src/drivers/at_wini/at_wini.c

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/* This file contains the device dependent part of a driver for the IBM-AT
 * winchester controller.  Written by Adri Koppes.
 *
 * The file contains one entry point:
 *
 *   at_winchester_task:        main entry when system is brought up
 *
 * Changes:
 *   Aug 19, 2005   ATA PCI support, supports SATA  (Ben Gras)
 *   Nov 18, 2004   moved AT disk driver to user-space  (Jorrit N. Herder)
 *   Aug 20, 2004   watchdogs replaced by sync alarms  (Jorrit N. Herder)
 *   Mar 23, 2000   added ATAPI CDROM support  (Michael Temari)
 *   May 14, 2000   d-d/i rewrite  (Kees J. Bot)
 *   Apr 13, 1992   device dependent/independent split  (Kees J. Bot)
 */

#include "at_wini.h"

#include <minix/sysutil.h>
#include <minix/type.h>
#include <minix/endpoint.h>
#include <sys/ioc_disk.h>
#include <ibm/pci.h>
#include <sys/mman.h>

/* Variables. */

/* Common command block */
struct command {
  u8_t  precomp;        /* REG_PRECOMP, etc. */
  u8_t  count;
  u8_t  sector;
  u8_t  cyl_lo;
  u8_t  cyl_hi;
  u8_t  ldh;
  u8_t  command;

  /* The following at for LBA48 */
  u8_t  count_prev;
  u8_t  sector_prev;
  u8_t  cyl_lo_prev;
  u8_t  cyl_hi_prev;
};

/* Timeouts and max retries. */
int timeout_ticks = DEF_TIMEOUT_TICKS, max_errors = MAX_ERRORS;
long w_standard_timeouts = 0, w_pci_debug = 0, w_instance = 0,
        disable_dma = 0, atapi_debug = 0, w_identify_wakeup_ticks,
        wakeup_ticks, w_atapi_dma;

int w_testing = 0, w_silent = 0;

int w_next_drive = 0;

u32_t system_hz;

/* The struct wini is indexed by controller first, then drive (0-3).
 * Controller 0 is always the 'compatability' ide controller, at
 * the fixed locations, whether present or not.
 */
PRIVATE struct wini {           /* main drive struct, one entry per drive */
  unsigned state;               /* drive state: deaf, initialized, dead */
  unsigned short w_status;      /* device status register */
  unsigned base_cmd;            /* command base register */
  unsigned base_ctl;            /* control base register */
  unsigned base_dma;            /* dma base register */
  int dma_intseen;
  unsigned irq;                 /* interrupt request line */
  unsigned irq_need_ack;        /* irq needs to be acknowledged */
  int irq_hook_id;              /* id of irq hook at the kernel */
  int lba48;                    /* supports lba48 */
  int dma;                      /* supports dma */
  unsigned lcylinders;          /* logical number of cylinders (BIOS) */
  unsigned lheads;              /* logical number of heads */
  unsigned lsectors;            /* logical number of sectors per track */
  unsigned pcylinders;          /* physical number of cylinders (translated) */
  unsigned pheads;              /* physical number of heads */
  unsigned psectors;            /* physical number of sectors per track */
  unsigned ldhpref;             /* top four bytes of the LDH (head) register */
  unsigned precomp;             /* write precompensation cylinder / 4 */
  unsigned max_count;           /* max request for this drive */
  unsigned open_ct;             /* in-use count */
  struct device part[DEV_PER_DRIVE];    /* disks and partitions */
  struct device subpart[SUB_PER_DRIVE]; /* subpartitions */
} wini[MAX_DRIVES], *w_wn;

PRIVATE int w_device = -1;
PRIVATE int w_controller = -1;
PRIVATE int w_major = -1;

PRIVATE int win_tasknr;                 /* my task number */
PUBLIC int w_command;                   /* current command in execution */
PRIVATE u8_t w_byteval;                 /* used for SYS_IRQCTL */
PRIVATE int w_drive;                    /* selected drive */
PRIVATE int w_controller;               /* selected controller */
PRIVATE struct device *w_dv;            /* device's base and size */

/* Unfortunately, DMA_SECTORS and DMA_BUF_SIZE are already defined libdriver
 * for 'tmp_buf'.
 */
#define ATA_DMA_SECTORS 64
#define ATA_DMA_BUF_SIZE        (ATA_DMA_SECTORS*SECTOR_SIZE)

PRIVATE char *dma_buf;
PRIVATE phys_bytes dma_buf_phys;

#define N_PRDTE 1024    /* Should be enough for large requests */

PRIVATE struct prdte
{
        u32_t prdte_base;
        u16_t prdte_count;
        u8_t prdte_reserved;
        u8_t prdte_flags;
};

#define PRDT_BYTES (sizeof(struct prdte) * N_PRDTE)
PRIVATE struct prdte *prdt;
PRIVATE phys_bytes prdt_phys;

#define PRDTE_FL_EOT    0x80    /* End of table */

/* Some IDE devices announce themselves as RAID controllers */
PRIVATE struct
{
        u16_t vendor;
        u16_t device;
} raid_table[]=
{
        { 0x1106,       0x3149  },      /* VIA VT6420 */
        { 0x1095,       0x3512  },
        { 0,            0       }       /* end of list */
};

FORWARD _PROTOTYPE( void init_params, (void)                            );
FORWARD _PROTOTYPE( void init_drive, (struct wini *w, int base_cmd,
        int base_ctl, int base_dma, int irq, int ack, int hook,
                                                        int drive)      );
FORWARD _PROTOTYPE( void init_params_pci, (int)                         );
FORWARD _PROTOTYPE( int w_do_open, (struct driver *dp, message *m_ptr)  );
FORWARD _PROTOTYPE( struct device *w_prepare, (int dev)                 );
FORWARD _PROTOTYPE( int w_identify, (void)                              );
FORWARD _PROTOTYPE( char *w_name, (void)                                );
FORWARD _PROTOTYPE( int w_specify, (void)                               );
FORWARD _PROTOTYPE( int w_io_test, (void)                               );
FORWARD _PROTOTYPE( int w_transfer, (int proc_nr, int opcode, u64_t position,
                                iovec_t *iov, unsigned nr_req));
FORWARD _PROTOTYPE( int com_out, (struct command *cmd)                  );
FORWARD _PROTOTYPE( int com_out_ext, (struct command *cmd)              );
FORWARD _PROTOTYPE( void setup_dma, (unsigned *sizep, int proc_nr,
                        iovec_t *iov, size_t addr_offset, int do_write,
                        int *do_copyoutp)                               );
FORWARD _PROTOTYPE( void w_need_reset, (void)                           );
FORWARD _PROTOTYPE( void ack_irqs, (unsigned int)                       );
FORWARD _PROTOTYPE( int w_do_close, (struct driver *dp, message *m_ptr) );
FORWARD _PROTOTYPE( int w_other, (struct driver *dp, message *m_ptr)    );
FORWARD _PROTOTYPE( int w_hw_int, (struct driver *dp, message *m_ptr)   );
FORWARD _PROTOTYPE( int com_simple, (struct command *cmd)               );
FORWARD _PROTOTYPE( void w_timeout, (void)                              );
FORWARD _PROTOTYPE( int w_reset, (void)                                 );
FORWARD _PROTOTYPE( void w_intr_wait, (void)                            );
FORWARD _PROTOTYPE( int at_intr_wait, (void)                            );
FORWARD _PROTOTYPE( int w_waitfor, (int mask, int value)                );
FORWARD _PROTOTYPE( int w_waitfor_dma, (int mask, int value)            );
FORWARD _PROTOTYPE( void w_geometry, (struct partition *entry)          );
#if ENABLE_ATAPI
FORWARD _PROTOTYPE( int atapi_sendpacket, (u8_t *packet, unsigned cnt, int do_dma)      );
FORWARD _PROTOTYPE( int atapi_intr_wait, (int dma, size_t max)          );
FORWARD _PROTOTYPE( int atapi_open, (void)                              );
FORWARD _PROTOTYPE( void atapi_close, (void)                            );
FORWARD _PROTOTYPE( int atapi_transfer, (int proc_nr, int opcode,
                u64_t position, iovec_t *iov, unsigned nr_req)          );
#endif

#define sys_voutb(out, n) at_voutb(__LINE__, (out), (n))
FORWARD _PROTOTYPE( int at_voutb, (int line, pvb_pair_t *, int n));
#define sys_vinb(in, n) at_vinb(__LINE__, (in), (n))
FORWARD _PROTOTYPE( int at_vinb, (int line, pvb_pair_t *, int n));

#undef sys_outb
#undef sys_inb
#undef sys_outw
#undef sys_inw
#undef sys_outl
#undef sys_inl

FORWARD _PROTOTYPE( int at_out, (int line, u32_t port, u32_t value,
        char *typename, int type));
FORWARD _PROTOTYPE( int at_in, (int line, u32_t port, u32_t *value,
        char *typename, int type));

#define sys_outb(p, v) at_out(__LINE__, (p), (v), "outb", _DIO_BYTE)
#define sys_inb(p, v) at_in(__LINE__, (p), (v), "inb", _DIO_BYTE)
#define sys_outw(p, v) at_out(__LINE__, (p), (v), "outw", _DIO_WORD)
#define sys_inw(p, v) at_in(__LINE__, (p), (v), "inw", _DIO_WORD)
#define sys_outl(p, v) at_out(__LINE__, (p), (v), "outl", _DIO_LONG)
#define sys_inl(p, v) at_in(__LINE__, (p), (v), "inl", _DIO_LONG)

/* Entry points to this driver. */
PRIVATE struct driver w_dtab = {
  w_name,               /* current device's name */
  w_do_open,            /* open or mount request, initialize device */
  w_do_close,           /* release device */
  do_diocntl,           /* get or set a partition's geometry */
  w_prepare,            /* prepare for I/O on a given minor device */
  w_transfer,           /* do the I/O */
  nop_cleanup,          /* nothing to clean up */
  w_geometry,           /* tell the geometry of the disk */
  nop_signal,           /* no cleanup needed on shutdown */
  nop_alarm,            /* ignore leftover alarms */
  nop_cancel,           /* ignore CANCELs */
  nop_select,           /* ignore selects */
  w_other,              /* catch-all for unrecognized commands and ioctls */
  w_hw_int              /* leftover hardware interrupts */
};

/* SEF functions and variables. */
FORWARD _PROTOTYPE( void sef_local_startup, (void) );
FORWARD _PROTOTYPE( int sef_cb_init_fresh, (int type, sef_init_info_t *info) );
EXTERN _PROTOTYPE( void sef_cb_lu_prepare, (int state) );
EXTERN _PROTOTYPE( int sef_cb_lu_state_isvalid, (int state) );
EXTERN _PROTOTYPE( void sef_cb_lu_state_dump, (int state) );

/*===========================================================================*
 *                              at_winchester_task                           *
 *===========================================================================*/
PUBLIC int main(int argc, char *argv[])
{
  /* SEF local startup. */
  env_setargs(argc, argv);
  sef_local_startup();

  /* Call the generic receive loop. */
  driver_task(&w_dtab, DRIVER_STD);

  return(OK);
}

/*===========================================================================*
 *                             sef_local_startup                             *
 *===========================================================================*/
PRIVATE void sef_local_startup()
{
  /* Register init callbacks. */
  sef_setcb_init_fresh(sef_cb_init_fresh);
  sef_setcb_init_lu(sef_cb_init_fresh);
  sef_setcb_init_restart(sef_cb_init_fresh);

  /* Register live update callbacks. */
  sef_setcb_lu_prepare(sef_cb_lu_prepare);
  sef_setcb_lu_state_isvalid(sef_cb_lu_state_isvalid);
  sef_setcb_lu_state_dump(sef_cb_lu_state_dump);

