DDB show command for CAM module

Hi all,
during a private discussion with attilio_at_ he pointed me out the lack
of DDB show commands for CAM/XPT layer.
Eventually I come up with this patch to add some command:

http://www.trematerra.net/patches/camddb.diff

This patch add the following show commands to DDB:
cam_sim <address>
to inspect cam_sim type variables

xpt_cam_eb [address]
to inspect cam_eb type variables.
whithout an address it shows the list of all busses connected.

xpt_cam_et <address>
to inspect cam_et type variables

xpt_cam_ed <address>
to inspect cam_ed type variables

The patch is all but complete. Actually what I'd like to know is how
useful this command could be in debugging problems related to CAM
layer.
This is my first try to hack FreeBSD kernel so any advice about the
code especially in regard of style(9) is welcomed.

Thanks for your time in reviewing my patch.

--
Trematerra Giovanni