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 "efx.h"
15 #include "nic.h"
16 #include "rx_common.h"
17 
18 /* This is the percentage fill level below which new RX descriptors
19  * will be added to the RX descriptor ring.
20  */
21 static unsigned int rx_refill_threshold;
22 module_param(rx_refill_threshold, uint, 0444);
23 MODULE_PARM_DESC(rx_refill_threshold,
24 		 "RX descriptor ring refill threshold (%)");
25 
26 /* RX maximum head room required.
27  *
28  * This must be at least 1 to prevent overflow, plus one packet-worth
29  * to allow pipelined receives.
30  */
31 #define EFX_RXD_HEAD_ROOM (1 + EFX_RX_MAX_FRAGS)
32 
33 /* Check the RX page recycle ring for a page that can be reused. */
34 static struct page *efx_reuse_page(struct efx_rx_queue *rx_queue)
35 {
36 	struct efx_nic *efx = rx_queue->efx;
37 	struct efx_rx_page_state *state;
38 	unsigned int index;
39 	struct page *page;
40 
41 	if (unlikely(!rx_queue->page_ring))
42 		return NULL;
43 	index = rx_queue->page_remove & rx_queue->page_ptr_mask;
44 	page = rx_queue->page_ring[index];
45 	if (page == NULL)
46 		return NULL;
47 
48 	rx_queue->page_ring[index] = NULL;
49 	/* page_remove cannot exceed page_add. */
50 	if (rx_queue->page_remove != rx_queue->page_add)
51 		++rx_queue->page_remove;
52 
53 	/* If page_count is 1 then we hold the only reference to this page. */
54 	if (page_count(page) == 1) {
55 		++rx_queue->page_recycle_count;
56 		return page;
57 	} else {
58 		state = page_address(page);
59 		dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
60 			       PAGE_SIZE << efx->rx_buffer_order,
61 			       DMA_FROM_DEVICE);
62 		put_page(page);
63 		++rx_queue->page_recycle_failed;
64 	}
65 
66 	return NULL;
67 }
68 
69 /* Attempt to recycle the page if there is an RX recycle ring; the page can
70  * only be added if this is the final RX buffer, to prevent pages being used in
71  * the descriptor ring and appearing in the recycle ring simultaneously.
72  */
73 static void efx_recycle_rx_page(struct efx_channel *channel,
74 				struct efx_rx_buffer *rx_buf)
75 {
76 	struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
77 	struct efx_nic *efx = rx_queue->efx;
78 	struct page *page = rx_buf->page;
79 	unsigned int index;
80 
81 	/* Only recycle the page after processing the final buffer. */
82 	if (!(rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE))
83 		return;
84 
85 	index = rx_queue->page_add & rx_queue->page_ptr_mask;
86 	if (rx_queue->page_ring[index] == NULL) {
87 		unsigned int read_index = rx_queue->page_remove &
88 			rx_queue->page_ptr_mask;
89 
90 		/* The next slot in the recycle ring is available, but
91 		 * increment page_remove if the read pointer currently
92 		 * points here.
93 		 */
94 		if (read_index == index)
95 			++rx_queue->page_remove;
96 		rx_queue->page_ring[index] = page;
97 		++rx_queue->page_add;
98 		return;
99 	}
100 	++rx_queue->page_recycle_full;
101 	efx_unmap_rx_buffer(efx, rx_buf);
102 	put_page(rx_buf->page);
103 }
104 
105 /* Recycle the pages that are used by buffers that have just been received. */
106 void efx_recycle_rx_pages(struct efx_channel *channel,
107 			  struct efx_rx_buffer *rx_buf,
108 			  unsigned int n_frags)
109 {
110 	struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
111 
112 	if (unlikely(!rx_queue->page_ring))
113 		return;
114 
115 	do {
116 		efx_recycle_rx_page(channel, rx_buf);
117 		rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
118 	} while (--n_frags);
119 }
120 
121 void efx_discard_rx_packet(struct efx_channel *channel,
122 			   struct efx_rx_buffer *rx_buf,
123 			   unsigned int n_frags)
124 {
125 	struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
126 
127 	efx_recycle_rx_pages(channel, rx_buf, n_frags);
128 
129 	efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
130 }
131 
132 static void efx_init_rx_recycle_ring(struct efx_rx_queue *rx_queue)
133 {
134 	unsigned int bufs_in_recycle_ring, page_ring_size;
135 	struct efx_nic *efx = rx_queue->efx;
136 
137 	bufs_in_recycle_ring = efx_rx_recycle_ring_size(efx);
138 	page_ring_size = roundup_pow_of_two(bufs_in_recycle_ring /
139 					    efx->rx_bufs_per_page);
140 	rx_queue->page_ring = kcalloc(page_ring_size,
141 				      sizeof(*rx_queue->page_ring), GFP_KERNEL);
142 	if (!rx_queue->page_ring)
143 		rx_queue->page_ptr_mask = 0;
144 	else
145 		rx_queue->page_ptr_mask = page_ring_size - 1;
146 }
147 
148 static void efx_fini_rx_recycle_ring(struct efx_rx_queue *rx_queue)
149 {
150 	struct efx_nic *efx = rx_queue->efx;
151 	int i;
152 
153 	/* Unmap and release the pages in the recycle ring. Remove the ring. */
154 	for (i = 0; i <= rx_queue->page_ptr_mask; i++) {
155 		struct page *page = rx_queue->page_ring[i];
