1/****************************************************************************
2 * Driver for Solarflare network controllers and boards
3 * Copyright 2005-2006 Fen Systems Ltd.
4 * Copyright 2005-2013 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 <linux/socket.h>
12#include <linux/in.h>
13#include <linux/slab.h>
14#include <linux/ip.h>
15#include <linux/ipv6.h>
16#include <linux/tcp.h>
17#include <linux/udp.h>
18#include <linux/prefetch.h>
19#include <linux/moduleparam.h>
20#include <linux/iommu.h>
21#include <net/ip.h>
22#include <net/checksum.h>
23#include "net_driver.h"
24#include "efx.h"
25#include "filter.h"
26#include "nic.h"
27#include "selftest.h"
28#include "workarounds.h"
29
30/* Preferred number of descriptors to fill at once */
31#define EFX_RX_PREFERRED_BATCH 8U
32
33/* Number of RX buffers to recycle pages for.  When creating the RX page recycle
34 * ring, this number is divided by the number of buffers per page to calculate
35 * the number of pages to store in the RX page recycle ring.
36 */
37#define EFX_RECYCLE_RING_SIZE_IOMMU 4096
38#define EFX_RECYCLE_RING_SIZE_NOIOMMU (2 * EFX_RX_PREFERRED_BATCH)
39
40/* Size of buffer allocated for skb header area. */
41#define EFX_SKB_HEADERS  128u
42
43/* This is the percentage fill level below which new RX descriptors
44 * will be added to the RX descriptor ring.
45 */
46static unsigned int rx_refill_threshold;
47
48/* Each packet can consume up to ceil(max_frame_len / buffer_size) buffers */
49#define EFX_RX_MAX_FRAGS DIV_ROUND_UP(EFX_MAX_FRAME_LEN(EFX_MAX_MTU), \
50				      EFX_RX_USR_BUF_SIZE)
51
52/*
53 * RX maximum head room required.
54 *
55 * This must be at least 1 to prevent overflow, plus one packet-worth
56 * to allow pipelined receives.
57 */
58#define EFX_RXD_HEAD_ROOM (1 + EFX_RX_MAX_FRAGS)
59
60static inline u8 *efx_rx_buf_va(struct efx_rx_buffer *buf)
61{
62	return page_address(buf->page) + buf->page_offset;
63}
64
65static inline u32 efx_rx_buf_hash(struct efx_nic *efx, const u8 *eh)
66{
67#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
68	return __le32_to_cpup((const __le32 *)(eh + efx->rx_packet_hash_offset));
69#else
70	const u8 *data = eh + efx->rx_packet_hash_offset;
71	return (u32)data[0]	  |
72	       (u32)data[1] << 8  |
73	       (u32)data[2] << 16 |
74	       (u32)data[3] << 24;
75#endif
76}
77
78static inline struct efx_rx_buffer *
79efx_rx_buf_next(struct efx_rx_queue *rx_queue, struct efx_rx_buffer *rx_buf)
80{
81	if (unlikely(rx_buf == efx_rx_buffer(rx_queue, rx_queue->ptr_mask)))
82		return efx_rx_buffer(rx_queue, 0);
83	else
84		return rx_buf + 1;
85}
86
87static inline void efx_sync_rx_buffer(struct efx_nic *efx,
88				      struct efx_rx_buffer *rx_buf,
89				      unsigned int len)
90{
91	dma_sync_single_for_cpu(&efx->pci_dev->dev, rx_buf->dma_addr, len,
92				DMA_FROM_DEVICE);
93}
94
95void efx_rx_config_page_split(struct efx_nic *efx)
96{
97	efx->rx_page_buf_step = ALIGN(efx->rx_dma_len + efx->rx_ip_align,
98				      EFX_RX_BUF_ALIGNMENT);
99	efx->rx_bufs_per_page = efx->rx_buffer_order ? 1 :
100		((PAGE_SIZE - sizeof(struct efx_rx_page_state)) /
101		 efx->rx_page_buf_step);
102	efx->rx_buffer_truesize = (PAGE_SIZE << efx->rx_buffer_order) /
103		efx->rx_bufs_per_page;
104	efx->rx_pages_per_batch = DIV_ROUND_UP(EFX_RX_PREFERRED_BATCH,
105					       efx->rx_bufs_per_page);
106}
107
108/* Check the RX page recycle ring for a page that can be reused. */
109static struct page *efx_reuse_page(struct efx_rx_queue *rx_queue)
110{
111	struct efx_nic *efx = rx_queue->efx;
112	struct page *page;
113	struct efx_rx_page_state *state;
114	unsigned index;
115
116	index = rx_queue->page_remove & rx_queue->page_ptr_mask;
117	page = rx_queue->page_ring[index];
118	if (page == NULL)
119		return NULL;
120
121	rx_queue->page_ring[index] = NULL;
