From 727b3668b730634228fc65c336c2a7a080e02885 Mon Sep 17 00:00:00 2001 From: Russell King Date: Fri, 8 Nov 2019 17:39:29 +0000 Subject: 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 Signed-off-by: David S. Miller --- 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(-) diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c index f16d9e92a81a..e3fbc8e93317 100644 --- a/drivers/net/phy/phylink.c +++ b/drivers/net/phy/phylink.c @@ -567,7 +567,7 @@ static int phylink_register_sfp(struct phylink *pl, 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); phylink_err(pl, "unable to attach SFP bus: %d\n", ret); @@ -576,7 +576,10 @@ static int phylink_register_sfp(struct phylink *pl, pl->sfp_bus = bus; - return 0; + ret = sfp_bus_add_upstream(bus, pl, &sfp_phylink_ops); + sfp_bus_put(bus); + + return ret; } /** @@ -670,8 +673,7 @@ 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); diff --git a/drivers/net/phy/sfp-bus.c b/drivers/net/phy/sfp-bus.c index d037aab6a71d..715d45214e18 100644 --- a/drivers/net/phy/sfp-bus.c +++ b/drivers/net/phy/sfp-bus.c @@ -329,10 +329,19 @@ static void sfp_bus_release(struct kref *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) { @@ -348,11 +357,11 @@ static int sfp_register_bus(struct sfp_bus *bus) 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; } @@ -446,13 +455,12 @@ static void sfp_upstream_clear(struct sfp_bus *bus) } /** - * 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, @@ -462,9 +470,7 @@ static void sfp_upstream_clear(struct sfp_bus *bus) * %-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; @@ -482,7 +488,39 @@ struct sfp_bus *sfp_register_upstream_node(struct fwnode_handle *fwnode, 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; @@ -495,33 +533,33 @@ struct sfp_bus *sfp_register_upstream_node(struct fwnode_handle *fwnode, } 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) diff --git a/include/linux/sfp.h b/include/linux/sfp.h index 355a08a76fd4..c8464de7cff5 100644 --- a/include/linux/sfp.h +++ b/include/linux/sfp.h @@ -508,10 +508,11 @@ int sfp_get_module_eeprom(struct sfp_bus *bus, struct ethtool_eeprom *ee, 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(struct sfp_bus *bus) { } -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 -- cgit v1.2.3-59-g8ed1b