xref: /linux/drivers/net/ethernet/sfc/rx_common.c (revision a3a02a52bcfcbcc4a637d4b68bf1bc391c9fad02)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /****************************************************************************
3  * Driver for Solarflare network controllers and boards
4  * Copyright 2018 Solarflare Communications 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 "net_driver.h"
12 #include <linux/module.h>
13 #include <linux/iommu.h>
14 #include <net/rps.h>
15 #include "efx.h"
16 #include "nic.h"
17 #include "rx_common.h"
18 
19 /* This is the percentage fill level below which new RX descriptors
20  * will be added to the RX descriptor ring.
21  */
22 static unsigned int rx_refill_threshold;
23 module_param(rx_refill_threshold, uint, 0444);
24 MODULE_PARM_DESC(rx_refill_threshold,
25 		 "RX descriptor ring refill threshold (%)");
26 
27 /* RX maximum head room required.
28  *
29  * This must be at least 1 to prevent overflow, plus one packet-worth
30  * to allow pipelined receives.
31  */
32 #define EFX_RXD_HEAD_ROOM (1 + EFX_RX_MAX_FRAGS)
33 
34 /* Check the RX page recycle ring for a page that can be reused. */
35 static struct page *efx_reuse_page(struct efx_rx_queue *rx_queue)
36 {
37 	struct efx_nic *efx = rx_queue->efx;
38 	struct efx_rx_page_state *state;
39 	unsigned int index;
40 	struct page *page;
41 
42 	if (unlikely(!rx_queue->page_ring))
43 		return NULL;
44 	index = rx_queue->page_remove & rx_queue->page_ptr_mask;
45 	page = rx_queue->page_ring[index];
46 	if (page == NULL)
47 		return NULL;
48 
49 	rx_queue->page_ring[index] = NULL;
50 	/* page_remove cannot exceed page_add. */
51 	if (rx_queue->page_remove != rx_queue->page_add)
52 		++rx_queue->page_remove;
53 
54 	/* If page_count is 1 then we hold the only reference to this page. */
55 	if (page_count(page) == 1) {
56 		++rx_queue->page_recycle_count;
57 		return page;
58 	} else {
59 		state = page_address(page);
60 		dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
61 			       PAGE_SIZE << efx->rx_buffer_order,
62 			       DMA_FROM_DEVICE);
63 		put_page(page);
64 		++rx_queue->page_recycle_failed;
65 	}
66 
67 	return NULL;
68 }
69 
70 /* Attempt to recycle the page if there is an RX recycle ring; the page can
71  * only be added if this is the final RX buffer, to prevent pages being used in
72  * the descriptor ring and appearing in the recycle ring simultaneously.
73  */
74 static void efx_recycle_rx_page(struct efx_channel *channel,
75 				struct efx_rx_buffer *rx_buf)
76 {
77 	struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
78 	struct efx_nic *efx = rx_queue->efx;
79 	struct page *page = rx_buf->page;
80 	unsigned int index;
81 
82 	/* Only recycle the page after processing the final buffer. */
83 	if (!(rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE))
84 		return;
85 
86 	index = rx_queue->page_add & rx_queue->page_ptr_mask;
87 	if (rx_queue->page_ring[index] == NULL) {
88 		unsigned int read_index = rx_queue->page_remove &
89 			rx_queue->page_ptr_mask;
90 
91 		/* The next slot in the recycle ring is available, but
92 		 * increment page_remove if the read pointer currently
93 		 * points here.
94 		 */
95 		if (read_index == index)
96 			++rx_queue->page_remove;
97 		rx_queue->page_ring[index] = page;
98 		++rx_queue->page_add;
99 		return;
100 	}
101 	++rx_queue->page_recycle_full;
102 	efx_unmap_rx_buffer(efx, rx_buf);
103 	put_page(rx_buf->page);
104 }
105 
106 /* Recycle the pages that are used by buffers that have just been received. */
107 void efx_recycle_rx_pages(struct efx_channel *channel,
108 			  struct efx_rx_buffer *rx_buf,
109 			  unsigned int n_frags)
110 {
111 	struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
112 
113 	if (unlikely(!rx_queue->page_ring))
114 		return;
115 
116 	do {
117 		efx_recycle_rx_page(channel, rx_buf);
118 		rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
119 	} while (--n_frags);
120 }
121 
122 void efx_discard_rx_packet(struct efx_channel *channel,
123 			   struct efx_rx_buffer *rx_buf,
124 			   unsigned int n_frags)
125 {
126 	struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
127 
128 	efx_recycle_rx_pages(channel, rx_buf, n_frags);
129 
130 	efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
131 }
132 
133 static void efx_init_rx_recycle_ring(struct efx_rx_queue *rx_queue)
134 {
135 	unsigned int bufs_in_recycle_ring, page_ring_size;
136 	struct efx_nic *efx = rx_queue->efx;
137 
138 	bufs_in_recycle_ring = efx_rx_recycle_ring_size(efx);
139 	page_ring_size = roundup_pow_of_two(bufs_in_recycle_ring /
140 					    efx->rx_bufs_per_page);
141 	rx_queue->page_ring = kcalloc(page_ring_size,
142 				      sizeof(*rx_queue->page_ring), GFP_KERNEL);
143 	if (!rx_queue->page_ring)
144 		rx_queue->page_ptr_mask = 0;
145 	else
146 		rx_queue->page_ptr_mask = page_ring_size - 1;
147 }
148 
149 static void efx_fini_rx_recycle_ring(struct efx_rx_queue *rx_queue)
150 {
151 	struct efx_nic *efx = rx_queue->efx;
152 	int i;
153 
154 	if (unlikely(!rx_queue->page_ring))
155 		return;
156 
