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, see <http://www.gnu.org/licenses/>.            *
16 *                                                                           *
17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED    *
18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF      *
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.                     *
20 *                                                                           *
21 * http://www.chelsio.com                                                    *
22 *                                                                           *
23 * Copyright (c) 2003 - 2005 Chelsio Communications, Inc.                    *
24 * All rights reserved.                                                      *
25 *                                                                           *
26 * Maintainers: maintainers@chelsio.com                                      *
27 *                                                                           *
28 * Authors: Dimitrios Michailidis   <dm@chelsio.com>                         *
29 *          Tina Yang               <tainay@chelsio.com>                     *
30 *          Felix Marti             <felix@chelsio.com>                      *
31 *          Scott Bardone           <sbardone@chelsio.com>                   *
32 *          Kurt Ottaway            <kottaway@chelsio.com>                   *
33 *          Frank DiMambro          <frank@chelsio.com>                      *
34 *                                                                           *
35 * History:                                                                  *
36 *                                                                           *
37 ****************************************************************************/
38
39#include "common.h"
40
41#include <linux/types.h>
42#include <linux/errno.h>
43#include <linux/pci.h>
44#include <linux/ktime.h>
45#include <linux/netdevice.h>
46#include <linux/etherdevice.h>
47#include <linux/if_vlan.h>
48#include <linux/skbuff.h>
49#include <linux/mm.h>
50#include <linux/tcp.h>
51#include <linux/ip.h>
52#include <linux/in.h>
53#include <linux/if_arp.h>
54#include <linux/slab.h>
55#include <linux/prefetch.h>
56
57#include "cpl5_cmd.h"
58#include "sge.h"
59#include "regs.h"
60#include "espi.h"
61
62/* This belongs in if_ether.h */
63#define ETH_P_CPL5 0xf
64
65#define SGE_CMDQ_N		2
66#define SGE_FREELQ_N		2
67#define SGE_CMDQ0_E_N		1024
68#define SGE_CMDQ1_E_N		128
69#define SGE_FREEL_SIZE		4096
70#define SGE_JUMBO_FREEL_SIZE	512
71#define SGE_FREEL_REFILL_THRESH	16
72#define SGE_RESPQ_E_N		1024
73#define SGE_INTRTIMER_NRES	1000
74#define SGE_RX_SM_BUF_SIZE	1536
75#define SGE_TX_DESC_MAX_PLEN	16384
76
77#define SGE_RESPQ_REPLENISH_THRES (SGE_RESPQ_E_N / 4)
78
79/*
80 * Period of the TX buffer reclaim timer.  This timer does not need to run
81 * frequently as TX buffers are usually reclaimed by new TX packets.
82 */
83#define TX_RECLAIM_PERIOD (HZ / 4)
84
85#define M_CMD_LEN       0x7fffffff
86#define V_CMD_LEN(v)    (v)
87#define G_CMD_LEN(v)    ((v) & M_CMD_LEN)
88#define V_CMD_GEN1(v)   ((v) << 31)
89#define V_CMD_GEN2(v)   (v)
90#define F_CMD_DATAVALID (1 << 1)
91#define F_CMD_SOP       (1 << 2)
92#define V_CMD_EOP(v)    ((v) << 3)
93
94/*
95 * Command queue, receive buffer list, and response queue descriptors.
96 */
97#if defined(__BIG_ENDIAN_BITFIELD)
98struct cmdQ_e {
99	u32 addr_lo;
100	u32 len_gen;
101	u32 flags;
102	u32 addr_hi;
103};
104
105struct freelQ_e {
106	u32 addr_lo;
107	u32 len_gen;
108	u32 gen2;
109	u32 addr_hi;
110};
111
112struct respQ_e {
113	u32 Qsleeping		: 4;
114	u32 Cmdq1CreditReturn	: 5;
115	u32 Cmdq1DmaComplete	: 5;
116	u32 Cmdq0CreditReturn	: 5;
117	u32 Cmdq0DmaComplete	: 5;
118	u32 FreelistQid		: 2;
119	u32 CreditValid		: 1;
120	u32 DataValid		: 1;
121	u32 Offload		: 1;
122	u32 Eop			: 1;
123	u32 Sop			: 1;
124	u32 GenerationBit	: 1;
125	u32 BufferLength;
126};
127#elif defined(__LITTLE_ENDIAN_BITFIELD)
128struct cmdQ_e {
129	u32 len_gen;
130	u32 addr_lo;
131	u32 addr_hi;
132	u32 flags;
133};
134
135struct freelQ_e {
136	u32 len_gen;
137	u32 addr_lo;
138	u32 addr_hi;
139	u32 gen2;
140};
141
142struct respQ_e {
143	u32 BufferLength;
144	u32 GenerationBit	: 1;
145	u32 Sop			: 1;
146	u32 Eop			: 1;
147	u32 Offload		: 1;
148	u32 DataValid		: 1;
149	u32 CreditValid		: 1;
150	u32 FreelistQid		: 2;
151	u32 Cmdq0DmaComplete	: 5;
152	u32 Cmdq0CreditReturn	: 5;
153	u32 Cmdq1DmaComplete	: 5;
154	u32 Cmdq1CreditReturn	: 5;
155	u32 Qsleeping		: 4;
156} ;
157#endif
158
159/*
160 * SW Context Command and Freelist Queue Descriptors
161 */
162struct cmdQ_ce {
163	struct sk_buff *skb;
164	DEFINE_DMA_UNMAP_ADDR(dma_addr);
165	DEFINE_DMA_UNMAP_LEN(dma_len);
166};
167
168struct freelQ_ce {
169	struct sk_buff *skb;
170	DEFINE_DMA_UNMAP_ADDR(dma_addr);
171	DEFINE_DMA_UNMAP_LEN(dma_len);
172};
173
174/*
175 * SW command, freelist and response rings
176 */
177struct cmdQ {
178	unsigned long   status;         /* HW DMA fetch status */
179	unsigned int    in_use;         /* # of in-use command descriptors */
180	unsigned int	size;	        /* # of descriptors */
181	unsigned int    processed;      /* total # of descs HW has processed */
182	unsigned int    cleaned;        /* total # of descs SW has reclaimed */
183	unsigned int    stop_thres;     /* SW TX queue suspend threshold */
184	u16		pidx;           /* producer index (SW) */
185	u16		cidx;           /* consumer index (HW) */
186	u8		genbit;         /* current generation (=valid) bit */
187	u8              sop;            /* is next entry start of packet? */
188	struct cmdQ_e  *entries;        /* HW command descriptor Q */
189	struct cmdQ_ce *centries;       /* SW command context descriptor Q */
190	dma_addr_t	dma_addr;       /* DMA addr HW command descriptor Q */
191	spinlock_t	lock;           /* Lock to protect cmdQ enqueuing */
192};
193
194struct freelQ {
195	unsigned int	credits;        /* # of available RX buffers */
196	unsigned int	size;	        /* free list capacity */
197	u16		pidx;           /* producer index (SW) */
198	u16		cidx;           /* consumer index (HW) */
199	u16		rx_buffer_size; /* Buffer size on this free list */
200	u16             dma_offset;     /* DMA offset to align IP headers */
201	u16             recycleq_idx;   /* skb recycle q to use */
202	u8		genbit;	        /* current generation (=valid) bit */
203	struct freelQ_e	*entries;       /* HW freelist descriptor Q */
204	struct freelQ_ce *centries;     /* SW freelist context descriptor Q */
205	dma_addr_t	dma_addr;       /* DMA addr HW freelist descriptor Q */
206};
207
208struct respQ {
209	unsigned int	credits;        /* credits to be returned to SGE */
210	unsigned int	size;	        /* # of response Q descriptors */
211	u16		cidx;	        /* consumer index (SW) */
212	u8		genbit;	        /* current generation(=valid) bit */
213	struct respQ_e *entries;        /* HW response descriptor Q */
214	dma_addr_t	dma_addr;       /* DMA addr HW response descriptor Q */
215};
216
217/* Bit flags for cmdQ.status */
218enum {
219	CMDQ_STAT_RUNNING = 1,          /* fetch engine is running */
220	CMDQ_STAT_LAST_PKT_DB = 2       /* last packet rung the doorbell */
221};
222
223/* T204 TX SW scheduler */
224
225/* Per T204 TX port */
226struct sched_port {
227	unsigned int	avail;		/* available bits - quota */
228	unsigned int	drain_bits_per_1024ns; /* drain rate */
229	unsigned int	speed;		/* drain rate, mbps */
230	unsigned int	mtu;		/* mtu size */
231	struct sk_buff_head skbq;	/* pending skbs */
232};
233
234/* Per T204 device */
235struct sched {
236	ktime_t         last_updated;   /* last time quotas were computed */
237	unsigned int	max_avail;	/* max bits to be sent to any port */
238	unsigned int	port;		/* port index (round robin ports) */
239	unsigned int	num;		/* num skbs in per port queues */
240	struct sched_port p[MAX_NPORTS];
241	struct tasklet_struct sched_tsk;/* tasklet used to run scheduler */
242};
243static void restart_sched(unsigned long);
244
245
246/*
247 * Main SGE data structure
248 *
249 * Interrupts are handled by a single CPU and it is likely that on a MP system
250 * the application is migrated to another CPU. In that scenario, we try to
251 * separate the RX(in irq context) and TX state in order to decrease memory
252 * contention.
253 */
254struct sge {
255	struct adapter *adapter;	/* adapter backpointer */
256	struct net_device *netdev;      /* netdevice backpointer */
257	struct freelQ	freelQ[SGE_FREELQ_N]; /* buffer free lists */
258	struct respQ	respQ;		/* response Q */
259	unsigned long   stopped_tx_queues; /* bitmap of suspended Tx queues */
260	unsigned int	rx_pkt_pad;     /* RX padding for L2 packets */
261	unsigned int	jumbo_fl;       /* jumbo freelist Q index */
262	unsigned int	intrtimer_nres;	/* no-resource interrupt timer */
263	unsigned int    fixed_intrtimer;/* non-adaptive interrupt timer */
264	struct timer_list tx_reclaim_timer; /* reclaims TX buffers */
265	struct timer_list espibug_timer;
266	unsigned long	espibug_timeout;
267	struct sk_buff	*espibug_skb[MAX_NPORTS];
268	u32		sge_control;	/* shadow value of sge control reg */
269	struct sge_intr_counts stats;
270	struct sge_port_stats __percpu *port_stats[MAX_NPORTS];
271	struct sched	*tx_sched;
272	struct cmdQ cmdQ[SGE_CMDQ_N] ____cacheline_aligned_in_smp;
273};
274
275static const u8 ch_mac_addr[ETH_ALEN] = {
276	0x0, 0x7, 0x43, 0x0, 0x0, 0x0
277};
278
279/*
280 * stop tasklet and free all pending skb's
281 */
282static void tx_sched_stop(struct sge *sge)
283{
284	struct sched *s = sge->tx_sched;
285	int i;
286
287	tasklet_kill(&s->sched_tsk);
288
289	for (i = 0; i < MAX_NPORTS; i++)
290		__skb_queue_purge(&s->p[s->port].skbq);
291}
292
293/*
294 * t1_sched_update_parms() is called when the MTU or link speed changes. It
295 * re-computes scheduler parameters to scope with the change.
