From e05c6840a1464552cb7462d76fbae2a9e3bc86d0 Mon Sep 17 00:00:00 2001
From: jhb <jhb@FreeBSD.org>
Date: Wed, 27 Apr 2016 16:29:03 +0000
Subject: [PATCH] Add a new rescan method to the bus interface.
The BUS_RESCAN() method rescans a single bus device checking for devices
that have been added or removed from the bus. A new 'rescan' command is
added to devctl(8) to trigger a rescan.
Differential Revision: https://reviews.freebsd.org/D6016
---
lib/libdevctl/devctl.3 | 22 ++++++++++++++--
lib/libdevctl/devctl.c | 7 +++++
lib/libdevctl/devctl.h | 1 +
share/man/man9/BUS_RESCAN.9 | 51 +++++++++++++++++++++++++++++++++++++
share/man/man9/Makefile | 1 +
sys/kern/bus_if.m | 13 ++++++++++
sys/kern/subr_bus.c | 8 ++++++
sys/sys/bus.h | 1 +
usr.sbin/devctl/devctl.8 | 8 +++++-
usr.sbin/devctl/devctl.c | 12 +++++++++
10 files changed, 121 insertions(+), 3 deletions(-)
create mode 100644 share/man/man9/BUS_RESCAN.9
diff --git a/lib/libdevctl/devctl.3 b/lib/libdevctl/devctl.3
index b2734cf4aa30..7d8ddbaaab7e 100644
--- a/lib/libdevctl/devctl.3
+++ b/lib/libdevctl/devctl.3
@@ -25,7 +25,7 @@
.\"
.\" $FreeBSD$
.\"
-.Dd February 2, 2016
+.Dd April 27, 2016
.Dt DEVCTL 3
.Os
.Sh NAME
@@ -34,6 +34,7 @@
.Nm devctl_detach ,
.Nm devctl_disable ,
.Nm devctl_enable ,
+.Nm devctl_rescan ,
.Nm devctl_resume ,
.Nm devctl_set_driver ,
.Nm devctl_suspend
@@ -51,6 +52,8 @@
.Ft int
.Fn devctl_enable "const char *device"
.Ft int
+.Fn devctl_rescan "const char *device"
+.Ft int
.Fn devctl_resume "const char *device"
.Ft int
.Fn devctl_set_driver "const char *device" "const char *driver" "bool force"
@@ -149,9 +152,14 @@ If the device is already attached and
is true,
the device will be detached from its current device driver before it is
attached to the new device driver.
+.Pp
+The
+.Fn devctl_rescan
+function rescans a bus device checking for devices that have been added or
+removed.
.Sh RETURN VALUES
.Rv -std devctl_attach devctl_detach devctl_disable devctl_enable \
-devctl_suspend devctl_resume devctl_set_driver
+devctl_suspend devctl_rescan devctl_resume devctl_set_driver
.Sh ERRORS
In addition to specific errors noted below,
all of the
@@ -280,6 +288,16 @@ The device is disabled.
.It Bq Er ENXIO
The new device driver failed to attach.
.El
+.Pp
+The
+.Fn devctl_rescan
+function may fail if:
+.Bl -tag -width Er
+.It Bq Er ENXIO
+The device is not attached to a driver.
+.It Bq Er ENXIO
+The bus driver does not support rescanning.
+.El
.Sh SEE ALSO
.Xr devinfo 3 ,
.Xr devstat 3 ,
diff --git a/lib/libdevctl/devctl.c b/lib/libdevctl/devctl.c
index 7be431e9bf53..33c891b8e853 100644
--- a/lib/libdevctl/devctl.c
+++ b/lib/libdevctl/devctl.c
@@ -122,3 +122,10 @@ devctl_set_driver(const char *device, const char *driver, bool force)
req.dr_flags |= DEVF_SET_DRIVER_DETACH;
return (devctl_request(DEV_SET_DRIVER, &req));
}
+
+int
+devctl_rescan(const char *device)
+{
+
+ return (devctl_simple_request(DEV_RESCAN, device, 0));
+}
diff --git a/lib/libdevctl/devctl.h b/lib/libdevctl/devctl.h
index f773b11dd43a..40c64c126dda 100644
--- a/lib/libdevctl/devctl.h
+++ b/lib/libdevctl/devctl.h
@@ -38,5 +38,6 @@ int devctl_disable(const char *device, bool force_detach);
int devctl_suspend(const char *device);
int devctl_resume(const char *device);
int devctl_set_driver(const char *device, const char *driver, bool force);
+int devctl_rescan(const char *device);
#endif /* !__DEVCTL_H__ */
diff --git a/share/man/man9/BUS_RESCAN.9 b/share/man/man9/BUS_RESCAN.9
new file mode 100644
index 000000000000..eb963bd618ae
--- /dev/null
+++ b/share/man/man9/BUS_RESCAN.9
@@ -0,0 +1,51 @@
+.\" -*- nroff -*-
+.\"
+.\" Copyright (c) 2016 John H. Baldwin <jhb@FreeBSD.org>
+.\" All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\" notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\" notice, this list of conditions and the following disclaimer in the
+.\" documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\" $FreeBSD$
+.\"
+.Dd April 27, 2016
+.Dt BUS_RESCAN 9
+.Os
+.Sh NAME
+.Nm BUS_RESCAN
+.Nd "rescan a bus checking for devices that have been added or removed"
+.Sh SYNOPSIS
+.In sys/param.h
+.In sys/bus.h
+.Ft void
+.Fn BUS_RESCAN "device_t dev"
+.Sh DESCRIPTION
+The
+.Fn BUS_RESCAN
+method is called to request a rescan of the child devices on a bus device.
