1 /*******************************************************************************
2  *
3  * Intel Ethernet Controller XL710 Family Linux Driver
4  * Copyright(c) 2013 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  * You should have received a copy of the GNU General Public License along with
16  * this program; if not, write to the Free Software Foundation, Inc.,
17  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
18  *
19  * The full GNU General Public License is included in this distribution in
20  * the file called "COPYING".
21  *
22  * Contact Information:
23  * e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
24  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
25  *
26  ******************************************************************************/
27 
28 #include "i40e.h"
29 
30 static inline __le64 build_ctob(u32 td_cmd, u32 td_offset, unsigned int size,
31 				u32 td_tag)
32 {
33 	return cpu_to_le64(I40E_TX_DESC_DTYPE_DATA |
34 			   ((u64)td_cmd  << I40E_TXD_QW1_CMD_SHIFT) |
35 			   ((u64)td_offset << I40E_TXD_QW1_OFFSET_SHIFT) |
36 			   ((u64)size  << I40E_TXD_QW1_TX_BUF_SZ_SHIFT) |
37 			   ((u64)td_tag  << I40E_TXD_QW1_L2TAG1_SHIFT));
38 }
39 
40 /**
41  * i40e_program_fdir_filter - Program a Flow Director filter
42  * @fdir_input: Packet data that will be filter parameters
43  * @pf: The pf pointer
44  * @add: True for add/update, False for remove
45  **/
46 int i40e_program_fdir_filter(struct i40e_fdir_data *fdir_data,
47 			     struct i40e_pf *pf, bool add)
48 {
49 	struct i40e_filter_program_desc *fdir_desc;
50 	struct i40e_tx_buffer *tx_buf;
51 	struct i40e_tx_desc *tx_desc;
52 	struct i40e_ring *tx_ring;
53 	struct i40e_vsi *vsi;
54 	struct device *dev;
55 	dma_addr_t dma;
56 	u32 td_cmd = 0;
57 	u16 i;
58 
59 	/* find existing FDIR VSI */
60 	vsi = NULL;
61 	for (i = 0; i < pf->hw.func_caps.num_vsis; i++)
62 		if (pf->vsi[i] && pf->vsi[i]->type == I40E_VSI_FDIR)
63 			vsi = pf->vsi[i];
64 	if (!vsi)
65 		return -ENOENT;
66 
67 	tx_ring = &vsi->tx_rings[0];
68 	dev = tx_ring->dev;
69 
70 	dma = dma_map_single(dev, fdir_data->raw_packet,
71 				I40E_FDIR_MAX_RAW_PACKET_LOOKUP, DMA_TO_DEVICE);
72 	if (dma_mapping_error(dev, dma))
73 		goto dma_fail;
74 
75 	/* grab the next descriptor */
76 	fdir_desc = I40E_TX_FDIRDESC(tx_ring, tx_ring->next_to_use);
77 	tx_buf = &tx_ring->tx_bi[tx_ring->next_to_use];
78 	tx_ring->next_to_use++;
79 	if (tx_ring->next_to_use == tx_ring->count)
80 		tx_ring->next_to_use = 0;
81 
82 	fdir_desc->qindex_flex_ptype_vsi = cpu_to_le32((fdir_data->q_index
83 					     << I40E_TXD_FLTR_QW0_QINDEX_SHIFT)
84 					     & I40E_TXD_FLTR_QW0_QINDEX_MASK);
85 
86 	fdir_desc->qindex_flex_ptype_vsi |= cpu_to_le32((fdir_data->flex_off
87 					    << I40E_TXD_FLTR_QW0_FLEXOFF_SHIFT)
88 					    & I40E_TXD_FLTR_QW0_FLEXOFF_MASK);
89 
90 	fdir_desc->qindex_flex_ptype_vsi |= cpu_to_le32((fdir_data->pctype
91 					     << I40E_TXD_FLTR_QW0_PCTYPE_SHIFT)
92 					     & I40E_TXD_FLTR_QW0_PCTYPE_MASK);
93 
94 	/* Use LAN VSI Id if not programmed by user */
95 	if (fdir_data->dest_vsi == 0)
96 		fdir_desc->qindex_flex_ptype_vsi |=
97 					  cpu_to_le32((pf->vsi[pf->lan_vsi]->id)
98 					   << I40E_TXD_FLTR_QW0_DEST_VSI_SHIFT);
99 	else
100 		fdir_desc->qindex_flex_ptype_vsi |=
101 					    cpu_to_le32((fdir_data->dest_vsi
102 					    << I40E_TXD_FLTR_QW0_DEST_VSI_SHIFT)
103 					    & I40E_TXD_FLTR_QW0_DEST_VSI_MASK);
104 
105 	fdir_desc->dtype_cmd_cntindex =
106 				    cpu_to_le32(I40E_TX_DESC_DTYPE_FILTER_PROG);
107 
108 	if (add)
109 		fdir_desc->dtype_cmd_cntindex |= cpu_to_le32(
110 				       I40E_FILTER_PROGRAM_DESC_PCMD_ADD_UPDATE
111 					<< I40E_TXD_FLTR_QW1_PCMD_SHIFT);
112 	else
113 		fdir_desc->dtype_cmd_cntindex |= cpu_to_le32(
114 					   I40E_FILTER_PROGRAM_DESC_PCMD_REMOVE
115 					   << I40E_TXD_FLTR_QW1_PCMD_SHIFT);
116 
117 	fdir_desc->dtype_cmd_cntindex |= cpu_to_le32((fdir_data->dest_ctl
118 					  << I40E_TXD_FLTR_QW1_DEST_SHIFT)
119 					  & I40E_TXD_FLTR_QW1_DEST_MASK);
120 
121 	fdir_desc->dtype_cmd_cntindex |= cpu_to_le32(
122 		     (fdir_data->fd_status << I40E_TXD_FLTR_QW1_FD_STATUS_SHIFT)
123 		      & I40E_TXD_FLTR_QW1_FD_STATUS_MASK);
124 
125 	if (fdir_data->cnt_index != 0) {
126 		fdir_desc->dtype_cmd_cntindex |=
127 				    cpu_to_le32(I40E_TXD_FLTR_QW1_CNT_ENA_MASK);
128 		fdir_desc->dtype_cmd_cntindex |=
129 					    cpu_to_le32((fdir_data->cnt_index
130 					    << I40E_TXD_FLTR_QW1_CNTINDEX_SHIFT)
131 					    & I40E_TXD_FLTR_QW1_CNTINDEX_MASK);
132 	}
133 
134 	fdir_desc->fd_id = cpu_to_le32(fdir_data->fd_id);
135 
136 	/* Now program a dummy descriptor */
137 	tx_desc = I40E_TX_DESC(tx_ring, tx_ring->next_to_use);
138 	tx_buf = &tx_ring->tx_bi[tx_ring->next_to_use];
139 	tx_ring->next_to_use++;
140 	if (tx_ring->next_to_use == tx_ring->count)
141 		tx_ring->next_to_use = 0;
142 
143 	tx_desc->buffer_addr = cpu_to_le64(dma);
144 	td_cmd = I40E_TX_DESC_CMD_EOP |
145 		 I40E_TX_DESC_CMD_RS  |
146 		 I40E_TX_DESC_CMD_DUMMY;
147 
148 	tx_desc->cmd_type_offset_bsz =
149 		build_ctob(td_cmd, 0, I40E_FDIR_MAX_RAW_PACKET_LOOKUP, 0);
150 
151 	/* Mark the data descriptor to be watched */
152 	tx_buf->next_to_watch = tx_desc;
153 
154 	/* Force memory writes to complete before letting h/w
155 	 * know there are new descriptors to fetch.  (Only
156 	 * applicable for weak-ordered memory model archs,
157 	 * such as IA-64).
158 	 */
159 	wmb();
160 
161 	writel(tx_ring->next_to_use, tx_ring->tail);
162 	return 0;
163 
164 dma_fail:
165 	return -1;
166 }
167 
168 /**
169  * i40e_fd_handle_status - check the Programming Status for FD
170  * @rx_ring: the Rx ring for this descriptor
171  * @qw: the descriptor data
172  * @prog_id: the id originally used for programming
173  *
174  * This is used to verify if the FD programming or invalidation
175  * requested by SW to the HW is successful or not and take actions accordingly.