296 */
297unsigned int t1_sched_update_parms(struct sge *sge, unsigned int port,
298				   unsigned int mtu, unsigned int speed)
299{
300	struct sched *s = sge->tx_sched;
301	struct sched_port *p = &s->p[port];
302	unsigned int max_avail_segs;
303
304	pr_debug("t1_sched_update_params mtu=%d speed=%d\n", mtu, speed);
305	if (speed)
306		p->speed = speed;
307	if (mtu)
308		p->mtu = mtu;
309
310	if (speed || mtu) {
311		unsigned long long drain = 1024ULL * p->speed * (p->mtu - 40);
312		do_div(drain, (p->mtu + 50) * 1000);
313		p->drain_bits_per_1024ns = (unsigned int) drain;
314
315		if (p->speed < 1000)
316			p->drain_bits_per_1024ns =
317				90 * p->drain_bits_per_1024ns / 100;
318	}
319
320	if (board_info(sge->adapter)->board == CHBT_BOARD_CHT204) {
321		p->drain_bits_per_1024ns -= 16;
322		s->max_avail = max(4096U, p->mtu + 16 + 14 + 4);
323		max_avail_segs = max(1U, 4096 / (p->mtu - 40));
324	} else {
325		s->max_avail = 16384;
326		max_avail_segs = max(1U, 9000 / (p->mtu - 40));
327	}
328
329	pr_debug("t1_sched_update_parms: mtu %u speed %u max_avail %u "
330		 "max_avail_segs %u drain_bits_per_1024ns %u\n", p->mtu,
331		 p->speed, s->max_avail, max_avail_segs,
332		 p->drain_bits_per_1024ns);
333
334	return max_avail_segs * (p->mtu - 40);
335}
336
337#if 0
338
339/*
340 * t1_sched_max_avail_bytes() tells the scheduler the maximum amount of
341 * data that can be pushed per port.
342 */
343void t1_sched_set_max_avail_bytes(struct sge *sge, unsigned int val)
344{
345	struct sched *s = sge->tx_sched;
346	unsigned int i;
347
348	s->max_avail = val;
349	for (i = 0; i < MAX_NPORTS; i++)
350		t1_sched_update_parms(sge, i, 0, 0);
351}
352
353/*
354 * t1_sched_set_drain_bits_per_us() tells the scheduler at which rate a port
355 * is draining.
356 */
357void t1_sched_set_drain_bits_per_us(struct sge *sge, unsigned int port,
358					 unsigned int val)
359{
360	struct sched *s = sge->tx_sched;
361	struct sched_port *p = &s->p[port];
362	p->drain_bits_per_1024ns = val * 1024 / 1000;
363	t1_sched_update_parms(sge, port, 0, 0);
364}
365
366#endif  /*  0  */
367
368/*
369 * tx_sched_init() allocates resources and does basic initialization.
370 */
371static int tx_sched_init(struct sge *sge)
372{
373	struct sched *s;
374	int i;
375
376	s = kzalloc(sizeof (struct sched), GFP_KERNEL);
377	if (!s)
378		return -ENOMEM;
379
380	pr_debug("tx_sched_init\n");
381	tasklet_init(&s->sched_tsk, restart_sched, (unsigned long) sge);
382	sge->tx_sched = s;
383
384	for (i = 0; i < MAX_NPORTS; i++) {
385		skb_queue_head_init(&s->p[i].skbq);
386		t1_sched_update_parms(sge, i, 1500, 1000);
387	}
388
389	return 0;
390}
391
392/*
393 * sched_update_avail() computes the delta since the last time it was called
394 * and updates the per port quota (number of bits that can be sent to the any
395 * port).
396 */
397static inline int sched_update_avail(struct sge *sge)
398{
399	struct sched *s = sge->tx_sched;
400	ktime_t now = ktime_get();
401	unsigned int i;
402	long long delta_time_ns;
403
404	delta_time_ns = ktime_to_ns(ktime_sub(now, s->last_updated));
405
406	pr_debug("sched_update_avail delta=%lld\n", delta_time_ns);
407	if (delta_time_ns < 15000)
408		return 0;
409
410	for (i = 0; i < MAX_NPORTS; i++) {
411		struct sched_port *p = &s->p[i];
412		unsigned int delta_avail;
413
414		delta_avail = (p->drain_bits_per_1024ns * delta_time_ns) >> 13;
415		p->avail = min(p->avail + delta_avail, s->max_avail);
416	}
417
418	s->last_updated = now;
419
420	return 1;
421}
422
423/*
424 * sched_skb() is called from two different places. In the tx path, any
425 * packet generating load on an output port will call sched_skb()
426 * (skb != NULL). In addition, sched_skb() is called from the irq/soft irq
427 * context (skb == NULL).
428 * The scheduler only returns a skb (which will then be sent) if the
429 * length of the skb is <= the current quota of the output port.
430 */
431static struct sk_buff *sched_skb(struct sge *sge, struct sk_buff *skb,
432				unsigned int credits)
433{
434	struct sched *s = sge->tx_sched;
435	struct sk_buff_head *skbq;
436	unsigned int i, len, update = 1;
437
438	pr_debug("sched_skb %p\n", skb);
439	if (!skb) {
440		if (!s->num)
441			return NULL;
442	} else {
443		skbq = &s->p[skb->dev->if_port].skbq;
444		__skb_queue_tail(skbq, skb);
445		s->num++;
446		skb = NULL;
447	}
448
449	if (credits < MAX_SKB_FRAGS + 1)
450		goto out;
451
452again:
453	for (i = 0; i < MAX_NPORTS; i++) {
454		s->port = (s->port + 1) & (MAX_NPORTS - 1);
455		skbq = &s->p[s->port].skbq;
456
457		skb = skb_peek(skbq);
458
459		if (!skb)
460			continue;
461
462		len = skb->len;
463		if (len <= s->p[s->port].avail) {
464			s->p[s->port].avail -= len;
465			s->num--;
466			__skb_unlink(skb, skbq);
467			goto out;
468		}
469		skb = NULL;
470	}
471
472	if (update-- && sched_update_avail(sge))
473		goto again;
474
475out:
476	/* If there are more pending skbs, we use the hardware to schedule us
477	 * again.
478	 */
479	if (s->num && !skb) {
480		struct cmdQ *q = &sge->cmdQ[0];
481		clear_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
482		if (test_and_set_bit(CMDQ_STAT_RUNNING, &q->status) == 0) {
483			set_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
484			writel(F_CMDQ0_ENABLE, sge->adapter->regs + A_SG_DOORBELL);
485		}
486	}
487	pr_debug("sched_skb ret %p\n", skb);
488
489	return skb;
490}
491
492/*
493 * PIO to indicate that memory mapped Q contains valid descriptor(s).
494 */
495static inline void doorbell_pio(struct adapter *adapter, u32 val)
496{
497	wmb();
498	writel(val, adapter->regs + A_SG_DOORBELL);
499}
500
501/*
502 * Frees all RX buffers on the freelist Q. The caller must make sure that
503 * the SGE is turned off before calling this function.
504 */
505static void free_freelQ_buffers(struct pci_dev *pdev, struct freelQ *q)
506{
507	unsigned int cidx = q->cidx;
508
509	while (q->credits--) {
510		struct freelQ_ce *ce = &q->centries[cidx];
511
512		pci_unmap_single(pdev, dma_unmap_addr(ce, dma_addr),
513				 dma_unmap_len(ce, dma_len),
514				 PCI_DMA_FROMDEVICE);
515		dev_kfree_skb(ce->skb);
516		ce->skb = NULL;
517		if (++cidx == q->size)
518			cidx = 0;
519	}
520}
521
522/*
523 * Free RX free list and response queue resources.
524 */
525static void free_rx_resources(struct sge *sge)
526{
527	struct pci_dev *pdev = sge->adapter->pdev;
528	unsigned int size, i;
529
530	if (sge->respQ.entries) {
531		size = sizeof(struct respQ_e) * sge->respQ.size;
532		pci_free_consistent(pdev, size, sge->respQ.entries,
533				    sge->respQ.dma_addr);
534	}
535
536	for (i = 0; i < SGE_FREELQ_N; i++) {
537		struct freelQ *q = &sge->freelQ[i];
538
539		if (q->centries) {
540			free_freelQ_buffers(pdev, q);
541			kfree(q->centries);
542		}
543		if (q->entries) {
544			size = sizeof(struct freelQ_e) * q->size;
545			pci_free_consistent(pdev, size, q->entries,
546					    q->dma_addr);
547		}
548	}
549}
550
551/*
552 * Allocates basic RX resources, consisting of memory mapped freelist Qs and a
553 * response queue.
554 */
555static int alloc_rx_resources(struct sge *sge, struct sge_params *p)
556{
557	struct pci_dev *pdev = sge->adapter->pdev;
558	unsigned int size, i;
559
560	for (i = 0; i < SGE_FREELQ_N; i++) {
561		struct freelQ *q = &sge->freelQ[i];
562
563		q->genbit = 1;
564		q->size = p->freelQ_size[i];
565		q->dma_offset = sge->rx_pkt_pad ? 0 : NET_IP_ALIGN;
566		size = sizeof(struct freelQ_e) * q->size;
567		q->entries = pci_alloc_consistent(pdev, size, &q->dma_addr);
568		if (!q->entries)
569			goto err_no_mem;
570
571		size = sizeof(struct freelQ_ce) * q->size;
572		q->centries = kzalloc(size, GFP_KERNEL);
573		if (!q->centries)
574			goto err_no_mem;
575	}
576
577	/*
578	 * Calculate the buffer sizes for the two free lists.  FL0 accommodates
579	 * regular sized Ethernet frames, FL1 is sized not to exceed 16K,
580	 * including all the sk_buff overhead.