  /* Let SEF perform startup. */
  sef_startup();
}

/*===========================================================================*
 *                          sef_cb_init_fresh                                *
 *===========================================================================*/
PRIVATE int sef_cb_init_fresh(int type, sef_init_info_t *info)
{
/* Initialize the at_wini driver. */
  struct sigaction sa;
  
  /* Install signal handlers. Ask PM to transform signal into message. */
  system_hz = sys_hz();

  init_buffer();

  w_identify_wakeup_ticks = WAKEUP_TICKS;
  wakeup_ticks = WAKEUP_TICKS;

  sa.sa_handler = SIG_MESS;
  sigemptyset(&sa.sa_mask);
  sa.sa_flags = 0;
  if (sigaction(SIGTERM,&sa,NULL)<0) panic("AT","sigaction failed", errno);

  /* Set special disk parameters. */
  init_params();
  signal(SIGTERM, SIG_IGN);

  return(OK);
}

/*===========================================================================*
 *                              init_params                                  *
 *===========================================================================*/
PRIVATE void init_params()
{
/* This routine is called at startup to initialize the drive parameters. */

  u16_t parv[2];
  unsigned int vector, size;
  int drive, nr_drives;
  struct wini *wn;
  u8_t params[16];
  int s;
  long wakeup_secs = WAKEUP_SECS;

  /* Boot variables. */
  env_parse("ata_std_timeout", "d", 0, &w_standard_timeouts, 0, 1);
  env_parse("ata_pci_debug", "d", 0, &w_pci_debug, 0, 1);
  env_parse("ata_instance", "d", 0, &w_instance, 0, 8);
  env_parse(NO_DMA_VAR, "d", 0, &disable_dma, 0, 1);
  env_parse("ata_id_timeout", "d", 0, &wakeup_secs, 1, 60);
  env_parse("atapi_debug", "d", 0, &atapi_debug, 0, 1);
  env_parse("atapi_dma", "d", 0, &w_atapi_dma, 0, 1);

  w_identify_wakeup_ticks = wakeup_secs * system_hz;

  if(atapi_debug)
        panic("at_wini", "atapi_debug", NO_NUM);

  if(w_identify_wakeup_ticks <= 0) {
        printf("changing wakeup from %d to %d ticks.\n",
                w_identify_wakeup_ticks, WAKEUP_TICKS);
        w_identify_wakeup_ticks = WAKEUP_TICKS;
  }

  if (disable_dma) {
        printf("at_wini%d: DMA for ATA devices is disabled.\n", w_instance);
  } else {
        /* Ask for anonymous memory for DMA, that is physically contiguous. */
        dma_buf = mmap(0, ATA_DMA_BUF_SIZE, PROT_READ|PROT_WRITE,
                MAP_PREALLOC | MAP_CONTIG | MAP_ANON, -1, 0);
        prdt = mmap(0, PRDT_BYTES,
                PROT_READ|PROT_WRITE,
                MAP_PREALLOC | MAP_CONTIG | MAP_ANON, -1, 0);
        if(dma_buf == MAP_FAILED || prdt == MAP_FAILED) {
                disable_dma = 1;
                printf("at_wini%d: no dma\n", w_instance);
        } else {
                s= sys_umap(SELF, VM_D, (vir_bytes)dma_buf,
                        ATA_DMA_BUF_SIZE, &dma_buf_phys);
                if (s != 0)
                        panic("at_wini", "can't map dma buffer", s);

                s= sys_umap(SELF, VM_D, (vir_bytes)prdt,
                        PRDT_BYTES, &prdt_phys);
                if (s != 0)
                        panic("at_wini", "can't map prd table", s);
#if 0
                printf("at_wini%d: physical dma_buf: 0x%lx, "
                        "prdt tab: 0x%lx\n",
                        w_instance, dma_buf_phys, prdt_phys);
#endif
        }
  }

  if (w_instance == 0) {
          /* Get the number of drives from the BIOS data area */
          s=sys_readbios(NR_HD_DRIVES_ADDR, params, NR_HD_DRIVES_SIZE);
          if (s != OK)
                panic(w_name(), "Couldn't read BIOS", s);
          if ((nr_drives = params[0]) > 2) nr_drives = 2;

          for (drive = 0, wn = wini; drive < COMPAT_DRIVES; drive++, wn++) {
                if (drive < nr_drives) {
                    /* Copy the BIOS parameter vector */
                    vector = (drive == 0) ? BIOS_HD0_PARAMS_ADDR :
                        BIOS_HD1_PARAMS_ADDR;
                    size = (drive == 0) ? BIOS_HD0_PARAMS_SIZE :
                        BIOS_HD1_PARAMS_SIZE;
                    s=sys_readbios(vector, parv, size);
                    if (s != OK)
                        panic(w_name(), "Couldn't read BIOS", s);
        
                    /* Calculate the address of the parameters and copy them */
                    s=sys_readbios(hclick_to_physb(parv[1]) + parv[0],
                        params, 16L);
                    if (s != OK)
                        panic(w_name(),"Couldn't copy parameters", s);
        
                    /* Copy the parameters to the structures of the drive */
                    wn->lcylinders = bp_cylinders(params);
                    wn->lheads = bp_heads(params);
                    wn->lsectors = bp_sectors(params);
                    wn->precomp = bp_precomp(params) >> 2;
                }

                /* Fill in non-BIOS parameters. */
                init_drive(wn,
                        drive < 2 ? REG_CMD_BASE0 : REG_CMD_BASE1,
                        drive < 2 ? REG_CTL_BASE0 : REG_CTL_BASE1,
                        0 /* no DMA */, NO_IRQ, 0, 0, drive);
                w_next_drive++;
        }
  } 

  /* Look for controllers on the pci bus. Skip none the first instance,
   * skip one and then 2 for every instance, for every next instance.
   */
  if (w_instance == 0)
        init_params_pci(0);
  else
        init_params_pci(w_instance*2-1);

}

#define ATA_IF_NOTCOMPAT1 (1L << 0)
#define ATA_IF_NOTCOMPAT2 (1L << 2)

/*===========================================================================*
 *                              init_drive                                   *
 *===========================================================================*/
PRIVATE void init_drive(struct wini *w, int base_cmd, int base_ctl,
        int base_dma, int irq, int ack, int hook, int drive)
{
        w->state = 0;
        w->w_status = 0;
        w->base_cmd = base_cmd;
        w->base_ctl = base_ctl;
        w->base_dma = base_dma;
        if(w_pci_debug)
           printf("at_wini%d: drive %d: base_cmd 0x%x, base_ctl 0x%x, base_dma 0x%x\n",
                w_instance, w-wini, w->base_cmd, w->base_ctl, w->base_dma);
        w->irq = irq;
        w->irq_need_ack = ack;
        w->irq_hook_id = hook;
        w->ldhpref = ldh_init(drive);
        w->max_count = MAX_SECS << SECTOR_SHIFT;
        w->lba48 = 0;
        w->dma = 0;
}

/*===========================================================================*
 *                              init_params_pci                              *
 *===========================================================================*/
PRIVATE void init_params_pci(int skip)
{
  int i, r, devind, drive, pci_compat = 0;
  int irq, irq_hook, raid;
  u8_t bcr, scr, interface;
  u16_t vid, did;
  u32_t base_dma, t3;

  pci_init();
  for(drive = w_next_drive; drive < MAX_DRIVES; drive++)
        wini[drive].state = IGNORING;
  for(r = pci_first_dev(&devind, &vid, &did); r != 0;
        r = pci_next_dev(&devind, &vid, &did)) {

        raid= 0;

        /* Except class 01h (mass storage), subclass be 01h (ATA).
         * Also check listed RAID controllers.
         */
        bcr= pci_attr_r8(devind, PCI_BCR);
        scr= pci_attr_r8(devind, PCI_SCR);
        interface= pci_attr_r8(devind, PCI_PIFR);
        t3= ((bcr << 16) | (scr << 8) | interface);
        if (bcr == PCI_BCR_MASS_STORAGE && scr == PCI_MS_IDE)
                ;       /* Okay */
        else if (t3 == PCI_T3_RAID)
        {
                for (i= 0; raid_table[i].vendor != 0; i++)
                {
                        if (raid_table[i].vendor == vid &&
                                raid_table[i].device == did)
                        {
                                break;
                        }
                }
                if (raid_table[i].vendor == 0)
                {
                        printf(
        "atapci skipping unsupported RAID controller 0x%04x / 0x%04x\n",
                                vid, did);
                        continue;
                }
                printf("found supported RAID controller\n");
                raid= 1;
        }
        else
                continue;       /* Unsupported device class */

        /* Found a controller.
         * Programming interface register tells us more.
         */
        irq = pci_attr_r8(devind, PCI_ILR);

        /* Any non-compat drives? */
        if (raid || (interface & (ATA_IF_NOTCOMPAT1 | ATA_IF_NOTCOMPAT2))) {
                if (w_next_drive >= MAX_DRIVES)
                {
                        /* We can't accept more drives, but have to search for
                         * controllers operating in compatibility mode.
                         */
                        continue;
                }

                irq_hook = irq;
                if (skip > 0) {
                        if (w_pci_debug)
                        {
                                printf(
                                "atapci skipping controller (remain %d)\n",
                                        skip);
                        }
                        skip--;
                        continue;
                }
                if(pci_reserve_ok(devind) != OK) {
                        printf("at_wini%d: pci_reserve %d failed - "
                                "ignoring controller!\n",
                                w_instance, devind);
                        continue;
                }
                if (sys_irqsetpolicy(irq, 0, &irq_hook) != OK) {
                        printf("atapci: couldn't set IRQ policy %d\n", irq);
                        continue;
                }
                if (sys_irqenable(&irq_hook) != OK) {
                        printf("atapci: couldn't enable IRQ line %d\n", irq);
                        continue;
                }
        } else if(w_pci_debug) printf("at_wini%d: dev %d: only compat drives\n", w_instance, devind); 

        base_dma = pci_attr_r32(devind, PCI_BAR_5) & 0xfffffffc;

        /* Primary channel not in compatability mode? */
        if (raid || (interface & ATA_IF_NOTCOMPAT1)) {
                u32_t base_cmd, base_ctl;

                base_cmd = pci_attr_r32(devind, PCI_BAR) & 0xfffffffc;
                base_ctl = pci_attr_r32(devind, PCI_BAR_2) & 0xfffffffc;
                if (base_cmd != REG_CMD_BASE0 && base_cmd != REG_CMD_BASE1) {
                        init_drive(&wini[w_next_drive],
                                base_cmd, base_ctl+PCI_CTL_OFF,
                                base_dma, irq, 1, irq_hook, 0);
                        init_drive(&wini[w_next_drive+1],
                                base_cmd, base_ctl+PCI_CTL_OFF,
                                base_dma, irq, 1, irq_hook, 1);
                        if (w_pci_debug)
                                printf("at_wini%d: atapci %d: 0x%x 0x%x irq %d\n", w_instance, devind, base_cmd, base_ctl, irq);
                        w_next_drive += 2;
                } else printf("at_wini%d: atapci: ignored drives on primary channel, base %x\n", w_instance, base_cmd);
        }
        else
        {
                /* Update base_dma for compatibility device */
                for (i= 0; i<MAX_DRIVES; i++)
                {
                        if (wini[i].base_cmd == REG_CMD_BASE0) {
                                wini[i].base_dma= base_dma;
                                if(w_pci_debug)
                                  printf("at_wini%d: drive %d: base_dma 0x%x\n",
                                        w_instance, i, wini[i].base_dma);
                                pci_compat = 1;
                        }
                }
        }

