1 /*
2  * Copyright (c) 2005-2008 Chelsio, Inc. All rights reserved.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the
8  * OpenIB.org BSD license below:
9  *
10  *     Redistribution and use in source and binary forms, with or
11  *     without modification, are permitted provided that the following
12  *     conditions are met:
13  *
14  *      - Redistributions of source code must retain the above
15  *        copyright notice, this list of conditions and the following
16  *        disclaimer.
17  *
18  *      - Redistributions in binary form must reproduce the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer in the documentation and/or other materials
21  *        provided with the distribution.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30  * SOFTWARE.
31  */
32 #include <linux/skbuff.h>
33 #include <linux/netdevice.h>
34 #include <linux/etherdevice.h>
35 #include <linux/if_vlan.h>
36 #include <linux/ip.h>
37 #include <linux/tcp.h>
38 #include <linux/dma-mapping.h>
39 #include <linux/slab.h>
40 #include <linux/prefetch.h>
41 #include <net/arp.h>
42 #include "common.h"
43 #include "regs.h"
44 #include "sge_defs.h"
45 #include "t3_cpl.h"
46 #include "firmware_exports.h"
47 #include "cxgb3_offload.h"
48 
49 #define USE_GTS 0
50 
51 #define SGE_RX_SM_BUF_SIZE 1536
52 
53 #define SGE_RX_COPY_THRES  256
54 #define SGE_RX_PULL_LEN    128
55 
56 #define SGE_PG_RSVD SMP_CACHE_BYTES
57 /*
58  * Page chunk size for FL0 buffers if FL0 is to be populated with page chunks.
59  * It must be a divisor of PAGE_SIZE.  If set to 0 FL0 will use sk_buffs
60  * directly.
61  */
62 #define FL0_PG_CHUNK_SIZE  2048
63 #define FL0_PG_ORDER 0
64 #define FL0_PG_ALLOC_SIZE (PAGE_SIZE << FL0_PG_ORDER)
65 #define FL1_PG_CHUNK_SIZE (PAGE_SIZE > 8192 ? 16384 : 8192)
66 #define FL1_PG_ORDER (PAGE_SIZE > 8192 ? 0 : 1)
67 #define FL1_PG_ALLOC_SIZE (PAGE_SIZE << FL1_PG_ORDER)
68 
69 #define SGE_RX_DROP_THRES 16
70 #define RX_RECLAIM_PERIOD (HZ/4)
71 
72 /*
73  * Max number of Rx buffers we replenish at a time.
74  */
75 #define MAX_RX_REFILL 16U
76 /*
77  * Period of the Tx buffer reclaim timer.  This timer does not need to run
78  * frequently as Tx buffers are usually reclaimed by new Tx packets.
79  */
80 #define TX_RECLAIM_PERIOD (HZ / 4)
81 #define TX_RECLAIM_TIMER_CHUNK 64U
82 #define TX_RECLAIM_CHUNK 16U
83 
84 /* WR size in bytes */
85 #define WR_LEN (WR_FLITS * 8)
86 
87 /*
88  * Types of Tx queues in each queue set.  Order here matters, do not change.
89  */
90 enum { TXQ_ETH, TXQ_OFLD, TXQ_CTRL };
91 
92 /* Values for sge_txq.flags */
93 enum {
94 	TXQ_RUNNING = 1 << 0,	/* fetch engine is running */
95 	TXQ_LAST_PKT_DB = 1 << 1,	/* last packet rang the doorbell */
96 };
97 
98 struct tx_desc {
99 	__be64 flit[TX_DESC_FLITS];
100 };
101 
102 struct rx_desc {
103 	__be32 addr_lo;
104 	__be32 len_gen;
105 	__be32 gen2;
106 	__be32 addr_hi;
107 };
108 
109 struct tx_sw_desc {		/* SW state per Tx descriptor */
110 	struct sk_buff *skb;
111 	u8 eop;       /* set if last descriptor for packet */
112 	u8 addr_idx;  /* buffer index of first SGL entry in descriptor */
113 	u8 fragidx;   /* first page fragment associated with descriptor */
114 	s8 sflit;     /* start flit of first SGL entry in descriptor */
115 };
116 
117 struct rx_sw_desc {                /* SW state per Rx descriptor */
118 	union {
119 		struct sk_buff *skb;
120 		struct fl_pg_chunk pg_chunk;
121 	};
122 	DEFINE_DMA_UNMAP_ADDR(dma_addr);
123 };
124 
125 struct rsp_desc {		/* response queue descriptor */
126 	struct rss_header rss_hdr;
127 	__be32 flags;
128 	__be32 len_cq;
129 	u8 imm_data[47];
130 	u8 intr_gen;
131 };
132 
133 /*
134  * Holds unmapping information for Tx packets that need deferred unmapping.
135  * This structure lives at skb->head and must be allocated by callers.
136  */
137 struct deferred_unmap_info {
138 	struct pci_dev *pdev;
139 	dma_addr_t addr[MAX_SKB_FRAGS + 1];
140 };
141 
142 /*
143  * Maps a number of flits to the number of Tx descriptors that can hold them.
144  * The formula is
145  *
146  * desc = 1 + (flits - 2) / (WR_FLITS - 1).
147  *
148  * HW allows up to 4 descriptors to be combined into a WR.
149  */
150 static u8 flit_desc_map[] = {
151 	0,
152 #if SGE_NUM_GENBITS == 1
153 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
154 	2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
155 	3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
156 	4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4
157 #elif SGE_NUM_GENBITS == 2
158 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
159 	2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
160 	3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
161 	4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
162 #else
163 # error "SGE_NUM_GENBITS must be 1 or 2"
164 #endif
165 };
166 
167 static inline struct sge_qset *fl_to_qset(const struct sge_fl *q, int qidx)
168 {
169 	return container_of(q, struct sge_qset, fl[qidx]);
170 }
171 
172 static inline struct sge_qset *rspq_to_qset(const struct sge_rspq *q)
173 {
174 	return container_of(q, struct sge_qset, rspq);
175 }
176 
177 static inline struct sge_qset *txq_to_qset(const struct sge_txq *q, int qidx)
178 {
179 	return container_of(q, struct sge_qset, txq[qidx]);
180 }
181 
182 /**
183  *	refill_rspq - replenish an SGE response queue
184  *	@adapter: the adapter
185  *	@q: the response queue to replenish
186  *	@credits: how many new responses to make available
187  *
188  *	Replenishes a response queue by making the supplied number of responses
189  *	available to HW.
190  */
191 static inline void refill_rspq(struct adapter *adapter,
192 			       const struct sge_rspq *q, unsigned int credits)
193 {
194 	rmb();
195 	t3_write_reg(adapter, A_SG_RSPQ_CREDIT_RETURN,
196 		     V_RSPQ(q->cntxt_id) | V_CREDITS(credits));
197 }
198 
199 /**
200  *	need_skb_unmap - does the platform need unmapping of sk_buffs?
201  *
202  *	Returns true if the platform needs sk_buff unmapping.  The compiler
203  *	optimizes away unnecessary code if this returns true.
204  */
205 static inline int need_skb_unmap(void)
206 {
207 #ifdef CONFIG_NEED_DMA_MAP_STATE
208 	return 1;
209 #else
210 	return 0;
211 #endif
212 }
213 
214 /**
215  *	unmap_skb - unmap a packet main body and its page fragments
216  *	@skb: the packet
217  *	@q: the Tx queue containing Tx descriptors for the packet
218  *	@cidx: index of Tx descriptor
219  *	@pdev: the PCI device
220  *
221  *	Unmap the main body of an sk_buff and its page fragments, if any.
222  *	Because of the fairly complicated structure of our SGLs and the desire
223  *	to conserve space for metadata, the information necessary to unmap an
224  *	sk_buff is spread across the sk_buff itself (buffer lengths), the HW Tx
225  *	descriptors (the physical addresses of the various data buffers), and
226  *	the SW descriptor state (assorted indices).  The send functions
227  *	initialize the indices for the first packet descriptor so we can unmap
228  *	the buffers held in the first Tx descriptor here, and we have enough
229  *	information at this point to set the state for the next Tx descriptor.
230  *
231  *	Note that it is possible to clean up the first descriptor of a packet
232  *	before the send routines have written the next descriptors, but this
233  *	race does not cause any problem.  We just end up writing the unmapping
234  *	info for the descriptor first.
235  */
236 static inline void unmap_skb(struct sk_buff *skb, struct sge_txq *q,
237 			     unsigned int cidx, struct pci_dev *pdev)
238 {
239 	const struct sg_ent *sgp;
240 	struct tx_sw_desc *d = &q->sdesc[cidx];
241 	int nfrags, frag_idx, curflit, j = d->addr_idx;
242 
243 	sgp = (struct sg_ent *)&q->desc[cidx].flit[d->sflit];
244 	frag_idx = d->fragidx;
245 
246 	if (frag_idx == 0 && skb_headlen(skb)) {
247 		pci_unmap_single(pdev, be64_to_cpu(sgp->addr[0]),
248 				 skb_headlen(skb), PCI_DMA_TODEVICE);
249 		j = 1;
250 	}
251 
252 	curflit = d->sflit + 1 + j;
253 	nfrags = skb_shinfo(skb)->nr_frags;
254 
255 	while (frag_idx < nfrags && curflit < WR_FLITS) {
256 		pci_unmap_page(pdev, be64_to_cpu(sgp->addr[j]),
257 			       skb_frag_size(&skb_shinfo(skb)->frags[frag_idx]),
258 			       PCI_DMA_TODEVICE);
259 		j ^= 1;
260 		if (j == 0) {
261 			sgp++;
262 			curflit++;
263 		}
264 		curflit++;
265 		frag_idx++;
266 	}
267 
268 	if (frag_idx < nfrags) {   /* SGL continues into next Tx descriptor */
269 		d = cidx + 1 == q->size ? q->sdesc : d + 1;
270 		d->fragidx = frag_idx;
271 		d->addr_idx = j;
272 		d->sflit = curflit - WR_FLITS - j; /* sflit can be -1 */
273 	}
274 }
275 
276 /**
277  *	free_tx_desc - reclaims Tx descriptors and their buffers
278  *	@adapter: the adapter
279  *	@q: the Tx queue to reclaim descriptors from
280  *	@n: the number of descriptors to reclaim
281  *
282  *	Reclaims Tx descriptors from an SGE Tx queue and frees the associated
283  *	Tx buffers.  Called with the Tx queue lock held.
284  */
285 static void free_tx_desc(struct adapter *adapter, struct sge_txq *q,
286 			 unsigned int n)
287 {
288 	struct tx_sw_desc *d;
289 	struct pci_dev *pdev = adapter->pdev;
290 	unsigned int cidx = q->cidx;
291 
292 	const int need_unmap = need_skb_unmap() &&
293 			       q->cntxt_id >= FW_TUNNEL_SGEEC_START;
294 
295 	d = &q->sdesc[cidx];
296 	while (n--) {
297 		if (d->skb) {	/* an SGL is present */
298 			if (need_unmap)
299 				unmap_skb(d->skb, q, cidx, pdev);
300 			if (d->eop) {
301 				dev_consume_skb_any(d->skb);
302 				d->skb = NULL;
303 			}
304 		}
305 		++d;
306 		if (++cidx == q->size) {
307 			cidx = 0;
308 			d = q->sdesc;
309 		}
310 	}
311 	q->cidx = cidx;
312 }
313 
314 /**
315  *	reclaim_completed_tx - reclaims completed Tx descriptors
316  *	@adapter: the adapter
317  *	@q: the Tx queue to reclaim completed descriptors from
318  *	@chunk: maximum number of descriptors to reclaim
319  *
320  *	Reclaims Tx descriptors that the SGE has indicated it has processed,
321  *	and frees the associated buffers if possible.  Called with the Tx
322  *	queue's lock held.
323  */
324 static inline unsigned int reclaim_completed_tx(struct adapter *adapter,
325 						struct sge_txq *q,
326 						unsigned int chunk)
327 {
328 	unsigned int reclaim = q->processed - q->cleaned;
329 
330 	reclaim = min(chunk, reclaim);
331 	if (reclaim) {
332 		free_tx_desc(adapter, q, reclaim);
333 		q->cleaned += reclaim;
334 		q->in_use -= reclaim;
335 	}
336 	return q->processed - q->cleaned;
337 }
338 
339 /**
340  *	should_restart_tx - are there enough resources to restart a Tx queue?
341  *	@q: the Tx queue
342  *
343  *	Checks if there are enough descriptors to restart a suspended Tx queue.
344  */
345 static inline int should_restart_tx(const struct sge_txq *q)
346 {
347 	unsigned int r = q->processed - q->cleaned;
348 
349 	return q->in_use - r < (q->size >> 1);
350 }
351 
352 static void clear_rx_desc(struct pci_dev *pdev, const struct sge_fl *q,
353 			  struct rx_sw_desc *d)
354 {
355 	if (q->use_pages && d->pg_chunk.page) {
356 		(*d->pg_chunk.p_cnt)--;
357 		if (!*d->pg_chunk.p_cnt)
358 			pci_unmap_page(pdev,
359 				       d->pg_chunk.mapping,
360 				       q->alloc_size, PCI_DMA_FROMDEVICE);
361 
362 		put_page(d->pg_chunk.page);
363 		d->pg_chunk.page = NULL;
364 	} else {
365 		pci_unmap_single(pdev, dma_unmap_addr(d, dma_addr),
366 				 q->buf_size, PCI_DMA_FROMDEVICE);
367 		kfree_skb(d->skb);
368 		d->skb = NULL;
369 	}
370 }
371 
372 /**
373  *	free_rx_bufs - free the Rx buffers on an SGE free list
374  *	@pdev: the PCI device associated with the adapter
375  *	@q: the SGE free list to clean up
376  *
377  *	Release the buffers on an SGE free-buffer Rx queue.  HW fetching from
378  *	this queue should be stopped before calling this function.
379  */
380 static void free_rx_bufs(struct pci_dev *pdev, struct sge_fl *q)
381 {
382 	unsigned int cidx = q->cidx;
383 
384 	while (q->credits--) {
385 		struct rx_sw_desc *d = &q->sdesc[cidx];
386 
387 
388 		clear_rx_desc(pdev, q, d);
389 		if (++cidx == q->size)
390 			cidx = 0;
391 	}
392 
393 	if (q->pg_chunk.page) {
394 		__free_pages(q->pg_chunk.page, q->order);
395 		q->pg_chunk.page = NULL;
396 	}
397 }
398 
399 /**
400  *	add_one_rx_buf - add a packet buffer to a free-buffer list
401  *	@va:  buffer start VA
402  *	@len: the buffer length
403  *	@d: the HW Rx descriptor to write
404  *	@sd: the SW Rx descriptor to write
405  *	@gen: the generation bit value
406  *	@pdev: the PCI device associated with the adapter
407  *
408  *	Add a buffer of the given length to the supplied HW and SW Rx
409  *	descriptors.
410  */
411 static inline int add_one_rx_buf(void *va, unsigned int len,
412 				 struct rx_desc *d, struct rx_sw_desc *sd,
413 				 unsigned int gen, struct pci_dev *pdev)
414 {
415 	dma_addr_t mapping;
416 
417 	mapping = pci_map_single(pdev, va, len, PCI_DMA_FROMDEVICE);
418 	if (unlikely(pci_dma_mapping_error(pdev, mapping)))
419 		return -ENOMEM;
420 
421 	dma_unmap_addr_set(sd, dma_addr, mapping);
422 
423 	d->addr_lo = cpu_to_be32(mapping);
424 	d->addr_hi = cpu_to_be32((u64) mapping >> 32);
425 	dma_wmb();
426 	d->len_gen = cpu_to_be32(V_FLD_GEN1(gen));
427 	d->gen2 = cpu_to_be32(V_FLD_GEN2(gen));
428 	return 0;
429 }
430 
431 static inline int add_one_rx_chunk(dma_addr_t mapping, struct rx_desc *d,
432 				   unsigned int gen)
433 {
434 	d->addr_lo = cpu_to_be32(mapping);
435 	d->addr_hi = cpu_to_be32((u64) mapping >> 32);
436 	dma_wmb();
437 	d->len_gen = cpu_to_be32(V_FLD_GEN1(gen));
438 	d->gen2 = cpu_to_be32(V_FLD_GEN2(gen));
439 	return 0;
440 }
441 
442 static int alloc_pg_chunk(struct adapter *adapter, struct sge_fl *q,
443 			  struct rx_sw_desc *sd, gfp_t gfp,
444 			  unsigned int order)
445 {
446 	if (!q->pg_chunk.page) {
447 		dma_addr_t mapping;
448 
449 		q->pg_chunk.page = alloc_pages(gfp, order);
450 		if (unlikely(!q->pg_chunk.page))
451 			return -ENOMEM;
452 		q->pg_chunk.va = page_address(q->pg_chunk.page);
453 		q->pg_chunk.p_cnt = q->pg_chunk.va + (PAGE_SIZE << order) -
454 				    SGE_PG_RSVD;
455 		q->pg_chunk.offset = 0;
456 		mapping = pci_map_page(adapter->pdev, q->pg_chunk.page,
457 				       0, q->alloc_size, PCI_DMA_FROMDEVICE);
458 		if (unlikely(pci_dma_mapping_error(adapter->pdev, mapping))) {
459 			__free_pages(q->pg_chunk.page, order);
460 			q->pg_chunk.page = NULL;
461 			return -EIO;
462 		}
463 		q->pg_chunk.mapping = mapping;
464 	}
465 	sd->pg_chunk = q->pg_chunk;
466 
467 	prefetch(sd->pg_chunk.p_cnt);
468 
469 	q->pg_chunk.offset += q->buf_size;
470 	if (q->pg_chunk.offset == (PAGE_SIZE << order))
471 		q->pg_chunk.page = NULL;
472 	else {
473 		q->pg_chunk.va += q->buf_size;
474 		get_page(q->pg_chunk.page);
475 	}
476 
477 	if (sd->pg_chunk.offset == 0)
478 		*sd->pg_chunk.p_cnt = 1;
479 	else
480 		*sd->pg_chunk.p_cnt += 1;
481 
482 	return 0;
483 }
484 
485 static inline void ring_fl_db(struct adapter *adap, struct sge_fl *q)
486 {
487 	if (q->pend_cred >= q->credits / 4) {
488 		q->pend_cred = 0;
489 		wmb();
490 		t3_write_reg(adap, A_SG_KDOORBELL, V_EGRCNTX(q->cntxt_id));
491 	}
492 }
493 
494 /**
495  *	refill_fl - refill an SGE free-buffer list
496  *	@adap: the adapter
497  *	@q: the free-list to refill
498  *	@n: the number of new buffers to allocate
499  *	@gfp: the gfp flags for allocating new buffers
500  *
501  *	(Re)populate an SGE free-buffer list with up to @n new packet buffers,
502  *	allocated with the supplied gfp flags.  The caller must assure that
503  *	@n does not exceed the queue's capacity.
