xref: /linux/drivers/net/ethernet/sfc/falcon/rx.c (revision 4f2c0a4acffbec01079c28f839422e64ddeff004)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /****************************************************************************
3  * Driver for Solarflare network controllers and boards
4  * Copyright 2005-2006 Fen Systems Ltd.
5  * Copyright 2005-2013 Solarflare Communications Inc.
6  */
7 
8 #include <linux/socket.h>
9 #include <linux/in.h>
10 #include <linux/slab.h>
11 #include <linux/ip.h>
12 #include <linux/ipv6.h>
13 #include <linux/tcp.h>
14 #include <linux/udp.h>
15 #include <linux/prefetch.h>
16 #include <linux/moduleparam.h>
17 #include <linux/iommu.h>
18 #include <net/ip.h>
19 #include <net/checksum.h>
20 #include "net_driver.h"
21 #include "efx.h"
22 #include "filter.h"
23 #include "nic.h"
24 #include "selftest.h"
25 #include "workarounds.h"
26 
27 /* Preferred number of descriptors to fill at once */
28 #define EF4_RX_PREFERRED_BATCH 8U
29 
30 /* Number of RX buffers to recycle pages for.  When creating the RX page recycle
31  * ring, this number is divided by the number of buffers per page to calculate
32  * the number of pages to store in the RX page recycle ring.
33  */
34 #define EF4_RECYCLE_RING_SIZE_IOMMU 4096
35 #define EF4_RECYCLE_RING_SIZE_NOIOMMU (2 * EF4_RX_PREFERRED_BATCH)
36 
37 /* Size of buffer allocated for skb header area. */
38 #define EF4_SKB_HEADERS  128u
39 
40 /* This is the percentage fill level below which new RX descriptors
41  * will be added to the RX descriptor ring.
42  */
43 static unsigned int rx_refill_threshold;
44 
45 /* Each packet can consume up to ceil(max_frame_len / buffer_size) buffers */
46 #define EF4_RX_MAX_FRAGS DIV_ROUND_UP(EF4_MAX_FRAME_LEN(EF4_MAX_MTU), \
47 				      EF4_RX_USR_BUF_SIZE)
48 
49 /*
50  * RX maximum head room required.
51  *
52  * This must be at least 1 to prevent overflow, plus one packet-worth
53  * to allow pipelined receives.
54  */
55 #define EF4_RXD_HEAD_ROOM (1 + EF4_RX_MAX_FRAGS)
56 
ef4_rx_buf_va(struct ef4_rx_buffer * buf)57 static inline u8 *ef4_rx_buf_va(struct ef4_rx_buffer *buf)
58 {
59 	return page_address(buf->page) + buf->page_offset;
60 }
61 
ef4_rx_buf_hash(struct ef4_nic * efx,const u8 * eh)62 static inline u32 ef4_rx_buf_hash(struct ef4_nic *efx, const u8 *eh)
63 {
64 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
65 	return __le32_to_cpup((const __le32 *)(eh + efx->rx_packet_hash_offset));
66 #else
67 	const u8 *data = eh + efx->rx_packet_hash_offset;
68 	return (u32)data[0]	  |
69 	       (u32)data[1] << 8  |
70 	       (u32)data[2] << 16 |
71 	       (u32)data[3] << 24;
72 #endif
73 }
74 
75 static inline struct ef4_rx_buffer *
ef4_rx_buf_next(struct ef4_rx_queue * rx_queue,struct ef4_rx_buffer * rx_buf)76 ef4_rx_buf_next(struct ef4_rx_queue *rx_queue, struct ef4_rx_buffer *rx_buf)
77 {
78 	if (unlikely(rx_buf == ef4_rx_buffer(rx_queue, rx_queue->ptr_mask)))
79 		return ef4_rx_buffer(rx_queue, 0);
80 	else
81 		return rx_buf + 1;
82 }
83 
ef4_sync_rx_buffer(struct ef4_nic * efx,struct ef4_rx_buffer * rx_buf,unsigned int len)84 static inline void ef4_sync_rx_buffer(struct ef4_nic *efx,
85 				      struct ef4_rx_buffer *rx_buf,
86 				      unsigned int len)
87 {
88 	dma_sync_single_for_cpu(&efx->pci_dev->dev, rx_buf->dma_addr, len,
89 				DMA_FROM_DEVICE);
90 }
91 
ef4_rx_config_page_split(struct ef4_nic * efx)92 void ef4_rx_config_page_split(struct ef4_nic *efx)
93 {
94 	efx->rx_page_buf_step = ALIGN(efx->rx_dma_len + efx->rx_ip_align,
95 				      EF4_RX_BUF_ALIGNMENT);
96 	efx->rx_bufs_per_page = efx->rx_buffer_order ? 1 :
97 		((PAGE_SIZE - sizeof(struct ef4_rx_page_state)) /
98 		 efx->rx_page_buf_step);
99 	efx->rx_buffer_truesize = (PAGE_SIZE << efx->rx_buffer_order) /
100 		efx->rx_bufs_per_page;
101 	efx->rx_pages_per_batch = DIV_ROUND_UP(EF4_RX_PREFERRED_BATCH,
102 					       efx->rx_bufs_per_page);
103 }
104 
105 /* Check the RX page recycle ring for a page that can be reused. */
ef4_reuse_page(struct ef4_rx_queue * rx_queue)106 static struct page *ef4_reuse_page(struct ef4_rx_queue *rx_queue)
107 {
108 	struct ef4_nic *efx = rx_queue->efx;
109 	struct page *page;
110 	struct ef4_rx_page_state *state;
111 	unsigned index;
112 
113 	if (unlikely(!rx_queue->page_ring))
114 		return NULL;
115 	index = rx_queue->page_remove & rx_queue->page_ptr_mask;
116 	page = rx_queue->page_ring[index];
117 	if (page == NULL)
118 		return NULL;
119 
120 	rx_queue->page_ring[index] = NULL;
121 	/* page_remove cannot exceed page_add. */
122 	if (rx_queue->page_remove != rx_queue->page_add)
123 		++rx_queue->page_remove;
124 
125 	/* If page_count is 1 then we hold the only reference to this page. */
126 	if (page_count(page) == 1) {
127 		++rx_queue->page_recycle_count;
128 		return page;
129 	} else {
130 		state = page_address(page);
131 		dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
132 			       PAGE_SIZE << efx->rx_buffer_order,
133 			       DMA_FROM_DEVICE);
134 		put_page(page);
135 		++rx_queue->page_recycle_failed;
136 	}
137 
138 	return NULL;
139 }
140 
141 /**
142  * ef4_init_rx_buffers - create EF4_RX_BATCH page-based RX buffers
143  *
144  * @rx_queue:		Efx RX queue
145  * @atomic:		control memory allocation flags
146  *
147  * This allocates a batch of pages, maps them for DMA, and populates
148  * struct ef4_rx_buffers for each one. Return a negative error code or
149  * 0 on success. If a single page can be used for multiple buffers,
150  * then the page will either be inserted fully, or not at all.
