linux/drivers/net/ethernet/chelsio/cxgb/sge.c
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   1/*****************************************************************************
   2 *                                                                           *
   3 * File: sge.c                                                               *
   4 * $Revision: 1.26 $                                                         *
   5 * $Date: 2005/06/21 18:29:48 $                                              *
   6 * Description:                                                              *
   7 *  DMA engine.                                                              *
   8 *  part of the Chelsio 10Gb Ethernet Driver.                                *
   9 *                                                                           *
  10 * This program is free software; you can redistribute it and/or modify      *
  11 * it under the terms of the GNU General Public License, version 2, as       *
  12 * published by the Free Software Foundation.                                *
  13 *                                                                           *
  14 * You should have received a copy of the GNU General Public License along   *
  15 * with this program; if not, write to the Free Software Foundation, Inc.,   *
  16 * 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.                 *
  17 *                                                                           *
  18 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED    *
  19 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF      *
  20 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.                     *
  21 *                                                                           *
  22 * http://www.chelsio.com                                                    *
  23 *                                                                           *
  24 * Copyright (c) 2003 - 2005 Chelsio Communications, Inc.                    *
  25 * All rights reserved.                                                      *
  26 *                                                                           *
  27 * Maintainers: maintainers@chelsio.com                                      *
  28 *                                                                           *
  29 * Authors: Dimitrios Michailidis   <dm@chelsio.com>                         *
  30 *          Tina Yang               <tainay@chelsio.com>                     *
  31 *          Felix Marti             <felix@chelsio.com>                      *
  32 *          Scott Bardone           <sbardone@chelsio.com>                   *
  33 *          Kurt Ottaway            <kottaway@chelsio.com>                   *
  34 *          Frank DiMambro          <frank@chelsio.com>                      *
  35 *                                                                           *
  36 * History:                                                                  *
  37 *                                                                           *
  38 ****************************************************************************/
  39
  40#include "common.h"
  41
  42#include <linux/types.h>
  43#include <linux/errno.h>
  44#include <linux/pci.h>
  45#include <linux/ktime.h>
  46#include <linux/netdevice.h>
  47#include <linux/etherdevice.h>
  48#include <linux/if_vlan.h>
  49#include <linux/skbuff.h>
  50#include <linux/init.h>
  51#include <linux/mm.h>
  52#include <linux/tcp.h>
  53#include <linux/ip.h>
  54#include <linux/in.h>
  55#include <linux/if_arp.h>
  56#include <linux/slab.h>
  57#include <linux/prefetch.h>
  58
  59#include "cpl5_cmd.h"
  60#include "sge.h"
  61#include "regs.h"
  62#include "espi.h"
  63
  64/* This belongs in if_ether.h */
  65#define ETH_P_CPL5 0xf
  66
  67#define SGE_CMDQ_N              2
  68#define SGE_FREELQ_N            2
  69#define SGE_CMDQ0_E_N           1024
  70#define SGE_CMDQ1_E_N           128
  71#define SGE_FREEL_SIZE          4096
  72#define SGE_JUMBO_FREEL_SIZE    512
  73#define SGE_FREEL_REFILL_THRESH 16
  74#define SGE_RESPQ_E_N           1024
  75#define SGE_INTRTIMER_NRES      1000
  76#define SGE_RX_SM_BUF_SIZE      1536
  77#define SGE_TX_DESC_MAX_PLEN    16384
  78
  79#define SGE_RESPQ_REPLENISH_THRES (SGE_RESPQ_E_N / 4)
  80
  81/*
  82 * Period of the TX buffer reclaim timer.  This timer does not need to run
  83 * frequently as TX buffers are usually reclaimed by new TX packets.
  84 */
  85#define TX_RECLAIM_PERIOD (HZ / 4)
  86
  87#define M_CMD_LEN       0x7fffffff
  88#define V_CMD_LEN(v)    (v)
  89#define G_CMD_LEN(v)    ((v) & M_CMD_LEN)
  90#define V_CMD_GEN1(v)   ((v) << 31)
  91#define V_CMD_GEN2(v)   (v)
  92#define F_CMD_DATAVALID (1 << 1)
  93#define F_CMD_SOP       (1 << 2)
  94#define V_CMD_EOP(v)    ((v) << 3)
  95
  96/*
  97 * Command queue, receive buffer list, and response queue descriptors.
  98 */
  99#if defined(__BIG_ENDIAN_BITFIELD)
 100struct cmdQ_e {
 101        u32 addr_lo;
 102        u32 len_gen;
 103        u32 flags;
 104        u32 addr_hi;
 105};
 106
 107struct freelQ_e {
 108        u32 addr_lo;
 109        u32 len_gen;
 110        u32 gen2;
 111        u32 addr_hi;
 112};
 113
 114struct respQ_e {
 115        u32 Qsleeping           : 4;
 116        u32 Cmdq1CreditReturn   : 5;
 117        u32 Cmdq1DmaComplete    : 5;
 118        u32 Cmdq0CreditReturn   : 5;
 119        u32 Cmdq0DmaComplete    : 5;
 120        u32 FreelistQid         : 2;
 121        u32 CreditValid         : 1;
 122        u32 DataValid           : 1;
 123        u32 Offload             : 1;
 124        u32 Eop                 : 1;
 125        u32 Sop                 : 1;
 126        u32 GenerationBit       : 1;
 127        u32 BufferLength;
 128};
 129#elif defined(__LITTLE_ENDIAN_BITFIELD)
 130struct cmdQ_e {
 131        u32 len_gen;
 132        u32 addr_lo;
 133        u32 addr_hi;
 134        u32 flags;
 135};
 136
 137struct freelQ_e {
 138        u32 len_gen;
 139        u32 addr_lo;
 140        u32 addr_hi;
 141        u32 gen2;
 142};
 143
 144struct respQ_e {
 145        u32 BufferLength;
 146        u32 GenerationBit       : 1;
 147        u32 Sop                 : 1;
 148        u32 Eop                 : 1;
 149        u32 Offload             : 1;
 150        u32 DataValid           : 1;
 151        u32 CreditValid         : 1;
 152        u32 FreelistQid         : 2;
 153        u32 Cmdq0DmaComplete    : 5;
 154        u32 Cmdq0CreditReturn   : 5;
 155        u32 Cmdq1DmaComplete    : 5;
 156        u32 Cmdq1CreditReturn   : 5;
 157        u32 Qsleeping           : 4;
 158} ;
 159#endif
 160
 161/*
 162 * SW Context Command and Freelist Queue Descriptors
 163 */
 164struct cmdQ_ce {
 165        struct sk_buff *skb;
 166        DEFINE_DMA_UNMAP_ADDR(dma_addr);
 167        DEFINE_DMA_UNMAP_LEN(dma_len);
 168};
 169
 170struct freelQ_ce {
 171        struct sk_buff *skb;
 172        DEFINE_DMA_UNMAP_ADDR(dma_addr);
 173        DEFINE_DMA_UNMAP_LEN(dma_len);
 174};
 175
 176/*
 177 * SW command, freelist and response rings
 178 */
 179struct cmdQ {
 180        unsigned long   status;         /* HW DMA fetch status */
 181        unsigned int    in_use;         /* # of in-use command descriptors */
 182        unsigned int    size;           /* # of descriptors */
 183        unsigned int    processed;      /* total # of descs HW has processed */
 184        unsigned int    cleaned;        /* total # of descs SW has reclaimed */
 185        unsigned int    stop_thres;     /* SW TX queue suspend threshold */
 186        u16             pidx;           /* producer index (SW) */
 187        u16             cidx;           /* consumer index (HW) */
 188        u8              genbit;         /* current generation (=valid) bit */
 189        u8              sop;            /* is next entry start of packet? */
 190        struct cmdQ_e  *entries;        /* HW command descriptor Q */
 191        struct cmdQ_ce *centries;       /* SW command context descriptor Q */
 192        dma_addr_t      dma_addr;       /* DMA addr HW command descriptor Q */
 193        spinlock_t      lock;           /* Lock to protect cmdQ enqueuing */
 194};
 195
 196struct freelQ {
 197        unsigned int    credits;        /* # of available RX buffers */
 198        unsigned int    size;           /* free list capacity */
 199        u16             pidx;           /* producer index (SW) */
 200        u16             cidx;           /* consumer index (HW) */
 201        u16             rx_buffer_size; /* Buffer size on this free list */
 202        u16             dma_offset;     /* DMA offset to align IP headers */
 203        u16             recycleq_idx;   /* skb recycle q to use */
 204        u8              genbit;         /* current generation (=valid) bit */
 205        struct freelQ_e *entries;       /* HW freelist descriptor Q */
 206        struct freelQ_ce *centries;     /* SW freelist context descriptor Q */
 207        dma_addr_t      dma_addr;       /* DMA addr HW freelist descriptor Q */
 208};
 209
 210struct respQ {
 211        unsigned int    credits;        /* credits to be returned to SGE */
 212        unsigned int    size;           /* # of response Q descriptors */
 213        u16             cidx;           /* consumer index (SW) */
 214        u8              genbit;         /* current generation(=valid) bit */
 215        struct respQ_e *entries;        /* HW response descriptor Q */
 216        dma_addr_t      dma_addr;       /* DMA addr HW response descriptor Q */
 217};
 218
 219/* Bit flags for cmdQ.status */
 220enum {
 221        CMDQ_STAT_RUNNING = 1,          /* fetch engine is running */
 222        CMDQ_STAT_LAST_PKT_DB = 2       /* last packet rung the doorbell */
 223};
 224
 225/* T204 TX SW scheduler */
 226
 227/* Per T204 TX port */
 228struct sched_port {
 229        unsigned int    avail;          /* available bits - quota */
 230        unsigned int    drain_bits_per_1024ns; /* drain rate */
 231        unsigned int    speed;          /* drain rate, mbps */
 232        unsigned int    mtu;            /* mtu size */
 233        struct sk_buff_head skbq;       /* pending skbs */
 234};
 235
 236/* Per T204 device */
 237struct sched {
 238        ktime_t         last_updated;   /* last time quotas were computed */
 239        unsigned int    max_avail;      /* max bits to be sent to any port */
 240        unsigned int    port;           /* port index (round robin ports) */
 241        unsigned int    num;            /* num skbs in per port queues */
 242        struct sched_port p[MAX_NPORTS];
 243        struct tasklet_struct sched_tsk;/* tasklet used to run scheduler */
 244};
 245static void restart_sched(unsigned long);
 246
 247
 248/*
 249 * Main SGE data structure
 250 *
 251 * Interrupts are handled by a single CPU and it is likely that on a MP system
 252 * the application is migrated to another CPU. In that scenario, we try to
 253 * separate the RX(in irq context) and TX state in order to decrease memory
 254 * contention.
