linux/drivers/net/chelsio/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
  57#include "cpl5_cmd.h"
  58#include "sge.h"
  59#include "regs.h"
  60#include "espi.h"
  61
  62/* This belongs in if_ether.h */
  63#define ETH_P_CPL5 0xf
  64
  65#define SGE_CMDQ_N              2
  66#define SGE_FREELQ_N            2
  67#define SGE_CMDQ0_E_N           1024
  68#define SGE_CMDQ1_E_N           128
  69#define SGE_FREEL_SIZE          4096
  70#define SGE_JUMBO_FREEL_SIZE    512
  71#define SGE_FREEL_REFILL_THRESH 16
  72#define SGE_RESPQ_E_N           1024
  73#define SGE_INTRTIMER_NRES      1000
  74#define SGE_RX_SM_BUF_SIZE      1536
  75#define SGE_TX_DESC_MAX_PLEN    16384
  76
  77#define SGE_RESPQ_REPLENISH_THRES (SGE_RESPQ_E_N / 4)
  78
  79/*
  80 * Period of the TX buffer reclaim timer.  This timer does not need to run
  81 * frequently as TX buffers are usually reclaimed by new TX packets.
  82 */
  83#define TX_RECLAIM_PERIOD (HZ / 4)
  84
  85#define M_CMD_LEN       0x7fffffff
  86#define V_CMD_LEN(v)    (v)
  87#define G_CMD_LEN(v)    ((v) & M_CMD_LEN)
  88#define V_CMD_GEN1(v)   ((v) << 31)
  89#define V_CMD_GEN2(v)   (v)
  90#define F_CMD_DATAVALID (1 << 1)
  91#define F_CMD_SOP       (1 << 2)
  92#define V_CMD_EOP(v)    ((v) << 3)
  93
  94/*
  95 * Command queue, receive buffer list, and response queue descriptors.
  96 */
  97#if defined(__BIG_ENDIAN_BITFIELD)
  98struct cmdQ_e {
  99        u32 addr_lo;
 100        u32 len_gen;
 101        u32 flags;
 102        u32 addr_hi;
 103};
 104
 105struct freelQ_e {
 106        u32 addr_lo;
 107        u32 len_gen;
 108        u32 gen2;
 109        u32 addr_hi;
 110};
 111
 112struct respQ_e {
 113        u32 Qsleeping           : 4;
 114        u32 Cmdq1CreditReturn   : 5;
 115        u32 Cmdq1DmaComplete    : 5;
 116        u32 Cmdq0CreditReturn   : 5;
 117        u32 Cmdq0DmaComplete    : 5;
 118        u32 FreelistQid         : 2;
 119        u32 CreditValid         : 1;
 120        u32 DataValid           : 1;
 121        u32 Offload             : 1;
 122        u32 Eop                 : 1;
 123        u32 Sop                 : 1;
 124        u32 GenerationBit       : 1;
 125        u32 BufferLength;
 126};
 127#elif defined(__LITTLE_ENDIAN_BITFIELD)
 128struct cmdQ_e {
 129        u32 len_gen;
 130        u32 addr_lo;
 131        u32 addr_hi;
 132        u32 flags;
 133};
 134
 135struct freelQ_e {
 136        u32 len_gen;
 137        u32 addr_lo;
 138        u32 addr_hi;
 139        u32 gen2;
 140};
 141
 142struct respQ_e {
 143        u32 BufferLength;
 144        u32 GenerationBit       : 1;
 145        u32 Sop                 : 1;
 146        u32 Eop                 : 1;
 147        u32 Offload             : 1;
 148        u32 DataValid           : 1;
 149        u32 CreditValid         : 1;
 150        u32 FreelistQid         : 2;
 151        u32 Cmdq0DmaComplete    : 5;
 152        u32 Cmdq0CreditReturn   : 5;
 153        u32 Cmdq1DmaComplete    : 5;
 154        u32 Cmdq1CreditReturn   : 5;
 155        u32 Qsleeping           : 4;
 156} ;
 157#endif
 158
 159/*
 160 * SW Context Command and Freelist Queue Descriptors
 161 */
 162struct cmdQ_ce {
 163        struct sk_buff *skb;
 164        DECLARE_PCI_UNMAP_ADDR(dma_addr);
 165        DECLARE_PCI_UNMAP_LEN(dma_len);
 166};
 167
 168struct freelQ_ce {
 169        struct sk_buff *skb;
 170        DECLARE_PCI_UNMAP_ADDR(dma_addr);
 171        DECLARE_PCI_UNMAP_LEN(dma_len);
 172};
 173
 174/*
 175 * SW command, freelist and response rings
 176 */
 177struct cmdQ {
 178        unsigned long   status;         /* HW DMA fetch status */
 179        unsigned int    in_use;         /* # of in-use command descriptors */
 180        unsigned int    size;           /* # of descriptors */
 181        unsigned int    processed;      /* total # of descs HW has processed */
 182        unsigned int    cleaned;        /* total # of descs SW has reclaimed */
 183        unsigned int    stop_thres;     /* SW TX queue suspend threshold */
 184        u16             pidx;           /* producer index (SW) */
 185        u16             cidx;           /* consumer index (HW) */
 186        u8              genbit;         /* current generation (=valid) bit */
 187        u8              sop;            /* is next entry start of packet? */
 188        struct cmdQ_e  *entries;        /* HW command descriptor Q */
 189        struct cmdQ_ce *centries;       /* SW command context descriptor Q */
 190        dma_addr_t      dma_addr;       /* DMA addr HW command descriptor Q */
 191        spinlock_t      lock;           /* Lock to protect cmdQ enqueuing */
 192};
 193
 194struct freelQ {
 195        unsigned int    credits;        /* # of available RX buffers */
 196        unsigned int    size;           /* free list capacity */
 197        u16             pidx;           /* producer index (SW) */
 198        u16             cidx;           /* consumer index (HW) */
 199        u16             rx_buffer_size; /* Buffer size on this free list */
 200        u16             dma_offset;     /* DMA offset to align IP headers */
 201        u16             recycleq_idx;   /* skb recycle q to use */
 202        u8              genbit;         /* current generation (=valid) bit */
 203        struct freelQ_e *entries;       /* HW freelist descriptor Q */
 204        struct freelQ_ce *centries;     /* SW freelist context descriptor Q */
 205        dma_addr_t      dma_addr;       /* DMA addr HW freelist descriptor Q */
 206};
 207
 208struct respQ {
 209        unsigned int    credits;        /* credits to be returned to SGE */
 210        unsigned int    size;           /* # of response Q descriptors */
 211        u16             cidx;           /* consumer index (SW) */
 212        u8              genbit;         /* current generation(=valid) bit */
 213        struct respQ_e *entries;        /* HW response descriptor Q */
 214        dma_addr_t      dma_addr;       /* DMA addr HW response descriptor Q */
 215};
 216
 217/* Bit flags for cmdQ.status */
 218enum {
 219        CMDQ_STAT_RUNNING = 1,          /* fetch engine is running */
 220        CMDQ_STAT_LAST_PKT_DB = 2       /* last packet rung the doorbell */
 221};
 222
 223/* T204 TX SW scheduler */
 224
 225/* Per T204 TX port */
 226struct sched_port {
 227        unsigned int    avail;          /* available bits - quota */
 228        unsigned int    drain_bits_per_1024ns; /* drain rate */
 229        unsigned int    speed;          /* drain rate, mbps */
 230        unsigned int    mtu;            /* mtu size */
 231        struct sk_buff_head skbq;       /* pending skbs */
 232};
 233
 234/* Per T204 device */
 235struct sched {
 236        ktime_t         last_updated;   /* last time quotas were computed */
 237        unsigned int    max_avail;      /* max bits to be sent to any port */
 238        unsigned int    port;           /* port index (round robin ports) */
 239        unsigned int    num;            /* num skbs in per port queues */
 240        struct sched_port p[MAX_NPORTS];
 241        struct tasklet_struct sched_tsk;/* tasklet used to run scheduler */
 242};
 243static void restart_sched(unsigned long);
 244
 245
 246/*
 247 * Main SGE data structure
 248 *
 249 * Interrupts are handled by a single CPU and it is likely that on a MP system
 250 * the application is migrated to another CPU. In that scenario, we try to
 251 * seperate the RX(in irq context) and TX state in order to decrease memory
 252 * contention.
 253 */
 254struct sge {
 255        struct adapter *adapter;        /* adapter backpointer */
 256        struct net_device *netdev;      /* netdevice backpointer */
 257        struct freelQ   freelQ[SGE_FREELQ_N]; /* buffer free lists */
 258        struct respQ    respQ;          /* response Q */
 259        unsigned long   stopped_tx_queues; /* bitmap of suspended Tx queues */
 260        unsigned int    rx_pkt_pad;     /* RX padding for L2 packets */
 261        unsigned int    jumbo_fl;       /* jumbo freelist Q index */
 262        unsigned int    intrtimer_nres; /* no-resource interrupt timer */
 263        unsigned int    fixed_intrtimer;/* non-adaptive interrupt timer */
 264        struct timer_list tx_reclaim_timer; /* reclaims TX buffers */
 265        struct timer_list espibug_timer;
 266        unsigned long   espibug_timeout;
 267        struct sk_buff  *espibug_skb[MAX_NPORTS];
 268        u32             sge_control;    /* shadow value of sge control reg */
 269        struct sge_intr_counts stats;
 270        struct sge_port_stats *port_stats[MAX_NPORTS];
 271        struct sched    *tx_sched;
 272        struct cmdQ cmdQ[SGE_CMDQ_N] ____cacheline_aligned_in_smp;
 273};
 274
 275/*
 276 * stop tasklet and free all pending skb's
 277 */
 278static void tx_sched_stop(struct sge *sge)
 279{
 280        struct sched *s = sge->tx_sched;
 281        int i;
 282
 283        tasklet_kill(&s->sched_tsk);
 284
 285        for (i = 0; i < MAX_NPORTS; i++)
 286                __skb_queue_purge(&s->p[s->port].skbq);
 287}
 288
 289/*
 290 * t1_sched_update_parms() is called when the MTU or link speed changes. It
 291 * re-computes scheduler parameters to scope with the change.
