Logo Search packages:      
Sourcecode: linux-fsl-imx51 version File versions  Download package

fas216.c

/*
 *  linux/drivers/acorn/scsi/fas216.c
 *
 *  Copyright (C) 1997-2003 Russell King
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Based on information in qlogicfas.c by Tom Zerucha, Michael Griffith, and
 * other sources, including:
 *   the AMD Am53CF94 data sheet
 *   the AMD Am53C94 data sheet
 *
 * This is a generic driver.  To use it, have a look at cumana_2.c.  You
 * should define your own structure that overlays FAS216_Info, eg:
 * struct my_host_data {
 *    FAS216_Info info;
 *    ... my host specific data ...
 * };
 *
 * Changelog:
 *  30-08-1997    RMK   Created
 *  14-09-1997    RMK   Started disconnect support
 *  08-02-1998    RMK   Corrected real DMA support
 *  15-02-1998    RMK   Started sync xfer support
 *  06-04-1998    RMK   Tightened conditions for printing incomplete
 *                transfers
 *  02-05-1998    RMK   Added extra checks in fas216_reset
 *  24-05-1998    RMK   Fixed synchronous transfers with period >= 200ns
 *  27-06-1998    RMK   Changed asm/delay.h to linux/delay.h
 *  26-08-1998    RMK   Improved message support wrt MESSAGE_REJECT
 *  02-04-2000    RMK   Converted to use the new error handling, and
 *                automatically request sense data upon check
 *                condition status from targets.
 */
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/ioport.h>
#include <linux/proc_fs.h>
#include <linux/delay.h>
#include <linux/bitops.h>
#include <linux/init.h>
#include <linux/interrupt.h>

#include <asm/dma.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/ecard.h>

#include "../scsi.h"
#include <scsi/scsi_dbg.h>
#include <scsi/scsi_host.h>
#include "fas216.h"
#include "scsi.h"

/* NOTE: SCSI2 Synchronous transfers *require* DMA according to
 *  the data sheet.  This restriction is crazy, especially when
 *  you only want to send 16 bytes!  What were the guys who
 *  designed this chip on at that time?  Did they read the SCSI2
 *  spec at all?  The following sections are taken from the SCSI2
 *  standard (s2r10) concerning this:
 *
 * > IMPLEMENTORS NOTES:
 * >   (1)  Re-negotiation at every selection is not recommended, since a
 * >   significant performance impact is likely.
 *
 * >  The implied synchronous agreement shall remain in effect until a BUS DEVICE
 * >  RESET message is received, until a hard reset condition occurs, or until one
 * >  of the two SCSI devices elects to modify the agreement.  The default data
 * >  transfer mode is asynchronous data transfer mode.  The default data transfer
 * >  mode is entered at power on, after a BUS DEVICE RESET message, or after a hard
 * >  reset condition.
 *
 *  In total, this means that once you have elected to use synchronous
 *  transfers, you must always use DMA.
 *
 *  I was thinking that this was a good chip until I found this restriction ;(
 */
#define SCSI2_SYNC
#undef  SCSI2_TAG

#undef DEBUG_CONNECT
#undef DEBUG_MESSAGES

#undef CHECK_STRUCTURE

#define LOG_CONNECT           (1 << 0)
#define LOG_BUSSERVICE        (1 << 1)
#define LOG_FUNCTIONDONE      (1 << 2)
#define LOG_MESSAGES          (1 << 3)
#define LOG_BUFFER            (1 << 4)
#define LOG_ERROR       (1 << 8)

static int level_mask = LOG_ERROR;

module_param(level_mask, int, 0644);

static int __init fas216_log_setup(char *str)
{
      char *s;

      level_mask = 0;

      while ((s = strsep(&str, ",")) != NULL) {
            switch (s[0]) {
            case 'a':
                  if (strcmp(s, "all") == 0)
                        level_mask |= -1;
                  break;
            case 'b':
                  if (strncmp(s, "bus", 3) == 0)
                        level_mask |= LOG_BUSSERVICE;
                  if (strncmp(s, "buf", 3) == 0)
                        level_mask |= LOG_BUFFER;
                  break;
            case 'c':
                  level_mask |= LOG_CONNECT;
                  break;
            case 'e':
                  level_mask |= LOG_ERROR;
                  break;
            case 'm':
                  level_mask |= LOG_MESSAGES;
                  break;
            case 'n':
                  if (strcmp(s, "none") == 0)
                        level_mask = 0;
                  break;
            case 's':
                  level_mask |= LOG_FUNCTIONDONE;
                  break;
            }
      }
      return 1;
}

__setup("fas216_logging=", fas216_log_setup);

static inline unsigned char fas216_readb(FAS216_Info *info, unsigned int reg)
{
      unsigned int off = reg << info->scsi.io_shift;
      return readb(info->scsi.io_base + off);
}

static inline void fas216_writeb(FAS216_Info *info, unsigned int reg, unsigned int val)
{
      unsigned int off = reg << info->scsi.io_shift;
      writeb(val, info->scsi.io_base + off);
}

static void fas216_dumpstate(FAS216_Info *info)
{
      unsigned char is, stat, inst;

      is   = fas216_readb(info, REG_IS);
      stat = fas216_readb(info, REG_STAT);
      inst = fas216_readb(info, REG_INST);
      
      printk("FAS216: CTCL=%02X CTCM=%02X CMD=%02X STAT=%02X"
             " INST=%02X IS=%02X CFIS=%02X",
            fas216_readb(info, REG_CTCL),
            fas216_readb(info, REG_CTCM),
            fas216_readb(info, REG_CMD),  stat, inst, is,
            fas216_readb(info, REG_CFIS));
      printk(" CNTL1=%02X CNTL2=%02X CNTL3=%02X CTCH=%02X\n",
            fas216_readb(info, REG_CNTL1),
            fas216_readb(info, REG_CNTL2),
            fas216_readb(info, REG_CNTL3),
            fas216_readb(info, REG_CTCH));
}

static void print_SCp(struct scsi_pointer *SCp, const char *prefix, const char *suffix)
{
      printk("%sptr %p this_residual 0x%x buffer %p buffers_residual 0x%x%s",
            prefix, SCp->ptr, SCp->this_residual, SCp->buffer,
            SCp->buffers_residual, suffix);
}

static void fas216_dumpinfo(FAS216_Info *info)
{
      static int used = 0;
      int i;

      if (used++)
            return;

      printk("FAS216_Info=\n");
      printk("  { magic_start=%lX host=%p SCpnt=%p origSCpnt=%p\n",
            info->magic_start, info->host, info->SCpnt,
            info->origSCpnt);
      printk("    scsi={ io_shift=%X irq=%X cfg={ %X %X %X %X }\n",
            info->scsi.io_shift, info->scsi.irq,
            info->scsi.cfg[0], info->scsi.cfg[1], info->scsi.cfg[2],
            info->scsi.cfg[3]);
      printk("           type=%p phase=%X\n",
            info->scsi.type, info->scsi.phase);
      print_SCp(&info->scsi.SCp, "           SCp={ ", " }\n");
      printk("      msgs async_stp=%X disconnectable=%d aborting=%d }\n",
            info->scsi.async_stp,
            info->scsi.disconnectable, info->scsi.aborting);
      printk("    stats={ queues=%X removes=%X fins=%X reads=%X writes=%X miscs=%X\n"
             "            disconnects=%X aborts=%X bus_resets=%X host_resets=%X}\n",
            info->stats.queues, info->stats.removes, info->stats.fins,
            info->stats.reads, info->stats.writes, info->stats.miscs,
            info->stats.disconnects, info->stats.aborts, info->stats.bus_resets,
            info->stats.host_resets);
      printk("    ifcfg={ clockrate=%X select_timeout=%X asyncperiod=%X sync_max_depth=%X }\n",
            info->ifcfg.clockrate, info->ifcfg.select_timeout,
            info->ifcfg.asyncperiod, info->ifcfg.sync_max_depth);
      for (i = 0; i < 8; i++) {
            printk("    busyluns[%d]=%08lx dev[%d]={ disconnect_ok=%d stp=%X sof=%X sync_state=%X }\n",
                  i, info->busyluns[i], i,
                  info->device[i].disconnect_ok, info->device[i].stp,
                  info->device[i].sof, info->device[i].sync_state);
      }
      printk("    dma={ transfer_type=%X setup=%p pseudo=%p stop=%p }\n",
            info->dma.transfer_type, info->dma.setup,
            info->dma.pseudo, info->dma.stop);
      printk("    internal_done=%X magic_end=%lX }\n",
            info->internal_done, info->magic_end);
}

#ifdef CHECK_STRUCTURE
static void __fas216_checkmagic(FAS216_Info *info, const char *func)
{
      int corruption = 0;
      if (info->magic_start != MAGIC) {
            printk(KERN_CRIT "FAS216 Error: magic at start corrupted\n");
            corruption++;
      }
      if (info->magic_end != MAGIC) {
            printk(KERN_CRIT "FAS216 Error: magic at end corrupted\n");
            corruption++;
      }
      if (corruption) {
            fas216_dumpinfo(info);
            panic("scsi memory space corrupted in %s", func);
      }
}
#define fas216_checkmagic(info) __fas216_checkmagic((info), __func__)
#else
#define fas216_checkmagic(info)
#endif

static const char *fas216_bus_phase(int stat)
{
      static const char *phases[] = {
            "DATA OUT", "DATA IN",
            "COMMAND", "STATUS",
            "MISC OUT", "MISC IN",
            "MESG OUT", "MESG IN"
      };

      return phases[stat & STAT_BUSMASK];
}

static const char *fas216_drv_phase(FAS216_Info *info)
{
      static const char *phases[] = {
            [PHASE_IDLE]            = "idle",
            [PHASE_SELECTION] = "selection",
            [PHASE_COMMAND]         = "command",
            [PHASE_DATAOUT]         = "data out",
            [PHASE_DATAIN]          = "data in",
            [PHASE_MSGIN]           = "message in",
            [PHASE_MSGIN_DISCONNECT]= "disconnect",
            [PHASE_MSGOUT_EXPECT]   = "expect message out",
            [PHASE_MSGOUT]          = "message out",
            [PHASE_STATUS]          = "status",
            [PHASE_DONE]            = "done",
      };

      if (info->scsi.phase < ARRAY_SIZE(phases) &&
          phases[info->scsi.phase])
            return phases[info->scsi.phase];
      return "???";
}

static char fas216_target(FAS216_Info *info)
{
      if (info->SCpnt)
            return '0' + info->SCpnt->device->id;
      else
            return 'H';
}

static void
fas216_do_log(FAS216_Info *info, char target, char *fmt, va_list ap)
{
      static char buf[1024];

      vsnprintf(buf, sizeof(buf), fmt, ap);
      printk("scsi%d.%c: %s", info->host->host_no, target, buf);
}

static void fas216_log_command(FAS216_Info *info, int level,
                         struct scsi_cmnd *SCpnt, char *fmt, ...)
{
      va_list args;

      if (level != 0 && !(level & level_mask))
            return;

      va_start(args, fmt);
      fas216_do_log(info, '0' + SCpnt->device->id, fmt, args);
      va_end(args);

      printk(" CDB: ");
      __scsi_print_command(SCpnt->cmnd);
}

static void
fas216_log_target(FAS216_Info *info, int level, int target, char *fmt, ...)
{
      va_list args;

      if (level != 0 && !(level & level_mask))
            return;

      if (target < 0)
            target = 'H';
      else
            target += '0';

      va_start(args, fmt);
      fas216_do_log(info, target, fmt, args);
      va_end(args);

      printk("\n");
}

static void fas216_log(FAS216_Info *info, int level, char *fmt, ...)
{
      va_list args;

      if (level != 0 && !(level & level_mask))
            return;

      va_start(args, fmt);
      fas216_do_log(info, fas216_target(info), fmt, args);
      va_end(args);

      printk("\n");
}

#define PH_SIZE   32

static struct { int stat, ssr, isr, ph; } ph_list[PH_SIZE];
static int ph_ptr;

static void add_debug_list(int stat, int ssr, int isr, int ph)
{
      ph_list[ph_ptr].stat = stat;
      ph_list[ph_ptr].ssr = ssr;
      ph_list[ph_ptr].isr = isr;
      ph_list[ph_ptr].ph = ph;

      ph_ptr = (ph_ptr + 1) & (PH_SIZE-1);
}

static struct { int command; void *from; } cmd_list[8];
static int cmd_ptr;

static void fas216_cmd(FAS216_Info *info, unsigned int command)
{
      cmd_list[cmd_ptr].command = command;
      cmd_list[cmd_ptr].from = __builtin_return_address(0);

      cmd_ptr = (cmd_ptr + 1) & 7;

      fas216_writeb(info, REG_CMD, command);
}

static void print_debug_list(void)
{
      int i;

      i = ph_ptr;

      printk(KERN_ERR "SCSI IRQ trail\n");
      do {
            printk(" %02x:%02x:%02x:%1x",
                  ph_list[i].stat, ph_list[i].ssr,
                  ph_list[i].isr, ph_list[i].ph);
            i = (i + 1) & (PH_SIZE - 1);
            if (((i ^ ph_ptr) & 7) == 0)
                  printk("\n");
      } while (i != ph_ptr);
      if ((i ^ ph_ptr) & 7)
            printk("\n");

      i = cmd_ptr;
      printk(KERN_ERR "FAS216 commands: ");
      do {
            printk("%02x:%p ", cmd_list[i].command, cmd_list[i].from);
            i = (i + 1) & 7;
      } while (i != cmd_ptr);
      printk("\n");
}

static void fas216_done(FAS216_Info *info, unsigned int result);

