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Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
[deliverable/linux.git] / drivers / net / ethernet / intel / i40evf / i40e_txrx.c
1 /*******************************************************************************
2 *
3 * Intel Ethernet Controller XL710 Family Linux Virtual Function Driver
4 * Copyright(c) 2013 - 2014 Intel Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 * The full GNU General Public License is included in this distribution in
16 * the file called "COPYING".
17 *
18 * Contact Information:
19 * e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
20 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
21 *
22 ******************************************************************************/
23
24 #include <linux/prefetch.h>
25
26 #include "i40evf.h"
27 #include "i40e_prototype.h"
28
29 static inline __le64 build_ctob(u32 td_cmd, u32 td_offset, unsigned int size,
30 u32 td_tag)
31 {
32 return cpu_to_le64(I40E_TX_DESC_DTYPE_DATA |
33 ((u64)td_cmd << I40E_TXD_QW1_CMD_SHIFT) |
34 ((u64)td_offset << I40E_TXD_QW1_OFFSET_SHIFT) |
35 ((u64)size << I40E_TXD_QW1_TX_BUF_SZ_SHIFT) |
36 ((u64)td_tag << I40E_TXD_QW1_L2TAG1_SHIFT));
37 }
38
39 #define I40E_TXD_CMD (I40E_TX_DESC_CMD_EOP | I40E_TX_DESC_CMD_RS)
40
41 /**
42 * i40e_unmap_and_free_tx_resource - Release a Tx buffer
43 * @ring: the ring that owns the buffer
44 * @tx_buffer: the buffer to free
45 **/
46 static void i40e_unmap_and_free_tx_resource(struct i40e_ring *ring,
47 struct i40e_tx_buffer *tx_buffer)
48 {
49 if (tx_buffer->skb) {
50 dev_kfree_skb_any(tx_buffer->skb);
51 if (dma_unmap_len(tx_buffer, len))
52 dma_unmap_single(ring->dev,
53 dma_unmap_addr(tx_buffer, dma),
54 dma_unmap_len(tx_buffer, len),
55 DMA_TO_DEVICE);
56 } else if (dma_unmap_len(tx_buffer, len)) {
57 dma_unmap_page(ring->dev,
58 dma_unmap_addr(tx_buffer, dma),
59 dma_unmap_len(tx_buffer, len),
60 DMA_TO_DEVICE);
61 }
62 tx_buffer->next_to_watch = NULL;
63 tx_buffer->skb = NULL;
64 dma_unmap_len_set(tx_buffer, len, 0);
65 /* tx_buffer must be completely set up in the transmit path */
66 }
67
68 /**
69 * i40evf_clean_tx_ring - Free any empty Tx buffers
70 * @tx_ring: ring to be cleaned
71 **/
72 void i40evf_clean_tx_ring(struct i40e_ring *tx_ring)
73 {
74 unsigned long bi_size;
75 u16 i;
76
77 /* ring already cleared, nothing to do */
78 if (!tx_ring->tx_bi)
79 return;
80
81 /* Free all the Tx ring sk_buffs */
82 for (i = 0; i < tx_ring->count; i++)
83 i40e_unmap_and_free_tx_resource(tx_ring, &tx_ring->tx_bi[i]);
84
85 bi_size = sizeof(struct i40e_tx_buffer) * tx_ring->count;
86 memset(tx_ring->tx_bi, 0, bi_size);
87
88 /* Zero out the descriptor ring */
89 memset(tx_ring->desc, 0, tx_ring->size);
90
91 tx_ring->next_to_use = 0;
92 tx_ring->next_to_clean = 0;
93
94 if (!tx_ring->netdev)
95 return;
96
97 /* cleanup Tx queue statistics */
98 netdev_tx_reset_queue(netdev_get_tx_queue(tx_ring->netdev,
99 tx_ring->queue_index));
100 }
101
102 /**
103 * i40evf_free_tx_resources - Free Tx resources per queue
104 * @tx_ring: Tx descriptor ring for a specific queue
105 *
106 * Free all transmit software resources
107 **/
108 void i40evf_free_tx_resources(struct i40e_ring *tx_ring)
109 {
110 i40evf_clean_tx_ring(tx_ring);
111 kfree(tx_ring->tx_bi);
112 tx_ring->tx_bi = NULL;
113
114 if (tx_ring->desc) {
115 dma_free_coherent(tx_ring->dev, tx_ring->size,
116 tx_ring->desc, tx_ring->dma);
117 tx_ring->desc = NULL;
118 }
119 }
120
121 /**
122 * i40e_get_tx_pending - how many tx descriptors not processed
123 * @tx_ring: the ring of descriptors
124 *
125 * Since there is no access to the ring head register
126 * in XL710, we need to use our local copies
127 **/
128 static u32 i40e_get_tx_pending(struct i40e_ring *ring)
129 {
130 u32 ntu = ((ring->next_to_clean <= ring->next_to_use)
131 ? ring->next_to_use
132 : ring->next_to_use + ring->count);
133 return ntu - ring->next_to_clean;
134 }
135
136 /**
137 * i40e_check_tx_hang - Is there a hang in the Tx queue
138 * @tx_ring: the ring of descriptors
139 **/
140 static bool i40e_check_tx_hang(struct i40e_ring *tx_ring)
141 {
142 u32 tx_pending = i40e_get_tx_pending(tx_ring);
143 bool ret = false;
144
145 clear_check_for_tx_hang(tx_ring);
146
147 /* Check for a hung queue, but be thorough. This verifies
148 * that a transmit has been completed since the previous
149 * check AND there is at least one packet pending. The
150 * ARMED bit is set to indicate a potential hang. The
151 * bit is cleared if a pause frame is received to remove
152 * false hang detection due to PFC or 802.3x frames. By
153 * requiring this to fail twice we avoid races with
154 * PFC clearing the ARMED bit and conditions where we
155 * run the check_tx_hang logic with a transmit completion
156 * pending but without time to complete it yet.
157 */
158 if ((tx_ring->tx_stats.tx_done_old == tx_ring->stats.packets) &&
159 tx_pending) {
160 /* make sure it is true for two checks in a row */
161 ret = test_and_set_bit(__I40E_HANG_CHECK_ARMED,
162 &tx_ring->state);
163 } else {
164 /* update completed stats and disarm the hang check */
165 tx_ring->tx_stats.tx_done_old = tx_ring->stats.packets;
166 clear_bit(__I40E_HANG_CHECK_ARMED, &tx_ring->state);
167 }
168
169 return ret;
170 }
171
172 /**
173 * i40e_get_head - Retrieve head from head writeback
174 * @tx_ring: tx ring to fetch head of
175 *
176 * Returns value of Tx ring head based on value stored
177 * in head write-back location
178 **/
179 static inline u32 i40e_get_head(struct i40e_ring *tx_ring)
180 {
181 void *head = (struct i40e_tx_desc *)tx_ring->desc + tx_ring->count;
182
183 return le32_to_cpu(*(volatile __le32 *)head);
184 }
185
186 /**
187 * i40e_clean_tx_irq - Reclaim resources after transmit completes
188 * @tx_ring: tx ring to clean
189 * @budget: how many cleans we're allowed
190 *
191 * Returns true if there's any budget left (e.g. the clean is finished)
192 **/
193 static bool i40e_clean_tx_irq(struct i40e_ring *tx_ring, int budget)
194 {
195 u16 i = tx_ring->next_to_clean;
196 struct i40e_tx_buffer *tx_buf;
197 struct i40e_tx_desc *tx_head;
198 struct i40e_tx_desc *tx_desc;
199 unsigned int total_packets = 0;
200 unsigned int total_bytes = 0;
201
202 tx_buf = &tx_ring->tx_bi[i];
203 tx_desc = I40E_TX_DESC(tx_ring, i);
204 i -= tx_ring->count;
205
206 tx_head = I40E_TX_DESC(tx_ring, i40e_get_head(tx_ring));
207
208 do {
