drivers/scsi/mesh.c

   1 /*
   2  * SCSI low-level driver for the MESH (Macintosh Enhanced SCSI Hardware)
   3  * bus adaptor found on Power Macintosh computers.
   4  * We assume the MESH is connected to a DBDMA (descriptor-based DMA)
   5  * controller.
   6  *
   7  * Paul Mackerras, August 1996.
   8  * Copyright (C) 1996 Paul Mackerras.
   9  *
  10  * Apr. 21 2002  - BenH         Rework bus reset code for new error handler
  11  *                              Add delay after initial bus reset
  12  *                              Add module parameters
  13  *
  14  * Sep. 27 2003  - BenH         Move to new driver model, fix some write posting
  15  *                              issues
  16  * To do:
  17  * - handle aborts correctly
  18  * - retry arbitration if lost (unless higher levels do this for us)
  19  * - power down the chip when no device is detected
  20  */
  21 #include <linux/module.h>
  22 #include <linux/kernel.h>
  23 #include <linux/delay.h>
  24 #include <linux/types.h>
  25 #include <linux/string.h>
  26 #include <linux/slab.h>
  27 #include <linux/blkdev.h>
  28 #include <linux/proc_fs.h>
  29 #include <linux/stat.h>
  30 #include <linux/interrupt.h>
  31 #include <linux/reboot.h>
  32 #include <linux/spinlock.h>
  33 #include <asm/dbdma.h>
  34 #include <asm/io.h>
  35 #include <asm/pgtable.h>
  36 #include <asm/prom.h>
  37 #include <asm/system.h>
  38 #include <asm/irq.h>
  39 #include <asm/hydra.h>
  40 #include <asm/processor.h>
  41 #include <asm/machdep.h>
  42 #include <asm/pmac_feature.h>
  43 #include <asm/pci-bridge.h>
  44 #include <asm/macio.h>
  45
  46 #include <scsi/scsi.h>
  47 #include <scsi/scsi_cmnd.h>
  48 #include <scsi/scsi_device.h>
  49 #include <scsi/scsi_host.h>
  50
  51 #include "mesh.h"
  52
  53 #if 1
  54 #undef KERN_DEBUG
  55 #define KERN_DEBUG KERN_WARNING
  56 #endif
  57
  58 MODULE_AUTHOR("Paul Mackerras (paulus@samba.org)");
  59 MODULE_DESCRIPTION("PowerMac MESH SCSI driver");
  60 MODULE_LICENSE("GPL");
  61
  62 static int sync_rate = CONFIG_SCSI_MESH_SYNC_RATE;
  63 static int sync_targets = 0xff;
  64 static int resel_targets = 0xff;
  65 static int debug_targets = 0;   /* print debug for these targets */
  66 static int init_reset_delay = CONFIG_SCSI_MESH_RESET_DELAY_MS;
  67
  68 module_param(sync_rate, int, 0);
  69 MODULE_PARM_DESC(sync_rate, "Synchronous rate (0..10, 0=async)");
  70 module_param(sync_targets, int, 0);
  71 MODULE_PARM_DESC(sync_targets, "Bitmask of targets allowed to set synchronous");
  72 module_param(resel_targets, int, 0);
  73 MODULE_PARM_DESC(resel_targets, "Bitmask of targets allowed to set disconnect");
  74 module_param(debug_targets, int, 0644);
  75 MODULE_PARM_DESC(debug_targets, "Bitmask of debugged targets");
  76 module_param(init_reset_delay, int, 0);
  77 MODULE_PARM_DESC(init_reset_delay, "Initial bus reset delay (0=no reset)");
  78
  79 static int mesh_sync_period = 100;
  80 static int mesh_sync_offset = 0;
  81 static unsigned char use_active_neg = 0;  /* bit mask for SEQ_ACTIVE_NEG if used */
  82
  83 #define ALLOW_SYNC(tgt)         ((sync_targets >> (tgt)) & 1)
  84 #define ALLOW_RESEL(tgt)        ((resel_targets >> (tgt)) & 1)
  85 #define ALLOW_DEBUG(tgt)        ((debug_targets >> (tgt)) & 1)
  86 #define DEBUG_TARGET(cmd)       ((cmd) && ALLOW_DEBUG((cmd)->device->id))
  87
  88 #undef MESH_DBG
  89 #define N_DBG_LOG       50
  90 #define N_DBG_SLOG      20
  91 #define NUM_DBG_EVENTS  13
  92 #undef  DBG_USE_TB              /* bombs on 601 */
  93
  94 struct dbglog {
  95         char    *fmt;
  96         u32     tb;
  97         u8      phase;
  98         u8      bs0;
  99         u8      bs1;
 100         u8      tgt;
 101         int     d;
 102 };
 103
 104 enum mesh_phase {
 105         idle,
 106         arbitrating,
 107         selecting,
 108         commanding,
 109         dataing,
 110         statusing,
 111         busfreeing,
 112         disconnecting,
 113         reselecting,
 114         sleeping
 115 };
 116
 117 enum msg_phase {
 118         msg_none,
 119         msg_out,
 120         msg_out_xxx,
 121         msg_out_last,
 122         msg_in,
 123         msg_in_bad,
 124 };
 125
 126 enum sdtr_phase {
 127         do_sdtr,
 128         sdtr_sent,
 129         sdtr_done
 130 };
 131
 132 struct mesh_target {
 133         enum sdtr_phase sdtr_state;
 134         int     sync_params;
 135         int     data_goes_out;          /* guess as to data direction */
 136         struct scsi_cmnd *current_req;
 137         u32     saved_ptr;
 138 #ifdef MESH_DBG
 139         int     log_ix;
 140         int     n_log;
 141         struct dbglog log[N_DBG_LOG];
 142 #endif
 143 };
 144
 145 struct mesh_state {
 146         volatile struct mesh_regs __iomem *mesh;
 147         int     meshintr;
 148         volatile struct dbdma_regs __iomem *dma;
 149         int     dmaintr;
 150         struct  Scsi_Host *host;
 151         struct  mesh_state *next;
 152         struct scsi_cmnd *request_q;
 153         struct scsi_cmnd *request_qtail;
 154         enum mesh_phase phase;          /* what we're currently trying to do */
 155         enum msg_phase msgphase;
 156         int     conn_tgt;               /* target we're connected to */
 157         struct scsi_cmnd *current_req;          /* req we're currently working on */
 158         int     data_ptr;
 159         int     dma_started;
 160         int     dma_count;
 161         int     stat;
 162         int     aborting;
 163         int     expect_reply;
 164         int     n_msgin;
 165         u8      msgin[16];
 166         int     n_msgout;
 167         int     last_n_msgout;
 168         u8      msgout[16];
 169         struct dbdma_cmd *dma_cmds;     /* space for dbdma commands, aligned */
 170         dma_addr_t dma_cmd_bus;
 171         void    *dma_cmd_space;
 172         int     dma_cmd_size;
 173         int     clk_freq;
 174         struct mesh_target tgts[8];
 175         struct macio_dev *mdev;
 176         struct pci_dev* pdev;
 177 #ifdef MESH_DBG
 178         int     log_ix;
 179         int     n_log;
 180         struct dbglog log[N_DBG_SLOG];
 181 #endif
 182 };
 183
 184 /*
 185  * Driver is too messy, we need a few prototypes...
 186  */
 187 static void mesh_done(struct mesh_state *ms, int start_next);
 188 static void mesh_interrupt(struct mesh_state *ms);
 189 static void cmd_complete(struct mesh_state *ms);
 190 static void set_dma_cmds(struct mesh_state *ms, struct scsi_cmnd *cmd);
 191 static void halt_dma(struct mesh_state *ms);
 192 static void phase_mismatch(struct mesh_state *ms);
 193
 194
 195 /*
 196  * Some debugging & logging routines
 197  */
 198
 199 #ifdef MESH_DBG
 200
 201 static inline u32 readtb(void)
 202 {
 203         u32 tb;
 204
 205 #ifdef DBG_USE_TB
 206         /* Beware: if you enable this, it will crash on 601s. */
 207         asm ("mftb %0" : "=r" (tb) : );
 208 #else
 209         tb = 0;
 210 #endif
 211         return tb;
 212 }
 213
 214 static void dlog(struct mesh_state *ms, char *fmt, int a)
 215 {
 216         struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
 217         struct dbglog *tlp, *slp;
 218
 219         tlp = &tp->log[tp->log_ix];
 220         slp = &ms->log[ms->log_ix];
 221         tlp->fmt = fmt;
 222         tlp->tb = readtb();
 223         tlp->phase = (ms->msgphase << 4) + ms->phase;
 224         tlp->bs0 = ms->mesh->bus_status0;
 225         tlp->bs1 = ms->mesh->bus_status1;
 226         tlp->tgt = ms->conn_tgt;
 227         tlp->d = a;
 228         *slp = *tlp;
 229         if (++tp->log_ix >= N_DBG_LOG)
 230                 tp->log_ix = 0;
 231         if (tp->n_log < N_DBG_LOG)
 232                 ++tp->n_log;
 233         if (++ms->log_ix >= N_DBG_SLOG)
 234                 ms->log_ix = 0;
 235         if (ms->n_log < N_DBG_SLOG)
 236                 ++ms->n_log;
 237 }
 238
 239 static void dumplog(struct mesh_state *ms, int t)
 240 {
 241         struct mesh_target *tp = &ms->tgts[t];
 242         struct dbglog *lp;
 243         int i;
 244
 245         if (tp->n_log == 0)
 246                 return;
 247         i = tp->log_ix - tp->n_log;
 248         if (i < 0)
 249                 i += N_DBG_LOG;
 250         tp->n_log = 0;
 251         do {
 252                 lp = &tp->log[i];
 253                 printk(KERN_DEBUG "mesh log %d: bs=%.2x%.2x ph=%.2x ",
 254                        t, lp->bs1, lp->bs0, lp->phase);
 255 #ifdef DBG_USE_TB
 256                 printk("tb=%10u ", lp->tb);
 257 #endif
 258                 printk(lp->fmt, lp->d);
 259                 printk("\n");
 260                 if (++i >= N_DBG_LOG)
 261                         i = 0;
 262         } while (i != tp->log_ix);
 263 }
 264
 265 static void dumpslog(struct mesh_state *ms)
 266 {
 267         struct dbglog *lp;
 268         int i;
 269
 270         if (ms->n_log == 0)
 271                 return;
 272         i = ms->log_ix - ms->n_log;
 273         if (i < 0)
 274                 i += N_DBG_SLOG;
 275         ms->n_log = 0;
 276         do {
 277                 lp = &ms->log[i];
 278                 printk(KERN_DEBUG "mesh log: bs=%.2x%.2x ph=%.2x t%d ",