156 		struct efx_rx_page_state *state;
157 
158 		if (page == NULL)
159 			continue;
160 
161 		state = page_address(page);
162 		dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
163 			       PAGE_SIZE << efx->rx_buffer_order,
164 			       DMA_FROM_DEVICE);
165 		put_page(page);
166 	}
167 	kfree(rx_queue->page_ring);
168 	rx_queue->page_ring = NULL;
169 }
170 
171 static void efx_fini_rx_buffer(struct efx_rx_queue *rx_queue,
172 			       struct efx_rx_buffer *rx_buf)
173 {
174 	/* Release the page reference we hold for the buffer. */
175 	if (rx_buf->page)
176 		put_page(rx_buf->page);
177 
178 	/* If this is the last buffer in a page, unmap and free it. */
179 	if (rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE) {
180 		efx_unmap_rx_buffer(rx_queue->efx, rx_buf);
181 		efx_free_rx_buffers(rx_queue, rx_buf, 1);
182 	}
183 	rx_buf->page = NULL;
184 }
185 
186 int efx_probe_rx_queue(struct efx_rx_queue *rx_queue)
187 {
188 	struct efx_nic *efx = rx_queue->efx;
189 	unsigned int entries;
190 	int rc;
191 
192 	/* Create the smallest power-of-two aligned ring */
193 	entries = max(roundup_pow_of_two(efx->rxq_entries), EFX_MIN_DMAQ_SIZE);
194 	EFX_WARN_ON_PARANOID(entries > EFX_MAX_DMAQ_SIZE);
195 	rx_queue->ptr_mask = entries - 1;
196 
197 	netif_dbg(efx, probe, efx->net_dev,
198 		  "creating RX queue %d size %#x mask %#x\n",
199 		  efx_rx_queue_index(rx_queue), efx->rxq_entries,
200 		  rx_queue->ptr_mask);
201 
202 	/* Allocate RX buffers */
203 	rx_queue->buffer = kcalloc(entries, sizeof(*rx_queue->buffer),
204 				   GFP_KERNEL);
205 	if (!rx_queue->buffer)
206 		return -ENOMEM;
207 
208 	rc = efx_nic_probe_rx(rx_queue);
209 	if (rc) {
210 		kfree(rx_queue->buffer);
211 		rx_queue->buffer = NULL;
212 	}
213 
214 	return rc;
215 }
216 
217 void efx_init_rx_queue(struct efx_rx_queue *rx_queue)
218 {
219 	unsigned int max_fill, trigger, max_trigger;
220 	struct efx_nic *efx = rx_queue->efx;
221 	int rc = 0;
222 
223 	netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
224 		  "initialising RX queue %d\n", efx_rx_queue_index(rx_queue));
225 
226 	/* Initialise ptr fields */
227 	rx_queue->added_count = 0;
228 	rx_queue->notified_count = 0;
229 	rx_queue->removed_count = 0;
230 	rx_queue->min_fill = -1U;
231 	efx_init_rx_recycle_ring(rx_queue);
232 
233 	rx_queue->page_remove = 0;
234 	rx_queue->page_add = rx_queue->page_ptr_mask + 1;
235 	rx_queue->page_recycle_count = 0;
236 	rx_queue->page_recycle_failed = 0;
237 	rx_queue->page_recycle_full = 0;
238 
239 	/* Initialise limit fields */
240 	max_fill = efx->rxq_entries - EFX_RXD_HEAD_ROOM;
241 	max_trigger =
242 		max_fill - efx->rx_pages_per_batch * efx->rx_bufs_per_page;
243 	if (rx_refill_threshold != 0) {
244 		trigger = max_fill * min(rx_refill_threshold, 100U) / 100U;
245 		if (trigger > max_trigger)
246 			trigger = max_trigger;
247 	} else {
248 		trigger = max_trigger;
249 	}
250 
251 	rx_queue->max_fill = max_fill;
252 	rx_queue->fast_fill_trigger = trigger;
253 	rx_queue->refill_enabled = true;
254 
255 	/* Initialise XDP queue information */
256 	rc = xdp_rxq_info_reg(&rx_queue->xdp_rxq_info, efx->net_dev,
257 			      rx_queue->core_index, 0);
258 
259 	if (rc) {
260 		netif_err(efx, rx_err, efx->net_dev,
261 			  "Failure to initialise XDP queue information rc=%d\n",
262 			  rc);
263 		efx->xdp_rxq_info_failed = true;
264 	} else {
265 		rx_queue->xdp_rxq_info_valid = true;
266 	}
267 
268 	/* Set up RX descriptor ring */
269 	efx_nic_init_rx(rx_queue);
270 }
271 
272 void efx_fini_rx_queue(struct efx_rx_queue *rx_queue)
273 {
274 	struct efx_rx_buffer *rx_buf;
275 	int i;
276 
277 	netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
278 		  "shutting down RX queue %d\n", efx_rx_queue_index(rx_queue));
279 
280 	del_timer_sync(&rx_queue->slow_fill);
281 
282 	/* Release RX buffers from the current read ptr to the write ptr */
283 	if (rx_queue->buffer) {
284 		for (i = rx_queue->removed_count; i < rx_queue->added_count;
285 		     i++) {
286 			unsigned int index = i & rx_queue->ptr_mask;
287 
288 			rx_buf = efx_rx_buffer(rx_queue, index);
289 			efx_fini_rx_buffer(rx_queue, rx_buf);
290 		}
291 	}
292 
293 	efx_fini_rx_recycle_ring(rx_queue);
294 
295 	if (rx_queue->xdp_rxq_info_valid)
296 		xdp_rxq_info_unreg(&rx_queue->xdp_rxq_info);
297 
298 	rx_queue->xdp_rxq_info_valid = false;
299 }
300 
301 void efx_remove_rx_queue(struct efx_rx_queue *rx_queue)
302 {
303 	netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
304 		  "destroying RX queue %d\n", efx_rx_queue_index(rx_queue));
305 
306 	efx_nic_remove_rx(rx_queue);
307 
308 	kfree(rx_queue->buffer);
309 	rx_queue->buffer = NULL;
310 }
311 
312 /* Unmap a DMA-mapped page.  This function is only called for the final RX
313  * buffer in a page.
