1 /*****************************************************************************
2  *                                                                           *
3  * File: sge.c                                                               *
4  * $Revision: 1.26 $                                                         *
5  * $Date: 2005/06/21 18:29:48 $                                              *
6  * Description:                                                              *
7  *  DMA engine.                                                              *
8  *  part of the Chelsio 10Gb Ethernet Driver.                                *
9  *                                                                           *
10  * This program is free software; you can redistribute it and/or modify      *
11  * it under the terms of the GNU General Public License, version 2, as       *
12  * published by the Free Software Foundation.                                *
13  *                                                                           *
14  * You should have received a copy of the GNU General Public License along   *
15  * with this program; if not, write to the Free Software Foundation, Inc.,   *
16  * 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.                 *
17  *                                                                           *
18  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED    *
19  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF      *
20  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.                     *
21  *                                                                           *
22  * http://www.chelsio.com                                                    *
23  *                                                                           *
24  * Copyright (c) 2003 - 2005 Chelsio Communications, Inc.                    *
25  * All rights reserved.                                                      *
26  *                                                                           *
27  * Maintainers: maintainers@chelsio.com                                      *
28  *                                                                           *
29  * Authors: Dimitrios Michailidis   <dm@chelsio.com>                         *
30  *          Tina Yang               <tainay@chelsio.com>                     *
31  *          Felix Marti             <felix@chelsio.com>                      *
32  *          Scott Bardone           <sbardone@chelsio.com>                   *
33  *          Kurt Ottaway            <kottaway@chelsio.com>                   *
34  *          Frank DiMambro          <frank@chelsio.com>                      *
35  *                                                                           *
36  * History:                                                                  *
37  *                                                                           *
38  ****************************************************************************/
39 
40 #include "common.h"
41 
42 #include <linux/types.h>
43 #include <linux/errno.h>
44 #include <linux/pci.h>
45 #include <linux/ktime.h>
46 #include <linux/netdevice.h>
47 #include <linux/etherdevice.h>
48 #include <linux/if_vlan.h>
49 #include <linux/skbuff.h>
50 #include <linux/init.h>
51 #include <linux/mm.h>
52 #include <linux/tcp.h>
53 #include <linux/ip.h>
54 #include <linux/in.h>
55 #include <linux/if_arp.h>
56 #include <linux/slab.h>
57 
58 #include "cpl5_cmd.h"
59 #include "sge.h"
60 #include "regs.h"
61 #include "espi.h"
62 
63 /* This belongs in if_ether.h */
64 #define ETH_P_CPL5 0xf
65 
66 #define SGE_CMDQ_N		2
67 #define SGE_FREELQ_N		2
68 #define SGE_CMDQ0_E_N		1024
69 #define SGE_CMDQ1_E_N		128
70 #define SGE_FREEL_SIZE		4096
71 #define SGE_JUMBO_FREEL_SIZE	512
72 #define SGE_FREEL_REFILL_THRESH	16
73 #define SGE_RESPQ_E_N		1024
74 #define SGE_INTRTIMER_NRES	1000
75 #define SGE_RX_SM_BUF_SIZE	1536
76 #define SGE_TX_DESC_MAX_PLEN	16384
77 
78 #define SGE_RESPQ_REPLENISH_THRES (SGE_RESPQ_E_N / 4)
79 
80 /*
81  * Period of the TX buffer reclaim timer.  This timer does not need to run
82  * frequently as TX buffers are usually reclaimed by new TX packets.
83  */
84 #define TX_RECLAIM_PERIOD (HZ / 4)
85 
86 #define M_CMD_LEN       0x7fffffff
87 #define V_CMD_LEN(v)    (v)
88 #define G_CMD_LEN(v)    ((v) & M_CMD_LEN)
89 #define V_CMD_GEN1(v)   ((v) << 31)
90 #define V_CMD_GEN2(v)   (v)
91 #define F_CMD_DATAVALID (1 << 1)
92 #define F_CMD_SOP       (1 << 2)
93 #define V_CMD_EOP(v)    ((v) << 3)
94 
95 /*
96  * Command queue, receive buffer list, and response queue descriptors.
97  */
98 #if defined(__BIG_ENDIAN_BITFIELD)
99 struct cmdQ_e {
100 	u32 addr_lo;
101 	u32 len_gen;
102 	u32 flags;
103 	u32 addr_hi;
104 };
105 
106 struct freelQ_e {
107 	u32 addr_lo;
108 	u32 len_gen;
109 	u32 gen2;
110 	u32 addr_hi;
111 };
112 
113 struct respQ_e {
114 	u32 Qsleeping		: 4;
115 	u32 Cmdq1CreditReturn	: 5;
116 	u32 Cmdq1DmaComplete	: 5;
117 	u32 Cmdq0CreditReturn	: 5;
118 	u32 Cmdq0DmaComplete	: 5;
119 	u32 FreelistQid		: 2;
120 	u32 CreditValid		: 1;
121 	u32 DataValid		: 1;
122 	u32 Offload		: 1;
123 	u32 Eop			: 1;
124 	u32 Sop			: 1;
125 	u32 GenerationBit	: 1;
126 	u32 BufferLength;
127 };
128 #elif defined(__LITTLE_ENDIAN_BITFIELD)
129 struct cmdQ_e {
130 	u32 len_gen;
131 	u32 addr_lo;
132 	u32 addr_hi;
133 	u32 flags;
134 };
135 
136 struct freelQ_e {
137 	u32 len_gen;
138 	u32 addr_lo;
139 	u32 addr_hi;
140 	u32 gen2;
141 };
142 
143 struct respQ_e {
144 	u32 BufferLength;
145 	u32 GenerationBit	: 1;
146 	u32 Sop			: 1;
147 	u32 Eop			: 1;
148 	u32 Offload		: 1;
149 	u32 DataValid		: 1;
150 	u32 CreditValid		: 1;
151 	u32 FreelistQid		: 2;
152 	u32 Cmdq0DmaComplete	: 5;
153 	u32 Cmdq0CreditReturn	: 5;
154 	u32 Cmdq1DmaComplete	: 5;
155 	u32 Cmdq1CreditReturn	: 5;
156 	u32 Qsleeping		: 4;
157 } ;
158 #endif
159 
160 /*
161  * SW Context Command and Freelist Queue Descriptors
162  */
163 struct cmdQ_ce {
164 	struct sk_buff *skb;
165 	DEFINE_DMA_UNMAP_ADDR(dma_addr);
166 	DEFINE_DMA_UNMAP_LEN(dma_len);
167 };
168 
169 struct freelQ_ce {
170 	struct sk_buff *skb;
171 	DEFINE_DMA_UNMAP_ADDR(dma_addr);
172 	DEFINE_DMA_UNMAP_LEN(dma_len);
173 };
174 
175 /*
176  * SW command, freelist and response rings
177  */
178 struct cmdQ {
179 	unsigned long   status;         /* HW DMA fetch status */
180 	unsigned int    in_use;         /* # of in-use command descriptors */
181 	unsigned int	size;	        /* # of descriptors */
182 	unsigned int    processed;      /* total # of descs HW has processed */
183 	unsigned int    cleaned;        /* total # of descs SW has reclaimed */
184 	unsigned int    stop_thres;     /* SW TX queue suspend threshold */
185 	u16		pidx;           /* producer index (SW) */
186 	u16		cidx;           /* consumer index (HW) */
187 	u8		genbit;         /* current generation (=valid) bit */
188 	u8              sop;            /* is next entry start of packet? */
189 	struct cmdQ_e  *entries;        /* HW command descriptor Q */
190 	struct cmdQ_ce *centries;       /* SW command context descriptor Q */
191 	dma_addr_t	dma_addr;       /* DMA addr HW command descriptor Q */
192 	spinlock_t	lock;           /* Lock to protect cmdQ enqueuing */
193 };
194 
195 struct freelQ {
196 	unsigned int	credits;        /* # of available RX buffers */
197 	unsigned int	size;	        /* free list capacity */
198 	u16		pidx;           /* producer index (SW) */
199 	u16		cidx;           /* consumer index (HW) */
200 	u16		rx_buffer_size; /* Buffer size on this free list */
201 	u16             dma_offset;     /* DMA offset to align IP headers */
202 	u16             recycleq_idx;   /* skb recycle q to use */
203 	u8		genbit;	        /* current generation (=valid) bit */
204 	struct freelQ_e	*entries;       /* HW freelist descriptor Q */
205 	struct freelQ_ce *centries;     /* SW freelist context descriptor Q */
206 	dma_addr_t	dma_addr;       /* DMA addr HW freelist descriptor Q */
207 };
208 
209 struct respQ {
210 	unsigned int	credits;        /* credits to be returned to SGE */
211 	unsigned int	size;	        /* # of response Q descriptors */
212 	u16		cidx;	        /* consumer index (SW) */
213 	u8		genbit;	        /* current generation(=valid) bit */
214 	struct respQ_e *entries;        /* HW response descriptor Q */
215 	dma_addr_t	dma_addr;       /* DMA addr HW response descriptor Q */
216 };
217 
218 /* Bit flags for cmdQ.status */
219 enum {
220 	CMDQ_STAT_RUNNING = 1,          /* fetch engine is running */
221 	CMDQ_STAT_LAST_PKT_DB = 2       /* last packet rung the doorbell */
222 };
223 
224 /* T204 TX SW scheduler */
225 
226 /* Per T204 TX port */
227 struct sched_port {
228 	unsigned int	avail;		/* available bits - quota */
229 	unsigned int	drain_bits_per_1024ns; /* drain rate */
230 	unsigned int	speed;		/* drain rate, mbps */
231 	unsigned int	mtu;		/* mtu size */
232 	struct sk_buff_head skbq;	/* pending skbs */
233 };
234 
235 /* Per T204 device */
236 struct sched {
237 	ktime_t         last_updated;   /* last time quotas were computed */
238 	unsigned int	max_avail;	/* max bits to be sent to any port */
239 	unsigned int	port;		/* port index (round robin ports) */
240 	unsigned int	num;		/* num skbs in per port queues */
241 	struct sched_port p[MAX_NPORTS];
242 	struct tasklet_struct sched_tsk;/* tasklet used to run scheduler */
243 };
244 static void restart_sched(unsigned long);
245 
246 
247 /*
248  * Main SGE data structure
249  *
250  * Interrupts are handled by a single CPU and it is likely that on a MP system
251  * the application is migrated to another CPU. In that scenario, we try to
252  * separate the RX(in irq context) and TX state in order to decrease memory
253  * contention.
254  */
255 struct sge {
256 	struct adapter *adapter;	/* adapter backpointer */
257 	struct net_device *netdev;      /* netdevice backpointer */
258 	struct freelQ	freelQ[SGE_FREELQ_N]; /* buffer free lists */
259 	struct respQ	respQ;		/* response Q */
260 	unsigned long   stopped_tx_queues; /* bitmap of suspended Tx queues */
261 	unsigned int	rx_pkt_pad;     /* RX padding for L2 packets */
262 	unsigned int	jumbo_fl;       /* jumbo freelist Q index */
263 	unsigned int	intrtimer_nres;	/* no-resource interrupt timer */
264 	unsigned int    fixed_intrtimer;/* non-adaptive interrupt timer */
265 	struct timer_list tx_reclaim_timer; /* reclaims TX buffers */
266 	struct timer_list espibug_timer;
267 	unsigned long	espibug_timeout;
268 	struct sk_buff	*espibug_skb[MAX_NPORTS];
269 	u32		sge_control;	/* shadow value of sge control reg */
270 	struct sge_intr_counts stats;
271 	struct sge_port_stats __percpu *port_stats[MAX_NPORTS];
272 	struct sched	*tx_sched;
273 	struct cmdQ cmdQ[SGE_CMDQ_N] ____cacheline_aligned_in_smp;
274 };
275 
276 static const u8 ch_mac_addr[ETH_ALEN] = {
277 	0x0, 0x7, 0x43, 0x0, 0x0, 0x0
278 };
279 
280 /*
281  * stop tasklet and free all pending skb's
282  */
tx_sched_stop(struct sge * sge)283 static void tx_sched_stop(struct sge *sge)
284 {
285 	struct sched *s = sge->tx_sched;
286 	int i;
287 
288 	tasklet_kill(&s->sched_tsk);
289 
290 	for (i = 0; i < MAX_NPORTS; i++)
291 		__skb_queue_purge(&s->p[s->port].skbq);
292 }
293 
294 /*
295  * t1_sched_update_parms() is called when the MTU or link speed changes. It
296  * re-computes scheduler parameters to scope with the change.
