ixgbe: Add upper limit to ring features

We are currently using indices to indicate the upper limit on a ring
feature.  However since we can switch back and forth on features such as
DCB and that has effects on other features such as RSS it is preferable to
instead store the upper limit separate from the current value for the
number of rings related to the feature.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/ixgbe/ixgbe.h

@@ -278,7 +278,8 @@ enum ixgbe_ring_f_enum {
 #define MAX_TX_QUEUES IXGBE_MAX_FDIR_INDICES
 #endif /* IXGBE_FCOE */
 struct ixgbe_ring_feature {
-	int indices;
+	u16 limit;	/* upper limit on feature indices */
+	u16 indices;	/* current value of indices */
 	int mask;
 } ____cacheline_internodealigned_in_smp;
 

drivers/net/ethernet/intel/ixgbe/ixgbe_fcoe.c

@@ -770,7 +770,7 @@ int ixgbe_fcoe_enable(struct net_device *netdev)
 	ixgbe_clear_interrupt_scheme(adapter);
 
 	adapter->flags |= IXGBE_FLAG_FCOE_ENABLED;
-	adapter->ring_feature[RING_F_FCOE].indices = IXGBE_FCRETA_SIZE;
+	adapter->ring_feature[RING_F_FCOE].limit = IXGBE_FCRETA_SIZE;
 	netdev->features |= NETIF_F_FCOE_CRC;
 	netdev->features |= NETIF_F_FSO;
 	netdev->features |= NETIF_F_FCOE_MTU;

drivers/net/ethernet/intel/ixgbe/ixgbe_lib.c

@@ -302,7 +302,7 @@ static inline bool ixgbe_set_fdir_queues(struct ixgbe_adapter *adapter)
 	bool ret = false;
 	struct ixgbe_ring_feature *f_fdir = &adapter->ring_feature[RING_F_FDIR];
 
-	f_fdir->indices = min_t(int, num_online_cpus(), f_fdir->indices);
+	f_fdir->indices = min_t(int, num_online_cpus(), f_fdir->limit);
 	f_fdir->mask = 0;
 
 	/*
@@ -339,7 +339,7 @@ static inline bool ixgbe_set_fcoe_queues(struct ixgbe_adapter *adapter)
 	if (!(adapter->flags & IXGBE_FLAG_FCOE_ENABLED))
 		return false;
 
-	f->indices = min_t(int, num_online_cpus(), f->indices);
+	f->indices = min_t(int, num_online_cpus(), f->limit);
 
 	adapter->num_rx_queues = 1;
 	adapter->num_tx_queues = 1;

drivers/net/ethernet/intel/ixgbe/ixgbe_main.c

@@ -4386,7 +4386,7 @@ static int __devinit ixgbe_sw_init(struct ixgbe_adapter *adapter)
 
 	/* Set capability flags */
 	rss = min_t(int, IXGBE_MAX_RSS_INDICES, num_online_cpus());
-	adapter->ring_feature[RING_F_RSS].indices = rss;
+	adapter->ring_feature[RING_F_RSS].limit = rss;
 	adapter->flags |= IXGBE_FLAG_RSS_ENABLED;
 	switch (hw->mac.type) {
 	case ixgbe_mac_82598EB:
@@ -4405,13 +4405,12 @@ static int __devinit ixgbe_sw_init(struct ixgbe_adapter *adapter)
 		/* Flow Director hash filters enabled */
 		adapter->flags |= IXGBE_FLAG_FDIR_HASH_CAPABLE;
 		adapter->atr_sample_rate = 20;
-		adapter->ring_feature[RING_F_FDIR].indices =
+		adapter->ring_feature[RING_F_FDIR].limit =
 							 IXGBE_MAX_FDIR_INDICES;
 		adapter->fdir_pballoc = IXGBE_FDIR_PBALLOC_64K;
 #ifdef IXGBE_FCOE
 		adapter->flags |= IXGBE_FLAG_FCOE_CAPABLE;
 		adapter->flags &= ~IXGBE_FLAG_FCOE_ENABLED;
-		adapter->ring_feature[RING_F_FCOE].indices = 0;
 #ifdef CONFIG_IXGBE_DCB
 		/* Default traffic class to use for FCoE */
 		adapter->fcoe.up = IXGBE_FCOE_DEFTC;
@@ -6206,8 +6205,14 @@ static u16 ixgbe_select_queue(struct net_device *dev, struct sk_buff *skb)
 	if (((protocol == htons(ETH_P_FCOE)) ||
 	    (protocol == htons(ETH_P_FIP))) &&
 	    (adapter->flags & IXGBE_FLAG_FCOE_ENABLED)) {
-		txq &= (adapter->ring_feature[RING_F_FCOE].indices - 1);
+		struct ixgbe_ring_feature *f;
+
+		f = &adapter->ring_feature[RING_F_FCOE];
+
+		while (txq >= f->indices)
+			txq -= f->indices;
 		txq += adapter->ring_feature[RING_F_FCOE].mask;
+
 		return txq;
 	}
 #endif