ac7c46b0eeb4c9c33fdf86554b82b9d6ef7ca42e
[linux-3.10.git] / drivers / net / chelsio / sge.c
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
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_COPY_THRES       256
75 #define SGE_RX_SM_BUF_SIZE      1536
76 #define SGE_TX_DESC_MAX_PLEN    16384
77
78 # define SGE_RX_DROP_THRES 2
79
80 #define SGE_RESPQ_REPLENISH_THRES (SGE_RESPQ_E_N / 4)
81
82 /*
83  * Period of the TX buffer reclaim timer.  This timer does not need to run
84  * frequently as TX buffers are usually reclaimed by new TX packets.
85  */
86 #define TX_RECLAIM_PERIOD (HZ / 4)
87
88 #ifndef NET_IP_ALIGN
89 # define NET_IP_ALIGN 2
90 #endif
91
92 #define M_CMD_LEN       0x7fffffff
93 #define V_CMD_LEN(v)    (v)
94 #define G_CMD_LEN(v)    ((v) & M_CMD_LEN)
95 #define V_CMD_GEN1(v)   ((v) << 31)
96 #define V_CMD_GEN2(v)   (v)
97 #define F_CMD_DATAVALID (1 << 1)
98 #define F_CMD_SOP       (1 << 2)
99 #define V_CMD_EOP(v)    ((v) << 3)
100
101 /*
102  * Command queue, receive buffer list, and response queue descriptors.
103  */
104 #if defined(__BIG_ENDIAN_BITFIELD)
105 struct cmdQ_e {
106         u32 addr_lo;
107         u32 len_gen;
108         u32 flags;
109         u32 addr_hi;
110 };
111
112 struct freelQ_e {
113         u32 addr_lo;
114         u32 len_gen;
115         u32 gen2;
116         u32 addr_hi;
117 };
118
119 struct respQ_e {
120         u32 Qsleeping           : 4;
121         u32 Cmdq1CreditReturn   : 5;
122         u32 Cmdq1DmaComplete    : 5;
123         u32 Cmdq0CreditReturn   : 5;
124         u32 Cmdq0DmaComplete    : 5;
125         u32 FreelistQid         : 2;
126         u32 CreditValid         : 1;
127         u32 DataValid           : 1;
128         u32 Offload             : 1;
129         u32 Eop                 : 1;
130         u32 Sop                 : 1;
131         u32 GenerationBit       : 1;
132         u32 BufferLength;
133 };
134 #elif defined(__LITTLE_ENDIAN_BITFIELD)
135 struct cmdQ_e {
136         u32 len_gen;
137         u32 addr_lo;
138         u32 addr_hi;
139         u32 flags;
140 };
141
142 struct freelQ_e {
143         u32 len_gen;
144         u32 addr_lo;
145         u32 addr_hi;
146         u32 gen2;
147 };
148
149 struct respQ_e {
150         u32 BufferLength;
151         u32 GenerationBit       : 1;
152         u32 Sop                 : 1;
153         u32 Eop                 : 1;
154         u32 Offload             : 1;
155         u32 DataValid           : 1;
156         u32 CreditValid         : 1;
157         u32 FreelistQid         : 2;
158         u32 Cmdq0DmaComplete    : 5;
159         u32 Cmdq0CreditReturn   : 5;
160         u32 Cmdq1DmaComplete    : 5;
161         u32 Cmdq1CreditReturn   : 5;
162         u32 Qsleeping           : 4;
163 } ;
164 #endif
165
166 /*
167  * SW Context Command and Freelist Queue Descriptors
168  */
169 struct cmdQ_ce {
170         struct sk_buff *skb;
171         DECLARE_PCI_UNMAP_ADDR(dma_addr);
172         DECLARE_PCI_UNMAP_LEN(dma_len);
173 };
174
175 struct freelQ_ce {
176         struct sk_buff *skb;
177         DECLARE_PCI_UNMAP_ADDR(dma_addr);
178         DECLARE_PCI_UNMAP_LEN(dma_len);
179 };
180
181 /*
182  * SW command, freelist and response rings
183  */
184 struct cmdQ {
185         unsigned long   status;         /* HW DMA fetch status */
186         unsigned int    in_use;         /* # of in-use command descriptors */
187         unsigned int    size;           /* # of descriptors */
188         unsigned int    processed;      /* total # of descs HW has processed */
189         unsigned int    cleaned;        /* total # of descs SW has reclaimed */
190         unsigned int    stop_thres;     /* SW TX queue suspend threshold */
191         u16             pidx;           /* producer index (SW) */
192         u16             cidx;           /* consumer index (HW) */
193         u8              genbit;         /* current generation (=valid) bit */
194         u8              sop;            /* is next entry start of packet? */
195         struct cmdQ_e  *entries;        /* HW command descriptor Q */
196         struct cmdQ_ce *centries;       /* SW command context descriptor Q */
197         dma_addr_t      dma_addr;       /* DMA addr HW command descriptor Q */
198         spinlock_t      lock;           /* Lock to protect cmdQ enqueuing */
199 };
200
201 struct freelQ {
202         unsigned int    credits;        /* # of available RX buffers */
203         unsigned int    size;           /* free list capacity */
204         u16             pidx;           /* producer index (SW) */
205         u16             cidx;           /* consumer index (HW) */
206         u16             rx_buffer_size; /* Buffer size on this free list */
207         u16             dma_offset;     /* DMA offset to align IP headers */
208         u16             recycleq_idx;   /* skb recycle q to use */
209         u8              genbit;         /* current generation (=valid) bit */
210         struct freelQ_e *entries;       /* HW freelist descriptor Q */
211         struct freelQ_ce *centries;     /* SW freelist context descriptor Q */
212         dma_addr_t      dma_addr;       /* DMA addr HW freelist descriptor Q */
213 };
214
215 struct respQ {
216         unsigned int    credits;        /* credits to be returned to SGE */
217         unsigned int    size;           /* # of response Q descriptors */
218         u16             cidx;           /* consumer index (SW) */
219         u8              genbit;         /* current generation(=valid) bit */
220         struct respQ_e *entries;        /* HW response descriptor Q */
221         dma_addr_t      dma_addr;       /* DMA addr HW response descriptor Q */
222 };
223
224 /* Bit flags for cmdQ.status */
225 enum {
226         CMDQ_STAT_RUNNING = 1,          /* fetch engine is running */
227         CMDQ_STAT_LAST_PKT_DB = 2       /* last packet rung the doorbell */
228 };
229
230 /* T204 TX SW scheduler */
231
232 /* Per T204 TX port */
233 struct sched_port {
234         unsigned int    avail;          /* available bits - quota */
235         unsigned int    drain_bits_per_1024ns; /* drain rate */
236         unsigned int    speed;          /* drain rate, mbps */
237         unsigned int    mtu;            /* mtu size */
238         struct sk_buff_head skbq;       /* pending skbs */
239 };
240
241 /* Per T204 device */
242 struct sched {
243         ktime_t         last_updated;   /* last time quotas were computed */
244         unsigned int    max_avail;      /* max bits to be sent to any port */
245         unsigned int    port;           /* port index (round robin ports) */
246         unsigned int    num;            /* num skbs in per port queues */
247         struct sched_port p[MAX_NPORTS];
248         struct tasklet_struct sched_tsk;/* tasklet used to run scheduler */
249 };
250 static void restart_sched(unsigned long);
251
252
253 /*
254  * Main SGE data structure
255  *
256  * Interrupts are handled by a single CPU and it is likely that on a MP system
257  * the application is migrated to another CPU. In that scenario, we try to
258  * seperate the RX(in irq context) and TX state in order to decrease memory
259  * contention.
260  */
261 struct sge {
262         struct adapter *adapter;        /* adapter backpointer */
263         struct net_device *netdev;      /* netdevice backpointer */
264         struct freelQ   freelQ[SGE_FREELQ_N]; /* buffer free lists */
265         struct respQ    respQ;          /* response Q */
266         unsigned long   stopped_tx_queues; /* bitmap of suspended Tx queues */
267         unsigned int    rx_pkt_pad;     /* RX padding for L2 packets */
268         unsigned int    jumbo_fl;       /* jumbo freelist Q index */
269         unsigned int    intrtimer_nres; /* no-resource interrupt timer */
270         unsigned int    fixed_intrtimer;/* non-adaptive interrupt timer */
271         struct timer_list tx_reclaim_timer; /* reclaims TX buffers */
272         struct timer_list espibug_timer;
273         unsigned long   espibug_timeout;
274         struct sk_buff  *espibug_skb[MAX_NPORTS];
275         u32             sge_control;    /* shadow value of sge control reg */
276         struct sge_intr_counts stats;
277         struct sge_port_stats *port_stats[MAX_NPORTS];
278         struct sched    *tx_sched;
279         struct cmdQ cmdQ[SGE_CMDQ_N] ____cacheline_aligned_in_smp;
280 };
281
282 /*
283  * stop tasklet and free all pending skb's
284  */
285 static void tx_sched_stop(struct sge *sge)
286 {
287         struct sched *s = sge->tx_sched;
288         int i;
289
290         tasklet_kill(&s->sched_tsk);
291
292         for (i = 0; i < MAX_NPORTS; i++)
293                 __skb_queue_purge(&s->p[s->port].skbq);
294 }
295
296 /*
297  * t1_sched_update_parms() is called when the MTU or link speed changes. It
298  * re-computes scheduler parameters to scope with the change.
299  */
300 unsigned int t1_sched_update_parms(struct sge *sge, unsigned int port,
301                                    unsigned int mtu, unsigned int speed)
302 {
303         struct sched *s = sge->tx_sched;
304         struct sched_port *p = &s->p[port];
305         unsigned int max_avail_segs;
306
307         pr_debug("t1_sched_update_params mtu=%d speed=%d\n", mtu, speed);
308         if (speed)
309                 p->speed = speed;
310         if (mtu)
311                 p->mtu = mtu;
312
313         if (speed || mtu) {
314                 unsigned long long drain = 1024ULL * p->speed * (p->mtu - 40);
315                 do_div(drain, (p->mtu + 50) * 1000);
316                 p->drain_bits_per_1024ns = (unsigned int) drain;
317
318                 if (p->speed < 1000)
319                         p->drain_bits_per_1024ns =
320                                 90 * p->drain_bits_per_1024ns / 100;
321         }
322
323         if (board_info(sge->adapter)->board == CHBT_BOARD_CHT204) {
324                 p->drain_bits_per_1024ns -= 16;
325                 s->max_avail = max(4096U, p->mtu + 16 + 14 + 4);
326                 max_avail_segs = max(1U, 4096 / (p->mtu - 40));
327         } else {
328                 s->max_avail = 16384;
329                 max_avail_segs = max(1U, 9000 / (p->mtu - 40));
330         }
331
332         pr_debug("t1_sched_update_parms: mtu %u speed %u max_avail %u "
333                  "max_avail_segs %u drain_bits_per_1024ns %u\n", p->mtu,
334                  p->speed, s->max_avail, max_avail_segs,
335                  p->drain_bits_per_1024ns);
336
337         return max_avail_segs * (p->mtu - 40);
338 }
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
368 /*
369  * get_clock() implements a ns clock (see ktime_get)
370  */
371 static inline ktime_t get_clock(void)
372 {
373         struct timespec ts;
374
375         ktime_get_ts(&ts);
376         return timespec_to_ktime(ts);
377 }
378
379 /*
380  * tx_sched_init() allocates resources and does basic initialization.
