1 /*******************************************************************************
2 
3   Intel 10 Gigabit PCI Express Linux driver
4   Copyright(c) 1999 - 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 "ixgbe.h"
29 #include "ixgbe_sriov.h"
30 
31 #ifdef CONFIG_IXGBE_DCB
32 /**
33  * ixgbe_cache_ring_dcb_sriov - Descriptor ring to register mapping for SR-IOV
34  * @adapter: board private structure to initialize
35  *
36  * Cache the descriptor ring offsets for SR-IOV to the assigned rings.  It
37  * will also try to cache the proper offsets if RSS/FCoE are enabled along
38  * with VMDq.
39  *
40  **/
41 static bool ixgbe_cache_ring_dcb_sriov(struct ixgbe_adapter *adapter)
42 {
43 #ifdef IXGBE_FCOE
44 	struct ixgbe_ring_feature *fcoe = &adapter->ring_feature[RING_F_FCOE];
45 #endif /* IXGBE_FCOE */
46 	struct ixgbe_ring_feature *vmdq = &adapter->ring_feature[RING_F_VMDQ];
47 	int i;
48 	u16 reg_idx;
49 	u8 tcs = netdev_get_num_tc(adapter->netdev);
50 
51 	/* verify we have DCB queueing enabled before proceeding */
52 	if (tcs <= 1)
53 		return false;
54 
55 	/* verify we have VMDq enabled before proceeding */
56 	if (!(adapter->flags & IXGBE_FLAG_SRIOV_ENABLED))
57 		return false;
58 
59 	/* start at VMDq register offset for SR-IOV enabled setups */
60 	reg_idx = vmdq->offset * __ALIGN_MASK(1, ~vmdq->mask);
61 	for (i = 0; i < adapter->num_rx_queues; i++, reg_idx++) {
62 		/* If we are greater than indices move to next pool */
63 		if ((reg_idx & ~vmdq->mask) >= tcs)
64 			reg_idx = __ALIGN_MASK(reg_idx, ~vmdq->mask);
65 		adapter->rx_ring[i]->reg_idx = reg_idx;
66 	}
67 
68 	reg_idx = vmdq->offset * __ALIGN_MASK(1, ~vmdq->mask);
69 	for (i = 0; i < adapter->num_tx_queues; i++, reg_idx++) {
70 		/* If we are greater than indices move to next pool */
71 		if ((reg_idx & ~vmdq->mask) >= tcs)
72 			reg_idx = __ALIGN_MASK(reg_idx, ~vmdq->mask);
73 		adapter->tx_ring[i]->reg_idx = reg_idx;
74 	}
75 
76 #ifdef IXGBE_FCOE
77 	/* nothing to do if FCoE is disabled */
78 	if (!(adapter->flags & IXGBE_FLAG_FCOE_ENABLED))
79 		return true;
80 
81 	/* The work is already done if the FCoE ring is shared */
82 	if (fcoe->offset < tcs)
83 		return true;
84 
85 	/* The FCoE rings exist separately, we need to move their reg_idx */
86 	if (fcoe->indices) {
87 		u16 queues_per_pool = __ALIGN_MASK(1, ~vmdq->mask);
88 		u8 fcoe_tc = ixgbe_fcoe_get_tc(adapter);
89 
90 		reg_idx = (vmdq->offset + vmdq->indices) * queues_per_pool;
91 		for (i = fcoe->offset; i < adapter->num_rx_queues; i++) {
92 			reg_idx = __ALIGN_MASK(reg_idx, ~vmdq->mask) + fcoe_tc;
93 			adapter->rx_ring[i]->reg_idx = reg_idx;
94 			reg_idx++;
95 		}
96 
97 		reg_idx = (vmdq->offset + vmdq->indices) * queues_per_pool;
98 		for (i = fcoe->offset; i < adapter->num_tx_queues; i++) {
99 			reg_idx = __ALIGN_MASK(reg_idx, ~vmdq->mask) + fcoe_tc;
100 			adapter->tx_ring[i]->reg_idx = reg_idx;
101 			reg_idx++;
102 		}
103 	}
104 
105 #endif /* IXGBE_FCOE */
106 	return true;
107 }
108 
109 /* ixgbe_get_first_reg_idx - Return first register index associated with ring */
110 static void ixgbe_get_first_reg_idx(struct ixgbe_adapter *adapter, u8 tc,
111 				    unsigned int *tx, unsigned int *rx)
112 {
113 	struct net_device *dev = adapter->netdev;
114 	struct ixgbe_hw *hw = &adapter->hw;
115 	u8 num_tcs = netdev_get_num_tc(dev);
116 
117 	*tx = 0;
118 	*rx = 0;
119 
120 	switch (hw->mac.type) {
121 	case ixgbe_mac_82598EB:
122 		/* TxQs/TC: 4	RxQs/TC: 8 */
123 		*tx = tc << 2; /* 0, 4,  8, 12, 16, 20, 24, 28 */
124 		*rx = tc << 3; /* 0, 8, 16, 24, 32, 40, 48, 56 */
125 		break;
126 	case ixgbe_mac_82599EB:
127 	case ixgbe_mac_X540:
128 		if (num_tcs > 4) {
129 			/*
130 			 * TCs    : TC0/1 TC2/3 TC4-7
131 			 * TxQs/TC:    32    16     8
132 			 * RxQs/TC:    16    16    16
133 			 */
134 			*rx = tc << 4;
135 			if (tc < 3)
136 				*tx = tc << 5;		/*   0,  32,  64 */
137 			else if (tc < 5)
138 				*tx = (tc + 2) << 4;	/*  80,  96 */
139 			else
140 				*tx = (tc + 8) << 3;	/* 104, 112, 120 */
141 		} else {
142 			/*
143 			 * TCs    : TC0 TC1 TC2/3
144 			 * TxQs/TC:  64  32    16
145 			 * RxQs/TC:  32  32    32
146 			 */
147 			*rx = tc << 5;
148 			if (tc < 2)
149 				*tx = tc << 6;		/*  0,  64 */
150 			else
151 				*tx = (tc + 4) << 4;	/* 96, 112 */
152 		}
153 	default:
154 		break;
155 	}
156 }
157 
158 /**
159  * ixgbe_cache_ring_dcb - Descriptor ring to register mapping for DCB
160  * @adapter: board private structure to initialize
161  *
162  * Cache the descriptor ring offsets for DCB to the assigned rings.
