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-rw-r--r--drivers/net/sfc/rx.c875
1 files changed, 875 insertions, 0 deletions
diff --git a/drivers/net/sfc/rx.c b/drivers/net/sfc/rx.c
new file mode 100644
index 000000000000..551299b462ae
--- /dev/null
+++ b/drivers/net/sfc/rx.c
@@ -0,0 +1,875 @@
1/****************************************************************************
2 * Driver for Solarflare Solarstorm network controllers and boards
3 * Copyright 2005-2006 Fen Systems Ltd.
4 * Copyright 2005-2008 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/ip.h>
14#include <linux/tcp.h>
15#include <linux/udp.h>
16#include <net/ip.h>
17#include <net/checksum.h>
18#include "net_driver.h"
19#include "rx.h"
20#include "efx.h"
21#include "falcon.h"
22#include "workarounds.h"
23
24/* Number of RX descriptors pushed at once. */
25#define EFX_RX_BATCH 8
26
27/* Size of buffer allocated for skb header area. */
28#define EFX_SKB_HEADERS 64u
29
30/*
31 * rx_alloc_method - RX buffer allocation method
32 *
33 * This driver supports two methods for allocating and using RX buffers:
34 * each RX buffer may be backed by an skb or by an order-n page.
35 *
36 * When LRO is in use then the second method has a lower overhead,
37 * since we don't have to allocate then free skbs on reassembled frames.
38 *
39 * Values:
40 * - RX_ALLOC_METHOD_AUTO = 0
41 * - RX_ALLOC_METHOD_SKB = 1
42 * - RX_ALLOC_METHOD_PAGE = 2
43 *
44 * The heuristic for %RX_ALLOC_METHOD_AUTO is a simple hysteresis count
45 * controlled by the parameters below.
46 *
47 * - Since pushing and popping descriptors are separated by the rx_queue
48 * size, so the watermarks should be ~rxd_size.
49 * - The performance win by using page-based allocation for LRO is less
50 * than the performance hit of using page-based allocation of non-LRO,
51 * so the watermarks should reflect this.
52 *
53 * Per channel we maintain a single variable, updated by each channel:
54 *
55 * rx_alloc_level += (lro_performed ? RX_ALLOC_FACTOR_LRO :
56 * RX_ALLOC_FACTOR_SKB)
57 * Per NAPI poll interval, we constrain rx_alloc_level to 0..MAX (which
58 * limits the hysteresis), and update the allocation strategy:
59 *
60 * rx_alloc_method = (rx_alloc_level > RX_ALLOC_LEVEL_LRO ?
61 * RX_ALLOC_METHOD_PAGE : RX_ALLOC_METHOD_SKB)
62 */
63static int rx_alloc_method = RX_ALLOC_METHOD_PAGE;
64
65#define RX_ALLOC_LEVEL_LRO 0x2000
66#define RX_ALLOC_LEVEL_MAX 0x3000
67#define RX_ALLOC_FACTOR_LRO 1
68#define RX_ALLOC_FACTOR_SKB (-2)
69
70/* This is the percentage fill level below which new RX descriptors
71 * will be added to the RX descriptor ring.
72 */
73static unsigned int rx_refill_threshold = 90;
74
75/* This is the percentage fill level to which an RX queue will be refilled
76 * when the "RX refill threshold" is reached.
77 */
78static unsigned int rx_refill_limit = 95;
79
80/*
81 * RX maximum head room required.
82 *
83 * This must be at least 1 to prevent overflow and at least 2 to allow
84 * pipelined receives.