381  */
382 static int tx_sched_init(struct sge *sge)
383 {
384         struct sched *s;
385         int i;
386
387         s = kzalloc(sizeof (struct sched), GFP_KERNEL);
388         if (!s)
389                 return -ENOMEM;
390
391         pr_debug("tx_sched_init\n");
392         tasklet_init(&s->sched_tsk, restart_sched, (unsigned long) sge);
393         sge->tx_sched = s;
394
395         for (i = 0; i < MAX_NPORTS; i++) {
396                 skb_queue_head_init(&s->p[i].skbq);
397                 t1_sched_update_parms(sge, i, 1500, 1000);
398         }
399
400         return 0;
401 }
402
403 /*
404  * sched_update_avail() computes the delta since the last time it was called
405  * and updates the per port quota (number of bits that can be sent to the any
406  * port).
407  */
408 static inline int sched_update_avail(struct sge *sge)
409 {
410         struct sched *s = sge->tx_sched;
411         ktime_t now = get_clock();
412         unsigned int i;
413         long long delta_time_ns;
414
415         delta_time_ns = ktime_to_ns(ktime_sub(now, s->last_updated));
416
417         pr_debug("sched_update_avail delta=%lld\n", delta_time_ns);
418         if (delta_time_ns < 15000)
419                 return 0;
420
421         for (i = 0; i < MAX_NPORTS; i++) {
422                 struct sched_port *p = &s->p[i];
423                 unsigned int delta_avail;
424
425                 delta_avail = (p->drain_bits_per_1024ns * delta_time_ns) >> 13;
426                 p->avail = min(p->avail + delta_avail, s->max_avail);
427         }
428
429         s->last_updated = now;
430
431         return 1;
432 }
433
434 /*
435  * sched_skb() is called from two different places. In the tx path, any
436  * packet generating load on an output port will call sched_skb()
437  * (skb != NULL). In addition, sched_skb() is called from the irq/soft irq
438  * context (skb == NULL).
439  * The scheduler only returns a skb (which will then be sent) if the
440  * length of the skb is <= the current quota of the output port.
441  */
442 static struct sk_buff *sched_skb(struct sge *sge, struct sk_buff *skb,
443                                 unsigned int credits)
444 {
445         struct sched *s = sge->tx_sched;
446         struct sk_buff_head *skbq;
447         unsigned int i, len, update = 1;
448
449         pr_debug("sched_skb %p\n", skb);
450         if (!skb) {
451                 if (!s->num)
452                         return NULL;
453         } else {
454                 skbq = &s->p[skb->dev->if_port].skbq;
455                 __skb_queue_tail(skbq, skb);
456                 s->num++;
457                 skb = NULL;
458         }
459
460         if (credits < MAX_SKB_FRAGS + 1)
461                 goto out;
462
463 again:
464         for (i = 0; i < MAX_NPORTS; i++) {
465                 s->port = ++s->port & (MAX_NPORTS - 1);
466                 skbq = &s->p[s->port].skbq;
467
468                 skb = skb_peek(skbq);
469
470                 if (!skb)
471                         continue;
472
473                 len = skb->len;
474                 if (len <= s->p[s->port].avail) {
475                         s->p[s->port].avail -= len;
476                         s->num--;
477                         __skb_unlink(skb, skbq);
478                         goto out;
479                 }
480                 skb = NULL;
481         }
482
483         if (update-- && sched_update_avail(sge))
484                 goto again;
485
486 out:
487         /* If there are more pending skbs, we use the hardware to schedule us
488          * again.
489          */
490         if (s->num && !skb) {
491                 struct cmdQ *q = &sge->cmdQ[0];
492                 clear_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
493                 if (test_and_set_bit(CMDQ_STAT_RUNNING, &q->status) == 0) {
494                         set_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
495                         writel(F_CMDQ0_ENABLE, sge->adapter->regs + A_SG_DOORBELL);
496                 }
497         }
498         pr_debug("sched_skb ret %p\n", skb);
499
500         return skb;
501 }
502
503 /*
504  * PIO to indicate that memory mapped Q contains valid descriptor(s).
505  */
506 static inline void doorbell_pio(struct adapter *adapter, u32 val)
507 {
508         wmb();
509         writel(val, adapter->regs + A_SG_DOORBELL);
510 }
511
512 /*
513  * Frees all RX buffers on the freelist Q. The caller must make sure that
514  * the SGE is turned off before calling this function.
515  */
516 static void free_freelQ_buffers(struct pci_dev *pdev, struct freelQ *q)
517 {
518         unsigned int cidx = q->cidx;
519
520         while (q->credits--) {
521                 struct freelQ_ce *ce = &q->centries[cidx];
522
523                 pci_unmap_single(pdev, pci_unmap_addr(ce, dma_addr),
524                                  pci_unmap_len(ce, dma_len),
525                                  PCI_DMA_FROMDEVICE);
526                 dev_kfree_skb(ce->skb);
527                 ce->skb = NULL;
528                 if (++cidx == q->size)
529                         cidx = 0;
530         }
531 }
532
533 /*
534  * Free RX free list and response queue resources.
535  */
536 static void free_rx_resources(struct sge *sge)
537 {
538         struct pci_dev *pdev = sge->adapter->pdev;
539         unsigned int size, i;
540
541         if (sge->respQ.entries) {
542                 size = sizeof(struct respQ_e) * sge->respQ.size;
543                 pci_free_consistent(pdev, size, sge->respQ.entries,
544                                     sge->respQ.dma_addr);
545         }
546
547         for (i = 0; i < SGE_FREELQ_N; i++) {
548                 struct freelQ *q = &sge->freelQ[i];
549
550                 if (q->centries) {
551                         free_freelQ_buffers(pdev, q);
552                         kfree(q->centries);
553                 }
554                 if (q->entries) {
555                         size = sizeof(struct freelQ_e) * q->size;
556                         pci_free_consistent(pdev, size, q->entries,
557                                             q->dma_addr);
558                 }
559         }
560 }
561
562 /*
563  * Allocates basic RX resources, consisting of memory mapped freelist Qs and a
564  * response queue.
565  */
566 static int alloc_rx_resources(struct sge *sge, struct sge_params *p)
567 {
568         struct pci_dev *pdev = sge->adapter->pdev;
569         unsigned int size, i;
570
571         for (i = 0; i < SGE_FREELQ_N; i++) {
572                 struct freelQ *q = &sge->freelQ[i];
573
574                 q->genbit = 1;
575                 q->size = p->freelQ_size[i];
576                 q->dma_offset = sge->rx_pkt_pad ? 0 : NET_IP_ALIGN;
577                 size = sizeof(struct freelQ_e) * q->size;
578                 q->entries = (struct freelQ_e *)
579                               pci_alloc_consistent(pdev, size, &q->dma_addr);
580                 if (!q->entries)
581                         goto err_no_mem;
582                 memset(q->entries, 0, size);
583                 size = sizeof(struct freelQ_ce) * q->size;
584                 q->centries = kzalloc(size, GFP_KERNEL);
585                 if (!q->centries)
586                         goto err_no_mem;
587         }
588
589         /*
590          * Calculate the buffer sizes for the two free lists.  FL0 accommodates
591          * regular sized Ethernet frames, FL1 is sized not to exceed 16K,
592          * including all the sk_buff overhead.
593          *
594          * Note: For T2 FL0 and FL1 are reversed.
595          */
596         sge->freelQ[!sge->jumbo_fl].rx_buffer_size = SGE_RX_SM_BUF_SIZE +
597                 sizeof(struct cpl_rx_data) +
598                 sge->freelQ[!sge->jumbo_fl].dma_offset;
599
600                 size = (16 * 1024) -
601                     SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
602
603         sge->freelQ[sge->jumbo_fl].rx_buffer_size = size;
604
605         /*
606          * Setup which skb recycle Q should be used when recycling buffers from
607          * each free list.
608          */
609         sge->freelQ[!sge->jumbo_fl].recycleq_idx = 0;
610         sge->freelQ[sge->jumbo_fl].recycleq_idx = 1;
611
612         sge->respQ.genbit = 1;
613         sge->respQ.size = SGE_RESPQ_E_N;
614         sge->respQ.credits = 0;
615         size = sizeof(struct respQ_e) * sge->respQ.size;
616         sge->respQ.entries = (struct respQ_e *)
617                 pci_alloc_consistent(pdev, size, &sge->respQ.dma_addr);
618         if (!sge->respQ.entries)
619                 goto err_no_mem;
620         memset(sge->respQ.entries, 0, size);
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  */
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 (q->sop) {
641                         if (likely(pci_unmap_len(ce, dma_len))) {
642                                 pci_unmap_single(pdev,
643                                                  pci_unmap_addr(ce, dma_addr),
644                                                  pci_unmap_len(ce, dma_len),
645                                                  PCI_DMA_TODEVICE);
646                                 q->sop = 0;
647                         }
648                 } else {
649                         if (likely(pci_unmap_len(ce, dma_len))) {
650                                 pci_unmap_page(pdev, pci_unmap_addr(ce, dma_addr),
651                                                pci_unmap_len(ce, dma_len),
652                                                PCI_DMA_TODEVICE);
653                         }
654                 }
655                 if (ce->skb) {
656                         dev_kfree_skb_any(ce->skb);
657                         q->sop = 1;
658                 }
659                 ce++;
660                 if (++cidx == q->size) {
661                         cidx = 0;
662                         ce = q->centries;
663                 }
664         }
665         q->cidx = cidx;
666 }
667
668 /*
669  * Free TX resources.
670  *
671  * Assumes that SGE is stopped and all interrupts are disabled.
672  */
673 static void free_tx_resources(struct sge *sge)
674 {
675         struct pci_dev *pdev = sge->adapter->pdev;
676         unsigned int size, i;
677
678         for (i = 0; i < SGE_CMDQ_N; i++) {
679                 struct cmdQ *q = &sge->cmdQ[i];
680
681                 if (q->centries) {
682                         if (q->in_use)
683                                 free_cmdQ_buffers(sge, q, q->in_use);
684                         kfree(q->centries);
685                 }
686                 if (q->entries) {
687                         size = sizeof(struct cmdQ_e) * q->size;
688                         pci_free_consistent(pdev, size, q->entries,
689                                             q->dma_addr);
690                 }
691         }
692 }
693
694 /*
695  * Allocates basic TX resources, consisting of memory mapped command Qs.
