ixgbe: IEEE 802.1Qaz, implement priority assignment table

This patch adds support to use the priority assignment
table in the ieee_ets structure to map priorities to
traffic classes. Previously ixgbe only supported a
1:1 mapping. Now we can enable and disable hardware
DCB support when multiple traffic classes are actually
being used. This allows the default case all priorities
mapped to traffic class 0 to work in normal hardware
mode and utilize the full packet buffer.

This patch does not address putting the hardware in
4TC mode so packet buffer space may be underutilized
in this case. A follow up patch can address this
optimization. But at least we have the hooks to do
this now.

Also CEE will behave as it always has and map priorities
1:1 with traffic classes.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 10 insertions, 2 deletions

diff --git a/drivers/net/ixgbe/ixgbe_dcb_nl.c b/drivers/net/ixgbe/ixgbe_dcb_nl.c
index 8abef8d..fec4c72 100644
--- a/drivers/net/ixgbe/ixgbe_dcb_nl.c
+++ b/drivers/net/ixgbe/ixgbe_dcb_nl.c
@@ -416,6 +416,8 @@ static u8 ixgbe_dcbnl_set_all(struct net_device *netdev)
 	if (adapter->dcb_set_bitmap & (BIT_PG_TX|BIT_PG_RX)) {
 		u16 refill[MAX_TRAFFIC_CLASS], max[MAX_TRAFFIC_CLASS];
 		u8 bwg_id[MAX_TRAFFIC_CLASS], prio_type[MAX_TRAFFIC_CLASS];
+		/* Priority to TC mapping in CEE case default to 1:1 */
+		u8 prio_tc[MAX_TRAFFIC_CLASS] = {0, 1, 2, 3, 4, 5, 6, 7};
 		int max_frame = adapter->netdev->mtu + ETH_HLEN + ETH_FCS_LEN;
 
 #ifdef CONFIG_FCOE
@@ -437,7 +439,7 @@ static u8 ixgbe_dcbnl_set_all(struct net_device *netdev)
 				      DCB_TX_CONFIG, prio_type);
 
 		ixgbe_dcb_hw_ets_config(&adapter->hw, refill, max,
-					bwg_id, prio_type);
+					bwg_id, prio_type, prio_tc);
 	}
 
 	if (adapter->dcb_cfg.pfc_mode_enable)
@@ -645,6 +647,7 @@ static int ixgbe_dcbnl_ieee_setets(struct net_device *dev,
 	__u8 prio_type[IEEE_8021QAZ_MAX_TCS];
 	int max_frame = dev->mtu + ETH_HLEN + ETH_FCS_LEN;
 	int i, err;
+	__u64 *p = (__u64 *) ets->prio_tc;
 	/* naively give each TC a bwg to map onto CEE hardware */
 	__u8 bwg_id[IEEE_8021QAZ_MAX_TCS] = {0, 1, 2, 3, 4, 5, 6, 7};
 
@@ -679,9 +682,14 @@ static int ixgbe_dcbnl_ieee_setets(struct net_device *dev,
 		}
 	}
 
+	if (*p)
+		ixgbe_dcbnl_set_state(dev, 1);
+	else
+		ixgbe_dcbnl_set_state(dev, 0);
+
 	ixgbe_ieee_credits(ets->tc_tx_bw, refill, max, max_frame);
 	err = ixgbe_dcb_hw_ets_config(&adapter->hw, refill, max,
-				      bwg_id, prio_type);
+				      bwg_id, prio_type, ets->prio_tc);
 	return err;
 }