504  */
505 static int refill_fl(struct adapter *adap, struct sge_fl *q, int n, gfp_t gfp)
506 {
507 	struct rx_sw_desc *sd = &q->sdesc[q->pidx];
508 	struct rx_desc *d = &q->desc[q->pidx];
509 	unsigned int count = 0;
510 
511 	while (n--) {
512 		dma_addr_t mapping;
513 		int err;
514 
515 		if (q->use_pages) {
516 			if (unlikely(alloc_pg_chunk(adap, q, sd, gfp,
517 						    q->order))) {
518 nomem:				q->alloc_failed++;
519 				break;
520 			}
521 			mapping = sd->pg_chunk.mapping + sd->pg_chunk.offset;
522 			dma_unmap_addr_set(sd, dma_addr, mapping);
523 
524 			add_one_rx_chunk(mapping, d, q->gen);
525 			pci_dma_sync_single_for_device(adap->pdev, mapping,
526 						q->buf_size - SGE_PG_RSVD,
527 						PCI_DMA_FROMDEVICE);
528 		} else {
529 			void *buf_start;
530 
531 			struct sk_buff *skb = alloc_skb(q->buf_size, gfp);
532 			if (!skb)
533 				goto nomem;
534 
535 			sd->skb = skb;
536 			buf_start = skb->data;
537 			err = add_one_rx_buf(buf_start, q->buf_size, d, sd,
538 					     q->gen, adap->pdev);
539 			if (unlikely(err)) {
540 				clear_rx_desc(adap->pdev, q, sd);
541 				break;
542 			}
543 		}
544 
545 		d++;
546 		sd++;
547 		if (++q->pidx == q->size) {
548 			q->pidx = 0;
549 			q->gen ^= 1;
550 			sd = q->sdesc;
551 			d = q->desc;
552 		}
553 		count++;
554 	}
555 
556 	q->credits += count;
557 	q->pend_cred += count;
558 	ring_fl_db(adap, q);
559 
560 	return count;
561 }
562 
563 static inline void __refill_fl(struct adapter *adap, struct sge_fl *fl)
564 {
565 	refill_fl(adap, fl, min(MAX_RX_REFILL, fl->size - fl->credits),
566 		  GFP_ATOMIC | __GFP_COMP);
567 }
568 
569 /**
570  *	recycle_rx_buf - recycle a receive buffer
571  *	@adap: the adapter
572  *	@q: the SGE free list
573  *	@idx: index of buffer to recycle
574  *
575  *	Recycles the specified buffer on the given free list by adding it at
576  *	the next available slot on the list.
577  */
578 static void recycle_rx_buf(struct adapter *adap, struct sge_fl *q,
579 			   unsigned int idx)
580 {
581 	struct rx_desc *from = &q->desc[idx];
582 	struct rx_desc *to = &q->desc[q->pidx];
583 
584 	q->sdesc[q->pidx] = q->sdesc[idx];
585 	to->addr_lo = from->addr_lo;	/* already big endian */
586 	to->addr_hi = from->addr_hi;	/* likewise */
587 	dma_wmb();
588 	to->len_gen = cpu_to_be32(V_FLD_GEN1(q->gen));
589 	to->gen2 = cpu_to_be32(V_FLD_GEN2(q->gen));
590 
591 	if (++q->pidx == q->size) {
592 		q->pidx = 0;
593 		q->gen ^= 1;
594 	}
595 
596 	q->credits++;
597 	q->pend_cred++;
598 	ring_fl_db(adap, q);
599 }
600 
601 /**
602  *	alloc_ring - allocate resources for an SGE descriptor ring
603  *	@pdev: the PCI device
604  *	@nelem: the number of descriptors
605  *	@elem_size: the size of each descriptor
606  *	@sw_size: the size of the SW state associated with each ring element
607  *	@phys: the physical address of the allocated ring
608  *	@metadata: address of the array holding the SW state for the ring
609  *
610  *	Allocates resources for an SGE descriptor ring, such as Tx queues,
611  *	free buffer lists, or response queues.  Each SGE ring requires
612  *	space for its HW descriptors plus, optionally, space for the SW state
613  *	associated with each HW entry (the metadata).  The function returns
614  *	three values: the virtual address for the HW ring (the return value
615  *	of the function), the physical address of the HW ring, and the address
616  *	of the SW ring.
617  */
618 static void *alloc_ring(struct pci_dev *pdev, size_t nelem, size_t elem_size,
619 			size_t sw_size, dma_addr_t * phys, void *metadata)
620 {
621 	size_t len = nelem * elem_size;
622 	void *s = NULL;
623 	void *p = dma_alloc_coherent(&pdev->dev, len, phys, GFP_KERNEL);
624 
625 	if (!p)
626 		return NULL;
627 	if (sw_size && metadata) {
628 		s = kcalloc(nelem, sw_size, GFP_KERNEL);
629 
630 		if (!s) {
631 			dma_free_coherent(&pdev->dev, len, p, *phys);
632 			return NULL;
633 		}
634 		*(void **)metadata = s;
635 	}
636 	return p;
637 }
638 
639 /**
640  *	t3_reset_qset - reset a sge qset
641  *	@q: the queue set
642  *
643  *	Reset the qset structure.
644  *	the NAPI structure is preserved in the event of
645  *	the qset's reincarnation, for example during EEH recovery.
646  */
647 static void t3_reset_qset(struct sge_qset *q)
648 {
649 	if (q->adap &&
650 	    !(q->adap->flags & NAPI_INIT)) {
651 		memset(q, 0, sizeof(*q));
652 		return;
653 	}
654 
655 	q->adap = NULL;
656 	memset(&q->rspq, 0, sizeof(q->rspq));
657 	memset(q->fl, 0, sizeof(struct sge_fl) * SGE_RXQ_PER_SET);
658 	memset(q->txq, 0, sizeof(struct sge_txq) * SGE_TXQ_PER_SET);
659 	q->txq_stopped = 0;
660 	q->tx_reclaim_timer.function = NULL; /* for t3_stop_sge_timers() */
661 	q->rx_reclaim_timer.function = NULL;
662 	q->nomem = 0;
663 	napi_free_frags(&q->napi);
664 }
665 
666 
667 /**
668  *	t3_free_qset - free the resources of an SGE queue set
669  *	@adapter: the adapter owning the queue set
670  *	@q: the queue set
671  *
672  *	Release the HW and SW resources associated with an SGE queue set, such
673  *	as HW contexts, packet buffers, and descriptor rings.  Traffic to the
674  *	queue set must be quiesced prior to calling this.
675  */
676 static void t3_free_qset(struct adapter *adapter, struct sge_qset *q)
677 {
678 	int i;
679 	struct pci_dev *pdev = adapter->pdev;
680 
681 	for (i = 0; i < SGE_RXQ_PER_SET; ++i)
682 		if (q->fl[i].desc) {
683 			spin_lock_irq(&adapter->sge.reg_lock);
684 			t3_sge_disable_fl(adapter, q->fl[i].cntxt_id);
685 			spin_unlock_irq(&adapter->sge.reg_lock);
686 			free_rx_bufs(pdev, &q->fl[i]);
687 			kfree(q->fl[i].sdesc);
688 			dma_free_coherent(&pdev->dev,
689 					  q->fl[i].size *
690 					  sizeof(struct rx_desc), q->fl[i].desc,
691 					  q->fl[i].phys_addr);
692 		}
693 
694 	for (i = 0; i < SGE_TXQ_PER_SET; ++i)
695 		if (q->txq[i].desc) {
696 			spin_lock_irq(&adapter->sge.reg_lock);
697 			t3_sge_enable_ecntxt(adapter, q->txq[i].cntxt_id, 0);
698 			spin_unlock_irq(&adapter->sge.reg_lock);
699 			if (q->txq[i].sdesc) {
700 				free_tx_desc(adapter, &q->txq[i],
701 					     q->txq[i].in_use);
702 				kfree(q->txq[i].sdesc);
703 			}
704 			dma_free_coherent(&pdev->dev,
705 					  q->txq[i].size *
706 					  sizeof(struct tx_desc),
707 					  q->txq[i].desc, q->txq[i].phys_addr);
708 			__skb_queue_purge(&q->txq[i].sendq);
709 		}
710 
711 	if (q->rspq.desc) {
712 		spin_lock_irq(&adapter->sge.reg_lock);
713 		t3_sge_disable_rspcntxt(adapter, q->rspq.cntxt_id);
714 		spin_unlock_irq(&adapter->sge.reg_lock);
715 		dma_free_coherent(&pdev->dev,
716 				  q->rspq.size * sizeof(struct rsp_desc),
717 				  q->rspq.desc, q->rspq.phys_addr);
718 	}
719 
720 	t3_reset_qset(q);
721 }
722 
723 /**
724  *	init_qset_cntxt - initialize an SGE queue set context info
725  *	@qs: the queue set
726  *	@id: the queue set id
727  *
728  *	Initializes the TIDs and context ids for the queues of a queue set.
729  */
730 static void init_qset_cntxt(struct sge_qset *qs, unsigned int id)
731 {
732 	qs->rspq.cntxt_id = id;
733 	qs->fl[0].cntxt_id = 2 * id;
734 	qs->fl[1].cntxt_id = 2 * id + 1;
735 	qs->txq[TXQ_ETH].cntxt_id = FW_TUNNEL_SGEEC_START + id;
736 	qs->txq[TXQ_ETH].token = FW_TUNNEL_TID_START + id;
737 	qs->txq[TXQ_OFLD].cntxt_id = FW_OFLD_SGEEC_START + id;
738 	qs->txq[TXQ_CTRL].cntxt_id = FW_CTRL_SGEEC_START + id;
739 	qs->txq[TXQ_CTRL].token = FW_CTRL_TID_START + id;
740 }
741 
742 /**
743  *	sgl_len - calculates the size of an SGL of the given capacity
744  *	@n: the number of SGL entries
745  *
746  *	Calculates the number of flits needed for a scatter/gather list that
747  *	can hold the given number of entries.
748  */
749 static inline unsigned int sgl_len(unsigned int n)
750 {
751 	/* alternatively: 3 * (n / 2) + 2 * (n & 1) */
752 	return (3 * n) / 2 + (n & 1);
753 }
754 
755 /**
756  *	flits_to_desc - returns the num of Tx descriptors for the given flits
757  *	@n: the number of flits
758  *
759  *	Calculates the number of Tx descriptors needed for the supplied number
760  *	of flits.
761  */
762 static inline unsigned int flits_to_desc(unsigned int n)
763 {
764 	BUG_ON(n >= ARRAY_SIZE(flit_desc_map));
765 	return flit_desc_map[n];
766 }
767 
768 /**
769  *	get_packet - return the next ingress packet buffer from a free list
770  *	@adap: the adapter that received the packet
771  *	@fl: the SGE free list holding the packet
772  *	@len: the packet length including any SGE padding
773  *	@drop_thres: # of remaining buffers before we start dropping packets
774  *
775  *	Get the next packet from a free list and complete setup of the
776  *	sk_buff.  If the packet is small we make a copy and recycle the
777  *	original buffer, otherwise we use the original buffer itself.  If a
778  *	positive drop threshold is supplied packets are dropped and their
779  *	buffers recycled if (a) the number of remaining buffers is under the
780  *	threshold and the packet is too big to copy, or (b) the packet should
781  *	be copied but there is no memory for the copy.
782  */
783 static struct sk_buff *get_packet(struct adapter *adap, struct sge_fl *fl,
784 				  unsigned int len, unsigned int drop_thres)
785 {
786 	struct sk_buff *skb = NULL;
787 	struct rx_sw_desc *sd = &fl->sdesc[fl->cidx];
788 
789 	prefetch(sd->skb->data);
790 	fl->credits--;
791 
792 	if (len <= SGE_RX_COPY_THRES) {
793 		skb = alloc_skb(len, GFP_ATOMIC);
794 		if (likely(skb != NULL)) {
795 			__skb_put(skb, len);
796 			pci_dma_sync_single_for_cpu(adap->pdev,
797 					    dma_unmap_addr(sd, dma_addr), len,
798 					    PCI_DMA_FROMDEVICE);
799 			memcpy(skb->data, sd->skb->data, len);
800 			pci_dma_sync_single_for_device(adap->pdev,
801 					    dma_unmap_addr(sd, dma_addr), len,
802 					    PCI_DMA_FROMDEVICE);
803 		} else if (!drop_thres)
804 			goto use_orig_buf;
805 recycle:
806 		recycle_rx_buf(adap, fl, fl->cidx);
807 		return skb;
808 	}
809 
810 	if (unlikely(fl->credits < drop_thres) &&
811 	    refill_fl(adap, fl, min(MAX_RX_REFILL, fl->size - fl->credits - 1),
812 		      GFP_ATOMIC | __GFP_COMP) == 0)
813 		goto recycle;
814 
815 use_orig_buf:
816 	pci_unmap_single(adap->pdev, dma_unmap_addr(sd, dma_addr),
817 			 fl->buf_size, PCI_DMA_FROMDEVICE);
818 	skb = sd->skb;
819 	skb_put(skb, len);
820 	__refill_fl(adap, fl);
821 	return skb;
822 }
823 
824 /**
825  *	get_packet_pg - return the next ingress packet buffer from a free list
826  *	@adap: the adapter that received the packet
827  *	@fl: the SGE free list holding the packet
828  *	@q: the queue
829  *	@len: the packet length including any SGE padding
830  *	@drop_thres: # of remaining buffers before we start dropping packets
831  *
832  *	Get the next packet from a free list populated with page chunks.
833  *	If the packet is small we make a copy and recycle the original buffer,
834  *	otherwise we attach the original buffer as a page fragment to a fresh
835  *	sk_buff.  If a positive drop threshold is supplied packets are dropped
836  *	and their buffers recycled if (a) the number of remaining buffers is
837  *	under the threshold and the packet is too big to copy, or (b) there's
838  *	no system memory.
839  *
840  * 	Note: this function is similar to @get_packet but deals with Rx buffers
841  * 	that are page chunks rather than sk_buffs.
842  */
843 static struct sk_buff *get_packet_pg(struct adapter *adap, struct sge_fl *fl,
844 				     struct sge_rspq *q, unsigned int len,
845 				     unsigned int drop_thres)
846 {
847 	struct sk_buff *newskb, *skb;
848 	struct rx_sw_desc *sd = &fl->sdesc[fl->cidx];
849 
850 	dma_addr_t dma_addr = dma_unmap_addr(sd, dma_addr);
851 
852 	newskb = skb = q->pg_skb;
853 	if (!skb && (len <= SGE_RX_COPY_THRES)) {
854 		newskb = alloc_skb(len, GFP_ATOMIC);
855 		if (likely(newskb != NULL)) {
856 			__skb_put(newskb, len);
857 			pci_dma_sync_single_for_cpu(adap->pdev, dma_addr, len,
858 					    PCI_DMA_FROMDEVICE);
859 			memcpy(newskb->data, sd->pg_chunk.va, len);
860 			pci_dma_sync_single_for_device(adap->pdev, dma_addr,
861 						       len,
862 						       PCI_DMA_FROMDEVICE);
863 		} else if (!drop_thres)
864 			return NULL;
865 recycle:
866 		fl->credits--;
867 		recycle_rx_buf(adap, fl, fl->cidx);
868 		q->rx_recycle_buf++;
869 		return newskb;
870 	}
871 
872 	if (unlikely(q->rx_recycle_buf || (!skb && fl->credits <= drop_thres)))
873 		goto recycle;
874 
875 	prefetch(sd->pg_chunk.p_cnt);
876 
877 	if (!skb)
878 		newskb = alloc_skb(SGE_RX_PULL_LEN, GFP_ATOMIC);
879 
880 	if (unlikely(!newskb)) {
881 		if (!drop_thres)
882 			return NULL;
883 		goto recycle;
884 	}
885 
886 	pci_dma_sync_single_for_cpu(adap->pdev, dma_addr, len,
887 				    PCI_DMA_FROMDEVICE);
888 	(*sd->pg_chunk.p_cnt)--;
889 	if (!*sd->pg_chunk.p_cnt && sd->pg_chunk.page != fl->pg_chunk.page)
890 		pci_unmap_page(adap->pdev,
891 			       sd->pg_chunk.mapping,
892 			       fl->alloc_size,
893 			       PCI_DMA_FROMDEVICE);
894 	if (!skb) {
895 		__skb_put(newskb, SGE_RX_PULL_LEN);
896 		memcpy(newskb->data, sd->pg_chunk.va, SGE_RX_PULL_LEN);
897 		skb_fill_page_desc(newskb, 0, sd->pg_chunk.page,
898 				   sd->pg_chunk.offset + SGE_RX_PULL_LEN,
899 				   len - SGE_RX_PULL_LEN);
900 		newskb->len = len;
901 		newskb->data_len = len - SGE_RX_PULL_LEN;
902 		newskb->truesize += newskb->data_len;
903 	} else {
904 		skb_fill_page_desc(newskb, skb_shinfo(newskb)->nr_frags,
905 				   sd->pg_chunk.page,
906 				   sd->pg_chunk.offset, len);
907 		newskb->len += len;
908 		newskb->data_len += len;
909 		newskb->truesize += len;
910 	}
911 
912 	fl->credits--;
913 	/*
914 	 * We do not refill FLs here, we let the caller do it to overlap a
915 	 * prefetch.
