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1/****************************************************************************
2 * Driver for Solarflare Solarstorm network controllers and boards
3 * Copyright 2005-2006 Fen Systems Ltd.
4 * Copyright 2005-2011 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/tcp.h>
16#include <linux/udp.h>
17#include <linux/prefetch.h>
18#include <net/ip.h>
19#include <net/checksum.h>
20#include "net_driver.h"
21#include "efx.h"
22#include "nic.h"
23#include "selftest.h"
24#include "workarounds.h"
25
26/* Number of RX descriptors pushed at once. */
27#define EFX_RX_BATCH 8
28
29/* Maximum size of a buffer sharing a page */
30#define EFX_RX_HALF_PAGE ((PAGE_SIZE >> 1) - sizeof(struct efx_rx_page_state))
31
32/* Size of buffer allocated for skb header area. */
33#define EFX_SKB_HEADERS 64u
34
35/*
36 * rx_alloc_method - RX buffer allocation method
37 *
38 * This driver supports two methods for allocating and using RX buffers:
39 * each RX buffer may be backed by an skb or by an order-n page.
40 *
41 * When GRO is in use then the second method has a lower overhead,
42 * since we don't have to allocate then free skbs on reassembled frames.
43 *
44 * Values:
45 * - RX_ALLOC_METHOD_AUTO = 0
46 * - RX_ALLOC_METHOD_SKB = 1
47 * - RX_ALLOC_METHOD_PAGE = 2
48 *
49 * The heuristic for %RX_ALLOC_METHOD_AUTO is a simple hysteresis count
50 * controlled by the parameters below.
51 *
52 * - Since pushing and popping descriptors are separated by the rx_queue
53 * size, so the watermarks should be ~rxd_size.
54 * - The performance win by using page-based allocation for GRO is less
55 * than the performance hit of using page-based allocation of non-GRO,
56 * so the watermarks should reflect this.
57 *
58 * Per channel we maintain a single variable, updated by each channel:
59 *
60 * rx_alloc_level += (gro_performed ? RX_ALLOC_FACTOR_GRO :
61 * RX_ALLOC_FACTOR_SKB)
62 * Per NAPI poll interval, we constrain rx_alloc_level to 0..MAX (which
63 * limits the hysteresis), and update the allocation strategy:
64 *
65 * rx_alloc_method = (rx_alloc_level > RX_ALLOC_LEVEL_GRO ?
66 * RX_ALLOC_METHOD_PAGE : RX_ALLOC_METHOD_SKB)
67 */
68static int rx_alloc_method = RX_ALLOC_METHOD_AUTO;
69
70#define RX_ALLOC_LEVEL_GRO 0x2000
71#define RX_ALLOC_LEVEL_MAX 0x3000
72#define RX_ALLOC_FACTOR_GRO 1
73#define RX_ALLOC_FACTOR_SKB (-2)
74
75/* This is the percentage fill level below which new RX descriptors
76 * will be added to the RX descriptor ring.
77 */
78static unsigned int rx_refill_threshold = 90;
79
80/* This is the percentage fill level to which an RX queue will be refilled
81 * when the "RX refill threshold" is reached.
82 */
83static unsigned int rx_refill_limit = 95;
84
85/*
86 * RX maximum head room required.
87 *
88 * This must be at least 1 to prevent overflow and at least 2 to allow
89 * pipelined receives.
90 */
91#define EFX_RXD_HEAD_ROOM 2
92
93/* Offset of ethernet header within page */
94static inline unsigned int efx_rx_buf_offset(struct efx_nic *efx,
95 struct efx_rx_buffer *buf)
96{
97 /* Offset is always within one page, so we don't need to consider
98 * the page order.