85 */
86#define EFX_RXD_HEAD_ROOM 2
87
88/* Macros for zero-order pages (potentially) containing multiple RX buffers */
89#define RX_DATA_OFFSET(_data) \
90 (((unsigned long) (_data)) & (PAGE_SIZE-1))
91#define RX_BUF_OFFSET(_rx_buf) \
92 RX_DATA_OFFSET((_rx_buf)->data)
93
94#define RX_PAGE_SIZE(_efx) \
95 (PAGE_SIZE * (1u << (_efx)->rx_buffer_order))
96
97
98/**************************************************************************
99 *
100 * Linux generic LRO handling
101 *
102 **************************************************************************
103 */
104
105static int efx_lro_get_skb_hdr(struct sk_buff *skb, void **ip_hdr,
106 void **tcpudp_hdr, u64 *hdr_flags, void *priv)
107{
108 struct efx_channel *channel = (struct efx_channel *)priv;
109 struct iphdr *iph;
110 struct tcphdr *th;
111
112 iph = (struct iphdr *)skb->data;
113 if (skb->protocol != htons(ETH_P_IP) || iph->protocol != IPPROTO_TCP)
114 goto fail;
115
116 th = (struct tcphdr *)(skb->data + iph->ihl * 4);
117
118 *tcpudp_hdr = th;
119 *ip_hdr = iph;
120 *hdr_flags = LRO_IPV4 | LRO_TCP;
121
122 channel->rx_alloc_level += RX_ALLOC_FACTOR_LRO;
123 return 0;
124fail:
125 channel->rx_alloc_level += RX_ALLOC_FACTOR_SKB;
126 return -1;
127}
128
129static int efx_get_frag_hdr(struct skb_frag_struct *frag, void **mac_hdr,
130 void **ip_hdr, void **tcpudp_hdr, u64 *hdr_flags,
131 void *priv)
132{
133 struct efx_channel *channel = (struct efx_channel *)priv;
134 struct ethhdr *eh;
135 struct iphdr *iph;
136
137 /* We support EtherII and VLAN encapsulated IPv4 */
138 eh = (struct ethhdr *)(page_address(frag->page) + frag->page_offset);
139 *mac_hdr = eh;
140
141 if (eh->h_proto == htons(ETH_P_IP)) {
142 iph = (struct iphdr *)(eh + 1);
143 } else {
144 struct vlan_ethhdr *veh = (struct vlan_ethhdr *)eh;
145 if (veh->h_vlan_encapsulated_proto != htons(ETH_P_IP))
146 goto fail;
147
148 iph = (struct iphdr *)(veh + 1);
149 }
150 *ip_hdr = iph;
151
152 /* We can only do LRO over TCP */
153 if (iph->protocol != IPPROTO_TCP)
154 goto fail;
155
156 *hdr_flags = LRO_IPV4 | LRO_TCP;
157 *tcpudp_hdr = (struct tcphdr *)((u8 *) iph + iph->ihl * 4);
158
159 channel->rx_alloc_level += RX_ALLOC_FACTOR_LRO;
160 return 0;
161 fail:
162 channel->rx_alloc_level += RX_ALLOC_FACTOR_SKB;
163 return -1;
164}
165
166int efx_lro_init(struct net_lro_mgr *lro_mgr, struct efx_nic *efx)
167{
168 size_t s = sizeof(struct net_lro_desc) * EFX_MAX_LRO_DESCRIPTORS;
169 struct net_lro_desc *lro_arr;
170
171 /* Allocate the LRO descriptors structure */
172 lro_arr = kzalloc(s, GFP_KERNEL);
173 if (lro_arr == NULL)
174 return -ENOMEM;
175
176 lro_mgr->lro_arr = lro_arr;
177 lro_mgr->max_desc = EFX_MAX_LRO_DESCRIPTORS;
178 lro_mgr->max_aggr = EFX_MAX_LRO_AGGR;
179 lro_mgr->frag_align_pad = EFX_PAGE_SKB_ALIGN;
180
181 lro_mgr->get_skb_header = efx_lro_get_skb_hdr;
182 lro_mgr->get_frag_header = efx_get_frag_hdr;
183 lro_mgr->dev = efx->net_dev;
184
185 lro_mgr->features = LRO_F_NAPI;
186
187 /* We can pass packets up with the checksum intact */
188 lro_mgr->ip_summed = CHECKSUM_UNNECESSARY;
189
190 lro_mgr->ip_summed_aggr = CHECKSUM_UNNECESSARY;
191
192 return 0;
193}
194
195void efx_lro_fini(struct net_lro_mgr *lro_mgr)
196{
197 kfree(lro_mgr->lro_arr);
198 lro_mgr->lro_arr = NULL;
199}
200
201/**
202 * efx_init_rx_buffer_skb - create new RX buffer using skb-based allocation
203 *
204 * @rx_queue: Efx RX queue
205 * @rx_buf: RX buffer structure to populate
206 *
207 * This allocates memory for a new receive buffer, maps it for DMA,
208 * and populates a struct efx_rx_buffer with the relevant
209 * information. Return a negative error code or 0 on success.