163  *
164  **/
165 static bool ixgbe_cache_ring_dcb(struct ixgbe_adapter *adapter)
166 {
167 	struct net_device *dev = adapter->netdev;
168 	unsigned int tx_idx, rx_idx;
169 	int tc, offset, rss_i, i;
170 	u8 num_tcs = netdev_get_num_tc(dev);
171 
172 	/* verify we have DCB queueing enabled before proceeding */
173 	if (num_tcs <= 1)
174 		return false;
175 
176 	rss_i = adapter->ring_feature[RING_F_RSS].indices;
177 
178 	for (tc = 0, offset = 0; tc < num_tcs; tc++, offset += rss_i) {
179 		ixgbe_get_first_reg_idx(adapter, tc, &tx_idx, &rx_idx);
180 		for (i = 0; i < rss_i; i++, tx_idx++, rx_idx++) {
181 			adapter->tx_ring[offset + i]->reg_idx = tx_idx;
182 			adapter->rx_ring[offset + i]->reg_idx = rx_idx;
183 			adapter->tx_ring[offset + i]->dcb_tc = tc;
184 			adapter->rx_ring[offset + i]->dcb_tc = tc;
185 		}
186 	}
187 
188 	return true;
189 }
190 
191 #endif
192 /**
193  * ixgbe_cache_ring_sriov - Descriptor ring to register mapping for sriov
194  * @adapter: board private structure to initialize
195  *
196  * SR-IOV doesn't use any descriptor rings but changes the default if
197  * no other mapping is used.
198  *
199  */
200 static bool ixgbe_cache_ring_sriov(struct ixgbe_adapter *adapter)
201 {
202 #ifdef IXGBE_FCOE
203 	struct ixgbe_ring_feature *fcoe = &adapter->ring_feature[RING_F_FCOE];
204 #endif /* IXGBE_FCOE */
205 	struct ixgbe_ring_feature *vmdq = &adapter->ring_feature[RING_F_VMDQ];
206 	struct ixgbe_ring_feature *rss = &adapter->ring_feature[RING_F_RSS];
207 	int i;
208 	u16 reg_idx;
209 
210 	/* only proceed if VMDq is enabled */
211 	if (!(adapter->flags & IXGBE_FLAG_VMDQ_ENABLED))
212 		return false;
213 
214 	/* start at VMDq register offset for SR-IOV enabled setups */
215 	reg_idx = vmdq->offset * __ALIGN_MASK(1, ~vmdq->mask);
216 	for (i = 0; i < adapter->num_rx_queues; i++, reg_idx++) {
217 #ifdef IXGBE_FCOE
218 		/* Allow first FCoE queue to be mapped as RSS */
219 		if (fcoe->offset && (i > fcoe->offset))
220 			break;
221 #endif
222 		/* If we are greater than indices move to next pool */
223 		if ((reg_idx & ~vmdq->mask) >= rss->indices)
224 			reg_idx = __ALIGN_MASK(reg_idx, ~vmdq->mask);
225 		adapter->rx_ring[i]->reg_idx = reg_idx;
226 	}
227 
228 #ifdef IXGBE_FCOE
229 	/* FCoE uses a linear block of queues so just assigning 1:1 */
230 	for (; i < adapter->num_rx_queues; i++, reg_idx++)
231 		adapter->rx_ring[i]->reg_idx = reg_idx;
232 
233 #endif
234 	reg_idx = vmdq->offset * __ALIGN_MASK(1, ~vmdq->mask);
235 	for (i = 0; i < adapter->num_tx_queues; i++, reg_idx++) {
236 #ifdef IXGBE_FCOE
237 		/* Allow first FCoE queue to be mapped as RSS */
238 		if (fcoe->offset && (i > fcoe->offset))
239 			break;
240 #endif
241 		/* If we are greater than indices move to next pool */
242 		if ((reg_idx & rss->mask) >= rss->indices)
243 			reg_idx = __ALIGN_MASK(reg_idx, ~vmdq->mask);
244 		adapter->tx_ring[i]->reg_idx = reg_idx;
245 	}
246 
247 #ifdef IXGBE_FCOE
248 	/* FCoE uses a linear block of queues so just assigning 1:1 */
249 	for (; i < adapter->num_tx_queues; i++, reg_idx++)
250 		adapter->tx_ring[i]->reg_idx = reg_idx;
251 
252 #endif
253 
254 	return true;
255 }
256 
257 /**
258  * ixgbe_cache_ring_rss - Descriptor ring to register mapping for RSS
259  * @adapter: board private structure to initialize
260  *
261  * Cache the descriptor ring offsets for RSS to the assigned rings.
262  *
263  **/
264 static bool ixgbe_cache_ring_rss(struct ixgbe_adapter *adapter)
265 {
266 	int i;
267 
268 	for (i = 0; i < adapter->num_rx_queues; i++)
269 		adapter->rx_ring[i]->reg_idx = i;
270 	for (i = 0; i < adapter->num_tx_queues; i++)
271 		adapter->tx_ring[i]->reg_idx = i;
272 
273 	return true;
274 }
275 
276 /**
277  * ixgbe_cache_ring_register - Descriptor ring to register mapping
278  * @adapter: board private structure to initialize
279  *
280  * Once we know the feature-set enabled for the device, we'll cache
281  * the register offset the descriptor ring is assigned to.
282  *
283  * Note, the order the various feature calls is important.  It must start with
284  * the "most" features enabled at the same time, then trickle down to the
285  * least amount of features turned on at once.
286  **/
287 static void ixgbe_cache_ring_register(struct ixgbe_adapter *adapter)
288 {
289 	/* start with default case */
290 	adapter->rx_ring[0]->reg_idx = 0;
291 	adapter->tx_ring[0]->reg_idx = 0;
292 
293 #ifdef CONFIG_IXGBE_DCB
294 	if (ixgbe_cache_ring_dcb_sriov(adapter))
295 		return;
296 
297 	if (ixgbe_cache_ring_dcb(adapter))
298 		return;
299 
300 #endif
301 	if (ixgbe_cache_ring_sriov(adapter))
302 		return;
303 
304 	ixgbe_cache_ring_rss(adapter);
305 }
306 
307 #define IXGBE_RSS_16Q_MASK	0xF
308 #define IXGBE_RSS_8Q_MASK	0x7
309 #define IXGBE_RSS_4Q_MASK	0x3
310 #define IXGBE_RSS_2Q_MASK	0x1
311 #define IXGBE_RSS_DISABLED_MASK	0x0
312 
313 #ifdef CONFIG_IXGBE_DCB
314 /**
315  * ixgbe_set_dcb_sriov_queues: Allocate queues for SR-IOV devices w/ DCB
316  * @adapter: board private structure to initialize
317  *
318  * When SR-IOV (Single Root IO Virtualiztion) is enabled, allocate queues
319  * and VM pools where appropriate.  Also assign queues based on DCB
320  * priorities and map accordingly..
