DCB: Add support for DCB BCN

Adds an interface to configure the Backward Congestion Notification
(BCN) feature.  In a BCN capabale network, congestion notifications
from congested points out in the network can cause the end station
limit the rate of a given traffic flow.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 202 insertions, 1 deletions

diff --git a/drivers/net/ixgbe/ixgbe_dcb.h b/drivers/net/ixgbe/ixgbe_dcb.h
index 62dfd243..75f6efe 100644
--- a/drivers/net/ixgbe/ixgbe_dcb.h
+++ b/drivers/net/ixgbe/ixgbe_dcb.h
@@ -108,7 +108,34 @@ enum dcb_rx_pba_cfg {
 	pba_80_48      /* PBA[0-3] each use 80KB, PBA[4-7] each use 48KB */
 };
 
+/*
+ * This structure contains many values encoded as fixed-point
+ * numbers, meaning that some of bits are dedicated to the
+ * magnitude and others to the fraction part. In the comments
+ * this is shown as f=n, where n is the number of fraction bits.
+ * These fraction bits are always the low-order bits. The size
+ * of the magnitude is not specified.
+ */
+struct bcn_config {
+	u32 rp_admin_mode[MAX_TRAFFIC_CLASS]; /* BCN enabled, per TC */
+	u32 bcna_option[2]; /* BCNA Port + MAC Addr */
+	u32 rp_w;        /* Derivative Weight, f=3 */
+	u32 rp_gi;       /* Increase Gain, f=12 */
+	u32 rp_gd;       /* Decrease Gain, f=12 */
+	u32 rp_ru;       /* Rate Unit */
+	u32 rp_alpha;    /* Max Decrease Factor, f=12 */
+	u32 rp_beta;     /* Max Increase Factor, f=12 */
+	u32 rp_ri;       /* Initial Rate */
+	u32 rp_td;       /* Drift Interval Timer */
+	u32 rp_rd;       /* Drift Increase */
+	u32 rp_tmax;     /* Severe Congestion Backoff Timer Range */
+	u32 rp_rmin;     /* Severe Congestion Restart Rate */
+	u32 rp_wrtt;     /* RTT Moving Average Weight */
+};
+
 struct ixgbe_dcb_config {
+	struct bcn_config bcn;
+
 	struct tc_configuration tc_config[MAX_TRAFFIC_CLASS];
 	u8     bw_percentage[2][MAX_BW_GROUP]; /* One each for Tx/Rx */
 
diff --git a/drivers/net/ixgbe/ixgbe_dcb_nl.c b/drivers/net/ixgbe/ixgbe_dcb_nl.c
index dd940a8..615c280 100644
--- a/drivers/net/ixgbe/ixgbe_dcb_nl.c
+++ b/drivers/net/ixgbe/ixgbe_dcb_nl.c
@@ -34,6 +34,7 @@
 #define BIT_PFC		0x02
 #define BIT_PG_RX	0x04
 #define BIT_PG_TX	0x08
+#define BIT_BCN         0x10
 
 int ixgbe_copy_dcb_cfg(struct ixgbe_dcb_config *src_dcb_cfg,
                        struct ixgbe_dcb_config *dst_dcb_cfg, int tc_max)
@@ -88,6 +89,23 @@ int ixgbe_copy_dcb_cfg(struct ixgbe_dcb_config *src_dcb_cfg,
 			src_dcb_cfg->tc_config[i - DCB_PFC_UP_ATTR_0].dcb_pfc;
 	}
 
+	for (i = DCB_BCN_ATTR_RP_0; i < DCB_BCN_ATTR_RP_ALL; i++) {
+		dst_dcb_cfg->bcn.rp_admin_mode[i - DCB_BCN_ATTR_RP_0] =
+			src_dcb_cfg->bcn.rp_admin_mode[i - DCB_BCN_ATTR_RP_0];
+	}
+	dst_dcb_cfg->bcn.rp_alpha = src_dcb_cfg->bcn.rp_alpha;
+	dst_dcb_cfg->bcn.rp_beta = src_dcb_cfg->bcn.rp_beta;
+	dst_dcb_cfg->bcn.rp_gd = src_dcb_cfg->bcn.rp_gd;
+	dst_dcb_cfg->bcn.rp_gi = src_dcb_cfg->bcn.rp_gi;
+	dst_dcb_cfg->bcn.rp_tmax = src_dcb_cfg->bcn.rp_tmax;
+	dst_dcb_cfg->bcn.rp_td = src_dcb_cfg->bcn.rp_td;
+	dst_dcb_cfg->bcn.rp_rmin = src_dcb_cfg->bcn.rp_rmin;
+	dst_dcb_cfg->bcn.rp_w = src_dcb_cfg->bcn.rp_w;
+	dst_dcb_cfg->bcn.rp_rd = src_dcb_cfg->bcn.rp_rd;
+	dst_dcb_cfg->bcn.rp_ru = src_dcb_cfg->bcn.rp_ru;
+	dst_dcb_cfg->bcn.rp_wrtt = src_dcb_cfg->bcn.rp_wrtt;
+	dst_dcb_cfg->bcn.rp_ri = src_dcb_cfg->bcn.rp_ri;
+
 	return 0;
 }
 