696  */
697 static int alloc_tx_resources(struct sge *sge, struct sge_params *p)
698 {
699         struct pci_dev *pdev = sge->adapter->pdev;
700         unsigned int size, i;
701
702         for (i = 0; i < SGE_CMDQ_N; i++) {
703                 struct cmdQ *q = &sge->cmdQ[i];
704
705                 q->genbit = 1;
706                 q->sop = 1;
707                 q->size = p->cmdQ_size[i];
708                 q->in_use = 0;
709                 q->status = 0;
710                 q->processed = q->cleaned = 0;
711                 q->stop_thres = 0;
712                 spin_lock_init(&q->lock);
713                 size = sizeof(struct cmdQ_e) * q->size;
714                 q->entries = (struct cmdQ_e *)
715                               pci_alloc_consistent(pdev, size, &q->dma_addr);
716                 if (!q->entries)
717                         goto err_no_mem;
718                 memset(q->entries, 0, size);
719                 size = sizeof(struct cmdQ_ce) * q->size;
720                 q->centries = kzalloc(size, GFP_KERNEL);
721                 if (!q->centries)
722                         goto err_no_mem;
723         }
724
725         /*
726          * CommandQ 0 handles Ethernet and TOE packets, while queue 1 is TOE
727          * only.  For queue 0 set the stop threshold so we can handle one more
728          * packet from each port, plus reserve an additional 24 entries for
729          * Ethernet packets only.  Queue 1 never suspends nor do we reserve
730          * space for Ethernet packets.
731          */
732         sge->cmdQ[0].stop_thres = sge->adapter->params.nports *
733                 (MAX_SKB_FRAGS + 1);
734         return 0;
735
736 err_no_mem:
737         free_tx_resources(sge);
738         return -ENOMEM;
739 }
740
741 static inline void setup_ring_params(struct adapter *adapter, u64 addr,
742                                      u32 size, int base_reg_lo,
743                                      int base_reg_hi, int size_reg)
744 {
745         writel((u32)addr, adapter->regs + base_reg_lo);
746         writel(addr >> 32, adapter->regs + base_reg_hi);
747         writel(size, adapter->regs + size_reg);
748 }
749
750 /*
751  * Enable/disable VLAN acceleration.
752  */
753 void t1_set_vlan_accel(struct adapter *adapter, int on_off)
754 {
755         struct sge *sge = adapter->sge;
756
757         sge->sge_control &= ~F_VLAN_XTRACT;
758         if (on_off)
759                 sge->sge_control |= F_VLAN_XTRACT;
760         if (adapter->open_device_map) {
761                 writel(sge->sge_control, adapter->regs + A_SG_CONTROL);
762                 readl(adapter->regs + A_SG_CONTROL);   /* flush */
763         }
764 }
765
766 /*
767  * Programs the various SGE registers. However, the engine is not yet enabled,
768  * but sge->sge_control is setup and ready to go.
769  */
770 static void configure_sge(struct sge *sge, struct sge_params *p)
771 {
772         struct adapter *ap = sge->adapter;
773
774         writel(0, ap->regs + A_SG_CONTROL);
775         setup_ring_params(ap, sge->cmdQ[0].dma_addr, sge->cmdQ[0].size,
776                           A_SG_CMD0BASELWR, A_SG_CMD0BASEUPR, A_SG_CMD0SIZE);
777         setup_ring_params(ap, sge->cmdQ[1].dma_addr, sge->cmdQ[1].size,
778                           A_SG_CMD1BASELWR, A_SG_CMD1BASEUPR, A_SG_CMD1SIZE);
779         setup_ring_params(ap, sge->freelQ[0].dma_addr,
780                           sge->freelQ[0].size, A_SG_FL0BASELWR,
781                           A_SG_FL0BASEUPR, A_SG_FL0SIZE);
782         setup_ring_params(ap, sge->freelQ[1].dma_addr,
783                           sge->freelQ[1].size, A_SG_FL1BASELWR,
784                           A_SG_FL1BASEUPR, A_SG_FL1SIZE);
785
786         /* The threshold comparison uses <. */
787         writel(SGE_RX_SM_BUF_SIZE + 1, ap->regs + A_SG_FLTHRESHOLD);
788
789         setup_ring_params(ap, sge->respQ.dma_addr, sge->respQ.size,
790                           A_SG_RSPBASELWR, A_SG_RSPBASEUPR, A_SG_RSPSIZE);
791         writel((u32)sge->respQ.size - 1, ap->regs + A_SG_RSPQUEUECREDIT);
792
793         sge->sge_control = F_CMDQ0_ENABLE | F_CMDQ1_ENABLE | F_FL0_ENABLE |
794                 F_FL1_ENABLE | F_CPL_ENABLE | F_RESPONSE_QUEUE_ENABLE |
795                 V_CMDQ_PRIORITY(2) | F_DISABLE_CMDQ1_GTS | F_ISCSI_COALESCE |
796                 V_RX_PKT_OFFSET(sge->rx_pkt_pad);
797
798 #if defined(__BIG_ENDIAN_BITFIELD)
799         sge->sge_control |= F_ENABLE_BIG_ENDIAN;
800 #endif
801
802         /* Initialize no-resource timer */
803         sge->intrtimer_nres = SGE_INTRTIMER_NRES * core_ticks_per_usec(ap);
804
805         t1_sge_set_coalesce_params(sge, p);
806 }
807
808 /*
809  * Return the payload capacity of the jumbo free-list buffers.
810  */
811 static inline unsigned int jumbo_payload_capacity(const struct sge *sge)
812 {
813         return sge->freelQ[sge->jumbo_fl].rx_buffer_size -
814                 sge->freelQ[sge->jumbo_fl].dma_offset -
815                 sizeof(struct cpl_rx_data);
816 }
817
818 /*
819  * Frees all SGE related resources and the sge structure itself
820  */
821 void t1_sge_destroy(struct sge *sge)
822 {
823         int i;
824
825         for_each_port(sge->adapter, i)
826                 free_percpu(sge->port_stats[i]);
827
828         kfree(sge->tx_sched);
829         free_tx_resources(sge);
830         free_rx_resources(sge);
831         kfree(sge);
832 }
833
834 /*
835  * Allocates new RX buffers on the freelist Q (and tracks them on the freelist
836  * context Q) until the Q is full or alloc_skb fails.
837  *
838  * It is possible that the generation bits already match, indicating that the
839  * buffer is already valid and nothing needs to be done. This happens when we
840  * copied a received buffer into a new sk_buff during the interrupt processing.
841  *
842  * If the SGE doesn't automatically align packets properly (!sge->rx_pkt_pad),
843  * we specify a RX_OFFSET in order to make sure that the IP header is 4B
844  * aligned.
845  */
846 static void refill_free_list(struct sge *sge, struct freelQ *q)
847 {
848         struct pci_dev *pdev = sge->adapter->pdev;
849         struct freelQ_ce *ce = &q->centries[q->pidx];
850         struct freelQ_e *e = &q->entries[q->pidx];
851         unsigned int dma_len = q->rx_buffer_size - q->dma_offset;
852
853         while (q->credits < q->size) {
854                 struct sk_buff *skb;
855                 dma_addr_t mapping;
856
857                 skb = alloc_skb(q->rx_buffer_size, GFP_ATOMIC);
858                 if (!skb)
859                         break;
860
861                 skb_reserve(skb, q->dma_offset);
862                 mapping = pci_map_single(pdev, skb->data, dma_len,
863                                          PCI_DMA_FROMDEVICE);
864                 ce->skb = skb;
865                 pci_unmap_addr_set(ce, dma_addr, mapping);
866                 pci_unmap_len_set(ce, dma_len, dma_len);
867                 e->addr_lo = (u32)mapping;
868                 e->addr_hi = (u64)mapping >> 32;
869                 e->len_gen = V_CMD_LEN(dma_len) | V_CMD_GEN1(q->genbit);
870                 wmb();
871                 e->gen2 = V_CMD_GEN2(q->genbit);
872
873                 e++;
874                 ce++;
875                 if (++q->pidx == q->size) {
876                         q->pidx = 0;
877                         q->genbit ^= 1;
878                         ce = q->centries;
879                         e = q->entries;
880                 }
881                 q->credits++;
882         }
883 }
884
885 /*
886  * Calls refill_free_list for both free lists. If we cannot fill at least 1/4
887  * of both rings, we go into 'few interrupt mode' in order to give the system
888  * time to free up resources.
889  */
890 static void freelQs_empty(struct sge *sge)
891 {
892         struct adapter *adapter = sge->adapter;
893         u32 irq_reg = readl(adapter->regs + A_SG_INT_ENABLE);
894         u32 irqholdoff_reg;
895
896         refill_free_list(sge, &sge->freelQ[0]);
897         refill_free_list(sge, &sge->freelQ[1]);
898
899         if (sge->freelQ[0].credits > (sge->freelQ[0].size >> 2) &&
900             sge->freelQ[1].credits > (sge->freelQ[1].size >> 2)) {
901                 irq_reg |= F_FL_EXHAUSTED;
902                 irqholdoff_reg = sge->fixed_intrtimer;
903         } else {
904                 /* Clear the F_FL_EXHAUSTED interrupts for now */
905                 irq_reg &= ~F_FL_EXHAUSTED;
906                 irqholdoff_reg = sge->intrtimer_nres;
907         }
908         writel(irqholdoff_reg, adapter->regs + A_SG_INTRTIMER);
909         writel(irq_reg, adapter->regs + A_SG_INT_ENABLE);
910
911         /* We reenable the Qs to force a freelist GTS interrupt later */
912         doorbell_pio(adapter, F_FL0_ENABLE | F_FL1_ENABLE);
913 }
914
915 #define SGE_PL_INTR_MASK (F_PL_INTR_SGE_ERR | F_PL_INTR_SGE_DATA)
916 #define SGE_INT_FATAL (F_RESPQ_OVERFLOW | F_PACKET_TOO_BIG | F_PACKET_MISMATCH)
917 #define SGE_INT_ENABLE (F_RESPQ_EXHAUSTED | F_RESPQ_OVERFLOW | \
918                         F_FL_EXHAUSTED | F_PACKET_TOO_BIG | F_PACKET_MISMATCH)
919
920 /*
921  * Disable SGE Interrupts
922  */
923 void t1_sge_intr_disable(struct sge *sge)
924 {
925         u32 val = readl(sge->adapter->regs + A_PL_ENABLE);
926
927         writel(val & ~SGE_PL_INTR_MASK, sge->adapter->regs + A_PL_ENABLE);
928         writel(0, sge->adapter->regs + A_SG_INT_ENABLE);
929 }
930
931 /*
932  * Enable SGE interrupts.