210 */
211static inline int efx_init_rx_buffer_skb(struct efx_rx_queue *rx_queue,
212 struct efx_rx_buffer *rx_buf)
213{
214 struct efx_nic *efx = rx_queue->efx;
215 struct net_device *net_dev = efx->net_dev;
216 int skb_len = efx->rx_buffer_len;
217
218 rx_buf->skb = netdev_alloc_skb(net_dev, skb_len);
219 if (unlikely(!rx_buf->skb))
220 return -ENOMEM;
221
222 /* Adjust the SKB for padding and checksum */
223 skb_reserve(rx_buf->skb, NET_IP_ALIGN);
224 rx_buf->len = skb_len - NET_IP_ALIGN;
225 rx_buf->data = (char *)rx_buf->skb->data;
226 rx_buf->skb->ip_summed = CHECKSUM_UNNECESSARY;
227
228 rx_buf->dma_addr = pci_map_single(efx->pci_dev,
229 rx_buf->data, rx_buf->len,
230 PCI_DMA_FROMDEVICE);
231
232 if (unlikely(pci_dma_mapping_error(rx_buf->dma_addr))) {
233 dev_kfree_skb_any(rx_buf->skb);
234 rx_buf->skb = NULL;
235 return -EIO;
236 }
237
238 return 0;
239}
240
241/**
242 * efx_init_rx_buffer_page - create new RX buffer using page-based allocation
243 *
244 * @rx_queue: Efx RX queue
245 * @rx_buf: RX buffer structure to populate
246 *
247 * This allocates memory for a new receive buffer, maps it for DMA,
248 * and populates a struct efx_rx_buffer with the relevant
249 * information. Return a negative error code or 0 on success.
250 */
251static inline int efx_init_rx_buffer_page(struct efx_rx_queue *rx_queue,
252 struct efx_rx_buffer *rx_buf)
253{
254 struct efx_nic *efx = rx_queue->efx;
255 int bytes, space, offset;
256
257 bytes = efx->rx_buffer_len - EFX_PAGE_IP_ALIGN;
258
259 /* If there is space left in the previously allocated page,
260 * then use it. Otherwise allocate a new one */
261 rx_buf->page = rx_queue->buf_page;
262 if (rx_buf->page == NULL) {
263 dma_addr_t dma_addr;
264
265 rx_buf->page = alloc_pages(__GFP_COLD | __GFP_COMP | GFP_ATOMIC,
266 efx->rx_buffer_order);
267 if (unlikely(rx_buf->page == NULL))
268 return -ENOMEM;
269
270 dma_addr = pci_map_page(efx->pci_dev, rx_buf->page,
271 0, RX_PAGE_SIZE(efx),
272 PCI_DMA_FROMDEVICE);
273
274 if (unlikely(pci_dma_mapping_error(dma_addr))) {
275 __free_pages(rx_buf->page, efx->rx_buffer_order);
276 rx_buf->page = NULL;
277 return -EIO;
278 }
279
280 rx_queue->buf_page = rx_buf->page;
281 rx_queue->buf_dma_addr = dma_addr;
282 rx_queue->buf_data = ((char *) page_address(rx_buf->page) +
283 EFX_PAGE_IP_ALIGN);
284 }
285
286 offset = RX_DATA_OFFSET(rx_queue->buf_data);
287 rx_buf->len = bytes;
288 rx_buf->dma_addr = rx_queue->buf_dma_addr + offset;
289 rx_buf->data = rx_queue->buf_data;
290
291 /* Try to pack multiple buffers per page */
292 if (efx->rx_buffer_order == 0) {
293 /* The next buffer starts on the next 512 byte boundary */
294 rx_queue->buf_data += ((bytes + 0x1ff) & ~0x1ff);
295 offset += ((bytes + 0x1ff) & ~0x1ff);
296
297 space = RX_PAGE_SIZE(efx) - offset;
298 if (space >= bytes) {
299 /* Refs dropped on kernel releasing each skb */
300 get_page(rx_queue->buf_page);
301 goto out;
302 }
303 }
304
305 /* This is the final RX buffer for this page, so mark it for
306 * unmapping */
307 rx_queue->buf_page = NULL;
308 rx_buf->unmap_addr = rx_queue->buf_dma_addr;
309
310 out:
311 return 0;
312}
313
314/* This allocates memory for a new receive buffer, maps it for DMA,
315 * and populates a struct efx_rx_buffer with the relevant
316 * information.