297  */
t1_sched_update_parms(struct sge * sge,unsigned int port,unsigned int mtu,unsigned int speed)298 unsigned int t1_sched_update_parms(struct sge *sge, unsigned int port,
299 				   unsigned int mtu, unsigned int speed)
300 {
301 	struct sched *s = sge->tx_sched;
302 	struct sched_port *p = &s->p[port];
303 	unsigned int max_avail_segs;
304 
305 	pr_debug("t1_sched_update_params mtu=%d speed=%d\n", mtu, speed);
306 	if (speed)
307 		p->speed = speed;
308 	if (mtu)
309 		p->mtu = mtu;
310 
311 	if (speed || mtu) {
312 		unsigned long long drain = 1024ULL * p->speed * (p->mtu - 40);
313 		do_div(drain, (p->mtu + 50) * 1000);
314 		p->drain_bits_per_1024ns = (unsigned int) drain;
315 
316 		if (p->speed < 1000)
317 			p->drain_bits_per_1024ns =
318 				90 * p->drain_bits_per_1024ns / 100;
319 	}
320 
321 	if (board_info(sge->adapter)->board == CHBT_BOARD_CHT204) {
322 		p->drain_bits_per_1024ns -= 16;
323 		s->max_avail = max(4096U, p->mtu + 16 + 14 + 4);
324 		max_avail_segs = max(1U, 4096 / (p->mtu - 40));
325 	} else {
326 		s->max_avail = 16384;
327 		max_avail_segs = max(1U, 9000 / (p->mtu - 40));
328 	}
329 
330 	pr_debug("t1_sched_update_parms: mtu %u speed %u max_avail %u "
331 		 "max_avail_segs %u drain_bits_per_1024ns %u\n", p->mtu,
332 		 p->speed, s->max_avail, max_avail_segs,
333 		 p->drain_bits_per_1024ns);
334 
335 	return max_avail_segs * (p->mtu - 40);
336 }
337 
338 #if 0
339 
340 /*
341  * t1_sched_max_avail_bytes() tells the scheduler the maximum amount of
342  * data that can be pushed per port.
343  */
344 void t1_sched_set_max_avail_bytes(struct sge *sge, unsigned int val)
345 {
346 	struct sched *s = sge->tx_sched;
347 	unsigned int i;
348 
349 	s->max_avail = val;
350 	for (i = 0; i < MAX_NPORTS; i++)
351 		t1_sched_update_parms(sge, i, 0, 0);
352 }
353 
354 /*
355  * t1_sched_set_drain_bits_per_us() tells the scheduler at which rate a port
356  * is draining.
357  */
358 void t1_sched_set_drain_bits_per_us(struct sge *sge, unsigned int port,
359 					 unsigned int val)
360 {
361 	struct sched *s = sge->tx_sched;
362 	struct sched_port *p = &s->p[port];
363 	p->drain_bits_per_1024ns = val * 1024 / 1000;
364 	t1_sched_update_parms(sge, port, 0, 0);
365 }
366 
367 #endif  /*  0  */
368 
369 
370 /*
371  * get_clock() implements a ns clock (see ktime_get)
372  */
get_clock(void)373 static inline ktime_t get_clock(void)
374 {
375 	struct timespec ts;
376 
377 	ktime_get_ts(&ts);
378 	return timespec_to_ktime(ts);
379 }
380 
381 /*
382  * tx_sched_init() allocates resources and does basic initialization.
383  */
tx_sched_init(struct sge * sge)384 static int tx_sched_init(struct sge *sge)
385 {
386 	struct sched *s;
387 	int i;
388 
389 	s = kzalloc(sizeof (struct sched), GFP_KERNEL);
390 	if (!s)
391 		return -ENOMEM;
392 
393 	pr_debug("tx_sched_init\n");
394 	tasklet_init(&s->sched_tsk, restart_sched, (unsigned long) sge);
395 	sge->tx_sched = s;
396 
397 	for (i = 0; i < MAX_NPORTS; i++) {
398 		skb_queue_head_init(&s->p[i].skbq);
399 		t1_sched_update_parms(sge, i, 1500, 1000);
400 	}
401 
402 	return 0;
403 }
404 
405 /*
406  * sched_update_avail() computes the delta since the last time it was called
407  * and updates the per port quota (number of bits that can be sent to the any
408  * port).
409  */
sched_update_avail(struct sge * sge)410 static inline int sched_update_avail(struct sge *sge)
411 {
412 	struct sched *s = sge->tx_sched;
413 	ktime_t now = get_clock();
414 	unsigned int i;
415 	long long delta_time_ns;
416 
417 	delta_time_ns = ktime_to_ns(ktime_sub(now, s->last_updated));
418 
419 	pr_debug("sched_update_avail delta=%lld\n", delta_time_ns);
420 	if (delta_time_ns < 15000)
421 		return 0;
422 
423 	for (i = 0; i < MAX_NPORTS; i++) {
424 		struct sched_port *p = &s->p[i];
425 		unsigned int delta_avail;
426 
427 		delta_avail = (p->drain_bits_per_1024ns * delta_time_ns) >> 13;
428 		p->avail = min(p->avail + delta_avail, s->max_avail);
429 	}
430 
431 	s->last_updated = now;
432 
433 	return 1;
434 }
435 
436 /*
437  * sched_skb() is called from two different places. In the tx path, any
438  * packet generating load on an output port will call sched_skb()
439  * (skb != NULL). In addition, sched_skb() is called from the irq/soft irq
440  * context (skb == NULL).
441  * The scheduler only returns a skb (which will then be sent) if the
442  * length of the skb is <= the current quota of the output port.
443  */
sched_skb(struct sge * sge,struct sk_buff * skb,unsigned int credits)444 static struct sk_buff *sched_skb(struct sge *sge, struct sk_buff *skb,
445 				unsigned int credits)
446 {
447 	struct sched *s = sge->tx_sched;
448 	struct sk_buff_head *skbq;
449 	unsigned int i, len, update = 1;
450 
451 	pr_debug("sched_skb %p\n", skb);
452 	if (!skb) {
453 		if (!s->num)
454 			return NULL;
455 	} else {
456 		skbq = &s->p[skb->dev->if_port].skbq;
457 		__skb_queue_tail(skbq, skb);
458 		s->num++;
459 		skb = NULL;
460 	}
461 
462 	if (credits < MAX_SKB_FRAGS + 1)
463 		goto out;
464 
465 again:
466 	for (i = 0; i < MAX_NPORTS; i++) {
467 		s->port = (s->port + 1) & (MAX_NPORTS - 1);
468 		skbq = &s->p[s->port].skbq;
469 
470 		skb = skb_peek(skbq);
471 
472 		if (!skb)
473 			continue;
474 
475 		len = skb->len;
476 		if (len <= s->p[s->port].avail) {
477 			s->p[s->port].avail -= len;
478 			s->num--;
479 			__skb_unlink(skb, skbq);
480 			goto out;
481 		}
482 		skb = NULL;
483 	}
484 
485 	if (update-- && sched_update_avail(sge))
486 		goto again;
487 
488 out:
489 	/* If there are more pending skbs, we use the hardware to schedule us
490 	 * again.
491 	 */
492 	if (s->num && !skb) {
493 		struct cmdQ *q = &sge->cmdQ[0];
494 		clear_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
495 		if (test_and_set_bit(CMDQ_STAT_RUNNING, &q->status) == 0) {
496 			set_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
497 			writel(F_CMDQ0_ENABLE, sge->adapter->regs + A_SG_DOORBELL);
498 		}
499 	}
500 	pr_debug("sched_skb ret %p\n", skb);
501 
502 	return skb;
503 }
504 
505 /*
506  * PIO to indicate that memory mapped Q contains valid descriptor(s).
507  */
doorbell_pio(struct adapter * adapter,u32 val)508 static inline void doorbell_pio(struct adapter *adapter, u32 val)
509 {
510 	wmb();
511 	writel(val, adapter->regs + A_SG_DOORBELL);
512 }
513 
514 /*
515  * Frees all RX buffers on the freelist Q. The caller must make sure that
516  * the SGE is turned off before calling this function.
517  */
free_freelQ_buffers(struct pci_dev * pdev,struct freelQ * q)518 static void free_freelQ_buffers(struct pci_dev *pdev, struct freelQ *q)
519 {
520 	unsigned int cidx = q->cidx;
521 
522 	while (q->credits--) {
523 		struct freelQ_ce *ce = &q->centries[cidx];
524 
525 		pci_unmap_single(pdev, dma_unmap_addr(ce, dma_addr),
526 				 dma_unmap_len(ce, dma_len),
527 				 PCI_DMA_FROMDEVICE);
528 		dev_kfree_skb(ce->skb);
529 		ce->skb = NULL;
530 		if (++cidx == q->size)
531 			cidx = 0;
532 	}
533 }
534 
535 /*
536  * Free RX free list and response queue resources.
537  */
free_rx_resources(struct sge * sge)538 static void free_rx_resources(struct sge *sge)
539 {
540 	struct pci_dev *pdev = sge->adapter->pdev;
541 	unsigned int size, i;
542 
543 	if (sge->respQ.entries) {
544 		size = sizeof(struct respQ_e) * sge->respQ.size;
545 		pci_free_consistent(pdev, size, sge->respQ.entries,
546 				    sge->respQ.dma_addr);
547 	}
548 
549 	for (i = 0; i < SGE_FREELQ_N; i++) {
550 		struct freelQ *q = &sge->freelQ[i];
551 
552 		if (q->centries) {
553 			free_freelQ_buffers(pdev, q);
554 			kfree(q->centries);
555 		}
556 		if (q->entries) {
557 			size = sizeof(struct freelQ_e) * q->size;
558 			pci_free_consistent(pdev, size, q->entries,
559 					    q->dma_addr);
560 		}
561 	}
562 }
563 
564 /*
565  * Allocates basic RX resources, consisting of memory mapped freelist Qs and a
566  * response queue.
567  */
alloc_rx_resources(struct sge * sge,struct sge_params * p)568 static int alloc_rx_resources(struct sge *sge, struct sge_params *p)
569 {
570 	struct pci_dev *pdev = sge->adapter->pdev;
571 	unsigned int size, i;
572 
573 	for (i = 0; i < SGE_FREELQ_N; i++) {
574 		struct freelQ *q = &sge->freelQ[i];
575 
576 		q->genbit = 1;
577 		q->size = p->freelQ_size[i];
578 		q->dma_offset = sge->rx_pkt_pad ? 0 : NET_IP_ALIGN;
579 		size = sizeof(struct freelQ_e) * q->size;
580 		q->entries = pci_alloc_consistent(pdev, size, &q->dma_addr);
581 		if (!q->entries)
582 			goto err_no_mem;
583 
584 		size = sizeof(struct freelQ_ce) * q->size;
585 		q->centries = kzalloc(size, GFP_KERNEL);
586 		if (!q->centries)
587 			goto err_no_mem;
588 	}
589 
590 	/*
591 	 * Calculate the buffer sizes for the two free lists.  FL0 accommodates
592 	 * regular sized Ethernet frames, FL1 is sized not to exceed 16K,
593 	 * including all the sk_buff overhead.