122	/* page_remove cannot exceed page_add. */
123	if (rx_queue->page_remove != rx_queue->page_add)
124		++rx_queue->page_remove;
125
126	/* If page_count is 1 then we hold the only reference to this page. */
127	if (page_count(page) == 1) {
128		++rx_queue->page_recycle_count;
129		return page;
130	} else {
131		state = page_address(page);
132		dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
133			       PAGE_SIZE << efx->rx_buffer_order,
134			       DMA_FROM_DEVICE);
135		put_page(page);
136		++rx_queue->page_recycle_failed;
137	}
138
139	return NULL;
140}
141
142/**
143 * efx_init_rx_buffers - create EFX_RX_BATCH page-based RX buffers
144 *
145 * @rx_queue:		Efx RX queue
146 *
147 * This allocates a batch of pages, maps them for DMA, and populates
148 * struct efx_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 */
152static int efx_init_rx_buffers(struct efx_rx_queue *rx_queue, bool atomic)
153{
154	struct efx_nic *efx = rx_queue->efx;
155	struct efx_rx_buffer *rx_buf;
156	struct page *page;
157	unsigned int page_offset;
158	struct efx_rx_page_state *state;
159	dma_addr_t dma_addr;
160	unsigned index, count;
161
162	count = 0;
163	do {
164		page = efx_reuse_page(rx_queue);
165		if (page == NULL) {
166			page = alloc_pages(__GFP_COLD | __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 efx_rx_page_state);
188		page_offset = sizeof(struct efx_rx_page_state);
189
190		do {
191			index = rx_queue->added_count & rx_queue->ptr_mask;
192			rx_buf = efx_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 = EFX_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 */
213static void efx_unmap_rx_buffer(struct efx_nic *efx,
214				struct efx_rx_buffer *rx_buf)
215{
216	struct page *page = rx_buf->page;
217
218	if (page) {
219		struct efx_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
227static void efx_free_rx_buffers(struct efx_rx_queue *rx_queue,
228				struct efx_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 = efx_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 */
244static void efx_recycle_rx_page(struct efx_channel *channel,
245				struct efx_rx_buffer *rx_buf)
246{
247	struct page *page = rx_buf->page;
248	struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
249	struct efx_nic *efx = rx_queue->efx;
250	unsigned index;
251
252	/* Only recycle the page after processing the final buffer. */
253	if (!(rx_buf->flags & EFX_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	efx_unmap_rx_buffer(efx, rx_buf);
273	put_page(rx_buf->page);
274}
275
276static void efx_fini_rx_buffer(struct efx_rx_queue *rx_queue,
277			       struct efx_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 & EFX_RX_BUF_LAST_IN_PAGE) {
285		efx_unmap_rx_buffer(rx_queue->efx, rx_buf);
286		efx_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. */
292static void efx_recycle_rx_pages(struct efx_channel *channel,
293				 struct efx_rx_buffer *rx_buf,
294				 unsigned int n_frags)
295{
296	struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
297
298	do {
299		efx_recycle_rx_page(channel, rx_buf);
300		rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
301	} while (--n_frags);
302}
303
304static void efx_discard_rx_packet(struct efx_channel *channel,
305				  struct efx_rx_buffer *rx_buf,
306				  unsigned int n_frags)
307{
308	struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
309
310	efx_recycle_rx_pages(channel, rx_buf, n_frags);
311
312	efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
313}
314
315/**
316 * efx_fast_push_rx_descriptors - push new RX descriptors quickly
317 * @rx_queue:		RX descriptor queue
318 *
319 * This will aim to fill the RX descriptor queue up to
320 * @rx_queue->@max_fill. If there is insufficient atomic
321 * memory to do so, a slow fill will be scheduled.