 292 */
 293unsigned int t1_sched_update_parms(struct sge *sge, unsigned int port,
 294                                   unsigned int mtu, unsigned int speed)
 295{
 296        struct sched *s = sge->tx_sched;
 297        struct sched_port *p = &s->p[port];
 298        unsigned int max_avail_segs;
 299
 300        pr_debug("t1_sched_update_params mtu=%d speed=%d\n", mtu, speed);
 301        if (speed)
 302                p->speed = speed;
 303        if (mtu)
 304                p->mtu = mtu;
 305
 306        if (speed || mtu) {
 307                unsigned long long drain = 1024ULL * p->speed * (p->mtu - 40);
 308                do_div(drain, (p->mtu + 50) * 1000);
 309                p->drain_bits_per_1024ns = (unsigned int) drain;
 310
 311                if (p->speed < 1000)
 312                        p->drain_bits_per_1024ns =
 313                                90 * p->drain_bits_per_1024ns / 100;
 314        }
 315
 316        if (board_info(sge->adapter)->board == CHBT_BOARD_CHT204) {
 317                p->drain_bits_per_1024ns -= 16;
 318                s->max_avail = max(4096U, p->mtu + 16 + 14 + 4);
 319                max_avail_segs = max(1U, 4096 / (p->mtu - 40));
 320        } else {
 321                s->max_avail = 16384;
 322                max_avail_segs = max(1U, 9000 / (p->mtu - 40));
 323        }
 324
 325        pr_debug("t1_sched_update_parms: mtu %u speed %u max_avail %u "
 326                 "max_avail_segs %u drain_bits_per_1024ns %u\n", p->mtu,
 327                 p->speed, s->max_avail, max_avail_segs,
 328                 p->drain_bits_per_1024ns);
 329
 330        return max_avail_segs * (p->mtu - 40);
 331}
 332
 333#if 0
 334
 335/*
 336 * t1_sched_max_avail_bytes() tells the scheduler the maximum amount of
 337 * data that can be pushed per port.
 338 */
 339void t1_sched_set_max_avail_bytes(struct sge *sge, unsigned int val)
 340{
 341        struct sched *s = sge->tx_sched;
 342        unsigned int i;
 343
 344        s->max_avail = val;
 345        for (i = 0; i < MAX_NPORTS; i++)
 346                t1_sched_update_parms(sge, i, 0, 0);
 347}
 348
 349/*
 350 * t1_sched_set_drain_bits_per_us() tells the scheduler at which rate a port
 351 * is draining.
 352 */
 353void t1_sched_set_drain_bits_per_us(struct sge *sge, unsigned int port,
 354                                         unsigned int val)
 355{
 356        struct sched *s = sge->tx_sched;
 357        struct sched_port *p = &s->p[port];
 358        p->drain_bits_per_1024ns = val * 1024 / 1000;
 359        t1_sched_update_parms(sge, port, 0, 0);
 360}
 361
 362#endif  /*  0  */
 363
 364
 365/*
 366 * get_clock() implements a ns clock (see ktime_get)
 367 */
 368static inline ktime_t get_clock(void)
 369{
 370        struct timespec ts;
 371
 372        ktime_get_ts(&ts);
 373        return timespec_to_ktime(ts);
 374}
 375
 376/*
 377 * tx_sched_init() allocates resources and does basic initialization.
 378 */
 379static int tx_sched_init(struct sge *sge)
 380{
 381        struct sched *s;
 382        int i;
 383
 384        s = kzalloc(sizeof (struct sched), GFP_KERNEL);
 385        if (!s)
 386                return -ENOMEM;
 387
 388        pr_debug("tx_sched_init\n");
 389        tasklet_init(&s->sched_tsk, restart_sched, (unsigned long) sge);
 390        sge->tx_sched = s;
 391
 392        for (i = 0; i < MAX_NPORTS; i++) {
 393                skb_queue_head_init(&s->p[i].skbq);
 394                t1_sched_update_parms(sge, i, 1500, 1000);
 395        }
 396
 397        return 0;
 398}
 399
 400/*
 401 * sched_update_avail() computes the delta since the last time it was called
 402 * and updates the per port quota (number of bits that can be sent to the any
 403 * port).
 404 */
 405static inline int sched_update_avail(struct sge *sge)
 406{
 407        struct sched *s = sge->tx_sched;
 408        ktime_t now = get_clock();
 409        unsigned int i;
 410        long long delta_time_ns;
 411
 412        delta_time_ns = ktime_to_ns(ktime_sub(now, s->last_updated));
 413
 414        pr_debug("sched_update_avail delta=%lld\n", delta_time_ns);
 415        if (delta_time_ns < 15000)
 416                return 0;
 417
 418        for (i = 0; i < MAX_NPORTS; i++) {
 419                struct sched_port *p = &s->p[i];
 420                unsigned int delta_avail;
 421
 422                delta_avail = (p->drain_bits_per_1024ns * delta_time_ns) >> 13;
 423                p->avail = min(p->avail + delta_avail, s->max_avail);
 424        }
 425
 426        s->last_updated = now;
 427
 428        return 1;
 429}
 430
 431/*
 432 * sched_skb() is called from two different places. In the tx path, any
 433 * packet generating load on an output port will call sched_skb()
 434 * (skb != NULL). In addition, sched_skb() is called from the irq/soft irq
 435 * context (skb == NULL).
 436 * The scheduler only returns a skb (which will then be sent) if the
 437 * length of the skb is <= the current quota of the output port.
 438 */
 439static struct sk_buff *sched_skb(struct sge *sge, struct sk_buff *skb,
 440                                unsigned int credits)
 441{
 442        struct sched *s = sge->tx_sched;
 443        struct sk_buff_head *skbq;
 444        unsigned int i, len, update = 1;
 445
 446        pr_debug("sched_skb %p\n", skb);
 447        if (!skb) {
 448                if (!s->num)
 449                        return NULL;
 450        } else {
 451                skbq = &s->p[skb->dev->if_port].skbq;
 452                __skb_queue_tail(skbq, skb);
 453                s->num++;
 454                skb = NULL;
 455        }
 456
 457        if (credits < MAX_SKB_FRAGS + 1)
 458                goto out;
 459
 460again:
 461        for (i = 0; i < MAX_NPORTS; i++) {
 462                s->port = ++s->port & (MAX_NPORTS - 1);
 463                skbq = &s->p[s->port].skbq;
 464
 465                skb = skb_peek(skbq);
 466
 467                if (!skb)
 468                        continue;
 469
 470                len = skb->len;
 471                if (len <= s->p[s->port].avail) {
 472                        s->p[s->port].avail -= len;
 473                        s->num--;
 474                        __skb_unlink(skb, skbq);
 475                        goto out;
 476                }
 477                skb = NULL;
 478        }
 479
 480        if (update-- && sched_update_avail(sge))
 481                goto again;
 482
 483out:
 484        /* If there are more pending skbs, we use the hardware to schedule us
 485         * again.
 486         */
 487        if (s->num && !skb) {
 488                struct cmdQ *q = &sge->cmdQ[0];
 489                clear_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
 490                if (test_and_set_bit(CMDQ_STAT_RUNNING, &q->status) == 0) {
 491                        set_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
 492                        writel(F_CMDQ0_ENABLE, sge->adapter->regs + A_SG_DOORBELL);
 493                }
 494        }
 495        pr_debug("sched_skb ret %p\n", skb);
 496
 497        return skb;
 498}
 499
 500/*
 501 * PIO to indicate that memory mapped Q contains valid descriptor(s).
 502 */
 503static inline void doorbell_pio(struct adapter *adapter, u32 val)
 504{
 505        wmb();
 506        writel(val, adapter->regs + A_SG_DOORBELL);
 507}
 508
 509/*
 510 * Frees all RX buffers on the freelist Q. The caller must make sure that
 511 * the SGE is turned off before calling this function.
 512 */
 513static void free_freelQ_buffers(struct pci_dev *pdev, struct freelQ *q)
 514{
 515        unsigned int cidx = q->cidx;
 516
 517        while (q->credits--) {
 518                struct freelQ_ce *ce = &q->centries[cidx];
 519
 520                pci_unmap_single(pdev, pci_unmap_addr(ce, dma_addr),
 521                                 pci_unmap_len(ce, dma_len),
 522                                 PCI_DMA_FROMDEVICE);
 523                dev_kfree_skb(ce->skb);
 524                ce->skb = NULL;
 525                if (++cidx == q->size)
 526                        cidx = 0;
 527        }
 528}
 529
 530/*
 531 * Free RX free list and response queue resources.
 532 */
 533static void free_rx_resources(struct sge *sge)
 534{
 535        struct pci_dev *pdev = sge->adapter->pdev;
 536        unsigned int size, i;
 537
 538        if (sge->respQ.entries) {
 539                size = sizeof(struct respQ_e) * sge->respQ.size;
 540                pci_free_consistent(pdev, size, sge->respQ.entries,
 541                                    sge->respQ.dma_addr);
 542        }
 543
 544        for (i = 0; i < SGE_FREELQ_N; i++) {
 545                struct freelQ *q = &sge->freelQ[i];
 546
 547                if (q->centries) {
 548                        free_freelQ_buffers(pdev, q);
 549                        kfree(q->centries);
 550                }
 551                if (q->entries) {
 552                        size = sizeof(struct freelQ_e) * q->size;
 553                        pci_free_consistent(pdev, size, q->entries,
 554                                            q->dma_addr);
 555                }
 556        }
 557}
 558
 559/*
 560 * Allocates basic RX resources, consisting of memory mapped freelist Qs and a
 561 * response queue.
 562 */
 563static int alloc_rx_resources(struct sge *sge, struct sge_params *p)
 564{
 565        struct pci_dev *pdev = sge->adapter->pdev;
 566        unsigned int size, i;
 567
 568        for (i = 0; i < SGE_FREELQ_N; i++) {
 569                struct freelQ *q = &sge->freelQ[i];
 570
 571                q->genbit = 1;
 572                q->size = p->freelQ_size[i];
 573                q->dma_offset = sge->rx_pkt_pad ? 0 : NET_IP_ALIGN;
 574                size = sizeof(struct freelQ_e) * q->size;
 575                q->entries = pci_alloc_consistent(pdev, size, &q->dma_addr);
 576                if (!q->entries)
 577                        goto err_no_mem;
 578
 579                size = sizeof(struct freelQ_ce) * q->size;
 580                q->centries = kzalloc(size, GFP_KERNEL);
 581                if (!q->centries)
 582                        goto err_no_mem;
 583        }
 584
 585        /*
 586         * Calculate the buffer sizes for the two free lists.  FL0 accommodates
 587         * regular sized Ethernet frames, FL1 is sized not to exceed 16K,
 588         * including all the sk_buff overhead.
 589         *
 590         * Note: For T2 FL0 and FL1 are reversed.
 591         */
 592        sge->freelQ[!sge->jumbo_fl].rx_buffer_size = SGE_RX_SM_BUF_SIZE +
 593                sizeof(struct cpl_rx_data) +
 594                sge->freelQ[!sge->jumbo_fl].dma_offset;
 595
 596                size = (16 * 1024) -
 597                    SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 598
 599        sge->freelQ[sge->jumbo_fl].rx_buffer_size = size;
 600
 601        /*
 602         * Setup which skb recycle Q should be used when recycling buffers from
 603         * each free list.
