// scsi tapset
// Copyright (C) 2005, 2006 IBM Corp.
//
// This file is part of systemtap, and is free software.  You can
// redistribute it and/or modify it under the terms of the GNU General
// Public License (GPL); either version 2, or (at your option) any
// later version.
// <tapsetdescription>
// This family of probe points is used to probe SCSI activities.  
// </tapsetdescription>
%{
#include <linux/types.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>
#include <linux/timer.h>
#include <linux/blkdev.h>
%}

/**
  * probe scsi.ioentry - Prepares a SCSI mid-layer request
  * @disk_major: The major number of the disk (-1 if no information)
  * @disk_minor: The minor number of the disk (-1 if no information)
  * @device_state: The current state of the device.
  */
// FIXME describe the device_state
probe scsi.ioentry
	= module("scsi_mod").function("scsi_prep_fn@drivers/scsi/scsi_lib.c")!,
	  kernel.function("scsi_prep_fn@drivers/scsi/scsi_lib.c")?
{
	if($req->rq_disk == 0)  {
		disk_major = -1
		disk_minor = -1
	} else {
		disk_major = $req->rq_disk->major
		disk_minor = $req->rq_disk->first_minor
	}
	device_state = get_devstate_from_req($q)
	req_addr = $req
}

/**
 * probe scsi.iodispatching - SCSI mid-layer dispatched low-level SCSI command
 * @host_no: The host number
 * @channel: The channel number
 * @lun: The lun number
 * @dev_id: The scsi device id
 * @device_state: The current state of the device.
 * @data_direction: The data_direction specifies whether this command is from/to the device.
 *		0 (DMA_BIDIRECTIONAL), 1 (DMA_TO_DEVICE),
 *		2 (DMA_FROM_DEVICE), 3 (DMA_NONE)
 * @request_buffer: The request buffer address
 * @req_bufflen: The request buffer length
 */
probe scsi.iodispatching
	= module("scsi_mod").function("scsi_dispatch_cmd@drivers/scsi/scsi.c")!,
	  kernel.function("scsi_dispatch_cmd@drivers/scsi/scsi.c")?
{

	host_no = $cmd->device->host->host_no
	channel = $cmd->device->channel
	lun = $cmd->device->lun
	dev_id = $cmd->device->id
	device_state = $cmd->device->sdev_state
	data_direction = $cmd->sc_data_direction
%( kernel_v >= "2.6.25" %?
	request_buffer = $cmd->sdb->table->sgl
	request_bufflen = $cmd->sdb->length
%:
	request_buffer = $cmd->request_buffer
	request_bufflen = $cmd->request_bufflen
%)
	req_addr = $cmd->request
}

/**
 * probe scsi.iodone - SCSI  command  completed by low level driver and enqueued into the done queue.
 * @host_no: The host number
 * @channel: The channel number
 * @lun: The lun number
 * @dev_id: The scsi device id
 * @device_state: The current state of the device
 * @data_direction: The data_direction specifies whether this command is
 * 		from/to the device.
 */
probe scsi.iodone
	= module("scsi_mod").function("scsi_done@drivers/scsi/scsi.c")!,
	  kernel.function("scsi_done@drivers/scsi/scsi.c")?

{
	host_no = $cmd->device->host->host_no
	channel = $cmd->device->channel
	lun = $cmd->device->lun
	dev_id = $cmd->device->id
	device_state = $cmd->device->sdev_state
	data_direction = $cmd->sc_data_direction
	req_addr = $cmd->request
	scsi_timer_pending = scsi_timer_pending($cmd);
}

/**
 * probe scsi.iocompleted - SCSI mid-layer running the completion processing for block device I/O requests
 * @host_no: The host number
 * @channel: The channel number
 * @lun: The lun number
 * @dev_id: The scsi device id
 * @device_state: The current state of the device
 * @data_direction: The data_direction specifies whether this command is from/to
 * 		the device
 * @goodbytes: The bytes completed.
 */
// mid-layer processes the completed IO
probe scsi.iocompleted
	= module("scsi_mod").function("scsi_io_completion@drivers/scsi/scsi_lib.c")!,
	  kernel.function("scsi_io_completion@drivers/scsi/scsi_lib.c")?
{
	host_no = $cmd->device->host->host_no
	channel = $cmd->device->channel
	lun = $cmd->device->lun
	dev_id = $cmd->device->id
	device_state = $cmd->device->sdev_state
	data_direction = $cmd->sc_data_direction
	req_addr = $cmd->request
	goodbytes = $good_bytes
}

function scsi_timer_pending:long(var:long)
%{ /* pure */
        struct scsi_cmnd *cmd = (struct scsi_cmnd *)((long)THIS->var);
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,28)
        THIS->__retvalue = timer_pending(&cmd->eh_timeout); /* FIXME: deref hazard! */
#else 
        struct request *req;
        struct request_queue *rq;
        req = (struct request *)kread(&cmd->request);
        rq = (struct request_queue *)kread(&req->q);
        THIS->__retvalue = timer_pending(&rq->timeout); /* FIXME: deref hazard! */
        CATCH_DEREF_FAULT();
#endif
%}

function get_devstate_from_req:long(var:long)
{
	sdev = @cast(var, "request_queue", "kernel:scsi_mod")->queuedata
	return @cast(sdev, "scsi_device", "kernel:scsi_mod")->sdev_state
}