Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

devctl: add getpath command

Retrieves that path for a device. Different methods to enumerat the path
are supported, called locators.

Sponsored by: Netflix
Reviewed by: jhb
Differential Revision: https://reviews.freebsd.org/D32747

Fix gcc warning about shadowed global.

Sponsored by: Mellanox Technologies
MFC after: 2 weeks

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

Drop "All rights reserved" from my copyright statements.

Reviewed by: rgrimes
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D19485

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

Implement 'devctl clear driver' to undo a previous 'devctl set driver'.

Add a new 'clear driver' command for devctl along with the accompanying
ioctl and devctl_clear_driver() library routine to reset a device to
use a wildcard devclass instead of a fixed devclass. This can be used
to undo a previous 'set driver' command. After the device's name has
been reset to permit wildcard names, it is reprobed so that it can
attach to newly-available (to it) device drivers.

MFC after: 1 month
Sponsored by: Chelsio Communications

Add 'devctl delete' that calls device_delete_child().

'devctl delete' can be used to delete a device that is no longer present.
As an anti-foot-shooting measure, 'delete' will not delete a device
unless it's parent bus says it is no longer present. This can be
overridden by passing the force ('-f') flag.

Note that this command should be used with care. If a device is deleted
that is actually present it can't be resurrected unless the parent bus
device's driver supports rescans.

Differential Revision: https://reviews.freebsd.org/D6019

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

Add a new device control utility for new-bus devices called devctl. This
allows the user to request administrative changes to individual devices
such as attach or detaching drivers or disabling and re-enabling devices.
- Add a new /dev/devctl2 character device which uses ioctls for device
requests. The ioctls use a common 'struct devreq' which is somewhat
similar to 'struct ifreq'.
- The ioctls identify the device to operate on via a string. This
string can either by the device's name, or it can be a bus-specific
address. (For unattached devices, a bus address is the only way to
locate a device.) Bus drivers register an eventhandler to claim
unrecognized device names that the driver recognizes as a valid address.
Two buses currently support addresses: ACPI recognizes any device
in the ACPI namespace via its full path starting with "\" and
the PCI bus driver recognizes an address specification of
'pci[<domain>:]<bus>:<slot>:<func>' (identical to the PCI selector
strings supported by pciconf).
- To make it easier to cut and paste, change the PnP location string
in the PCI bus driver to output a full PCI selector string rather
than 'slot=<slot> function=<func>'.
- Add a devctl(3) interface in libdevctl which provides a wrapper around
the ioctls and is the preferred interface for other userland code.
- Add a devctl(8) program which is a simple wrapper around the requests
supported by devctl(3).
- Add a device_is_suspended() function to check DF_SUSPENDED.
- Add a resource_unset_value() function that can be used to remove a
hint from the kernel environment. This is used to clear a
hint.<driver>.<unit>.disabled hint when re-enabling a boot-time
disabled device.

Reviewed by: imp (parts)
Requested by: imp (changing PCI location string)
Relnotes: yes