@@ -313,6 +331,7 @@ static u8 ixgbe_dcbnl_set_all(struct net_device *netdev)
 	struct ixgbe_adapter *adapter = netdev_priv(netdev);
 	int ret;
 
+	adapter->dcb_set_bitmap &= ~BIT_BCN;	/* no set for BCN */
 	if (!adapter->dcb_set_bitmap)
 		return 1;
 
@@ -417,6 +436,157 @@ static void ixgbe_dcbnl_setpfcstate(struct net_device *netdev, u8 state)
 	return;
 }
 
+static void ixgbe_dcbnl_getbcnrp(struct net_device *netdev, int priority,
+				  u8 *setting)
+{
+	struct ixgbe_adapter *adapter = netdev_priv(netdev);
+
+	*setting = adapter->dcb_cfg.bcn.rp_admin_mode[priority];
+}
+
+
+static void ixgbe_dcbnl_getbcncfg(struct net_device *netdev, int enum_index,
+				  u32 *setting)
+{
+	struct ixgbe_adapter *adapter = netdev_priv(netdev);
+
+	switch (enum_index) {
+	case DCB_BCN_ATTR_ALPHA:
+		*setting = adapter->dcb_cfg.bcn.rp_alpha;
+		break;
+	case DCB_BCN_ATTR_BETA:
+		*setting = adapter->dcb_cfg.bcn.rp_beta;
+		break;
+	case DCB_BCN_ATTR_GD:
+		*setting = adapter->dcb_cfg.bcn.rp_gd;
+		break;
+	case DCB_BCN_ATTR_GI:
+		*setting = adapter->dcb_cfg.bcn.rp_gi;
+		break;
+	case DCB_BCN_ATTR_TMAX:
+		*setting = adapter->dcb_cfg.bcn.rp_tmax;
+		break;
+	case DCB_BCN_ATTR_TD:
+		*setting = adapter->dcb_cfg.bcn.rp_td;
+		break;
+	case DCB_BCN_ATTR_RMIN:
+		*setting = adapter->dcb_cfg.bcn.rp_rmin;
+		break;
+	case DCB_BCN_ATTR_W:
+		*setting = adapter->dcb_cfg.bcn.rp_w;
+		break;
+	case DCB_BCN_ATTR_RD:
+		*setting = adapter->dcb_cfg.bcn.rp_rd;
+		break;
+	case DCB_BCN_ATTR_RU:
+		*setting = adapter->dcb_cfg.bcn.rp_ru;
+		break;
+	case DCB_BCN_ATTR_WRTT:
+		*setting = adapter->dcb_cfg.bcn.rp_wrtt;
+		break;
+	case DCB_BCN_ATTR_RI:
+		*setting = adapter->dcb_cfg.bcn.rp_ri;
+		break;
+	default:
+		*setting = -1;
+	}
+}
+
+static void ixgbe_dcbnl_setbcnrp(struct net_device *netdev, int priority,
+				 u8 setting)
+{
+	struct ixgbe_adapter *adapter = netdev_priv(netdev);
+
+	adapter->temp_dcb_cfg.bcn.rp_admin_mode[priority] = setting;
+
+	if (adapter->temp_dcb_cfg.bcn.rp_admin_mode[priority] !=
+	    adapter->dcb_cfg.bcn.rp_admin_mode[priority])
+		adapter->dcb_set_bitmap |= BIT_BCN;
+}
+
+static void ixgbe_dcbnl_setbcncfg(struct net_device *netdev, int enum_index,
+				 u32 setting)
+{
+	struct ixgbe_adapter *adapter = netdev_priv(netdev);
+
+	switch (enum_index) {
+	case DCB_BCN_ATTR_ALPHA:
+		adapter->temp_dcb_cfg.bcn.rp_alpha = setting;
+		if (adapter->temp_dcb_cfg.bcn.rp_alpha !=
+		    adapter->dcb_cfg.bcn.rp_alpha)
+			adapter->dcb_set_bitmap |= BIT_BCN;
+		break;
+	case DCB_BCN_ATTR_BETA:
+		adapter->temp_dcb_cfg.bcn.rp_beta = setting;
+		if (adapter->temp_dcb_cfg.bcn.rp_beta !=