581	 *
582	 * Note: For T2 FL0 and FL1 are reversed.
583	 */
584	sge->freelQ[!sge->jumbo_fl].rx_buffer_size = SGE_RX_SM_BUF_SIZE +
585		sizeof(struct cpl_rx_data) +
586		sge->freelQ[!sge->jumbo_fl].dma_offset;
587
588		size = (16 * 1024) -
589		    SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
590
591	sge->freelQ[sge->jumbo_fl].rx_buffer_size = size;
592
593	/*
594	 * Setup which skb recycle Q should be used when recycling buffers from
595	 * each free list.
596	 */
597	sge->freelQ[!sge->jumbo_fl].recycleq_idx = 0;
598	sge->freelQ[sge->jumbo_fl].recycleq_idx = 1;
599
600	sge->respQ.genbit = 1;
601	sge->respQ.size = SGE_RESPQ_E_N;
602	sge->respQ.credits = 0;
603	size = sizeof(struct respQ_e) * sge->respQ.size;
604	sge->respQ.entries =
605		pci_alloc_consistent(pdev, size, &sge->respQ.dma_addr);
606	if (!sge->respQ.entries)
607		goto err_no_mem;
608	return 0;
609
610err_no_mem:
611	free_rx_resources(sge);
612	return -ENOMEM;
613}
614
615/*
616 * Reclaims n TX descriptors and frees the buffers associated with them.
617 */
618static void free_cmdQ_buffers(struct sge *sge, struct cmdQ *q, unsigned int n)
619{
620	struct cmdQ_ce *ce;
621	struct pci_dev *pdev = sge->adapter->pdev;
622	unsigned int cidx = q->cidx;
623
624	q->in_use -= n;
625	ce = &q->centries[cidx];
626	while (n--) {
627		if (likely(dma_unmap_len(ce, dma_len))) {
628			pci_unmap_single(pdev, dma_unmap_addr(ce, dma_addr),
629					 dma_unmap_len(ce, dma_len),
630					 PCI_DMA_TODEVICE);
631			if (q->sop)
632				q->sop = 0;
633		}
634		if (ce->skb) {
635			dev_kfree_skb_any(ce->skb);
636			q->sop = 1;
637		}
638		ce++;
639		if (++cidx == q->size) {
640			cidx = 0;
641			ce = q->centries;
642		}
643	}
644	q->cidx = cidx;
645}
646
647/*
648 * Free TX resources.
649 *
650 * Assumes that SGE is stopped and all interrupts are disabled.
651 */
652static void free_tx_resources(struct sge *sge)
653{
654	struct pci_dev *pdev = sge->adapter->pdev;
655	unsigned int size, i;
656
657	for (i = 0; i < SGE_CMDQ_N; i++) {
658		struct cmdQ *q = &sge->cmdQ[i];
659
660		if (q->centries) {
661			if (q->in_use)
662				free_cmdQ_buffers(sge, q, q->in_use);
663			kfree(q->centries);
664		}
665		if (q->entries) {
666			size = sizeof(struct cmdQ_e) * q->size;
667			pci_free_consistent(pdev, size, q->entries,
668					    q->dma_addr);
669		}
670	}
671}
672
673/*
674 * Allocates basic TX resources, consisting of memory mapped command Qs.
675 */
676static int alloc_tx_resources(struct sge *sge, struct sge_params *p)
677{
678	struct pci_dev *pdev = sge->adapter->pdev;
679	unsigned int size, i;
680
681	for (i = 0; i < SGE_CMDQ_N; i++) {
682		struct cmdQ *q = &sge->cmdQ[i];
683
684		q->genbit = 1;
685		q->sop = 1;
686		q->size = p->cmdQ_size[i];
687		q->in_use = 0;
688		q->status = 0;
689		q->processed = q->cleaned = 0;
690		q->stop_thres = 0;
691		spin_lock_init(&q->lock);
692		size = sizeof(struct cmdQ_e) * q->size;
693		q->entries = pci_alloc_consistent(pdev, size, &q->dma_addr);
694		if (!q->entries)
695			goto err_no_mem;
696
697		size = sizeof(struct cmdQ_ce) * q->size;
698		q->centries = kzalloc(size, GFP_KERNEL);
699		if (!q->centries)
700			goto err_no_mem;
701	}
702
703	/*
704	 * CommandQ 0 handles Ethernet and TOE packets, while queue 1 is TOE
705	 * only.  For queue 0 set the stop threshold so we can handle one more
706	 * packet from each port, plus reserve an additional 24 entries for
707	 * Ethernet packets only.  Queue 1 never suspends nor do we reserve
708	 * space for Ethernet packets.
709	 */
710	sge->cmdQ[0].stop_thres = sge->adapter->params.nports *
711		(MAX_SKB_FRAGS + 1);
712	return 0;
713
714err_no_mem:
715	free_tx_resources(sge);
716	return -ENOMEM;
717}
718
719static inline void setup_ring_params(struct adapter *adapter, u64 addr,
720				     u32 size, int base_reg_lo,
721				     int base_reg_hi, int size_reg)
722{
723	writel((u32)addr, adapter->regs + base_reg_lo);
724	writel(addr >> 32, adapter->regs + base_reg_hi);
725	writel(size, adapter->regs + size_reg);
726}
727
728/*
729 * Enable/disable VLAN acceleration.
730 */
731void t1_vlan_mode(struct adapter *adapter, netdev_features_t features)
732{
733	struct sge *sge = adapter->sge;
734
735	if (features & NETIF_F_HW_VLAN_CTAG_RX)
736		sge->sge_control |= F_VLAN_XTRACT;
737	else
738		sge->sge_control &= ~F_VLAN_XTRACT;
739	if (adapter->open_device_map) {
740		writel(sge->sge_control, adapter->regs + A_SG_CONTROL);
741		readl(adapter->regs + A_SG_CONTROL);   /* flush */
742	}
743}
744
745/*
746 * Programs the various SGE registers. However, the engine is not yet enabled,
747 * but sge->sge_control is setup and ready to go.
748 */
749static void configure_sge(struct sge *sge, struct sge_params *p)
750{
751	struct adapter *ap = sge->adapter;
752
753	writel(0, ap->regs + A_SG_CONTROL);
754	setup_ring_params(ap, sge->cmdQ[0].dma_addr, sge->cmdQ[0].size,
755			  A_SG_CMD0BASELWR, A_SG_CMD0BASEUPR, A_SG_CMD0SIZE);
756	setup_ring_params(ap, sge->cmdQ[1].dma_addr, sge->cmdQ[1].size,
757			  A_SG_CMD1BASELWR, A_SG_CMD1BASEUPR, A_SG_CMD1SIZE);
758	setup_ring_params(ap, sge->freelQ[0].dma_addr,
759			  sge->freelQ[0].size, A_SG_FL0BASELWR,
760			  A_SG_FL0BASEUPR, A_SG_FL0SIZE);
761	setup_ring_params(ap, sge->freelQ[1].dma_addr,
762			  sge->freelQ[1].size, A_SG_FL1BASELWR,
763			  A_SG_FL1BASEUPR, A_SG_FL1SIZE);
764
765	/* The threshold comparison uses <. */
766	writel(SGE_RX_SM_BUF_SIZE + 1, ap->regs + A_SG_FLTHRESHOLD);
767
768	setup_ring_params(ap, sge->respQ.dma_addr, sge->respQ.size,
769			  A_SG_RSPBASELWR, A_SG_RSPBASEUPR, A_SG_RSPSIZE);
770	writel((u32)sge->respQ.size - 1, ap->regs + A_SG_RSPQUEUECREDIT);
771
772	sge->sge_control = F_CMDQ0_ENABLE | F_CMDQ1_ENABLE | F_FL0_ENABLE |
773		F_FL1_ENABLE | F_CPL_ENABLE | F_RESPONSE_QUEUE_ENABLE |
774		V_CMDQ_PRIORITY(2) | F_DISABLE_CMDQ1_GTS | F_ISCSI_COALESCE |
775		V_RX_PKT_OFFSET(sge->rx_pkt_pad);
776
777#if defined(__BIG_ENDIAN_BITFIELD)
778	sge->sge_control |= F_ENABLE_BIG_ENDIAN;
779#endif
780
781	/* Initialize no-resource timer */
782	sge->intrtimer_nres = SGE_INTRTIMER_NRES * core_ticks_per_usec(ap);
783
784	t1_sge_set_coalesce_params(sge, p);
785}
786
787/*
788 * Return the payload capacity of the jumbo free-list buffers.
789 */
790static inline unsigned int jumbo_payload_capacity(const struct sge *sge)
791{
792	return sge->freelQ[sge->jumbo_fl].rx_buffer_size -
793		sge->freelQ[sge->jumbo_fl].dma_offset -
794		sizeof(struct cpl_rx_data);
795}
796
797/*
798 * Frees all SGE related resources and the sge structure itself
799 */
800void t1_sge_destroy(struct sge *sge)
801{
802	int i;
803
804	for_each_port(sge->adapter, i)
805		free_percpu(sge->port_stats[i]);
806
807	kfree(sge->tx_sched);
808	free_tx_resources(sge);
809	free_rx_resources(sge);
810	kfree(sge);
811}
812
813/*
814 * Allocates new RX buffers on the freelist Q (and tracks them on the freelist
815 * context Q) until the Q is full or alloc_skb fails.
816 *
817 * It is possible that the generation bits already match, indicating that the
818 * buffer is already valid and nothing needs to be done. This happens when we
819 * copied a received buffer into a new sk_buff during the interrupt processing.
820 *
821 * If the SGE doesn't automatically align packets properly (!sge->rx_pkt_pad),
822 * we specify a RX_OFFSET in order to make sure that the IP header is 4B
823 * aligned.