        /* Secondary channel not in compatability mode? */
        if (raid || (interface & ATA_IF_NOTCOMPAT2)) {
                u32_t base_cmd, base_ctl;

                base_cmd = pci_attr_r32(devind, PCI_BAR_3) & 0xfffffffc;
                base_ctl = pci_attr_r32(devind, PCI_BAR_4) & 0xfffffffc;
                if (base_dma != 0)
                        base_dma += PCI_DMA_2ND_OFF;
                if (base_cmd != REG_CMD_BASE0 && base_cmd != REG_CMD_BASE1) {
                        init_drive(&wini[w_next_drive],
                                base_cmd, base_ctl+PCI_CTL_OFF, base_dma,
                                irq, 1, irq_hook, 2);
                        init_drive(&wini[w_next_drive+1],
                                base_cmd, base_ctl+PCI_CTL_OFF, base_dma,
                                irq, 1, irq_hook, 3);
                        if (w_pci_debug)
                          printf("at_wini%d: atapci %d: 0x%x 0x%x irq %d\n",
                                w_instance, devind, base_cmd, base_ctl, irq);
                        w_next_drive += 2;
                } else printf("at_wini%d: atapci: ignored drives on "
                        "secondary channel, base %x\n", w_instance, base_cmd);
        }
        else
        {
                /* Update base_dma for compatibility device */
                for (i= 0; i<MAX_DRIVES; i++)
                {
                        if (wini[i].base_cmd == REG_CMD_BASE1 && base_dma != 0) {
                                wini[i].base_dma= base_dma+PCI_DMA_2ND_OFF;
                                if (w_pci_debug)
                                  printf("at_wini%d: drive %d: base_dma 0x%x\n",
                                        w_instance, i, wini[i].base_dma);
                                pci_compat = 1;
                        }
                }
        }

        if(pci_compat) {
                if(pci_reserve_ok(devind) != OK) {
                        printf("at_wini%d (compat): pci_reserve %d failed!\n",
                                w_instance, devind);
                }
        }
  }
}

/*===========================================================================*
 *                              w_do_open                                    *
 *===========================================================================*/
PRIVATE int w_do_open(dp, m_ptr)
struct driver *dp;
message *m_ptr;
{
/* Device open: Initialize the controller and read the partition table. */

  struct wini *wn;

  if (w_prepare(m_ptr->DEVICE) == NIL_DEV) return(ENXIO);

  wn = w_wn;

  /* If we've probed it before and it failed, don't probe it again. */
  if (wn->state & IGNORING) return ENXIO;

  /* If we haven't identified it yet, or it's gone deaf, 
   * (re-)identify it.
   */
  if (!(wn->state & IDENTIFIED) || (wn->state & DEAF)) {
        /* Try to identify the device. */
        if (w_identify() != OK) {
#if VERBOSE
                printf("%s: probe failed\n", w_name());
#endif
                if (wn->state & DEAF) w_reset();
                wn->state = IGNORING;
                return(ENXIO);
        }
          /* Do a test transaction unless it's a CD drive (then
           * we can believe the controller, and a test may fail
           * due to no CD being in the drive). If it fails, ignore
           * the device forever.
           */
          if (!(wn->state & ATAPI) && w_io_test() != OK) {
                wn->state |= IGNORING;
                return(ENXIO);
          }
  }

#if ENABLE_ATAPI
   if ((wn->state & ATAPI) && (m_ptr->COUNT & W_BIT))
        return(EACCES);
#endif

  /* Partition the drive if it's being opened for the first time,
   * or being opened after being closed.
   */
  if (wn->open_ct == 0) {
#if ENABLE_ATAPI
        if (wn->state & ATAPI) {
                int r;
                if ((r = atapi_open()) != OK) return(r);
        }
#endif

        /* Partition the disk. */
        partition(&w_dtab, w_drive * DEV_PER_DRIVE, P_PRIMARY, wn->state & ATAPI);
  }
  wn->open_ct++;
  return(OK);
}

/*===========================================================================*
 *                              w_prepare                                    *
 *===========================================================================*/
PRIVATE struct device *w_prepare(int device)
{
  /* Prepare for I/O on a device. */
  w_device = device;

  if (device < NR_MINORS) {                     /* d0, d0p[0-3], d1, ... */
        w_drive = device / DEV_PER_DRIVE;       /* save drive number */
        w_wn = &wini[w_drive];
        w_dv = &w_wn->part[device % DEV_PER_DRIVE];
  } else
  if ((unsigned) (device -= MINOR_d0p0s0) < NR_SUBDEVS) {/*d[0-7]p[0-3]s[0-3]*/
        w_drive = device / SUB_PER_DRIVE;
        w_wn = &wini[w_drive];
        w_dv = &w_wn->subpart[device % SUB_PER_DRIVE];
  } else {
        w_device = -1;
        return(NIL_DEV);
  }
  return(w_dv);
}

#define id_byte(n)      (&tmp_buf[2 * (n)])
#define id_word(n)      (((u16_t) id_byte(n)[0] <<  0) \
                        |((u16_t) id_byte(n)[1] <<  8))
#define id_longword(n)  (((u32_t) id_byte(n)[0] <<  0) \
                        |((u32_t) id_byte(n)[1] <<  8) \
                        |((u32_t) id_byte(n)[2] << 16) \
                        |((u32_t) id_byte(n)[3] << 24))

/*===========================================================================*
 *                              check_dma                                    *
 *===========================================================================*/
void
check_dma(struct wini *wn)
{
        unsigned long dma_status = 0;
        u32_t dma_base;
        int id_dma, ultra_dma;
        u16_t w;

        wn->dma= 0;

        if (disable_dma)
                return;

        w= id_word(ID_CAPABILITIES);
        id_dma= !!(w & ID_CAP_DMA);
        w= id_byte(ID_FIELD_VALIDITY)[0];
        ultra_dma= !!(w & ID_FV_88);
        dma_base= wn->base_dma;

        if (dma_base) {
                if (sys_inb(dma_base + DMA_STATUS, &dma_status) != OK) {
                        panic(w_name(),
                                "unable to read DMA status register",
                                NO_NUM);
                }
        }

        if (id_dma && dma_base) {
                w= id_word(ID_MULTIWORD_DMA);
                if (w_pci_debug &&
                (w & (ID_MWDMA_2_SUP|ID_MWDMA_1_SUP|ID_MWDMA_0_SUP))) {
                        printf(
                        "%s: multiword DMA modes supported:%s%s%s\n",
                                w_name(),
                                (w & ID_MWDMA_0_SUP) ? " 0" : "",
                                (w & ID_MWDMA_1_SUP) ? " 1" : "",
                                (w & ID_MWDMA_2_SUP) ? " 2" : "");
                }
                if (w_pci_debug &&
                (w & (ID_MWDMA_0_SEL|ID_MWDMA_1_SEL|ID_MWDMA_2_SEL))) {
                        printf(
                        "%s: multiword DMA mode selected:%s%s%s\n",
                                w_name(),
                                (w & ID_MWDMA_0_SEL) ? " 0" : "",
                                (w & ID_MWDMA_1_SEL) ? " 1" : "",
                                (w & ID_MWDMA_2_SEL) ? " 2" : "");
                }
                if (w_pci_debug && ultra_dma) {
                        w= id_word(ID_ULTRA_DMA);
                        if (w & (ID_UDMA_0_SUP|ID_UDMA_1_SUP|
                                ID_UDMA_2_SUP|ID_UDMA_3_SUP|
                                ID_UDMA_4_SUP|ID_UDMA_5_SUP)) {
                                printf(
                        "%s: Ultra DMA modes supported:%s%s%s%s%s%s\n",
                                w_name(),
                                (w & ID_UDMA_0_SUP) ? " 0" : "",
                                (w & ID_UDMA_1_SUP) ? " 1" : "",
                                (w & ID_UDMA_2_SUP) ? " 2" : "",
                                (w & ID_UDMA_3_SUP) ? " 3" : "",
                                (w & ID_UDMA_4_SUP) ? " 4" : "",
                                (w & ID_UDMA_5_SUP) ? " 5" : "");
                        }
                        if (w & (ID_UDMA_0_SEL|ID_UDMA_1_SEL|
                                ID_UDMA_2_SEL|ID_UDMA_3_SEL|
                                ID_UDMA_4_SEL|ID_UDMA_5_SEL)) {
                                printf(
                        "%s: Ultra DMA mode selected:%s%s%s%s%s%s\n",
                                w_name(),
                                (w & ID_UDMA_0_SEL) ? " 0" : "",
                                (w & ID_UDMA_1_SEL) ? " 1" : "",
                                (w & ID_UDMA_2_SEL) ? " 2" : "",
                                (w & ID_UDMA_3_SEL) ? " 3" : "",
                                (w & ID_UDMA_4_SEL) ? " 4" : "",
                                (w & ID_UDMA_5_SEL) ? " 5" : "");
                        }
                }
                wn->dma= 1;
        } else if (id_dma || dma_base) {
                printf("id_dma %d, dma_base 0x%x\n", id_dma, dma_base);
        } else
                printf("no DMA support\n");
}

/*===========================================================================*
 *                              w_identify                                   *
 *===========================================================================*/
PRIVATE int w_identify()
{
/* Find out if a device exists, if it is an old AT disk, or a newer ATA
 * drive, a removable media device, etc.
 */

  struct wini *wn = w_wn;
  struct command cmd;
  int s;
  u16_t w;
  unsigned long size;
  int prev_wakeup;
  int r;

  /* Try to identify the device. */
  cmd.ldh     = wn->ldhpref;
  cmd.command = ATA_IDENTIFY;

  /* In testing mode, a drive will get ignored at the first timeout. */
  w_testing = 1;

  /* Execute *_IDENTIFY with configured *_IDENTIFY timeout. */
  prev_wakeup = wakeup_ticks;
  wakeup_ticks = w_identify_wakeup_ticks;
  r = com_simple(&cmd);

  if (r == OK && w_waitfor(STATUS_DRQ, STATUS_DRQ) &&
        !(wn->w_status & (STATUS_ERR|STATUS_WF))) {

        /* Device information. */
        if ((s=sys_insw(wn->base_cmd + REG_DATA, SELF, tmp_buf, SECTOR_SIZE)) != OK)
                panic(w_name(),"Call to sys_insw() failed", s);

#if 0
        if (id_word(0) & ID_GEN_NOT_ATA)
        {
                printf("%s: not an ATA device?\n", w_name());
                wakeup_ticks = prev_wakeup;
                w_testing = 0;
                return ERR;
        }
#endif

        /* This is an ATA device. */
        wn->state |= SMART;

        /* Preferred CHS translation mode. */
        wn->pcylinders = id_word(1);
        wn->pheads = id_word(3);
        wn->psectors = id_word(6);
        size = (u32_t) wn->pcylinders * wn->pheads * wn->psectors;

        w= id_word(ID_CAPABILITIES);
        if ((w & ID_CAP_LBA) && size > 512L*1024*2) {
                /* Drive is LBA capable and is big enough to trust it to
                 * not make a mess of it.
                 */
                wn->ldhpref |= LDH_LBA;
                size = id_longword(60);

                w= id_word(ID_CSS);
                if (size < LBA48_CHECK_SIZE)
                {
                        /* No need to check for LBA48 */
                }
                else if (w & ID_CSS_LBA48) {
                        /* Drive is LBA48 capable (and LBA48 is turned on). */
                        if (id_longword(102)) {
                                /* If no. of sectors doesn't fit in 32 bits,
                                 * trunacte to this. So it's LBA32 for now.
                                 * This can still address devices up to 2TB
                                 * though.
                                 */
                                size = ULONG_MAX;
                        } else {
                                /* Actual number of sectors fits in 32 bits. */
                                size = id_longword(100);
                        }
                        wn->lba48 = 1;
                }

                check_dma(wn);
        }

        if (wn->lcylinders == 0 || wn->lheads == 0 || wn->lsectors == 0) {
                /* No BIOS parameters?  Then make some up. */
                wn->lcylinders = wn->pcylinders;
                wn->lheads = wn->pheads;
                wn->lsectors = wn->psectors;
                while (wn->lcylinders > 1024) {
                        wn->lheads *= 2;
                        wn->lcylinders /= 2;
                }
        }
#if ENABLE_ATAPI
  } else
  if (cmd.command = ATAPI_IDENTIFY,
        com_simple(&cmd) == OK && w_waitfor(STATUS_DRQ, STATUS_DRQ) &&
        !(wn->w_status & (STATUS_ERR|STATUS_WF))) {
        /* An ATAPI device. */
        wn->state |= ATAPI;