 255 */
 256struct sge {
 257        struct adapter *adapter;        /* adapter backpointer */
 258        struct net_device *netdev;      /* netdevice backpointer */
 259        struct freelQ   freelQ[SGE_FREELQ_N]; /* buffer free lists */
 260        struct respQ    respQ;          /* response Q */
 261        unsigned long   stopped_tx_queues; /* bitmap of suspended Tx queues */
 262        unsigned int    rx_pkt_pad;     /* RX padding for L2 packets */
 263        unsigned int    jumbo_fl;       /* jumbo freelist Q index */
 264        unsigned int    intrtimer_nres; /* no-resource interrupt timer */
 265        unsigned int    fixed_intrtimer;/* non-adaptive interrupt timer */
 266        struct timer_list tx_reclaim_timer; /* reclaims TX buffers */
 267        struct timer_list espibug_timer;
 268        unsigned long   espibug_timeout;
 269        struct sk_buff  *espibug_skb[MAX_NPORTS];
 270        u32             sge_control;    /* shadow value of sge control reg */
 271        struct sge_intr_counts stats;
 272        struct sge_port_stats __percpu *port_stats[MAX_NPORTS];
 273        struct sched    *tx_sched;
 274        struct cmdQ cmdQ[SGE_CMDQ_N] ____cacheline_aligned_in_smp;
 275};
 276
 277static const u8 ch_mac_addr[ETH_ALEN] = {
 278        0x0, 0x7, 0x43, 0x0, 0x0, 0x0
 279};
 280
 281/*
 282 * stop tasklet and free all pending skb's
 283 */
 284static void tx_sched_stop(struct sge *sge)
 285{
 286        struct sched *s = sge->tx_sched;
 287        int i;
 288
 289        tasklet_kill(&s->sched_tsk);
 290
 291        for (i = 0; i < MAX_NPORTS; i++)
 292                __skb_queue_purge(&s->p[s->port].skbq);
 293}
 294
 295/*
 296 * t1_sched_update_parms() is called when the MTU or link speed changes. It
 297 * re-computes scheduler parameters to scope with the change.
 298 */
 299unsigned int t1_sched_update_parms(struct sge *sge, unsigned int port,
 300                                   unsigned int mtu, unsigned int speed)
 301{
 302        struct sched *s = sge->tx_sched;
 303        struct sched_port *p = &s->p[port];
 304        unsigned int max_avail_segs;
 305
 306        pr_debug("t1_sched_update_params mtu=%d speed=%d\n", mtu, speed);
 307        if (speed)
 308                p->speed = speed;
 309        if (mtu)
 310                p->mtu = mtu;
 311
 312        if (speed || mtu) {
 313                unsigned long long drain = 1024ULL * p->speed * (p->mtu - 40);
 314                do_div(drain, (p->mtu + 50) * 1000);
 315                p->drain_bits_per_1024ns = (unsigned int) drain;
 316
 317                if (p->speed < 1000)
 318                        p->drain_bits_per_1024ns =
 319                                90 * p->drain_bits_per_1024ns / 100;
 320        }
 321
 322        if (board_info(sge->adapter)->board == CHBT_BOARD_CHT204) {
 323                p->drain_bits_per_1024ns -= 16;
 324                s->max_avail = max(4096U, p->mtu + 16 + 14 + 4);
 325                max_avail_segs = max(1U, 4096 / (p->mtu - 40));
 326        } else {
 327                s->max_avail = 16384;
 328                max_avail_segs = max(1U, 9000 / (p->mtu - 40));
 329        }
 330
 331        pr_debug("t1_sched_update_parms: mtu %u speed %u max_avail %u "
 332                 "max_avail_segs %u drain_bits_per_1024ns %u\n", p->mtu,
 333                 p->speed, s->max_avail, max_avail_segs,
 334                 p->drain_bits_per_1024ns);
 335
 336        return max_avail_segs * (p->mtu - 40);
 337}
 338
 339#if 0
 340
 341/*
 342 * t1_sched_max_avail_bytes() tells the scheduler the maximum amount of
 343 * data that can be pushed per port.
 344 */
 345void t1_sched_set_max_avail_bytes(struct sge *sge, unsigned int val)
 346{
 347        struct sched *s = sge->tx_sched;
 348        unsigned int i;
 349
 350        s->max_avail = val;
 351        for (i = 0; i < MAX_NPORTS; i++)
 352                t1_sched_update_parms(sge, i, 0, 0);
 353}
 354
 355/*
 356 * t1_sched_set_drain_bits_per_us() tells the scheduler at which rate a port
 357 * is draining.
 358 */
 359void t1_sched_set_drain_bits_per_us(struct sge *sge, unsigned int port,
 360                                         unsigned int val)
 361{
 362        struct sched *s = sge->tx_sched;
 363        struct sched_port *p = &s->p[port];
 364        p->drain_bits_per_1024ns = val * 1024 / 1000;
 365        t1_sched_update_parms(sge, port, 0, 0);
 366}
 367
 368#endif  /*  0  */
 369
 370
 371/*
 372 * get_clock() implements a ns clock (see ktime_get)
 373 */
 374static inline ktime_t get_clock(void)
 375{
 376        struct timespec ts;
 377
 378        ktime_get_ts(&ts);
 379        return timespec_to_ktime(ts);
 380}
 381
 382/*
 383 * tx_sched_init() allocates resources and does basic initialization.
 384 */
 385static int tx_sched_init(struct sge *sge)
 386{
 387        struct sched *s;
 388        int i;
 389
 390        s = kzalloc(sizeof (struct sched), GFP_KERNEL);
 391        if (!s)
 392                return -ENOMEM;
 393
 394        pr_debug("tx_sched_init\n");
 395        tasklet_init(&s->sched_tsk, restart_sched, (unsigned long) sge);
 396        sge->tx_sched = s;
 397
 398        for (i = 0; i < MAX_NPORTS; i++) {
 399                skb_queue_head_init(&s->p[i].skbq);
 400                t1_sched_update_parms(sge, i, 1500, 1000);
 401        }
 402
 403        return 0;
 404}
 405
 406/*
 407 * sched_update_avail() computes the delta since the last time it was called
 408 * and updates the per port quota (number of bits that can be sent to the any
 409 * port).
 410 */
 411static inline int sched_update_avail(struct sge *sge)
 412{
 413        struct sched *s = sge->tx_sched;
 414        ktime_t now = get_clock();
 415        unsigned int i;
 416        long long delta_time_ns;
 417
 418        delta_time_ns = ktime_to_ns(ktime_sub(now, s->last_updated));
 419
 420        pr_debug("sched_update_avail delta=%lld\n", delta_time_ns);
 421        if (delta_time_ns < 15000)
 422                return 0;
 423
 424        for (i = 0; i < MAX_NPORTS; i++) {
 425                struct sched_port *p = &s->p[i];
 426                unsigned int delta_avail;
 427
 428                delta_avail = (p->drain_bits_per_1024ns * delta_time_ns) >> 13;
 429                p->avail = min(p->avail + delta_avail, s->max_avail);
 430        }
 431
 432        s->last_updated = now;
 433
 434        return 1;
 435}
 436
 437/*
 438 * sched_skb() is called from two different places. In the tx path, any
 439 * packet generating load on an output port will call sched_skb()
 440 * (skb != NULL). In addition, sched_skb() is called from the irq/soft irq
 441 * context (skb == NULL).
 442 * The scheduler only returns a skb (which will then be sent) if the
 443 * length of the skb is <= the current quota of the output port.
 444 */
 445static struct sk_buff *sched_skb(struct sge *sge, struct sk_buff *skb,
 446                                unsigned int credits)
 447{
 448        struct sched *s = sge->tx_sched;
 449        struct sk_buff_head *skbq;
 450        unsigned int i, len, update = 1;
 451
 452        pr_debug("sched_skb %p\n", skb);
 453        if (!skb) {
 454                if (!s->num)
 455                        return NULL;
 456        } else {
 457                skbq = &s->p[skb->dev->if_port].skbq;
 458                __skb_queue_tail(skbq, skb);
 459                s->num++;
 460                skb = NULL;
 461        }
 462
 463        if (credits < MAX_SKB_FRAGS + 1)
 464                goto out;
 465
 466again:
 467        for (i = 0; i < MAX_NPORTS; i++) {
 468                s->port = (s->port + 1) & (MAX_NPORTS - 1);
 469                skbq = &s->p[s->port].skbq;
 470
 471                skb = skb_peek(skbq);
 472
 473                if (!skb)
 474                        continue;
 475
 476                len = skb->len;
 477                if (len <= s->p[s->port].avail) {
 478                        s->p[s->port].avail -= len;
 479                        s->num--;
 480                        __skb_unlink(skb, skbq);
 481                        goto out;
 482                }
 483                skb = NULL;
 484        }
 485
 486        if (update-- && sched_update_avail(sge))
 487                goto again;
 488
 489out:
 490        /* If there are more pending skbs, we use the hardware to schedule us
 491         * again.
 492         */
 493        if (s->num && !skb) {
 494                struct cmdQ *q = &sge->cmdQ[0];
 495                clear_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
 496                if (test_and_set_bit(CMDQ_STAT_RUNNING, &q->status) == 0) {
 497                        set_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
 498                        writel(F_CMDQ0_ENABLE, sge->adapter->regs + A_SG_DOORBELL);
 499                }
 500        }
 501        pr_debug("sched_skb ret %p\n", skb);
 502
 503        return skb;
 504}
 505
 506/*
 507 * PIO to indicate that memory mapped Q contains valid descriptor(s).
 508 */
 509static inline void doorbell_pio(struct adapter *adapter, u32 val)
 510{
 511        wmb();
 512        writel(val, adapter->regs + A_SG_DOORBELL);
 513}
 514
 515/*
 516 * Frees all RX buffers on the freelist Q. The caller must make sure that
 517 * the SGE is turned off before calling this function.
 518 */
 519static void free_freelQ_buffers(struct pci_dev *pdev, struct freelQ *q)
 520{
 521        unsigned int cidx = q->cidx;
 522
 523        while (q->credits--) {
 524                struct freelQ_ce *ce = &q->centries[cidx];
 525
 526                pci_unmap_single(pdev, dma_unmap_addr(ce, dma_addr),
 527                                 dma_unmap_len(ce, dma_len),
 528                                 PCI_DMA_FROMDEVICE);
 529                dev_kfree_skb(ce->skb);
 530                ce->skb = NULL;
 531                if (++cidx == q->size)
 532                        cidx = 0;
 533        }
 534}
 535
 536/*
 537 * Free RX free list and response queue resources.
 538 */
 539static void free_rx_resources(struct sge *sge)
 540{
 541        struct pci_dev *pdev = sge->adapter->pdev;
 542        unsigned int size, i;
 543
 544        if (sge->respQ.entries) {
 545                size = sizeof(struct respQ_e) * sge->respQ.size;
 546                pci_free_consistent(pdev, size, sge->respQ.entries,
 547                                    sge->respQ.dma_addr);
 548        }
 549
 550        for (i = 0; i < SGE_FREELQ_N; i++) {
 551                struct freelQ *q = &sge->freelQ[i];
 552
 553                if (q->centries) {
 554                        free_freelQ_buffers(pdev, q);
 555                        kfree(q->centries);
 556                }
 557                if (q->entries) {
 558                        size = sizeof(struct freelQ_e) * q->size;
 559                        pci_free_consistent(pdev, size, q->entries,
 560                                            q->dma_addr);
 561                }
 562        }
 563}
 564
 565/*
 566 * Allocates basic RX resources, consisting of memory mapped freelist Qs and a
 567 * response queue.