/**
 * fas216_get_last_msg - retrive last message from the list
 * @info: interface to search
 * @pos: current fifo position
 *
 * Retrieve a last message from the list, using position in fifo.
 */
static inline unsigned short
fas216_get_last_msg(FAS216_Info *info, int pos)
{
      unsigned short packed_msg = NOP;
      struct message *msg;
      int msgnr = 0;

      while ((msg = msgqueue_getmsg(&info->scsi.msgs, msgnr++)) != NULL) {
            if (pos >= msg->fifo)
                  break;
      }

      if (msg) {
            if (msg->msg[0] == EXTENDED_MESSAGE)
                  packed_msg = EXTENDED_MESSAGE | msg->msg[2] << 8;
            else
                  packed_msg = msg->msg[0];
      }

      fas216_log(info, LOG_MESSAGES,
            "Message: %04x found at position %02x\n", packed_msg, pos);

      return packed_msg;
}

/**
 * fas216_syncperiod - calculate STP register value
 * @info: state structure for interface connected to device
 * @ns: period in ns (between subsequent bytes)
 *
 * Calculate value to be loaded into the STP register for a given period
 * in ns. Returns a value suitable for REG_STP.
 */
static int fas216_syncperiod(FAS216_Info *info, int ns)
{
      int value = (info->ifcfg.clockrate * ns) / 1000;

      fas216_checkmagic(info);

      if (value < 4)
            value = 4;
      else if (value > 35)
            value = 35;

      return value & 31;
}

/**
 * fas216_set_sync - setup FAS216 chip for specified transfer period.
 * @info: state structure for interface connected to device
 * @target: target
 *
 * Correctly setup FAS216 chip for specified transfer period.
 * Notes   : we need to switch the chip out of FASTSCSI mode if we have
 *           a transfer period >= 200ns - otherwise the chip will violate
 *           the SCSI timings.
 */
static void fas216_set_sync(FAS216_Info *info, int target)
{
      unsigned int cntl3;

      fas216_writeb(info, REG_SOF, info->device[target].sof);
      fas216_writeb(info, REG_STP, info->device[target].stp);

      cntl3 = info->scsi.cfg[2];
      if (info->device[target].period >= (200 / 4))
            cntl3 = cntl3 & ~CNTL3_FASTSCSI;

      fas216_writeb(info, REG_CNTL3, cntl3);
}

/* Synchronous transfer support
 *
 * Note: The SCSI II r10 spec says (5.6.12):
 *
 *  (2)  Due to historical problems with early host adapters that could
 *  not accept an SDTR message, some targets may not initiate synchronous
 *  negotiation after a power cycle as required by this standard.  Host
 *  adapters that support synchronous mode may avoid the ensuing failure
 *  modes when the target is independently power cycled by initiating a
 *  synchronous negotiation on each REQUEST SENSE and INQUIRY command.
 *  This approach increases the SCSI bus overhead and is not recommended
 *  for new implementations.  The correct method is to respond to an
 *  SDTR message with a MESSAGE REJECT message if the either the
 *  initiator or target devices does not support synchronous transfers
 *  or does not want to negotiate for synchronous transfers at the time.
 *  Using the correct method assures compatibility with wide data
 *  transfers and future enhancements.
 *
 * We will always initiate a synchronous transfer negotiation request on
 * every INQUIRY or REQUEST SENSE message, unless the target itself has
 * at some point performed a synchronous transfer negotiation request, or
 * we have synchronous transfers disabled for this device.
 */

/**
 * fas216_handlesync - Handle a synchronous transfer message
 * @info: state structure for interface
 * @msg: message from target
 *
 * Handle a synchronous transfer message from the target
 */
static void fas216_handlesync(FAS216_Info *info, char *msg)
{
      struct fas216_device *dev = &info->device[info->SCpnt->device->id];
      enum { sync, async, none, reject } res = none;

#ifdef SCSI2_SYNC
      switch (msg[0]) {
      case MESSAGE_REJECT:
            /* Synchronous transfer request failed.
             * Note: SCSI II r10:
             *
             *  SCSI devices that are capable of synchronous
             *  data transfers shall not respond to an SDTR
             *  message with a MESSAGE REJECT message.
             *
             * Hence, if we get this condition, we disable
             * negotiation for this device.
             */
            if (dev->sync_state == neg_inprogress) {
                  dev->sync_state = neg_invalid;
                  res = async;
            }
            break;

      case EXTENDED_MESSAGE:
            switch (dev->sync_state) {
            /* We don't accept synchronous transfer requests.
             * Respond with a MESSAGE_REJECT to prevent a
             * synchronous transfer agreement from being reached.
             */
            case neg_invalid:
                  res = reject;
                  break;

            /* We were not negotiating a synchronous transfer,
             * but the device sent us a negotiation request.
             * Honour the request by sending back a SDTR
             * message containing our capability, limited by
             * the targets capability.
             */
            default:
                  fas216_cmd(info, CMD_SETATN);
                  if (msg[4] > info->ifcfg.sync_max_depth)
                        msg[4] = info->ifcfg.sync_max_depth;
                  if (msg[3] < 1000 / info->ifcfg.clockrate)
                        msg[3] = 1000 / info->ifcfg.clockrate;

                  msgqueue_flush(&info->scsi.msgs);
                  msgqueue_addmsg(&info->scsi.msgs, 5,
                              EXTENDED_MESSAGE, 3, EXTENDED_SDTR,
                              msg[3], msg[4]);
                  info->scsi.phase = PHASE_MSGOUT_EXPECT;

                  /* This is wrong.  The agreement is not in effect
                   * until this message is accepted by the device
                   */
                  dev->sync_state = neg_targcomplete;
                  res = sync;
                  break;

            /* We initiated the synchronous transfer negotiation,
             * and have successfully received a response from the
             * target.  The synchronous transfer agreement has been
             * reached.  Note: if the values returned are out of our
             * bounds, we must reject the message.
             */
            case neg_inprogress:
                  res = reject;
                  if (msg[4] <= info->ifcfg.sync_max_depth &&
                      msg[3] >= 1000 / info->ifcfg.clockrate) {
                        dev->sync_state = neg_complete;
                        res = sync;
                  }
                  break;
            }
      }
#else
      res = reject;
#endif

      switch (res) {
      case sync:
            dev->period = msg[3];
            dev->sof    = msg[4];
            dev->stp    = fas216_syncperiod(info, msg[3] * 4);
            fas216_set_sync(info, info->SCpnt->device->id);
            break;

      case reject:
            fas216_cmd(info, CMD_SETATN);
            msgqueue_flush(&info->scsi.msgs);
            msgqueue_addmsg(&info->scsi.msgs, 1, MESSAGE_REJECT);
            info->scsi.phase = PHASE_MSGOUT_EXPECT;

      case async:
            dev->period = info->ifcfg.asyncperiod / 4;
            dev->sof    = 0;
            dev->stp    = info->scsi.async_stp;
            fas216_set_sync(info, info->SCpnt->device->id);
            break;

      case none:
            break;
      }
}

/**
 * fas216_updateptrs - update data pointers after transfer suspended/paused
 * @info: interface's local pointer to update
 * @bytes_transferred: number of bytes transferred
 *
 * Update data pointers after transfer suspended/paused
 */
static void fas216_updateptrs(FAS216_Info *info, int bytes_transferred)
{
      struct scsi_pointer *SCp = &info->scsi.SCp;

      fas216_checkmagic(info);

      BUG_ON(bytes_transferred < 0);

      SCp->phase -= bytes_transferred;

      while (bytes_transferred != 0) {
            if (SCp->this_residual > bytes_transferred)
                  break;
            /*
             * We have used up this buffer.  Move on to the
             * next buffer.
             */
            bytes_transferred -= SCp->this_residual;
            if (!next_SCp(SCp) && bytes_transferred) {
                  printk(KERN_WARNING "scsi%d.%c: out of buffers\n",
                        info->host->host_no, '0' + info->SCpnt->device->id);
                  return;
            }
      }

      SCp->this_residual -= bytes_transferred;
      if (SCp->this_residual)
            SCp->ptr += bytes_transferred;
      else
            SCp->ptr = NULL;
}

/**
 * fas216_pio - transfer data off of/on to card using programmed IO
 * @info: interface to transfer data to/from
 * @direction: direction to transfer data (DMA_OUT/DMA_IN)
 *
 * Transfer data off of/on to card using programmed IO.
 * Notes: this is incredibly slow.
 */
static void fas216_pio(FAS216_Info *info, fasdmadir_t direction)
{
      struct scsi_pointer *SCp = &info->scsi.SCp;

      fas216_checkmagic(info);

      if (direction == DMA_OUT)
            fas216_writeb(info, REG_FF, get_next_SCp_byte(SCp));
      else
            put_next_SCp_byte(SCp, fas216_readb(info, REG_FF));

      if (SCp->this_residual == 0)
            next_SCp(SCp);
}

static void fas216_set_stc(FAS216_Info *info, unsigned int length)
{
      fas216_writeb(info, REG_STCL, length);
      fas216_writeb(info, REG_STCM, length >> 8);
      fas216_writeb(info, REG_STCH, length >> 16);
}

static unsigned int fas216_get_ctc(FAS216_Info *info)
{
      return fas216_readb(info, REG_CTCL) +
             (fas216_readb(info, REG_CTCM) << 8) +
             (fas216_readb(info, REG_CTCH) << 16);
}

/**
 * fas216_cleanuptransfer - clean up after a transfer has completed.
 * @info: interface to clean up
 *
 * Update the data pointers according to the number of bytes transferred
 * on the SCSI bus.
 */
static void fas216_cleanuptransfer(FAS216_Info *info)
{
      unsigned long total, residual, fifo;
      fasdmatype_t dmatype = info->dma.transfer_type;

      info->dma.transfer_type = fasdma_none;

      /*
       * PIO transfers do not need to be cleaned up.
       */
      if (dmatype == fasdma_pio || dmatype == fasdma_none)
            return;

      if (dmatype == fasdma_real_all)
            total = info->scsi.SCp.phase;
      else
            total = info->scsi.SCp.this_residual;

      residual = fas216_get_ctc(info);

      fifo = fas216_readb(info, REG_CFIS) & CFIS_CF;

      fas216_log(info, LOG_BUFFER, "cleaning up from previous "
               "transfer: length 0x%06x, residual 0x%x, fifo %d",
               total, residual, fifo);

      /*
       * If we were performing Data-Out, the transfer counter
       * counts down each time a byte is transferred by the
       * host to the FIFO.  This means we must include the
       * bytes left in the FIFO from the transfer counter.
       */
      if (info->scsi.phase == PHASE_DATAOUT)
            residual += fifo;

      fas216_updateptrs(info, total - residual);
}

/**
 * fas216_transfer - Perform a DMA/PIO transfer off of/on to card
 * @info: interface from which device disconnected from
 *
 * Start a DMA/PIO transfer off of/on to card
 */
static void fas216_transfer(FAS216_Info *info)
{
      fasdmadir_t direction;
      fasdmatype_t dmatype;

      fas216_log(info, LOG_BUFFER,
               "starttransfer: buffer %p length 0x%06x reqlen 0x%06x",
               info->scsi.SCp.ptr, info->scsi.SCp.this_residual,
               info->scsi.SCp.phase);

      if (!info->scsi.SCp.ptr) {
            fas216_log(info, LOG_ERROR, "null buffer passed to "
                     "fas216_starttransfer");
            print_SCp(&info->scsi.SCp, "SCp: ", "\n");
            print_SCp(&info->SCpnt->SCp, "Cmnd SCp: ", "\n");
            return;
      }