        /* Device information. */
        if ((s=sys_insw(wn->base_cmd + REG_DATA, SELF, tmp_buf, 512)) != OK)
                panic(w_name(),"Call to sys_insw() failed", s);

        size = 0;       /* Size set later. */
        check_dma(wn);
#endif
  } else {
        /* Not an ATA device; no translations, no special features.  Don't
         * touch it unless the BIOS knows about it.
         */
        if (wn->lcylinders == 0) { 
                wakeup_ticks = prev_wakeup;
                w_testing = 0;
                return(ERR);
        }       /* no BIOS parameters */
        wn->pcylinders = wn->lcylinders;
        wn->pheads = wn->lheads;
        wn->psectors = wn->lsectors;
        size = (u32_t) wn->pcylinders * wn->pheads * wn->psectors;
  }

  /* Restore wakeup_ticks and unset testing mode. */
  wakeup_ticks = prev_wakeup;
  w_testing = 0;

  /* Size of the whole drive */
  wn->part[0].dv_size = mul64u(size, SECTOR_SIZE);

  /* Reset/calibrate (where necessary) */
  if (w_specify() != OK && w_specify() != OK) {
        return(ERR);
  }

  if (wn->irq == NO_IRQ) {
          /* Everything looks OK; register IRQ so we can stop polling. */
          wn->irq = w_drive < 2 ? AT_WINI_0_IRQ : AT_WINI_1_IRQ;
          wn->irq_hook_id = wn->irq;    /* id to be returned if interrupt occurs */
          if ((s=sys_irqsetpolicy(wn->irq, IRQ_REENABLE, &wn->irq_hook_id)) != OK) 
                panic(w_name(), "couldn't set IRQ policy", s);
          if ((s=sys_irqenable(&wn->irq_hook_id)) != OK)
                panic(w_name(), "couldn't enable IRQ line", s);
  }
  wn->state |= IDENTIFIED;
  return(OK);
}

/*===========================================================================*
 *                              w_name                                       *
 *===========================================================================*/
PRIVATE char *w_name()
{
/* Return a name for the current device. */
  static char name[] = "AT0-D0";

  name[2] = '0' + w_instance;
  name[5] = '0' + w_drive;
  return name;
}

/*===========================================================================*
 *                              w_io_test                                    *
 *===========================================================================*/
PRIVATE int w_io_test(void)
{
        int r, save_dev;
        int save_timeout, save_errors, save_wakeup;
        iovec_t iov;
        static char *buf;

#ifdef CD_SECTOR_SIZE
#define BUFSIZE CD_SECTOR_SIZE
#else
#define BUFSIZE SECTOR_SIZE
#endif
        STATICINIT(buf, BUFSIZE);

        iov.iov_addr = (vir_bytes) buf;
        iov.iov_size = BUFSIZE;
        save_dev = w_device;

        /* Reduce timeout values for this test transaction. */
        save_timeout = timeout_ticks;
        save_errors = max_errors;
        save_wakeup = wakeup_ticks;

        if (!w_standard_timeouts) {
                timeout_ticks = system_hz * 4;
                wakeup_ticks = system_hz * 6;
                max_errors = 3;
        }

        w_testing = 1;

        /* Try I/O on the actual drive (not any (sub)partition). */
        if (w_prepare(w_drive * DEV_PER_DRIVE) == NIL_DEV)
                panic(w_name(), "Couldn't switch devices", NO_NUM);

        r = w_transfer(SELF, DEV_GATHER_S, cvu64(0), &iov, 1);

        /* Switch back. */
        if (w_prepare(save_dev) == NIL_DEV)
                panic(w_name(), "Couldn't switch back devices", NO_NUM);

        /* Restore parameters. */
        timeout_ticks = save_timeout;
        max_errors = save_errors;
        wakeup_ticks = save_wakeup;
        w_testing = 0;

        /* Test if everything worked. */
        if (r != OK || iov.iov_size != 0) {
                return ERR;
        }

        /* Everything worked. */

        return OK;
}

/*===========================================================================*
 *                              w_specify                                    *
 *===========================================================================*/
PRIVATE int w_specify()
{
/* Routine to initialize the drive after boot or when a reset is needed. */

  struct wini *wn = w_wn;
  struct command cmd;

  if ((wn->state & DEAF) && w_reset() != OK) {
        return(ERR);
  }

  if (!(wn->state & ATAPI)) {
        /* Specify parameters: precompensation, number of heads and sectors. */
        cmd.precomp = wn->precomp;
        cmd.count   = wn->psectors;
        cmd.ldh     = w_wn->ldhpref | (wn->pheads - 1);
        cmd.command = CMD_SPECIFY;              /* Specify some parameters */

        /* Output command block and see if controller accepts the parameters. */
        if (com_simple(&cmd) != OK) return(ERR);

        if (!(wn->state & SMART)) {
                /* Calibrate an old disk. */
                cmd.sector  = 0;
                cmd.cyl_lo  = 0;
                cmd.cyl_hi  = 0;
                cmd.ldh     = w_wn->ldhpref;
                cmd.command = CMD_RECALIBRATE;

                if (com_simple(&cmd) != OK) return(ERR);
        }
  }
  wn->state |= INITIALIZED;
  return(OK);
}

/*===========================================================================*
 *                              do_transfer                                  *
 *===========================================================================*/
PRIVATE int do_transfer(struct wini *wn, unsigned int precomp,
        unsigned int count, unsigned int sector,
        unsigned int opcode, int do_dma)
{
        struct command cmd;
        unsigned int sector_high;
        unsigned secspcyl = wn->pheads * wn->psectors;
        int do_lba48;

        sector_high= 0; /* For future extensions */

        do_lba48= 0;
        if (sector >= LBA48_CHECK_SIZE || sector_high != 0)
        {
                if (wn->lba48)
                        do_lba48= 1;
                else if (sector > LBA_MAX_SIZE || sector_high != 0)
                {
                        /* Strange sector count for LBA device */
                        return EIO;
                }
        }

        cmd.precomp = precomp;
        cmd.count   = count;
        if (do_dma)
        {
                cmd.command = opcode == DEV_SCATTER_S ? CMD_WRITE_DMA :
                        CMD_READ_DMA;
        }
        else
                cmd.command = opcode == DEV_SCATTER_S ? CMD_WRITE : CMD_READ;

        if (do_lba48) {
                if (do_dma)
                {
                        cmd.command = ((opcode == DEV_SCATTER_S) ?
                                CMD_WRITE_DMA_EXT : CMD_READ_DMA_EXT);
                }
                else
                {
                        cmd.command = ((opcode == DEV_SCATTER_S) ?
                                CMD_WRITE_EXT : CMD_READ_EXT);
                }
                cmd.count_prev= (count >> 8);
                cmd.sector  = (sector >>  0) & 0xFF;
                cmd.cyl_lo  = (sector >>  8) & 0xFF;
                cmd.cyl_hi  = (sector >> 16) & 0xFF;
                cmd.sector_prev= (sector >> 24) & 0xFF;
                cmd.cyl_lo_prev= (sector_high) & 0xFF;
                cmd.cyl_hi_prev= (sector_high >> 8) & 0xFF;
                cmd.ldh     = wn->ldhpref;

                return com_out_ext(&cmd);
        } else if (wn->ldhpref & LDH_LBA) {
                cmd.sector  = (sector >>  0) & 0xFF;
                cmd.cyl_lo  = (sector >>  8) & 0xFF;
                cmd.cyl_hi  = (sector >> 16) & 0xFF;
                cmd.ldh     = wn->ldhpref | ((sector >> 24) & 0xF);
        } else {
                int cylinder, head, sec;
                cylinder = sector / secspcyl;
                head = (sector % secspcyl) / wn->psectors;
                sec = sector % wn->psectors;
                cmd.sector  = sec + 1;
                cmd.cyl_lo  = cylinder & BYTE;
                cmd.cyl_hi  = (cylinder >> 8) & BYTE;
                cmd.ldh     = wn->ldhpref | head;
        }

        return com_out(&cmd);
}

void stop_dma(struct wini *wn)
{
        int r;

        /* Stop bus master operation */
        r= sys_outb(wn->base_dma + DMA_COMMAND, 0);
        if (r != 0) panic("at_wini", "stop_dma: sys_outb failed", r);
}

void start_dma(struct wini *wn, int do_write)
{
        u32_t v;
        int r;

        /* Assume disk reads. Start DMA */
        v= DMA_CMD_START;
        if (!do_write)
        {
                /* Disk reads generate PCI write cycles. */
                v |= DMA_CMD_WRITE;     
        }
        r= sys_outb(wn->base_dma + DMA_COMMAND, v);
        if (r != 0) panic("at_wini", "start_dma: sys_outb failed", r);
}

int error_dma(struct wini *wn)
{
        int r;
        u32_t v;

#define DMAERR(msg) \
        printf("at_wini%d: bad DMA: %s. Disabling DMA for drive %d.\n", \
                w_instance, msg, wn - wini);                            \
        printf("at_wini%d: workaround: set %s=1 in boot monitor.\n", \
                w_instance, NO_DMA_VAR); \
        return 1;       \

        r= sys_inb(wn->base_dma + DMA_STATUS, &v);
        if (r != 0) panic("at_wini", "w_transfer: sys_inb failed", r);

        if (!wn->dma_intseen) {
                /* DMA did not complete successfully */
                if (v & DMA_ST_BM_ACTIVE) {
                        DMAERR("DMA did not complete");
                } else if (v & DMA_ST_ERROR) {
                        DMAERR("DMA error");
                } else {
                        DMAERR("DMA buffer too small");
                }
        } else if ((v & DMA_ST_BM_ACTIVE)) {
                DMAERR("DMA buffer too large");
        }

        return 0;
}


/*===========================================================================*
 *                              w_transfer                                   *
 *===========================================================================*/
PRIVATE int w_transfer(proc_nr, opcode, position, iov, nr_req)
int proc_nr;                    /* process doing the request */
int opcode;                     /* DEV_GATHER_S or DEV_SCATTER_S */
u64_t position;                 /* offset on device to read or write */
iovec_t *iov;                   /* pointer to read or write request vector */
unsigned nr_req;                /* length of request vector */
{
  struct wini *wn = w_wn;
  iovec_t *iop, *iov_end = iov + nr_req;
  int n, r, s, errors, do_dma, do_write, do_copyout;
  unsigned long block, w_status;
  u64_t dv_size = w_dv->dv_size;
  unsigned nbytes;
  unsigned dma_buf_offset;
  size_t addr_offset = 0;

#if ENABLE_ATAPI
  if (w_wn->state & ATAPI) {
        return atapi_transfer(proc_nr, opcode, position, iov, nr_req);
  }
#endif

  /* Check disk address. */
  if (rem64u(position, SECTOR_SIZE) != 0) return(EINVAL);

  errors = 0;

  while (nr_req > 0) {
        /* How many bytes to transfer? */
        nbytes = 0;
        for (iop = iov; iop < iov_end; iop++) nbytes += iop->iov_size;
        if ((nbytes & SECTOR_MASK) != 0) return(EINVAL);