 279                        lp->bs1, lp->bs0, lp->phase, lp->tgt);
 280 #ifdef DBG_USE_TB
 281                 printk("tb=%10u ", lp->tb);
 282 #endif
 283                 printk(lp->fmt, lp->d);
 284                 printk("\n");
 285                 if (++i >= N_DBG_SLOG)
 286                         i = 0;
 287         } while (i != ms->log_ix);
 288 }
 289
 290 #else
 291
 292 static inline void dlog(struct mesh_state *ms, char *fmt, int a)
 293 {}
 294 static inline void dumplog(struct mesh_state *ms, int tgt)
 295 {}
 296 static inline void dumpslog(struct mesh_state *ms)
 297 {}
 298
 299 #endif /* MESH_DBG */
 300
 301 #define MKWORD(a, b, c, d)      (((a) << 24) + ((b) << 16) + ((c) << 8) + (d))
 302
 303 static void
 304 mesh_dump_regs(struct mesh_state *ms)
 305 {
 306         volatile struct mesh_regs __iomem *mr = ms->mesh;
 307         volatile struct dbdma_regs __iomem *md = ms->dma;
 308         int t;
 309         struct mesh_target *tp;
 310
 311         printk(KERN_DEBUG "mesh: state at %p, regs at %p, dma at %p\n",
 312                ms, mr, md);
 313         printk(KERN_DEBUG "    ct=%4x seq=%2x bs=%4x fc=%2x "
 314                "exc=%2x err=%2x im=%2x int=%2x sp=%2x\n",
 315                (mr->count_hi << 8) + mr->count_lo, mr->sequence,
 316                (mr->bus_status1 << 8) + mr->bus_status0, mr->fifo_count,
 317                mr->exception, mr->error, mr->intr_mask, mr->interrupt,
 318                mr->sync_params);
 319         while(in_8(&mr->fifo_count))
 320                 printk(KERN_DEBUG " fifo data=%.2x\n",in_8(&mr->fifo));
 321         printk(KERN_DEBUG "    dma stat=%x cmdptr=%x\n",
 322                in_le32(&md->status), in_le32(&md->cmdptr));
 323         printk(KERN_DEBUG "    phase=%d msgphase=%d conn_tgt=%d data_ptr=%d\n",
 324                ms->phase, ms->msgphase, ms->conn_tgt, ms->data_ptr);
 325         printk(KERN_DEBUG "    dma_st=%d dma_ct=%d n_msgout=%d\n",
 326                ms->dma_started, ms->dma_count, ms->n_msgout);
 327         for (t = 0; t < 8; ++t) {
 328                 tp = &ms->tgts[t];
 329                 if (tp->current_req == NULL)
 330                         continue;
 331                 printk(KERN_DEBUG "    target %d: req=%p goes_out=%d saved_ptr=%d\n",
 332                        t, tp->current_req, tp->data_goes_out, tp->saved_ptr);
 333         }
 334 }
 335
 336
 337 /*
 338  * Flush write buffers on the bus path to the mesh
 339  */
 340 static inline void mesh_flush_io(volatile struct mesh_regs __iomem *mr)
 341 {
 342         (void)in_8(&mr->mesh_id);
 343 }
 344
 345
 346 /*
 347  * Complete a SCSI command
 348  */
 349 static void mesh_completed(struct mesh_state *ms, struct scsi_cmnd *cmd)
 350 {
 351         (*cmd->scsi_done)(cmd);
 352 }
 353
 354
 355 /* Called with  meshinterrupt disabled, initialize the chipset
 356  * and eventually do the initial bus reset. The lock must not be
 357  * held since we can schedule.
 358  */
 359 static void mesh_init(struct mesh_state *ms)
 360 {
 361         volatile struct mesh_regs __iomem *mr = ms->mesh;
 362         volatile struct dbdma_regs __iomem *md = ms->dma;
 363
 364         mesh_flush_io(mr);
 365         udelay(100);
 366
 367         /* Reset controller */
 368         out_le32(&md->control, (RUN|PAUSE|FLUSH|WAKE) << 16);   /* stop dma */
 369         out_8(&mr->exception, 0xff);    /* clear all exception bits */
 370         out_8(&mr->error, 0xff);        /* clear all error bits */
 371         out_8(&mr->sequence, SEQ_RESETMESH);
 372         mesh_flush_io(mr);
 373         udelay(10);
 374         out_8(&mr->intr_mask, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
 375         out_8(&mr->source_id, ms->host->this_id);
 376         out_8(&mr->sel_timeout, 25);    /* 250ms */
 377         out_8(&mr->sync_params, ASYNC_PARAMS);
 378
 379         if (init_reset_delay) {
 380                 printk(KERN_INFO "mesh: performing initial bus reset...\n");
 381
 382                 /* Reset bus */
 383                 out_8(&mr->bus_status1, BS1_RST);       /* assert RST */
 384                 mesh_flush_io(mr);
 385                 udelay(30);                     /* leave it on for >= 25us */
 386                 out_8(&mr->bus_status1, 0);     /* negate RST */
 387                 mesh_flush_io(mr);
 388
 389                 /* Wait for bus to come back */
 390                 msleep(init_reset_delay);
 391         }
 392
 393         /* Reconfigure controller */
 394         out_8(&mr->interrupt, 0xff);    /* clear all interrupt bits */
 395         out_8(&mr->sequence, SEQ_FLUSHFIFO);
 396         mesh_flush_io(mr);
 397         udelay(1);
 398         out_8(&mr->sync_params, ASYNC_PARAMS);
 399         out_8(&mr->sequence, SEQ_ENBRESEL);
 400
 401         ms->phase = idle;
 402         ms->msgphase = msg_none;
 403 }
 404
 405
 406 static void mesh_start_cmd(struct mesh_state *ms, struct scsi_cmnd *cmd)
 407 {
 408         volatile struct mesh_regs __iomem *mr = ms->mesh;
 409         int t, id;
 410
 411         id = cmd->device->id;
 412         ms->current_req = cmd;
 413         ms->tgts[id].data_goes_out = cmd->sc_data_direction == DMA_TO_DEVICE;
 414         ms->tgts[id].current_req = cmd;
 415
 416 #if 1
 417         if (DEBUG_TARGET(cmd)) {
 418                 int i;
 419                 printk(KERN_DEBUG "mesh_start: %p ser=%lu tgt=%d cmd=",
 420                        cmd, cmd->serial_number, id);
 421                 for (i = 0; i < cmd->cmd_len; ++i)
 422                         printk(" %x", cmd->cmnd[i]);
 423                 printk(" use_sg=%d buffer=%p bufflen=%u\n",
 424                        cmd->use_sg, cmd->request_buffer, cmd->request_bufflen);
 425         }
 426 #endif
 427         if (ms->dma_started)
 428                 panic("mesh: double DMA start !\n");
 429
 430         ms->phase = arbitrating;
 431         ms->msgphase = msg_none;
 432         ms->data_ptr = 0;
 433         ms->dma_started = 0;
 434         ms->n_msgout = 0;
 435         ms->last_n_msgout = 0;
 436         ms->expect_reply = 0;
 437         ms->conn_tgt = id;
 438         ms->tgts[id].saved_ptr = 0;
 439         ms->stat = DID_OK;
 440         ms->aborting = 0;
 441 #ifdef MESH_DBG
 442         ms->tgts[id].n_log = 0;
 443         dlog(ms, "start cmd=%x", (int) cmd);
 444 #endif
 445
 446         /* Off we go */
 447         dlog(ms, "about to arb, intr/exc/err/fc=%.8x",
 448              MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
 449         out_8(&mr->interrupt, INT_CMDDONE);
 450         out_8(&mr->sequence, SEQ_ENBRESEL);
 451         mesh_flush_io(mr);
 452         udelay(1);
 453
 454         if (in_8(&mr->bus_status1) & (BS1_BSY | BS1_SEL)) {
 455                 /*
 456                  * Some other device has the bus or is arbitrating for it -
 457                  * probably a target which is about to reselect us.
 458                  */
 459                 dlog(ms, "busy b4 arb, intr/exc/err/fc=%.8x",
 460                      MKWORD(mr->interrupt, mr->exception,
 461                             mr->error, mr->fifo_count));
 462                 for (t = 100; t > 0; --t) {
 463                         if ((in_8(&mr->bus_status1) & (BS1_BSY | BS1_SEL)) == 0)
 464                                 break;
 465                         if (in_8(&mr->interrupt) != 0) {
 466                                 dlog(ms, "intr b4 arb, intr/exc/err/fc=%.8x",
 467                                      MKWORD(mr->interrupt, mr->exception,
 468                                             mr->error, mr->fifo_count));
 469                                 mesh_interrupt(ms);
 470                                 if (ms->phase != arbitrating)
 471                                         return;
 472                         }
 473                         udelay(1);
 474                 }
 475                 if (in_8(&mr->bus_status1) & (BS1_BSY | BS1_SEL)) {
 476                         /* XXX should try again in a little while */
 477                         ms->stat = DID_BUS_BUSY;
 478                         ms->phase = idle;
 479                         mesh_done(ms, 0);
 480                         return;
 481                 }
 482         }
 483
 484         /*
 485          * Apparently the mesh has a bug where it will assert both its
 486          * own bit and the target's bit on the bus during arbitration.
 487          */
 488         out_8(&mr->dest_id, mr->source_id);
 489
 490         /*
 491          * There appears to be a race with reselection sometimes,
 492          * where a target reselects us just as we issue the
 493          * arbitrate command.  It seems that then the arbitrate
 494          * command just hangs waiting for the bus to be free
 495          * without giving us a reselection exception.
 496          * The only way I have found to get it to respond correctly
 497          * is this: disable reselection before issuing the arbitrate
 498          * command, then after issuing it, if it looks like a target
 499          * is trying to reselect us, reset the mesh and then enable
 500          * reselection.