176  **/
177 static void i40e_fd_handle_status(struct i40e_ring *rx_ring, u32 qw, u8 prog_id)
178 {
179 	struct pci_dev *pdev = rx_ring->vsi->back->pdev;
180 	u32 error;
181 
182 	error = (qw & I40E_RX_PROG_STATUS_DESC_QW1_ERROR_MASK) >>
183 		I40E_RX_PROG_STATUS_DESC_QW1_ERROR_SHIFT;
184 
185 	/* for now just print the Status */
186 	dev_info(&pdev->dev, "FD programming id %02x, Status %08x\n",
187 		 prog_id, error);
188 }
189 
190 /**
191  * i40e_unmap_tx_resource - Release a Tx buffer
192  * @ring:      the ring that owns the buffer
193  * @tx_buffer: the buffer to free
194  **/
195 static inline void i40e_unmap_tx_resource(struct i40e_ring *ring,
196 					  struct i40e_tx_buffer *tx_buffer)
197 {
198 	if (tx_buffer->dma) {
199 		if (tx_buffer->tx_flags & I40E_TX_FLAGS_MAPPED_AS_PAGE)
200 			dma_unmap_page(ring->dev,
201 				       tx_buffer->dma,
202 				       tx_buffer->length,
203 				       DMA_TO_DEVICE);
204 		else
205 			dma_unmap_single(ring->dev,
206 					 tx_buffer->dma,
207 					 tx_buffer->length,
208 					 DMA_TO_DEVICE);
209 	}
210 	tx_buffer->dma = 0;
211 	tx_buffer->time_stamp = 0;
212 }
213 
214 /**
215  * i40e_clean_tx_ring - Free any empty Tx buffers
216  * @tx_ring: ring to be cleaned
217  **/
218 void i40e_clean_tx_ring(struct i40e_ring *tx_ring)
219 {
220 	struct i40e_tx_buffer *tx_buffer;
221 	unsigned long bi_size;
222 	u16 i;
223 
224 	/* ring already cleared, nothing to do */
225 	if (!tx_ring->tx_bi)
226 		return;
227 
228 	/* Free all the Tx ring sk_buffs */
229 	for (i = 0; i < tx_ring->count; i++) {
230 		tx_buffer = &tx_ring->tx_bi[i];
231 		i40e_unmap_tx_resource(tx_ring, tx_buffer);
232 		if (tx_buffer->skb)
233 			dev_kfree_skb_any(tx_buffer->skb);
234 		tx_buffer->skb = NULL;
235 	}
236 
237 	bi_size = sizeof(struct i40e_tx_buffer) * tx_ring->count;
238 	memset(tx_ring->tx_bi, 0, bi_size);
239 
240 	/* Zero out the descriptor ring */
241 	memset(tx_ring->desc, 0, tx_ring->size);
242 
243 	tx_ring->next_to_use = 0;
244 	tx_ring->next_to_clean = 0;
245 }
246 
247 /**
248  * i40e_free_tx_resources - Free Tx resources per queue
249  * @tx_ring: Tx descriptor ring for a specific queue
250  *
251  * Free all transmit software resources
252  **/
253 void i40e_free_tx_resources(struct i40e_ring *tx_ring)
254 {
255 	i40e_clean_tx_ring(tx_ring);
256 	kfree(tx_ring->tx_bi);
257 	tx_ring->tx_bi = NULL;
258 
259 	if (tx_ring->desc) {
260 		dma_free_coherent(tx_ring->dev, tx_ring->size,
261 				  tx_ring->desc, tx_ring->dma);
262 		tx_ring->desc = NULL;
263 	}
264 }
265 
266 /**
267  * i40e_get_tx_pending - how many tx descriptors not processed
268  * @tx_ring: the ring of descriptors
269  *
270  * Since there is no access to the ring head register
271  * in XL710, we need to use our local copies
272  **/
273 static u32 i40e_get_tx_pending(struct i40e_ring *ring)
274 {
275 	u32 ntu = ((ring->next_to_clean <= ring->next_to_use)
276 			? ring->next_to_use
277 			: ring->next_to_use + ring->count);
278 	return ntu - ring->next_to_clean;
279 }
280 
281 /**
282  * i40e_check_tx_hang - Is there a hang in the Tx queue
283  * @tx_ring: the ring of descriptors
284  **/
285 static bool i40e_check_tx_hang(struct i40e_ring *tx_ring)
286 {
287 	u32 tx_pending = i40e_get_tx_pending(tx_ring);
288 	bool ret = false;
289 
290 	clear_check_for_tx_hang(tx_ring);
291 
292 	/* Check for a hung queue, but be thorough. This verifies
293 	 * that a transmit has been completed since the previous
294 	 * check AND there is at least one packet pending. The
295 	 * ARMED bit is set to indicate a potential hang. The
296 	 * bit is cleared if a pause frame is received to remove
297 	 * false hang detection due to PFC or 802.3x frames. By
298 	 * requiring this to fail twice we avoid races with
299 	 * PFC clearing the ARMED bit and conditions where we
300 	 * run the check_tx_hang logic with a transmit completion
301 	 * pending but without time to complete it yet.
302 	 */
303 	if ((tx_ring->tx_stats.tx_done_old == tx_ring->tx_stats.packets) &&
304 	    tx_pending) {
305 		/* make sure it is true for two checks in a row */
306 		ret = test_and_set_bit(__I40E_HANG_CHECK_ARMED,
307 				       &tx_ring->state);
308 	} else {
309 		/* update completed stats and disarm the hang check */
310 		tx_ring->tx_stats.tx_done_old = tx_ring->tx_stats.packets;
311 		clear_bit(__I40E_HANG_CHECK_ARMED, &tx_ring->state);
312 	}
313 
314 	return ret;
315 }
316 
317 /**
318  * i40e_clean_tx_irq - Reclaim resources after transmit completes
319  * @tx_ring:  tx ring to clean
320  * @budget:   how many cleans we're allowed
321  *
322  * Returns true if there's any budget left (e.g. the clean is finished)
323  **/
324 static bool i40e_clean_tx_irq(struct i40e_ring *tx_ring, int budget)
325 {
326 	u16 i = tx_ring->next_to_clean;
327 	struct i40e_tx_buffer *tx_buf;
328 	struct i40e_tx_desc *tx_desc;
329 	unsigned int total_packets = 0;
330 	unsigned int total_bytes = 0;
331 
332 	tx_buf = &tx_ring->tx_bi[i];
333 	tx_desc = I40E_TX_DESC(tx_ring, i);
334 
335 	for (; budget; budget--) {
336 		struct i40e_tx_desc *eop_desc;
337 
338 		eop_desc = tx_buf->next_to_watch;
339 
340 		/* if next_to_watch is not set then there is no work pending */
341 		if (!eop_desc)
342 			break;
343 
344 		/* if the descriptor isn't done, no work yet to do */
345 		if (!(eop_desc->cmd_type_offset_bsz &
346 		      cpu_to_le64(I40E_TX_DESC_DTYPE_DESC_DONE)))
347 			break;
348 
349 		/* count the packet as being completed */
350 		tx_ring->tx_stats.completed++;
351 		tx_buf->next_to_watch = NULL;
352 		tx_buf->time_stamp = 0;
353 
354 		/* set memory barrier before eop_desc is verified */
355 		rmb();
356 
357 		do {
358 			i40e_unmap_tx_resource(tx_ring, tx_buf);
359 
360 			/* clear dtype status */
361 			tx_desc->cmd_type_offset_bsz &=
362 				~cpu_to_le64(I40E_TXD_QW1_DTYPE_MASK);
363 
364 			if (likely(tx_desc == eop_desc)) {
365 				eop_desc = NULL;
366 
367 				dev_kfree_skb_any(tx_buf->skb);
368 				tx_buf->skb = NULL;
369 
370 				total_bytes += tx_buf->bytecount;
371 				total_packets += tx_buf->gso_segs;
372 			}
373 
374 			tx_buf++;
375 			tx_desc++;
376 			i++;
377 			if (unlikely(i == tx_ring->count)) {
378 				i = 0;
379 				tx_buf = tx_ring->tx_bi;
380 				tx_desc = I40E_TX_DESC(tx_ring, 0);
381 			}
382 		} while (eop_desc);
383 	}
384 
385 	tx_ring->next_to_clean = i;
386 	tx_ring->tx_stats.bytes += total_bytes;
387 	tx_ring->tx_stats.packets += total_packets;
388 	tx_ring->q_vector->tx.total_bytes += total_bytes;
389 	tx_ring->q_vector->tx.total_packets += total_packets;
390 	if (check_for_tx_hang(tx_ring) && i40e_check_tx_hang(tx_ring)) {
391 		/* schedule immediate reset if we believe we hung */
392 		dev_info(tx_ring->dev, "Detected Tx Unit Hang\n"
393 			 "  VSI                  <%d>\n"
394 			 "  Tx Queue             <%d>\n"
395 			 "  next_to_use          <%x>\n"
396 			 "  next_to_clean        <%x>\n",
397 			 tx_ring->vsi->seid,
398 			 tx_ring->queue_index,
399 			 tx_ring->next_to_use, i);
400 		dev_info(tx_ring->dev, "tx_bi[next_to_clean]\n"
401 			 "  time_stamp           <%lx>\n"
402 			 "  jiffies              <%lx>\n",
403 			 tx_ring->tx_bi[i].time_stamp, jiffies);
404 
405 		netif_stop_subqueue(tx_ring->netdev, tx_ring->queue_index);
406 
407 		dev_info(tx_ring->dev,
408 			 "tx hang detected on queue %d, resetting adapter\n",
409 			 tx_ring->queue_index);
410 
411 		tx_ring->netdev->netdev_ops->ndo_tx_timeout(tx_ring->netdev);
412 
413 		/* the adapter is about to reset, no point in enabling stuff */
414 		return true;
415 	}
416 
417 #define TX_WAKE_THRESHOLD (DESC_NEEDED * 2)
418 	if (unlikely(total_packets && netif_carrier_ok(tx_ring->netdev) &&
419 		     (I40E_DESC_UNUSED(tx_ring) >= TX_WAKE_THRESHOLD))) {
420 		/* Make sure that anybody stopping the queue after this
421 		 * sees the new next_to_clean.
422 		 */
423 		smp_mb();
424 		if (__netif_subqueue_stopped(tx_ring->netdev,
425 					     tx_ring->queue_index) &&
426 		   !test_bit(__I40E_DOWN, &tx_ring->vsi->state)) {
427 			netif_wake_subqueue(tx_ring->netdev,
428 					    tx_ring->queue_index);
429 			++tx_ring->tx_stats.restart_queue;
430 		}
431 	}
432 
433 	return budget > 0;
434 }
435 
436 /**
437  * i40e_set_new_dynamic_itr - Find new ITR level
438  * @rc: structure containing ring performance data
439  *
440  * Stores a new ITR value based on packets and byte counts during
441  * the last interrupt.  The advantage of per interrupt computation
442  * is faster updates and more accurate ITR for the current traffic
443  * pattern.  Constants in this function were computed based on
444  * theoretical maximum wire speed and thresholds were set based on
445  * testing data as well as attempting to minimize response time
446  * while increasing bulk throughput.