 604         */
 605        sge->freelQ[!sge->jumbo_fl].recycleq_idx = 0;
 606        sge->freelQ[sge->jumbo_fl].recycleq_idx = 1;
 607
 608        sge->respQ.genbit = 1;
 609        sge->respQ.size = SGE_RESPQ_E_N;
 610        sge->respQ.credits = 0;
 611        size = sizeof(struct respQ_e) * sge->respQ.size;
 612        sge->respQ.entries =
 613                pci_alloc_consistent(pdev, size, &sge->respQ.dma_addr);
 614        if (!sge->respQ.entries)
 615                goto err_no_mem;
 616        return 0;
 617
 618err_no_mem:
 619        free_rx_resources(sge);
 620        return -ENOMEM;
 621}
 622
 623/*
 624 * Reclaims n TX descriptors and frees the buffers associated with them.
 625 */
 626static void free_cmdQ_buffers(struct sge *sge, struct cmdQ *q, unsigned int n)
 627{
 628        struct cmdQ_ce *ce;
 629        struct pci_dev *pdev = sge->adapter->pdev;
 630        unsigned int cidx = q->cidx;
 631
 632        q->in_use -= n;
 633        ce = &q->centries[cidx];
 634        while (n--) {
 635                if (likely(pci_unmap_len(ce, dma_len))) {
 636                        pci_unmap_single(pdev, pci_unmap_addr(ce, dma_addr),
 637                                         pci_unmap_len(ce, dma_len),
 638                                         PCI_DMA_TODEVICE);
 639                        if (q->sop)
 640                                q->sop = 0;
 641                }
 642                if (ce->skb) {
 643                        dev_kfree_skb_any(ce->skb);
 644                        q->sop = 1;
 645                }
 646                ce++;
 647                if (++cidx == q->size) {
 648                        cidx = 0;
 649                        ce = q->centries;
 650                }
 651        }
 652        q->cidx = cidx;
 653}
 654
 655/*
 656 * Free TX resources.
 657 *
 658 * Assumes that SGE is stopped and all interrupts are disabled.
 659 */
 660static void free_tx_resources(struct sge *sge)
 661{
 662        struct pci_dev *pdev = sge->adapter->pdev;
 663        unsigned int size, i;
 664
 665        for (i = 0; i < SGE_CMDQ_N; i++) {
 666                struct cmdQ *q = &sge->cmdQ[i];
 667
 668                if (q->centries) {
 669                        if (q->in_use)
 670                                free_cmdQ_buffers(sge, q, q->in_use);
 671                        kfree(q->centries);
 672                }
 673                if (q->entries) {
 674                        size = sizeof(struct cmdQ_e) * q->size;
 675                        pci_free_consistent(pdev, size, q->entries,
 676                                            q->dma_addr);
 677                }
 678        }
 679}
 680
 681/*
 682 * Allocates basic TX resources, consisting of memory mapped command Qs.
 683 */
 684static int alloc_tx_resources(struct sge *sge, struct sge_params *p)
 685{
 686        struct pci_dev *pdev = sge->adapter->pdev;
 687        unsigned int size, i;
 688
 689        for (i = 0; i < SGE_CMDQ_N; i++) {
 690                struct cmdQ *q = &sge->cmdQ[i];
 691
 692                q->genbit = 1;
 693                q->sop = 1;
 694                q->size = p->cmdQ_size[i];
 695                q->in_use = 0;
 696                q->status = 0;
 697                q->processed = q->cleaned = 0;
 698                q->stop_thres = 0;
 699                spin_lock_init(&q->lock);
 700                size = sizeof(struct cmdQ_e) * q->size;
 701                q->entries = pci_alloc_consistent(pdev, size, &q->dma_addr);
 702                if (!q->entries)
 703                        goto err_no_mem;
 704
 705                size = sizeof(struct cmdQ_ce) * q->size;
 706                q->centries = kzalloc(size, GFP_KERNEL);
 707                if (!q->centries)
 708                        goto err_no_mem;
 709        }
 710
 711        /*
 712         * CommandQ 0 handles Ethernet and TOE packets, while queue 1 is TOE
 713         * only.  For queue 0 set the stop threshold so we can handle one more
 714         * packet from each port, plus reserve an additional 24 entries for
 715         * Ethernet packets only.  Queue 1 never suspends nor do we reserve
 716         * space for Ethernet packets.
 717         */
 718        sge->cmdQ[0].stop_thres = sge->adapter->params.nports *
 719                (MAX_SKB_FRAGS + 1);
 720        return 0;
 721
 722err_no_mem:
 723        free_tx_resources(sge);
 724        return -ENOMEM;
 725}
 726
 727static inline void setup_ring_params(struct adapter *adapter, u64 addr,
 728                                     u32 size, int base_reg_lo,
 729                                     int base_reg_hi, int size_reg)
 730{
 731        writel((u32)addr, adapter->regs + base_reg_lo);
 732        writel(addr >> 32, adapter->regs + base_reg_hi);
 733        writel(size, adapter->regs + size_reg);
 734}
 735
 736/*
 737 * Enable/disable VLAN acceleration.
 738 */
 739void t1_set_vlan_accel(struct adapter *adapter, int on_off)
 740{
 741        struct sge *sge = adapter->sge;
 742
 743        sge->sge_control &= ~F_VLAN_XTRACT;
 744        if (on_off)
 745                sge->sge_control |= F_VLAN_XTRACT;
 746        if (adapter->open_device_map) {
 747                writel(sge->sge_control, adapter->regs + A_SG_CONTROL);
 748                readl(adapter->regs + A_SG_CONTROL);   /* flush */
 749        }
 750}
 751
 752/*
 753 * Programs the various SGE registers. However, the engine is not yet enabled,
 754 * but sge->sge_control is setup and ready to go.
 755 */
 756static void configure_sge(struct sge *sge, struct sge_params *p)
 757{
 758        struct adapter *ap = sge->adapter;
 759
 760        writel(0, ap->regs + A_SG_CONTROL);
 761        setup_ring_params(ap, sge->cmdQ[0].dma_addr, sge->cmdQ[0].size,
 762                          A_SG_CMD0BASELWR, A_SG_CMD0BASEUPR, A_SG_CMD0SIZE);
 763        setup_ring_params(ap, sge->cmdQ[1].dma_addr, sge->cmdQ[1].size,
 764                          A_SG_CMD1BASELWR, A_SG_CMD1BASEUPR, A_SG_CMD1SIZE);
 765        setup_ring_params(ap, sge->freelQ[0].dma_addr,
 766                          sge->freelQ[0].size, A_SG_FL0BASELWR,
 767                          A_SG_FL0BASEUPR, A_SG_FL0SIZE);
 768        setup_ring_params(ap, sge->freelQ[1].dma_addr,
 769                          sge->freelQ[1].size, A_SG_FL1BASELWR,
 770                          A_SG_FL1BASEUPR, A_SG_FL1SIZE);
 771
 772        /* The threshold comparison uses <. */
 773        writel(SGE_RX_SM_BUF_SIZE + 1, ap->regs + A_SG_FLTHRESHOLD);
 774
 775        setup_ring_params(ap, sge->respQ.dma_addr, sge->respQ.size,
 776                          A_SG_RSPBASELWR, A_SG_RSPBASEUPR, A_SG_RSPSIZE);
 777        writel((u32)sge->respQ.size - 1, ap->regs + A_SG_RSPQUEUECREDIT);
 778
 779        sge->sge_control = F_CMDQ0_ENABLE | F_CMDQ1_ENABLE | F_FL0_ENABLE |
 780                F_FL1_ENABLE | F_CPL_ENABLE | F_RESPONSE_QUEUE_ENABLE |
 781                V_CMDQ_PRIORITY(2) | F_DISABLE_CMDQ1_GTS | F_ISCSI_COALESCE |
 782                V_RX_PKT_OFFSET(sge->rx_pkt_pad);
 783
 784#if defined(__BIG_ENDIAN_BITFIELD)
 785        sge->sge_control |= F_ENABLE_BIG_ENDIAN;
 786#endif
 787
 788        /* Initialize no-resource timer */
 789        sge->intrtimer_nres = SGE_INTRTIMER_NRES * core_ticks_per_usec(ap);
 790
 791        t1_sge_set_coalesce_params(sge, p);
 792}
 793
 794/*
 795 * Return the payload capacity of the jumbo free-list buffers.
 796 */
 797static inline unsigned int jumbo_payload_capacity(const struct sge *sge)
 798{
 799        return sge->freelQ[sge->jumbo_fl].rx_buffer_size -
 800                sge->freelQ[sge->jumbo_fl].dma_offset -
 801                sizeof(struct cpl_rx_data);
 802}
 803
 804/*
 805 * Frees all SGE related resources and the sge structure itself
 806 */
 807void t1_sge_destroy(struct sge *sge)
 808{
 809        int i;
 810
 811        for_each_port(sge->adapter, i)
 812                free_percpu(sge->port_stats[i]);
 813
 814        kfree(sge->tx_sched);
 815        free_tx_resources(sge);
 816        free_rx_resources(sge);
 817        kfree(sge);
 818}
 819
 820/*
 821 * Allocates new RX buffers on the freelist Q (and tracks them on the freelist
 822 * context Q) until the Q is full or alloc_skb fails.
 823 *
 824 * It is possible that the generation bits already match, indicating that the
 825 * buffer is already valid and nothing needs to be done. This happens when we
 826 * copied a received buffer into a new sk_buff during the interrupt processing.
 827 *
 828 * If the SGE doesn't automatically align packets properly (!sge->rx_pkt_pad),
 829 * we specify a RX_OFFSET in order to make sure that the IP header is 4B
 830 * aligned.
 831 */
 832static void refill_free_list(struct sge *sge, struct freelQ *q)
 833{
 834        struct pci_dev *pdev = sge->adapter->pdev;
 835        struct freelQ_ce *ce = &q->centries[q->pidx];
 836        struct freelQ_e *e = &q->entries[q->pidx];
 837        unsigned int dma_len = q->rx_buffer_size - q->dma_offset;
 838
 839        while (q->credits < q->size) {
 840                struct sk_buff *skb;
 841                dma_addr_t mapping;
 842
 843                skb = alloc_skb(q->rx_buffer_size, GFP_ATOMIC);
 844                if (!skb)
 845                        break;
 846
 847                skb_reserve(skb, q->dma_offset);
 848                mapping = pci_map_single(pdev, skb->data, dma_len,
 849                                         PCI_DMA_FROMDEVICE);
 850                skb_reserve(skb, sge->rx_pkt_pad);
 851
 852                ce->skb = skb;
 853                pci_unmap_addr_set(ce, dma_addr, mapping);
 854                pci_unmap_len_set(ce, dma_len, dma_len);
 855                e->addr_lo = (u32)mapping;
 856                e->addr_hi = (u64)mapping >> 32;
 857                e->len_gen = V_CMD_LEN(dma_len) | V_CMD_GEN1(q->genbit);
 858                wmb();
 859                e->gen2 = V_CMD_GEN2(q->genbit);
 860
 861                e++;
 862                ce++;
 863                if (++q->pidx == q->size) {
 864                        q->pidx = 0;
 865                        q->genbit ^= 1;
 866                        ce = q->centries;
 867                        e = q->entries;
 868                }
 869                q->credits++;
 870        }
 871}
 872
 873/*
 874 * Calls refill_free_list for both free lists. If we cannot fill at least 1/4
 875 * of both rings, we go into 'few interrupt mode' in order to give the system
 876 * time to free up resources.