 501          */
 502         out_8(&mr->sequence, SEQ_DISRESEL);
 503         if (in_8(&mr->interrupt) != 0) {
 504                 dlog(ms, "intr after disresel, intr/exc/err/fc=%.8x",
 505                      MKWORD(mr->interrupt, mr->exception,
 506                             mr->error, mr->fifo_count));
 507                 mesh_interrupt(ms);
 508                 if (ms->phase != arbitrating)
 509                         return;
 510                 dlog(ms, "after intr after disresel, intr/exc/err/fc=%.8x",
 511                      MKWORD(mr->interrupt, mr->exception,
 512                             mr->error, mr->fifo_count));
 513         }
 514
 515         out_8(&mr->sequence, SEQ_ARBITRATE);
 516
 517         for (t = 230; t > 0; --t) {
 518                 if (in_8(&mr->interrupt) != 0)
 519                         break;
 520                 udelay(1);
 521         }
 522         dlog(ms, "after arb, intr/exc/err/fc=%.8x",
 523              MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
 524         if (in_8(&mr->interrupt) == 0 && (in_8(&mr->bus_status1) & BS1_SEL)
 525             && (in_8(&mr->bus_status0) & BS0_IO)) {
 526                 /* looks like a reselection - try resetting the mesh */
 527                 dlog(ms, "resel? after arb, intr/exc/err/fc=%.8x",
 528                      MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
 529                 out_8(&mr->sequence, SEQ_RESETMESH);
 530                 mesh_flush_io(mr);
 531                 udelay(10);
 532                 out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
 533                 out_8(&mr->intr_mask, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
 534                 out_8(&mr->sequence, SEQ_ENBRESEL);
 535                 mesh_flush_io(mr);
 536                 for (t = 10; t > 0 && in_8(&mr->interrupt) == 0; --t)
 537                         udelay(1);
 538                 dlog(ms, "tried reset after arb, intr/exc/err/fc=%.8x",
 539                      MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
 540 #ifndef MESH_MULTIPLE_HOSTS
 541                 if (in_8(&mr->interrupt) == 0 && (in_8(&mr->bus_status1) & BS1_SEL)
 542                     && (in_8(&mr->bus_status0) & BS0_IO)) {
 543                         printk(KERN_ERR "mesh: controller not responding"
 544                                " to reselection!\n");
 545                         /*
 546                          * If this is a target reselecting us, and the
 547                          * mesh isn't responding, the higher levels of
 548                          * the scsi code will eventually time out and
 549                          * reset the bus.
 550                          */
 551                 }
 552 #endif
 553         }
 554 }
 555
 556 /*
 557  * Start the next command for a MESH.
 558  * Should be called with interrupts disabled.
 559  */
 560 static void mesh_start(struct mesh_state *ms)
 561 {
 562         struct scsi_cmnd *cmd, *prev, *next;
 563
 564         if (ms->phase != idle || ms->current_req != NULL) {
 565                 printk(KERN_ERR "inappropriate mesh_start (phase=%d, ms=%p)",
 566                        ms->phase, ms);
 567                 return;
 568         }
 569
 570         while (ms->phase == idle) {
 571                 prev = NULL;
 572                 for (cmd = ms->request_q; ; cmd = (struct scsi_cmnd *) cmd->host_scribble) {
 573                         if (cmd == NULL)
 574                                 return;
 575                         if (ms->tgts[cmd->device->id].current_req == NULL)
 576                                 break;
 577                         prev = cmd;
 578                 }
 579                 next = (struct scsi_cmnd *) cmd->host_scribble;
 580                 if (prev == NULL)
 581                         ms->request_q = next;
 582                 else
 583                         prev->host_scribble = (void *) next;
 584                 if (next == NULL)
 585                         ms->request_qtail = prev;
 586
 587                 mesh_start_cmd(ms, cmd);
 588         }
 589 }
 590
 591 static void mesh_done(struct mesh_state *ms, int start_next)
 592 {
 593         struct scsi_cmnd *cmd;
 594         struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
 595
 596         cmd = ms->current_req;
 597         ms->current_req = NULL;
 598         tp->current_req = NULL;
 599         if (cmd) {
 600                 cmd->result = (ms->stat << 16) + cmd->SCp.Status;
 601                 if (ms->stat == DID_OK)
 602                         cmd->result += (cmd->SCp.Message << 8);
 603                 if (DEBUG_TARGET(cmd)) {
 604                         printk(KERN_DEBUG "mesh_done: result = %x, data_ptr=%d, buflen=%d\n",
 605                                cmd->result, ms->data_ptr, cmd->request_bufflen);
 606                         if ((cmd->cmnd[0] == 0 || cmd->cmnd[0] == 0x12 || cmd->cmnd[0] == 3)
 607                             && cmd->request_buffer != 0) {
 608                                 unsigned char *b = cmd->request_buffer;
 609                                 printk(KERN_DEBUG "buffer = %x %x %x %x %x %x %x %x\n",
 610                                        b[0], b[1], b[2], b[3], b[4], b[5], b[6], b[7]);
 611                         }
 612                 }
 613                 cmd->SCp.this_residual -= ms->data_ptr;
 614                 mesh_completed(ms, cmd);
 615         }
 616         if (start_next) {
 617                 out_8(&ms->mesh->sequence, SEQ_ENBRESEL);
 618                 mesh_flush_io(ms->mesh);
 619                 udelay(1);
 620                 ms->phase = idle;
 621                 mesh_start(ms);
 622         }
 623 }
 624
 625 static inline void add_sdtr_msg(struct mesh_state *ms)
 626 {
 627         int i = ms->n_msgout;
 628
 629         ms->msgout[i] = EXTENDED_MESSAGE;
 630         ms->msgout[i+1] = 3;
 631         ms->msgout[i+2] = EXTENDED_SDTR;
 632         ms->msgout[i+3] = mesh_sync_period/4;
 633         ms->msgout[i+4] = (ALLOW_SYNC(ms->conn_tgt)? mesh_sync_offset: 0);
 634         ms->n_msgout = i + 5;
 635 }
 636
 637 static void set_sdtr(struct mesh_state *ms, int period, int offset)
 638 {
 639         struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
 640         volatile struct mesh_regs __iomem *mr = ms->mesh;
 641         int v, tr;
 642
 643         tp->sdtr_state = sdtr_done;
 644         if (offset == 0) {
 645                 /* asynchronous */
 646                 if (SYNC_OFF(tp->sync_params))
 647                         printk(KERN_INFO "mesh: target %d now asynchronous\n",
 648                                ms->conn_tgt);
 649                 tp->sync_params = ASYNC_PARAMS;
 650                 out_8(&mr->sync_params, ASYNC_PARAMS);
 651                 return;
 652         }
 653         /*
 654          * We need to compute ceil(clk_freq * period / 500e6) - 2
 655          * without incurring overflow.
 656          */
 657         v = (ms->clk_freq / 5000) * period;
 658         if (v <= 250000) {
 659                 /* special case: sync_period == 5 * clk_period */
 660                 v = 0;
 661                 /* units of tr are 100kB/s */
 662                 tr = (ms->clk_freq + 250000) / 500000;
 663         } else {
 664                 /* sync_period == (v + 2) * 2 * clk_period */
 665                 v = (v + 99999) / 100000 - 2;
 666                 if (v > 15)
 667                         v = 15; /* oops */
 668                 tr = ((ms->clk_freq / (v + 2)) + 199999) / 200000;
 669         }
 670         if (offset > 15)
 671                 offset = 15;    /* can't happen */
 672         tp->sync_params = SYNC_PARAMS(offset, v);
 673         out_8(&mr->sync_params, tp->sync_params);
 674         printk(KERN_INFO "mesh: target %d synchronous at %d.%d MB/s\n",
 675                ms->conn_tgt, tr/10, tr%10);
 676 }
 677
 678 static void start_phase(struct mesh_state *ms)
 679 {
 680         int i, seq, nb;
 681         volatile struct mesh_regs __iomem *mr = ms->mesh;
 682         volatile struct dbdma_regs __iomem *md = ms->dma;
 683         struct scsi_cmnd *cmd = ms->current_req;
 684         struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
 685
 686         dlog(ms, "start_phase nmo/exc/fc/seq = %.8x",
 687              MKWORD(ms->n_msgout, mr->exception, mr->fifo_count, mr->sequence));
 688         out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
 689         seq = use_active_neg + (ms->n_msgout? SEQ_ATN: 0);
 690         switch (ms->msgphase) {
 691         case msg_none:
 692                 break;
 693
 694         case msg_in:
 695                 out_8(&mr->count_hi, 0);
 696                 out_8(&mr->count_lo, 1);
 697                 out_8(&mr->sequence, SEQ_MSGIN + seq);
 698                 ms->n_msgin = 0;
 699                 return;
 700
 701         case msg_out:
 702                 /*
 703                  * To make sure ATN drops before we assert ACK for
 704                  * the last byte of the message, we have to do the
 705                  * last byte specially.
 706                  */
 707                 if (ms->n_msgout <= 0) {
 708                         printk(KERN_ERR "mesh: msg_out but n_msgout=%d\n",
 709                                ms->n_msgout);
 710                         mesh_dump_regs(ms);
 711                         ms->msgphase = msg_none;
 712                         break;
 713                 }
 714                 if (ALLOW_DEBUG(ms->conn_tgt)) {
 715                         printk(KERN_DEBUG "mesh: sending %d msg bytes:",
 716                                ms->n_msgout);
 717                         for (i = 0; i < ms->n_msgout; ++i)
 718                                 printk(" %x", ms->msgout[i]);
 719                         printk("\n");
 720                 }
 721                 dlog(ms, "msgout msg=%.8x", MKWORD(ms->n_msgout, ms->msgout[0],
 722                                                 ms->msgout[1], ms->msgout[2]));
 723                 out_8(&mr->count_hi, 0);
 724                 out_8(&mr->sequence, SEQ_FLUSHFIFO);
 725                 mesh_flush_io(mr);
 726                 udelay(1);
 727                 /*
 728                  * If ATN is not already asserted, we assert it, then
 729                  * issue a SEQ_MSGOUT to get the mesh to drop ACK.
 730                  */
 731                 if ((in_8(&mr->bus_status0) & BS0_ATN) == 0) {
 732                         dlog(ms, "bus0 was %.2x explicitly asserting ATN", mr->bus_status0);
 733                         out_8(&mr->bus_status0, BS0_ATN); /* explicit ATN */
 734                         mesh_flush_io(mr);
 735                         udelay(1);
 736                         out_8(&mr->count_lo, 1);
 737                         out_8(&mr->sequence, SEQ_MSGOUT + seq);
 738                         out_8(&mr->bus_status0, 0); /* release explicit ATN */
 739                         dlog(ms,"hace: after explicit ATN bus0=%.2x",mr->bus_status0);
 740                 }
 741                 if (ms->n_msgout == 1) {
 742                         /*
 743                          * We can't issue the SEQ_MSGOUT without ATN
 744                          * until the target has asserted REQ.  The logic
 745                          * in cmd_complete handles both situations:
 746                          * REQ already asserted or not.