209 struct i40e_tx_desc *eop_desc = tx_buf->next_to_watch;
210
211 /* if next_to_watch is not set then there is no work pending */
212 if (!eop_desc)
213 break;
214
215 /* prevent any other reads prior to eop_desc */
216 read_barrier_depends();
217
218 /* we have caught up to head, no work left to do */
219 if (tx_head == tx_desc)
220 break;
221
222 /* clear next_to_watch to prevent false hangs */
223 tx_buf->next_to_watch = NULL;
224
225 /* update the statistics for this packet */
226 total_bytes += tx_buf->bytecount;
227 total_packets += tx_buf->gso_segs;
228
229 /* free the skb */
230 dev_kfree_skb_any(tx_buf->skb);
231
232 /* unmap skb header data */
233 dma_unmap_single(tx_ring->dev,
234 dma_unmap_addr(tx_buf, dma),
235 dma_unmap_len(tx_buf, len),
236 DMA_TO_DEVICE);
237
238 /* clear tx_buffer data */
239 tx_buf->skb = NULL;
240 dma_unmap_len_set(tx_buf, len, 0);
241
242 /* unmap remaining buffers */
243 while (tx_desc != eop_desc) {
244
245 tx_buf++;
246 tx_desc++;
247 i++;
248 if (unlikely(!i)) {
249 i -= tx_ring->count;
250 tx_buf = tx_ring->tx_bi;
251 tx_desc = I40E_TX_DESC(tx_ring, 0);
252 }
253
254 /* unmap any remaining paged data */
255 if (dma_unmap_len(tx_buf, len)) {
256 dma_unmap_page(tx_ring->dev,
257 dma_unmap_addr(tx_buf, dma),
258 dma_unmap_len(tx_buf, len),
259 DMA_TO_DEVICE);
260 dma_unmap_len_set(tx_buf, len, 0);
261 }
262 }
263
264 /* move us one more past the eop_desc for start of next pkt */
265 tx_buf++;
266 tx_desc++;
267 i++;
268 if (unlikely(!i)) {
269 i -= tx_ring->count;
270 tx_buf = tx_ring->tx_bi;
271 tx_desc = I40E_TX_DESC(tx_ring, 0);
272 }
273
274 /* update budget accounting */
275 budget--;
276 } while (likely(budget));
277
278 i += tx_ring->count;
279 tx_ring->next_to_clean = i;
280 u64_stats_update_begin(&tx_ring->syncp);
281 tx_ring->stats.bytes += total_bytes;
282 tx_ring->stats.packets += total_packets;
283 u64_stats_update_end(&tx_ring->syncp);
284 tx_ring->q_vector->tx.total_bytes += total_bytes;
285 tx_ring->q_vector->tx.total_packets += total_packets;
286
287 if (check_for_tx_hang(tx_ring) && i40e_check_tx_hang(tx_ring)) {
288 /* schedule immediate reset if we believe we hung */
289 dev_info(tx_ring->dev, "Detected Tx Unit Hang\n"
290 " VSI <%d>\n"
291 " Tx Queue <%d>\n"
292 " next_to_use <%x>\n"
293 " next_to_clean <%x>\n",
294 tx_ring->vsi->seid,
295 tx_ring->queue_index,
296 tx_ring->next_to_use, i);
297 dev_info(tx_ring->dev, "tx_bi[next_to_clean]\n"
298 " time_stamp <%lx>\n"
299 " jiffies <%lx>\n",
300 tx_ring->tx_bi[i].time_stamp, jiffies);
301
302 netif_stop_subqueue(tx_ring->netdev, tx_ring->queue_index);
303
304 dev_info(tx_ring->dev,
305 "tx hang detected on queue %d, resetting adapter\n",
306 tx_ring->queue_index);
307
308 tx_ring->netdev->netdev_ops->ndo_tx_timeout(tx_ring->netdev);
309
310 /* the adapter is about to reset, no point in enabling stuff */
311 return true;
312 }
313
314 netdev_tx_completed_queue(netdev_get_tx_queue(tx_ring->netdev,
315 tx_ring->queue_index),
316 total_packets, total_bytes);
317
318 #define TX_WAKE_THRESHOLD (DESC_NEEDED * 2)
319 if (unlikely(total_packets && netif_carrier_ok(tx_ring->netdev) &&
320 (I40E_DESC_UNUSED(tx_ring) >= TX_WAKE_THRESHOLD))) {
321 /* Make sure that anybody stopping the queue after this
322 * sees the new next_to_clean.
323 */
324 smp_mb();
325 if (__netif_subqueue_stopped(tx_ring->netdev,
326 tx_ring->queue_index) &&
327 !test_bit(__I40E_DOWN, &tx_ring->vsi->state)) {
328 netif_wake_subqueue(tx_ring->netdev,
329 tx_ring->queue_index);
330 ++tx_ring->tx_stats.restart_queue;
331 }
332 }
333
334 return budget > 0;
335 }
336
337 /**
338 * i40e_set_new_dynamic_itr - Find new ITR level
339 * @rc: structure containing ring performance data
340 *
341 * Stores a new ITR value based on packets and byte counts during
342 * the last interrupt. The advantage of per interrupt computation
343 * is faster updates and more accurate ITR for the current traffic
344 * pattern. Constants in this function were computed based on
345 * theoretical maximum wire speed and thresholds were set based on
346 * testing data as well as attempting to minimize response time
347 * while increasing bulk throughput.
348 **/
349 static void i40e_set_new_dynamic_itr(struct i40e_ring_container *rc)
350 {
351 enum i40e_latency_range new_latency_range = rc->latency_range;
352 u32 new_itr = rc->itr;
353 int bytes_per_int;
354
355 if (rc->total_packets == 0 || !rc->itr)
356 return;
357
358 /* simple throttlerate management
359 * 0-10MB/s lowest (100000 ints/s)
360 * 10-20MB/s low (20000 ints/s)
361 * 20-1249MB/s bulk (8000 ints/s)
362 */
363 bytes_per_int = rc->total_bytes / rc->itr;
364 switch (rc->itr) {
365 case I40E_LOWEST_LATENCY:
366 if (bytes_per_int > 10)
367 new_latency_range = I40E_LOW_LATENCY;
368 break;
369 case I40E_LOW_LATENCY:
370 if (bytes_per_int > 20)
371 new_latency_range = I40E_BULK_LATENCY;
372 else if (bytes_per_int <= 10)
373 new_latency_range = I40E_LOWEST_LATENCY;
374 break;
375 case I40E_BULK_LATENCY:
376 if (bytes_per_int <= 20)
377 rc->latency_range = I40E_LOW_LATENCY;
378 break;
379 }
380
381 switch (new_latency_range) {
382 case I40E_LOWEST_LATENCY:
383 new_itr = I40E_ITR_100K;
384 break;
385 case I40E_LOW_LATENCY:
386 new_itr = I40E_ITR_20K;
387 break;
388 case I40E_BULK_LATENCY:
389 new_itr = I40E_ITR_8K;
390 break;
391 default:
392 break;
393 }
394
395 if (new_itr != rc->itr) {
396 /* do an exponential smoothing */
397 new_itr = (10 * new_itr * rc->itr) /
398 ((9 * new_itr) + rc->itr);
399 rc->itr = new_itr & I40E_MAX_ITR;
400 }
401
402 rc->total_bytes = 0;
403 rc->total_packets = 0;
404 }
405
406 /**
407 * i40e_update_dynamic_itr - Adjust ITR based on bytes per int
408 * @q_vector: the vector to adjust
409 **/
410 static void i40e_update_dynamic_itr(struct i40e_q_vector *q_vector)
411 {
412 u16 vector = q_vector->vsi->base_vector + q_vector->v_idx;
413 struct i40e_hw *hw = &q_vector->vsi->back->hw;
414 u32 reg_addr;
415 u16 old_itr;
416
417 reg_addr = I40E_VFINT_ITRN1(I40E_RX_ITR, vector - 1);
418 old_itr = q_vector->rx.itr;
419 i40e_set_new_dynamic_itr(&q_vector->rx);
420 if (old_itr != q_vector->rx.itr)
421 wr32(hw, reg_addr, q_vector->rx.itr);
422
423 reg_addr = I40E_VFINT_ITRN1(I40E_TX_ITR, vector - 1);
424 old_itr = q_vector->tx.itr;
425 i40e_set_new_dynamic_itr(&q_vector->tx);
426 if (old_itr != q_vector->tx.itr)
427 wr32(hw, reg_addr, q_vector->tx.itr);
428 }
429
430 /**
431 * i40evf_setup_tx_descriptors - Allocate the Tx descriptors