        /* Which block on disk and how close to EOF? */
        if (cmp64(position, dv_size) >= 0) return(OK);          /* At EOF */
        if (cmp64(add64ul(position, nbytes), dv_size) > 0)
                nbytes = diff64(dv_size, position);
        block = div64u(add64(w_dv->dv_base, position), SECTOR_SIZE);

        do_write= (opcode == DEV_SCATTER_S);
        do_dma= wn->dma;
        
        if (nbytes >= wn->max_count) {
                /* The drive can't do more then max_count at once. */
                nbytes = wn->max_count;
        }

        /* First check to see if a reinitialization is needed. */
        if (!(wn->state & INITIALIZED) && w_specify() != OK) return(EIO);

        if (do_dma) {
                stop_dma(wn);
                setup_dma(&nbytes, proc_nr, iov, addr_offset, do_write,
                        &do_copyout);
#if 0
                printf("nbytes = %d\n", nbytes);
#endif
        }

        /* Tell the controller to transfer nbytes bytes. */
        r = do_transfer(wn, wn->precomp, (nbytes >> SECTOR_SHIFT),
                block, opcode, do_dma);

        if (do_dma)
                start_dma(wn, do_write);

        if (opcode == DEV_SCATTER_S) {
                /* The specs call for a 400 ns wait after issuing the command.
                 * Reading the alternate status register is the suggested 
                 * way to implement this wait.
                 */
                if (sys_inb((wn->base_ctl+REG_CTL_ALTSTAT), &w_status) != OK)
                        panic(w_name(), "couldn't get status", NO_NUM);
        }

        if (do_dma) {
                /* Wait for the interrupt, check DMA status and optionally
                 * copy out.
                 */

                wn->dma_intseen = 0;
                if ((r = at_intr_wait()) != OK) 
                {
                        /* Don't retry if sector marked bad or too many
                         * errors.
                         */
                        if (r == ERR_BAD_SECTOR || ++errors == max_errors) {
                                w_command = CMD_IDLE;
                                return(EIO);
                        }
                        continue;
                }

                /* Wait for DMA_ST_INT to get set */
                if(!wn->dma_intseen) {
                        if(w_waitfor_dma(DMA_ST_INT, DMA_ST_INT))
                                wn->dma_intseen = 1;
                } 

                if(error_dma(wn)) {
                        wn->dma = 0;
                        continue;
                }

                stop_dma(wn);

                dma_buf_offset= 0;
                while (r == OK && nbytes > 0)
                {
                        n= iov->iov_size;
                        if (n > nbytes)
                                n= nbytes;

                        if (do_copyout)
                        {
                                if(proc_nr != SELF) {
                                   s= sys_safecopyto(proc_nr, iov->iov_addr,
                                        addr_offset,
                                        (vir_bytes)dma_buf+dma_buf_offset, n, D);
                                   if (s != OK)
                                   {
                                        panic(w_name(),
                                        "w_transfer: sys_vircopy failed",
                                                s);
                                   }
                                } else {
                                   memcpy((char *) iov->iov_addr + addr_offset,
                                         dma_buf + dma_buf_offset, n);
                                }
                        }

                        /* Book the bytes successfully transferred. */
                        nbytes -= n;
                        position= add64ul(position, n);
                        addr_offset += n;
                        if ((iov->iov_size -= n) == 0) {
                                iov++; nr_req--; addr_offset = 0;
                        }
                        dma_buf_offset += n;
                }
        }

        while (r == OK && nbytes > 0) {
                /* For each sector, wait for an interrupt and fetch the data
                 * (read), or supply data to the controller and wait for an
                 * interrupt (write).
                 */

                if (opcode == DEV_GATHER_S) {
                        /* First an interrupt, then data. */
                        if ((r = at_intr_wait()) != OK) {
                                /* An error, send data to the bit bucket. */
                                if (w_wn->w_status & STATUS_DRQ) {
                                        if ((s=sys_insw(wn->base_cmd+REG_DATA,
                                                SELF, tmp_buf,
                                                SECTOR_SIZE)) != OK)
                                        {
                                                panic(w_name(),
                                                "Call to sys_insw() failed",
                                                        s);
                                        }
                                }
                                break;
                        }
                }

                /* Wait for busy to clear. */
                if (!w_waitfor(STATUS_BSY, 0)) { r = ERR; break; }

                /* Wait for data transfer requested. */
                if (!w_waitfor(STATUS_DRQ, STATUS_DRQ)) { r = ERR; break; }

                /* Copy bytes to or from the device's buffer. */
                if (opcode == DEV_GATHER_S) {
                   if(proc_nr != SELF) {
                        s=sys_safe_insw(wn->base_cmd + REG_DATA, proc_nr, 
                                (void *) (iov->iov_addr), addr_offset,
                                        SECTOR_SIZE);
                   } else {
                        s=sys_insw(wn->base_cmd + REG_DATA, proc_nr, 
                                (void *) (iov->iov_addr + addr_offset),
                                        SECTOR_SIZE);
                   }
                   if(s != OK) {
                        panic(w_name(),"Call to sys_insw() failed", s);
                   }
                } else {
                   if(proc_nr != SELF) {
                        s=sys_safe_outsw(wn->base_cmd + REG_DATA, proc_nr,
                                (void *) (iov->iov_addr), addr_offset,
                                SECTOR_SIZE);
                   } else {
                        s=sys_outsw(wn->base_cmd + REG_DATA, proc_nr,
                                (void *) (iov->iov_addr + addr_offset),
                                SECTOR_SIZE);
                   }

                   if(s != OK) {
                        panic(w_name(),"Call to sys_outsw() failed", s);
                   }

                   /* Data sent, wait for an interrupt. */
                   if ((r = at_intr_wait()) != OK) break;
                }

                /* Book the bytes successfully transferred. */
                nbytes -= SECTOR_SIZE;
                position= add64u(position, SECTOR_SIZE);
                addr_offset += SECTOR_SIZE;
                if ((iov->iov_size -= SECTOR_SIZE) == 0) {
                        iov++;
                        nr_req--;
                        addr_offset = 0;
                }
        }

        /* Any errors? */
        if (r != OK) {
                /* Don't retry if sector marked bad or too many errors. */
                if (r == ERR_BAD_SECTOR || ++errors == max_errors) {
                        w_command = CMD_IDLE;
                        return(EIO);
                }
        }
  }

  w_command = CMD_IDLE;
  return(OK);
}

/*===========================================================================*
 *                              com_out                                      *
 *===========================================================================*/
PRIVATE int com_out(cmd)
struct command *cmd;            /* Command block */
{
/* Output the command block to the winchester controller and return status */

  struct wini *wn = w_wn;
  unsigned base_cmd = wn->base_cmd;
  unsigned base_ctl = wn->base_ctl;
  pvb_pair_t outbyte[7];                /* vector for sys_voutb() */
  int s;                                /* status for sys_(v)outb() */

  if (w_wn->state & IGNORING) return ERR;

  if (!w_waitfor(STATUS_BSY, 0)) {
        printf("%s: controller not ready\n", w_name());
        return(ERR);
  }

  /* Select drive. */
  if ((s=sys_outb(base_cmd + REG_LDH, cmd->ldh)) != OK)
        panic(w_name(),"Couldn't write register to select drive",s);

  if (!w_waitfor(STATUS_BSY, 0)) {
        printf("%s: com_out: drive not ready\n", w_name());
        return(ERR);
  }

  /* Schedule a wakeup call, some controllers are flaky. This is done with a
   * synchronous alarm. If a timeout occurs a notify from CLOCK is sent, so that
   * w_intr_wait() can call w_timeout() in case the controller was not able to
   * execute the command. Leftover timeouts are simply ignored by the main loop. 
   */
  sys_setalarm(wakeup_ticks, 0);

  wn->w_status = STATUS_ADMBSY;
  w_command = cmd->command;
  pv_set(outbyte[0], base_ctl + REG_CTL, wn->pheads >= 8 ? CTL_EIGHTHEADS : 0);
  pv_set(outbyte[1], base_cmd + REG_PRECOMP, cmd->precomp);
  pv_set(outbyte[2], base_cmd + REG_COUNT, cmd->count);
  pv_set(outbyte[3], base_cmd + REG_SECTOR, cmd->sector);
  pv_set(outbyte[4], base_cmd + REG_CYL_LO, cmd->cyl_lo);
  pv_set(outbyte[5], base_cmd + REG_CYL_HI, cmd->cyl_hi);
  pv_set(outbyte[6], base_cmd + REG_COMMAND, cmd->command);
  if ((s=sys_voutb(outbyte,7)) != OK)
        panic(w_name(),"Couldn't write registers with sys_voutb()",s);
  return(OK);
}

/*===========================================================================*
 *                              com_out_ext                                  *
 *===========================================================================*/
PRIVATE int com_out_ext(cmd)
struct command *cmd;            /* Command block */
{
/* Output the command block to the winchester controller and return status */

  struct wini *wn = w_wn;
  unsigned base_cmd = wn->base_cmd;
  unsigned base_ctl = wn->base_ctl;
  pvb_pair_t outbyte[11];               /* vector for sys_voutb() */
  int s;                                /* status for sys_(v)outb() */

  if (w_wn->state & IGNORING) return ERR;

  if (!w_waitfor(STATUS_BSY, 0)) {
        printf("%s: controller not ready\n", w_name());
        return(ERR);
  }

  /* Select drive. */
  if ((s=sys_outb(base_cmd + REG_LDH, cmd->ldh)) != OK)
        panic(w_name(),"Couldn't write register to select drive",s);

  if (!w_waitfor(STATUS_BSY, 0)) {
        printf("%s: com_out: drive not ready\n", w_name());
        return(ERR);
  }

  /* Schedule a wakeup call, some controllers are flaky. This is done with a
   * synchronous alarm. If a timeout occurs a notify from CLOCK is sent, so that
   * w_intr_wait() can call w_timeout() in case the controller was not able to
   * execute the command. Leftover timeouts are simply ignored by the main loop. 
   */
  sys_setalarm(wakeup_ticks, 0);

  wn->w_status = STATUS_ADMBSY;
  w_command = cmd->command;
  pv_set(outbyte[0], base_ctl + REG_CTL, 0);
  pv_set(outbyte[1], base_cmd + REG_COUNT, cmd->count_prev);
  pv_set(outbyte[2], base_cmd + REG_SECTOR, cmd->sector_prev);
  pv_set(outbyte[3], base_cmd + REG_CYL_LO, cmd->cyl_lo_prev);
  pv_set(outbyte[4], base_cmd + REG_CYL_HI, cmd->cyl_hi_prev);
  pv_set(outbyte[5], base_cmd + REG_COUNT, cmd->count);
  pv_set(outbyte[6], base_cmd + REG_SECTOR, cmd->sector);
  pv_set(outbyte[7], base_cmd + REG_CYL_LO, cmd->cyl_lo);
  pv_set(outbyte[8], base_cmd + REG_CYL_HI, cmd->cyl_hi);
  pv_set(outbyte[9], base_cmd + REG_COMMAND, cmd->command);
  if ((s=sys_voutb(outbyte, 10)) != OK)
        panic(w_name(),"Couldn't write registers with sys_voutb()",s);

  return(OK);
}
/*===========================================================================*
 *                              setup_dma                                    *
 *===========================================================================*/
PRIVATE void setup_dma(sizep, proc_nr, iov, addr_offset, do_write,
        do_copyoutp)
unsigned *sizep;
int proc_nr;
iovec_t *iov;
size_t addr_offset;
int do_write;
int *do_copyoutp;
{
        phys_bytes phys, user_phys;
        unsigned n, offset, size;
        int i, j, r, bad;
        unsigned long v;
        struct wini *wn = w_wn;
        int verbose = 0;