99 */
100 return (((__force unsigned long) buf->dma_addr & (PAGE_SIZE - 1)) +
101 efx->type->rx_buffer_hash_size);
102}
103static inline unsigned int efx_rx_buf_size(struct efx_nic *efx)
104{
105 return PAGE_SIZE << efx->rx_buffer_order;
106}
107
108static u8 *efx_rx_buf_eh(struct efx_nic *efx, struct efx_rx_buffer *buf)
109{
110 if (buf->is_page)
111 return page_address(buf->u.page) + efx_rx_buf_offset(efx, buf);
112 else
113 return ((u8 *)buf->u.skb->data +
114 efx->type->rx_buffer_hash_size);
115}
116
117static inline u32 efx_rx_buf_hash(const u8 *eh)
118{
119 /* The ethernet header is always directly after any hash. */
120#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) || NET_IP_ALIGN % 4 == 0
121 return __le32_to_cpup((const __le32 *)(eh - 4));
122#else
123 const u8 *data = eh - 4;
124 return ((u32)data[0] |
125 (u32)data[1] << 8 |
126 (u32)data[2] << 16 |
127 (u32)data[3] << 24);
128#endif
129}
130
131/**
132 * efx_init_rx_buffers_skb - create EFX_RX_BATCH skb-based RX buffers
133 *
134 * @rx_queue: Efx RX queue
135 *
136 * This allocates EFX_RX_BATCH skbs, maps them for DMA, and populates a
137 * struct efx_rx_buffer for each one. Return a negative error code or 0
138 * on success. May fail having only inserted fewer than EFX_RX_BATCH
139 * buffers.
140 */
141static int efx_init_rx_buffers_skb(struct efx_rx_queue *rx_queue)
142{
143 struct efx_nic *efx = rx_queue->efx;
144 struct net_device *net_dev = efx->net_dev;
145 struct efx_rx_buffer *rx_buf;
146 struct sk_buff *skb;
147 int skb_len = efx->rx_buffer_len;
148 unsigned index, count;
149
150 for (count = 0; count < EFX_RX_BATCH; ++count) {
151 index = rx_queue->added_count & rx_queue->ptr_mask;
152 rx_buf = efx_rx_buffer(rx_queue, index);
153
154 rx_buf->u.skb = skb = netdev_alloc_skb(net_dev, skb_len);
155 if (unlikely(!skb))
156 return -ENOMEM;
157
158 /* Adjust the SKB for padding and checksum */
159 skb_reserve(skb, NET_IP_ALIGN);
160 rx_buf->len = skb_len - NET_IP_ALIGN;
161 rx_buf->is_page = false;
162 skb->ip_summed = CHECKSUM_UNNECESSARY;
163
164 rx_buf->dma_addr = pci_map_single(efx->pci_dev,
165 skb->data, rx_buf->len,
166 PCI_DMA_FROMDEVICE);
167 if (unlikely(pci_dma_mapping_error(efx->pci_dev,
168 rx_buf->dma_addr))) {
169 dev_kfree_skb_any(skb);
170 rx_buf->u.skb = NULL;
171 return -EIO;
172 }
173
174 ++rx_queue->added_count;
175 ++rx_queue->alloc_skb_count;
176 }
177
178 return 0;
179}
180
181/**
182 * efx_init_rx_buffers_page - create EFX_RX_BATCH page-based RX buffers
183 *
184 * @rx_queue: Efx RX queue
185 *
186 * This allocates memory for EFX_RX_BATCH receive buffers, maps them for DMA,
187 * and populates struct efx_rx_buffers for each one. Return a negative error
188 * code or 0 on success. If a single page can be split between two buffers,
189 * then the page will either be inserted fully, or not at at all.