432 * @tx_ring: the tx ring to set up
433 *
434 * Return 0 on success, negative on error
435 **/
436 int i40evf_setup_tx_descriptors(struct i40e_ring *tx_ring)
437 {
438 struct device *dev = tx_ring->dev;
439 int bi_size;
440
441 if (!dev)
442 return -ENOMEM;
443
444 bi_size = sizeof(struct i40e_tx_buffer) * tx_ring->count;
445 tx_ring->tx_bi = kzalloc(bi_size, GFP_KERNEL);
446 if (!tx_ring->tx_bi)
447 goto err;
448
449 /* round up to nearest 4K */
450 tx_ring->size = tx_ring->count * sizeof(struct i40e_tx_desc);
451 /* add u32 for head writeback, align after this takes care of
452 * guaranteeing this is at least one cache line in size
453 */
454 tx_ring->size += sizeof(u32);
455 tx_ring->size = ALIGN(tx_ring->size, 4096);
456 tx_ring->desc = dma_alloc_coherent(dev, tx_ring->size,
457 &tx_ring->dma, GFP_KERNEL);
458 if (!tx_ring->desc) {
459 dev_info(dev, "Unable to allocate memory for the Tx descriptor ring, size=%d\n",
460 tx_ring->size);
461 goto err;
462 }
463
464 tx_ring->next_to_use = 0;
465 tx_ring->next_to_clean = 0;
466 return 0;
467
468 err:
469 kfree(tx_ring->tx_bi);
470 tx_ring->tx_bi = NULL;
471 return -ENOMEM;
472 }
473
474 /**
475 * i40evf_clean_rx_ring - Free Rx buffers
476 * @rx_ring: ring to be cleaned
477 **/
478 void i40evf_clean_rx_ring(struct i40e_ring *rx_ring)
479 {
480 struct device *dev = rx_ring->dev;
481 struct i40e_rx_buffer *rx_bi;
482 unsigned long bi_size;
483 u16 i;
484
485 /* ring already cleared, nothing to do */
486 if (!rx_ring->rx_bi)
487 return;
488
489 /* Free all the Rx ring sk_buffs */
490 for (i = 0; i < rx_ring->count; i++) {
491 rx_bi = &rx_ring->rx_bi[i];
492 if (rx_bi->dma) {
493 dma_unmap_single(dev,
494 rx_bi->dma,
495 rx_ring->rx_buf_len,
496 DMA_FROM_DEVICE);
497 rx_bi->dma = 0;
498 }
499 if (rx_bi->skb) {
500 dev_kfree_skb(rx_bi->skb);
501 rx_bi->skb = NULL;
502 }
503 if (rx_bi->page) {
504 if (rx_bi->page_dma) {
505 dma_unmap_page(dev,
506 rx_bi->page_dma,
507 PAGE_SIZE / 2,
508 DMA_FROM_DEVICE);
509 rx_bi->page_dma = 0;
510 }
511 __free_page(rx_bi->page);
512 rx_bi->page = NULL;
513 rx_bi->page_offset = 0;
514 }
515 }
516
517 bi_size = sizeof(struct i40e_rx_buffer) * rx_ring->count;
518 memset(rx_ring->rx_bi, 0, bi_size);
519
520 /* Zero out the descriptor ring */
521 memset(rx_ring->desc, 0, rx_ring->size);
522
523 rx_ring->next_to_clean = 0;
524 rx_ring->next_to_use = 0;
525 }
526
527 /**
528 * i40evf_free_rx_resources - Free Rx resources
529 * @rx_ring: ring to clean the resources from
530 *
531 * Free all receive software resources
532 **/
533 void i40evf_free_rx_resources(struct i40e_ring *rx_ring)
534 {
535 i40evf_clean_rx_ring(rx_ring);
536 kfree(rx_ring->rx_bi);
537 rx_ring->rx_bi = NULL;
538
539 if (rx_ring->desc) {
540 dma_free_coherent(rx_ring->dev, rx_ring->size,
541 rx_ring->desc, rx_ring->dma);
542 rx_ring->desc = NULL;
543 }
544 }
545
546 /**
547 * i40evf_setup_rx_descriptors - Allocate Rx descriptors
548 * @rx_ring: Rx descriptor ring (for a specific queue) to setup
549 *
550 * Returns 0 on success, negative on failure
551 **/
552 int i40evf_setup_rx_descriptors(struct i40e_ring *rx_ring)
553 {
554 struct device *dev = rx_ring->dev;
555 int bi_size;
556
557 bi_size = sizeof(struct i40e_rx_buffer) * rx_ring->count;
558 rx_ring->rx_bi = kzalloc(bi_size, GFP_KERNEL);
559 if (!rx_ring->rx_bi)
560 goto err;
561
562 /* Round up to nearest 4K */
563 rx_ring->size = ring_is_16byte_desc_enabled(rx_ring)
564 ? rx_ring->count * sizeof(union i40e_16byte_rx_desc)
565 : rx_ring->count * sizeof(union i40e_32byte_rx_desc);
566 rx_ring->size = ALIGN(rx_ring->size, 4096);
567 rx_ring->desc = dma_alloc_coherent(dev, rx_ring->size,
568 &rx_ring->dma, GFP_KERNEL);
569
570 if (!rx_ring->desc) {
571 dev_info(dev, "Unable to allocate memory for the Rx descriptor ring, size=%d\n",
572 rx_ring->size);
573 goto err;
574 }
575
576 rx_ring->next_to_clean = 0;
577 rx_ring->next_to_use = 0;
578
579 return 0;
580 err:
581 kfree(rx_ring->rx_bi);
582 rx_ring->rx_bi = NULL;
583 return -ENOMEM;
584 }
585
586 /**
587 * i40e_release_rx_desc - Store the new tail and head values
588 * @rx_ring: ring to bump
589 * @val: new head index
590 **/
591 static inline void i40e_release_rx_desc(struct i40e_ring *rx_ring, u32 val)
592 {
593 rx_ring->next_to_use = val;
594 /* Force memory writes to complete before letting h/w
595 * know there are new descriptors to fetch. (Only
596 * applicable for weak-ordered memory model archs,
597 * such as IA-64).
598 */
599 wmb();
600 writel(val, rx_ring->tail);
601 }
602
603 /**
604 * i40evf_alloc_rx_buffers - Replace used receive buffers; packet split
605 * @rx_ring: ring to place buffers on
606 * @cleaned_count: number of buffers to replace
607 **/
608 void i40evf_alloc_rx_buffers(struct i40e_ring *rx_ring, u16 cleaned_count)
609 {
610 u16 i = rx_ring->next_to_use;
611 union i40e_rx_desc *rx_desc;
612 struct i40e_rx_buffer *bi;
613 struct sk_buff *skb;
614
615 /* do nothing if no valid netdev defined */
616 if (!rx_ring->netdev || !cleaned_count)
617 return;
618
619 while (cleaned_count--) {
620 rx_desc = I40E_RX_DESC(rx_ring, i);
621 bi = &rx_ring->rx_bi[i];
622 skb = bi->skb;
623
624 if (!skb) {
625 skb = netdev_alloc_skb_ip_align(rx_ring->netdev,
626 rx_ring->rx_buf_len);
627 if (!skb) {
628 rx_ring->rx_stats.alloc_buff_failed++;
629 goto no_buffers;
630 }
631 /* initialize queue mapping */
632 skb_record_rx_queue(skb, rx_ring->queue_index);
633 bi->skb = skb;
634 }
635
636 if (!bi->dma) {
637 bi->dma = dma_map_single(rx_ring->dev,
638 skb->data,
639 rx_ring->rx_buf_len,
640 DMA_FROM_DEVICE);
641 if (dma_mapping_error(rx_ring->dev, bi->dma)) {
642 rx_ring->rx_stats.alloc_buff_failed++;
643 bi->dma = 0;
644 goto no_buffers;
645 }
646 }
647
648 if (ring_is_ps_enabled(rx_ring)) {
649 if (!bi->page) {
650 bi->page = alloc_page(GFP_ATOMIC);
651 if (!bi->page) {
652 rx_ring->rx_stats.alloc_page_failed++;
653 goto no_buffers;
654 }
655 }
656
657 if (!bi->page_dma) {
658 /* use a half page if we're re-using */
659 bi->page_offset ^= PAGE_SIZE / 2;
660 bi->page_dma = dma_map_page(rx_ring->dev,
661 bi->page,
662 bi->page_offset,
663 PAGE_SIZE / 2,
664 DMA_FROM_DEVICE);
665 if (dma_mapping_error(rx_ring->dev,
666 bi->page_dma)) {
667 rx_ring->rx_stats.alloc_page_failed++;
668 bi->page_dma = 0;
669 goto no_buffers;
670 }
671 }
672
673 /* Refresh the desc even if buffer_addrs didn't change
674 * because each write-back erases this info.