 747                          */
 748                         cmd_complete(ms);
 749                 } else {
 750                         out_8(&mr->count_lo, ms->n_msgout - 1);
 751                         out_8(&mr->sequence, SEQ_MSGOUT + seq);
 752                         for (i = 0; i < ms->n_msgout - 1; ++i)
 753                                 out_8(&mr->fifo, ms->msgout[i]);
 754                 }
 755                 return;
 756
 757         default:
 758                 printk(KERN_ERR "mesh bug: start_phase msgphase=%d\n",
 759                        ms->msgphase);
 760         }
 761
 762         switch (ms->phase) {
 763         case selecting:
 764                 out_8(&mr->dest_id, ms->conn_tgt);
 765                 out_8(&mr->sequence, SEQ_SELECT + SEQ_ATN);
 766                 break;
 767         case commanding:
 768                 out_8(&mr->sync_params, tp->sync_params);
 769                 out_8(&mr->count_hi, 0);
 770                 if (cmd) {
 771                         out_8(&mr->count_lo, cmd->cmd_len);
 772                         out_8(&mr->sequence, SEQ_COMMAND + seq);
 773                         for (i = 0; i < cmd->cmd_len; ++i)
 774                                 out_8(&mr->fifo, cmd->cmnd[i]);
 775                 } else {
 776                         out_8(&mr->count_lo, 6);
 777                         out_8(&mr->sequence, SEQ_COMMAND + seq);
 778                         for (i = 0; i < 6; ++i)
 779                                 out_8(&mr->fifo, 0);
 780                 }
 781                 break;
 782         case dataing:
 783                 /* transfer data, if any */
 784                 if (!ms->dma_started) {
 785                         set_dma_cmds(ms, cmd);
 786                         out_le32(&md->cmdptr, virt_to_phys(ms->dma_cmds));
 787                         out_le32(&md->control, (RUN << 16) | RUN);
 788                         ms->dma_started = 1;
 789                 }
 790                 nb = ms->dma_count;
 791                 if (nb > 0xfff0)
 792                         nb = 0xfff0;
 793                 ms->dma_count -= nb;
 794                 ms->data_ptr += nb;
 795                 out_8(&mr->count_lo, nb);
 796                 out_8(&mr->count_hi, nb >> 8);
 797                 out_8(&mr->sequence, (tp->data_goes_out?
 798                                 SEQ_DATAOUT: SEQ_DATAIN) + SEQ_DMA_MODE + seq);
 799                 break;
 800         case statusing:
 801                 out_8(&mr->count_hi, 0);
 802                 out_8(&mr->count_lo, 1);
 803                 out_8(&mr->sequence, SEQ_STATUS + seq);
 804                 break;
 805         case busfreeing:
 806         case disconnecting:
 807                 out_8(&mr->sequence, SEQ_ENBRESEL);
 808                 mesh_flush_io(mr);
 809                 udelay(1);
 810                 dlog(ms, "enbresel intr/exc/err/fc=%.8x",
 811                      MKWORD(mr->interrupt, mr->exception, mr->error,
 812                             mr->fifo_count));
 813                 out_8(&mr->sequence, SEQ_BUSFREE);
 814                 break;
 815         default:
 816                 printk(KERN_ERR "mesh: start_phase called with phase=%d\n",
 817                        ms->phase);
 818                 dumpslog(ms);
 819         }
 820
 821 }
 822
 823 static inline void get_msgin(struct mesh_state *ms)
 824 {
 825         volatile struct mesh_regs __iomem *mr = ms->mesh;
 826         int i, n;
 827
 828         n = mr->fifo_count;
 829         if (n != 0) {
 830                 i = ms->n_msgin;
 831                 ms->n_msgin = i + n;
 832                 for (; n > 0; --n)
 833                         ms->msgin[i++] = in_8(&mr->fifo);
 834         }
 835 }
 836
 837 static inline int msgin_length(struct mesh_state *ms)
 838 {
 839         int b, n;
 840
 841         n = 1;
 842         if (ms->n_msgin > 0) {
 843                 b = ms->msgin[0];
 844                 if (b == 1) {
 845                         /* extended message */
 846                         n = ms->n_msgin < 2? 2: ms->msgin[1] + 2;
 847                 } else if (0x20 <= b && b <= 0x2f) {
 848                         /* 2-byte message */
 849                         n = 2;
 850                 }
 851         }
 852         return n;
 853 }
 854
 855 static void reselected(struct mesh_state *ms)
 856 {
 857         volatile struct mesh_regs __iomem *mr = ms->mesh;
 858         struct scsi_cmnd *cmd;
 859         struct mesh_target *tp;
 860         int b, t, prev;
 861
 862         switch (ms->phase) {
 863         case idle:
 864                 break;
 865         case arbitrating:
 866                 if ((cmd = ms->current_req) != NULL) {
 867                         /* put the command back on the queue */
 868                         cmd->host_scribble = (void *) ms->request_q;
 869                         if (ms->request_q == NULL)
 870                                 ms->request_qtail = cmd;
 871                         ms->request_q = cmd;
 872                         tp = &ms->tgts[cmd->device->id];
 873                         tp->current_req = NULL;
 874                 }
 875                 break;
 876         case busfreeing:
 877                 ms->phase = reselecting;
 878                 mesh_done(ms, 0);
 879                 break;
 880         case disconnecting:
 881                 break;
 882         default:
 883                 printk(KERN_ERR "mesh: reselected in phase %d/%d tgt %d\n",
 884                        ms->msgphase, ms->phase, ms->conn_tgt);
 885                 dumplog(ms, ms->conn_tgt);
 886                 dumpslog(ms);
 887         }
 888
 889         if (ms->dma_started) {
 890                 printk(KERN_ERR "mesh: reselected with DMA started !\n");
 891                 halt_dma(ms);
 892         }
 893         ms->current_req = NULL;
 894         ms->phase = dataing;
 895         ms->msgphase = msg_in;
 896         ms->n_msgout = 0;
 897         ms->last_n_msgout = 0;
 898         prev = ms->conn_tgt;
 899
 900         /*
 901          * We seem to get abortive reselections sometimes.
 902          */
 903         while ((in_8(&mr->bus_status1) & BS1_BSY) == 0) {
 904                 static int mesh_aborted_resels;
 905                 mesh_aborted_resels++;
 906                 out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
 907                 mesh_flush_io(mr);
 908                 udelay(1);
 909                 out_8(&mr->sequence, SEQ_ENBRESEL);
 910                 mesh_flush_io(mr);
 911                 udelay(5);
 912                 dlog(ms, "extra resel err/exc/fc = %.6x",
 913                      MKWORD(0, mr->error, mr->exception, mr->fifo_count));
 914         }
 915         out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
 916         mesh_flush_io(mr);
 917         udelay(1);
 918         out_8(&mr->sequence, SEQ_ENBRESEL);
 919         mesh_flush_io(mr);
 920         udelay(1);
 921         out_8(&mr->sync_params, ASYNC_PARAMS);
 922
 923         /*
 924          * Find out who reselected us.
 925          */
 926         if (in_8(&mr->fifo_count) == 0) {
 927                 printk(KERN_ERR "mesh: reselection but nothing in fifo?\n");
 928                 ms->conn_tgt = ms->host->this_id;
 929                 goto bogus;
 930         }
 931         /* get the last byte in the fifo */
 932         do {
 933                 b = in_8(&mr->fifo);
 934                 dlog(ms, "reseldata %x", b);
 935         } while (in_8(&mr->fifo_count));
 936         for (t = 0; t < 8; ++t)
 937                 if ((b & (1 << t)) != 0 && t != ms->host->this_id)
 938                         break;
 939         if (b != (1 << t) + (1 << ms->host->this_id)) {
 940                 printk(KERN_ERR "mesh: bad reselection data %x\n", b);
 941                 ms->conn_tgt = ms->host->this_id;
 942                 goto bogus;
 943         }
 944
 945
 946         /*
 947          * Set up to continue with that target's transfer.
 948          */
 949         ms->conn_tgt = t;
 950         tp = &ms->tgts[t];
 951         out_8(&mr->sync_params, tp->sync_params);
 952         if (ALLOW_DEBUG(t)) {
 953                 printk(KERN_DEBUG "mesh: reselected by target %d\n", t);
 954                 printk(KERN_DEBUG "mesh: saved_ptr=%x goes_out=%d cmd=%p\n",
 955                        tp->saved_ptr, tp->data_goes_out, tp->current_req);
 956         }
 957         ms->current_req = tp->current_req;
 958         if (tp->current_req == NULL) {
 959                 printk(KERN_ERR "mesh: reselected by tgt %d but no cmd!\n", t);
 960                 goto bogus;
 961         }
 962         ms->data_ptr = tp->saved_ptr;
 963         dlog(ms, "resel prev tgt=%d", prev);
 964         dlog(ms, "resel err/exc=%.4x", MKWORD(0, 0, mr->error, mr->exception));
 965         start_phase(ms);
 966         return;
 967
 968 bogus:
 969         dumplog(ms, ms->conn_tgt);
 970         dumpslog(ms);
 971         ms->data_ptr = 0;
 972         ms->aborting = 1;
 973         start_phase(ms);
 974 }
 975
 976 static void do_abort(struct mesh_state *ms)
 977 {
 978         ms->msgout[0] = ABORT;
 979         ms->n_msgout = 1;
 980         ms->aborting = 1;
 981         ms->stat = DID_ABORT;
 982         dlog(ms, "abort", 0);
 983 }
 984
 985 static void handle_reset(struct mesh_state *ms)
 986 {
 987         int tgt;
 988         struct mesh_target *tp;
 989         struct scsi_cmnd *cmd;
 990         volatile struct mesh_regs __iomem *mr = ms->mesh;
 991
 992         for (tgt = 0; tgt < 8; ++tgt) {
 993                 tp = &ms->tgts[tgt];
 994                 if ((cmd = tp->current_req) != NULL) {
 995                         cmd->result = DID_RESET << 16;
 996                         tp->current_req = NULL;
 997                         mesh_completed(ms, cmd);
 998                 }
 999                 ms->tgts[tgt].sdtr_state = do_sdtr;
1000                 ms->tgts[tgt].sync_params = ASYNC_PARAMS;
1001         }
1002         ms->current_req = NULL;
1003         while ((cmd = ms->request_q) != NULL) {
1004                 ms->request_q = (struct scsi_cmnd *) cmd->host_scribble;
1005                 cmd->result = DID_RESET << 16;
1006                 mesh_completed(ms, cmd);
1007         }
1008         ms->phase = idle;
1009         ms->msgphase = msg_none;
1010         out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1011         out_8(&mr->sequence, SEQ_FLUSHFIFO);
1012         mesh_flush_io(mr);
1013         udelay(1);