916 	 */
917 	return newskb;
918 }
919 
920 /**
921  *	get_imm_packet - return the next ingress packet buffer from a response
922  *	@resp: the response descriptor containing the packet data
923  *
924  *	Return a packet containing the immediate data of the given response.
925  */
926 static inline struct sk_buff *get_imm_packet(const struct rsp_desc *resp)
927 {
928 	struct sk_buff *skb = alloc_skb(IMMED_PKT_SIZE, GFP_ATOMIC);
929 
930 	if (skb) {
931 		__skb_put(skb, IMMED_PKT_SIZE);
932 		skb_copy_to_linear_data(skb, resp->imm_data, IMMED_PKT_SIZE);
933 	}
934 	return skb;
935 }
936 
937 /**
938  *	calc_tx_descs - calculate the number of Tx descriptors for a packet
939  *	@skb: the packet
940  *
941  * 	Returns the number of Tx descriptors needed for the given Ethernet
942  * 	packet.  Ethernet packets require addition of WR and CPL headers.
943  */
944 static inline unsigned int calc_tx_descs(const struct sk_buff *skb)
945 {
946 	unsigned int flits;
947 
948 	if (skb->len <= WR_LEN - sizeof(struct cpl_tx_pkt))
949 		return 1;
950 
951 	flits = sgl_len(skb_shinfo(skb)->nr_frags + 1) + 2;
952 	if (skb_shinfo(skb)->gso_size)
953 		flits++;
954 	return flits_to_desc(flits);
955 }
956 
957 /*	map_skb - map a packet main body and its page fragments
958  *	@pdev: the PCI device
959  *	@skb: the packet
960  *	@addr: placeholder to save the mapped addresses
961  *
962  *	map the main body of an sk_buff and its page fragments, if any.
963  */
964 static int map_skb(struct pci_dev *pdev, const struct sk_buff *skb,
965 		   dma_addr_t *addr)
966 {
967 	const skb_frag_t *fp, *end;
968 	const struct skb_shared_info *si;
969 
970 	if (skb_headlen(skb)) {
971 		*addr = pci_map_single(pdev, skb->data, skb_headlen(skb),
972 				       PCI_DMA_TODEVICE);
973 		if (pci_dma_mapping_error(pdev, *addr))
974 			goto out_err;
975 		addr++;
976 	}
977 
978 	si = skb_shinfo(skb);
979 	end = &si->frags[si->nr_frags];
980 
981 	for (fp = si->frags; fp < end; fp++) {
982 		*addr = skb_frag_dma_map(&pdev->dev, fp, 0, skb_frag_size(fp),
983 					 DMA_TO_DEVICE);
984 		if (pci_dma_mapping_error(pdev, *addr))
985 			goto unwind;
986 		addr++;
987 	}
988 	return 0;
989 
990 unwind:
991 	while (fp-- > si->frags)
992 		dma_unmap_page(&pdev->dev, *--addr, skb_frag_size(fp),
993 			       DMA_TO_DEVICE);
994 
995 	pci_unmap_single(pdev, addr[-1], skb_headlen(skb), PCI_DMA_TODEVICE);
996 out_err:
997 	return -ENOMEM;
998 }
999 
1000 /**
1001  *	write_sgl - populate a scatter/gather list for a packet
1002  *	@skb: the packet
1003  *	@sgp: the SGL to populate
1004  *	@start: start address of skb main body data to include in the SGL
1005  *	@len: length of skb main body data to include in the SGL
1006  *	@addr: the list of the mapped addresses
1007  *
1008  *	Copies the scatter/gather list for the buffers that make up a packet
1009  *	and returns the SGL size in 8-byte words.  The caller must size the SGL
1010  *	appropriately.
1011  */
1012 static inline unsigned int write_sgl(const struct sk_buff *skb,
1013 				     struct sg_ent *sgp, unsigned char *start,
1014 				     unsigned int len, const dma_addr_t *addr)
1015 {
1016 	unsigned int i, j = 0, k = 0, nfrags;
1017 
1018 	if (len) {
1019 		sgp->len[0] = cpu_to_be32(len);
1020 		sgp->addr[j++] = cpu_to_be64(addr[k++]);
1021 	}
1022 
1023 	nfrags = skb_shinfo(skb)->nr_frags;
1024 	for (i = 0; i < nfrags; i++) {
1025 		const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1026 
1027 		sgp->len[j] = cpu_to_be32(skb_frag_size(frag));
1028 		sgp->addr[j] = cpu_to_be64(addr[k++]);
1029 		j ^= 1;
1030 		if (j == 0)
1031 			++sgp;
1032 	}
1033 	if (j)
1034 		sgp->len[j] = 0;
1035 	return ((nfrags + (len != 0)) * 3) / 2 + j;
1036 }
1037 
1038 /**
1039  *	check_ring_tx_db - check and potentially ring a Tx queue's doorbell
1040  *	@adap: the adapter
1041  *	@q: the Tx queue
1042  *
1043  *	Ring the doorbel if a Tx queue is asleep.  There is a natural race,
1044  *	where the HW is going to sleep just after we checked, however,
1045  *	then the interrupt handler will detect the outstanding TX packet
1046  *	and ring the doorbell for us.
1047  *
1048  *	When GTS is disabled we unconditionally ring the doorbell.
1049  */
1050 static inline void check_ring_tx_db(struct adapter *adap, struct sge_txq *q)
1051 {
1052 #if USE_GTS
1053 	clear_bit(TXQ_LAST_PKT_DB, &q->flags);
1054 	if (test_and_set_bit(TXQ_RUNNING, &q->flags) == 0) {
1055 		set_bit(TXQ_LAST_PKT_DB, &q->flags);
1056 		t3_write_reg(adap, A_SG_KDOORBELL,
1057 			     F_SELEGRCNTX | V_EGRCNTX(q->cntxt_id));
1058 	}
1059 #else
1060 	wmb();			/* write descriptors before telling HW */
1061 	t3_write_reg(adap, A_SG_KDOORBELL,
1062 		     F_SELEGRCNTX | V_EGRCNTX(q->cntxt_id));
1063 #endif
1064 }
1065 
1066 static inline void wr_gen2(struct tx_desc *d, unsigned int gen)
1067 {
1068 #if SGE_NUM_GENBITS == 2
1069 	d->flit[TX_DESC_FLITS - 1] = cpu_to_be64(gen);
1070 #endif
1071 }
1072 
1073 /**
1074  *	write_wr_hdr_sgl - write a WR header and, optionally, SGL
1075  *	@ndesc: number of Tx descriptors spanned by the SGL
1076  *	@skb: the packet corresponding to the WR
1077  *	@d: first Tx descriptor to be written
1078  *	@pidx: index of above descriptors
1079  *	@q: the SGE Tx queue
1080  *	@sgl: the SGL
1081  *	@flits: number of flits to the start of the SGL in the first descriptor
1082  *	@sgl_flits: the SGL size in flits
1083  *	@gen: the Tx descriptor generation
1084  *	@wr_hi: top 32 bits of WR header based on WR type (big endian)
1085  *	@wr_lo: low 32 bits of WR header based on WR type (big endian)
1086  *
1087  *	Write a work request header and an associated SGL.  If the SGL is
1088  *	small enough to fit into one Tx descriptor it has already been written
1089  *	and we just need to write the WR header.  Otherwise we distribute the
1090  *	SGL across the number of descriptors it spans.
1091  */
1092 static void write_wr_hdr_sgl(unsigned int ndesc, struct sk_buff *skb,
1093 			     struct tx_desc *d, unsigned int pidx,
1094 			     const struct sge_txq *q,
1095 			     const struct sg_ent *sgl,
1096 			     unsigned int flits, unsigned int sgl_flits,
1097 			     unsigned int gen, __be32 wr_hi,
1098 			     __be32 wr_lo)
1099 {
1100 	struct work_request_hdr *wrp = (struct work_request_hdr *)d;
1101 	struct tx_sw_desc *sd = &q->sdesc[pidx];
1102 
1103 	sd->skb = skb;
1104 	if (need_skb_unmap()) {
1105 		sd->fragidx = 0;
1106 		sd->addr_idx = 0;
1107 		sd->sflit = flits;
1108 	}
1109 
1110 	if (likely(ndesc == 1)) {
1111 		sd->eop = 1;
1112 		wrp->wr_hi = htonl(F_WR_SOP | F_WR_EOP | V_WR_DATATYPE(1) |
1113 				   V_WR_SGLSFLT(flits)) | wr_hi;
1114 		dma_wmb();
1115 		wrp->wr_lo = htonl(V_WR_LEN(flits + sgl_flits) |
1116 				   V_WR_GEN(gen)) | wr_lo;
1117 		wr_gen2(d, gen);
1118 	} else {
1119 		unsigned int ogen = gen;
1120 		const u64 *fp = (const u64 *)sgl;
1121 		struct work_request_hdr *wp = wrp;
1122 
1123 		wrp->wr_hi = htonl(F_WR_SOP | V_WR_DATATYPE(1) |
1124 				   V_WR_SGLSFLT(flits)) | wr_hi;
1125 
1126 		while (sgl_flits) {
1127 			unsigned int avail = WR_FLITS - flits;
1128 
1129 			if (avail > sgl_flits)
1130 				avail = sgl_flits;
1131 			memcpy(&d->flit[flits], fp, avail * sizeof(*fp));
1132 			sgl_flits -= avail;
1133 			ndesc--;
1134 			if (!sgl_flits)
1135 				break;
1136 
1137 			fp += avail;
1138 			d++;
1139 			sd->eop = 0;
1140 			sd++;
1141 			if (++pidx == q->size) {
1142 				pidx = 0;
1143 				gen ^= 1;
1144 				d = q->desc;
1145 				sd = q->sdesc;
1146 			}
1147 
1148 			sd->skb = skb;
1149 			wrp = (struct work_request_hdr *)d;
1150 			wrp->wr_hi = htonl(V_WR_DATATYPE(1) |
1151 					   V_WR_SGLSFLT(1)) | wr_hi;
1152 			wrp->wr_lo = htonl(V_WR_LEN(min(WR_FLITS,
1153 							sgl_flits + 1)) |
1154 					   V_WR_GEN(gen)) | wr_lo;
1155 			wr_gen2(d, gen);
1156 			flits = 1;
1157 		}
1158 		sd->eop = 1;
1159 		wrp->wr_hi |= htonl(F_WR_EOP);
1160 		dma_wmb();
1161 		wp->wr_lo = htonl(V_WR_LEN(WR_FLITS) | V_WR_GEN(ogen)) | wr_lo;
1162 		wr_gen2((struct tx_desc *)wp, ogen);
1163 		WARN_ON(ndesc != 0);
1164 	}
1165 }
1166 
1167 /**
1168  *	write_tx_pkt_wr - write a TX_PKT work request
1169  *	@adap: the adapter
1170  *	@skb: the packet to send
1171  *	@pi: the egress interface
1172  *	@pidx: index of the first Tx descriptor to write
1173  *	@gen: the generation value to use
1174  *	@q: the Tx queue
1175  *	@ndesc: number of descriptors the packet will occupy
1176  *	@compl: the value of the COMPL bit to use
1177  *	@addr: address
1178  *
1179  *	Generate a TX_PKT work request to send the supplied packet.
1180  */
1181 static void write_tx_pkt_wr(struct adapter *adap, struct sk_buff *skb,
1182 			    const struct port_info *pi,
1183 			    unsigned int pidx, unsigned int gen,
1184 			    struct sge_txq *q, unsigned int ndesc,
1185 			    unsigned int compl, const dma_addr_t *addr)
1186 {
1187 	unsigned int flits, sgl_flits, cntrl, tso_info;
1188 	struct sg_ent *sgp, sgl[MAX_SKB_FRAGS / 2 + 1];
1189 	struct tx_desc *d = &q->desc[pidx];
1190 	struct cpl_tx_pkt *cpl = (struct cpl_tx_pkt *)d;
1191 
1192 	cpl->len = htonl(skb->len);
1193 	cntrl = V_TXPKT_INTF(pi->port_id);
1194 
1195 	if (skb_vlan_tag_present(skb))
1196 		cntrl |= F_TXPKT_VLAN_VLD | V_TXPKT_VLAN(skb_vlan_tag_get(skb));
1197 
1198 	tso_info = V_LSO_MSS(skb_shinfo(skb)->gso_size);
1199 	if (tso_info) {
1200 		int eth_type;
1201 		struct cpl_tx_pkt_lso *hdr = (struct cpl_tx_pkt_lso *)cpl;
1202 
1203 		d->flit[2] = 0;
1204 		cntrl |= V_TXPKT_OPCODE(CPL_TX_PKT_LSO);
1205 		hdr->cntrl = htonl(cntrl);
1206 		eth_type = skb_network_offset(skb) == ETH_HLEN ?
1207 		    CPL_ETH_II : CPL_ETH_II_VLAN;
1208 		tso_info |= V_LSO_ETH_TYPE(eth_type) |
1209 		    V_LSO_IPHDR_WORDS(ip_hdr(skb)->ihl) |
1210 		    V_LSO_TCPHDR_WORDS(tcp_hdr(skb)->doff);
1211 		hdr->lso_info = htonl(tso_info);
1212 		flits = 3;
1213 	} else {
1214 		cntrl |= V_TXPKT_OPCODE(CPL_TX_PKT);
1215 		cntrl |= F_TXPKT_IPCSUM_DIS;	/* SW calculates IP csum */
1216 		cntrl |= V_TXPKT_L4CSUM_DIS(skb->ip_summed != CHECKSUM_PARTIAL);
1217 		cpl->cntrl = htonl(cntrl);
1218 
1219 		if (skb->len <= WR_LEN - sizeof(*cpl)) {
1220 			q->sdesc[pidx].skb = NULL;
1221 			if (!skb->data_len)
1222 				skb_copy_from_linear_data(skb, &d->flit[2],
1223 							  skb->len);
1224 			else
1225 				skb_copy_bits(skb, 0, &d->flit[2], skb->len);
1226 
1227 			flits = (skb->len + 7) / 8 + 2;
1228 			cpl->wr.wr_hi = htonl(V_WR_BCNTLFLT(skb->len & 7) |
1229 					      V_WR_OP(FW_WROPCODE_TUNNEL_TX_PKT)
1230 					      | F_WR_SOP | F_WR_EOP | compl);
1231 			dma_wmb();
1232 			cpl->wr.wr_lo = htonl(V_WR_LEN(flits) | V_WR_GEN(gen) |
1233 					      V_WR_TID(q->token));
1234 			wr_gen2(d, gen);
1235 			dev_consume_skb_any(skb);
1236 			return;
1237 		}
1238 
1239 		flits = 2;
1240 	}
1241 
1242 	sgp = ndesc == 1 ? (struct sg_ent *)&d->flit[flits] : sgl;
1243 	sgl_flits = write_sgl(skb, sgp, skb->data, skb_headlen(skb), addr);
1244 
1245 	write_wr_hdr_sgl(ndesc, skb, d, pidx, q, sgl, flits, sgl_flits, gen,
1246 			 htonl(V_WR_OP(FW_WROPCODE_TUNNEL_TX_PKT) | compl),
1247 			 htonl(V_WR_TID(q->token)));
1248 }
1249 
1250 static inline void t3_stop_tx_queue(struct netdev_queue *txq,
1251 				    struct sge_qset *qs, struct sge_txq *q)
1252 {
1253 	netif_tx_stop_queue(txq);
1254 	set_bit(TXQ_ETH, &qs->txq_stopped);
1255 	q->stops++;
1256 }
1257 
1258 /**
1259  *	t3_eth_xmit - add a packet to the Ethernet Tx queue
1260  *	@skb: the packet
1261  *	@dev: the egress net device
1262  *
1263  *	Add a packet to an SGE Tx queue.  Runs with softirqs disabled.
1264  */
1265 netdev_tx_t t3_eth_xmit(struct sk_buff *skb, struct net_device *dev)
1266 {
1267 	int qidx;
1268 	unsigned int ndesc, pidx, credits, gen, compl;
1269 	const struct port_info *pi = netdev_priv(dev);
1270 	struct adapter *adap = pi->adapter;
1271 	struct netdev_queue *txq;
1272 	struct sge_qset *qs;
1273 	struct sge_txq *q;
1274 	dma_addr_t addr[MAX_SKB_FRAGS + 1];
1275 
1276 	/*
1277 	 * The chip min packet length is 9 octets but play safe and reject
1278 	 * anything shorter than an Ethernet header.
1279 	 */
1280 	if (unlikely(skb->len < ETH_HLEN)) {
1281 		dev_kfree_skb_any(skb);
1282 		return NETDEV_TX_OK;
1283 	}
1284 
1285 	qidx = skb_get_queue_mapping(skb);
1286 	qs = &pi->qs[qidx];
1287 	q = &qs->txq[TXQ_ETH];
1288 	txq = netdev_get_tx_queue(dev, qidx);
1289 
1290 	reclaim_completed_tx(adap, q, TX_RECLAIM_CHUNK);
1291 
1292 	credits = q->size - q->in_use;
1293 	ndesc = calc_tx_descs(skb);
1294 
1295 	if (unlikely(credits < ndesc)) {
1296 		t3_stop_tx_queue(txq, qs, q);
1297 		dev_err(&adap->pdev->dev,
1298 			"%s: Tx ring %u full while queue awake!\n",
1299 			dev->name, q->cntxt_id & 7);
1300 		return NETDEV_TX_BUSY;
1301 	}
1302 
1303 	/* Check if ethernet packet can't be sent as immediate data */
1304 	if (skb->len > (WR_LEN - sizeof(struct cpl_tx_pkt))) {
1305 		if (unlikely(map_skb(adap->pdev, skb, addr) < 0)) {
1306 			dev_kfree_skb(skb);
1307 			return NETDEV_TX_OK;
1308 		}
1309 	}
1310 
1311 	q->in_use += ndesc;
1312 	if (unlikely(credits - ndesc < q->stop_thres)) {
1313 		t3_stop_tx_queue(txq, qs, q);
1314 
1315 		if (should_restart_tx(q) &&
1316 		    test_and_clear_bit(TXQ_ETH, &qs->txq_stopped)) {
1317 			q->restarts++;
1318 			netif_tx_start_queue(txq);
1319 		}
1320 	}
1321 
1322 	gen = q->gen;
1323 	q->unacked += ndesc;
1324 	compl = (q->unacked & 8) << (S_WR_COMPL - 3);
1325 	q->unacked &= 7;
1326 	pidx = q->pidx;
1327 	q->pidx += ndesc;
1328 	if (q->pidx >= q->size) {
1329 		q->pidx -= q->size;
1330 		q->gen ^= 1;
1331 	}
1332 
1333 	/* update port statistics */
1334 	if (skb->ip_summed == CHECKSUM_PARTIAL)
1335 		qs->port_stats[SGE_PSTAT_TX_CSUM]++;
1336 	if (skb_shinfo(skb)->gso_size)
1337 		qs->port_stats[SGE_PSTAT_TSO]++;
1338 	if (skb_vlan_tag_present(skb))
1339 		qs->port_stats[SGE_PSTAT_VLANINS]++;
1340 
1341 	/*
1342 	 * We do not use Tx completion interrupts to free DMAd Tx packets.