675 */
676 rx_desc->read.pkt_addr = cpu_to_le64(bi->page_dma);
677 rx_desc->read.hdr_addr = cpu_to_le64(bi->dma);
678 } else {
679 rx_desc->read.pkt_addr = cpu_to_le64(bi->dma);
680 rx_desc->read.hdr_addr = 0;
681 }
682 i++;
683 if (i == rx_ring->count)
684 i = 0;
685 }
686
687 no_buffers:
688 if (rx_ring->next_to_use != i)
689 i40e_release_rx_desc(rx_ring, i);
690 }
691
692 /**
693 * i40e_receive_skb - Send a completed packet up the stack
694 * @rx_ring: rx ring in play
695 * @skb: packet to send up
696 * @vlan_tag: vlan tag for packet
697 **/
698 static void i40e_receive_skb(struct i40e_ring *rx_ring,
699 struct sk_buff *skb, u16 vlan_tag)
700 {
701 struct i40e_q_vector *q_vector = rx_ring->q_vector;
702 struct i40e_vsi *vsi = rx_ring->vsi;
703 u64 flags = vsi->back->flags;
704
705 if (vlan_tag & VLAN_VID_MASK)
706 __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan_tag);
707
708 if (flags & I40E_FLAG_IN_NETPOLL)
709 netif_rx(skb);
710 else
711 napi_gro_receive(&q_vector->napi, skb);
712 }
713
714 /**
715 * i40e_rx_checksum - Indicate in skb if hw indicated a good cksum
716 * @vsi: the VSI we care about
717 * @skb: skb currently being received and modified
718 * @rx_status: status value of last descriptor in packet
719 * @rx_error: error value of last descriptor in packet
720 * @rx_ptype: ptype value of last descriptor in packet
721 **/
722 static inline void i40e_rx_checksum(struct i40e_vsi *vsi,
723 struct sk_buff *skb,
724 u32 rx_status,
725 u32 rx_error,
726 u16 rx_ptype)
727 {
728 bool ipv4_tunnel, ipv6_tunnel;
729 __wsum rx_udp_csum;
730 __sum16 csum;
731 struct iphdr *iph;
732
733 ipv4_tunnel = (rx_ptype > I40E_RX_PTYPE_GRENAT4_MAC_PAY3) &&
734 (rx_ptype < I40E_RX_PTYPE_GRENAT4_MACVLAN_IPV6_ICMP_PAY4);
735 ipv6_tunnel = (rx_ptype > I40E_RX_PTYPE_GRENAT6_MAC_PAY3) &&
736 (rx_ptype < I40E_RX_PTYPE_GRENAT6_MACVLAN_IPV6_ICMP_PAY4);
737
738 skb->encapsulation = ipv4_tunnel || ipv6_tunnel;
739 skb->ip_summed = CHECKSUM_NONE;
740
741 /* Rx csum enabled and ip headers found? */
742 if (!(vsi->netdev->features & NETIF_F_RXCSUM &&
743 rx_status & (1 << I40E_RX_DESC_STATUS_L3L4P_SHIFT)))
744 return;
745
746 /* likely incorrect csum if alternate IP extension headers found */
747 if (rx_status & (1 << I40E_RX_DESC_STATUS_IPV6EXADD_SHIFT))
748 return;
749
750 /* IP or L4 or outmost IP checksum error */
751 if (rx_error & ((1 << I40E_RX_DESC_ERROR_IPE_SHIFT) |
752 (1 << I40E_RX_DESC_ERROR_L4E_SHIFT) |
753 (1 << I40E_RX_DESC_ERROR_EIPE_SHIFT))) {
754 vsi->back->hw_csum_rx_error++;
755 return;
756 }
757
758 if (ipv4_tunnel &&
759 !(rx_status & (1 << I40E_RX_DESC_STATUS_UDP_0_SHIFT))) {
760 /* If VXLAN traffic has an outer UDPv4 checksum we need to check
761 * it in the driver, hardware does not do it for us.
762 * Since L3L4P bit was set we assume a valid IHL value (>=5)
763 * so the total length of IPv4 header is IHL*4 bytes
764 */
765 skb->transport_header = skb->mac_header +
766 sizeof(struct ethhdr) +
767 (ip_hdr(skb)->ihl * 4);
768
769 /* Add 4 bytes for VLAN tagged packets */
770 skb->transport_header += (skb->protocol == htons(ETH_P_8021Q) ||
771 skb->protocol == htons(ETH_P_8021AD))
772 ? VLAN_HLEN : 0;
773
774 rx_udp_csum = udp_csum(skb);
775 iph = ip_hdr(skb);
776 csum = csum_tcpudp_magic(
777 iph->saddr, iph->daddr,
778 (skb->len - skb_transport_offset(skb)),
779 IPPROTO_UDP, rx_udp_csum);
780
781 if (udp_hdr(skb)->check != csum) {
782 vsi->back->hw_csum_rx_error++;
783 return;
784 }
785 }
786
787 skb->ip_summed = CHECKSUM_UNNECESSARY;
788 }
789
790 /**
791 * i40e_rx_hash - returns the hash value from the Rx descriptor
792 * @ring: descriptor ring
793 * @rx_desc: specific descriptor
794 **/
795 static inline u32 i40e_rx_hash(struct i40e_ring *ring,
796 union i40e_rx_desc *rx_desc)
797 {
798 const __le64 rss_mask =
799 cpu_to_le64((u64)I40E_RX_DESC_FLTSTAT_RSS_HASH <<
800 I40E_RX_DESC_STATUS_FLTSTAT_SHIFT);
801
802 if ((ring->netdev->features & NETIF_F_RXHASH) &&
803 (rx_desc->wb.qword1.status_error_len & rss_mask) == rss_mask)
804 return le32_to_cpu(rx_desc->wb.qword0.hi_dword.rss);
805 else
806 return 0;
807 }
808
809 /**
810 * i40e_ptype_to_hash - get a hash type
811 * @ptype: the ptype value from the descriptor
812 *
813 * Returns a hash type to be used by skb_set_hash
814 **/
815 static inline enum pkt_hash_types i40e_ptype_to_hash(u8 ptype)
816 {
817 struct i40e_rx_ptype_decoded decoded = decode_rx_desc_ptype(ptype);
818
819 if (!decoded.known)
820 return PKT_HASH_TYPE_NONE;
821
822 if (decoded.outer_ip == I40E_RX_PTYPE_OUTER_IP &&
823 decoded.payload_layer == I40E_RX_PTYPE_PAYLOAD_LAYER_PAY4)
824 return PKT_HASH_TYPE_L4;
825 else if (decoded.outer_ip == I40E_RX_PTYPE_OUTER_IP &&
826 decoded.payload_layer == I40E_RX_PTYPE_PAYLOAD_LAYER_PAY3)
827 return PKT_HASH_TYPE_L3;
828 else
829 return PKT_HASH_TYPE_L2;
830 }
831
832 /**
833 * i40e_clean_rx_irq - Reclaim resources after receive completes
834 * @rx_ring: rx ring to clean
835 * @budget: how many cleans we're allowed
836 *
837 * Returns true if there's any budget left (e.g. the clean is finished)
838 **/
839 static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget)
840 {
841 unsigned int total_rx_bytes = 0, total_rx_packets = 0;
842 u16 rx_packet_len, rx_header_len, rx_sph, rx_hbo;
843 u16 cleaned_count = I40E_DESC_UNUSED(rx_ring);
844 const int current_node = numa_node_id();
845 struct i40e_vsi *vsi = rx_ring->vsi;
846 u16 i = rx_ring->next_to_clean;
847 union i40e_rx_desc *rx_desc;
848 u32 rx_error, rx_status;
849 u8 rx_ptype;
850 u64 qword;
851
852 rx_desc = I40E_RX_DESC(rx_ring, i);
853 qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
854 rx_status = (qword & I40E_RXD_QW1_STATUS_MASK) >>
855 I40E_RXD_QW1_STATUS_SHIFT;
856
857 while (rx_status & (1 << I40E_RX_DESC_STATUS_DD_SHIFT)) {
858 union i40e_rx_desc *next_rxd;
859 struct i40e_rx_buffer *rx_bi;
860 struct sk_buff *skb;
861 u16 vlan_tag;
862 rx_bi = &rx_ring->rx_bi[i];
863 skb = rx_bi->skb;
864 prefetch(skb->data);
865
866 rx_packet_len = (qword & I40E_RXD_QW1_LENGTH_PBUF_MASK) >>
867 I40E_RXD_QW1_LENGTH_PBUF_SHIFT;
868 rx_header_len = (qword & I40E_RXD_QW1_LENGTH_HBUF_MASK) >>
869 I40E_RXD_QW1_LENGTH_HBUF_SHIFT;