447  **/
448 static void i40e_set_new_dynamic_itr(struct i40e_ring_container *rc)
449 {
450 	enum i40e_latency_range new_latency_range = rc->latency_range;
451 	u32 new_itr = rc->itr;
452 	int bytes_per_int;
453 
454 	if (rc->total_packets == 0 || !rc->itr)
455 		return;
456 
457 	/* simple throttlerate management
458 	 *   0-10MB/s   lowest (100000 ints/s)
459 	 *  10-20MB/s   low    (20000 ints/s)
460 	 *  20-1249MB/s bulk   (8000 ints/s)
461 	 */
462 	bytes_per_int = rc->total_bytes / rc->itr;
463 	switch (rc->itr) {
464 	case I40E_LOWEST_LATENCY:
465 		if (bytes_per_int > 10)
466 			new_latency_range = I40E_LOW_LATENCY;
467 		break;
468 	case I40E_LOW_LATENCY:
469 		if (bytes_per_int > 20)
470 			new_latency_range = I40E_BULK_LATENCY;
471 		else if (bytes_per_int <= 10)
472 			new_latency_range = I40E_LOWEST_LATENCY;
473 		break;
474 	case I40E_BULK_LATENCY:
475 		if (bytes_per_int <= 20)
476 			rc->latency_range = I40E_LOW_LATENCY;
477 		break;
478 	}
479 
480 	switch (new_latency_range) {
481 	case I40E_LOWEST_LATENCY:
482 		new_itr = I40E_ITR_100K;
483 		break;
484 	case I40E_LOW_LATENCY:
485 		new_itr = I40E_ITR_20K;
486 		break;
487 	case I40E_BULK_LATENCY:
488 		new_itr = I40E_ITR_8K;
489 		break;
490 	default:
491 		break;
492 	}
493 
494 	if (new_itr != rc->itr) {
495 		/* do an exponential smoothing */
496 		new_itr = (10 * new_itr * rc->itr) /
497 			  ((9 * new_itr) + rc->itr);
498 		rc->itr = new_itr & I40E_MAX_ITR;
499 	}
500 
501 	rc->total_bytes = 0;
502 	rc->total_packets = 0;
503 }
504 
505 /**
506  * i40e_update_dynamic_itr - Adjust ITR based on bytes per int
507  * @q_vector: the vector to adjust
508  **/
509 static void i40e_update_dynamic_itr(struct i40e_q_vector *q_vector)
510 {
511 	u16 vector = q_vector->vsi->base_vector + q_vector->v_idx;
512 	struct i40e_hw *hw = &q_vector->vsi->back->hw;
513 	u32 reg_addr;
514 	u16 old_itr;
515 
516 	reg_addr = I40E_PFINT_ITRN(I40E_RX_ITR, vector - 1);
517 	old_itr = q_vector->rx.itr;
518 	i40e_set_new_dynamic_itr(&q_vector->rx);
519 	if (old_itr != q_vector->rx.itr)
520 		wr32(hw, reg_addr, q_vector->rx.itr);
521 
522 	reg_addr = I40E_PFINT_ITRN(I40E_TX_ITR, vector - 1);
523 	old_itr = q_vector->tx.itr;
524 	i40e_set_new_dynamic_itr(&q_vector->tx);
525 	if (old_itr != q_vector->tx.itr)
526 		wr32(hw, reg_addr, q_vector->tx.itr);
527 
528 	i40e_flush(hw);
529 }
530 
531 /**
532  * i40e_clean_programming_status - clean the programming status descriptor
533  * @rx_ring: the rx ring that has this descriptor
534  * @rx_desc: the rx descriptor written back by HW
535  *
536  * Flow director should handle FD_FILTER_STATUS to check its filter programming
537  * status being successful or not and take actions accordingly. FCoE should
538  * handle its context/filter programming/invalidation status and take actions.
539  *
540  **/
541 static void i40e_clean_programming_status(struct i40e_ring *rx_ring,
542 					  union i40e_rx_desc *rx_desc)
543 {
544 	u64 qw;
545 	u8 id;
546 
547 	qw = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
548 	id = (qw & I40E_RX_PROG_STATUS_DESC_QW1_PROGID_MASK) >>
549 		  I40E_RX_PROG_STATUS_DESC_QW1_PROGID_SHIFT;
550 
551 	if (id == I40E_RX_PROG_STATUS_DESC_FD_FILTER_STATUS)
552 		i40e_fd_handle_status(rx_ring, qw, id);
553 }
554 
555 /**
556  * i40e_setup_tx_descriptors - Allocate the Tx descriptors
557  * @tx_ring: the tx ring to set up
558  *
559  * Return 0 on success, negative on error
560  **/
561 int i40e_setup_tx_descriptors(struct i40e_ring *tx_ring)
562 {
563 	struct device *dev = tx_ring->dev;
564 	int bi_size;
565 
566 	if (!dev)
567 		return -ENOMEM;
568 
569 	bi_size = sizeof(struct i40e_tx_buffer) * tx_ring->count;
570 	tx_ring->tx_bi = kzalloc(bi_size, GFP_KERNEL);
571 	if (!tx_ring->tx_bi)
572 		goto err;
573 
574 	/* round up to nearest 4K */
575 	tx_ring->size = tx_ring->count * sizeof(struct i40e_tx_desc);
576 	tx_ring->size = ALIGN(tx_ring->size, 4096);
577 	tx_ring->desc = dma_alloc_coherent(dev, tx_ring->size,
578 					   &tx_ring->dma, GFP_KERNEL);
579 	if (!tx_ring->desc) {
580 		dev_info(dev, "Unable to allocate memory for the Tx descriptor ring, size=%d\n",
581 			 tx_ring->size);
582 		goto err;
583 	}
584 
585 	tx_ring->next_to_use = 0;
586 	tx_ring->next_to_clean = 0;
587 	return 0;
588 
589 err:
590 	kfree(tx_ring->tx_bi);
591 	tx_ring->tx_bi = NULL;
592 	return -ENOMEM;
593 }
594 
595 /**
596  * i40e_clean_rx_ring - Free Rx buffers
597  * @rx_ring: ring to be cleaned
598  **/
599 void i40e_clean_rx_ring(struct i40e_ring *rx_ring)
600 {
601 	struct device *dev = rx_ring->dev;
602 	struct i40e_rx_buffer *rx_bi;
603 	unsigned long bi_size;
604 	u16 i;
605 
606 	/* ring already cleared, nothing to do */
607 	if (!rx_ring->rx_bi)
608 		return;
609 
610 	/* Free all the Rx ring sk_buffs */
611 	for (i = 0; i < rx_ring->count; i++) {
612 		rx_bi = &rx_ring->rx_bi[i];
613 		if (rx_bi->dma) {
614 			dma_unmap_single(dev,
615 					 rx_bi->dma,
616 					 rx_ring->rx_buf_len,
617 					 DMA_FROM_DEVICE);
618 			rx_bi->dma = 0;
619 		}
620 		if (rx_bi->skb) {
621 			dev_kfree_skb(rx_bi->skb);
622 			rx_bi->skb = NULL;
623 		}
624 		if (rx_bi->page) {
625 			if (rx_bi->page_dma) {
626 				dma_unmap_page(dev,
627 					       rx_bi->page_dma,
628 					       PAGE_SIZE / 2,
629 					       DMA_FROM_DEVICE);
630 				rx_bi->page_dma = 0;
631 			}
632 			__free_page(rx_bi->page);
633 			rx_bi->page = NULL;
634 			rx_bi->page_offset = 0;
635 		}
636 	}
637 
638 	bi_size = sizeof(struct i40e_rx_buffer) * rx_ring->count;
639 	memset(rx_ring->rx_bi, 0, bi_size);
640 
641 	/* Zero out the descriptor ring */
642 	memset(rx_ring->desc, 0, rx_ring->size);
643 
644 	rx_ring->next_to_clean = 0;
645 	rx_ring->next_to_use = 0;
646 }
647 
648 /**
649  * i40e_free_rx_resources - Free Rx resources
650  * @rx_ring: ring to clean the resources from
651  *
652  * Free all receive software resources
653  **/
654 void i40e_free_rx_resources(struct i40e_ring *rx_ring)
655 {
656 	i40e_clean_rx_ring(rx_ring);
657 	kfree(rx_ring->rx_bi);
658 	rx_ring->rx_bi = NULL;
659 
660 	if (rx_ring->desc) {
661 		dma_free_coherent(rx_ring->dev, rx_ring->size,
662 				  rx_ring->desc, rx_ring->dma);
663 		rx_ring->desc = NULL;
664 	}
665 }
666 
667 /**
668  * i40e_setup_rx_descriptors - Allocate Rx descriptors
669  * @rx_ring: Rx descriptor ring (for a specific queue) to setup
670  *
671  * Returns 0 on success, negative on failure
672  **/
673 int i40e_setup_rx_descriptors(struct i40e_ring *rx_ring)
674 {
675 	struct device *dev = rx_ring->dev;
676 	int bi_size;
677 
678 	bi_size = sizeof(struct i40e_rx_buffer) * rx_ring->count;
679 	rx_ring->rx_bi = kzalloc(bi_size, GFP_KERNEL);
680 	if (!rx_ring->rx_bi)
681 		goto err;
682 
683 	/* Round up to nearest 4K */
684 	rx_ring->size = ring_is_16byte_desc_enabled(rx_ring)
685 		? rx_ring->count * sizeof(union i40e_16byte_rx_desc)
686 		: rx_ring->count * sizeof(union i40e_32byte_rx_desc);
687 	rx_ring->size = ALIGN(rx_ring->size, 4096);
688 	rx_ring->desc = dma_alloc_coherent(dev, rx_ring->size,
689 					   &rx_ring->dma, GFP_KERNEL);
690 
691 	if (!rx_ring->desc) {
692 		dev_info(dev, "Unable to allocate memory for the Rx descriptor ring, size=%d\n",
693 			 rx_ring->size);
694 		goto err;
695 	}
696 
697 	rx_ring->next_to_clean = 0;
698 	rx_ring->next_to_use = 0;
699 
700 	return 0;
701 err:
702 	kfree(rx_ring->rx_bi);
703 	rx_ring->rx_bi = NULL;
704 	return -ENOMEM;
705 }
706 
707 /**
708  * i40e_release_rx_desc - Store the new tail and head values
709  * @rx_ring: ring to bump
710  * @val: new head index
711  **/
712 static inline void i40e_release_rx_desc(struct i40e_ring *rx_ring, u32 val)
713 {
714 	rx_ring->next_to_use = val;
715 	/* Force memory writes to complete before letting h/w
716 	 * know there are new descriptors to fetch.  (Only
717 	 * applicable for weak-ordered memory model archs,
718 	 * such as IA-64).