317 */
318static inline int efx_init_rx_buffer(struct efx_rx_queue *rx_queue,
319 struct efx_rx_buffer *new_rx_buf)
320{
321 int rc = 0;
322
323 if (rx_queue->channel->rx_alloc_push_pages) {
324 new_rx_buf->skb = NULL;
325 rc = efx_init_rx_buffer_page(rx_queue, new_rx_buf);
326 rx_queue->alloc_page_count++;
327 } else {
328 new_rx_buf->page = NULL;
329 rc = efx_init_rx_buffer_skb(rx_queue, new_rx_buf);
330 rx_queue->alloc_skb_count++;
331 }
332
333 if (unlikely(rc < 0))
334 EFX_LOG_RL(rx_queue->efx, "%s RXQ[%d] =%d\n", __func__,
335 rx_queue->queue, rc);
336 return rc;
337}
338
339static inline void efx_unmap_rx_buffer(struct efx_nic *efx,
340 struct efx_rx_buffer *rx_buf)
341{
342 if (rx_buf->page) {
343 EFX_BUG_ON_PARANOID(rx_buf->skb);
344 if (rx_buf->unmap_addr) {
345 pci_unmap_page(efx->pci_dev, rx_buf->unmap_addr,
346 RX_PAGE_SIZE(efx), PCI_DMA_FROMDEVICE);
347 rx_buf->unmap_addr = 0;
348 }
349 } else if (likely(rx_buf->skb)) {
350 pci_unmap_single(efx->pci_dev, rx_buf->dma_addr,
351 rx_buf->len, PCI_DMA_FROMDEVICE);
352 }
353}
354
355static inline void efx_free_rx_buffer(struct efx_nic *efx,
356 struct efx_rx_buffer *rx_buf)
357{
358 if (rx_buf->page) {
359 __free_pages(rx_buf->page, efx->rx_buffer_order);
360 rx_buf->page = NULL;
361 } else if (likely(rx_buf->skb)) {
362 dev_kfree_skb_any(rx_buf->skb);
363 rx_buf->skb = NULL;
364 }
365}
366
367static inline void efx_fini_rx_buffer(struct efx_rx_queue *rx_queue,
368 struct efx_rx_buffer *rx_buf)
369{
370 efx_unmap_rx_buffer(rx_queue->efx, rx_buf);
371 efx_free_rx_buffer(rx_queue->efx, rx_buf);
372}
373
374/**
375 * efx_fast_push_rx_descriptors - push new RX descriptors quickly
376 * @rx_queue: RX descriptor queue
377 * @retry: Recheck the fill level
378 * This will aim to fill the RX descriptor queue up to
379 * @rx_queue->@fast_fill_limit. If there is insufficient atomic
380 * memory to do so, the caller should retry.
381 */
382static int __efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue,
383 int retry)
384{
385 struct efx_rx_buffer *rx_buf;
386 unsigned fill_level, index;
387 int i, space, rc = 0;
388
389 /* Calculate current fill level. Do this outside the lock,
390 * because most of the time we'll end up not wanting to do the
391 * fill anyway.
392 */
393 fill_level = (rx_queue->added_count - rx_queue->removed_count);
394 EFX_BUG_ON_PARANOID(fill_level >
395 rx_queue->efx->type->rxd_ring_mask + 1);
396
397 /* Don't fill if we don't need to */
398 if (fill_level >= rx_queue->fast_fill_trigger)
399 return 0;
400
401 /* Record minimum fill level */
402 if (unlikely(fill_level < rx_queue->min_fill))
403 if (fill_level)
404 rx_queue->min_fill = fill_level;
405
406 /* Acquire RX add lock. If this lock is contended, then a fast
407 * fill must already be in progress (e.g. in the refill
408 * tasklet), so we don't need to do anything
409 */
410 if (!spin_trylock_bh(&rx_queue->add_lock))
411 return -1;
412
413 retry:
414 /* Recalculate current fill level now that we have the lock */
415 fill_level = (rx_queue->added_count - rx_queue->removed_count);
416 EFX_BUG_ON_PARANOID(fill_level >
417 rx_queue->efx->type->rxd_ring_mask + 1);
418 space = rx_queue->fast_fill_limit - fill_level;
419 if (space < EFX_RX_BATCH)
420 goto out_unlock;
421
422 EFX_TRACE(rx_queue->efx, "RX queue %d fast-filling descriptor ring from"