322 *
323 * The caller must provide serialisation (none is used here). In practise,
324 * this means this function must run from the NAPI handler, or be called
325 * when NAPI is disabled.
326 */
327void efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue, bool atomic)
328{
329	struct efx_nic *efx = rx_queue->efx;
330	unsigned int fill_level, batch_size;
331	int space, rc = 0;
332
333	if (!rx_queue->refill_enabled)
334		return;
335
336	/* Calculate current fill level, and exit if we don't need to fill */
337	fill_level = (rx_queue->added_count - rx_queue->removed_count);
338	EFX_BUG_ON_PARANOID(fill_level > rx_queue->efx->rxq_entries);
339	if (fill_level >= rx_queue->fast_fill_trigger)
340		goto out;
341
342	/* Record minimum fill level */
343	if (unlikely(fill_level < rx_queue->min_fill)) {
344		if (fill_level)
345			rx_queue->min_fill = fill_level;
346	}
347
348	batch_size = efx->rx_pages_per_batch * efx->rx_bufs_per_page;
349	space = rx_queue->max_fill - fill_level;
350	EFX_BUG_ON_PARANOID(space < batch_size);
351
352	netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
353		   "RX queue %d fast-filling descriptor ring from"
354		   " level %d to level %d\n",
355		   efx_rx_queue_index(rx_queue), fill_level,
356		   rx_queue->max_fill);
357
358
359	do {
360		rc = efx_init_rx_buffers(rx_queue, atomic);
361		if (unlikely(rc)) {
362			/* Ensure that we don't leave the rx queue empty */
363			if (rx_queue->added_count == rx_queue->removed_count)
364				efx_schedule_slow_fill(rx_queue);
365			goto out;
366		}
367	} while ((space -= batch_size) >= batch_size);
368
369	netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
370		   "RX queue %d fast-filled descriptor ring "
371		   "to level %d\n", efx_rx_queue_index(rx_queue),
372		   rx_queue->added_count - rx_queue->removed_count);
373
374 out:
375	if (rx_queue->notified_count != rx_queue->added_count)
376		efx_nic_notify_rx_desc(rx_queue);
377}
378
379void efx_rx_slow_fill(unsigned long context)
380{
381	struct efx_rx_queue *rx_queue = (struct efx_rx_queue *)context;
382
383	/* Post an event to cause NAPI to run and refill the queue */
384	efx_nic_generate_fill_event(rx_queue);
385	++rx_queue->slow_fill_count;
386}
387
388static void efx_rx_packet__check_len(struct efx_rx_queue *rx_queue,
389				     struct efx_rx_buffer *rx_buf,
390				     int len)
391{
392	struct efx_nic *efx = rx_queue->efx;
393	unsigned max_len = rx_buf->len - efx->type->rx_buffer_padding;
394
395	if (likely(len <= max_len))
396		return;
397
398	/* The packet must be discarded, but this is only a fatal error
399	 * if the caller indicated it was
400	 */
401	rx_buf->flags |= EFX_RX_PKT_DISCARD;
402
403	if ((len > rx_buf->len) && EFX_WORKAROUND_8071(efx)) {
404		if (net_ratelimit())
405			netif_err(efx, rx_err, efx->net_dev,
406				  " RX queue %d seriously overlength "
407				  "RX event (0x%x > 0x%x+0x%x). Leaking\n",
408				  efx_rx_queue_index(rx_queue), len, max_len,
409				  efx->type->rx_buffer_padding);
410		efx_schedule_reset(efx, RESET_TYPE_RX_RECOVERY);
411	} else {
412		if (net_ratelimit())
413			netif_err(efx, rx_err, efx->net_dev,
414				  " RX queue %d overlength RX event "
415				  "(0x%x > 0x%x)\n",
416				  efx_rx_queue_index(rx_queue), len, max_len);
417	}
418
419	efx_rx_queue_channel(rx_queue)->n_rx_overlength++;
420}
421
422/* Pass a received packet up through GRO.  GRO can handle pages
423 * regardless of checksum state and skbs with a good checksum.