      /*
       * If we have a synchronous transfer agreement in effect, we must
       * use DMA mode.  If we are using asynchronous transfers, we may
       * use DMA mode or PIO mode.
       */
      if (info->device[info->SCpnt->device->id].sof)
            dmatype = fasdma_real_all;
      else
            dmatype = fasdma_pio;

      if (info->scsi.phase == PHASE_DATAOUT)
            direction = DMA_OUT;
      else
            direction = DMA_IN;

      if (info->dma.setup)
            dmatype = info->dma.setup(info->host, &info->scsi.SCp,
                                direction, dmatype);
      info->dma.transfer_type = dmatype;

      if (dmatype == fasdma_real_all)
            fas216_set_stc(info, info->scsi.SCp.phase);
      else
            fas216_set_stc(info, info->scsi.SCp.this_residual);

      switch (dmatype) {
      case fasdma_pio:
            fas216_log(info, LOG_BUFFER, "PIO transfer");
            fas216_writeb(info, REG_SOF, 0);
            fas216_writeb(info, REG_STP, info->scsi.async_stp);
            fas216_cmd(info, CMD_TRANSFERINFO);
            fas216_pio(info, direction);
            break;

      case fasdma_pseudo:
            fas216_log(info, LOG_BUFFER, "pseudo transfer");
            fas216_cmd(info, CMD_TRANSFERINFO | CMD_WITHDMA);
            info->dma.pseudo(info->host, &info->scsi.SCp,
                         direction, info->SCpnt->transfersize);
            break;

      case fasdma_real_block:
            fas216_log(info, LOG_BUFFER, "block dma transfer");
            fas216_cmd(info, CMD_TRANSFERINFO | CMD_WITHDMA);
            break;

      case fasdma_real_all:
            fas216_log(info, LOG_BUFFER, "total dma transfer");
            fas216_cmd(info, CMD_TRANSFERINFO | CMD_WITHDMA);
            break;

      default:
            fas216_log(info, LOG_BUFFER | LOG_ERROR,
                     "invalid FAS216 DMA type");
            break;
      }
}

/**
 * fas216_stoptransfer - Stop a DMA transfer onto / off of the card
 * @info: interface from which device disconnected from
 *
 * Called when we switch away from DATA IN or DATA OUT phases.
 */
static void fas216_stoptransfer(FAS216_Info *info)
{
      fas216_checkmagic(info);

      if (info->dma.transfer_type == fasdma_real_all ||
          info->dma.transfer_type == fasdma_real_block)
            info->dma.stop(info->host, &info->scsi.SCp);

      fas216_cleanuptransfer(info);

      if (info->scsi.phase == PHASE_DATAIN) {
            unsigned int fifo;

            /*
             * If we were performing Data-In, then the FIFO counter
             * contains the number of bytes not transferred via DMA
             * from the on-board FIFO.  Read them manually.
             */
            fifo = fas216_readb(info, REG_CFIS) & CFIS_CF;
            while (fifo && info->scsi.SCp.ptr) {
                  *info->scsi.SCp.ptr = fas216_readb(info, REG_FF);
                  fas216_updateptrs(info, 1);
                  fifo--;
            }
      } else {
            /*
             * After a Data-Out phase, there may be unsent
             * bytes left in the FIFO.  Flush them out.
             */
            fas216_cmd(info, CMD_FLUSHFIFO);
      }
}

static void fas216_aborttransfer(FAS216_Info *info)
{
      fas216_checkmagic(info);

      if (info->dma.transfer_type == fasdma_real_all ||
          info->dma.transfer_type == fasdma_real_block)
            info->dma.stop(info->host, &info->scsi.SCp);

      info->dma.transfer_type = fasdma_none;
      fas216_cmd(info, CMD_FLUSHFIFO);
}

static void fas216_kick(FAS216_Info *info);

/**
 * fas216_disconnected_intr - handle device disconnection
 * @info: interface from which device disconnected from
 *
 * Handle device disconnection
 */
static void fas216_disconnect_intr(FAS216_Info *info)
{
      unsigned long flags;

      fas216_checkmagic(info);

      fas216_log(info, LOG_CONNECT, "disconnect phase=%02x",
               info->scsi.phase);

      msgqueue_flush(&info->scsi.msgs);

      switch (info->scsi.phase) {
      case PHASE_SELECTION:               /* while selecting - no target            */
      case PHASE_SELSTEPS:
            fas216_done(info, DID_NO_CONNECT);
            break;

      case PHASE_MSGIN_DISCONNECT:        /* message in - disconnecting       */
            info->scsi.disconnectable = 1;
            info->scsi.phase = PHASE_IDLE;
            info->stats.disconnects += 1;
            spin_lock_irqsave(&info->host_lock, flags);
            if (info->scsi.phase == PHASE_IDLE)
                  fas216_kick(info);
            spin_unlock_irqrestore(&info->host_lock, flags);
            break;

      case PHASE_DONE:              /* at end of command - complete           */
            fas216_done(info, DID_OK);
            break;

      case PHASE_MSGOUT:                  /* message out - possible ABORT message   */
            if (fas216_get_last_msg(info, info->scsi.msgin_fifo) == ABORT) {
                  info->scsi.aborting = 0;
                  fas216_done(info, DID_ABORT);
                  break;
            }

      default:                      /* huh?                             */
            printk(KERN_ERR "scsi%d.%c: unexpected disconnect in phase %s\n",
                  info->host->host_no, fas216_target(info), fas216_drv_phase(info));
            print_debug_list();
            fas216_stoptransfer(info);
            fas216_done(info, DID_ERROR);
            break;
      }
}

/**
 * fas216_reselected_intr - start reconnection of a device
 * @info: interface which was reselected
 *
 * Start reconnection of a device
 */
static void
fas216_reselected_intr(FAS216_Info *info)
{
      unsigned int cfis, i;
      unsigned char msg[4];
      unsigned char target, lun, tag;

      fas216_checkmagic(info);

      WARN_ON(info->scsi.phase == PHASE_SELECTION ||
            info->scsi.phase == PHASE_SELSTEPS);

      cfis = fas216_readb(info, REG_CFIS);

      fas216_log(info, LOG_CONNECT, "reconnect phase=%02x cfis=%02x",
               info->scsi.phase, cfis);

      cfis &= CFIS_CF;

      if (cfis < 2 || cfis > 4) {
            printk(KERN_ERR "scsi%d.H: incorrect number of bytes after reselect\n",
                  info->host->host_no);
            goto bad_message;
      }

      for (i = 0; i < cfis; i++)
            msg[i] = fas216_readb(info, REG_FF);

      if (!(msg[0] & (1 << info->host->this_id)) ||
          !(msg[1] & 0x80))
            goto initiator_error;

      target = msg[0] & ~(1 << info->host->this_id);
      target = ffs(target) - 1;
      lun = msg[1] & 7;
      tag = 0;

      if (cfis >= 3) {
            if (msg[2] != SIMPLE_QUEUE_TAG)
                  goto initiator_error;

            tag = msg[3];
      }

      /* set up for synchronous transfers */
      fas216_writeb(info, REG_SDID, target);
      fas216_set_sync(info, target);
      msgqueue_flush(&info->scsi.msgs);

      fas216_log(info, LOG_CONNECT, "Reconnected: target %1x lun %1x tag %02x",
               target, lun, tag);

      if (info->scsi.disconnectable && info->SCpnt) {
            info->scsi.disconnectable = 0;
            if (info->SCpnt->device->id  == target &&
                info->SCpnt->device->lun == lun &&
                info->SCpnt->tag         == tag) {
                  fas216_log(info, LOG_CONNECT, "reconnected previously executing command");
            } else {
                  queue_add_cmd_tail(&info->queues.disconnected, info->SCpnt);
                  fas216_log(info, LOG_CONNECT, "had to move command to disconnected queue");
                  info->SCpnt = NULL;
            }
      }
      if (!info->SCpnt) {
            info->SCpnt = queue_remove_tgtluntag(&info->queues.disconnected,
                              target, lun, tag);
            fas216_log(info, LOG_CONNECT, "had to get command");
      }

      if (info->SCpnt) {
            /*
             * Restore data pointer from SAVED data pointer
             */
            info->scsi.SCp = info->SCpnt->SCp;

            fas216_log(info, LOG_CONNECT, "data pointers: [%p, %X]",
                  info->scsi.SCp.ptr, info->scsi.SCp.this_residual);
            info->scsi.phase = PHASE_MSGIN;
      } else {
            /*
             * Our command structure not found - abort the
             * command on the target.  Since we have no
             * record of this command, we can't send
             * an INITIATOR DETECTED ERROR message.
             */
            fas216_cmd(info, CMD_SETATN);

#if 0
            if (tag)
                  msgqueue_addmsg(&info->scsi.msgs, 2, ABORT_TAG, tag);
            else
#endif
                  msgqueue_addmsg(&info->scsi.msgs, 1, ABORT);
            info->scsi.phase = PHASE_MSGOUT_EXPECT;
            info->scsi.aborting = 1;
      }

      fas216_cmd(info, CMD_MSGACCEPTED);
      return;

 initiator_error:
      printk(KERN_ERR "scsi%d.H: error during reselection: bytes",
            info->host->host_no);
      for (i = 0; i < cfis; i++)
            printk(" %02x", msg[i]);
      printk("\n");
 bad_message:
      fas216_cmd(info, CMD_SETATN);
      msgqueue_flush(&info->scsi.msgs);
      msgqueue_addmsg(&info->scsi.msgs, 1, INITIATOR_ERROR);
      info->scsi.phase = PHASE_MSGOUT_EXPECT;
      fas216_cmd(info, CMD_MSGACCEPTED);
}

static void fas216_parse_message(FAS216_Info *info, unsigned char *message, int msglen)
{
      int i;

      switch (message[0]) {
      case COMMAND_COMPLETE:
            if (msglen != 1)
                  goto unrecognised;

            printk(KERN_ERR "scsi%d.%c: command complete with no "
                  "status in MESSAGE_IN?\n",
                  info->host->host_no, fas216_target(info));
            break;

      case SAVE_POINTERS:
            if (msglen != 1)
                  goto unrecognised;

            /*
             * Save current data pointer to SAVED data pointer
             * SCSI II standard says that we must not acknowledge
             * this until we have really saved pointers.
             * NOTE: we DO NOT save the command nor status pointers
             * as required by the SCSI II standard.  These always
             * point to the start of their respective areas.
             */
            info->SCpnt->SCp = info->scsi.SCp;
            info->SCpnt->SCp.sent_command = 0;
            fas216_log(info, LOG_CONNECT | LOG_MESSAGES | LOG_BUFFER,
                  "save data pointers: [%p, %X]",
                  info->scsi.SCp.ptr, info->scsi.SCp.this_residual);
            break;

      case RESTORE_POINTERS:
            if (msglen != 1)
                  goto unrecognised;

            /*
             * Restore current data pointer from SAVED data pointer
             */
            info->scsi.SCp = info->SCpnt->SCp;
            fas216_log(info, LOG_CONNECT | LOG_MESSAGES | LOG_BUFFER,
                  "restore data pointers: [%p, 0x%x]",
                  info->scsi.SCp.ptr, info->scsi.SCp.this_residual);
            break;

      case DISCONNECT:
            if (msglen != 1)
                  goto unrecognised;

            info->scsi.phase = PHASE_MSGIN_DISCONNECT;
            break;

      case MESSAGE_REJECT:
            if (msglen != 1)
                  goto unrecognised;

            switch (fas216_get_last_msg(info, info->scsi.msgin_fifo)) {
            case EXTENDED_MESSAGE | EXTENDED_SDTR << 8:
                  fas216_handlesync(info, message);
                  break;

            default:
                  fas216_log(info, 0, "reject, last message 0x%04x",
                        fas216_get_last_msg(info, info->scsi.msgin_fifo));
            }
            break;

      case NOP:
            break;

      case EXTENDED_MESSAGE:
            if (msglen < 3)
                  goto unrecognised;

            switch (message[2]) {
            case EXTENDED_SDTR:     /* Sync transfer negotiation request/reply */
                  fas216_handlesync(info, message);
                  break;

            default:
                  goto unrecognised;
            }
            break;

      default:
            goto unrecognised;
      }
      return;

unrecognised:
      fas216_log(info, 0, "unrecognised message, rejecting");
      printk("scsi%d.%c: message was", info->host->host_no, fas216_target(info));
      for (i = 0; i < msglen; i++)
            printk("%s%02X", i & 31 ? " " : "\n  ", message[i]);
      printk("\n");

