cdx: Introduce lock to protect controller ops

Add a mutex lock to prevent race between controller ops initiated by
the bus subsystem and the controller registration/unregistration.

Signed-off-by: Abhijit Gangurde <abhijit.gangurde@amd.com>
Link: https://lore.kernel.org/r/20231017160505.10640-3-abhijit.gangurde@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Abhijit Gangurde 2023-10-17 21:35:00 +05:30 committed by Greg Kroah-Hartman
parent 54b406e10f
commit f0af816834

View File

@ -72,6 +72,8 @@
/* IDA for CDX controllers registered with the CDX bus */
static DEFINE_IDA(cdx_controller_ida);
/* Lock to protect controller ops */
static DEFINE_MUTEX(cdx_controller_lock);
static char *compat_node_name = "xlnx,versal-net-cdx";
@ -396,6 +398,8 @@ static ssize_t rescan_store(const struct bus_type *bus,
if (!val)
return -EINVAL;
mutex_lock(&cdx_controller_lock);
/* Unregister all the devices on the bus */
cdx_unregister_devices(&cdx_bus_type);
@ -415,6 +419,8 @@ static ssize_t rescan_store(const struct bus_type *bus,
put_device(&pd->dev);
}
mutex_unlock(&cdx_controller_lock);
return count;
}
static BUS_ATTR_WO(rescan);
@ -538,12 +544,14 @@ int cdx_register_controller(struct cdx_controller *cdx)
return ret;
}
mutex_lock(&cdx_controller_lock);
cdx->id = ret;
/* Scan all the devices */
if (cdx->ops->scan)
cdx->ops->scan(cdx);
cdx->controller_registered = true;
mutex_unlock(&cdx_controller_lock);
return 0;
}
@ -554,9 +562,13 @@ void cdx_unregister_controller(struct cdx_controller *cdx)
if (cdx->id >= MAX_CDX_CONTROLLERS)
return;
mutex_lock(&cdx_controller_lock);
cdx->controller_registered = false;
device_for_each_child(cdx->dev, NULL, cdx_unregister_device);
ida_free(&cdx_controller_ida, cdx->id);
mutex_unlock(&cdx_controller_lock);
}
EXPORT_SYMBOL_GPL(cdx_unregister_controller);