 568 */
 569static int alloc_rx_resources(struct sge *sge, struct sge_params *p)
 570{
 571        struct pci_dev *pdev = sge->adapter->pdev;
 572        unsigned int size, i;
 573
 574        for (i = 0; i < SGE_FREELQ_N; i++) {
 575                struct freelQ *q = &sge->freelQ[i];
 576
 577                q->genbit = 1;
 578                q->size = p->freelQ_size[i];
 579                q->dma_offset = sge->rx_pkt_pad ? 0 : NET_IP_ALIGN;
 580                size = sizeof(struct freelQ_e) * q->size;
 581                q->entries = pci_alloc_consistent(pdev, size, &q->dma_addr);
 582                if (!q->entries)
 583                        goto err_no_mem;
 584
 585                size = sizeof(struct freelQ_ce) * q->size;
 586                q->centries = kzalloc(size, GFP_KERNEL);
 587                if (!q->centries)
 588                        goto err_no_mem;
 589        }
 590
 591        /*
 592         * Calculate the buffer sizes for the two free lists.  FL0 accommodates
 593         * regular sized Ethernet frames, FL1 is sized not to exceed 16K,
 594         * including all the sk_buff overhead.
 595         *
 596         * Note: For T2 FL0 and FL1 are reversed.
 597         */
 598        sge->freelQ[!sge->jumbo_fl].rx_buffer_size = SGE_RX_SM_BUF_SIZE +
 599                sizeof(struct cpl_rx_data) +
 600                sge->freelQ[!sge->jumbo_fl].dma_offset;
 601
 602                size = (16 * 1024) -
 603                    SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 604
 605        sge->freelQ[sge->jumbo_fl].rx_buffer_size = size;
 606
 607        /*
 608         * Setup which skb recycle Q should be used when recycling buffers from
 609         * each free list.
 610         */
 611        sge->freelQ[!sge->jumbo_fl].recycleq_idx = 0;
 612        sge->freelQ[sge->jumbo_fl].recycleq_idx = 1;
 613
 614        sge->respQ.genbit = 1;
 615        sge->respQ.size = SGE_RESPQ_E_N;
 616        sge->respQ.credits = 0;
 617        size = sizeof(struct respQ_e) * sge->respQ.size;
 618        sge->respQ.entries =
 619                pci_alloc_consistent(pdev, size, &sge->respQ.dma_addr);
 620        if (!sge->respQ.entries)
 621                goto err_no_mem;
 622        return 0;
 623
 624err_no_mem:
 625        free_rx_resources(sge);
 626        return -ENOMEM;
 627}
 628
 629/*
 630 * Reclaims n TX descriptors and frees the buffers associated with them.
 631 */
 632static void free_cmdQ_buffers(struct sge *sge, struct cmdQ *q, unsigned int n)
 633{
 634        struct cmdQ_ce *ce;
 635        struct pci_dev *pdev = sge->adapter->pdev;
 636        unsigned int cidx = q->cidx;
 637
 638        q->in_use -= n;
 639        ce = &q->centries[cidx];
 640        while (n--) {
 641                if (likely(dma_unmap_len(ce, dma_len))) {
 642                        pci_unmap_single(pdev, dma_unmap_addr(ce, dma_addr),
 643                                         dma_unmap_len(ce, dma_len),
 644                                         PCI_DMA_TODEVICE);
 645                        if (q->sop)
 646                                q->sop = 0;
 647                }
 648                if (ce->skb) {
 649                        dev_kfree_skb_any(ce->skb);
 650                        q->sop = 1;
 651                }
 652                ce++;
 653                if (++cidx == q->size) {
 654                        cidx = 0;
 655                        ce = q->centries;
 656                }
 657        }
 658        q->cidx = cidx;
 659}
 660
 661/*
 662 * Free TX resources.
 663 *
 664 * Assumes that SGE is stopped and all interrupts are disabled.
 665 */
 666static void free_tx_resources(struct sge *sge)
 667{
 668        struct pci_dev *pdev = sge->adapter->pdev;
 669        unsigned int size, i;
 670
 671        for (i = 0; i < SGE_CMDQ_N; i++) {
 672                struct cmdQ *q = &sge->cmdQ[i];
 673
 674                if (q->centries) {
 675                        if (q->in_use)
 676                                free_cmdQ_buffers(sge, q, q->in_use);
 677                        kfree(q->centries);
 678                }
 679                if (q->entries) {
 680                        size = sizeof(struct cmdQ_e) * q->size;
 681                        pci_free_consistent(pdev, size, q->entries,
 682                                            q->dma_addr);
 683                }
 684        }
 685}
 686
 687/*
 688 * Allocates basic TX resources, consisting of memory mapped command Qs.
 689 */
 690static int alloc_tx_resources(struct sge *sge, struct sge_params *p)
 691{
 692        struct pci_dev *pdev = sge->adapter->pdev;
 693        unsigned int size, i;
 694
 695        for (i = 0; i < SGE_CMDQ_N; i++) {
 696                struct cmdQ *q = &sge->cmdQ[i];
 697
 698                q->genbit = 1;
 699                q->sop = 1;
 700                q->size = p->cmdQ_size[i];
 701                q->in_use = 0;
 702                q->status = 0;
 703                q->processed = q->cleaned = 0;
 704                q->stop_thres = 0;
 705                spin_lock_init(&q->lock);
 706                size = sizeof(struct cmdQ_e) * q->size;
 707                q->entries = pci_alloc_consistent(pdev, size, &q->dma_addr);
 708                if (!q->entries)
 709                        goto err_no_mem;
 710
 711                size = sizeof(struct cmdQ_ce) * q->size;
 712                q->centries = kzalloc(size, GFP_KERNEL);
 713                if (!q->centries)
 714                        goto err_no_mem;
 715        }
 716
 717        /*
 718         * CommandQ 0 handles Ethernet and TOE packets, while queue 1 is TOE
 719         * only.  For queue 0 set the stop threshold so we can handle one more
 720         * packet from each port, plus reserve an additional 24 entries for
 721         * Ethernet packets only.  Queue 1 never suspends nor do we reserve
 722         * space for Ethernet packets.
 723         */
 724        sge->cmdQ[0].stop_thres = sge->adapter->params.nports *
 725                (MAX_SKB_FRAGS + 1);
 726        return 0;
 727
 728err_no_mem:
 729        free_tx_resources(sge);
 730        return -ENOMEM;
 731}
 732
 733static inline void setup_ring_params(struct adapter *adapter, u64 addr,
 734                                     u32 size, int base_reg_lo,
 735                                     int base_reg_hi, int size_reg)
 736{
 737        writel((u32)addr, adapter->regs + base_reg_lo);
 738        writel(addr >> 32, adapter->regs + base_reg_hi);
 739        writel(size, adapter->regs + size_reg);
 740}
 741
 742/*
 743 * Enable/disable VLAN acceleration.
 744 */
 745void t1_vlan_mode(struct adapter *adapter, u32 features)
 746{
 747        struct sge *sge = adapter->sge;
 748
 749        if (features & NETIF_F_HW_VLAN_RX)
 750                sge->sge_control |= F_VLAN_XTRACT;
 751        else
 752                sge->sge_control &= ~F_VLAN_XTRACT;
 753        if (adapter->open_device_map) {
 754                writel(sge->sge_control, adapter->regs + A_SG_CONTROL);
 755                readl(adapter->regs + A_SG_CONTROL);   /* flush */
 756        }
 757}
 758
 759/*
 760 * Programs the various SGE registers. However, the engine is not yet enabled,
 761 * but sge->sge_control is setup and ready to go.
 762 */
 763static void configure_sge(struct sge *sge, struct sge_params *p)
 764{
 765        struct adapter *ap = sge->adapter;
 766
 767        writel(0, ap->regs + A_SG_CONTROL);
 768        setup_ring_params(ap, sge->cmdQ[0].dma_addr, sge->cmdQ[0].size,
 769                          A_SG_CMD0BASELWR, A_SG_CMD0BASEUPR, A_SG_CMD0SIZE);
 770        setup_ring_params(ap, sge->cmdQ[1].dma_addr, sge->cmdQ[1].size,
 771                          A_SG_CMD1BASELWR, A_SG_CMD1BASEUPR, A_SG_CMD1SIZE);
 772        setup_ring_params(ap, sge->freelQ[0].dma_addr,
 773                          sge->freelQ[0].size, A_SG_FL0BASELWR,
 774                          A_SG_FL0BASEUPR, A_SG_FL0SIZE);
 775        setup_ring_params(ap, sge->freelQ[1].dma_addr,
 776                          sge->freelQ[1].size, A_SG_FL1BASELWR,
 777                          A_SG_FL1BASEUPR, A_SG_FL1SIZE);
 778
 779        /* The threshold comparison uses <. */
 780        writel(SGE_RX_SM_BUF_SIZE + 1, ap->regs + A_SG_FLTHRESHOLD);
 781
 782        setup_ring_params(ap, sge->respQ.dma_addr, sge->respQ.size,
 783                          A_SG_RSPBASELWR, A_SG_RSPBASEUPR, A_SG_RSPSIZE);
 784        writel((u32)sge->respQ.size - 1, ap->regs + A_SG_RSPQUEUECREDIT);
 785
 786        sge->sge_control = F_CMDQ0_ENABLE | F_CMDQ1_ENABLE | F_FL0_ENABLE |
 787                F_FL1_ENABLE | F_CPL_ENABLE | F_RESPONSE_QUEUE_ENABLE |
 788                V_CMDQ_PRIORITY(2) | F_DISABLE_CMDQ1_GTS | F_ISCSI_COALESCE |
 789                V_RX_PKT_OFFSET(sge->rx_pkt_pad);
 790
 791#if defined(__BIG_ENDIAN_BITFIELD)
 792        sge->sge_control |= F_ENABLE_BIG_ENDIAN;
 793#endif
 794
 795        /* Initialize no-resource timer */
 796        sge->intrtimer_nres = SGE_INTRTIMER_NRES * core_ticks_per_usec(ap);
 797
 798        t1_sge_set_coalesce_params(sge, p);
 799}
 800
 801/*
 802 * Return the payload capacity of the jumbo free-list buffers.