933  */
934 void t1_sge_intr_enable(struct sge *sge)
935 {
936         u32 en = SGE_INT_ENABLE;
937         u32 val = readl(sge->adapter->regs + A_PL_ENABLE);
938
939         if (sge->adapter->flags & TSO_CAPABLE)
940                 en &= ~F_PACKET_TOO_BIG;
941         writel(en, sge->adapter->regs + A_SG_INT_ENABLE);
942         writel(val | SGE_PL_INTR_MASK, sge->adapter->regs + A_PL_ENABLE);
943 }
944
945 /*
946  * Clear SGE interrupts.
947  */
948 void t1_sge_intr_clear(struct sge *sge)
949 {
950         writel(SGE_PL_INTR_MASK, sge->adapter->regs + A_PL_CAUSE);
951         writel(0xffffffff, sge->adapter->regs + A_SG_INT_CAUSE);
952 }
953
954 /*
955  * SGE 'Error' interrupt handler
956  */
957 int t1_sge_intr_error_handler(struct sge *sge)
958 {
959         struct adapter *adapter = sge->adapter;
960         u32 cause = readl(adapter->regs + A_SG_INT_CAUSE);
961
962         if (adapter->flags & TSO_CAPABLE)
963                 cause &= ~F_PACKET_TOO_BIG;
964         if (cause & F_RESPQ_EXHAUSTED)
965                 sge->stats.respQ_empty++;
966         if (cause & F_RESPQ_OVERFLOW) {
967                 sge->stats.respQ_overflow++;
968                 CH_ALERT("%s: SGE response queue overflow\n",
969                          adapter->name);
970         }
971         if (cause & F_FL_EXHAUSTED) {
972                 sge->stats.freelistQ_empty++;
973                 freelQs_empty(sge);
974         }
975         if (cause & F_PACKET_TOO_BIG) {
976                 sge->stats.pkt_too_big++;
977                 CH_ALERT("%s: SGE max packet size exceeded\n",
978                          adapter->name);
979         }
980         if (cause & F_PACKET_MISMATCH) {
981                 sge->stats.pkt_mismatch++;
982                 CH_ALERT("%s: SGE packet mismatch\n", adapter->name);
983         }
984         if (cause & SGE_INT_FATAL)
985                 t1_fatal_err(adapter);
986
987         writel(cause, adapter->regs + A_SG_INT_CAUSE);
988         return 0;
989 }
990
991 const struct sge_intr_counts *t1_sge_get_intr_counts(const struct sge *sge)
992 {
993         return &sge->stats;
994 }
995
996 void t1_sge_get_port_stats(const struct sge *sge, int port,
997                            struct sge_port_stats *ss)
998 {
999         int cpu;
1000
1001         memset(ss, 0, sizeof(*ss));
1002         for_each_possible_cpu(cpu) {
1003                 struct sge_port_stats *st = per_cpu_ptr(sge->port_stats[port], cpu);
1004
1005                 ss->rx_packets += st->rx_packets;
1006                 ss->rx_cso_good += st->rx_cso_good;
1007                 ss->tx_packets += st->tx_packets;
1008                 ss->tx_cso += st->tx_cso;
1009                 ss->tx_tso += st->tx_tso;
1010                 ss->vlan_xtract += st->vlan_xtract;
1011                 ss->vlan_insert += st->vlan_insert;
1012         }
1013 }
1014
1015 /**
1016  *      recycle_fl_buf - recycle a free list buffer
1017  *      @fl: the free list
1018  *      @idx: index of buffer to recycle
1019  *
1020  *      Recycles the specified buffer on the given free list by adding it at
1021  *      the next available slot on the list.
1022  */
1023 static void recycle_fl_buf(struct freelQ *fl, int idx)
1024 {
1025         struct freelQ_e *from = &fl->entries[idx];
1026         struct freelQ_e *to = &fl->entries[fl->pidx];
1027
1028         fl->centries[fl->pidx] = fl->centries[idx];
1029         to->addr_lo = from->addr_lo;
1030         to->addr_hi = from->addr_hi;
1031         to->len_gen = G_CMD_LEN(from->len_gen) | V_CMD_GEN1(fl->genbit);
1032         wmb();
1033         to->gen2 = V_CMD_GEN2(fl->genbit);
1034         fl->credits++;
1035
1036         if (++fl->pidx == fl->size) {
1037                 fl->pidx = 0;
1038                 fl->genbit ^= 1;
1039         }
1040 }
1041
1042 /**
1043  *      get_packet - return the next ingress packet buffer
1044  *      @pdev: the PCI device that received the packet
1045  *      @fl: the SGE free list holding the packet
1046  *      @len: the actual packet length, excluding any SGE padding
1047  *      @dma_pad: padding at beginning of buffer left by SGE DMA
1048  *      @skb_pad: padding to be used if the packet is copied
1049  *      @copy_thres: length threshold under which a packet should be copied
1050  *      @drop_thres: # of remaining buffers before we start dropping packets
1051  *
1052  *      Get the next packet from a free list and complete setup of the
1053  *      sk_buff.  If the packet is small we make a copy and recycle the
1054  *      original buffer, otherwise we use the original buffer itself.  If a
1055  *      positive drop threshold is supplied packets are dropped and their
1056  *      buffers recycled if (a) the number of remaining buffers is under the
1057  *      threshold and the packet is too big to copy, or (b) the packet should
1058  *      be copied but there is no memory for the copy.
1059  */
1060 static inline struct sk_buff *get_packet(struct pci_dev *pdev,
1061                                          struct freelQ *fl, unsigned int len,
1062                                          int dma_pad, int skb_pad,
1063                                          unsigned int copy_thres,
1064                                          unsigned int drop_thres)
1065 {
1066         struct sk_buff *skb;
1067         struct freelQ_ce *ce = &fl->centries[fl->cidx];
1068
1069         if (len < copy_thres) {
1070                 skb = alloc_skb(len + skb_pad, GFP_ATOMIC);
1071                 if (likely(skb != NULL)) {
1072                         skb_reserve(skb, skb_pad);
1073                         skb_put(skb, len);
1074                         pci_dma_sync_single_for_cpu(pdev,
1075                                             pci_unmap_addr(ce, dma_addr),
1076                                             pci_unmap_len(ce, dma_len),
1077                                             PCI_DMA_FROMDEVICE);
1078                         memcpy(skb->data, ce->skb->data + dma_pad, len);
1079                         pci_dma_sync_single_for_device(pdev,
1080                                             pci_unmap_addr(ce, dma_addr),
1081                                             pci_unmap_len(ce, dma_len),
1082                                             PCI_DMA_FROMDEVICE);
1083                 } else if (!drop_thres)
1084                         goto use_orig_buf;
1085
1086                 recycle_fl_buf(fl, fl->cidx);
1087                 return skb;
1088         }
1089
1090         if (fl->credits < drop_thres) {
1091                 recycle_fl_buf(fl, fl->cidx);
1092                 return NULL;
1093         }
1094
1095 use_orig_buf:
1096         pci_unmap_single(pdev, pci_unmap_addr(ce, dma_addr),
1097                          pci_unmap_len(ce, dma_len), PCI_DMA_FROMDEVICE);
1098         skb = ce->skb;
1099         skb_reserve(skb, dma_pad);
1100         skb_put(skb, len);
1101         return skb;
1102 }
1103
1104 /**
1105  *      unexpected_offload - handle an unexpected offload packet
1106  *      @adapter: the adapter
1107  *      @fl: the free list that received the packet
1108  *
1109  *      Called when we receive an unexpected offload packet (e.g., the TOE
1110  *      function is disabled or the card is a NIC).  Prints a message and
1111  *      recycles the buffer.
1112  */
1113 static void unexpected_offload(struct adapter *adapter, struct freelQ *fl)
1114 {
1115         struct freelQ_ce *ce = &fl->centries[fl->cidx];
1116         struct sk_buff *skb = ce->skb;
1117
1118         pci_dma_sync_single_for_cpu(adapter->pdev, pci_unmap_addr(ce, dma_addr),
1119                             pci_unmap_len(ce, dma_len), PCI_DMA_FROMDEVICE);
1120         CH_ERR("%s: unexpected offload packet, cmd %u\n",
1121                adapter->name, *skb->data);
1122         recycle_fl_buf(fl, fl->cidx);
1123 }
1124
1125 /*
1126  * T1/T2 SGE limits the maximum DMA size per TX descriptor to
1127  * SGE_TX_DESC_MAX_PLEN (16KB). If the PAGE_SIZE is larger than 16KB, the
1128  * stack might send more than SGE_TX_DESC_MAX_PLEN in a contiguous manner.
1129  * Note that the *_large_page_tx_descs stuff will be optimized out when
1130  * PAGE_SIZE <= SGE_TX_DESC_MAX_PLEN.
1131  *
1132  * compute_large_page_descs() computes how many additional descriptors are
1133  * required to break down the stack's request.
1134  */
1135 static inline unsigned int compute_large_page_tx_descs(struct sk_buff *skb)
1136 {
1137         unsigned int count = 0;
1138
1139         if (PAGE_SIZE > SGE_TX_DESC_MAX_PLEN) {
1140                 unsigned int nfrags = skb_shinfo(skb)->nr_frags;
1141                 unsigned int i, len = skb->len - skb->data_len;
1142                 while (len > SGE_TX_DESC_MAX_PLEN) {
1143                         count++;
1144                         len -= SGE_TX_DESC_MAX_PLEN;
1145                 }
1146                 for (i = 0; nfrags--; i++) {
1147                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1148                         len = frag->size;
1149                         while (len > SGE_TX_DESC_MAX_PLEN) {
1150                                 count++;
1151                                 len -= SGE_TX_DESC_MAX_PLEN;
1152                         }
1153                 }
1154         }
1155         return count;
1156 }
1157
1158 /*
1159  * Write a cmdQ entry.
1160  *
1161  * Since this function writes the 'flags' field, it must not be used to
1162  * write the first cmdQ entry.
1163  */
1164 static inline void write_tx_desc(struct cmdQ_e *e, dma_addr_t mapping,
1165                                  unsigned int len, unsigned int gen,
1166                                  unsigned int eop)
1167 {
1168         if (unlikely(len > SGE_TX_DESC_MAX_PLEN))
1169                 BUG();
1170         e->addr_lo = (u32)mapping;
1171         e->addr_hi = (u64)mapping >> 32;
1172         e->len_gen = V_CMD_LEN(len) | V_CMD_GEN1(gen);
1173         e->flags = F_CMD_DATAVALID | V_CMD_EOP(eop) | V_CMD_GEN2(gen);
1174 }
1175
1176 /*
1177  * See comment for previous function.
1178  *
1179  * write_tx_descs_large_page() writes additional SGE tx descriptors if
1180  * *desc_len exceeds HW's capability.