321  *
322  **/
323 static bool ixgbe_set_dcb_sriov_queues(struct ixgbe_adapter *adapter)
324 {
325 	int i;
326 	u16 vmdq_i = adapter->ring_feature[RING_F_VMDQ].limit;
327 	u16 vmdq_m = 0;
328 #ifdef IXGBE_FCOE
329 	u16 fcoe_i = 0;
330 #endif
331 	u8 tcs = netdev_get_num_tc(adapter->netdev);
332 
333 	/* verify we have DCB queueing enabled before proceeding */
334 	if (tcs <= 1)
335 		return false;
336 
337 	/* verify we have VMDq enabled before proceeding */
338 	if (!(adapter->flags & IXGBE_FLAG_SRIOV_ENABLED))
339 		return false;
340 
341 	/* Add starting offset to total pool count */
342 	vmdq_i += adapter->ring_feature[RING_F_VMDQ].offset;
343 
344 	/* 16 pools w/ 8 TC per pool */
345 	if (tcs > 4) {
346 		vmdq_i = min_t(u16, vmdq_i, 16);
347 		vmdq_m = IXGBE_82599_VMDQ_8Q_MASK;
348 	/* 32 pools w/ 4 TC per pool */
349 	} else {
350 		vmdq_i = min_t(u16, vmdq_i, 32);
351 		vmdq_m = IXGBE_82599_VMDQ_4Q_MASK;
352 	}
353 
354 #ifdef IXGBE_FCOE
355 	/* queues in the remaining pools are available for FCoE */
356 	fcoe_i = (128 / __ALIGN_MASK(1, ~vmdq_m)) - vmdq_i;
357 
358 #endif
359 	/* remove the starting offset from the pool count */
360 	vmdq_i -= adapter->ring_feature[RING_F_VMDQ].offset;
361 
362 	/* save features for later use */
363 	adapter->ring_feature[RING_F_VMDQ].indices = vmdq_i;
364 	adapter->ring_feature[RING_F_VMDQ].mask = vmdq_m;
365 
366 	/*
367 	 * We do not support DCB, VMDq, and RSS all simultaneously
368 	 * so we will disable RSS since it is the lowest priority
369 	 */
370 	adapter->ring_feature[RING_F_RSS].indices = 1;
371 	adapter->ring_feature[RING_F_RSS].mask = IXGBE_RSS_DISABLED_MASK;
372 
373 	/* disable ATR as it is not supported when VMDq is enabled */
374 	adapter->flags &= ~IXGBE_FLAG_FDIR_HASH_CAPABLE;
375 
376 	adapter->num_rx_pools = vmdq_i;
377 	adapter->num_rx_queues_per_pool = tcs;
378 
379 	adapter->num_tx_queues = vmdq_i * tcs;
380 	adapter->num_rx_queues = vmdq_i * tcs;
381 
382 #ifdef IXGBE_FCOE
383 	if (adapter->flags & IXGBE_FLAG_FCOE_ENABLED) {
384 		struct ixgbe_ring_feature *fcoe;
385 
386 		fcoe = &adapter->ring_feature[RING_F_FCOE];
387 
388 		/* limit ourselves based on feature limits */
389 		fcoe_i = min_t(u16, fcoe_i, fcoe->limit);
390 
391 		if (fcoe_i) {
392 			/* alloc queues for FCoE separately */
393 			fcoe->indices = fcoe_i;
394 			fcoe->offset = vmdq_i * tcs;
395 
396 			/* add queues to adapter */
397 			adapter->num_tx_queues += fcoe_i;
398 			adapter->num_rx_queues += fcoe_i;
399 		} else if (tcs > 1) {
400 			/* use queue belonging to FcoE TC */
401 			fcoe->indices = 1;
402 			fcoe->offset = ixgbe_fcoe_get_tc(adapter);
403 		} else {
404 			adapter->flags &= ~IXGBE_FLAG_FCOE_ENABLED;
405 
406 			fcoe->indices = 0;
407 			fcoe->offset = 0;
408 		}
409 	}
410 
411 #endif /* IXGBE_FCOE */
412 	/* configure TC to queue mapping */
413 	for (i = 0; i < tcs; i++)
414 		netdev_set_tc_queue(adapter->netdev, i, 1, i);
415 
416 	return true;
417 }
418 
419 static bool ixgbe_set_dcb_queues(struct ixgbe_adapter *adapter)
420 {
421 	struct net_device *dev = adapter->netdev;
422 	struct ixgbe_ring_feature *f;
423 	int rss_i, rss_m, i;
424 	int tcs;
425 
426 	/* Map queue offset and counts onto allocated tx queues */
427 	tcs = netdev_get_num_tc(dev);
428 
429 	/* verify we have DCB queueing enabled before proceeding */
430 	if (tcs <= 1)
431 		return false;
432 
433 	/* determine the upper limit for our current DCB mode */
434 	rss_i = dev->num_tx_queues / tcs;
435 	if (adapter->hw.mac.type == ixgbe_mac_82598EB) {
436 		/* 8 TC w/ 4 queues per TC */
437 		rss_i = min_t(u16, rss_i, 4);
438 		rss_m = IXGBE_RSS_4Q_MASK;
439 	} else if (tcs > 4) {
440 		/* 8 TC w/ 8 queues per TC */
441 		rss_i = min_t(u16, rss_i, 8);
442 		rss_m = IXGBE_RSS_8Q_MASK;
443 	} else {
444 		/* 4 TC w/ 16 queues per TC */
445 		rss_i = min_t(u16, rss_i, 16);
446 		rss_m = IXGBE_RSS_16Q_MASK;
447 	}
448 
449 	/* set RSS mask and indices */
450 	f = &adapter->ring_feature[RING_F_RSS];
451 	rss_i = min_t(int, rss_i, f->limit);
452 	f->indices = rss_i;
453 	f->mask = rss_m;
454 
455 	/* disable ATR as it is not supported when multiple TCs are enabled */
456 	adapter->flags &= ~IXGBE_FLAG_FDIR_HASH_CAPABLE;
457 
458 #ifdef IXGBE_FCOE
459 	/* FCoE enabled queues require special configuration indexed
460 	 * by feature specific indices and offset. Here we map FCoE
461 	 * indices onto the DCB queue pairs allowing FCoE to own
462 	 * configuration later.