424 */
425static void
426efx_rx_packet_gro(struct efx_channel *channel, struct efx_rx_buffer *rx_buf,
427		  unsigned int n_frags, u8 *eh)
428{
429	struct napi_struct *napi = &channel->napi_str;
430	gro_result_t gro_result;
431	struct efx_nic *efx = channel->efx;
432	struct sk_buff *skb;
433
434	skb = napi_get_frags(napi);
435	if (unlikely(!skb)) {
436		struct efx_rx_queue *rx_queue;
437
438		rx_queue = efx_channel_get_rx_queue(channel);
439		efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
440		return;
441	}
442
443	if (efx->net_dev->features & NETIF_F_RXHASH)
444		skb_set_hash(skb, efx_rx_buf_hash(efx, eh),
445			     PKT_HASH_TYPE_L3);
446	skb->ip_summed = ((rx_buf->flags & EFX_RX_PKT_CSUMMED) ?
447			  CHECKSUM_UNNECESSARY : CHECKSUM_NONE);
448
449	for (;;) {
450		skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
451				   rx_buf->page, rx_buf->page_offset,
452				   rx_buf->len);
453		rx_buf->page = NULL;
454		skb->len += rx_buf->len;
455		if (skb_shinfo(skb)->nr_frags == n_frags)
456			break;
457
458		rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf);
459	}
460
461	skb->data_len = skb->len;
462	skb->truesize += n_frags * efx->rx_buffer_truesize;
463
464	skb_record_rx_queue(skb, channel->rx_queue.core_index);
465
466	skb_mark_napi_id(skb, &channel->napi_str);
467	gro_result = napi_gro_frags(napi);
468	if (gro_result != GRO_DROP)
469		channel->irq_mod_score += 2;
470}
471
472/* Allocate and construct an SKB around page fragments */
473static struct sk_buff *efx_rx_mk_skb(struct efx_channel *channel,
474				     struct efx_rx_buffer *rx_buf,
475				     unsigned int n_frags,
476				     u8 *eh, int hdr_len)
477{
478	struct efx_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	EFX_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 = efx_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
530void efx_rx_packet(struct efx_rx_queue *rx_queue, unsigned int index,
531		   unsigned int n_frags, unsigned int len, u16 flags)
532{
533	struct efx_nic *efx = rx_queue->efx;
534	struct efx_channel *channel = efx_rx_queue_channel(rx_queue);
535	struct efx_rx_buffer *rx_buf;
536
537	rx_queue->rx_packets++;
538
539	rx_buf = efx_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 & EFX_RX_PKT_PREFIX_LEN))
545			efx_rx_packet__check_len(rx_queue, rx_buf, len);
546	} else if (unlikely(n_frags > EFX_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 & EFX_RX_PKT_DISCARD));
554		rx_buf->flags |= EFX_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		   efx_rx_queue_index(rx_queue), index,
560		   (index + n_frags - 1) & rx_queue->ptr_mask, len,
561		   (rx_buf->flags & EFX_RX_PKT_CSUMMED) ? " [SUMMED]" : "",
562		   (rx_buf->flags & EFX_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 & EFX_RX_PKT_DISCARD)) {
568		efx_rx_flush_packet(channel);
569		efx_discard_rx_packet(channel, rx_buf, n_frags);
570		return;
571	}
572
573	if (n_frags == 1 && !(flags & EFX_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	efx_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(efx_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 = efx_rx_buf_next(rx_queue, rx_buf);