 877 */
 878static void freelQs_empty(struct sge *sge)
 879{
 880        struct adapter *adapter = sge->adapter;
 881        u32 irq_reg = readl(adapter->regs + A_SG_INT_ENABLE);
 882        u32 irqholdoff_reg;
 883
 884        refill_free_list(sge, &sge->freelQ[0]);
 885        refill_free_list(sge, &sge->freelQ[1]);
 886
 887        if (sge->freelQ[0].credits > (sge->freelQ[0].size >> 2) &&
 888            sge->freelQ[1].credits > (sge->freelQ[1].size >> 2)) {
 889                irq_reg |= F_FL_EXHAUSTED;
 890                irqholdoff_reg = sge->fixed_intrtimer;
 891        } else {
 892                /* Clear the F_FL_EXHAUSTED interrupts for now */
 893                irq_reg &= ~F_FL_EXHAUSTED;
 894                irqholdoff_reg = sge->intrtimer_nres;
 895        }
 896        writel(irqholdoff_reg, adapter->regs + A_SG_INTRTIMER);
 897        writel(irq_reg, adapter->regs + A_SG_INT_ENABLE);
 898
 899        /* We reenable the Qs to force a freelist GTS interrupt later */
 900        doorbell_pio(adapter, F_FL0_ENABLE | F_FL1_ENABLE);
 901}
 902
 903#define SGE_PL_INTR_MASK (F_PL_INTR_SGE_ERR | F_PL_INTR_SGE_DATA)
 904#define SGE_INT_FATAL (F_RESPQ_OVERFLOW | F_PACKET_TOO_BIG | F_PACKET_MISMATCH)
 905#define SGE_INT_ENABLE (F_RESPQ_EXHAUSTED | F_RESPQ_OVERFLOW | \
 906                        F_FL_EXHAUSTED | F_PACKET_TOO_BIG | F_PACKET_MISMATCH)
 907
 908/*
 909 * Disable SGE Interrupts
 910 */
 911void t1_sge_intr_disable(struct sge *sge)
 912{
 913        u32 val = readl(sge->adapter->regs + A_PL_ENABLE);
 914
 915        writel(val & ~SGE_PL_INTR_MASK, sge->adapter->regs + A_PL_ENABLE);
 916        writel(0, sge->adapter->regs + A_SG_INT_ENABLE);
 917}
 918
 919/*
 920 * Enable SGE interrupts.
 921 */
 922void t1_sge_intr_enable(struct sge *sge)
 923{
 924        u32 en = SGE_INT_ENABLE;
 925        u32 val = readl(sge->adapter->regs + A_PL_ENABLE);
 926
 927        if (sge->adapter->flags & TSO_CAPABLE)
 928                en &= ~F_PACKET_TOO_BIG;
 929        writel(en, sge->adapter->regs + A_SG_INT_ENABLE);
 930        writel(val | SGE_PL_INTR_MASK, sge->adapter->regs + A_PL_ENABLE);
 931}
 932
 933/*
 934 * Clear SGE interrupts.
 935 */
 936void t1_sge_intr_clear(struct sge *sge)
 937{
 938        writel(SGE_PL_INTR_MASK, sge->adapter->regs + A_PL_CAUSE);
 939        writel(0xffffffff, sge->adapter->regs + A_SG_INT_CAUSE);
 940}
 941
 942/*
 943 * SGE 'Error' interrupt handler
 944 */
 945int t1_sge_intr_error_handler(struct sge *sge)
 946{
 947        struct adapter *adapter = sge->adapter;
 948        u32 cause = readl(adapter->regs + A_SG_INT_CAUSE);
 949
 950        if (adapter->flags & TSO_CAPABLE)
 951                cause &= ~F_PACKET_TOO_BIG;
 952        if (cause & F_RESPQ_EXHAUSTED)
 953                sge->stats.respQ_empty++;
 954        if (cause & F_RESPQ_OVERFLOW) {
 955                sge->stats.respQ_overflow++;
 956                CH_ALERT("%s: SGE response queue overflow\n",
 957                         adapter->name);
 958        }
 959        if (cause & F_FL_EXHAUSTED) {
 960                sge->stats.freelistQ_empty++;
 961                freelQs_empty(sge);
 962        }
 963        if (cause & F_PACKET_TOO_BIG) {
 964                sge->stats.pkt_too_big++;
 965                CH_ALERT("%s: SGE max packet size exceeded\n",
 966                         adapter->name);
 967        }
 968        if (cause & F_PACKET_MISMATCH) {
 969                sge->stats.pkt_mismatch++;
 970                CH_ALERT("%s: SGE packet mismatch\n", adapter->name);
 971        }
 972        if (cause & SGE_INT_FATAL)
 973                t1_fatal_err(adapter);
 974
 975        writel(cause, adapter->regs + A_SG_INT_CAUSE);
 976        return 0;
 977}
 978
 979const struct sge_intr_counts *t1_sge_get_intr_counts(const struct sge *sge)
 980{
 981        return &sge->stats;
 982}
 983
 984void t1_sge_get_port_stats(const struct sge *sge, int port,
 985                           struct sge_port_stats *ss)
 986{
 987        int cpu;
 988
 989        memset(ss, 0, sizeof(*ss));
 990        for_each_possible_cpu(cpu) {
 991                struct sge_port_stats *st = per_cpu_ptr(sge->port_stats[port], cpu);
 992
 993                ss->rx_cso_good += st->rx_cso_good;
 994                ss->tx_cso += st->tx_cso;
 995                ss->tx_tso += st->tx_tso;
 996                ss->tx_need_hdrroom += st->tx_need_hdrroom;
 997                ss->vlan_xtract += st->vlan_xtract;
 998                ss->vlan_insert += st->vlan_insert;
 999        }
1000}
1001
1002/**
1003 *      recycle_fl_buf - recycle a free list buffer
1004 *      @fl: the free list
1005 *      @idx: index of buffer to recycle
1006 *
1007 *      Recycles the specified buffer on the given free list by adding it at
1008 *      the next available slot on the list.
1009 */
1010static void recycle_fl_buf(struct freelQ *fl, int idx)
1011{
1012        struct freelQ_e *from = &fl->entries[idx];
1013        struct freelQ_e *to = &fl->entries[fl->pidx];
1014
1015        fl->centries[fl->pidx] = fl->centries[idx];
1016        to->addr_lo = from->addr_lo;
1017        to->addr_hi = from->addr_hi;
1018        to->len_gen = G_CMD_LEN(from->len_gen) | V_CMD_GEN1(fl->genbit);
1019        wmb();
1020        to->gen2 = V_CMD_GEN2(fl->genbit);
1021        fl->credits++;
1022
1023        if (++fl->pidx == fl->size) {
1024                fl->pidx = 0;
1025                fl->genbit ^= 1;
1026        }
1027}
1028
1029static int copybreak __read_mostly = 256;
1030module_param(copybreak, int, 0);
1031MODULE_PARM_DESC(copybreak, "Receive copy threshold");
1032
1033/**
1034 *      get_packet - return the next ingress packet buffer
1035 *      @pdev: the PCI device that received the packet
1036 *      @fl: the SGE free list holding the packet
1037 *      @len: the actual packet length, excluding any SGE padding
1038 *
1039 *      Get the next packet from a free list and complete setup of the
1040 *      sk_buff.  If the packet is small we make a copy and recycle the
1041 *      original buffer, otherwise we use the original buffer itself.  If a
1042 *      positive drop threshold is supplied packets are dropped and their
1043 *      buffers recycled if (a) the number of remaining buffers is under the
1044 *      threshold and the packet is too big to copy, or (b) the packet should
1045 *      be copied but there is no memory for the copy.
1046 */
1047static inline struct sk_buff *get_packet(struct pci_dev *pdev,
1048                                         struct freelQ *fl, unsigned int len)
1049{
1050        struct sk_buff *skb;
1051        const struct freelQ_ce *ce = &fl->centries[fl->cidx];
1052
1053        if (len < copybreak) {
1054                skb = alloc_skb(len + 2, GFP_ATOMIC);
1055                if (!skb)
1056                        goto use_orig_buf;
1057
1058                skb_reserve(skb, 2);    /* align IP header */
1059                skb_put(skb, len);
1060                pci_dma_sync_single_for_cpu(pdev,
1061                                            pci_unmap_addr(ce, dma_addr),
1062                                            pci_unmap_len(ce, dma_len),
1063                                            PCI_DMA_FROMDEVICE);
1064                skb_copy_from_linear_data(ce->skb, skb->data, len);
1065                pci_dma_sync_single_for_device(pdev,
1066                                               pci_unmap_addr(ce, dma_addr),
1067                                               pci_unmap_len(ce, dma_len),
1068                                               PCI_DMA_FROMDEVICE);
1069                recycle_fl_buf(fl, fl->cidx);
1070                return skb;
1071        }
1072
1073use_orig_buf:
1074        if (fl->credits < 2) {
1075                recycle_fl_buf(fl, fl->cidx);
1076                return NULL;
1077        }
1078
1079        pci_unmap_single(pdev, pci_unmap_addr(ce, dma_addr),
1080                         pci_unmap_len(ce, dma_len), PCI_DMA_FROMDEVICE);
1081        skb = ce->skb;
1082        prefetch(skb->data);
1083
1084        skb_put(skb, len);
1085        return skb;
1086}
1087
1088/**
1089 *      unexpected_offload - handle an unexpected offload packet
1090 *      @adapter: the adapter
1091 *      @fl: the free list that received the packet
1092 *
1093 *      Called when we receive an unexpected offload packet (e.g., the TOE
1094 *      function is disabled or the card is a NIC).  Prints a message and
1095 *      recycles the buffer.
