[PATCH net-next v3 14/15] devlink: add devlink_alloc_drv()

[Przemek Kitszel <przemyslaw.kitszel@intel.com>]

devlink_alloc() records the driver bound to @dev at the time of the
call as the owner of the new instance. That fits the common case of
a driver creating an instance for the device it is bound to, but not
a PF driver that creates instances for its VFs, as the VF device could
be:
 * not bound to any driver yet (VF driver not loaded, or
   sriov_drivers_autoprobe disabled), what triggers the WARN_ON() in
   __devlink_alloc();
 * bound to another driver (VF driver, or vfio-pci), which could be
   unloaded while the instance is still registered, leaving the stored
   driver pointer dangling (it is used to report the driver name in
   devlink dev info).

Add devlink_alloc_drv(), a variant of devlink_alloc() that takes the
owning driver explicitly, as devlink_shd_get() already does.

The first user is ice, in the next patch, which creates a devlink
instance for each of its VFs.

Signed-off-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
---
v3:
 * new patch
---
 include/net/devlink.h |  4 ++++
 net/devlink/core.c    | 20 ++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/include/net/devlink.h b/include/net/devlink.h
index d01128ef393d..5c90edf9a92d 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -1693,6 +1693,10 @@ static inline struct devlink *devlink_alloc(const struct devlink_ops *ops,
 	return devlink_alloc_ns(ops, priv_size, &init_net, dev);
 }
 
+struct devlink *devlink_alloc_drv(const struct devlink_ops *ops,
+				  size_t priv_size, struct device *dev,
+				  const struct device_driver *drv);
+
 int devl_register(struct devlink *devlink);
 void devl_unregister(struct devlink *devlink);
 void devlink_register(struct devlink *devlink);
diff --git a/net/devlink/core.c b/net/devlink/core.c
index bddbbbf000fe..8590a22b0d93 100644
--- a/net/devlink/core.c
+++ b/net/devlink/core.c
@@ -531,6 +531,26 @@ struct devlink *devlink_alloc_ns(const struct devlink_ops *ops,
 }
 EXPORT_SYMBOL_GPL(devlink_alloc_ns);
 
+/**
+ * devlink_alloc_drv - Allocate new devlink instance resources for given driver
+ * @ops: ops
+ * @priv_size: size of user private data
+ * @dev: parent device
+ * @drv: driver that owns the instance
+ *
+ * Variant of devlink_alloc() for a driver that creates an instance for
+ * a device bound to another (or no) driver, e.g. a PF driver for its VFs.
+ *
+ * Return: new devlink instance, NULL on failure.
+ */
+struct devlink *devlink_alloc_drv(const struct devlink_ops *ops,
+				  size_t priv_size, struct device *dev,
+				  const struct device_driver *drv)
+{
+	return __devlink_alloc(ops, priv_size, &init_net, dev, drv);
+}
+EXPORT_SYMBOL_GPL(devlink_alloc_drv);
+
 /**
  *	devlink_free - Free devlink instance resources
  *
-- 
2.51.1