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>

drivers/net/sfc/ethtool.c

@@ -12,11 +12,13 @@
 #include <linux/ethtool.h>
 #include <linux/rtnetlink.h>
 #include "net_driver.h"
+#include "workarounds.h"
 #include "selftest.h"
 #include "efx.h"
 #include "ethtool.h"
 #include "falcon.h"
 #include "spi.h"
+#include "mdio_10g.h"
 
 const char *efx_loopback_mode_names[] = {
 	[LOOPBACK_NONE]		= "NONE",
@@ -674,14 +676,51 @@ static int efx_ethtool_set_pauseparam(struct net_device *net_dev,
 				      struct ethtool_pauseparam *pause)
 {
 	struct efx_nic *efx = netdev_priv(net_dev);
-	enum efx_fc_type flow_control = efx->flow_control;
+	enum efx_fc_type wanted_fc;
+	bool reset;
 
-	flow_control &= ~(EFX_FC_RX | EFX_FC_TX | EFX_FC_AUTO);
-	flow_control |= pause->rx_pause ? EFX_FC_RX : 0;
-	flow_control |= pause->tx_pause ? EFX_FC_TX : 0;
-	flow_control |= pause->autoneg ? EFX_FC_AUTO : 0;
+	wanted_fc = ((pause->rx_pause ? EFX_FC_RX : 0) |
+		     (pause->tx_pause ? EFX_FC_TX : 0) |
+		     (pause->autoneg ? EFX_FC_AUTO : 0));
+
+	if ((wanted_fc & EFX_FC_TX) && !(wanted_fc & EFX_FC_RX)) {
+		EFX_LOG(efx, "Flow control unsupported: tx ON rx OFF\n");
+		return -EINVAL;
+	}
+
+	if (!(efx->phy_op->mmds & DEV_PRESENT_BIT(MDIO_MMD_AN)) &&
+	    (wanted_fc & EFX_FC_AUTO)) {
+		EFX_LOG(efx, "PHY does not support flow control "
+			"autonegotiation\n");
+		return -EINVAL;
+	}
+
+	/* TX flow control may automatically turn itself off if the
+	 * link partner (intermittently) stops responding to pause
+	 * frames. There isn't any indication that this has happened,
+	 * so the best we do is leave it up to the user to spot this
+	 * and fix it be cycling transmit flow control on this end. */
+	reset = (wanted_fc & EFX_FC_TX) && !(efx->wanted_fc & EFX_FC_TX);
+	if (EFX_WORKAROUND_11482(efx) && reset) {
+		if (falcon_rev(efx) >= FALCON_REV_B0) {
+			/* Recover by resetting the EM block */
+			if (efx->link_up)
+				falcon_drain_tx_fifo(efx);
+		} else {
+			/* Schedule a reset to recover */
+			efx_schedule_reset(efx, RESET_TYPE_INVISIBLE);
+		}
+	}
+
+	/* Try to push the pause parameters */
+	mutex_lock(&efx->mac_lock);
+
+	efx->wanted_fc = wanted_fc;
+	mdio_clause45_set_pause(efx);
+	__efx_reconfigure_port(efx);
+
+	mutex_unlock(&efx->mac_lock);
 
-	efx_reconfigure_port(efx);
 	return 0;
 }
 
@@ -690,9 +729,9 @@ static void efx_ethtool_get_pauseparam(struct net_device *net_dev,
 {
 	struct efx_nic *efx = netdev_priv(net_dev);
 
-	pause->rx_pause = !!(efx->flow_control & EFX_FC_RX);
-	pause->tx_pause = !!(efx->flow_control & EFX_FC_TX);
-	pause->autoneg = !!(efx->flow_control & EFX_FC_AUTO);
+	pause->rx_pause = !!(efx->wanted_fc & EFX_FC_RX);
+	pause->tx_pause = !!(efx->wanted_fc & EFX_FC_TX);
+	pause->autoneg = !!(efx->wanted_fc & EFX_FC_AUTO);
 }
 