463 	 */
464 	if (adapter->flags & IXGBE_FLAG_FCOE_ENABLED) {
465 		u8 tc = ixgbe_fcoe_get_tc(adapter);
466 
467 		f = &adapter->ring_feature[RING_F_FCOE];
468 		f->indices = min_t(u16, rss_i, f->limit);
469 		f->offset = rss_i * tc;
470 	}
471 
472 #endif /* IXGBE_FCOE */
473 	for (i = 0; i < tcs; i++)
474 		netdev_set_tc_queue(dev, i, rss_i, rss_i * i);
475 
476 	adapter->num_tx_queues = rss_i * tcs;
477 	adapter->num_rx_queues = rss_i * tcs;
478 
479 	return true;
480 }
481 
482 #endif
483 /**
484  * ixgbe_set_sriov_queues - Allocate queues for SR-IOV devices
485  * @adapter: board private structure to initialize
486  *
487  * When SR-IOV (Single Root IO Virtualiztion) is enabled, allocate queues
488  * and VM pools where appropriate.  If RSS is available, then also try and
489  * enable RSS and map accordingly.
490  *
491  **/
492 static bool ixgbe_set_sriov_queues(struct ixgbe_adapter *adapter)
493 {
494 	u16 vmdq_i = adapter->ring_feature[RING_F_VMDQ].limit;
495 	u16 vmdq_m = 0;
496 	u16 rss_i = adapter->ring_feature[RING_F_RSS].limit;
497 	u16 rss_m = IXGBE_RSS_DISABLED_MASK;
498 #ifdef IXGBE_FCOE
499 	u16 fcoe_i = 0;
500 #endif
501 
502 	/* only proceed if SR-IOV is enabled */
503 	if (!(adapter->flags & IXGBE_FLAG_SRIOV_ENABLED))
504 		return false;
505 
506 	/* Add starting offset to total pool count */
507 	vmdq_i += adapter->ring_feature[RING_F_VMDQ].offset;
508 
509 	/* double check we are limited to maximum pools */
510 	vmdq_i = min_t(u16, IXGBE_MAX_VMDQ_INDICES, vmdq_i);
511 
512 	/* 64 pool mode with 2 queues per pool */
513 	if ((vmdq_i > 32) || (rss_i < 4)) {
514 		vmdq_m = IXGBE_82599_VMDQ_2Q_MASK;
515 		rss_m = IXGBE_RSS_2Q_MASK;
516 		rss_i = min_t(u16, rss_i, 2);
517 	/* 32 pool mode with 4 queues per pool */
518 	} else {
519 		vmdq_m = IXGBE_82599_VMDQ_4Q_MASK;
520 		rss_m = IXGBE_RSS_4Q_MASK;
521 		rss_i = 4;
522 	}
523 
524 #ifdef IXGBE_FCOE
525 	/* queues in the remaining pools are available for FCoE */
526 	fcoe_i = 128 - (vmdq_i * __ALIGN_MASK(1, ~vmdq_m));
527 
528 #endif
529 	/* remove the starting offset from the pool count */
530 	vmdq_i -= adapter->ring_feature[RING_F_VMDQ].offset;
531 
532 	/* save features for later use */
533 	adapter->ring_feature[RING_F_VMDQ].indices = vmdq_i;
534 	adapter->ring_feature[RING_F_VMDQ].mask = vmdq_m;
535 
536 	/* limit RSS based on user input and save for later use */
537 	adapter->ring_feature[RING_F_RSS].indices = rss_i;
538 	adapter->ring_feature[RING_F_RSS].mask = rss_m;
539 
540 	adapter->num_rx_pools = vmdq_i;
541 	adapter->num_rx_queues_per_pool = rss_i;
542 
543 	adapter->num_rx_queues = vmdq_i * rss_i;
544 	adapter->num_tx_queues = vmdq_i * rss_i;
545 
546 	/* disable ATR as it is not supported when VMDq is enabled */
547 	adapter->flags &= ~IXGBE_FLAG_FDIR_HASH_CAPABLE;
548 
549 #ifdef IXGBE_FCOE
550 	/*
551 	 * FCoE can use rings from adjacent buffers to allow RSS
552 	 * like behavior.  To account for this we need to add the
553 	 * FCoE indices to the total ring count.
554 	 */
555 	if (adapter->flags & IXGBE_FLAG_FCOE_ENABLED) {
556 		struct ixgbe_ring_feature *fcoe;
557 
558 		fcoe = &adapter->ring_feature[RING_F_FCOE];
559 
560 		/* limit ourselves based on feature limits */
561 		fcoe_i = min_t(u16, fcoe_i, fcoe->limit);
562 
563 		if (vmdq_i > 1 && fcoe_i) {
564 			/* alloc queues for FCoE separately */
565 			fcoe->indices = fcoe_i;
566 			fcoe->offset = vmdq_i * rss_i;
567 		} else {
568 			/* merge FCoE queues with RSS queues */
569 			fcoe_i = min_t(u16, fcoe_i + rss_i, num_online_cpus());
570 
571 			/* limit indices to rss_i if MSI-X is disabled */
572 			if (!(adapter->flags & IXGBE_FLAG_MSIX_ENABLED))
573 				fcoe_i = rss_i;
574 
575 			/* attempt to reserve some queues for just FCoE */
576 			fcoe->indices = min_t(u16, fcoe_i, fcoe->limit);
577 			fcoe->offset = fcoe_i - fcoe->indices;
578 
579 			fcoe_i -= rss_i;
580 		}
581 
582 		/* add queues to adapter */
583 		adapter->num_tx_queues += fcoe_i;
584 		adapter->num_rx_queues += fcoe_i;
585 	}
586 
587 #endif
588 	return true;
589 }
590 
591 /**
592  * ixgbe_set_rss_queues - Allocate queues for RSS
593  * @adapter: board private structure to initialize
594  *
595  * This is our "base" multiqueue mode.  RSS (Receive Side Scaling) will try
596  * to allocate one Rx queue per CPU, and if available, one Tx queue per CPU.