597			if (--tail_frags == 0)
598				break;
599			efx_sync_rx_buffer(efx, rx_buf, efx->rx_dma_len);
600		}
601		rx_buf->len = len - (n_frags - 1) * efx->rx_dma_len;
602		efx_sync_rx_buffer(efx, rx_buf, rx_buf->len);
603	}
604
605	/* All fragments have been DMA-synced, so recycle pages. */
606	rx_buf = efx_rx_buffer(rx_queue, index);
607	efx_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	efx_rx_flush_packet(channel);
613	channel->rx_pkt_n_frags = n_frags;
614	channel->rx_pkt_index = index;
615}
616
617static void efx_rx_deliver(struct efx_channel *channel, u8 *eh,
618			   struct efx_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, EFX_SKB_HEADERS);
623
624	skb = efx_rx_mk_skb(channel, rx_buf, n_frags, eh, hdr_len);
625	if (unlikely(skb == NULL)) {
626		struct efx_rx_queue *rx_queue;
627
628		rx_queue = efx_channel_get_rx_queue(channel);
629		efx_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 & EFX_RX_PKT_CSUMMED))
637		skb->ip_summed = CHECKSUM_UNNECESSARY;
638
639	efx_rx_skb_attach_timestamp(channel, skb);
640
641	if (channel->type->receive_skb)
642		if (channel->type->receive_skb(channel, skb))
643			return;
644
645	/* Pass the packet up */
646	netif_receive_skb(skb);
647}
648
649/* Handle a received packet.  Second half: Touches packet payload. */
650void __efx_rx_packet(struct efx_channel *channel)
651{
652	struct efx_nic *efx = channel->efx;
653	struct efx_rx_buffer *rx_buf =
654		efx_rx_buffer(&channel->rx_queue, channel->rx_pkt_index);
655	u8 *eh = efx_rx_buf_va(rx_buf);
656
657	/* Read length from the prefix if necessary.  This already
658	 * excludes the length of the prefix itself.
659	 */
660	if (rx_buf->flags & EFX_RX_PKT_PREFIX_LEN)
661		rx_buf->len = le16_to_cpup((__le16 *)
662					   (eh + efx->rx_packet_len_offset));
663
664	/* If we're in loopback test, then pass the packet directly to the
665	 * loopback layer, and free the rx_buf here
666	 */
667	if (unlikely(efx->loopback_selftest)) {
668		struct efx_rx_queue *rx_queue;
669
670		efx_loopback_rx_packet(efx, eh, rx_buf->len);
671		rx_queue = efx_channel_get_rx_queue(channel);
672		efx_free_rx_buffers(rx_queue, rx_buf,
673				    channel->rx_pkt_n_frags);
674		goto out;
675	}
676
677	if (unlikely(!(efx->net_dev->features & NETIF_F_RXCSUM)))
678		rx_buf->flags &= ~EFX_RX_PKT_CSUMMED;
679
680	if ((rx_buf->flags & EFX_RX_PKT_TCP) && !channel->type->receive_skb &&
681	    !efx_channel_busy_polling(channel))
682		efx_rx_packet_gro(channel, rx_buf, channel->rx_pkt_n_frags, eh);
683	else
684		efx_rx_deliver(channel, eh, rx_buf, channel->rx_pkt_n_frags);
685out:
686	channel->rx_pkt_n_frags = 0;
687}
688
689int efx_probe_rx_queue(struct efx_rx_queue *rx_queue)
690{
691	struct efx_nic *efx = rx_queue->efx;
692	unsigned int entries;
693	int rc;
694
695	/* Create the smallest power-of-two aligned ring */
696	entries = max(roundup_pow_of_two(efx->rxq_entries), EFX_MIN_DMAQ_SIZE);
697	EFX_BUG_ON_PARANOID(entries > EFX_MAX_DMAQ_SIZE);
698	rx_queue->ptr_mask = entries - 1;
699
700	netif_dbg(efx, probe, efx->net_dev,
701		  "creating RX queue %d size %#x mask %#x\n",
702		  efx_rx_queue_index(rx_queue), efx->rxq_entries,