 

drivers/net/sfc/falcon.c

@@ -1998,7 +1998,7 @@ void falcon_reconfigure_mac_wrapper(struct efx_nic *efx)
 	/* Transmission of pause frames when RX crosses the threshold is
 	 * covered by RX_XOFF_MAC_EN and XM_TX_CFG_REG:XM_FCNTL.
 	 * Action on receipt of pause frames is controller by XM_DIS_FCNTL */
-	tx_fc = !!(efx->flow_control & EFX_FC_TX);
+	tx_fc = !!(efx->link_fc & EFX_FC_TX);
 	falcon_read(efx, &reg, RX_CFG_REG_KER);
 	EFX_SET_OWORD_FIELD_VER(efx, reg, RX_XOFF_MAC_EN, tx_fc);
 
@@ -2328,9 +2328,9 @@ int falcon_probe_port(struct efx_nic *efx)
 
 	/* Hardware flow ctrl. FalconA RX FIFO too small for pause generation */
 	if (falcon_rev(efx) >= FALCON_REV_B0)
-		efx->flow_control = EFX_FC_RX | EFX_FC_TX;
+		efx->wanted_fc = EFX_FC_RX | EFX_FC_TX;
 	else
-		efx->flow_control = EFX_FC_RX;
+		efx->wanted_fc = EFX_FC_RX;
 
 	/* Allocate buffer for stats */
 	rc = falcon_alloc_buffer(efx, &efx->stats_buffer,

drivers/net/sfc/falcon_gmac.c

@@ -31,8 +31,8 @@ static void falcon_reconfigure_gmac(struct efx_nic *efx)
 	efx_oword_t reg;
 
 	/* Configuration register 1 */
-	tx_fc = (efx->flow_control & EFX_FC_TX) || !efx->link_fd;
-	rx_fc = !!(efx->flow_control & EFX_FC_RX);
+	tx_fc = (efx->link_fc & EFX_FC_TX) || !efx->link_fd;
+	rx_fc = !!(efx->link_fc & EFX_FC_RX);
 	loopback = (efx->loopback_mode == LOOPBACK_GMAC);
 	bytemode = (efx->link_speed == 1000);
 

drivers/net/sfc/falcon_xmac.c

@@ -142,7 +142,7 @@ static void falcon_reconfigure_xmac_core(struct efx_nic *efx)
 {
 	unsigned int max_frame_len;
 	efx_oword_t reg;
-	bool rx_fc = !!(efx->flow_control & EFX_FC_RX);
+	bool rx_fc = !!(efx->link_fc & EFX_FC_RX);
 
 	/* Configure MAC  - cut-thru mode is hard wired on */
 	EFX_POPULATE_DWORD_3(reg,

drivers/net/sfc/mdio_10g.h

@@ -81,6 +81,17 @@
 #define MDIO_MMDREG_DEVS_PHYXS	DEV_PRESENT_BIT(MDIO_MMD_PHYXS)
 #define MDIO_MMDREG_DEVS_PCS	DEV_PRESENT_BIT(MDIO_MMD_PCS)
 #define MDIO_MMDREG_DEVS_PMAPMD	DEV_PRESENT_BIT(MDIO_MMD_PMAPMD)
+#define MDIO_MMDREG_DEVS_AN	DEV_PRESENT_BIT(MDIO_MMD_AN)
+
+/* Bits in MMDREG_SPEED */
+#define MDIO_MMDREG_SPEED_10G_LBN	0
+#define MDIO_MMDREG_SPEED_10G_WIDTH	1
+#define MDIO_MMDREG_SPEED_1000M_LBN	4
+#define MDIO_MMDREG_SPEED_1000M_WIDTH	1
+#define MDIO_MMDREG_SPEED_100M_LBN	5
+#define MDIO_MMDREG_SPEED_100M_WIDTH	1
+#define MDIO_MMDREG_SPEED_10M_LBN	6
+#define MDIO_MMDREG_SPEED_10M_WIDTH	1
 
 /* Bits in MMDREG_STAT2 */
 #define MDIO_MMDREG_STAT2_PRESENT_VAL	(2)
@@ -119,12 +130,20 @@
 #define MDIO_PHYXS_LANE_ALIGNED_LBN	(12)
 
 /* AN registers */
+#define MDIO_AN_CTRL_XNP_LBN		13
 #define MDIO_AN_STATUS			(1)
 #define MDIO_AN_STATUS_XNP_LBN		(7)
 #define MDIO_AN_STATUS_PAGE_LBN		(6)
 #define MDIO_AN_STATUS_AN_DONE_LBN	(5)
 #define MDIO_AN_STATUS_LP_AN_CAP_LBN	(0)
 