824 */
825static void refill_free_list(struct sge *sge, struct freelQ *q)
826{
827	struct pci_dev *pdev = sge->adapter->pdev;
828	struct freelQ_ce *ce = &q->centries[q->pidx];
829	struct freelQ_e *e = &q->entries[q->pidx];
830	unsigned int dma_len = q->rx_buffer_size - q->dma_offset;
831
832	while (q->credits < q->size) {
833		struct sk_buff *skb;
834		dma_addr_t mapping;
835
836		skb = dev_alloc_skb(q->rx_buffer_size);
837		if (!skb)
838			break;
839
840		skb_reserve(skb, q->dma_offset);
841		mapping = pci_map_single(pdev, skb->data, dma_len,
842					 PCI_DMA_FROMDEVICE);
843		skb_reserve(skb, sge->rx_pkt_pad);
844
845		ce->skb = skb;
846		dma_unmap_addr_set(ce, dma_addr, mapping);
847		dma_unmap_len_set(ce, dma_len, dma_len);
848		e->addr_lo = (u32)mapping;
849		e->addr_hi = (u64)mapping >> 32;
850		e->len_gen = V_CMD_LEN(dma_len) | V_CMD_GEN1(q->genbit);
851		wmb();
852		e->gen2 = V_CMD_GEN2(q->genbit);
853
854		e++;
855		ce++;
856		if (++q->pidx == q->size) {
857			q->pidx = 0;
858			q->genbit ^= 1;
859			ce = q->centries;
860			e = q->entries;
861		}
862		q->credits++;
863	}
864}
865
866/*
867 * Calls refill_free_list for both free lists. If we cannot fill at least 1/4
868 * of both rings, we go into 'few interrupt mode' in order to give the system
869 * time to free up resources.
870 */
871static void freelQs_empty(struct sge *sge)
872{
873	struct adapter *adapter = sge->adapter;
874	u32 irq_reg = readl(adapter->regs + A_SG_INT_ENABLE);
875	u32 irqholdoff_reg;
876
877	refill_free_list(sge, &sge->freelQ[0]);
878	refill_free_list(sge, &sge->freelQ[1]);
879
880	if (sge->freelQ[0].credits > (sge->freelQ[0].size >> 2) &&
881	    sge->freelQ[1].credits > (sge->freelQ[1].size >> 2)) {
882		irq_reg |= F_FL_EXHAUSTED;
883		irqholdoff_reg = sge->fixed_intrtimer;
884	} else {
885		/* Clear the F_FL_EXHAUSTED interrupts for now */
886		irq_reg &= ~F_FL_EXHAUSTED;
887		irqholdoff_reg = sge->intrtimer_nres;
888	}
889	writel(irqholdoff_reg, adapter->regs + A_SG_INTRTIMER);
890	writel(irq_reg, adapter->regs + A_SG_INT_ENABLE);
891
892	/* We reenable the Qs to force a freelist GTS interrupt later */
893	doorbell_pio(adapter, F_FL0_ENABLE | F_FL1_ENABLE);
894}
895
896#define SGE_PL_INTR_MASK (F_PL_INTR_SGE_ERR | F_PL_INTR_SGE_DATA)
897#define SGE_INT_FATAL (F_RESPQ_OVERFLOW | F_PACKET_TOO_BIG | F_PACKET_MISMATCH)
898#define SGE_INT_ENABLE (F_RESPQ_EXHAUSTED | F_RESPQ_OVERFLOW | \
899			F_FL_EXHAUSTED | F_PACKET_TOO_BIG | F_PACKET_MISMATCH)
900
901/*
902 * Disable SGE Interrupts
903 */
904void t1_sge_intr_disable(struct sge *sge)
905{
906	u32 val = readl(sge->adapter->regs + A_PL_ENABLE);
907
908	writel(val & ~SGE_PL_INTR_MASK, sge->adapter->regs + A_PL_ENABLE);
909	writel(0, sge->adapter->regs + A_SG_INT_ENABLE);
910}
911
912/*
913 * Enable SGE interrupts.
914 */
915void t1_sge_intr_enable(struct sge *sge)
916{
917	u32 en = SGE_INT_ENABLE;
918	u32 val = readl(sge->adapter->regs + A_PL_ENABLE);
919
920	if (sge->adapter->port[0].dev->hw_features & NETIF_F_TSO)
921		en &= ~F_PACKET_TOO_BIG;
922	writel(en, sge->adapter->regs + A_SG_INT_ENABLE);
923	writel(val | SGE_PL_INTR_MASK, sge->adapter->regs + A_PL_ENABLE);
924}
925
926/*
927 * Clear SGE interrupts.
928 */
929void t1_sge_intr_clear(struct sge *sge)
930{
931	writel(SGE_PL_INTR_MASK, sge->adapter->regs + A_PL_CAUSE);
932	writel(0xffffffff, sge->adapter->regs + A_SG_INT_CAUSE);
933}
934
935/*
936 * SGE 'Error' interrupt handler
937 */
938int t1_sge_intr_error_handler(struct sge *sge)
939{
940	struct adapter *adapter = sge->adapter;
941	u32 cause = readl(adapter->regs + A_SG_INT_CAUSE);
942
943	if (adapter->port[0].dev->hw_features & NETIF_F_TSO)
944		cause &= ~F_PACKET_TOO_BIG;
945	if (cause & F_RESPQ_EXHAUSTED)
946		sge->stats.respQ_empty++;
947	if (cause & F_RESPQ_OVERFLOW) {
948		sge->stats.respQ_overflow++;
949		pr_alert("%s: SGE response queue overflow\n",
950			 adapter->name);
951	}
952	if (cause & F_FL_EXHAUSTED) {
953		sge->stats.freelistQ_empty++;
954		freelQs_empty(sge);
955	}
956	if (cause & F_PACKET_TOO_BIG) {
957		sge->stats.pkt_too_big++;
958		pr_alert("%s: SGE max packet size exceeded\n",
959			 adapter->name);
960	}
961	if (cause & F_PACKET_MISMATCH) {
962		sge->stats.pkt_mismatch++;
963		pr_alert("%s: SGE packet mismatch\n", adapter->name);
964	}
965	if (cause & SGE_INT_FATAL)
966		t1_fatal_err(adapter);
967
968	writel(cause, adapter->regs + A_SG_INT_CAUSE);
969	return 0;
970}
971
972const struct sge_intr_counts *t1_sge_get_intr_counts(const struct sge *sge)
973{
974	return &sge->stats;
975}
976
977void t1_sge_get_port_stats(const struct sge *sge, int port,
978			   struct sge_port_stats *ss)
979{
980	int cpu;
981
982	memset(ss, 0, sizeof(*ss));
983	for_each_possible_cpu(cpu) {
984		struct sge_port_stats *st = per_cpu_ptr(sge->port_stats[port], cpu);
985
986		ss->rx_cso_good += st->rx_cso_good;
987		ss->tx_cso += st->tx_cso;
988		ss->tx_tso += st->tx_tso;
989		ss->tx_need_hdrroom += st->tx_need_hdrroom;
990		ss->vlan_xtract += st->vlan_xtract;
991		ss->vlan_insert += st->vlan_insert;
992	}
993}
994
995/**
996 *	recycle_fl_buf - recycle a free list buffer
997 *	@fl: the free list
998 *	@idx: index of buffer to recycle
999 *
1000 *	Recycles the specified buffer on the given free list by adding it at
1001 *	the next available slot on the list.
1002 */
1003static void recycle_fl_buf(struct freelQ *fl, int idx)
1004{
1005	struct freelQ_e *from = &fl->entries[idx];
1006	struct freelQ_e *to = &fl->entries[fl->pidx];
1007
1008	fl->centries[fl->pidx] = fl->centries[idx];
1009	to->addr_lo = from->addr_lo;
1010	to->addr_hi = from->addr_hi;
1011	to->len_gen = G_CMD_LEN(from->len_gen) | V_CMD_GEN1(fl->genbit);
1012	wmb();
1013	to->gen2 = V_CMD_GEN2(fl->genbit);
1014	fl->credits++;
1015
1016	if (++fl->pidx == fl->size) {
1017		fl->pidx = 0;
1018		fl->genbit ^= 1;
1019	}
1020}
1021
1022static int copybreak __read_mostly = 256;
1023module_param(copybreak, int, 0);
1024MODULE_PARM_DESC(copybreak, "Receive copy threshold");
1025
1026/**
1027 *	get_packet - return the next ingress packet buffer
1028 *	@pdev: the PCI device that received the packet
1029 *	@fl: the SGE free list holding the packet
1030 *	@len: the actual packet length, excluding any SGE padding
1031 *
1032 *	Get the next packet from a free list and complete setup of the
1033 *	sk_buff.  If the packet is small we make a copy and recycle the
1034 *	original buffer, otherwise we use the original buffer itself.  If a
1035 *	positive drop threshold is supplied packets are dropped and their
1036 *	buffers recycled if (a) the number of remaining buffers is under the
1037 *	threshold and the packet is too big to copy, or (b) the packet should
1038 *	be copied but there is no memory for the copy.
1039 */
1040static inline struct sk_buff *get_packet(struct pci_dev *pdev,
1041					 struct freelQ *fl, unsigned int len)
1042{
1043	struct sk_buff *skb;
1044	const struct freelQ_ce *ce = &fl->centries[fl->cidx];
1045
1046	if (len < copybreak) {
1047		skb = netdev_alloc_skb_ip_align(NULL, len);
1048		if (!skb)
1049			goto use_orig_buf;
1050
1051		skb_put(skb, len);
1052		pci_dma_sync_single_for_cpu(pdev,
1053					    dma_unmap_addr(ce, dma_addr),
1054					    dma_unmap_len(ce, dma_len),
1055					    PCI_DMA_FROMDEVICE);
1056		skb_copy_from_linear_data(ce->skb, skb->data, len);
1057		pci_dma_sync_single_for_device(pdev,
1058					       dma_unmap_addr(ce, dma_addr),
1059					       dma_unmap_len(ce, dma_len),
1060					       PCI_DMA_FROMDEVICE);
1061		recycle_fl_buf(fl, fl->cidx);
1062		return skb;
1063	}
1064
1065use_orig_buf:
1066	if (fl->credits < 2) {
1067		recycle_fl_buf(fl, fl->cidx);
1068		return NULL;
1069	}
1070
1071	pci_unmap_single(pdev, dma_unmap_addr(ce, dma_addr),
1072			 dma_unmap_len(ce, dma_len), PCI_DMA_FROMDEVICE);
1073	skb = ce->skb;
1074	prefetch(skb->data);
1075
1076	skb_put(skb, len);
1077	return skb;
1078}
1079
1080/**
1081 *	unexpected_offload - handle an unexpected offload packet
1082 *	@adapter: the adapter
1083 *	@fl: the free list that received the packet
1084 *
1085 *	Called when we receive an unexpected offload packet (e.g., the TOE
1086 *	function is disabled or the card is a NIC).  Prints a message and
1087 *	recycles the buffer.