1014         out_8(&mr->sync_params, ASYNC_PARAMS);
1015         out_8(&mr->sequence, SEQ_ENBRESEL);
1016 }
1017
1018 static irqreturn_t do_mesh_interrupt(int irq, void *dev_id)
1019 {
1020         unsigned long flags;
1021         struct mesh_state *ms = dev_id;
1022         struct Scsi_Host *dev = ms->host;
1023
1024         spin_lock_irqsave(dev->host_lock, flags);
1025         mesh_interrupt(ms);
1026         spin_unlock_irqrestore(dev->host_lock, flags);
1027         return IRQ_HANDLED;
1028 }
1029
1030 static void handle_error(struct mesh_state *ms)
1031 {
1032         int err, exc, count;
1033         volatile struct mesh_regs __iomem *mr = ms->mesh;
1034
1035         err = in_8(&mr->error);
1036         exc = in_8(&mr->exception);
1037         out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1038         dlog(ms, "error err/exc/fc/cl=%.8x",
1039              MKWORD(err, exc, mr->fifo_count, mr->count_lo));
1040         if (err & ERR_SCSIRESET) {
1041                 /* SCSI bus was reset */
1042                 printk(KERN_INFO "mesh: SCSI bus reset detected: "
1043                        "waiting for end...");
1044                 while ((in_8(&mr->bus_status1) & BS1_RST) != 0)
1045                         udelay(1);
1046                 printk("done\n");
1047                 handle_reset(ms);
1048                 /* request_q is empty, no point in mesh_start() */
1049                 return;
1050         }
1051         if (err & ERR_UNEXPDISC) {
1052                 /* Unexpected disconnect */
1053                 if (exc & EXC_RESELECTED) {
1054                         reselected(ms);
1055                         return;
1056                 }
1057                 if (!ms->aborting) {
1058                         printk(KERN_WARNING "mesh: target %d aborted\n",
1059                                ms->conn_tgt);
1060                         dumplog(ms, ms->conn_tgt);
1061                         dumpslog(ms);
1062                 }
1063                 out_8(&mr->interrupt, INT_CMDDONE);
1064                 ms->stat = DID_ABORT;
1065                 mesh_done(ms, 1);
1066                 return;
1067         }
1068         if (err & ERR_PARITY) {
1069                 if (ms->msgphase == msg_in) {
1070                         printk(KERN_ERR "mesh: msg parity error, target %d\n",
1071                                ms->conn_tgt);
1072                         ms->msgout[0] = MSG_PARITY_ERROR;
1073                         ms->n_msgout = 1;
1074                         ms->msgphase = msg_in_bad;
1075                         cmd_complete(ms);
1076                         return;
1077                 }
1078                 if (ms->stat == DID_OK) {
1079                         printk(KERN_ERR "mesh: parity error, target %d\n",
1080                                ms->conn_tgt);
1081                         ms->stat = DID_PARITY;
1082                 }
1083                 count = (mr->count_hi << 8) + mr->count_lo;
1084                 if (count == 0) {
1085                         cmd_complete(ms);
1086                 } else {
1087                         /* reissue the data transfer command */
1088                         out_8(&mr->sequence, mr->sequence);
1089                 }
1090                 return;
1091         }
1092         if (err & ERR_SEQERR) {
1093                 if (exc & EXC_RESELECTED) {
1094                         /* This can happen if we issue a command to
1095                            get the bus just after the target reselects us. */
1096                         static int mesh_resel_seqerr;
1097                         mesh_resel_seqerr++;
1098                         reselected(ms);
1099                         return;
1100                 }
1101                 if (exc == EXC_PHASEMM) {
1102                         static int mesh_phasemm_seqerr;
1103                         mesh_phasemm_seqerr++;
1104                         phase_mismatch(ms);
1105                         return;
1106                 }
1107                 printk(KERN_ERR "mesh: sequence error (err=%x exc=%x)\n",
1108                        err, exc);
1109         } else {
1110                 printk(KERN_ERR "mesh: unknown error %x (exc=%x)\n", err, exc);
1111         }
1112         mesh_dump_regs(ms);
1113         dumplog(ms, ms->conn_tgt);
1114         if (ms->phase > selecting && (in_8(&mr->bus_status1) & BS1_BSY)) {
1115                 /* try to do what the target wants */
1116                 do_abort(ms);
1117                 phase_mismatch(ms);
1118                 return;
1119         }
1120         ms->stat = DID_ERROR;
1121         mesh_done(ms, 1);
1122 }
1123
1124 static void handle_exception(struct mesh_state *ms)
1125 {
1126         int exc;
1127         volatile struct mesh_regs __iomem *mr = ms->mesh;
1128
1129         exc = in_8(&mr->exception);
1130         out_8(&mr->interrupt, INT_EXCEPTION | INT_CMDDONE);
1131         if (exc & EXC_RESELECTED) {
1132                 static int mesh_resel_exc;
1133                 mesh_resel_exc++;
1134                 reselected(ms);
1135         } else if (exc == EXC_ARBLOST) {
1136                 printk(KERN_DEBUG "mesh: lost arbitration\n");
1137                 ms->stat = DID_BUS_BUSY;
1138                 mesh_done(ms, 1);
1139         } else if (exc == EXC_SELTO) {
1140                 /* selection timed out */
1141                 ms->stat = DID_BAD_TARGET;
1142                 mesh_done(ms, 1);
1143         } else if (exc == EXC_PHASEMM) {
1144                 /* target wants to do something different:
1145                    find out what it wants and do it. */
1146                 phase_mismatch(ms);
1147         } else {
1148                 printk(KERN_ERR "mesh: can't cope with exception %x\n", exc);
1149                 mesh_dump_regs(ms);
1150                 dumplog(ms, ms->conn_tgt);
1151                 do_abort(ms);
1152                 phase_mismatch(ms);
1153         }
1154 }
1155
1156 static void handle_msgin(struct mesh_state *ms)
1157 {
1158         int i, code;
1159         struct scsi_cmnd *cmd = ms->current_req;
1160         struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
1161
1162         if (ms->n_msgin == 0)
1163                 return;
1164         code = ms->msgin[0];
1165         if (ALLOW_DEBUG(ms->conn_tgt)) {
1166                 printk(KERN_DEBUG "got %d message bytes:", ms->n_msgin);
1167                 for (i = 0; i < ms->n_msgin; ++i)
1168                         printk(" %x", ms->msgin[i]);
1169                 printk("\n");
1170         }
1171         dlog(ms, "msgin msg=%.8x",
1172              MKWORD(ms->n_msgin, code, ms->msgin[1], ms->msgin[2]));
1173
1174         ms->expect_reply = 0;
1175         ms->n_msgout = 0;
1176         if (ms->n_msgin < msgin_length(ms))
1177                 goto reject;
1178         if (cmd)
1179                 cmd->SCp.Message = code;
1180         switch (code) {
1181         case COMMAND_COMPLETE:
1182                 break;
1183         case EXTENDED_MESSAGE:
1184                 switch (ms->msgin[2]) {
1185                 case EXTENDED_MODIFY_DATA_POINTER:
1186                         ms->data_ptr += (ms->msgin[3] << 24) + ms->msgin[6]
1187                                 + (ms->msgin[4] << 16) + (ms->msgin[5] << 8);
1188                         break;
1189                 case EXTENDED_SDTR:
1190                         if (tp->sdtr_state != sdtr_sent) {
1191                                 /* reply with an SDTR */
1192                                 add_sdtr_msg(ms);
1193                                 /* limit period to at least his value,
1194                                    offset to no more than his */
1195                                 if (ms->msgout[3] < ms->msgin[3])
1196                                         ms->msgout[3] = ms->msgin[3];
1197                                 if (ms->msgout[4] > ms->msgin[4])
1198                                         ms->msgout[4] = ms->msgin[4];
1199                                 set_sdtr(ms, ms->msgout[3], ms->msgout[4]);
1200                                 ms->msgphase = msg_out;
1201                         } else {
1202                                 set_sdtr(ms, ms->msgin[3], ms->msgin[4]);
1203                         }
1204                         break;
1205                 default:
1206                         goto reject;
1207                 }
1208                 break;
1209         case SAVE_POINTERS:
1210                 tp->saved_ptr = ms->data_ptr;
1211                 break;
1212         case RESTORE_POINTERS:
1213                 ms->data_ptr = tp->saved_ptr;
1214                 break;
1215         case DISCONNECT:
1216                 ms->phase = disconnecting;
1217                 break;
1218         case ABORT:
1219                 break;
1220         case MESSAGE_REJECT:
1221                 if (tp->sdtr_state == sdtr_sent)
1222                         set_sdtr(ms, 0, 0);
1223                 break;
1224         case NOP:
1225                 break;
1226         default:
1227                 if (IDENTIFY_BASE <= code && code <= IDENTIFY_BASE + 7) {
1228                         if (cmd == NULL) {
1229                                 do_abort(ms);
1230                                 ms->msgphase = msg_out;
1231                         } else if (code != cmd->device->lun + IDENTIFY_BASE) {
1232                                 printk(KERN_WARNING "mesh: lun mismatch "
1233                                        "(%d != %d) on reselection from "
1234                                        "target %d\n", code - IDENTIFY_BASE,
1235                                        cmd->device->lun, ms->conn_tgt);
1236                         }
1237                         break;
1238                 }
1239                 goto reject;
1240         }
1241         return;
1242
1243  reject:
1244         printk(KERN_WARNING "mesh: rejecting message from target %d:",
1245                ms->conn_tgt);
1246         for (i = 0; i < ms->n_msgin; ++i)
1247                 printk(" %x", ms->msgin[i]);
1248         printk("\n");
1249         ms->msgout[0] = MESSAGE_REJECT;
1250         ms->n_msgout = 1;
1251         ms->msgphase = msg_out;
1252 }
1253
1254 /*
1255  * Set up DMA commands for transferring data.
1256  */
1257 static void set_dma_cmds(struct mesh_state *ms, struct scsi_cmnd *cmd)
1258 {
1259         int i, dma_cmd, total, off, dtot;
1260         struct scatterlist *scl;
1261         struct dbdma_cmd *dcmds;
1262
1263         dma_cmd = ms->tgts[ms->conn_tgt].data_goes_out?