+#define MDIO_AN_ADVERTISE		16
+#define MDIO_AN_ADVERTISE_XNP_LBN	12
+#define MDIO_AN_LPA			19
+#define MDIO_AN_XNP			22
+#define MDIO_AN_LPA_XNP			25
+
+#define MDIO_AN_10GBT_ADVERTISE		32
 #define MDIO_AN_10GBT_STATUS		(33)
 #define MDIO_AN_10GBT_STATUS_MS_FLT_LBN (15) /* MASTER/SLAVE config fault */
 #define MDIO_AN_10GBT_STATUS_MS_LBN     (14) /* MASTER/SLAVE config */
@@ -251,10 +270,23 @@ extern void mdio_clause45_set_mmds_lpower(struct efx_nic *efx,
 extern void mdio_clause45_get_settings(struct efx_nic *efx,
 				       struct ethtool_cmd *ecmd);
 
+/* Read (some of) the PHY settings over MDIO */
+extern void
+mdio_clause45_get_settings_ext(struct efx_nic *efx, struct ethtool_cmd *ecmd,
+			       u32 xnp, u32 xnp_lpa);
+
 /* Set (some of) the PHY settings over MDIO */
 extern int mdio_clause45_set_settings(struct efx_nic *efx,
 				      struct ethtool_cmd *ecmd);
 
+/* Set pause parameters to be advertised through AN (if available) */
+extern void mdio_clause45_set_pause(struct efx_nic *efx);
+
+/* Get pause parameters from AN if available (otherwise return
+ * requested pause parameters)
+ */
+enum efx_fc_type mdio_clause45_get_pause(struct efx_nic *efx);
+
 /* Wait for specified MMDs to exit reset within a timeout */
 extern int mdio_clause45_wait_reset_mmds(struct efx_nic *efx,
 					 unsigned int mmd_mask);

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;

drivers/net/sfc/tenxpress.c

@@ -17,10 +17,10 @@
 #include "boards.h"
 
 /* We expect these MMDs to be in the package */
-/* AN not here as mdio_check_mmds() requires STAT2 support */
 #define TENXPRESS_REQUIRED_DEVS (MDIO_MMDREG_DEVS_PMAPMD	| \
 				 MDIO_MMDREG_DEVS_PCS		| \
-				 MDIO_MMDREG_DEVS_PHYXS)
+				 MDIO_MMDREG_DEVS_PHYXS		| \
+				 MDIO_MMDREG_DEVS_AN)
 
 #define TENXPRESS_LOOPBACKS ((1 << LOOPBACK_PHYXS) |	\
 			     (1 << LOOPBACK_PCS) |	\
@@ -57,6 +57,7 @@
 #define	PMA_PMD_LED_ON		(1)
 #define	PMA_PMD_LED_OFF		(2)
 #define PMA_PMD_LED_FLASH	(3)
+#define PMA_PMD_LED_MASK	3
 /* All LEDs under hardware control */
 #define PMA_PMD_LED_FULL_AUTO	(0)
 /* Green and Amber under hardware control, Red off */
@@ -242,78 +243,60 @@ static int tenxpress_special_reset(struct efx_nic *efx)
 	return rc;
 }
 
-static void tenxpress_set_bad_lp(struct efx_nic *efx, bool bad_lp)
+static void tenxpress_check_bad_lp(struct efx_nic *efx, bool link_ok)
 {
 	struct tenxpress_phy_data *pd = efx->phy_data;
+	int phy_id = efx->mii.phy_id;
+	bool bad_lp;
 	int reg;
 
+	if (link_ok) {
+		bad_lp = false;
+	} else {
+		/* Check that AN has started but not completed. */
+		reg = mdio_clause45_read(efx, phy_id, MDIO_MMD_AN,
+					 MDIO_AN_STATUS);
+		if (!(reg & (1 << MDIO_AN_STATUS_LP_AN_CAP_LBN)))
+			return; /* LP status is unknown */
+		bad_lp = !(reg & (1 << MDIO_AN_STATUS_AN_DONE_LBN));
+		if (bad_lp)
+			pd->bad_lp_tries++;
+	}
+
 	/* Nothing to do if all is well and was previously so. */
-	if (!(bad_lp || pd->bad_lp_tries))
+	if (!pd->bad_lp_tries)
 		return;
 