157 	/* Unmap and release the pages in the recycle ring. Remove the ring. */
158 	for (i = 0; i <= rx_queue->page_ptr_mask; i++) {
159 		struct page *page = rx_queue->page_ring[i];
160 		struct efx_rx_page_state *state;
161 
162 		if (page == NULL)
163 			continue;
164 
165 		state = page_address(page);
166 		dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
167 			       PAGE_SIZE << efx->rx_buffer_order,
168 			       DMA_FROM_DEVICE);
169 		put_page(page);
170 	}
171 	kfree(rx_queue->page_ring);
172 	rx_queue->page_ring = NULL;
173 }
174 
175 static void efx_fini_rx_buffer(struct efx_rx_queue *rx_queue,
176 			       struct efx_rx_buffer *rx_buf)
177 {
178 	/* Release the page reference we hold for the buffer. */
179 	if (rx_buf->page)
180 		put_page(rx_buf->page);
181 
182 	/* If this is the last buffer in a page, unmap and free it. */
183 	if (rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE) {
184 		efx_unmap_rx_buffer(rx_queue->efx, rx_buf);
185 		efx_free_rx_buffers(rx_queue, rx_buf, 1);
186 	}
187 	rx_buf->page = NULL;
188 }
189 
190 int efx_probe_rx_queue(struct efx_rx_queue *rx_queue)
191 {
192 	struct efx_nic *efx = rx_queue->efx;
193 	unsigned int entries;
194 	int rc;
195 
196 	/* Create the smallest power-of-two aligned ring */
197 	entries = max(roundup_pow_of_two(efx->rxq_entries), EFX_MIN_DMAQ_SIZE);
198 	EFX_WARN_ON_PARANOID(entries > EFX_MAX_DMAQ_SIZE);
199 	rx_queue->ptr_mask = entries - 1;
200 
201 	netif_dbg(efx, probe, efx->net_dev,
202 		  "creating RX queue %d size %#x mask %#x\n",
203 		  efx_rx_queue_index(rx_queue), efx->rxq_entries,
204 		  rx_queue->ptr_mask);
205 
206 	/* Allocate RX buffers */
207 	rx_queue->buffer = kcalloc(entries, sizeof(*rx_queue->buffer),
208 				   GFP_KERNEL);
209 	if (!rx_queue->buffer)
210 		return -ENOMEM;
211 
212 	rc = efx_nic_probe_rx(rx_queue);
213 	if (rc) {
214 		kfree(rx_queue->buffer);
215 		rx_queue->buffer = NULL;
216 	}
217 
218 	return rc;
219 }
220 
221 void efx_init_rx_queue(struct efx_rx_queue *rx_queue)
222 {
223 	unsigned int max_fill, trigger, max_trigger;
224 	struct efx_nic *efx = rx_queue->efx;
225 	int rc = 0;
226 
227 	netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
228 		  "initialising RX queue %d\n", efx_rx_queue_index(rx_queue));
229 
230 	/* Initialise ptr fields */
231 	rx_queue->added_count = 0;
232 	rx_queue->notified_count = 0;
233 	rx_queue->granted_count = 0;
234 	rx_queue->removed_count = 0;
235 	rx_queue->min_fill = -1U;
236 	efx_init_rx_recycle_ring(rx_queue);
237 
238 	rx_queue->page_remove = 0;
239 	rx_queue->page_add = rx_queue->page_ptr_mask + 1;
240 	rx_queue->page_recycle_count = 0;
241 	rx_queue->page_recycle_failed = 0;
242 	rx_queue->page_recycle_full = 0;
243 
244 	/* Initialise limit fields */
245 	max_fill = efx->rxq_entries - EFX_RXD_HEAD_ROOM;
246 	max_trigger =
247 		max_fill - efx->rx_pages_per_batch * efx->rx_bufs_per_page;
248 	if (rx_refill_threshold != 0) {
249 		trigger = max_fill * min(rx_refill_threshold, 100U) / 100U;
250 		if (trigger > max_trigger)
251 			trigger = max_trigger;
252 	} else {
253 		trigger = max_trigger;
254 	}
255 
256 	rx_queue->max_fill = max_fill;
257 	rx_queue->fast_fill_trigger = trigger;
258 	rx_queue->refill_enabled = true;
259 
260 	/* Initialise XDP queue information */
261 	rc = xdp_rxq_info_reg(&rx_queue->xdp_rxq_info, efx->net_dev,
262 			      rx_queue->core_index, 0);
263 
264 	if (rc) {
265 		netif_err(efx, rx_err, efx->net_dev,
266 			  "Failure to initialise XDP queue information rc=%d\n",
267 			  rc);
268 		efx->xdp_rxq_info_failed = true;
269 	} else {
270 		rx_queue->xdp_rxq_info_valid = true;
271 	}
272 
273 	/* Set up RX descriptor ring */
274 	efx_nic_init_rx(rx_queue);
275 }
276 
277 void efx_fini_rx_queue(struct efx_rx_queue *rx_queue)
278 {
279 	struct efx_rx_buffer *rx_buf;
280 	int i;
281 
282 	netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
283 		  "shutting down RX queue %d\n", efx_rx_queue_index(rx_queue));
284 
285 	del_timer_sync(&rx_queue->slow_fill);
286 	if (rx_queue->grant_credits)
287 		flush_work(&rx_queue->grant_work);
288 
289 	/* Release RX buffers from the current read ptr to the write ptr */
290 	if (rx_queue->buffer) {
291 		for (i = rx_queue->removed_count; i < rx_queue->added_count;
292 		     i++) {
293 			unsigned int index = i & rx_queue->ptr_mask;
294 
295 			rx_buf = efx_rx_buffer(rx_queue, index);
296 			efx_fini_rx_buffer(rx_queue, rx_buf);
297 		}
298 	}
299 
300 	efx_fini_rx_recycle_ring(rx_queue);
301 
302 	if (rx_queue->xdp_rxq_info_valid)
303 		xdp_rxq_info_unreg(&rx_queue->xdp_rxq_info);
304 
305 	rx_queue->xdp_rxq_info_valid = false;
306 }
307 
308 void efx_remove_rx_queue(struct efx_rx_queue *rx_queue)
309 {
310 	netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
311 		  "destroying RX queue %d\n", efx_rx_queue_index(rx_queue));
312 
313 	efx_nic_remove_rx(rx_queue);
314 
315 	kfree(rx_queue->buffer);
316 	rx_queue->buffer = NULL;
317 }
318 
319 /* Unmap a DMA-mapped page.  This function is only called for the final RX
320  * buffer in a page.
