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

1 files changed, 29 insertions, 1 deletions

diff --git a/sys/dev/acpica/acpi.c b/sys/dev/acpica/acpi.c
index a4732c4..bf2cc54 100644
--- a/sys/dev/acpica/acpi.c
+++ b/sys/dev/acpica/acpi.c
@@ -101,6 +101,7 @@ int		acpi_quirks;
 /* Supported sleep states. */
 static BOOLEAN	acpi_sleep_states[ACPI_S_STATE_COUNT];
 
+static void	acpi_lookup(void *arg, const char *name, device_t *dev);
 static int	acpi_modevent(struct module *mod, int event, void *junk);
 static int	acpi_probe(device_t dev);
 static int	acpi_attach(device_t dev);
@@ -671,8 +672,10 @@ acpi_attach(device_t dev)
     /* Register ACPI again to pass the correct argument of pm_func. */
     power_pm_register(POWER_PM_TYPE_ACPI, acpi_pm_func, sc);
 
-    if (!acpi_disabled("bus"))
+    if (!acpi_disabled("bus")) {
+	EVENTHANDLER_REGISTER(dev_lookup, acpi_lookup, NULL, 1000);
 	acpi_probe_children(dev);
+    }
 
     /* Update all GPEs and enable runtime GPEs. */
     status = AcpiUpdateAllGpes();
@@ -3401,6 +3404,31 @@ acpi_disabled(char *subsys)
     return (0);
 }
 
+static void
+acpi_lookup(void *arg, const char *name, device_t *dev)
+{
+    ACPI_HANDLE handle;
+
+    if (*dev != NULL)
+	return;
+
+    /*
+     * Allow any handle name that is specified as an absolute path and
+     * starts with '\'.  We could restrict this to \_SB and friends,
+     * but see acpi_probe_children() for notes on why we scan the entire
+     * namespace for devices.
+     *
+     * XXX: The pathname argument to AcpiGetHandle() should be fixed to
+     * be const.
+     */
+    if (name[0] != '\\')
+	return;
+    if (ACPI_FAILURE(AcpiGetHandle(ACPI_ROOT_OBJECT, __DECONST(char *, name),
+	&handle)))
+	return;
+    *dev = acpi_get_device(handle);
+}
+
 /*
  * Control interface.
  *