Merge branch 'Decoupling-PHYLINK-from-struct-net_device'

Ioana Ciornei says:

====================
Decoupling PHYLINK from struct net_device

Following two separate discussion threads in:
  https://www.spinics.net/lists/netdev/msg569087.html
and:
  https://www.spinics.net/lists/netdev/msg570450.html

Previous RFC patch set: https://www.spinics.net/lists/netdev/msg571995.html

PHYLINK was reworked in order to accept multiple operation types,
PHYLINK_NETDEV and PHYLINK_DEV, passed through a phylink_config
structure alongside the corresponding struct device.

One of the main concerns expressed in the RFC was that using notifiers
to signal the corresponding phylink_mac_ops would break PHYLINK's API
unity and that it would become harder to grep for its users.
Using the current approach, we maintain a common API for all users.
Also, printing useful information in PHYLINK, when decoupled from a
net_device, is achieved using dev_err&co on the struct device received
(in DSA's case is the device corresponding to the dsa_switch).

PHYLIB (which PHYLINK uses) was reworked to the extent that it does not
crash when connecting to a PHY and the net_device pointer is NULL.

Lastly, DSA has been reworked in its way that it handles PHYs for ports
that lack a net_device (CPU and DSA ports).  For these, it was
previously using PHYLIB and is now using the PHYLINK_DEV operation type.
Previously, a driver that wanted to support PHY operations on CPU/DSA
ports has to implement .adjust_link(). This patch set not only gives
drivers the options to use PHYLINK uniformly but also urges them to
convert to it. For compatibility, the old code is kept but it will be
removed once all drivers switch over.

The patchset was tested on the NXP LS1021A-TSN board having the
following Ethernet layout:
  https://lkml.org/lkml/2019/5/5/279
The CPU port was moved from the internal RGMII fixed-link (enet2 ->
switch port 4) to an external loopback Cat5 cable between the enet1 port
and the front-facing swp2 SJA1105 port. In this mode, both the master
and the CPU port have an attached PHY which detects link change events:

[   49.105426] fsl-gianfar soc:ethernet@2d50000 eth1: Link is Down
[   50.305486] sja1105 spi0.1: Link is Down
[   53.265596] fsl-gianfar soc:ethernet@2d50000 eth1: Link is Up - 1Gbps/Full - flow control off
[   54.466304] sja1105 spi0.1: Link is Up - 1Gbps/Full - flow control off

Changes in v2:
  - fixed sparse warnings
  - updated 'Documentation/ABI/testing/sysfs-class-net-phydev'
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 39 insertions, 20 deletions

diff --git a/include/linux/phylink.h b/include/linux/phylink.h
index 6411c624f63a..0f6f65bb9d44 100644
--- a/include/linux/phylink.h
+++ b/include/linux/phylink.h
@@ -54,6 +54,21 @@ struct phylink_link_state {
 	unsigned int an_complete:1;
 };
 
+enum phylink_op_type {
+	PHYLINK_NETDEV = 0,
+	PHYLINK_DEV,
+};
+
+/**
+ * struct phylink_config - PHYLINK configuration structure
+ * @dev: a pointer to a struct device associated with the MAC
+ * @type: operation type of PHYLINK instance
+ */
+struct phylink_config {
+	struct device *dev;
+	enum phylink_op_type type;
+};
+
 /**
  * struct phylink_mac_ops - MAC operations structure.
  * @validate: Validate and update the link configuration.
@@ -66,16 +81,17 @@ struct phylink_link_state {
  * The individual methods are described more fully below.
  */
 struct phylink_mac_ops {
-	void (*validate)(struct net_device *ndev, unsigned long *supported,
+	void (*validate)(struct phylink_config *config,
+			 unsigned long *supported,
 			 struct phylink_link_state *state);
-	int (*mac_link_state)(struct net_device *ndev,
+	int (*mac_link_state)(struct phylink_config *config,
 			      struct phylink_link_state *state);
-	void (*mac_config)(struct net_device *ndev, unsigned int mode,
+	void (*mac_config)(struct phylink_config *config, unsigned int mode,
 			   const struct phylink_link_state *state);
-	void (*mac_an_restart)(struct net_device *ndev);
-	void (*mac_link_down)(struct net_device *ndev, unsigned int mode,
+	void (*mac_an_restart)(struct phylink_config *config);
+	void (*mac_link_down)(struct phylink_config *config, unsigned int mode,
 			      phy_interface_t interface);
-	void (*mac_link_up)(struct net_device *ndev, unsigned int mode,
+	void (*mac_link_up)(struct phylink_config *config, unsigned int mode,
 			    phy_interface_t interface,
 			    struct phy_device *phy);
 };
@@ -83,7 +99,7 @@ struct phylink_mac_ops {
 #if 0 /* For kernel-doc purposes only. */
 /**
  * validate - Validate and update the link configuration
- * @ndev: a pointer to a &struct net_device for the MAC.
+ * @config: a pointer to a &struct phylink_config.
  * @supported: ethtool bitmask for supported link modes.
  * @state: a pointer to a &struct phylink_link_state.
  *
@@ -100,12 +116,12 @@ struct phylink_mac_ops {
  * based on @state->advertising and/or @state->speed and update
  * @state->interface accordingly.
  */
-void validate(struct net_device *ndev, unsigned long *supported,
+void validate(struct phylink_config *config, unsigned long *supported,
 	      struct phylink_link_state *state);
 