 803 */
 804static inline unsigned int jumbo_payload_capacity(const struct sge *sge)
 805{
 806        return sge->freelQ[sge->jumbo_fl].rx_buffer_size -
 807                sge->freelQ[sge->jumbo_fl].dma_offset -
 808                sizeof(struct cpl_rx_data);
 809}
 810
 811/*
 812 * Frees all SGE related resources and the sge structure itself
 813 */
 814void t1_sge_destroy(struct sge *sge)
 815{
 816        int i;
 817
 818        for_each_port(sge->adapter, i)
 819                free_percpu(sge->port_stats[i]);
 820
 821        kfree(sge->tx_sched);
 822        free_tx_resources(sge);
 823        free_rx_resources(sge);
 824        kfree(sge);
 825}
 826
 827/*
 828 * Allocates new RX buffers on the freelist Q (and tracks them on the freelist
 829 * context Q) until the Q is full or alloc_skb fails.
 830 *
 831 * It is possible that the generation bits already match, indicating that the
 832 * buffer is already valid and nothing needs to be done. This happens when we
 833 * copied a received buffer into a new sk_buff during the interrupt processing.
 834 *
 835 * If the SGE doesn't automatically align packets properly (!sge->rx_pkt_pad),
 836 * we specify a RX_OFFSET in order to make sure that the IP header is 4B
 837 * aligned.
 838 */
 839static void refill_free_list(struct sge *sge, struct freelQ *q)
 840{
 841        struct pci_dev *pdev = sge->adapter->pdev;
 842        struct freelQ_ce *ce = &q->centries[q->pidx];
 843        struct freelQ_e *e = &q->entries[q->pidx];
 844        unsigned int dma_len = q->rx_buffer_size - q->dma_offset;
 845
 846        while (q->credits < q->size) {
 847                struct sk_buff *skb;
 848                dma_addr_t mapping;
 849
 850                skb = alloc_skb(q->rx_buffer_size, GFP_ATOMIC);
 851                if (!skb)
 852                        break;
 853
 854                skb_reserve(skb, q->dma_offset);
 855                mapping = pci_map_single(pdev, skb->data, dma_len,
 856                                         PCI_DMA_FROMDEVICE);
 857                skb_reserve(skb, sge->rx_pkt_pad);
 858
 859                ce->skb = skb;
 860                dma_unmap_addr_set(ce, dma_addr, mapping);
 861                dma_unmap_len_set(ce, dma_len, dma_len);
 862                e->addr_lo = (u32)mapping;
 863                e->addr_hi = (u64)mapping >> 32;
 864                e->len_gen = V_CMD_LEN(dma_len) | V_CMD_GEN1(q->genbit);
 865                wmb();
 866                e->gen2 = V_CMD_GEN2(q->genbit);
 867
 868                e++;
 869                ce++;
 870                if (++q->pidx == q->size) {
 871                        q->pidx = 0;
 872                        q->genbit ^= 1;
 873                        ce = q->centries;
 874                        e = q->entries;
 875                }
 876                q->credits++;
 877        }
 878}
 879
 880/*
 881 * Calls refill_free_list for both free lists. If we cannot fill at least 1/4
 882 * of both rings, we go into 'few interrupt mode' in order to give the system
 883 * time to free up resources.
 884 */
 885static void freelQs_empty(struct sge *sge)
 886{
 887        struct adapter *adapter = sge->adapter;
 888        u32 irq_reg = readl(adapter->regs + A_SG_INT_ENABLE);
 889        u32 irqholdoff_reg;
 890
 891        refill_free_list(sge, &sge->freelQ[0]);
 892        refill_free_list(sge, &sge->freelQ[1]);
 893
 894        if (sge->freelQ[0].credits > (sge->freelQ[0].size >> 2) &&
 895            sge->freelQ[1].credits > (sge->freelQ[1].size >> 2)) {
 896                irq_reg |= F_FL_EXHAUSTED;
 897                irqholdoff_reg = sge->fixed_intrtimer;
 898        } else {
 899                /* Clear the F_FL_EXHAUSTED interrupts for now */
 900                irq_reg &= ~F_FL_EXHAUSTED;
 901                irqholdoff_reg = sge->intrtimer_nres;
 902        }
 903        writel(irqholdoff_reg, adapter->regs + A_SG_INTRTIMER);
 904        writel(irq_reg, adapter->regs + A_SG_INT_ENABLE);
 905
 906        /* We reenable the Qs to force a freelist GTS interrupt later */
 907        doorbell_pio(adapter, F_FL0_ENABLE | F_FL1_ENABLE);
 908}
 909
 910#define SGE_PL_INTR_MASK (F_PL_INTR_SGE_ERR | F_PL_INTR_SGE_DATA)
 911#define SGE_INT_FATAL (F_RESPQ_OVERFLOW | F_PACKET_TOO_BIG | F_PACKET_MISMATCH)
 912#define SGE_INT_ENABLE (F_RESPQ_EXHAUSTED | F_RESPQ_OVERFLOW | \
 913                        F_FL_EXHAUSTED | F_PACKET_TOO_BIG | F_PACKET_MISMATCH)
 914
 915/*
 916 * Disable SGE Interrupts
 917 */
 918void t1_sge_intr_disable(struct sge *sge)
 919{
 920        u32 val = readl(sge->adapter->regs + A_PL_ENABLE);
 921
 922        writel(val & ~SGE_PL_INTR_MASK, sge->adapter->regs + A_PL_ENABLE);
 923        writel(0, sge->adapter->regs + A_SG_INT_ENABLE);
 924}
 925
 926/*
 927 * Enable SGE interrupts.
 928 */
 929void t1_sge_intr_enable(struct sge *sge)
 930{
 931        u32 en = SGE_INT_ENABLE;
 932        u32 val = readl(sge->adapter->regs + A_PL_ENABLE);
 933
 934        if (sge->adapter->port[0].dev->hw_features & NETIF_F_TSO)
 935                en &= ~F_PACKET_TOO_BIG;
 936        writel(en, sge->adapter->regs + A_SG_INT_ENABLE);
 937        writel(val | SGE_PL_INTR_MASK, sge->adapter->regs + A_PL_ENABLE);
 938}
 939
 940/*
 941 * Clear SGE interrupts.
 942 */
 943void t1_sge_intr_clear(struct sge *sge)
 944{
 945        writel(SGE_PL_INTR_MASK, sge->adapter->regs + A_PL_CAUSE);
 946        writel(0xffffffff, sge->adapter->regs + A_SG_INT_CAUSE);
 947}
 948
 949/*
 950 * SGE 'Error' interrupt handler
 951 */
 952int t1_sge_intr_error_handler(struct sge *sge)
 953{
 954        struct adapter *adapter = sge->adapter;
 955        u32 cause = readl(adapter->regs + A_SG_INT_CAUSE);
 956
 957        if (adapter->port[0].dev->hw_features & NETIF_F_TSO)
 958                cause &= ~F_PACKET_TOO_BIG;
 959        if (cause & F_RESPQ_EXHAUSTED)
 960                sge->stats.respQ_empty++;
 961        if (cause & F_RESPQ_OVERFLOW) {
 962                sge->stats.respQ_overflow++;
 963                pr_alert("%s: SGE response queue overflow\n",
 964                         adapter->name);
 965        }
 966        if (cause & F_FL_EXHAUSTED) {
 967                sge->stats.freelistQ_empty++;
 968                freelQs_empty(sge);
 969        }
 970        if (cause & F_PACKET_TOO_BIG) {
 971                sge->stats.pkt_too_big++;
 972                pr_alert("%s: SGE max packet size exceeded\n",
 973                         adapter->name);
 974        }
 975        if (cause & F_PACKET_MISMATCH) {
 976                sge->stats.pkt_mismatch++;
 977                pr_alert("%s: SGE packet mismatch\n", adapter->name);
 978        }
 979        if (cause & SGE_INT_FATAL)
 980                t1_fatal_err(adapter);
 981
 982        writel(cause, adapter->regs + A_SG_INT_CAUSE);
 983        return 0;
 984}
 985
 986const struct sge_intr_counts *t1_sge_get_intr_counts(const struct sge *sge)
 987{
 988        return &sge->stats;
 989}
 990
 991void t1_sge_get_port_stats(const struct sge *sge, int port,
 992                           struct sge_port_stats *ss)
 993{
 994        int cpu;
 995
 996        memset(ss, 0, sizeof(*ss));
 997        for_each_possible_cpu(cpu) {
 998                struct sge_port_stats *st = per_cpu_ptr(sge->port_stats[port], cpu);
 999
1000                ss->rx_cso_good += st->rx_cso_good;
1001                ss->tx_cso += st->tx_cso;
1002                ss->tx_tso += st->tx_tso;
1003                ss->tx_need_hdrroom += st->tx_need_hdrroom;
1004                ss->vlan_xtract += st->vlan_xtract;
1005                ss->vlan_insert += st->vlan_insert;
1006        }
1007}
1008
1009/**
1010 *      recycle_fl_buf - recycle a free list buffer
1011 *      @fl: the free list
1012 *      @idx: index of buffer to recycle
1013 *
1014 *      Recycles the specified buffer on the given free list by adding it at
1015 *      the next available slot on the list.
1016 */
1017static void recycle_fl_buf(struct freelQ *fl, int idx)
1018{
1019        struct freelQ_e *from = &fl->entries[idx];
1020        struct freelQ_e *to = &fl->entries[fl->pidx];
1021
1022        fl->centries[fl->pidx] = fl->centries[idx];
1023        to->addr_lo = from->addr_lo;
1024        to->addr_hi = from->addr_hi;
1025        to->len_gen = G_CMD_LEN(from->len_gen) | V_CMD_GEN1(fl->genbit);
1026        wmb();
1027        to->gen2 = V_CMD_GEN2(fl->genbit);
1028        fl->credits++;
1029
1030        if (++fl->pidx == fl->size) {
1031                fl->pidx = 0;
1032                fl->genbit ^= 1;
1033        }
1034}
1035
1036static int copybreak __read_mostly = 256;
1037module_param(copybreak, int, 0);
1038MODULE_PARM_DESC(copybreak, "Receive copy threshold");
1039
1040/**
1041 *      get_packet - return the next ingress packet buffer
1042 *      @pdev: the PCI device that received the packet
1043 *      @fl: the SGE free list holding the packet
1044 *      @len: the actual packet length, excluding any SGE padding
1045 *
1046 *      Get the next packet from a free list and complete setup of the
1047 *      sk_buff.  If the packet is small we make a copy and recycle the
1048 *      original buffer, otherwise we use the original buffer itself.  If a
1049 *      positive drop threshold is supplied packets are dropped and their
1050 *      buffers recycled if (a) the number of remaining buffers is under the
1051 *      threshold and the packet is too big to copy, or (b) the packet should
1052 *      be copied but there is no memory for the copy.