-	reg = mdio_clause45_read(efx, efx->mii.phy_id,
-				 MDIO_MMD_PMAPMD, PMA_PMD_LED_OVERR_REG);
-
-	if (bad_lp)
-		pd->bad_lp_tries++;
-	else
-		pd->bad_lp_tries = 0;
-
-	if (pd->bad_lp_tries == MAX_BAD_LP_TRIES) {
-		pd->bad_lp_tries = 0;	/* Restart count */
-		reg &= ~(PMA_PMD_LED_FLASH << PMA_PMD_LED_RX_LBN);
-		reg |= (PMA_PMD_LED_FLASH << PMA_PMD_LED_RX_LBN);
-		EFX_ERR(efx, "This NIC appears to be plugged into"
-			" a port that is not 10GBASE-T capable.\n"
-			" This PHY is 10GBASE-T ONLY, so no link can"
-			" be established.\n");
+	/* Use the RX (red) LED as an error indicator once we've seen AN
+	 * failure several times in a row, and also log a message. */
+	if (!bad_lp || pd->bad_lp_tries == MAX_BAD_LP_TRIES) {
+		reg = mdio_clause45_read(efx, phy_id, MDIO_MMD_PMAPMD,
+					 PMA_PMD_LED_OVERR_REG);
+		reg &= ~(PMA_PMD_LED_MASK << PMA_PMD_LED_RX_LBN);
+		if (!bad_lp) {
+			reg |= PMA_PMD_LED_OFF << PMA_PMD_LED_RX_LBN;
 		} else {
-		reg |= (PMA_PMD_LED_OFF << PMA_PMD_LED_RX_LBN);
+			reg |= PMA_PMD_LED_FLASH << PMA_PMD_LED_RX_LBN;
+			EFX_ERR(efx, "appears to be plugged into a port"
+				" that is not 10GBASE-T capable. The PHY"
+				" supports 10GBASE-T ONLY, so no link can"
+				" be established\n");
 		}
-	mdio_clause45_write(efx, efx->mii.phy_id, MDIO_MMD_PMAPMD,
+		mdio_clause45_write(efx, phy_id, MDIO_MMD_PMAPMD,
 				    PMA_PMD_LED_OVERR_REG, reg);
+		pd->bad_lp_tries = bad_lp;
+	}
 }
 
-/* Check link status and return a boolean OK value. If the link is NOT
- * OK we have a quick rummage round to see if we appear to be plugged
- * into a non-10GBT port and if so warn the user that they won't get
- * link any time soon as we are 10GBT only, unless caller specified
- * not to do this check (it isn't useful in loopback) */
-static bool tenxpress_link_ok(struct efx_nic *efx, bool check_lp)
+static bool tenxpress_link_ok(struct efx_nic *efx)
 {
-	bool ok = mdio_clause45_links_ok(efx, TENXPRESS_REQUIRED_DEVS);
-
-	if (ok) {
-		tenxpress_set_bad_lp(efx, false);
-	} else if (check_lp) {
-		/* Are we plugged into the wrong sort of link? */
-		bool bad_lp = false;
-		int phy_id = efx->mii.phy_id;
-		int an_stat = mdio_clause45_read(efx, phy_id, MDIO_MMD_AN,
-						 MDIO_AN_STATUS);
-		int xphy_stat = mdio_clause45_read(efx, phy_id,
-						   MDIO_MMD_PMAPMD,
-						   PMA_PMD_XSTATUS_REG);
-		/* Are we plugged into anything that sends FLPs? If
-		 * not we can't distinguish between not being plugged
-		 * in and being plugged into a non-AN antique. The FLP
-		 * bit has the advantage of not clearing when autoneg
-		 * restarts. */
-		if (!(xphy_stat & (1 << PMA_PMD_XSTAT_FLP_LBN))) {
-			tenxpress_set_bad_lp(efx, false);
-			return ok;
-		}
-
-		/* If it can do 10GBT it must be XNP capable */
-		bad_lp = !(an_stat & (1 << MDIO_AN_STATUS_XNP_LBN));
-		if (!bad_lp && (an_stat & (1 << MDIO_AN_STATUS_PAGE_LBN))) {
-			bad_lp = !(mdio_clause45_read(efx, phy_id,
-					MDIO_MMD_AN, MDIO_AN_10GBT_STATUS) &
-					(1 << MDIO_AN_10GBT_STATUS_LP_10G_LBN));
-		}
-		tenxpress_set_bad_lp(efx, bad_lp);
-	}
-	return ok;
+	if (efx->loopback_mode == LOOPBACK_NONE)
+		return mdio_clause45_links_ok(efx, MDIO_MMDREG_DEVS_AN);
+	else
+		return mdio_clause45_links_ok(efx,
+					      MDIO_MMDREG_DEVS_PMAPMD |
+					      MDIO_MMDREG_DEVS_PCS |
+					      MDIO_MMDREG_DEVS_PHYXS);
 }
 