151  */
ef4_init_rx_buffers(struct ef4_rx_queue * rx_queue,bool atomic)152 static int ef4_init_rx_buffers(struct ef4_rx_queue *rx_queue, bool atomic)
153 {
154 	struct ef4_nic *efx = rx_queue->efx;
155 	struct ef4_rx_buffer *rx_buf;
156 	struct page *page;
157 	unsigned int page_offset;
158 	struct ef4_rx_page_state *state;
159 	dma_addr_t dma_addr;
160 	unsigned index, count;
161 
162 	count = 0;
163 	do {
164 		page = ef4_reuse_page(rx_queue);
165 		if (page == NULL) {
166 			page = alloc_pages(__GFP_COMP |
167 					   (atomic ? GFP_ATOMIC : GFP_KERNEL),
168 					   efx->rx_buffer_order);
169 			if (unlikely(page == NULL))
170 				return -ENOMEM;
171 			dma_addr =
172 				dma_map_page(&efx->pci_dev->dev, page, 0,
173 					     PAGE_SIZE << efx->rx_buffer_order,
174 					     DMA_FROM_DEVICE);
175 			if (unlikely(dma_mapping_error(&efx->pci_dev->dev,
176 						       dma_addr))) {
177 				__free_pages(page, efx->rx_buffer_order);
178 				return -EIO;
179 			}
180 			state = page_address(page);
181 			state->dma_addr = dma_addr;
182 		} else {
183 			state = page_address(page);
184 			dma_addr = state->dma_addr;
185 		}
186 
187 		dma_addr += sizeof(struct ef4_rx_page_state);
188 		page_offset = sizeof(struct ef4_rx_page_state);
189 
190 		do {
191 			index = rx_queue->added_count & rx_queue->ptr_mask;
192 			rx_buf = ef4_rx_buffer(rx_queue, index);
193 			rx_buf->dma_addr = dma_addr + efx->rx_ip_align;
194 			rx_buf->page = page;
195 			rx_buf->page_offset = page_offset + efx->rx_ip_align;
196 			rx_buf->len = efx->rx_dma_len;
197 			rx_buf->flags = 0;
198 			++rx_queue->added_count;
199 			get_page(page);
200 			dma_addr += efx->rx_page_buf_step;
201 			page_offset += efx->rx_page_buf_step;
202 		} while (page_offset + efx->rx_page_buf_step <= PAGE_SIZE);
203 
204 		rx_buf->flags = EF4_RX_BUF_LAST_IN_PAGE;
205 	} while (++count < efx->rx_pages_per_batch);
206 
207 	return 0;
208 }
209 
210 /* Unmap a DMA-mapped page.  This function is only called for the final RX
211  * buffer in a page.
212  */
ef4_unmap_rx_buffer(struct ef4_nic * efx,struct ef4_rx_buffer * rx_buf)213 static void ef4_unmap_rx_buffer(struct ef4_nic *efx,
214 				struct ef4_rx_buffer *rx_buf)
215 {
216 	struct page *page = rx_buf->page;
217 
218 	if (page) {
219 		struct ef4_rx_page_state *state = page_address(page);
220 		dma_unmap_page(&efx->pci_dev->dev,
221 			       state->dma_addr,
222 			       PAGE_SIZE << efx->rx_buffer_order,
223 			       DMA_FROM_DEVICE);
224 	}
225 }
226 
ef4_free_rx_buffers(struct ef4_rx_queue * rx_queue,struct ef4_rx_buffer * rx_buf,unsigned int num_bufs)227 static void ef4_free_rx_buffers(struct ef4_rx_queue *rx_queue,
228 				struct ef4_rx_buffer *rx_buf,
229 				unsigned int num_bufs)
230 {
231 	do {
232 		if (rx_buf->page) {
233 			put_page(rx_buf->page);
234 			rx_buf->page = NULL;
235 		}
236 		rx_buf = ef4_rx_buf_next(rx_queue, rx_buf);
237 	} while (--num_bufs);
238 }
239 
240 /* Attempt to recycle the page if there is an RX recycle ring; the page can
241  * only be added if this is the final RX buffer, to prevent pages being used in
242  * the descriptor ring and appearing in the recycle ring simultaneously.