719 	 */
720 	wmb();
721 	writel(val, rx_ring->tail);
722 }
723 
724 /**
725  * i40e_alloc_rx_buffers - Replace used receive buffers; packet split
726  * @rx_ring: ring to place buffers on
727  * @cleaned_count: number of buffers to replace
728  **/
729 void i40e_alloc_rx_buffers(struct i40e_ring *rx_ring, u16 cleaned_count)
730 {
731 	u16 i = rx_ring->next_to_use;
732 	union i40e_rx_desc *rx_desc;
733 	struct i40e_rx_buffer *bi;
734 	struct sk_buff *skb;
735 
736 	/* do nothing if no valid netdev defined */
737 	if (!rx_ring->netdev || !cleaned_count)
738 		return;
739 
740 	while (cleaned_count--) {
741 		rx_desc = I40E_RX_DESC(rx_ring, i);
742 		bi = &rx_ring->rx_bi[i];
743 		skb = bi->skb;
744 
745 		if (!skb) {
746 			skb = netdev_alloc_skb_ip_align(rx_ring->netdev,
747 							rx_ring->rx_buf_len);
748 			if (!skb) {
749 				rx_ring->rx_stats.alloc_rx_buff_failed++;
750 				goto no_buffers;
751 			}
752 			/* initialize queue mapping */
753 			skb_record_rx_queue(skb, rx_ring->queue_index);
754 			bi->skb = skb;
755 		}
756 
757 		if (!bi->dma) {
758 			bi->dma = dma_map_single(rx_ring->dev,
759 						 skb->data,
760 						 rx_ring->rx_buf_len,
761 						 DMA_FROM_DEVICE);
762 			if (dma_mapping_error(rx_ring->dev, bi->dma)) {
763 				rx_ring->rx_stats.alloc_rx_buff_failed++;
764 				bi->dma = 0;
765 				goto no_buffers;
766 			}
767 		}
768 
769 		if (ring_is_ps_enabled(rx_ring)) {
770 			if (!bi->page) {
771 				bi->page = alloc_page(GFP_ATOMIC);
772 				if (!bi->page) {
773 					rx_ring->rx_stats.alloc_rx_page_failed++;
774 					goto no_buffers;
775 				}
776 			}
777 
778 			if (!bi->page_dma) {
779 				/* use a half page if we're re-using */
780 				bi->page_offset ^= PAGE_SIZE / 2;
781 				bi->page_dma = dma_map_page(rx_ring->dev,
782 							    bi->page,
783 							    bi->page_offset,
784 							    PAGE_SIZE / 2,
785 							    DMA_FROM_DEVICE);
786 				if (dma_mapping_error(rx_ring->dev,
787 						      bi->page_dma)) {
788 					rx_ring->rx_stats.alloc_rx_page_failed++;
789 					bi->page_dma = 0;
790 					goto no_buffers;
791 				}
792 			}
793 
794 			/* Refresh the desc even if buffer_addrs didn't change
795 			 * because each write-back erases this info.
796 			 */
797 			rx_desc->read.pkt_addr = cpu_to_le64(bi->page_dma);
798 			rx_desc->read.hdr_addr = cpu_to_le64(bi->dma);
799 		} else {
800 			rx_desc->read.pkt_addr = cpu_to_le64(bi->dma);
801 			rx_desc->read.hdr_addr = 0;
802 		}
803 		i++;
804 		if (i == rx_ring->count)
805 			i = 0;
806 	}
807 
808 no_buffers:
809 	if (rx_ring->next_to_use != i)
810 		i40e_release_rx_desc(rx_ring, i);
811 }
812 
813 /**
814  * i40e_receive_skb - Send a completed packet up the stack
815  * @rx_ring:  rx ring in play
816  * @skb: packet to send up
817  * @vlan_tag: vlan tag for packet
818  **/
819 static void i40e_receive_skb(struct i40e_ring *rx_ring,
820 			     struct sk_buff *skb, u16 vlan_tag)
821 {
822 	struct i40e_q_vector *q_vector = rx_ring->q_vector;
823 	struct i40e_vsi *vsi = rx_ring->vsi;
824 	u64 flags = vsi->back->flags;
825 
826 	if (vlan_tag & VLAN_VID_MASK)
827 		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan_tag);
828 
829 	if (flags & I40E_FLAG_IN_NETPOLL)
830 		netif_rx(skb);
831 	else
832 		napi_gro_receive(&q_vector->napi, skb);
833 }
834 
835 /**
836  * i40e_rx_checksum - Indicate in skb if hw indicated a good cksum
837  * @vsi: the VSI we care about
838  * @skb: skb currently being received and modified
839  * @rx_status: status value of last descriptor in packet
840  * @rx_error: error value of last descriptor in packet
841  **/
842 static inline void i40e_rx_checksum(struct i40e_vsi *vsi,
843 				    struct sk_buff *skb,
844 				    u32 rx_status,
845 				    u32 rx_error)
846 {
847 	skb->ip_summed = CHECKSUM_NONE;
848 
849 	/* Rx csum enabled and ip headers found? */
850 	if (!(vsi->netdev->features & NETIF_F_RXCSUM &&
851 	      rx_status & (1 << I40E_RX_DESC_STATUS_L3L4P_SHIFT)))
852 		return;
853 
854 	/* IP or L4 checksum error */
855 	if (rx_error & ((1 << I40E_RX_DESC_ERROR_IPE_SHIFT) |
856 			(1 << I40E_RX_DESC_ERROR_L4E_SHIFT))) {
857 		vsi->back->hw_csum_rx_error++;
858 		return;
859 	}
860 
861 	skb->ip_summed = CHECKSUM_UNNECESSARY;
862 }
863 
864 /**
865  * i40e_rx_hash - returns the hash value from the Rx descriptor
866  * @ring: descriptor ring
867  * @rx_desc: specific descriptor
868  **/
869 static inline u32 i40e_rx_hash(struct i40e_ring *ring,
870 			       union i40e_rx_desc *rx_desc)
871 {
872 	if (ring->netdev->features & NETIF_F_RXHASH) {
873 		if ((le64_to_cpu(rx_desc->wb.qword1.status_error_len) >>
874 		     I40E_RX_DESC_STATUS_FLTSTAT_SHIFT) &
875 		    I40E_RX_DESC_FLTSTAT_RSS_HASH)
876 			return le32_to_cpu(rx_desc->wb.qword0.hi_dword.rss);
877 	}
878 	return 0;
879 }
880 
881 /**
882  * i40e_clean_rx_irq - Reclaim resources after receive completes
883  * @rx_ring:  rx ring to clean
884  * @budget:   how many cleans we're allowed
885  *
886  * Returns true if there's any budget left (e.g. the clean is finished)
887  **/
888 static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget)
889 {
890 	unsigned int total_rx_bytes = 0, total_rx_packets = 0;
891 	u16 rx_packet_len, rx_header_len, rx_sph, rx_hbo;
892 	u16 cleaned_count = I40E_DESC_UNUSED(rx_ring);
893 	const int current_node = numa_node_id();
894 	struct i40e_vsi *vsi = rx_ring->vsi;
895 	u16 i = rx_ring->next_to_clean;
896 	union i40e_rx_desc *rx_desc;
897 	u32 rx_error, rx_status;
898 	u64 qword;
899 
900 	rx_desc = I40E_RX_DESC(rx_ring, i);
901 	qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
902 	rx_status = (qword & I40E_RXD_QW1_STATUS_MASK)
903 				>> I40E_RXD_QW1_STATUS_SHIFT;
904 
905 	while (rx_status & (1 << I40E_RX_DESC_STATUS_DD_SHIFT)) {
906 		union i40e_rx_desc *next_rxd;
907 		struct i40e_rx_buffer *rx_bi;
908 		struct sk_buff *skb;
909 		u16 vlan_tag;
910 		if (i40e_rx_is_programming_status(qword)) {
911 			i40e_clean_programming_status(rx_ring, rx_desc);
912 			I40E_RX_NEXT_DESC_PREFETCH(rx_ring, i, next_rxd);
913 			goto next_desc;
914 		}
915 		rx_bi = &rx_ring->rx_bi[i];
916 		skb = rx_bi->skb;
917 		prefetch(skb->data);
918 
919 		rx_packet_len = (qword & I40E_RXD_QW1_LENGTH_PBUF_MASK)
920 					      >> I40E_RXD_QW1_LENGTH_PBUF_SHIFT;
921 		rx_header_len = (qword & I40E_RXD_QW1_LENGTH_HBUF_MASK)
922 					      >> I40E_RXD_QW1_LENGTH_HBUF_SHIFT;
923 		rx_sph = (qword & I40E_RXD_QW1_LENGTH_SPH_MASK)
924 					      >> I40E_RXD_QW1_LENGTH_SPH_SHIFT;
925 
926 		rx_error = (qword & I40E_RXD_QW1_ERROR_MASK)
927 					      >> I40E_RXD_QW1_ERROR_SHIFT;
928 		rx_hbo = rx_error & (1 << I40E_RX_DESC_ERROR_HBO_SHIFT);
929 		rx_error &= ~(1 << I40E_RX_DESC_ERROR_HBO_SHIFT);
930 
931 		rx_bi->skb = NULL;
932 
933 		/* This memory barrier is needed to keep us from reading
934 		 * any other fields out of the rx_desc until we know the
935 		 * STATUS_DD bit is set
936 		 */
937 		rmb();
938 
939 		/* Get the header and possibly the whole packet
940 		 * If this is an skb from previous receive dma will be 0
941 		 */
942 		if (rx_bi->dma) {
943 			u16 len;
944 
945 			if (rx_hbo)
946 				len = I40E_RX_HDR_SIZE;
947 			else if (rx_sph)
948 				len = rx_header_len;
949 			else if (rx_packet_len)
950 				len = rx_packet_len;   /* 1buf/no split found */
951 			else
952 				len = rx_header_len;   /* split always mode */
953 
954 			skb_put(skb, len);
955 			dma_unmap_single(rx_ring->dev,
956 					 rx_bi->dma,
957 					 rx_ring->rx_buf_len,
958 					 DMA_FROM_DEVICE);
959 			rx_bi->dma = 0;
960 		}
961 
962 		/* Get the rest of the data if this was a header split */