1053 */
1054static inline struct sk_buff *get_packet(struct pci_dev *pdev,
1055                                         struct freelQ *fl, unsigned int len)
1056{
1057        struct sk_buff *skb;
1058        const struct freelQ_ce *ce = &fl->centries[fl->cidx];
1059
1060        if (len < copybreak) {
1061                skb = alloc_skb(len + 2, GFP_ATOMIC);
1062                if (!skb)
1063                        goto use_orig_buf;
1064
1065                skb_reserve(skb, 2);    /* align IP header */
1066                skb_put(skb, len);
1067                pci_dma_sync_single_for_cpu(pdev,
1068                                            dma_unmap_addr(ce, dma_addr),
1069                                            dma_unmap_len(ce, dma_len),
1070                                            PCI_DMA_FROMDEVICE);
1071                skb_copy_from_linear_data(ce->skb, skb->data, len);
1072                pci_dma_sync_single_for_device(pdev,
1073                                               dma_unmap_addr(ce, dma_addr),
1074                                               dma_unmap_len(ce, dma_len),
1075                                               PCI_DMA_FROMDEVICE);
1076                recycle_fl_buf(fl, fl->cidx);
1077                return skb;
1078        }
1079
1080use_orig_buf:
1081        if (fl->credits < 2) {
1082                recycle_fl_buf(fl, fl->cidx);
1083                return NULL;
1084        }
1085
1086        pci_unmap_single(pdev, dma_unmap_addr(ce, dma_addr),
1087                         dma_unmap_len(ce, dma_len), PCI_DMA_FROMDEVICE);
1088        skb = ce->skb;
1089        prefetch(skb->data);
1090
1091        skb_put(skb, len);
1092        return skb;
1093}
1094
1095/**
1096 *      unexpected_offload - handle an unexpected offload packet
1097 *      @adapter: the adapter
1098 *      @fl: the free list that received the packet
1099 *
1100 *      Called when we receive an unexpected offload packet (e.g., the TOE
1101 *      function is disabled or the card is a NIC).  Prints a message and
1102 *      recycles the buffer.
1103 */
1104static void unexpected_offload(struct adapter *adapter, struct freelQ *fl)
1105{
1106        struct freelQ_ce *ce = &fl->centries[fl->cidx];
1107        struct sk_buff *skb = ce->skb;
1108
1109        pci_dma_sync_single_for_cpu(adapter->pdev, dma_unmap_addr(ce, dma_addr),
1110                            dma_unmap_len(ce, dma_len), PCI_DMA_FROMDEVICE);
1111        pr_err("%s: unexpected offload packet, cmd %u\n",
1112               adapter->name, *skb->data);
1113        recycle_fl_buf(fl, fl->cidx);
1114}
1115
1116/*
1117 * T1/T2 SGE limits the maximum DMA size per TX descriptor to
1118 * SGE_TX_DESC_MAX_PLEN (16KB). If the PAGE_SIZE is larger than 16KB, the
1119 * stack might send more than SGE_TX_DESC_MAX_PLEN in a contiguous manner.
1120 * Note that the *_large_page_tx_descs stuff will be optimized out when
1121 * PAGE_SIZE <= SGE_TX_DESC_MAX_PLEN.
1122 *
1123 * compute_large_page_descs() computes how many additional descriptors are
1124 * required to break down the stack's request.
1125 */
1126static inline unsigned int compute_large_page_tx_descs(struct sk_buff *skb)
1127{
1128        unsigned int count = 0;
1129
1130        if (PAGE_SIZE > SGE_TX_DESC_MAX_PLEN) {
1131                unsigned int nfrags = skb_shinfo(skb)->nr_frags;
1132                unsigned int i, len = skb_headlen(skb);
1133                while (len > SGE_TX_DESC_MAX_PLEN) {
1134                        count++;
1135                        len -= SGE_TX_DESC_MAX_PLEN;
1136                }
1137                for (i = 0; nfrags--; i++) {
1138                        const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1139                        len = skb_frag_size(frag);
1140                        while (len > SGE_TX_DESC_MAX_PLEN) {
1141                                count++;
1142                                len -= SGE_TX_DESC_MAX_PLEN;
1143                        }
1144                }
1145        }
1146        return count;
1147}
1148
1149/*
1150 * Write a cmdQ entry.
1151 *
1152 * Since this function writes the 'flags' field, it must not be used to
1153 * write the first cmdQ entry.
1154 */
1155static inline void write_tx_desc(struct cmdQ_e *e, dma_addr_t mapping,
1156                                 unsigned int len, unsigned int gen,
1157                                 unsigned int eop)
1158{
1159        BUG_ON(len > SGE_TX_DESC_MAX_PLEN);
1160
1161        e->addr_lo = (u32)mapping;
1162        e->addr_hi = (u64)mapping >> 32;
1163        e->len_gen = V_CMD_LEN(len) | V_CMD_GEN1(gen);
1164        e->flags = F_CMD_DATAVALID | V_CMD_EOP(eop) | V_CMD_GEN2(gen);
1165}
1166
1167/*
1168 * See comment for previous function.
1169 *
1170 * write_tx_descs_large_page() writes additional SGE tx descriptors if
1171 * *desc_len exceeds HW's capability.
1172 */
1173static inline unsigned int write_large_page_tx_descs(unsigned int pidx,
1174                                                     struct cmdQ_e **e,
1175                                                     struct cmdQ_ce **ce,
1176                                                     unsigned int *gen,
1177                                                     dma_addr_t *desc_mapping,
1178                                                     unsigned int *desc_len,
1179                                                     unsigned int nfrags,
1180                                                     struct cmdQ *q)
1181{
1182        if (PAGE_SIZE > SGE_TX_DESC_MAX_PLEN) {
1183                struct cmdQ_e *e1 = *e;
1184                struct cmdQ_ce *ce1 = *ce;
1185
1186                while (*desc_len > SGE_TX_DESC_MAX_PLEN) {
1187                        *desc_len -= SGE_TX_DESC_MAX_PLEN;
1188                        write_tx_desc(e1, *desc_mapping, SGE_TX_DESC_MAX_PLEN,
1189                                      *gen, nfrags == 0 && *desc_len == 0);
1190                        ce1->skb = NULL;
1191                        dma_unmap_len_set(ce1, dma_len, 0);
1192                        *desc_mapping += SGE_TX_DESC_MAX_PLEN;
1193                        if (*desc_len) {
1194                                ce1++;
1195                                e1++;
1196                                if (++pidx == q->size) {
1197                                        pidx = 0;
1198                                        *gen ^= 1;
1199                                        ce1 = q->centries;
1200                                        e1 = q->entries;
1201                                }
1202                        }
1203                }
1204                *e = e1;
1205                *ce = ce1;
1206        }
1207        return pidx;
1208}
1209
1210/*
1211 * Write the command descriptors to transmit the given skb starting at
1212 * descriptor pidx with the given generation.
1213 */
1214static inline void write_tx_descs(struct adapter *adapter, struct sk_buff *skb,
1215                                  unsigned int pidx, unsigned int gen,
1216                                  struct cmdQ *q)
1217{
1218        dma_addr_t mapping, desc_mapping;
1219        struct cmdQ_e *e, *e1;
1220        struct cmdQ_ce *ce;
1221        unsigned int i, flags, first_desc_len, desc_len,
1222            nfrags = skb_shinfo(skb)->nr_frags;
1223
1224        e = e1 = &q->entries[pidx];
1225        ce = &q->centries[pidx];
1226
1227        mapping = pci_map_single(adapter->pdev, skb->data,
1228                                 skb_headlen(skb), PCI_DMA_TODEVICE);
1229
1230        desc_mapping = mapping;
1231        desc_len = skb_headlen(skb);
1232
1233        flags = F_CMD_DATAVALID | F_CMD_SOP |
1234            V_CMD_EOP(nfrags == 0 && desc_len <= SGE_TX_DESC_MAX_PLEN) |
1235            V_CMD_GEN2(gen);
1236        first_desc_len = (desc_len <= SGE_TX_DESC_MAX_PLEN) ?
1237            desc_len : SGE_TX_DESC_MAX_PLEN;
1238        e->addr_lo = (u32)desc_mapping;
1239        e->addr_hi = (u64)desc_mapping >> 32;
1240        e->len_gen = V_CMD_LEN(first_desc_len) | V_CMD_GEN1(gen);
1241        ce->skb = NULL;
1242        dma_unmap_len_set(ce, dma_len, 0);
1243
1244        if (PAGE_SIZE > SGE_TX_DESC_MAX_PLEN &&
1245            desc_len > SGE_TX_DESC_MAX_PLEN) {
1246                desc_mapping += first_desc_len;
1247                desc_len -= first_desc_len;
1248                e1++;
1249                ce++;
1250                if (++pidx == q->size) {
1251                        pidx = 0;
1252                        gen ^= 1;
1253                        e1 = q->entries;
1254                        ce = q->centries;
1255                }
1256                pidx = write_large_page_tx_descs(pidx, &e1, &ce, &gen,
1257                                                 &desc_mapping, &desc_len,
1258                                                 nfrags, q);
1259
1260                if (likely(desc_len))
1261                        write_tx_desc(e1, desc_mapping, desc_len, gen,
1262                                      nfrags == 0);
1263        }
1264
1265        ce->skb = NULL;
1266        dma_unmap_addr_set(ce, dma_addr, mapping);
1267        dma_unmap_len_set(ce, dma_len, skb_headlen(skb));
1268
1269        for (i = 0; nfrags--; i++) {
1270                skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1271                e1++;
1272                ce++;
1273                if (++pidx == q->size) {
1274                        pidx = 0;
1275                        gen ^= 1;
1276                        e1 = q->entries;
1277                        ce = q->centries;
1278                }
1279
1280                mapping = skb_frag_dma_map(&adapter->pdev->dev, frag, 0,
1281                                           skb_frag_size(frag), DMA_TO_DEVICE);
1282                desc_mapping = mapping;
1283                desc_len = skb_frag_size(frag);
1284
1285                pidx = write_large_page_tx_descs(pidx, &e1, &ce, &gen,
1286                                                 &desc_mapping, &desc_len,
1287                                                 nfrags, q);
1288                if (likely(desc_len))
1289                        write_tx_desc(e1, desc_mapping, desc_len, gen,
1290                                      nfrags == 0);
1291                ce->skb = NULL;
1292                dma_unmap_addr_set(ce, dma_addr, mapping);
1293                dma_unmap_len_set(ce, dma_len, skb_frag_size(frag));
1294        }
1295        ce->skb = skb;
1296        wmb();
1297        e->flags = flags;
1298}
1299
1300/*
1301 * Clean up completed Tx buffers.
1302 */
1303static inline void reclaim_completed_tx(struct sge *sge, struct cmdQ *q)
1304{
1305        unsigned int reclaim = q->processed - q->cleaned;
1306
1307        if (reclaim) {
1308                pr_debug("reclaim_completed_tx processed:%d cleaned:%d\n",
1309                         q->processed, q->cleaned);
1310                free_cmdQ_buffers(sge, q, reclaim);
1311                q->cleaned += reclaim;
1312        }
1313}
1314
1315/*
1316 * Called from tasklet. Checks the scheduler for any
1317 * pending skbs that can be sent.