243  */
ef4_recycle_rx_page(struct ef4_channel * channel,struct ef4_rx_buffer * rx_buf)244 static void ef4_recycle_rx_page(struct ef4_channel *channel,
245 				struct ef4_rx_buffer *rx_buf)
246 {
247 	struct page *page = rx_buf->page;
248 	struct ef4_rx_queue *rx_queue = ef4_channel_get_rx_queue(channel);
249 	struct ef4_nic *efx = rx_queue->efx;
250 	unsigned index;
251 
252 	/* Only recycle the page after processing the final buffer. */
253 	if (!(rx_buf->flags & EF4_RX_BUF_LAST_IN_PAGE))
254 		return;
255 
256 	index = rx_queue->page_add & rx_queue->page_ptr_mask;
257 	if (rx_queue->page_ring[index] == NULL) {
258 		unsigned read_index = rx_queue->page_remove &
259 			rx_queue->page_ptr_mask;
260 
261 		/* The next slot in the recycle ring is available, but
262 		 * increment page_remove if the read pointer currently
263 		 * points here.
264 		 */
265 		if (read_index == index)
266 			++rx_queue->page_remove;
267 		rx_queue->page_ring[index] = page;
268 		++rx_queue->page_add;
269 		return;
270 	}
271 	++rx_queue->page_recycle_full;
272 	ef4_unmap_rx_buffer(efx, rx_buf);
273 	put_page(rx_buf->page);
274 }
275 
ef4_fini_rx_buffer(struct ef4_rx_queue * rx_queue,struct ef4_rx_buffer * rx_buf)276 static void ef4_fini_rx_buffer(struct ef4_rx_queue *rx_queue,
277 			       struct ef4_rx_buffer *rx_buf)
278 {
279 	/* Release the page reference we hold for the buffer. */
280 	if (rx_buf->page)
281 		put_page(rx_buf->page);
282 
283 	/* If this is the last buffer in a page, unmap and free it. */
284 	if (rx_buf->flags & EF4_RX_BUF_LAST_IN_PAGE) {
285 		ef4_unmap_rx_buffer(rx_queue->efx, rx_buf);
286 		ef4_free_rx_buffers(rx_queue, rx_buf, 1);
287 	}
288 	rx_buf->page = NULL;
289 }
290 
291 /* Recycle the pages that are used by buffers that have just been received. */
ef4_recycle_rx_pages(struct ef4_channel * channel,struct ef4_rx_buffer * rx_buf,unsigned int n_frags)292 static void ef4_recycle_rx_pages(struct ef4_channel *channel,
293 				 struct ef4_rx_buffer *rx_buf,
294 				 unsigned int n_frags)
295 {
296 	struct ef4_rx_queue *rx_queue = ef4_channel_get_rx_queue(channel);
297 
298 	if (unlikely(!rx_queue->page_ring))
299 		return;
300 
301 	do {
302 		ef4_recycle_rx_page(channel, rx_buf);
303 		rx_buf = ef4_rx_buf_next(rx_queue, rx_buf);
304 	} while (--n_frags);
305 }
306 
ef4_discard_rx_packet(struct ef4_channel * channel,struct ef4_rx_buffer * rx_buf,unsigned int n_frags)307 static void ef4_discard_rx_packet(struct ef4_channel *channel,
308 				  struct ef4_rx_buffer *rx_buf,
309 				  unsigned int n_frags)
310 {
311 	struct ef4_rx_queue *rx_queue = ef4_channel_get_rx_queue(channel);
312 
313 	ef4_recycle_rx_pages(channel, rx_buf, n_frags);
314 
315 	ef4_free_rx_buffers(rx_queue, rx_buf, n_frags);
316 }
317 
318 /**
319  * ef4_fast_push_rx_descriptors - push new RX descriptors quickly
320  * @rx_queue:		RX descriptor queue
321  *
322  * This will aim to fill the RX descriptor queue up to
323  * @rx_queue->@max_fill. If there is insufficient atomic
324  * memory to do so, a slow fill will be scheduled.
325  * @atomic: control memory allocation flags
326  *
327  * The caller must provide serialisation (none is used here). In practise,
328  * this means this function must run from the NAPI handler, or be called
329  * when NAPI is disabled.
330  */
ef4_fast_push_rx_descriptors(struct ef4_rx_queue * rx_queue,bool atomic)331 void ef4_fast_push_rx_descriptors(struct ef4_rx_queue *rx_queue, bool atomic)
332 {
333 	struct ef4_nic *efx = rx_queue->efx;
334 	unsigned int fill_level, batch_size;
335 	int space, rc = 0;
336 
337 	if (!rx_queue->refill_enabled)
338 		return;
339 
340 	/* Calculate current fill level, and exit if we don't need to fill */
341 	fill_level = (rx_queue->added_count - rx_queue->removed_count);
342 	EF4_BUG_ON_PARANOID(fill_level > rx_queue->efx->rxq_entries);
343 	if (fill_level >= rx_queue->fast_fill_trigger)
344 		goto out;
345 
346 	/* Record minimum fill level */
347 	if (unlikely(fill_level < rx_queue->min_fill)) {
348 		if (fill_level)
349 			rx_queue->min_fill = fill_level;
350 	}
351 
352 	batch_size = efx->rx_pages_per_batch * efx->rx_bufs_per_page;
353 	space = rx_queue->max_fill - fill_level;
354 	EF4_BUG_ON_PARANOID(space < batch_size);
355 
356 	netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
357 		   "RX queue %d fast-filling descriptor ring from"
358 		   " level %d to level %d\n",
