hosts.c

arm平台上的uclinux系统全部源代码

/*
 *  hosts.c Copyright (C) 1992 Drew Eckhardt
 *          Copyright (C) 1993, 1994, 1995 Eric Youngdale
 *
 *  mid to lowlevel SCSI driver interface
 *      Initial versions: Drew Eckhardt
 *      Subsequent revisions: Eric Youngdale
 *
 *  <[e-mail]>
 */


/*
 *  This file contains the medium level SCSI
 *  host interface initialization, as well as the scsi_hosts array of SCSI
 *  hosts currently present in the system.
 */

/*
 * Don't import our own symbols, as this would severely mess up our
 * symbol tables.
 */
#define _SCSI_SYMS_VER_
#define __NO_VERSION__
#include <linux/module.h>

#include <linux/config.h>
#include <linux/blk.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/proc_fs.h>

#include "scsi.h"

#ifndef NULL
#define NULL 0L
#endif

#define HOSTS_C

#include "hosts.h"

#ifdef CONFIG_SCSI_ACORNSCSI_3
#include "acornscsi.h"
#endif

#ifdef CONFIG_SCSI_CUMANA_1
#include "cumana_1.h"
#endif

#ifdef CONFIG_SCSI_OAK1
#include "oak.h"
#endif

#ifdef CONFIG_SCSI_ECOSCSI
#include "ecoscsi.h"
#endif

#ifdef CONFIG_SCSI_POWERTECSCSI
#include "powertec.h"
#endif

#ifdef CONFIG_SCSI_EESOXSCSI
#include "eesox.h"
#endif

#ifdef CONFIG_BLK_DEV_IDESCSI
#include "ide-scsi.h"
#endif

#ifdef CONFIG_SCSI_DEBUG
#include "scsi_debug.h"
#endif

/*
static const char RCSid[] = "$Header: /usr/local/cvsroot/AplioTRIO/linux/arch/armnommu/drivers/scsi/hosts.c,v 1.1.1.1 1999/11/15 13:42:32 vadim Exp $";
*/

/*
 *  The scsi host entries should be in the order you wish the
 *  cards to be detected.  A driver may appear more than once IFF
 *  it can deal with being detected (and therefore initialized)
 *  with more than one simultaneous host number, can handle being
 *  reentrant, etc.
 *
 *  They may appear in any order, as each SCSI host is told which host 
 *  number it is during detection.
 */

/* This is a placeholder for controllers that are not configured into
 * the system - we do this to ensure that the controller numbering is
 * always consistent, no matter how the kernel is configured. */

#define NO_CONTROLLER {NULL, NULL, NULL, NULL, NULL, NULL, NULL, \
			   NULL, NULL, 0, 0, 0, 0, 0, 0}

/*
 *  When figure is run, we don't want to link to any object code.  Since
 *  the macro for each host will contain function pointers, we cannot
 *  use it and instead must use a "blank" that does no such
 *  idiocy.
 */

Scsi_Host_Template * scsi_hosts = NULL;

static Scsi_Host_Template builtin_scsi_hosts[] =
{
#ifdef CONFIG_SCSI_ACORNSCSI_3
    ACORNSCSI_3,
#endif
#ifdef CONFIG_SCSI_CUMANA_1
    CUMANA_NCR5380,
#endif
#ifdef CONFIG_SCSI_OAK1
    OAK_NCR5380,
#endif
#ifdef CONFIG_SCSI_ECOSCSI
    ECOSCSI_NCR5380,
#endif
#ifdef CONFIG_BLK_DEV_IDESCSI
    IDESCSI,
#endif
#ifdef CONFIG_SCSI_POWERTECSCSI
    POWERTECSCSI,
#endif
#ifdef CONFIG_SCSI_EESOXSCSI
    EESOXSCSI,
#endif
#ifdef CONFIG_SCSI_DEBUG
    SCSI_DEBUG,
#endif
};

#define MAX_SCSI_HOSTS (sizeof(builtin_scsi_hosts) / sizeof(Scsi_Host_Template))


/*
 *  Our semaphores and timeout counters, where size depends on 
 *      MAX_SCSI_HOSTS here.
 */

struct Scsi_Host * scsi_hostlist = NULL;
struct Scsi_Device_Template * scsi_devicelist = NULL;

int max_scsi_hosts = 0;
int next_scsi_host = 0;

void
scsi_unregister(struct Scsi_Host * sh){
    struct Scsi_Host * shpnt;
    
    if(scsi_hostlist == sh)
	scsi_hostlist = sh->next;
    else {
	shpnt = scsi_hostlist;
	while(shpnt->next != sh) shpnt = shpnt->next;
	shpnt->next = shpnt->next->next;
    }
    
    /* If we are removing the last host registered, it is safe to reuse
     * its host number (this avoids "holes" at boot time) (DB) 
     */
    if (max_scsi_hosts == next_scsi_host)
	max_scsi_hosts--;
    
    next_scsi_host--;
    scsi_init_free((char *) sh, sizeof(struct Scsi_Host) + sh->extra_bytes);
}

