Implement device_quiesce. This method means 'you are about to be
unloaded, cleanup, or return ebusy of that's inconvenient.' The default module hanlder for newbus will now call this when we get a MOD_QUIESCE event, but in the future may call this at other times. This shouldn't change any actual behavior until drivers start to use it.
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Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=139507
@ -57,6 +57,11 @@ CODE {
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{
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return 0;
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}
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static int null_quiesce(device_t dev)
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{
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return EOPNOTSUPP;
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}
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};
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/**
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@ -283,3 +288,29 @@ METHOD int suspend {
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METHOD int resume {
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device_t dev;
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} DEFAULT null_resume;
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/**
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* @brief This is called when the driver is asked to quiesce itself.
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*
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* The driver should arrange for the orderly shutdown of this device.
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* All further access to the device should be curtailed. Soon there
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* will be a request to detach, but there won't necessarily be one.
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*
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* To include this method in a device driver, use a line like this
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* in the driver's method list:
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*
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* @code
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* KOBJMETHOD(device_quiesce, foo_quiesce)
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* @endcode
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*
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* @param dev the device being quiesced
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*
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* @retval 0 success
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* @retval non-zero an error occurred while attempting to quiesce the
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* device
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*
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* @see DEVICE_DETACH()
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*/
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METHOD int quiesce {
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device_t dev;
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} DEFAULT null_quiesce;
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@ -947,6 +947,71 @@ devclass_delete_driver(devclass_t busclass, driver_t *driver)
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return (0);
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}
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/**
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* @brief Quiesces a set of device drivers from a device class
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*
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* Quiesce a device driver from a devclass. This is normally called
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* automatically by DRIVER_MODULE().
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*
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* If the driver is currently attached to any devices,
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* devclass_quiesece_driver() will first attempt to quiesce each
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* device.
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*
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* @param dc the devclass to edit
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* @param driver the driver to unregister
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*/
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int
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devclass_quiesce_driver(devclass_t busclass, driver_t *driver)
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{
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devclass_t dc = devclass_find(driver->name);
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driverlink_t dl;
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device_t dev;
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int i;
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int error;
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PDEBUG(("%s from devclass %s", driver->name, DEVCLANAME(busclass)));
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if (!dc)
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return (0);
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/*
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* Find the link structure in the bus' list of drivers.
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*/
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TAILQ_FOREACH(dl, &busclass->drivers, link) {
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if (dl->driver == driver)
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break;
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}
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if (!dl) {
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PDEBUG(("%s not found in %s list", driver->name,
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busclass->name));
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return (ENOENT);
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}
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/*
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* Quiesce all devices. We iterate through all the devices in
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* the devclass of the driver and quiesce any which are using
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* the driver and which have a parent in the devclass which we
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* are quiescing.
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*
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* Note that since a driver can be in multiple devclasses, we
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* should not quiesce devices which are not children of
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* devices in the affected devclass.
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*/
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for (i = 0; i < dc->maxunit; i++) {
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if (dc->devices[i]) {
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dev = dc->devices[i];
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if (dev->driver == driver && dev->parent &&
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dev->parent->devclass == busclass) {
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if ((error = device_quiesce(dev)) != 0)
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return (error);
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}
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}
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}
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return (0);
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}
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/**
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* @internal
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*/
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@ -2313,6 +2378,32 @@ device_detach(device_t dev)
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return (0);
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}
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/**
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* @brief Tells a driver to quiesce itself.
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*
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* This function is a wrapper around the DEVICE_QUIESCE() driver
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* method. If the call to DEVICE_QUIESCE() succeeds.
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*
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* @param dev the device to quiesce
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*
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* @retval 0 success
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* @retval ENXIO no driver was found
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* @retval ENOMEM memory allocation failure
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* @retval non-zero some other unix error code
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*/
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int
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device_quiesce(device_t dev)
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{
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PDEBUG(("%s", DEVICENAME(dev)));
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if (dev->state == DS_BUSY)
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return (EBUSY);
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if (dev->state != DS_ATTACHED)
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return (0);
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return (DEVICE_QUIESCE(dev));
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}
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/**
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* @brief Notify a device of system shutdown
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*
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@ -3561,6 +3652,16 @@ driver_module_handler(module_t mod, int what, void *arg)
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error = devclass_delete_driver(bus_devclass,
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dmd->dmd_driver);
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if (!error && dmd->dmd_chainevh)
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error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
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break;
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case MOD_QUIESCE:
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PDEBUG(("Quiesce module: driver %s from bus %s",
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DRIVERNAME(dmd->dmd_driver),
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dmd->dmd_busname));
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error = devclass_quiesce_driver(bus_devclass,
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dmd->dmd_driver);
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if (!error && dmd->dmd_chainevh)
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error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
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break;
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@ -357,6 +357,7 @@ int device_is_quiet(device_t dev);
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int device_print_prettyname(device_t dev);
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int device_printf(device_t dev, const char *, ...) __printflike(2, 3);
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int device_probe_and_attach(device_t dev);
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int device_quiesce(device_t dev);
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void device_quiet(device_t dev);
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void device_set_desc(device_t dev, const char* desc);
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void device_set_desc_copy(device_t dev, const char* desc);
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@ -388,6 +389,7 @@ void devclass_set_parent(devclass_t dc, devclass_t pdc);
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devclass_t devclass_get_parent(devclass_t dc);
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struct sysctl_ctx_list *devclass_get_sysctl_ctx(devclass_t dc);
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struct sysctl_oid *devclass_get_sysctl_tree(devclass_t dc);
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int devclass_quiesce_driver(devclass_t dc, kobj_class_t driver);
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/*
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* Access functions for device resources.
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