321  */
322 void efx_unmap_rx_buffer(struct efx_nic *efx,
323 			 struct efx_rx_buffer *rx_buf)
324 {
325 	struct page *page = rx_buf->page;
326 
327 	if (page) {
328 		struct efx_rx_page_state *state = page_address(page);
329 
330 		dma_unmap_page(&efx->pci_dev->dev,
331 			       state->dma_addr,
332 			       PAGE_SIZE << efx->rx_buffer_order,
333 			       DMA_FROM_DEVICE);
334 	}
335 }
336 
337 void efx_free_rx_buffers(struct efx_rx_queue *rx_queue,
338 			 struct efx_rx_buffer *rx_buf,
339 			 unsigned int num_bufs)
340 {
341 	do {
342 		if (rx_buf->page) {
343 			put_page(rx_buf->page);
344 			rx_buf->page = NULL;
345 		}
346 		rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
347 	} while (--num_bufs);
348 }
349 
350 void efx_rx_slow_fill(struct timer_list *t)
351 {
352 	struct efx_rx_queue *rx_queue = from_timer(rx_queue, t, slow_fill);
353 
354 	/* Post an event to cause NAPI to run and refill the queue */
355 	efx_nic_generate_fill_event(rx_queue);
356 	++rx_queue->slow_fill_count;
357 }
358 
359 void efx_schedule_slow_fill(struct efx_rx_queue *rx_queue)
360 {
361 	mod_timer(&rx_queue->slow_fill, jiffies + msecs_to_jiffies(10));
362 }
363 
364 /* efx_init_rx_buffers - create EFX_RX_BATCH page-based RX buffers
365  *
366  * @rx_queue:		Efx RX queue
367  *
368  * This allocates a batch of pages, maps them for DMA, and populates
369  * struct efx_rx_buffers for each one. Return a negative error code or
370  * 0 on success. If a single page can be used for multiple buffers,
371  * then the page will either be inserted fully, or not at all.
372  */
373 static int efx_init_rx_buffers(struct efx_rx_queue *rx_queue, bool atomic)
374 {
375 	unsigned int page_offset, index, count;
376 	struct efx_nic *efx = rx_queue->efx;
377 	struct efx_rx_page_state *state;
378 	struct efx_rx_buffer *rx_buf;
379 	dma_addr_t dma_addr;
380 	struct page *page;
381 
382 	count = 0;
383 	do {
384 		page = efx_reuse_page(rx_queue);
385 		if (page == NULL) {
386 			page = alloc_pages(__GFP_COMP |
387 					   (atomic ? GFP_ATOMIC : GFP_KERNEL),
388 					   efx->rx_buffer_order);
389 			if (unlikely(page == NULL))
390 				return -ENOMEM;
391 			dma_addr =
392 				dma_map_page(&efx->pci_dev->dev, page, 0,
393 					     PAGE_SIZE << efx->rx_buffer_order,
394 					     DMA_FROM_DEVICE);
395 			if (unlikely(dma_mapping_error(&efx->pci_dev->dev,
396 						       dma_addr))) {
397 				__free_pages(page, efx->rx_buffer_order);
398 				return -EIO;
399 			}
400 			state = page_address(page);
401 			state->dma_addr = dma_addr;
402 		} else {
403 			state = page_address(page);
404 			dma_addr = state->dma_addr;
405 		}
406 
407 		dma_addr += sizeof(struct efx_rx_page_state);
408 		page_offset = sizeof(struct efx_rx_page_state);
409 
410 		do {
411 			index = rx_queue->added_count & rx_queue->ptr_mask;
412 			rx_buf = efx_rx_buffer(rx_queue, index);
413 			rx_buf->dma_addr = dma_addr + efx->rx_ip_align +
414 					   EFX_XDP_HEADROOM;
415 			rx_buf->page = page;
416 			rx_buf->page_offset = page_offset + efx->rx_ip_align +
417 					      EFX_XDP_HEADROOM;
418 			rx_buf->len = efx->rx_dma_len;
419 			rx_buf->flags = 0;
420 			++rx_queue->added_count;
421 			get_page(page);
422 			dma_addr += efx->rx_page_buf_step;
423 			page_offset += efx->rx_page_buf_step;
424 		} while (page_offset + efx->rx_page_buf_step <= PAGE_SIZE);
425 
426 		rx_buf->flags = EFX_RX_BUF_LAST_IN_PAGE;
427 	} while (++count < efx->rx_pages_per_batch);
428 
429 	return 0;
430 }
431 
432 void efx_rx_config_page_split(struct efx_nic *efx)
433 {
434 	efx->rx_page_buf_step = ALIGN(efx->rx_dma_len + efx->rx_ip_align +
435 				      EFX_XDP_HEADROOM + EFX_XDP_TAILROOM,
