From 5fa29797910346fc0c54829bd979856e83b9b7ea Mon Sep 17 00:00:00 2001
From: Warner Losh <imp@FreeBSD.org>
Date: Thu, 23 Aug 2018 05:05:47 +0000
Subject: Create devctl freeze/thaw.

This adds it to devctl, libdevctl, defines the two IOCTLs and
implements the kernel bits. causes any new drivers that are added via
kldload to be deferred until a 'thaw' comes in. These do not stack: it
is an error to freeze while frozen, or thaw while thawed.

Differential Revision: https://reviews.freebsd.org/D16735
---
 lib/libdevctl/devctl.3 | 18 +++++++++++++++++-
 lib/libdevctl/devctl.c | 14 ++++++++++++++
 lib/libdevctl/devctl.h |  2 ++
 3 files changed, 33 insertions(+), 1 deletion(-)

(limited to 'lib/libdevctl')

diff --git a/lib/libdevctl/devctl.3 b/lib/libdevctl/devctl.3
index a4fe0620ac3f..8749515ecd74 100644
--- a/lib/libdevctl/devctl.3
+++ b/lib/libdevctl/devctl.3
@@ -36,10 +36,12 @@
 .Nm devctl_detach ,
 .Nm devctl_disable ,
 .Nm devctl_enable ,
+.Nm devctl_freeze ,
 .Nm devctl_rescan ,
 .Nm devctl_resume ,
 .Nm devctl_set_driver ,
-.Nm devctl_suspend
+.Nm devctl_suspend ,
+.Nm devctl_thaw
 .Nd device control library
 .Sh LIBRARY
 .Lb libdevctl
@@ -58,6 +60,8 @@
 .Ft int
 .Fn devctl_enable "const char *device"
 .Ft int
+.Fn devctl_freeze "void"
+.Ft int
 .Fn devctl_rescan "const char *device"
 .Ft int
 .Fn devctl_resume "const char *device"
@@ -65,6 +69,8 @@
 .Fn devctl_set_driver "const char *device" "const char *driver" "bool force"
 .Ft int
 .Fn devctl_suspend "const char *device"
+.Ft int
+.Fn devctl_thaw "void"
 .Sh DESCRIPTION
 The
 .Nm
@@ -189,6 +195,16 @@ The
 .Fn devctl_rescan
 function rescans a bus device checking for devices that have been added or
 removed.
+.Pp
+The
+.Fn devctl_freeze
+function freezes probe and attach processing initiated in response to
+drivers being loaded.
+.Pp
+The
+.Fn devctl_thaw
+function resumes (thaws the freeze) probe and attach processing
+initiated in response to drivers being loaded.
 .Sh RETURN VALUES
 .Rv -std devctl_attach devctl_clear_driver devctl_delete devctl_detach \
 devctl_disable devctl_enable devctl_suspend devctl_rescan devctl_resume \
diff --git a/lib/libdevctl/devctl.c b/lib/libdevctl/devctl.c
index 5013fb0b9d57..9c9ab7805672 100644
--- a/lib/libdevctl/devctl.c
+++ b/lib/libdevctl/devctl.c
@@ -145,3 +145,17 @@ devctl_delete(const char *device, bool force)
 	return (devctl_simple_request(DEV_DELETE, device, force ?
 	    DEVF_FORCE_DELETE : 0));
 }
+
+int
+devctl_freeze(void)
+{
+
+	return (devctl_simple_request(DEV_FREEZE, "", 0));
+}
+
+int
+devctl_thaw(void)
+{
+
+	return (devctl_simple_request(DEV_THAW, "", 0));
+}
diff --git a/lib/libdevctl/devctl.h b/lib/libdevctl/devctl.h
index d49199ad0b59..11a21753809d 100644
--- a/lib/libdevctl/devctl.h
+++ b/lib/libdevctl/devctl.h
@@ -41,5 +41,7 @@ int	devctl_set_driver(const char *device, const char *driver, bool force);
 int	devctl_clear_driver(const char *device, bool force);
 int	devctl_rescan(const char *device);
 int	devctl_delete(const char *device, bool force);
+int	devctl_freeze(void);
+int	devctl_thaw(void);
 
 #endif /* !__DEVCTL_H__ */
-- 
cgit v1.3