314  */
315 void efx_unmap_rx_buffer(struct efx_nic *efx,
316 			 struct efx_rx_buffer *rx_buf)
317 {
318 	struct page *page = rx_buf->page;
319 
320 	if (page) {
321 		struct efx_rx_page_state *state = page_address(page);
322 
323 		dma_unmap_page(&efx->pci_dev->dev,
324 			       state->dma_addr,
325 			       PAGE_SIZE << efx->rx_buffer_order,
326 			       DMA_FROM_DEVICE);
327 	}
328 }
329 
330 void efx_free_rx_buffers(struct efx_rx_queue *rx_queue,
331 			 struct efx_rx_buffer *rx_buf,
332 			 unsigned int num_bufs)
333 {
334 	do {
335 		if (rx_buf->page) {
336 			put_page(rx_buf->page);
337 			rx_buf->page = NULL;
338 		}
339 		rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
340 	} while (--num_bufs);
341 }
342 
343 void efx_rx_slow_fill(struct timer_list *t)
344 {
345 	struct efx_rx_queue *rx_queue = from_timer(rx_queue, t, slow_fill);
346 
347 	/* Post an event to cause NAPI to run and refill the queue */
348 	efx_nic_generate_fill_event(rx_queue);
349 	++rx_queue->slow_fill_count;
350 }
351 
352 void efx_schedule_slow_fill(struct efx_rx_queue *rx_queue)
353 {
354 	mod_timer(&rx_queue->slow_fill, jiffies + msecs_to_jiffies(10));
355 }
356 
357 /* efx_init_rx_buffers - create EFX_RX_BATCH page-based RX buffers
358  *
359  * @rx_queue:		Efx RX queue
360  *
361  * This allocates a batch of pages, maps them for DMA, and populates
362  * struct efx_rx_buffers for each one. Return a negative error code or
363  * 0 on success. If a single page can be used for multiple buffers,
364  * then the page will either be inserted fully, or not at all.
365  */
366 static int efx_init_rx_buffers(struct efx_rx_queue *rx_queue, bool atomic)
367 {
368 	unsigned int page_offset, index, count;
369 	struct efx_nic *efx = rx_queue->efx;
370 	struct efx_rx_page_state *state;
371 	struct efx_rx_buffer *rx_buf;
372 	dma_addr_t dma_addr;
373 	struct page *page;
374 
375 	count = 0;
376 	do {
377 		page = efx_reuse_page(rx_queue);
378 		if (page == NULL) {
379 			page = alloc_pages(__GFP_COMP |
380 					   (atomic ? GFP_ATOMIC : GFP_KERNEL),
381 					   efx->rx_buffer_order);
382 			if (unlikely(page == NULL))
383 				return -ENOMEM;
384 			dma_addr =
385 				dma_map_page(&efx->pci_dev->dev, page, 0,
386 					     PAGE_SIZE << efx->rx_buffer_order,
387 					     DMA_FROM_DEVICE);
388 			if (unlikely(dma_mapping_error(&efx->pci_dev->dev,
389 						       dma_addr))) {
390 				__free_pages(page, efx->rx_buffer_order);
391 				return -EIO;
392 			}
393 			state = page_address(page);
394 			state->dma_addr = dma_addr;
395 		} else {
396 			state = page_address(page);
397 			dma_addr = state->dma_addr;
398 		}
399 
400 		dma_addr += sizeof(struct efx_rx_page_state);
401 		page_offset = sizeof(struct efx_rx_page_state);
402 
403 		do {
404 			index = rx_queue->added_count & rx_queue->ptr_mask;
405 			rx_buf = efx_rx_buffer(rx_queue, index);
406 			rx_buf->dma_addr = dma_addr + efx->rx_ip_align +
407 					   EFX_XDP_HEADROOM;
408 			rx_buf->page = page;
409 			rx_buf->page_offset = page_offset + efx->rx_ip_align +
410 					      EFX_XDP_HEADROOM;
411 			rx_buf->len = efx->rx_dma_len;
412 			rx_buf->flags = 0;
413 			++rx_queue->added_count;
414 			get_page(page);
415 			dma_addr += efx->rx_page_buf_step;
416 			page_offset += efx->rx_page_buf_step;
417 		} while (page_offset + efx->rx_page_buf_step <= PAGE_SIZE);
418 
419 		rx_buf->flags = EFX_RX_BUF_LAST_IN_PAGE;
420 	} while (++count < efx->rx_pages_per_batch);
421 
422 	return 0;
423 }
424 
425 void efx_rx_config_page_split(struct efx_nic *efx)
426 {
427 	efx->rx_page_buf_step = ALIGN(efx->rx_dma_len + efx->rx_ip_align +
428 				      EFX_XDP_HEADROOM + EFX_XDP_TAILROOM,
429 				      EFX_RX_BUF_ALIGNMENT);
430 	efx->rx_bufs_per_page = efx->rx_buffer_order ? 1 :
431 		((PAGE_SIZE - sizeof(struct efx_rx_page_state)) /
432 		efx->rx_page_buf_step);
433 	efx->rx_buffer_truesize = (PAGE_SIZE << efx->rx_buffer_order) /
434 		efx->rx_bufs_per_page;
435 	efx->rx_pages_per_batch = DIV_ROUND_UP(EFX_RX_PREFERRED_BATCH,
436 					       efx->rx_bufs_per_page);
437 }
438 
439 /* efx_fast_push_rx_descriptors - push new RX descriptors quickly
440  * @rx_queue:		RX descriptor queue
441  *
442  * This will aim to fill the RX descriptor queue up to
443  * @rx_queue->@max_fill. If there is insufficient atomic
444  * memory to do so, a slow fill will be scheduled.