436 				      EFX_RX_BUF_ALIGNMENT);
437 	efx->rx_bufs_per_page = efx->rx_buffer_order ? 1 :
438 		((PAGE_SIZE - sizeof(struct efx_rx_page_state)) /
439 		efx->rx_page_buf_step);
440 	efx->rx_buffer_truesize = (PAGE_SIZE << efx->rx_buffer_order) /
441 		efx->rx_bufs_per_page;
442 	efx->rx_pages_per_batch = DIV_ROUND_UP(EFX_RX_PREFERRED_BATCH,
443 					       efx->rx_bufs_per_page);
444 }
445 
446 /* efx_fast_push_rx_descriptors - push new RX descriptors quickly
447  * @rx_queue:		RX descriptor queue
448  *
449  * This will aim to fill the RX descriptor queue up to
450  * @rx_queue->@max_fill. If there is insufficient atomic
451  * memory to do so, a slow fill will be scheduled.
452  *
453  * The caller must provide serialisation (none is used here). In practise,
454  * this means this function must run from the NAPI handler, or be called
455  * when NAPI is disabled.
456  */
457 void efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue, bool atomic)
458 {
459 	struct efx_nic *efx = rx_queue->efx;
460 	unsigned int fill_level, batch_size;
461 	int space, rc = 0;
462 
463 	if (!rx_queue->refill_enabled)
464 		return;
465 
466 	/* Calculate current fill level, and exit if we don't need to fill */
467 	fill_level = (rx_queue->added_count - rx_queue->removed_count);
468 	EFX_WARN_ON_ONCE_PARANOID(fill_level > rx_queue->efx->rxq_entries);
469 	if (fill_level >= rx_queue->fast_fill_trigger)
470 		goto out;
471 
472 	/* Record minimum fill level */
473 	if (unlikely(fill_level < rx_queue->min_fill)) {
474 		if (fill_level)
475 			rx_queue->min_fill = fill_level;
476 	}
477 
478 	batch_size = efx->rx_pages_per_batch * efx->rx_bufs_per_page;
479 	space = rx_queue->max_fill - fill_level;
480 	EFX_WARN_ON_ONCE_PARANOID(space < batch_size);
481 
482 	netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
483 		   "RX queue %d fast-filling descriptor ring from"
484 		   " level %d to level %d\n",
485 		   efx_rx_queue_index(rx_queue), fill_level,
486 		   rx_queue->max_fill);
487 
488 	do {
489 		rc = efx_init_rx_buffers(rx_queue, atomic);
490 		if (unlikely(rc)) {
491 			/* Ensure that we don't leave the rx queue empty */
492 			efx_schedule_slow_fill(rx_queue);
493 			goto out;
494 		}
495 	} while ((space -= batch_size) >= batch_size);
496 
497 	netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
498 		   "RX queue %d fast-filled descriptor ring "
499 		   "to level %d\n", efx_rx_queue_index(rx_queue),
500 		   rx_queue->added_count - rx_queue->removed_count);
501 
502  out:
503 	if (rx_queue->notified_count != rx_queue->added_count)
504 		efx_nic_notify_rx_desc(rx_queue);
505 }
506 
507 /* Pass a received packet up through GRO.  GRO can handle pages
508  * regardless of checksum state and skbs with a good checksum.
509  */
510 void
511 efx_rx_packet_gro(struct efx_channel *channel, struct efx_rx_buffer *rx_buf,
512 		  unsigned int n_frags, u8 *eh, __wsum csum)
513 {
514 	struct napi_struct *napi = &channel->napi_str;
515 	struct efx_nic *efx = channel->efx;
516 	struct sk_buff *skb;
517 
518 	skb = napi_get_frags(napi);
519 	if (unlikely(!skb)) {
520 		struct efx_rx_queue *rx_queue;
521 
522 		rx_queue = efx_channel_get_rx_queue(channel);
523 		efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
524 		return;
525 	}
526 
527 	if (efx->net_dev->features & NETIF_F_RXHASH &&
528 	    efx_rx_buf_hash_valid(efx, eh))
529 		skb_set_hash(skb, efx_rx_buf_hash(efx, eh),
530 			     PKT_HASH_TYPE_L3);
531 	if (csum) {
532 		skb->csum = csum;
533 		skb->ip_summed = CHECKSUM_COMPLETE;
534 	} else {
535 		skb->ip_summed = ((rx_buf->flags & EFX_RX_PKT_CSUMMED) ?