1264                 OUTPUT_MORE: INPUT_MORE;
1265         dcmds = ms->dma_cmds;
1266         dtot = 0;
1267         if (cmd) {
1268                 cmd->SCp.this_residual = cmd->request_bufflen;
1269                 if (cmd->use_sg > 0) {
1270                         int nseg;
1271                         total = 0;
1272                         scl = (struct scatterlist *) cmd->request_buffer;
1273                         off = ms->data_ptr;
1274                         nseg = pci_map_sg(ms->pdev, scl, cmd->use_sg,
1275                                           cmd->sc_data_direction);
1276                         for (i = 0; i <nseg; ++i, ++scl) {
1277                                 u32 dma_addr = sg_dma_address(scl);
1278                                 u32 dma_len = sg_dma_len(scl);
1279
1280                                 total += scl->length;
1281                                 if (off >= dma_len) {
1282                                         off -= dma_len;
1283                                         continue;
1284                                 }
1285                                 if (dma_len > 0xffff)
1286                                         panic("mesh: scatterlist element >= 64k");
1287                                 st_le16(&dcmds->req_count, dma_len - off);
1288                                 st_le16(&dcmds->command, dma_cmd);
1289                                 st_le32(&dcmds->phy_addr, dma_addr + off);
1290                                 dcmds->xfer_status = 0;
1291                                 ++dcmds;
1292                                 dtot += dma_len - off;
1293                                 off = 0;
1294                         }
1295                 } else if (ms->data_ptr < cmd->request_bufflen) {
1296                         dtot = cmd->request_bufflen - ms->data_ptr;
1297                         if (dtot > 0xffff)
1298                                 panic("mesh: transfer size >= 64k");
1299                         st_le16(&dcmds->req_count, dtot);
1300                         /* XXX Use pci DMA API here ... */
1301                         st_le32(&dcmds->phy_addr,
1302                                 virt_to_phys(cmd->request_buffer) + ms->data_ptr);
1303                         dcmds->xfer_status = 0;
1304                         ++dcmds;
1305                 }
1306         }
1307         if (dtot == 0) {
1308                 /* Either the target has overrun our buffer,
1309                    or the caller didn't provide a buffer. */
1310                 static char mesh_extra_buf[64];
1311
1312                 dtot = sizeof(mesh_extra_buf);
1313                 st_le16(&dcmds->req_count, dtot);
1314                 st_le32(&dcmds->phy_addr, virt_to_phys(mesh_extra_buf));
1315                 dcmds->xfer_status = 0;
1316                 ++dcmds;
1317         }
1318         dma_cmd += OUTPUT_LAST - OUTPUT_MORE;
1319         st_le16(&dcmds[-1].command, dma_cmd);
1320         memset(dcmds, 0, sizeof(*dcmds));
1321         st_le16(&dcmds->command, DBDMA_STOP);
1322         ms->dma_count = dtot;
1323 }
1324
1325 static void halt_dma(struct mesh_state *ms)
1326 {
1327         volatile struct dbdma_regs __iomem *md = ms->dma;
1328         volatile struct mesh_regs __iomem *mr = ms->mesh;
1329         struct scsi_cmnd *cmd = ms->current_req;
1330         int t, nb;
1331
1332         if (!ms->tgts[ms->conn_tgt].data_goes_out) {
1333                 /* wait a little while until the fifo drains */
1334                 t = 50;
1335                 while (t > 0 && in_8(&mr->fifo_count) != 0
1336                        && (in_le32(&md->status) & ACTIVE) != 0) {
1337                         --t;
1338                         udelay(1);
1339                 }
1340         }
1341         out_le32(&md->control, RUN << 16);      /* turn off RUN bit */
1342         nb = (mr->count_hi << 8) + mr->count_lo;
1343         dlog(ms, "halt_dma fc/count=%.6x",
1344              MKWORD(0, mr->fifo_count, 0, nb));
1345         if (ms->tgts[ms->conn_tgt].data_goes_out)
1346                 nb += mr->fifo_count;
1347         /* nb is the number of bytes not yet transferred
1348            to/from the target. */
1349         ms->data_ptr -= nb;
1350         dlog(ms, "data_ptr %x", ms->data_ptr);
1351         if (ms->data_ptr < 0) {
1352                 printk(KERN_ERR "mesh: halt_dma: data_ptr=%d (nb=%d, ms=%p)\n",
1353                        ms->data_ptr, nb, ms);
1354                 ms->data_ptr = 0;
1355 #ifdef MESH_DBG
1356                 dumplog(ms, ms->conn_tgt);
1357                 dumpslog(ms);
1358 #endif /* MESH_DBG */
1359         } else if (cmd && cmd->request_bufflen != 0 &&
1360                    ms->data_ptr > cmd->request_bufflen) {
1361                 printk(KERN_DEBUG "mesh: target %d overrun, "
1362                        "data_ptr=%x total=%x goes_out=%d\n",
1363                        ms->conn_tgt, ms->data_ptr, cmd->request_bufflen,
1364                        ms->tgts[ms->conn_tgt].data_goes_out);
1365         }
1366         if (cmd->use_sg != 0) {
1367                 struct scatterlist *sg;
1368                 sg = (struct scatterlist *)cmd->request_buffer;
1369                 pci_unmap_sg(ms->pdev, sg, cmd->use_sg, cmd->sc_data_direction);
1370         }
1371         ms->dma_started = 0;
1372 }
1373
1374 static void phase_mismatch(struct mesh_state *ms)
1375 {
1376         volatile struct mesh_regs __iomem *mr = ms->mesh;
1377         int phase;
1378
1379         dlog(ms, "phasemm ch/cl/seq/fc=%.8x",
1380              MKWORD(mr->count_hi, mr->count_lo, mr->sequence, mr->fifo_count));
1381         phase = in_8(&mr->bus_status0) & BS0_PHASE;
1382         if (ms->msgphase == msg_out_xxx && phase == BP_MSGOUT) {
1383                 /* output the last byte of the message, without ATN */
1384                 out_8(&mr->count_lo, 1);
1385                 out_8(&mr->sequence, SEQ_MSGOUT + use_active_neg);
1386                 mesh_flush_io(mr);
1387                 udelay(1);
1388                 out_8(&mr->fifo, ms->msgout[ms->n_msgout-1]);
1389                 ms->msgphase = msg_out_last;
1390                 return;
1391         }
1392
1393         if (ms->msgphase == msg_in) {
1394                 get_msgin(ms);
1395                 if (ms->n_msgin)
1396                         handle_msgin(ms);
1397         }
1398
1399         if (ms->dma_started)
1400                 halt_dma(ms);
1401         if (mr->fifo_count) {
1402                 out_8(&mr->sequence, SEQ_FLUSHFIFO);
1403                 mesh_flush_io(mr);
1404                 udelay(1);
1405         }
1406
1407         ms->msgphase = msg_none;
1408         switch (phase) {
1409         case BP_DATAIN:
1410                 ms->tgts[ms->conn_tgt].data_goes_out = 0;
1411                 ms->phase = dataing;
1412                 break;
1413         case BP_DATAOUT:
1414                 ms->tgts[ms->conn_tgt].data_goes_out = 1;
1415                 ms->phase = dataing;
1416                 break;
1417         case BP_COMMAND:
1418                 ms->phase = commanding;
1419                 break;
1420         case BP_STATUS:
1421                 ms->phase = statusing;
1422                 break;
1423         case BP_MSGIN:
1424                 ms->msgphase = msg_in;
1425                 ms->n_msgin = 0;
1426                 break;
1427         case BP_MSGOUT:
1428                 ms->msgphase = msg_out;
1429                 if (ms->n_msgout == 0) {
1430                         if (ms->aborting) {
1431                                 do_abort(ms);
1432                         } else {
1433                                 if (ms->last_n_msgout == 0) {
1434                                         printk(KERN_DEBUG
1435                                                "mesh: no msg to repeat\n");
1436                                         ms->msgout[0] = NOP;
1437                                         ms->last_n_msgout = 1;
1438                                 }
1439                                 ms->n_msgout = ms->last_n_msgout;
1440                         }
1441                 }
1442                 break;
1443         default:
1444                 printk(KERN_DEBUG "mesh: unknown scsi phase %x\n", phase);
1445                 ms->stat = DID_ERROR;
1446                 mesh_done(ms, 1);
1447                 return;
1448         }
1449
1450         start_phase(ms);
1451 }
1452
1453 static void cmd_complete(struct mesh_state *ms)
1454 {
1455         volatile struct mesh_regs __iomem *mr = ms->mesh;
1456         struct scsi_cmnd *cmd = ms->current_req;
1457         struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
1458         int seq, n, t;
1459
1460         dlog(ms, "cmd_complete fc=%x", mr->fifo_count);
1461         seq = use_active_neg + (ms->n_msgout? SEQ_ATN: 0);
1462         switch (ms->msgphase) {
1463         case msg_out_xxx:
1464                 /* huh?  we expected a phase mismatch */
1465                 ms->n_msgin = 0;
1466                 ms->msgphase = msg_in;
1467                 /* fall through */
1468
1469         case msg_in:
1470                 /* should have some message bytes in fifo */
1471                 get_msgin(ms);
1472                 n = msgin_length(ms);
1473                 if (ms->n_msgin < n) {
1474                         out_8(&mr->count_lo, n - ms->n_msgin);
1475                         out_8(&mr->sequence, SEQ_MSGIN + seq);
1476                 } else {
1477                         ms->msgphase = msg_none;
1478                         handle_msgin(ms);
1479                         start_phase(ms);
1480                 }
1481                 break;
1482
1483         case msg_in_bad:
1484                 out_8(&mr->sequence, SEQ_FLUSHFIFO);
1485                 mesh_flush_io(mr);
1486                 udelay(1);
1487                 out_8(&mr->count_lo, 1);
1488                 out_8(&mr->sequence, SEQ_MSGIN + SEQ_ATN + use_active_neg);
1489                 break;
1490
1491         case msg_out:
1492                 /*
1493                  * To get the right timing on ATN wrt ACK, we have
1494                  * to get the MESH to drop ACK, wait until REQ gets
1495                  * asserted, then drop ATN.  To do this we first
1496                  * issue a SEQ_MSGOUT with ATN and wait for REQ,
1497                  * then change the command to a SEQ_MSGOUT w/o ATN.
1498                  * If we don't see REQ in a reasonable time, we
1499                  * change the command to SEQ_MSGIN with ATN,
1500                  * wait for the phase mismatch interrupt, then
1501                  * issue the SEQ_MSGOUT without ATN.