      /*
       * Something strange seems to be happening here -
       * I can't use SETATN since the chip gives me an
       * invalid command interrupt when I do.  Weird.
       */
fas216_cmd(info, CMD_NOP);
fas216_dumpstate(info);
      fas216_cmd(info, CMD_SETATN);
      msgqueue_flush(&info->scsi.msgs);
      msgqueue_addmsg(&info->scsi.msgs, 1, MESSAGE_REJECT);
      info->scsi.phase = PHASE_MSGOUT_EXPECT;
fas216_dumpstate(info);
}

static int fas216_wait_cmd(FAS216_Info *info, int cmd)
{
      int tout;
      int stat;

      fas216_cmd(info, cmd);

      for (tout = 1000; tout; tout -= 1) {
            stat = fas216_readb(info, REG_STAT);
            if (stat & (STAT_INT|STAT_PARITYERROR))
                  break;
            udelay(1);
      }

      return stat;
}

static int fas216_get_msg_byte(FAS216_Info *info)
{
      unsigned int stat = fas216_wait_cmd(info, CMD_MSGACCEPTED);

      if ((stat & STAT_INT) == 0)
            goto timedout;

      if ((stat & STAT_BUSMASK) != STAT_MESGIN)
            goto unexpected_phase_change;

      fas216_readb(info, REG_INST);

      stat = fas216_wait_cmd(info, CMD_TRANSFERINFO);

      if ((stat & STAT_INT) == 0)
            goto timedout;

      if (stat & STAT_PARITYERROR)
            goto parity_error;

      if ((stat & STAT_BUSMASK) != STAT_MESGIN)
            goto unexpected_phase_change;

      fas216_readb(info, REG_INST);

      return fas216_readb(info, REG_FF);

timedout:
      fas216_log(info, LOG_ERROR, "timed out waiting for message byte");
      return -1;

unexpected_phase_change:
      fas216_log(info, LOG_ERROR, "unexpected phase change: status = %02x", stat);
      return -2;

parity_error:
      fas216_log(info, LOG_ERROR, "parity error during message in phase");
      return -3;
}

/**
 * fas216_message - handle a function done interrupt from FAS216 chip
 * @info: interface which caused function done interrupt
 *
 * Handle a function done interrupt from FAS216 chip
 */
static void fas216_message(FAS216_Info *info)
{
      unsigned char *message = info->scsi.message;
      unsigned int msglen = 1;
      int msgbyte = 0;

      fas216_checkmagic(info);

      message[0] = fas216_readb(info, REG_FF);

      if (message[0] == EXTENDED_MESSAGE) {
            msgbyte = fas216_get_msg_byte(info);

            if (msgbyte >= 0) {
                  message[1] = msgbyte;

                  for (msglen = 2; msglen < message[1] + 2; msglen++) {
                        msgbyte = fas216_get_msg_byte(info);

                        if (msgbyte >= 0)
                              message[msglen] = msgbyte;
                        else
                              break;
                  }
            }
      }

      if (msgbyte == -3)
            goto parity_error;

#ifdef DEBUG_MESSAGES
      {
            int i;

            printk("scsi%d.%c: message in: ",
                  info->host->host_no, fas216_target(info));
            for (i = 0; i < msglen; i++)
                  printk("%02X ", message[i]);
            printk("\n");
      }
#endif

      fas216_parse_message(info, message, msglen);
      fas216_cmd(info, CMD_MSGACCEPTED);
      return;

parity_error:
      fas216_cmd(info, CMD_SETATN);
      msgqueue_flush(&info->scsi.msgs);
      msgqueue_addmsg(&info->scsi.msgs, 1, MSG_PARITY_ERROR);
      info->scsi.phase = PHASE_MSGOUT_EXPECT;
      fas216_cmd(info, CMD_MSGACCEPTED);
      return;
}

/**
 * fas216_send_command - send command after all message bytes have been sent
 * @info: interface which caused bus service
 *
 * Send a command to a target after all message bytes have been sent
 */
static void fas216_send_command(FAS216_Info *info)
{
      int i;

      fas216_checkmagic(info);

      fas216_cmd(info, CMD_NOP|CMD_WITHDMA);
      fas216_cmd(info, CMD_FLUSHFIFO);

      /* load command */
      for (i = info->scsi.SCp.sent_command; i < info->SCpnt->cmd_len; i++)
            fas216_writeb(info, REG_FF, info->SCpnt->cmnd[i]);

      fas216_cmd(info, CMD_TRANSFERINFO);

      info->scsi.phase = PHASE_COMMAND;
}

/**
 * fas216_send_messageout - handle bus service to send a message
 * @info: interface which caused bus service
 *
 * Handle bus service to send a message.
 * Note: We do not allow the device to change the data direction!
 */
static void fas216_send_messageout(FAS216_Info *info, int start)
{
      unsigned int tot_msglen = msgqueue_msglength(&info->scsi.msgs);

      fas216_checkmagic(info);

      fas216_cmd(info, CMD_FLUSHFIFO);

      if (tot_msglen) {
            struct message *msg;
            int msgnr = 0;

            while ((msg = msgqueue_getmsg(&info->scsi.msgs, msgnr++)) != NULL) {
                  int i;

                  for (i = start; i < msg->length; i++)
                        fas216_writeb(info, REG_FF, msg->msg[i]);

                  msg->fifo = tot_msglen - (fas216_readb(info, REG_CFIS) & CFIS_CF);
                  start = 0;
            }
      } else
            fas216_writeb(info, REG_FF, NOP);

      fas216_cmd(info, CMD_TRANSFERINFO);

      info->scsi.phase = PHASE_MSGOUT;
}

/**
 * fas216_busservice_intr - handle bus service interrupt from FAS216 chip
 * @info: interface which caused bus service interrupt
 * @stat: Status register contents
 * @is: SCSI Status register contents
 *
 * Handle a bus service interrupt from FAS216 chip
 */
static void fas216_busservice_intr(FAS216_Info *info, unsigned int stat, unsigned int is)
{
      fas216_checkmagic(info);

      fas216_log(info, LOG_BUSSERVICE,
               "bus service: stat=%02x is=%02x phase=%02x",
               stat, is, info->scsi.phase);

      switch (info->scsi.phase) {
      case PHASE_SELECTION:
            if ((is & IS_BITS) != IS_MSGBYTESENT)
                  goto bad_is;
            break;

      case PHASE_SELSTEPS:
            switch (is & IS_BITS) {
            case IS_SELARB:
            case IS_MSGBYTESENT:
                  goto bad_is;

            case IS_NOTCOMMAND:
            case IS_EARLYPHASE:
                  if ((stat & STAT_BUSMASK) == STAT_MESGIN)
                        break;
                  goto bad_is;

            case IS_COMPLETE:
                  break;
            }

      default:
            break;
      }

      fas216_cmd(info, CMD_NOP);

#define STATE(st,ph) ((ph) << 3 | (st))
      /* This table describes the legal SCSI state transitions,
       * as described by the SCSI II spec.
       */
      switch (STATE(stat & STAT_BUSMASK, info->scsi.phase)) {
      case STATE(STAT_DATAIN, PHASE_SELSTEPS):/* Sel w/ steps -> Data In      */
      case STATE(STAT_DATAIN, PHASE_MSGOUT):  /* Message Out  -> Data In      */
      case STATE(STAT_DATAIN, PHASE_COMMAND): /* Command      -> Data In      */
      case STATE(STAT_DATAIN, PHASE_MSGIN):   /* Message In   -> Data In      */
            info->scsi.phase = PHASE_DATAIN;
            fas216_transfer(info);
            return;

      case STATE(STAT_DATAIN, PHASE_DATAIN):  /* Data In      -> Data In      */
      case STATE(STAT_DATAOUT, PHASE_DATAOUT):/* Data Out     -> Data Out     */
            fas216_cleanuptransfer(info);
            fas216_transfer(info);
            return;

      case STATE(STAT_DATAOUT, PHASE_SELSTEPS):/* Sel w/ steps-> Data Out     */
      case STATE(STAT_DATAOUT, PHASE_MSGOUT): /* Message Out  -> Data Out     */
      case STATE(STAT_DATAOUT, PHASE_COMMAND):/* Command      -> Data Out     */
      case STATE(STAT_DATAOUT, PHASE_MSGIN):  /* Message In   -> Data Out     */
            fas216_cmd(info, CMD_FLUSHFIFO);
            info->scsi.phase = PHASE_DATAOUT;
            fas216_transfer(info);
            return;

      case STATE(STAT_STATUS, PHASE_DATAOUT): /* Data Out     -> Status       */
      case STATE(STAT_STATUS, PHASE_DATAIN):  /* Data In      -> Status       */
            fas216_stoptransfer(info);
      case STATE(STAT_STATUS, PHASE_SELSTEPS):/* Sel w/ steps -> Status       */
      case STATE(STAT_STATUS, PHASE_MSGOUT):  /* Message Out  -> Status       */
      case STATE(STAT_STATUS, PHASE_COMMAND): /* Command      -> Status       */
      case STATE(STAT_STATUS, PHASE_MSGIN):   /* Message In   -> Status       */
            fas216_cmd(info, CMD_INITCMDCOMPLETE);
            info->scsi.phase = PHASE_STATUS;
            return;

      case STATE(STAT_MESGIN, PHASE_DATAOUT): /* Data Out     -> Message In   */
      case STATE(STAT_MESGIN, PHASE_DATAIN):  /* Data In      -> Message In   */
            fas216_stoptransfer(info);
      case STATE(STAT_MESGIN, PHASE_COMMAND):   /* Command  -> Message In     */
      case STATE(STAT_MESGIN, PHASE_SELSTEPS):/* Sel w/ steps -> Message In   */
      case STATE(STAT_MESGIN, PHASE_MSGOUT):  /* Message Out  -> Message In   */
            info->scsi.msgin_fifo = fas216_readb(info, REG_CFIS) & CFIS_CF;
            fas216_cmd(info, CMD_FLUSHFIFO);
            fas216_cmd(info, CMD_TRANSFERINFO);
            info->scsi.phase = PHASE_MSGIN;
            return;

      case STATE(STAT_MESGIN, PHASE_MSGIN):
            info->scsi.msgin_fifo = fas216_readb(info, REG_CFIS) & CFIS_CF;
            fas216_cmd(info, CMD_TRANSFERINFO);
            return;

      case STATE(STAT_COMMAND, PHASE_MSGOUT): /* Message Out  -> Command      */
      case STATE(STAT_COMMAND, PHASE_MSGIN):  /* Message In   -> Command      */
            fas216_send_command(info);
            info->scsi.phase = PHASE_COMMAND;
            return;


      /*
       * Selection    -> Message Out
       */
      case STATE(STAT_MESGOUT, PHASE_SELECTION):
            fas216_send_messageout(info, 1);
            return;

      /*
       * Message Out  -> Message Out
       */
      case STATE(STAT_MESGOUT, PHASE_SELSTEPS):
      case STATE(STAT_MESGOUT, PHASE_MSGOUT):
            /*
             * If we get another message out phase, this usually
             * means some parity error occurred.  Resend complete
             * set of messages.  If we have more than one byte to
             * send, we need to assert ATN again.
             */
            if (info->device[info->SCpnt->device->id].parity_check) {
                  /*
                   * We were testing... good, the device
                   * supports parity checking.
                   */
                  info->device[info->SCpnt->device->id].parity_check = 0;
                  info->device[info->SCpnt->device->id].parity_enabled = 1;
                  fas216_writeb(info, REG_CNTL1, info->scsi.cfg[0]);
            }

            if (msgqueue_msglength(&info->scsi.msgs) > 1)
                  fas216_cmd(info, CMD_SETATN);
            /*FALLTHROUGH*/

      /*
       * Any          -> Message Out
       */
      case STATE(STAT_MESGOUT, PHASE_MSGOUT_EXPECT):
            fas216_send_messageout(info, 0);
            return;