536 				  CHECKSUM_UNNECESSARY : CHECKSUM_NONE);
537 	}
538 	skb->csum_level = !!(rx_buf->flags & EFX_RX_PKT_CSUM_LEVEL);
539 
540 	for (;;) {
541 		skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
542 				   rx_buf->page, rx_buf->page_offset,
543 				   rx_buf->len);
544 		rx_buf->page = NULL;
545 		skb->len += rx_buf->len;
546 		if (skb_shinfo(skb)->nr_frags == n_frags)
547 			break;
548 
549 		rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf);
550 	}
551 
552 	skb->data_len = skb->len;
553 	skb->truesize += n_frags * efx->rx_buffer_truesize;
554 
555 	skb_record_rx_queue(skb, channel->rx_queue.core_index);
556 
557 	napi_gro_frags(napi);
558 }
559 
560 struct efx_rss_context_priv *efx_find_rss_context_entry(struct efx_nic *efx,
561 							u32 id)
562 {
563 	struct ethtool_rxfh_context *ctx;
564 
565 	WARN_ON(!mutex_is_locked(&efx->net_dev->ethtool->rss_lock));
566 
567 	ctx = xa_load(&efx->net_dev->ethtool->rss_ctx, id);
568 	if (!ctx)
569 		return NULL;
570 	return ethtool_rxfh_context_priv(ctx);
571 }
572 
573 void efx_set_default_rx_indir_table(struct efx_nic *efx, u32 *indir)
574 {
575 	size_t i;
576 
577 	for (i = 0; i < ARRAY_SIZE(efx->rss_context.rx_indir_table); i++)
578 		indir[i] = ethtool_rxfh_indir_default(i, efx->rss_spread);
579 }
580 
581 /**
582  * efx_filter_is_mc_recipient - test whether spec is a multicast recipient
583  * @spec: Specification to test
584  *
585  * Return: %true if the specification is a non-drop RX filter that
586  * matches a local MAC address I/G bit value of 1 or matches a local
587  * IPv4 or IPv6 address value in the respective multicast address
588  * range.  Otherwise %false.
589  */
590 bool efx_filter_is_mc_recipient(const struct efx_filter_spec *spec)
591 {
592 	if (!(spec->flags & EFX_FILTER_FLAG_RX) ||
593 	    spec->dmaq_id == EFX_FILTER_RX_DMAQ_ID_DROP)
594 		return false;
595 
596 	if (spec->match_flags &
597 	    (EFX_FILTER_MATCH_LOC_MAC | EFX_FILTER_MATCH_LOC_MAC_IG) &&
598 	    is_multicast_ether_addr(spec->loc_mac))
599 		return true;
600 
601 	if ((spec->match_flags &
602 	     (EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_LOC_HOST)) ==
603 	    (EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_LOC_HOST)) {
604 		if (spec->ether_type == htons(ETH_P_IP) &&
605 		    ipv4_is_multicast(spec->loc_host[0]))
606 			return true;
607 		if (spec->ether_type == htons(ETH_P_IPV6) &&
608 		    ((const u8 *)spec->loc_host)[0] == 0xff)
609 			return true;
610 	}
611 
612 	return false;
613 }
614 
615 bool efx_filter_spec_equal(const struct efx_filter_spec *left,
616 			   const struct efx_filter_spec *right)
617 {
618 	if ((left->match_flags ^ right->match_flags) |
619 	    ((left->flags ^ right->flags) &
620 	     (EFX_FILTER_FLAG_RX | EFX_FILTER_FLAG_TX)))
621 		return false;
622 
623 	return memcmp(&left->vport_id, &right->vport_id,
624 		      sizeof(struct efx_filter_spec) -
625 		      offsetof(struct efx_filter_spec, vport_id)) == 0;
626 }
627 
628 u32 efx_filter_spec_hash(const struct efx_filter_spec *spec)
629 {
630 	BUILD_BUG_ON(offsetof(struct efx_filter_spec, vport_id) & 3);
631 	return jhash2((const u32 *)&spec->vport_id,
632 		      (sizeof(struct efx_filter_spec) -
633 		       offsetof(struct efx_filter_spec, vport_id)) / 4,
634 		      0);
635 }
636 
637 #ifdef CONFIG_RFS_ACCEL
638 bool efx_rps_check_rule(struct efx_arfs_rule *rule, unsigned int filter_idx,
639 			bool *force)
640 {
641 	if (rule->filter_id == EFX_ARFS_FILTER_ID_PENDING) {
642 		/* ARFS is currently updating this entry, leave it */
643 		return false;
644 	}
645 	if (rule->filter_id == EFX_ARFS_FILTER_ID_ERROR) {
646 		/* ARFS tried and failed to update this, so it's probably out
647 		 * of date.  Remove the filter and the ARFS rule entry.
648 		 */
649 		rule->filter_id = EFX_ARFS_FILTER_ID_REMOVING;
650 		*force = true;
651 		return true;
652 	} else if (WARN_ON(rule->filter_id != filter_idx)) { /* can't happen */
653 		/* ARFS has moved on, so old filter is not needed.  Since we did
654 		 * not mark the rule with EFX_ARFS_FILTER_ID_REMOVING, it will
655 		 * not be removed by efx_rps_hash_del() subsequently.