1343 	 * This is good for performance but means that we rely on new Tx
1344 	 * packets arriving to run the destructors of completed packets,
1345 	 * which open up space in their sockets' send queues.  Sometimes
1346 	 * we do not get such new packets causing Tx to stall.  A single
1347 	 * UDP transmitter is a good example of this situation.  We have
1348 	 * a clean up timer that periodically reclaims completed packets
1349 	 * but it doesn't run often enough (nor do we want it to) to prevent
1350 	 * lengthy stalls.  A solution to this problem is to run the
1351 	 * destructor early, after the packet is queued but before it's DMAd.
1352 	 * A cons is that we lie to socket memory accounting, but the amount
1353 	 * of extra memory is reasonable (limited by the number of Tx
1354 	 * descriptors), the packets do actually get freed quickly by new
1355 	 * packets almost always, and for protocols like TCP that wait for
1356 	 * acks to really free up the data the extra memory is even less.
1357 	 * On the positive side we run the destructors on the sending CPU
1358 	 * rather than on a potentially different completing CPU, usually a
1359 	 * good thing.  We also run them without holding our Tx queue lock,
1360 	 * unlike what reclaim_completed_tx() would otherwise do.
1361 	 *
1362 	 * Run the destructor before telling the DMA engine about the packet
1363 	 * to make sure it doesn't complete and get freed prematurely.
1364 	 */
1365 	if (likely(!skb_shared(skb)))
1366 		skb_orphan(skb);
1367 
1368 	write_tx_pkt_wr(adap, skb, pi, pidx, gen, q, ndesc, compl, addr);
1369 	check_ring_tx_db(adap, q);
1370 	return NETDEV_TX_OK;
1371 }
1372 
1373 /**
1374  *	write_imm - write a packet into a Tx descriptor as immediate data
1375  *	@d: the Tx descriptor to write
1376  *	@skb: the packet
1377  *	@len: the length of packet data to write as immediate data
1378  *	@gen: the generation bit value to write
1379  *
1380  *	Writes a packet as immediate data into a Tx descriptor.  The packet
1381  *	contains a work request at its beginning.  We must write the packet
1382  *	carefully so the SGE doesn't read it accidentally before it's written
1383  *	in its entirety.
1384  */
1385 static inline void write_imm(struct tx_desc *d, struct sk_buff *skb,
1386 			     unsigned int len, unsigned int gen)
1387 {
1388 	struct work_request_hdr *from = (struct work_request_hdr *)skb->data;
1389 	struct work_request_hdr *to = (struct work_request_hdr *)d;
1390 
1391 	if (likely(!skb->data_len))
1392 		memcpy(&to[1], &from[1], len - sizeof(*from));
1393 	else
1394 		skb_copy_bits(skb, sizeof(*from), &to[1], len - sizeof(*from));
1395 
1396 	to->wr_hi = from->wr_hi | htonl(F_WR_SOP | F_WR_EOP |
1397 					V_WR_BCNTLFLT(len & 7));
1398 	dma_wmb();
1399 	to->wr_lo = from->wr_lo | htonl(V_WR_GEN(gen) |
1400 					V_WR_LEN((len + 7) / 8));
1401 	wr_gen2(d, gen);
1402 	kfree_skb(skb);
1403 }
1404 
1405 /**
1406  *	check_desc_avail - check descriptor availability on a send queue
1407  *	@adap: the adapter
1408  *	@q: the send queue
1409  *	@skb: the packet needing the descriptors
1410  *	@ndesc: the number of Tx descriptors needed
1411  *	@qid: the Tx queue number in its queue set (TXQ_OFLD or TXQ_CTRL)
1412  *
1413  *	Checks if the requested number of Tx descriptors is available on an
1414  *	SGE send queue.  If the queue is already suspended or not enough
1415  *	descriptors are available the packet is queued for later transmission.
1416  *	Must be called with the Tx queue locked.
1417  *
1418  *	Returns 0 if enough descriptors are available, 1 if there aren't
1419  *	enough descriptors and the packet has been queued, and 2 if the caller
1420  *	needs to retry because there weren't enough descriptors at the
1421  *	beginning of the call but some freed up in the mean time.
1422  */
1423 static inline int check_desc_avail(struct adapter *adap, struct sge_txq *q,
1424 				   struct sk_buff *skb, unsigned int ndesc,
1425 				   unsigned int qid)
1426 {
1427 	if (unlikely(!skb_queue_empty(&q->sendq))) {
1428 	      addq_exit:__skb_queue_tail(&q->sendq, skb);
1429 		return 1;
1430 	}
1431 	if (unlikely(q->size - q->in_use < ndesc)) {
1432 		struct sge_qset *qs = txq_to_qset(q, qid);
1433 
1434 		set_bit(qid, &qs->txq_stopped);
1435 		smp_mb__after_atomic();
1436 
1437 		if (should_restart_tx(q) &&
1438 		    test_and_clear_bit(qid, &qs->txq_stopped))
1439 			return 2;
1440 
1441 		q->stops++;
1442 		goto addq_exit;
1443 	}
1444 	return 0;
1445 }
1446 
1447 /**
1448  *	reclaim_completed_tx_imm - reclaim completed control-queue Tx descs
1449  *	@q: the SGE control Tx queue
1450  *
1451  *	This is a variant of reclaim_completed_tx() that is used for Tx queues
1452  *	that send only immediate data (presently just the control queues) and
1453  *	thus do not have any sk_buffs to release.
1454  */
1455 static inline void reclaim_completed_tx_imm(struct sge_txq *q)
1456 {
1457 	unsigned int reclaim = q->processed - q->cleaned;
1458 
1459 	q->in_use -= reclaim;
1460 	q->cleaned += reclaim;
1461 }
1462 
1463 static inline int immediate(const struct sk_buff *skb)
1464 {
1465 	return skb->len <= WR_LEN;
1466 }
1467 
1468 /**
1469  *	ctrl_xmit - send a packet through an SGE control Tx queue
1470  *	@adap: the adapter
1471  *	@q: the control queue
1472  *	@skb: the packet
1473  *
1474  *	Send a packet through an SGE control Tx queue.  Packets sent through
1475  *	a control queue must fit entirely as immediate data in a single Tx
1476  *	descriptor and have no page fragments.
1477  */
1478 static int ctrl_xmit(struct adapter *adap, struct sge_txq *q,
1479 		     struct sk_buff *skb)
1480 {
1481 	int ret;
1482 	struct work_request_hdr *wrp = (struct work_request_hdr *)skb->data;
1483 
1484 	if (unlikely(!immediate(skb))) {
1485 		WARN_ON(1);
1486 		dev_kfree_skb(skb);
1487 		return NET_XMIT_SUCCESS;
1488 	}
1489 
1490 	wrp->wr_hi |= htonl(F_WR_SOP | F_WR_EOP);
1491 	wrp->wr_lo = htonl(V_WR_TID(q->token));
1492 
1493 	spin_lock(&q->lock);
1494       again:reclaim_completed_tx_imm(q);
1495 
1496 	ret = check_desc_avail(adap, q, skb, 1, TXQ_CTRL);
1497 	if (unlikely(ret)) {
1498 		if (ret == 1) {
1499 			spin_unlock(&q->lock);
1500 			return NET_XMIT_CN;
1501 		}
1502 		goto again;
1503 	}
1504 
1505 	write_imm(&q->desc[q->pidx], skb, skb->len, q->gen);
1506 
1507 	q->in_use++;
1508 	if (++q->pidx >= q->size) {
1509 		q->pidx = 0;
1510 		q->gen ^= 1;
1511 	}
1512 	spin_unlock(&q->lock);
1513 	wmb();
1514 	t3_write_reg(adap, A_SG_KDOORBELL,
1515 		     F_SELEGRCNTX | V_EGRCNTX(q->cntxt_id));
1516 	return NET_XMIT_SUCCESS;
1517 }
1518 
1519 /**
1520  *	restart_ctrlq - restart a suspended control queue
1521  *	@w: pointer to the work associated with this handler
1522  *
1523  *	Resumes transmission on a suspended Tx control queue.
1524  */
1525 static void restart_ctrlq(struct work_struct *w)
1526 {
1527 	struct sk_buff *skb;
1528 	struct sge_qset *qs = container_of(w, struct sge_qset,
1529 					   txq[TXQ_CTRL].qresume_task);
1530 	struct sge_txq *q = &qs->txq[TXQ_CTRL];
1531 
1532 	spin_lock(&q->lock);
1533       again:reclaim_completed_tx_imm(q);
1534 
1535 	while (q->in_use < q->size &&
1536 	       (skb = __skb_dequeue(&q->sendq)) != NULL) {
1537 
1538 		write_imm(&q->desc[q->pidx], skb, skb->len, q->gen);
1539 
1540 		if (++q->pidx >= q->size) {
1541 			q->pidx = 0;
1542 			q->gen ^= 1;
1543 		}
1544 		q->in_use++;
1545 	}
1546 
1547 	if (!skb_queue_empty(&q->sendq)) {
1548 		set_bit(TXQ_CTRL, &qs->txq_stopped);
1549 		smp_mb__after_atomic();
1550 
1551 		if (should_restart_tx(q) &&
1552 		    test_and_clear_bit(TXQ_CTRL, &qs->txq_stopped))
1553 			goto again;
1554 		q->stops++;
1555 	}
1556 
1557 	spin_unlock(&q->lock);
1558 	wmb();
1559 	t3_write_reg(qs->adap, A_SG_KDOORBELL,
1560 		     F_SELEGRCNTX | V_EGRCNTX(q->cntxt_id));
1561 }
1562 
1563 /*
1564  * Send a management message through control queue 0
1565  */
1566 int t3_mgmt_tx(struct adapter *adap, struct sk_buff *skb)
1567 {
1568 	int ret;
1569 	local_bh_disable();
1570 	ret = ctrl_xmit(adap, &adap->sge.qs[0].txq[TXQ_CTRL], skb);
1571 	local_bh_enable();
1572 
1573 	return ret;
1574 }
1575 
1576 /**
1577  *	deferred_unmap_destructor - unmap a packet when it is freed
1578  *	@skb: the packet
1579  *
1580  *	This is the packet destructor used for Tx packets that need to remain
1581  *	mapped until they are freed rather than until their Tx descriptors are
1582  *	freed.
1583  */
1584 static void deferred_unmap_destructor(struct sk_buff *skb)
1585 {
1586 	int i;
1587 	const dma_addr_t *p;
1588 	const struct skb_shared_info *si;
1589 	const struct deferred_unmap_info *dui;
1590 
1591 	dui = (struct deferred_unmap_info *)skb->head;
1592 	p = dui->addr;
1593 
1594 	if (skb_tail_pointer(skb) - skb_transport_header(skb))
1595 		pci_unmap_single(dui->pdev, *p++, skb_tail_pointer(skb) -
1596 				 skb_transport_header(skb), PCI_DMA_TODEVICE);
1597 
1598 	si = skb_shinfo(skb);
1599 	for (i = 0; i < si->nr_frags; i++)
1600 		pci_unmap_page(dui->pdev, *p++, skb_frag_size(&si->frags[i]),
1601 			       PCI_DMA_TODEVICE);
1602 }
1603 
1604 static void setup_deferred_unmapping(struct sk_buff *skb, struct pci_dev *pdev,
1605 				     const struct sg_ent *sgl, int sgl_flits)
1606 {
1607 	dma_addr_t *p;
1608 	struct deferred_unmap_info *dui;
1609 
1610 	dui = (struct deferred_unmap_info *)skb->head;
1611 	dui->pdev = pdev;
1612 	for (p = dui->addr; sgl_flits >= 3; sgl++, sgl_flits -= 3) {
1613 		*p++ = be64_to_cpu(sgl->addr[0]);
1614 		*p++ = be64_to_cpu(sgl->addr[1]);
1615 	}
1616 	if (sgl_flits)
1617 		*p = be64_to_cpu(sgl->addr[0]);
1618 }
1619 
1620 /**
1621  *	write_ofld_wr - write an offload work request
1622  *	@adap: the adapter
1623  *	@skb: the packet to send
1624  *	@q: the Tx queue
1625  *	@pidx: index of the first Tx descriptor to write
1626  *	@gen: the generation value to use
1627  *	@ndesc: number of descriptors the packet will occupy
1628  *	@addr: the address
1629  *
1630  *	Write an offload work request to send the supplied packet.  The packet
1631  *	data already carry the work request with most fields populated.
1632  */
1633 static void write_ofld_wr(struct adapter *adap, struct sk_buff *skb,
1634 			  struct sge_txq *q, unsigned int pidx,
1635 			  unsigned int gen, unsigned int ndesc,
1636 			  const dma_addr_t *addr)
1637 {
1638 	unsigned int sgl_flits, flits;
1639 	struct work_request_hdr *from;
1640 	struct sg_ent *sgp, sgl[MAX_SKB_FRAGS / 2 + 1];
1641 	struct tx_desc *d = &q->desc[pidx];
1642 
1643 	if (immediate(skb)) {
1644 		q->sdesc[pidx].skb = NULL;
1645 		write_imm(d, skb, skb->len, gen);
1646 		return;
1647 	}
1648 
1649 	/* Only TX_DATA builds SGLs */
1650 
1651 	from = (struct work_request_hdr *)skb->data;
1652 	memcpy(&d->flit[1], &from[1],
1653 	       skb_transport_offset(skb) - sizeof(*from));
1654 
1655 	flits = skb_transport_offset(skb) / 8;
1656 	sgp = ndesc == 1 ? (struct sg_ent *)&d->flit[flits] : sgl;
1657 	sgl_flits = write_sgl(skb, sgp, skb_transport_header(skb),
1658 			      skb_tail_pointer(skb) - skb_transport_header(skb),
1659 			      addr);
1660 	if (need_skb_unmap()) {
1661 		setup_deferred_unmapping(skb, adap->pdev, sgp, sgl_flits);
1662 		skb->destructor = deferred_unmap_destructor;
1663 	}
1664 
1665 	write_wr_hdr_sgl(ndesc, skb, d, pidx, q, sgl, flits, sgl_flits,
1666 			 gen, from->wr_hi, from->wr_lo);
1667 }
1668 
1669 /**
1670  *	calc_tx_descs_ofld - calculate # of Tx descriptors for an offload packet
1671  *	@skb: the packet
1672  *
1673  * 	Returns the number of Tx descriptors needed for the given offload
1674  * 	packet.  These packets are already fully constructed.
1675  */
1676 static inline unsigned int calc_tx_descs_ofld(const struct sk_buff *skb)
1677 {
1678 	unsigned int flits, cnt;
1679 
1680 	if (skb->len <= WR_LEN)
1681 		return 1;	/* packet fits as immediate data */
1682 
1683 	flits = skb_transport_offset(skb) / 8;	/* headers */
1684 	cnt = skb_shinfo(skb)->nr_frags;
1685 	if (skb_tail_pointer(skb) != skb_transport_header(skb))
1686 		cnt++;
1687 	return flits_to_desc(flits + sgl_len(cnt));
1688 }
1689 
1690 /**
1691  *	ofld_xmit - send a packet through an offload queue
1692  *	@adap: the adapter
1693  *	@q: the Tx offload queue
1694  *	@skb: the packet
1695  *
1696  *	Send an offload packet through an SGE offload queue.
1697  */
1698 static int ofld_xmit(struct adapter *adap, struct sge_txq *q,
1699 		     struct sk_buff *skb)
1700 {
1701 	int ret;
1702 	unsigned int ndesc = calc_tx_descs_ofld(skb), pidx, gen;
1703 
1704 	spin_lock(&q->lock);
1705 again:	reclaim_completed_tx(adap, q, TX_RECLAIM_CHUNK);
1706 
1707 	ret = check_desc_avail(adap, q, skb, ndesc, TXQ_OFLD);
1708 	if (unlikely(ret)) {
1709 		if (ret == 1) {
1710 			skb->priority = ndesc;	/* save for restart */
1711 			spin_unlock(&q->lock);
1712 			return NET_XMIT_CN;
1713 		}
1714 		goto again;
1715 	}
1716 
1717 	if (!immediate(skb) &&
1718 	    map_skb(adap->pdev, skb, (dma_addr_t *)skb->head)) {
1719 		spin_unlock(&q->lock);
1720 		return NET_XMIT_SUCCESS;
1721 	}
1722 
1723 	gen = q->gen;
1724 	q->in_use += ndesc;
1725 	pidx = q->pidx;
1726 	q->pidx += ndesc;
1727 	if (q->pidx >= q->size) {
1728 		q->pidx -= q->size;
1729 		q->gen ^= 1;
1730 	}
1731 	spin_unlock(&q->lock);
1732 
1733 	write_ofld_wr(adap, skb, q, pidx, gen, ndesc, (dma_addr_t *)skb->head);
1734 	check_ring_tx_db(adap, q);
1735 	return NET_XMIT_SUCCESS;
1736 }
1737 
1738 /**
1739  *	restart_offloadq - restart a suspended offload queue
1740  *	@w: pointer to the work associated with this handler
1741  *
1742  *	Resumes transmission on a suspended Tx offload queue.