423 " level %d to level %d using %s allocation\n",
424 rx_queue->queue, fill_level, rx_queue->fast_fill_limit,
425 rx_queue->channel->rx_alloc_push_pages ? "page" : "skb");
426
427 do {
428 for (i = 0; i < EFX_RX_BATCH; ++i) {
429 index = (rx_queue->added_count &
430 rx_queue->efx->type->rxd_ring_mask);
431 rx_buf = efx_rx_buffer(rx_queue, index);
432 rc = efx_init_rx_buffer(rx_queue, rx_buf);
433 if (unlikely(rc))
434 goto out;
435 ++rx_queue->added_count;
436 }
437 } while ((space -= EFX_RX_BATCH) >= EFX_RX_BATCH);
438
439 EFX_TRACE(rx_queue->efx, "RX queue %d fast-filled descriptor ring "
440 "to level %d\n", rx_queue->queue,
441 rx_queue->added_count - rx_queue->removed_count);
442
443 out:
444 /* Send write pointer to card. */
445 falcon_notify_rx_desc(rx_queue);
446
447 /* If the fast fill is running inside from the refill tasklet, then
448 * for SMP systems it may be running on a different CPU to
449 * RX event processing, which means that the fill level may now be
450 * out of date. */
451 if (unlikely(retry && (rc == 0)))
452 goto retry;
453
454 out_unlock:
455 spin_unlock_bh(&rx_queue->add_lock);
456
457 return rc;
458}
459
460/**
461 * efx_fast_push_rx_descriptors - push new RX descriptors quickly
462 * @rx_queue: RX descriptor queue
463 *
464 * This will aim to fill the RX descriptor queue up to
465 * @rx_queue->@fast_fill_limit. If there is insufficient memory to do so,
466 * it will schedule a work item to immediately continue the fast fill
467 */
468void efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue)
469{
470 int rc;
471
472 rc = __efx_fast_push_rx_descriptors(rx_queue, 0);
473 if (unlikely(rc)) {
474 /* Schedule the work item to run immediately. The hope is
475 * that work is immediately pending to free some memory
476 * (e.g. an RX event or TX completion)
477 */
478 efx_schedule_slow_fill(rx_queue, 0);
479 }
480}
481
482void efx_rx_work(struct work_struct *data)
483{
484 struct efx_rx_queue *rx_queue;
485 int rc;
486
487 rx_queue = container_of(data, struct efx_rx_queue, work.work);
488
489 if (unlikely(!rx_queue->channel->enabled))
490 return;
491
492 EFX_TRACE(rx_queue->efx, "RX queue %d worker thread executing on CPU "
493 "%d\n", rx_queue->queue, raw_smp_processor_id());
494
495 ++rx_queue->slow_fill_count;
496 /* Push new RX descriptors, allowing at least 1 jiffy for
497 * the kernel to free some more memory. */
498 rc = __efx_fast_push_rx_descriptors(rx_queue, 1);
499 if (rc)
500 efx_schedule_slow_fill(rx_queue, 1);
501}
502
503static inline void efx_rx_packet__check_len(struct efx_rx_queue *rx_queue,
504 struct efx_rx_buffer *rx_buf,
505 int len, int *discard,
506 int *leak_packet)
507{
508 struct efx_nic *efx = rx_queue->efx;
509 unsigned max_len = rx_buf->len - efx->type->rx_buffer_padding;
510
511 if (likely(len <= max_len))
512 return;
513
514 /* The packet must be discarded, but this is only a fatal error
515 * if the caller indicated it was
516 */
517 *discard = 1;
518
519 if ((len > rx_buf->len) && EFX_WORKAROUND_8071(efx)) {
520 EFX_ERR_RL(efx, " RX queue %d seriously overlength "
521 "RX event (0x%x > 0x%x+0x%x). Leaking\n",
522 rx_queue->queue, len, max_len,
523 efx->type->rx_buffer_padding);
524 /* If this buffer was skb-allocated, then the meta
525 * data at the end of the skb will be trashed. So
526 * we have no choice but to leak the fragment.
