Commit f0af8168 authored by Abhijit Gangurde's avatar Abhijit Gangurde Committed by Greg Kroah-Hartman
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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: default avatarAbhijit Gangurde <abhijit.gangurde@amd.com>
Link: https://lore.kernel.org/r/20231017160505.10640-3-abhijit.gangurde@amd.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 54b406e1

drivers/cdx/cdx.c

+12 −0
Original line number Diff line number Diff line
@@ -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);