sfc: Implement auto-negotiation

Add infrastructure for auto-negotiation of speed, duplex and flow
control.

When using 10Xpress, auto-negotiate flow control.  While we're
at it, clean up the code to warn when partner is not 10GBASE-T
capable.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 36 insertions, 2 deletions

diff --git a/drivers/net/sfc/net_driver.h b/drivers/net/sfc/net_driver.h
index 883086e39455..fb8d72527a34 100644
--- a/drivers/net/sfc/net_driver.h
+++ b/drivers/net/sfc/net_driver.h
@@ -511,6 +511,35 @@ enum efx_mac_type {
         EFX_XMAC = 2,
 };
 
+static inline unsigned int efx_fc_advertise(enum efx_fc_type wanted_fc)
+{
+        unsigned int adv = 0;
+        if (wanted_fc & EFX_FC_RX)
+                adv = ADVERTISE_PAUSE_CAP | ADVERTISE_PAUSE_ASYM;
+        if (wanted_fc & EFX_FC_TX)
+                adv ^= ADVERTISE_PAUSE_ASYM;
+        return adv;
+}
+
+static inline enum efx_fc_type efx_fc_resolve(enum efx_fc_type wanted_fc,
+                                              unsigned int lpa)
+{
+        unsigned int adv = efx_fc_advertise(wanted_fc);
+
+        if (!(wanted_fc & EFX_FC_AUTO))
+                return wanted_fc;
+
+        if (adv & lpa & ADVERTISE_PAUSE_CAP)
+                return EFX_FC_RX | EFX_FC_TX;
+        if (adv & lpa & ADVERTISE_PAUSE_ASYM) {
+                if (adv & ADVERTISE_PAUSE_CAP)
+                        return EFX_FC_RX;
+                if (lpa & ADVERTISE_PAUSE_CAP)
+                        return EFX_FC_TX;
+        }
+        return 0;
+}
+
 /**
  * struct efx_mac_operations - Efx MAC operations table
  * @reconfigure: Reconfigure MAC. Serialised by the mac_lock
@@ -533,6 +562,8 @@ struct efx_mac_operations {
  * @check_hw: Check hardware
  * @get_settings: Get ethtool settings. Serialised by the mac_lock.
  * @set_settings: Set ethtool settings. Serialised by the mac_lock.
+ * @set_xnp_advertise: Set abilities advertised in Extended Next Page
+ *      (only needed where AN bit is set in mmds)
  * @mmds: MMD presence mask
  * @loopbacks: Supported loopback modes mask
  */
@@ -548,6 +579,7 @@ struct efx_phy_operations {
                               struct ethtool_cmd *ecmd);
         int (*set_settings) (struct efx_nic *efx,
                              struct ethtool_cmd *ecmd);
+        bool (*set_xnp_advertise) (struct efx_nic *efx, u32);
         int mmds;
         unsigned loopbacks;
 };
@@ -724,11 +756,12 @@ union efx_multicast_hash {
  * @mac_up: MAC link state
  * @link_up: Link status
  * @link_fd: Link is full duplex
+ * @link_fc: Actualy flow control flags
  * @link_speed: Link speed (Mbps)
  * @n_link_state_changes: Number of times the link has changed state
  * @promiscuous: Promiscuous flag. Protected by netif_tx_lock.
  * @multicast_hash: Multicast hash table
- * @flow_control: Flow control flags - separate RX/TX so can't use link_options
+ * @wanted_fc: Wanted flow control flags
  * @reconfigure_work: work item for dealing with PHY events
  * @loopback_mode: Loopback status
  * @loopback_modes: Supported loopback mode bitmask
@@ -805,12 +838,13 @@ struct efx_nic {
         bool mac_up;
         bool link_up;
         bool link_fd;
+        enum efx_fc_type link_fc;
         unsigned int link_speed;
         unsigned int n_link_state_changes;
 
         bool promiscuous;
         union efx_multicast_hash multicast_hash;
-        enum efx_fc_type flow_control;
+        enum efx_fc_type wanted_fc;
         struct work_struct reconfigure_work;
 
         atomic_t rx_reset;