190 */
191static int efx_init_rx_buffers_page(struct efx_rx_queue *rx_queue)
192{
193 struct efx_nic *efx = rx_queue->efx;
194 struct efx_rx_buffer *rx_buf;
195 struct page *page;
196 void *page_addr;
197 struct efx_rx_page_state *state;
198 dma_addr_t dma_addr;
199 unsigned index, count;
200
201 /* We can split a page between two buffers */
202 BUILD_BUG_ON(EFX_RX_BATCH & 1);
203
204 for (count = 0; count < EFX_RX_BATCH; ++count) {
205 page = alloc_pages(__GFP_COLD | __GFP_COMP | GFP_ATOMIC,
206 efx->rx_buffer_order);
207 if (unlikely(page == NULL))
208 return -ENOMEM;
209 dma_addr = pci_map_page(efx->pci_dev, page, 0,
210 efx_rx_buf_size(efx),
211 PCI_DMA_FROMDEVICE);
212 if (unlikely(pci_dma_mapping_error(efx->pci_dev, dma_addr))) {
213 __free_pages(page, efx->rx_buffer_order);
214 return -EIO;
215 }
216 page_addr = page_address(page);
217 state = page_addr;
218 state->refcnt = 0;
219 state->dma_addr = dma_addr;
220
221 page_addr += sizeof(struct efx_rx_page_state);
222 dma_addr += sizeof(struct efx_rx_page_state);
223
224 split:
225 index = rx_queue->added_count & rx_queue->ptr_mask;
226 rx_buf = efx_rx_buffer(rx_queue, index);
227 rx_buf->dma_addr = dma_addr + EFX_PAGE_IP_ALIGN;
228 rx_buf->u.page = page;
229 rx_buf->len = efx->rx_buffer_len - EFX_PAGE_IP_ALIGN;
230 rx_buf->is_page = true;
231 ++rx_queue->added_count;
232 ++rx_queue->alloc_page_count;
233 ++state->refcnt;
234
235 if ((~count & 1) && (efx->rx_buffer_len <= EFX_RX_HALF_PAGE)) {
236 /* Use the second half of the page */
237 get_page(page);
238 dma_addr += (PAGE_SIZE >> 1);
239 page_addr += (PAGE_SIZE >> 1);
240 ++count;
241 goto split;
242 }
243 }
244
245 return 0;
246}
247
248static void efx_unmap_rx_buffer(struct efx_nic *efx,
249 struct efx_rx_buffer *rx_buf)
250{
251 if (rx_buf->is_page && rx_buf->u.page) {
252 struct efx_rx_page_state *state;
253
254 state = page_address(rx_buf->u.page);
255 if (--state->refcnt == 0) {
256 pci_unmap_page(efx->pci_dev,
257 state->dma_addr,
258 efx_rx_buf_size(efx),
259 PCI_DMA_FROMDEVICE);
260 }
261 } else if (!rx_buf->is_page && rx_buf->u.skb) {
262 pci_unmap_single(efx->pci_dev, rx_buf->dma_addr,
263 rx_buf->len, PCI_DMA_FROMDEVICE);
264 }
265}
266
267static void efx_free_rx_buffer(struct efx_nic *efx,
268 struct efx_rx_buffer *rx_buf)
269{
270 if (rx_buf->is_page && rx_buf->u.page) {
271 __free_pages(rx_buf->u.page, efx->rx_buffer_order);
272 rx_buf->u.page = NULL;
273 } else if (!rx_buf->is_page && rx_buf->u.skb) {
274 dev_kfree_skb_any(rx_buf->u.skb);
275 rx_buf->u.skb = NULL;
276 }
277}
278
279static void efx_fini_rx_buffer(struct efx_rx_queue *rx_queue,
280 struct efx_rx_buffer *rx_buf)
281{
282 efx_unmap_rx_buffer(rx_queue->efx, rx_buf);
283 efx_free_rx_buffer(rx_queue->efx, rx_buf);
284}
285
286/* Attempt to resurrect the other receive buffer that used to share this page,
287 * which had previously been passed up to the kernel and freed. */
288static void efx_resurrect_rx_buffer(struct efx_rx_queue *rx_queue,
289 struct efx_rx_buffer *rx_buf)
290{
291 struct efx_rx_page_state *state = page_address(rx_buf->u.page);
292 struct efx_rx_buffer *new_buf;
293 unsigned fill_level, index;
294
295 /* +1 because efx_rx_packet() incremented removed_count. +1 because
296 * we'd like to insert an additional descriptor whilst leaving
297 * EFX_RXD_HEAD_ROOM for the non-recycle path */
298 fill_level = (rx_queue->added_count - rx_queue->removed_count + 2);
299 if (unlikely(fill_level > rx_queue->max_fill)) {
300 /* We could place "state" on a list, and drain the list in
301 * efx_fast_push_rx_descriptors(). For now, this will do. */
302 return;
303 }
304
305 ++state->refcnt;
306 get_page(rx_buf->u.page);
307
308 index = rx_queue->added_count & rx_queue->ptr_mask;
309 new_buf = efx_rx_buffer(rx_queue, index);
310 new_buf->dma_addr = rx_buf->dma_addr ^ (PAGE_SIZE >> 1);
311 new_buf->u.page = rx_buf->u.page;
312 new_buf->len = rx_buf->len;
313 new_buf->is_page = true;
314 ++rx_queue->added_count;
315}
316
317/* Recycle the given rx buffer directly back into the rx_queue. There is
318 * always room to add this buffer, because we've just popped a buffer. */
319static void efx_recycle_rx_buffer(struct efx_channel *channel,
320 struct efx_rx_buffer *rx_buf)
321{
322 struct efx_nic *efx = channel->efx;
323 struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
324 struct efx_rx_buffer *new_buf;
325 unsigned index;
326
327 if (rx_buf->is_page && efx->rx_buffer_len <= EFX_RX_HALF_PAGE &&
328 page_count(rx_buf->u.page) == 1)
329 efx_resurrect_rx_buffer(rx_queue, rx_buf);
330
331 index = rx_queue->added_count & rx_queue->ptr_mask;
332 new_buf = efx_rx_buffer(rx_queue, index);
333
334 memcpy(new_buf, rx_buf, sizeof(*new_buf));
335 rx_buf->u.page = NULL;
336 ++rx_queue->added_count;
337}
338
339/**
340 * efx_fast_push_rx_descriptors - push new RX descriptors quickly
341 * @rx_queue: RX descriptor queue
342 * This will aim to fill the RX descriptor queue up to
343 * @rx_queue->@fast_fill_limit. If there is insufficient atomic
344 * memory to do so, a slow fill will be scheduled.