1502                  */
1503                 out_8(&mr->count_lo, 1);
1504                 out_8(&mr->sequence, SEQ_MSGOUT + use_active_neg + SEQ_ATN);
1505                 t = 30;         /* wait up to 30us */
1506                 while ((in_8(&mr->bus_status0) & BS0_REQ) == 0 && --t >= 0)
1507                         udelay(1);
1508                 dlog(ms, "last_mbyte err/exc/fc/cl=%.8x",
1509                      MKWORD(mr->error, mr->exception,
1510                             mr->fifo_count, mr->count_lo));
1511                 if (in_8(&mr->interrupt) & (INT_ERROR | INT_EXCEPTION)) {
1512                         /* whoops, target didn't do what we expected */
1513                         ms->last_n_msgout = ms->n_msgout;
1514                         ms->n_msgout = 0;
1515                         if (in_8(&mr->interrupt) & INT_ERROR) {
1516                                 printk(KERN_ERR "mesh: error %x in msg_out\n",
1517                                        in_8(&mr->error));
1518                                 handle_error(ms);
1519                                 return;
1520                         }
1521                         if (in_8(&mr->exception) != EXC_PHASEMM)
1522                                 printk(KERN_ERR "mesh: exc %x in msg_out\n",
1523                                        in_8(&mr->exception));
1524                         else
1525                                 printk(KERN_DEBUG "mesh: bs0=%x in msg_out\n",
1526                                        in_8(&mr->bus_status0));
1527                         handle_exception(ms);
1528                         return;
1529                 }
1530                 if (in_8(&mr->bus_status0) & BS0_REQ) {
1531                         out_8(&mr->sequence, SEQ_MSGOUT + use_active_neg);
1532                         mesh_flush_io(mr);
1533                         udelay(1);
1534                         out_8(&mr->fifo, ms->msgout[ms->n_msgout-1]);
1535                         ms->msgphase = msg_out_last;
1536                 } else {
1537                         out_8(&mr->sequence, SEQ_MSGIN + use_active_neg + SEQ_ATN);
1538                         ms->msgphase = msg_out_xxx;
1539                 }
1540                 break;
1541
1542         case msg_out_last:
1543                 ms->last_n_msgout = ms->n_msgout;
1544                 ms->n_msgout = 0;
1545                 ms->msgphase = ms->expect_reply? msg_in: msg_none;
1546                 start_phase(ms);
1547                 break;
1548
1549         case msg_none:
1550                 switch (ms->phase) {
1551                 case idle:
1552                         printk(KERN_ERR "mesh: interrupt in idle phase?\n");
1553                         dumpslog(ms);
1554                         return;
1555                 case selecting:
1556                         dlog(ms, "Selecting phase at command completion",0);
1557                         ms->msgout[0] = IDENTIFY(ALLOW_RESEL(ms->conn_tgt),
1558                                                  (cmd? cmd->device->lun: 0));
1559                         ms->n_msgout = 1;
1560                         ms->expect_reply = 0;
1561                         if (ms->aborting) {
1562                                 ms->msgout[0] = ABORT;
1563                                 ms->n_msgout++;
1564                         } else if (tp->sdtr_state == do_sdtr) {
1565                                 /* add SDTR message */
1566                                 add_sdtr_msg(ms);
1567                                 ms->expect_reply = 1;
1568                                 tp->sdtr_state = sdtr_sent;
1569                         }
1570                         ms->msgphase = msg_out;
1571                         /*
1572                          * We need to wait for REQ before dropping ATN.
1573                          * We wait for at most 30us, then fall back to
1574                          * a scheme where we issue a SEQ_COMMAND with ATN,
1575                          * which will give us a phase mismatch interrupt
1576                          * when REQ does come, and then we send the message.
1577                          */
1578                         t = 230;                /* wait up to 230us */
1579                         while ((in_8(&mr->bus_status0) & BS0_REQ) == 0) {
1580                                 if (--t < 0) {
1581                                         dlog(ms, "impatient for req", ms->n_msgout);
1582                                         ms->msgphase = msg_none;
1583                                         break;
1584                                 }
1585                                 udelay(1);
1586                         }
1587                         break;
1588                 case dataing:
1589                         if (ms->dma_count != 0) {
1590                                 start_phase(ms);
1591                                 return;
1592                         }
1593                         /*
1594                          * We can get a phase mismatch here if the target
1595                          * changes to the status phase, even though we have
1596                          * had a command complete interrupt.  Then, if we
1597                          * issue the SEQ_STATUS command, we'll get a sequence
1598                          * error interrupt.  Which isn't so bad except that
1599                          * occasionally the mesh actually executes the
1600                          * SEQ_STATUS *as well as* giving us the sequence
1601                          * error and phase mismatch exception.
1602                          */
1603                         out_8(&mr->sequence, 0);
1604                         out_8(&mr->interrupt,
1605                               INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1606                         halt_dma(ms);
1607                         break;
1608                 case statusing:
1609                         if (cmd) {
1610                                 cmd->SCp.Status = mr->fifo;
1611                                 if (DEBUG_TARGET(cmd))
1612                                         printk(KERN_DEBUG "mesh: status is %x\n",
1613                                                cmd->SCp.Status);
1614                         }
1615                         ms->msgphase = msg_in;
1616                         break;
1617                 case busfreeing:
1618                         mesh_done(ms, 1);
1619                         return;
1620                 case disconnecting:
1621                         ms->current_req = NULL;
1622                         ms->phase = idle;
1623                         mesh_start(ms);
1624                         return;
1625                 default:
1626                         break;
1627                 }
1628                 ++ms->phase;
1629                 start_phase(ms);
1630                 break;
1631         }
1632 }
1633
1634
1635 /*
1636  * Called by midlayer with host locked to queue a new
1637  * request
1638  */
1639 static int mesh_queue(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
1640 {
1641         struct mesh_state *ms;
1642
1643         cmd->scsi_done = done;
1644         cmd->host_scribble = NULL;
1645
1646         ms = (struct mesh_state *) cmd->device->host->hostdata;
1647
1648         if (ms->request_q == NULL)
1649                 ms->request_q = cmd;
1650         else
1651                 ms->request_qtail->host_scribble = (void *) cmd;
1652         ms->request_qtail = cmd;
1653
1654         if (ms->phase == idle)
1655                 mesh_start(ms);
1656
1657         return 0;
1658 }
1659
1660 /*
1661  * Called to handle interrupts, either call by the interrupt
1662  * handler (do_mesh_interrupt) or by other functions in
1663  * exceptional circumstances
1664  */
1665 static void mesh_interrupt(struct mesh_state *ms)
1666 {
1667         volatile struct mesh_regs __iomem *mr = ms->mesh;
1668         int intr;
1669
1670 #if 0
1671         if (ALLOW_DEBUG(ms->conn_tgt))
1672                 printk(KERN_DEBUG "mesh_intr, bs0=%x int=%x exc=%x err=%x "
1673                        "phase=%d msgphase=%d\n", mr->bus_status0,
1674                        mr->interrupt, mr->exception, mr->error,
1675                        ms->phase, ms->msgphase);
1676 #endif
1677         while ((intr = in_8(&mr->interrupt)) != 0) {
1678                 dlog(ms, "interrupt intr/err/exc/seq=%.8x",
1679                      MKWORD(intr, mr->error, mr->exception, mr->sequence));
1680                 if (intr & INT_ERROR) {
1681                         handle_error(ms);
1682                 } else if (intr & INT_EXCEPTION) {
1683                         handle_exception(ms);
1684                 } else if (intr & INT_CMDDONE) {
1685                         out_8(&mr->interrupt, INT_CMDDONE);
1686                         cmd_complete(ms);
1687                 }
1688         }
1689 }
1690
1691 /* Todo: here we can at least try to remove the command from the
1692  * queue if it isn't connected yet, and for pending command, assert
1693  * ATN until the bus gets freed.
1694  */
1695 static int mesh_abort(struct scsi_cmnd *cmd)
1696 {
1697         struct mesh_state *ms = (struct mesh_state *) cmd->device->host->hostdata;
1698
1699         printk(KERN_DEBUG "mesh_abort(%p)\n", cmd);
1700         mesh_dump_regs(ms);
1701         dumplog(ms, cmd->device->id);
1702         dumpslog(ms);
1703         return FAILED;
1704 }
1705
1706 /*
1707  * Called by the midlayer with the lock held to reset the
1708  * SCSI host and bus.
1709  * The midlayer will wait for devices to come back, we don't need
1710  * to do that ourselves
1711  */
1712 static int mesh_host_reset(struct scsi_cmnd *cmd)
1713 {
1714         struct mesh_state *ms = (struct mesh_state *) cmd->device->host->hostdata;
1715         volatile struct mesh_regs __iomem *mr = ms->mesh;
1716         volatile struct dbdma_regs __iomem *md = ms->dma;
1717         unsigned long flags;
1718
1719         printk(KERN_DEBUG "mesh_host_reset\n");
1720
1721         spin_lock_irqsave(ms->host->host_lock, flags);
1722
1723         /* Reset the controller & dbdma channel */
1724         out_le32(&md->control, (RUN|PAUSE|FLUSH|WAKE) << 16);   /* stop dma */
1725         out_8(&mr->exception, 0xff);    /* clear all exception bits */
1726         out_8(&mr->error, 0xff);        /* clear all error bits */
1727         out_8(&mr->sequence, SEQ_RESETMESH);
1728         mesh_flush_io(mr);
1729         udelay(1);
1730         out_8(&mr->intr_mask, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1731         out_8(&mr->source_id, ms->host->this_id);
1732         out_8(&mr->sel_timeout, 25);    /* 250ms */
1733         out_8(&mr->sync_params, ASYNC_PARAMS);
1734
1735         /* Reset the bus */
1736         out_8(&mr->bus_status1, BS1_RST);       /* assert RST */
1737         mesh_flush_io(mr);
1738         udelay(30);                     /* leave it on for >= 25us */
1739         out_8(&mr->bus_status1, 0);     /* negate RST */
1740
1741         /* Complete pending commands */
1742         handle_reset(ms);
1743
1744         spin_unlock_irqrestore(ms->host->host_lock, flags);
1745         return SUCCESS;
1746 }
1747
1748 static void set_mesh_power(struct mesh_state *ms, int state)
1749 {
1750         if (!machine_is(powermac))
1751                 return;
1752         if (state) {
1753                 pmac_call_feature(PMAC_FTR_MESH_ENABLE, macio_get_of_node(ms->mdev), 0, 1);
1754                 msleep(200);
1755         } else {
1756                 pmac_call_feature(PMAC_FTR_MESH_ENABLE, macio_get_of_node(ms->mdev), 0, 0);
1757                 msleep(10);
1758         }
1759 }
1760
1761
1762 #ifdef CONFIG_PM
1763 static int mesh_suspend(struct macio_dev *mdev, pm_message_t mesg)
1764 {
1765         struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
1766         unsigned long flags;
1767
1768         switch (mesg.event) {
1769         case PM_EVENT_SUSPEND:
1770         case PM_EVENT_FREEZE:
1771                 break;
1772         default:
1773                 return 0;
1774         }
1775         if (mesg.event == mdev->ofdev.dev.power.power_state.event)
1776                 return 0;
1777
1778         scsi_block_requests(ms->host);
1779         spin_lock_irqsave(ms->host->host_lock, flags);
1780         while(ms->phase != idle) {
1781                 spin_unlock_irqrestore(ms->host->host_lock, flags);
1782                 msleep(10);
1783                 spin_lock_irqsave(ms->host->host_lock, flags);
1784         }
1785         ms->phase = sleeping;
1786         spin_unlock_irqrestore(ms->host->host_lock, flags);
1787         disable_irq(ms->meshintr);
1788         set_mesh_power(ms, 0);
1789
1790         mdev->ofdev.dev.power.power_state = mesg;
1791
1792         return 0;
1793 }
1794
1795 static int mesh_resume(struct macio_dev *mdev)
1796 {
1797         struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
1798         unsigned long flags;
1799
1800         if (mdev->ofdev.dev.power.power_state.event == PM_EVENT_ON)
1801                 return 0;
1802
1803         set_mesh_power(ms, 1);
1804         mesh_init(ms);
1805         spin_lock_irqsave(ms->host->host_lock, flags);
1806         mesh_start(ms);
1807         spin_unlock_irqrestore(ms->host->host_lock, flags);
1808         enable_irq(ms->meshintr);
1809         scsi_unblock_requests(ms->host);
1810
1811         mdev->ofdev.dev.power.power_state.event = PM_EVENT_ON;
1812
1813         return 0;
1814 }
1815
1816 #endif /* CONFIG_PM */
1817
1818 /*
1819  * If we leave drives set for synchronous transfers (especially
1820  * CDROMs), and reboot to MacOS, it gets confused, poor thing.