445  *
446  * The caller must provide serialisation (none is used here). In practise,
447  * this means this function must run from the NAPI handler, or be called
448  * when NAPI is disabled.
449  */
450 void efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue, bool atomic)
451 {
452 	struct efx_nic *efx = rx_queue->efx;
453 	unsigned int fill_level, batch_size;
454 	int space, rc = 0;
455 
456 	if (!rx_queue->refill_enabled)
457 		return;
458 
459 	/* Calculate current fill level, and exit if we don't need to fill */
460 	fill_level = (rx_queue->added_count - rx_queue->removed_count);
461 	EFX_WARN_ON_ONCE_PARANOID(fill_level > rx_queue->efx->rxq_entries);
462 	if (fill_level >= rx_queue->fast_fill_trigger)
463 		goto out;
464 
465 	/* Record minimum fill level */
466 	if (unlikely(fill_level < rx_queue->min_fill)) {
467 		if (fill_level)
468 			rx_queue->min_fill = fill_level;
469 	}
470 
471 	batch_size = efx->rx_pages_per_batch * efx->rx_bufs_per_page;
472 	space = rx_queue->max_fill - fill_level;
473 	EFX_WARN_ON_ONCE_PARANOID(space < batch_size);
474 
475 	netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
476 		   "RX queue %d fast-filling descriptor ring from"
477 		   " level %d to level %d\n",
478 		   efx_rx_queue_index(rx_queue), fill_level,
479 		   rx_queue->max_fill);
480 
481 	do {
482 		rc = efx_init_rx_buffers(rx_queue, atomic);
483 		if (unlikely(rc)) {
484 			/* Ensure that we don't leave the rx queue empty */
485 			efx_schedule_slow_fill(rx_queue);
486 			goto out;
487 		}
488 	} while ((space -= batch_size) >= batch_size);
489 
490 	netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
491 		   "RX queue %d fast-filled descriptor ring "
492 		   "to level %d\n", efx_rx_queue_index(rx_queue),
493 		   rx_queue->added_count - rx_queue->removed_count);
494 
495  out:
496 	if (rx_queue->notified_count != rx_queue->added_count)
497 		efx_nic_notify_rx_desc(rx_queue);
498 }
499 
500 /* Pass a received packet up through GRO.  GRO can handle pages
501  * regardless of checksum state and skbs with a good checksum.
502  */
503 void
504 efx_rx_packet_gro(struct efx_channel *channel, struct efx_rx_buffer *rx_buf,
505 		  unsigned int n_frags, u8 *eh, __wsum csum)
506 {
507 	struct napi_struct *napi = &channel->napi_str;
508 	struct efx_nic *efx = channel->efx;
509 	struct sk_buff *skb;
510 
511 	skb = napi_get_frags(napi);
512 	if (unlikely(!skb)) {
513 		struct efx_rx_queue *rx_queue;
514 
515 		rx_queue = efx_channel_get_rx_queue(channel);
516 		efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
517 		return;
518 	}
519 
520 	if (efx->net_dev->features & NETIF_F_RXHASH &&
521 	    efx_rx_buf_hash_valid(efx, eh))
522 		skb_set_hash(skb, efx_rx_buf_hash(efx, eh),
523 			     PKT_HASH_TYPE_L3);
524 	if (csum) {
525 		skb->csum = csum;
526 		skb->ip_summed = CHECKSUM_COMPLETE;
527 	} else {
528 		skb->ip_summed = ((rx_buf->flags & EFX_RX_PKT_CSUMMED) ?
529 				  CHECKSUM_UNNECESSARY : CHECKSUM_NONE);
530 	}
531 	skb->csum_level = !!(rx_buf->flags & EFX_RX_PKT_CSUM_LEVEL);
532 
533 	for (;;) {
534 		skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
535 				   rx_buf->page, rx_buf->page_offset,
536 				   rx_buf->len);
537 		rx_buf->page = NULL;
538 		skb->len += rx_buf->len;
539 		if (skb_shinfo(skb)->nr_frags == n_frags)
540 			break;
541 
542 		rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf);
543 	}
544 
545 	skb->data_len = skb->len;
546 	skb->truesize += n_frags * efx->rx_buffer_truesize;
547 
548 	skb_record_rx_queue(skb, channel->rx_queue.core_index);
549 
550 	napi_gro_frags(napi);
551 }
552 
553 /* RSS contexts.  We're using linked lists and crappy O(n) algorithms, because
554  * (a) this is an infrequent control-plane operation and (b) n is small (max 64)
555  */
556 struct efx_rss_context *efx_alloc_rss_context_entry(struct efx_nic *efx)
557 {
558 	struct list_head *head = &efx->rss_context.list;
559 	struct efx_rss_context *ctx, *new;
560 	u32 id = 1; /* Don't use zero, that refers to the master RSS context */
561 
562 	WARN_ON(!mutex_is_locked(&efx->rss_lock));
563 
564 	/* Search for first gap in the numbering */
565 	list_for_each_entry(ctx, head, list) {
566 		if (ctx->user_id != id)
567 			break;
568 		id++;
569 		/* Check for wrap.  If this happens, we have nearly 2^32
570 		 * allocated RSS contexts, which seems unlikely.