1743  */
1744 static void restart_offloadq(struct work_struct *w)
1745 {
1746 	struct sk_buff *skb;
1747 	struct sge_qset *qs = container_of(w, struct sge_qset,
1748 					   txq[TXQ_OFLD].qresume_task);
1749 	struct sge_txq *q = &qs->txq[TXQ_OFLD];
1750 	const struct port_info *pi = netdev_priv(qs->netdev);
1751 	struct adapter *adap = pi->adapter;
1752 	unsigned int written = 0;
1753 
1754 	spin_lock(&q->lock);
1755 again:	reclaim_completed_tx(adap, q, TX_RECLAIM_CHUNK);
1756 
1757 	while ((skb = skb_peek(&q->sendq)) != NULL) {
1758 		unsigned int gen, pidx;
1759 		unsigned int ndesc = skb->priority;
1760 
1761 		if (unlikely(q->size - q->in_use < ndesc)) {
1762 			set_bit(TXQ_OFLD, &qs->txq_stopped);
1763 			smp_mb__after_atomic();
1764 
1765 			if (should_restart_tx(q) &&
1766 			    test_and_clear_bit(TXQ_OFLD, &qs->txq_stopped))
1767 				goto again;
1768 			q->stops++;
1769 			break;
1770 		}
1771 
1772 		if (!immediate(skb) &&
1773 		    map_skb(adap->pdev, skb, (dma_addr_t *)skb->head))
1774 			break;
1775 
1776 		gen = q->gen;
1777 		q->in_use += ndesc;
1778 		pidx = q->pidx;
1779 		q->pidx += ndesc;
1780 		written += ndesc;
1781 		if (q->pidx >= q->size) {
1782 			q->pidx -= q->size;
1783 			q->gen ^= 1;
1784 		}
1785 		__skb_unlink(skb, &q->sendq);
1786 		spin_unlock(&q->lock);
1787 
1788 		write_ofld_wr(adap, skb, q, pidx, gen, ndesc,
1789 			      (dma_addr_t *)skb->head);
1790 		spin_lock(&q->lock);
1791 	}
1792 	spin_unlock(&q->lock);
1793 
1794 #if USE_GTS
1795 	set_bit(TXQ_RUNNING, &q->flags);
1796 	set_bit(TXQ_LAST_PKT_DB, &q->flags);
1797 #endif
1798 	wmb();
1799 	if (likely(written))
1800 		t3_write_reg(adap, A_SG_KDOORBELL,
1801 			     F_SELEGRCNTX | V_EGRCNTX(q->cntxt_id));
1802 }
1803 
1804 /**
1805  *	queue_set - return the queue set a packet should use
1806  *	@skb: the packet
1807  *
1808  *	Maps a packet to the SGE queue set it should use.  The desired queue
1809  *	set is carried in bits 1-3 in the packet's priority.
1810  */
1811 static inline int queue_set(const struct sk_buff *skb)
1812 {
1813 	return skb->priority >> 1;
1814 }
1815 
1816 /**
1817  *	is_ctrl_pkt - return whether an offload packet is a control packet
1818  *	@skb: the packet
1819  *
1820  *	Determines whether an offload packet should use an OFLD or a CTRL
1821  *	Tx queue.  This is indicated by bit 0 in the packet's priority.
1822  */
1823 static inline int is_ctrl_pkt(const struct sk_buff *skb)
1824 {
1825 	return skb->priority & 1;
1826 }
1827 
1828 /**
1829  *	t3_offload_tx - send an offload packet
1830  *	@tdev: the offload device to send to
1831  *	@skb: the packet
1832  *
1833  *	Sends an offload packet.  We use the packet priority to select the
1834  *	appropriate Tx queue as follows: bit 0 indicates whether the packet
1835  *	should be sent as regular or control, bits 1-3 select the queue set.
1836  */
1837 int t3_offload_tx(struct t3cdev *tdev, struct sk_buff *skb)
1838 {
1839 	struct adapter *adap = tdev2adap(tdev);
1840 	struct sge_qset *qs = &adap->sge.qs[queue_set(skb)];
1841 
1842 	if (unlikely(is_ctrl_pkt(skb)))
1843 		return ctrl_xmit(adap, &qs->txq[TXQ_CTRL], skb);
1844 
1845 	return ofld_xmit(adap, &qs->txq[TXQ_OFLD], skb);
1846 }
1847 
1848 /**
1849  *	offload_enqueue - add an offload packet to an SGE offload receive queue
1850  *	@q: the SGE response queue
1851  *	@skb: the packet
1852  *
1853  *	Add a new offload packet to an SGE response queue's offload packet
1854  *	queue.  If the packet is the first on the queue it schedules the RX
1855  *	softirq to process the queue.
1856  */
1857 static inline void offload_enqueue(struct sge_rspq *q, struct sk_buff *skb)
1858 {
1859 	int was_empty = skb_queue_empty(&q->rx_queue);
1860 
1861 	__skb_queue_tail(&q->rx_queue, skb);
1862 
1863 	if (was_empty) {
1864 		struct sge_qset *qs = rspq_to_qset(q);
1865 
1866 		napi_schedule(&qs->napi);
1867 	}
1868 }
1869 
1870 /**
1871  *	deliver_partial_bundle - deliver a (partial) bundle of Rx offload pkts
1872  *	@tdev: the offload device that will be receiving the packets
1873  *	@q: the SGE response queue that assembled the bundle
1874  *	@skbs: the partial bundle
1875  *	@n: the number of packets in the bundle
1876  *
1877  *	Delivers a (partial) bundle of Rx offload packets to an offload device.
1878  */
1879 static inline void deliver_partial_bundle(struct t3cdev *tdev,
1880 					  struct sge_rspq *q,
1881 					  struct sk_buff *skbs[], int n)
1882 {
1883 	if (n) {
1884 		q->offload_bundles++;
1885 		tdev->recv(tdev, skbs, n);
1886 	}
1887 }
1888 
1889 /**
1890  *	ofld_poll - NAPI handler for offload packets in interrupt mode
1891  *	@napi: the network device doing the polling
1892  *	@budget: polling budget
1893  *
1894  *	The NAPI handler for offload packets when a response queue is serviced
1895  *	by the hard interrupt handler, i.e., when it's operating in non-polling
1896  *	mode.  Creates small packet batches and sends them through the offload
1897  *	receive handler.  Batches need to be of modest size as we do prefetches
1898  *	on the packets in each.
1899  */
1900 static int ofld_poll(struct napi_struct *napi, int budget)
1901 {
1902 	struct sge_qset *qs = container_of(napi, struct sge_qset, napi);
1903 	struct sge_rspq *q = &qs->rspq;
1904 	struct adapter *adapter = qs->adap;
1905 	int work_done = 0;
1906 
1907 	while (work_done < budget) {
1908 		struct sk_buff *skb, *tmp, *skbs[RX_BUNDLE_SIZE];
1909 		struct sk_buff_head queue;
1910 		int ngathered;
1911 
1912 		spin_lock_irq(&q->lock);
1913 		__skb_queue_head_init(&queue);
1914 		skb_queue_splice_init(&q->rx_queue, &queue);
1915 		if (skb_queue_empty(&queue)) {
1916 			napi_complete_done(napi, work_done);
1917 			spin_unlock_irq(&q->lock);
1918 			return work_done;
1919 		}
1920 		spin_unlock_irq(&q->lock);
1921 
1922 		ngathered = 0;
1923 		skb_queue_walk_safe(&queue, skb, tmp) {
1924 			if (work_done >= budget)
1925 				break;
1926 			work_done++;
1927 
1928 			__skb_unlink(skb, &queue);
1929 			prefetch(skb->data);
1930 			skbs[ngathered] = skb;
1931 			if (++ngathered == RX_BUNDLE_SIZE) {
1932 				q->offload_bundles++;
1933 				adapter->tdev.recv(&adapter->tdev, skbs,
1934 						   ngathered);
1935 				ngathered = 0;
1936 			}
1937 		}
1938 		if (!skb_queue_empty(&queue)) {
1939 			/* splice remaining packets back onto Rx queue */
1940 			spin_lock_irq(&q->lock);
1941 			skb_queue_splice(&queue, &q->rx_queue);
1942 			spin_unlock_irq(&q->lock);
1943 		}
1944 		deliver_partial_bundle(&adapter->tdev, q, skbs, ngathered);
1945 	}
1946 
1947 	return work_done;
1948 }
1949 
1950 /**
1951  *	rx_offload - process a received offload packet
1952  *	@tdev: the offload device receiving the packet
1953  *	@rq: the response queue that received the packet
1954  *	@skb: the packet
1955  *	@rx_gather: a gather list of packets if we are building a bundle
1956  *	@gather_idx: index of the next available slot in the bundle
1957  *
1958  *	Process an ingress offload pakcet and add it to the offload ingress
1959  *	queue. 	Returns the index of the next available slot in the bundle.
1960  */
1961 static inline int rx_offload(struct t3cdev *tdev, struct sge_rspq *rq,
1962 			     struct sk_buff *skb, struct sk_buff *rx_gather[],
1963 			     unsigned int gather_idx)
1964 {
1965 	skb_reset_mac_header(skb);
1966 	skb_reset_network_header(skb);
1967 	skb_reset_transport_header(skb);
1968 
1969 	if (rq->polling) {
1970 		rx_gather[gather_idx++] = skb;
1971 		if (gather_idx == RX_BUNDLE_SIZE) {
1972 			tdev->recv(tdev, rx_gather, RX_BUNDLE_SIZE);
1973 			gather_idx = 0;
1974 			rq->offload_bundles++;
1975 		}
1976 	} else
1977 		offload_enqueue(rq, skb);
1978 
1979 	return gather_idx;
1980 }
1981 
1982 /**
1983  *	restart_tx - check whether to restart suspended Tx queues
1984  *	@qs: the queue set to resume
1985  *
1986  *	Restarts suspended Tx queues of an SGE queue set if they have enough
1987  *	free resources to resume operation.
1988  */
1989 static void restart_tx(struct sge_qset *qs)
1990 {
1991 	if (test_bit(TXQ_ETH, &qs->txq_stopped) &&
1992 	    should_restart_tx(&qs->txq[TXQ_ETH]) &&
1993 	    test_and_clear_bit(TXQ_ETH, &qs->txq_stopped)) {
1994 		qs->txq[TXQ_ETH].restarts++;
1995 		if (netif_running(qs->netdev))
1996 			netif_tx_wake_queue(qs->tx_q);
1997 	}
1998 
1999 	if (test_bit(TXQ_OFLD, &qs->txq_stopped) &&
2000 	    should_restart_tx(&qs->txq[TXQ_OFLD]) &&
2001 	    test_and_clear_bit(TXQ_OFLD, &qs->txq_stopped)) {
2002 		qs->txq[TXQ_OFLD].restarts++;
2003 
2004 		/* The work can be quite lengthy so we use driver's own queue */
2005 		queue_work(cxgb3_wq, &qs->txq[TXQ_OFLD].qresume_task);
2006 	}
2007 	if (test_bit(TXQ_CTRL, &qs->txq_stopped) &&
2008 	    should_restart_tx(&qs->txq[TXQ_CTRL]) &&
2009 	    test_and_clear_bit(TXQ_CTRL, &qs->txq_stopped)) {
2010 		qs->txq[TXQ_CTRL].restarts++;
2011 
2012 		/* The work can be quite lengthy so we use driver's own queue */
2013 		queue_work(cxgb3_wq, &qs->txq[TXQ_CTRL].qresume_task);
2014 	}
2015 }
2016 
2017 /**
2018  *	cxgb3_arp_process - process an ARP request probing a private IP address
2019  *	@pi: the port info
2020  *	@skb: the skbuff containing the ARP request
2021  *
2022  *	Check if the ARP request is probing the private IP address
2023  *	dedicated to iSCSI, generate an ARP reply if so.
2024  */
2025 static void cxgb3_arp_process(struct port_info *pi, struct sk_buff *skb)
2026 {
2027 	struct net_device *dev = skb->dev;
2028 	struct arphdr *arp;
2029 	unsigned char *arp_ptr;
2030 	unsigned char *sha;
2031 	__be32 sip, tip;
2032 
2033 	if (!dev)
2034 		return;
2035 
2036 	skb_reset_network_header(skb);
2037 	arp = arp_hdr(skb);
2038 
2039 	if (arp->ar_op != htons(ARPOP_REQUEST))
2040 		return;
2041 
2042 	arp_ptr = (unsigned char *)(arp + 1);
2043 	sha = arp_ptr;
2044 	arp_ptr += dev->addr_len;
2045 	memcpy(&sip, arp_ptr, sizeof(sip));
2046 	arp_ptr += sizeof(sip);
2047 	arp_ptr += dev->addr_len;
2048 	memcpy(&tip, arp_ptr, sizeof(tip));
2049 
2050 	if (tip != pi->iscsi_ipv4addr)
2051 		return;
2052 
2053 	arp_send(ARPOP_REPLY, ETH_P_ARP, sip, dev, tip, sha,
2054 		 pi->iscsic.mac_addr, sha);
2055 
2056 }
2057 
2058 static inline int is_arp(struct sk_buff *skb)
2059 {
2060 	return skb->protocol == htons(ETH_P_ARP);
2061 }
2062 
2063 static void cxgb3_process_iscsi_prov_pack(struct port_info *pi,
2064 					struct sk_buff *skb)
2065 {
2066 	if (is_arp(skb)) {
2067 		cxgb3_arp_process(pi, skb);
2068 		return;
2069 	}
2070 
2071 	if (pi->iscsic.recv)
2072 		pi->iscsic.recv(pi, skb);
2073 
2074 }
2075 
2076 /**
2077  *	rx_eth - process an ingress ethernet packet
2078  *	@adap: the adapter
2079  *	@rq: the response queue that received the packet
2080  *	@skb: the packet
2081  *	@pad: padding
2082  *	@lro: large receive offload
2083  *
2084  *	Process an ingress ethernet pakcet and deliver it to the stack.
2085  *	The padding is 2 if the packet was delivered in an Rx buffer and 0
2086  *	if it was immediate data in a response.
2087  */
2088 static void rx_eth(struct adapter *adap, struct sge_rspq *rq,
2089 		   struct sk_buff *skb, int pad, int lro)
2090 {
2091 	struct cpl_rx_pkt *p = (struct cpl_rx_pkt *)(skb->data + pad);
2092 	struct sge_qset *qs = rspq_to_qset(rq);
2093 	struct port_info *pi;
2094 
2095 	skb_pull(skb, sizeof(*p) + pad);
2096 	skb->protocol = eth_type_trans(skb, adap->port[p->iff]);
2097 	pi = netdev_priv(skb->dev);
2098 	if ((skb->dev->features & NETIF_F_RXCSUM) && p->csum_valid &&
2099 	    p->csum == htons(0xffff) && !p->fragment) {
2100 		qs->port_stats[SGE_PSTAT_RX_CSUM_GOOD]++;
2101 		skb->ip_summed = CHECKSUM_UNNECESSARY;
2102 	} else
2103 		skb_checksum_none_assert(skb);
2104 	skb_record_rx_queue(skb, qs - &adap->sge.qs[pi->first_qset]);
2105 
2106 	if (p->vlan_valid) {
2107 		qs->port_stats[SGE_PSTAT_VLANEX]++;
2108 		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), ntohs(p->vlan));
2109 	}
2110 	if (rq->polling) {
2111 		if (lro)
2112 			napi_gro_receive(&qs->napi, skb);
2113 		else {
2114 			if (unlikely(pi->iscsic.flags))
2115 				cxgb3_process_iscsi_prov_pack(pi, skb);
2116 			netif_receive_skb(skb);
2117 		}
2118 	} else
2119 		netif_rx(skb);
2120 }
2121 
2122 static inline int is_eth_tcp(u32 rss)
2123 {
2124 	return G_HASHTYPE(ntohl(rss)) == RSS_HASH_4_TUPLE;
2125 }
2126 
2127 /**
2128  *	lro_add_page - add a page chunk to an LRO session
2129  *	@adap: the adapter
2130  *	@qs: the associated queue set
2131  *	@fl: the free list containing the page chunk to add
2132  *	@len: packet length
2133  *	@complete: Indicates the last fragment of a frame
2134  *
2135  *	Add a received packet contained in a page chunk to an existing LRO
2136  *	session.
