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From 863b5b6941f9f43b924393b6ba2b36647e7dee42 Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@armlinux.org.uk>
Date: Thu, 7 Nov 2019 17:06:08 +0000
Subject: [PATCH 615/660] net: sfp: rework upstream interface
The current upstream interface is an all-or-nothing, which is
sub-optimal for future changes, as it doesn't allow the upstream driver
to prepare for the SFP module becoming available, as it is at boot.
Switch to a find-sfp-bus, add-upstream, del-upstream, put-sfp-bus
interface structure instead, which allows the upstream driver to
prepare for a module being available as soon as add-upstream is called.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
drivers/net/phy/phylink.c | 10 +++--
drivers/net/phy/sfp-bus.c | 92 +++++++++++++++++++++++++++------------
include/linux/sfp.h | 25 +++++++----
3 files changed, 88 insertions(+), 39 deletions(-)
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -541,7 +541,7 @@ static int phylink_register_sfp(struct p
struct sfp_bus *bus;
int ret;
- bus = sfp_register_upstream_node(fwnode, pl, &sfp_phylink_ops);
+ bus = sfp_bus_find_fwnode(fwnode);
if (IS_ERR(bus)) {
ret = PTR_ERR(bus);
netdev_err(pl->netdev, "unable to attach SFP bus: %d\n", ret);
@@ -550,7 +550,10 @@ static int phylink_register_sfp(struct p
pl->sfp_bus = bus;
- return 0;
+ ret = sfp_bus_add_upstream(bus, pl, &sfp_phylink_ops);
+ sfp_bus_put(bus);
+
+ return ret;
}
/**
@@ -634,8 +637,7 @@ EXPORT_SYMBOL_GPL(phylink_create);
*/
void phylink_destroy(struct phylink *pl)
{
- if (pl->sfp_bus)
- sfp_unregister_upstream(pl->sfp_bus);
+ sfp_bus_del_upstream(pl->sfp_bus);
if (pl->link_gpio)
gpiod_put(pl->link_gpio);
--- a/drivers/net/phy/sfp-bus.c
+++ b/drivers/net/phy/sfp-bus.c
@@ -328,10 +328,19 @@ static void sfp_bus_release(struct kref
kfree(bus);
}
-static void sfp_bus_put(struct sfp_bus *bus)
+/**
+ * sfp_bus_put() - put a reference on the &struct sfp_bus
+ * bus: the &struct sfp_bus found via sfp_bus_find_fwnode()
+ *
+ * Put a reference on the &struct sfp_bus and free the underlying structure
+ * if this was the last reference.
+ */
+void sfp_bus_put(struct sfp_bus *bus)
{
- kref_put_mutex(&bus->kref, sfp_bus_release, &sfp_mutex);
+ if (bus)
+ kref_put_mutex(&bus->kref, sfp_bus_release, &sfp_mutex);
}
+EXPORT_SYMBOL_GPL(sfp_bus_put);
static int sfp_register_bus(struct sfp_bus *bus)
{
@@ -347,11 +356,11 @@ static int sfp_register_bus(struct sfp_b
return ret;
}
}
+ bus->registered = true;
bus->socket_ops->attach(bus->sfp);
if (bus->started)
bus->socket_ops->start(bus->sfp);
bus->upstream_ops->attach(bus->upstream, bus);
- bus->registered = true;
return 0;
}
@@ -445,13 +454,12 @@ static void sfp_upstream_clear(struct sf
}
/**
- * sfp_register_upstream_node() - parse and register the neighbouring device
+ * sfp_bus_find_fwnode() - parse and locate the SFP bus from fwnode
* @fwnode: firmware node for the parent device (MAC or PHY)
- * @upstream: the upstream private data
- * @ops: the upstream's &struct sfp_upstream_ops
*
- * Parse the parent device's firmware node for a SFP bus, and register the
- * SFP bus using sfp_register_upstream().
+ * Parse the parent device's firmware node for a SFP bus, and locate
+ * the sfp_bus structure, incrementing its reference count. This must
+ * be put via sfp_bus_put() when done.
*
* Returns: on success, a pointer to the sfp_bus structure,
* %NULL if no SFP is specified,
@@ -461,9 +469,7 @@ static void sfp_upstream_clear(struct sf
* %-ENOMEM if we failed to allocate the bus.
* an error from the upstream's connect_phy() method.
*/
-struct sfp_bus *sfp_register_upstream_node(struct fwnode_handle *fwnode,
- void *upstream,
- const struct sfp_upstream_ops *ops)
+struct sfp_bus *sfp_bus_find_fwnode(struct fwnode_handle *fwnode)
{
struct fwnode_reference_args ref;
struct sfp_bus *bus;
@@ -481,7 +487,39 @@ struct sfp_bus *sfp_register_upstream_no
if (!bus)
return ERR_PTR(-ENOMEM);
+ return bus;
+}
+EXPORT_SYMBOL_GPL(sfp_bus_find_fwnode);
+
+/**
+ * sfp_bus_add_upstream() - parse and register the neighbouring device
+ * @bus: the &struct sfp_bus found via sfp_bus_find_fwnode()
+ * @upstream: the upstream private data
+ * @ops: the upstream's &struct sfp_upstream_ops
+ *
+ * Add upstream driver for the SFP bus, and if the bus is complete, register
+ * the SFP bus using sfp_register_upstream(). This takes a reference on the
+ * bus, so it is safe to put the bus after this call.