703		  rx_queue->ptr_mask);
704
705	/* Allocate RX buffers */
706	rx_queue->buffer = kcalloc(entries, sizeof(*rx_queue->buffer),
707				   GFP_KERNEL);
708	if (!rx_queue->buffer)
709		return -ENOMEM;
710
711	rc = efx_nic_probe_rx(rx_queue);
712	if (rc) {
713		kfree(rx_queue->buffer);
714		rx_queue->buffer = NULL;
715	}
716
717	return rc;
718}
719
720static void efx_init_rx_recycle_ring(struct efx_nic *efx,
721				     struct efx_rx_queue *rx_queue)
722{
723	unsigned int bufs_in_recycle_ring, page_ring_size;
724
725	/* Set the RX recycle ring size */
726#ifdef CONFIG_PPC64
727	bufs_in_recycle_ring = EFX_RECYCLE_RING_SIZE_IOMMU;
728#else
729	if (iommu_present(&pci_bus_type))
730		bufs_in_recycle_ring = EFX_RECYCLE_RING_SIZE_IOMMU;
731	else
732		bufs_in_recycle_ring = EFX_RECYCLE_RING_SIZE_NOIOMMU;
733#endif /* CONFIG_PPC64 */
734
735	page_ring_size = roundup_pow_of_two(bufs_in_recycle_ring /
736					    efx->rx_bufs_per_page);
737	rx_queue->page_ring = kcalloc(page_ring_size,
738				      sizeof(*rx_queue->page_ring), GFP_KERNEL);
739	rx_queue->page_ptr_mask = page_ring_size - 1;
740}
741
742void efx_init_rx_queue(struct efx_rx_queue *rx_queue)
743{
744	struct efx_nic *efx = rx_queue->efx;
745	unsigned int max_fill, trigger, max_trigger;
746
747	netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
748		  "initialising RX queue %d\n", efx_rx_queue_index(rx_queue));
749
750	/* Initialise ptr fields */
751	rx_queue->added_count = 0;
752	rx_queue->notified_count = 0;
753	rx_queue->removed_count = 0;
754	rx_queue->min_fill = -1U;
755	efx_init_rx_recycle_ring(efx, rx_queue);
756
757	rx_queue->page_remove = 0;
758	rx_queue->page_add = rx_queue->page_ptr_mask + 1;
759	rx_queue->page_recycle_count = 0;
760	rx_queue->page_recycle_failed = 0;
761	rx_queue->page_recycle_full = 0;
762
763	/* Initialise limit fields */
764	max_fill = efx->rxq_entries - EFX_RXD_HEAD_ROOM;
765	max_trigger =
766		max_fill - efx->rx_pages_per_batch * efx->rx_bufs_per_page;
767	if (rx_refill_threshold != 0) {
768		trigger = max_fill * min(rx_refill_threshold, 100U) / 100U;
769		if (trigger > max_trigger)
770			trigger = max_trigger;
771	} else {
772		trigger = max_trigger;
773	}
774
775	rx_queue->max_fill = max_fill;
776	rx_queue->fast_fill_trigger = trigger;
777	rx_queue->refill_enabled = true;
778
779	/* Set up RX descriptor ring */
780	efx_nic_init_rx(rx_queue);
781}
782
783void efx_fini_rx_queue(struct efx_rx_queue *rx_queue)
784{
785	int i;
786	struct efx_nic *efx = rx_queue->efx;
787	struct efx_rx_buffer *rx_buf;
788
789	netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
790		  "shutting down RX queue %d\n", efx_rx_queue_index(rx_queue));
791
792	del_timer_sync(&rx_queue->slow_fill);
793
794	/* Release RX buffers from the current read ptr to the write ptr */
795	if (rx_queue->buffer) {
796		for (i = rx_queue->removed_count; i < rx_queue->added_count;
797		     i++) {
798			unsigned index = i & rx_queue->ptr_mask;
799			rx_buf = efx_rx_buffer(rx_queue, index);
800			efx_fini_rx_buffer(rx_queue, rx_buf);
801		}
802	}
803
804	/* Unmap and release the pages in the recycle ring. Remove the ring. */