359 		   ef4_rx_queue_index(rx_queue), fill_level,
360 		   rx_queue->max_fill);
361 
362 
363 	do {
364 		rc = ef4_init_rx_buffers(rx_queue, atomic);
365 		if (unlikely(rc)) {
366 			/* Ensure that we don't leave the rx queue empty */
367 			if (rx_queue->added_count == rx_queue->removed_count)
368 				ef4_schedule_slow_fill(rx_queue);
369 			goto out;
370 		}
371 	} while ((space -= batch_size) >= batch_size);
372 
373 	netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
374 		   "RX queue %d fast-filled descriptor ring "
375 		   "to level %d\n", ef4_rx_queue_index(rx_queue),
376 		   rx_queue->added_count - rx_queue->removed_count);
377 
378  out:
379 	if (rx_queue->notified_count != rx_queue->added_count)
380 		ef4_nic_notify_rx_desc(rx_queue);
381 }
382 
ef4_rx_slow_fill(struct timer_list * t)383 void ef4_rx_slow_fill(struct timer_list *t)
384 {
385 	struct ef4_rx_queue *rx_queue = from_timer(rx_queue, t, slow_fill);
386 
387 	/* Post an event to cause NAPI to run and refill the queue */
388 	ef4_nic_generate_fill_event(rx_queue);
389 	++rx_queue->slow_fill_count;
390 }
391 
ef4_rx_packet__check_len(struct ef4_rx_queue * rx_queue,struct ef4_rx_buffer * rx_buf,int len)392 static void ef4_rx_packet__check_len(struct ef4_rx_queue *rx_queue,
393 				     struct ef4_rx_buffer *rx_buf,
394 				     int len)
395 {
396 	struct ef4_nic *efx = rx_queue->efx;
397 	unsigned max_len = rx_buf->len - efx->type->rx_buffer_padding;
398 
399 	if (likely(len <= max_len))
400 		return;
401 
402 	/* The packet must be discarded, but this is only a fatal error
403 	 * if the caller indicated it was
404 	 */
405 	rx_buf->flags |= EF4_RX_PKT_DISCARD;
406 
407 	if ((len > rx_buf->len) && EF4_WORKAROUND_8071(efx)) {
408 		if (net_ratelimit())
409 			netif_err(efx, rx_err, efx->net_dev,
410 				  " RX queue %d seriously overlength "
411 				  "RX event (0x%x > 0x%x+0x%x). Leaking\n",
412 				  ef4_rx_queue_index(rx_queue), len, max_len,
413 				  efx->type->rx_buffer_padding);
414 		ef4_schedule_reset(efx, RESET_TYPE_RX_RECOVERY);
415 	} else {
416 		if (net_ratelimit())
417 			netif_err(efx, rx_err, efx->net_dev,
418 				  " RX queue %d overlength RX event "
419 				  "(0x%x > 0x%x)\n",
420 				  ef4_rx_queue_index(rx_queue), len, max_len);
421 	}
422 
423 	ef4_rx_queue_channel(rx_queue)->n_rx_overlength++;
424 }
425 
426 /* Pass a received packet up through GRO.  GRO can handle pages
427  * regardless of checksum state and skbs with a good checksum.
428  */
429 static void
ef4_rx_packet_gro(struct ef4_channel * channel,struct ef4_rx_buffer * rx_buf,unsigned int n_frags,u8 * eh)430 ef4_rx_packet_gro(struct ef4_channel *channel, struct ef4_rx_buffer *rx_buf,
431 		  unsigned int n_frags, u8 *eh)
432 {
433 	struct napi_struct *napi = &channel->napi_str;
434 	struct ef4_nic *efx = channel->efx;
435 	struct sk_buff *skb;
436 
437 	skb = napi_get_frags(napi);
438 	if (unlikely(!skb)) {
439 		struct ef4_rx_queue *rx_queue;
440 
441 		rx_queue = ef4_channel_get_rx_queue(channel);
442 		ef4_free_rx_buffers(rx_queue, rx_buf, n_frags);
443 		return;
444 	}
445 
446 	if (efx->net_dev->features & NETIF_F_RXHASH)
447 		skb_set_hash(skb, ef4_rx_buf_hash(efx, eh),
448 			     PKT_HASH_TYPE_L3);
449 	skb->ip_summed = ((rx_buf->flags & EF4_RX_PKT_CSUMMED) ?
450 			  CHECKSUM_UNNECESSARY : CHECKSUM_NONE);
451 
452 	for (;;) {
453 		skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
454 				   rx_buf->page, rx_buf->page_offset,
455 				   rx_buf->len);
456 		rx_buf->page = NULL;
457 		skb->len += rx_buf->len;
458 		if (skb_shinfo(skb)->nr_frags == n_frags)
459 			break;
460 
461 		rx_buf = ef4_rx_buf_next(&channel->rx_queue, rx_buf);
462 	}
463 
464 	skb->data_len = skb->len;
465 	skb->truesize += n_frags * efx->rx_buffer_truesize;
466 
467 	skb_record_rx_queue(skb, channel->rx_queue.core_index);
468 
469 	napi_gro_frags(napi);
470 }
471 
472 /* Allocate and construct an SKB around page fragments */
ef4_rx_mk_skb(struct ef4_channel * channel,struct ef4_rx_buffer * rx_buf,unsigned int n_frags,u8 * eh,int hdr_len)473 static struct sk_buff *ef4_rx_mk_skb(struct ef4_channel *channel,
474 				     struct ef4_rx_buffer *rx_buf,
475 				     unsigned int n_frags,
476 				     u8 *eh, int hdr_len)
477 {
478 	struct ef4_nic *efx = channel->efx;
479 	struct sk_buff *skb;
480 
481 	/* Allocate an SKB to store the headers */
482 	skb = netdev_alloc_skb(efx->net_dev,