963 		if (ring_is_ps_enabled(rx_ring) && rx_packet_len) {
964 
965 			skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
966 					   rx_bi->page,
967 					   rx_bi->page_offset,
968 					   rx_packet_len);
969 
970 			skb->len += rx_packet_len;
971 			skb->data_len += rx_packet_len;
972 			skb->truesize += rx_packet_len;
973 
974 			if ((page_count(rx_bi->page) == 1) &&
975 			    (page_to_nid(rx_bi->page) == current_node))
976 				get_page(rx_bi->page);
977 			else
978 				rx_bi->page = NULL;
979 
980 			dma_unmap_page(rx_ring->dev,
981 				       rx_bi->page_dma,
982 				       PAGE_SIZE / 2,
983 				       DMA_FROM_DEVICE);
984 			rx_bi->page_dma = 0;
985 		}
986 		I40E_RX_NEXT_DESC_PREFETCH(rx_ring, i, next_rxd);
987 
988 		if (unlikely(
989 		    !(rx_status & (1 << I40E_RX_DESC_STATUS_EOF_SHIFT)))) {
990 			struct i40e_rx_buffer *next_buffer;
991 
992 			next_buffer = &rx_ring->rx_bi[i];
993 
994 			if (ring_is_ps_enabled(rx_ring)) {
995 				rx_bi->skb = next_buffer->skb;
996 				rx_bi->dma = next_buffer->dma;
997 				next_buffer->skb = skb;
998 				next_buffer->dma = 0;
999 			}
1000 			rx_ring->rx_stats.non_eop_descs++;
1001 			goto next_desc;
1002 		}
1003 
1004 		/* ERR_MASK will only have valid bits if EOP set */
1005 		if (unlikely(rx_error & (1 << I40E_RX_DESC_ERROR_RXE_SHIFT))) {
1006 			dev_kfree_skb_any(skb);
1007 			goto next_desc;
1008 		}
1009 
1010 		skb->rxhash = i40e_rx_hash(rx_ring, rx_desc);
1011 		i40e_rx_checksum(vsi, skb, rx_status, rx_error);
1012 
1013 		/* probably a little skewed due to removing CRC */
1014 		total_rx_bytes += skb->len;
1015 		total_rx_packets++;
1016 
1017 		skb->protocol = eth_type_trans(skb, rx_ring->netdev);
1018 		vlan_tag = rx_status & (1 << I40E_RX_DESC_STATUS_L2TAG1P_SHIFT)
1019 			 ? le16_to_cpu(rx_desc->wb.qword0.lo_dword.l2tag1)
1020 			 : 0;
1021 		i40e_receive_skb(rx_ring, skb, vlan_tag);
1022 
1023 		rx_ring->netdev->last_rx = jiffies;
1024 		budget--;
1025 next_desc:
1026 		rx_desc->wb.qword1.status_error_len = 0;
1027 		if (!budget)
1028 			break;
1029 
1030 		cleaned_count++;
1031 		/* return some buffers to hardware, one at a time is too slow */
1032 		if (cleaned_count >= I40E_RX_BUFFER_WRITE) {
1033 			i40e_alloc_rx_buffers(rx_ring, cleaned_count);
1034 			cleaned_count = 0;
1035 		}
1036 
1037 		/* use prefetched values */
1038 		rx_desc = next_rxd;
1039 		qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
1040 		rx_status = (qword & I40E_RXD_QW1_STATUS_MASK)
1041 						>> I40E_RXD_QW1_STATUS_SHIFT;
1042 	}
1043 
1044 	rx_ring->next_to_clean = i;
1045 	rx_ring->rx_stats.packets += total_rx_packets;
1046 	rx_ring->rx_stats.bytes += total_rx_bytes;
1047 	rx_ring->q_vector->rx.total_packets += total_rx_packets;
1048 	rx_ring->q_vector->rx.total_bytes += total_rx_bytes;
1049 
1050 	if (cleaned_count)
1051 		i40e_alloc_rx_buffers(rx_ring, cleaned_count);
1052 
1053 	return budget > 0;
1054 }
1055 
1056 /**
1057  * i40e_napi_poll - NAPI polling Rx/Tx cleanup routine
1058  * @napi: napi struct with our devices info in it
1059  * @budget: amount of work driver is allowed to do this pass, in packets
1060  *
1061  * This function will clean all queues associated with a q_vector.
1062  *
1063  * Returns the amount of work done
1064  **/
1065 int i40e_napi_poll(struct napi_struct *napi, int budget)
1066 {
1067 	struct i40e_q_vector *q_vector =
1068 			       container_of(napi, struct i40e_q_vector, napi);
1069 	struct i40e_vsi *vsi = q_vector->vsi;
1070 	bool clean_complete = true;
1071 	int budget_per_ring;
1072 	int i;
1073 
1074 	if (test_bit(__I40E_DOWN, &vsi->state)) {
1075 		napi_complete(napi);
1076 		return 0;
1077 	}
1078 
1079 	/* We attempt to distribute budget to each Rx queue fairly, but don't
1080 	 * allow the budget to go below 1 because that would exit polling early.
1081 	 * Since the actual Tx work is minimal, we can give the Tx a larger
1082 	 * budget and be more aggressive about cleaning up the Tx descriptors.
1083 	 */
1084 	budget_per_ring = max(budget/q_vector->num_ringpairs, 1);
1085 	for (i = 0; i < q_vector->num_ringpairs; i++) {
1086 		clean_complete &= i40e_clean_tx_irq(q_vector->tx.ring[i],
1087 						    vsi->work_limit);
1088 		clean_complete &= i40e_clean_rx_irq(q_vector->rx.ring[i],
1089 						    budget_per_ring);
1090 	}
1091 
1092 	/* If work not completed, return budget and polling will return */
1093 	if (!clean_complete)
1094 		return budget;
1095 
1096 	/* Work is done so exit the polling mode and re-enable the interrupt */
1097 	napi_complete(napi);
1098 	if (ITR_IS_DYNAMIC(vsi->rx_itr_setting) ||
1099 	    ITR_IS_DYNAMIC(vsi->tx_itr_setting))
1100 		i40e_update_dynamic_itr(q_vector);
1101 
1102 	if (!test_bit(__I40E_DOWN, &vsi->state)) {
1103 		if (vsi->back->flags & I40E_FLAG_MSIX_ENABLED) {
1104 			i40e_irq_dynamic_enable(vsi,
1105 					q_vector->v_idx + vsi->base_vector);
1106 		} else {
1107 			struct i40e_hw *hw = &vsi->back->hw;
1108 			/* We re-enable the queue 0 cause, but
1109 			 * don't worry about dynamic_enable
1110 			 * because we left it on for the other
1111 			 * possible interrupts during napi
1112 			 */
1113 			u32 qval = rd32(hw, I40E_QINT_RQCTL(0));
1114 			qval |= I40E_QINT_RQCTL_CAUSE_ENA_MASK;
1115 			wr32(hw, I40E_QINT_RQCTL(0), qval);
1116 
1117 			qval = rd32(hw, I40E_QINT_TQCTL(0));
1118 			qval |= I40E_QINT_TQCTL_CAUSE_ENA_MASK;
1119 			wr32(hw, I40E_QINT_TQCTL(0), qval);
1120 			i40e_flush(hw);
1121 		}
1122 	}
1123 
1124 	return 0;
1125 }
1126 
1127 /**
1128  * i40e_atr - Add a Flow Director ATR filter
1129  * @tx_ring:  ring to add programming descriptor to
1130  * @skb:      send buffer
1131  * @flags:    send flags
1132  * @protocol: wire protocol
1133  **/
1134 static void i40e_atr(struct i40e_ring *tx_ring, struct sk_buff *skb,
1135 		     u32 flags, __be16 protocol)
1136 {
1137 	struct i40e_filter_program_desc *fdir_desc;
1138 	struct i40e_pf *pf = tx_ring->vsi->back;
1139 	union {
1140 		unsigned char *network;
1141 		struct iphdr *ipv4;
1142 		struct ipv6hdr *ipv6;
1143 	} hdr;
1144 	struct tcphdr *th;
1145 	unsigned int hlen;
1146 	u32 flex_ptype, dtype_cmd;
1147 
1148 	/* make sure ATR is enabled */
1149 	if (!(pf->flags & I40E_FLAG_FDIR_ATR_ENABLED))
1150 		return;
1151 
1152 	/* if sampling is disabled do nothing */
1153 	if (!tx_ring->atr_sample_rate)
1154 		return;
1155 
1156 	tx_ring->atr_count++;
1157 
1158 	/* snag network header to get L4 type and address */
1159 	hdr.network = skb_network_header(skb);
1160 
1161 	/* Currently only IPv4/IPv6 with TCP is supported */
1162 	if (protocol == htons(ETH_P_IP)) {
1163 		if (hdr.ipv4->protocol != IPPROTO_TCP)
1164 			return;
1165 
1166 		/* access ihl as a u8 to avoid unaligned access on ia64 */
1167 		hlen = (hdr.network[0] & 0x0F) << 2;
1168 	} else if (protocol == htons(ETH_P_IPV6)) {
1169 		if (hdr.ipv6->nexthdr != IPPROTO_TCP)
1170 			return;
1171 
1172 		hlen = sizeof(struct ipv6hdr);
1173 	} else {
1174 		return;
1175 	}
1176 
1177 	th = (struct tcphdr *)(hdr.network + hlen);
1178 
1179 	/* sample on all syn/fin packets or once every atr sample rate */
1180 	if (!th->fin && !th->syn && (tx_ring->atr_count < tx_ring->atr_sample_rate))
1181 		return;
1182 
1183 	tx_ring->atr_count = 0;
1184 
1185 	/* grab the next descriptor */
1186 	fdir_desc = I40E_TX_FDIRDESC(tx_ring, tx_ring->next_to_use);
1187 	tx_ring->next_to_use++;
1188 	if (tx_ring->next_to_use == tx_ring->count)
1189 		tx_ring->next_to_use = 0;
1190 
1191 	flex_ptype = (tx_ring->queue_index << I40E_TXD_FLTR_QW0_QINDEX_SHIFT) &
1192 		      I40E_TXD_FLTR_QW0_QINDEX_MASK;
1193 	flex_ptype |= (protocol == htons(ETH_P_IP)) ?