571 		 */
572 		if (WARN_ON_ONCE(!id))
573 			return NULL;
574 	}
575 
576 	/* Create the new entry */
577 	new = kmalloc(sizeof(*new), GFP_KERNEL);
578 	if (!new)
579 		return NULL;
580 	new->context_id = EFX_MCDI_RSS_CONTEXT_INVALID;
581 	new->rx_hash_udp_4tuple = false;
582 
583 	/* Insert the new entry into the gap */
584 	new->user_id = id;
585 	list_add_tail(&new->list, &ctx->list);
586 	return new;
587 }
588 
589 struct efx_rss_context *efx_find_rss_context_entry(struct efx_nic *efx, u32 id)
590 {
591 	struct list_head *head = &efx->rss_context.list;
592 	struct efx_rss_context *ctx;
593 
594 	WARN_ON(!mutex_is_locked(&efx->rss_lock));
595 
596 	list_for_each_entry(ctx, head, list)
597 		if (ctx->user_id == id)
598 			return ctx;
599 	return NULL;
600 }
601 
602 void efx_free_rss_context_entry(struct efx_rss_context *ctx)
603 {
604 	list_del(&ctx->list);
605 	kfree(ctx);
606 }
607 
608 void efx_set_default_rx_indir_table(struct efx_nic *efx,
609 				    struct efx_rss_context *ctx)
610 {
611 	size_t i;
612 
613 	for (i = 0; i < ARRAY_SIZE(ctx->rx_indir_table); i++)
614 		ctx->rx_indir_table[i] =
615 			ethtool_rxfh_indir_default(i, efx->rss_spread);
616 }
617 
618 /**
619  * efx_filter_is_mc_recipient - test whether spec is a multicast recipient
620  * @spec: Specification to test
621  *
622  * Return: %true if the specification is a non-drop RX filter that
623  * matches a local MAC address I/G bit value of 1 or matches a local
624  * IPv4 or IPv6 address value in the respective multicast address
625  * range.  Otherwise %false.
626  */
627 bool efx_filter_is_mc_recipient(const struct efx_filter_spec *spec)
628 {
629 	if (!(spec->flags & EFX_FILTER_FLAG_RX) ||
630 	    spec->dmaq_id == EFX_FILTER_RX_DMAQ_ID_DROP)
631 		return false;
632 
633 	if (spec->match_flags &
634 	    (EFX_FILTER_MATCH_LOC_MAC | EFX_FILTER_MATCH_LOC_MAC_IG) &&
635 	    is_multicast_ether_addr(spec->loc_mac))
636 		return true;
637 
638 	if ((spec->match_flags &
639 	     (EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_LOC_HOST)) ==
640 	    (EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_LOC_HOST)) {
641 		if (spec->ether_type == htons(ETH_P_IP) &&
642 		    ipv4_is_multicast(spec->loc_host[0]))
643 			return true;
644 		if (spec->ether_type == htons(ETH_P_IPV6) &&
645 		    ((const u8 *)spec->loc_host)[0] == 0xff)
646 			return true;
647 	}
648 
649 	return false;
650 }
651 
652 bool efx_filter_spec_equal(const struct efx_filter_spec *left,
653 			   const struct efx_filter_spec *right)
654 {
655 	if ((left->match_flags ^ right->match_flags) |
656 	    ((left->flags ^ right->flags) &
657 	     (EFX_FILTER_FLAG_RX | EFX_FILTER_FLAG_TX)))
658 		return false;
659 
660 	return memcmp(&left->outer_vid, &right->outer_vid,
661 		      sizeof(struct efx_filter_spec) -
662 		      offsetof(struct efx_filter_spec, outer_vid)) == 0;
663 }
664 
665 u32 efx_filter_spec_hash(const struct efx_filter_spec *spec)
666 {
667 	BUILD_BUG_ON(offsetof(struct efx_filter_spec, outer_vid) & 3);
668 	return jhash2((const u32 *)&spec->outer_vid,
669 		      (sizeof(struct efx_filter_spec) -
670 		       offsetof(struct efx_filter_spec, outer_vid)) / 4,
671 		      0);
672 }
673 
674 #ifdef CONFIG_RFS_ACCEL
675 bool efx_rps_check_rule(struct efx_arfs_rule *rule, unsigned int filter_idx,
676 			bool *force)
677 {
678 	if (rule->filter_id == EFX_ARFS_FILTER_ID_PENDING) {
679 		/* ARFS is currently updating this entry, leave it */
680 		return false;
681 	}
682 	if (rule->filter_id == EFX_ARFS_FILTER_ID_ERROR) {
683 		/* ARFS tried and failed to update this, so it's probably out
684 		 * of date.  Remove the filter and the ARFS rule entry.
685 		 */
686 		rule->filter_id = EFX_ARFS_FILTER_ID_REMOVING;
687 		*force = true;
688 		return true;
689 	} else if (WARN_ON(rule->filter_id != filter_idx)) { /* can't happen */
690 		/* ARFS has moved on, so old filter is not needed.  Since we did
691 		 * not mark the rule with EFX_ARFS_FILTER_ID_REMOVING, it will
692 		 * not be removed by efx_rps_hash_del() subsequently.