870 rx_sph = (qword & I40E_RXD_QW1_LENGTH_SPH_MASK) >>
871 I40E_RXD_QW1_LENGTH_SPH_SHIFT;
872
873 rx_error = (qword & I40E_RXD_QW1_ERROR_MASK) >>
874 I40E_RXD_QW1_ERROR_SHIFT;
875 rx_hbo = rx_error & (1 << I40E_RX_DESC_ERROR_HBO_SHIFT);
876 rx_error &= ~(1 << I40E_RX_DESC_ERROR_HBO_SHIFT);
877
878 rx_ptype = (qword & I40E_RXD_QW1_PTYPE_MASK) >>
879 I40E_RXD_QW1_PTYPE_SHIFT;
880 rx_bi->skb = NULL;
881
882 /* This memory barrier is needed to keep us from reading
883 * any other fields out of the rx_desc until we know the
884 * STATUS_DD bit is set
885 */
886 rmb();
887
888 /* Get the header and possibly the whole packet
889 * If this is an skb from previous receive dma will be 0
890 */
891 if (rx_bi->dma) {
892 u16 len;
893
894 if (rx_hbo)
895 len = I40E_RX_HDR_SIZE;
896 else if (rx_sph)
897 len = rx_header_len;
898 else if (rx_packet_len)
899 len = rx_packet_len; /* 1buf/no split found */
900 else
901 len = rx_header_len; /* split always mode */
902
903 skb_put(skb, len);
904 dma_unmap_single(rx_ring->dev,
905 rx_bi->dma,
906 rx_ring->rx_buf_len,
907 DMA_FROM_DEVICE);
908 rx_bi->dma = 0;
909 }
910
911 /* Get the rest of the data if this was a header split */
912 if (ring_is_ps_enabled(rx_ring) && rx_packet_len) {
913
914 skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
915 rx_bi->page,
916 rx_bi->page_offset,
917 rx_packet_len);
918
919 skb->len += rx_packet_len;
920 skb->data_len += rx_packet_len;
921 skb->truesize += rx_packet_len;
922
923 if ((page_count(rx_bi->page) == 1) &&
924 (page_to_nid(rx_bi->page) == current_node))
925 get_page(rx_bi->page);
926 else
927 rx_bi->page = NULL;
928
929 dma_unmap_page(rx_ring->dev,
930 rx_bi->page_dma,
931 PAGE_SIZE / 2,
932 DMA_FROM_DEVICE);
933 rx_bi->page_dma = 0;
934 }
935 I40E_RX_NEXT_DESC_PREFETCH(rx_ring, i, next_rxd);
936
937 if (unlikely(
938 !(rx_status & (1 << I40E_RX_DESC_STATUS_EOF_SHIFT)))) {
939 struct i40e_rx_buffer *next_buffer;
940
941 next_buffer = &rx_ring->rx_bi[i];
942
943 if (ring_is_ps_enabled(rx_ring)) {
944 rx_bi->skb = next_buffer->skb;
945 rx_bi->dma = next_buffer->dma;
946 next_buffer->skb = skb;
947 next_buffer->dma = 0;
948 }
949 rx_ring->rx_stats.non_eop_descs++;
950 goto next_desc;
951 }
952
953 /* ERR_MASK will only have valid bits if EOP set */
954 if (unlikely(rx_error & (1 << I40E_RX_DESC_ERROR_RXE_SHIFT))) {
955 dev_kfree_skb_any(skb);
956 goto next_desc;
957 }
958
959 skb_set_hash(skb, i40e_rx_hash(rx_ring, rx_desc),
960 i40e_ptype_to_hash(rx_ptype));
961 /* probably a little skewed due to removing CRC */
962 total_rx_bytes += skb->len;
963 total_rx_packets++;
964
965 skb->protocol = eth_type_trans(skb, rx_ring->netdev);
966
967 i40e_rx_checksum(vsi, skb, rx_status, rx_error, rx_ptype);
968
969 vlan_tag = rx_status & (1 << I40E_RX_DESC_STATUS_L2TAG1P_SHIFT)
970 ? le16_to_cpu(rx_desc->wb.qword0.lo_dword.l2tag1)
971 : 0;
972 i40e_receive_skb(rx_ring, skb, vlan_tag);
973
974 rx_ring->netdev->last_rx = jiffies;
975 budget--;
976 next_desc:
977 rx_desc->wb.qword1.status_error_len = 0;
978 if (!budget)
979 break;
980
981 cleaned_count++;
982 /* return some buffers to hardware, one at a time is too slow */
983 if (cleaned_count >= I40E_RX_BUFFER_WRITE) {
984 i40evf_alloc_rx_buffers(rx_ring, cleaned_count);
985 cleaned_count = 0;
986 }
987
988 /* use prefetched values */
989 rx_desc = next_rxd;
990 qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
991 rx_status = (qword & I40E_RXD_QW1_STATUS_MASK) >>
992 I40E_RXD_QW1_STATUS_SHIFT;
993 }
994
995 rx_ring->next_to_clean = i;
996 u64_stats_update_begin(&rx_ring->syncp);
997 rx_ring->stats.packets += total_rx_packets;
998 rx_ring->stats.bytes += total_rx_bytes;
999 u64_stats_update_end(&rx_ring->syncp);
1000 rx_ring->q_vector->rx.total_packets += total_rx_packets;
1001 rx_ring->q_vector->rx.total_bytes += total_rx_bytes;
1002
1003 if (cleaned_count)
1004 i40evf_alloc_rx_buffers(rx_ring, cleaned_count);
1005
1006 return budget > 0;
1007 }
1008
1009 /**
1010 * i40evf_napi_poll - NAPI polling Rx/Tx cleanup routine
1011 * @napi: napi struct with our devices info in it
1012 * @budget: amount of work driver is allowed to do this pass, in packets
1013 *
1014 * This function will clean all queues associated with a q_vector.
1015 *
1016 * Returns the amount of work done
1017 **/
1018 int i40evf_napi_poll(struct napi_struct *napi, int budget)
1019 {
1020 struct i40e_q_vector *q_vector =
1021 container_of(napi, struct i40e_q_vector, napi);
1022 struct i40e_vsi *vsi = q_vector->vsi;
1023 struct i40e_ring *ring;
1024 bool clean_complete = true;
1025 int budget_per_ring;
1026
1027 if (test_bit(__I40E_DOWN, &vsi->state)) {
1028 napi_complete(napi);
1029 return 0;
1030 }
1031
1032 /* Since the actual Tx work is minimal, we can give the Tx a larger
1033 * budget and be more aggressive about cleaning up the Tx descriptors.
1034 */
1035 i40e_for_each_ring(ring, q_vector->tx)
1036 clean_complete &= i40e_clean_tx_irq(ring, vsi->work_limit);
1037
1038 /* We attempt to distribute budget to each Rx queue fairly, but don't
1039 * allow the budget to go below 1 because that would exit polling early.
1040 */
1041 budget_per_ring = max(budget/q_vector->num_ringpairs, 1);
1042
1043 i40e_for_each_ring(ring, q_vector->rx)
1044 clean_complete &= i40e_clean_rx_irq(ring, budget_per_ring);
1045
1046 /* If work not completed, return budget and polling will return */
1047 if (!clean_complete)
1048 return budget;
1049
1050 /* Work is done so exit the polling mode and re-enable the interrupt */
1051 napi_complete(napi);
1052 if (ITR_IS_DYNAMIC(vsi->rx_itr_setting) ||
1053 ITR_IS_DYNAMIC(vsi->tx_itr_setting))
1054 i40e_update_dynamic_itr(q_vector);
1055
1056 if (!test_bit(__I40E_DOWN, &vsi->state))
1057 i40evf_irq_enable_queues(vsi->back, 1 << q_vector->v_idx);
1058
1059 return 0;
1060 }
1061
1062 /**
1063 * i40e_tx_prepare_vlan_flags - prepare generic TX VLAN tagging flags for HW
1064 * @skb: send buffer
1065 * @tx_ring: ring to send buffer on
1066 * @flags: the tx flags to be set
1067 *
1068 * Checks the skb and set up correspondingly several generic transmit flags
1069 * related to VLAN tagging for the HW, such as VLAN, DCB, etc.