1181  */
1182 static inline unsigned int write_large_page_tx_descs(unsigned int pidx,
1183                                                      struct cmdQ_e **e,
1184                                                      struct cmdQ_ce **ce,
1185                                                      unsigned int *gen,
1186                                                      dma_addr_t *desc_mapping,
1187                                                      unsigned int *desc_len,
1188                                                      unsigned int nfrags,
1189                                                      struct cmdQ *q)
1190 {
1191         if (PAGE_SIZE > SGE_TX_DESC_MAX_PLEN) {
1192                 struct cmdQ_e *e1 = *e;
1193                 struct cmdQ_ce *ce1 = *ce;
1194
1195                 while (*desc_len > SGE_TX_DESC_MAX_PLEN) {
1196                         *desc_len -= SGE_TX_DESC_MAX_PLEN;
1197                         write_tx_desc(e1, *desc_mapping, SGE_TX_DESC_MAX_PLEN,
1198                                       *gen, nfrags == 0 && *desc_len == 0);
1199                         ce1->skb = NULL;
1200                         pci_unmap_len_set(ce1, dma_len, 0);
1201                         *desc_mapping += SGE_TX_DESC_MAX_PLEN;
1202                         if (*desc_len) {
1203                                 ce1++;
1204                                 e1++;
1205                                 if (++pidx == q->size) {
1206                                         pidx = 0;
1207                                         *gen ^= 1;
1208                                         ce1 = q->centries;
1209                                         e1 = q->entries;
1210                                 }
1211                         }
1212                 }
1213                 *e = e1;
1214                 *ce = ce1;
1215         }
1216         return pidx;
1217 }
1218
1219 /*
1220  * Write the command descriptors to transmit the given skb starting at
1221  * descriptor pidx with the given generation.
1222  */
1223 static inline void write_tx_descs(struct adapter *adapter, struct sk_buff *skb,
1224                                   unsigned int pidx, unsigned int gen,
1225                                   struct cmdQ *q)
1226 {
1227         dma_addr_t mapping, desc_mapping;
1228         struct cmdQ_e *e, *e1;
1229         struct cmdQ_ce *ce;
1230         unsigned int i, flags, first_desc_len, desc_len,
1231             nfrags = skb_shinfo(skb)->nr_frags;
1232
1233         e = e1 = &q->entries[pidx];
1234         ce = &q->centries[pidx];
1235
1236         mapping = pci_map_single(adapter->pdev, skb->data,
1237                                 skb->len - skb->data_len, PCI_DMA_TODEVICE);
1238
1239         desc_mapping = mapping;
1240         desc_len = skb->len - skb->data_len;
1241
1242         flags = F_CMD_DATAVALID | F_CMD_SOP |
1243             V_CMD_EOP(nfrags == 0 && desc_len <= SGE_TX_DESC_MAX_PLEN) |
1244             V_CMD_GEN2(gen);
1245         first_desc_len = (desc_len <= SGE_TX_DESC_MAX_PLEN) ?
1246             desc_len : SGE_TX_DESC_MAX_PLEN;
1247         e->addr_lo = (u32)desc_mapping;
1248         e->addr_hi = (u64)desc_mapping >> 32;
1249         e->len_gen = V_CMD_LEN(first_desc_len) | V_CMD_GEN1(gen);
1250         ce->skb = NULL;
1251         pci_unmap_len_set(ce, dma_len, 0);
1252
1253         if (PAGE_SIZE > SGE_TX_DESC_MAX_PLEN &&
1254             desc_len > SGE_TX_DESC_MAX_PLEN) {
1255                 desc_mapping += first_desc_len;
1256                 desc_len -= first_desc_len;
1257                 e1++;
1258                 ce++;
1259                 if (++pidx == q->size) {
1260                         pidx = 0;
1261                         gen ^= 1;
1262                         e1 = q->entries;
1263                         ce = q->centries;
1264                 }
1265                 pidx = write_large_page_tx_descs(pidx, &e1, &ce, &gen,
1266                                                  &desc_mapping, &desc_len,
1267                                                  nfrags, q);
1268
1269                 if (likely(desc_len))
1270                         write_tx_desc(e1, desc_mapping, desc_len, gen,
1271                                       nfrags == 0);
1272         }
1273
1274         ce->skb = NULL;
1275         pci_unmap_addr_set(ce, dma_addr, mapping);
1276         pci_unmap_len_set(ce, dma_len, skb->len - skb->data_len);
1277
1278         for (i = 0; nfrags--; i++) {
1279                 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1280                 e1++;
1281                 ce++;
1282                 if (++pidx == q->size) {
1283                         pidx = 0;
1284                         gen ^= 1;
1285                         e1 = q->entries;
1286                         ce = q->centries;
1287                 }
1288
1289                 mapping = pci_map_page(adapter->pdev, frag->page,
1290                                        frag->page_offset, frag->size,
1291                                        PCI_DMA_TODEVICE);
1292                 desc_mapping = mapping;
1293                 desc_len = frag->size;
1294
1295                 pidx = write_large_page_tx_descs(pidx, &e1, &ce, &gen,
1296                                                  &desc_mapping, &desc_len,
1297                                                  nfrags, q);
1298                 if (likely(desc_len))
1299                         write_tx_desc(e1, desc_mapping, desc_len, gen,
1300                                       nfrags == 0);
1301                 ce->skb = NULL;
1302                 pci_unmap_addr_set(ce, dma_addr, mapping);
1303                 pci_unmap_len_set(ce, dma_len, frag->size);
1304         }
1305         ce->skb = skb;
1306         wmb();
1307         e->flags = flags;
1308 }
1309
1310 /*
1311  * Clean up completed Tx buffers.
1312  */
1313 static inline void reclaim_completed_tx(struct sge *sge, struct cmdQ *q)
1314 {
1315         unsigned int reclaim = q->processed - q->cleaned;
1316
1317         if (reclaim) {
1318                 pr_debug("reclaim_completed_tx processed:%d cleaned:%d\n",
1319                          q->processed, q->cleaned);
1320                 free_cmdQ_buffers(sge, q, reclaim);
1321                 q->cleaned += reclaim;
1322         }
1323 }
1324
1325 /*
1326  * Called from tasklet. Checks the scheduler for any
1327  * pending skbs that can be sent.
1328  */
1329 static void restart_sched(unsigned long arg)
1330 {
1331         struct sge *sge = (struct sge *) arg;
1332         struct adapter *adapter = sge->adapter;
1333         struct cmdQ *q = &sge->cmdQ[0];
1334         struct sk_buff *skb;
1335         unsigned int credits, queued_skb = 0;
1336
1337         spin_lock(&q->lock);
1338         reclaim_completed_tx(sge, q);
1339
1340         credits = q->size - q->in_use;
1341         pr_debug("restart_sched credits=%d\n", credits);
1342         while ((skb = sched_skb(sge, NULL, credits)) != NULL) {
1343                 unsigned int genbit, pidx, count;
1344                 count = 1 + skb_shinfo(skb)->nr_frags;
1345                 count += compute_large_page_tx_descs(skb);
1346                 q->in_use += count;
1347                 genbit = q->genbit;
1348                 pidx = q->pidx;
1349                 q->pidx += count;
1350                 if (q->pidx >= q->size) {
1351                         q->pidx -= q->size;
1352                         q->genbit ^= 1;
1353                 }
1354                 write_tx_descs(adapter, skb, pidx, genbit, q);
1355                 credits = q->size - q->in_use;
1356                 queued_skb = 1;
1357         }
1358
1359         if (queued_skb) {
1360                 clear_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
1361                 if (test_and_set_bit(CMDQ_STAT_RUNNING, &q->status) == 0) {
1362                         set_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
1363                         writel(F_CMDQ0_ENABLE, adapter->regs + A_SG_DOORBELL);
1364                 }
1365         }
1366         spin_unlock(&q->lock);
1367 }
1368
1369 /**
1370  *      sge_rx - process an ingress ethernet packet
1371  *      @sge: the sge structure
1372  *      @fl: the free list that contains the packet buffer
1373  *      @len: the packet length
1374  *
1375  *      Process an ingress ethernet pakcet and deliver it to the stack.
1376  */
1377 static int sge_rx(struct sge *sge, struct freelQ *fl, unsigned int len)
1378 {
1379         struct sk_buff *skb;
1380         struct cpl_rx_pkt *p;
1381         struct adapter *adapter = sge->adapter;
1382         struct sge_port_stats *st;
1383
1384         skb = get_packet(adapter->pdev, fl, len - sge->rx_pkt_pad,
1385                          sge->rx_pkt_pad, 2, SGE_RX_COPY_THRES,
1386                          SGE_RX_DROP_THRES);
1387         if (unlikely(!skb)) {
1388                 sge->stats.rx_drops++;
1389                 return 0;
1390         }
1391
1392         p = (struct cpl_rx_pkt *)skb->data;
1393         skb_pull(skb, sizeof(*p));
1394         if (p->iff >= adapter->params.nports) {
1395                 kfree_skb(skb);
1396                 return 0;
1397         }
1398
1399         skb->dev = adapter->port[p->iff].dev;
1400         skb->dev->last_rx = jiffies;
1401         st = per_cpu_ptr(sge->port_stats[p->iff], smp_processor_id());
1402         st->rx_packets++;
1403
1404         skb->protocol = eth_type_trans(skb, skb->dev);
1405         if ((adapter->flags & RX_CSUM_ENABLED) && p->csum == 0xffff &&
1406             skb->protocol == htons(ETH_P_IP) &&
1407             (skb->data[9] == IPPROTO_TCP || skb->data[9] == IPPROTO_UDP)) {
1408                 ++st->rx_cso_good;
1409                 skb->ip_summed = CHECKSUM_UNNECESSARY;
1410         } else
1411                 skb->ip_summed = CHECKSUM_NONE;
1412
1413         if (unlikely(adapter->vlan_grp && p->vlan_valid)) {
1414                 st->vlan_xtract++;
1415 #ifdef CONFIG_CHELSIO_T1_NAPI
1416                         vlan_hwaccel_receive_skb(skb, adapter->vlan_grp,
1417                                                  ntohs(p->vlan));
1418 #else
1419                         vlan_hwaccel_rx(skb, adapter->vlan_grp,
1420                                         ntohs(p->vlan));
1421 #endif
1422         } else {
1423 #ifdef CONFIG_CHELSIO_T1_NAPI
1424                 netif_receive_skb(skb);
1425 #else
1426                 netif_rx(skb);
1427 #endif
1428         }
1429         return 0;
1430 }
1431
1432 /*
1433  * Returns true if a command queue has enough available descriptors that
1434  * we can resume Tx operation after temporarily disabling its packet queue.
1435  */
1436 static inline int enough_free_Tx_descs(const struct cmdQ *q)
1437 {
1438         unsigned int r = q->processed - q->cleaned;
1439
1440         return q->in_use - r < (q->size >> 1);
1441 }
1442
1443 /*
1444  * Called when sufficient space has become available in the SGE command queues
1445  * after the Tx packet schedulers have been suspended to restart the Tx path.