345 *
346 * The caller must provide serialisation (none is used here). In practise,
347 * this means this function must run from the NAPI handler, or be called
348 * when NAPI is disabled.
349 */
350void efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue)
351{
352 struct efx_channel *channel = efx_rx_queue_channel(rx_queue);
353 unsigned fill_level;
354 int space, rc = 0;
355
356 /* Calculate current fill level, and exit if we don't need to fill */
357 fill_level = (rx_queue->added_count - rx_queue->removed_count);
358 EFX_BUG_ON_PARANOID(fill_level > rx_queue->efx->rxq_entries);
359 if (fill_level >= rx_queue->fast_fill_trigger)
360 goto out;
361
362 /* Record minimum fill level */
363 if (unlikely(fill_level < rx_queue->min_fill)) {
364 if (fill_level)
365 rx_queue->min_fill = fill_level;
366 }
367
368 space = rx_queue->fast_fill_limit - fill_level;
369 if (space < EFX_RX_BATCH)
370 goto out;
371
372 netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
373 "RX queue %d fast-filling descriptor ring from"
374 " level %d to level %d using %s allocation\n",
375 efx_rx_queue_index(rx_queue), fill_level,
376 rx_queue->fast_fill_limit,
377 channel->rx_alloc_push_pages ? "page" : "skb");
378
379 do {
380 if (channel->rx_alloc_push_pages)
381 rc = efx_init_rx_buffers_page(rx_queue);
382 else
383 rc = efx_init_rx_buffers_skb(rx_queue);
384 if (unlikely(rc)) {
385 /* Ensure that we don't leave the rx queue empty */
386 if (rx_queue->added_count == rx_queue->removed_count)
387 efx_schedule_slow_fill(rx_queue);
388 goto out;
389 }
390 } while ((space -= EFX_RX_BATCH) >= EFX_RX_BATCH);
391
392 netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
393 "RX queue %d fast-filled descriptor ring "
394 "to level %d\n", efx_rx_queue_index(rx_queue),
395 rx_queue->added_count - rx_queue->removed_count);
396
397 out:
398 if (rx_queue->notified_count != rx_queue->added_count)
399 efx_nic_notify_rx_desc(rx_queue);
400}
401
402void efx_rx_slow_fill(unsigned long context)
403{
404 struct efx_rx_queue *rx_queue = (struct efx_rx_queue *)context;
405 struct efx_channel *channel = efx_rx_queue_channel(rx_queue);
406
407 /* Post an event to cause NAPI to run and refill the queue */
408 efx_nic_generate_fill_event(channel);
409 ++rx_queue->slow_fill_count;
410}
411
412static void efx_rx_packet__check_len(struct efx_rx_queue *rx_queue,
413 struct efx_rx_buffer *rx_buf,
414 int len, bool *discard,
415 bool *leak_packet)
416{
417 struct efx_nic *efx = rx_queue->efx;
418 unsigned max_len = rx_buf->len - efx->type->rx_buffer_padding;
419
420 if (likely(len <= max_len))
421 return;
422
423 /* The packet must be discarded, but this is only a fatal error
424 * if the caller indicated it was
425 */
426 *discard = true;
427
428 if ((len > rx_buf->len) && EFX_WORKAROUND_8071(efx)) {
429 if (net_ratelimit())
430 netif_err(efx, rx_err, efx->net_dev,
431 " RX queue %d seriously overlength "
432 "RX event (0x%x > 0x%x+0x%x). Leaking\n",
433 efx_rx_queue_index(rx_queue), len, max_len,
434 efx->type->rx_buffer_padding);
435 /* If this buffer was skb-allocated, then the meta
436 * data at the end of the skb will be trashed. So
437 * we have no choice but to leak the fragment.