      /* Error recovery rules.
       *   These either attempt to abort or retry the operation.
       * TODO: we need more of these
       */
      case STATE(STAT_COMMAND, PHASE_COMMAND):/* Command      -> Command      */
            /* error - we've sent out all the command bytes
             * we have.
             * NOTE: we need SAVE DATA POINTERS/RESTORE DATA POINTERS
             * to include the command bytes sent for this to work
             * correctly.
             */
            printk(KERN_ERR "scsi%d.%c: "
                  "target trying to receive more command bytes\n",
                  info->host->host_no, fas216_target(info));
            fas216_cmd(info, CMD_SETATN);
            fas216_set_stc(info, 15);
            fas216_cmd(info, CMD_PADBYTES | CMD_WITHDMA);
            msgqueue_flush(&info->scsi.msgs);
            msgqueue_addmsg(&info->scsi.msgs, 1, INITIATOR_ERROR);
            info->scsi.phase = PHASE_MSGOUT_EXPECT;
            return;
      }

      if (info->scsi.phase == PHASE_MSGIN_DISCONNECT) {
            printk(KERN_ERR "scsi%d.%c: disconnect message received, but bus service %s?\n",
                  info->host->host_no, fas216_target(info),
                  fas216_bus_phase(stat));
            msgqueue_flush(&info->scsi.msgs);
            fas216_cmd(info, CMD_SETATN);
            msgqueue_addmsg(&info->scsi.msgs, 1, INITIATOR_ERROR);
            info->scsi.phase = PHASE_MSGOUT_EXPECT;
            info->scsi.aborting = 1;
            fas216_cmd(info, CMD_TRANSFERINFO);
            return;
      }
      printk(KERN_ERR "scsi%d.%c: bus phase %s after %s?\n",
            info->host->host_no, fas216_target(info),
            fas216_bus_phase(stat),
            fas216_drv_phase(info));
      print_debug_list();
      return;

bad_is:
      fas216_log(info, 0, "bus service at step %d?", is & IS_BITS);
      fas216_dumpstate(info);
      print_debug_list();

      fas216_done(info, DID_ERROR);
}

/**
 * fas216_funcdone_intr - handle a function done interrupt from FAS216 chip
 * @info: interface which caused function done interrupt
 * @stat: Status register contents
 * @is: SCSI Status register contents
 *
 * Handle a function done interrupt from FAS216 chip
 */
static void fas216_funcdone_intr(FAS216_Info *info, unsigned int stat, unsigned int is)
{
      unsigned int fifo_len = fas216_readb(info, REG_CFIS) & CFIS_CF;

      fas216_checkmagic(info);

      fas216_log(info, LOG_FUNCTIONDONE,
               "function done: stat=%02x is=%02x phase=%02x",
               stat, is, info->scsi.phase);

      switch (info->scsi.phase) {
      case PHASE_STATUS:                  /* status phase - read status and msg     */
            if (fifo_len != 2) {
                  fas216_log(info, 0, "odd number of bytes in FIFO: %d", fifo_len);
            }
            /*
             * Read status then message byte.
             */
            info->scsi.SCp.Status = fas216_readb(info, REG_FF);
            info->scsi.SCp.Message = fas216_readb(info, REG_FF);
            info->scsi.phase = PHASE_DONE;
            fas216_cmd(info, CMD_MSGACCEPTED);
            break;

      case PHASE_IDLE:
      case PHASE_SELECTION:
      case PHASE_SELSTEPS:
            break;

      case PHASE_MSGIN:             /* message in phase                 */
            if ((stat & STAT_BUSMASK) == STAT_MESGIN) {
                  info->scsi.msgin_fifo = fifo_len;
                  fas216_message(info);
                  break;
            }

      default:
            fas216_log(info, 0, "internal phase %s for function done?"
                  "  What do I do with this?",
                  fas216_target(info), fas216_drv_phase(info));
      }
}

static void fas216_bus_reset(FAS216_Info *info)
{
      neg_t sync_state;
      int i;

      msgqueue_flush(&info->scsi.msgs);

      sync_state = neg_invalid;

#ifdef SCSI2_SYNC
      if (info->ifcfg.capabilities & (FASCAP_DMA|FASCAP_PSEUDODMA))
            sync_state = neg_wait;
#endif

      info->scsi.phase = PHASE_IDLE;
      info->SCpnt = NULL; /* bug! */
      memset(&info->scsi.SCp, 0, sizeof(info->scsi.SCp));

      for (i = 0; i < 8; i++) {
            info->device[i].disconnect_ok = info->ifcfg.disconnect_ok;
            info->device[i].sync_state    = sync_state;
            info->device[i].period        = info->ifcfg.asyncperiod / 4;
            info->device[i].stp           = info->scsi.async_stp;
            info->device[i].sof           = 0;
            info->device[i].wide_xfer     = 0;
      }

      info->rst_bus_status = 1;
      wake_up(&info->eh_wait);
}

/**
 * fas216_intr - handle interrupts to progress a command
 * @info: interface to service
 *
 * Handle interrupts from the interface to progress a command
 */
irqreturn_t fas216_intr(FAS216_Info *info)
{
      unsigned char inst, is, stat;
      int handled = IRQ_NONE;

      fas216_checkmagic(info);

      stat = fas216_readb(info, REG_STAT);
      is = fas216_readb(info, REG_IS);
      inst = fas216_readb(info, REG_INST);

      add_debug_list(stat, is, inst, info->scsi.phase);

      if (stat & STAT_INT) {
            if (inst & INST_BUSRESET) {
                  fas216_log(info, 0, "bus reset detected");
                  fas216_bus_reset(info);
                  scsi_report_bus_reset(info->host, 0);
            } else if (inst & INST_ILLEGALCMD) {
                  fas216_log(info, LOG_ERROR, "illegal command given\n");
                  fas216_dumpstate(info);
                  print_debug_list();
            } else if (inst & INST_DISCONNECT)
                  fas216_disconnect_intr(info);
            else if (inst & INST_RESELECTED)    /* reselected                 */
                  fas216_reselected_intr(info);
            else if (inst & INST_BUSSERVICE)    /* bus service request        */
                  fas216_busservice_intr(info, stat, is);
            else if (inst & INST_FUNCDONE)            /* function done        */
                  fas216_funcdone_intr(info, stat, is);
            else
                  fas216_log(info, 0, "unknown interrupt received:"
                        " phase %s inst %02X is %02X stat %02X",
                        fas216_drv_phase(info), inst, is, stat);
            handled = IRQ_HANDLED;
      }
      return handled;
}

static void __fas216_start_command(FAS216_Info *info, struct scsi_cmnd *SCpnt)
{
      int tot_msglen;

      /* following what the ESP driver says */
      fas216_set_stc(info, 0);
      fas216_cmd(info, CMD_NOP | CMD_WITHDMA);

      /* flush FIFO */
      fas216_cmd(info, CMD_FLUSHFIFO);

      /* load bus-id and timeout */
      fas216_writeb(info, REG_SDID, BUSID(SCpnt->device->id));
      fas216_writeb(info, REG_STIM, info->ifcfg.select_timeout);

      /* synchronous transfers */
      fas216_set_sync(info, SCpnt->device->id);

      tot_msglen = msgqueue_msglength(&info->scsi.msgs);

#ifdef DEBUG_MESSAGES
      {
            struct message *msg;
            int msgnr = 0, i;

            printk("scsi%d.%c: message out: ",
                  info->host->host_no, '0' + SCpnt->device->id);
            while ((msg = msgqueue_getmsg(&info->scsi.msgs, msgnr++)) != NULL) {
                  printk("{ ");
                  for (i = 0; i < msg->length; i++)
                        printk("%02x ", msg->msg[i]);
                  printk("} ");
            }
            printk("\n");
      }
#endif

      if (tot_msglen == 1 || tot_msglen == 3) {
            /*
             * We have an easy message length to send...
             */
            struct message *msg;
            int msgnr = 0, i;

            info->scsi.phase = PHASE_SELSTEPS;

            /* load message bytes */
            while ((msg = msgqueue_getmsg(&info->scsi.msgs, msgnr++)) != NULL) {
                  for (i = 0; i < msg->length; i++)
                        fas216_writeb(info, REG_FF, msg->msg[i]);
                  msg->fifo = tot_msglen - (fas216_readb(info, REG_CFIS) & CFIS_CF);
            }

            /* load command */
            for (i = 0; i < SCpnt->cmd_len; i++)
                  fas216_writeb(info, REG_FF, SCpnt->cmnd[i]);

            if (tot_msglen == 1)
                  fas216_cmd(info, CMD_SELECTATN);
            else
                  fas216_cmd(info, CMD_SELECTATN3);
      } else {
            /*
             * We have an unusual number of message bytes to send.
             *  Load first byte into fifo, and issue SELECT with ATN and
             *  stop steps.
             */
            struct message *msg = msgqueue_getmsg(&info->scsi.msgs, 0);

            fas216_writeb(info, REG_FF, msg->msg[0]);
            msg->fifo = 1;

            fas216_cmd(info, CMD_SELECTATNSTOP);
      }
}

/*
 * Decide whether we need to perform a parity test on this device.
 * Can also be used to force parity error conditions during initial
 * information transfer phase (message out) for test purposes.
 */
static int parity_test(FAS216_Info *info, int target)
{
#if 0
      if (target == 3) {
            info->device[target].parity_check = 0;
            return 1;
      }
#endif
      return info->device[target].parity_check;
}

static void fas216_start_command(FAS216_Info *info, struct scsi_cmnd *SCpnt)
{
      int disconnect_ok;

      /*
       * claim host busy
       */
      info->scsi.phase = PHASE_SELECTION;
      info->scsi.SCp = SCpnt->SCp;
      info->SCpnt = SCpnt;
      info->dma.transfer_type = fasdma_none;

      if (parity_test(info, SCpnt->device->id))
            fas216_writeb(info, REG_CNTL1, info->scsi.cfg[0] | CNTL1_PTE);
      else
            fas216_writeb(info, REG_CNTL1, info->scsi.cfg[0]);

      /*
       * Don't allow request sense commands to disconnect.
       */
      disconnect_ok = SCpnt->cmnd[0] != REQUEST_SENSE &&
                  info->device[SCpnt->device->id].disconnect_ok;

      /*
       * build outgoing message bytes
       */
      msgqueue_flush(&info->scsi.msgs);
      msgqueue_addmsg(&info->scsi.msgs, 1, IDENTIFY(disconnect_ok, SCpnt->device->lun));

      /*
       * add tag message if required
       */
      if (SCpnt->tag)
            msgqueue_addmsg(&info->scsi.msgs, 2, SIMPLE_QUEUE_TAG, SCpnt->tag);

      do {
#ifdef SCSI2_SYNC
            if ((info->device[SCpnt->device->id].sync_state == neg_wait ||
                 info->device[SCpnt->device->id].sync_state == neg_complete) &&
                (SCpnt->cmnd[0] == REQUEST_SENSE ||
                 SCpnt->cmnd[0] == INQUIRY)) {
                  info->device[SCpnt->device->id].sync_state = neg_inprogress;
                  msgqueue_addmsg(&info->scsi.msgs, 5,
                              EXTENDED_MESSAGE, 3, EXTENDED_SDTR,
                              1000 / info->ifcfg.clockrate,
                              info->ifcfg.sync_max_depth);
                  break;
            }
#endif
      } while (0);

      __fas216_start_command(info, SCpnt);
}

static void fas216_allocate_tag(FAS216_Info *info, struct scsi_cmnd *SCpnt)
{
#ifdef SCSI2_TAG
      /*
       * tagged queuing - allocate a new tag to this command
       */
      if (SCpnt->device->simple_tags && SCpnt->cmnd[0] != REQUEST_SENSE &&
          SCpnt->cmnd[0] != INQUIRY) {
          SCpnt->device->current_tag += 1;
            if (SCpnt->device->current_tag == 0)
                SCpnt->device->current_tag = 1;
                  SCpnt->tag = SCpnt->device->current_tag;
      } else
#endif
            set_bit(SCpnt->device->id * 8 + SCpnt->device->lun, info->busyluns);

      info->stats.removes += 1;
      switch (SCpnt->cmnd[0]) {
      case WRITE_6:
      case WRITE_10:
      case WRITE_12:
            info->stats.writes += 1;
            break;
      case READ_6:
      case READ_10:
      case READ_12:
            info->stats.reads += 1;
            break;
      default:
            info->stats.miscs += 1;
            break;
      }
}

static void fas216_do_bus_device_reset(FAS216_Info *info,
                               struct scsi_cmnd *SCpnt)
{
      struct message *msg;