597  *
598  **/
599 static bool ixgbe_set_rss_queues(struct ixgbe_adapter *adapter)
600 {
601 	struct ixgbe_ring_feature *f;
602 	u16 rss_i;
603 
604 	/* set mask for 16 queue limit of RSS */
605 	f = &adapter->ring_feature[RING_F_RSS];
606 	rss_i = f->limit;
607 
608 	f->indices = rss_i;
609 	f->mask = IXGBE_RSS_16Q_MASK;
610 
611 	/* disable ATR by default, it will be configured below */
612 	adapter->flags &= ~IXGBE_FLAG_FDIR_HASH_CAPABLE;
613 
614 	/*
615 	 * Use Flow Director in addition to RSS to ensure the best
616 	 * distribution of flows across cores, even when an FDIR flow
617 	 * isn't matched.
618 	 */
619 	if (rss_i > 1 && adapter->atr_sample_rate) {
620 		f = &adapter->ring_feature[RING_F_FDIR];
621 
622 		rss_i = f->indices = f->limit;
623 
624 		if (!(adapter->flags & IXGBE_FLAG_FDIR_PERFECT_CAPABLE))
625 			adapter->flags |= IXGBE_FLAG_FDIR_HASH_CAPABLE;
626 	}
627 
628 #ifdef IXGBE_FCOE
629 	/*
630 	 * FCoE can exist on the same rings as standard network traffic
631 	 * however it is preferred to avoid that if possible.  In order
632 	 * to get the best performance we allocate as many FCoE queues
633 	 * as we can and we place them at the end of the ring array to
634 	 * avoid sharing queues with standard RSS on systems with 24 or
635 	 * more CPUs.
636 	 */
637 	if (adapter->flags & IXGBE_FLAG_FCOE_ENABLED) {
638 		struct net_device *dev = adapter->netdev;
639 		u16 fcoe_i;
640 
641 		f = &adapter->ring_feature[RING_F_FCOE];
642 
643 		/* merge FCoE queues with RSS queues */
644 		fcoe_i = min_t(u16, f->limit + rss_i, num_online_cpus());
645 		fcoe_i = min_t(u16, fcoe_i, dev->num_tx_queues);
646 
647 		/* limit indices to rss_i if MSI-X is disabled */
648 		if (!(adapter->flags & IXGBE_FLAG_MSIX_ENABLED))
649 			fcoe_i = rss_i;
650 
651 		/* attempt to reserve some queues for just FCoE */
652 		f->indices = min_t(u16, fcoe_i, f->limit);
653 		f->offset = fcoe_i - f->indices;
654 		rss_i = max_t(u16, fcoe_i, rss_i);
655 	}
656 
657 #endif /* IXGBE_FCOE */
658 	adapter->num_rx_queues = rss_i;
659 	adapter->num_tx_queues = rss_i;
660 
661 	return true;
662 }
663 
664 /**
665  * ixgbe_set_num_queues - Allocate queues for device, feature dependent
666  * @adapter: board private structure to initialize
667  *
668  * This is the top level queue allocation routine.  The order here is very
669  * important, starting with the "most" number of features turned on at once,
670  * and ending with the smallest set of features.  This way large combinations
671  * can be allocated if they're turned on, and smaller combinations are the
672  * fallthrough conditions.
673  *
674  **/
675 static void ixgbe_set_num_queues(struct ixgbe_adapter *adapter)
676 {
677 	/* Start with base case */
678 	adapter->num_rx_queues = 1;
679 	adapter->num_tx_queues = 1;
680 	adapter->num_rx_pools = adapter->num_rx_queues;
681 	adapter->num_rx_queues_per_pool = 1;
682 
683 #ifdef CONFIG_IXGBE_DCB
684 	if (ixgbe_set_dcb_sriov_queues(adapter))
685 		return;
686 
687 	if (ixgbe_set_dcb_queues(adapter))
688 		return;
689 
690 #endif
691 	if (ixgbe_set_sriov_queues(adapter))
692 		return;
693 
694 	ixgbe_set_rss_queues(adapter);
695 }
696 
697 static void ixgbe_acquire_msix_vectors(struct ixgbe_adapter *adapter,
698 				       int vectors)
699 {
700 	int err, vector_threshold;
701 
702 	/* We'll want at least 2 (vector_threshold):
703 	 * 1) TxQ[0] + RxQ[0] handler
704 	 * 2) Other (Link Status Change, etc.)
705 	 */
706 	vector_threshold = MIN_MSIX_COUNT;
707 
708 	/*
709 	 * The more we get, the more we will assign to Tx/Rx Cleanup
710 	 * for the separate queues...where Rx Cleanup >= Tx Cleanup.
711 	 * Right now, we simply care about how many we'll get; we'll
712 	 * set them up later while requesting irq's.
713 	 */
714 	while (vectors >= vector_threshold) {
715 		err = pci_enable_msix(adapter->pdev, adapter->msix_entries,
716 				      vectors);
717 		if (!err) /* Success in acquiring all requested vectors. */
718 			break;
719 		else if (err < 0)
720 			vectors = 0; /* Nasty failure, quit now */
721 		else /* err == number of vectors we should try again with */
722 			vectors = err;
723 	}
724 
725 	if (vectors < vector_threshold) {
726 		/* Can't allocate enough MSI-X interrupts?  Oh well.
727 		 * This just means we'll go with either a single MSI
728 		 * vector or fall back to legacy interrupts.
729 		 */
730 		netif_printk(adapter, hw, KERN_DEBUG, adapter->netdev,
731 			     "Unable to allocate MSI-X interrupts\n");
732 		adapter->flags &= ~IXGBE_FLAG_MSIX_ENABLED;
733 		kfree(adapter->msix_entries);
734 		adapter->msix_entries = NULL;
735 	} else {
736 		adapter->flags |= IXGBE_FLAG_MSIX_ENABLED; /* Woot! */
737 		/*
738 		 * Adjust for only the vectors we'll use, which is minimum
739 		 * of max_msix_q_vectors + NON_Q_VECTORS, or the number of
740 		 * vectors we were allocated.