+		    adapter->dcb_cfg.bcn.rp_beta)
+			adapter->dcb_set_bitmap |= BIT_BCN;
+		break;
+	case DCB_BCN_ATTR_GD:
+		adapter->temp_dcb_cfg.bcn.rp_gd = setting;
+		if (adapter->temp_dcb_cfg.bcn.rp_gd !=
+		    adapter->dcb_cfg.bcn.rp_gd)
+			adapter->dcb_set_bitmap |= BIT_BCN;
+		break;
+	case DCB_BCN_ATTR_GI:
+		adapter->temp_dcb_cfg.bcn.rp_gi = setting;
+		if (adapter->temp_dcb_cfg.bcn.rp_gi !=
+		    adapter->dcb_cfg.bcn.rp_gi)
+			adapter->dcb_set_bitmap |= BIT_BCN;
+		break;
+	case DCB_BCN_ATTR_TMAX:
+		adapter->temp_dcb_cfg.bcn.rp_tmax = setting;
+		if (adapter->temp_dcb_cfg.bcn.rp_tmax !=
+		    adapter->dcb_cfg.bcn.rp_tmax)
+			adapter->dcb_set_bitmap |= BIT_BCN;
+		break;
+	case DCB_BCN_ATTR_TD:
+		adapter->temp_dcb_cfg.bcn.rp_td = setting;
+		if (adapter->temp_dcb_cfg.bcn.rp_td !=
+		    adapter->dcb_cfg.bcn.rp_td)
+			adapter->dcb_set_bitmap |= BIT_BCN;
+		break;
+	case DCB_BCN_ATTR_RMIN:
+		adapter->temp_dcb_cfg.bcn.rp_rmin = setting;
+		if (adapter->temp_dcb_cfg.bcn.rp_rmin !=
+		    adapter->dcb_cfg.bcn.rp_rmin)
+			adapter->dcb_set_bitmap |= BIT_BCN;
+		break;
+	case DCB_BCN_ATTR_W:
+		adapter->temp_dcb_cfg.bcn.rp_w = setting;
+		if (adapter->temp_dcb_cfg.bcn.rp_w !=
+		    adapter->dcb_cfg.bcn.rp_w)
+			adapter->dcb_set_bitmap |= BIT_BCN;
+		break;
+	case DCB_BCN_ATTR_RD:
+		adapter->temp_dcb_cfg.bcn.rp_rd = setting;
+		if (adapter->temp_dcb_cfg.bcn.rp_rd !=
+		    adapter->dcb_cfg.bcn.rp_rd)
+			adapter->dcb_set_bitmap |= BIT_BCN;
+		break;
+	case DCB_BCN_ATTR_RU:
+		adapter->temp_dcb_cfg.bcn.rp_ru = setting;
+		if (adapter->temp_dcb_cfg.bcn.rp_ru !=
+		    adapter->dcb_cfg.bcn.rp_ru)
+			adapter->dcb_set_bitmap |= BIT_BCN;
+		break;
+	case DCB_BCN_ATTR_WRTT:
+		adapter->temp_dcb_cfg.bcn.rp_wrtt = setting;
+		if (adapter->temp_dcb_cfg.bcn.rp_wrtt !=
+		    adapter->dcb_cfg.bcn.rp_wrtt)
+			adapter->dcb_set_bitmap |= BIT_BCN;
+		break;
+	case DCB_BCN_ATTR_RI:
+		adapter->temp_dcb_cfg.bcn.rp_ri = setting;
+		if (adapter->temp_dcb_cfg.bcn.rp_ri !=
+		    adapter->dcb_cfg.bcn.rp_ri)
+			adapter->dcb_set_bitmap |= BIT_BCN;
+		break;
+	default:
+		break;
+	}
+}
+
 struct dcbnl_rtnl_ops dcbnl_ops = {
 	.getstate	= ixgbe_dcbnl_get_state,
 	.setstate	= ixgbe_dcbnl_set_state,
@@ -436,6 +606,10 @@ struct dcbnl_rtnl_ops dcbnl_ops = {
 	.getnumtcs	= ixgbe_dcbnl_getnumtcs,
 	.setnumtcs	= ixgbe_dcbnl_setnumtcs,
 	.getpfcstate	= ixgbe_dcbnl_getpfcstate,
-	.setpfcstate	= ixgbe_dcbnl_setpfcstate
+	.setpfcstate	= ixgbe_dcbnl_setpfcstate,
+	.getbcncfg      = ixgbe_dcbnl_getbcncfg,
+	.getbcnrp       = ixgbe_dcbnl_getbcnrp,
+	.setbcncfg      = ixgbe_dcbnl_setbcncfg,
+	.setbcnrp       = ixgbe_dcbnl_setbcnrp
 };