527 */
528 *leak_packet = (rx_buf->skb != NULL);
529 efx_schedule_reset(efx, RESET_TYPE_RX_RECOVERY);
530 } else {
531 EFX_ERR_RL(efx, " RX queue %d overlength RX event "
532 "(0x%x > 0x%x)\n", rx_queue->queue, len, max_len);
533 }
534
535 rx_queue->channel->n_rx_overlength++;
536}
537
538/* Pass a received packet up through the generic LRO stack
539 *
540 * Handles driverlink veto, and passes the fragment up via
541 * the appropriate LRO method
542 */
543static inline void efx_rx_packet_lro(struct efx_channel *channel,
544 struct efx_rx_buffer *rx_buf)
545{
546 struct net_lro_mgr *lro_mgr = &channel->lro_mgr;
547 void *priv = channel;
548
549 /* Pass the skb/page into the LRO engine */
550 if (rx_buf->page) {
551 struct skb_frag_struct frags;
552
553 frags.page = rx_buf->page;
554 frags.page_offset = RX_BUF_OFFSET(rx_buf);
555 frags.size = rx_buf->len;
556
557 lro_receive_frags(lro_mgr, &frags, rx_buf->len,
558 rx_buf->len, priv, 0);
559
560 EFX_BUG_ON_PARANOID(rx_buf->skb);
561 rx_buf->page = NULL;
562 } else {
563 EFX_BUG_ON_PARANOID(!rx_buf->skb);
564
565 lro_receive_skb(lro_mgr, rx_buf->skb, priv);
566 rx_buf->skb = NULL;
567 }
568}
569
570/* Allocate and construct an SKB around a struct page.*/
571static inline struct sk_buff *efx_rx_mk_skb(struct efx_rx_buffer *rx_buf,
572 struct efx_nic *efx,
573 int hdr_len)
574{
575 struct sk_buff *skb;
576
577 /* Allocate an SKB to store the headers */
578 skb = netdev_alloc_skb(efx->net_dev, hdr_len + EFX_PAGE_SKB_ALIGN);
579 if (unlikely(skb == NULL)) {
580 EFX_ERR_RL(efx, "RX out of memory for skb\n");
581 return NULL;
582 }
583
584 EFX_BUG_ON_PARANOID(skb_shinfo(skb)->nr_frags);
585 EFX_BUG_ON_PARANOID(rx_buf->len < hdr_len);
586
587 skb->ip_summed = CHECKSUM_UNNECESSARY;
588 skb_reserve(skb, EFX_PAGE_SKB_ALIGN);
589
590 skb->len = rx_buf->len;
591 skb->truesize = rx_buf->len + sizeof(struct sk_buff);
592 memcpy(skb->data, rx_buf->data, hdr_len);
593 skb->tail += hdr_len;
594
595 /* Append the remaining page onto the frag list */
596 if (unlikely(rx_buf->len > hdr_len)) {
597 struct skb_frag_struct *frag = skb_shinfo(skb)->frags;
598 frag->page = rx_buf->page;
599 frag->page_offset = RX_BUF_OFFSET(rx_buf) + hdr_len;
600 frag->size = skb->len - hdr_len;
601 skb_shinfo(skb)->nr_frags = 1;
602 skb->data_len = frag->size;
603 } else {
604 __free_pages(rx_buf->page, efx->rx_buffer_order);
605 skb->data_len = 0;
606 }
607
608 /* Ownership has transferred from the rx_buf to skb */
609 rx_buf->page = NULL;
610
611 /* Move past the ethernet header */
612 skb->protocol = eth_type_trans(skb, efx->net_dev);
613
614 return skb;
615}
616
617void efx_rx_packet(struct efx_rx_queue *rx_queue, unsigned int index,
618 unsigned int len, int checksummed, int discard)
619{
620 struct efx_nic *efx = rx_queue->efx;
621 struct efx_rx_buffer *rx_buf;
622 int leak_packet = 0;
623
624 rx_buf = efx_rx_buffer(rx_queue, index);
625 EFX_BUG_ON_PARANOID(!rx_buf->data);
626 EFX_BUG_ON_PARANOID(rx_buf->skb && rx_buf->page);
627 EFX_BUG_ON_PARANOID(!(rx_buf->skb || rx_buf->page));
628
629 /* This allows the refill path to post another buffer.
630 * EFX_RXD_HEAD_ROOM ensures that the slot we are using
631 * isn't overwritten yet.
632 */
633 rx_queue->removed_count++;
634
635 /* Validate the length encoded in the event vs the descriptor pushed */
636 efx_rx_packet__check_len(rx_queue, rx_buf, len,
637 &discard, &leak_packet);
638
639 EFX_TRACE(efx, "RX queue %d received id %x at %llx+%x %s%s\n",
640 rx_queue->queue, index,
641 (unsigned long long)rx_buf->dma_addr, len,
642 (checksummed ? " [SUMMED]" : ""),
643 (discard ? " [DISCARD]" : ""));
644
645 /* Discard packet, if instructed to do so */
646 if (unlikely(discard)) {
647 if (unlikely(leak_packet))
648 rx_queue->channel->n_skbuff_leaks++;
649 else
650 /* We haven't called efx_unmap_rx_buffer yet,
651 * so fini the entire rx_buffer here */
652 efx_fini_rx_buffer(rx_queue, rx_buf);
653 return;
654 }
655
656 /* Release card resources - assumes all RX buffers consumed in-order
657 * per RX queue
658 */
659 efx_unmap_rx_buffer(efx, rx_buf);
660
661 /* Prefetch nice and early so data will (hopefully) be in cache by
662 * the time we look at it.