1070 *
1071 * Returns error code indicate the frame should be dropped upon error and the
1072 * otherwise returns 0 to indicate the flags has been set properly.
1073 **/
1074 static int i40e_tx_prepare_vlan_flags(struct sk_buff *skb,
1075 struct i40e_ring *tx_ring,
1076 u32 *flags)
1077 {
1078 __be16 protocol = skb->protocol;
1079 u32 tx_flags = 0;
1080
1081 /* if we have a HW VLAN tag being added, default to the HW one */
1082 if (vlan_tx_tag_present(skb)) {
1083 tx_flags |= vlan_tx_tag_get(skb) << I40E_TX_FLAGS_VLAN_SHIFT;
1084 tx_flags |= I40E_TX_FLAGS_HW_VLAN;
1085 /* else if it is a SW VLAN, check the next protocol and store the tag */
1086 } else if (protocol == htons(ETH_P_8021Q)) {
1087 struct vlan_hdr *vhdr, _vhdr;
1088 vhdr = skb_header_pointer(skb, ETH_HLEN, sizeof(_vhdr), &_vhdr);
1089 if (!vhdr)
1090 return -EINVAL;
1091
1092 protocol = vhdr->h_vlan_encapsulated_proto;
1093 tx_flags |= ntohs(vhdr->h_vlan_TCI) << I40E_TX_FLAGS_VLAN_SHIFT;
1094 tx_flags |= I40E_TX_FLAGS_SW_VLAN;
1095 }
1096
1097 *flags = tx_flags;
1098 return 0;
1099 }
1100
1101 /**
1102 * i40e_tso - set up the tso context descriptor
1103 * @tx_ring: ptr to the ring to send
1104 * @skb: ptr to the skb we're sending
1105 * @tx_flags: the collected send information
1106 * @protocol: the send protocol
1107 * @hdr_len: ptr to the size of the packet header
1108 * @cd_tunneling: ptr to context descriptor bits
1109 *
1110 * Returns 0 if no TSO can happen, 1 if tso is going, or error
1111 **/
1112 static int i40e_tso(struct i40e_ring *tx_ring, struct sk_buff *skb,
1113 u32 tx_flags, __be16 protocol, u8 *hdr_len,
1114 u64 *cd_type_cmd_tso_mss, u32 *cd_tunneling)
1115 {
1116 u32 cd_cmd, cd_tso_len, cd_mss;
1117 struct ipv6hdr *ipv6h;
1118 struct tcphdr *tcph;
1119 struct iphdr *iph;
1120 u32 l4len;
1121 int err;
1122
1123 if (!skb_is_gso(skb))
1124 return 0;
1125
1126 err = skb_cow_head(skb, 0);
1127 if (err < 0)
1128 return err;
1129
1130 if (protocol == htons(ETH_P_IP)) {
1131 iph = skb->encapsulation ? inner_ip_hdr(skb) : ip_hdr(skb);
1132 tcph = skb->encapsulation ? inner_tcp_hdr(skb) : tcp_hdr(skb);
1133 iph->tot_len = 0;
1134 iph->check = 0;
1135 tcph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
1136 0, IPPROTO_TCP, 0);
1137 } else if (skb_is_gso_v6(skb)) {
1138
1139 ipv6h = skb->encapsulation ? inner_ipv6_hdr(skb)
1140 : ipv6_hdr(skb);
1141 tcph = skb->encapsulation ? inner_tcp_hdr(skb) : tcp_hdr(skb);
1142 ipv6h->payload_len = 0;
1143 tcph->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,
1144 0, IPPROTO_TCP, 0);
1145 }
1146
1147 l4len = skb->encapsulation ? inner_tcp_hdrlen(skb) : tcp_hdrlen(skb);
1148 *hdr_len = (skb->encapsulation
1149 ? (skb_inner_transport_header(skb) - skb->data)
1150 : skb_transport_offset(skb)) + l4len;
1151
1152 /* find the field values */
1153 cd_cmd = I40E_TX_CTX_DESC_TSO;
1154 cd_tso_len = skb->len - *hdr_len;
1155 cd_mss = skb_shinfo(skb)->gso_size;
1156 *cd_type_cmd_tso_mss |= ((u64)cd_cmd << I40E_TXD_CTX_QW1_CMD_SHIFT) |
1157 ((u64)cd_tso_len <<
1158 I40E_TXD_CTX_QW1_TSO_LEN_SHIFT) |
1159 ((u64)cd_mss << I40E_TXD_CTX_QW1_MSS_SHIFT);
1160 return 1;
1161 }
1162
1163 /**
1164 * i40e_tx_enable_csum - Enable Tx checksum offloads
1165 * @skb: send buffer
1166 * @tx_flags: Tx flags currently set
1167 * @td_cmd: Tx descriptor command bits to set
1168 * @td_offset: Tx descriptor header offsets to set
1169 * @cd_tunneling: ptr to context desc bits
1170 **/
1171 static void i40e_tx_enable_csum(struct sk_buff *skb, u32 tx_flags,
1172 u32 *td_cmd, u32 *td_offset,
1173 struct i40e_ring *tx_ring,
1174 u32 *cd_tunneling)
1175 {
1176 struct ipv6hdr *this_ipv6_hdr;
1177 unsigned int this_tcp_hdrlen;
1178 struct iphdr *this_ip_hdr;
1179 u32 network_hdr_len;
1180 u8 l4_hdr = 0;
1181
1182 if (skb->encapsulation) {
1183 network_hdr_len = skb_inner_network_header_len(skb);
1184 this_ip_hdr = inner_ip_hdr(skb);
1185 this_ipv6_hdr = inner_ipv6_hdr(skb);
1186 this_tcp_hdrlen = inner_tcp_hdrlen(skb);
1187
1188 if (tx_flags & I40E_TX_FLAGS_IPV4) {
1189
1190 if (tx_flags & I40E_TX_FLAGS_TSO) {
1191 *cd_tunneling |= I40E_TX_CTX_EXT_IP_IPV4;
1192 ip_hdr(skb)->check = 0;
1193 } else {
1194 *cd_tunneling |=
1195 I40E_TX_CTX_EXT_IP_IPV4_NO_CSUM;
1196 }
1197 } else if (tx_flags & I40E_TX_FLAGS_IPV6) {
1198 if (tx_flags & I40E_TX_FLAGS_TSO) {
1199 *cd_tunneling |= I40E_TX_CTX_EXT_IP_IPV6;
1200 ip_hdr(skb)->check = 0;
1201 } else {
1202 *cd_tunneling |=
1203 I40E_TX_CTX_EXT_IP_IPV4_NO_CSUM;
1204 }
1205 }
1206
1207 /* Now set the ctx descriptor fields */
1208 *cd_tunneling |= (skb_network_header_len(skb) >> 2) <<
1209 I40E_TXD_CTX_QW0_EXT_IPLEN_SHIFT |
1210 I40E_TXD_CTX_UDP_TUNNELING |
1211 ((skb_inner_network_offset(skb) -
1212 skb_transport_offset(skb)) >> 1) <<
1213 I40E_TXD_CTX_QW0_NATLEN_SHIFT;
1214
1215 } else {
1216 network_hdr_len = skb_network_header_len(skb);
1217 this_ip_hdr = ip_hdr(skb);
1218 this_ipv6_hdr = ipv6_hdr(skb);
1219 this_tcp_hdrlen = tcp_hdrlen(skb);
1220 }
1221
1222 /* Enable IP checksum offloads */
1223 if (tx_flags & I40E_TX_FLAGS_IPV4) {
1224 l4_hdr = this_ip_hdr->protocol;
1225 /* the stack computes the IP header already, the only time we
1226 * need the hardware to recompute it is in the case of TSO.