438 */
439 *leak_packet = !rx_buf->is_page;
440 efx_schedule_reset(efx, RESET_TYPE_RX_RECOVERY);
441 } else {
442 if (net_ratelimit())
443 netif_err(efx, rx_err, efx->net_dev,
444 " RX queue %d overlength RX event "
445 "(0x%x > 0x%x)\n",
446 efx_rx_queue_index(rx_queue), len, max_len);
447 }
448
449 efx_rx_queue_channel(rx_queue)->n_rx_overlength++;
450}
451
452/* Pass a received packet up through the generic GRO stack
453 *
454 * Handles driverlink veto, and passes the fragment up via
455 * the appropriate GRO method
456 */
457static void efx_rx_packet_gro(struct efx_channel *channel,
458 struct efx_rx_buffer *rx_buf,
459 const u8 *eh, bool checksummed)
460{
461 struct napi_struct *napi = &channel->napi_str;
462 gro_result_t gro_result;
463
464 /* Pass the skb/page into the GRO engine */
465 if (rx_buf->is_page) {
466 struct efx_nic *efx = channel->efx;
467 struct page *page = rx_buf->u.page;
468 struct sk_buff *skb;
469
470 rx_buf->u.page = NULL;
471
472 skb = napi_get_frags(napi);
473 if (!skb) {
474 put_page(page);
475 return;
476 }
477
478 if (efx->net_dev->features & NETIF_F_RXHASH)
479 skb->rxhash = efx_rx_buf_hash(eh);
480
481 skb_shinfo(skb)->frags[0].page = page;
482 skb_shinfo(skb)->frags[0].page_offset =
483 efx_rx_buf_offset(efx, rx_buf);
484 skb_shinfo(skb)->frags[0].size = rx_buf->len;
485 skb_shinfo(skb)->nr_frags = 1;
486
487 skb->len = rx_buf->len;
488 skb->data_len = rx_buf->len;
489 skb->truesize += rx_buf->len;
490 skb->ip_summed =
491 checksummed ? CHECKSUM_UNNECESSARY : CHECKSUM_NONE;
492
493 skb_record_rx_queue(skb, channel->channel);
494
495 gro_result = napi_gro_frags(napi);
496 } else {
497 struct sk_buff *skb = rx_buf->u.skb;
498
499 EFX_BUG_ON_PARANOID(!checksummed);
500 rx_buf->u.skb = NULL;
501
502 gro_result = napi_gro_receive(napi, skb);
503 }
504
505 if (gro_result == GRO_NORMAL) {
506 channel->rx_alloc_level += RX_ALLOC_FACTOR_SKB;
507 } else if (gro_result != GRO_DROP) {
508 channel->rx_alloc_level += RX_ALLOC_FACTOR_GRO;
509 channel->irq_mod_score += 2;
510 }
511}
512
513void efx_rx_packet(struct efx_rx_queue *rx_queue, unsigned int index,
514 unsigned int len, bool checksummed, bool discard)
515{
516 struct efx_nic *efx = rx_queue->efx;
517 struct efx_channel *channel = efx_rx_queue_channel(rx_queue);
518 struct efx_rx_buffer *rx_buf;
519 bool leak_packet = false;
520
521 rx_buf = efx_rx_buffer(rx_queue, index);
522
523 /* This allows the refill path to post another buffer.
524 * EFX_RXD_HEAD_ROOM ensures that the slot we are using
525 * isn't overwritten yet.
