From 4fbf8e1c2efb16431c174d7a77c23e700af1160b Mon Sep 17 00:00:00 2001
From: Konstantin Belousov <kib@FreeBSD.org>
Date: Fri, 5 Apr 2019 19:32:26 +0000
Subject: Implement devctl(8) command 'reset', using DEV_RESET /dev/devctl2
 ioctl.

Reviewed by:	imp (previous version), jhb (previous version)
Sponsored by:	Mellanox Technologies
MFC after:	2 weeks
Differential revision:	https://reviews.freebsd.org/D19646
---
 lib/libdevctl/devctl.3 | 46 +++++++++++++++++++++++++++++++++++++++++++++-
 lib/libdevctl/devctl.c |  8 ++++++++
 lib/libdevctl/devctl.h |  1 +
 3 files changed, 54 insertions(+), 1 deletion(-)

(limited to 'lib')

diff --git a/lib/libdevctl/devctl.3 b/lib/libdevctl/devctl.3
index 55fdd712ab99..34d1c03c2840 100644
--- a/lib/libdevctl/devctl.3
+++ b/lib/libdevctl/devctl.3
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd August 22, 2018
+.Dd April 4, 2019
 .Dt DEVCTL 3
 .Os
 .Sh NAME
@@ -37,6 +37,7 @@
 .Nm devctl_enable ,
 .Nm devctl_freeze ,
 .Nm devctl_rescan ,
+.Nm devctl_reset ,
 .Nm devctl_resume ,
 .Nm devctl_set_driver ,
 .Nm devctl_suspend ,
@@ -63,6 +64,8 @@
 .Ft int
 .Fn devctl_rescan "const char *device"
 .Ft int
+.Fn devctl_reset "const char *device" "bool detach"
+.Ft int
 .Fn devctl_resume "const char *device"
 .Ft int
 .Fn devctl_set_driver "const char *device" "const char *driver" "bool force"
@@ -204,6 +207,15 @@ The
 .Fn devctl_thaw
 function resumes (thaws the freeze) probe and attach processing
 initiated in response to drivers being loaded.
+.Pp
+The
+.Fn devctl_reset
+function resets the specified device using bus-specific reset method.
+The
+.Fa detach
+argument, if true, specifies that the device driver is detached before
+the reset, and re-attached afterwards.
+If false, the device is suspended before the reset, and resumed after.
 .Sh RETURN VALUES
 .Rv -std devctl_attach devctl_clear_driver devctl_delete devctl_detach \
 devctl_disable devctl_enable devctl_suspend devctl_rescan devctl_resume \
@@ -377,6 +389,21 @@ is false.
 .Fa dev
 is the root device of the device tree.
 .El
+.Pp
+The
+.Fn devctl_reset
+function may fail if:
+.Bl -tag -width Er
+.It Bq Er ENXIO
+The bus does not implement the reset method.
+.It Bq Er ETIMEDOUT
+The device failed to respond after the reset in the time limits
+specific to the bus.
+.El
+The
+.Fn devctl_reset
+function may also return errors caused by the attach, detach, suspend,
+and resume methods of the device driver.
 .Sh SEE ALSO
 .Xr devinfo 3 ,
 .Xr devstat 3 ,
@@ -391,3 +418,20 @@ If a device is suspended individually via
 .Fn devctl_suspend
 and the entire machine is subsequently suspended,
 the device will be resumed when the machine resumes.
+.Pp
+Similarly, if the device is suspended, and
+.Fn devctl_reset
+is called on the device with
+.Fa detach
+set to
+.Va false ,
+the device is resumed by the
+.Fn devctl_reset
+call.
+Or, if the driver for the device is detached manually, and
+.Fn devctl_reset
+is called on the device with
+.Fa detach
+set to
+.Va true ,
+device reset re-attaches the driver.
diff --git a/lib/libdevctl/devctl.c b/lib/libdevctl/devctl.c
index 34ced3c5da65..528e3a3c407a 100644
--- a/lib/libdevctl/devctl.c
+++ b/lib/libdevctl/devctl.c
@@ -158,3 +158,11 @@ devctl_thaw(void)
 
 	return (devctl_simple_request(DEV_THAW, "", 0));
 }
+
+int
+devctl_reset(const char *device, bool detach)
+{
+
+	return (devctl_simple_request(DEV_RESET, device, detach ?
+	    DEVF_RESET_DETACH : 0));
+}
diff --git a/lib/libdevctl/devctl.h b/lib/libdevctl/devctl.h
index e30576b14702..c6af8c480d47 100644
--- a/lib/libdevctl/devctl.h
+++ b/lib/libdevctl/devctl.h
@@ -43,6 +43,7 @@ int	devctl_rescan(const char *device);
 int	devctl_delete(const char *device, bool force);
 int	devctl_freeze(void);
 int	devctl_thaw(void);
+int	devctl_reset(const char *device, bool detach);
 __END_DECLS
 
 #endif /* !__DEVCTL_H__ */
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