663 */
664 prefetch(rx_buf->data);
665
666 /* Pipeline receives so that we give time for packet headers to be
667 * prefetched into cache.
668 */
669 rx_buf->len = len;
670 if (rx_queue->channel->rx_pkt)
671 __efx_rx_packet(rx_queue->channel,
672 rx_queue->channel->rx_pkt,
673 rx_queue->channel->rx_pkt_csummed);
674 rx_queue->channel->rx_pkt = rx_buf;
675 rx_queue->channel->rx_pkt_csummed = checksummed;
676}
677
678/* Handle a received packet. Second half: Touches packet payload. */
679void __efx_rx_packet(struct efx_channel *channel,
680 struct efx_rx_buffer *rx_buf, int checksummed)
681{
682 struct efx_nic *efx = channel->efx;
683 struct sk_buff *skb;
684 int lro = efx->net_dev->features & NETIF_F_LRO;
685
686 if (rx_buf->skb) {
687 prefetch(skb_shinfo(rx_buf->skb));
688
689 skb_put(rx_buf->skb, rx_buf->len);
690
691 /* Move past the ethernet header. rx_buf->data still points
692 * at the ethernet header */
693 rx_buf->skb->protocol = eth_type_trans(rx_buf->skb,
694 efx->net_dev);
695 }
696
697 /* Both our generic-LRO and SFC-SSR support skb and page based
698 * allocation, but neither support switching from one to the
699 * other on the fly. If we spot that the allocation mode has
700 * changed, then flush the LRO state.
701 */
702 if (unlikely(channel->rx_alloc_pop_pages != (rx_buf->page != NULL))) {
703 efx_flush_lro(channel);
704 channel->rx_alloc_pop_pages = (rx_buf->page != NULL);
705 }
706 if (likely(checksummed && lro)) {
707 efx_rx_packet_lro(channel, rx_buf);
708 goto done;
709 }
710
711 /* Form an skb if required */
712 if (rx_buf->page) {
713 int hdr_len = min(rx_buf->len, EFX_SKB_HEADERS);
714 skb = efx_rx_mk_skb(rx_buf, efx, hdr_len);
715 if (unlikely(skb == NULL)) {
716 efx_free_rx_buffer(efx, rx_buf);
717 goto done;
718 }
719 } else {
720 /* We now own the SKB */
721 skb = rx_buf->skb;
722 rx_buf->skb = NULL;
723 }
724
725 EFX_BUG_ON_PARANOID(rx_buf->page);
726 EFX_BUG_ON_PARANOID(rx_buf->skb);
727 EFX_BUG_ON_PARANOID(!skb);
728
729 /* Set the SKB flags */
730 if (unlikely(!checksummed || !efx->rx_checksum_enabled))
731 skb->ip_summed = CHECKSUM_NONE;
732
733 /* Pass the packet up */
734 netif_receive_skb(skb);
735
736 /* Update allocation strategy method */
737 channel->rx_alloc_level += RX_ALLOC_FACTOR_SKB;
738
739 /* fall-thru */
740done:
741 efx->net_dev->last_rx = jiffies;
742}
743
744void efx_rx_strategy(struct efx_channel *channel)
745{
746 enum efx_rx_alloc_method method = rx_alloc_method;
747
748 /* Only makes sense to use page based allocation if LRO is enabled */
749 if (!(channel->efx->net_dev->features & NETIF_F_LRO)) {
750 method = RX_ALLOC_METHOD_SKB;
751 } else if (method == RX_ALLOC_METHOD_AUTO) {
752 /* Constrain the rx_alloc_level */
753 if (channel->rx_alloc_level < 0)
754 channel->rx_alloc_level = 0;
755 else if (channel->rx_alloc_level > RX_ALLOC_LEVEL_MAX)
756 channel->rx_alloc_level = RX_ALLOC_LEVEL_MAX;
757
758 /* Decide on the allocation method */
759 method = ((channel->rx_alloc_level > RX_ALLOC_LEVEL_LRO) ?