2137  */
2138 static void lro_add_page(struct adapter *adap, struct sge_qset *qs,
2139 			 struct sge_fl *fl, int len, int complete)
2140 {
2141 	struct rx_sw_desc *sd = &fl->sdesc[fl->cidx];
2142 	struct port_info *pi = netdev_priv(qs->netdev);
2143 	struct sk_buff *skb = NULL;
2144 	struct cpl_rx_pkt *cpl;
2145 	skb_frag_t *rx_frag;
2146 	int nr_frags;
2147 	int offset = 0;
2148 
2149 	if (!qs->nomem) {
2150 		skb = napi_get_frags(&qs->napi);
2151 		qs->nomem = !skb;
2152 	}
2153 
2154 	fl->credits--;
2155 
2156 	pci_dma_sync_single_for_cpu(adap->pdev,
2157 				    dma_unmap_addr(sd, dma_addr),
2158 				    fl->buf_size - SGE_PG_RSVD,
2159 				    PCI_DMA_FROMDEVICE);
2160 
2161 	(*sd->pg_chunk.p_cnt)--;
2162 	if (!*sd->pg_chunk.p_cnt && sd->pg_chunk.page != fl->pg_chunk.page)
2163 		pci_unmap_page(adap->pdev,
2164 			       sd->pg_chunk.mapping,
2165 			       fl->alloc_size,
2166 			       PCI_DMA_FROMDEVICE);
2167 
2168 	if (!skb) {
2169 		put_page(sd->pg_chunk.page);
2170 		if (complete)
2171 			qs->nomem = 0;
2172 		return;
2173 	}
2174 
2175 	rx_frag = skb_shinfo(skb)->frags;
2176 	nr_frags = skb_shinfo(skb)->nr_frags;
2177 
2178 	if (!nr_frags) {
2179 		offset = 2 + sizeof(struct cpl_rx_pkt);
2180 		cpl = qs->lro_va = sd->pg_chunk.va + 2;
2181 
2182 		if ((qs->netdev->features & NETIF_F_RXCSUM) &&
2183 		     cpl->csum_valid && cpl->csum == htons(0xffff)) {
2184 			skb->ip_summed = CHECKSUM_UNNECESSARY;
2185 			qs->port_stats[SGE_PSTAT_RX_CSUM_GOOD]++;
2186 		} else
2187 			skb->ip_summed = CHECKSUM_NONE;
2188 	} else
2189 		cpl = qs->lro_va;
2190 
2191 	len -= offset;
2192 
2193 	rx_frag += nr_frags;
2194 	__skb_frag_set_page(rx_frag, sd->pg_chunk.page);
2195 	skb_frag_off_set(rx_frag, sd->pg_chunk.offset + offset);
2196 	skb_frag_size_set(rx_frag, len);
2197 
2198 	skb->len += len;
2199 	skb->data_len += len;
2200 	skb->truesize += len;
2201 	skb_shinfo(skb)->nr_frags++;
2202 
2203 	if (!complete)
2204 		return;
2205 
2206 	skb_record_rx_queue(skb, qs - &adap->sge.qs[pi->first_qset]);
2207 
2208 	if (cpl->vlan_valid) {
2209 		qs->port_stats[SGE_PSTAT_VLANEX]++;
2210 		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), ntohs(cpl->vlan));
2211 	}
2212 	napi_gro_frags(&qs->napi);
2213 }
2214 
2215 /**
2216  *	handle_rsp_cntrl_info - handles control information in a response
2217  *	@qs: the queue set corresponding to the response
2218  *	@flags: the response control flags
2219  *
2220  *	Handles the control information of an SGE response, such as GTS
2221  *	indications and completion credits for the queue set's Tx queues.
2222  *	HW coalesces credits, we don't do any extra SW coalescing.
2223  */
2224 static inline void handle_rsp_cntrl_info(struct sge_qset *qs, u32 flags)
2225 {
2226 	unsigned int credits;
2227 
2228 #if USE_GTS
2229 	if (flags & F_RSPD_TXQ0_GTS)
2230 		clear_bit(TXQ_RUNNING, &qs->txq[TXQ_ETH].flags);
2231 #endif
2232 
2233 	credits = G_RSPD_TXQ0_CR(flags);
2234 	if (credits)
2235 		qs->txq[TXQ_ETH].processed += credits;
2236 
2237 	credits = G_RSPD_TXQ2_CR(flags);
2238 	if (credits)
2239 		qs->txq[TXQ_CTRL].processed += credits;
2240 
2241 # if USE_GTS
2242 	if (flags & F_RSPD_TXQ1_GTS)
2243 		clear_bit(TXQ_RUNNING, &qs->txq[TXQ_OFLD].flags);
2244 # endif
2245 	credits = G_RSPD_TXQ1_CR(flags);
2246 	if (credits)
2247 		qs->txq[TXQ_OFLD].processed += credits;
2248 }
2249 
2250 /**
2251  *	check_ring_db - check if we need to ring any doorbells
2252  *	@adap: the adapter
2253  *	@qs: the queue set whose Tx queues are to be examined
2254  *	@sleeping: indicates which Tx queue sent GTS
2255  *
2256  *	Checks if some of a queue set's Tx queues need to ring their doorbells
2257  *	to resume transmission after idling while they still have unprocessed
2258  *	descriptors.
2259  */
2260 static void check_ring_db(struct adapter *adap, struct sge_qset *qs,
2261 			  unsigned int sleeping)
2262 {
2263 	if (sleeping & F_RSPD_TXQ0_GTS) {
2264 		struct sge_txq *txq = &qs->txq[TXQ_ETH];
2265 
2266 		if (txq->cleaned + txq->in_use != txq->processed &&
2267 		    !test_and_set_bit(TXQ_LAST_PKT_DB, &txq->flags)) {
2268 			set_bit(TXQ_RUNNING, &txq->flags);
2269 			t3_write_reg(adap, A_SG_KDOORBELL, F_SELEGRCNTX |
2270 				     V_EGRCNTX(txq->cntxt_id));
2271 		}
2272 	}
2273 
2274 	if (sleeping & F_RSPD_TXQ1_GTS) {
2275 		struct sge_txq *txq = &qs->txq[TXQ_OFLD];
2276 
2277 		if (txq->cleaned + txq->in_use != txq->processed &&
2278 		    !test_and_set_bit(TXQ_LAST_PKT_DB, &txq->flags)) {
2279 			set_bit(TXQ_RUNNING, &txq->flags);
2280 			t3_write_reg(adap, A_SG_KDOORBELL, F_SELEGRCNTX |
2281 				     V_EGRCNTX(txq->cntxt_id));
2282 		}
2283 	}
2284 }
2285 
2286 /**
2287  *	is_new_response - check if a response is newly written
2288  *	@r: the response descriptor
2289  *	@q: the response queue
2290  *
2291  *	Returns true if a response descriptor contains a yet unprocessed
2292  *	response.
2293  */
2294 static inline int is_new_response(const struct rsp_desc *r,
2295 				  const struct sge_rspq *q)
2296 {
2297 	return (r->intr_gen & F_RSPD_GEN2) == q->gen;
2298 }
2299 
2300 static inline void clear_rspq_bufstate(struct sge_rspq * const q)
2301 {
2302 	q->pg_skb = NULL;
2303 	q->rx_recycle_buf = 0;
2304 }
2305 
2306 #define RSPD_GTS_MASK  (F_RSPD_TXQ0_GTS | F_RSPD_TXQ1_GTS)
2307 #define RSPD_CTRL_MASK (RSPD_GTS_MASK | \
2308 			V_RSPD_TXQ0_CR(M_RSPD_TXQ0_CR) | \
2309 			V_RSPD_TXQ1_CR(M_RSPD_TXQ1_CR) | \
2310 			V_RSPD_TXQ2_CR(M_RSPD_TXQ2_CR))
2311 
2312 /* How long to delay the next interrupt in case of memory shortage, in 0.1us. */
2313 #define NOMEM_INTR_DELAY 2500
2314 
2315 /**
2316  *	process_responses - process responses from an SGE response queue
2317  *	@adap: the adapter
2318  *	@qs: the queue set to which the response queue belongs
2319  *	@budget: how many responses can be processed in this round
2320  *
2321  *	Process responses from an SGE response queue up to the supplied budget.
2322  *	Responses include received packets as well as credits and other events
2323  *	for the queues that belong to the response queue's queue set.
2324  *	A negative budget is effectively unlimited.
2325  *
2326  *	Additionally choose the interrupt holdoff time for the next interrupt
2327  *	on this queue.  If the system is under memory shortage use a fairly
2328  *	long delay to help recovery.
2329  */
2330 static int process_responses(struct adapter *adap, struct sge_qset *qs,
2331 			     int budget)
2332 {
2333 	struct sge_rspq *q = &qs->rspq;
2334 	struct rsp_desc *r = &q->desc[q->cidx];
2335 	int budget_left = budget;
2336 	unsigned int sleeping = 0;
2337 	struct sk_buff *offload_skbs[RX_BUNDLE_SIZE];
2338 	int ngathered = 0;
2339 
2340 	q->next_holdoff = q->holdoff_tmr;
2341 
2342 	while (likely(budget_left && is_new_response(r, q))) {
2343 		int packet_complete, eth, ethpad = 2;
2344 		int lro = !!(qs->netdev->features & NETIF_F_GRO);
2345 		struct sk_buff *skb = NULL;
2346 		u32 len, flags;
2347 		__be32 rss_hi, rss_lo;
2348 
2349 		dma_rmb();
2350 		eth = r->rss_hdr.opcode == CPL_RX_PKT;
2351 		rss_hi = *(const __be32 *)r;
2352 		rss_lo = r->rss_hdr.rss_hash_val;
2353 		flags = ntohl(r->flags);
2354 
2355 		if (unlikely(flags & F_RSPD_ASYNC_NOTIF)) {
2356 			skb = alloc_skb(AN_PKT_SIZE, GFP_ATOMIC);
2357 			if (!skb)
2358 				goto no_mem;
2359 
2360 			__skb_put_data(skb, r, AN_PKT_SIZE);
2361 			skb->data[0] = CPL_ASYNC_NOTIF;
2362 			rss_hi = htonl(CPL_ASYNC_NOTIF << 24);
2363 			q->async_notif++;
2364 		} else if (flags & F_RSPD_IMM_DATA_VALID) {
2365 			skb = get_imm_packet(r);
2366 			if (unlikely(!skb)) {
2367 no_mem:
2368 				q->next_holdoff = NOMEM_INTR_DELAY;
2369 				q->nomem++;
2370 				/* consume one credit since we tried */
2371 				budget_left--;
2372 				break;
2373 			}
2374 			q->imm_data++;
2375 			ethpad = 0;
2376 		} else if ((len = ntohl(r->len_cq)) != 0) {
2377 			struct sge_fl *fl;
2378 
2379 			lro &= eth && is_eth_tcp(rss_hi);
2380 
2381 			fl = (len & F_RSPD_FLQ) ? &qs->fl[1] : &qs->fl[0];
2382 			if (fl->use_pages) {
2383 				void *addr = fl->sdesc[fl->cidx].pg_chunk.va;
2384 
2385 				net_prefetch(addr);
2386 				__refill_fl(adap, fl);
2387 				if (lro > 0) {
2388 					lro_add_page(adap, qs, fl,
2389 						     G_RSPD_LEN(len),
2390 						     flags & F_RSPD_EOP);
2391 					goto next_fl;
2392 				}
2393 
2394 				skb = get_packet_pg(adap, fl, q,
2395 						    G_RSPD_LEN(len),
2396 						    eth ?
2397 						    SGE_RX_DROP_THRES : 0);
2398 				q->pg_skb = skb;
2399 			} else
2400 				skb = get_packet(adap, fl, G_RSPD_LEN(len),
2401 						 eth ? SGE_RX_DROP_THRES : 0);
2402 			if (unlikely(!skb)) {
2403 				if (!eth)
2404 					goto no_mem;
2405 				q->rx_drops++;
2406 			} else if (unlikely(r->rss_hdr.opcode == CPL_TRACE_PKT))
2407 				__skb_pull(skb, 2);
2408 next_fl:
2409 			if (++fl->cidx == fl->size)
2410 				fl->cidx = 0;
2411 		} else
2412 			q->pure_rsps++;
2413 
2414 		if (flags & RSPD_CTRL_MASK) {
2415 			sleeping |= flags & RSPD_GTS_MASK;
2416 			handle_rsp_cntrl_info(qs, flags);
2417 		}
2418 
2419 		r++;
2420 		if (unlikely(++q->cidx == q->size)) {
2421 			q->cidx = 0;
2422 			q->gen ^= 1;
2423 			r = q->desc;
2424 		}
2425 		prefetch(r);
2426 
2427 		if (++q->credits >= (q->size / 4)) {
2428 			refill_rspq(adap, q, q->credits);
2429 			q->credits = 0;
2430 		}
2431 
2432 		packet_complete = flags &
2433 				  (F_RSPD_EOP | F_RSPD_IMM_DATA_VALID |
2434 				   F_RSPD_ASYNC_NOTIF);
2435 
2436 		if (skb != NULL && packet_complete) {
2437 			if (eth)
2438 				rx_eth(adap, q, skb, ethpad, lro);
2439 			else {
2440 				q->offload_pkts++;
2441 				/* Preserve the RSS info in csum & priority */
2442 				skb->csum = rss_hi;
2443 				skb->priority = rss_lo;
2444 				ngathered = rx_offload(&adap->tdev, q, skb,
2445 						       offload_skbs,
2446 						       ngathered);
2447 			}
2448 
2449 			if (flags & F_RSPD_EOP)
2450 				clear_rspq_bufstate(q);
2451 		}
2452 		--budget_left;
2453 	}
2454 
2455 	deliver_partial_bundle(&adap->tdev, q, offload_skbs, ngathered);
2456 
2457 	if (sleeping)
2458 		check_ring_db(adap, qs, sleeping);
2459 
2460 	smp_mb();		/* commit Tx queue .processed updates */
2461 	if (unlikely(qs->txq_stopped != 0))
2462 		restart_tx(qs);
2463 
2464 	budget -= budget_left;
2465 	return budget;
2466 }
2467 
2468 static inline int is_pure_response(const struct rsp_desc *r)
2469 {
2470 	__be32 n = r->flags & htonl(F_RSPD_ASYNC_NOTIF | F_RSPD_IMM_DATA_VALID);
2471 
2472 	return (n | r->len_cq) == 0;
2473 }
2474 
2475 /**
2476  *	napi_rx_handler - the NAPI handler for Rx processing
2477  *	@napi: the napi instance
2478  *	@budget: how many packets we can process in this round
2479  *
2480  *	Handler for new data events when using NAPI.
2481  */
2482 static int napi_rx_handler(struct napi_struct *napi, int budget)
2483 {
2484 	struct sge_qset *qs = container_of(napi, struct sge_qset, napi);
2485 	struct adapter *adap = qs->adap;
2486 	int work_done = process_responses(adap, qs, budget);
2487 
2488 	if (likely(work_done < budget)) {
2489 		napi_complete_done(napi, work_done);
2490 
2491 		/*
2492 		 * Because we don't atomically flush the following
2493 		 * write it is possible that in very rare cases it can
2494 		 * reach the device in a way that races with a new
2495 		 * response being written plus an error interrupt
2496 		 * causing the NAPI interrupt handler below to return
2497 		 * unhandled status to the OS.  To protect against
2498 		 * this would require flushing the write and doing
2499 		 * both the write and the flush with interrupts off.
2500 		 * Way too expensive and unjustifiable given the
2501 		 * rarity of the race.
2502 		 *
2503 		 * The race cannot happen at all with MSI-X.
2504 		 */
2505 		t3_write_reg(adap, A_SG_GTS, V_RSPQ(qs->rspq.cntxt_id) |
2506 			     V_NEWTIMER(qs->rspq.next_holdoff) |
2507 			     V_NEWINDEX(qs->rspq.cidx));
2508 	}
2509 	return work_done;
2510 }
2511 
2512 /*
2513  * Returns true if the device is already scheduled for polling.
2514  */
2515 static inline int napi_is_scheduled(struct napi_struct *napi)
2516 {
2517 	return test_bit(NAPI_STATE_SCHED, &napi->state);
2518 }
2519 
2520 /**
2521  *	process_pure_responses - process pure responses from a response queue
2522  *	@adap: the adapter
2523  *	@qs: the queue set owning the response queue
2524  *	@r: the first pure response to process
2525  *
2526  *	A simpler version of process_responses() that handles only pure (i.e.,
2527  *	non data-carrying) responses.  Such respones are too light-weight to
2528  *	justify calling a softirq under NAPI, so we handle them specially in
2529  *	the interrupt handler.  The function is called with a pointer to a
2530  *	response, which the caller must ensure is a valid pure response.
2531  *
2532  *	Returns 1 if it encounters a valid data-carrying response, 0 otherwise.
2533  */
2534 static int process_pure_responses(struct adapter *adap, struct sge_qset *qs,
2535 				  struct rsp_desc *r)
2536 {
2537 	struct sge_rspq *q = &qs->rspq;
2538 	unsigned int sleeping = 0;
2539 
2540 	do {
2541 		u32 flags = ntohl(r->flags);
2542 
2543 		r++;
2544 		if (unlikely(++q->cidx == q->size)) {
2545 			q->cidx = 0;
2546 			q->gen ^= 1;
2547 			r = q->desc;
2548 		}
2549 		prefetch(r);
2550 
2551 		if (flags & RSPD_CTRL_MASK) {
2552 			sleeping |= flags & RSPD_GTS_MASK;
2553 			handle_rsp_cntrl_info(qs, flags);
2554 		}
2555 
2556 		q->pure_rsps++;
2557 		if (++q->credits >= (q->size / 4)) {
2558 			refill_rspq(adap, q, q->credits);
2559 			q->credits = 0;
2560 		}
2561 		if (!is_new_response(r, q))
2562 			break;
2563 		dma_rmb();
2564 	} while (is_pure_response(r));
2565 
2566 	if (sleeping)
2567 		check_ring_db(adap, qs, sleeping);
2568 
2569 	smp_mb();		/* commit Tx queue .processed updates */
2570 	if (unlikely(qs->txq_stopped != 0))
2571 		restart_tx(qs);
2572 
2573 	return is_new_response(r, q);
2574 }
2575 
2576 /**
2577  *	handle_responses - decide what to do with new responses in NAPI mode
2578  *	@adap: the adapter
2579  *	@q: the response queue
2580  *
2581  *	This is used by the NAPI interrupt handlers to decide what to do with
2582  *	new SGE responses.  If there are no new responses it returns -1.  If
2583  *	there are new responses and they are pure (i.e., non-data carrying)
2584  *	it handles them straight in hard interrupt context as they are very
2585  *	cheap and don't deliver any packets.  Finally, if there are any data
2586  *	signaling responses it schedules the NAPI handler.  Returns 1 if it
2587  *	schedules NAPI, 0 if all new responses were pure.
2588  *
2589  *	The caller must ascertain NAPI is not already running.
2590  */
2591 static inline int handle_responses(struct adapter *adap, struct sge_rspq *q)
2592 {
2593 	struct sge_qset *qs = rspq_to_qset(q);
2594 	struct rsp_desc *r = &q->desc[q->cidx];
2595 
2596 	if (!is_new_response(r, q))
2597 		return -1;
2598 	dma_rmb();
2599 	if (is_pure_response(r) && process_pure_responses(adap, qs, r) == 0) {
2600 		t3_write_reg(adap, A_SG_GTS, V_RSPQ(q->cntxt_id) |
2601 			     V_NEWTIMER(q->holdoff_tmr) | V_NEWINDEX(q->cidx));
2602 		return 0;
2603 	}
2604 	napi_schedule(&qs->napi);
2605 	return 1;
2606 }
2607 
2608 /*
2609  * The MSI-X interrupt handler for an SGE response queue for the non-NAPI case
2610  * (i.e., response queue serviced in hard interrupt).