1096 */
1097static void unexpected_offload(struct adapter *adapter, struct freelQ *fl)
1098{
1099        struct freelQ_ce *ce = &fl->centries[fl->cidx];
1100        struct sk_buff *skb = ce->skb;
1101
1102        pci_dma_sync_single_for_cpu(adapter->pdev, pci_unmap_addr(ce, dma_addr),
1103                            pci_unmap_len(ce, dma_len), PCI_DMA_FROMDEVICE);
1104        CH_ERR("%s: unexpected offload packet, cmd %u\n",
1105               adapter->name, *skb->data);
1106        recycle_fl_buf(fl, fl->cidx);
1107}
1108
1109/*
1110 * T1/T2 SGE limits the maximum DMA size per TX descriptor to
1111 * SGE_TX_DESC_MAX_PLEN (16KB). If the PAGE_SIZE is larger than 16KB, the
1112 * stack might send more than SGE_TX_DESC_MAX_PLEN in a contiguous manner.
1113 * Note that the *_large_page_tx_descs stuff will be optimized out when
1114 * PAGE_SIZE <= SGE_TX_DESC_MAX_PLEN.
1115 *
1116 * compute_large_page_descs() computes how many additional descriptors are
1117 * required to break down the stack's request.
1118 */
1119static inline unsigned int compute_large_page_tx_descs(struct sk_buff *skb)
1120{
1121        unsigned int count = 0;
1122
1123        if (PAGE_SIZE > SGE_TX_DESC_MAX_PLEN) {
1124                unsigned int nfrags = skb_shinfo(skb)->nr_frags;
1125                unsigned int i, len = skb->len - skb->data_len;
1126                while (len > SGE_TX_DESC_MAX_PLEN) {
1127                        count++;
1128                        len -= SGE_TX_DESC_MAX_PLEN;
1129                }
1130                for (i = 0; nfrags--; i++) {
1131                        skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1132                        len = frag->size;
1133                        while (len > SGE_TX_DESC_MAX_PLEN) {
1134                                count++;
1135                                len -= SGE_TX_DESC_MAX_PLEN;
1136                        }
1137                }
1138        }
1139        return count;
1140}
1141
1142/*
1143 * Write a cmdQ entry.
1144 *
1145 * Since this function writes the 'flags' field, it must not be used to
1146 * write the first cmdQ entry.
1147 */
1148static inline void write_tx_desc(struct cmdQ_e *e, dma_addr_t mapping,
1149                                 unsigned int len, unsigned int gen,
1150                                 unsigned int eop)
1151{
1152        BUG_ON(len > SGE_TX_DESC_MAX_PLEN);
1153
1154        e->addr_lo = (u32)mapping;
1155        e->addr_hi = (u64)mapping >> 32;
1156        e->len_gen = V_CMD_LEN(len) | V_CMD_GEN1(gen);
1157        e->flags = F_CMD_DATAVALID | V_CMD_EOP(eop) | V_CMD_GEN2(gen);
1158}
1159
1160/*
1161 * See comment for previous function.
1162 *
1163 * write_tx_descs_large_page() writes additional SGE tx descriptors if
1164 * *desc_len exceeds HW's capability.
1165 */
1166static inline unsigned int write_large_page_tx_descs(unsigned int pidx,
1167                                                     struct cmdQ_e **e,
1168                                                     struct cmdQ_ce **ce,
1169                                                     unsigned int *gen,
1170                                                     dma_addr_t *desc_mapping,
1171                                                     unsigned int *desc_len,
1172                                                     unsigned int nfrags,
1173                                                     struct cmdQ *q)
1174{
1175        if (PAGE_SIZE > SGE_TX_DESC_MAX_PLEN) {
1176                struct cmdQ_e *e1 = *e;
1177                struct cmdQ_ce *ce1 = *ce;
1178
1179                while (*desc_len > SGE_TX_DESC_MAX_PLEN) {
1180                        *desc_len -= SGE_TX_DESC_MAX_PLEN;
1181                        write_tx_desc(e1, *desc_mapping, SGE_TX_DESC_MAX_PLEN,
1182                                      *gen, nfrags == 0 && *desc_len == 0);
1183                        ce1->skb = NULL;
1184                        pci_unmap_len_set(ce1, dma_len, 0);
1185                        *desc_mapping += SGE_TX_DESC_MAX_PLEN;
1186                        if (*desc_len) {
1187                                ce1++;
1188                                e1++;
1189                                if (++pidx == q->size) {
1190                                        pidx = 0;
1191                                        *gen ^= 1;
1192                                        ce1 = q->centries;
1193                                        e1 = q->entries;
1194                                }
1195                        }
1196                }
1197                *e = e1;
1198                *ce = ce1;
1199        }
1200        return pidx;
1201}
1202
1203/*
1204 * Write the command descriptors to transmit the given skb starting at
1205 * descriptor pidx with the given generation.
1206 */
1207static inline void write_tx_descs(struct adapter *adapter, struct sk_buff *skb,
1208                                  unsigned int pidx, unsigned int gen,
1209                                  struct cmdQ *q)
1210{
1211        dma_addr_t mapping, desc_mapping;
1212        struct cmdQ_e *e, *e1;
1213        struct cmdQ_ce *ce;
1214        unsigned int i, flags, first_desc_len, desc_len,
1215            nfrags = skb_shinfo(skb)->nr_frags;
1216
1217        e = e1 = &q->entries[pidx];
1218        ce = &q->centries[pidx];
1219
1220        mapping = pci_map_single(adapter->pdev, skb->data,
1221                                skb->len - skb->data_len, PCI_DMA_TODEVICE);
1222
1223        desc_mapping = mapping;
1224        desc_len = skb->len - skb->data_len;
1225
1226        flags = F_CMD_DATAVALID | F_CMD_SOP |
1227            V_CMD_EOP(nfrags == 0 && desc_len <= SGE_TX_DESC_MAX_PLEN) |
1228            V_CMD_GEN2(gen);
1229        first_desc_len = (desc_len <= SGE_TX_DESC_MAX_PLEN) ?
1230            desc_len : SGE_TX_DESC_MAX_PLEN;
1231        e->addr_lo = (u32)desc_mapping;
1232        e->addr_hi = (u64)desc_mapping >> 32;
1233        e->len_gen = V_CMD_LEN(first_desc_len) | V_CMD_GEN1(gen);
1234        ce->skb = NULL;
1235        pci_unmap_len_set(ce, dma_len, 0);
1236
1237        if (PAGE_SIZE > SGE_TX_DESC_MAX_PLEN &&
1238            desc_len > SGE_TX_DESC_MAX_PLEN) {
1239                desc_mapping += first_desc_len;
1240                desc_len -= first_desc_len;
1241                e1++;
1242                ce++;
1243                if (++pidx == q->size) {
1244                        pidx = 0;
1245                        gen ^= 1;
1246                        e1 = q->entries;
1247                        ce = q->centries;
1248                }
1249                pidx = write_large_page_tx_descs(pidx, &e1, &ce, &gen,
1250                                                 &desc_mapping, &desc_len,
1251                                                 nfrags, q);
1252
1253                if (likely(desc_len))
1254                        write_tx_desc(e1, desc_mapping, desc_len, gen,
1255                                      nfrags == 0);
1256        }
1257
1258        ce->skb = NULL;
1259        pci_unmap_addr_set(ce, dma_addr, mapping);
1260        pci_unmap_len_set(ce, dma_len, skb->len - skb->data_len);
1261
1262        for (i = 0; nfrags--; i++) {
1263                skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1264                e1++;
1265                ce++;
1266                if (++pidx == q->size) {
1267                        pidx = 0;
1268                        gen ^= 1;
1269                        e1 = q->entries;
1270                        ce = q->centries;
1271                }
1272
1273                mapping = pci_map_page(adapter->pdev, frag->page,
1274                                       frag->page_offset, frag->size,
1275                                       PCI_DMA_TODEVICE);
1276                desc_mapping = mapping;
1277                desc_len = frag->size;
1278
1279                pidx = write_large_page_tx_descs(pidx, &e1, &ce, &gen,
1280                                                 &desc_mapping, &desc_len,
1281                                                 nfrags, q);
1282                if (likely(desc_len))
1283                        write_tx_desc(e1, desc_mapping, desc_len, gen,
1284                                      nfrags == 0);
1285                ce->skb = NULL;
1286                pci_unmap_addr_set(ce, dma_addr, mapping);
1287                pci_unmap_len_set(ce, dma_len, frag->size);
1288        }
1289        ce->skb = skb;
1290        wmb();
1291        e->flags = flags;
1292}
1293
1294/*
1295 * Clean up completed Tx buffers.
1296 */
1297static inline void reclaim_completed_tx(struct sge *sge, struct cmdQ *q)
1298{
1299        unsigned int reclaim = q->processed - q->cleaned;
1300
1301        if (reclaim) {
1302                pr_debug("reclaim_completed_tx processed:%d cleaned:%d\n",
1303                         q->processed, q->cleaned);
1304                free_cmdQ_buffers(sge, q, reclaim);
1305                q->cleaned += reclaim;
1306        }
1307}
1308
1309/*
1310 * Called from tasklet. Checks the scheduler for any
1311 * pending skbs that can be sent.
1312 */
1313static void restart_sched(unsigned long arg)
1314{
1315        struct sge *sge = (struct sge *) arg;
1316        struct adapter *adapter = sge->adapter;
1317        struct cmdQ *q = &sge->cmdQ[0];
1318        struct sk_buff *skb;
1319        unsigned int credits, queued_skb = 0;
1320
1321        spin_lock(&q->lock);
1322        reclaim_completed_tx(sge, q);
1323
1324        credits = q->size - q->in_use;
1325        pr_debug("restart_sched credits=%d\n", credits);
1326        while ((skb = sched_skb(sge, NULL, credits)) != NULL) {
1327                unsigned int genbit, pidx, count;
1328                count = 1 + skb_shinfo(skb)->nr_frags;
1329                count += compute_large_page_tx_descs(skb);
1330                q->in_use += count;
1331                genbit = q->genbit;
1332                pidx = q->pidx;
1333                q->pidx += count;
1334                if (q->pidx >= q->size) {
1335                        q->pidx -= q->size;
1336                        q->genbit ^= 1;
1337                }
1338                write_tx_descs(adapter, skb, pidx, genbit, q);
1339                credits = q->size - q->in_use;
1340                queued_skb = 1;
1341        }
1342
1343        if (queued_skb) {
1344                clear_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
1345                if (test_and_set_bit(CMDQ_STAT_RUNNING, &q->status) == 0) {
1346                        set_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
1347                        writel(F_CMDQ0_ENABLE, adapter->regs + A_SG_DOORBELL);
1348                }
1349        }
1350        spin_unlock(&q->lock);
1351}
1352
1353/**
1354 *      sge_rx - process an ingress ethernet packet
1355 *      @sge: the sge structure
1356 *      @fl: the free list that contains the packet buffer
1357 *      @len: the packet length
1358 *
1359 *      Process an ingress ethernet pakcet and deliver it to the stack.
