periph_mgr.c

newos is new operation system

/* 
** Copyright 2002, Thomas Kurschel. All rights reserved.
** Distributed under the terms of the NewOS License.
*/

#include "xpt_internal.h"
#include "periph_mgr.h"

#include <kernel/heap.h>
#include <kernel/module.h>
#include <kernel/debug.h>

#include "bus_mgr.h"

mutex xpt_periphs_mutex;
xpt_periph_info *xpt_periphs;

static void inform_driver_about_devices( xpt_periph_info *periph )
{
	int path_id;
	
	SHOW_FLOW0( 3, "" );
	
	recursive_lock_lock( &registration_lock );
	
	for( path_id = 0; path_id < MAX_PATH_ID; ++path_id ) {
		int target_id;
		xpt_bus_info *bus;
		
		bus = xpt_busses[path_id];
		if( bus == NULL )
			continue;
			
		for( target_id = 0; target_id <= MAX_TARGET_ID; ++target_id ) {
			int target_lun;
				
			for( target_lun = 0; target_lun <= MAX_LUN_ID; ++target_lun ) {
				xpt_target_info *target;
				xpt_device_info *device;	
			
				// check target each time - not sure whether recursive 
				// registration lock really requiers that though...
				target = bus->targets[target_id];
				if( target == NULL )
					break;
				
				device = target->devices[target_lun];
				if( device == NULL )
					continue;
					
				if( device->temporary )
					continue;
					
				periph->interface->async( periph->periph_cookie, 
					path_id, target_id, target_lun, 
					AC_FOUND_DEVICE, NULL, 0 );
			}
		}
	}
	
	recursive_lock_unlock( &registration_lock );
}

xpt_periph_info *xpt_register_driver( cam_periph_interface *interface,
	cam_periph_cookie periph_cookie )
{
	xpt_periph_info *periph;
	
	SHOW_FLOW0( 3, "" );
	
	periph = kmalloc( sizeof( *periph ));
	if( periph == NULL )
		return NULL;
	
	mutex_lock( &xpt_periphs_mutex );
	
	if( xpt_periphs )
		xpt_periphs->prev = periph;
	
	periph->next = xpt_periphs;
	periph->prev = NULL;
	xpt_periphs = periph;
	
	periph->interface = interface;
	periph->periph_cookie = periph_cookie;

	mutex_unlock( &xpt_periphs_mutex );
	
	inform_driver_about_devices( periph );
	
	return periph;
}

int xpt_unregister_driver( xpt_periph_info *periph )
{
	mutex_lock( &xpt_periphs_mutex );

	if( periph->next )
		periph->next->prev = periph->prev;
		
	if( periph->prev )
		periph->prev->next = periph->next;
	else
		xpt_periphs = periph->next;
		
	mutex_unlock( &xpt_periphs_mutex );
	
	kfree( periph );
	
	return NO_ERROR;
}