.\" Copyright 2018 IBM Corp.
.\"
.TH CXL_AFU_HOST_THREAD_WAIT 3 2018-04-24 "LIBCXL 1.6" "CXL Manual"
.SH NAME
cxl_afu_host_thread_wait \- wait for AFU notification
.SH SYNOPSIS
.B #include <libcxl.h>
.PP
.B "int afu_host_thread_wait(struct cxl_afu_h"
.BI * afu ", volatile __u64 *" uword );
.SH DESCRIPTION
The tunneled operation as_notify is supported on POWER9. See
.BR cxl_get_tunneled_ops_supported ().
.PP
The thread calling
.BR afu_host_thread_wait ()
executes the instruction "wait" and goes to sleep.
It will resume execution upon receiving an interrupt or an
.I afu
notification. It will then check the value
of the shared memory word pointed to by
.IR uword .
The thread will loop and sleep again while the value of
.I uword
is equal to zero. It will return from
.BR afu_host_thread_wait ()
when the value of
.I uword
becomes different from zero.
.PP
The thread calling
.BR afu_host_thread_wait ()
must have attached an
.I afu
context to a work structure with
.BR cxl_afu_attach_work ()
The work structure must have been wait-enabled with
.BR cxl_work_enable_wait ().
.SH RETURN VALUE
On success, 0 is returned.
On error, \-1 is returned and
.I errno
is set appropriately.
.SH ERRORS
.TP
.B EINVAL
Invalid argument value
.TP
.B EPERM
AFU context not attached by current thread, or wait not enabled
.SH SEE ALSO
.BR cxl (3),
.BR cxl_afu_attach_work (3),
.BR cxl_afu_host_thread_wait (3),
.BR cxl_get_tunneled_ops_supported (3),
.BR cxl_work_disable_wait (3),
.BR cxl_work_enable_wait (3),
.BR cxl_work_get_tid (3)