594 	 *
595 	 * Note: For T2 FL0 and FL1 are reversed.
596 	 */
597 	sge->freelQ[!sge->jumbo_fl].rx_buffer_size = SGE_RX_SM_BUF_SIZE +
598 		sizeof(struct cpl_rx_data) +
599 		sge->freelQ[!sge->jumbo_fl].dma_offset;
600 
601 		size = (16 * 1024) -
602 		    SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
603 
604 	sge->freelQ[sge->jumbo_fl].rx_buffer_size = size;
605 
606 	/*
607 	 * Setup which skb recycle Q should be used when recycling buffers from
608 	 * each free list.
609 	 */
610 	sge->freelQ[!sge->jumbo_fl].recycleq_idx = 0;
611 	sge->freelQ[sge->jumbo_fl].recycleq_idx = 1;
612 
613 	sge->respQ.genbit = 1;
614 	sge->respQ.size = SGE_RESPQ_E_N;
615 	sge->respQ.credits = 0;
616 	size = sizeof(struct respQ_e) * sge->respQ.size;
617 	sge->respQ.entries =
618 		pci_alloc_consistent(pdev, size, &sge->respQ.dma_addr);
619 	if (!sge->respQ.entries)
620 		goto err_no_mem;
621 	return 0;
622 
623 err_no_mem:
624 	free_rx_resources(sge);
625 	return -ENOMEM;
626 }
627 
628 /*
629  * Reclaims n TX descriptors and frees the buffers associated with them.
630  */
free_cmdQ_buffers(struct sge * sge,struct cmdQ * q,unsigned int n)631 static void free_cmdQ_buffers(struct sge *sge, struct cmdQ *q, unsigned int n)
632 {
633 	struct cmdQ_ce *ce;
634 	struct pci_dev *pdev = sge->adapter->pdev;
635 	unsigned int cidx = q->cidx;
636 
637 	q->in_use -= n;
638 	ce = &q->centries[cidx];
639 	while (n--) {
640 		if (likely(dma_unmap_len(ce, dma_len))) {
641 			pci_unmap_single(pdev, dma_unmap_addr(ce, dma_addr),
642 					 dma_unmap_len(ce, dma_len),
643 					 PCI_DMA_TODEVICE);
644 			if (q->sop)
645 				q->sop = 0;
646 		}
647 		if (ce->skb) {
648 			dev_kfree_skb_any(ce->skb);
649 			q->sop = 1;
650 		}
651 		ce++;
652 		if (++cidx == q->size) {
653 			cidx = 0;
654 			ce = q->centries;
655 		}
656 	}
657 	q->cidx = cidx;
658 }
659 
660 /*
661  * Free TX resources.
662  *
663  * Assumes that SGE is stopped and all interrupts are disabled.
664  */
free_tx_resources(struct sge * sge)665 static void free_tx_resources(struct sge *sge)
666 {
667 	struct pci_dev *pdev = sge->adapter->pdev;
668 	unsigned int size, i;
669 
670 	for (i = 0; i < SGE_CMDQ_N; i++) {
671 		struct cmdQ *q = &sge->cmdQ[i];
672 
673 		if (q->centries) {
674 			if (q->in_use)
675 				free_cmdQ_buffers(sge, q, q->in_use);
676 			kfree(q->centries);
677 		}
678 		if (q->entries) {
679 			size = sizeof(struct cmdQ_e) * q->size;
680 			pci_free_consistent(pdev, size, q->entries,
681 					    q->dma_addr);
682 		}
683 	}
684 }
685 
686 /*
687  * Allocates basic TX resources, consisting of memory mapped command Qs.
688  */
alloc_tx_resources(struct sge * sge,struct sge_params * p)689 static int alloc_tx_resources(struct sge *sge, struct sge_params *p)
690 {
691 	struct pci_dev *pdev = sge->adapter->pdev;
692 	unsigned int size, i;
693 
694 	for (i = 0; i < SGE_CMDQ_N; i++) {
695 		struct cmdQ *q = &sge->cmdQ[i];
696 
697 		q->genbit = 1;
698 		q->sop = 1;
699 		q->size = p->cmdQ_size[i];
700 		q->in_use = 0;
701 		q->status = 0;
702 		q->processed = q->cleaned = 0;
703 		q->stop_thres = 0;
704 		spin_lock_init(&q->lock);
705 		size = sizeof(struct cmdQ_e) * q->size;
706 		q->entries = pci_alloc_consistent(pdev, size, &q->dma_addr);
707 		if (!q->entries)
708 			goto err_no_mem;
709 
710 		size = sizeof(struct cmdQ_ce) * q->size;
711 		q->centries = kzalloc(size, GFP_KERNEL);
712 		if (!q->centries)
713 			goto err_no_mem;
714 	}
715 
716 	/*
717 	 * CommandQ 0 handles Ethernet and TOE packets, while queue 1 is TOE
718 	 * only.  For queue 0 set the stop threshold so we can handle one more
719 	 * packet from each port, plus reserve an additional 24 entries for
720 	 * Ethernet packets only.  Queue 1 never suspends nor do we reserve
721 	 * space for Ethernet packets.
722 	 */
723 	sge->cmdQ[0].stop_thres = sge->adapter->params.nports *
724 		(MAX_SKB_FRAGS + 1);
725 	return 0;
726 
727 err_no_mem:
728 	free_tx_resources(sge);
729 	return -ENOMEM;
730 }
731 
setup_ring_params(struct adapter * adapter,u64 addr,u32 size,int base_reg_lo,int base_reg_hi,int size_reg)732 static inline void setup_ring_params(struct adapter *adapter, u64 addr,
733 				     u32 size, int base_reg_lo,
734 				     int base_reg_hi, int size_reg)
735 {
736 	writel((u32)addr, adapter->regs + base_reg_lo);
737 	writel(addr >> 32, adapter->regs + base_reg_hi);
738 	writel(size, adapter->regs + size_reg);
739 }
740 
741 /*
742  * Enable/disable VLAN acceleration.
743  */
t1_set_vlan_accel(struct adapter * adapter,int on_off)744 void t1_set_vlan_accel(struct adapter *adapter, int on_off)
745 {
746 	struct sge *sge = adapter->sge;
747 
748 	sge->sge_control &= ~F_VLAN_XTRACT;
749 	if (on_off)
750 		sge->sge_control |= F_VLAN_XTRACT;
751 	if (adapter->open_device_map) {
752 		writel(sge->sge_control, adapter->regs + A_SG_CONTROL);
753 		readl(adapter->regs + A_SG_CONTROL);   /* flush */
754 	}
755 }
756 
757 /*
758  * Programs the various SGE registers. However, the engine is not yet enabled,
759  * but sge->sge_control is setup and ready to go.
760  */
configure_sge(struct sge * sge,struct sge_params * p)761 static void configure_sge(struct sge *sge, struct sge_params *p)
762 {
763 	struct adapter *ap = sge->adapter;
764 
765 	writel(0, ap->regs + A_SG_CONTROL);
766 	setup_ring_params(ap, sge->cmdQ[0].dma_addr, sge->cmdQ[0].size,
767 			  A_SG_CMD0BASELWR, A_SG_CMD0BASEUPR, A_SG_CMD0SIZE);
768 	setup_ring_params(ap, sge->cmdQ[1].dma_addr, sge->cmdQ[1].size,
769 			  A_SG_CMD1BASELWR, A_SG_CMD1BASEUPR, A_SG_CMD1SIZE);
770 	setup_ring_params(ap, sge->freelQ[0].dma_addr,
771 			  sge->freelQ[0].size, A_SG_FL0BASELWR,
772 			  A_SG_FL0BASEUPR, A_SG_FL0SIZE);
773 	setup_ring_params(ap, sge->freelQ[1].dma_addr,
774 			  sge->freelQ[1].size, A_SG_FL1BASELWR,
775 			  A_SG_FL1BASEUPR, A_SG_FL1SIZE);
776 
777 	/* The threshold comparison uses <. */
778 	writel(SGE_RX_SM_BUF_SIZE + 1, ap->regs + A_SG_FLTHRESHOLD);
779 
780 	setup_ring_params(ap, sge->respQ.dma_addr, sge->respQ.size,
781 			  A_SG_RSPBASELWR, A_SG_RSPBASEUPR, A_SG_RSPSIZE);
782 	writel((u32)sge->respQ.size - 1, ap->regs + A_SG_RSPQUEUECREDIT);
783 
784 	sge->sge_control = F_CMDQ0_ENABLE | F_CMDQ1_ENABLE | F_FL0_ENABLE |
785 		F_FL1_ENABLE | F_CPL_ENABLE | F_RESPONSE_QUEUE_ENABLE |
786 		V_CMDQ_PRIORITY(2) | F_DISABLE_CMDQ1_GTS | F_ISCSI_COALESCE |
787 		V_RX_PKT_OFFSET(sge->rx_pkt_pad);
788 
789 #if defined(__BIG_ENDIAN_BITFIELD)
790 	sge->sge_control |= F_ENABLE_BIG_ENDIAN;
791 #endif
792 
793 	/* Initialize no-resource timer */
794 	sge->intrtimer_nres = SGE_INTRTIMER_NRES * core_ticks_per_usec(ap);
795 
796 	t1_sge_set_coalesce_params(sge, p);
797 }
798 
799 /*
800  * Return the payload capacity of the jumbo free-list buffers.
801  */
jumbo_payload_capacity(const struct sge * sge)802 static inline unsigned int jumbo_payload_capacity(const struct sge *sge)
803 {
804 	return sge->freelQ[sge->jumbo_fl].rx_buffer_size -
805 		sge->freelQ[sge->jumbo_fl].dma_offset -
806 		sizeof(struct cpl_rx_data);
807 }
808 
809 /*
810  * Frees all SGE related resources and the sge structure itself
811  */
t1_sge_destroy(struct sge * sge)812 void t1_sge_destroy(struct sge *sge)
813 {
814 	int i;
815 
816 	for_each_port(sge->adapter, i)
817 		free_percpu(sge->port_stats[i]);
818 
819 	kfree(sge->tx_sched);
820 	free_tx_resources(sge);
821 	free_rx_resources(sge);
822 	kfree(sge);
823 }
824 
825 /*
826  * Allocates new RX buffers on the freelist Q (and tracks them on the freelist
827  * context Q) until the Q is full or alloc_skb fails.
828  *
829  * It is possible that the generation bits already match, indicating that the
830  * buffer is already valid and nothing needs to be done. This happens when we
831  * copied a received buffer into a new sk_buff during the interrupt processing.
832  *
833  * If the SGE doesn't automatically align packets properly (!sge->rx_pkt_pad),
834  * we specify a RX_OFFSET in order to make sure that the IP header is 4B
835  * aligned.