      /*
       * claim host busy
       */
      info->scsi.phase = PHASE_SELECTION;
      info->scsi.SCp = SCpnt->SCp;
      info->SCpnt = SCpnt;
      info->dma.transfer_type = fasdma_none;

      fas216_log(info, LOG_ERROR, "sending bus device reset");

      msgqueue_flush(&info->scsi.msgs);
      msgqueue_addmsg(&info->scsi.msgs, 1, BUS_DEVICE_RESET);

      /* following what the ESP driver says */
      fas216_set_stc(info, 0);
      fas216_cmd(info, CMD_NOP | CMD_WITHDMA);

      /* flush FIFO */
      fas216_cmd(info, CMD_FLUSHFIFO);

      /* load bus-id and timeout */
      fas216_writeb(info, REG_SDID, BUSID(SCpnt->device->id));
      fas216_writeb(info, REG_STIM, info->ifcfg.select_timeout);

      /* synchronous transfers */
      fas216_set_sync(info, SCpnt->device->id);

      msg = msgqueue_getmsg(&info->scsi.msgs, 0);

      fas216_writeb(info, REG_FF, BUS_DEVICE_RESET);
      msg->fifo = 1;

      fas216_cmd(info, CMD_SELECTATNSTOP);
}

/**
 * fas216_kick - kick a command to the interface
 * @info: our host interface to kick
 *
 * Kick a command to the interface, interface should be idle.
 * Notes: Interrupts are always disabled!
 */
static void fas216_kick(FAS216_Info *info)
{
      struct scsi_cmnd *SCpnt = NULL;
#define TYPE_OTHER      0
#define TYPE_RESET      1
#define TYPE_QUEUE      2
      int where_from = TYPE_OTHER;

      fas216_checkmagic(info);

      /*
       * Obtain the next command to process.
       */
      do {
            if (info->rstSCpnt) {
                  SCpnt = info->rstSCpnt;
                  /* don't remove it */
                  where_from = TYPE_RESET;
                  break;
            }

            if (info->reqSCpnt) {
                  SCpnt = info->reqSCpnt;
                  info->reqSCpnt = NULL;
                  break;
            }

            if (info->origSCpnt) {
                  SCpnt = info->origSCpnt;
                  info->origSCpnt = NULL;
                  break;
            }

            /* retrieve next command */
            if (!SCpnt) {
                  SCpnt = queue_remove_exclude(&info->queues.issue,
                                         info->busyluns);
                  where_from = TYPE_QUEUE;
                  break;
            }
      } while (0);

      if (!SCpnt) {
            /*
             * no command pending, so enable reselection.
             */
            fas216_cmd(info, CMD_ENABLESEL);
            return;
      }

      /*
       * We're going to start a command, so disable reselection
       */
      fas216_cmd(info, CMD_DISABLESEL);

      if (info->scsi.disconnectable && info->SCpnt) {
            fas216_log(info, LOG_CONNECT,
                  "moved command for %d to disconnected queue",
                  info->SCpnt->device->id);
            queue_add_cmd_tail(&info->queues.disconnected, info->SCpnt);
            info->scsi.disconnectable = 0;
            info->SCpnt = NULL;
      }

      fas216_log_command(info, LOG_CONNECT | LOG_MESSAGES, SCpnt,
                     "starting");

      switch (where_from) {
      case TYPE_QUEUE:
            fas216_allocate_tag(info, SCpnt);
      case TYPE_OTHER:
            fas216_start_command(info, SCpnt);
            break;
      case TYPE_RESET:
            fas216_do_bus_device_reset(info, SCpnt);
            break;
      }

      fas216_log(info, LOG_CONNECT, "select: data pointers [%p, %X]",
            info->scsi.SCp.ptr, info->scsi.SCp.this_residual);

      /*
       * should now get either DISCONNECT or
       * (FUNCTION DONE with BUS SERVICE) interrupt
       */
}

/*
 * Clean up from issuing a BUS DEVICE RESET message to a device.
 */
static void fas216_devicereset_done(FAS216_Info *info, struct scsi_cmnd *SCpnt,
                            unsigned int result)
{
      fas216_log(info, LOG_ERROR, "fas216 device reset complete");

      info->rstSCpnt = NULL;
      info->rst_dev_status = 1;
      wake_up(&info->eh_wait);
}

/**
 * fas216_rq_sns_done - Finish processing automatic request sense command
 * @info: interface that completed
 * @SCpnt: command that completed
 * @result: driver byte of result
 *
 * Finish processing automatic request sense command
 */
static void fas216_rq_sns_done(FAS216_Info *info, struct scsi_cmnd *SCpnt,
                         unsigned int result)
{
      fas216_log_target(info, LOG_CONNECT, SCpnt->device->id,
               "request sense complete, result=0x%04x%02x%02x",
               result, SCpnt->SCp.Message, SCpnt->SCp.Status);

      if (result != DID_OK || SCpnt->SCp.Status != GOOD)
            /*
             * Something went wrong.  Make sure that we don't
             * have valid data in the sense buffer that could
             * confuse the higher levels.
             */
            memset(SCpnt->sense_buffer, 0, sizeof(SCpnt->sense_buffer));
//printk("scsi%d.%c: sense buffer: ", info->host->host_no, '0' + SCpnt->device->id);
//{ int i; for (i = 0; i < 32; i++) printk("%02x ", SCpnt->sense_buffer[i]); printk("\n"); }
      /*
       * Note that we don't set SCpnt->result, since that should
       * reflect the status of the command that we were asked by
       * the upper layers to process.  This would have been set
       * correctly by fas216_std_done.
       */
      scsi_eh_restore_cmnd(SCpnt, &info->ses);
      SCpnt->scsi_done(SCpnt);
}

/**
 * fas216_std_done - finish processing of standard command
 * @info: interface that completed
 * @SCpnt: command that completed
 * @result: driver byte of result
 *
 * Finish processing of standard command
 */
static void
fas216_std_done(FAS216_Info *info, struct scsi_cmnd *SCpnt, unsigned int result)
{
      info->stats.fins += 1;

      SCpnt->result = result << 16 | info->scsi.SCp.Message << 8 |
                  info->scsi.SCp.Status;

      fas216_log_command(info, LOG_CONNECT, SCpnt,
            "command complete, result=0x%08x", SCpnt->result);

      /*
       * If the driver detected an error, we're all done.
       */
      if (host_byte(SCpnt->result) != DID_OK ||
          msg_byte(SCpnt->result) != COMMAND_COMPLETE)
            goto done;

      /*
       * If the command returned CHECK_CONDITION or COMMAND_TERMINATED
       * status, request the sense information.
       */
      if (status_byte(SCpnt->result) == CHECK_CONDITION ||
          status_byte(SCpnt->result) == COMMAND_TERMINATED)
            goto request_sense;

      /*
       * If the command did not complete with GOOD status,
       * we are all done here.
       */
      if (status_byte(SCpnt->result) != GOOD)
            goto done;

      /*
       * We have successfully completed a command.  Make sure that
       * we do not have any buffers left to transfer.  The world
       * is not perfect, and we seem to occasionally hit this.
       * It can be indicative of a buggy driver, target or the upper
       * levels of the SCSI code.
       */
      if (info->scsi.SCp.ptr) {
            switch (SCpnt->cmnd[0]) {
            case INQUIRY:
            case START_STOP:
            case MODE_SENSE:
                  break;

            default:
                  printk(KERN_ERR "scsi%d.%c: incomplete data transfer "
                        "detected: res=%08X ptr=%p len=%X CDB: ",
                        info->host->host_no, '0' + SCpnt->device->id,
                        SCpnt->result, info->scsi.SCp.ptr,
                        info->scsi.SCp.this_residual);
                  __scsi_print_command(SCpnt->cmnd);
                  SCpnt->result &= ~(255 << 16);
                  SCpnt->result |= DID_BAD_TARGET << 16;
                  goto request_sense;
            }
      }

done:
      if (SCpnt->scsi_done) {
            SCpnt->scsi_done(SCpnt);
            return;
      }

      panic("scsi%d.H: null scsi_done function in fas216_done",
            info->host->host_no);


request_sense:
      if (SCpnt->cmnd[0] == REQUEST_SENSE)
            goto done;

      scsi_eh_prep_cmnd(SCpnt, &info->ses, NULL, 0, ~0);
      fas216_log_target(info, LOG_CONNECT, SCpnt->device->id,
                    "requesting sense");
      init_SCp(SCpnt);
      SCpnt->SCp.Message = 0;
      SCpnt->SCp.Status = 0;
      SCpnt->tag = 0;
      SCpnt->host_scribble = (void *)fas216_rq_sns_done;

      /*
       * Place this command into the high priority "request
       * sense" slot.  This will be the very next command
       * executed, unless a target connects to us.
       */
      if (info->reqSCpnt)
            printk(KERN_WARNING "scsi%d.%c: loosing request command\n",
                  info->host->host_no, '0' + SCpnt->device->id);
      info->reqSCpnt = SCpnt;
}

/**
 * fas216_done - complete processing for current command
 * @info: interface that completed
 * @result: driver byte of result
 *
 * Complete processing for current command
 */
static void fas216_done(FAS216_Info *info, unsigned int result)
{
      void (*fn)(FAS216_Info *, struct scsi_cmnd *, unsigned int);
      struct scsi_cmnd *SCpnt;
      unsigned long flags;

      fas216_checkmagic(info);

      if (!info->SCpnt)
            goto no_command;

      SCpnt = info->SCpnt;
      info->SCpnt = NULL;
      info->scsi.phase = PHASE_IDLE;

      if (info->scsi.aborting) {
            fas216_log(info, 0, "uncaught abort - returning DID_ABORT");
            result = DID_ABORT;
            info->scsi.aborting = 0;
      }

      /*
       * Sanity check the completion - if we have zero bytes left
       * to transfer, we should not have a valid pointer.
       */
      if (info->scsi.SCp.ptr && info->scsi.SCp.this_residual == 0) {
            printk("scsi%d.%c: zero bytes left to transfer, but "
                   "buffer pointer still valid: ptr=%p len=%08x CDB: ",
                   info->host->host_no, '0' + SCpnt->device->id,
                   info->scsi.SCp.ptr, info->scsi.SCp.this_residual);
            info->scsi.SCp.ptr = NULL;
            __scsi_print_command(SCpnt->cmnd);
      }

      /*
       * Clear down this command as completed.  If we need to request
       * the sense information, fas216_kick will re-assert the busy
       * status.
       */
      info->device[SCpnt->device->id].parity_check = 0;
      clear_bit(SCpnt->device->id * 8 + SCpnt->device->lun, info->busyluns);

      fn = (void (*)(FAS216_Info *, struct scsi_cmnd *, unsigned int))SCpnt->host_scribble;
      fn(info, SCpnt, result);

      if (info->scsi.irq != NO_IRQ) {
            spin_lock_irqsave(&info->host_lock, flags);
            if (info->scsi.phase == PHASE_IDLE)
                  fas216_kick(info);
            spin_unlock_irqrestore(&info->host_lock, flags);
      }
      return;

no_command:
      panic("scsi%d.H: null command in fas216_done",
            info->host->host_no);
}

/**
 * fas216_queue_command - queue a command for adapter to process.
 * @SCpnt: Command to queue
 * @done: done function to call once command is complete
 *
 * Queue a command for adapter to process.
 * Returns: 0 on success, else error.
 * Notes: io_request_lock is held, interrupts are disabled.
 */
int fas216_queue_command(struct scsi_cmnd *SCpnt,
                   void (*done)(struct scsi_cmnd *))
{
      FAS216_Info *info = (FAS216_Info *)SCpnt->device->host->hostdata;
      int result;

      fas216_checkmagic(info);

      fas216_log_command(info, LOG_CONNECT, SCpnt,
                     "received command (%p)", SCpnt);

      SCpnt->scsi_done = done;
      SCpnt->host_scribble = (void *)fas216_std_done;
      SCpnt->result = 0;

      init_SCp(SCpnt);

      info->stats.queues += 1;
      SCpnt->tag = 0;

      spin_lock(&info->host_lock);

      /*
       * Add command into execute queue and let it complete under
       * whatever scheme we're using.
       */
      result = !queue_add_cmd_ordered(&info->queues.issue, SCpnt);