483 			       efx->rx_ip_align + efx->rx_prefix_size +
484 			       hdr_len);
485 	if (unlikely(skb == NULL)) {
486 		atomic_inc(&efx->n_rx_noskb_drops);
487 		return NULL;
488 	}
489 
490 	EF4_BUG_ON_PARANOID(rx_buf->len < hdr_len);
491 
492 	memcpy(skb->data + efx->rx_ip_align, eh - efx->rx_prefix_size,
493 	       efx->rx_prefix_size + hdr_len);
494 	skb_reserve(skb, efx->rx_ip_align + efx->rx_prefix_size);
495 	__skb_put(skb, hdr_len);
496 
497 	/* Append the remaining page(s) onto the frag list */
498 	if (rx_buf->len > hdr_len) {
499 		rx_buf->page_offset += hdr_len;
500 		rx_buf->len -= hdr_len;
501 
502 		for (;;) {
503 			skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
504 					   rx_buf->page, rx_buf->page_offset,
505 					   rx_buf->len);
506 			rx_buf->page = NULL;
507 			skb->len += rx_buf->len;
508 			skb->data_len += rx_buf->len;
509 			if (skb_shinfo(skb)->nr_frags == n_frags)
510 				break;
511 
512 			rx_buf = ef4_rx_buf_next(&channel->rx_queue, rx_buf);
513 		}
514 	} else {
515 		__free_pages(rx_buf->page, efx->rx_buffer_order);
516 		rx_buf->page = NULL;
517 		n_frags = 0;
518 	}
519 
520 	skb->truesize += n_frags * efx->rx_buffer_truesize;
521 
522 	/* Move past the ethernet header */
523 	skb->protocol = eth_type_trans(skb, efx->net_dev);
524 
525 	skb_mark_napi_id(skb, &channel->napi_str);
526 
527 	return skb;
528 }
529 
ef4_rx_packet(struct ef4_rx_queue * rx_queue,unsigned int index,unsigned int n_frags,unsigned int len,u16 flags)530 void ef4_rx_packet(struct ef4_rx_queue *rx_queue, unsigned int index,
531 		   unsigned int n_frags, unsigned int len, u16 flags)
532 {
533 	struct ef4_nic *efx = rx_queue->efx;
534 	struct ef4_channel *channel = ef4_rx_queue_channel(rx_queue);
535 	struct ef4_rx_buffer *rx_buf;
536 
537 	rx_queue->rx_packets++;
538 
539 	rx_buf = ef4_rx_buffer(rx_queue, index);
540 	rx_buf->flags |= flags;
541 
542 	/* Validate the number of fragments and completed length */
543 	if (n_frags == 1) {
544 		if (!(flags & EF4_RX_PKT_PREFIX_LEN))
545 			ef4_rx_packet__check_len(rx_queue, rx_buf, len);
546 	} else if (unlikely(n_frags > EF4_RX_MAX_FRAGS) ||
547 		   unlikely(len <= (n_frags - 1) * efx->rx_dma_len) ||
548 		   unlikely(len > n_frags * efx->rx_dma_len) ||
549 		   unlikely(!efx->rx_scatter)) {
550 		/* If this isn't an explicit discard request, either
551 		 * the hardware or the driver is broken.
552 		 */
553 		WARN_ON(!(len == 0 && rx_buf->flags & EF4_RX_PKT_DISCARD));
554 		rx_buf->flags |= EF4_RX_PKT_DISCARD;
555 	}
556 
557 	netif_vdbg(efx, rx_status, efx->net_dev,
558 		   "RX queue %d received ids %x-%x len %d %s%s\n",
559 		   ef4_rx_queue_index(rx_queue), index,
560 		   (index + n_frags - 1) & rx_queue->ptr_mask, len,
561 		   (rx_buf->flags & EF4_RX_PKT_CSUMMED) ? " [SUMMED]" : "",
562 		   (rx_buf->flags & EF4_RX_PKT_DISCARD) ? " [DISCARD]" : "");
563 
564 	/* Discard packet, if instructed to do so.  Process the
565 	 * previous receive first.
566 	 */
567 	if (unlikely(rx_buf->flags & EF4_RX_PKT_DISCARD)) {
568 		ef4_rx_flush_packet(channel);
569 		ef4_discard_rx_packet(channel, rx_buf, n_frags);
570 		return;
571 	}
572 
573 	if (n_frags == 1 && !(flags & EF4_RX_PKT_PREFIX_LEN))
574 		rx_buf->len = len;
575 
576 	/* Release and/or sync the DMA mapping - assumes all RX buffers
577 	 * consumed in-order per RX queue.
578 	 */
579 	ef4_sync_rx_buffer(efx, rx_buf, rx_buf->len);
580 
581 	/* Prefetch nice and early so data will (hopefully) be in cache by
582 	 * the time we look at it.
583 	 */
584 	prefetch(ef4_rx_buf_va(rx_buf));
585 
586 	rx_buf->page_offset += efx->rx_prefix_size;
587 	rx_buf->len -= efx->rx_prefix_size;
588 
589 	if (n_frags > 1) {
590 		/* Release/sync DMA mapping for additional fragments.
591 		 * Fix length for last fragment.
592 		 */
593 		unsigned int tail_frags = n_frags - 1;
594 
595 		for (;;) {
596 			rx_buf = ef4_rx_buf_next(rx_queue, rx_buf);
597 			if (--tail_frags == 0)
598 				break;
599 			ef4_sync_rx_buffer(efx, rx_buf, efx->rx_dma_len);
600 		}
601 		rx_buf->len = len - (n_frags - 1) * efx->rx_dma_len;
602 		ef4_sync_rx_buffer(efx, rx_buf, rx_buf->len);
603 	}
604 
605 	/* All fragments have been DMA-synced, so recycle pages. */
606 	rx_buf = ef4_rx_buffer(rx_queue, index);
607 	ef4_recycle_rx_pages(channel, rx_buf, n_frags);
608 
609 	/* Pipeline receives so that we give time for packet headers to be
610 	 * prefetched into cache.