1446  */
1447 static void restart_tx_queues(struct sge *sge)
1448 {
1449         struct adapter *adap = sge->adapter;
1450
1451         if (enough_free_Tx_descs(&sge->cmdQ[0])) {
1452                 int i;
1453
1454                 for_each_port(adap, i) {
1455                         struct net_device *nd = adap->port[i].dev;
1456
1457                         if (test_and_clear_bit(nd->if_port,
1458                                                &sge->stopped_tx_queues) &&
1459                             netif_running(nd)) {
1460                                 sge->stats.cmdQ_restarted[2]++;
1461                                 netif_wake_queue(nd);
1462                         }
1463                 }
1464         }
1465 }
1466
1467 /*
1468  * update_tx_info is called from the interrupt handler/NAPI to return cmdQ0
1469  * information.
1470  */
1471 static unsigned int update_tx_info(struct adapter *adapter,
1472                                           unsigned int flags,
1473                                           unsigned int pr0)
1474 {
1475         struct sge *sge = adapter->sge;
1476         struct cmdQ *cmdq = &sge->cmdQ[0];
1477
1478         cmdq->processed += pr0;
1479         if (flags & (F_FL0_ENABLE | F_FL1_ENABLE)) {
1480                 freelQs_empty(sge);
1481                 flags &= ~(F_FL0_ENABLE | F_FL1_ENABLE);
1482         }
1483         if (flags & F_CMDQ0_ENABLE) {
1484                 clear_bit(CMDQ_STAT_RUNNING, &cmdq->status);
1485
1486                 if (cmdq->cleaned + cmdq->in_use != cmdq->processed &&
1487                     !test_and_set_bit(CMDQ_STAT_LAST_PKT_DB, &cmdq->status)) {
1488                         set_bit(CMDQ_STAT_RUNNING, &cmdq->status);
1489                         writel(F_CMDQ0_ENABLE, adapter->regs + A_SG_DOORBELL);
1490                 }
1491                 if (sge->tx_sched)
1492                         tasklet_hi_schedule(&sge->tx_sched->sched_tsk);
1493
1494                 flags &= ~F_CMDQ0_ENABLE;
1495         }
1496
1497         if (unlikely(sge->stopped_tx_queues != 0))
1498                 restart_tx_queues(sge);
1499
1500         return flags;
1501 }
1502
1503 /*
1504  * Process SGE responses, up to the supplied budget.  Returns the number of
1505  * responses processed.  A negative budget is effectively unlimited.
1506  */
1507 static int process_responses(struct adapter *adapter, int budget)
1508 {
1509         struct sge *sge = adapter->sge;
1510         struct respQ *q = &sge->respQ;
1511         struct respQ_e *e = &q->entries[q->cidx];
1512         int budget_left = budget;
1513         unsigned int flags = 0;
1514         unsigned int cmdq_processed[SGE_CMDQ_N] = {0, 0};
1515
1516
1517         while (likely(budget_left && e->GenerationBit == q->genbit)) {
1518                 flags |= e->Qsleeping;
1519
1520                 cmdq_processed[0] += e->Cmdq0CreditReturn;
1521                 cmdq_processed[1] += e->Cmdq1CreditReturn;
1522
1523                 /* We batch updates to the TX side to avoid cacheline
1524                  * ping-pong of TX state information on MP where the sender
1525                  * might run on a different CPU than this function...
1526                  */
1527                 if (unlikely(flags & F_CMDQ0_ENABLE || cmdq_processed[0] > 64)) {
1528                         flags = update_tx_info(adapter, flags, cmdq_processed[0]);
1529                         cmdq_processed[0] = 0;
1530                 }
1531                 if (unlikely(cmdq_processed[1] > 16)) {
1532                         sge->cmdQ[1].processed += cmdq_processed[1];
1533                         cmdq_processed[1] = 0;
1534                 }
1535                 if (likely(e->DataValid)) {
1536                         struct freelQ *fl = &sge->freelQ[e->FreelistQid];
1537
1538                         BUG_ON(!e->Sop || !e->Eop);
1539                         if (unlikely(e->Offload))
1540                                 unexpected_offload(adapter, fl);
1541                         else
1542                                 sge_rx(sge, fl, e->BufferLength);
1543
1544                         /*
1545                          * Note: this depends on each packet consuming a
1546                          * single free-list buffer; cf. the BUG above.
1547                          */
1548                         if (++fl->cidx == fl->size)
1549                                 fl->cidx = 0;
1550                         if (unlikely(--fl->credits <
1551                                      fl->size - SGE_FREEL_REFILL_THRESH))
1552                                 refill_free_list(sge, fl);
1553                 } else
1554                         sge->stats.pure_rsps++;
1555
1556                 e++;
1557                 if (unlikely(++q->cidx == q->size)) {
1558                         q->cidx = 0;
1559                         q->genbit ^= 1;
1560                         e = q->entries;
1561                 }
1562                 prefetch(e);
1563
1564                 if (++q->credits > SGE_RESPQ_REPLENISH_THRES) {
1565                         writel(q->credits, adapter->regs + A_SG_RSPQUEUECREDIT);
1566                         q->credits = 0;
1567                 }
1568                 --budget_left;
1569         }
1570
1571         flags = update_tx_info(adapter, flags, cmdq_processed[0]);
1572         sge->cmdQ[1].processed += cmdq_processed[1];
1573
1574         budget -= budget_left;
1575         return budget;
1576 }
1577
1578 #ifdef CONFIG_CHELSIO_T1_NAPI
1579 /*
1580  * A simpler version of process_responses() that handles only pure (i.e.,
1581  * non data-carrying) responses.  Such respones are too light-weight to justify
1582  * calling a softirq when using NAPI, so we handle them specially in hard
1583  * interrupt context.  The function is called with a pointer to a response,
1584  * which the caller must ensure is a valid pure response.  Returns 1 if it
1585  * encounters a valid data-carrying response, 0 otherwise.
1586  */
1587 static int process_pure_responses(struct adapter *adapter, struct respQ_e *e)
1588 {
1589         struct sge *sge = adapter->sge;
1590         struct respQ *q = &sge->respQ;
1591         unsigned int flags = 0;
1592         unsigned int cmdq_processed[SGE_CMDQ_N] = {0, 0};
1593
1594         do {
1595                 flags |= e->Qsleeping;
1596
1597                 cmdq_processed[0] += e->Cmdq0CreditReturn;
1598                 cmdq_processed[1] += e->Cmdq1CreditReturn;
1599
1600                 e++;
1601                 if (unlikely(++q->cidx == q->size)) {
1602                         q->cidx = 0;
1603                         q->genbit ^= 1;
1604                         e = q->entries;
1605                 }
1606                 prefetch(e);
1607
1608                 if (++q->credits > SGE_RESPQ_REPLENISH_THRES) {
1609                         writel(q->credits, adapter->regs + A_SG_RSPQUEUECREDIT);
1610                         q->credits = 0;
1611                 }
1612                 sge->stats.pure_rsps++;
1613         } while (e->GenerationBit == q->genbit && !e->DataValid);
1614
1615         flags = update_tx_info(adapter, flags, cmdq_processed[0]);
1616         sge->cmdQ[1].processed += cmdq_processed[1];
1617
1618         return e->GenerationBit == q->genbit;
1619 }
1620
1621 /*
1622  * Handler for new data events when using NAPI.  This does not need any locking
1623  * or protection from interrupts as data interrupts are off at this point and
1624  * other adapter interrupts do not interfere.
1625  */
1626 int t1_poll(struct net_device *dev, int *budget)
1627 {
1628         struct adapter *adapter = dev->priv;
1629         int effective_budget = min(*budget, dev->quota);
1630         int work_done = process_responses(adapter, effective_budget);
1631
1632         *budget -= work_done;
1633         dev->quota -= work_done;
1634
1635         if (work_done >= effective_budget)
1636                 return 1;
1637
1638         spin_lock_irq(&adapter->async_lock);
1639         __netif_rx_complete(dev);
1640         writel(adapter->sge->respQ.cidx, adapter->regs + A_SG_SLEEPING);
1641         writel(adapter->slow_intr_mask | F_PL_INTR_SGE_DATA,
1642                adapter->regs + A_PL_ENABLE);
1643         spin_unlock_irq(&adapter->async_lock);
1644
1645         return 0;
1646 }
1647
1648 /*
1649  * NAPI version of the main interrupt handler.
1650  */
1651 irqreturn_t t1_interrupt(int irq, void *data)
1652 {
1653         struct adapter *adapter = data;
1654         struct net_device *dev = adapter->sge->netdev;
1655         struct sge *sge = adapter->sge;
1656         u32 cause;
1657         int handled = 0;
1658
1659         cause = readl(adapter->regs + A_PL_CAUSE);
1660         if (cause == 0 || cause == ~0)
1661                 return IRQ_NONE;
1662
1663         spin_lock(&adapter->async_lock);
1664         if (cause & F_PL_INTR_SGE_DATA) {
1665                 struct respQ *q = &adapter->sge->respQ;
1666                 struct respQ_e *e = &q->entries[q->cidx];
1667
1668                 handled = 1;
1669                 writel(F_PL_INTR_SGE_DATA, adapter->regs + A_PL_CAUSE);
1670
1671                 if (e->GenerationBit == q->genbit &&
1672                     __netif_rx_schedule_prep(dev)) {
1673                         if (e->DataValid || process_pure_responses(adapter, e)) {
1674                                 /* mask off data IRQ */
1675                                 writel(adapter->slow_intr_mask,
1676                                        adapter->regs + A_PL_ENABLE);
1677                                 __netif_rx_schedule(sge->netdev);
1678                                 goto unlock;
1679                         }
1680                         /* no data, no NAPI needed */
1681                         netif_poll_enable(dev);
1682
1683                 }
1684                 writel(q->cidx, adapter->regs + A_SG_SLEEPING);
1685         } else
1686                 handled = t1_slow_intr_handler(adapter);
1687
1688         if (!handled)
1689                 sge->stats.unhandled_irqs++;
1690 unlock:
1691         spin_unlock(&adapter->async_lock);
1692         return IRQ_RETVAL(handled != 0);
1693 }
1694
1695 #else
1696 /*
1697  * Main interrupt handler, optimized assuming that we took a 'DATA'
1698  * interrupt.
1699  *
1700  * 1. Clear the interrupt
1701  * 2. Loop while we find valid descriptors and process them; accumulate
1702  *      information that can be processed after the loop
1703  * 3. Tell the SGE at which index we stopped processing descriptors
1704  * 4. Bookkeeping; free TX buffers, ring doorbell if there are any
1705  *      outstanding TX buffers waiting, replenish RX buffers, potentially
1706  *      reenable upper layers if they were turned off due to lack of TX
1707  *      resources which are available again.
1708  * 5. If we took an interrupt, but no valid respQ descriptors was found we
1709  *      let the slow_intr_handler run and do error handling.