+The method should add any devices that have been added since the previous
+scan and remove devices that have been removed.
+This method is not required to re-examine existing devices to determine if
+their properties have changed.
+This method is also not required to propagate the rescan request to child
+devices.
+.Sh SEE ALSO
+.Xr device 9
diff --git a/share/man/man9/Makefile b/share/man/man9/Makefile
index 702fafa0530a..20ff6ae0efb4 100644
--- a/share/man/man9/Makefile
+++ b/share/man/man9/Makefile
@@ -46,6 +46,7 @@ MAN= accept_filter.9 \
BUS_NEW_PASS.9 \
BUS_PRINT_CHILD.9 \
BUS_READ_IVAR.9 \
+ BUS_RESCAN.9 \
bus_release_resource.9 \
bus_set_pass.9 \
bus_set_resource.9 \
diff --git a/sys/kern/bus_if.m b/sys/kern/bus_if.m
index 3a6a9d625935..c359b41d8895 100644
--- a/sys/kern/bus_if.m
+++ b/sys/kern/bus_if.m
@@ -231,6 +231,19 @@ METHOD device_t add_child {
int _unit;
} DEFAULT null_add_child;
+/**
+ * @brief Rescan the bus
+ *
+ * This method is called by a parent bridge or devctl to trigger a bus
+ * rescan. The rescan should delete devices no longer present and
+ * enumerate devices that have newly arrived.
+ *
+ * @param _dev the bus device
+ */
+METHOD int rescan {
+ device_t _dev;
+}
+
/**
* @brief Allocate a system resource
*
diff --git a/sys/kern/subr_bus.c b/sys/kern/subr_bus.c
index 81be36894079..d9c2ac1b6e24 100644
--- a/sys/kern/subr_bus.c
+++ b/sys/kern/subr_bus.c
@@ -5203,6 +5203,7 @@ devctl2_ioctl(struct cdev *cdev, u_long cmd, caddr_t data, int fflag,
case DEV_SUSPEND:
case DEV_RESUME:
case DEV_SET_DRIVER:
+ case DEV_RESCAN:
error = priv_check(td, PRIV_DRIVER);
if (error == 0)
error = find_device(req, &dev);
@@ -5366,6 +5367,13 @@ devctl2_ioctl(struct cdev *cdev, u_long cmd, caddr_t data, int fflag,
error = device_probe_and_attach(dev);
break;
}
+ case DEV_RESCAN:
+ if (!device_is_attached(dev)) {
+ error = ENXIO;
+ break;
+ }
+ error = BUS_RESCAN(dev);
+ break;
}
mtx_unlock(&Giant);
return (error);
diff --git a/sys/sys/bus.h b/sys/sys/bus.h
index 01b98f5e18e9..c46fbb24a544 100644
--- a/sys/sys/bus.h
+++ b/sys/sys/bus.h
@@ -117,6 +117,7 @@ struct devreq {
#define DEV_SUSPEND _IOW('D', 5, struct devreq)
#define DEV_RESUME _IOW('D', 6, struct devreq)
#define DEV_SET_DRIVER _IOW('D', 7, struct devreq)
+#define DEV_RESCAN _IOW('D', 9, struct devreq)
/* Flags for DEV_DETACH and DEV_DISABLE. */
#define DEVF_FORCE_DETACH 0x0000001
diff --git a/usr.sbin/devctl/devctl.8 b/usr.sbin/devctl/devctl.8
index 2257cb63cc3d..bfa6dcc62031 100644
--- a/usr.sbin/devctl/devctl.8
+++ b/usr.sbin/devctl/devctl.8
@@ -25,7 +25,7 @@
.\"
.\" $FreeBSD$
.\"
-.Dd February 2, 2016
+.Dd April 27, 2016
.Dt DEVCTL 8
.Os
.Sh NAME
@@ -56,6 +56,9 @@
.Cm set driver
.Op Fl f
.Ar device driver
+.Nm
+.Cm rescan
+.Ar device
.Sh DESCRIPTION
The
.Nm
@@ -126,6 +129,9 @@ If the device is already attached to a device driver and the
.Fl f
flag is not specified,
the device will not be changed.
+.It Cm rescan Ar device
+Rescan a bus device checking for devices that have been added or
+removed.
.El
.Sh SEE ALSO
.Xr devctl 3 ,
diff --git a/usr.sbin/devctl/devctl.c b/usr.sbin/devctl/devctl.c
index 076c6503885e..545224b502d1 100644
--- a/usr.sbin/devctl/devctl.c
+++ b/usr.sbin/devctl/devctl.c
@@ -259,6 +259,18 @@ set_driver(int ac, char **av)
}
DEVCTL_COMMAND(set, driver, set_driver);
+static int
+rescan(int ac, char **av)
+{
+
+ if (ac != 2)
+ usage();
+ if (devctl_rescan(av[1]) < 0)
+ err(1, "Failed to rescan %s", av[1]);
+ return (0);
+}
+DEVCTL_COMMAND(top, rescan, rescan);
+
int
main(int ac, char *av[])
{