1194 		      (I40E_FILTER_PCTYPE_NONF_IPV4_TCP <<
1195 		       I40E_TXD_FLTR_QW0_PCTYPE_SHIFT) :
1196 		      (I40E_FILTER_PCTYPE_NONF_IPV6_TCP <<
1197 		       I40E_TXD_FLTR_QW0_PCTYPE_SHIFT);
1198 
1199 	flex_ptype |= tx_ring->vsi->id << I40E_TXD_FLTR_QW0_DEST_VSI_SHIFT;
1200 
1201 	dtype_cmd = I40E_TX_DESC_DTYPE_FILTER_PROG;
1202 
1203 	dtype_cmd |= th->fin ?
1204 		     (I40E_FILTER_PROGRAM_DESC_PCMD_REMOVE <<
1205 		      I40E_TXD_FLTR_QW1_PCMD_SHIFT) :
1206 		     (I40E_FILTER_PROGRAM_DESC_PCMD_ADD_UPDATE <<
1207 		      I40E_TXD_FLTR_QW1_PCMD_SHIFT);
1208 
1209 	dtype_cmd |= I40E_FILTER_PROGRAM_DESC_DEST_DIRECT_PACKET_QINDEX <<
1210 		     I40E_TXD_FLTR_QW1_DEST_SHIFT;
1211 
1212 	dtype_cmd |= I40E_FILTER_PROGRAM_DESC_FD_STATUS_FD_ID <<
1213 		     I40E_TXD_FLTR_QW1_FD_STATUS_SHIFT;
1214 
1215 	fdir_desc->qindex_flex_ptype_vsi = cpu_to_le32(flex_ptype);
1216 	fdir_desc->dtype_cmd_cntindex = cpu_to_le32(dtype_cmd);
1217 }
1218 
1219 #define I40E_TXD_CMD (I40E_TX_DESC_CMD_EOP | I40E_TX_DESC_CMD_RS)
1220 /**
1221  * i40e_tx_prepare_vlan_flags - prepare generic TX VLAN tagging flags for HW
1222  * @skb:     send buffer
1223  * @tx_ring: ring to send buffer on
1224  * @flags:   the tx flags to be set
1225  *
1226  * Checks the skb and set up correspondingly several generic transmit flags
1227  * related to VLAN tagging for the HW, such as VLAN, DCB, etc.
1228  *
1229  * Returns error code indicate the frame should be dropped upon error and the
1230  * otherwise  returns 0 to indicate the flags has been set properly.
1231  **/
1232 static int i40e_tx_prepare_vlan_flags(struct sk_buff *skb,
1233 				      struct i40e_ring *tx_ring,
1234 				      u32 *flags)
1235 {
1236 	__be16 protocol = skb->protocol;
1237 	u32  tx_flags = 0;
1238 
1239 	/* if we have a HW VLAN tag being added, default to the HW one */
1240 	if (vlan_tx_tag_present(skb)) {
1241 		tx_flags |= vlan_tx_tag_get(skb) << I40E_TX_FLAGS_VLAN_SHIFT;
1242 		tx_flags |= I40E_TX_FLAGS_HW_VLAN;
1243 	/* else if it is a SW VLAN, check the next protocol and store the tag */
1244 	} else if (protocol == __constant_htons(ETH_P_8021Q)) {
1245 		struct vlan_hdr *vhdr, _vhdr;
1246 		vhdr = skb_header_pointer(skb, ETH_HLEN, sizeof(_vhdr), &_vhdr);
1247 		if (!vhdr)
1248 			return -EINVAL;
1249 
1250 		protocol = vhdr->h_vlan_encapsulated_proto;
1251 		tx_flags |= ntohs(vhdr->h_vlan_TCI) << I40E_TX_FLAGS_VLAN_SHIFT;
1252 		tx_flags |= I40E_TX_FLAGS_SW_VLAN;
1253 	}
1254 
1255 	/* Insert 802.1p priority into VLAN header */
1256 	if ((tx_ring->vsi->back->flags & I40E_FLAG_DCB_ENABLED) &&
1257 	    ((tx_flags & (I40E_TX_FLAGS_HW_VLAN | I40E_TX_FLAGS_SW_VLAN)) ||
1258 	     (skb->priority != TC_PRIO_CONTROL))) {
1259 		tx_flags &= ~I40E_TX_FLAGS_VLAN_PRIO_MASK;
1260 		tx_flags |= (skb->priority & 0x7) <<
1261 				I40E_TX_FLAGS_VLAN_PRIO_SHIFT;
1262 		if (tx_flags & I40E_TX_FLAGS_SW_VLAN) {
1263 			struct vlan_ethhdr *vhdr;
1264 			if (skb_header_cloned(skb) &&
1265 			    pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
1266 				return -ENOMEM;
1267 			vhdr = (struct vlan_ethhdr *)skb->data;
1268 			vhdr->h_vlan_TCI = htons(tx_flags >>
1269 						 I40E_TX_FLAGS_VLAN_SHIFT);
1270 		} else {
1271 			tx_flags |= I40E_TX_FLAGS_HW_VLAN;
1272 		}
1273 	}
1274 	*flags = tx_flags;
1275 	return 0;
1276 }
1277 
1278 /**
1279  * i40e_tx_csum - is checksum offload requested
1280  * @tx_ring:  ptr to the ring to send
1281  * @skb:      ptr to the skb we're sending
1282  * @tx_flags: the collected send information
1283  * @protocol: the send protocol
1284  *
1285  * Returns true if checksum offload is requested
1286  **/
1287 static bool i40e_tx_csum(struct i40e_ring *tx_ring, struct sk_buff *skb,
1288 			 u32 tx_flags, __be16 protocol)
1289 {
1290 	if ((skb->ip_summed != CHECKSUM_PARTIAL) &&
1291 	    !(tx_flags & I40E_TX_FLAGS_TXSW)) {
1292 		if (!(tx_flags & I40E_TX_FLAGS_HW_VLAN))
1293 			return false;
1294 	}
1295 
1296 	return skb->ip_summed == CHECKSUM_PARTIAL;
1297 }
1298 
1299 /**
1300  * i40e_tso - set up the tso context descriptor
1301  * @tx_ring:  ptr to the ring to send
1302  * @skb:      ptr to the skb we're sending
1303  * @tx_flags: the collected send information
1304  * @protocol: the send protocol
1305  * @hdr_len:  ptr to the size of the packet header
1306  * @cd_tunneling: ptr to context descriptor bits
1307  *
1308  * Returns 0 if no TSO can happen, 1 if tso is going, or error
1309  **/
1310 static int i40e_tso(struct i40e_ring *tx_ring, struct sk_buff *skb,
1311 		    u32 tx_flags, __be16 protocol, u8 *hdr_len,
1312 		    u64 *cd_type_cmd_tso_mss, u32 *cd_tunneling)
1313 {
1314 	u32 cd_cmd, cd_tso_len, cd_mss;
1315 	struct tcphdr *tcph;
1316 	struct iphdr *iph;
1317 	u32 l4len;
1318 	int err;
1319 	struct ipv6hdr *ipv6h;
1320 
1321 	if (!skb_is_gso(skb))
1322 		return 0;
1323 
1324 	if (skb_header_cloned(skb)) {
1325 		err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
1326 		if (err)
1327 			return err;
1328 	}
1329 
1330 	if (protocol == __constant_htons(ETH_P_IP)) {
1331 		iph = skb->encapsulation ? inner_ip_hdr(skb) : ip_hdr(skb);
1332 		tcph = skb->encapsulation ? inner_tcp_hdr(skb) : tcp_hdr(skb);
1333 		iph->tot_len = 0;
1334 		iph->check = 0;
1335 		tcph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
1336 						 0, IPPROTO_TCP, 0);
1337 	} else if (skb_is_gso_v6(skb)) {
1338 
1339 		ipv6h = skb->encapsulation ? inner_ipv6_hdr(skb)
1340 					   : ipv6_hdr(skb);
1341 		tcph = skb->encapsulation ? inner_tcp_hdr(skb) : tcp_hdr(skb);
1342 		ipv6h->payload_len = 0;
1343 		tcph->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,
1344 					       0, IPPROTO_TCP, 0);
1345 	}
1346 
1347 	l4len = skb->encapsulation ? inner_tcp_hdrlen(skb) : tcp_hdrlen(skb);
1348 	*hdr_len = (skb->encapsulation
1349 		    ? (skb_inner_transport_header(skb) - skb->data)
1350 		    : skb_transport_offset(skb)) + l4len;
1351 
1352 	/* find the field values */
1353 	cd_cmd = I40E_TX_CTX_DESC_TSO;
1354 	cd_tso_len = skb->len - *hdr_len;
1355 	cd_mss = skb_shinfo(skb)->gso_size;
1356 	*cd_type_cmd_tso_mss |= ((u64)cd_cmd << I40E_TXD_CTX_QW1_CMD_SHIFT)
1357 			     | ((u64)cd_tso_len
1358 				<< I40E_TXD_CTX_QW1_TSO_LEN_SHIFT)
1359 			     | ((u64)cd_mss << I40E_TXD_CTX_QW1_MSS_SHIFT);
1360 	return 1;
1361 }
1362 
1363 /**
1364  * i40e_tx_enable_csum - Enable Tx checksum offloads
1365  * @skb: send buffer
1366  * @tx_flags: Tx flags currently set
1367  * @td_cmd: Tx descriptor command bits to set
1368  * @td_offset: Tx descriptor header offsets to set
1369  * @cd_tunneling: ptr to context desc bits
1370  **/
1371 static void i40e_tx_enable_csum(struct sk_buff *skb, u32 tx_flags,
1372 				u32 *td_cmd, u32 *td_offset,
1373 				struct i40e_ring *tx_ring,
1374 				u32 *cd_tunneling)
1375 {
1376 	struct ipv6hdr *this_ipv6_hdr;
1377 	unsigned int this_tcp_hdrlen;
1378 	struct iphdr *this_ip_hdr;
1379 	u32 network_hdr_len;
1380 	u8 l4_hdr = 0;
1381 
1382 	if (skb->encapsulation) {
1383 		network_hdr_len = skb_inner_network_header_len(skb);
1384 		this_ip_hdr = inner_ip_hdr(skb);
1385 		this_ipv6_hdr = inner_ipv6_hdr(skb);
1386 		this_tcp_hdrlen = inner_tcp_hdrlen(skb);
1387 
1388 		if (tx_flags & I40E_TX_FLAGS_IPV4) {
1389 
1390 			if (tx_flags & I40E_TX_FLAGS_TSO) {
1391 				*cd_tunneling |= I40E_TX_CTX_EXT_IP_IPV4;
1392 				ip_hdr(skb)->check = 0;
1393 			} else {
1394 				*cd_tunneling |=
1395 					 I40E_TX_CTX_EXT_IP_IPV4_NO_CSUM;
1396 			}
1397 		} else if (tx_flags & I40E_TX_FLAGS_IPV6) {
1398 			if (tx_flags & I40E_TX_FLAGS_TSO) {
1399 				*cd_tunneling |= I40E_TX_CTX_EXT_IP_IPV6;
1400 				ip_hdr(skb)->check = 0;
1401 			} else {
1402 				*cd_tunneling |=
1403 					 I40E_TX_CTX_EXT_IP_IPV4_NO_CSUM;
1404 			}
1405 		}
1406 
1407 		/* Now set the ctx descriptor fields */
1408 		*cd_tunneling |= (skb_network_header_len(skb) >> 2) <<
1409 					I40E_TXD_CTX_QW0_EXT_IPLEN_SHIFT |
1410 				   I40E_TXD_CTX_UDP_TUNNELING            |
1411 				   ((skb_inner_network_offset(skb) -
1412 					skb_transport_offset(skb)) >> 1) <<
1413 				   I40E_TXD_CTX_QW0_NATLEN_SHIFT;
1414 
1415 	} else {
1416 		network_hdr_len = skb_network_header_len(skb);
1417 		this_ip_hdr = ip_hdr(skb);
1418 		this_ipv6_hdr = ipv6_hdr(skb);
1419 		this_tcp_hdrlen = tcp_hdrlen(skb);
1420 	}
1421 
1422 	/* Enable IP checksum offloads */
1423 	if (tx_flags & I40E_TX_FLAGS_IPV4) {
1424 		l4_hdr = this_ip_hdr->protocol;
1425 		/* the stack computes the IP header already, the only time we
1426 		 * need the hardware to recompute it is in the case of TSO.