2611  */
2612 static irqreturn_t t3_sge_intr_msix(int irq, void *cookie)
2613 {
2614 	struct sge_qset *qs = cookie;
2615 	struct adapter *adap = qs->adap;
2616 	struct sge_rspq *q = &qs->rspq;
2617 
2618 	spin_lock(&q->lock);
2619 	if (process_responses(adap, qs, -1) == 0)
2620 		q->unhandled_irqs++;
2621 	t3_write_reg(adap, A_SG_GTS, V_RSPQ(q->cntxt_id) |
2622 		     V_NEWTIMER(q->next_holdoff) | V_NEWINDEX(q->cidx));
2623 	spin_unlock(&q->lock);
2624 	return IRQ_HANDLED;
2625 }
2626 
2627 /*
2628  * The MSI-X interrupt handler for an SGE response queue for the NAPI case
2629  * (i.e., response queue serviced by NAPI polling).
2630  */
2631 static irqreturn_t t3_sge_intr_msix_napi(int irq, void *cookie)
2632 {
2633 	struct sge_qset *qs = cookie;
2634 	struct sge_rspq *q = &qs->rspq;
2635 
2636 	spin_lock(&q->lock);
2637 
2638 	if (handle_responses(qs->adap, q) < 0)
2639 		q->unhandled_irqs++;
2640 	spin_unlock(&q->lock);
2641 	return IRQ_HANDLED;
2642 }
2643 
2644 /*
2645  * The non-NAPI MSI interrupt handler.  This needs to handle data events from
2646  * SGE response queues as well as error and other async events as they all use
2647  * the same MSI vector.  We use one SGE response queue per port in this mode
2648  * and protect all response queues with queue 0's lock.
2649  */
2650 static irqreturn_t t3_intr_msi(int irq, void *cookie)
2651 {
2652 	int new_packets = 0;
2653 	struct adapter *adap = cookie;
2654 	struct sge_rspq *q = &adap->sge.qs[0].rspq;
2655 
2656 	spin_lock(&q->lock);
2657 
2658 	if (process_responses(adap, &adap->sge.qs[0], -1)) {
2659 		t3_write_reg(adap, A_SG_GTS, V_RSPQ(q->cntxt_id) |
2660 			     V_NEWTIMER(q->next_holdoff) | V_NEWINDEX(q->cidx));
2661 		new_packets = 1;
2662 	}
2663 
2664 	if (adap->params.nports == 2 &&
2665 	    process_responses(adap, &adap->sge.qs[1], -1)) {
2666 		struct sge_rspq *q1 = &adap->sge.qs[1].rspq;
2667 
2668 		t3_write_reg(adap, A_SG_GTS, V_RSPQ(q1->cntxt_id) |
2669 			     V_NEWTIMER(q1->next_holdoff) |
2670 			     V_NEWINDEX(q1->cidx));
2671 		new_packets = 1;
2672 	}
2673 
2674 	if (!new_packets && t3_slow_intr_handler(adap) == 0)
2675 		q->unhandled_irqs++;
2676 
2677 	spin_unlock(&q->lock);
2678 	return IRQ_HANDLED;
2679 }
2680 
2681 static int rspq_check_napi(struct sge_qset *qs)
2682 {
2683 	struct sge_rspq *q = &qs->rspq;
2684 
2685 	if (!napi_is_scheduled(&qs->napi) &&
2686 	    is_new_response(&q->desc[q->cidx], q)) {
2687 		napi_schedule(&qs->napi);
2688 		return 1;
2689 	}
2690 	return 0;
2691 }
2692 
2693 /*
2694  * The MSI interrupt handler for the NAPI case (i.e., response queues serviced
2695  * by NAPI polling).  Handles data events from SGE response queues as well as
2696  * error and other async events as they all use the same MSI vector.  We use
2697  * one SGE response queue per port in this mode and protect all response
2698  * queues with queue 0's lock.
2699  */
2700 static irqreturn_t t3_intr_msi_napi(int irq, void *cookie)
2701 {
2702 	int new_packets;
2703 	struct adapter *adap = cookie;
2704 	struct sge_rspq *q = &adap->sge.qs[0].rspq;
2705 
2706 	spin_lock(&q->lock);
2707 
2708 	new_packets = rspq_check_napi(&adap->sge.qs[0]);
2709 	if (adap->params.nports == 2)
2710 		new_packets += rspq_check_napi(&adap->sge.qs[1]);
2711 	if (!new_packets && t3_slow_intr_handler(adap) == 0)
2712 		q->unhandled_irqs++;
2713 
2714 	spin_unlock(&q->lock);
2715 	return IRQ_HANDLED;
2716 }
2717 
2718 /*
2719  * A helper function that processes responses and issues GTS.
2720  */
2721 static inline int process_responses_gts(struct adapter *adap,
2722 					struct sge_rspq *rq)
2723 {
2724 	int work;
2725 
2726 	work = process_responses(adap, rspq_to_qset(rq), -1);
2727 	t3_write_reg(adap, A_SG_GTS, V_RSPQ(rq->cntxt_id) |
2728 		     V_NEWTIMER(rq->next_holdoff) | V_NEWINDEX(rq->cidx));
2729 	return work;
2730 }
2731 
2732 /*
2733  * The legacy INTx interrupt handler.  This needs to handle data events from
2734  * SGE response queues as well as error and other async events as they all use
2735  * the same interrupt pin.  We use one SGE response queue per port in this mode
2736  * and protect all response queues with queue 0's lock.
2737  */
2738 static irqreturn_t t3_intr(int irq, void *cookie)
2739 {
2740 	int work_done, w0, w1;
2741 	struct adapter *adap = cookie;
2742 	struct sge_rspq *q0 = &adap->sge.qs[0].rspq;
2743 	struct sge_rspq *q1 = &adap->sge.qs[1].rspq;
2744 
2745 	spin_lock(&q0->lock);
2746 
2747 	w0 = is_new_response(&q0->desc[q0->cidx], q0);
2748 	w1 = adap->params.nports == 2 &&
2749 	    is_new_response(&q1->desc[q1->cidx], q1);
2750 
2751 	if (likely(w0 | w1)) {
2752 		t3_write_reg(adap, A_PL_CLI, 0);
2753 		t3_read_reg(adap, A_PL_CLI);	/* flush */
2754 
2755 		if (likely(w0))
2756 			process_responses_gts(adap, q0);
2757 
2758 		if (w1)
2759 			process_responses_gts(adap, q1);
2760 
2761 		work_done = w0 | w1;
2762 	} else
2763 		work_done = t3_slow_intr_handler(adap);
2764 
2765 	spin_unlock(&q0->lock);
2766 	return IRQ_RETVAL(work_done != 0);
2767 }
2768 
2769 /*
2770  * Interrupt handler for legacy INTx interrupts for T3B-based cards.
2771  * Handles data events from SGE response queues as well as error and other
2772  * async events as they all use the same interrupt pin.  We use one SGE
2773  * response queue per port in this mode and protect all response queues with
2774  * queue 0's lock.
2775  */
2776 static irqreturn_t t3b_intr(int irq, void *cookie)
2777 {
2778 	u32 map;
2779 	struct adapter *adap = cookie;
2780 	struct sge_rspq *q0 = &adap->sge.qs[0].rspq;
2781 
2782 	t3_write_reg(adap, A_PL_CLI, 0);
2783 	map = t3_read_reg(adap, A_SG_DATA_INTR);
2784 
2785 	if (unlikely(!map))	/* shared interrupt, most likely */
2786 		return IRQ_NONE;
2787 
2788 	spin_lock(&q0->lock);
2789 
2790 	if (unlikely(map & F_ERRINTR))
2791 		t3_slow_intr_handler(adap);
2792 
2793 	if (likely(map & 1))
2794 		process_responses_gts(adap, q0);
2795 
2796 	if (map & 2)
2797 		process_responses_gts(adap, &adap->sge.qs[1].rspq);
2798 
2799 	spin_unlock(&q0->lock);
2800 	return IRQ_HANDLED;
2801 }
2802 
2803 /*
2804  * NAPI interrupt handler for legacy INTx interrupts for T3B-based cards.
2805  * Handles data events from SGE response queues as well as error and other
2806  * async events as they all use the same interrupt pin.  We use one SGE
2807  * response queue per port in this mode and protect all response queues with
2808  * queue 0's lock.
2809  */
2810 static irqreturn_t t3b_intr_napi(int irq, void *cookie)
2811 {
2812 	u32 map;
2813 	struct adapter *adap = cookie;
2814 	struct sge_qset *qs0 = &adap->sge.qs[0];
2815 	struct sge_rspq *q0 = &qs0->rspq;
2816 
2817 	t3_write_reg(adap, A_PL_CLI, 0);
2818 	map = t3_read_reg(adap, A_SG_DATA_INTR);
2819 
2820 	if (unlikely(!map))	/* shared interrupt, most likely */
2821 		return IRQ_NONE;
2822 
2823 	spin_lock(&q0->lock);
2824 
2825 	if (unlikely(map & F_ERRINTR))
2826 		t3_slow_intr_handler(adap);
2827 
2828 	if (likely(map & 1))
2829 		napi_schedule(&qs0->napi);
2830 
2831 	if (map & 2)
2832 		napi_schedule(&adap->sge.qs[1].napi);
2833 
2834 	spin_unlock(&q0->lock);
2835 	return IRQ_HANDLED;
2836 }
2837 
2838 /**
2839  *	t3_intr_handler - select the top-level interrupt handler
2840  *	@adap: the adapter
2841  *	@polling: whether using NAPI to service response queues
2842  *
2843  *	Selects the top-level interrupt handler based on the type of interrupts
2844  *	(MSI-X, MSI, or legacy) and whether NAPI will be used to service the
2845  *	response queues.
2846  */
2847 irq_handler_t t3_intr_handler(struct adapter *adap, int polling)
2848 {
2849 	if (adap->flags & USING_MSIX)
2850 		return polling ? t3_sge_intr_msix_napi : t3_sge_intr_msix;
2851 	if (adap->flags & USING_MSI)
2852 		return polling ? t3_intr_msi_napi : t3_intr_msi;
2853 	if (adap->params.rev > 0)
2854 		return polling ? t3b_intr_napi : t3b_intr;
2855 	return t3_intr;
2856 }
2857 
2858 #define SGE_PARERR (F_CPPARITYERROR | F_OCPARITYERROR | F_RCPARITYERROR | \
2859 		    F_IRPARITYERROR | V_ITPARITYERROR(M_ITPARITYERROR) | \
2860 		    V_FLPARITYERROR(M_FLPARITYERROR) | F_LODRBPARITYERROR | \
2861 		    F_HIDRBPARITYERROR | F_LORCQPARITYERROR | \
2862 		    F_HIRCQPARITYERROR)
2863 #define SGE_FRAMINGERR (F_UC_REQ_FRAMINGERROR | F_R_REQ_FRAMINGERROR)
2864 #define SGE_FATALERR (SGE_PARERR | SGE_FRAMINGERR | F_RSPQCREDITOVERFOW | \
2865 		      F_RSPQDISABLED)
2866 
2867 /**
2868  *	t3_sge_err_intr_handler - SGE async event interrupt handler
2869  *	@adapter: the adapter
2870  *
2871  *	Interrupt handler for SGE asynchronous (non-data) events.
2872  */
2873 void t3_sge_err_intr_handler(struct adapter *adapter)
2874 {
2875 	unsigned int v, status = t3_read_reg(adapter, A_SG_INT_CAUSE) &
2876 				 ~F_FLEMPTY;
2877 
2878 	if (status & SGE_PARERR)
2879 		CH_ALERT(adapter, "SGE parity error (0x%x)\n",
2880 			 status & SGE_PARERR);
2881 	if (status & SGE_FRAMINGERR)
2882 		CH_ALERT(adapter, "SGE framing error (0x%x)\n",
2883 			 status & SGE_FRAMINGERR);
2884 
2885 	if (status & F_RSPQCREDITOVERFOW)
2886 		CH_ALERT(adapter, "SGE response queue credit overflow\n");
2887 
2888 	if (status & F_RSPQDISABLED) {
2889 		v = t3_read_reg(adapter, A_SG_RSPQ_FL_STATUS);
2890 
2891 		CH_ALERT(adapter,
2892 			 "packet delivered to disabled response queue "
2893 			 "(0x%x)\n", (v >> S_RSPQ0DISABLED) & 0xff);
2894 	}
2895 
2896 	if (status & (F_HIPIODRBDROPERR | F_LOPIODRBDROPERR))
2897 		queue_work(cxgb3_wq, &adapter->db_drop_task);
2898 
2899 	if (status & (F_HIPRIORITYDBFULL | F_LOPRIORITYDBFULL))
2900 		queue_work(cxgb3_wq, &adapter->db_full_task);
2901 
2902 	if (status & (F_HIPRIORITYDBEMPTY | F_LOPRIORITYDBEMPTY))
2903 		queue_work(cxgb3_wq, &adapter->db_empty_task);
2904 
2905 	t3_write_reg(adapter, A_SG_INT_CAUSE, status);
2906 	if (status &  SGE_FATALERR)
2907 		t3_fatal_err(adapter);
2908 }
2909 
2910 /**
2911  *	sge_timer_tx - perform periodic maintenance of an SGE qset
2912  *	@t: a timer list containing the SGE queue set to maintain
2913  *
2914  *	Runs periodically from a timer to perform maintenance of an SGE queue
2915  *	set.  It performs two tasks:
2916  *
2917  *	Cleans up any completed Tx descriptors that may still be pending.
2918  *	Normal descriptor cleanup happens when new packets are added to a Tx
2919  *	queue so this timer is relatively infrequent and does any cleanup only
2920  *	if the Tx queue has not seen any new packets in a while.  We make a
2921  *	best effort attempt to reclaim descriptors, in that we don't wait
2922  *	around if we cannot get a queue's lock (which most likely is because
2923  *	someone else is queueing new packets and so will also handle the clean
2924  *	up).  Since control queues use immediate data exclusively we don't
2925  *	bother cleaning them up here.
2926  *
2927  */
2928 static void sge_timer_tx(struct timer_list *t)
2929 {
2930 	struct sge_qset *qs = from_timer(qs, t, tx_reclaim_timer);
2931 	struct port_info *pi = netdev_priv(qs->netdev);
2932 	struct adapter *adap = pi->adapter;
2933 	unsigned int tbd[SGE_TXQ_PER_SET] = {0, 0};
2934 	unsigned long next_period;
2935 
2936 	if (__netif_tx_trylock(qs->tx_q)) {
2937                 tbd[TXQ_ETH] = reclaim_completed_tx(adap, &qs->txq[TXQ_ETH],
2938                                                      TX_RECLAIM_TIMER_CHUNK);
2939 		__netif_tx_unlock(qs->tx_q);
2940 	}
2941 
2942 	if (spin_trylock(&qs->txq[TXQ_OFLD].lock)) {
2943 		tbd[TXQ_OFLD] = reclaim_completed_tx(adap, &qs->txq[TXQ_OFLD],
2944 						     TX_RECLAIM_TIMER_CHUNK);
2945 		spin_unlock(&qs->txq[TXQ_OFLD].lock);
2946 	}
2947 
2948 	next_period = TX_RECLAIM_PERIOD >>
2949                       (max(tbd[TXQ_ETH], tbd[TXQ_OFLD]) /
2950                       TX_RECLAIM_TIMER_CHUNK);
2951 	mod_timer(&qs->tx_reclaim_timer, jiffies + next_period);
2952 }
2953 
2954 /**
2955  *	sge_timer_rx - perform periodic maintenance of an SGE qset
2956  *	@t: the timer list containing the SGE queue set to maintain
2957  *
2958  *	a) Replenishes Rx queues that have run out due to memory shortage.
2959  *	Normally new Rx buffers are added when existing ones are consumed but
2960  *	when out of memory a queue can become empty.  We try to add only a few
2961  *	buffers here, the queue will be replenished fully as these new buffers
2962  *	are used up if memory shortage has subsided.
2963  *
2964  *	b) Return coalesced response queue credits in case a response queue is
2965  *	starved.
2966  *
2967  */
2968 static void sge_timer_rx(struct timer_list *t)
2969 {
2970 	spinlock_t *lock;
2971 	struct sge_qset *qs = from_timer(qs, t, rx_reclaim_timer);
2972 	struct port_info *pi = netdev_priv(qs->netdev);
2973 	struct adapter *adap = pi->adapter;
2974 	u32 status;
2975 
2976 	lock = adap->params.rev > 0 ?
2977 	       &qs->rspq.lock : &adap->sge.qs[0].rspq.lock;
2978 
2979 	if (!spin_trylock_irq(lock))
2980 		goto out;
2981 
2982 	if (napi_is_scheduled(&qs->napi))
2983 		goto unlock;
2984 
2985 	if (adap->params.rev < 4) {
2986 		status = t3_read_reg(adap, A_SG_RSPQ_FL_STATUS);
2987 
2988 		if (status & (1 << qs->rspq.cntxt_id)) {
2989 			qs->rspq.starved++;
2990 			if (qs->rspq.credits) {
2991 				qs->rspq.credits--;
2992 				refill_rspq(adap, &qs->rspq, 1);
2993 				qs->rspq.restarted++;
2994 				t3_write_reg(adap, A_SG_RSPQ_FL_STATUS,
2995 					     1 << qs->rspq.cntxt_id);
2996 			}
2997 		}
2998 	}
2999 
3000 	if (qs->fl[0].credits < qs->fl[0].size)
3001 		__refill_fl(adap, &qs->fl[0]);
3002 	if (qs->fl[1].credits < qs->fl[1].size)
3003 		__refill_fl(adap, &qs->fl[1]);
3004 
3005 unlock:
3006 	spin_unlock_irq(lock);
3007 out:
3008 	mod_timer(&qs->rx_reclaim_timer, jiffies + RX_RECLAIM_PERIOD);
3009 }
3010 
3011 /**
3012  *	t3_update_qset_coalesce - update coalescing settings for a queue set
3013  *	@qs: the SGE queue set
3014  *	@p: new queue set parameters
3015  *
3016  *	Update the coalescing settings for an SGE queue set.  Nothing is done
3017  *	if the queue set is not initialized yet.