693 		 */
694 		*force = true;
695 		return true;
696 	}
697 	/* Remove it iff ARFS wants to. */
698 	return true;
699 }
700 
701 static
702 struct hlist_head *efx_rps_hash_bucket(struct efx_nic *efx,
703 				       const struct efx_filter_spec *spec)
704 {
705 	u32 hash = efx_filter_spec_hash(spec);
706 
707 	lockdep_assert_held(&efx->rps_hash_lock);
708 	if (!efx->rps_hash_table)
709 		return NULL;
710 	return &efx->rps_hash_table[hash % EFX_ARFS_HASH_TABLE_SIZE];
711 }
712 
713 struct efx_arfs_rule *efx_rps_hash_find(struct efx_nic *efx,
714 					const struct efx_filter_spec *spec)
715 {
716 	struct efx_arfs_rule *rule;
717 	struct hlist_head *head;
718 	struct hlist_node *node;
719 
720 	head = efx_rps_hash_bucket(efx, spec);
721 	if (!head)
722 		return NULL;
723 	hlist_for_each(node, head) {
724 		rule = container_of(node, struct efx_arfs_rule, node);
725 		if (efx_filter_spec_equal(spec, &rule->spec))
726 			return rule;
727 	}
728 	return NULL;
729 }
730 
731 struct efx_arfs_rule *efx_rps_hash_add(struct efx_nic *efx,
732 				       const struct efx_filter_spec *spec,
733 				       bool *new)
734 {
735 	struct efx_arfs_rule *rule;
736 	struct hlist_head *head;
737 	struct hlist_node *node;
738 
739 	head = efx_rps_hash_bucket(efx, spec);
740 	if (!head)
741 		return NULL;
742 	hlist_for_each(node, head) {
743 		rule = container_of(node, struct efx_arfs_rule, node);
744 		if (efx_filter_spec_equal(spec, &rule->spec)) {
745 			*new = false;
746 			return rule;
747 		}
748 	}
749 	rule = kmalloc(sizeof(*rule), GFP_ATOMIC);
750 	*new = true;
751 	if (rule) {
752 		memcpy(&rule->spec, spec, sizeof(rule->spec));
753 		hlist_add_head(&rule->node, head);
754 	}
755 	return rule;
756 }
757 
758 void efx_rps_hash_del(struct efx_nic *efx, const struct efx_filter_spec *spec)
759 {
760 	struct efx_arfs_rule *rule;
761 	struct hlist_head *head;
762 	struct hlist_node *node;
763 
764 	head = efx_rps_hash_bucket(efx, spec);
765 	if (WARN_ON(!head))
766 		return;
767 	hlist_for_each(node, head) {
768 		rule = container_of(node, struct efx_arfs_rule, node);
769 		if (efx_filter_spec_equal(spec, &rule->spec)) {
770 			/* Someone already reused the entry.  We know that if
771 			 * this check doesn't fire (i.e. filter_id == REMOVING)
772 			 * then the REMOVING mark was put there by our caller,
773 			 * because caller is holding a lock on filter table and
774 			 * only holders of that lock set REMOVING.
775 			 */
776 			if (rule->filter_id != EFX_ARFS_FILTER_ID_REMOVING)
777 				return;
778 			hlist_del(node);
779 			kfree(rule);
780 			return;
781 		}
782 	}
783 	/* We didn't find it. */
784 	WARN_ON(1);
785 }
786 #endif
787 
788 int efx_probe_filters(struct efx_nic *efx)
789 {
790 	int rc;
791 
792 	mutex_lock(&efx->mac_lock);
793 	down_write(&efx->filter_sem);
794 	rc = efx->type->filter_table_probe(efx);
795 	if (rc)
796 		goto out_unlock;
797 
798 #ifdef CONFIG_RFS_ACCEL
799 	if (efx->type->offload_features & NETIF_F_NTUPLE) {
800 		struct efx_channel *channel;
801 		int i, success = 1;
802 
803 		efx_for_each_channel(channel, efx) {
804 			channel->rps_flow_id =
805 				kcalloc(efx->type->max_rx_ip_filters,
806 					sizeof(*channel->rps_flow_id),
807 					GFP_KERNEL);
808 			if (!channel->rps_flow_id)
809 				success = 0;
810 			else
811 				for (i = 0;
812 				     i < efx->type->max_rx_ip_filters;
813 				     ++i)
814 					channel->rps_flow_id[i] =
815 						RPS_FLOW_ID_INVALID;
816 			channel->rfs_expire_index = 0;
817 			channel->rfs_filter_count = 0;
818 		}
819 
820 		if (!success) {
821 			efx_for_each_channel(channel, efx)
822 				kfree(channel->rps_flow_id);
823 			efx->type->filter_table_remove(efx);
824 			rc = -ENOMEM;
825 			goto out_unlock;
826 		}
827 	}
828 #endif
829 out_unlock:
830 	up_write(&efx->filter_sem);
831 	mutex_unlock(&efx->mac_lock);
832 	return rc;
833 }
834 
835 void efx_remove_filters(struct efx_nic *efx)
836 {
837 #ifdef CONFIG_RFS_ACCEL
838 	struct efx_channel *channel;
839 
840 	efx_for_each_channel(channel, efx) {
841 		cancel_delayed_work_sync(&channel->filter_work);
842 		kfree(channel->rps_flow_id);
843 		channel->rps_flow_id = NULL;
844 	}
845 #endif
846 	down_write(&efx->filter_sem);
847 	efx->type->filter_table_remove(efx);
848 	up_write(&efx->filter_sem);
849 }
850 
851 #ifdef CONFIG_RFS_ACCEL
852 
853 static void efx_filter_rfs_work(struct work_struct *data)
854 {
855 	struct efx_async_filter_insertion *req = container_of(data, struct efx_async_filter_insertion,
856 							      work);
857 	struct efx_nic *efx = netdev_priv(req->net_dev);
858 	struct efx_channel *channel = efx_get_channel(efx, req->rxq_index);
859 	int slot_idx = req - efx->rps_slot;
860 	struct efx_arfs_rule *rule;
861 	u16 arfs_id = 0;
862 	int rc;
863 
864 	rc = efx->type->filter_insert(efx, &req->spec, true);
865 	if (rc >= 0)
866 		/* Discard 'priority' part of EF10+ filter ID (mcdi_filters) */
867 		rc %= efx->type->max_rx_ip_filters;
868 	if (efx->rps_hash_table) {
869 		spin_lock_bh(&efx->rps_hash_lock);
870 		rule = efx_rps_hash_find(efx, &req->spec);
871 		/* The rule might have already gone, if someone else's request
872 		 * for the same spec was already worked and then expired before
873 		 * we got around to our work.  In that case we have nothing
874 		 * tying us to an arfs_id, meaning that as soon as the filter
875 		 * is considered for expiry it will be removed.