1427 		 */
1428 		if (tx_flags & I40E_TX_FLAGS_TSO) {
1429 			*td_cmd |= I40E_TX_DESC_CMD_IIPT_IPV4_CSUM;
1430 			this_ip_hdr->check = 0;
1431 		} else {
1432 			*td_cmd |= I40E_TX_DESC_CMD_IIPT_IPV4;
1433 		}
1434 		/* Now set the td_offset for IP header length */
1435 		*td_offset = (network_hdr_len >> 2) <<
1436 			      I40E_TX_DESC_LENGTH_IPLEN_SHIFT;
1437 	} else if (tx_flags & I40E_TX_FLAGS_IPV6) {
1438 		l4_hdr = this_ipv6_hdr->nexthdr;
1439 		*td_cmd |= I40E_TX_DESC_CMD_IIPT_IPV6;
1440 		/* Now set the td_offset for IP header length */
1441 		*td_offset = (network_hdr_len >> 2) <<
1442 			      I40E_TX_DESC_LENGTH_IPLEN_SHIFT;
1443 	}
1444 	/* words in MACLEN + dwords in IPLEN + dwords in L4Len */
1445 	*td_offset |= (skb_network_offset(skb) >> 1) <<
1446 		       I40E_TX_DESC_LENGTH_MACLEN_SHIFT;
1447 
1448 	/* Enable L4 checksum offloads */
1449 	switch (l4_hdr) {
1450 	case IPPROTO_TCP:
1451 		/* enable checksum offloads */
1452 		*td_cmd |= I40E_TX_DESC_CMD_L4T_EOFT_TCP;
1453 		*td_offset |= (this_tcp_hdrlen >> 2) <<
1454 			       I40E_TX_DESC_LENGTH_L4_FC_LEN_SHIFT;
1455 		break;
1456 	case IPPROTO_SCTP:
1457 		/* enable SCTP checksum offload */
1458 		*td_cmd |= I40E_TX_DESC_CMD_L4T_EOFT_SCTP;
1459 		*td_offset |= (sizeof(struct sctphdr) >> 2) <<
1460 			       I40E_TX_DESC_LENGTH_L4_FC_LEN_SHIFT;
1461 		break;
1462 	case IPPROTO_UDP:
1463 		/* enable UDP checksum offload */
1464 		*td_cmd |= I40E_TX_DESC_CMD_L4T_EOFT_UDP;
1465 		*td_offset |= (sizeof(struct udphdr) >> 2) <<
1466 			       I40E_TX_DESC_LENGTH_L4_FC_LEN_SHIFT;
1467 		break;
1468 	default:
1469 		break;
1470 	}
1471 }
1472 
1473 /**
1474  * i40e_create_tx_ctx Build the Tx context descriptor
1475  * @tx_ring:  ring to create the descriptor on
1476  * @cd_type_cmd_tso_mss: Quad Word 1
1477  * @cd_tunneling: Quad Word 0 - bits 0-31
1478  * @cd_l2tag2: Quad Word 0 - bits 32-63
1479  **/
1480 static void i40e_create_tx_ctx(struct i40e_ring *tx_ring,
1481 			       const u64 cd_type_cmd_tso_mss,
1482 			       const u32 cd_tunneling, const u32 cd_l2tag2)
1483 {
1484 	struct i40e_tx_context_desc *context_desc;
1485 
1486 	if (!cd_type_cmd_tso_mss && !cd_tunneling && !cd_l2tag2)
1487 		return;
1488 
1489 	/* grab the next descriptor */
1490 	context_desc = I40E_TX_CTXTDESC(tx_ring, tx_ring->next_to_use);
1491 	tx_ring->next_to_use++;
1492 	if (tx_ring->next_to_use == tx_ring->count)
1493 		tx_ring->next_to_use = 0;
1494 
1495 	/* cpu_to_le32 and assign to struct fields */
1496 	context_desc->tunneling_params = cpu_to_le32(cd_tunneling);
1497 	context_desc->l2tag2 = cpu_to_le16(cd_l2tag2);
1498 	context_desc->type_cmd_tso_mss = cpu_to_le64(cd_type_cmd_tso_mss);
1499 }
1500 
1501 /**
1502  * i40e_tx_map - Build the Tx descriptor
1503  * @tx_ring:  ring to send buffer on
1504  * @skb:      send buffer
1505  * @first:    first buffer info buffer to use
1506  * @tx_flags: collected send information
1507  * @hdr_len:  size of the packet header
1508  * @td_cmd:   the command field in the descriptor
1509  * @td_offset: offset for checksum or crc
1510  **/
1511 static void i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb,
1512 			struct i40e_tx_buffer *first, u32 tx_flags,
1513 			const u8 hdr_len, u32 td_cmd, u32 td_offset)
1514 {
1515 	struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[0];
1516 	unsigned int data_len = skb->data_len;
1517 	unsigned int size = skb_headlen(skb);
1518 	struct device *dev = tx_ring->dev;
1519 	u32 paylen = skb->len - hdr_len;
1520 	u16 i = tx_ring->next_to_use;
1521 	struct i40e_tx_buffer *tx_bi;
1522 	struct i40e_tx_desc *tx_desc;
1523 	u32 buf_offset = 0;
1524 	u32 td_tag = 0;
1525 	dma_addr_t dma;
1526 	u16 gso_segs;
1527 
1528 	dma = dma_map_single(dev, skb->data, size, DMA_TO_DEVICE);
1529 	if (dma_mapping_error(dev, dma))
1530 		goto dma_error;
1531 
1532 	if (tx_flags & I40E_TX_FLAGS_HW_VLAN) {
1533 		td_cmd |= I40E_TX_DESC_CMD_IL2TAG1;
1534 		td_tag = (tx_flags & I40E_TX_FLAGS_VLAN_MASK) >>
1535 			 I40E_TX_FLAGS_VLAN_SHIFT;
1536 	}
1537 
1538 	tx_desc = I40E_TX_DESC(tx_ring, i);
1539 	for (;;) {
1540 		while (size > I40E_MAX_DATA_PER_TXD) {
1541 			tx_desc->buffer_addr = cpu_to_le64(dma + buf_offset);
1542 			tx_desc->cmd_type_offset_bsz =
1543 				build_ctob(td_cmd, td_offset,
1544 					   I40E_MAX_DATA_PER_TXD, td_tag);
1545 
1546 			buf_offset += I40E_MAX_DATA_PER_TXD;
1547 			size -= I40E_MAX_DATA_PER_TXD;
1548 
1549 			tx_desc++;
1550 			i++;
1551 			if (i == tx_ring->count) {
1552 				tx_desc = I40E_TX_DESC(tx_ring, 0);
1553 				i = 0;
1554 			}
1555 		}
1556 
1557 		tx_bi = &tx_ring->tx_bi[i];
1558 		tx_bi->length = buf_offset + size;
1559 		tx_bi->tx_flags = tx_flags;
1560 		tx_bi->dma = dma;
1561 
1562 		tx_desc->buffer_addr = cpu_to_le64(dma + buf_offset);
1563 		tx_desc->cmd_type_offset_bsz = build_ctob(td_cmd, td_offset,
1564 							  size, td_tag);
1565 
1566 		if (likely(!data_len))
1567 			break;
1568 
1569 		size = skb_frag_size(frag);
1570 		data_len -= size;
1571 		buf_offset = 0;
1572 		tx_flags |= I40E_TX_FLAGS_MAPPED_AS_PAGE;
1573 
1574 		dma = skb_frag_dma_map(dev, frag, 0, size, DMA_TO_DEVICE);
1575 		if (dma_mapping_error(dev, dma))
1576 			goto dma_error;
1577 
1578 		tx_desc++;
1579 		i++;
1580 		if (i == tx_ring->count) {
1581 			tx_desc = I40E_TX_DESC(tx_ring, 0);
1582 			i = 0;
1583 		}
1584 
1585 		frag++;
1586 	}
1587 
1588 	tx_desc->cmd_type_offset_bsz |=
1589 		       cpu_to_le64((u64)I40E_TXD_CMD << I40E_TXD_QW1_CMD_SHIFT);
1590 
1591 	i++;
1592 	if (i == tx_ring->count)
1593 		i = 0;
1594 
1595 	tx_ring->next_to_use = i;
1596 
1597 	if (tx_flags & (I40E_TX_FLAGS_TSO | I40E_TX_FLAGS_FSO))
1598 		gso_segs = skb_shinfo(skb)->gso_segs;
1599 	else
1600 		gso_segs = 1;
1601 
1602 	/* multiply data chunks by size of headers */
1603 	tx_bi->bytecount = paylen + (gso_segs * hdr_len);
1604 	tx_bi->gso_segs = gso_segs;
1605 	tx_bi->skb = skb;
1606 
1607 	/* set the timestamp and next to watch values */
1608 	first->time_stamp = jiffies;
1609 	first->next_to_watch = tx_desc;
1610 
1611 	/* Force memory writes to complete before letting h/w
1612 	 * know there are new descriptors to fetch.  (Only
1613 	 * applicable for weak-ordered memory model archs,
1614 	 * such as IA-64).