1088 */
1089static void unexpected_offload(struct adapter *adapter, struct freelQ *fl)
1090{
1091	struct freelQ_ce *ce = &fl->centries[fl->cidx];
1092	struct sk_buff *skb = ce->skb;
1093
1094	pci_dma_sync_single_for_cpu(adapter->pdev, dma_unmap_addr(ce, dma_addr),
1095			    dma_unmap_len(ce, dma_len), PCI_DMA_FROMDEVICE);
1096	pr_err("%s: unexpected offload packet, cmd %u\n",
1097	       adapter->name, *skb->data);
1098	recycle_fl_buf(fl, fl->cidx);
1099}
1100
1101/*
1102 * T1/T2 SGE limits the maximum DMA size per TX descriptor to
1103 * SGE_TX_DESC_MAX_PLEN (16KB). If the PAGE_SIZE is larger than 16KB, the
1104 * stack might send more than SGE_TX_DESC_MAX_PLEN in a contiguous manner.
1105 * Note that the *_large_page_tx_descs stuff will be optimized out when
1106 * PAGE_SIZE <= SGE_TX_DESC_MAX_PLEN.
1107 *
1108 * compute_large_page_descs() computes how many additional descriptors are
1109 * required to break down the stack's request.
1110 */
1111static inline unsigned int compute_large_page_tx_descs(struct sk_buff *skb)
1112{
1113	unsigned int count = 0;
1114
1115	if (PAGE_SIZE > SGE_TX_DESC_MAX_PLEN) {
1116		unsigned int nfrags = skb_shinfo(skb)->nr_frags;
1117		unsigned int i, len = skb_headlen(skb);
1118		while (len > SGE_TX_DESC_MAX_PLEN) {
1119			count++;
1120			len -= SGE_TX_DESC_MAX_PLEN;
1121		}
1122		for (i = 0; nfrags--; i++) {
1123			const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1124			len = skb_frag_size(frag);
1125			while (len > SGE_TX_DESC_MAX_PLEN) {
1126				count++;
1127				len -= SGE_TX_DESC_MAX_PLEN;
1128			}
1129		}
1130	}
1131	return count;
1132}
1133
1134/*
1135 * Write a cmdQ entry.
1136 *
1137 * Since this function writes the 'flags' field, it must not be used to
1138 * write the first cmdQ entry.
1139 */
1140static inline void write_tx_desc(struct cmdQ_e *e, dma_addr_t mapping,
1141				 unsigned int len, unsigned int gen,
1142				 unsigned int eop)
1143{
1144	BUG_ON(len > SGE_TX_DESC_MAX_PLEN);
1145
1146	e->addr_lo = (u32)mapping;
1147	e->addr_hi = (u64)mapping >> 32;
1148	e->len_gen = V_CMD_LEN(len) | V_CMD_GEN1(gen);
1149	e->flags = F_CMD_DATAVALID | V_CMD_EOP(eop) | V_CMD_GEN2(gen);
1150}
1151
1152/*
1153 * See comment for previous function.
1154 *
1155 * write_tx_descs_large_page() writes additional SGE tx descriptors if
1156 * *desc_len exceeds HW's capability.
1157 */
1158static inline unsigned int write_large_page_tx_descs(unsigned int pidx,
1159						     struct cmdQ_e **e,
1160						     struct cmdQ_ce **ce,
1161						     unsigned int *gen,
1162						     dma_addr_t *desc_mapping,
1163						     unsigned int *desc_len,
1164						     unsigned int nfrags,
1165						     struct cmdQ *q)
1166{
1167	if (PAGE_SIZE > SGE_TX_DESC_MAX_PLEN) {
1168		struct cmdQ_e *e1 = *e;
1169		struct cmdQ_ce *ce1 = *ce;
1170
1171		while (*desc_len > SGE_TX_DESC_MAX_PLEN) {
1172			*desc_len -= SGE_TX_DESC_MAX_PLEN;
1173			write_tx_desc(e1, *desc_mapping, SGE_TX_DESC_MAX_PLEN,
1174				      *gen, nfrags == 0 && *desc_len == 0);
1175			ce1->skb = NULL;
1176			dma_unmap_len_set(ce1, dma_len, 0);
1177			*desc_mapping += SGE_TX_DESC_MAX_PLEN;
1178			if (*desc_len) {
1179				ce1++;
1180				e1++;
1181				if (++pidx == q->size) {
1182					pidx = 0;
1183					*gen ^= 1;
1184					ce1 = q->centries;
1185					e1 = q->entries;
1186				}
1187			}
1188		}
1189		*e = e1;
1190		*ce = ce1;
1191	}
1192	return pidx;
1193}
1194
1195/*
1196 * Write the command descriptors to transmit the given skb starting at
1197 * descriptor pidx with the given generation.
1198 */
1199static inline void write_tx_descs(struct adapter *adapter, struct sk_buff *skb,
1200				  unsigned int pidx, unsigned int gen,
1201				  struct cmdQ *q)
1202{
1203	dma_addr_t mapping, desc_mapping;
1204	struct cmdQ_e *e, *e1;
1205	struct cmdQ_ce *ce;
1206	unsigned int i, flags, first_desc_len, desc_len,
1207	    nfrags = skb_shinfo(skb)->nr_frags;
1208
1209	e = e1 = &q->entries[pidx];
1210	ce = &q->centries[pidx];
1211
1212	mapping = pci_map_single(adapter->pdev, skb->data,
1213				 skb_headlen(skb), PCI_DMA_TODEVICE);
1214
1215	desc_mapping = mapping;
1216	desc_len = skb_headlen(skb);
1217
1218	flags = F_CMD_DATAVALID | F_CMD_SOP |
1219	    V_CMD_EOP(nfrags == 0 && desc_len <= SGE_TX_DESC_MAX_PLEN) |
1220	    V_CMD_GEN2(gen);
1221	first_desc_len = (desc_len <= SGE_TX_DESC_MAX_PLEN) ?
1222	    desc_len : SGE_TX_DESC_MAX_PLEN;
1223	e->addr_lo = (u32)desc_mapping;
1224	e->addr_hi = (u64)desc_mapping >> 32;
1225	e->len_gen = V_CMD_LEN(first_desc_len) | V_CMD_GEN1(gen);
1226	ce->skb = NULL;
1227	dma_unmap_len_set(ce, dma_len, 0);
1228
1229	if (PAGE_SIZE > SGE_TX_DESC_MAX_PLEN &&
1230	    desc_len > SGE_TX_DESC_MAX_PLEN) {
1231		desc_mapping += first_desc_len;
1232		desc_len -= first_desc_len;
1233		e1++;
1234		ce++;
1235		if (++pidx == q->size) {
1236			pidx = 0;
1237			gen ^= 1;
1238			e1 = q->entries;
1239			ce = q->centries;
1240		}
1241		pidx = write_large_page_tx_descs(pidx, &e1, &ce, &gen,
1242						 &desc_mapping, &desc_len,
1243						 nfrags, q);
1244
1245		if (likely(desc_len))
1246			write_tx_desc(e1, desc_mapping, desc_len, gen,
1247				      nfrags == 0);
1248	}
1249
1250	ce->skb = NULL;
1251	dma_unmap_addr_set(ce, dma_addr, mapping);
1252	dma_unmap_len_set(ce, dma_len, skb_headlen(skb));
1253
1254	for (i = 0; nfrags--; i++) {
1255		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1256		e1++;
1257		ce++;
1258		if (++pidx == q->size) {
1259			pidx = 0;
1260			gen ^= 1;
1261			e1 = q->entries;
1262			ce = q->centries;
1263		}
1264
1265		mapping = skb_frag_dma_map(&adapter->pdev->dev, frag, 0,
1266					   skb_frag_size(frag), DMA_TO_DEVICE);
1267		desc_mapping = mapping;
1268		desc_len = skb_frag_size(frag);
1269
1270		pidx = write_large_page_tx_descs(pidx, &e1, &ce, &gen,
1271						 &desc_mapping, &desc_len,
1272						 nfrags, q);
1273		if (likely(desc_len))
1274			write_tx_desc(e1, desc_mapping, desc_len, gen,
1275				      nfrags == 0);
1276		ce->skb = NULL;
1277		dma_unmap_addr_set(ce, dma_addr, mapping);
1278		dma_unmap_len_set(ce, dma_len, skb_frag_size(frag));
1279	}
1280	ce->skb = skb;
1281	wmb();
1282	e->flags = flags;
1283}
1284
1285/*
1286 * Clean up completed Tx buffers.
1287 */
1288static inline void reclaim_completed_tx(struct sge *sge, struct cmdQ *q)
1289{
1290	unsigned int reclaim = q->processed - q->cleaned;
1291
1292	if (reclaim) {
1293		pr_debug("reclaim_completed_tx processed:%d cleaned:%d\n",
1294			 q->processed, q->cleaned);
1295		free_cmdQ_buffers(sge, q, reclaim);
1296		q->cleaned += reclaim;
1297	}
1298}
1299
1300/*
1301 * Called from tasklet. Checks the scheduler for any
1302 * pending skbs that can be sent.
1303 */
1304static void restart_sched(unsigned long arg)
1305{
1306	struct sge *sge = (struct sge *) arg;
1307	struct adapter *adapter = sge->adapter;
1308	struct cmdQ *q = &sge->cmdQ[0];
1309	struct sk_buff *skb;
1310	unsigned int credits, queued_skb = 0;
1311
1312	spin_lock(&q->lock);
1313	reclaim_completed_tx(sge, q);
1314
1315	credits = q->size - q->in_use;
1316	pr_debug("restart_sched credits=%d\n", credits);
1317	while ((skb = sched_skb(sge, NULL, credits)) != NULL) {
1318		unsigned int genbit, pidx, count;
1319	        count = 1 + skb_shinfo(skb)->nr_frags;
1320		count += compute_large_page_tx_descs(skb);
1321		q->in_use += count;
1322		genbit = q->genbit;
1323		pidx = q->pidx;
1324		q->pidx += count;
1325		if (q->pidx >= q->size) {
1326			q->pidx -= q->size;
1327			q->genbit ^= 1;
1328		}
1329		write_tx_descs(adapter, skb, pidx, genbit, q);
1330	        credits = q->size - q->in_use;
1331		queued_skb = 1;
1332	}
1333
1334	if (queued_skb) {
1335		clear_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
1336		if (test_and_set_bit(CMDQ_STAT_RUNNING, &q->status) == 0) {
1337			set_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
1338			writel(F_CMDQ0_ENABLE, adapter->regs + A_SG_DOORBELL);
1339		}
1340	}
1341	spin_unlock(&q->lock);
1342}
1343
1344/**
1345 *	sge_rx - process an ingress ethernet packet
1346 *	@sge: the sge structure
1347 *	@fl: the free list that contains the packet buffer
1348 *	@len: the packet length
1349 *
1350 *	Process an ingress ethernet pakcet and deliver it to the stack.