876 		 */
877 		if (rule) {
878 			if (rc < 0)
879 				rule->filter_id = EFX_ARFS_FILTER_ID_ERROR;
880 			else
881 				rule->filter_id = rc;
882 			arfs_id = rule->arfs_id;
883 		}
884 		spin_unlock_bh(&efx->rps_hash_lock);
885 	}
886 	if (rc >= 0) {
887 		/* Remember this so we can check whether to expire the filter
888 		 * later.
889 		 */
890 		mutex_lock(&efx->rps_mutex);
891 		if (channel->rps_flow_id[rc] == RPS_FLOW_ID_INVALID)
892 			channel->rfs_filter_count++;
893 		channel->rps_flow_id[rc] = req->flow_id;
894 		mutex_unlock(&efx->rps_mutex);
895 
896 		if (req->spec.ether_type == htons(ETH_P_IP))
897 			netif_info(efx, rx_status, efx->net_dev,
898 				   "steering %s %pI4:%u:%pI4:%u to queue %u [flow %u filter %d id %u]\n",
899 				   (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
900 				   req->spec.rem_host, ntohs(req->spec.rem_port),
901 				   req->spec.loc_host, ntohs(req->spec.loc_port),
902 				   req->rxq_index, req->flow_id, rc, arfs_id);
903 		else
904 			netif_info(efx, rx_status, efx->net_dev,
905 				   "steering %s [%pI6]:%u:[%pI6]:%u to queue %u [flow %u filter %d id %u]\n",
906 				   (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
907 				   req->spec.rem_host, ntohs(req->spec.rem_port),
908 				   req->spec.loc_host, ntohs(req->spec.loc_port),
909 				   req->rxq_index, req->flow_id, rc, arfs_id);
910 		channel->n_rfs_succeeded++;
911 	} else {
912 		if (req->spec.ether_type == htons(ETH_P_IP))
913 			netif_dbg(efx, rx_status, efx->net_dev,
914 				  "failed to steer %s %pI4:%u:%pI4:%u to queue %u [flow %u rc %d id %u]\n",
915 				  (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
916 				  req->spec.rem_host, ntohs(req->spec.rem_port),
917 				  req->spec.loc_host, ntohs(req->spec.loc_port),
918 				  req->rxq_index, req->flow_id, rc, arfs_id);
919 		else
920 			netif_dbg(efx, rx_status, efx->net_dev,
921 				  "failed to steer %s [%pI6]:%u:[%pI6]:%u to queue %u [flow %u rc %d id %u]\n",
922 				  (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
923 				  req->spec.rem_host, ntohs(req->spec.rem_port),
924 				  req->spec.loc_host, ntohs(req->spec.loc_port),
925 				  req->rxq_index, req->flow_id, rc, arfs_id);
926 		channel->n_rfs_failed++;
927 		/* We're overloading the NIC's filter tables, so let's do a
928 		 * chunk of extra expiry work.
