linit.c

这个linux源代码是很全面的~基本完整了~使用c编译的~由于时间问题我没有亲自测试~但就算用来做参考资料也是非常好的

 *	aac_driverinfo		-	Returns the host adapter name
 *	@host_ptr:	Scsi host to report on
 *
 *	Returns a static string describing the device in question
 */

const char *aac_driverinfo(struct Scsi_Host *host_ptr)
{
	struct aac_dev *dev = (struct aac_dev *)host_ptr->hostdata;
	return aac_drivers[dev->cardtype].name;
}

/**
 *	aac_get_driver_ident
 * 	@devtype: index into lookup table
 *
 * 	Returns a pointer to the entry in the driver lookup table.
 */
struct aac_driver_ident* aac_get_driver_ident(int devtype)
{
	return  &aac_drivers[devtype];
}

/**
 *	aac_biosparm	-	return BIOS parameters for disk
 *	@disk: SCSI disk object to process
 *	@device: kdev_t of the disk in question
 *	@geom: geometry block to fill in
 *
 *	Return the Heads/Sectors/Cylinders BIOS Disk Parameters for Disk.  
 *	The default disk geometry is 64 heads, 32 sectors, and the appropriate 
 *	number of cylinders so as not to exceed drive capacity.  In order for 
 *	disks equal to or larger than 1 GB to be addressable by the BIOS
 *	without exceeding the BIOS limitation of 1024 cylinders, Extended 
 *	Translation should be enabled.   With Extended Translation enabled, 
 *	drives between 1 GB inclusive and 2 GB exclusive are given a disk 
 *	geometry of 128 heads and 32 sectors, and drives above 2 GB inclusive 
 *	are given a disk geometry of 255 heads and 63 sectors.  However, if 
 *	the BIOS detects that the Extended Translation setting does not match 
 *	the geometry in the partition table, then the translation inferred 
 *	from the partition table will be used by the BIOS, and a warning may 
 *	be displayed.
 */
 
static int aac_biosparm(Scsi_Disk *disk, kdev_t dev, int *geom)
{
	struct diskparm *param = (struct diskparm *)geom;
	struct buffer_head * buf;

	dprintk((KERN_DEBUG "aac_biosparm.\n"));

	/*
	 *	Assuming extended translation is enabled - #REVISIT#
	 */
	if( disk->capacity >= 2 * 1024 * 1024 ) /* 1 GB in 512 byte sectors */
	{
		if( disk->capacity >= 4 * 1024 * 1024 ) /* 2 GB in 512 byte sectors */
		{
			param->heads = 255;
			param->sectors = 63;
		}
		else
		{
			param->heads = 128;
			param->sectors = 32;
		}
	}
	else
	{
		param->heads = 64;
		param->sectors = 32;
	}

	param->cylinders = disk->capacity/(param->heads * param->sectors);

	/*
	 *	Read the first 1024 bytes from the disk device
	 */

	buf = bread(MKDEV(MAJOR(dev), MINOR(dev)&~0xf), 0, block_size(dev));
	if(buf == NULL)
		return 0;
	/* 
	 *	If the boot sector partition table is valid, search for a partition 
	 *	table entry whose end_head matches one of the standard geometry 
	 *	translations ( 64/32, 128/32, 255/63 ).
	 */
	 
	if(*(unsigned short *)(buf->b_data + 0x1fe) == cpu_to_le16(0xaa55))
	{
		struct partition *first = (struct partition * )(buf->b_data + 0x1be);
		struct partition *entry = first;
		int saved_cylinders = param->cylinders;
		int num;
		unsigned char end_head, end_sec;

		for(num = 0; num < 4; num++)
		{
			end_head = entry->end_head;
			end_sec = entry->end_sector & 0x3f;

			if(end_head == 63)
			{
				param->heads = 64;
				param->sectors = 32;
				break;
			}
			else if(end_head == 127)
			{
				param->heads = 128;
				param->sectors = 32;
				break;
			}
			else if(end_head == 254) 
			{
				param->heads = 255;
				param->sectors = 63;
				break;
			}
			entry++;
		}

		if(num == 4)
		{
			end_head = first->end_head;
			end_sec = first->end_sector & 0x3f;
		}