 static void tenxpress_phyxs_loopback(struct efx_nic *efx)
@@ -359,9 +342,10 @@ static void tenxpress_phy_reconfigure(struct efx_nic *efx)
 
 	phy_data->loopback_mode = efx->loopback_mode;
 	phy_data->phy_mode = efx->phy_mode;
-	efx->link_up = tenxpress_link_ok(efx, false);
+	efx->link_up = tenxpress_link_ok(efx);
 	efx->link_speed = 10000;
 	efx->link_fd = true;
+	efx->link_fc = mdio_clause45_get_pause(efx);
 }
 
 static void tenxpress_phy_clear_interrupt(struct efx_nic *efx)
@@ -377,7 +361,8 @@ static int tenxpress_phy_check_hw(struct efx_nic *efx)
 	bool link_ok;
 	int rc = 0;
 
-	link_ok = tenxpress_link_ok(efx, true);
+	link_ok = tenxpress_link_ok(efx);
+	tenxpress_check_bad_lp(efx, link_ok);
 
 	if (link_ok != efx->link_up)
 		falcon_sim_phy_event(efx);
@@ -451,6 +436,27 @@ static int tenxpress_phy_test(struct efx_nic *efx)
 	return tenxpress_special_reset(efx);
 }
 
+static u32 tenxpress_get_xnp_lpa(struct efx_nic *efx)
+{
+	int phy = efx->mii.phy_id;
+	u32 lpa = 0;
+	int reg;
+
+	reg = mdio_clause45_read(efx, phy, MDIO_MMD_AN, MDIO_AN_10GBT_STATUS);
+	if (reg & (1 << MDIO_AN_10GBT_STATUS_LP_10G_LBN))
+		lpa |= ADVERTISED_10000baseT_Full;
+	return lpa;
+}
+
+static void
+tenxpress_get_settings(struct efx_nic *efx, struct ethtool_cmd *ecmd)
+{
+	mdio_clause45_get_settings_ext(efx, ecmd, ADVERTISED_10000baseT_Full,
+				       tenxpress_get_xnp_lpa(efx));
+	ecmd->supported |= SUPPORTED_10000baseT_Full;
+	ecmd->advertising |= ADVERTISED_10000baseT_Full;
+}
+
 struct efx_phy_operations falcon_tenxpress_phy_ops = {
 	.macs		  = EFX_XMAC,
 	.init             = tenxpress_phy_init,
@@ -459,7 +465,7 @@ struct efx_phy_operations falcon_tenxpress_phy_ops = {
 	.fini             = tenxpress_phy_fini,
 	.clear_interrupt  = tenxpress_phy_clear_interrupt,
 	.test             = tenxpress_phy_test,
-	.get_settings	  = mdio_clause45_get_settings,
+	.get_settings	  = tenxpress_get_settings,
 	.set_settings	  = mdio_clause45_set_settings,
 	.mmds             = TENXPRESS_REQUIRED_DEVS,
 	.loopbacks        = TENXPRESS_LOOPBACKS,

drivers/net/sfc/xfp_phy.c

@@ -155,6 +155,7 @@ static void xfp_phy_reconfigure(struct efx_nic *efx)
 	efx->link_up = xfp_link_ok(efx);
 	efx->link_speed = 10000;
 	efx->link_fd = true;
+	efx->link_fc = efx->wanted_fc;
 }