836  */
refill_free_list(struct sge * sge,struct freelQ * q)837 static void refill_free_list(struct sge *sge, struct freelQ *q)
838 {
839 	struct pci_dev *pdev = sge->adapter->pdev;
840 	struct freelQ_ce *ce = &q->centries[q->pidx];
841 	struct freelQ_e *e = &q->entries[q->pidx];
842 	unsigned int dma_len = q->rx_buffer_size - q->dma_offset;
843 
844 	while (q->credits < q->size) {
845 		struct sk_buff *skb;
846 		dma_addr_t mapping;
847 
848 		skb = alloc_skb(q->rx_buffer_size, GFP_ATOMIC);
849 		if (!skb)
850 			break;
851 
852 		skb_reserve(skb, q->dma_offset);
853 		mapping = pci_map_single(pdev, skb->data, dma_len,
854 					 PCI_DMA_FROMDEVICE);
855 		skb_reserve(skb, sge->rx_pkt_pad);
856 
857 		ce->skb = skb;
858 		dma_unmap_addr_set(ce, dma_addr, mapping);
859 		dma_unmap_len_set(ce, dma_len, dma_len);
860 		e->addr_lo = (u32)mapping;
861 		e->addr_hi = (u64)mapping >> 32;
862 		e->len_gen = V_CMD_LEN(dma_len) | V_CMD_GEN1(q->genbit);
863 		wmb();
864 		e->gen2 = V_CMD_GEN2(q->genbit);
865 
866 		e++;
867 		ce++;
868 		if (++q->pidx == q->size) {
869 			q->pidx = 0;
870 			q->genbit ^= 1;
871 			ce = q->centries;
872 			e = q->entries;
873 		}
874 		q->credits++;
875 	}
876 }
877 
878 /*
879  * Calls refill_free_list for both free lists. If we cannot fill at least 1/4
880  * of both rings, we go into 'few interrupt mode' in order to give the system
881  * time to free up resources.
882  */
freelQs_empty(struct sge * sge)883 static void freelQs_empty(struct sge *sge)
884 {
885 	struct adapter *adapter = sge->adapter;
886 	u32 irq_reg = readl(adapter->regs + A_SG_INT_ENABLE);
887 	u32 irqholdoff_reg;
888 
889 	refill_free_list(sge, &sge->freelQ[0]);
890 	refill_free_list(sge, &sge->freelQ[1]);
891 
892 	if (sge->freelQ[0].credits > (sge->freelQ[0].size >> 2) &&
893 	    sge->freelQ[1].credits > (sge->freelQ[1].size >> 2)) {
894 		irq_reg |= F_FL_EXHAUSTED;
895 		irqholdoff_reg = sge->fixed_intrtimer;
896 	} else {
897 		/* Clear the F_FL_EXHAUSTED interrupts for now */
898 		irq_reg &= ~F_FL_EXHAUSTED;
899 		irqholdoff_reg = sge->intrtimer_nres;
900 	}
901 	writel(irqholdoff_reg, adapter->regs + A_SG_INTRTIMER);
902 	writel(irq_reg, adapter->regs + A_SG_INT_ENABLE);
903 
904 	/* We reenable the Qs to force a freelist GTS interrupt later */
905 	doorbell_pio(adapter, F_FL0_ENABLE | F_FL1_ENABLE);
906 }
907 
908 #define SGE_PL_INTR_MASK (F_PL_INTR_SGE_ERR | F_PL_INTR_SGE_DATA)
909 #define SGE_INT_FATAL (F_RESPQ_OVERFLOW | F_PACKET_TOO_BIG | F_PACKET_MISMATCH)
910 #define SGE_INT_ENABLE (F_RESPQ_EXHAUSTED | F_RESPQ_OVERFLOW | \
911 			F_FL_EXHAUSTED | F_PACKET_TOO_BIG | F_PACKET_MISMATCH)
912 
913 /*
914  * Disable SGE Interrupts
915  */
t1_sge_intr_disable(struct sge * sge)916 void t1_sge_intr_disable(struct sge *sge)
917 {
918 	u32 val = readl(sge->adapter->regs + A_PL_ENABLE);
919 
920 	writel(val & ~SGE_PL_INTR_MASK, sge->adapter->regs + A_PL_ENABLE);
921 	writel(0, sge->adapter->regs + A_SG_INT_ENABLE);
922 }
923 
924 /*
925  * Enable SGE interrupts.
926  */
t1_sge_intr_enable(struct sge * sge)927 void t1_sge_intr_enable(struct sge *sge)
928 {
929 	u32 en = SGE_INT_ENABLE;
930 	u32 val = readl(sge->adapter->regs + A_PL_ENABLE);
931 
932 	if (sge->adapter->flags & TSO_CAPABLE)
933 		en &= ~F_PACKET_TOO_BIG;
934 	writel(en, sge->adapter->regs + A_SG_INT_ENABLE);
935 	writel(val | SGE_PL_INTR_MASK, sge->adapter->regs + A_PL_ENABLE);
936 }
937 
938 /*
939  * Clear SGE interrupts.
940  */
t1_sge_intr_clear(struct sge * sge)941 void t1_sge_intr_clear(struct sge *sge)
942 {
943 	writel(SGE_PL_INTR_MASK, sge->adapter->regs + A_PL_CAUSE);
944 	writel(0xffffffff, sge->adapter->regs + A_SG_INT_CAUSE);
945 }
946 
947 /*
948  * SGE 'Error' interrupt handler
949  */
t1_sge_intr_error_handler(struct sge * sge)950 int t1_sge_intr_error_handler(struct sge *sge)
951 {
952 	struct adapter *adapter = sge->adapter;
953 	u32 cause = readl(adapter->regs + A_SG_INT_CAUSE);
954 
955 	if (adapter->flags & TSO_CAPABLE)
956 		cause &= ~F_PACKET_TOO_BIG;
957 	if (cause & F_RESPQ_EXHAUSTED)
958 		sge->stats.respQ_empty++;
959 	if (cause & F_RESPQ_OVERFLOW) {
960 		sge->stats.respQ_overflow++;
961 		pr_alert("%s: SGE response queue overflow\n",
962 			 adapter->name);
963 	}
964 	if (cause & F_FL_EXHAUSTED) {
965 		sge->stats.freelistQ_empty++;
966 		freelQs_empty(sge);
967 	}
968 	if (cause & F_PACKET_TOO_BIG) {
969 		sge->stats.pkt_too_big++;
970 		pr_alert("%s: SGE max packet size exceeded\n",
971 			 adapter->name);
972 	}
973 	if (cause & F_PACKET_MISMATCH) {
974 		sge->stats.pkt_mismatch++;
975 		pr_alert("%s: SGE packet mismatch\n", adapter->name);
976 	}
977 	if (cause & SGE_INT_FATAL)
978 		t1_fatal_err(adapter);
979 
980 	writel(cause, adapter->regs + A_SG_INT_CAUSE);
981 	return 0;
982 }
983 
t1_sge_get_intr_counts(const struct sge * sge)984 const struct sge_intr_counts *t1_sge_get_intr_counts(const struct sge *sge)
985 {
986 	return &sge->stats;
987 }
988 
t1_sge_get_port_stats(const struct sge * sge,int port,struct sge_port_stats * ss)989 void t1_sge_get_port_stats(const struct sge *sge, int port,
990 			   struct sge_port_stats *ss)
991 {
992 	int cpu;
993 
994 	memset(ss, 0, sizeof(*ss));
995 	for_each_possible_cpu(cpu) {
996 		struct sge_port_stats *st = per_cpu_ptr(sge->port_stats[port], cpu);
997 
998 		ss->rx_cso_good += st->rx_cso_good;
999 		ss->tx_cso += st->tx_cso;
1000 		ss->tx_tso += st->tx_tso;
1001 		ss->tx_need_hdrroom += st->tx_need_hdrroom;
1002 		ss->vlan_xtract += st->vlan_xtract;
1003 		ss->vlan_insert += st->vlan_insert;
1004 	}
1005 }
1006 
1007 /**
1008  *	recycle_fl_buf - recycle a free list buffer
1009  *	@fl: the free list
1010  *	@idx: index of buffer to recycle
1011  *
1012  *	Recycles the specified buffer on the given free list by adding it at
1013  *	the next available slot on the list.
1014  */
recycle_fl_buf(struct freelQ * fl,int idx)1015 static void recycle_fl_buf(struct freelQ *fl, int idx)
1016 {
1017 	struct freelQ_e *from = &fl->entries[idx];
1018 	struct freelQ_e *to = &fl->entries[fl->pidx];
1019 
1020 	fl->centries[fl->pidx] = fl->centries[idx];
1021 	to->addr_lo = from->addr_lo;
1022 	to->addr_hi = from->addr_hi;
1023 	to->len_gen = G_CMD_LEN(from->len_gen) | V_CMD_GEN1(fl->genbit);
1024 	wmb();
1025 	to->gen2 = V_CMD_GEN2(fl->genbit);
1026 	fl->credits++;
1027 
1028 	if (++fl->pidx == fl->size) {
1029 		fl->pidx = 0;
1030 		fl->genbit ^= 1;
1031 	}
1032 }
1033 
1034 static int copybreak __read_mostly = 256;
1035 module_param(copybreak, int, 0);
1036 MODULE_PARM_DESC(copybreak, "Receive copy threshold");
1037 
1038 /**
1039  *	get_packet - return the next ingress packet buffer
1040  *	@pdev: the PCI device that received the packet
1041  *	@fl: the SGE free list holding the packet
1042  *	@len: the actual packet length, excluding any SGE padding
1043  *
1044  *	Get the next packet from a free list and complete setup of the
1045  *	sk_buff.  If the packet is small we make a copy and recycle the
1046  *	original buffer, otherwise we use the original buffer itself.  If a
1047  *	positive drop threshold is supplied packets are dropped and their
1048  *	buffers recycled if (a) the number of remaining buffers is under the
1049  *	threshold and the packet is too big to copy, or (b) the packet should
1050  *	be copied but there is no memory for the copy.
1051  */
get_packet(struct pci_dev * pdev,struct freelQ * fl,unsigned int len)1052 static inline struct sk_buff *get_packet(struct pci_dev *pdev,
1053 					 struct freelQ *fl, unsigned int len)
1054 {
1055 	struct sk_buff *skb;
1056 	const struct freelQ_ce *ce = &fl->centries[fl->cidx];
1057 
1058 	if (len < copybreak) {
1059 		skb = alloc_skb(len + 2, GFP_ATOMIC);
1060 		if (!skb)
1061 			goto use_orig_buf;
1062 
1063 		skb_reserve(skb, 2);	/* align IP header */
1064 		skb_put(skb, len);
1065 		pci_dma_sync_single_for_cpu(pdev,
1066 					    dma_unmap_addr(ce, dma_addr),
1067 					    dma_unmap_len(ce, dma_len),
1068 					    PCI_DMA_FROMDEVICE);
1069 		skb_copy_from_linear_data(ce->skb, skb->data, len);
1070 		pci_dma_sync_single_for_device(pdev,
1071 					       dma_unmap_addr(ce, dma_addr),
1072 					       dma_unmap_len(ce, dma_len),
1073 					       PCI_DMA_FROMDEVICE);
1074 		recycle_fl_buf(fl, fl->cidx);
1075 		return skb;
1076 	}
1077 
1078 use_orig_buf:
1079 	if (fl->credits < 2) {
1080 		recycle_fl_buf(fl, fl->cidx);
1081 		return NULL;
1082 	}
1083 
1084 	pci_unmap_single(pdev, dma_unmap_addr(ce, dma_addr),
1085 			 dma_unmap_len(ce, dma_len), PCI_DMA_FROMDEVICE);
1086 	skb = ce->skb;
1087 	prefetch(skb->data);
1088 
1089 	skb_put(skb, len);
1090 	return skb;
1091 }
1092 
1093 /**
1094  *	unexpected_offload - handle an unexpected offload packet
1095  *	@adapter: the adapter
1096  *	@fl: the free list that received the packet
1097  *
1098  *	Called when we receive an unexpected offload packet (e.g., the TOE
1099  *	function is disabled or the card is a NIC).  Prints a message and
1100  *	recycles the buffer.