741 		 */
742 		vectors -= NON_Q_VECTORS;
743 		adapter->num_q_vectors = min(vectors, adapter->max_q_vectors);
744 	}
745 }
746 
747 static void ixgbe_add_ring(struct ixgbe_ring *ring,
748 			   struct ixgbe_ring_container *head)
749 {
750 	ring->next = head->ring;
751 	head->ring = ring;
752 	head->count++;
753 }
754 
755 /**
756  * ixgbe_alloc_q_vector - Allocate memory for a single interrupt vector
757  * @adapter: board private structure to initialize
758  * @v_count: q_vectors allocated on adapter, used for ring interleaving
759  * @v_idx: index of vector in adapter struct
760  * @txr_count: total number of Tx rings to allocate
761  * @txr_idx: index of first Tx ring to allocate
762  * @rxr_count: total number of Rx rings to allocate
763  * @rxr_idx: index of first Rx ring to allocate
764  *
765  * We allocate one q_vector.  If allocation fails we return -ENOMEM.
766  **/
767 static int ixgbe_alloc_q_vector(struct ixgbe_adapter *adapter,
768 				int v_count, int v_idx,
769 				int txr_count, int txr_idx,
770 				int rxr_count, int rxr_idx)
771 {
772 	struct ixgbe_q_vector *q_vector;
773 	struct ixgbe_ring *ring;
774 	int node = NUMA_NO_NODE;
775 	int cpu = -1;
776 	int ring_count, size;
777 	u8 tcs = netdev_get_num_tc(adapter->netdev);
778 
779 	ring_count = txr_count + rxr_count;
780 	size = sizeof(struct ixgbe_q_vector) +
781 	       (sizeof(struct ixgbe_ring) * ring_count);
782 
783 	/* customize cpu for Flow Director mapping */
784 	if ((tcs <= 1) && !(adapter->flags & IXGBE_FLAG_SRIOV_ENABLED)) {
785 		u16 rss_i = adapter->ring_feature[RING_F_RSS].indices;
786 		if (rss_i > 1 && adapter->atr_sample_rate) {
787 			if (cpu_online(v_idx)) {
788 				cpu = v_idx;
789 				node = cpu_to_node(cpu);
790 			}
791 		}
792 	}
793 
794 	/* allocate q_vector and rings */
795 	q_vector = kzalloc_node(size, GFP_KERNEL, node);
796 	if (!q_vector)
797 		q_vector = kzalloc(size, GFP_KERNEL);
798 	if (!q_vector)
799 		return -ENOMEM;
800 
801 	/* setup affinity mask and node */
802 	if (cpu != -1)
803 		cpumask_set_cpu(cpu, &q_vector->affinity_mask);
804 	q_vector->numa_node = node;
805 
806 #ifdef CONFIG_IXGBE_DCA
807 	/* initialize CPU for DCA */
808 	q_vector->cpu = -1;
809 
810 #endif
811 	/* initialize NAPI */
812 	netif_napi_add(adapter->netdev, &q_vector->napi,
813 		       ixgbe_poll, 64);
814 	napi_hash_add(&q_vector->napi);
815 
816 	/* tie q_vector and adapter together */
817 	adapter->q_vector[v_idx] = q_vector;
818 	q_vector->adapter = adapter;
819 	q_vector->v_idx = v_idx;
820 
821 	/* initialize work limits */
822 	q_vector->tx.work_limit = adapter->tx_work_limit;
823 
824 	/* initialize pointer to rings */
825 	ring = q_vector->ring;
826 
827 	/* intialize ITR */
828 	if (txr_count && !rxr_count) {
829 		/* tx only vector */
830 		if (adapter->tx_itr_setting == 1)
831 			q_vector->itr = IXGBE_10K_ITR;
832 		else
833 			q_vector->itr = adapter->tx_itr_setting;
834 	} else {
835 		/* rx or rx/tx vector */
836 		if (adapter->rx_itr_setting == 1)
837 			q_vector->itr = IXGBE_20K_ITR;
838 		else
839 			q_vector->itr = adapter->rx_itr_setting;
840 	}
841 
842 	while (txr_count) {
843 		/* assign generic ring traits */
844 		ring->dev = &adapter->pdev->dev;
845 		ring->netdev = adapter->netdev;
846 
847 		/* configure backlink on ring */
848 		ring->q_vector = q_vector;
849 
850 		/* update q_vector Tx values */
851 		ixgbe_add_ring(ring, &q_vector->tx);
852 
853 		/* apply Tx specific ring traits */
854 		ring->count = adapter->tx_ring_count;
855 		ring->queue_index = txr_idx;
856 
857 		/* assign ring to adapter */
858 		adapter->tx_ring[txr_idx] = ring;
859 
860 		/* update count and index */
861 		txr_count--;
862 		txr_idx += v_count;
863 
864 		/* push pointer to next ring */
865 		ring++;
866 	}
867 
868 	while (rxr_count) {
869 		/* assign generic ring traits */
870 		ring->dev = &adapter->pdev->dev;
871 		ring->netdev = adapter->netdev;
872 
873 		/* configure backlink on ring */
874 		ring->q_vector = q_vector;
875 
876 		/* update q_vector Rx values */
877 		ixgbe_add_ring(ring, &q_vector->rx);
878 
879 		/*
880 		 * 82599 errata, UDP frames with a 0 checksum
881 		 * can be marked as checksum errors.
882 		 */
883 		if (adapter->hw.mac.type == ixgbe_mac_82599EB)
884 			set_bit(__IXGBE_RX_CSUM_UDP_ZERO_ERR, &ring->state);
885 
886 #ifdef IXGBE_FCOE
887 		if (adapter->netdev->features & NETIF_F_FCOE_MTU) {
888 			struct ixgbe_ring_feature *f;
889 			f = &adapter->ring_feature[RING_F_FCOE];
890 			if ((rxr_idx >= f->offset) &&
891 			    (rxr_idx < f->offset + f->indices))
892 				set_bit(__IXGBE_RX_FCOE, &ring->state);
893 		}
894 
895 #endif /* IXGBE_FCOE */
896 		/* apply Rx specific ring traits */
897 		ring->count = adapter->rx_ring_count;
898 		ring->queue_index = rxr_idx;
899 
900 		/* assign ring to adapter */
901 		adapter->rx_ring[rxr_idx] = ring;
902 
903 		/* update count and index */
904 		rxr_count--;
905 		rxr_idx += v_count;
906 
907 		/* push pointer to next ring */
908 		ring++;
909 	}
910 
911 	return 0;
912 }
913 
914 /**
915  * ixgbe_free_q_vector - Free memory allocated for specific interrupt vector
916  * @adapter: board private structure to initialize
917  * @v_idx: Index of vector to be freed
918  *
919  * This function frees the memory allocated to the q_vector.  In addition if
920  * NAPI is enabled it will delete any references to the NAPI struct prior
921  * to freeing the q_vector.