611 	 */
612 	ef4_rx_flush_packet(channel);
613 	channel->rx_pkt_n_frags = n_frags;
614 	channel->rx_pkt_index = index;
615 }
616 
ef4_rx_deliver(struct ef4_channel * channel,u8 * eh,struct ef4_rx_buffer * rx_buf,unsigned int n_frags)617 static void ef4_rx_deliver(struct ef4_channel *channel, u8 *eh,
618 			   struct ef4_rx_buffer *rx_buf,
619 			   unsigned int n_frags)
620 {
621 	struct sk_buff *skb;
622 	u16 hdr_len = min_t(u16, rx_buf->len, EF4_SKB_HEADERS);
623 
624 	skb = ef4_rx_mk_skb(channel, rx_buf, n_frags, eh, hdr_len);
625 	if (unlikely(skb == NULL)) {
626 		struct ef4_rx_queue *rx_queue;
627 
628 		rx_queue = ef4_channel_get_rx_queue(channel);
629 		ef4_free_rx_buffers(rx_queue, rx_buf, n_frags);
630 		return;
631 	}
632 	skb_record_rx_queue(skb, channel->rx_queue.core_index);
633 
634 	/* Set the SKB flags */
635 	skb_checksum_none_assert(skb);
636 	if (likely(rx_buf->flags & EF4_RX_PKT_CSUMMED))
637 		skb->ip_summed = CHECKSUM_UNNECESSARY;
638 
639 	if (channel->type->receive_skb)
640 		if (channel->type->receive_skb(channel, skb))
641 			return;
642 
643 	/* Pass the packet up */
644 	netif_receive_skb(skb);
645 }
646 
647 /* Handle a received packet.  Second half: Touches packet payload. */
__ef4_rx_packet(struct ef4_channel * channel)648 void __ef4_rx_packet(struct ef4_channel *channel)
649 {
650 	struct ef4_nic *efx = channel->efx;
651 	struct ef4_rx_buffer *rx_buf =
652 		ef4_rx_buffer(&channel->rx_queue, channel->rx_pkt_index);
653 	u8 *eh = ef4_rx_buf_va(rx_buf);
654 
655 	/* Read length from the prefix if necessary.  This already
656 	 * excludes the length of the prefix itself.
657 	 */
658 	if (rx_buf->flags & EF4_RX_PKT_PREFIX_LEN)
659 		rx_buf->len = le16_to_cpup((__le16 *)
660 					   (eh + efx->rx_packet_len_offset));
661 
662 	/* If we're in loopback test, then pass the packet directly to the
663 	 * loopback layer, and free the rx_buf here
664 	 */
665 	if (unlikely(efx->loopback_selftest)) {
666 		struct ef4_rx_queue *rx_queue;
667 
668 		ef4_loopback_rx_packet(efx, eh, rx_buf->len);
669 		rx_queue = ef4_channel_get_rx_queue(channel);
670 		ef4_free_rx_buffers(rx_queue, rx_buf,
671 				    channel->rx_pkt_n_frags);
672 		goto out;
673 	}
674 
675 	if (unlikely(!(efx->net_dev->features & NETIF_F_RXCSUM)))
676 		rx_buf->flags &= ~EF4_RX_PKT_CSUMMED;
677 
678 	if ((rx_buf->flags & EF4_RX_PKT_TCP) && !channel->type->receive_skb)
679 		ef4_rx_packet_gro(channel, rx_buf, channel->rx_pkt_n_frags, eh);
680 	else
681 		ef4_rx_deliver(channel, eh, rx_buf, channel->rx_pkt_n_frags);
682 out:
683 	channel->rx_pkt_n_frags = 0;
684 }
685 
ef4_probe_rx_queue(struct ef4_rx_queue * rx_queue)686 int ef4_probe_rx_queue(struct ef4_rx_queue *rx_queue)
687 {
688 	struct ef4_nic *efx = rx_queue->efx;
689 	unsigned int entries;
690 	int rc;
691 
692 	/* Create the smallest power-of-two aligned ring */
693 	entries = max(roundup_pow_of_two(efx->rxq_entries), EF4_MIN_DMAQ_SIZE);
694 	EF4_BUG_ON_PARANOID(entries > EF4_MAX_DMAQ_SIZE);
695 	rx_queue->ptr_mask = entries - 1;
696 
697 	netif_dbg(efx, probe, efx->net_dev,
698 		  "creating RX queue %d size %#x mask %#x\n",
699 		  ef4_rx_queue_index(rx_queue), efx->rxq_entries,
700 		  rx_queue->ptr_mask);
701 
702 	/* Allocate RX buffers */
703 	rx_queue->buffer = kcalloc(entries, sizeof(*rx_queue->buffer),
704 				   GFP_KERNEL);
705 	if (!rx_queue->buffer)
706 		return -ENOMEM;
707 
708 	rc = ef4_nic_probe_rx(rx_queue);
709 	if (rc) {
710 		kfree(rx_queue->buffer);
711 		rx_queue->buffer = NULL;
712 	}
713 
714 	return rc;
715 }
716 
ef4_init_rx_recycle_ring(struct ef4_nic * efx,struct ef4_rx_queue * rx_queue)717 static void ef4_init_rx_recycle_ring(struct ef4_nic *efx,
718 				     struct ef4_rx_queue *rx_queue)
719 {
720 	unsigned int bufs_in_recycle_ring, page_ring_size;
721 	struct iommu_domain __maybe_unused *domain;
722 
723 	/* Set the RX recycle ring size */
724 #ifdef CONFIG_PPC64
725 	bufs_in_recycle_ring = EF4_RECYCLE_RING_SIZE_IOMMU;
726 #else
727 	domain = iommu_get_domain_for_dev(&efx->pci_dev->dev);
728 	if (domain && domain->type != IOMMU_DOMAIN_IDENTITY)
729 		bufs_in_recycle_ring = EF4_RECYCLE_RING_SIZE_IOMMU;
730 	else
731 		bufs_in_recycle_ring = EF4_RECYCLE_RING_SIZE_NOIOMMU;
732 #endif /* CONFIG_PPC64 */
733 
734 	page_ring_size = roundup_pow_of_two(bufs_in_recycle_ring /