1360 */
1361static void sge_rx(struct sge *sge, struct freelQ *fl, unsigned int len)
1362{
1363        struct sk_buff *skb;
1364        const struct cpl_rx_pkt *p;
1365        struct adapter *adapter = sge->adapter;
1366        struct sge_port_stats *st;
1367
1368        skb = get_packet(adapter->pdev, fl, len - sge->rx_pkt_pad);
1369        if (unlikely(!skb)) {
1370                sge->stats.rx_drops++;
1371                return;
1372        }
1373
1374        p = (const struct cpl_rx_pkt *) skb->data;
1375        if (p->iff >= adapter->params.nports) {
1376                kfree_skb(skb);
1377                return;
1378        }
1379        __skb_pull(skb, sizeof(*p));
1380
1381        st = per_cpu_ptr(sge->port_stats[p->iff], smp_processor_id());
1382
1383        skb->protocol = eth_type_trans(skb, adapter->port[p->iff].dev);
1384        if ((adapter->flags & RX_CSUM_ENABLED) && p->csum == 0xffff &&
1385            skb->protocol == htons(ETH_P_IP) &&
1386            (skb->data[9] == IPPROTO_TCP || skb->data[9] == IPPROTO_UDP)) {
1387                ++st->rx_cso_good;
1388                skb->ip_summed = CHECKSUM_UNNECESSARY;
1389        } else
1390                skb->ip_summed = CHECKSUM_NONE;
1391
1392        if (unlikely(adapter->vlan_grp && p->vlan_valid)) {
1393                st->vlan_xtract++;
1394                vlan_hwaccel_receive_skb(skb, adapter->vlan_grp,
1395                                         ntohs(p->vlan));
1396        } else
1397                netif_receive_skb(skb);
1398}
1399
1400/*
1401 * Returns true if a command queue has enough available descriptors that
1402 * we can resume Tx operation after temporarily disabling its packet queue.
1403 */
1404static inline int enough_free_Tx_descs(const struct cmdQ *q)
1405{
1406        unsigned int r = q->processed - q->cleaned;
1407
1408        return q->in_use - r < (q->size >> 1);
1409}
1410
1411/*
1412 * Called when sufficient space has become available in the SGE command queues
1413 * after the Tx packet schedulers have been suspended to restart the Tx path.
1414 */
1415static void restart_tx_queues(struct sge *sge)
1416{
1417        struct adapter *adap = sge->adapter;
1418        int i;
1419
1420        if (!enough_free_Tx_descs(&sge->cmdQ[0]))
1421                return;
1422
1423        for_each_port(adap, i) {
1424                struct net_device *nd = adap->port[i].dev;
1425
1426                if (test_and_clear_bit(nd->if_port, &sge->stopped_tx_queues) &&
1427                    netif_running(nd)) {
1428                        sge->stats.cmdQ_restarted[2]++;
1429                        netif_wake_queue(nd);
1430                }
1431        }
1432}
1433
1434/*
1435 * update_tx_info is called from the interrupt handler/NAPI to return cmdQ0
1436 * information.
1437 */
1438static unsigned int update_tx_info(struct adapter *adapter,
1439                                          unsigned int flags,
1440                                          unsigned int pr0)
1441{
1442        struct sge *sge = adapter->sge;
1443        struct cmdQ *cmdq = &sge->cmdQ[0];
1444
1445        cmdq->processed += pr0;
1446        if (flags & (F_FL0_ENABLE | F_FL1_ENABLE)) {
1447                freelQs_empty(sge);
1448                flags &= ~(F_FL0_ENABLE | F_FL1_ENABLE);
1449        }
1450        if (flags & F_CMDQ0_ENABLE) {
1451                clear_bit(CMDQ_STAT_RUNNING, &cmdq->status);
1452
1453                if (cmdq->cleaned + cmdq->in_use != cmdq->processed &&
1454                    !test_and_set_bit(CMDQ_STAT_LAST_PKT_DB, &cmdq->status)) {
1455                        set_bit(CMDQ_STAT_RUNNING, &cmdq->status);
1456                        writel(F_CMDQ0_ENABLE, adapter->regs + A_SG_DOORBELL);
1457                }
1458                if (sge->tx_sched)
1459                        tasklet_hi_schedule(&sge->tx_sched->sched_tsk);
1460
1461                flags &= ~F_CMDQ0_ENABLE;
1462        }
1463
1464        if (unlikely(sge->stopped_tx_queues != 0))
1465                restart_tx_queues(sge);
1466
1467        return flags;
1468}
1469
1470/*
1471 * Process SGE responses, up to the supplied budget.  Returns the number of
1472 * responses processed.  A negative budget is effectively unlimited.
1473 */
1474static int process_responses(struct adapter *adapter, int budget)
1475{
1476        struct sge *sge = adapter->sge;
1477        struct respQ *q = &sge->respQ;
1478        struct respQ_e *e = &q->entries[q->cidx];
1479        int done = 0;
1480        unsigned int flags = 0;
1481        unsigned int cmdq_processed[SGE_CMDQ_N] = {0, 0};
1482
1483        while (done < budget && e->GenerationBit == q->genbit) {
1484                flags |= e->Qsleeping;
1485
1486                cmdq_processed[0] += e->Cmdq0CreditReturn;
1487                cmdq_processed[1] += e->Cmdq1CreditReturn;
1488
1489                /* We batch updates to the TX side to avoid cacheline
1490                 * ping-pong of TX state information on MP where the sender
1491                 * might run on a different CPU than this function...
1492                 */
1493                if (unlikely((flags & F_CMDQ0_ENABLE) || cmdq_processed[0] > 64)) {
1494                        flags = update_tx_info(adapter, flags, cmdq_processed[0]);
1495                        cmdq_processed[0] = 0;
1496                }
1497
1498                if (unlikely(cmdq_processed[1] > 16)) {
1499                        sge->cmdQ[1].processed += cmdq_processed[1];
1500                        cmdq_processed[1] = 0;
1501                }
1502
1503                if (likely(e->DataValid)) {
1504                        struct freelQ *fl = &sge->freelQ[e->FreelistQid];
1505
1506                        BUG_ON(!e->Sop || !e->Eop);
1507                        if (unlikely(e->Offload))
1508                                unexpected_offload(adapter, fl);
1509                        else
1510                                sge_rx(sge, fl, e->BufferLength);
1511
1512                        ++done;
1513
1514                        /*
1515                         * Note: this depends on each packet consuming a
1516                         * single free-list buffer; cf. the BUG above.
1517                         */
1518                        if (++fl->cidx == fl->size)
1519                                fl->cidx = 0;
1520                        prefetch(fl->centries[fl->cidx].skb);
1521
1522                        if (unlikely(--fl->credits <
1523                                     fl->size - SGE_FREEL_REFILL_THRESH))
1524                                refill_free_list(sge, fl);
1525                } else
1526                        sge->stats.pure_rsps++;
1527
1528                e++;
1529                if (unlikely(++q->cidx == q->size)) {
1530                        q->cidx = 0;
1531                        q->genbit ^= 1;
1532                        e = q->entries;
1533                }
1534                prefetch(e);
1535
1536                if (++q->credits > SGE_RESPQ_REPLENISH_THRES) {
1537                        writel(q->credits, adapter->regs + A_SG_RSPQUEUECREDIT);
1538                        q->credits = 0;
1539                }
1540        }
1541
1542        flags = update_tx_info(adapter, flags, cmdq_processed[0]);
1543        sge->cmdQ[1].processed += cmdq_processed[1];
1544
1545        return done;
1546}
1547
1548static inline int responses_pending(const struct adapter *adapter)
1549{
1550        const struct respQ *Q = &adapter->sge->respQ;
1551        const struct respQ_e *e = &Q->entries[Q->cidx];
1552
1553        return (e->GenerationBit == Q->genbit);
1554}
1555
1556/*
1557 * A simpler version of process_responses() that handles only pure (i.e.,
1558 * non data-carrying) responses.  Such respones are too light-weight to justify
1559 * calling a softirq when using NAPI, so we handle them specially in hard
1560 * interrupt context.  The function is called with a pointer to a response,
1561 * which the caller must ensure is a valid pure response.  Returns 1 if it
1562 * encounters a valid data-carrying response, 0 otherwise.
1563 */
1564static int process_pure_responses(struct adapter *adapter)
1565{
1566        struct sge *sge = adapter->sge;
1567        struct respQ *q = &sge->respQ;
1568        struct respQ_e *e = &q->entries[q->cidx];
1569        const struct freelQ *fl = &sge->freelQ[e->FreelistQid];
1570        unsigned int flags = 0;
1571        unsigned int cmdq_processed[SGE_CMDQ_N] = {0, 0};
1572
1573        prefetch(fl->centries[fl->cidx].skb);
1574        if (e->DataValid)
1575                return 1;
1576
1577        do {
1578                flags |= e->Qsleeping;
1579
1580                cmdq_processed[0] += e->Cmdq0CreditReturn;
1581                cmdq_processed[1] += e->Cmdq1CreditReturn;
1582
1583                e++;
1584                if (unlikely(++q->cidx == q->size)) {
1585                        q->cidx = 0;
1586                        q->genbit ^= 1;
1587                        e = q->entries;
1588                }
1589                prefetch(e);
1590
1591                if (++q->credits > SGE_RESPQ_REPLENISH_THRES) {
1592                        writel(q->credits, adapter->regs + A_SG_RSPQUEUECREDIT);
1593                        q->credits = 0;
1594                }
1595                sge->stats.pure_rsps++;
1596        } while (e->GenerationBit == q->genbit && !e->DataValid);
1597
1598        flags = update_tx_info(adapter, flags, cmdq_processed[0]);
1599        sge->cmdQ[1].processed += cmdq_processed[1];
1600
1601        return e->GenerationBit == q->genbit;
1602}
1603
1604/*
1605 * Handler for new data events when using NAPI.  This does not need any locking
1606 * or protection from interrupts as data interrupts are off at this point and
1607 * other adapter interrupts do not interfere.