1101  */
unexpected_offload(struct adapter * adapter,struct freelQ * fl)1102 static void unexpected_offload(struct adapter *adapter, struct freelQ *fl)
1103 {
1104 	struct freelQ_ce *ce = &fl->centries[fl->cidx];
1105 	struct sk_buff *skb = ce->skb;
1106 
1107 	pci_dma_sync_single_for_cpu(adapter->pdev, dma_unmap_addr(ce, dma_addr),
1108 			    dma_unmap_len(ce, dma_len), PCI_DMA_FROMDEVICE);
1109 	pr_err("%s: unexpected offload packet, cmd %u\n",
1110 	       adapter->name, *skb->data);
1111 	recycle_fl_buf(fl, fl->cidx);
1112 }
1113 
1114 /*
1115  * T1/T2 SGE limits the maximum DMA size per TX descriptor to
1116  * SGE_TX_DESC_MAX_PLEN (16KB). If the PAGE_SIZE is larger than 16KB, the
1117  * stack might send more than SGE_TX_DESC_MAX_PLEN in a contiguous manner.
1118  * Note that the *_large_page_tx_descs stuff will be optimized out when
1119  * PAGE_SIZE <= SGE_TX_DESC_MAX_PLEN.
1120  *
1121  * compute_large_page_descs() computes how many additional descriptors are
1122  * required to break down the stack's request.
1123  */
compute_large_page_tx_descs(struct sk_buff * skb)1124 static inline unsigned int compute_large_page_tx_descs(struct sk_buff *skb)
1125 {
1126 	unsigned int count = 0;
1127 
1128 	if (PAGE_SIZE > SGE_TX_DESC_MAX_PLEN) {
1129 		unsigned int nfrags = skb_shinfo(skb)->nr_frags;
1130 		unsigned int i, len = skb_headlen(skb);
1131 		while (len > SGE_TX_DESC_MAX_PLEN) {
1132 			count++;
1133 			len -= SGE_TX_DESC_MAX_PLEN;
1134 		}
1135 		for (i = 0; nfrags--; i++) {
1136 			skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1137 			len = frag->size;
1138 			while (len > SGE_TX_DESC_MAX_PLEN) {
1139 				count++;
1140 				len -= SGE_TX_DESC_MAX_PLEN;
1141 			}
1142 		}
1143 	}
1144 	return count;
1145 }
1146 
1147 /*
1148  * Write a cmdQ entry.
1149  *
1150  * Since this function writes the 'flags' field, it must not be used to
1151  * write the first cmdQ entry.
1152  */
write_tx_desc(struct cmdQ_e * e,dma_addr_t mapping,unsigned int len,unsigned int gen,unsigned int eop)1153 static inline void write_tx_desc(struct cmdQ_e *e, dma_addr_t mapping,
1154 				 unsigned int len, unsigned int gen,
1155 				 unsigned int eop)
1156 {
1157 	BUG_ON(len > SGE_TX_DESC_MAX_PLEN);
1158 
1159 	e->addr_lo = (u32)mapping;
1160 	e->addr_hi = (u64)mapping >> 32;
1161 	e->len_gen = V_CMD_LEN(len) | V_CMD_GEN1(gen);
1162 	e->flags = F_CMD_DATAVALID | V_CMD_EOP(eop) | V_CMD_GEN2(gen);
1163 }
1164 
1165 /*
1166  * See comment for previous function.
1167  *
1168  * write_tx_descs_large_page() writes additional SGE tx descriptors if
1169  * *desc_len exceeds HW's capability.
1170  */
write_large_page_tx_descs(unsigned int pidx,struct cmdQ_e ** e,struct cmdQ_ce ** ce,unsigned int * gen,dma_addr_t * desc_mapping,unsigned int * desc_len,unsigned int nfrags,struct cmdQ * q)1171 static inline unsigned int write_large_page_tx_descs(unsigned int pidx,
1172 						     struct cmdQ_e **e,
1173 						     struct cmdQ_ce **ce,
1174 						     unsigned int *gen,
1175 						     dma_addr_t *desc_mapping,
1176 						     unsigned int *desc_len,
1177 						     unsigned int nfrags,
1178 						     struct cmdQ *q)
1179 {
1180 	if (PAGE_SIZE > SGE_TX_DESC_MAX_PLEN) {
1181 		struct cmdQ_e *e1 = *e;
1182 		struct cmdQ_ce *ce1 = *ce;
1183 
1184 		while (*desc_len > SGE_TX_DESC_MAX_PLEN) {
1185 			*desc_len -= SGE_TX_DESC_MAX_PLEN;
1186 			write_tx_desc(e1, *desc_mapping, SGE_TX_DESC_MAX_PLEN,
1187 				      *gen, nfrags == 0 && *desc_len == 0);
1188 			ce1->skb = NULL;
1189 			dma_unmap_len_set(ce1, dma_len, 0);
1190 			*desc_mapping += SGE_TX_DESC_MAX_PLEN;
1191 			if (*desc_len) {
1192 				ce1++;
1193 				e1++;
1194 				if (++pidx == q->size) {
1195 					pidx = 0;
1196 					*gen ^= 1;
1197 					ce1 = q->centries;
1198 					e1 = q->entries;
1199 				}
1200 			}
1201 		}
1202 		*e = e1;
1203 		*ce = ce1;
1204 	}
1205 	return pidx;
1206 }
1207 
1208 /*
1209  * Write the command descriptors to transmit the given skb starting at
1210  * descriptor pidx with the given generation.
1211  */
write_tx_descs(struct adapter * adapter,struct sk_buff * skb,unsigned int pidx,unsigned int gen,struct cmdQ * q)1212 static inline void write_tx_descs(struct adapter *adapter, struct sk_buff *skb,
1213 				  unsigned int pidx, unsigned int gen,
1214 				  struct cmdQ *q)
1215 {
1216 	dma_addr_t mapping, desc_mapping;
1217 	struct cmdQ_e *e, *e1;
1218 	struct cmdQ_ce *ce;
1219 	unsigned int i, flags, first_desc_len, desc_len,
1220 	    nfrags = skb_shinfo(skb)->nr_frags;
1221 
1222 	e = e1 = &q->entries[pidx];
1223 	ce = &q->centries[pidx];
1224 
1225 	mapping = pci_map_single(adapter->pdev, skb->data,
1226 				 skb_headlen(skb), PCI_DMA_TODEVICE);
1227 
1228 	desc_mapping = mapping;
1229 	desc_len = skb_headlen(skb);
1230 
1231 	flags = F_CMD_DATAVALID | F_CMD_SOP |
1232 	    V_CMD_EOP(nfrags == 0 && desc_len <= SGE_TX_DESC_MAX_PLEN) |
1233 	    V_CMD_GEN2(gen);
1234 	first_desc_len = (desc_len <= SGE_TX_DESC_MAX_PLEN) ?
1235 	    desc_len : SGE_TX_DESC_MAX_PLEN;
1236 	e->addr_lo = (u32)desc_mapping;
1237 	e->addr_hi = (u64)desc_mapping >> 32;
1238 	e->len_gen = V_CMD_LEN(first_desc_len) | V_CMD_GEN1(gen);
1239 	ce->skb = NULL;
1240 	dma_unmap_len_set(ce, dma_len, 0);
1241 
1242 	if (PAGE_SIZE > SGE_TX_DESC_MAX_PLEN &&
1243 	    desc_len > SGE_TX_DESC_MAX_PLEN) {
1244 		desc_mapping += first_desc_len;
1245 		desc_len -= first_desc_len;
1246 		e1++;
1247 		ce++;
1248 		if (++pidx == q->size) {
1249 			pidx = 0;
1250 			gen ^= 1;
1251 			e1 = q->entries;
1252 			ce = q->centries;
1253 		}
1254 		pidx = write_large_page_tx_descs(pidx, &e1, &ce, &gen,
1255 						 &desc_mapping, &desc_len,
1256 						 nfrags, q);
1257 
1258 		if (likely(desc_len))
1259 			write_tx_desc(e1, desc_mapping, desc_len, gen,
1260 				      nfrags == 0);
1261 	}
1262 
1263 	ce->skb = NULL;
1264 	dma_unmap_addr_set(ce, dma_addr, mapping);
1265 	dma_unmap_len_set(ce, dma_len, skb_headlen(skb));
1266 
1267 	for (i = 0; nfrags--; i++) {
1268 		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1269 		e1++;
1270 		ce++;
1271 		if (++pidx == q->size) {
1272 			pidx = 0;
1273 			gen ^= 1;
1274 			e1 = q->entries;
1275 			ce = q->centries;
1276 		}
1277 
1278 		mapping = pci_map_page(adapter->pdev, frag->page,
1279 				       frag->page_offset, frag->size,
1280 				       PCI_DMA_TODEVICE);
1281 		desc_mapping = mapping;
1282 		desc_len = frag->size;
1283 
1284 		pidx = write_large_page_tx_descs(pidx, &e1, &ce, &gen,
1285 						 &desc_mapping, &desc_len,
1286 						 nfrags, q);
1287 		if (likely(desc_len))
1288 			write_tx_desc(e1, desc_mapping, desc_len, gen,
1289 				      nfrags == 0);
1290 		ce->skb = NULL;
1291 		dma_unmap_addr_set(ce, dma_addr, mapping);
1292 		dma_unmap_len_set(ce, dma_len, frag->size);
1293 	}
1294 	ce->skb = skb;
1295 	wmb();
1296 	e->flags = flags;
1297 }
1298 
1299 /*
1300  * Clean up completed Tx buffers.
1301  */
reclaim_completed_tx(struct sge * sge,struct cmdQ * q)1302 static inline void reclaim_completed_tx(struct sge *sge, struct cmdQ *q)
1303 {
1304 	unsigned int reclaim = q->processed - q->cleaned;
1305 
1306 	if (reclaim) {
1307 		pr_debug("reclaim_completed_tx processed:%d cleaned:%d\n",
1308 			 q->processed, q->cleaned);
1309 		free_cmdQ_buffers(sge, q, reclaim);
1310 		q->cleaned += reclaim;
1311 	}
1312 }
1313 
1314 /*
1315  * Called from tasklet. Checks the scheduler for any
1316  * pending skbs that can be sent.
1317  */
restart_sched(unsigned long arg)1318 static void restart_sched(unsigned long arg)
1319 {
1320 	struct sge *sge = (struct sge *) arg;
1321 	struct adapter *adapter = sge->adapter;
1322 	struct cmdQ *q = &sge->cmdQ[0];
1323 	struct sk_buff *skb;
1324 	unsigned int credits, queued_skb = 0;
1325 
1326 	spin_lock(&q->lock);
1327 	reclaim_completed_tx(sge, q);
1328 
1329 	credits = q->size - q->in_use;
1330 	pr_debug("restart_sched credits=%d\n", credits);
1331 	while ((skb = sched_skb(sge, NULL, credits)) != NULL) {
1332 		unsigned int genbit, pidx, count;
1333 	        count = 1 + skb_shinfo(skb)->nr_frags;
1334 		count += compute_large_page_tx_descs(skb);
1335 		q->in_use += count;
1336 		genbit = q->genbit;
1337 		pidx = q->pidx;
1338 		q->pidx += count;
1339 		if (q->pidx >= q->size) {
1340 			q->pidx -= q->size;
1341 			q->genbit ^= 1;
1342 		}
1343 		write_tx_descs(adapter, skb, pidx, genbit, q);
1344 	        credits = q->size - q->in_use;
1345 		queued_skb = 1;
1346 	}
1347 
1348 	if (queued_skb) {
1349 		clear_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
1350 		if (test_and_set_bit(CMDQ_STAT_RUNNING, &q->status) == 0) {
1351 			set_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
1352 			writel(F_CMDQ0_ENABLE, adapter->regs + A_SG_DOORBELL);
1353 		}
1354 	}
1355 	spin_unlock(&q->lock);
1356 }
1357 
1358 /**
1359  *	sge_rx - process an ingress ethernet packet
1360  *	@sge: the sge structure
1361  *	@fl: the free list that contains the packet buffer
1362  *	@len: the packet length
1363  *
1364  *	Process an ingress ethernet pakcet and deliver it to the stack.