922  **/
923 static void ixgbe_free_q_vector(struct ixgbe_adapter *adapter, int v_idx)
924 {
925 	struct ixgbe_q_vector *q_vector = adapter->q_vector[v_idx];
926 	struct ixgbe_ring *ring;
927 
928 	ixgbe_for_each_ring(ring, q_vector->tx)
929 		adapter->tx_ring[ring->queue_index] = NULL;
930 
931 	ixgbe_for_each_ring(ring, q_vector->rx)
932 		adapter->rx_ring[ring->queue_index] = NULL;
933 
934 	adapter->q_vector[v_idx] = NULL;
935 	napi_hash_del(&q_vector->napi);
936 	netif_napi_del(&q_vector->napi);
937 
938 	/*
939 	 * ixgbe_get_stats64() might access the rings on this vector,
940 	 * we must wait a grace period before freeing it.
941 	 */
942 	kfree_rcu(q_vector, rcu);
943 }
944 
945 /**
946  * ixgbe_alloc_q_vectors - Allocate memory for interrupt vectors
947  * @adapter: board private structure to initialize
948  *
949  * We allocate one q_vector per queue interrupt.  If allocation fails we
950  * return -ENOMEM.
951  **/
952 static int ixgbe_alloc_q_vectors(struct ixgbe_adapter *adapter)
953 {
954 	int q_vectors = adapter->num_q_vectors;
955 	int rxr_remaining = adapter->num_rx_queues;
956 	int txr_remaining = adapter->num_tx_queues;
957 	int rxr_idx = 0, txr_idx = 0, v_idx = 0;
958 	int err;
959 
960 	/* only one q_vector if MSI-X is disabled. */
961 	if (!(adapter->flags & IXGBE_FLAG_MSIX_ENABLED))
962 		q_vectors = 1;
963 
964 	if (q_vectors >= (rxr_remaining + txr_remaining)) {
965 		for (; rxr_remaining; v_idx++) {
966 			err = ixgbe_alloc_q_vector(adapter, q_vectors, v_idx,
967 						   0, 0, 1, rxr_idx);
968 
969 			if (err)
970 				goto err_out;
971 
972 			/* update counts and index */
973 			rxr_remaining--;
974 			rxr_idx++;
975 		}
976 	}
977 
978 	for (; v_idx < q_vectors; v_idx++) {
979 		int rqpv = DIV_ROUND_UP(rxr_remaining, q_vectors - v_idx);
980 		int tqpv = DIV_ROUND_UP(txr_remaining, q_vectors - v_idx);
981 		err = ixgbe_alloc_q_vector(adapter, q_vectors, v_idx,
982 					   tqpv, txr_idx,
983 					   rqpv, rxr_idx);
984 
985 		if (err)
986 			goto err_out;
987 
988 		/* update counts and index */
989 		rxr_remaining -= rqpv;
990 		txr_remaining -= tqpv;
991 		rxr_idx++;
992 		txr_idx++;
993 	}
994 
995 	return 0;
996 
997 err_out:
998 	adapter->num_tx_queues = 0;
999 	adapter->num_rx_queues = 0;
1000 	adapter->num_q_vectors = 0;
1001 
1002 	while (v_idx--)
1003 		ixgbe_free_q_vector(adapter, v_idx);
1004 
1005 	return -ENOMEM;
1006 }
1007 
1008 /**
1009  * ixgbe_free_q_vectors - Free memory allocated for interrupt vectors
1010  * @adapter: board private structure to initialize
1011  *
1012  * This function frees the memory allocated to the q_vectors.  In addition if
1013  * NAPI is enabled it will delete any references to the NAPI struct prior
1014  * to freeing the q_vector.
1015  **/
1016 static void ixgbe_free_q_vectors(struct ixgbe_adapter *adapter)
1017 {
1018 	int v_idx = adapter->num_q_vectors;
1019 
1020 	adapter->num_tx_queues = 0;
1021 	adapter->num_rx_queues = 0;
1022 	adapter->num_q_vectors = 0;
1023 
1024 	while (v_idx--)
1025 		ixgbe_free_q_vector(adapter, v_idx);
1026 }
1027 
1028 static void ixgbe_reset_interrupt_capability(struct ixgbe_adapter *adapter)
1029 {
1030 	if (adapter->flags & IXGBE_FLAG_MSIX_ENABLED) {
1031 		adapter->flags &= ~IXGBE_FLAG_MSIX_ENABLED;
1032 		pci_disable_msix(adapter->pdev);
1033 		kfree(adapter->msix_entries);
1034 		adapter->msix_entries = NULL;
1035 	} else if (adapter->flags & IXGBE_FLAG_MSI_ENABLED) {
1036 		adapter->flags &= ~IXGBE_FLAG_MSI_ENABLED;
1037 		pci_disable_msi(adapter->pdev);
1038 	}
1039 }
1040 
1041 /**
1042  * ixgbe_set_interrupt_capability - set MSI-X or MSI if supported
1043  * @adapter: board private structure to initialize
1044  *
1045  * Attempt to configure the interrupts using the best available
1046  * capabilities of the hardware and the kernel.
1047  **/
1048 static void ixgbe_set_interrupt_capability(struct ixgbe_adapter *adapter)
1049 {
1050 	struct ixgbe_hw *hw = &adapter->hw;
1051 	int vector, v_budget, err;
1052 
1053 	/*
1054 	 * It's easy to be greedy for MSI-X vectors, but it really
1055 	 * doesn't do us much good if we have a lot more vectors
1056 	 * than CPU's.  So let's be conservative and only ask for
1057 	 * (roughly) the same number of vectors as there are CPU's.
1058 	 * The default is to use pairs of vectors.