1318 */
1319static void restart_sched(unsigned long arg)
1320{
1321        struct sge *sge = (struct sge *) arg;
1322        struct adapter *adapter = sge->adapter;
1323        struct cmdQ *q = &sge->cmdQ[0];
1324        struct sk_buff *skb;
1325        unsigned int credits, queued_skb = 0;
1326
1327        spin_lock(&q->lock);
1328        reclaim_completed_tx(sge, q);
1329
1330        credits = q->size - q->in_use;
1331        pr_debug("restart_sched credits=%d\n", credits);
1332        while ((skb = sched_skb(sge, NULL, credits)) != NULL) {
1333                unsigned int genbit, pidx, count;
1334                count = 1 + skb_shinfo(skb)->nr_frags;
1335                count += compute_large_page_tx_descs(skb);
1336                q->in_use += count;
1337                genbit = q->genbit;
1338                pidx = q->pidx;
1339                q->pidx += count;
1340                if (q->pidx >= q->size) {
1341                        q->pidx -= q->size;
1342                        q->genbit ^= 1;
1343                }
1344                write_tx_descs(adapter, skb, pidx, genbit, q);
1345                credits = q->size - q->in_use;
1346                queued_skb = 1;
1347        }
1348
1349        if (queued_skb) {
1350                clear_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
1351                if (test_and_set_bit(CMDQ_STAT_RUNNING, &q->status) == 0) {
1352                        set_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
1353                        writel(F_CMDQ0_ENABLE, adapter->regs + A_SG_DOORBELL);
1354                }
1355        }
1356        spin_unlock(&q->lock);
1357}
1358
1359/**
1360 *      sge_rx - process an ingress ethernet packet
1361 *      @sge: the sge structure
1362 *      @fl: the free list that contains the packet buffer
1363 *      @len: the packet length
1364 *
1365 *      Process an ingress ethernet pakcet and deliver it to the stack.
1366 */
1367static void sge_rx(struct sge *sge, struct freelQ *fl, unsigned int len)
1368{
1369        struct sk_buff *skb;
1370        const struct cpl_rx_pkt *p;
1371        struct adapter *adapter = sge->adapter;
1372        struct sge_port_stats *st;
1373        struct net_device *dev;
1374
1375        skb = get_packet(adapter->pdev, fl, len - sge->rx_pkt_pad);
1376        if (unlikely(!skb)) {
1377                sge->stats.rx_drops++;
1378                return;
1379        }
1380
1381        p = (const struct cpl_rx_pkt *) skb->data;
1382        if (p->iff >= adapter->params.nports) {
1383                kfree_skb(skb);
1384                return;
1385        }
1386        __skb_pull(skb, sizeof(*p));
1387
1388        st = this_cpu_ptr(sge->port_stats[p->iff]);
1389        dev = adapter->port[p->iff].dev;
1390
1391        skb->protocol = eth_type_trans(skb, dev);
1392        if ((dev->features & NETIF_F_RXCSUM) && p->csum == 0xffff &&
1393            skb->protocol == htons(ETH_P_IP) &&
1394            (skb->data[9] == IPPROTO_TCP || skb->data[9] == IPPROTO_UDP)) {
1395                ++st->rx_cso_good;
1396                skb->ip_summed = CHECKSUM_UNNECESSARY;
1397        } else
1398                skb_checksum_none_assert(skb);
1399
1400        if (p->vlan_valid) {
1401                st->vlan_xtract++;
1402                __vlan_hwaccel_put_tag(skb, ntohs(p->vlan));
1403        }
1404        netif_receive_skb(skb);
1405}
1406
1407/*
1408 * Returns true if a command queue has enough available descriptors that
1409 * we can resume Tx operation after temporarily disabling its packet queue.
1410 */
1411static inline int enough_free_Tx_descs(const struct cmdQ *q)
1412{
1413        unsigned int r = q->processed - q->cleaned;
1414
1415        return q->in_use - r < (q->size >> 1);
1416}
1417
1418/*
1419 * Called when sufficient space has become available in the SGE command queues
1420 * after the Tx packet schedulers have been suspended to restart the Tx path.
1421 */
1422static void restart_tx_queues(struct sge *sge)
1423{
1424        struct adapter *adap = sge->adapter;
1425        int i;
1426
1427        if (!enough_free_Tx_descs(&sge->cmdQ[0]))
1428                return;
1429
1430        for_each_port(adap, i) {
1431                struct net_device *nd = adap->port[i].dev;
1432
1433                if (test_and_clear_bit(nd->if_port, &sge->stopped_tx_queues) &&
1434                    netif_running(nd)) {
1435                        sge->stats.cmdQ_restarted[2]++;
1436                        netif_wake_queue(nd);
1437                }
1438        }
1439}
1440
1441/*
1442 * update_tx_info is called from the interrupt handler/NAPI to return cmdQ0
1443 * information.
1444 */
1445static unsigned int update_tx_info(struct adapter *adapter,
1446                                          unsigned int flags,
1447                                          unsigned int pr0)
1448{
1449        struct sge *sge = adapter->sge;
1450        struct cmdQ *cmdq = &sge->cmdQ[0];
1451
1452        cmdq->processed += pr0;
1453        if (flags & (F_FL0_ENABLE | F_FL1_ENABLE)) {
1454                freelQs_empty(sge);
1455                flags &= ~(F_FL0_ENABLE | F_FL1_ENABLE);
1456        }
1457        if (flags & F_CMDQ0_ENABLE) {
1458                clear_bit(CMDQ_STAT_RUNNING, &cmdq->status);
1459
1460                if (cmdq->cleaned + cmdq->in_use != cmdq->processed &&
1461                    !test_and_set_bit(CMDQ_STAT_LAST_PKT_DB, &cmdq->status)) {
1462                        set_bit(CMDQ_STAT_RUNNING, &cmdq->status);
1463                        writel(F_CMDQ0_ENABLE, adapter->regs + A_SG_DOORBELL);
1464                }
1465                if (sge->tx_sched)
1466                        tasklet_hi_schedule(&sge->tx_sched->sched_tsk);
1467
1468                flags &= ~F_CMDQ0_ENABLE;
1469        }
1470
1471        if (unlikely(sge->stopped_tx_queues != 0))
1472                restart_tx_queues(sge);
1473
1474        return flags;
1475}
1476
1477/*
1478 * Process SGE responses, up to the supplied budget.  Returns the number of
1479 * responses processed.  A negative budget is effectively unlimited.
1480 */
1481static int process_responses(struct adapter *adapter, int budget)
1482{
1483        struct sge *sge = adapter->sge;
1484        struct respQ *q = &sge->respQ;
1485        struct respQ_e *e = &q->entries[q->cidx];
1486        int done = 0;
1487        unsigned int flags = 0;
1488        unsigned int cmdq_processed[SGE_CMDQ_N] = {0, 0};
1489
1490        while (done < budget && e->GenerationBit == q->genbit) {
1491                flags |= e->Qsleeping;
1492
1493                cmdq_processed[0] += e->Cmdq0CreditReturn;
1494                cmdq_processed[1] += e->Cmdq1CreditReturn;
1495
1496                /* We batch updates to the TX side to avoid cacheline
1497                 * ping-pong of TX state information on MP where the sender
1498                 * might run on a different CPU than this function...
1499                 */
1500                if (unlikely((flags & F_CMDQ0_ENABLE) || cmdq_processed[0] > 64)) {
1501                        flags = update_tx_info(adapter, flags, cmdq_processed[0]);
1502                        cmdq_processed[0] = 0;
1503                }
1504
1505                if (unlikely(cmdq_processed[1] > 16)) {
1506                        sge->cmdQ[1].processed += cmdq_processed[1];
1507                        cmdq_processed[1] = 0;
1508                }
1509
1510                if (likely(e->DataValid)) {
1511                        struct freelQ *fl = &sge->freelQ[e->FreelistQid];
1512
1513                        BUG_ON(!e->Sop || !e->Eop);
1514                        if (unlikely(e->Offload))
1515                                unexpected_offload(adapter, fl);
1516                        else
1517                                sge_rx(sge, fl, e->BufferLength);
1518
1519                        ++done;
1520
1521                        /*
1522                         * Note: this depends on each packet consuming a
1523                         * single free-list buffer; cf. the BUG above.
1524                         */
1525                        if (++fl->cidx == fl->size)
1526                                fl->cidx = 0;
1527                        prefetch(fl->centries[fl->cidx].skb);
1528
1529                        if (unlikely(--fl->credits <
1530                                     fl->size - SGE_FREEL_REFILL_THRESH))
1531                                refill_free_list(sge, fl);
1532                } else
1533                        sge->stats.pure_rsps++;
1534
1535                e++;
1536                if (unlikely(++q->cidx == q->size)) {
1537                        q->cidx = 0;
1538                        q->genbit ^= 1;
1539                        e = q->entries;
1540                }
1541                prefetch(e);
1542
1543                if (++q->credits > SGE_RESPQ_REPLENISH_THRES) {
1544                        writel(q->credits, adapter->regs + A_SG_RSPQUEUECREDIT);
1545                        q->credits = 0;
1546                }
1547        }
1548
1549        flags = update_tx_info(adapter, flags, cmdq_processed[0]);
1550        sge->cmdQ[1].processed += cmdq_processed[1];
1551
1552        return done;
1553}
1554
1555static inline int responses_pending(const struct adapter *adapter)
1556{
1557        const struct respQ *Q = &adapter->sge->respQ;
1558        const struct respQ_e *e = &Q->entries[Q->cidx];
1559
1560        return e->GenerationBit == Q->genbit;
1561}
1562
1563/*
1564 * A simpler version of process_responses() that handles only pure (i.e.,
1565 * non data-carrying) responses.  Such respones are too light-weight to justify
1566 * calling a softirq when using NAPI, so we handle them specially in hard
1567 * interrupt context.  The function is called with a pointer to a response,
1568 * which the caller must ensure is a valid pure response.  Returns 1 if it
1569 * encounters a valid data-carrying response, 0 otherwise.
1570 */
1571static int process_pure_responses(struct adapter *adapter)
1572{
1573        struct sge *sge = adapter->sge;
1574        struct respQ *q = &sge->respQ;
1575        struct respQ_e *e = &q->entries[q->cidx];
1576        const struct freelQ *fl = &sge->freelQ[e->FreelistQid];
1577        unsigned int flags = 0;
1578        unsigned int cmdq_processed[SGE_CMDQ_N] = {0, 0};
1579
1580        prefetch(fl->centries[fl->cidx].skb);
1581        if (e->DataValid)
1582                return 1;
1583
1584        do {
1585                flags |= e->Qsleeping;
1586
1587                cmdq_processed[0] += e->Cmdq0CreditReturn;
1588                cmdq_processed[1] += e->Cmdq1CreditReturn;
1589
1590                e++;
1591                if (unlikely(++q->cidx == q->size)) {
1592                        q->cidx = 0;
1593                        q->genbit ^= 1;
1594                        e = q->entries;
1595                }
1596                prefetch(e);
1597
1598                if (++q->credits > SGE_RESPQ_REPLENISH_THRES) {
1599                        writel(q->credits, adapter->regs + A_SG_RSPQUEUECREDIT);
1600                        q->credits = 0;
1601                }
1602                sge->stats.pure_rsps++;
1603        } while (e->GenerationBit == q->genbit && !e->DataValid);
1604
1605        flags = update_tx_info(adapter, flags, cmdq_processed[0]);
1606        sge->cmdQ[1].processed += cmdq_processed[1];
1607
1608        return e->GenerationBit == q->genbit;
1609}
1610
1611/*
1612 * Handler for new data events when using NAPI.  This does not need any locking
1613 * or protection from interrupts as data interrupts are off at this point and
1614 * other adapter interrupts do not interfere.