1365  */
sge_rx(struct sge * sge,struct freelQ * fl,unsigned int len)1366 static void sge_rx(struct sge *sge, struct freelQ *fl, unsigned int len)
1367 {
1368 	struct sk_buff *skb;
1369 	const struct cpl_rx_pkt *p;
1370 	struct adapter *adapter = sge->adapter;
1371 	struct sge_port_stats *st;
1372 
1373 	skb = get_packet(adapter->pdev, fl, len - sge->rx_pkt_pad);
1374 	if (unlikely(!skb)) {
1375 		sge->stats.rx_drops++;
1376 		return;
1377 	}
1378 
1379 	p = (const struct cpl_rx_pkt *) skb->data;
1380 	if (p->iff >= adapter->params.nports) {
1381 		kfree_skb(skb);
1382 		return;
1383 	}
1384 	__skb_pull(skb, sizeof(*p));
1385 
1386 	st = this_cpu_ptr(sge->port_stats[p->iff]);
1387 
1388 	skb->protocol = eth_type_trans(skb, adapter->port[p->iff].dev);
1389 	if ((adapter->flags & RX_CSUM_ENABLED) && p->csum == 0xffff &&
1390 	    skb->protocol == htons(ETH_P_IP) &&
1391 	    (skb->data[9] == IPPROTO_TCP || skb->data[9] == IPPROTO_UDP)) {
1392 		++st->rx_cso_good;
1393 		skb->ip_summed = CHECKSUM_UNNECESSARY;
1394 	} else
1395 		skb_checksum_none_assert(skb);
1396 
1397 	if (unlikely(adapter->vlan_grp && p->vlan_valid)) {
1398 		st->vlan_xtract++;
1399 		vlan_hwaccel_receive_skb(skb, adapter->vlan_grp,
1400 					 ntohs(p->vlan));
1401 	} else
1402 		netif_receive_skb(skb);
1403 }
1404 
1405 /*
1406  * Returns true if a command queue has enough available descriptors that
1407  * we can resume Tx operation after temporarily disabling its packet queue.
1408  */
enough_free_Tx_descs(const struct cmdQ * q)1409 static inline int enough_free_Tx_descs(const struct cmdQ *q)
1410 {
1411 	unsigned int r = q->processed - q->cleaned;
1412 
1413 	return q->in_use - r < (q->size >> 1);
1414 }
1415 
1416 /*
1417  * Called when sufficient space has become available in the SGE command queues
1418  * after the Tx packet schedulers have been suspended to restart the Tx path.
1419  */
restart_tx_queues(struct sge * sge)1420 static void restart_tx_queues(struct sge *sge)
1421 {
1422 	struct adapter *adap = sge->adapter;
1423 	int i;
1424 
1425 	if (!enough_free_Tx_descs(&sge->cmdQ[0]))
1426 		return;
1427 
1428 	for_each_port(adap, i) {
1429 		struct net_device *nd = adap->port[i].dev;
1430 
1431 		if (test_and_clear_bit(nd->if_port, &sge->stopped_tx_queues) &&
1432 		    netif_running(nd)) {
1433 			sge->stats.cmdQ_restarted[2]++;
1434 			netif_wake_queue(nd);
1435 		}
1436 	}
1437 }
1438 
1439 /*
1440  * update_tx_info is called from the interrupt handler/NAPI to return cmdQ0
1441  * information.
1442  */
update_tx_info(struct adapter * adapter,unsigned int flags,unsigned int pr0)1443 static unsigned int update_tx_info(struct adapter *adapter,
1444 					  unsigned int flags,
1445 					  unsigned int pr0)
1446 {
1447 	struct sge *sge = adapter->sge;
1448 	struct cmdQ *cmdq = &sge->cmdQ[0];
1449 
1450 	cmdq->processed += pr0;
1451 	if (flags & (F_FL0_ENABLE | F_FL1_ENABLE)) {
1452 		freelQs_empty(sge);
1453 		flags &= ~(F_FL0_ENABLE | F_FL1_ENABLE);
1454 	}
1455 	if (flags & F_CMDQ0_ENABLE) {
1456 		clear_bit(CMDQ_STAT_RUNNING, &cmdq->status);
1457 
1458 		if (cmdq->cleaned + cmdq->in_use != cmdq->processed &&
1459 		    !test_and_set_bit(CMDQ_STAT_LAST_PKT_DB, &cmdq->status)) {
1460 			set_bit(CMDQ_STAT_RUNNING, &cmdq->status);
1461 			writel(F_CMDQ0_ENABLE, adapter->regs + A_SG_DOORBELL);
1462 		}
1463 		if (sge->tx_sched)
1464 			tasklet_hi_schedule(&sge->tx_sched->sched_tsk);
1465 
1466 		flags &= ~F_CMDQ0_ENABLE;
1467 	}
1468 
1469 	if (unlikely(sge->stopped_tx_queues != 0))
1470 		restart_tx_queues(sge);
1471 
1472 	return flags;
1473 }
1474 
1475 /*
1476  * Process SGE responses, up to the supplied budget.  Returns the number of
1477  * responses processed.  A negative budget is effectively unlimited.
1478  */
process_responses(struct adapter * adapter,int budget)1479 static int process_responses(struct adapter *adapter, int budget)
1480 {
1481 	struct sge *sge = adapter->sge;
1482 	struct respQ *q = &sge->respQ;
1483 	struct respQ_e *e = &q->entries[q->cidx];
1484 	int done = 0;
1485 	unsigned int flags = 0;
1486 	unsigned int cmdq_processed[SGE_CMDQ_N] = {0, 0};
1487 
1488 	while (done < budget && e->GenerationBit == q->genbit) {
1489 		flags |= e->Qsleeping;
1490 
1491 		cmdq_processed[0] += e->Cmdq0CreditReturn;
1492 		cmdq_processed[1] += e->Cmdq1CreditReturn;
1493 
1494 		/* We batch updates to the TX side to avoid cacheline
1495 		 * ping-pong of TX state information on MP where the sender
1496 		 * might run on a different CPU than this function...
1497 		 */
1498 		if (unlikely((flags & F_CMDQ0_ENABLE) || cmdq_processed[0] > 64)) {
1499 			flags = update_tx_info(adapter, flags, cmdq_processed[0]);
1500 			cmdq_processed[0] = 0;
1501 		}
1502 
1503 		if (unlikely(cmdq_processed[1] > 16)) {
1504 			sge->cmdQ[1].processed += cmdq_processed[1];
1505 			cmdq_processed[1] = 0;
1506 		}
1507 
1508 		if (likely(e->DataValid)) {
1509 			struct freelQ *fl = &sge->freelQ[e->FreelistQid];
1510 
1511 			BUG_ON(!e->Sop || !e->Eop);
1512 			if (unlikely(e->Offload))
1513 				unexpected_offload(adapter, fl);
1514 			else
1515 				sge_rx(sge, fl, e->BufferLength);
1516 
1517 			++done;
1518 
1519 			/*
1520 			 * Note: this depends on each packet consuming a
1521 			 * single free-list buffer; cf. the BUG above.
1522 			 */
1523 			if (++fl->cidx == fl->size)
1524 				fl->cidx = 0;
1525 			prefetch(fl->centries[fl->cidx].skb);
1526 
1527 			if (unlikely(--fl->credits <
1528 				     fl->size - SGE_FREEL_REFILL_THRESH))
1529 				refill_free_list(sge, fl);
1530 		} else
1531 			sge->stats.pure_rsps++;
1532 
1533 		e++;
1534 		if (unlikely(++q->cidx == q->size)) {
1535 			q->cidx = 0;
1536 			q->genbit ^= 1;
1537 			e = q->entries;
1538 		}
1539 		prefetch(e);
1540 
1541 		if (++q->credits > SGE_RESPQ_REPLENISH_THRES) {
1542 			writel(q->credits, adapter->regs + A_SG_RSPQUEUECREDIT);
1543 			q->credits = 0;
1544 		}
1545 	}
1546 
1547 	flags = update_tx_info(adapter, flags, cmdq_processed[0]);
1548 	sge->cmdQ[1].processed += cmdq_processed[1];
1549 
1550 	return done;
1551 }
1552 
responses_pending(const struct adapter * adapter)1553 static inline int responses_pending(const struct adapter *adapter)
1554 {
1555 	const struct respQ *Q = &adapter->sge->respQ;
1556 	const struct respQ_e *e = &Q->entries[Q->cidx];
1557 
1558 	return e->GenerationBit == Q->genbit;
1559 }
1560 
1561 /*
1562  * A simpler version of process_responses() that handles only pure (i.e.,
1563  * non data-carrying) responses.  Such respones are too light-weight to justify
1564  * calling a softirq when using NAPI, so we handle them specially in hard
1565  * interrupt context.  The function is called with a pointer to a response,
1566  * which the caller must ensure is a valid pure response.  Returns 1 if it
1567  * encounters a valid data-carrying response, 0 otherwise.
1568  */
process_pure_responses(struct adapter * adapter)1569 static int process_pure_responses(struct adapter *adapter)
1570 {
1571 	struct sge *sge = adapter->sge;
1572 	struct respQ *q = &sge->respQ;
1573 	struct respQ_e *e = &q->entries[q->cidx];
1574 	const struct freelQ *fl = &sge->freelQ[e->FreelistQid];
1575 	unsigned int flags = 0;
1576 	unsigned int cmdq_processed[SGE_CMDQ_N] = {0, 0};
1577 
1578 	prefetch(fl->centries[fl->cidx].skb);
1579 	if (e->DataValid)
1580 		return 1;
1581 
1582 	do {
1583 		flags |= e->Qsleeping;
1584 
1585 		cmdq_processed[0] += e->Cmdq0CreditReturn;
1586 		cmdq_processed[1] += e->Cmdq1CreditReturn;
1587 
1588 		e++;
1589 		if (unlikely(++q->cidx == q->size)) {
1590 			q->cidx = 0;
1591 			q->genbit ^= 1;
1592 			e = q->entries;
1593 		}
1594 		prefetch(e);
1595 
1596 		if (++q->credits > SGE_RESPQ_REPLENISH_THRES) {
1597 			writel(q->credits, adapter->regs + A_SG_RSPQUEUECREDIT);
1598 			q->credits = 0;
1599 		}
1600 		sge->stats.pure_rsps++;
1601 	} while (e->GenerationBit == q->genbit && !e->DataValid);
1602 
1603 	flags = update_tx_info(adapter, flags, cmdq_processed[0]);
1604 	sge->cmdQ[1].processed += cmdq_processed[1];
1605 
1606 	return e->GenerationBit == q->genbit;
1607 }
1608 
1609 /*
1610  * Handler for new data events when using NAPI.  This does not need any locking
1611  * or protection from interrupts as data interrupts are off at this point and
1612  * other adapter interrupts do not interfere.