        /* First try direct scatter/gather to the supplied buffers */
        size= *sizep;
        i= 0;   /* iov index */
        j= 0;   /* prdt index */
        bad= 0;
        offset= 0;      /* Offset in current iov */

        if(verbose)
                printf("at_wini: setup_dma: proc_nr %d\n", proc_nr);

        while (size > 0)
        {
           if(verbose)  {
                printf(
                "at_wini: setup_dma: iov[%d]: addr 0x%x, size %d offset %d, size %d\n",
                        i, iov[i].iov_addr, iov[i].iov_size, offset, size);
           }
                        
                n= iov[i].iov_size-offset;
                if (n > size)
                        n= size;
                if (n == 0 || (n & 1))
                        panic("at_wini", "bad size in iov", iov[i].iov_size);
                if(proc_nr != SELF) {
                        r= sys_umap(proc_nr, VM_GRANT, iov[i].iov_addr, n,
                                &user_phys);
                        if (r != 0)
                                panic("at_wini",
                                        "can't map user buffer (VM_GRANT)", r);
                        user_phys += offset + addr_offset;
                } else {
                        r= sys_umap(proc_nr, VM_D,
                                iov[i].iov_addr+offset+addr_offset, n,
                                &user_phys);
                        if (r != 0)
                                panic("at_wini",
                                        "can't map user buffer (VM_D)", r);
                }
                if (user_phys & 1)
                {
                        /* Buffer is not aligned */
                        printf("setup_dma: user buffer is not aligned\n");
                        bad= 1;
                        break;
                }

                /* vector is not allowed to cross a 64K boundary */
                if (user_phys/0x10000 != (user_phys+n-1)/0x10000)
                        n= ((user_phys/0x10000)+1)*0x10000 - user_phys;

                /* vector is not allowed to be bigger than 64K, but we get that
                 * for free.
                 */

                if (j >= N_PRDTE)
                {
                        /* Too many entries */

                        bad= 1;
                        break;
                }

                prdt[j].prdte_base= user_phys;
                prdt[j].prdte_count= n;
                prdt[j].prdte_reserved= 0;
                prdt[j].prdte_flags= 0;
                j++;

                offset += n;
                if (offset >= iov[i].iov_size)
                {
                        i++;
                        offset= 0;
                        addr_offset= 0;
                }

                size -= n;
        }

        if (!bad)
        {
                if (j <= 0 || j > N_PRDTE)
                        panic("at_wini", "bad prdt index", j);
                prdt[j-1].prdte_flags |= PRDTE_FL_EOT;

           if(verbose) {
                printf("dma not bad\n");
                for (i= 0; i<j; i++) {
                        printf("prdt[%d]: base 0x%x, size %d, flags 0x%x\n",
                                i, prdt[i].prdte_base, prdt[i].prdte_count,
                                prdt[i].prdte_flags);
                }
           }
        }

        /* The caller needs to perform a copy-out from the dma buffer if
         * this is a read request and we can't DMA directly to the user's
         * buffers.
         */
        *do_copyoutp= (!do_write && bad);

        if (bad)
        {
                if(verbose)
                        printf("partially bad dma\n");
                /* Adjust request size */
                size= *sizep;
                if (size > ATA_DMA_BUF_SIZE)
                        *sizep= size= ATA_DMA_BUF_SIZE;

                if (do_write)
                {
                        /* Copy-in */
                        for (offset= 0; offset < size; offset += n)
                        {
                                n= size-offset;
                                if (n > iov->iov_size)
                                        n= iov->iov_size;
                        
                                if(proc_nr != SELF) {
                                  r= sys_safecopyfrom(proc_nr, iov->iov_addr,
                                        addr_offset, (vir_bytes)dma_buf+offset,
                                        n, D);
                                  if (r != OK)
                                  {
                                        panic(w_name(),
                                        "setup_dma: sys_vircopy failed", r);
                                  }
                                } else {
                                  memcpy(dma_buf + offset,
                                         (char *) iov->iov_addr + addr_offset,
                                         n);
                                }
                                iov++;
                                addr_offset= 0;
                        }
                }
        
                /* Fill-in the physical region descriptor table */
                phys= dma_buf_phys;
                if (phys & 1)
                {
                        /* Two byte alignment is required */
                        panic("at_wini", "bad buffer alignment in setup_dma",
                                phys);
                }
                for (j= 0; j<N_PRDTE; i++)
                {
                        if (size == 0)
                        {
                                panic("at_wini", "bad size in setup_dma",
                                        size);
                        }
                        if (size & 1)
                        {
                                /* Two byte alignment is required for size */
                                panic("at_wini",
                                        "bad size alignment in setup_dma",
                                        size);
                        }
                        n= size;

                        /* Buffer is not allowed to cross a 64K boundary */
                        if (phys / 0x10000 != (phys+n-1) / 0x10000)
                        {
                                n= ((phys/0x10000)+1)*0x10000 - phys;
                        }
                        prdt[j].prdte_base= phys;
                        prdt[j].prdte_count= n;
                        prdt[j].prdte_reserved= 0;
                        prdt[j].prdte_flags= 0;

                        size -= n;
                        if (size == 0)
                        {
                                prdt[j].prdte_flags |= PRDTE_FL_EOT;
                                break;
                        }
                }
                if (size != 0)
                        panic("at_wini", "size to large for prdt", NO_NUM);

           if(verbose) {
                for (i= 0; i<=j; i++)
                {
                        printf("prdt[%d]: base 0x%x, size %d, flags 0x%x\n",
                                i, prdt[i].prdte_base, prdt[i].prdte_count,
                                prdt[i].prdte_flags);
                }
          }
        }

        /* Verify that the bus master is not active */
        r= sys_inb(wn->base_dma + DMA_STATUS, &v);
        if (r != 0) panic("at_wini", "setup_dma: sys_inb failed", r);
        if (v & DMA_ST_BM_ACTIVE)
                panic("at_wini", "Bus master IDE active", NO_NUM);

        if (prdt_phys & 3)
                panic("at_wini", "prdt not aligned", prdt_phys);
        r= sys_outl(wn->base_dma + DMA_PRDTP, prdt_phys);
        if (r != 0) panic("at_wini", "setup_dma: sys_outl failed", r);

        /* Clear interrupt and error flags */
        r= sys_outb(wn->base_dma + DMA_STATUS, DMA_ST_INT | DMA_ST_ERROR);
        if (r != 0) panic("at_wini", "setup_dma: sys_outb failed", r);

}


/*===========================================================================*
 *                              w_need_reset                                 *
 *===========================================================================*/
PRIVATE void w_need_reset()
{
/* The controller needs to be reset. */
  struct wini *wn;
  int dr = 0;

  for (wn = wini; wn < &wini[MAX_DRIVES]; wn++, dr++) {
        if (wn->base_cmd == w_wn->base_cmd) {
                wn->state |= DEAF;
                wn->state &= ~INITIALIZED;
        }
  }
}

/*===========================================================================*
 *                              w_do_close                                   *
 *===========================================================================*/
PRIVATE int w_do_close(dp, m_ptr)
struct driver *dp;
message *m_ptr;
{
/* Device close: Release a device. */
  if (w_prepare(m_ptr->DEVICE) == NIL_DEV)
        return(ENXIO);
  w_wn->open_ct--;
#if ENABLE_ATAPI
  if (w_wn->open_ct == 0 && (w_wn->state & ATAPI)) atapi_close();
#endif
  return(OK);
}

/*===========================================================================*
 *                              com_simple                                   *
 *===========================================================================*/
PRIVATE int com_simple(cmd)
struct command *cmd;            /* Command block */
{
/* A simple controller command, only one interrupt and no data-out phase. */
  int r;

  if (w_wn->state & IGNORING) return ERR;

  if ((r = com_out(cmd)) == OK) r = at_intr_wait();
  w_command = CMD_IDLE;
  return(r);
}

/*===========================================================================*
 *                              w_timeout                                    *
 *===========================================================================*/
PRIVATE void w_timeout(void)
{
  struct wini *wn = w_wn;

  switch (w_command) {
  case CMD_IDLE:
        break;          /* fine */
  case CMD_READ:
  case CMD_READ_EXT:
  case CMD_WRITE:
  case CMD_WRITE_EXT:
        /* Impossible, but not on PC's:  The controller does not respond. */

        /* Limiting multisector I/O seems to help. */
        if (wn->max_count > 8 * SECTOR_SIZE) {
                wn->max_count = 8 * SECTOR_SIZE;
        } else {
                wn->max_count = SECTOR_SIZE;
        }
        /*FALL THROUGH*/
  default:
        /* Some other command. */
        if (w_testing)  wn->state |= IGNORING;  /* Kick out this drive. */
        else if (!w_silent) printf("%s: timeout on command 0x%02x\n",
                w_name(), w_command);
        w_need_reset();
        wn->w_status = 0;
  }
}

/*===========================================================================*
 *                              w_reset                                      *
 *===========================================================================*/
PRIVATE int w_reset()
{
/* Issue a reset to the controller.  This is done after any catastrophe,
 * like the controller refusing to respond.
 */
  int s;
  struct wini *wn = w_wn;

  /* Don't bother if this drive is forgotten. */
  if (w_wn->state & IGNORING) return ERR;

  /* Wait for any internal drive recovery. */
  tickdelay(RECOVERY_TICKS);

  /* Strobe reset bit */
  if ((s=sys_outb(wn->base_ctl + REG_CTL, CTL_RESET)) != OK)
        panic(w_name(),"Couldn't strobe reset bit",s);
  tickdelay(DELAY_TICKS);
  if ((s=sys_outb(wn->base_ctl + REG_CTL, 0)) != OK)
        panic(w_name(),"Couldn't strobe reset bit",s);
  tickdelay(DELAY_TICKS);

  /* Wait for controller ready */
  if (!w_waitfor(STATUS_BSY, 0)) {
        printf("%s: reset failed, drive busy\n", w_name());
        return(ERR);
  }

  /* The error register should be checked now, but some drives mess it up. */

  for (wn = wini; wn < &wini[MAX_DRIVES]; wn++) {
        if (wn->base_cmd == w_wn->base_cmd) {
                wn->state &= ~DEAF;
                if (w_wn->irq_need_ack) {
                        /* Make sure irq is actually enabled.. */
                        sys_irqenable(&w_wn->irq_hook_id);
                }
        }
  }
                

  return(OK);
}

/*===========================================================================*
 *                              w_intr_wait                                  *
 *===========================================================================*/
PRIVATE void w_intr_wait()
{
/* Wait for a task completion interrupt. */

  int r;
  unsigned long w_status;
  message m;

  if (w_wn->irq != NO_IRQ) {
        /* Wait for an interrupt that sets w_status to "not busy".
         * (w_timeout() also clears w_status.)
         */
        while (w_wn->w_status & (STATUS_ADMBSY|STATUS_BSY)) {
                int rr;
                if((rr=sef_receive(ANY, &m)) != OK)
                        panic("at_wini", "sef_receive(ANY) failed", rr);
                if (is_notify(m.m_type)) {
                        switch (_ENDPOINT_P(m.m_source)) {
                                case CLOCK:
                                        /* Timeout. */
                                        w_timeout(); /* a.o. set w_status */
                                        break;
                                case HARDWARE:
                                        /* Interrupt. */
                                        r= sys_inb(w_wn->base_cmd +
                                                        REG_STATUS, &w_status);
                                        if (r != 0)
                                                panic("at_wini",
                                                        "sys_inb failed", r);
                                        w_wn->w_status= w_status;
                                        ack_irqs(m.NOTIFY_ARG);
                                        break;
                                default:
                                        /* 
                                         * unhandled message.  queue it and
                                         * handle it in the libdriver loop.
                                         */
                                        mq_queue(&m);
                        }
                }
                else {
                        /* 
                         * unhandled message.  queue it and handle it in the
                         * libdriver loop.
                         */
                        mq_queue(&m);
                }
        }
  } else {
        /* Interrupt not yet allocated; use polling. */
        (void) w_waitfor(STATUS_BSY, 0);
  }
}

