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/*
* 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
*
* <drew@colorado.edu>
*
* Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli
* Added QLOGIC QLA1280 SCSI controller kernel host support.
* August 4, 1999 Fred Lewis, Intel DuPont
*
* Updated to reflect the new initialization scheme for the higher
* level of scsi drivers (sd/sr/st)
* September 17, 2000 Torben Mathiasen <tmm@image.dk>
*/
/*
* 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.
*/
#define __NO_VERSION__
#include <linux/module.h>
#include <linux/blk.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#define __KERNEL_SYSCALLS__
#include <linux/unistd.h>
#include "scsi.h"
#include "hosts.h"
/*
static const char RCSid[] = "$Header: /vger/u4/cvs/linux/drivers/scsi/hosts.c,v 1.20 1996/12/12 19:18:32 davem 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;
/*
* Our semaphores and timeout counters, where size depends on
* MAX_SCSI_HOSTS here.
*/
Scsi_Host_Name * scsi_host_no_list;
struct Scsi_Host * scsi_hostlist;
struct Scsi_Device_Template * scsi_devicelist;
int max_scsi_hosts;
int next_scsi_host;
void
scsi_unregister(struct Scsi_Host * sh){
struct Scsi_Host * shpnt;
Scsi_Host_Name *shn;
if(scsi_hostlist == sh)
scsi_hostlist = sh->next;
else {
shpnt = scsi_hostlist;
while(shpnt->next != sh) shpnt = shpnt->next;
shpnt->next = shpnt->next->next;
}
/*
* We have to unregister the host from the scsi_host_no_list as well.
* Decide by the host_no not by the name because most host drivers are
* able to handle more than one adapters from the same kind (or family).
*/
for ( shn=scsi_host_no_list; shn && (sh->host_no != shn->host_no);
shn=shn->next);
if (shn) shn->host_registered = 0;
/* else {} : This should not happen, we should panic here... */
/* If we are removing the last host registered, it is safe to reuse
* its host number (this avoids "holes" at boot time) (DB)
* It is also safe to reuse those of numbers directly below which have
* been released earlier (to avoid some holes in numbering).
*/
if(sh->host_no == max_scsi_hosts - 1) {
while(--max_scsi_hosts >= next_scsi_host) {
shpnt = scsi_hostlist;
while(shpnt && shpnt->host_no != max_scsi_hosts - 1)
shpnt = shpnt->next;
if(shpnt)
break;
}
}
next_scsi_host--;
kfree((char *) sh);
}
/* 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, *o_shp;
Scsi_Host_Name *shn, *shn2;
int flag_new = 1;
const char * hname;
size_t hname_len;
retval = (struct Scsi_Host *)kmalloc(sizeof(struct Scsi_Host) + j,
(tpnt->unchecked_isa_dma && j ?
GFP_DMA : 0) | GFP_ATOMIC);
if(retval == NULL)
{
printk("scsi: out of memory in scsi_register.\n");
return NULL;
}
memset(retval, 0, sizeof(struct Scsi_Host) + j);
/* trying to find a reserved entry (host_no) */
hname = (tpnt->proc_name) ? tpnt->proc_name : "";
hname_len = strlen(hname);
for (shn = scsi_host_no_list;shn;shn = shn->next) {
if (!(shn->host_registered) &&
(hname_len > 0) && (0 == strncmp(hname, shn->name, hname_len))) {
flag_new = 0;
retval->host_no = shn->host_no;
shn->host_registered = 1;
shn->loaded_as_module = 1;
break;
}
}
atomic_set(&retval->host_active,0);
retval->host_busy = 0;
retval->host_failed = 0;
if(j > 0xffff) panic("Too many extra bytes requested\n");
retval->extra_bytes = j;
retval->loaded_as_module = 1;
if (flag_new) {
shn = (Scsi_Host_Name *) kmalloc(sizeof(Scsi_Host_Name), GFP_ATOMIC);
if (!shn) {
kfree(retval);
printk(KERN_ERR "scsi: out of memory(2) in scsi_register.\n");
return NULL;
}
shn->name = kmalloc(hname_len + 1, GFP_ATOMIC);
if (hname_len > 0)
strncpy(shn->name, hname, hname_len);
shn->name[hname_len] = 0;
shn->host_no = max_scsi_hosts++;
shn->host_registered = 1;
shn->loaded_as_module = 1;
shn->next = NULL;
if (scsi_host_no_list) {
for (shn2 = scsi_host_no_list;shn2->next;shn2 = shn2->next)
;
shn2->next = shn;
}
else
scsi_host_no_list = shn;
retval->host_no = shn->host_no;
}
next_scsi_host++;
retval->host_queue = NULL;
init_waitqueue_head(&retval->host_wait);
retval->resetting = 0;
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;
/*
* All drivers right now should be able to handle 12 byte commands.
* Every so often there are requests for 16 byte commands, but individual
* low-level drivers need to certify that they actually do something
* sensible with such commands.
*/
retval->max_cmd_len = 12;
retval->unique_id = 0;
retval->io_port = 0;
retval->hostt = tpnt;
retval->next = NULL;
retval->in_recovery = 0;
retval->ehandler = NULL; /* Initial value until the thing starts up. */
retval->eh_notify = NULL; /* Who we notify when we exit. */
retval->host_blocked = FALSE;
retval->host_self_blocked = FALSE;
#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 = tpnt->select_queue_depths;
retval->max_sectors = tpnt->max_sectors;
if(!scsi_hostlist)
scsi_hostlist = retval;
else {
shpnt = scsi_hostlist;
if (retval->host_no < shpnt->host_no) {
retval->next = shpnt;
wmb(); /* want all to see these writes in this order */
scsi_hostlist = retval;
}
else {
for (o_shp = shpnt, shpnt = shpnt->next; shpnt;
o_shp = shpnt, shpnt = shpnt->next) {
if (retval->host_no < shpnt->host_no) {
retval->next = shpnt;
wmb();
o_shp->next = retval;
break;
}
}
if (! shpnt)
o_shp->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;
}
void
scsi_deregister_device(struct Scsi_Device_Template * tpnt)
{
struct Scsi_Device_Template *spnt;
struct Scsi_Device_Template *prev_spnt;
spnt = scsi_devicelist;
prev_spnt = NULL;
while (spnt != tpnt) {
prev_spnt = spnt;
spnt = spnt->next;
}
if (prev_spnt == NULL)
scsi_devicelist = tpnt->next;
else
prev_spnt->next = spnt->next;
}
/*
* 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:
*/
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