1613  */
t1_poll(struct napi_struct * napi,int budget)1614 int t1_poll(struct napi_struct *napi, int budget)
1615 {
1616 	struct adapter *adapter = container_of(napi, struct adapter, napi);
1617 	int work_done = process_responses(adapter, budget);
1618 
1619 	if (likely(work_done < budget)) {
1620 		napi_complete(napi);
1621 		writel(adapter->sge->respQ.cidx,
1622 		       adapter->regs + A_SG_SLEEPING);
1623 	}
1624 	return work_done;
1625 }
1626 
t1_interrupt(int irq,void * data)1627 irqreturn_t t1_interrupt(int irq, void *data)
1628 {
1629 	struct adapter *adapter = data;
1630 	struct sge *sge = adapter->sge;
1631 	int handled;
1632 
1633 	if (likely(responses_pending(adapter))) {
1634 		writel(F_PL_INTR_SGE_DATA, adapter->regs + A_PL_CAUSE);
1635 
1636 		if (napi_schedule_prep(&adapter->napi)) {
1637 			if (process_pure_responses(adapter))
1638 				__napi_schedule(&adapter->napi);
1639 			else {
1640 				/* no data, no NAPI needed */
1641 				writel(sge->respQ.cidx, adapter->regs + A_SG_SLEEPING);
1642 				/* undo schedule_prep */
1643 				napi_enable(&adapter->napi);
1644 			}
1645 		}
1646 		return IRQ_HANDLED;
1647 	}
1648 
1649 	spin_lock(&adapter->async_lock);
1650 	handled = t1_slow_intr_handler(adapter);
1651 	spin_unlock(&adapter->async_lock);
1652 
1653 	if (!handled)
1654 		sge->stats.unhandled_irqs++;
1655 
1656 	return IRQ_RETVAL(handled != 0);
1657 }
1658 
1659 /*
1660  * Enqueues the sk_buff onto the cmdQ[qid] and has hardware fetch it.
1661  *
1662  * The code figures out how many entries the sk_buff will require in the
1663  * cmdQ and updates the cmdQ data structure with the state once the enqueue
1664  * has complete. Then, it doesn't access the global structure anymore, but
1665  * uses the corresponding fields on the stack. In conjunction with a spinlock
1666  * around that code, we can make the function reentrant without holding the
1667  * lock when we actually enqueue (which might be expensive, especially on
1668  * architectures with IO MMUs).
1669  *
1670  * This runs with softirqs disabled.
1671  */
t1_sge_tx(struct sk_buff * skb,struct adapter * adapter,unsigned int qid,struct net_device * dev)1672 static int t1_sge_tx(struct sk_buff *skb, struct adapter *adapter,
1673 		     unsigned int qid, struct net_device *dev)
1674 {
1675 	struct sge *sge = adapter->sge;
1676 	struct cmdQ *q = &sge->cmdQ[qid];
1677 	unsigned int credits, pidx, genbit, count, use_sched_skb = 0;
1678 
1679 	if (!spin_trylock(&q->lock))
1680 		return NETDEV_TX_LOCKED;
1681 
1682 	reclaim_completed_tx(sge, q);
1683 
1684 	pidx = q->pidx;
1685 	credits = q->size - q->in_use;
1686 	count = 1 + skb_shinfo(skb)->nr_frags;
1687 	count += compute_large_page_tx_descs(skb);
1688 
1689 	/* Ethernet packet */
1690 	if (unlikely(credits < count)) {
1691 		if (!netif_queue_stopped(dev)) {
1692 			netif_stop_queue(dev);
1693 			set_bit(dev->if_port, &sge->stopped_tx_queues);
1694 			sge->stats.cmdQ_full[2]++;
1695 			pr_err("%s: Tx ring full while queue awake!\n",
1696 			       adapter->name);
1697 		}
1698 		spin_unlock(&q->lock);
1699 		return NETDEV_TX_BUSY;
1700 	}
1701 
1702 	if (unlikely(credits - count < q->stop_thres)) {
1703 		netif_stop_queue(dev);
1704 		set_bit(dev->if_port, &sge->stopped_tx_queues);
1705 		sge->stats.cmdQ_full[2]++;
1706 	}
1707 
1708 	/* T204 cmdQ0 skbs that are destined for a certain port have to go
1709 	 * through the scheduler.
1710 	 */
1711 	if (sge->tx_sched && !qid && skb->dev) {
1712 use_sched:
1713 		use_sched_skb = 1;
1714 		/* Note that the scheduler might return a different skb than
1715 		 * the one passed in.
1716 		 */
1717 		skb = sched_skb(sge, skb, credits);
1718 		if (!skb) {
1719 			spin_unlock(&q->lock);
1720 			return NETDEV_TX_OK;
1721 		}
1722 		pidx = q->pidx;
1723 		count = 1 + skb_shinfo(skb)->nr_frags;
1724 		count += compute_large_page_tx_descs(skb);
1725 	}
1726 
1727 	q->in_use += count;
1728 	genbit = q->genbit;
1729 	pidx = q->pidx;
1730 	q->pidx += count;
1731 	if (q->pidx >= q->size) {
1732 		q->pidx -= q->size;
1733 		q->genbit ^= 1;
1734 	}
1735 	spin_unlock(&q->lock);
1736 
1737 	write_tx_descs(adapter, skb, pidx, genbit, q);
1738 
1739 	/*
1740 	 * We always ring the doorbell for cmdQ1.  For cmdQ0, we only ring
1741 	 * the doorbell if the Q is asleep. There is a natural race, where
1742 	 * the hardware is going to sleep just after we checked, however,
1743 	 * then the interrupt handler will detect the outstanding TX packet
1744 	 * and ring the doorbell for us.
1745 	 */
1746 	if (qid)
1747 		doorbell_pio(adapter, F_CMDQ1_ENABLE);
1748 	else {
1749 		clear_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
1750 		if (test_and_set_bit(CMDQ_STAT_RUNNING, &q->status) == 0) {
1751 			set_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
1752 			writel(F_CMDQ0_ENABLE, adapter->regs + A_SG_DOORBELL);
1753 		}
1754 	}
1755 
1756 	if (use_sched_skb) {
1757 		if (spin_trylock(&q->lock)) {
1758 			credits = q->size - q->in_use;
1759 			skb = NULL;
1760 			goto use_sched;
1761 		}
1762 	}
1763 	return NETDEV_TX_OK;
1764 }
1765 
1766 #define MK_ETH_TYPE_MSS(type, mss) (((mss) & 0x3FFF) | ((type) << 14))
1767 
1768 /*
1769  *	eth_hdr_len - return the length of an Ethernet header
1770  *	@data: pointer to the start of the Ethernet header
1771  *
1772  *	Returns the length of an Ethernet header, including optional VLAN tag.
1773  */
eth_hdr_len(const void * data)1774 static inline int eth_hdr_len(const void *data)
1775 {
1776 	const struct ethhdr *e = data;
1777 
1778 	return e->h_proto == htons(ETH_P_8021Q) ? VLAN_ETH_HLEN : ETH_HLEN;
1779 }
1780 
1781 /*
1782  * Adds the CPL header to the sk_buff and passes it to t1_sge_tx.
1783  */
t1_start_xmit(struct sk_buff * skb,struct net_device * dev)1784 netdev_tx_t t1_start_xmit(struct sk_buff *skb, struct net_device *dev)
1785 {
1786 	struct adapter *adapter = dev->ml_priv;
1787 	struct sge *sge = adapter->sge;
1788 	struct sge_port_stats *st = this_cpu_ptr(sge->port_stats[dev->if_port]);
1789 	struct cpl_tx_pkt *cpl;
1790 	struct sk_buff *orig_skb = skb;
1791 	int ret;
1792 
1793 	if (skb->protocol == htons(ETH_P_CPL5))
1794 		goto send;
1795 
1796 	/*
1797 	 * We are using a non-standard hard_header_len.
1798 	 * Allocate more header room in the rare cases it is not big enough.
1799 	 */
1800 	if (unlikely(skb_headroom(skb) < dev->hard_header_len - ETH_HLEN)) {
1801 		skb = skb_realloc_headroom(skb, sizeof(struct cpl_tx_pkt_lso));
1802 		++st->tx_need_hdrroom;
1803 		dev_kfree_skb_any(orig_skb);
1804 		if (!skb)
1805 			return NETDEV_TX_OK;
1806 	}
1807 
1808 	if (skb_shinfo(skb)->gso_size) {
1809 		int eth_type;
1810 		struct cpl_tx_pkt_lso *hdr;
1811 
1812 		++st->tx_tso;
1813 
1814 		eth_type = skb_network_offset(skb) == ETH_HLEN ?
1815 			CPL_ETH_II : CPL_ETH_II_VLAN;
1816 
1817 		hdr = (struct cpl_tx_pkt_lso *)skb_push(skb, sizeof(*hdr));
1818 		hdr->opcode = CPL_TX_PKT_LSO;
1819 		hdr->ip_csum_dis = hdr->l4_csum_dis = 0;
1820 		hdr->ip_hdr_words = ip_hdr(skb)->ihl;
1821 		hdr->tcp_hdr_words = tcp_hdr(skb)->doff;
1822 		hdr->eth_type_mss = htons(MK_ETH_TYPE_MSS(eth_type,
1823 							  skb_shinfo(skb)->gso_size));
1824 		hdr->len = htonl(skb->len - sizeof(*hdr));
1825 		cpl = (struct cpl_tx_pkt *)hdr;
1826 	} else {
1827 		/*
1828 		 * Packets shorter than ETH_HLEN can break the MAC, drop them
1829 		 * early.  Also, we may get oversized packets because some
1830 		 * parts of the kernel don't handle our unusual hard_header_len
1831 		 * right, drop those too.
1832 		 */
1833 		if (unlikely(skb->len < ETH_HLEN ||
1834 			     skb->len > dev->mtu + eth_hdr_len(skb->data))) {
1835 			pr_debug("%s: packet size %d hdr %d mtu%d\n", dev->name,
1836 				 skb->len, eth_hdr_len(skb->data), dev->mtu);
1837 			dev_kfree_skb_any(skb);
1838 			return NETDEV_TX_OK;
1839 		}
1840 
1841 		if (!(adapter->flags & UDP_CSUM_CAPABLE) &&
1842 		    skb->ip_summed == CHECKSUM_PARTIAL &&
1843 		    ip_hdr(skb)->protocol == IPPROTO_UDP) {
1844 			if (unlikely(skb_checksum_help(skb))) {
1845 				pr_debug("%s: unable to do udp checksum\n", dev->name);
1846 				dev_kfree_skb_any(skb);
1847 				return NETDEV_TX_OK;
1848 			}
1849 		}
1850 
1851 		/* Hmmm, assuming to catch the gratious arp... and we'll use
1852 		 * it to flush out stuck espi packets...
1853 		 */
1854 		if ((unlikely(!adapter->sge->espibug_skb[dev->if_port]))) {
1855 			if (skb->protocol == htons(ETH_P_ARP) &&
1856 			    arp_hdr(skb)->ar_op == htons(ARPOP_REQUEST)) {
1857 				adapter->sge->espibug_skb[dev->if_port] = skb;
1858 				/* We want to re-use this skb later. We
1859 				 * simply bump the reference count and it
1860 				 * will not be freed...