1710  */
1711 irqreturn_t t1_interrupt(int irq, void *cookie)
1712 {
1713         int work_done;
1714         struct respQ_e *e;
1715         struct adapter *adapter = cookie;
1716         struct respQ *Q = &adapter->sge->respQ;
1717
1718         spin_lock(&adapter->async_lock);
1719         e = &Q->entries[Q->cidx];
1720         prefetch(e);
1721
1722         writel(F_PL_INTR_SGE_DATA, adapter->regs + A_PL_CAUSE);
1723
1724         if (likely(e->GenerationBit == Q->genbit))
1725                 work_done = process_responses(adapter, -1);
1726         else
1727                 work_done = t1_slow_intr_handler(adapter);
1728
1729         /*
1730          * The unconditional clearing of the PL_CAUSE above may have raced
1731          * with DMA completion and the corresponding generation of a response
1732          * to cause us to miss the resulting data interrupt.  The next write
1733          * is also unconditional to recover the missed interrupt and render
1734          * this race harmless.
1735          */
1736         writel(Q->cidx, adapter->regs + A_SG_SLEEPING);
1737
1738         if (!work_done)
1739                 adapter->sge->stats.unhandled_irqs++;
1740         spin_unlock(&adapter->async_lock);
1741         return IRQ_RETVAL(work_done != 0);
1742 }
1743 #endif
1744
1745 /*
1746  * Enqueues the sk_buff onto the cmdQ[qid] and has hardware fetch it.
1747  *
1748  * The code figures out how many entries the sk_buff will require in the
1749  * cmdQ and updates the cmdQ data structure with the state once the enqueue
1750  * has complete. Then, it doesn't access the global structure anymore, but
1751  * uses the corresponding fields on the stack. In conjuction with a spinlock
1752  * around that code, we can make the function reentrant without holding the
1753  * lock when we actually enqueue (which might be expensive, especially on
1754  * architectures with IO MMUs).
1755  *
1756  * This runs with softirqs disabled.
1757  */
1758 static int t1_sge_tx(struct sk_buff *skb, struct adapter *adapter,
1759                      unsigned int qid, struct net_device *dev)
1760 {
1761         struct sge *sge = adapter->sge;
1762         struct cmdQ *q = &sge->cmdQ[qid];
1763         unsigned int credits, pidx, genbit, count, use_sched_skb = 0;
1764
1765         if (!spin_trylock(&q->lock))
1766                 return NETDEV_TX_LOCKED;
1767
1768         reclaim_completed_tx(sge, q);
1769
1770         pidx = q->pidx;
1771         credits = q->size - q->in_use;
1772         count = 1 + skb_shinfo(skb)->nr_frags;
1773         count += compute_large_page_tx_descs(skb);
1774
1775         /* Ethernet packet */
1776         if (unlikely(credits < count)) {
1777                 if (!netif_queue_stopped(dev)) {
1778                         netif_stop_queue(dev);
1779                         set_bit(dev->if_port, &sge->stopped_tx_queues);
1780                         sge->stats.cmdQ_full[2]++;
1781                         CH_ERR("%s: Tx ring full while queue awake!\n",
1782                                adapter->name);
1783                 }
1784                 spin_unlock(&q->lock);
1785                 return NETDEV_TX_BUSY;
1786         }
1787
1788         if (unlikely(credits - count < q->stop_thres)) {
1789                 netif_stop_queue(dev);
1790                 set_bit(dev->if_port, &sge->stopped_tx_queues);
1791                 sge->stats.cmdQ_full[2]++;
1792         }
1793
1794         /* T204 cmdQ0 skbs that are destined for a certain port have to go
1795          * through the scheduler.
1796          */
1797         if (sge->tx_sched && !qid && skb->dev) {
1798 use_sched:
1799                 use_sched_skb = 1;
1800                 /* Note that the scheduler might return a different skb than
1801                  * the one passed in.
1802                  */
1803                 skb = sched_skb(sge, skb, credits);
1804                 if (!skb) {
1805                         spin_unlock(&q->lock);
1806                         return NETDEV_TX_OK;
1807                 }
1808                 pidx = q->pidx;
1809                 count = 1 + skb_shinfo(skb)->nr_frags;
1810                 count += compute_large_page_tx_descs(skb);
1811         }
1812
1813         q->in_use += count;
1814         genbit = q->genbit;
1815         pidx = q->pidx;
1816         q->pidx += count;
1817         if (q->pidx >= q->size) {
1818                 q->pidx -= q->size;
1819                 q->genbit ^= 1;
1820         }
1821         spin_unlock(&q->lock);
1822
1823         write_tx_descs(adapter, skb, pidx, genbit, q);
1824
1825         /*
1826          * We always ring the doorbell for cmdQ1.  For cmdQ0, we only ring
1827          * the doorbell if the Q is asleep. There is a natural race, where
1828          * the hardware is going to sleep just after we checked, however,
1829          * then the interrupt handler will detect the outstanding TX packet
1830          * and ring the doorbell for us.
1831          */
1832         if (qid)
1833                 doorbell_pio(adapter, F_CMDQ1_ENABLE);
1834         else {
1835                 clear_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
1836                 if (test_and_set_bit(CMDQ_STAT_RUNNING, &q->status) == 0) {
1837                         set_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
1838                         writel(F_CMDQ0_ENABLE, adapter->regs + A_SG_DOORBELL);
1839                 }
1840         }
1841
1842         if (use_sched_skb) {
1843                 if (spin_trylock(&q->lock)) {
1844                         credits = q->size - q->in_use;
1845                         skb = NULL;
1846                         goto use_sched;
1847                 }
1848         }
1849         return NETDEV_TX_OK;
1850 }
1851
1852 #define MK_ETH_TYPE_MSS(type, mss) (((mss) & 0x3FFF) | ((type) << 14))
1853
1854 /*
1855  *      eth_hdr_len - return the length of an Ethernet header
1856  *      @data: pointer to the start of the Ethernet header
1857  *
1858  *      Returns the length of an Ethernet header, including optional VLAN tag.
1859  */
1860 static inline int eth_hdr_len(const void *data)
1861 {
1862         const struct ethhdr *e = data;
1863
1864         return e->h_proto == htons(ETH_P_8021Q) ? VLAN_ETH_HLEN : ETH_HLEN;
1865 }
1866
1867 /*
1868  * Adds the CPL header to the sk_buff and passes it to t1_sge_tx.
1869  */
1870 int t1_start_xmit(struct sk_buff *skb, struct net_device *dev)
1871 {
1872         struct adapter *adapter = dev->priv;
1873         struct sge *sge = adapter->sge;
1874         struct sge_port_stats *st = per_cpu_ptr(sge->port_stats[dev->if_port], smp_processor_id());
1875         struct cpl_tx_pkt *cpl;
1876         struct sk_buff *orig_skb = skb;
1877         int ret;
1878
1879         if (skb->protocol == htons(ETH_P_CPL5))
1880                 goto send;
1881
1882         if (skb_shinfo(skb)->gso_size) {
1883                 int eth_type;
1884                 struct cpl_tx_pkt_lso *hdr;
1885
1886                 ++st->tx_tso;
1887
1888                 eth_type = skb->nh.raw - skb->data == ETH_HLEN ?
1889                         CPL_ETH_II : CPL_ETH_II_VLAN;
1890
1891                 hdr = (struct cpl_tx_pkt_lso *)skb_push(skb, sizeof(*hdr));
1892                 hdr->opcode = CPL_TX_PKT_LSO;
1893                 hdr->ip_csum_dis = hdr->l4_csum_dis = 0;
1894                 hdr->ip_hdr_words = skb->nh.iph->ihl;
1895                 hdr->tcp_hdr_words = skb->h.th->doff;
1896                 hdr->eth_type_mss = htons(MK_ETH_TYPE_MSS(eth_type,
1897                                                           skb_shinfo(skb)->gso_size));
1898                 hdr->len = htonl(skb->len - sizeof(*hdr));
1899                 cpl = (struct cpl_tx_pkt *)hdr;
1900         } else {
1901                 /*
1902                  * Packets shorter than ETH_HLEN can break the MAC, drop them
1903                  * early.  Also, we may get oversized packets because some
1904                  * parts of the kernel don't handle our unusual hard_header_len
1905                  * right, drop those too.
1906                  */
1907                 if (unlikely(skb->len < ETH_HLEN ||
1908                              skb->len > dev->mtu + eth_hdr_len(skb->data))) {
1909                         pr_debug("%s: packet size %d hdr %d mtu%d\n", dev->name,
1910                                  skb->len, eth_hdr_len(skb->data), dev->mtu);
1911                         dev_kfree_skb_any(skb);
1912                         return NETDEV_TX_OK;
1913                 }
1914
1915                 /*
1916                  * We are using a non-standard hard_header_len and some kernel
1917                  * components, such as pktgen, do not handle it right.
1918                  * Complain when this happens but try to fix things up.
1919                  */
1920                 if (unlikely(skb_headroom(skb) < dev->hard_header_len - ETH_HLEN)) {
1921                         pr_debug("%s: headroom %d header_len %d\n", dev->name,
1922                                  skb_headroom(skb), dev->hard_header_len);
1923
1924                         if (net_ratelimit())
1925                                 printk(KERN_ERR "%s: inadequate headroom in "
1926                                        "Tx packet\n", dev->name);
1927                         skb = skb_realloc_headroom(skb, sizeof(*cpl));
1928                         dev_kfree_skb_any(orig_skb);
1929                         if (!skb)
1930                                 return NETDEV_TX_OK;
1931                 }
1932
1933                 if (!(adapter->flags & UDP_CSUM_CAPABLE) &&
1934                     skb->ip_summed == CHECKSUM_PARTIAL &&
1935                     skb->nh.iph->protocol == IPPROTO_UDP) {
1936                         if (unlikely(skb_checksum_help(skb))) {
1937                                 pr_debug("%s: unable to do udp checksum\n", dev->name);
1938                                 dev_kfree_skb_any(skb);
1939                                 return NETDEV_TX_OK;
1940                         }
1941                 }
1942
1943                 /* Hmmm, assuming to catch the gratious arp... and we'll use
1944                  * it to flush out stuck espi packets...
1945                  */
1946                 if ((unlikely(!adapter->sge->espibug_skb[dev->if_port]))) {
1947                         if (skb->protocol == htons(ETH_P_ARP) &&
1948                             skb->nh.arph->ar_op == htons(ARPOP_REQUEST)) {
1949                                 adapter->sge->espibug_skb[dev->if_port] = skb;
1950                                 /* We want to re-use this skb later. We
1951                                  * simply bump the reference count and it
1952                                  * will not be freed...