/*===========================================================================*
 *                              at_intr_wait                                 *
 *===========================================================================*/
PRIVATE int at_intr_wait()
{
/* Wait for an interrupt, study the status bits and return error/success. */
  int r, s;
  unsigned long inbval;

  w_intr_wait();
  if ((w_wn->w_status & (STATUS_BSY | STATUS_WF | STATUS_ERR)) == 0) {
        r = OK;
  } else {
        if ((s=sys_inb(w_wn->base_cmd + REG_ERROR, &inbval)) != OK)
                panic(w_name(),"Couldn't read register",s);
        if ((w_wn->w_status & STATUS_ERR) && (inbval & ERROR_BB)) {
                r = ERR_BAD_SECTOR;     /* sector marked bad, retries won't help */
        } else {
                r = ERR;                /* any other error */
        }
  }
  w_wn->w_status |= STATUS_ADMBSY;      /* assume still busy with I/O */
  return(r);
}

/*===========================================================================*
 *                              w_waitfor                                    *
 *===========================================================================*/
PRIVATE int w_waitfor(mask, value)
int mask;                       /* status mask */
int value;                      /* required status */
{
/* Wait until controller is in the required state.  Return zero on timeout.
 * An alarm that set a timeout flag is used. TIMEOUT is in micros, we need
 * ticks. Disabling the alarm is not needed, because a static flag is used
 * and a leftover timeout cannot do any harm.
 */
  unsigned long w_status;
  clock_t t0, t1;
  int s;

  getuptime(&t0);
  do {
        if ((s=sys_inb(w_wn->base_cmd + REG_STATUS, &w_status)) != OK)
                panic(w_name(),"Couldn't read register",s);
        w_wn->w_status= w_status;
        if ((w_wn->w_status & mask) == value) {
                return 1;
        }
  } while ((s=getuptime(&t1)) == OK && (t1-t0) < timeout_ticks );
  if (OK != s) printf("AT_WINI: warning, get_uptime failed: %d\n",s);

  w_need_reset();                       /* controller gone deaf */
  return(0);
}

/*===========================================================================*
 *                              w_waitfor_dma                                *
 *===========================================================================*/
PRIVATE int w_waitfor_dma(mask, value)
int mask;                       /* status mask */
int value;                      /* required status */
{
/* Wait until controller is in the required state.  Return zero on timeout.
 * An alarm that set a timeout flag is used. TIMEOUT is in micros, we need
 * ticks. Disabling the alarm is not needed, because a static flag is used
 * and a leftover timeout cannot do any harm.
 */
  unsigned long w_status;
  clock_t t0, t1;
  int s;

  getuptime(&t0);
  do {
        if ((s=sys_inb(w_wn->base_dma + DMA_STATUS, &w_status)) != OK)
                panic(w_name(),"Couldn't read register",s);
        if ((w_status & mask) == value) {
                return 1;
        }
  } while ((s=getuptime(&t1)) == OK && (t1-t0) < timeout_ticks );
  if (OK != s) printf("AT_WINI: warning, get_uptime failed: %d\n",s);

  return(0);
}

/*===========================================================================*
 *                              w_geometry                                   *
 *===========================================================================*/
PRIVATE void w_geometry(entry)
struct partition *entry;
{
  struct wini *wn = w_wn;

  if (wn->state & ATAPI) {              /* Make up some numbers. */
        entry->cylinders = div64u(wn->part[0].dv_size, SECTOR_SIZE) / (64*32);
        entry->heads = 64;
        entry->sectors = 32;
  } else {                              /* Return logical geometry. */
        entry->cylinders = wn->lcylinders;
        entry->heads = wn->lheads;
        entry->sectors = wn->lsectors;
  }
}

#if ENABLE_ATAPI
/*===========================================================================*
 *                              atapi_open                                   *
 *===========================================================================*/
PRIVATE int atapi_open()
{
/* Should load and lock the device and obtain its size.  For now just set the
 * size of the device to something big.  What is really needed is a generic
 * SCSI layer that does all this stuff for ATAPI and SCSI devices (kjb). (XXX)
 */
  w_wn->part[0].dv_size = mul64u(800L*1024, 1024);
  return(OK);
}

/*===========================================================================*
 *                              atapi_close                                  *
 *===========================================================================*/
PRIVATE void atapi_close()
{
/* Should unlock the device.  For now do nothing.  (XXX) */
}

void sense_request(void)
{
        int r, i;
        static u8_t sense[100], packet[ATAPI_PACKETSIZE];

        packet[0] = SCSI_SENSE;
        packet[1] = 0;
        packet[2] = 0;
        packet[3] = 0;
        packet[4] = SENSE_PACKETSIZE;
        packet[5] = 0;
        packet[7] = 0;
        packet[8] = 0;
        packet[9] = 0;
        packet[10] = 0;
        packet[11] = 0;

        for(i = 0; i < SENSE_PACKETSIZE; i++) sense[i] = 0xff;
        r = atapi_sendpacket(packet, SENSE_PACKETSIZE, 0);
        if (r != OK) { printf("request sense command failed\n"); return; }
        if (atapi_intr_wait(0, 0) <= 0) { printf("WARNING: request response failed\n"); }

        if (sys_insw(w_wn->base_cmd + REG_DATA, SELF, (void *) sense, SENSE_PACKETSIZE) != OK)
                printf("WARNING: sense reading failed\n");

        printf("sense data:");
        for(i = 0; i < SENSE_PACKETSIZE; i++) printf(" %02x", sense[i]);
        printf("\n");
}

/*===========================================================================*
 *                              atapi_transfer                               *
 *===========================================================================*/
PRIVATE int atapi_transfer(proc_nr, opcode, position, iov, nr_req)
int proc_nr;                    /* process doing the request */
int opcode;                     /* DEV_GATHER_S or DEV_SCATTER_S */
u64_t position;                 /* offset on device to read or write */
iovec_t *iov;                   /* pointer to read or write request vector */
unsigned nr_req;                /* length of request vector */
{
  struct wini *wn = w_wn;
  iovec_t *iop, *iov_end = iov + nr_req;
  int r, s, errors, fresh;
  u64_t pos;
  unsigned long block;
  u64_t dv_size = w_dv->dv_size;
  unsigned nbytes, nblocks, before, chunk;
  static u8_t packet[ATAPI_PACKETSIZE];
  size_t addr_offset = 0;
  int dmabytes = 0, piobytes = 0;

  errors = fresh = 0;

  while (nr_req > 0 && !fresh) {
        int do_dma = wn->dma && w_atapi_dma;
        /* The Minix block size is smaller than the CD block size, so we
         * may have to read extra before or after the good data.
         */
        pos = add64(w_dv->dv_base, position);
        block = div64u(pos, CD_SECTOR_SIZE);
        before = rem64u(pos, CD_SECTOR_SIZE);

        if(before)
                do_dma = 0;

        /* How many bytes to transfer? */
        nbytes = 0;
        for (iop = iov; iop < iov_end; iop++) {
                nbytes += iop->iov_size;
                if(iop->iov_size % CD_SECTOR_SIZE)
                        do_dma = 0;
        }

        /* Data comes in as words, so we have to enforce even byte counts. */
        if ((before | nbytes) & 1) return(EINVAL);

        /* Which block on disk and how close to EOF? */
        if (cmp64(position, dv_size) >= 0) return(OK);          /* At EOF */
        if (cmp64(add64ul(position, nbytes), dv_size) > 0)
                nbytes = diff64(dv_size, position);

        nblocks = (before + nbytes + CD_SECTOR_SIZE - 1) / CD_SECTOR_SIZE;

        /* First check to see if a reinitialization is needed. */
        if (!(wn->state & INITIALIZED) && w_specify() != OK) return(EIO);

        /* Build an ATAPI command packet. */
        packet[0] = SCSI_READ10;
        packet[1] = 0;
        packet[2] = (block >> 24) & 0xFF;
        packet[3] = (block >> 16) & 0xFF;
        packet[4] = (block >>  8) & 0xFF;
        packet[5] = (block >>  0) & 0xFF;
        packet[6] = 0;
        packet[7] = (nblocks >> 8) & 0xFF;
        packet[8] = (nblocks >> 0) & 0xFF;
        packet[9] = 0;
        packet[10] = 0;
        packet[11] = 0;

        if(do_dma) {
                int do_copyout = 0;
                stop_dma(wn);
                setup_dma(&nbytes, proc_nr, iov, addr_offset, 0,
                        &do_copyout);
                if(do_copyout || (nbytes != nblocks * CD_SECTOR_SIZE)) {
                        stop_dma(wn);
                        do_dma = 0;
                }
        }

        /* Tell the controller to execute the packet command. */
        r = atapi_sendpacket(packet, nblocks * CD_SECTOR_SIZE, do_dma);
        if (r != OK) goto err;

        if(do_dma) {
                wn->dma_intseen = 0;
                start_dma(wn, 0);
                w_intr_wait();
                if(!wn->dma_intseen) {
                        if(w_waitfor_dma(DMA_ST_INT, DMA_ST_INT)) {
                                wn->dma_intseen = 1;
                        }
                }
                if(error_dma(wn)) {
                        printf("Disabling DMA (ATAPI)\n");
                        wn->dma = 0;
                } else {
                        dmabytes += nbytes;
                        while (nbytes > 0) {
                                size_t chunk;
                                chunk = nbytes;
                                if (chunk > iov->iov_size)
                                        chunk = iov->iov_size;
                                position= add64ul(position, chunk);
                                nbytes -= chunk;
                                if ((iov->iov_size -= chunk) == 0) {
                                        iov++;
                                        nr_req--;
                                }
                        }
                }
                continue;
        }

        /* Read chunks of data. */
        while ((r = atapi_intr_wait(do_dma, nblocks * CD_SECTOR_SIZE)) > 0) {
                size_t count;
                count = r;

                while (before > 0 && count > 0) {       /* Discard before. */
                        chunk = before;
                        if (chunk > count) chunk = count;
                        if (chunk > DMA_BUF_SIZE) chunk = DMA_BUF_SIZE;
                        if ((s=sys_insw(wn->base_cmd + REG_DATA,
                                SELF, tmp_buf, chunk)) != OK)
                                panic(w_name(),"Call to sys_insw() failed", s);
                        before -= chunk;
                        count -= chunk;
                }

                while (nbytes > 0 && count > 0) {       /* Requested data. */
                        chunk = nbytes;
                        if (chunk > count) chunk = count;
                        if (chunk > iov->iov_size) chunk = iov->iov_size;
                        if(proc_nr != SELF) {
                                s=sys_safe_insw(wn->base_cmd + REG_DATA,
                                        proc_nr, (void *) iov->iov_addr,
                                        addr_offset, chunk);
                        } else {
                                s=sys_insw(wn->base_cmd + REG_DATA, proc_nr,
                                        (void *) (iov->iov_addr + addr_offset),
                                        chunk);
                        }
                        if (s != OK)
                                panic(w_name(),"Call to sys_insw() failed", s);
                        position= add64ul(position, chunk);
                        nbytes -= chunk;
                        count -= chunk;
                        addr_offset += chunk;
                        piobytes += chunk;
                        fresh = 0;
                        if ((iov->iov_size -= chunk) == 0) {
                                iov++;
                                nr_req--;
                                fresh = 1;      /* new element is optional */
                                addr_offset = 0;
                        }

                }

                while (count > 0) {             /* Excess data. */
                        chunk = count;
                        if (chunk > DMA_BUF_SIZE) chunk = DMA_BUF_SIZE;
                        if ((s=sys_insw(wn->base_cmd + REG_DATA,
                                SELF, tmp_buf, chunk)) != OK)
                                panic(w_name(),"Call to sys_insw() failed", s);
                        count -= chunk;
                }
        }

        if (r < 0) {
  err:          /* Don't retry if too many errors. */
                if (atapi_debug) sense_request();
                if (++errors == max_errors) {
                        w_command = CMD_IDLE;
                        if (atapi_debug) printf("giving up (%d)\n", errors);
                        return(EIO);
                }
                if (atapi_debug) printf("retry (%d)\n", errors);
        }
  }

