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 62dfd243bedc..75f6efe1e369 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 dd940a8f9357..615c2803202a 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
 };