1351 */
1352static void sge_rx(struct sge *sge, struct freelQ *fl, unsigned int len)
1353{
1354	struct sk_buff *skb;
1355	const struct cpl_rx_pkt *p;
1356	struct adapter *adapter = sge->adapter;
1357	struct sge_port_stats *st;
1358	struct net_device *dev;
1359
1360	skb = get_packet(adapter->pdev, fl, len - sge->rx_pkt_pad);
1361	if (unlikely(!skb)) {
1362		sge->stats.rx_drops++;
1363		return;
1364	}
1365
1366	p = (const struct cpl_rx_pkt *) skb->data;
1367	if (p->iff >= adapter->params.nports) {
1368		kfree_skb(skb);
1369		return;
1370	}
1371	__skb_pull(skb, sizeof(*p));
1372
1373	st = this_cpu_ptr(sge->port_stats[p->iff]);
1374	dev = adapter->port[p->iff].dev;
1375
1376	skb->protocol = eth_type_trans(skb, dev);
1377	if ((dev->features & NETIF_F_RXCSUM) && p->csum == 0xffff &&
1378	    skb->protocol == htons(ETH_P_IP) &&
1379	    (skb->data[9] == IPPROTO_TCP || skb->data[9] == IPPROTO_UDP)) {
1380		++st->rx_cso_good;
1381		skb->ip_summed = CHECKSUM_UNNECESSARY;
1382	} else
1383		skb_checksum_none_assert(skb);
1384
1385	if (p->vlan_valid) {
1386		st->vlan_xtract++;
1387		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), ntohs(p->vlan));
1388	}
1389	netif_receive_skb(skb);
1390}
1391
1392/*
1393 * Returns true if a command queue has enough available descriptors that
1394 * we can resume Tx operation after temporarily disabling its packet queue.
1395 */
1396static inline int enough_free_Tx_descs(const struct cmdQ *q)
1397{
1398	unsigned int r = q->processed - q->cleaned;
1399
1400	return q->in_use - r < (q->size >> 1);
1401}
1402
1403/*
1404 * Called when sufficient space has become available in the SGE command queues
1405 * after the Tx packet schedulers have been suspended to restart the Tx path.
1406 */
1407static void restart_tx_queues(struct sge *sge)
1408{
1409	struct adapter *adap = sge->adapter;
1410	int i;
1411
1412	if (!enough_free_Tx_descs(&sge->cmdQ[0]))
1413		return;
1414
1415	for_each_port(adap, i) {
1416		struct net_device *nd = adap->port[i].dev;
1417
1418		if (test_and_clear_bit(nd->if_port, &sge->stopped_tx_queues) &&
1419		    netif_running(nd)) {
1420			sge->stats.cmdQ_restarted[2]++;
1421			netif_wake_queue(nd);
1422		}
1423	}
1424}
1425
1426/*
1427 * update_tx_info is called from the interrupt handler/NAPI to return cmdQ0
1428 * information.
1429 */
1430static unsigned int update_tx_info(struct adapter *adapter,
1431					  unsigned int flags,
1432					  unsigned int pr0)
1433{
1434	struct sge *sge = adapter->sge;
1435	struct cmdQ *cmdq = &sge->cmdQ[0];
1436
1437	cmdq->processed += pr0;
1438	if (flags & (F_FL0_ENABLE | F_FL1_ENABLE)) {
1439		freelQs_empty(sge);
1440		flags &= ~(F_FL0_ENABLE | F_FL1_ENABLE);
1441	}
1442	if (flags & F_CMDQ0_ENABLE) {
1443		clear_bit(CMDQ_STAT_RUNNING, &cmdq->status);
1444
1445		if (cmdq->cleaned + cmdq->in_use != cmdq->processed &&
1446		    !test_and_set_bit(CMDQ_STAT_LAST_PKT_DB, &cmdq->status)) {
1447			set_bit(CMDQ_STAT_RUNNING, &cmdq->status);
1448			writel(F_CMDQ0_ENABLE, adapter->regs + A_SG_DOORBELL);
1449		}
1450		if (sge->tx_sched)
1451			tasklet_hi_schedule(&sge->tx_sched->sched_tsk);
1452
1453		flags &= ~F_CMDQ0_ENABLE;
1454	}
1455
1456	if (unlikely(sge->stopped_tx_queues != 0))
1457		restart_tx_queues(sge);
1458
1459	return flags;
1460}
1461
1462/*
1463 * Process SGE responses, up to the supplied budget.  Returns the number of
1464 * responses processed.  A negative budget is effectively unlimited.
1465 */
1466static int process_responses(struct adapter *adapter, int budget)
1467{
1468	struct sge *sge = adapter->sge;
1469	struct respQ *q = &sge->respQ;
1470	struct respQ_e *e = &q->entries[q->cidx];
1471	int done = 0;
1472	unsigned int flags = 0;
1473	unsigned int cmdq_processed[SGE_CMDQ_N] = {0, 0};
1474
1475	while (done < budget && e->GenerationBit == q->genbit) {
1476		flags |= e->Qsleeping;
1477
1478		cmdq_processed[0] += e->Cmdq0CreditReturn;
1479		cmdq_processed[1] += e->Cmdq1CreditReturn;
1480
1481		/* We batch updates to the TX side to avoid cacheline
1482		 * ping-pong of TX state information on MP where the sender
1483		 * might run on a different CPU than this function...
1484		 */
1485		if (unlikely((flags & F_CMDQ0_ENABLE) || cmdq_processed[0] > 64)) {
1486			flags = update_tx_info(adapter, flags, cmdq_processed[0]);
1487			cmdq_processed[0] = 0;
1488		}
1489
1490		if (unlikely(cmdq_processed[1] > 16)) {
1491			sge->cmdQ[1].processed += cmdq_processed[1];
1492			cmdq_processed[1] = 0;
1493		}
1494
1495		if (likely(e->DataValid)) {
1496			struct freelQ *fl = &sge->freelQ[e->FreelistQid];
1497
1498			BUG_ON(!e->Sop || !e->Eop);
1499			if (unlikely(e->Offload))
1500				unexpected_offload(adapter, fl);
1501			else
1502				sge_rx(sge, fl, e->BufferLength);
1503
1504			++done;
1505
1506			/*
1507			 * Note: this depends on each packet consuming a
1508			 * single free-list buffer; cf. the BUG above.
1509			 */
1510			if (++fl->cidx == fl->size)
1511				fl->cidx = 0;
1512			prefetch(fl->centries[fl->cidx].skb);
1513
1514			if (unlikely(--fl->credits <
1515				     fl->size - SGE_FREEL_REFILL_THRESH))
1516				refill_free_list(sge, fl);
1517		} else
1518			sge->stats.pure_rsps++;
1519
1520		e++;
1521		if (unlikely(++q->cidx == q->size)) {
1522			q->cidx = 0;
1523			q->genbit ^= 1;
1524			e = q->entries;
1525		}
1526		prefetch(e);
1527
1528		if (++q->credits > SGE_RESPQ_REPLENISH_THRES) {
1529			writel(q->credits, adapter->regs + A_SG_RSPQUEUECREDIT);
1530			q->credits = 0;
1531		}
1532	}
1533
1534	flags = update_tx_info(adapter, flags, cmdq_processed[0]);
1535	sge->cmdQ[1].processed += cmdq_processed[1];
1536
1537	return done;
1538}
1539
1540static inline int responses_pending(const struct adapter *adapter)
1541{
1542	const struct respQ *Q = &adapter->sge->respQ;
1543	const struct respQ_e *e = &Q->entries[Q->cidx];
1544
1545	return e->GenerationBit == Q->genbit;
1546}
1547
1548/*
1549 * A simpler version of process_responses() that handles only pure (i.e.,
1550 * non data-carrying) responses.  Such respones are too light-weight to justify
1551 * calling a softirq when using NAPI, so we handle them specially in hard
1552 * interrupt context.  The function is called with a pointer to a response,
1553 * which the caller must ensure is a valid pure response.  Returns 1 if it
1554 * encounters a valid data-carrying response, 0 otherwise.
1555 */
1556static int process_pure_responses(struct adapter *adapter)
1557{
1558	struct sge *sge = adapter->sge;
1559	struct respQ *q = &sge->respQ;
1560	struct respQ_e *e = &q->entries[q->cidx];
1561	const struct freelQ *fl = &sge->freelQ[e->FreelistQid];
1562	unsigned int flags = 0;
1563	unsigned int cmdq_processed[SGE_CMDQ_N] = {0, 0};
1564
1565	prefetch(fl->centries[fl->cidx].skb);
1566	if (e->DataValid)
1567		return 1;
1568
1569	do {
1570		flags |= e->Qsleeping;
1571
1572		cmdq_processed[0] += e->Cmdq0CreditReturn;
1573		cmdq_processed[1] += e->Cmdq1CreditReturn;
1574
1575		e++;
1576		if (unlikely(++q->cidx == q->size)) {
1577			q->cidx = 0;
1578			q->genbit ^= 1;
1579			e = q->entries;
1580		}
1581		prefetch(e);
1582
1583		if (++q->credits > SGE_RESPQ_REPLENISH_THRES) {
1584			writel(q->credits, adapter->regs + A_SG_RSPQUEUECREDIT);
1585			q->credits = 0;
1586		}
1587		sge->stats.pure_rsps++;
1588	} while (e->GenerationBit == q->genbit && !e->DataValid);
1589
1590	flags = update_tx_info(adapter, flags, cmdq_processed[0]);
1591	sge->cmdQ[1].processed += cmdq_processed[1];
1592
1593	return e->GenerationBit == q->genbit;
1594}
1595
1596/*
1597 * Handler for new data events when using NAPI.  This does not need any locking
1598 * or protection from interrupts as data interrupts are off at this point and
1599 * other adapter interrupts do not interfere.