1953                                  */
1954                                 skb = skb_get(skb);
1955                         }
1956                 }
1957
1958                 cpl = (struct cpl_tx_pkt *)__skb_push(skb, sizeof(*cpl));
1959                 cpl->opcode = CPL_TX_PKT;
1960                 cpl->ip_csum_dis = 1;    /* SW calculates IP csum */
1961                 cpl->l4_csum_dis = skb->ip_summed == CHECKSUM_PARTIAL ? 0 : 1;
1962                 /* the length field isn't used so don't bother setting it */
1963
1964                 st->tx_cso += (skb->ip_summed == CHECKSUM_PARTIAL);
1965         }
1966         cpl->iff = dev->if_port;
1967
1968 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
1969         if (adapter->vlan_grp && vlan_tx_tag_present(skb)) {
1970                 cpl->vlan_valid = 1;
1971                 cpl->vlan = htons(vlan_tx_tag_get(skb));
1972                 st->vlan_insert++;
1973         } else
1974 #endif
1975                 cpl->vlan_valid = 0;
1976
1977 send:
1978         st->tx_packets++;
1979         dev->trans_start = jiffies;
1980         ret = t1_sge_tx(skb, adapter, 0, dev);
1981
1982         /* If transmit busy, and we reallocated skb's due to headroom limit,
1983          * then silently discard to avoid leak.
1984          */
1985         if (unlikely(ret != NETDEV_TX_OK && skb != orig_skb)) {
1986                 dev_kfree_skb_any(skb);
1987                 ret = NETDEV_TX_OK;
1988         }
1989         return ret;
1990 }
1991
1992 /*
1993  * Callback for the Tx buffer reclaim timer.  Runs with softirqs disabled.
1994  */
1995 static void sge_tx_reclaim_cb(unsigned long data)
1996 {
1997         int i;
1998         struct sge *sge = (struct sge *)data;
1999
2000         for (i = 0; i < SGE_CMDQ_N; ++i) {
2001                 struct cmdQ *q = &sge->cmdQ[i];
2002
2003                 if (!spin_trylock(&q->lock))
2004                         continue;
2005
2006                 reclaim_completed_tx(sge, q);
2007                 if (i == 0 && q->in_use) {    /* flush pending credits */
2008                         writel(F_CMDQ0_ENABLE, sge->adapter->regs + A_SG_DOORBELL);
2009                 }
2010                 spin_unlock(&q->lock);
2011         }
2012         mod_timer(&sge->tx_reclaim_timer, jiffies + TX_RECLAIM_PERIOD);
2013 }
2014
2015 /*
2016  * Propagate changes of the SGE coalescing parameters to the HW.
2017  */
2018 int t1_sge_set_coalesce_params(struct sge *sge, struct sge_params *p)
2019 {
2020         sge->fixed_intrtimer = p->rx_coalesce_usecs *
2021                 core_ticks_per_usec(sge->adapter);
2022         writel(sge->fixed_intrtimer, sge->adapter->regs + A_SG_INTRTIMER);
2023         return 0;
2024 }
2025
2026 /*
2027  * Allocates both RX and TX resources and configures the SGE. However,
2028  * the hardware is not enabled yet.
2029  */
2030 int t1_sge_configure(struct sge *sge, struct sge_params *p)
2031 {
2032         if (alloc_rx_resources(sge, p))
2033                 return -ENOMEM;
2034         if (alloc_tx_resources(sge, p)) {
2035                 free_rx_resources(sge);
2036                 return -ENOMEM;
2037         }
2038         configure_sge(sge, p);
2039
2040         /*
2041          * Now that we have sized the free lists calculate the payload
2042          * capacity of the large buffers.  Other parts of the driver use
2043          * this to set the max offload coalescing size so that RX packets
2044          * do not overflow our large buffers.
2045          */
2046         p->large_buf_capacity = jumbo_payload_capacity(sge);
2047         return 0;
2048 }
2049
2050 /*
2051  * Disables the DMA engine.
2052  */
2053 void t1_sge_stop(struct sge *sge)
2054 {
2055         int i;
2056         writel(0, sge->adapter->regs + A_SG_CONTROL);
2057         readl(sge->adapter->regs + A_SG_CONTROL); /* flush */
2058
2059         if (is_T2(sge->adapter))
2060                 del_timer_sync(&sge->espibug_timer);
2061
2062         del_timer_sync(&sge->tx_reclaim_timer);
2063         if (sge->tx_sched)
2064                 tx_sched_stop(sge);
2065
2066         for (i = 0; i < MAX_NPORTS; i++)
2067                 if (sge->espibug_skb[i])
2068                         kfree_skb(sge->espibug_skb[i]);
2069 }
2070
2071 /*
2072  * Enables the DMA engine.
2073  */
2074 void t1_sge_start(struct sge *sge)
2075 {
2076         refill_free_list(sge, &sge->freelQ[0]);
2077         refill_free_list(sge, &sge->freelQ[1]);
2078
2079         writel(sge->sge_control, sge->adapter->regs + A_SG_CONTROL);
2080         doorbell_pio(sge->adapter, F_FL0_ENABLE | F_FL1_ENABLE);
2081         readl(sge->adapter->regs + A_SG_CONTROL); /* flush */
2082
2083         mod_timer(&sge->tx_reclaim_timer, jiffies + TX_RECLAIM_PERIOD);
2084
2085         if (is_T2(sge->adapter))
2086                 mod_timer(&sge->espibug_timer, jiffies + sge->espibug_timeout);
2087 }
2088
2089 /*
2090  * Callback for the T2 ESPI 'stuck packet feature' workaorund
2091  */
2092 static void espibug_workaround_t204(unsigned long data)
2093 {
2094         struct adapter *adapter = (struct adapter *)data;
2095         struct sge *sge = adapter->sge;
2096         unsigned int nports = adapter->params.nports;
2097         u32 seop[MAX_NPORTS];
2098
2099         if (adapter->open_device_map & PORT_MASK) {
2100                 int i;
2101
2102                 if (t1_espi_get_mon_t204(adapter, &(seop[0]), 0) < 0)
2103                         return;
2104
2105                 for (i = 0; i < nports; i++) {
2106                         struct sk_buff *skb = sge->espibug_skb[i];
2107
2108                         if (!netif_running(adapter->port[i].dev) ||
2109                             netif_queue_stopped(adapter->port[i].dev) ||
2110                             !seop[i] || ((seop[i] & 0xfff) != 0) || !skb)
2111                                 continue;
2112
2113                         if (!skb->cb[0]) {
2114                                 u8 ch_mac_addr[ETH_ALEN] = {
2115                                         0x0, 0x7, 0x43, 0x0, 0x0, 0x0
2116                                 };
2117
2118                                 memcpy(skb->data + sizeof(struct cpl_tx_pkt),
2119                                         ch_mac_addr, ETH_ALEN);
2120                                 memcpy(skb->data + skb->len - 10,
2121                                         ch_mac_addr, ETH_ALEN);
2122                                 skb->cb[0] = 0xff;
2123                         }
2124
2125                         /* bump the reference count to avoid freeing of
2126                          * the skb once the DMA has completed.
2127                          */
2128                         skb = skb_get(skb);
2129                         t1_sge_tx(skb, adapter, 0, adapter->port[i].dev);
2130                 }
2131         }
2132         mod_timer(&sge->espibug_timer, jiffies + sge->espibug_timeout);
2133 }
2134
2135 static void espibug_workaround(unsigned long data)
2136 {
2137         struct adapter *adapter = (struct adapter *)data;
2138         struct sge *sge = adapter->sge;
2139
2140         if (netif_running(adapter->port[0].dev)) {
2141                 struct sk_buff *skb = sge->espibug_skb[0];
2142                 u32 seop = t1_espi_get_mon(adapter, 0x930, 0);
2143
2144                 if ((seop & 0xfff0fff) == 0xfff && skb) {
2145                         if (!skb->cb[0]) {
2146                                 u8 ch_mac_addr[ETH_ALEN] =
2147                                     {0x0, 0x7, 0x43, 0x0, 0x0, 0x0};
2148                                 memcpy(skb->data + sizeof(struct cpl_tx_pkt),
2149                                        ch_mac_addr, ETH_ALEN);
2150                                 memcpy(skb->data + skb->len - 10, ch_mac_addr,
2151                                        ETH_ALEN);
2152                                 skb->cb[0] = 0xff;
2153                         }
2154
2155                         /* bump the reference count to avoid freeing of the
2156                          * skb once the DMA has completed.
2157                          */
2158                         skb = skb_get(skb);
2159                         t1_sge_tx(skb, adapter, 0, adapter->port[0].dev);
2160                 }
2161         }
2162         mod_timer(&sge->espibug_timer, jiffies + sge->espibug_timeout);
2163 }
2164
2165 /*
2166  * Creates a t1_sge structure and returns suggested resource parameters.
2167  */
2168 struct sge * __devinit t1_sge_create(struct adapter *adapter,
2169                                      struct sge_params *p)
2170 {
2171         struct sge *sge = kzalloc(sizeof(*sge), GFP_KERNEL);
2172         int i;
2173
2174         if (!sge)
2175                 return NULL;
2176
2177         sge->adapter = adapter;
2178         sge->netdev = adapter->port[0].dev;
2179         sge->rx_pkt_pad = t1_is_T1B(adapter) ? 0 : 2;
2180         sge->jumbo_fl = t1_is_T1B(adapter) ? 1 : 0;
2181
2182         for_each_port(adapter, i) {
2183                 sge->port_stats[i] = alloc_percpu(struct sge_port_stats);
2184                 if (!sge->port_stats[i])
2185                         goto nomem_port;
2186         }
2187
2188         init_timer(&sge->tx_reclaim_timer);
2189         sge->tx_reclaim_timer.data = (unsigned long)sge;
2190         sge->tx_reclaim_timer.function = sge_tx_reclaim_cb;
2191
2192         if (is_T2(sge->adapter)) {
2193                 init_timer(&sge->espibug_timer);
2194
2195                 if (adapter->params.nports > 1) {
2196                         tx_sched_init(sge);
2197                         sge->espibug_timer.function = espibug_workaround_t204;
2198                 } else
2199                         sge->espibug_timer.function = espibug_workaround;
2200                 sge->espibug_timer.data = (unsigned long)sge->adapter;
2201
2202                 sge->espibug_timeout = 1;
2203                 /* for T204, every 10ms */
2204                 if (adapter->params.nports > 1)
2205                         sge->espibug_timeout = HZ/100;
2206         }
2207
2208
2209         p->cmdQ_size[0] = SGE_CMDQ0_E_N;
2210         p->cmdQ_size[1] = SGE_CMDQ1_E_N;
2211         p->freelQ_size[!sge->jumbo_fl] = SGE_FREEL_SIZE;
2212         p->freelQ_size[sge->jumbo_fl] = SGE_JUMBO_FREEL_SIZE;
2213         if (sge->tx_sched) {
2214                 if (board_info(sge->adapter)->board == CHBT_BOARD_CHT204)
2215                         p->rx_coalesce_usecs = 15;
2216                 else
2217                         p->rx_coalesce_usecs = 50;
2218         } else
2219                 p->rx_coalesce_usecs = 50;
2220
2221         p->coalesce_enable = 0;
2222         p->sample_interval_usecs = 0;
2223
2224         return sge;
2225 nomem_port:
2226         while (i >= 0) {
2227                 free_percpu(sge->port_stats[i]);
2228                 --i;
2229         }
2230         kfree(sge);
2231         return NULL;
2232
2233 }