#if 0
  if(dmabytes) printf("dmabytes %d ", dmabytes);
  if(piobytes) printf("piobytes %d", piobytes);
  if(dmabytes || piobytes) printf("\n");
#endif

  w_command = CMD_IDLE;
  return(OK);
}

/*===========================================================================*
 *                              atapi_sendpacket                             *
 *===========================================================================*/
PRIVATE int atapi_sendpacket(packet, cnt, do_dma)
u8_t *packet;
unsigned cnt;
int do_dma;
{
/* Send an Atapi Packet Command */
  struct wini *wn = w_wn;
  pvb_pair_t outbyte[6];                /* vector for sys_voutb() */
  int s;

  if (wn->state & IGNORING) return ERR;

  /* Select Master/Slave drive */
  if ((s=sys_outb(wn->base_cmd + REG_DRIVE, wn->ldhpref)) != OK)
        panic(w_name(),"Couldn't select master/ slave drive",s);

  if (!w_waitfor(STATUS_BSY | STATUS_DRQ, 0)) {
        printf("%s: atapi_sendpacket: drive not ready\n", w_name());
        return(ERR);
  }

  /* Schedule a wakeup call, some controllers are flaky. This is done with
   * a synchronous alarm. If a timeout occurs a SYN_ALARM message is sent
   * from HARDWARE, so that w_intr_wait() can call w_timeout() in case the
   * controller was not able to execute the command. Leftover timeouts are
   * simply ignored by the main loop. 
   */
  sys_setalarm(wakeup_ticks, 0);

#if _WORD_SIZE > 2
  if (cnt > 0xFFFE) cnt = 0xFFFE;       /* Max data per interrupt. */
#endif

  w_command = ATAPI_PACKETCMD;
  pv_set(outbyte[0], wn->base_cmd + REG_FEAT, do_dma ? FEAT_DMA : 0);
  pv_set(outbyte[1], wn->base_cmd + REG_IRR, 0);
  pv_set(outbyte[2], wn->base_cmd + REG_SAMTAG, 0);
  pv_set(outbyte[3], wn->base_cmd + REG_CNT_LO, (cnt >> 0) & 0xFF);
  pv_set(outbyte[4], wn->base_cmd + REG_CNT_HI, (cnt >> 8) & 0xFF);
  pv_set(outbyte[5], wn->base_cmd + REG_COMMAND, w_command);
  if (atapi_debug) printf("cmd: %x  ", w_command);
  if ((s=sys_voutb(outbyte,6)) != OK)
        panic(w_name(),"Couldn't write registers with sys_voutb()",s);

  if (!w_waitfor(STATUS_BSY | STATUS_DRQ, STATUS_DRQ)) {
        printf("%s: timeout (BSY|DRQ -> DRQ)\n", w_name());
        return(ERR);
  }
  wn->w_status |= STATUS_ADMBSY;                /* Command not at all done yet. */

  /* Send the command packet to the device. */
  if ((s=sys_outsw(wn->base_cmd + REG_DATA, SELF, packet, ATAPI_PACKETSIZE)) != OK)
        panic(w_name(),"sys_outsw() failed", s);

  return(OK);
}


#endif /* ENABLE_ATAPI */

/*===========================================================================*
 *                              w_other                                      *
 *===========================================================================*/
PRIVATE int w_other(dr, m)
struct driver *dr;
message *m;
{
        int r, timeout, prev;

        if (m->m_type != DEV_IOCTL_S )
                return EINVAL;

        if (m->REQUEST == DIOCTIMEOUT) {
                r= sys_safecopyfrom(m->IO_ENDPT, (vir_bytes) m->IO_GRANT,
                        0, (vir_bytes)&timeout, sizeof(timeout), D);

                if(r != OK)
                    return r;
        
                if (timeout == 0) {
                        /* Restore defaults. */
                        timeout_ticks = DEF_TIMEOUT_TICKS;
                        max_errors = MAX_ERRORS;
                        wakeup_ticks = WAKEUP_TICKS;
                        w_silent = 0;
                } else if (timeout < 0) {
                        return EINVAL;
                } else  {
                        prev = wakeup_ticks;
        
                        if (!w_standard_timeouts) {
                                /* Set (lower) timeout, lower error
                                 * tolerance and set silent mode.
                                 */
                                wakeup_ticks = timeout;
                                max_errors = 3;
                                w_silent = 1;
        
                                if (timeout_ticks > timeout)
                                        timeout_ticks = timeout;
                        }
        
                        r= sys_safecopyto(m->IO_ENDPT, (vir_bytes) m->IO_GRANT,
                                0, (vir_bytes)&prev, sizeof(prev), D);

                        if(r != OK)
                                return r;
                }
        
                return OK;
        } else  if (m->REQUEST == DIOCOPENCT) {
                int count;
                if (w_prepare(m->DEVICE) == NIL_DEV) return ENXIO;
                count = w_wn->open_ct;
                r= sys_safecopyto(m->IO_ENDPT, (vir_bytes) m->IO_GRANT,
                        0, (vir_bytes)&count, sizeof(count), D);

                if(r != OK)
                        return r;

                return OK;
        }
        return EINVAL;
}

/*===========================================================================*
 *                              w_hw_int                                     *
 *===========================================================================*/
PRIVATE int w_hw_int(dr, m)
struct driver *dr;
message *m;
{
  /* Leftover interrupt(s) received; ack it/them. */
  ack_irqs(m->NOTIFY_ARG);

  return OK;
}


/*===========================================================================*
 *                              ack_irqs                                     *
 *===========================================================================*/
PRIVATE void ack_irqs(unsigned int irqs)
{
  unsigned int drive;
  unsigned long w_status;

  for (drive = 0; drive < MAX_DRIVES; drive++) {
        if (!(wini[drive].state & IGNORING) && wini[drive].irq_need_ack &&
                ((1L << wini[drive].irq) & irqs)) {
                if (sys_inb((wini[drive].base_cmd + REG_STATUS),
                        &w_status) != OK)
                {
                        panic(w_name(), "couldn't ack irq on drive %d\n",
                                drive);
                }
                wini[drive].w_status= w_status;
                sys_inb(wini[drive].base_dma + DMA_STATUS, &w_status);
                if(w_status & DMA_ST_INT) {
                        sys_outb(wini[drive].base_dma + DMA_STATUS, DMA_ST_INT);
                        wini[drive].dma_intseen = 1;
                }
                if (sys_irqenable(&wini[drive].irq_hook_id) != OK)
                        printf("couldn't re-enable drive %d\n", drive);
        }
  }
}


#define STSTR(a) if (status & STATUS_ ## a) { strcat(str, #a); strcat(str, " "); }
#define ERRSTR(a) if (e & ERROR_ ## a) { strcat(str, #a); strcat(str, " "); }
char *strstatus(int status)
{
        static char str[200];
        str[0] = '\0';

        STSTR(BSY);
        STSTR(DRDY);
        STSTR(DMADF);
        STSTR(SRVCDSC);
        STSTR(DRQ);
        STSTR(CORR);
        STSTR(CHECK);
        return str;
}

char *strerr(int e)
{
        static char str[200];
        str[0] = '\0';

        ERRSTR(BB);
        ERRSTR(ECC);
        ERRSTR(ID);
        ERRSTR(AC);
        ERRSTR(TK);
        ERRSTR(DM);

        return str;
}

#if ENABLE_ATAPI

/*===========================================================================*
 *                              atapi_intr_wait                              *
 *===========================================================================*/
PRIVATE int atapi_intr_wait(int do_dma, size_t max)
{
/* Wait for an interrupt and study the results.  Returns a number of bytes
 * that need to be transferred, or an error code.
 */
  struct wini *wn = w_wn;
  pvb_pair_t inbyte[4];         /* vector for sys_vinb() */
  int s;                        /* status for sys_vinb() */
  int e;
  int len;
  int irr;
  int r;
  int phase;

  w_intr_wait();

  /* Request series of device I/O. */
  inbyte[0].port = wn->base_cmd + REG_ERROR;
  inbyte[1].port = wn->base_cmd + REG_CNT_LO;
  inbyte[2].port = wn->base_cmd + REG_CNT_HI;
  inbyte[3].port = wn->base_cmd + REG_IRR;
  if ((s=sys_vinb(inbyte, 4)) != OK)
        panic(w_name(),"ATAPI failed sys_vinb()", s);
  e = inbyte[0].value;
  len = inbyte[1].value;
  len |= inbyte[2].value << 8;
  irr = inbyte[3].value;

  if (wn->w_status & (STATUS_BSY | STATUS_CHECK)) {
        if (atapi_debug) {
                printf("atapi fail:  S=%x=%s E=%02x=%s L=%04x I=%02x\n", wn->w_status, strstatus(wn->w_status), e, strerr(e), len, irr);
        }
        return ERR;
  }

  phase = (wn->w_status & STATUS_DRQ) | (irr & (IRR_COD | IRR_IO));

  switch (phase) {
  case IRR_COD | IRR_IO:
        if (ATAPI_DEBUG) printf("ACD: Phase Command Complete\n");
        r = OK;
        break;
  case 0:
        if (ATAPI_DEBUG) printf("ACD: Phase Command Aborted\n");
        r = ERR;
        break;
  case STATUS_DRQ | IRR_COD:
        if (ATAPI_DEBUG) printf("ACD: Phase Command Out\n");
        r = ERR;
        break;
  case STATUS_DRQ:
        if (ATAPI_DEBUG) printf("ACD: Phase Data Out %d\n", len);
        r = len;
        break;
  case STATUS_DRQ | IRR_IO:
        if (ATAPI_DEBUG) printf("ACD: Phase Data In %d\n", len);
        r = len;
        break;
  default:
        if (ATAPI_DEBUG) printf("ACD: Phase Unknown\n");
        r = ERR;
        break;
  }

  wn->w_status |= STATUS_ADMBSY;        /* Assume not done yet. */
  return(r);
}

#endif /* ENABLE_ATAPI */

#undef sys_voutb
#undef sys_vinb

PRIVATE int at_voutb(int line, pvb_pair_t *pvb, int n)
{
  int s, i;
  if ((s=sys_voutb(pvb,n)) == OK)
        return OK;
  printf("at_wini%d: sys_voutb failed: %d pvb (%d):\n", w_instance, s, n);
  for(i = 0; i < n; i++)
        printf("%2d: %4x -> %4x\n", i, pvb[i].value, pvb[i].port);
  panic(w_name(), "sys_voutb failed", NO_NUM);
}

PRIVATE int at_vinb(int line, pvb_pair_t *pvb, int n)
{
  int s, i;
  if ((s=sys_vinb(pvb,n)) == OK)
        return OK;
  printf("at_wini%d: sys_vinb failed: %d pvb (%d):\n", w_instance, s, n);
  for(i = 0; i < n; i++)
        printf("%2d: %4x\n", i, pvb[i].port);
  panic(w_name(), "sys_vinb failed", NO_NUM);
}

PRIVATE int at_out(int line, u32_t port, u32_t value,
        char *typename, int type)
{
        int s;
        s = sys_out(port, value, type);
        if(s == OK)
                return OK;
        printf("at_wini%d: line %d: %s failed: %d; %x -> %x\n", 
                w_instance, line, typename, s, value, port);
        panic(w_name(), "sys_out failed", NO_NUM);
}


PRIVATE int at_in(int line, u32_t port, u32_t *value,
        char *typename, int type)
{
        int s;
        s = sys_in(port, value, type);
        if(s == OK)
                return OK;
        printf("at_wini%d: line %d: %s failed: %d; port %x\n", 
                w_instance, line, typename, s, value, port);
        panic(w_name(), "sys_in failed", NO_NUM);
}

---