1227 */
1228 if (tx_flags & I40E_TX_FLAGS_TSO) {
1229 *td_cmd |= I40E_TX_DESC_CMD_IIPT_IPV4_CSUM;
1230 this_ip_hdr->check = 0;
1231 } else {
1232 *td_cmd |= I40E_TX_DESC_CMD_IIPT_IPV4;
1233 }
1234 /* Now set the td_offset for IP header length */
1235 *td_offset = (network_hdr_len >> 2) <<
1236 I40E_TX_DESC_LENGTH_IPLEN_SHIFT;
1237 } else if (tx_flags & I40E_TX_FLAGS_IPV6) {
1238 l4_hdr = this_ipv6_hdr->nexthdr;
1239 *td_cmd |= I40E_TX_DESC_CMD_IIPT_IPV6;
1240 /* Now set the td_offset for IP header length */
1241 *td_offset = (network_hdr_len >> 2) <<
1242 I40E_TX_DESC_LENGTH_IPLEN_SHIFT;
1243 }
1244 /* words in MACLEN + dwords in IPLEN + dwords in L4Len */
1245 *td_offset |= (skb_network_offset(skb) >> 1) <<
1246 I40E_TX_DESC_LENGTH_MACLEN_SHIFT;
1247
1248 /* Enable L4 checksum offloads */
1249 switch (l4_hdr) {
1250 case IPPROTO_TCP:
1251 /* enable checksum offloads */
1252 *td_cmd |= I40E_TX_DESC_CMD_L4T_EOFT_TCP;
1253 *td_offset |= (this_tcp_hdrlen >> 2) <<
1254 I40E_TX_DESC_LENGTH_L4_FC_LEN_SHIFT;
1255 break;
1256 case IPPROTO_SCTP:
1257 /* enable SCTP checksum offload */
1258 *td_cmd |= I40E_TX_DESC_CMD_L4T_EOFT_SCTP;
1259 *td_offset |= (sizeof(struct sctphdr) >> 2) <<
1260 I40E_TX_DESC_LENGTH_L4_FC_LEN_SHIFT;
1261 break;
1262 case IPPROTO_UDP:
1263 /* enable UDP checksum offload */
1264 *td_cmd |= I40E_TX_DESC_CMD_L4T_EOFT_UDP;
1265 *td_offset |= (sizeof(struct udphdr) >> 2) <<
1266 I40E_TX_DESC_LENGTH_L4_FC_LEN_SHIFT;
1267 break;
1268 default:
1269 break;
1270 }
1271 }
1272
1273 /**
1274 * i40e_create_tx_ctx Build the Tx context descriptor
1275 * @tx_ring: ring to create the descriptor on
1276 * @cd_type_cmd_tso_mss: Quad Word 1
1277 * @cd_tunneling: Quad Word 0 - bits 0-31
1278 * @cd_l2tag2: Quad Word 0 - bits 32-63
1279 **/
1280 static void i40e_create_tx_ctx(struct i40e_ring *tx_ring,
1281 const u64 cd_type_cmd_tso_mss,
1282 const u32 cd_tunneling, const u32 cd_l2tag2)
1283 {
1284 struct i40e_tx_context_desc *context_desc;
1285 int i = tx_ring->next_to_use;
1286
1287 if ((cd_type_cmd_tso_mss == I40E_TX_DESC_DTYPE_CONTEXT) &&
1288 !cd_tunneling && !cd_l2tag2)
1289 return;
1290
1291 /* grab the next descriptor */
1292 context_desc = I40E_TX_CTXTDESC(tx_ring, i);
1293
1294 i++;
1295 tx_ring->next_to_use = (i < tx_ring->count) ? i : 0;
1296
1297 /* cpu_to_le32 and assign to struct fields */
1298 context_desc->tunneling_params = cpu_to_le32(cd_tunneling);
1299 context_desc->l2tag2 = cpu_to_le16(cd_l2tag2);
1300 context_desc->type_cmd_tso_mss = cpu_to_le64(cd_type_cmd_tso_mss);
1301 }
1302
1303 /**
1304 * i40e_tx_map - Build the Tx descriptor
1305 * @tx_ring: ring to send buffer on
1306 * @skb: send buffer
1307 * @first: first buffer info buffer to use
1308 * @tx_flags: collected send information
1309 * @hdr_len: size of the packet header
1310 * @td_cmd: the command field in the descriptor
1311 * @td_offset: offset for checksum or crc
1312 **/
1313 static void i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
1314 struct i40e_tx_buffer *first, u32 tx_flags,
1315 const u8 hdr_len, u32 td_cmd, u32 td_offset)
1316 {
1317 unsigned int data_len = skb->data_len;
1318 unsigned int size = skb_headlen(skb);
1319 struct skb_frag_struct *frag;
1320 struct i40e_tx_buffer *tx_bi;
1321 struct i40e_tx_desc *tx_desc;
1322 u16 i = tx_ring->next_to_use;
1323 u32 td_tag = 0;
1324 dma_addr_t dma;
1325 u16 gso_segs;
1326
1327 if (tx_flags & I40E_TX_FLAGS_HW_VLAN) {
1328 td_cmd |= I40E_TX_DESC_CMD_IL2TAG1;
1329 td_tag = (tx_flags & I40E_TX_FLAGS_VLAN_MASK) >>
1330 I40E_TX_FLAGS_VLAN_SHIFT;
1331 }
1332
1333 if (tx_flags & (I40E_TX_FLAGS_TSO | I40E_TX_FLAGS_FSO))
1334 gso_segs = skb_shinfo(skb)->gso_segs;
1335 else
1336 gso_segs = 1;
1337
1338 /* multiply data chunks by size of headers */
1339 first->bytecount = skb->len - hdr_len + (gso_segs * hdr_len);
1340 first->gso_segs = gso_segs;
1341 first->skb = skb;
1342 first->tx_flags = tx_flags;
1343
1344 dma = dma_map_single(tx_ring->dev, skb->data, size, DMA_TO_DEVICE);
1345
1346 tx_desc = I40E_TX_DESC(tx_ring, i);
1347 tx_bi = first;
1348
1349 for (frag = &skb_shinfo(skb)->frags[0];; frag++) {
1350 if (dma_mapping_error(tx_ring->dev, dma))
1351 goto dma_error;
1352
1353 /* record length, and DMA address */
1354 dma_unmap_len_set(tx_bi, len, size);
1355 dma_unmap_addr_set(tx_bi, dma, dma);
1356
1357 tx_desc->buffer_addr = cpu_to_le64(dma);
1358
1359 while (unlikely(size > I40E_MAX_DATA_PER_TXD)) {
1360 tx_desc->cmd_type_offset_bsz =
1361 build_ctob(td_cmd, td_offset,
1362 I40E_MAX_DATA_PER_TXD, td_tag);
1363
1364 tx_desc++;
1365 i++;
1366 if (i == tx_ring->count) {
1367 tx_desc = I40E_TX_DESC(tx_ring, 0);
1368 i = 0;
1369 }
1370
1371 dma += I40E_MAX_DATA_PER_TXD;
1372 size -= I40E_MAX_DATA_PER_TXD;
1373
1374 tx_desc->buffer_addr = cpu_to_le64(dma);
1375 }
1376
1377 if (likely(!data_len))
1378 break;
1379
1380 tx_desc->cmd_type_offset_bsz = build_ctob(td_cmd, td_offset,
1381 size, td_tag);
1382
1383 tx_desc++;
1384 i++;
1385 if (i == tx_ring->count) {
1386 tx_desc = I40E_TX_DESC(tx_ring, 0);
1387 i = 0;
1388 }
1389
1390 size = skb_frag_size(frag);
1391 data_len -= size;
1392
1393 dma = skb_frag_dma_map(tx_ring->dev, frag, 0, size,
1394 DMA_TO_DEVICE);
1395
1396 tx_bi = &tx_ring->tx_bi[i];
1397 }
1398
1399 /* Place RS bit on last descriptor of any packet that spans across the
1400 * 4th descriptor (WB_STRIDE aka 0x3) in a 64B cacheline.
1401 */
1402 #define WB_STRIDE 0x3
1403 if (((i & WB_STRIDE) != WB_STRIDE) &&
1404 (first <= &tx_ring->tx_bi[i]) &&
1405 (first >= &tx_ring->tx_bi[i & ~WB_STRIDE])) {
1406 tx_desc->cmd_type_offset_bsz =
1407 build_ctob(td_cmd, td_offset, size, td_tag) |
1408 cpu_to_le64((u64)I40E_TX_DESC_CMD_EOP <<
1409 I40E_TXD_QW1_CMD_SHIFT);
1410 } else {
1411 tx_desc->cmd_type_offset_bsz =
1412 build_ctob(td_cmd, td_offset, size, td_tag) |
1413 cpu_to_le64((u64)I40E_TXD_CMD <<
1414 I40E_TXD_QW1_CMD_SHIFT);
1415 }
1416
1417 netdev_tx_sent_queue(netdev_get_tx_queue(tx_ring->netdev,
1418 tx_ring->queue_index),
1419 first->bytecount);
1420
1421 /* set the timestamp */
1422 first->time_stamp = jiffies;
1423
1424 /* Force memory writes to complete before letting h/w
1425 * know there are new descriptors to fetch. (Only
1426 * applicable for weak-ordered memory model archs,
1427 * such as IA-64).