656 		 */
657 		*force = true;
658 		return true;
659 	}
660 	/* Remove it iff ARFS wants to. */
661 	return true;
662 }
663 
664 static
665 struct hlist_head *efx_rps_hash_bucket(struct efx_nic *efx,
666 				       const struct efx_filter_spec *spec)
667 {
668 	u32 hash = efx_filter_spec_hash(spec);
669 
670 	lockdep_assert_held(&efx->rps_hash_lock);
671 	if (!efx->rps_hash_table)
672 		return NULL;
673 	return &efx->rps_hash_table[hash % EFX_ARFS_HASH_TABLE_SIZE];
674 }
675 
676 struct efx_arfs_rule *efx_rps_hash_find(struct efx_nic *efx,
677 					const struct efx_filter_spec *spec)
678 {
679 	struct efx_arfs_rule *rule;
680 	struct hlist_head *head;
681 	struct hlist_node *node;
682 
683 	head = efx_rps_hash_bucket(efx, spec);
684 	if (!head)
685 		return NULL;
686 	hlist_for_each(node, head) {
687 		rule = container_of(node, struct efx_arfs_rule, node);
688 		if (efx_filter_spec_equal(spec, &rule->spec))
689 			return rule;
690 	}
691 	return NULL;
692 }
693 
694 struct efx_arfs_rule *efx_rps_hash_add(struct efx_nic *efx,
695 				       const struct efx_filter_spec *spec,
696 				       bool *new)
697 {
698 	struct efx_arfs_rule *rule;
699 	struct hlist_head *head;
700 	struct hlist_node *node;
701 
702 	head = efx_rps_hash_bucket(efx, spec);
703 	if (!head)
704 		return NULL;
705 	hlist_for_each(node, head) {
706 		rule = container_of(node, struct efx_arfs_rule, node);
707 		if (efx_filter_spec_equal(spec, &rule->spec)) {
708 			*new = false;
709 			return rule;
710 		}
711 	}
712 	rule = kmalloc(sizeof(*rule), GFP_ATOMIC);
713 	*new = true;
714 	if (rule) {
715 		memcpy(&rule->spec, spec, sizeof(rule->spec));
716 		hlist_add_head(&rule->node, head);
717 	}
718 	return rule;
719 }
720 
721 void efx_rps_hash_del(struct efx_nic *efx, const struct efx_filter_spec *spec)
722 {
723 	struct efx_arfs_rule *rule;
724 	struct hlist_head *head;
725 	struct hlist_node *node;
726 
727 	head = efx_rps_hash_bucket(efx, spec);
728 	if (WARN_ON(!head))
729 		return;
730 	hlist_for_each(node, head) {
731 		rule = container_of(node, struct efx_arfs_rule, node);
732 		if (efx_filter_spec_equal(spec, &rule->spec)) {
733 			/* Someone already reused the entry.  We know that if
734 			 * this check doesn't fire (i.e. filter_id == REMOVING)
735 			 * then the REMOVING mark was put there by our caller,
736 			 * because caller is holding a lock on filter table and
737 			 * only holders of that lock set REMOVING.
738 			 */
739 			if (rule->filter_id != EFX_ARFS_FILTER_ID_REMOVING)
740 				return;
741 			hlist_del(node);
742 			kfree(rule);
743 			return;
744 		}
745 	}
746 	/* We didn't find it. */
747 	WARN_ON(1);
748 }
749 #endif
750 
751 int efx_probe_filters(struct efx_nic *efx)
752 {
753 	int rc;
754 
755 	mutex_lock(&efx->mac_lock);
756 	rc = efx->type->filter_table_probe(efx);
757 	if (rc)
758 		goto out_unlock;
759 
760 #ifdef CONFIG_RFS_ACCEL
761 	if (efx->type->offload_features & NETIF_F_NTUPLE) {
762 		struct efx_channel *channel;
763 		int i, success = 1;
764 
765 		efx_for_each_channel(channel, efx) {
766 			channel->rps_flow_id =
767 				kcalloc(efx->type->max_rx_ip_filters,
768 					sizeof(*channel->rps_flow_id),
769 					GFP_KERNEL);
770 			if (!channel->rps_flow_id)
771 				success = 0;
772 			else
773 				for (i = 0;
774 				     i < efx->type->max_rx_ip_filters;
775 				     ++i)
776 					channel->rps_flow_id[i] =
777 						RPS_FLOW_ID_INVALID;
778 			channel->rfs_expire_index = 0;
779 			channel->rfs_filter_count = 0;
780 		}
781 
782 		if (!success) {
783 			efx_for_each_channel(channel, efx) {
784 				kfree(channel->rps_flow_id);
785 				channel->rps_flow_id = NULL;
786 			}
787 			efx->type->filter_table_remove(efx);
788 			rc = -ENOMEM;
789 			goto out_unlock;
790 		}
791 	}
792 #endif
793 out_unlock:
794 	mutex_unlock(&efx->mac_lock);
795 	return rc;
796 }
797 
798 void efx_remove_filters(struct efx_nic *efx)
799 {
800 #ifdef CONFIG_RFS_ACCEL
801 	struct efx_channel *channel;
802 
803 	efx_for_each_channel(channel, efx) {
804 		cancel_delayed_work_sync(&channel->filter_work);
805 		kfree(channel->rps_flow_id);
806 		channel->rps_flow_id = NULL;
807 	}
808 #endif
809 	efx->type->filter_table_remove(efx);
810 }
811 
812 #ifdef CONFIG_RFS_ACCEL
813 
814 static void efx_filter_rfs_work(struct work_struct *data)
815 {
816 	struct efx_async_filter_insertion *req = container_of(data, struct efx_async_filter_insertion,
817 							      work);
818 	struct efx_nic *efx = efx_netdev_priv(req->net_dev);
819 	struct efx_channel *channel = efx_get_channel(efx, req->rxq_index);
820 	int slot_idx = req - efx->rps_slot;
821 	struct efx_arfs_rule *rule;
822 	u16 arfs_id = 0;
823 	int rc;
824 
825 	rc = efx->type->filter_insert(efx, &req->spec, true);
826 	if (rc >= 0)
827 		/* Discard 'priority' part of EF10+ filter ID (mcdi_filters) */
828 		rc %= efx->type->max_rx_ip_filters;
829 	if (efx->rps_hash_table) {
830 		spin_lock_bh(&efx->rps_hash_lock);
831 		rule = efx_rps_hash_find(efx, &req->spec);
832 		/* The rule might have already gone, if someone else's request
833 		 * for the same spec was already worked and then expired before
834 		 * we got around to our work.  In that case we have nothing
835 		 * tying us to an arfs_id, meaning that as soon as the filter
836 		 * is considered for expiry it will be removed.