1608 */
1609int t1_poll(struct napi_struct *napi, int budget)
1610{
1611        struct adapter *adapter = container_of(napi, struct adapter, napi);
1612        int work_done = process_responses(adapter, budget);
1613
1614        if (likely(work_done < budget)) {
1615                napi_complete(napi);
1616                writel(adapter->sge->respQ.cidx,
1617                       adapter->regs + A_SG_SLEEPING);
1618        }
1619        return work_done;
1620}
1621
1622irqreturn_t t1_interrupt(int irq, void *data)
1623{
1624        struct adapter *adapter = data;
1625        struct sge *sge = adapter->sge;
1626        int handled;
1627
1628        if (likely(responses_pending(adapter))) {
1629                writel(F_PL_INTR_SGE_DATA, adapter->regs + A_PL_CAUSE);
1630
1631                if (napi_schedule_prep(&adapter->napi)) {
1632                        if (process_pure_responses(adapter))
1633                                __napi_schedule(&adapter->napi);
1634                        else {
1635                                /* no data, no NAPI needed */
1636                                writel(sge->respQ.cidx, adapter->regs + A_SG_SLEEPING);
1637                                /* undo schedule_prep */
1638                                napi_enable(&adapter->napi);
1639                        }
1640                }
1641                return IRQ_HANDLED;
1642        }
1643
1644        spin_lock(&adapter->async_lock);
1645        handled = t1_slow_intr_handler(adapter);
1646        spin_unlock(&adapter->async_lock);
1647
1648        if (!handled)
1649                sge->stats.unhandled_irqs++;
1650
1651        return IRQ_RETVAL(handled != 0);
1652}
1653
1654/*
1655 * Enqueues the sk_buff onto the cmdQ[qid] and has hardware fetch it.
1656 *
1657 * The code figures out how many entries the sk_buff will require in the
1658 * cmdQ and updates the cmdQ data structure with the state once the enqueue
1659 * has complete. Then, it doesn't access the global structure anymore, but
1660 * uses the corresponding fields on the stack. In conjuction with a spinlock
1661 * around that code, we can make the function reentrant without holding the
1662 * lock when we actually enqueue (which might be expensive, especially on
1663 * architectures with IO MMUs).
1664 *
1665 * This runs with softirqs disabled.
1666 */
1667static int t1_sge_tx(struct sk_buff *skb, struct adapter *adapter,
1668                     unsigned int qid, struct net_device *dev)
1669{
1670        struct sge *sge = adapter->sge;
1671        struct cmdQ *q = &sge->cmdQ[qid];
1672        unsigned int credits, pidx, genbit, count, use_sched_skb = 0;
1673
1674        if (!spin_trylock(&q->lock))
1675                return NETDEV_TX_LOCKED;
1676
1677        reclaim_completed_tx(sge, q);
1678
1679        pidx = q->pidx;
1680        credits = q->size - q->in_use;
1681        count = 1 + skb_shinfo(skb)->nr_frags;
1682        count += compute_large_page_tx_descs(skb);
1683
1684        /* Ethernet packet */
1685        if (unlikely(credits < count)) {
1686                if (!netif_queue_stopped(dev)) {
1687                        netif_stop_queue(dev);
1688                        set_bit(dev->if_port, &sge->stopped_tx_queues);
1689                        sge->stats.cmdQ_full[2]++;
1690                        CH_ERR("%s: Tx ring full while queue awake!\n",
1691                               adapter->name);
1692                }
1693                spin_unlock(&q->lock);
1694                return NETDEV_TX_BUSY;
1695        }
1696
1697        if (unlikely(credits - count < q->stop_thres)) {
1698                netif_stop_queue(dev);
1699                set_bit(dev->if_port, &sge->stopped_tx_queues);
1700                sge->stats.cmdQ_full[2]++;
1701        }
1702
1703        /* T204 cmdQ0 skbs that are destined for a certain port have to go
1704         * through the scheduler.
1705         */
1706        if (sge->tx_sched && !qid && skb->dev) {
1707use_sched:
1708                use_sched_skb = 1;
1709                /* Note that the scheduler might return a different skb than
1710                 * the one passed in.
1711                 */
1712                skb = sched_skb(sge, skb, credits);
1713                if (!skb) {
1714                        spin_unlock(&q->lock);
1715                        return NETDEV_TX_OK;
1716                }
1717                pidx = q->pidx;
1718                count = 1 + skb_shinfo(skb)->nr_frags;
1719                count += compute_large_page_tx_descs(skb);
1720        }
1721
1722        q->in_use += count;
1723        genbit = q->genbit;
1724        pidx = q->pidx;
1725        q->pidx += count;
1726        if (q->pidx >= q->size) {
1727                q->pidx -= q->size;
1728                q->genbit ^= 1;
1729        }
1730        spin_unlock(&q->lock);
1731
1732        write_tx_descs(adapter, skb, pidx, genbit, q);
1733
1734        /*
1735         * We always ring the doorbell for cmdQ1.  For cmdQ0, we only ring
1736         * the doorbell if the Q is asleep. There is a natural race, where
1737         * the hardware is going to sleep just after we checked, however,
1738         * then the interrupt handler will detect the outstanding TX packet
1739         * and ring the doorbell for us.
1740         */
1741        if (qid)
1742                doorbell_pio(adapter, F_CMDQ1_ENABLE);
1743        else {
1744                clear_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
1745                if (test_and_set_bit(CMDQ_STAT_RUNNING, &q->status) == 0) {
1746                        set_bit(CMDQ_STAT_LAST_PKT_DB, &q->status);
1747                        writel(F_CMDQ0_ENABLE, adapter->regs + A_SG_DOORBELL);
1748                }
1749        }
1750
1751        if (use_sched_skb) {
1752                if (spin_trylock(&q->lock)) {
1753                        credits = q->size - q->in_use;
1754                        skb = NULL;
1755                        goto use_sched;
1756                }
1757        }
1758        return NETDEV_TX_OK;
1759}
1760
1761#define MK_ETH_TYPE_MSS(type, mss) (((mss) & 0x3FFF) | ((type) << 14))
1762
1763/*
1764 *      eth_hdr_len - return the length of an Ethernet header
1765 *      @data: pointer to the start of the Ethernet header
1766 *
1767 *      Returns the length of an Ethernet header, including optional VLAN tag.
1768 */
1769static inline int eth_hdr_len(const void *data)
1770{
1771        const struct ethhdr *e = data;
1772
1773        return e->h_proto == htons(ETH_P_8021Q) ? VLAN_ETH_HLEN : ETH_HLEN;
1774}
1775
1776/*
1777 * Adds the CPL header to the sk_buff and passes it to t1_sge_tx.
1778 */
1779netdev_tx_t t1_start_xmit(struct sk_buff *skb, struct net_device *dev)
1780{
1781        struct adapter *adapter = dev->ml_priv;
1782        struct sge *sge = adapter->sge;
1783        struct sge_port_stats *st = per_cpu_ptr(sge->port_stats[dev->if_port],
1784                                                smp_processor_id());
1785        struct cpl_tx_pkt *cpl;
1786        struct sk_buff *orig_skb = skb;
1787        int ret;
1788
1789        if (skb->protocol == htons(ETH_P_CPL5))
1790                goto send;
1791
1792        /*
1793         * We are using a non-standard hard_header_len.
1794         * Allocate more header room in the rare cases it is not big enough.
1795         */
1796        if (unlikely(skb_headroom(skb) < dev->hard_header_len - ETH_HLEN)) {
1797                skb = skb_realloc_headroom(skb, sizeof(struct cpl_tx_pkt_lso));
1798                ++st->tx_need_hdrroom;
1799                dev_kfree_skb_any(orig_skb);
1800                if (!skb)
1801                        return NETDEV_TX_OK;
1802        }
1803
1804        if (skb_shinfo(skb)->gso_size) {
1805                int eth_type;
1806                struct cpl_tx_pkt_lso *hdr;
1807
1808                ++st->tx_tso;
1809
1810                eth_type = skb_network_offset(skb) == ETH_HLEN ?
1811                        CPL_ETH_II : CPL_ETH_II_VLAN;
1812
1813                hdr = (struct cpl_tx_pkt_lso *)skb_push(skb, sizeof(*hdr));
1814                hdr->opcode = CPL_TX_PKT_LSO;
1815                hdr->ip_csum_dis = hdr->l4_csum_dis = 0;
1816                hdr->ip_hdr_words = ip_hdr(skb)->ihl;
1817                hdr->tcp_hdr_words = tcp_hdr(skb)->doff;
1818                hdr->eth_type_mss = htons(MK_ETH_TYPE_MSS(eth_type,
1819                                                          skb_shinfo(skb)->gso_size));
1820                hdr->len = htonl(skb->len - sizeof(*hdr));
1821                cpl = (struct cpl_tx_pkt *)hdr;
1822        } else {
1823                /*
1824                 * Packets shorter than ETH_HLEN can break the MAC, drop them
1825                 * early.  Also, we may get oversized packets because some
1826                 * parts of the kernel don't handle our unusual hard_header_len
1827                 * right, drop those too.
1828                 */
1829                if (unlikely(skb->len < ETH_HLEN ||
1830                             skb->len > dev->mtu + eth_hdr_len(skb->data))) {
1831                        pr_debug("%s: packet size %d hdr %d mtu%d\n", dev->name,
1832                                 skb->len, eth_hdr_len(skb->data), dev->mtu);
1833                        dev_kfree_skb_any(skb);
1834                        return NETDEV_TX_OK;
1835                }
1836
1837                if (!(adapter->flags & UDP_CSUM_CAPABLE) &&
1838                    skb->ip_summed == CHECKSUM_PARTIAL &&
1839                    ip_hdr(skb)->protocol == IPPROTO_UDP) {
1840                        if (unlikely(skb_checksum_help(skb))) {
1841                                pr_debug("%s: unable to do udp checksum\n", dev->name);
1842                                dev_kfree_skb_any(skb);
1843                                return NETDEV_TX_OK;
1844                        }
1845                }
1846
1847                /* Hmmm, assuming to catch the gratious arp... and we'll use
1848                 * it to flush out stuck espi packets...
1849                 */
1850                if ((unlikely(!adapter->sge->espibug_skb[dev->if_port]))) {
1851                        if (skb->protocol == htons(ETH_P_ARP) &&
1852                            arp_hdr(skb)->ar_op == htons(ARPOP_REQUEST)) {
1853                                adapter->sge->espibug_skb[dev->if_port] = skb;
1854                                /* We want to re-use this skb later. We
1855                                 * simply bump the reference count and it
1856                                 * will not be freed...
1857                                 */
1858                                skb = skb_get(skb);
1859                        }
1860                }
1861
1862                cpl = (struct cpl_tx_pkt *)__skb_push(skb, sizeof(*cpl));
1863                cpl->opcode = CPL_TX_PKT;
1864                cpl->ip_csum_dis = 1;    /* SW calculates IP csum */
1865                cpl->l4_csum_dis = skb->ip_summed == CHECKSUM_PARTIAL ? 0 : 1;
1866                /* the length field isn't used so don't bother setting it */
1867
1868                st->tx_cso += (skb->ip_summed == CHECKSUM_PARTIAL);
1869        }
1870        cpl->iff = dev->if_port;
1871
1872#if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
1873        if (adapter->vlan_grp && vlan_tx_tag_present(skb)) {
1874                cpl->vlan_valid = 1;
1875                cpl->vlan = htons(vlan_tx_tag_get(skb));
1876                st->vlan_insert++;
1877        } else
1878#endif
1879                cpl->vlan_valid = 0;
1880
1881send:
1882        ret = t1_sge_tx(skb, adapter, 0, dev);
1883
1884        /* If transmit busy, and we reallocated skb's due to headroom limit,
1885         * then silently discard to avoid leak.