1615 */
1616int t1_poll(struct napi_struct *napi, int budget)
1617{
1618        struct adapter *adapter = container_of(napi, struct adapter, napi);
1619        int work_done = process_responses(adapter, budget);
1620
1621        if (likely(work_done < budget)) {
1622                napi_complete(napi);
1623                writel(adapter->sge->respQ.cidx,
1624                       adapter->regs + A_SG_SLEEPING);
1625        }
1626        return work_done;
1627}
1628
1629irqreturn_t t1_interrupt(int irq, void *data)
1630{
1631        struct adapter *adapter = data;
1632        struct sge *sge = adapter->sge;
1633        int handled;
1634
1635        if (likely(responses_pending(adapter))) {
1636                writel(F_PL_INTR_SGE_DATA, adapter->regs + A_PL_CAUSE);
1637
1638                if (napi_schedule_prep(&adapter->napi)) {
1639                        if (process_pure_responses(adapter))
1640                                __napi_schedule(&adapter->napi);
1641                        else {
1642                                /* no data, no NAPI needed */
1643                                writel(sge->respQ.cidx, adapter->regs + A_SG_SLEEPING);
1644                                /* undo schedule_prep */
1645                                napi_enable(&adapter->napi);
1646                        }
1647                }
1648                return IRQ_HANDLED;
1649        }
1650
1651        spin_lock(&adapter->async_lock);
1652        handled = t1_slow_intr_handler(adapter);
1653        spin_unlock(&adapter->async_lock);
1654
1655        if (!handled)
1656                sge->stats.unhandled_irqs++;
1657
1658        return IRQ_RETVAL(handled != 0);
1659}
1660
1661/*
1662 * Enqueues the sk_buff onto the cmdQ[qid] and has hardware fetch it.
1663 *
1664 * The code figures out how many entries the sk_buff will require in the
1665 * cmdQ and updates the cmdQ data structure with the state once the enqueue
1666 * has complete. Then, it doesn't access the global structure anymore, but
1667 * uses the corresponding fields on the stack. In conjunction with a spinlock
1668 * around that code, we can make the function reentrant without holding the
1669 * lock when we actually enqueue (which might be expensive, especially on
1670 * architectures with IO MMUs).
1671 *
1672 * This runs with softirqs disabled.
1673 */
1674static int t1_sge_tx(struct sk_buff *skb, struct adapter *adapter,
1675                     unsigned int qid, struct net_device *dev)
1676{
1677        struct sge *sge = adapter->sge;
1678        struct cmdQ *q = &sge->cmdQ[qid];
1679        unsigned int credits, pidx, genbit, count, use_sched_skb = 0;
1680
1681        if (!spin_trylock(&q->lock))
1682                return NETDEV_TX_LOCKED;
1683
1684        reclaim_completed_tx(sge, q);
1685
1686        pidx = q->pidx;
1687        credits = q->size - q->in_use;
1688        count = 1 + skb_shinfo(skb)->nr_frags;
1689        count += compute_large_page_tx_descs(skb);
1690
1691        /* Ethernet packet */
1692        if (unlikely(credits < count)) {
1693                if (!netif_queue_stopped(dev)) {
1694                        netif_stop_queue(dev);
1695                        set_bit(dev->if_port, &sge->stopped_tx_queues);
1696                        sge->stats.cmdQ_full[2]++;
1697                        pr_err("%s: Tx ring full while queue awake!\n",
1698                               adapter->name);
1699                }
1700                spin_unlock(&q->lock);
1701                return NETDEV_TX_BUSY;
1702        }
1703
1704        if (unlikely(credits - count < q->stop_thres)) {
1705                netif_stop_queue(dev);
1706                set_bit(dev->if_port, &sge->stopped_tx_queues);
1707                sge->stats.cmdQ_full[2]++;
1708        }
1709
1710        /* T204 cmdQ0 skbs that are destined for a certain port have to go
1711         * through the scheduler.
1712         */
1713        if (sge->tx_sched && !qid && skb->dev) {
1714use_sched:
1715                use_sched_skb = 1;
1716                /* Note that the scheduler might return a different skb than
1717                 * the one passed in.
1718                 */
1719                skb = sched_skb(sge, skb, credits);
1720                if (!skb) {
1721                        spin_unlock(&q->lock);
1722                        return NETDEV_TX_OK;
1723                }
1724                pidx = q->pidx;
1725                count = 1 + skb_shinfo(skb)->nr_frags;
1726                count += compute_large_page_tx_descs(skb);
1727        }
1728
1729        q->in_use += count;
1730        genbit = q->genbit;
1731        pidx = q->pidx;
1732        q->pidx += count;
1733        if (q->pidx >= q->size) {
1734                q->pidx -= q->size;
1735                q->genbit ^= 1;
1736        }
1737        spin_unlock(&q->lock);
1738
1739        write_tx_descs(adapter, skb, pidx, genbit, q);
1740
1741        /*
1742         * We always ring the doorbell for cmdQ1.  For cmdQ0, we only ring
1743         * the doorbell if the Q is asleep. There is a natural race, where
1744         * the hardware is going to sleep just after we checked, however,
1745         * then the interrupt handler will detect the outstanding TX packet
1746         * and ring the doorbell for us.
1747         */
1748        if (qid)
1749                doorbell_pio(adapter, F_CMDQ1_ENABLE);
1750        else {
1751                clear_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
1752                if (test_and_set_bit(CMDQ_STAT_RUNNING, &q->status) == 0) {
1753                        set_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
1754                        writel(F_CMDQ0_ENABLE, adapter->regs + A_SG_DOORBELL);
1755                }
1756        }
1757
1758        if (use_sched_skb) {
1759                if (spin_trylock(&q->lock)) {
1760                        credits = q->size - q->in_use;
1761                        skb = NULL;
1762                        goto use_sched;
1763                }
1764        }
1765        return NETDEV_TX_OK;
1766}
1767
1768#define MK_ETH_TYPE_MSS(type, mss) (((mss) & 0x3FFF) | ((type) << 14))
1769
1770/*
1771 *      eth_hdr_len - return the length of an Ethernet header
1772 *      @data: pointer to the start of the Ethernet header
1773 *
1774 *      Returns the length of an Ethernet header, including optional VLAN tag.
1775 */
1776static inline int eth_hdr_len(const void *data)
1777{
1778        const struct ethhdr *e = data;
1779
1780        return e->h_proto == htons(ETH_P_8021Q) ? VLAN_ETH_HLEN : ETH_HLEN;
1781}
1782
1783/*
1784 * Adds the CPL header to the sk_buff and passes it to t1_sge_tx.
1785 */
1786netdev_tx_t t1_start_xmit(struct sk_buff *skb, struct net_device *dev)
1787{
1788        struct adapter *adapter = dev->ml_priv;
1789        struct sge *sge = adapter->sge;
1790        struct sge_port_stats *st = this_cpu_ptr(sge->port_stats[dev->if_port]);
1791        struct cpl_tx_pkt *cpl;
1792        struct sk_buff *orig_skb = skb;
1793        int ret;
1794
1795        if (skb->protocol == htons(ETH_P_CPL5))
1796                goto send;
1797
1798        /*
1799         * We are using a non-standard hard_header_len.
1800         * Allocate more header room in the rare cases it is not big enough.
1801         */
1802        if (unlikely(skb_headroom(skb) < dev->hard_header_len - ETH_HLEN)) {
1803                skb = skb_realloc_headroom(skb, sizeof(struct cpl_tx_pkt_lso));
1804                ++st->tx_need_hdrroom;
1805                dev_kfree_skb_any(orig_skb);
1806                if (!skb)
1807                        return NETDEV_TX_OK;
1808        }
1809
1810        if (skb_shinfo(skb)->gso_size) {
1811                int eth_type;
1812                struct cpl_tx_pkt_lso *hdr;
1813
1814                ++st->tx_tso;
1815
1816                eth_type = skb_network_offset(skb) == ETH_HLEN ?
1817                        CPL_ETH_II : CPL_ETH_II_VLAN;
1818
1819                hdr = (struct cpl_tx_pkt_lso *)skb_push(skb, sizeof(*hdr));
1820                hdr->opcode = CPL_TX_PKT_LSO;
1821                hdr->ip_csum_dis = hdr->l4_csum_dis = 0;
1822                hdr->ip_hdr_words = ip_hdr(skb)->ihl;
1823                hdr->tcp_hdr_words = tcp_hdr(skb)->doff;
1824                hdr->eth_type_mss = htons(MK_ETH_TYPE_MSS(eth_type,
1825                                                          skb_shinfo(skb)->gso_size));
1826                hdr->len = htonl(skb->len - sizeof(*hdr));
1827                cpl = (struct cpl_tx_pkt *)hdr;
1828        } else {
1829                /*
1830                 * Packets shorter than ETH_HLEN can break the MAC, drop them
1831                 * early.  Also, we may get oversized packets because some
1832                 * parts of the kernel don't handle our unusual hard_header_len
1833                 * right, drop those too.
1834                 */
1835                if (unlikely(skb->len < ETH_HLEN ||
1836                             skb->len > dev->mtu + eth_hdr_len(skb->data))) {
1837                        pr_debug("%s: packet size %d hdr %d mtu%d\n", dev->name,
1838                                 skb->len, eth_hdr_len(skb->data), dev->mtu);
1839                        dev_kfree_skb_any(skb);
1840                        return NETDEV_TX_OK;
1841                }
1842
1843                if (skb->ip_summed == CHECKSUM_PARTIAL &&
1844                    ip_hdr(skb)->protocol == IPPROTO_UDP) {
1845                        if (unlikely(skb_checksum_help(skb))) {
1846                                pr_debug("%s: unable to do udp checksum\n", dev->name);
1847                                dev_kfree_skb_any(skb);
1848                                return NETDEV_TX_OK;
1849                        }
1850                }
1851
1852                /* Hmmm, assuming to catch the gratious arp... and we'll use
1853                 * it to flush out stuck espi packets...
1854                 */
1855                if ((unlikely(!adapter->sge->espibug_skb[dev->if_port]))) {
1856                        if (skb->protocol == htons(ETH_P_ARP) &&
1857                            arp_hdr(skb)->ar_op == htons(ARPOP_REQUEST)) {
1858                                adapter->sge->espibug_skb[dev->if_port] = skb;
1859                                /* We want to re-use this skb later. We
1860                                 * simply bump the reference count and it
1861                                 * will not be freed...