+ *
+ * Returns: on success, a pointer to the sfp_bus structure,
+ * %NULL if no SFP is specified,
+ * on failure, an error pointer value:
+ * corresponding to the errors detailed for
+ * fwnode_property_get_reference_args().
+ * %-ENOMEM if we failed to allocate the bus.
+ * an error from the upstream's connect_phy() method.
+ */
+int sfp_bus_add_upstream(struct sfp_bus *bus, void *upstream,
+ const struct sfp_upstream_ops *ops)
+{
+ int ret;
+
+ /* If no bus, return success */
+ if (!bus)
+ return 0;
+
rtnl_lock();
+ kref_get(&bus->kref);
bus->upstream_ops = ops;
bus->upstream = upstream;
@@ -494,33 +532,33 @@ struct sfp_bus *sfp_register_upstream_no
}
rtnl_unlock();
- if (ret) {
+ if (ret)
sfp_bus_put(bus);
- bus = ERR_PTR(ret);
- }
- return bus;
+ return ret;
}
-EXPORT_SYMBOL_GPL(sfp_register_upstream_node);
+EXPORT_SYMBOL_GPL(sfp_bus_add_upstream);
/**
- * sfp_unregister_upstream() - Unregister sfp bus
+ * sfp_bus_del_upstream() - Delete a sfp bus
* @bus: a pointer to the &struct sfp_bus structure for the sfp module
*
- * Unregister a previously registered upstream connection for the SFP
- * module. @bus is returned from sfp_register_upstream().
+ * Delete a previously registered upstream connection for the SFP
+ * module. @bus should have been added by sfp_bus_add_upstream().
*/
-void sfp_unregister_upstream(struct sfp_bus *bus)
+void sfp_bus_del_upstream(struct sfp_bus *bus)
{
- rtnl_lock();
- if (bus->sfp)
- sfp_unregister_bus(bus);
- sfp_upstream_clear(bus);
- rtnl_unlock();
+ if (bus) {
+ rtnl_lock();
+ if (bus->sfp)
+ sfp_unregister_bus(bus);
+ sfp_upstream_clear(bus);
+ rtnl_unlock();
- sfp_bus_put(bus);
+ sfp_bus_put(bus);
+ }
}
-EXPORT_SYMBOL_GPL(sfp_unregister_upstream);
+EXPORT_SYMBOL_GPL(sfp_bus_del_upstream);
/* Socket driver entry points */
int sfp_add_phy(struct sfp_bus *bus, struct phy_device *phydev)
--- a/include/linux/sfp.h
+++ b/include/linux/sfp.h
@@ -508,10 +508,11 @@ int sfp_get_module_eeprom(struct sfp_bus
u8 *data);
void sfp_upstream_start(struct sfp_bus *bus);
void sfp_upstream_stop(struct sfp_bus *bus);
-struct sfp_bus *sfp_register_upstream_node(struct fwnode_handle *fwnode,
- void *upstream,
- const struct sfp_upstream_ops *ops);
-void sfp_unregister_upstream(struct sfp_bus *bus);
+void sfp_bus_put(struct sfp_bus *bus);
+struct sfp_bus *sfp_bus_find_fwnode(struct fwnode_handle *fwnode);
+int sfp_bus_add_upstream(struct sfp_bus *bus, void *upstream,
+ const struct sfp_upstream_ops *ops);
+void sfp_bus_del_upstream(struct sfp_bus *bus);
#else
static inline int sfp_parse_port(struct sfp_bus *bus,
const struct sfp_eeprom_id *id,
@@ -553,14 +554,22 @@ static inline void sfp_upstream_stop(str
{
}
-static inline struct sfp_bus *sfp_register_upstream_node(
- struct fwnode_handle *fwnode, void *upstream,
- const struct sfp_upstream_ops *ops)
+static inline void sfp_bus_put(struct sfp_bus *bus)
+{
+}
+
+static inline struct sfp_bus *sfp_bus_find_fwnode(struct fwnode_handle *fwnode)
{
return NULL;
}
-static inline void sfp_unregister_upstream(struct sfp_bus *bus)
+static int sfp_bus_add_upstream(struct sfp_bus *bus, void *upstream,
+ const struct sfp_upstream_ops *ops)
+{
+ return 0;
+}
+
+static inline void sfp_bus_del_upstream(struct sfp_bus *bus)
{
}
#endif
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