805	for (i = 0; i <= rx_queue->page_ptr_mask; i++) {
806		struct page *page = rx_queue->page_ring[i];
807		struct efx_rx_page_state *state;
808
809		if (page == NULL)
810			continue;
811
812		state = page_address(page);
813		dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
814			       PAGE_SIZE << efx->rx_buffer_order,
815			       DMA_FROM_DEVICE);
816		put_page(page);
817	}
818	kfree(rx_queue->page_ring);
819	rx_queue->page_ring = NULL;
820}
821
822void efx_remove_rx_queue(struct efx_rx_queue *rx_queue)
823{
824	netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
825		  "destroying RX queue %d\n", efx_rx_queue_index(rx_queue));
826
827	efx_nic_remove_rx(rx_queue);
828
829	kfree(rx_queue->buffer);
830	rx_queue->buffer = NULL;
831}
832
833
834module_param(rx_refill_threshold, uint, 0444);
835MODULE_PARM_DESC(rx_refill_threshold,
836		 "RX descriptor ring refill threshold (%)");
837
838#ifdef CONFIG_RFS_ACCEL
839
840int efx_filter_rfs(struct net_device *net_dev, const struct sk_buff *skb,
841		   u16 rxq_index, u32 flow_id)
842{
843	struct efx_nic *efx = netdev_priv(net_dev);
844	struct efx_channel *channel;
845	struct efx_filter_spec spec;
846	const __be16 *ports;
847	__be16 ether_type;
848	int nhoff;
849	int rc;
850
851	/* The core RPS/RFS code has already parsed and validated
852	 * VLAN, IP and transport headers.  We assume they are in the
853	 * header area.
854	 */
855
856	if (skb->protocol == htons(ETH_P_8021Q)) {
857		const struct vlan_hdr *vh =
858			(const struct vlan_hdr *)skb->data;
859
860		/* We can't filter on the IP 5-tuple and the vlan
861		 * together, so just strip the vlan header and filter
862		 * on the IP part.
863		 */
864		EFX_BUG_ON_PARANOID(skb_headlen(skb) < sizeof(*vh));
865		ether_type = vh->h_vlan_encapsulated_proto;
866		nhoff = sizeof(struct vlan_hdr);
867	} else {
868		ether_type = skb->protocol;
869		nhoff = 0;
870	}
871
872	if (ether_type != htons(ETH_P_IP) && ether_type != htons(ETH_P_IPV6))
873		return -EPROTONOSUPPORT;
874
875	efx_filter_init_rx(&spec, EFX_FILTER_PRI_HINT,
876			   efx->rx_scatter ? EFX_FILTER_FLAG_RX_SCATTER : 0,
877			   rxq_index);
878	spec.match_flags =
879		EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_IP_PROTO |
880		EFX_FILTER_MATCH_LOC_HOST | EFX_FILTER_MATCH_LOC_PORT |
881		EFX_FILTER_MATCH_REM_HOST | EFX_FILTER_MATCH_REM_PORT;
882	spec.ether_type = ether_type;
883
884	if (ether_type == htons(ETH_P_IP)) {
885		const struct iphdr *ip =
886			(const struct iphdr *)(skb->data + nhoff);
887
888		EFX_BUG_ON_PARANOID(skb_headlen(skb) < nhoff + sizeof(*ip));
889		if (ip_is_fragment(ip))
890			return -EPROTONOSUPPORT;
891		spec.ip_proto = ip->protocol;
892		spec.rem_host[0] = ip->saddr;
893		spec.loc_host[0] = ip->daddr;
894		EFX_BUG_ON_PARANOID(skb_headlen(skb) < nhoff + 4 * ip->ihl + 4);
895		ports = (const __be16 *)(skb->data + nhoff + 4 * ip->ihl);
896	} else {
897		const struct ipv6hdr *ip6 =
898			(const struct ipv6hdr *)(skb->data + nhoff);
899
900		EFX_BUG_ON_PARANOID(skb_headlen(skb) <
901				    nhoff + sizeof(*ip6) + 4);
902		spec.ip_proto = ip6->nexthdr;
903		memcpy(spec.rem_host, &ip6->saddr, sizeof(ip6->saddr));