3018  */
3019 void t3_update_qset_coalesce(struct sge_qset *qs, const struct qset_params *p)
3020 {
3021 	qs->rspq.holdoff_tmr = max(p->coalesce_usecs * 10, 1U);/* can't be 0 */
3022 	qs->rspq.polling = p->polling;
3023 	qs->napi.poll = p->polling ? napi_rx_handler : ofld_poll;
3024 }
3025 
3026 /**
3027  *	t3_sge_alloc_qset - initialize an SGE queue set
3028  *	@adapter: the adapter
3029  *	@id: the queue set id
3030  *	@nports: how many Ethernet ports will be using this queue set
3031  *	@irq_vec_idx: the IRQ vector index for response queue interrupts
3032  *	@p: configuration parameters for this queue set
3033  *	@ntxq: number of Tx queues for the queue set
3034  *	@dev: net device associated with this queue set
3035  *	@netdevq: net device TX queue associated with this queue set
3036  *
3037  *	Allocate resources and initialize an SGE queue set.  A queue set
3038  *	comprises a response queue, two Rx free-buffer queues, and up to 3
3039  *	Tx queues.  The Tx queues are assigned roles in the order Ethernet
3040  *	queue, offload queue, and control queue.
3041  */
3042 int t3_sge_alloc_qset(struct adapter *adapter, unsigned int id, int nports,
3043 		      int irq_vec_idx, const struct qset_params *p,
3044 		      int ntxq, struct net_device *dev,
3045 		      struct netdev_queue *netdevq)
3046 {
3047 	int i, avail, ret = -ENOMEM;
3048 	struct sge_qset *q = &adapter->sge.qs[id];
3049 
3050 	init_qset_cntxt(q, id);
3051 	timer_setup(&q->tx_reclaim_timer, sge_timer_tx, 0);
3052 	timer_setup(&q->rx_reclaim_timer, sge_timer_rx, 0);
3053 
3054 	q->fl[0].desc = alloc_ring(adapter->pdev, p->fl_size,
3055 				   sizeof(struct rx_desc),
3056 				   sizeof(struct rx_sw_desc),
3057 				   &q->fl[0].phys_addr, &q->fl[0].sdesc);
3058 	if (!q->fl[0].desc)
3059 		goto err;
3060 
3061 	q->fl[1].desc = alloc_ring(adapter->pdev, p->jumbo_size,
3062 				   sizeof(struct rx_desc),
3063 				   sizeof(struct rx_sw_desc),
3064 				   &q->fl[1].phys_addr, &q->fl[1].sdesc);
3065 	if (!q->fl[1].desc)
3066 		goto err;
3067 
3068 	q->rspq.desc = alloc_ring(adapter->pdev, p->rspq_size,
3069 				  sizeof(struct rsp_desc), 0,
3070 				  &q->rspq.phys_addr, NULL);
3071 	if (!q->rspq.desc)
3072 		goto err;
3073 
3074 	for (i = 0; i < ntxq; ++i) {
3075 		/*
3076 		 * The control queue always uses immediate data so does not
3077 		 * need to keep track of any sk_buffs.
3078 		 */
3079 		size_t sz = i == TXQ_CTRL ? 0 : sizeof(struct tx_sw_desc);
3080 
3081 		q->txq[i].desc = alloc_ring(adapter->pdev, p->txq_size[i],
3082 					    sizeof(struct tx_desc), sz,
3083 					    &q->txq[i].phys_addr,
3084 					    &q->txq[i].sdesc);
3085 		if (!q->txq[i].desc)
3086 			goto err;
3087 
3088 		q->txq[i].gen = 1;
3089 		q->txq[i].size = p->txq_size[i];
3090 		spin_lock_init(&q->txq[i].lock);
3091 		skb_queue_head_init(&q->txq[i].sendq);
3092 	}
3093 
3094 	INIT_WORK(&q->txq[TXQ_OFLD].qresume_task, restart_offloadq);
3095 	INIT_WORK(&q->txq[TXQ_CTRL].qresume_task, restart_ctrlq);
3096 
3097 	q->fl[0].gen = q->fl[1].gen = 1;
3098 	q->fl[0].size = p->fl_size;
3099 	q->fl[1].size = p->jumbo_size;
3100 
3101 	q->rspq.gen = 1;
3102 	q->rspq.size = p->rspq_size;
3103 	spin_lock_init(&q->rspq.lock);
3104 	skb_queue_head_init(&q->rspq.rx_queue);
3105 
3106 	q->txq[TXQ_ETH].stop_thres = nports *
3107 	    flits_to_desc(sgl_len(MAX_SKB_FRAGS + 1) + 3);
3108 
3109 #if FL0_PG_CHUNK_SIZE > 0
3110 	q->fl[0].buf_size = FL0_PG_CHUNK_SIZE;
3111 #else
3112 	q->fl[0].buf_size = SGE_RX_SM_BUF_SIZE + sizeof(struct cpl_rx_data);
3113 #endif
3114 #if FL1_PG_CHUNK_SIZE > 0
3115 	q->fl[1].buf_size = FL1_PG_CHUNK_SIZE;
3116 #else
3117 	q->fl[1].buf_size = is_offload(adapter) ?
3118 		(16 * 1024) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) :
3119 		MAX_FRAME_SIZE + 2 + sizeof(struct cpl_rx_pkt);
3120 #endif
3121 
3122 	q->fl[0].use_pages = FL0_PG_CHUNK_SIZE > 0;
3123 	q->fl[1].use_pages = FL1_PG_CHUNK_SIZE > 0;
3124 	q->fl[0].order = FL0_PG_ORDER;
3125 	q->fl[1].order = FL1_PG_ORDER;
3126 	q->fl[0].alloc_size = FL0_PG_ALLOC_SIZE;
3127 	q->fl[1].alloc_size = FL1_PG_ALLOC_SIZE;
3128 
3129 	spin_lock_irq(&adapter->sge.reg_lock);
3130 
3131 	/* FL threshold comparison uses < */
3132 	ret = t3_sge_init_rspcntxt(adapter, q->rspq.cntxt_id, irq_vec_idx,
3133 				   q->rspq.phys_addr, q->rspq.size,
3134 				   q->fl[0].buf_size - SGE_PG_RSVD, 1, 0);
3135 	if (ret)
3136 		goto err_unlock;
3137 
3138 	for (i = 0; i < SGE_RXQ_PER_SET; ++i) {
3139 		ret = t3_sge_init_flcntxt(adapter, q->fl[i].cntxt_id, 0,
3140 					  q->fl[i].phys_addr, q->fl[i].size,
3141 					  q->fl[i].buf_size - SGE_PG_RSVD,
3142 					  p->cong_thres, 1, 0);
3143 		if (ret)
3144 			goto err_unlock;
3145 	}
3146 
3147 	ret = t3_sge_init_ecntxt(adapter, q->txq[TXQ_ETH].cntxt_id, USE_GTS,
3148 				 SGE_CNTXT_ETH, id, q->txq[TXQ_ETH].phys_addr,
3149 				 q->txq[TXQ_ETH].size, q->txq[TXQ_ETH].token,
3150 				 1, 0);
3151 	if (ret)
3152 		goto err_unlock;
3153 
3154 	if (ntxq > 1) {
3155 		ret = t3_sge_init_ecntxt(adapter, q->txq[TXQ_OFLD].cntxt_id,
3156 					 USE_GTS, SGE_CNTXT_OFLD, id,
3157 					 q->txq[TXQ_OFLD].phys_addr,
3158 					 q->txq[TXQ_OFLD].size, 0, 1, 0);
3159 		if (ret)
3160 			goto err_unlock;
3161 	}
3162 
3163 	if (ntxq > 2) {
3164 		ret = t3_sge_init_ecntxt(adapter, q->txq[TXQ_CTRL].cntxt_id, 0,
3165 					 SGE_CNTXT_CTRL, id,
3166 					 q->txq[TXQ_CTRL].phys_addr,
3167 					 q->txq[TXQ_CTRL].size,
3168 					 q->txq[TXQ_CTRL].token, 1, 0);
3169 		if (ret)
3170 			goto err_unlock;
3171 	}
3172 
3173 	spin_unlock_irq(&adapter->sge.reg_lock);
3174 
3175 	q->adap = adapter;
3176 	q->netdev = dev;
3177 	q->tx_q = netdevq;
3178 	t3_update_qset_coalesce(q, p);
3179 
3180 	avail = refill_fl(adapter, &q->fl[0], q->fl[0].size,
3181 			  GFP_KERNEL | __GFP_COMP);
3182 	if (!avail) {
3183 		CH_ALERT(adapter, "free list queue 0 initialization failed\n");
3184 		ret = -ENOMEM;
3185 		goto err;
3186 	}
3187 	if (avail < q->fl[0].size)
3188 		CH_WARN(adapter, "free list queue 0 enabled with %d credits\n",
3189 			avail);
3190 
3191 	avail = refill_fl(adapter, &q->fl[1], q->fl[1].size,
3192 			  GFP_KERNEL | __GFP_COMP);
3193 	if (avail < q->fl[1].size)
3194 		CH_WARN(adapter, "free list queue 1 enabled with %d credits\n",
3195 			avail);
3196 	refill_rspq(adapter, &q->rspq, q->rspq.size - 1);
3197 
3198 	t3_write_reg(adapter, A_SG_GTS, V_RSPQ(q->rspq.cntxt_id) |
3199 		     V_NEWTIMER(q->rspq.holdoff_tmr));
3200 
3201 	return 0;
3202 
3203 err_unlock:
3204 	spin_unlock_irq(&adapter->sge.reg_lock);
3205 err:
3206 	t3_free_qset(adapter, q);
3207 	return ret;
3208 }
3209 
3210 /**
3211  *      t3_start_sge_timers - start SGE timer call backs
3212  *      @adap: the adapter
3213  *
3214  *      Starts each SGE queue set's timer call back
3215  */
3216 void t3_start_sge_timers(struct adapter *adap)
3217 {
3218 	int i;
3219 
3220 	for (i = 0; i < SGE_QSETS; ++i) {
3221 		struct sge_qset *q = &adap->sge.qs[i];
3222 
3223 		if (q->tx_reclaim_timer.function)
3224 			mod_timer(&q->tx_reclaim_timer,
3225 				  jiffies + TX_RECLAIM_PERIOD);
3226 
3227 		if (q->rx_reclaim_timer.function)
3228 			mod_timer(&q->rx_reclaim_timer,
3229 				  jiffies + RX_RECLAIM_PERIOD);
3230 	}
3231 }
3232 
3233 /**
3234  *	t3_stop_sge_timers - stop SGE timer call backs
3235  *	@adap: the adapter
3236  *
3237  *	Stops each SGE queue set's timer call back
3238  */
3239 void t3_stop_sge_timers(struct adapter *adap)
3240 {
3241 	int i;
3242 
3243 	for (i = 0; i < SGE_QSETS; ++i) {
3244 		struct sge_qset *q = &adap->sge.qs[i];
3245 
3246 		if (q->tx_reclaim_timer.function)
3247 			del_timer_sync(&q->tx_reclaim_timer);
3248 		if (q->rx_reclaim_timer.function)
3249 			del_timer_sync(&q->rx_reclaim_timer);
3250 	}
3251 }
3252 
3253 /**
3254  *	t3_free_sge_resources - free SGE resources
3255  *	@adap: the adapter
3256  *
3257  *	Frees resources used by the SGE queue sets.
3258  */
3259 void t3_free_sge_resources(struct adapter *adap)
3260 {
3261 	int i;
3262 
3263 	for (i = 0; i < SGE_QSETS; ++i)
3264 		t3_free_qset(adap, &adap->sge.qs[i]);
3265 }
3266 
3267 /**
3268  *	t3_sge_start - enable SGE
3269  *	@adap: the adapter
3270  *
3271  *	Enables the SGE for DMAs.  This is the last step in starting packet
3272  *	transfers.
3273  */
3274 void t3_sge_start(struct adapter *adap)
3275 {
3276 	t3_set_reg_field(adap, A_SG_CONTROL, F_GLOBALENABLE, F_GLOBALENABLE);
3277 }
3278 
3279 /**
3280  *	t3_sge_stop_dma - Disable SGE DMA engine operation
3281  *	@adap: the adapter
3282  *
3283  *	Can be invoked from interrupt context e.g.  error handler.
3284  *
3285  *	Note that this function cannot disable the restart of works as
3286  *	it cannot wait if called from interrupt context, however the
3287  *	works will have no effect since the doorbells are disabled. The
3288  *	driver will call tg3_sge_stop() later from process context, at
3289  *	which time the works will be stopped if they are still running.
3290  */
3291 void t3_sge_stop_dma(struct adapter *adap)
3292 {
3293 	t3_set_reg_field(adap, A_SG_CONTROL, F_GLOBALENABLE, 0);
3294 }
3295 
3296 /**
3297  *	t3_sge_stop - disable SGE operation completly
3298  *	@adap: the adapter
3299  *
3300  *	Called from process context. Disables the DMA engine and any
3301  *	pending queue restart works.
3302  */
3303 void t3_sge_stop(struct adapter *adap)
3304 {
3305 	int i;
3306 
3307 	t3_sge_stop_dma(adap);
3308 
3309 	for (i = 0; i < SGE_QSETS; ++i) {
3310 		struct sge_qset *qs = &adap->sge.qs[i];
3311 
3312 		cancel_work_sync(&qs->txq[TXQ_OFLD].qresume_task);
3313 		cancel_work_sync(&qs->txq[TXQ_CTRL].qresume_task);
3314 	}
3315 }
3316 
3317 /**
3318  *	t3_sge_init - initialize SGE
3319  *	@adap: the adapter
3320  *	@p: the SGE parameters
3321  *
3322  *	Performs SGE initialization needed every time after a chip reset.
3323  *	We do not initialize any of the queue sets here, instead the driver
3324  *	top-level must request those individually.  We also do not enable DMA
3325  *	here, that should be done after the queues have been set up.
3326  */
3327 void t3_sge_init(struct adapter *adap, struct sge_params *p)
3328 {
3329 	unsigned int ctrl, ups = ffs(pci_resource_len(adap->pdev, 2) >> 12);
3330 
3331 	ctrl = F_DROPPKT | V_PKTSHIFT(2) | F_FLMODE | F_AVOIDCQOVFL |
3332 	    F_CQCRDTCTRL | F_CONGMODE | F_TNLFLMODE | F_FATLPERREN |
3333 	    V_HOSTPAGESIZE(PAGE_SHIFT - 11) | F_BIGENDIANINGRESS |
3334 	    V_USERSPACESIZE(ups ? ups - 1 : 0) | F_ISCSICOALESCING;
3335 #if SGE_NUM_GENBITS == 1
3336 	ctrl |= F_EGRGENCTRL;
3337 #endif
3338 	if (adap->params.rev > 0) {
3339 		if (!(adap->flags & (USING_MSIX | USING_MSI)))
3340 			ctrl |= F_ONEINTMULTQ | F_OPTONEINTMULTQ;
3341 	}
3342 	t3_write_reg(adap, A_SG_CONTROL, ctrl);
3343 	t3_write_reg(adap, A_SG_EGR_RCQ_DRB_THRSH, V_HIRCQDRBTHRSH(512) |
3344 		     V_LORCQDRBTHRSH(512));
3345 	t3_write_reg(adap, A_SG_TIMER_TICK, core_ticks_per_usec(adap) / 10);
3346 	t3_write_reg(adap, A_SG_CMDQ_CREDIT_TH, V_THRESHOLD(32) |
3347 		     V_TIMEOUT(200 * core_ticks_per_usec(adap)));
3348 	t3_write_reg(adap, A_SG_HI_DRB_HI_THRSH,
3349 		     adap->params.rev < T3_REV_C ? 1000 : 500);
3350 	t3_write_reg(adap, A_SG_HI_DRB_LO_THRSH, 256);
3351 	t3_write_reg(adap, A_SG_LO_DRB_HI_THRSH, 1000);
3352 	t3_write_reg(adap, A_SG_LO_DRB_LO_THRSH, 256);
3353 	t3_write_reg(adap, A_SG_OCO_BASE, V_BASE1(0xfff));
3354 	t3_write_reg(adap, A_SG_DRB_PRI_THRESH, 63 * 1024);
3355 }
3356 
3357 /**
3358  *	t3_sge_prep - one-time SGE initialization
3359  *	@adap: the associated adapter
3360  *	@p: SGE parameters
3361  *
3362  *	Performs one-time initialization of SGE SW state.  Includes determining
3363  *	defaults for the assorted SGE parameters, which admins can change until
3364  *	they are used to initialize the SGE.
3365  */
3366 void t3_sge_prep(struct adapter *adap, struct sge_params *p)
3367 {
3368 	int i;
3369 
3370 	p->max_pkt_size = (16 * 1024) - sizeof(struct cpl_rx_data) -
3371 	    SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
3372 
3373 	for (i = 0; i < SGE_QSETS; ++i) {
3374 		struct qset_params *q = p->qset + i;
3375 
3376 		q->polling = adap->params.rev > 0;
3377 		q->coalesce_usecs = 5;
3378 		q->rspq_size = 1024;
3379 		q->fl_size = 1024;
3380 		q->jumbo_size = 512;
3381 		q->txq_size[TXQ_ETH] = 1024;
3382 		q->txq_size[TXQ_OFLD] = 1024;
3383 		q->txq_size[TXQ_CTRL] = 256;
3384 		q->cong_thres = 0;
3385 	}
3386 
3387 	spin_lock_init(&adap->sge.reg_lock);
3388 }
3389