760 RX_ALLOC_METHOD_PAGE : RX_ALLOC_METHOD_SKB);
761 }
762
763 /* Push the option */
764 channel->rx_alloc_push_pages = (method == RX_ALLOC_METHOD_PAGE);
765}
766
767int efx_probe_rx_queue(struct efx_rx_queue *rx_queue)
768{
769 struct efx_nic *efx = rx_queue->efx;
770 unsigned int rxq_size;
771 int rc;
772
773 EFX_LOG(efx, "creating RX queue %d\n", rx_queue->queue);
774
775 /* Allocate RX buffers */
776 rxq_size = (efx->type->rxd_ring_mask + 1) * sizeof(*rx_queue->buffer);
777 rx_queue->buffer = kzalloc(rxq_size, GFP_KERNEL);
778 if (!rx_queue->buffer) {
779 rc = -ENOMEM;
780 goto fail1;
781 }
782
783 rc = falcon_probe_rx(rx_queue);
784 if (rc)
785 goto fail2;
786
787 return 0;
788
789 fail2:
790 kfree(rx_queue->buffer);
791 rx_queue->buffer = NULL;
792 fail1:
793 rx_queue->used = 0;
794
795 return rc;
796}
797
798int efx_init_rx_queue(struct efx_rx_queue *rx_queue)
799{
800 struct efx_nic *efx = rx_queue->efx;
801 unsigned int max_fill, trigger, limit;
802
803 EFX_LOG(rx_queue->efx, "initialising RX queue %d\n", rx_queue->queue);
804
805 /* Initialise ptr fields */
806 rx_queue->added_count = 0;
807 rx_queue->notified_count = 0;
808 rx_queue->removed_count = 0;
809 rx_queue->min_fill = -1U;
810 rx_queue->min_overfill = -1U;
811
812 /* Initialise limit fields */
813 max_fill = efx->type->rxd_ring_mask + 1 - EFX_RXD_HEAD_ROOM;
814 trigger = max_fill * min(rx_refill_threshold, 100U) / 100U;
815 limit = max_fill * min(rx_refill_limit, 100U) / 100U;
816
817 rx_queue->max_fill = max_fill;
818 rx_queue->fast_fill_trigger = trigger;
819 rx_queue->fast_fill_limit = limit;
820
821 /* Set up RX descriptor ring */
822 return falcon_init_rx(rx_queue);
823}
824
825void efx_fini_rx_queue(struct efx_rx_queue *rx_queue)
826{
827 int i;
828 struct efx_rx_buffer *rx_buf;
829
830 EFX_LOG(rx_queue->efx, "shutting down RX queue %d\n", rx_queue->queue);
831
832 falcon_fini_rx(rx_queue);
833
834 /* Release RX buffers NB start at index 0 not current HW ptr */
835 if (rx_queue->buffer) {
836 for (i = 0; i <= rx_queue->efx->type->rxd_ring_mask; i++) {
837 rx_buf = efx_rx_buffer(rx_queue, i);
838 efx_fini_rx_buffer(rx_queue, rx_buf);
839 }
840 }
841
842 /* For a page that is part-way through splitting into RX buffers */
843 if (rx_queue->buf_page != NULL) {
844 pci_unmap_page(rx_queue->efx->pci_dev, rx_queue->buf_dma_addr,
845 RX_PAGE_SIZE(rx_queue->efx), PCI_DMA_FROMDEVICE);
846 __free_pages(rx_queue->buf_page,
847 rx_queue->efx->rx_buffer_order);
848 rx_queue->buf_page = NULL;
849 }
850}
851
852void efx_remove_rx_queue(struct efx_rx_queue *rx_queue)
853{
854 EFX_LOG(rx_queue->efx, "destroying RX queue %d\n", rx_queue->queue);
855
856 falcon_remove_rx(rx_queue);
857
858 kfree(rx_queue->buffer);
859 rx_queue->buffer = NULL;
860 rx_queue->used = 0;
861}
862
863void efx_flush_lro(struct efx_channel *channel)
864{
865 lro_flush_all(&channel->lro_mgr);
866}
867
868
869module_param(rx_alloc_method, int, 0644);
870MODULE_PARM_DESC(rx_alloc_method, "Allocation method used for RX buffers");
871
872module_param(rx_refill_threshold, uint, 0444);
873MODULE_PARM_DESC(rx_refill_threshold,
874 "RX descriptor ring fast/slow fill threshold (%)");
875