_counter_update(efx, type, counter_idx, packet_count,
441 				      byte_count, mark);
442 	}
443 	return type;
444 }
445 
446 /* We always swallow the packet, whether successful or not, since it's not
447  * a network packet and shouldn't ever be forwarded to the stack.
448  * @mark is the generation count for counter allocations.
449  */
450 static bool efx_tc_rx(struct efx_rx_queue *rx_queue, u32 mark)
451 {
452 	struct efx_channel *channel = efx_rx_queue_channel(rx_queue);
453 	struct efx_rx_buffer *rx_buf = efx_rx_buffer(rx_queue,
454 						     channel->rx_pkt_index);
455 	const u8 *data = efx_rx_buf_va(rx_buf);
456 	struct efx_nic *efx = rx_queue->efx;
457 	enum efx_tc_counter_type type;
458 	u8 version;
459 
460 	/* version is always first byte of packet */
461 	version = *data;
462 	switch (version) {
463 	case 1:
464 		type = EFX_TC_COUNTER_TYPE_AR;
465 		efx_tc_rx_version_1(efx, data, mark);
466 		break;
467 	case ERF_SC_PACKETISER_HEADER_VERSION_VALUE: // 2
468 		type = efx_tc_rx_version_2(efx, data, mark);
469 		break;
470 	default:
471 		if (net_ratelimit())
472 			netif_err(efx, drv, efx->net_dev,
473 				  "choked on MAE counter packet (bad version %u"
474 				  "); counters may be inaccurate\n",
475 				  version);
476 		goto out;
477 	}
478 
479 	if (type < EFX_TC_COUNTER_TYPE_MAX) {
480 		/* Update seen_gen unconditionally, to avoid a missed wakeup if
481 		 * we race with efx_mae_stop_counters().
482 		 */
483 		efx->tc->seen_gen[type] = mark;
484 		if (efx->tc->flush_counters &&
485 		    (s32)(efx->tc->flush_gen[type] - mark) <= 0)
486 			wake_up(&efx->tc->flush_wq);
487 	}
488 out:
489 	efx_free_rx_buffers(rx_queue, rx_buf, 1);
490 	channel->rx_pkt_n_frags = 0;
491 	return true;
492 }
493 
494 const struct efx_channel_type efx_tc_channel_type = {
495 	.handle_no_channel	= efx_tc_handle_no_channel,
496 	.pre_probe		= efx_tc_probe_channel,
497 	.start			= efx_tc_start_channel,
498 	.stop			= efx_tc_stop_channel,
499 	.post_remove		= efx_tc_remove_channel,
500 	.get_name		= efx_tc_get_channel_name,
501 	.receive_raw		= efx_tc_rx,
502 	.keep_eventq		= true,
503 };
504