      /*
       * If we successfully added the command,
       * kick the interface to get it moving.
       */
      if (result == 0 && info->scsi.phase == PHASE_IDLE)
            fas216_kick(info);
      spin_unlock(&info->host_lock);

      fas216_log_target(info, LOG_CONNECT, -1, "queue %s",
            result ? "failure" : "success");

      return result;
}

/**
 * fas216_internal_done - trigger restart of a waiting thread in fas216_noqueue_command
 * @SCpnt: Command to wake
 *
 * Trigger restart of a waiting thread in fas216_command
 */
static void fas216_internal_done(struct scsi_cmnd *SCpnt)
{
      FAS216_Info *info = (FAS216_Info *)SCpnt->device->host->hostdata;

      fas216_checkmagic(info);

      info->internal_done = 1;
}

/**
 * fas216_noqueue_command - process a command for the adapter.
 * @SCpnt: Command to queue
 *
 * Queue a command for adapter to process.
 * Returns: scsi result code.
 * Notes: io_request_lock is held, interrupts are disabled.
 */
int fas216_noqueue_command(struct scsi_cmnd *SCpnt,
                     void (*done)(struct scsi_cmnd *))
{
      FAS216_Info *info = (FAS216_Info *)SCpnt->device->host->hostdata;

      fas216_checkmagic(info);

      /*
       * We should only be using this if we don't have an interrupt.
       * Provide some "incentive" to use the queueing code.
       */
      BUG_ON(info->scsi.irq != NO_IRQ);

      info->internal_done = 0;
      fas216_queue_command(SCpnt, fas216_internal_done);

      /*
       * This wastes time, since we can't return until the command is
       * complete. We can't sleep either since we may get re-entered!
       * However, we must re-enable interrupts, or else we'll be
       * waiting forever.
       */
      spin_unlock_irq(info->host->host_lock);

      while (!info->internal_done) {
            /*
             * If we don't have an IRQ, then we must poll the card for
             * it's interrupt, and use that to call this driver's
             * interrupt routine.  That way, we keep the command
             * progressing.  Maybe we can add some inteligence here
             * and go to sleep if we know that the device is going
             * to be some time (eg, disconnected).
             */
            if (fas216_readb(info, REG_STAT) & STAT_INT) {
                  spin_lock_irq(info->host->host_lock);
                  fas216_intr(info);
                  spin_unlock_irq(info->host->host_lock);
            }
      }

      spin_lock_irq(info->host->host_lock);

      done(SCpnt);

      return 0;
}

/*
 * Error handler timeout function.  Indicate that we timed out,
 * and wake up any error handler process so it can continue.
 */
static void fas216_eh_timer(unsigned long data)
{
      FAS216_Info *info = (FAS216_Info *)data;

      fas216_log(info, LOG_ERROR, "error handling timed out\n");

      del_timer(&info->eh_timer);

      if (info->rst_bus_status == 0)
            info->rst_bus_status = -1;
      if (info->rst_dev_status == 0)
            info->rst_dev_status = -1;

      wake_up(&info->eh_wait);
}

enum res_find {
      res_failed,       /* not found                  */
      res_success,            /* command on issue queue     */
      res_hw_abort            /* command on disconnected dev      */
};

/**
 * fas216_do_abort - decide how to abort a command
 * @SCpnt: command to abort
 *
 * Decide how to abort a command.
 * Returns: abort status
 */
static enum res_find fas216_find_command(FAS216_Info *info,
                               struct scsi_cmnd *SCpnt)
{
      enum res_find res = res_failed;

      if (queue_remove_cmd(&info->queues.issue, SCpnt)) {
            /*
             * The command was on the issue queue, and has not been
             * issued yet.  We can remove the command from the queue,
             * and acknowledge the abort.  Neither the device nor the
             * interface know about the command.
             */
            printk("on issue queue ");

            res = res_success;
      } else if (queue_remove_cmd(&info->queues.disconnected, SCpnt)) {
            /*
             * The command was on the disconnected queue.  We must
             * reconnect with the device if possible, and send it
             * an abort message.
             */
            printk("on disconnected queue ");

            res = res_hw_abort;
      } else if (info->SCpnt == SCpnt) {
            printk("executing ");

            switch (info->scsi.phase) {
            /*
             * If the interface is idle, and the command is 'disconnectable',
             * then it is the same as on the disconnected queue.
             */
            case PHASE_IDLE:
                  if (info->scsi.disconnectable) {
                        info->scsi.disconnectable = 0;
                        info->SCpnt = NULL;
                        res = res_hw_abort;
                  }
                  break;

            default:
                  break;
            }
      } else if (info->origSCpnt == SCpnt) {
            /*
             * The command will be executed next, but a command
             * is currently using the interface.  This is similar to
             * being on the issue queue, except the busylun bit has
             * been set.
             */
            info->origSCpnt = NULL;
            clear_bit(SCpnt->device->id * 8 + SCpnt->device->lun, info->busyluns);
            printk("waiting for execution ");
            res = res_success;
      } else
            printk("unknown ");

      return res;
}

/**
 * fas216_eh_abort - abort this command
 * @SCpnt: command to abort
 *
 * Abort this command.
 * Returns: FAILED if unable to abort
 * Notes: io_request_lock is taken, and irqs are disabled
 */
int fas216_eh_abort(struct scsi_cmnd *SCpnt)
{
      FAS216_Info *info = (FAS216_Info *)SCpnt->device->host->hostdata;
      int result = FAILED;

      fas216_checkmagic(info);

      info->stats.aborts += 1;

      printk(KERN_WARNING "scsi%d: abort command ", info->host->host_no);
      __scsi_print_command(SCpnt->cmnd);

      print_debug_list();
      fas216_dumpstate(info);

      printk(KERN_WARNING "scsi%d: abort %p ", info->host->host_no, SCpnt);

      switch (fas216_find_command(info, SCpnt)) {
      /*
       * We found the command, and cleared it out.  Either
       * the command is still known to be executing on the
       * target, or the busylun bit is not set.
       */
      case res_success:
            printk("success\n");
            result = SUCCESS;
            break;

      /*
       * We need to reconnect to the target and send it an
       * ABORT or ABORT_TAG message.  We can only do this
       * if the bus is free.
       */
      case res_hw_abort:
            

      /*
       * We are unable to abort the command for some reason.
       */
      default:
      case res_failed:
            printk("failed\n");
            break;
      }

      return result;
}

/**
 * fas216_eh_device_reset - Reset the device associated with this command
 * @SCpnt: command specifing device to reset
 *
 * Reset the device associated with this command.
 * Returns: FAILED if unable to reset.
 * Notes: We won't be re-entered, so we'll only have one device
 * reset on the go at one time.
 */
int fas216_eh_device_reset(struct scsi_cmnd *SCpnt)
{
      FAS216_Info *info = (FAS216_Info *)SCpnt->device->host->hostdata;
      unsigned long flags;
      int i, res = FAILED, target = SCpnt->device->id;

      fas216_log(info, LOG_ERROR, "device reset for target %d", target);

      spin_lock_irqsave(&info->host_lock, flags);

      do {
            /*
             * If we are currently connected to a device, and
             * it is the device we want to reset, there is
             * nothing we can do here.  Chances are it is stuck,
             * and we need a bus reset.
             */
            if (info->SCpnt && !info->scsi.disconnectable &&
                info->SCpnt->device->id == SCpnt->device->id)
                  break;

            /*
             * We're going to be resetting this device.  Remove
             * all pending commands from the driver.  By doing
             * so, we guarantee that we won't touch the command
             * structures except to process the reset request.
             */
            queue_remove_all_target(&info->queues.issue, target);
            queue_remove_all_target(&info->queues.disconnected, target);
            if (info->origSCpnt && info->origSCpnt->device->id == target)
                  info->origSCpnt = NULL;
            if (info->reqSCpnt && info->reqSCpnt->device->id == target)
                  info->reqSCpnt = NULL;
            for (i = 0; i < 8; i++)
                  clear_bit(target * 8 + i, info->busyluns);

            /*
             * Hijack this SCSI command structure to send
             * a bus device reset message to this device.
             */
            SCpnt->host_scribble = (void *)fas216_devicereset_done;

            info->rst_dev_status = 0;
            info->rstSCpnt = SCpnt;

            if (info->scsi.phase == PHASE_IDLE)
                  fas216_kick(info);

            mod_timer(&info->eh_timer, 30 * HZ);
            spin_unlock_irqrestore(&info->host_lock, flags);

            /*
             * Wait up to 30 seconds for the reset to complete.
             */
            wait_event(info->eh_wait, info->rst_dev_status);

            del_timer_sync(&info->eh_timer);
            spin_lock_irqsave(&info->host_lock, flags);
            info->rstSCpnt = NULL;

            if (info->rst_dev_status == 1)
                  res = SUCCESS;
      } while (0);

      SCpnt->host_scribble = NULL;
      spin_unlock_irqrestore(&info->host_lock, flags);

      fas216_log(info, LOG_ERROR, "device reset complete: %s\n",
               res == SUCCESS ? "success" : "failed");

      return res;
}

/**
 * fas216_eh_bus_reset - Reset the bus associated with the command
 * @SCpnt: command specifing bus to reset
 *
 * Reset the bus associated with the command.
 * Returns: FAILED if unable to reset.
 * Notes: Further commands are blocked.
 */
int fas216_eh_bus_reset(struct scsi_cmnd *SCpnt)
{
      FAS216_Info *info = (FAS216_Info *)SCpnt->device->host->hostdata;
      unsigned long flags;
      struct scsi_device *SDpnt;

      fas216_checkmagic(info);
      fas216_log(info, LOG_ERROR, "resetting bus");

      info->stats.bus_resets += 1;

      spin_lock_irqsave(&info->host_lock, flags);

      /*
       * Stop all activity on this interface.
       */
      fas216_aborttransfer(info);
      fas216_writeb(info, REG_CNTL3, info->scsi.cfg[2]);

      /*
       * Clear any pending interrupts.
       */
      while (fas216_readb(info, REG_STAT) & STAT_INT)
            fas216_readb(info, REG_INST);

      info->rst_bus_status = 0;

      /*
       * For each attached hard-reset device, clear out
       * all command structures.  Leave the running
       * command in place.
       */
      shost_for_each_device(SDpnt, info->host) {
            int i;

            if (SDpnt->soft_reset)
                  continue;

            queue_remove_all_target(&info->queues.issue, SDpnt->id);
            queue_remove_all_target(&info->queues.disconnected, SDpnt->id);
            if (info->origSCpnt && info->origSCpnt->device->id == SDpnt->id)
                  info->origSCpnt = NULL;
            if (info->reqSCpnt && info->reqSCpnt->device->id == SDpnt->id)
                  info->reqSCpnt = NULL;
            info->SCpnt = NULL;

            for (i = 0; i < 8; i++)
                  clear_bit(SDpnt->id * 8 + i, info->busyluns);
      }

      info->scsi.phase = PHASE_IDLE;

      /*
       * Reset the SCSI bus.  Device cleanup happens in
       * the interrupt handler.
       */
      fas216_cmd(info, CMD_RESETSCSI);

      mod_timer(&info->eh_timer, jiffies + HZ);
      spin_unlock_irqrestore(&info->host_lock, flags);

      /*
       * Wait one second for the interrupt.
       */
      wait_event(info->eh_wait, info->rst_bus_status);
      del_timer_sync(&info->eh_timer);

      fas216_log(info, LOG_ERROR, "bus reset complete: %s\n",
               info->rst_bus_status == 1 ? "success" : "failed");

      return info->rst_bus_status == 1 ? SUCCESS : FAILED;
}

/**
 * fas216_init_chip - Initialise FAS216 state after reset
 * @info: state structure for interface
 *
 * Initialise FAS216 state after reset
 */
static void fas216_init_chip(FAS216_Info *info)
{
      unsigned int clock = ((info->ifcfg.clockrate - 1) / 5 + 1) & 7;
      fas216_writeb(info, REG_CLKF, clock);
      fas216_writeb(info, REG_CNTL1, info->scsi.cfg[0]);
      fas216_writeb(info, REG_CNTL2, info->scsi.cfg[1]);
      fas216_writeb(info, REG_CNTL3, info->scsi.cfg[2]);
      fas216_writeb(info, REG_STIM, info->ifcfg.select_timeout);
      fas216_writeb(info, REG_SOF, 0);
      fas216_writeb(info, REG_STP, info->scsi.async_stp);
      fas216_writeb(info, REG_CNTL1, info->scsi.cfg[0]);
}