 /**
  * mac_link_state() - Read the current link state from the hardware
- * @ndev: a pointer to a &struct net_device for the MAC.
+ * @config: a pointer to a &struct phylink_config.
  * @state: a pointer to a &struct phylink_link_state.
  *
  * Read the current link state from the MAC, reporting the current
@@ -114,12 +130,12 @@ void validate(struct net_device *ndev, unsigned long *supported,
  * negotiation completion state in @state->an_complete, and link
  * up state in @state->link.
  */
-int mac_link_state(struct net_device *ndev,
+int mac_link_state(struct phylink_config *config,
 		   struct phylink_link_state *state);
 
 /**
  * mac_config() - configure the MAC for the selected mode and state
- * @ndev: a pointer to a &struct net_device for the MAC.
+ * @config: a pointer to a &struct phylink_config.
  * @mode: one of %MLO_AN_FIXED, %MLO_AN_PHY, %MLO_AN_INBAND.
  * @state: a pointer to a &struct phylink_link_state.
  *
@@ -157,18 +173,18 @@ int mac_link_state(struct net_device *ndev,
  * down.  This "update" behaviour is critical to avoid bouncing the
  * link up status.
  */
-void mac_config(struct net_device *ndev, unsigned int mode,
+void mac_config(struct phylink_config *config, unsigned int mode,
 		const struct phylink_link_state *state);
 
 /**
  * mac_an_restart() - restart 802.3z BaseX autonegotiation
- * @ndev: a pointer to a &struct net_device for the MAC.
+ * @config: a pointer to a &struct phylink_config.
  */
-void mac_an_restart(struct net_device *ndev);
+void mac_an_restart(struct phylink_config *config);
 
 /**
  * mac_link_down() - take the link down
- * @ndev: a pointer to a &struct net_device for the MAC.
+ * @config: a pointer to a &struct phylink_config.
  * @mode: link autonegotiation mode
  * @interface: link &typedef phy_interface_t mode
  *
@@ -177,12 +193,12 @@ void mac_an_restart(struct net_device *ndev);
  * Energy Efficient Ethernet MAC configuration. Interface type
  * selection must be done in mac_config().
  */
-void mac_link_down(struct net_device *ndev, unsigned int mode,
+void mac_link_down(struct phylink_config *config, unsigned int mode,
 		   phy_interface_t interface);
 
 /**
  * mac_link_up() - allow the link to come up
- * @ndev: a pointer to a &struct net_device for the MAC.
+ * @config: a pointer to a &struct phylink_config.
  * @mode: link autonegotiation mode
  * @interface: link &typedef phy_interface_t mode
  * @phy: any attached phy
@@ -193,13 +209,14 @@ void mac_link_down(struct net_device *ndev, unsigned int mode,
  * phy_init_eee() and perform appropriate MAC configuration for EEE.
  * Interface type selection must be done in mac_config().
  */
-void mac_link_up(struct net_device *ndev, unsigned int mode,
+void mac_link_up(struct phylink_config *config, unsigned int mode,
 		 phy_interface_t interface,
 		 struct phy_device *phy);
 #endif
 
-struct phylink *phylink_create(struct net_device *, struct fwnode_handle *,
-	phy_interface_t iface, const struct phylink_mac_ops *ops);
+struct phylink *phylink_create(struct phylink_config *, struct fwnode_handle *,
+			       phy_interface_t iface,
+			       const struct phylink_mac_ops *ops);
 void phylink_destroy(struct phylink *);
 
 int phylink_connect_phy(struct phylink *, struct phy_device *);
diff --git a/include/net/dsa.h b/include/net/dsa.h
index 685294817712..a7f36219904f 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -22,6 +22,7 @@
 #include <linux/net_tstamp.h>
 #include <linux/phy.h>
 #include <linux/platform_data/dsa.h>
+#include <linux/phylink.h>
 #include <net/devlink.h>
 #include <net/switchdev.h>
 
@@ -193,6 +194,7 @@ struct dsa_port {
 	struct net_device	*bridge_dev;
 	struct devlink_port	devlink_port;
 	struct phylink		*pl;
+	struct phylink_config	pl_config;
 
 	struct work_struct	xmit_work;
 	struct sk_buff_head	xmit_queue;