1861 				 */
1862 				skb = skb_get(skb);
1863 			}
1864 		}
1865 
1866 		cpl = (struct cpl_tx_pkt *)__skb_push(skb, sizeof(*cpl));
1867 		cpl->opcode = CPL_TX_PKT;
1868 		cpl->ip_csum_dis = 1;    /* SW calculates IP csum */
1869 		cpl->l4_csum_dis = skb->ip_summed == CHECKSUM_PARTIAL ? 0 : 1;
1870 		/* the length field isn't used so don't bother setting it */
1871 
1872 		st->tx_cso += (skb->ip_summed == CHECKSUM_PARTIAL);
1873 	}
1874 	cpl->iff = dev->if_port;
1875 
1876 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
1877 	if (vlan_tx_tag_present(skb)) {
1878 		cpl->vlan_valid = 1;
1879 		cpl->vlan = htons(vlan_tx_tag_get(skb));
1880 		st->vlan_insert++;
1881 	} else
1882 #endif
1883 		cpl->vlan_valid = 0;
1884 
1885 send:
1886 	ret = t1_sge_tx(skb, adapter, 0, dev);
1887 
1888 	/* If transmit busy, and we reallocated skb's due to headroom limit,
1889 	 * then silently discard to avoid leak.
1890 	 */
1891 	if (unlikely(ret != NETDEV_TX_OK && skb != orig_skb)) {
1892 		dev_kfree_skb_any(skb);
1893 		ret = NETDEV_TX_OK;
1894 	}
1895 	return ret;
1896 }
1897 
1898 /*
1899  * Callback for the Tx buffer reclaim timer.  Runs with softirqs disabled.
1900  */
sge_tx_reclaim_cb(unsigned long data)1901 static void sge_tx_reclaim_cb(unsigned long data)
1902 {
1903 	int i;
1904 	struct sge *sge = (struct sge *)data;
1905 
1906 	for (i = 0; i < SGE_CMDQ_N; ++i) {
1907 		struct cmdQ *q = &sge->cmdQ[i];
1908 
1909 		if (!spin_trylock(&q->lock))
1910 			continue;
1911 
1912 		reclaim_completed_tx(sge, q);
1913 		if (i == 0 && q->in_use) {    /* flush pending credits */
1914 			writel(F_CMDQ0_ENABLE, sge->adapter->regs + A_SG_DOORBELL);
1915 		}
1916 		spin_unlock(&q->lock);
1917 	}
1918 	mod_timer(&sge->tx_reclaim_timer, jiffies + TX_RECLAIM_PERIOD);
1919 }
1920 
1921 /*
1922  * Propagate changes of the SGE coalescing parameters to the HW.
1923  */
t1_sge_set_coalesce_params(struct sge * sge,struct sge_params * p)1924 int t1_sge_set_coalesce_params(struct sge *sge, struct sge_params *p)
1925 {
1926 	sge->fixed_intrtimer = p->rx_coalesce_usecs *
1927 		core_ticks_per_usec(sge->adapter);
1928 	writel(sge->fixed_intrtimer, sge->adapter->regs + A_SG_INTRTIMER);
1929 	return 0;
1930 }
1931 
1932 /*
1933  * Allocates both RX and TX resources and configures the SGE. However,
1934  * the hardware is not enabled yet.
1935  */
t1_sge_configure(struct sge * sge,struct sge_params * p)1936 int t1_sge_configure(struct sge *sge, struct sge_params *p)
1937 {
1938 	if (alloc_rx_resources(sge, p))
1939 		return -ENOMEM;
1940 	if (alloc_tx_resources(sge, p)) {
1941 		free_rx_resources(sge);
1942 		return -ENOMEM;
1943 	}
1944 	configure_sge(sge, p);
1945 
1946 	/*
1947 	 * Now that we have sized the free lists calculate the payload
1948 	 * capacity of the large buffers.  Other parts of the driver use
1949 	 * this to set the max offload coalescing size so that RX packets
1950 	 * do not overflow our large buffers.
1951 	 */
1952 	p->large_buf_capacity = jumbo_payload_capacity(sge);
1953 	return 0;
1954 }
1955 
1956 /*
1957  * Disables the DMA engine.
1958  */
t1_sge_stop(struct sge * sge)1959 void t1_sge_stop(struct sge *sge)
1960 {
1961 	int i;
1962 	writel(0, sge->adapter->regs + A_SG_CONTROL);
1963 	readl(sge->adapter->regs + A_SG_CONTROL); /* flush */
1964 
1965 	if (is_T2(sge->adapter))
1966 		del_timer_sync(&sge->espibug_timer);
1967 
1968 	del_timer_sync(&sge->tx_reclaim_timer);
1969 	if (sge->tx_sched)
1970 		tx_sched_stop(sge);
1971 
1972 	for (i = 0; i < MAX_NPORTS; i++)
1973 		kfree_skb(sge->espibug_skb[i]);
1974 }
1975 
1976 /*
1977  * Enables the DMA engine.
1978  */
t1_sge_start(struct sge * sge)1979 void t1_sge_start(struct sge *sge)
1980 {
1981 	refill_free_list(sge, &sge->freelQ[0]);
1982 	refill_free_list(sge, &sge->freelQ[1]);
1983 
1984 	writel(sge->sge_control, sge->adapter->regs + A_SG_CONTROL);
1985 	doorbell_pio(sge->adapter, F_FL0_ENABLE | F_FL1_ENABLE);
1986 	readl(sge->adapter->regs + A_SG_CONTROL); /* flush */
1987 
1988 	mod_timer(&sge->tx_reclaim_timer, jiffies + TX_RECLAIM_PERIOD);
1989 
1990 	if (is_T2(sge->adapter))
1991 		mod_timer(&sge->espibug_timer, jiffies + sge->espibug_timeout);
1992 }
1993 
1994 /*
1995  * Callback for the T2 ESPI 'stuck packet feature' workaorund
1996  */
espibug_workaround_t204(unsigned long data)1997 static void espibug_workaround_t204(unsigned long data)
1998 {
1999 	struct adapter *adapter = (struct adapter *)data;
2000 	struct sge *sge = adapter->sge;
2001 	unsigned int nports = adapter->params.nports;
2002 	u32 seop[MAX_NPORTS];
2003 
2004 	if (adapter->open_device_map & PORT_MASK) {
2005 		int i;
2006 
2007 		if (t1_espi_get_mon_t204(adapter, &(seop[0]), 0) < 0)
2008 			return;
2009 
2010 		for (i = 0; i < nports; i++) {
2011 			struct sk_buff *skb = sge->espibug_skb[i];
2012 
2013 			if (!netif_running(adapter->port[i].dev) ||
2014 			    netif_queue_stopped(adapter->port[i].dev) ||
2015 			    !seop[i] || ((seop[i] & 0xfff) != 0) || !skb)
2016 				continue;
2017 
2018 			if (!skb->cb[0]) {
2019 				skb_copy_to_linear_data_offset(skb,
2020 						    sizeof(struct cpl_tx_pkt),
2021 							       ch_mac_addr,
2022 							       ETH_ALEN);
2023 				skb_copy_to_linear_data_offset(skb,
2024 							       skb->len - 10,
2025 							       ch_mac_addr,
2026 							       ETH_ALEN);
2027 				skb->cb[0] = 0xff;
2028 			}
2029 
2030 			/* bump the reference count to avoid freeing of
2031 			 * the skb once the DMA has completed.
2032 			 */
2033 			skb = skb_get(skb);
2034 			t1_sge_tx(skb, adapter, 0, adapter->port[i].dev);
2035 		}
2036 	}
2037 	mod_timer(&sge->espibug_timer, jiffies + sge->espibug_timeout);
2038 }
2039 
espibug_workaround(unsigned long data)2040 static void espibug_workaround(unsigned long data)
2041 {
2042 	struct adapter *adapter = (struct adapter *)data;
2043 	struct sge *sge = adapter->sge;
2044 
2045 	if (netif_running(adapter->port[0].dev)) {
2046 	        struct sk_buff *skb = sge->espibug_skb[0];
2047 	        u32 seop = t1_espi_get_mon(adapter, 0x930, 0);
2048 
2049 	        if ((seop & 0xfff0fff) == 0xfff && skb) {
2050 	                if (!skb->cb[0]) {
2051 	                        skb_copy_to_linear_data_offset(skb,
2052 						     sizeof(struct cpl_tx_pkt),
2053 							       ch_mac_addr,
2054 							       ETH_ALEN);
2055 	                        skb_copy_to_linear_data_offset(skb,
2056 							       skb->len - 10,
2057 							       ch_mac_addr,
2058 							       ETH_ALEN);
2059 	                        skb->cb[0] = 0xff;
2060 	                }
2061 
2062 	                /* bump the reference count to avoid freeing of the
2063 	                 * skb once the DMA has completed.
2064 	                 */
2065 	                skb = skb_get(skb);
2066 	                t1_sge_tx(skb, adapter, 0, adapter->port[0].dev);
2067 	        }
2068 	}
2069 	mod_timer(&sge->espibug_timer, jiffies + sge->espibug_timeout);
2070 }
2071 
2072 /*
2073  * Creates a t1_sge structure and returns suggested resource parameters.
2074  */
t1_sge_create(struct adapter * adapter,struct sge_params * p)2075 struct sge * __devinit t1_sge_create(struct adapter *adapter,
2076 				     struct sge_params *p)
2077 {
2078 	struct sge *sge = kzalloc(sizeof(*sge), GFP_KERNEL);
2079 	int i;
2080 
2081 	if (!sge)
2082 		return NULL;
2083 
2084 	sge->adapter = adapter;
2085 	sge->netdev = adapter->port[0].dev;
2086 	sge->rx_pkt_pad = t1_is_T1B(adapter) ? 0 : 2;
2087 	sge->jumbo_fl = t1_is_T1B(adapter) ? 1 : 0;
2088 
2089 	for_each_port(adapter, i) {
2090 		sge->port_stats[i] = alloc_percpu(struct sge_port_stats);
2091 		if (!sge->port_stats[i])
2092 			goto nomem_port;
2093 	}
2094 
2095 	init_timer(&sge->tx_reclaim_timer);
2096 	sge->tx_reclaim_timer.data = (unsigned long)sge;
2097 	sge->tx_reclaim_timer.function = sge_tx_reclaim_cb;
2098 
2099 	if (is_T2(sge->adapter)) {
2100 		init_timer(&sge->espibug_timer);
2101 
2102 		if (adapter->params.nports > 1) {
2103 			tx_sched_init(sge);
2104 			sge->espibug_timer.function = espibug_workaround_t204;
2105 		} else
2106 			sge->espibug_timer.function = espibug_workaround;
2107 		sge->espibug_timer.data = (unsigned long)sge->adapter;
2108 
2109 		sge->espibug_timeout = 1;
2110 		/* for T204, every 10ms */
2111 		if (adapter->params.nports > 1)
2112 			sge->espibug_timeout = HZ/100;
2113 	}
2114 
2115 
2116 	p->cmdQ_size[0] = SGE_CMDQ0_E_N;
2117 	p->cmdQ_size[1] = SGE_CMDQ1_E_N;
2118 	p->freelQ_size[!sge->jumbo_fl] = SGE_FREEL_SIZE;
2119 	p->freelQ_size[sge->jumbo_fl] = SGE_JUMBO_FREEL_SIZE;
2120 	if (sge->tx_sched) {
2121 		if (board_info(sge->adapter)->board == CHBT_BOARD_CHT204)
2122 			p->rx_coalesce_usecs = 15;
2123 		else
2124 			p->rx_coalesce_usecs = 50;
2125 	} else
2126 		p->rx_coalesce_usecs = 50;
2127 
2128 	p->coalesce_enable = 0;
2129 	p->sample_interval_usecs = 0;
2130 
2131 	return sge;
2132 nomem_port:
2133 	while (i >= 0) {
2134 		free_percpu(sge->port_stats[i]);
2135 		--i;
2136 	}
2137 	kfree(sge);
2138 	return NULL;
2139 
2140 }
2141