/**
 * fas216_eh_host_reset - Reset the host associated with this command
 * @SCpnt: command specifing host to reset
 *
 * Reset the host associated with this command.
 * Returns: FAILED if unable to reset.
 * Notes: io_request_lock is taken, and irqs are disabled
 */
int fas216_eh_host_reset(struct scsi_cmnd *SCpnt)
{
      FAS216_Info *info = (FAS216_Info *)SCpnt->device->host->hostdata;

      spin_lock_irq(info->host->host_lock);

      fas216_checkmagic(info);

      printk("scsi%d.%c: %s: resetting host\n",
            info->host->host_no, '0' + SCpnt->device->id, __func__);

      /*
       * Reset the SCSI chip.
       */
      fas216_cmd(info, CMD_RESETCHIP);

      /*
       * Ugly ugly ugly!
       * We need to release the host_lock and enable
       * IRQs if we sleep, but we must relock and disable
       * IRQs after the sleep.
       */
      spin_unlock_irq(info->host->host_lock);
      msleep(50 * 1000/100);
      spin_lock_irq(info->host->host_lock);

      /*
       * Release the SCSI reset.
       */
      fas216_cmd(info, CMD_NOP);

      fas216_init_chip(info);

      spin_unlock_irq(info->host->host_lock);
      return SUCCESS;
}

#define TYPE_UNKNOWN    0
#define TYPE_NCR53C90   1
#define TYPE_NCR53C90A  2
#define TYPE_NCR53C9x   3
#define TYPE_Am53CF94   4
#define TYPE_EmFAS216   5
#define TYPE_QLFAS216   6

static char *chip_types[] = {
      "unknown",
      "NS NCR53C90",
      "NS NCR53C90A",
      "NS NCR53C9x",
      "AMD Am53CF94",
      "Emulex FAS216",
      "QLogic FAS216"
};

static int fas216_detect_type(FAS216_Info *info)
{
      int family, rev;

      /*
       * Reset the chip.
       */
      fas216_writeb(info, REG_CMD, CMD_RESETCHIP);
      udelay(50);
      fas216_writeb(info, REG_CMD, CMD_NOP);

      /*
       * Check to see if control reg 2 is present.
       */
      fas216_writeb(info, REG_CNTL3, 0);
      fas216_writeb(info, REG_CNTL2, CNTL2_S2FE);

      /*
       * If we are unable to read back control reg 2
       * correctly, it is not present, and we have a
       * NCR53C90.
       */
      if ((fas216_readb(info, REG_CNTL2) & (~0xe0)) != CNTL2_S2FE)
            return TYPE_NCR53C90;

      /*
       * Now, check control register 3
       */
      fas216_writeb(info, REG_CNTL2, 0);
      fas216_writeb(info, REG_CNTL3, 0);
      fas216_writeb(info, REG_CNTL3, 5);

      /*
       * If we are unable to read the register back
       * correctly, we have a NCR53C90A
       */
      if (fas216_readb(info, REG_CNTL3) != 5)
            return TYPE_NCR53C90A;

      /*
       * Now read the ID from the chip.
       */
      fas216_writeb(info, REG_CNTL3, 0);

      fas216_writeb(info, REG_CNTL3, CNTL3_ADIDCHK);
      fas216_writeb(info, REG_CNTL3, 0);

      fas216_writeb(info, REG_CMD, CMD_RESETCHIP);
      udelay(50);
      fas216_writeb(info, REG_CMD, CMD_WITHDMA | CMD_NOP);

      fas216_writeb(info, REG_CNTL2, CNTL2_ENF);
      fas216_writeb(info, REG_CMD, CMD_RESETCHIP);
      udelay(50);
      fas216_writeb(info, REG_CMD, CMD_NOP);

      rev     = fas216_readb(info, REG_ID);
      family  = rev >> 3;
      rev    &= 7;

      switch (family) {
      case 0x01:
            if (rev == 4)
                  return TYPE_Am53CF94;
            break;

      case 0x02:
            switch (rev) {
            case 2:
                  return TYPE_EmFAS216;
            case 3:
                  return TYPE_QLFAS216;
            }
            break;

      default:
            break;
      }
      printk("family %x rev %x\n", family, rev);
      return TYPE_NCR53C9x;
}

/**
 * fas216_reset_state - Initialise driver internal state
 * @info: state to initialise
 *
 * Initialise driver internal state
 */
static void fas216_reset_state(FAS216_Info *info)
{
      int i;

      fas216_checkmagic(info);

      fas216_bus_reset(info);

      /*
       * Clear out all stale info in our state structure
       */
      memset(info->busyluns, 0, sizeof(info->busyluns));
      info->scsi.disconnectable = 0;
      info->scsi.aborting = 0;

      for (i = 0; i < 8; i++) {
            info->device[i].parity_enabled      = 0;
            info->device[i].parity_check  = 1;
      }

      /*
       * Drain all commands on disconnected queue
       */
      while (queue_remove(&info->queues.disconnected) != NULL);

      /*
       * Remove executing commands.
       */
      info->SCpnt     = NULL;
      info->reqSCpnt  = NULL;
      info->rstSCpnt  = NULL;
      info->origSCpnt = NULL;
}

/**
 * fas216_init - initialise FAS/NCR/AMD SCSI structures.
 * @host: a driver-specific filled-out structure
 *
 * Initialise FAS/NCR/AMD SCSI structures.
 * Returns: 0 on success
 */
int fas216_init(struct Scsi_Host *host)
{
      FAS216_Info *info = (FAS216_Info *)host->hostdata;

      info->magic_start    = MAGIC;
      info->magic_end      = MAGIC;
      info->host           = host;
      info->scsi.cfg[0]    = host->this_id | CNTL1_PERE;
      info->scsi.cfg[1]    = CNTL2_ENF | CNTL2_S2FE;
      info->scsi.cfg[2]    = info->ifcfg.cntl3 |
                         CNTL3_ADIDCHK | CNTL3_QTAG | CNTL3_G2CB | CNTL3_LBTM;
      info->scsi.async_stp = fas216_syncperiod(info, info->ifcfg.asyncperiod);

      info->rst_dev_status = -1;
      info->rst_bus_status = -1;
      init_waitqueue_head(&info->eh_wait);
      init_timer(&info->eh_timer);
      info->eh_timer.data  = (unsigned long)info;
      info->eh_timer.function = fas216_eh_timer;
      
      spin_lock_init(&info->host_lock);

      memset(&info->stats, 0, sizeof(info->stats));

      msgqueue_initialise(&info->scsi.msgs);

      if (!queue_initialise(&info->queues.issue))
            return -ENOMEM;

      if (!queue_initialise(&info->queues.disconnected)) {
            queue_free(&info->queues.issue);
            return -ENOMEM;
      }

      return 0;
}

/**
 * fas216_add - initialise FAS/NCR/AMD SCSI ic.
 * @host: a driver-specific filled-out structure
 * @dev: parent device
 *
 * Initialise FAS/NCR/AMD SCSI ic.
 * Returns: 0 on success
 */
int fas216_add(struct Scsi_Host *host, struct device *dev)
{
      FAS216_Info *info = (FAS216_Info *)host->hostdata;
      int type, ret;

      if (info->ifcfg.clockrate <= 10 || info->ifcfg.clockrate > 40) {
            printk(KERN_CRIT "fas216: invalid clock rate %u MHz\n",
                  info->ifcfg.clockrate);
            return -EINVAL;
      }

      fas216_reset_state(info);
      type = fas216_detect_type(info);
      info->scsi.type = chip_types[type];

      udelay(300);

      /*
       * Initialise the chip correctly.
       */
      fas216_init_chip(info);

      /*
       * Reset the SCSI bus.  We don't want to see
       * the resulting reset interrupt, so mask it
       * out.
       */
      fas216_writeb(info, REG_CNTL1, info->scsi.cfg[0] | CNTL1_DISR);
      fas216_writeb(info, REG_CMD, CMD_RESETSCSI);

      /*
       * scsi standard says wait 250ms
       */
      spin_unlock_irq(info->host->host_lock);
      msleep(100*1000/100);
      spin_lock_irq(info->host->host_lock);

      fas216_writeb(info, REG_CNTL1, info->scsi.cfg[0]);
      fas216_readb(info, REG_INST);

      fas216_checkmagic(info);

      ret = scsi_add_host(host, dev);
      if (ret)
            fas216_writeb(info, REG_CMD, CMD_RESETCHIP);
      else
            scsi_scan_host(host);

      return ret;
}

void fas216_remove(struct Scsi_Host *host)
{
      FAS216_Info *info = (FAS216_Info *)host->hostdata;

      fas216_checkmagic(info);
      scsi_remove_host(host);

      fas216_writeb(info, REG_CMD, CMD_RESETCHIP);
      scsi_host_put(host);
}

/**
 * fas216_release - release all resources for FAS/NCR/AMD SCSI ic.
 * @host: a driver-specific filled-out structure
 *
 * release all resources and put everything to bed for FAS/NCR/AMD SCSI ic.
 */
void fas216_release(struct Scsi_Host *host)
{
      FAS216_Info *info = (FAS216_Info *)host->hostdata;

      queue_free(&info->queues.disconnected);
      queue_free(&info->queues.issue);
}

int fas216_print_host(FAS216_Info *info, char *buffer)
{
      return sprintf(buffer,
                  "\n"
                  "Chip    : %s\n"
                  " Address: 0x%p\n"
                  " IRQ    : %d\n"
                  " DMA    : %d\n",
                  info->scsi.type, info->scsi.io_base,
                  info->scsi.irq, info->scsi.dma);
}

int fas216_print_stats(FAS216_Info *info, char *buffer)
{
      char *p = buffer;

      p += sprintf(p, "\n"
                  "Command Statistics:\n"
                  " Queued     : %u\n"
                  " Issued     : %u\n"
                  " Completed  : %u\n"
                  " Reads      : %u\n"
                  " Writes     : %u\n"
                  " Others     : %u\n"
                  " Disconnects: %u\n"
                  " Aborts     : %u\n"
                  " Bus resets : %u\n"
                  " Host resets: %u\n",
                  info->stats.queues,      info->stats.removes,
                  info->stats.fins,  info->stats.reads,
                  info->stats.writes,      info->stats.miscs,
                  info->stats.disconnects, info->stats.aborts,
                  info->stats.bus_resets,  info->stats.host_resets);

      return p - buffer;
}

int fas216_print_devices(FAS216_Info *info, char *buffer)
{
      struct fas216_device *dev;
      struct scsi_device *scd;
      char *p = buffer;

      p += sprintf(p, "Device/Lun TaggedQ       Parity   Sync\n");

      shost_for_each_device(scd, info->host) {
            dev = &info->device[scd->id];
            p += sprintf(p, "     %d/%d   ", scd->id, scd->lun);
            if (scd->tagged_supported)
                  p += sprintf(p, "%3sabled(%3d) ",
                             scd->simple_tags ? "en" : "dis",
                             scd->current_tag);
            else
                  p += sprintf(p, "unsupported   ");

            p += sprintf(p, "%3sabled ", dev->parity_enabled ? "en" : "dis");

            if (dev->sof)
                  p += sprintf(p, "offset %d, %d ns\n",
                             dev->sof, dev->period * 4);
            else
                  p += sprintf(p, "async\n");
      }

      return p - buffer;
}

EXPORT_SYMBOL(fas216_init);
EXPORT_SYMBOL(fas216_add);
EXPORT_SYMBOL(fas216_queue_command);
EXPORT_SYMBOL(fas216_noqueue_command);
EXPORT_SYMBOL(fas216_intr);
EXPORT_SYMBOL(fas216_remove);
EXPORT_SYMBOL(fas216_release);
EXPORT_SYMBOL(fas216_eh_abort);
EXPORT_SYMBOL(fas216_eh_device_reset);
EXPORT_SYMBOL(fas216_eh_bus_reset);
EXPORT_SYMBOL(fas216_eh_host_reset);
EXPORT_SYMBOL(fas216_print_host);
EXPORT_SYMBOL(fas216_print_stats);
EXPORT_SYMBOL(fas216_print_devices);

MODULE_AUTHOR("Russell King");
MODULE_DESCRIPTION("Generic FAS216/NCR53C9x driver core");
MODULE_LICENSE("GPL");

Generated by  Doxygen 1.6.0   Back to index