1600 */
1601int t1_poll(struct napi_struct *napi, int budget)
1602{
1603	struct adapter *adapter = container_of(napi, struct adapter, napi);
1604	int work_done = process_responses(adapter, budget);
1605
1606	if (likely(work_done < budget)) {
1607		napi_complete(napi);
1608		writel(adapter->sge->respQ.cidx,
1609		       adapter->regs + A_SG_SLEEPING);
1610	}
1611	return work_done;
1612}
1613
1614irqreturn_t t1_interrupt(int irq, void *data)
1615{
1616	struct adapter *adapter = data;
1617	struct sge *sge = adapter->sge;
1618	int handled;
1619
1620	if (likely(responses_pending(adapter))) {
1621		writel(F_PL_INTR_SGE_DATA, adapter->regs + A_PL_CAUSE);
1622
1623		if (napi_schedule_prep(&adapter->napi)) {
1624			if (process_pure_responses(adapter))
1625				__napi_schedule(&adapter->napi);
1626			else {
1627				/* no data, no NAPI needed */
1628				writel(sge->respQ.cidx, adapter->regs + A_SG_SLEEPING);
1629				/* undo schedule_prep */
1630				napi_enable(&adapter->napi);
1631			}
1632		}
1633		return IRQ_HANDLED;
1634	}
1635
1636	spin_lock(&adapter->async_lock);
1637	handled = t1_slow_intr_handler(adapter);
1638	spin_unlock(&adapter->async_lock);
1639
1640	if (!handled)
1641		sge->stats.unhandled_irqs++;
1642
1643	return IRQ_RETVAL(handled != 0);
1644}
1645
1646/*
1647 * Enqueues the sk_buff onto the cmdQ[qid] and has hardware fetch it.
1648 *
1649 * The code figures out how many entries the sk_buff will require in the
1650 * cmdQ and updates the cmdQ data structure with the state once the enqueue
1651 * has complete. Then, it doesn't access the global structure anymore, but
1652 * uses the corresponding fields on the stack. In conjunction with a spinlock
1653 * around that code, we can make the function reentrant without holding the
1654 * lock when we actually enqueue (which might be expensive, especially on
1655 * architectures with IO MMUs).
1656 *
1657 * This runs with softirqs disabled.
1658 */
1659static int t1_sge_tx(struct sk_buff *skb, struct adapter *adapter,
1660		     unsigned int qid, struct net_device *dev)
1661{
1662	struct sge *sge = adapter->sge;
1663	struct cmdQ *q = &sge->cmdQ[qid];
1664	unsigned int credits, pidx, genbit, count, use_sched_skb = 0;
1665
1666	if (!spin_trylock(&q->lock))
1667		return NETDEV_TX_LOCKED;
1668
1669	reclaim_completed_tx(sge, q);
1670
1671	pidx = q->pidx;
1672	credits = q->size - q->in_use;
1673	count = 1 + skb_shinfo(skb)->nr_frags;
1674	count += compute_large_page_tx_descs(skb);
1675
1676	/* Ethernet packet */
1677	if (unlikely(credits < count)) {
1678		if (!netif_queue_stopped(dev)) {
1679			netif_stop_queue(dev);
1680			set_bit(dev->if_port, &sge->stopped_tx_queues);
1681			sge->stats.cmdQ_full[2]++;
1682			pr_err("%s: Tx ring full while queue awake!\n",
1683			       adapter->name);
1684		}
1685		spin_unlock(&q->lock);
1686		return NETDEV_TX_BUSY;
1687	}
1688
1689	if (unlikely(credits - count < q->stop_thres)) {
1690		netif_stop_queue(dev);
1691		set_bit(dev->if_port, &sge->stopped_tx_queues);
1692		sge->stats.cmdQ_full[2]++;
1693	}
1694
1695	/* T204 cmdQ0 skbs that are destined for a certain port have to go
1696	 * through the scheduler.
1697	 */
1698	if (sge->tx_sched && !qid && skb->dev) {
1699use_sched:
1700		use_sched_skb = 1;
1701		/* Note that the scheduler might return a different skb than
1702		 * the one passed in.
1703		 */
1704		skb = sched_skb(sge, skb, credits);
1705		if (!skb) {
1706			spin_unlock(&q->lock);
1707			return NETDEV_TX_OK;
1708		}
1709		pidx = q->pidx;
1710		count = 1 + skb_shinfo(skb)->nr_frags;
1711		count += compute_large_page_tx_descs(skb);
1712	}
1713
1714	q->in_use += count;
1715	genbit = q->genbit;
1716	pidx = q->pidx;
1717	q->pidx += count;
1718	if (q->pidx >= q->size) {
1719		q->pidx -= q->size;
1720		q->genbit ^= 1;
1721	}
1722	spin_unlock(&q->lock);
1723
1724	write_tx_descs(adapter, skb, pidx, genbit, q);
1725
1726	/*
1727	 * We always ring the doorbell for cmdQ1.  For cmdQ0, we only ring
1728	 * the doorbell if the Q is asleep. There is a natural race, where
1729	 * the hardware is going to sleep just after we checked, however,
1730	 * then the interrupt handler will detect the outstanding TX packet
1731	 * and ring the doorbell for us.
1732	 */
1733	if (qid)
1734		doorbell_pio(adapter, F_CMDQ1_ENABLE);
1735	else {
1736		clear_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
1737		if (test_and_set_bit(CMDQ_STAT_RUNNING, &q->status) == 0) {
1738			set_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
1739			writel(F_CMDQ0_ENABLE, adapter->regs + A_SG_DOORBELL);
1740		}
1741	}
1742
1743	if (use_sched_skb) {
1744		if (spin_trylock(&q->lock)) {
1745			credits = q->size - q->in_use;
1746			skb = NULL;
1747			goto use_sched;
1748		}
1749	}
1750	return NETDEV_TX_OK;
1751}
1752
1753#define MK_ETH_TYPE_MSS(type, mss) (((mss) & 0x3FFF) | ((type) << 14))
1754
1755/*
1756 *	eth_hdr_len - return the length of an Ethernet header
1757 *	@data: pointer to the start of the Ethernet header
1758 *
1759 *	Returns the length of an Ethernet header, including optional VLAN tag.
1760 */
1761static inline int eth_hdr_len(const void *data)
1762{
1763	const struct ethhdr *e = data;
1764
1765	return e->h_proto == htons(ETH_P_8021Q) ? VLAN_ETH_HLEN : ETH_HLEN;
1766}
1767
1768/*
1769 * Adds the CPL header to the sk_buff and passes it to t1_sge_tx.
1770 */
1771netdev_tx_t t1_start_xmit(struct sk_buff *skb, struct net_device *dev)
1772{
1773	struct adapter *adapter = dev->ml_priv;
1774	struct sge *sge = adapter->sge;
1775	struct sge_port_stats *st = this_cpu_ptr(sge->port_stats[dev->if_port]);
1776	struct cpl_tx_pkt *cpl;
1777	struct sk_buff *orig_skb = skb;
1778	int ret;
1779
1780	if (skb->protocol == htons(ETH_P_CPL5))
1781		goto send;
1782
1783	/*
1784	 * We are using a non-standard hard_header_len.
1785	 * Allocate more header room in the rare cases it is not big enough.
1786	 */
1787	if (unlikely(skb_headroom(skb) < dev->hard_header_len - ETH_HLEN)) {
1788		skb = skb_realloc_headroom(skb, sizeof(struct cpl_tx_pkt_lso));
1789		++st->tx_need_hdrroom;
1790		dev_kfree_skb_any(orig_skb);
1791		if (!skb)
1792			return NETDEV_TX_OK;
1793	}
1794
1795	if (skb_shinfo(skb)->gso_size) {
1796		int eth_type;
1797		struct cpl_tx_pkt_lso *hdr;
1798
1799		++st->tx_tso;
1800
1801		eth_type = skb_network_offset(skb) == ETH_HLEN ?
1802			CPL_ETH_II : CPL_ETH_II_VLAN;
1803
1804		hdr = (struct cpl_tx_pkt_lso *)skb_push(skb, sizeof(*hdr));
1805		hdr->opcode = CPL_TX_PKT_LSO;
1806		hdr->ip_csum_dis = hdr->l4_csum_dis = 0;
1807		hdr->ip_hdr_words = ip_hdr(skb)->ihl;
1808		hdr->tcp_hdr_words = tcp_hdr(skb)->doff;
1809		hdr->eth_type_mss = htons(MK_ETH_TYPE_MSS(eth_type,
1810							  skb_shinfo(skb)->gso_size));
1811		hdr->len = htonl(skb->len - sizeof(*hdr));
1812		cpl = (struct cpl_tx_pkt *)hdr;
1813	} else {
1814		/*
1815		 * Packets shorter than ETH_HLEN can break the MAC, drop them
1816		 * early.  Also, we may get oversized packets because some
1817		 * parts of the kernel don't handle our unusual hard_header_len
1818		 * right, drop those too.
1819		 */
1820		if (unlikely(skb->len < ETH_HLEN ||
1821			     skb->len > dev->mtu + eth_hdr_len(skb->data))) {
1822			netdev_dbg(dev, "packet size %d hdr %d mtu%d\n",
1823				   skb->len, eth_hdr_len(skb->data), dev->mtu);
1824			dev_kfree_skb_any(skb);
1825			return NETDEV_TX_OK;
1826		}
1827
1828		if (skb->ip_summed == CHECKSUM_PARTIAL &&
1829		    ip_hdr(skb)->protocol == IPPROTO_UDP) {
1830			if (unlikely(skb_checksum_help(skb))) {
1831				netdev_dbg(dev, "unable to do udp checksum\n");
1832				dev_kfree_skb_any(skb);
1833				return NETDEV_TX_OK;
1834			}
1835		}
1836
1837		/* Hmmm, assuming to catch the gratious arp... and we'll use
1838		 * it to flush out stuck espi packets...
1839		 */
1840		if ((unlikely(!adapter->sge->espibug_skb[dev->if_port]))) {
1841			if (skb->protocol == htons(ETH_P_ARP) &&
1842			    arp_hdr(skb)->ar_op == htons(ARPOP_REQUEST)) {
1843				adapter->sge->espibug_skb[dev->if_port] = skb;
1844				/* We want to re-use this skb later. We
1845				 * simply bump the reference count and it
1846				 * will not be freed...