837 		 */
838 		if (rule) {
839 			if (rc < 0)
840 				rule->filter_id = EFX_ARFS_FILTER_ID_ERROR;
841 			else
842 				rule->filter_id = rc;
843 			arfs_id = rule->arfs_id;
844 		}
845 		spin_unlock_bh(&efx->rps_hash_lock);
846 	}
847 	if (rc >= 0) {
848 		/* Remember this so we can check whether to expire the filter
849 		 * later.
850 		 */
851 		mutex_lock(&efx->rps_mutex);
852 		if (channel->rps_flow_id[rc] == RPS_FLOW_ID_INVALID)
853 			channel->rfs_filter_count++;
854 		channel->rps_flow_id[rc] = req->flow_id;
855 		mutex_unlock(&efx->rps_mutex);
856 
857 		if (req->spec.ether_type == htons(ETH_P_IP))
858 			netif_info(efx, rx_status, efx->net_dev,
859 				   "steering %s %pI4:%u:%pI4:%u to queue %u [flow %u filter %d id %u]\n",
860 				   (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
861 				   req->spec.rem_host, ntohs(req->spec.rem_port),
862 				   req->spec.loc_host, ntohs(req->spec.loc_port),
863 				   req->rxq_index, req->flow_id, rc, arfs_id);
864 		else
865 			netif_info(efx, rx_status, efx->net_dev,
866 				   "steering %s [%pI6]:%u:[%pI6]:%u to queue %u [flow %u filter %d id %u]\n",
867 				   (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
868 				   req->spec.rem_host, ntohs(req->spec.rem_port),
869 				   req->spec.loc_host, ntohs(req->spec.loc_port),
870 				   req->rxq_index, req->flow_id, rc, arfs_id);
871 		channel->n_rfs_succeeded++;
872 	} else {
873 		if (req->spec.ether_type == htons(ETH_P_IP))
874 			netif_dbg(efx, rx_status, efx->net_dev,
875 				  "failed to steer %s %pI4:%u:%pI4:%u to queue %u [flow %u rc %d id %u]\n",
876 				  (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
877 				  req->spec.rem_host, ntohs(req->spec.rem_port),
878 				  req->spec.loc_host, ntohs(req->spec.loc_port),
879 				  req->rxq_index, req->flow_id, rc, arfs_id);
880 		else
881 			netif_dbg(efx, rx_status, efx->net_dev,
882 				  "failed to steer %s [%pI6]:%u:[%pI6]:%u to queue %u [flow %u rc %d id %u]\n",
883 				  (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
884 				  req->spec.rem_host, ntohs(req->spec.rem_port),
885 				  req->spec.loc_host, ntohs(req->spec.loc_port),
886 				  req->rxq_index, req->flow_id, rc, arfs_id);
887 		channel->n_rfs_failed++;
888 		/* We're overloading the NIC's filter tables, so let's do a
889 		 * chunk of extra expiry work.