1428 */
1429 wmb();
1430
1431 /* set next_to_watch value indicating a packet is present */
1432 first->next_to_watch = tx_desc;
1433
1434 i++;
1435 if (i == tx_ring->count)
1436 i = 0;
1437
1438 tx_ring->next_to_use = i;
1439
1440 /* notify HW of packet */
1441 writel(i, tx_ring->tail);
1442
1443 return;
1444
1445 dma_error:
1446 dev_info(tx_ring->dev, "TX DMA map failed\n");
1447
1448 /* clear dma mappings for failed tx_bi map */
1449 for (;;) {
1450 tx_bi = &tx_ring->tx_bi[i];
1451 i40e_unmap_and_free_tx_resource(tx_ring, tx_bi);
1452 if (tx_bi == first)
1453 break;
1454 if (i == 0)
1455 i = tx_ring->count;
1456 i--;
1457 }
1458
1459 tx_ring->next_to_use = i;
1460 }
1461
1462 /**
1463 * __i40e_maybe_stop_tx - 2nd level check for tx stop conditions
1464 * @tx_ring: the ring to be checked
1465 * @size: the size buffer we want to assure is available
1466 *
1467 * Returns -EBUSY if a stop is needed, else 0
1468 **/
1469 static inline int __i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size)
1470 {
1471 netif_stop_subqueue(tx_ring->netdev, tx_ring->queue_index);
1472 /* Memory barrier before checking head and tail */
1473 smp_mb();
1474
1475 /* Check again in a case another CPU has just made room available. */
1476 if (likely(I40E_DESC_UNUSED(tx_ring) < size))
1477 return -EBUSY;
1478
1479 /* A reprieve! - use start_queue because it doesn't call schedule */
1480 netif_start_subqueue(tx_ring->netdev, tx_ring->queue_index);
1481 ++tx_ring->tx_stats.restart_queue;
1482 return 0;
1483 }
1484
1485 /**
1486 * i40e_maybe_stop_tx - 1st level check for tx stop conditions
1487 * @tx_ring: the ring to be checked
1488 * @size: the size buffer we want to assure is available
1489 *
1490 * Returns 0 if stop is not needed
1491 **/
1492 static int i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size)
1493 {
1494 if (likely(I40E_DESC_UNUSED(tx_ring) >= size))
1495 return 0;
1496 return __i40e_maybe_stop_tx(tx_ring, size);
1497 }
1498
1499 /**
1500 * i40e_xmit_descriptor_count - calculate number of tx descriptors needed
1501 * @skb: send buffer
1502 * @tx_ring: ring to send buffer on
1503 *
1504 * Returns number of data descriptors needed for this skb. Returns 0 to indicate
1505 * there is not enough descriptors available in this ring since we need at least
1506 * one descriptor.
1507 **/
1508 static int i40e_xmit_descriptor_count(struct sk_buff *skb,
1509 struct i40e_ring *tx_ring)
1510 {
1511 #if PAGE_SIZE > I40E_MAX_DATA_PER_TXD
1512 unsigned int f;
1513 #endif
1514 int count = 0;
1515
1516 /* need: 1 descriptor per page * PAGE_SIZE/I40E_MAX_DATA_PER_TXD,
1517 * + 1 desc for skb_head_len/I40E_MAX_DATA_PER_TXD,
1518 * + 4 desc gap to avoid the cache line where head is,
1519 * + 1 desc for context descriptor,
1520 * otherwise try next time
1521 */
1522 #if PAGE_SIZE > I40E_MAX_DATA_PER_TXD
1523 for (f = 0; f < skb_shinfo(skb)->nr_frags; f++)
1524 count += TXD_USE_COUNT(skb_shinfo(skb)->frags[f].size);
1525 #else
1526 count += skb_shinfo(skb)->nr_frags;
1527 #endif
1528 count += TXD_USE_COUNT(skb_headlen(skb));
1529 if (i40e_maybe_stop_tx(tx_ring, count + 4 + 1)) {
1530 tx_ring->tx_stats.tx_busy++;
1531 return 0;
1532 }
1533 return count;
1534 }
1535
1536 /**
1537 * i40e_xmit_frame_ring - Sends buffer on Tx ring
1538 * @skb: send buffer
1539 * @tx_ring: ring to send buffer on
1540 *
1541 * Returns NETDEV_TX_OK if sent, else an error code
1542 **/
1543 static netdev_tx_t i40e_xmit_frame_ring(struct sk_buff *skb,
1544 struct i40e_ring *tx_ring)
1545 {
1546 u64 cd_type_cmd_tso_mss = I40E_TX_DESC_DTYPE_CONTEXT;
1547 u32 cd_tunneling = 0, cd_l2tag2 = 0;
1548 struct i40e_tx_buffer *first;
1549 u32 td_offset = 0;
1550 u32 tx_flags = 0;
1551 __be16 protocol;
1552 u32 td_cmd = 0;
1553 u8 hdr_len = 0;
1554 int tso;
1555 if (0 == i40e_xmit_descriptor_count(skb, tx_ring))
1556 return NETDEV_TX_BUSY;
1557
1558 /* prepare the xmit flags */
1559 if (i40e_tx_prepare_vlan_flags(skb, tx_ring, &tx_flags))
1560 goto out_drop;
1561
1562 /* obtain protocol of skb */
1563 protocol = skb->protocol;
1564
1565 /* record the location of the first descriptor for this packet */
1566 first = &tx_ring->tx_bi[tx_ring->next_to_use];
1567
1568 /* setup IPv4/IPv6 offloads */
1569 if (protocol == htons(ETH_P_IP))
1570 tx_flags |= I40E_TX_FLAGS_IPV4;
1571 else if (protocol == htons(ETH_P_IPV6))
1572 tx_flags |= I40E_TX_FLAGS_IPV6;
1573
1574 tso = i40e_tso(tx_ring, skb, tx_flags, protocol, &hdr_len,
1575 &cd_type_cmd_tso_mss, &cd_tunneling);
1576
1577 if (tso < 0)
1578 goto out_drop;
1579 else if (tso)
1580 tx_flags |= I40E_TX_FLAGS_TSO;
1581
1582 skb_tx_timestamp(skb);
1583
1584 /* always enable CRC insertion offload */
1585 td_cmd |= I40E_TX_DESC_CMD_ICRC;
1586
1587 /* Always offload the checksum, since it's in the data descriptor */
1588 if (skb->ip_summed == CHECKSUM_PARTIAL) {
1589 tx_flags |= I40E_TX_FLAGS_CSUM;
1590
1591 i40e_tx_enable_csum(skb, tx_flags, &td_cmd, &td_offset,
1592 tx_ring, &cd_tunneling);
1593 }
1594
1595 i40e_create_tx_ctx(tx_ring, cd_type_cmd_tso_mss,
1596 cd_tunneling, cd_l2tag2);
1597
1598 i40e_tx_map(tx_ring, skb, first, tx_flags, hdr_len,
1599 td_cmd, td_offset);
1600
1601 i40e_maybe_stop_tx(tx_ring, DESC_NEEDED);
1602
1603 return NETDEV_TX_OK;
1604
1605 out_drop:
1606 dev_kfree_skb_any(skb);
1607 return NETDEV_TX_OK;
1608 }
1609
1610 /**
1611 * i40evf_xmit_frame - Selects the correct VSI and Tx queue to send buffer
1612 * @skb: send buffer
1613 * @netdev: network interface device structure
1614 *
1615 * Returns NETDEV_TX_OK if sent, else an error code
1616 **/
1617 netdev_tx_t i40evf_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
1618 {
1619 struct i40evf_adapter *adapter = netdev_priv(netdev);
1620 struct i40e_ring *tx_ring = adapter->tx_rings[skb->queue_mapping];
1621
1622 /* hardware can't handle really short frames, hardware padding works
1623 * beyond this point
1624 */
1625 if (unlikely(skb->len < I40E_MIN_TX_LEN)) {
1626 if (skb_pad(skb, I40E_MIN_TX_LEN - skb->len))
1627 return NETDEV_TX_OK;
1628 skb->len = I40E_MIN_TX_LEN;
1629 skb_set_tail_pointer(skb, I40E_MIN_TX_LEN);
1630 }
1631
1632 return i40e_xmit_frame_ring(skb, tx_ring);
1633 }
Linux kernel - Deliverables
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