904		memcpy(spec.loc_host, &ip6->daddr, sizeof(ip6->daddr));
905		ports = (const __be16 *)(ip6 + 1);
906	}
907
908	spec.rem_port = ports[0];
909	spec.loc_port = ports[1];
910
911	rc = efx->type->filter_rfs_insert(efx, &spec);
912	if (rc < 0)
913		return rc;
914
915	/* Remember this so we can check whether to expire the filter later */
916	efx->rps_flow_id[rc] = flow_id;
917	channel = efx_get_channel(efx, skb_get_rx_queue(skb));
918	++channel->rfs_filters_added;
919
920	if (ether_type == htons(ETH_P_IP))
921		netif_info(efx, rx_status, efx->net_dev,
922			   "steering %s %pI4:%u:%pI4:%u to queue %u [flow %u filter %d]\n",
923			   (spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
924			   spec.rem_host, ntohs(ports[0]), spec.loc_host,
925			   ntohs(ports[1]), rxq_index, flow_id, rc);
926	else
927		netif_info(efx, rx_status, efx->net_dev,
928			   "steering %s [%pI6]:%u:[%pI6]:%u to queue %u [flow %u filter %d]\n",
929			   (spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
930			   spec.rem_host, ntohs(ports[0]), spec.loc_host,
931			   ntohs(ports[1]), rxq_index, flow_id, rc);
932
933	return rc;
934}
935
936bool __efx_filter_rfs_expire(struct efx_nic *efx, unsigned int quota)
937{
938	bool (*expire_one)(struct efx_nic *efx, u32 flow_id, unsigned int index);
939	unsigned int index, size;
940	u32 flow_id;
941
942	if (!spin_trylock_bh(&efx->filter_lock))
943		return false;
944
945	expire_one = efx->type->filter_rfs_expire_one;
946	index = efx->rps_expire_index;
947	size = efx->type->max_rx_ip_filters;
948	while (quota--) {
949		flow_id = efx->rps_flow_id[index];
950		if (expire_one(efx, flow_id, index))
951			netif_info(efx, rx_status, efx->net_dev,
952				   "expired filter %d [flow %u]\n",
953				   index, flow_id);
954		if (++index == size)
955			index = 0;
956	}
957	efx->rps_expire_index = index;
958
959	spin_unlock_bh(&efx->filter_lock);
960	return true;
961}
962
963#endif /* CONFIG_RFS_ACCEL */
964
965/**
966 * efx_filter_is_mc_recipient - test whether spec is a multicast recipient
967 * @spec: Specification to test
968 *
969 * Return: %true if the specification is a non-drop RX filter that
970 * matches a local MAC address I/G bit value of 1 or matches a local
971 * IPv4 or IPv6 address value in the respective multicast address
972 * range.  Otherwise %false.
973 */
974bool efx_filter_is_mc_recipient(const struct efx_filter_spec *spec)
975{
976	if (!(spec->flags & EFX_FILTER_FLAG_RX) ||
977	    spec->dmaq_id == EFX_FILTER_RX_DMAQ_ID_DROP)
978		return false;
979
980	if (spec->match_flags &
981	    (EFX_FILTER_MATCH_LOC_MAC | EFX_FILTER_MATCH_LOC_MAC_IG) &&
982	    is_multicast_ether_addr(spec->loc_mac))
983		return true;
984
985	if ((spec->match_flags &
986	     (EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_LOC_HOST)) ==
987	    (EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_LOC_HOST)) {
988		if (spec->ether_type == htons(ETH_P_IP) &&
989		    ipv4_is_multicast(spec->loc_host[0]))
990			return true;
991		if (spec->ether_type == htons(ETH_P_IPV6) &&
992		    ((const u8 *)spec->loc_host)[0] == 0xff)
993			return true;
994	}
995
996	return false;
997}
998