1862                                 */
1863                                skb = skb_get(skb);
1864                        }
1865                }
1866
1867                cpl = (struct cpl_tx_pkt *)__skb_push(skb, sizeof(*cpl));
1868                cpl->opcode = CPL_TX_PKT;
1869                cpl->ip_csum_dis = 1;    /* SW calculates IP csum */
1870                cpl->l4_csum_dis = skb->ip_summed == CHECKSUM_PARTIAL ? 0 : 1;
1871                /* the length field isn't used so don't bother setting it */
1872
1873                st->tx_cso += (skb->ip_summed == CHECKSUM_PARTIAL);
1874        }
1875        cpl->iff = dev->if_port;
1876
1877        if (vlan_tx_tag_present(skb)) {
1878                cpl->vlan_valid = 1;
1879                cpl->vlan = htons(vlan_tx_tag_get(skb));
1880                st->vlan_insert++;
1881        } else
1882                cpl->vlan_valid = 0;
1883
1884send:
1885        ret = t1_sge_tx(skb, adapter, 0, dev);
1886
1887        /* If transmit busy, and we reallocated skb's due to headroom limit,
1888         * then silently discard to avoid leak.
1889         */
1890        if (unlikely(ret != NETDEV_TX_OK && skb != orig_skb)) {
1891                dev_kfree_skb_any(skb);
1892                ret = NETDEV_TX_OK;
1893        }
1894        return ret;
1895}
1896
1897/*
1898 * Callback for the Tx buffer reclaim timer.  Runs with softirqs disabled.
1899 */
1900static void sge_tx_reclaim_cb(unsigned long data)
1901{
1902        int i;
1903        struct sge *sge = (struct sge *)data;
1904
1905        for (i = 0; i < SGE_CMDQ_N; ++i) {
1906                struct cmdQ *q = &sge->cmdQ[i];
1907
1908                if (!spin_trylock(&q->lock))
1909                        continue;
1910
1911                reclaim_completed_tx(sge, q);
1912                if (i == 0 && q->in_use) {    /* flush pending credits */
1913                        writel(F_CMDQ0_ENABLE, sge->adapter->regs + A_SG_DOORBELL);
1914                }
1915                spin_unlock(&q->lock);
1916        }
1917        mod_timer(&sge->tx_reclaim_timer, jiffies + TX_RECLAIM_PERIOD);
1918}
1919
1920/*
1921 * Propagate changes of the SGE coalescing parameters to the HW.
1922 */
1923int t1_sge_set_coalesce_params(struct sge *sge, struct sge_params *p)
1924{
1925        sge->fixed_intrtimer = p->rx_coalesce_usecs *
1926                core_ticks_per_usec(sge->adapter);
1927        writel(sge->fixed_intrtimer, sge->adapter->regs + A_SG_INTRTIMER);
1928        return 0;
1929}
1930
1931/*
1932 * Allocates both RX and TX resources and configures the SGE. However,
1933 * the hardware is not enabled yet.
1934 */
1935int t1_sge_configure(struct sge *sge, struct sge_params *p)
1936{
1937        if (alloc_rx_resources(sge, p))
1938                return -ENOMEM;
1939        if (alloc_tx_resources(sge, p)) {
1940                free_rx_resources(sge);
1941                return -ENOMEM;
1942        }
1943        configure_sge(sge, p);
1944
1945        /*
1946         * Now that we have sized the free lists calculate the payload
1947         * capacity of the large buffers.  Other parts of the driver use
1948         * this to set the max offload coalescing size so that RX packets
1949         * do not overflow our large buffers.
1950         */
1951        p->large_buf_capacity = jumbo_payload_capacity(sge);
1952        return 0;
1953}
1954
1955/*
1956 * Disables the DMA engine.
1957 */
1958void t1_sge_stop(struct sge *sge)
1959{
1960        int i;
1961        writel(0, sge->adapter->regs + A_SG_CONTROL);
1962        readl(sge->adapter->regs + A_SG_CONTROL); /* flush */
1963
1964        if (is_T2(sge->adapter))
1965                del_timer_sync(&sge->espibug_timer);
1966
1967        del_timer_sync(&sge->tx_reclaim_timer);
1968        if (sge->tx_sched)
1969                tx_sched_stop(sge);
1970
1971        for (i = 0; i < MAX_NPORTS; i++)
1972                kfree_skb(sge->espibug_skb[i]);
1973}
1974
1975/*
1976 * Enables the DMA engine.
1977 */
1978void t1_sge_start(struct sge *sge)
1979{
1980        refill_free_list(sge, &sge->freelQ[0]);
1981        refill_free_list(sge, &sge->freelQ[1]);
1982
1983        writel(sge->sge_control, sge->adapter->regs + A_SG_CONTROL);
1984        doorbell_pio(sge->adapter, F_FL0_ENABLE | F_FL1_ENABLE);
1985        readl(sge->adapter->regs + A_SG_CONTROL); /* flush */
1986
1987        mod_timer(&sge->tx_reclaim_timer, jiffies + TX_RECLAIM_PERIOD);
1988
1989        if (is_T2(sge->adapter))
1990                mod_timer(&sge->espibug_timer, jiffies + sge->espibug_timeout);
1991}
1992
1993/*
1994 * Callback for the T2 ESPI 'stuck packet feature' workaorund
1995 */
1996static void espibug_workaround_t204(unsigned long data)
1997{
1998        struct adapter *adapter = (struct adapter *)data;
1999        struct sge *sge = adapter->sge;
2000        unsigned int nports = adapter->params.nports;
2001        u32 seop[MAX_NPORTS];
2002
2003        if (adapter->open_device_map & PORT_MASK) {
2004                int i;
2005
2006                if (t1_espi_get_mon_t204(adapter, &(seop[0]), 0) < 0)
2007                        return;
2008
2009                for (i = 0; i < nports; i++) {
2010                        struct sk_buff *skb = sge->espibug_skb[i];
2011
2012                        if (!netif_running(adapter->port[i].dev) ||
2013                            netif_queue_stopped(adapter->port[i].dev) ||
2014                            !seop[i] || ((seop[i] & 0xfff) != 0) || !skb)
2015                                continue;
2016
2017                        if (!skb->cb[0]) {
2018                                skb_copy_to_linear_data_offset(skb,
2019                                                    sizeof(struct cpl_tx_pkt),
2020                                                               ch_mac_addr,
2021                                                               ETH_ALEN);
2022                                skb_copy_to_linear_data_offset(skb,
2023                                                               skb->len - 10,
2024                                                               ch_mac_addr,
2025                                                               ETH_ALEN);
2026                                skb->cb[0] = 0xff;
2027                        }
2028
2029                        /* bump the reference count to avoid freeing of
2030                         * the skb once the DMA has completed.
2031                         */
2032                        skb = skb_get(skb);
2033                        t1_sge_tx(skb, adapter, 0, adapter->port[i].dev);
2034                }
2035        }
2036        mod_timer(&sge->espibug_timer, jiffies + sge->espibug_timeout);
2037}
2038
2039static void espibug_workaround(unsigned long data)
2040{
2041        struct adapter *adapter = (struct adapter *)data;
2042        struct sge *sge = adapter->sge;
2043
2044        if (netif_running(adapter->port[0].dev)) {
2045                struct sk_buff *skb = sge->espibug_skb[0];
2046                u32 seop = t1_espi_get_mon(adapter, 0x930, 0);
2047
2048                if ((seop & 0xfff0fff) == 0xfff && skb) {
2049                        if (!skb->cb[0]) {
2050                                skb_copy_to_linear_data_offset(skb,
2051                                                     sizeof(struct cpl_tx_pkt),
2052                                                               ch_mac_addr,
2053                                                               ETH_ALEN);
2054                                skb_copy_to_linear_data_offset(skb,
2055                                                               skb->len - 10,
2056                                                               ch_mac_addr,
2057                                                               ETH_ALEN);
2058                                skb->cb[0] = 0xff;
2059                        }
2060
2061                        /* bump the reference count to avoid freeing of the
2062                         * skb once the DMA has completed.
2063                         */
2064                        skb = skb_get(skb);
2065                        t1_sge_tx(skb, adapter, 0, adapter->port[0].dev);
2066                }
2067        }
2068        mod_timer(&sge->espibug_timer, jiffies + sge->espibug_timeout);
2069}
2070
2071/*
2072 * Creates a t1_sge structure and returns suggested resource parameters.
2073 */
2074struct sge * __devinit t1_sge_create(struct adapter *adapter,
2075                                     struct sge_params *p)
2076{
2077        struct sge *sge = kzalloc(sizeof(*sge), GFP_KERNEL);
2078        int i;
2079
2080        if (!sge)
2081                return NULL;
2082
2083        sge->adapter = adapter;
2084        sge->netdev = adapter->port[0].dev;
2085        sge->rx_pkt_pad = t1_is_T1B(adapter) ? 0 : 2;
2086        sge->jumbo_fl = t1_is_T1B(adapter) ? 1 : 0;
2087
2088        for_each_port(adapter, i) {
2089                sge->port_stats[i] = alloc_percpu(struct sge_port_stats);
2090                if (!sge->port_stats[i])
2091                        goto nomem_port;
2092        }
2093
2094        init_timer(&sge->tx_reclaim_timer);
2095        sge->tx_reclaim_timer.data = (unsigned long)sge;
2096        sge->tx_reclaim_timer.function = sge_tx_reclaim_cb;
2097
2098        if (is_T2(sge->adapter)) {
2099                init_timer(&sge->espibug_timer);
2100
2101                if (adapter->params.nports > 1) {
2102                        tx_sched_init(sge);
2103                        sge->espibug_timer.function = espibug_workaround_t204;
2104                } else
2105                        sge->espibug_timer.function = espibug_workaround;
2106                sge->espibug_timer.data = (unsigned long)sge->adapter;
2107
2108                sge->espibug_timeout = 1;
2109                /* for T204, every 10ms */
2110                if (adapter->params.nports > 1)
2111                        sge->espibug_timeout = HZ/100;
2112        }
2113
2114
2115        p->cmdQ_size[0] = SGE_CMDQ0_E_N;
2116        p->cmdQ_size[1] = SGE_CMDQ1_E_N;
2117        p->freelQ_size[!sge->jumbo_fl] = SGE_FREEL_SIZE;
2118        p->freelQ_size[sge->jumbo_fl] = SGE_JUMBO_FREEL_SIZE;
2119        if (sge->tx_sched) {
2120                if (board_info(sge->adapter)->board == CHBT_BOARD_CHT204)
2121                        p->rx_coalesce_usecs = 15;
2122                else
2123                        p->rx_coalesce_usecs = 50;
2124        } else
2125                p->rx_coalesce_usecs = 50;
2126
2127        p->coalesce_enable = 0;
2128        p->sample_interval_usecs = 0;
2129
2130        return sge;
2131nomem_port:
2132        while (i >= 0) {
2133                free_percpu(sge->port_stats[i]);
2134                --i;
2135        }
2136        kfree(sge);
2137        return NULL;
2138
2139}
2140
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