735 					    efx->rx_bufs_per_page);
736 	rx_queue->page_ring = kcalloc(page_ring_size,
737 				      sizeof(*rx_queue->page_ring), GFP_KERNEL);
738 	if (!rx_queue->page_ring)
739 		rx_queue->page_ptr_mask = 0;
740 	else
741 		rx_queue->page_ptr_mask = page_ring_size - 1;
742 }
743 
ef4_init_rx_queue(struct ef4_rx_queue * rx_queue)744 void ef4_init_rx_queue(struct ef4_rx_queue *rx_queue)
745 {
746 	struct ef4_nic *efx = rx_queue->efx;
747 	unsigned int max_fill, trigger, max_trigger;
748 
749 	netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
750 		  "initialising RX queue %d\n", ef4_rx_queue_index(rx_queue));
751 
752 	/* Initialise ptr fields */
753 	rx_queue->added_count = 0;
754 	rx_queue->notified_count = 0;
755 	rx_queue->removed_count = 0;
756 	rx_queue->min_fill = -1U;
757 	ef4_init_rx_recycle_ring(efx, rx_queue);
758 
759 	rx_queue->page_remove = 0;
760 	rx_queue->page_add = rx_queue->page_ptr_mask + 1;
761 	rx_queue->page_recycle_count = 0;
762 	rx_queue->page_recycle_failed = 0;
763 	rx_queue->page_recycle_full = 0;
764 
765 	/* Initialise limit fields */
766 	max_fill = efx->rxq_entries - EF4_RXD_HEAD_ROOM;
767 	max_trigger =
768 		max_fill - efx->rx_pages_per_batch * efx->rx_bufs_per_page;
769 	if (rx_refill_threshold != 0) {
770 		trigger = max_fill * min(rx_refill_threshold, 100U) / 100U;
771 		if (trigger > max_trigger)
772 			trigger = max_trigger;
773 	} else {
774 		trigger = max_trigger;
775 	}
776 
777 	rx_queue->max_fill = max_fill;
778 	rx_queue->fast_fill_trigger = trigger;
779 	rx_queue->refill_enabled = true;
780 
781 	/* Set up RX descriptor ring */
782 	ef4_nic_init_rx(rx_queue);
783 }
784 
ef4_fini_rx_queue(struct ef4_rx_queue * rx_queue)785 void ef4_fini_rx_queue(struct ef4_rx_queue *rx_queue)
786 {
787 	int i;
788 	struct ef4_nic *efx = rx_queue->efx;
789 	struct ef4_rx_buffer *rx_buf;
790 
791 	netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
792 		  "shutting down RX queue %d\n", ef4_rx_queue_index(rx_queue));
793 
794 	del_timer_sync(&rx_queue->slow_fill);
795 
796 	/* Release RX buffers from the current read ptr to the write ptr */
797 	if (rx_queue->buffer) {
798 		for (i = rx_queue->removed_count; i < rx_queue->added_count;
799 		     i++) {
800 			unsigned index = i & rx_queue->ptr_mask;
801 			rx_buf = ef4_rx_buffer(rx_queue, index);
802 			ef4_fini_rx_buffer(rx_queue, rx_buf);
803 		}
804 	}
805 
806 	/* Unmap and release the pages in the recycle ring. Remove the ring. */
807 	for (i = 0; i <= rx_queue->page_ptr_mask; i++) {
808 		struct page *page = rx_queue->page_ring[i];
809 		struct ef4_rx_page_state *state;
810 
811 		if (page == NULL)
812 			continue;
813 
814 		state = page_address(page);
815 		dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
816 			       PAGE_SIZE << efx->rx_buffer_order,
817 			       DMA_FROM_DEVICE);
818 		put_page(page);
819 	}
820 	kfree(rx_queue->page_ring);
821 	rx_queue->page_ring = NULL;
822 }
823 
ef4_remove_rx_queue(struct ef4_rx_queue * rx_queue)824 void ef4_remove_rx_queue(struct ef4_rx_queue *rx_queue)
825 {
826 	netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
827 		  "destroying RX queue %d\n", ef4_rx_queue_index(rx_queue));
828 
829 	ef4_nic_remove_rx(rx_queue);
830 
831 	kfree(rx_queue->buffer);
832 	rx_queue->buffer = NULL;
833 }
834 
835 
836 module_param(rx_refill_threshold, uint, 0444);
837 MODULE_PARM_DESC(rx_refill_threshold,
838 		 "RX descriptor ring refill threshold (%)");
839 
840 #ifdef CONFIG_RFS_ACCEL
841 
ef4_filter_rfs(struct net_device * net_dev,const struct sk_buff * skb,u16 rxq_index,u32 flow_id)842 int ef4_filter_rfs(struct net_device *net_dev, const struct sk_buff *skb,
843 		   u16 rxq_index, u32 flow_id)
844 {
845 	struct ef4_nic *efx = netdev_priv(net_dev);
846 	struct ef4_channel *channel;
847 	struct ef4_filter_spec spec;
848 	struct flow_keys fk;
849 	int rc;
850 
851 	if (flow_id == RPS_FLOW_ID_INVALID)
852 		return -EINVAL;
853 
854 	if (!skb_flow_dissect_flow_keys(skb, &fk, 0))
855 		return -EPROTONOSUPPORT;
856 
857 	if (fk.basic.n_proto != htons(ETH_P_IP) && fk.basic.n_proto != htons(ETH_P_IPV6))
858 		return -EPROTONOSUPPORT;
859 	if (fk.control.flags & FLOW_DIS_IS_FRAGMENT)
860 		return -EPROTONOSUPPORT;
861 
862 	ef4_filter_init_rx(&spec, EF4_FILTER_PRI_HINT,
863 			   efx->rx_scatter ? EF4_FILTER_FLAG_RX_SCATTER : 0,