1886         */
1887        if (unlikely(ret != NETDEV_TX_OK && skb != orig_skb)) {
1888                dev_kfree_skb_any(skb);
1889                ret = NETDEV_TX_OK;
1890        }
1891        return ret;
1892}
1893
1894/*
1895 * Callback for the Tx buffer reclaim timer.  Runs with softirqs disabled.
1896 */
1897static void sge_tx_reclaim_cb(unsigned long data)
1898{
1899        int i;
1900        struct sge *sge = (struct sge *)data;
1901
1902        for (i = 0; i < SGE_CMDQ_N; ++i) {
1903                struct cmdQ *q = &sge->cmdQ[i];
1904
1905                if (!spin_trylock(&q->lock))
1906                        continue;
1907
1908                reclaim_completed_tx(sge, q);
1909                if (i == 0 && q->in_use) {    /* flush pending credits */
1910                        writel(F_CMDQ0_ENABLE, sge->adapter->regs + A_SG_DOORBELL);
1911                }
1912                spin_unlock(&q->lock);
1913        }
1914        mod_timer(&sge->tx_reclaim_timer, jiffies + TX_RECLAIM_PERIOD);
1915}
1916
1917/*
1918 * Propagate changes of the SGE coalescing parameters to the HW.
1919 */
1920int t1_sge_set_coalesce_params(struct sge *sge, struct sge_params *p)
1921{
1922        sge->fixed_intrtimer = p->rx_coalesce_usecs *
1923                core_ticks_per_usec(sge->adapter);
1924        writel(sge->fixed_intrtimer, sge->adapter->regs + A_SG_INTRTIMER);
1925        return 0;
1926}
1927
1928/*
1929 * Allocates both RX and TX resources and configures the SGE. However,
1930 * the hardware is not enabled yet.
1931 */
1932int t1_sge_configure(struct sge *sge, struct sge_params *p)
1933{
1934        if (alloc_rx_resources(sge, p))
1935                return -ENOMEM;
1936        if (alloc_tx_resources(sge, p)) {
1937                free_rx_resources(sge);
1938                return -ENOMEM;
1939        }
1940        configure_sge(sge, p);
1941
1942        /*
1943         * Now that we have sized the free lists calculate the payload
1944         * capacity of the large buffers.  Other parts of the driver use
1945         * this to set the max offload coalescing size so that RX packets
1946         * do not overflow our large buffers.
1947         */
1948        p->large_buf_capacity = jumbo_payload_capacity(sge);
1949        return 0;
1950}
1951
1952/*
1953 * Disables the DMA engine.
1954 */
1955void t1_sge_stop(struct sge *sge)
1956{
1957        int i;
1958        writel(0, sge->adapter->regs + A_SG_CONTROL);
1959        readl(sge->adapter->regs + A_SG_CONTROL); /* flush */
1960
1961        if (is_T2(sge->adapter))
1962                del_timer_sync(&sge->espibug_timer);
1963
1964        del_timer_sync(&sge->tx_reclaim_timer);
1965        if (sge->tx_sched)
1966                tx_sched_stop(sge);
1967
1968        for (i = 0; i < MAX_NPORTS; i++)
1969                kfree_skb(sge->espibug_skb[i]);
1970}
1971
1972/*
1973 * Enables the DMA engine.
1974 */
1975void t1_sge_start(struct sge *sge)
1976{
1977        refill_free_list(sge, &sge->freelQ[0]);
1978        refill_free_list(sge, &sge->freelQ[1]);
1979
1980        writel(sge->sge_control, sge->adapter->regs + A_SG_CONTROL);
1981        doorbell_pio(sge->adapter, F_FL0_ENABLE | F_FL1_ENABLE);
1982        readl(sge->adapter->regs + A_SG_CONTROL); /* flush */
1983
1984        mod_timer(&sge->tx_reclaim_timer, jiffies + TX_RECLAIM_PERIOD);
1985
1986        if (is_T2(sge->adapter))
1987                mod_timer(&sge->espibug_timer, jiffies + sge->espibug_timeout);
1988}
1989
1990/*
1991 * Callback for the T2 ESPI 'stuck packet feature' workaorund
1992 */
1993static void espibug_workaround_t204(unsigned long data)
1994{
1995        struct adapter *adapter = (struct adapter *)data;
1996        struct sge *sge = adapter->sge;
1997        unsigned int nports = adapter->params.nports;
1998        u32 seop[MAX_NPORTS];
1999
2000        if (adapter->open_device_map & PORT_MASK) {
2001                int i;
2002
2003                if (t1_espi_get_mon_t204(adapter, &(seop[0]), 0) < 0)
2004                        return;
2005
2006                for (i = 0; i < nports; i++) {
2007                        struct sk_buff *skb = sge->espibug_skb[i];
2008
2009                        if (!netif_running(adapter->port[i].dev) ||
2010                            netif_queue_stopped(adapter->port[i].dev) ||
2011                            !seop[i] || ((seop[i] & 0xfff) != 0) || !skb)
2012                                continue;
2013
2014                        if (!skb->cb[0]) {
2015                                u8 ch_mac_addr[ETH_ALEN] = {
2016                                        0x0, 0x7, 0x43, 0x0, 0x0, 0x0
2017                                };
2018
2019                                skb_copy_to_linear_data_offset(skb,
2020                                                    sizeof(struct cpl_tx_pkt),
2021                                                               ch_mac_addr,
2022                                                               ETH_ALEN);
2023                                skb_copy_to_linear_data_offset(skb,
2024                                                               skb->len - 10,
2025                                                               ch_mac_addr,
2026                                                               ETH_ALEN);
2027                                skb->cb[0] = 0xff;
2028                        }
2029
2030                        /* bump the reference count to avoid freeing of
2031                         * the skb once the DMA has completed.
2032                         */
2033                        skb = skb_get(skb);
2034                        t1_sge_tx(skb, adapter, 0, adapter->port[i].dev);
2035                }
2036        }
2037        mod_timer(&sge->espibug_timer, jiffies + sge->espibug_timeout);
2038}
2039
2040static void espibug_workaround(unsigned long data)
2041{
2042        struct adapter *adapter = (struct adapter *)data;
2043        struct sge *sge = adapter->sge;
2044
2045        if (netif_running(adapter->port[0].dev)) {
2046                struct sk_buff *skb = sge->espibug_skb[0];
2047                u32 seop = t1_espi_get_mon(adapter, 0x930, 0);
2048
2049                if ((seop & 0xfff0fff) == 0xfff && skb) {
2050                        if (!skb->cb[0]) {
2051                                u8 ch_mac_addr[ETH_ALEN] =
2052                                    {0x0, 0x7, 0x43, 0x0, 0x0, 0x0};
2053                                skb_copy_to_linear_data_offset(skb,
2054                                                     sizeof(struct cpl_tx_pkt),
2055                                                               ch_mac_addr,
2056                                                               ETH_ALEN);
2057                                skb_copy_to_linear_data_offset(skb,
2058                                                               skb->len - 10,
2059                                                               ch_mac_addr,
2060                                                               ETH_ALEN);
2061                                skb->cb[0] = 0xff;
2062                        }
2063
2064                        /* bump the reference count to avoid freeing of the
2065                         * skb once the DMA has completed.
2066                         */
2067                        skb = skb_get(skb);
2068                        t1_sge_tx(skb, adapter, 0, adapter->port[0].dev);
2069                }
2070        }
2071        mod_timer(&sge->espibug_timer, jiffies + sge->espibug_timeout);
2072}
2073
2074/*
2075 * Creates a t1_sge structure and returns suggested resource parameters.
2076 */
2077struct sge * __devinit t1_sge_create(struct adapter *adapter,
2078                                     struct sge_params *p)
2079{
2080        struct sge *sge = kzalloc(sizeof(*sge), GFP_KERNEL);
2081        int i;
2082
2083        if (!sge)
2084                return NULL;
2085
2086        sge->adapter = adapter;
2087        sge->netdev = adapter->port[0].dev;
2088        sge->rx_pkt_pad = t1_is_T1B(adapter) ? 0 : 2;
2089        sge->jumbo_fl = t1_is_T1B(adapter) ? 1 : 0;
2090
2091        for_each_port(adapter, i) {
2092                sge->port_stats[i] = alloc_percpu(struct sge_port_stats);
2093                if (!sge->port_stats[i])
2094                        goto nomem_port;
2095        }
2096
2097        init_timer(&sge->tx_reclaim_timer);
2098        sge->tx_reclaim_timer.data = (unsigned long)sge;
2099        sge->tx_reclaim_timer.function = sge_tx_reclaim_cb;
2100
2101        if (is_T2(sge->adapter)) {
2102                init_timer(&sge->espibug_timer);
2103
2104                if (adapter->params.nports > 1) {
2105                        tx_sched_init(sge);
2106                        sge->espibug_timer.function = espibug_workaround_t204;
2107                } else
2108                        sge->espibug_timer.function = espibug_workaround;
2109                sge->espibug_timer.data = (unsigned long)sge->adapter;
2110
2111                sge->espibug_timeout = 1;
2112                /* for T204, every 10ms */
2113                if (adapter->params.nports > 1)
2114                        sge->espibug_timeout = HZ/100;
2115        }
2116
2117
2118        p->cmdQ_size[0] = SGE_CMDQ0_E_N;
2119        p->cmdQ_size[1] = SGE_CMDQ1_E_N;
2120        p->freelQ_size[!sge->jumbo_fl] = SGE_FREEL_SIZE;
2121        p->freelQ_size[sge->jumbo_fl] = SGE_JUMBO_FREEL_SIZE;
2122        if (sge->tx_sched) {
2123                if (board_info(sge->adapter)->board == CHBT_BOARD_CHT204)
2124                        p->rx_coalesce_usecs = 15;
2125                else
2126                        p->rx_coalesce_usecs = 50;
2127        } else
2128                p->rx_coalesce_usecs = 50;
2129
2130        p->coalesce_enable = 0;
2131        p->sample_interval_usecs = 0;
2132
2133        return sge;
2134nomem_port:
2135        while (i >= 0) {
2136                free_percpu(sge->port_stats[i]);
2137                --i;
2138        }
2139        kfree(sge);
2140        return NULL;
2141
2142}
2143