890 		 */
891 		__efx_filter_rfs_expire(channel, min(channel->rfs_filter_count,
892 						     100u));
893 	}
894 
895 	/* Release references */
896 	clear_bit(slot_idx, &efx->rps_slot_map);
897 	dev_put(req->net_dev);
898 }
899 
900 int efx_filter_rfs(struct net_device *net_dev, const struct sk_buff *skb,
901 		   u16 rxq_index, u32 flow_id)
902 {
903 	struct efx_nic *efx = efx_netdev_priv(net_dev);
904 	struct efx_async_filter_insertion *req;
905 	struct efx_arfs_rule *rule;
906 	struct flow_keys fk;
907 	int slot_idx;
908 	bool new;
909 	int rc;
910 
911 	/* find a free slot */
912 	for (slot_idx = 0; slot_idx < EFX_RPS_MAX_IN_FLIGHT; slot_idx++)
913 		if (!test_and_set_bit(slot_idx, &efx->rps_slot_map))
914 			break;
915 	if (slot_idx >= EFX_RPS_MAX_IN_FLIGHT)
916 		return -EBUSY;
917 
918 	if (flow_id == RPS_FLOW_ID_INVALID) {
919 		rc = -EINVAL;
920 		goto out_clear;
921 	}
922 
923 	if (!skb_flow_dissect_flow_keys(skb, &fk, 0)) {
924 		rc = -EPROTONOSUPPORT;
925 		goto out_clear;
926 	}
927 
928 	if (fk.basic.n_proto != htons(ETH_P_IP) && fk.basic.n_proto != htons(ETH_P_IPV6)) {
929 		rc = -EPROTONOSUPPORT;
930 		goto out_clear;
931 	}
932 	if (fk.control.flags & FLOW_DIS_IS_FRAGMENT) {
933 		rc = -EPROTONOSUPPORT;
934 		goto out_clear;
935 	}
936 
937 	req = efx->rps_slot + slot_idx;
938 	efx_filter_init_rx(&req->spec, EFX_FILTER_PRI_HINT,
939 			   efx->rx_scatter ? EFX_FILTER_FLAG_RX_SCATTER : 0,
940 			   rxq_index);
941 	req->spec.match_flags =
942 		EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_IP_PROTO |
943 		EFX_FILTER_MATCH_LOC_HOST | EFX_FILTER_MATCH_LOC_PORT |
944 		EFX_FILTER_MATCH_REM_HOST | EFX_FILTER_MATCH_REM_PORT;
945 	req->spec.ether_type = fk.basic.n_proto;
946 	req->spec.ip_proto = fk.basic.ip_proto;
947 
948 	if (fk.basic.n_proto == htons(ETH_P_IP)) {
949 		req->spec.rem_host[0] = fk.addrs.v4addrs.src;
950 		req->spec.loc_host[0] = fk.addrs.v4addrs.dst;
951 	} else {
952 		memcpy(req->spec.rem_host, &fk.addrs.v6addrs.src,
953 		       sizeof(struct in6_addr));
954 		memcpy(req->spec.loc_host, &fk.addrs.v6addrs.dst,
955 		       sizeof(struct in6_addr));
956 	}
957 
958 	req->spec.rem_port = fk.ports.src;
959 	req->spec.loc_port = fk.ports.dst;
960 
961 	if (efx->rps_hash_table) {
962 		/* Add it to ARFS hash table */
963 		spin_lock(&efx->rps_hash_lock);
964 		rule = efx_rps_hash_add(efx, &req->spec, &new);
965 		if (!rule) {
966 			rc = -ENOMEM;
967 			goto out_unlock;
968 		}
969 		if (new)
970 			rule->arfs_id = efx->rps_next_id++ % RPS_NO_FILTER;
971 		rc = rule->arfs_id;
972 		/* Skip if existing or pending filter already does the right thing */
973 		if (!new && rule->rxq_index == rxq_index &&
974 		    rule->filter_id >= EFX_ARFS_FILTER_ID_PENDING)
975 			goto out_unlock;
976 		rule->rxq_index = rxq_index;
977 		rule->filter_id = EFX_ARFS_FILTER_ID_PENDING;
978 		spin_unlock(&efx->rps_hash_lock);
979 	} else {
980 		/* Without an ARFS hash table, we just use arfs_id 0 for all
981 		 * filters.  This means if multiple flows hash to the same
982 		 * flow_id, all but the most recently touched will be eligible
983 		 * for expiry.
984 		 */
985 		rc = 0;
986 	}
987 
988 	/* Queue the request */
989 	dev_hold(req->net_dev = net_dev);
990 	INIT_WORK(&req->work, efx_filter_rfs_work);
991 	req->rxq_index = rxq_index;
992 	req->flow_id = flow_id;
993 	schedule_work(&req->work);
994 	return rc;
995 out_unlock:
996 	spin_unlock(&efx->rps_hash_lock);
997 out_clear:
998 	clear_bit(slot_idx, &efx->rps_slot_map);
999 	return rc;
1000 }
1001 
1002 bool __efx_filter_rfs_expire(struct efx_channel *channel, unsigned int quota)
1003 {
1004 	bool (*expire_one)(struct efx_nic *efx, u32 flow_id, unsigned int index);
1005 	struct efx_nic *efx = channel->efx;
1006 	unsigned int index, size, start;
1007 	u32 flow_id;
1008 
1009 	if (!mutex_trylock(&efx->rps_mutex))
1010 		return false;
1011 	expire_one = efx->type->filter_rfs_expire_one;
1012 	index = channel->rfs_expire_index;
1013 	start = index;
1014 	size = efx->type->max_rx_ip_filters;
1015 	while (quota) {
1016 		flow_id = channel->rps_flow_id[index];
1017 
1018 		if (flow_id != RPS_FLOW_ID_INVALID) {
1019 			quota--;
1020 			if (expire_one(efx, flow_id, index)) {
1021 				netif_info(efx, rx_status, efx->net_dev,
1022 					   "expired filter %d [channel %u flow %u]\n",
1023 					   index, channel->channel, flow_id);
1024 				channel->rps_flow_id[index] = RPS_FLOW_ID_INVALID;
1025 				channel->rfs_filter_count--;
1026 			}
1027 		}
1028 		if (++index == size)
1029 			index = 0;
1030 		/* If we were called with a quota that exceeds the total number
1031 		 * of filters in the table (which shouldn't happen, but could
1032 		 * if two callers race), ensure that we don't loop forever -
1033 		 * stop when we've examined every row of the table.
1034 		 */
1035 		if (index == start)
1036 			break;
1037 	}
1038 
1039 	channel->rfs_expire_index = index;
1040 	mutex_unlock(&efx->rps_mutex);
1041 	return true;
1042 }
1043 
1044 #endif /* CONFIG_RFS_ACCEL */
1045