864 			   rxq_index);
865 	spec.match_flags =
866 		EF4_FILTER_MATCH_ETHER_TYPE | EF4_FILTER_MATCH_IP_PROTO |
867 		EF4_FILTER_MATCH_LOC_HOST | EF4_FILTER_MATCH_LOC_PORT |
868 		EF4_FILTER_MATCH_REM_HOST | EF4_FILTER_MATCH_REM_PORT;
869 	spec.ether_type = fk.basic.n_proto;
870 	spec.ip_proto = fk.basic.ip_proto;
871 
872 	if (fk.basic.n_proto == htons(ETH_P_IP)) {
873 		spec.rem_host[0] = fk.addrs.v4addrs.src;
874 		spec.loc_host[0] = fk.addrs.v4addrs.dst;
875 	} else {
876 		memcpy(spec.rem_host, &fk.addrs.v6addrs.src, sizeof(struct in6_addr));
877 		memcpy(spec.loc_host, &fk.addrs.v6addrs.dst, sizeof(struct in6_addr));
878 	}
879 
880 	spec.rem_port = fk.ports.src;
881 	spec.loc_port = fk.ports.dst;
882 
883 	rc = efx->type->filter_rfs_insert(efx, &spec);
884 	if (rc < 0)
885 		return rc;
886 
887 	/* Remember this so we can check whether to expire the filter later */
888 	channel = ef4_get_channel(efx, rxq_index);
889 	channel->rps_flow_id[rc] = flow_id;
890 	++channel->rfs_filters_added;
891 
892 	if (spec.ether_type == htons(ETH_P_IP))
893 		netif_info(efx, rx_status, efx->net_dev,
894 			   "steering %s %pI4:%u:%pI4:%u to queue %u [flow %u filter %d]\n",
895 			   (spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
896 			   spec.rem_host, ntohs(spec.rem_port), spec.loc_host,
897 			   ntohs(spec.loc_port), rxq_index, flow_id, rc);
898 	else
899 		netif_info(efx, rx_status, efx->net_dev,
900 			   "steering %s [%pI6]:%u:[%pI6]:%u to queue %u [flow %u filter %d]\n",
901 			   (spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
902 			   spec.rem_host, ntohs(spec.rem_port), spec.loc_host,
903 			   ntohs(spec.loc_port), rxq_index, flow_id, rc);
904 
905 	return rc;
906 }
907 
__ef4_filter_rfs_expire(struct ef4_nic * efx,unsigned int quota)908 bool __ef4_filter_rfs_expire(struct ef4_nic *efx, unsigned int quota)
909 {
910 	bool (*expire_one)(struct ef4_nic *efx, u32 flow_id, unsigned int index);
911 	unsigned int channel_idx, index, size;
912 	u32 flow_id;
913 
914 	if (!spin_trylock_bh(&efx->filter_lock))
915 		return false;
916 
917 	expire_one = efx->type->filter_rfs_expire_one;
918 	channel_idx = efx->rps_expire_channel;
919 	index = efx->rps_expire_index;
920 	size = efx->type->max_rx_ip_filters;
921 	while (quota--) {
922 		struct ef4_channel *channel = ef4_get_channel(efx, channel_idx);
923 		flow_id = channel->rps_flow_id[index];
924 
925 		if (flow_id != RPS_FLOW_ID_INVALID &&
926 		    expire_one(efx, flow_id, index)) {
927 			netif_info(efx, rx_status, efx->net_dev,
928 				   "expired filter %d [queue %u flow %u]\n",
929 				   index, channel_idx, flow_id);
930 			channel->rps_flow_id[index] = RPS_FLOW_ID_INVALID;
931 		}
932 		if (++index == size) {
933 			if (++channel_idx == efx->n_channels)
934 				channel_idx = 0;
935 			index = 0;
936 		}
937 	}
938 	efx->rps_expire_channel = channel_idx;
939 	efx->rps_expire_index = index;
940 
941 	spin_unlock_bh(&efx->filter_lock);
942 	return true;
943 }
944 
945 #endif /* CONFIG_RFS_ACCEL */
946 
947 /**
948  * ef4_filter_is_mc_recipient - test whether spec is a multicast recipient
949  * @spec: Specification to test
950  *
951  * Return: %true if the specification is a non-drop RX filter that
952  * matches a local MAC address I/G bit value of 1 or matches a local
953  * IPv4 or IPv6 address value in the respective multicast address
954  * range.  Otherwise %false.
955  */
ef4_filter_is_mc_recipient(const struct ef4_filter_spec * spec)956 bool ef4_filter_is_mc_recipient(const struct ef4_filter_spec *spec)
957 {
958 	if (!(spec->flags & EF4_FILTER_FLAG_RX) ||
959 	    spec->dmaq_id == EF4_FILTER_RX_DMAQ_ID_DROP)
960 		return false;
961 
962 	if (spec->match_flags &
963 	    (EF4_FILTER_MATCH_LOC_MAC | EF4_FILTER_MATCH_LOC_MAC_IG) &&
964 	    is_multicast_ether_addr(spec->loc_mac))
965 		return true;
966 
967 	if ((spec->match_flags &
968 	     (EF4_FILTER_MATCH_ETHER_TYPE | EF4_FILTER_MATCH_LOC_HOST)) ==
969 	    (EF4_FILTER_MATCH_ETHER_TYPE | EF4_FILTER_MATCH_LOC_HOST)) {
970 		if (spec->ether_type == htons(ETH_P_IP) &&
971 		    ipv4_is_multicast(spec->loc_host[0]))
972 			return true;
973 		if (spec->ether_type == htons(ETH_P_IPV6) &&
974 		    ((const u8 *)spec->loc_host)[0] == 0xff)
975 			return true;
976 	}
977 
978 	return false;
979 }
980