		param->cylinders = disk->capacity / (param->heads * param->sectors);

		if(num < 4 && end_sec == param->sectors)
		{
			if(param->cylinders != saved_cylinders)
				dprintk((KERN_DEBUG "Adopting geometry: heads=%d, sectors=%d from partition table %d.\n",
					param->heads, param->sectors, num));
		}
		else if(end_head > 0 || end_sec > 0)
		{
			dprintk((KERN_DEBUG "Strange geometry: heads=%d, sectors=%d in partition table %d.\n",
				end_head + 1, end_sec, num));
			dprintk((KERN_DEBUG "Using geometry: heads=%d, sectors=%d.\n",
					param->heads, param->sectors));
		}
	}
	brelse(buf);
	return 0;
}

/**
 *	aac_queuedepth		-	compute queue depths
 *	@host:	SCSI host in question
 *	@dev:	SCSI device we are considering
 *
 *	Selects queue depths for each target device based on the host adapter's
 *	total capacity and the queue depth supported by the target device.
 *	A queue depth of one automatically disables tagged queueing.
 */

static void aac_queuedepth(struct Scsi_Host * host, Scsi_Device * dev )
{
	Scsi_Device * dptr;

	dprintk((KERN_DEBUG "aac_queuedepth.\n"));
	dprintk((KERN_DEBUG "Device #   Q Depth   Online\n"));
	dprintk((KERN_DEBUG "---------------------------\n"));
	for(dptr = dev; dptr != NULL; dptr = dptr->next)
	{
		if(dptr->host == host)
		{
			dptr->queue_depth = 10;		
			dprintk((KERN_DEBUG "  %2d         %d        %d\n", 
				dptr->id, dptr->queue_depth, dptr->online));
		}
	}
}


/**
 *	aac_eh_abort	-	Abort command if possible.
 *	@cmd:	SCSI command block to abort
 *
 *	Called when the midlayer wishes to abort a command. We don't support
 *	this facility, and our firmware looks after life for us. We just
 *	report this as failing
 */
 
static int aac_eh_abort(Scsi_Cmnd *cmd)
{
	return FAILED;
}

/**
 *	aac_eh_device_reset	-	Reset command handling
 *	@cmd:	SCSI command block causing the reset
 *
 *	Issue a reset of a SCSI device. We are ourselves not truely a SCSI
 *	controller and our firmware will do the work for us anyway. Thus this
 *	is a no-op. We just return FAILED.
 */

static int aac_eh_device_reset(Scsi_Cmnd *cmd)
{
	return FAILED;
}

/**
 *	aac_eh_bus_reset	-	Reset command handling
 *	@scsi_cmd:	SCSI command block causing the reset
 *
 *	Issue a reset of a SCSI bus. We are ourselves not truely a SCSI
 *	controller and our firmware will do the work for us anyway. Thus this
 *	is a no-op. We just return FAILED.
 */

static int aac_eh_bus_reset(Scsi_Cmnd* cmd)
{
	return FAILED;
}

/**
 *	aac_eh_hba_reset	-	Reset command handling
 *	@scsi_cmd:	SCSI command block causing the reset
 *
 *	Issue a reset of a SCSI host. If things get this bad then arguably we should
 *	go take a look at what the host adapter is doing and see if something really
 *	broke (as can occur at least on my Dell QC card if a drive keeps failing spinup)
 */

static int aac_eh_reset(Scsi_Cmnd* cmd)
{
	printk(KERN_ERR "aacraid: Host adapter reset request. SCSI hang ?\n");
	return FAILED;
}

/**
 *	aac_ioctl 	-	Handle SCSI ioctls
 *	@scsi_dev_ptr: scsi device to operate upon
 *	@cmd: ioctl command to use issue
 *	@arg: ioctl data pointer
 *
 *	Issue an ioctl on an aacraid device. Returns a standard unix error code or
 *	zero for success
 */
 
static int aac_ioctl(Scsi_Device * scsi_dev_ptr, int cmd, void * arg)
{
	struct aac_dev *dev;
	dprintk((KERN_DEBUG "aac_ioctl.\n"));
	dev = (struct aac_dev *)scsi_dev_ptr->host->hostdata;
	return aac_do_ioctl(dev, cmd, arg);
}