1059 	 */
1060 	v_budget = max(adapter->num_rx_queues, adapter->num_tx_queues);
1061 	v_budget = min_t(int, v_budget, num_online_cpus());
1062 	v_budget += NON_Q_VECTORS;
1063 
1064 	/*
1065 	 * At the same time, hardware can only support a maximum of
1066 	 * hw.mac->max_msix_vectors vectors.  With features
1067 	 * such as RSS and VMDq, we can easily surpass the number of Rx and Tx
1068 	 * descriptor queues supported by our device.  Thus, we cap it off in
1069 	 * those rare cases where the cpu count also exceeds our vector limit.
1070 	 */
1071 	v_budget = min_t(int, v_budget, hw->mac.max_msix_vectors);
1072 
1073 	/* A failure in MSI-X entry allocation isn't fatal, but it does
1074 	 * mean we disable MSI-X capabilities of the adapter. */
1075 	adapter->msix_entries = kcalloc(v_budget,
1076 					sizeof(struct msix_entry), GFP_KERNEL);
1077 	if (adapter->msix_entries) {
1078 		for (vector = 0; vector < v_budget; vector++)
1079 			adapter->msix_entries[vector].entry = vector;
1080 
1081 		ixgbe_acquire_msix_vectors(adapter, v_budget);
1082 
1083 		if (adapter->flags & IXGBE_FLAG_MSIX_ENABLED)
1084 			return;
1085 	}
1086 
1087 	/* disable DCB if number of TCs exceeds 1 */
1088 	if (netdev_get_num_tc(adapter->netdev) > 1) {
1089 		e_err(probe, "num TCs exceeds number of queues - disabling DCB\n");
1090 		netdev_reset_tc(adapter->netdev);
1091 
1092 		if (adapter->hw.mac.type == ixgbe_mac_82598EB)
1093 			adapter->hw.fc.requested_mode = adapter->last_lfc_mode;
1094 
1095 		adapter->flags &= ~IXGBE_FLAG_DCB_ENABLED;
1096 		adapter->temp_dcb_cfg.pfc_mode_enable = false;
1097 		adapter->dcb_cfg.pfc_mode_enable = false;
1098 	}
1099 	adapter->dcb_cfg.num_tcs.pg_tcs = 1;
1100 	adapter->dcb_cfg.num_tcs.pfc_tcs = 1;
1101 
1102 	/* disable SR-IOV */
1103 	ixgbe_disable_sriov(adapter);
1104 
1105 	/* disable RSS */
1106 	adapter->ring_feature[RING_F_RSS].limit = 1;
1107 
1108 	ixgbe_set_num_queues(adapter);
1109 	adapter->num_q_vectors = 1;
1110 
1111 	err = pci_enable_msi(adapter->pdev);
1112 	if (err) {
1113 		netif_printk(adapter, hw, KERN_DEBUG, adapter->netdev,
1114 			     "Unable to allocate MSI interrupt, "
1115 			     "falling back to legacy.  Error: %d\n", err);
1116 		return;
1117 	}
1118 	adapter->flags |= IXGBE_FLAG_MSI_ENABLED;
1119 }
1120 
1121 /**
1122  * ixgbe_init_interrupt_scheme - Determine proper interrupt scheme
1123  * @adapter: board private structure to initialize
1124  *
1125  * We determine which interrupt scheme to use based on...
1126  * - Kernel support (MSI, MSI-X)
1127  *   - which can be user-defined (via MODULE_PARAM)
1128  * - Hardware queue count (num_*_queues)
1129  *   - defined by miscellaneous hardware support/features (RSS, etc.)
1130  **/
1131 int ixgbe_init_interrupt_scheme(struct ixgbe_adapter *adapter)
1132 {
1133 	int err;
1134 
1135 	/* Number of supported queues */
1136 	ixgbe_set_num_queues(adapter);
1137 
1138 	/* Set interrupt mode */
1139 	ixgbe_set_interrupt_capability(adapter);
1140 
1141 	err = ixgbe_alloc_q_vectors(adapter);
1142 	if (err) {
1143 		e_dev_err("Unable to allocate memory for queue vectors\n");
1144 		goto err_alloc_q_vectors;
1145 	}
1146 
1147 	ixgbe_cache_ring_register(adapter);
1148 
1149 	e_dev_info("Multiqueue %s: Rx Queue count = %u, Tx Queue count = %u\n",
1150 		   (adapter->num_rx_queues > 1) ? "Enabled" : "Disabled",
1151 		   adapter->num_rx_queues, adapter->num_tx_queues);
1152 
1153 	set_bit(__IXGBE_DOWN, &adapter->state);
1154 
1155 	return 0;
1156 
1157 err_alloc_q_vectors:
1158 	ixgbe_reset_interrupt_capability(adapter);
1159 	return err;
1160 }
1161 
1162 /**
1163  * ixgbe_clear_interrupt_scheme - Clear the current interrupt scheme settings
1164  * @adapter: board private structure to clear interrupt scheme on
1165  *
1166  * We go through and clear interrupt specific resources and reset the structure
1167  * to pre-load conditions
1168  **/
1169 void ixgbe_clear_interrupt_scheme(struct ixgbe_adapter *adapter)
1170 {
1171 	adapter->num_tx_queues = 0;
1172 	adapter->num_rx_queues = 0;
1173 
1174 	ixgbe_free_q_vectors(adapter);
1175 	ixgbe_reset_interrupt_capability(adapter);
1176 }
1177 
1178 void ixgbe_tx_ctxtdesc(struct ixgbe_ring *tx_ring, u32 vlan_macip_lens,
1179 		       u32 fcoe_sof_eof, u32 type_tucmd, u32 mss_l4len_idx)
1180 {
1181 	struct ixgbe_adv_tx_context_desc *context_desc;
1182 	u16 i = tx_ring->next_to_use;
1183 
1184 	context_desc = IXGBE_TX_CTXTDESC(tx_ring, i);
1185 
1186 	i++;
1187 	tx_ring->next_to_use = (i < tx_ring->count) ? i : 0;
1188 
1189 	/* set bits to identify this as an advanced context descriptor */
1190 	type_tucmd |= IXGBE_TXD_CMD_DEXT | IXGBE_ADVTXD_DTYP_CTXT;
1191 
1192 	context_desc->vlan_macip_lens	= cpu_to_le32(vlan_macip_lens);
1193 	context_desc->seqnum_seed	= cpu_to_le32(fcoe_sof_eof);
1194 	context_desc->type_tucmd_mlhl	= cpu_to_le32(type_tucmd);
1195 	context_desc->mss_l4len_idx	= cpu_to_le32(mss_l4len_idx);
1196 }
1197 
1198