Index: head/share/man/man4/pci.4
===================================================================
--- head/share/man/man4/pci.4
+++ head/share/man/man4/pci.4
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd June 14, 2018
+.Dd June 17, 2019
 .Dt PCI 4
 .Os
 .Sh NAME
@@ -333,6 +333,26 @@
 reading registers, above, also apply to writing
 .Tn PCI
 configuration registers.
+.It PCIOCATTACHED
+This
+.Xr ioctl 2
+allows users to query if a driver is attached to the
+.Tn PCI
+specified in the passed-in
+.Va pci_io
+structure.
+The
+.Va pci_io
+structure is described above, however, the
+.Va pi_reg
+and
+.Va pi_width
+fields are not used.
+The status of the device is stored in the
+.Va pi_data
+field.
+A value of 0 indicates no driver is attached, while a value larger than 0
+indicates that a driver is attached.
 .It PCIOCBARMMAP
 This
 .Xr ioctl 2