/**
 *	aac_cfg_open		-	open a configuration file
 *	@inode: inode being opened
 *	@file: file handle attached
 *
 *	Called when the configuration device is opened. Does the needed
 *	set up on the handle and then returns
 *
 *	Bugs: This needs extending to check a given adapter is present
 *	so we can support hot plugging, and to ref count adapters.
 */

static int aac_cfg_open(struct inode * inode, struct file * file )
{
	unsigned minor_number = MINOR(inode->i_rdev);
	if(minor_number >= aac_count)
		return -ENODEV;
	return 0;
}

/**
 *	aac_cfg_release		-	close down an AAC config device
 *	@inode: inode of configuration file
 *	@file: file handle of configuration file
 *	
 *	Called when the last close of the configuration file handle
 *	is performed.
 */
 
static int aac_cfg_release(struct inode * inode, struct file * file )
{
	return 0;
}

/**
 *	aac_cfg_ioctl		-	AAC configuration request
 *	@inode: inode of device
 *	@file: file handle
 *	@cmd: ioctl command code
 *	@arg: argument
 *
 *	Handles a configuration ioctl. Currently this involves wrapping it
 *	up and feeding it into the nasty windowsalike glue layer.
 *
 *	Bugs: Needs locking against parallel ioctls lower down
 *	Bugs: Needs to handle hot plugging
 */
 
static int aac_cfg_ioctl(struct inode * inode,  struct file * file, unsigned int cmd, unsigned long arg )
{
	struct aac_dev *dev = aac_devices[MINOR(inode->i_rdev)];
	return aac_do_ioctl(dev, cmd, (void *)arg);
}

/*
 *	To use the low level SCSI driver support using the linux kernel loadable 
 *	module interface we should initialize the global variable driver_interface  
 *	(datatype Scsi_Host_Template) and then include the file scsi_module.c.
 */
 
static Scsi_Host_Template driver_template = {
	module:			THIS_MODULE,
	name:           	"AAC",
	proc_info:      	aac_procinfo,
	detect:         	aac_detect,
	release:        	aac_release,
	info:           	aac_driverinfo,
	ioctl:          	aac_ioctl,
	queuecommand:   	aac_queuecommand,
	bios_param:     	aac_biosparm,	
	can_queue:      	AAC_NUM_IO_FIB,	
	this_id:        	16,
	sg_tablesize:   	16,
	max_sectors:    	128,
	cmd_per_lun:    	AAC_NUM_IO_FIB,
	eh_abort_handler:       aac_eh_abort,
	eh_device_reset_handler:aac_eh_device_reset,
	eh_bus_reset_handler:	aac_eh_bus_reset,
	eh_host_reset_handler:	aac_eh_reset,
	use_new_eh_code:	1, 

	use_clustering:		ENABLE_CLUSTERING,
};

#include "scsi_module.c"

/**
 *	aac_procinfo	-	Implement /proc/scsi/<drivername>/<n>
 *	@proc_buffer: memory buffer for I/O
 *	@start_ptr: pointer to first valid data
 *	@offset: offset into file
 *	@bytes_available: space left
 *	@host_no: scsi host ident
 *	@write: direction of I/O
 *
 *	Used to export driver statistics and other infos to the world outside 
 *	the kernel using the proc file system. Also provides an interface to
 *	feed the driver with information.
 *
 *		For reads
 *			- if offset > 0 return 0
 *			- if offset == 0 write data to proc_buffer and set the start_ptr to
 *			beginning of proc_buffer, return the number of characters written.
 *		For writes
 *			- writes currently not supported, return 0
 *
 *	Bugs:	Only offset zero is handled
 */

static int aac_procinfo(char *proc_buffer, char **start_ptr,off_t offset,
			int bytes_available, int host_no, int write)
{
	if(write || offset > 0)
		return 0;
	*start_ptr = proc_buffer;
	return sprintf(proc_buffer, "%s  %d\n", "Raid Controller, scsi hba number", host_no);
}

EXPORT_NO_SYMBOLS;