929 		 */
930 		__efx_filter_rfs_expire(channel, min(channel->rfs_filter_count,
931 						     100u));
932 	}
933 
934 	/* Release references */
935 	clear_bit(slot_idx, &efx->rps_slot_map);
936 	dev_put(req->net_dev);
937 }
938 
939 int efx_filter_rfs(struct net_device *net_dev, const struct sk_buff *skb,
940 		   u16 rxq_index, u32 flow_id)
941 {
942 	struct efx_nic *efx = netdev_priv(net_dev);
943 	struct efx_async_filter_insertion *req;
944 	struct efx_arfs_rule *rule;
945 	struct flow_keys fk;
946 	int slot_idx;
947 	bool new;
948 	int rc;
949 
950 	/* find a free slot */
951 	for (slot_idx = 0; slot_idx < EFX_RPS_MAX_IN_FLIGHT; slot_idx++)
952 		if (!test_and_set_bit(slot_idx, &efx->rps_slot_map))
953 			break;
954 	if (slot_idx >= EFX_RPS_MAX_IN_FLIGHT)
955 		return -EBUSY;
956 
957 	if (flow_id == RPS_FLOW_ID_INVALID) {
958 		rc = -EINVAL;
959 		goto out_clear;
960 	}
961 
962 	if (!skb_flow_dissect_flow_keys(skb, &fk, 0)) {
963 		rc = -EPROTONOSUPPORT;
964 		goto out_clear;
965 	}
966 
967 	if (fk.basic.n_proto != htons(ETH_P_IP) && fk.basic.n_proto != htons(ETH_P_IPV6)) {
968 		rc = -EPROTONOSUPPORT;
969 		goto out_clear;
970 	}
971 	if (fk.control.flags & FLOW_DIS_IS_FRAGMENT) {
972 		rc = -EPROTONOSUPPORT;
973 		goto out_clear;
974 	}
975 
976 	req = efx->rps_slot + slot_idx;
977 	efx_filter_init_rx(&req->spec, EFX_FILTER_PRI_HINT,
978 			   efx->rx_scatter ? EFX_FILTER_FLAG_RX_SCATTER : 0,
979 			   rxq_index);
980 	req->spec.match_flags =
981 		EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_IP_PROTO |
982 		EFX_FILTER_MATCH_LOC_HOST | EFX_FILTER_MATCH_LOC_PORT |
983 		EFX_FILTER_MATCH_REM_HOST | EFX_FILTER_MATCH_REM_PORT;
984 	req->spec.ether_type = fk.basic.n_proto;
985 	req->spec.ip_proto = fk.basic.ip_proto;
986 
987 	if (fk.basic.n_proto == htons(ETH_P_IP)) {
988 		req->spec.rem_host[0] = fk.addrs.v4addrs.src;
989 		req->spec.loc_host[0] = fk.addrs.v4addrs.dst;
990 	} else {
991 		memcpy(req->spec.rem_host, &fk.addrs.v6addrs.src,
992 		       sizeof(struct in6_addr));
993 		memcpy(req->spec.loc_host, &fk.addrs.v6addrs.dst,
994 		       sizeof(struct in6_addr));
995 	}
996 
997 	req->spec.rem_port = fk.ports.src;
998 	req->spec.loc_port = fk.ports.dst;
999 
1000 	if (efx->rps_hash_table) {
1001 		/* Add it to ARFS hash table */
1002 		spin_lock(&efx->rps_hash_lock);
1003 		rule = efx_rps_hash_add(efx, &req->spec, &new);
1004 		if (!rule) {
1005 			rc = -ENOMEM;
1006 			goto out_unlock;
1007 		}
1008 		if (new)
1009 			rule->arfs_id = efx->rps_next_id++ % RPS_NO_FILTER;
1010 		rc = rule->arfs_id;
1011 		/* Skip if existing or pending filter already does the right thing */
1012 		if (!new && rule->rxq_index == rxq_index &&
1013 		    rule->filter_id >= EFX_ARFS_FILTER_ID_PENDING)
1014 			goto out_unlock;
1015 		rule->rxq_index = rxq_index;
1016 		rule->filter_id = EFX_ARFS_FILTER_ID_PENDING;
1017 		spin_unlock(&efx->rps_hash_lock);
1018 	} else {
1019 		/* Without an ARFS hash table, we just use arfs_id 0 for all
1020 		 * filters.  This means if multiple flows hash to the same
1021 		 * flow_id, all but the most recently touched will be eligible
1022 		 * for expiry.
1023 		 */
1024 		rc = 0;
1025 	}
1026 
1027 	/* Queue the request */
1028 	dev_hold(req->net_dev = net_dev);
1029 	INIT_WORK(&req->work, efx_filter_rfs_work);
1030 	req->rxq_index = rxq_index;
1031 	req->flow_id = flow_id;
1032 	schedule_work(&req->work);
1033 	return rc;
1034 out_unlock:
1035 	spin_unlock(&efx->rps_hash_lock);
1036 out_clear:
1037 	clear_bit(slot_idx, &efx->rps_slot_map);
1038 	return rc;
1039 }
1040 
1041 bool __efx_filter_rfs_expire(struct efx_channel *channel, unsigned int quota)
1042 {
1043 	bool (*expire_one)(struct efx_nic *efx, u32 flow_id, unsigned int index);
1044 	struct efx_nic *efx = channel->efx;
1045 	unsigned int index, size, start;
1046 	u32 flow_id;
1047 
1048 	if (!mutex_trylock(&efx->rps_mutex))
1049 		return false;
1050 	expire_one = efx->type->filter_rfs_expire_one;
1051 	index = channel->rfs_expire_index;
1052 	start = index;
1053 	size = efx->type->max_rx_ip_filters;
1054 	while (quota) {
1055 		flow_id = channel->rps_flow_id[index];
1056 
1057 		if (flow_id != RPS_FLOW_ID_INVALID) {
1058 			quota--;
1059 			if (expire_one(efx, flow_id, index)) {
1060 				netif_info(efx, rx_status, efx->net_dev,
1061 					   "expired filter %d [channel %u flow %u]\n",
1062 					   index, channel->channel, flow_id);
1063 				channel->rps_flow_id[index] = RPS_FLOW_ID_INVALID;
1064 				channel->rfs_filter_count--;
1065 			}
1066 		}
1067 		if (++index == size)
1068 			index = 0;
1069 		/* If we were called with a quota that exceeds the total number
1070 		 * of filters in the table (which shouldn't happen, but could
1071 		 * if two callers race), ensure that we don't loop forever -
1072 		 * stop when we've examined every row of the table.
1073 		 */
1074 		if (index == start)
1075 			break;
1076 	}
1077 
1078 	channel->rfs_expire_index = index;
1079 	mutex_unlock(&efx->rps_mutex);
1080 	return true;
1081 }
1082 
1083 #endif /* CONFIG_RFS_ACCEL */
1084