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.Dd January 19, 2016
.Dt CAM_PERIPH_GETCCB 9
.Os
.Sh NAME
.Nm cam_periph_getccb
.Nd allocate ccb from the periph's pool
.Sh SYNOPSIS
.In cam/cam_xpt_periph.h
.Ft union ccb *
.Fn cam_periph_getccb "struct cam_periph *periph" "u_int32_t priority"
.Sh DESCRIPTION
A periph CAM driver gets CCBs with the
.Nm
function call.
It must be called with the periph lock held.
It returns a CCB for the periph driver to use for its transaction.
If there are CCBs of a different priority in the periph's
.Va ccb_list ,
then this function will run the periph's alloc queue, as
described in
.Xr periph 9 .
If the CCB is a lower priority one than the periph's
.Va immediate_priority 
or if there's no free CCBs for this periph,
.Nm
will sleep until a suitable CCB is available.
The CCB returned should be setup with
.Xr xpt_setup_ccb 9
to set its priority.
.Pp
Should document what the heck the
.Va ccb_list
in the periph is, maybe in
.Xr cam_periph 9 .
Should document what the heck the running the allocq means
in the periph is, maybe in
.Xr periph 9 .
.Sh SEE ALSO
.Xr cam_periph 9 ,
.Xr xpt_release_ccb 9 ,
.Xr xpt_setup_cbb 9
.Sh AUTHORS
This manual page was written by
.An M. Warner Losh .