526 */
527 rx_queue->removed_count++;
528
529 /* Validate the length encoded in the event vs the descriptor pushed */
530 efx_rx_packet__check_len(rx_queue, rx_buf, len,
531 &discard, &leak_packet);
532
533 netif_vdbg(efx, rx_status, efx->net_dev,
534 "RX queue %d received id %x at %llx+%x %s%s\n",
535 efx_rx_queue_index(rx_queue), index,
536 (unsigned long long)rx_buf->dma_addr, len,
537 (checksummed ? " [SUMMED]" : ""),
538 (discard ? " [DISCARD]" : ""));
539
540 /* Discard packet, if instructed to do so */
541 if (unlikely(discard)) {
542 if (unlikely(leak_packet))
543 channel->n_skbuff_leaks++;
544 else
545 efx_recycle_rx_buffer(channel, rx_buf);
546
547 /* Don't hold off the previous receive */
548 rx_buf = NULL;
549 goto out;
550 }
551
552 /* Release card resources - assumes all RX buffers consumed in-order
553 * per RX queue
554 */
555 efx_unmap_rx_buffer(efx, rx_buf);
556
557 /* Prefetch nice and early so data will (hopefully) be in cache by
558 * the time we look at it.
559 */
560 prefetch(efx_rx_buf_eh(efx, rx_buf));
561
562 /* Pipeline receives so that we give time for packet headers to be
563 * prefetched into cache.
564 */
565 rx_buf->len = len - efx->type->rx_buffer_hash_size;
566out:
567 if (channel->rx_pkt)
568 __efx_rx_packet(channel,
569 channel->rx_pkt, channel->rx_pkt_csummed);
570 channel->rx_pkt = rx_buf;
571 channel->rx_pkt_csummed = checksummed;
572}
573
574/* Handle a received packet. Second half: Touches packet payload. */
575void __efx_rx_packet(struct efx_channel *channel,
576 struct efx_rx_buffer *rx_buf, bool checksummed)
577{
578 struct efx_nic *efx = channel->efx;
579 struct sk_buff *skb;
580 u8 *eh = efx_rx_buf_eh(efx, rx_buf);
581
582 /* If we're in loopback test, then pass the packet directly to the
583 * loopback layer, and free the rx_buf here
584 */
585 if (unlikely(efx->loopback_selftest)) {
586 efx_loopback_rx_packet(efx, eh, rx_buf->len);
587 efx_free_rx_buffer(efx, rx_buf);
588 return;
589 }
590
591 if (!rx_buf->is_page) {
592 skb = rx_buf->u.skb;
593
594 prefetch(skb_shinfo(skb));
595
596 skb_reserve(skb, efx->type->rx_buffer_hash_size);
597 skb_put(skb, rx_buf->len);
598
599 if (efx->net_dev->features & NETIF_F_RXHASH)
600 skb->rxhash = efx_rx_buf_hash(eh);
601
602 /* Move past the ethernet header. rx_buf->data still points
603 * at the ethernet header */
604 skb->protocol = eth_type_trans(skb, efx->net_dev);
605
606 skb_record_rx_queue(skb, channel->channel);
607 }
608
609 if (unlikely(!(efx->net_dev->features & NETIF_F_RXCSUM)))
610 checksummed = false;
611
612 if (likely(checksummed || rx_buf->is_page)) {
613 efx_rx_packet_gro(channel, rx_buf, eh, checksummed);
614 return;
615 }
616
617 /* We now own the SKB */
618 skb = rx_buf->u.skb;
619 rx_buf->u.skb = NULL;
620
621 /* Set the SKB flags */
622 skb_checksum_none_assert(skb);
623
624 /* Pass the packet up */
625 netif_receive_skb(skb);
626
627 /* Update allocation strategy method */
628 channel->rx_alloc_level += RX_ALLOC_FACTOR_SKB;
629}
630
631void efx_rx_strategy(struct efx_channel *channel)
632{
633 enum efx_rx_alloc_method method = rx_alloc_method;
634
635 /* Only makes sense to use page based allocation if GRO is enabled */
636 if (!(channel->efx->net_dev->features & NETIF_F_GRO)) {
637 method = RX_ALLOC_METHOD_SKB;
638 } else if (method == RX_ALLOC_METHOD_AUTO) {
639 /* Constrain the rx_alloc_level */
640 if (channel->rx_alloc_level < 0)
641 channel->rx_alloc_level = 0;
642 else if (channel->rx_alloc_level > RX_ALLOC_LEVEL_MAX)
643 channel->rx_alloc_level = RX_ALLOC_LEVEL_MAX;
644
645 /* Decide on the allocation method */
646 method = ((channel->rx_alloc_level > RX_ALLOC_LEVEL_GRO) ?