1615 	 */
1616 	wmb();
1617 
1618 	writel(i, tx_ring->tail);
1619 	return;
1620 
1621 dma_error:
1622 	dev_info(dev, "TX DMA map failed\n");
1623 
1624 	/* clear dma mappings for failed tx_bi map */
1625 	for (;;) {
1626 		tx_bi = &tx_ring->tx_bi[i];
1627 		i40e_unmap_tx_resource(tx_ring, tx_bi);
1628 		if (tx_bi == first)
1629 			break;
1630 		if (i == 0)
1631 			i = tx_ring->count;
1632 		i--;
1633 	}
1634 
1635 	dev_kfree_skb_any(skb);
1636 
1637 	tx_ring->next_to_use = i;
1638 }
1639 
1640 /**
1641  * __i40e_maybe_stop_tx - 2nd level check for tx stop conditions
1642  * @tx_ring: the ring to be checked
1643  * @size:    the size buffer we want to assure is available
1644  *
1645  * Returns -EBUSY if a stop is needed, else 0
1646  **/
1647 static inline int __i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size)
1648 {
1649 	netif_stop_subqueue(tx_ring->netdev, tx_ring->queue_index);
1650 	smp_mb();
1651 
1652 	/* Check again in a case another CPU has just made room available. */
1653 	if (likely(I40E_DESC_UNUSED(tx_ring) < size))
1654 		return -EBUSY;
1655 
1656 	/* A reprieve! - use start_queue because it doesn't call schedule */
1657 	netif_start_subqueue(tx_ring->netdev, tx_ring->queue_index);
1658 	++tx_ring->tx_stats.restart_queue;
1659 	return 0;
1660 }
1661 
1662 /**
1663  * i40e_maybe_stop_tx - 1st level check for tx stop conditions
1664  * @tx_ring: the ring to be checked
1665  * @size:    the size buffer we want to assure is available
1666  *
1667  * Returns 0 if stop is not needed
1668  **/
1669 static int i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size)
1670 {
1671 	if (likely(I40E_DESC_UNUSED(tx_ring) >= size))
1672 		return 0;
1673 	return __i40e_maybe_stop_tx(tx_ring, size);
1674 }
1675 
1676 /**
1677  * i40e_xmit_descriptor_count - calculate number of tx descriptors needed
1678  * @skb:     send buffer
1679  * @tx_ring: ring to send buffer on
1680  *
1681  * Returns number of data descriptors needed for this skb. Returns 0 to indicate
1682  * there is not enough descriptors available in this ring since we need at least
1683  * one descriptor.
1684  **/
1685 static int i40e_xmit_descriptor_count(struct sk_buff *skb,
1686 				      struct i40e_ring *tx_ring)
1687 {
1688 #if PAGE_SIZE > I40E_MAX_DATA_PER_TXD
1689 	unsigned int f;
1690 #endif
1691 	int count = 0;
1692 
1693 	/* need: 1 descriptor per page * PAGE_SIZE/I40E_MAX_DATA_PER_TXD,
1694 	 *       + 1 desc for skb_head_len/I40E_MAX_DATA_PER_TXD,
1695 	 *       + 2 desc gap to keep tail from touching head,
1696 	 *       + 1 desc for context descriptor,
1697 	 * otherwise try next time
1698 	 */
1699 #if PAGE_SIZE > I40E_MAX_DATA_PER_TXD
1700 	for (f = 0; f < skb_shinfo(skb)->nr_frags; f++)
1701 		count += TXD_USE_COUNT(skb_shinfo(skb)->frags[f].size);
1702 #else
1703 	count += skb_shinfo(skb)->nr_frags;
1704 #endif
1705 	count += TXD_USE_COUNT(skb_headlen(skb));
1706 	if (i40e_maybe_stop_tx(tx_ring, count + 3)) {
1707 		tx_ring->tx_stats.tx_busy++;
1708 		return 0;
1709 	}
1710 	return count;
1711 }
1712 
1713 /**
1714  * i40e_xmit_frame_ring - Sends buffer on Tx ring
1715  * @skb:     send buffer
1716  * @tx_ring: ring to send buffer on
1717  *
1718  * Returns NETDEV_TX_OK if sent, else an error code
1719  **/
1720 static netdev_tx_t i40e_xmit_frame_ring(struct sk_buff *skb,
1721 					struct i40e_ring *tx_ring)
1722 {
1723 	u64 cd_type_cmd_tso_mss = I40E_TX_DESC_DTYPE_CONTEXT;
1724 	u32 cd_tunneling = 0, cd_l2tag2 = 0;
1725 	struct i40e_tx_buffer *first;
1726 	u32 td_offset = 0;
1727 	u32 tx_flags = 0;
1728 	__be16 protocol;
1729 	u32 td_cmd = 0;
1730 	u8 hdr_len = 0;
1731 	int tso;
1732 	if (0 == i40e_xmit_descriptor_count(skb, tx_ring))
1733 		return NETDEV_TX_BUSY;
1734 
1735 	/* prepare the xmit flags */
1736 	if (i40e_tx_prepare_vlan_flags(skb, tx_ring, &tx_flags))
1737 		goto out_drop;
1738 
1739 	/* obtain protocol of skb */
1740 	protocol = skb->protocol;
1741 
1742 	/* record the location of the first descriptor for this packet */
1743 	first = &tx_ring->tx_bi[tx_ring->next_to_use];
1744 
1745 	/* setup IPv4/IPv6 offloads */
1746 	if (protocol == __constant_htons(ETH_P_IP))
1747 		tx_flags |= I40E_TX_FLAGS_IPV4;
1748 	else if (protocol == __constant_htons(ETH_P_IPV6))
1749 		tx_flags |= I40E_TX_FLAGS_IPV6;
1750 
1751 	tso = i40e_tso(tx_ring, skb, tx_flags, protocol, &hdr_len,
1752 		       &cd_type_cmd_tso_mss, &cd_tunneling);
1753 
1754 	if (tso < 0)
1755 		goto out_drop;
1756 	else if (tso)
1757 		tx_flags |= I40E_TX_FLAGS_TSO;
1758 
1759 	skb_tx_timestamp(skb);
1760 
1761 	/* Always offload the checksum, since it's in the data descriptor */
1762 	if (i40e_tx_csum(tx_ring, skb, tx_flags, protocol))
1763 		tx_flags |= I40E_TX_FLAGS_CSUM;
1764 
1765 	/* always enable offload insertion */
1766 	td_cmd |= I40E_TX_DESC_CMD_ICRC;
1767 
1768 	if (tx_flags & I40E_TX_FLAGS_CSUM)
1769 		i40e_tx_enable_csum(skb, tx_flags, &td_cmd, &td_offset,
1770 				    tx_ring, &cd_tunneling);
1771 
1772 	i40e_create_tx_ctx(tx_ring, cd_type_cmd_tso_mss,
1773 			   cd_tunneling, cd_l2tag2);
1774 
1775 	/* Add Flow Director ATR if it's enabled.
1776 	 *
1777 	 * NOTE: this must always be directly before the data descriptor.
1778 	 */
1779 	i40e_atr(tx_ring, skb, tx_flags, protocol);
1780 
1781 	i40e_tx_map(tx_ring, skb, first, tx_flags, hdr_len,
1782 		    td_cmd, td_offset);
1783 
1784 	i40e_maybe_stop_tx(tx_ring, DESC_NEEDED);
1785 
1786 	return NETDEV_TX_OK;
1787 
1788 out_drop:
1789 	dev_kfree_skb_any(skb);
1790 	return NETDEV_TX_OK;
1791 }
1792 
1793 /**
1794  * i40e_lan_xmit_frame - Selects the correct VSI and Tx queue to send buffer
1795  * @skb:    send buffer
1796  * @netdev: network interface device structure
1797  *
1798  * Returns NETDEV_TX_OK if sent, else an error code
1799  **/
1800 netdev_tx_t i40e_lan_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
1801 {
1802 	struct i40e_netdev_priv *np = netdev_priv(netdev);
1803 	struct i40e_vsi *vsi = np->vsi;
1804 	struct i40e_ring *tx_ring = &vsi->tx_rings[skb->queue_mapping];
1805 
1806 	/* hardware can't handle really short frames, hardware padding works
1807 	 * beyond this point
1808 	 */
1809 	if (unlikely(skb->len < I40E_MIN_TX_LEN)) {
1810 		if (skb_pad(skb, I40E_MIN_TX_LEN - skb->len))
1811 			return NETDEV_TX_OK;
1812 		skb->len = I40E_MIN_TX_LEN;
1813 		skb_set_tail_pointer(skb, I40E_MIN_TX_LEN);
1814 	}
1815 
1816 	return i40e_xmit_frame_ring(skb, tx_ring);
1817 }
1818