/* We call this when we come across a new host adapter. We only do this
 * once we are 100% sure that we want to use this host adapter -  it is a
 * pain to reverse this, so we try to avoid it 
 */

struct Scsi_Host * scsi_register(Scsi_Host_Template * tpnt, int j){
    struct Scsi_Host * retval, *shpnt;
    retval = (struct Scsi_Host *)scsi_init_malloc(sizeof(struct Scsi_Host) + j,
						  (tpnt->unchecked_isa_dma && j ? GFP_DMA : 0) | GFP_ATOMIC);
    retval->host_busy = 0;
    retval->block = NULL;
    retval->wish_block = 0;
    if(j > 0xffff) panic("Too many extra bytes requested\n");
    retval->extra_bytes = j;
    retval->loaded_as_module = scsi_loadable_module_flag;
    retval->host_no = max_scsi_hosts++; /* never reuse host_no (DB) */
    next_scsi_host++;
    retval->host_queue = NULL;
    retval->host_wait = NULL;
    retval->last_reset = 0;
    retval->irq = 0;
    retval->dma_channel = 0xff;

    /* These three are default values which can be overridden */
    retval->max_channel = 0; 
    retval->max_id = 8;      
    retval->max_lun = 8;

    retval->unique_id = 0;
    retval->io_port = 0;
    retval->hostt = tpnt;
    retval->next = NULL;
#ifdef DEBUG
    printk("Register %x %x: %d\n", (int)retval, (int)retval->hostt, j);
#endif

    /* The next six are the default values which can be overridden
     * if need be */
    retval->this_id = tpnt->this_id;
    retval->can_queue = tpnt->can_queue;
    retval->sg_tablesize = tpnt->sg_tablesize;
    retval->cmd_per_lun = tpnt->cmd_per_lun;
    retval->unchecked_isa_dma = tpnt->unchecked_isa_dma;
    retval->use_clustering = tpnt->use_clustering;   

    retval->select_queue_depths = NULL;

    if(!scsi_hostlist)
	scsi_hostlist = retval;
    else
    {
	shpnt = scsi_hostlist;
	while(shpnt->next) shpnt = shpnt->next;
	shpnt->next = retval;
    }
    
    return retval;
}

int
scsi_register_device(struct Scsi_Device_Template * sdpnt)
{
    if(sdpnt->next) panic("Device already registered");
    sdpnt->next = scsi_devicelist;
    scsi_devicelist = sdpnt;
    return 0;
}

unsigned int scsi_init()
{
    static int called = 0;
    int i, pcount;
    Scsi_Host_Template * tpnt;
    struct Scsi_Host * shpnt;
    const char * name;
    
    if(called) return 0;
    
    called = 1;
    for (tpnt = &builtin_scsi_hosts[0], i = 0; i < MAX_SCSI_HOSTS; ++i, tpnt++)
    {
	/*
	 * Initialize our semaphores.  -1 is interpreted to mean
	 * "inactive" - where as 0 will indicate a time out condition.
	 */
	
	pcount = next_scsi_host;
	if ((tpnt->detect) &&
	    (tpnt->present =
	     tpnt->detect(tpnt)))
	{
	    /* The only time this should come up is when people use
	     * some kind of patched driver of some kind or another. */
	    if(pcount == next_scsi_host) {
		if(tpnt->present > 1)
		    panic("Failure to register low-level scsi driver");
		/* The low-level driver failed to register a driver.  We
		 * can do this now. */
		scsi_register(tpnt,0);
	    }
	    tpnt->next = scsi_hosts;
	    scsi_hosts = tpnt;

            /* Add the driver to /proc/scsi */
#if CONFIG_PROC_FS 
            build_proc_dir_entries(tpnt);    
#endif
	}
    }
        
    for(shpnt=scsi_hostlist; shpnt; shpnt = shpnt->next)
    {
	if(shpnt->hostt->info)
	    name = shpnt->hostt->info(shpnt);
	else
	    name = shpnt->hostt->name;
	printk ("scsi%d : %s\n", /* And print a little message */
		shpnt->host_no, name);
    }
    
    printk ("scsi : %d host%s.\n", next_scsi_host,
	    (next_scsi_host == 1) ? "" : "s");
    
    scsi_make_blocked_list();

    /* Now attach the high level drivers */
#ifdef CONFIG_BLK_DEV_SD
    scsi_register_device(&sd_template);
#endif
#ifdef CONFIG_BLK_DEV_SR
    scsi_register_device(&sr_template);
#endif
#ifdef CONFIG_CHR_DEV_ST
    scsi_register_device(&st_template);
#endif
#ifdef CONFIG_CHR_DEV_SG
    scsi_register_device(&sg_template);
#endif
    
#if 0      
    max_scsi_hosts = next_scsi_host;
#endif
    return 0;
}

/*
 * Overrides for Emacs so that we follow Linus's tabbing style.
 * Emacs will notice this stuff at the end of the file and automatically
 * adjust the settings for this buffer only.  This must remain at the end
 * of the file.
 * ---------------------------------------------------------------------------
 * Local variables:
 * c-indent-level: 4
 * c-brace-imaginary-offset: 0
 * c-brace-offset: -4
 * c-argdecl-indent: 4
 * c-label-offset: -4
 * c-continued-statement-offset: 4
 * c-continued-brace-offset: 0
 * indent-tabs-mode: nil
 * tab-width: 8
 * End:
 */