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