1847				 */
1848				skb = skb_get(skb);
1849			}
1850		}
1851
1852		cpl = (struct cpl_tx_pkt *)__skb_push(skb, sizeof(*cpl));
1853		cpl->opcode = CPL_TX_PKT;
1854		cpl->ip_csum_dis = 1;    /* SW calculates IP csum */
1855		cpl->l4_csum_dis = skb->ip_summed == CHECKSUM_PARTIAL ? 0 : 1;
1856		/* the length field isn't used so don't bother setting it */
1857
1858		st->tx_cso += (skb->ip_summed == CHECKSUM_PARTIAL);
1859	}
1860	cpl->iff = dev->if_port;
1861
1862	if (vlan_tx_tag_present(skb)) {
1863		cpl->vlan_valid = 1;
1864		cpl->vlan = htons(vlan_tx_tag_get(skb));
1865		st->vlan_insert++;
1866	} else
1867		cpl->vlan_valid = 0;
1868
1869send:
1870	ret = t1_sge_tx(skb, adapter, 0, dev);
1871
1872	/* If transmit busy, and we reallocated skb's due to headroom limit,
1873	 * then silently discard to avoid leak.
1874	 */
1875	if (unlikely(ret != NETDEV_TX_OK && skb != orig_skb)) {
1876		dev_kfree_skb_any(skb);
1877		ret = NETDEV_TX_OK;
1878	}
1879	return ret;
1880}
1881
1882/*
1883 * Callback for the Tx buffer reclaim timer.  Runs with softirqs disabled.
1884 */
1885static void sge_tx_reclaim_cb(unsigned long data)
1886{
1887	int i;
1888	struct sge *sge = (struct sge *)data;
1889
1890	for (i = 0; i < SGE_CMDQ_N; ++i) {
1891		struct cmdQ *q = &sge->cmdQ[i];
1892
1893		if (!spin_trylock(&q->lock))
1894			continue;
1895
1896		reclaim_completed_tx(sge, q);
1897		if (i == 0 && q->in_use) {    /* flush pending credits */
1898			writel(F_CMDQ0_ENABLE, sge->adapter->regs + A_SG_DOORBELL);
1899		}
1900		spin_unlock(&q->lock);
1901	}
1902	mod_timer(&sge->tx_reclaim_timer, jiffies + TX_RECLAIM_PERIOD);
1903}
1904
1905/*
1906 * Propagate changes of the SGE coalescing parameters to the HW.
1907 */
1908int t1_sge_set_coalesce_params(struct sge *sge, struct sge_params *p)
1909{
1910	sge->fixed_intrtimer = p->rx_coalesce_usecs *
1911		core_ticks_per_usec(sge->adapter);
1912	writel(sge->fixed_intrtimer, sge->adapter->regs + A_SG_INTRTIMER);
1913	return 0;
1914}
1915
1916/*
1917 * Allocates both RX and TX resources and configures the SGE. However,
1918 * the hardware is not enabled yet.
1919 */
1920int t1_sge_configure(struct sge *sge, struct sge_params *p)
1921{
1922	if (alloc_rx_resources(sge, p))
1923		return -ENOMEM;
1924	if (alloc_tx_resources(sge, p)) {
1925		free_rx_resources(sge);
1926		return -ENOMEM;
1927	}
1928	configure_sge(sge, p);
1929
1930	/*
1931	 * Now that we have sized the free lists calculate the payload
1932	 * capacity of the large buffers.  Other parts of the driver use
1933	 * this to set the max offload coalescing size so that RX packets
1934	 * do not overflow our large buffers.
1935	 */
1936	p->large_buf_capacity = jumbo_payload_capacity(sge);
1937	return 0;
1938}
1939
1940/*
1941 * Disables the DMA engine.
1942 */
1943void t1_sge_stop(struct sge *sge)
1944{
1945	int i;
1946	writel(0, sge->adapter->regs + A_SG_CONTROL);
1947	readl(sge->adapter->regs + A_SG_CONTROL); /* flush */
1948
1949	if (is_T2(sge->adapter))
1950		del_timer_sync(&sge->espibug_timer);
1951
1952	del_timer_sync(&sge->tx_reclaim_timer);
1953	if (sge->tx_sched)
1954		tx_sched_stop(sge);
1955
1956	for (i = 0; i < MAX_NPORTS; i++)
1957		kfree_skb(sge->espibug_skb[i]);
1958}
1959
1960/*
1961 * Enables the DMA engine.
1962 */
1963void t1_sge_start(struct sge *sge)
1964{
1965	refill_free_list(sge, &sge->freelQ[0]);
1966	refill_free_list(sge, &sge->freelQ[1]);
1967
1968	writel(sge->sge_control, sge->adapter->regs + A_SG_CONTROL);
1969	doorbell_pio(sge->adapter, F_FL0_ENABLE | F_FL1_ENABLE);
1970	readl(sge->adapter->regs + A_SG_CONTROL); /* flush */
1971
1972	mod_timer(&sge->tx_reclaim_timer, jiffies + TX_RECLAIM_PERIOD);
1973
1974	if (is_T2(sge->adapter))
1975		mod_timer(&sge->espibug_timer, jiffies + sge->espibug_timeout);
1976}
1977
1978/*
1979 * Callback for the T2 ESPI 'stuck packet feature' workaorund
1980 */
1981static void espibug_workaround_t204(unsigned long data)
1982{
1983	struct adapter *adapter = (struct adapter *)data;
1984	struct sge *sge = adapter->sge;
1985	unsigned int nports = adapter->params.nports;
1986	u32 seop[MAX_NPORTS];
1987
1988	if (adapter->open_device_map & PORT_MASK) {
1989		int i;
1990
1991		if (t1_espi_get_mon_t204(adapter, &(seop[0]), 0) < 0)
1992			return;
1993
1994		for (i = 0; i < nports; i++) {
1995			struct sk_buff *skb = sge->espibug_skb[i];
1996
1997			if (!netif_running(adapter->port[i].dev) ||
1998			    netif_queue_stopped(adapter->port[i].dev) ||
1999			    !seop[i] || ((seop[i] & 0xfff) != 0) || !skb)
2000				continue;
2001
2002			if (!skb->cb[0]) {
2003				skb_copy_to_linear_data_offset(skb,
2004						    sizeof(struct cpl_tx_pkt),
2005							       ch_mac_addr,
2006							       ETH_ALEN);
2007				skb_copy_to_linear_data_offset(skb,
2008							       skb->len - 10,
2009							       ch_mac_addr,
2010							       ETH_ALEN);
2011				skb->cb[0] = 0xff;
2012			}
2013
2014			/* bump the reference count to avoid freeing of
2015			 * the skb once the DMA has completed.
2016			 */
2017			skb = skb_get(skb);
2018			t1_sge_tx(skb, adapter, 0, adapter->port[i].dev);
2019		}
2020	}
2021	mod_timer(&sge->espibug_timer, jiffies + sge->espibug_timeout);
2022}
2023
2024static void espibug_workaround(unsigned long data)
2025{
2026	struct adapter *adapter = (struct adapter *)data;
2027	struct sge *sge = adapter->sge;
2028
2029	if (netif_running(adapter->port[0].dev)) {
2030	        struct sk_buff *skb = sge->espibug_skb[0];
2031	        u32 seop = t1_espi_get_mon(adapter, 0x930, 0);
2032
2033	        if ((seop & 0xfff0fff) == 0xfff && skb) {
2034	                if (!skb->cb[0]) {
2035	                        skb_copy_to_linear_data_offset(skb,
2036						     sizeof(struct cpl_tx_pkt),
2037							       ch_mac_addr,
2038							       ETH_ALEN);
2039	                        skb_copy_to_linear_data_offset(skb,
2040							       skb->len - 10,
2041							       ch_mac_addr,
2042							       ETH_ALEN);
2043	                        skb->cb[0] = 0xff;
2044	                }
2045
2046	                /* bump the reference count to avoid freeing of the
2047	                 * skb once the DMA has completed.
2048	                 */
2049	                skb = skb_get(skb);
2050	                t1_sge_tx(skb, adapter, 0, adapter->port[0].dev);
2051	        }
2052	}
2053	mod_timer(&sge->espibug_timer, jiffies + sge->espibug_timeout);
2054}
2055
2056/*
2057 * Creates a t1_sge structure and returns suggested resource parameters.
2058 */
2059struct sge *t1_sge_create(struct adapter *adapter, struct sge_params *p)
2060{
2061	struct sge *sge = kzalloc(sizeof(*sge), GFP_KERNEL);
2062	int i;
2063
2064	if (!sge)
2065		return NULL;
2066
2067	sge->adapter = adapter;
2068	sge->netdev = adapter->port[0].dev;
2069	sge->rx_pkt_pad = t1_is_T1B(adapter) ? 0 : 2;
2070	sge->jumbo_fl = t1_is_T1B(adapter) ? 1 : 0;
2071
2072	for_each_port(adapter, i) {
2073		sge->port_stats[i] = alloc_percpu(struct sge_port_stats);
2074		if (!sge->port_stats[i])
2075			goto nomem_port;
2076	}
2077
2078	init_timer(&sge->tx_reclaim_timer);
2079	sge->tx_reclaim_timer.data = (unsigned long)sge;
2080	sge->tx_reclaim_timer.function = sge_tx_reclaim_cb;
2081
2082	if (is_T2(sge->adapter)) {
2083		init_timer(&sge->espibug_timer);
2084
2085		if (adapter->params.nports > 1) {
2086			tx_sched_init(sge);
2087			sge->espibug_timer.function = espibug_workaround_t204;
2088		} else
2089			sge->espibug_timer.function = espibug_workaround;
2090		sge->espibug_timer.data = (unsigned long)sge->adapter;
2091
2092		sge->espibug_timeout = 1;
2093		/* for T204, every 10ms */
2094		if (adapter->params.nports > 1)
2095			sge->espibug_timeout = HZ/100;
2096	}
2097
2098
2099	p->cmdQ_size[0] = SGE_CMDQ0_E_N;
2100	p->cmdQ_size[1] = SGE_CMDQ1_E_N;
2101	p->freelQ_size[!sge->jumbo_fl] = SGE_FREEL_SIZE;
2102	p->freelQ_size[sge->jumbo_fl] = SGE_JUMBO_FREEL_SIZE;
2103	if (sge->tx_sched) {
2104		if (board_info(sge->adapter)->board == CHBT_BOARD_CHT204)
2105			p->rx_coalesce_usecs = 15;
2106		else
2107			p->rx_coalesce_usecs = 50;
2108	} else
2109		p->rx_coalesce_usecs = 50;
2110
2111	p->coalesce_enable = 0;
2112	p->sample_interval_usecs = 0;
2113
2114	return sge;
2115nomem_port:
2116	while (i >= 0) {
2117		free_percpu(sge->port_stats[i]);
2118		--i;
2119	}
2120	kfree(sge);
2121	return NULL;
2122
2123}
2124