1821  * So, on reboot we reset the SCSI bus.
1822  */
1823 static int mesh_shutdown(struct macio_dev *mdev)
1824 {
1825         struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
1826         volatile struct mesh_regs __iomem *mr;
1827         unsigned long flags;
1828
1829         printk(KERN_INFO "resetting MESH scsi bus(es)\n");
1830         spin_lock_irqsave(ms->host->host_lock, flags);
1831         mr = ms->mesh;
1832         out_8(&mr->intr_mask, 0);
1833         out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1834         out_8(&mr->bus_status1, BS1_RST);
1835         mesh_flush_io(mr);
1836         udelay(30);
1837         out_8(&mr->bus_status1, 0);
1838         spin_unlock_irqrestore(ms->host->host_lock, flags);
1839
1840         return 0;
1841 }
1842
1843 static struct scsi_host_template mesh_template = {
1844         .proc_name                      = "mesh",
1845         .name                           = "MESH",
1846         .queuecommand                   = mesh_queue,
1847         .eh_abort_handler               = mesh_abort,
1848         .eh_host_reset_handler          = mesh_host_reset,
1849         .can_queue                      = 20,
1850         .this_id                        = 7,
1851         .sg_tablesize                   = SG_ALL,
1852         .cmd_per_lun                    = 2,
1853         .use_clustering                 = DISABLE_CLUSTERING,
1854 };
1855
1856 static int mesh_probe(struct macio_dev *mdev, const struct of_device_id *match)
1857 {
1858         struct device_node *mesh = macio_get_of_node(mdev);
1859         struct pci_dev* pdev = macio_get_pci_dev(mdev);
1860         int tgt, minper;
1861         const int *cfp;
1862         struct mesh_state *ms;
1863         struct Scsi_Host *mesh_host;
1864         void *dma_cmd_space;
1865         dma_addr_t dma_cmd_bus;
1866
1867         switch (mdev->bus->chip->type) {
1868         case macio_heathrow:
1869         case macio_gatwick:
1870         case macio_paddington:
1871                 use_active_neg = 0;
1872                 break;
1873         default:
1874                 use_active_neg = SEQ_ACTIVE_NEG;
1875         }
1876
1877         if (macio_resource_count(mdev) != 2 || macio_irq_count(mdev) != 2) {
1878                 printk(KERN_ERR "mesh: expected 2 addrs and 2 intrs"
1879                        " (got %d,%d)\n", macio_resource_count(mdev),
1880                        macio_irq_count(mdev));
1881                 return -ENODEV;
1882         }
1883
1884         if (macio_request_resources(mdev, "mesh") != 0) {
1885                 printk(KERN_ERR "mesh: unable to request memory resources");
1886                 return -EBUSY;
1887         }
1888         mesh_host = scsi_host_alloc(&mesh_template, sizeof(struct mesh_state));
1889         if (mesh_host == NULL) {
1890                 printk(KERN_ERR "mesh: couldn't register host");
1891                 goto out_release;
1892         }
1893
1894         /* Old junk for root discovery, that will die ultimately */
1895 #if !defined(MODULE)
1896         note_scsi_host(mesh, mesh_host);
1897 #endif
1898
1899         mesh_host->base = macio_resource_start(mdev, 0);
1900         mesh_host->irq = macio_irq(mdev, 0);
1901         ms = (struct mesh_state *) mesh_host->hostdata;
1902         macio_set_drvdata(mdev, ms);
1903         ms->host = mesh_host;
1904         ms->mdev = mdev;
1905         ms->pdev = pdev;
1906
1907         ms->mesh = ioremap(macio_resource_start(mdev, 0), 0x1000);
1908         if (ms->mesh == NULL) {
1909                 printk(KERN_ERR "mesh: can't map registers\n");
1910                 goto out_free;
1911         }
1912         ms->dma = ioremap(macio_resource_start(mdev, 1), 0x1000);
1913         if (ms->dma == NULL) {
1914                 printk(KERN_ERR "mesh: can't map registers\n");
1915                 iounmap(ms->mesh);
1916                 goto out_free;
1917         }
1918
1919         ms->meshintr = macio_irq(mdev, 0);
1920         ms->dmaintr = macio_irq(mdev, 1);
1921
1922         /* Space for dma command list: +1 for stop command,
1923          * +1 to allow for aligning.
1924          */
1925         ms->dma_cmd_size = (mesh_host->sg_tablesize + 2) * sizeof(struct dbdma_cmd);
1926
1927         /* We use the PCI APIs for now until the generic one gets fixed
1928          * enough or until we get some macio-specific versions
1929          */
1930         dma_cmd_space = pci_alloc_consistent(macio_get_pci_dev(mdev),
1931                                              ms->dma_cmd_size,
1932                                              &dma_cmd_bus);
1933         if (dma_cmd_space == NULL) {
1934                 printk(KERN_ERR "mesh: can't allocate DMA table\n");
1935                 goto out_unmap;
1936         }
1937         memset(dma_cmd_space, 0, ms->dma_cmd_size);
1938
1939         ms->dma_cmds = (struct dbdma_cmd *) DBDMA_ALIGN(dma_cmd_space);
1940         ms->dma_cmd_space = dma_cmd_space;
1941         ms->dma_cmd_bus = dma_cmd_bus + ((unsigned long)ms->dma_cmds)
1942                 - (unsigned long)dma_cmd_space;
1943         ms->current_req = NULL;
1944         for (tgt = 0; tgt < 8; ++tgt) {
1945                 ms->tgts[tgt].sdtr_state = do_sdtr;
1946                 ms->tgts[tgt].sync_params = ASYNC_PARAMS;
1947                 ms->tgts[tgt].current_req = NULL;
1948         }
1949
1950         if ((cfp = of_get_property(mesh, "clock-frequency", NULL)))
1951                 ms->clk_freq = *cfp;
1952         else {
1953                 printk(KERN_INFO "mesh: assuming 50MHz clock frequency\n");
1954                 ms->clk_freq = 50000000;
1955         }
1956
1957         /* The maximum sync rate is clock / 5; increase
1958          * mesh_sync_period if necessary.
1959          */
1960         minper = 1000000000 / (ms->clk_freq / 5); /* ns */
1961         if (mesh_sync_period < minper)
1962                 mesh_sync_period = minper;
1963
1964         /* Power up the chip */
1965         set_mesh_power(ms, 1);
1966
1967         /* Set it up */
1968         mesh_init(ms);
1969
1970         /* Request interrupt */
1971         if (request_irq(ms->meshintr, do_mesh_interrupt, 0, "MESH", ms)) {
1972                 printk(KERN_ERR "MESH: can't get irq %d\n", ms->meshintr);
1973                 goto out_shutdown;
1974         }
1975
1976         /* Add scsi host & scan */
1977         if (scsi_add_host(mesh_host, &mdev->ofdev.dev))
1978                 goto out_release_irq;
1979         scsi_scan_host(mesh_host);
1980
1981         return 0;
1982
1983  out_release_irq:
1984         free_irq(ms->meshintr, ms);
1985  out_shutdown:
1986         /* shutdown & reset bus in case of error or macos can be confused
1987          * at reboot if the bus was set to synchronous mode already
1988          */
1989         mesh_shutdown(mdev);
1990         set_mesh_power(ms, 0);
1991         pci_free_consistent(macio_get_pci_dev(mdev), ms->dma_cmd_size,
1992                             ms->dma_cmd_space, ms->dma_cmd_bus);
1993  out_unmap:
1994         iounmap(ms->dma);
1995         iounmap(ms->mesh);
1996  out_free:
1997         scsi_host_put(mesh_host);
1998  out_release:
1999         macio_release_resources(mdev);
2000
2001         return -ENODEV;
2002 }
2003
2004 static int mesh_remove(struct macio_dev *mdev)
2005 {
2006         struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
2007         struct Scsi_Host *mesh_host = ms->host;
2008
2009         scsi_remove_host(mesh_host);
2010
2011         free_irq(ms->meshintr, ms);
2012
2013         /* Reset scsi bus */
2014         mesh_shutdown(mdev);
2015
2016         /* Shut down chip & termination */
2017         set_mesh_power(ms, 0);
2018
2019         /* Unmap registers & dma controller */
2020         iounmap(ms->mesh);
2021         iounmap(ms->dma);
2022
2023         /* Free DMA commands memory */
2024         pci_free_consistent(macio_get_pci_dev(mdev), ms->dma_cmd_size,
2025                             ms->dma_cmd_space, ms->dma_cmd_bus);
2026
2027         /* Release memory resources */
2028         macio_release_resources(mdev);
2029
2030         scsi_host_put(mesh_host);
2031
2032         return 0;
2033 }
2034
2035
2036 static struct of_device_id mesh_match[] =
2037 {
2038         {
2039         .name           = "mesh",
2040         },
2041         {
2042         .type           = "scsi",
2043         .compatible     = "chrp,mesh0"
2044         },
2045         {},
2046 };
2047 MODULE_DEVICE_TABLE (of, mesh_match);
2048
2049 static struct macio_driver mesh_driver =
2050 {
2051         .name           = "mesh",
2052         .match_table    = mesh_match,
2053         .probe          = mesh_probe,
2054         .remove         = mesh_remove,
2055         .shutdown       = mesh_shutdown,
2056 #ifdef CONFIG_PM
2057         .suspend        = mesh_suspend,
2058         .resume         = mesh_resume,
2059 #endif
2060 };
2061
2062
2063 static int __init init_mesh(void)
2064 {
2065
2066         /* Calculate sync rate from module parameters */
2067         if (sync_rate > 10)
2068                 sync_rate = 10;
2069         if (sync_rate > 0) {
2070                 printk(KERN_INFO "mesh: configured for synchronous %d MB/s\n", sync_rate);
2071                 mesh_sync_period = 1000 / sync_rate;    /* ns */
2072                 mesh_sync_offset = 15;
2073         } else
2074                 printk(KERN_INFO "mesh: configured for asynchronous\n");
2075
2076         return macio_register_driver(&mesh_driver);
2077 }
2078
2079 static void __exit exit_mesh(void)
2080 {
2081         return macio_unregister_driver(&mesh_driver);
2082 }
2083
2084 module_init(init_mesh);
2085 module_exit(exit_mesh);