647 RX_ALLOC_METHOD_PAGE : RX_ALLOC_METHOD_SKB);
648 }
649
650 /* Push the option */
651 channel->rx_alloc_push_pages = (method == RX_ALLOC_METHOD_PAGE);
652}
653
654int efx_probe_rx_queue(struct efx_rx_queue *rx_queue)
655{
656 struct efx_nic *efx = rx_queue->efx;
657 unsigned int entries;
658 int rc;
659
660 /* Create the smallest power-of-two aligned ring */
661 entries = max(roundup_pow_of_two(efx->rxq_entries), EFX_MIN_DMAQ_SIZE);
662 EFX_BUG_ON_PARANOID(entries > EFX_MAX_DMAQ_SIZE);
663 rx_queue->ptr_mask = entries - 1;
664
665 netif_dbg(efx, probe, efx->net_dev,
666 "creating RX queue %d size %#x mask %#x\n",
667 efx_rx_queue_index(rx_queue), efx->rxq_entries,
668 rx_queue->ptr_mask);
669
670 /* Allocate RX buffers */
671 rx_queue->buffer = kzalloc(entries * sizeof(*rx_queue->buffer),
672 GFP_KERNEL);
673 if (!rx_queue->buffer)
674 return -ENOMEM;
675
676 rc = efx_nic_probe_rx(rx_queue);
677 if (rc) {
678 kfree(rx_queue->buffer);
679 rx_queue->buffer = NULL;
680 }
681 return rc;
682}
683
684void efx_init_rx_queue(struct efx_rx_queue *rx_queue)
685{
686 struct efx_nic *efx = rx_queue->efx;
687 unsigned int max_fill, trigger, limit;
688
689 netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
690 "initialising RX queue %d\n", efx_rx_queue_index(rx_queue));
691
692 /* Initialise ptr fields */
693 rx_queue->added_count = 0;
694 rx_queue->notified_count = 0;
695 rx_queue->removed_count = 0;
696 rx_queue->min_fill = -1U;
697
698 /* Initialise limit fields */
699 max_fill = efx->rxq_entries - EFX_RXD_HEAD_ROOM;
700 trigger = max_fill * min(rx_refill_threshold, 100U) / 100U;
701 limit = max_fill * min(rx_refill_limit, 100U) / 100U;
702
703 rx_queue->max_fill = max_fill;
704 rx_queue->fast_fill_trigger = trigger;
705 rx_queue->fast_fill_limit = limit;
706
707 /* Set up RX descriptor ring */
708 efx_nic_init_rx(rx_queue);
709}
710
711void efx_fini_rx_queue(struct efx_rx_queue *rx_queue)
712{
713 int i;
714 struct efx_rx_buffer *rx_buf;
715
716 netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
717 "shutting down RX queue %d\n", efx_rx_queue_index(rx_queue));
718
719 del_timer_sync(&rx_queue->slow_fill);
720 efx_nic_fini_rx(rx_queue);
721
722 /* Release RX buffers NB start at index 0 not current HW ptr */
723 if (rx_queue->buffer) {
724 for (i = 0; i <= rx_queue->ptr_mask; i++) {
725 rx_buf = efx_rx_buffer(rx_queue, i);
726 efx_fini_rx_buffer(rx_queue, rx_buf);
727 }
728 }
729}
730
731void efx_remove_rx_queue(struct efx_rx_queue *rx_queue)
732{
733 netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
734 "destroying RX queue %d\n", efx_rx_queue_index(rx_queue));
735
736 efx_nic_remove_rx(rx_queue);
737
738 kfree(rx_queue->buffer);
739 rx_queue->buffer = NULL;
740}
741
742
743module_param(rx_alloc_method, int, 0644);
744MODULE_PARM_DESC(rx_alloc_method, "Allocation method used for RX buffers");
745
746module_param(rx_refill_threshold, uint, 0444);
747MODULE_PARM_DESC(rx_refill_threshold,
748 "RX descriptor ring fast/slow fill threshold (%)");
749