fm10k: use ethtool_rxfh_indir_default for default redirection table

The fm10k driver used its own code for generating a default indirection
table on device load, which was not the same as the default generated by
ethtool when indir_size of 0 is passed to SRXFH. Take advantage of
ethtool_rxfh_indir_default() and simplify code to write the redirection
table to reduce some code duplication.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Krishneil Singh <Krishneil.k.singh@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/fm10k/fm10k.h

@@ -510,6 +510,8 @@ int fm10k_close(struct net_device *netdev);
 
 /* Ethtool */
 void fm10k_set_ethtool_ops(struct net_device *dev);
+u32 fm10k_get_reta_size(struct net_device *netdev);
+void fm10k_write_reta(struct fm10k_intfc *interface, const u32 *indir);
 
 /* IOV */
 s32 fm10k_iov_event(struct fm10k_intfc *interface);

drivers/net/ethernet/intel/fm10k/fm10k_ethtool.c

@@ -1027,11 +1027,31 @@ static int fm10k_set_priv_flags(struct net_device *netdev, u32 priv_flags)
 	return 0;
 }
 
-static u32 fm10k_get_reta_size(struct net_device __always_unused *netdev)
+u32 fm10k_get_reta_size(struct net_device __always_unused *netdev)
 {
 	return FM10K_RETA_SIZE * FM10K_RETA_ENTRIES_PER_REG;
 }
 
+void fm10k_write_reta(struct fm10k_intfc *interface, const u32 *indir)
+{
+	struct fm10k_hw *hw = &interface->hw;
+	int i;
+
+	/* record entries to reta table */
+	for (i = 0; i < FM10K_RETA_SIZE; i++, indir += 4) {
+		u32 reta = indir[0] |
+			   (indir[1] << 8) |
+			   (indir[2] << 16) |
+			   (indir[3] << 24);
+
+		if (interface->reta[i] == reta)
+			continue;
+
+		interface->reta[i] = reta;
+		fm10k_write_reg(hw, FM10K_RETA(0, i), reta);
+	}
+}
+
 static int fm10k_get_reta(struct net_device *netdev, u32 *indir)
 {
 	struct fm10k_intfc *interface = netdev_priv(netdev);
@@ -1055,7 +1075,6 @@ static int fm10k_get_reta(struct net_device *netdev, u32 *indir)
 static int fm10k_set_reta(struct net_device *netdev, const u32 *indir)
 {
 	struct fm10k_intfc *interface = netdev_priv(netdev);
-	struct fm10k_hw *hw = &interface->hw;
 	int i;
 	u16 rss_i;
 
@@ -1070,19 +1089,7 @@ static int fm10k_set_reta(struct net_device *netdev, const u32 *indir)
 		return -EINVAL;
 	}
 
-	/* record entries to reta table */
-	for (i = 0; i < FM10K_RETA_SIZE; i++, indir += 4) {
-		u32 reta = indir[0] |
-			   (indir[1] << 8) |
-			   (indir[2] << 16) |
-			   (indir[3] << 24);
-
-		if (interface->reta[i] == reta)
-			continue;
-
-		interface->reta[i] = reta;
-		fm10k_write_reg(hw, FM10K_RETA(0, i), reta);
-	}
+	fm10k_write_reta(interface, indir);
 
 	return 0;
 }

drivers/net/ethernet/intel/fm10k/fm10k_main.c

@@ -1943,7 +1943,8 @@ static void fm10k_assign_rings(struct fm10k_intfc *interface)
 static void fm10k_init_reta(struct fm10k_intfc *interface)
 {
 	u16 i, rss_i = interface->ring_feature[RING_F_RSS].indices;
-	u32 reta, base;
+	struct net_device *netdev = interface->netdev;
+	u32 reta, *indir;
 
 	/* If the Rx flow indirection table has been configured manually, we
 	 * need to maintain it when possible.
@@ -1968,21 +1969,16 @@ static void fm10k_init_reta(struct fm10k_intfc *interface)
 	}
 
 repopulate_reta:
-	/* Populate the redirection table 4 entries at a time.  To do this
-	 * we are generating the results for n and n+2 and then interleaving
-	 * those with the results with n+1 and n+3.
-	 */
-	for (i = FM10K_RETA_SIZE; i--;) {
-		/* first pass generates n and n+2 */
-		base = ((i * 0x00040004) + 0x00020000) * rss_i;
-		reta = (base & 0x3F803F80) >> 7;
+	indir = kcalloc(fm10k_get_reta_size(netdev),
+			sizeof(indir[0]), GFP_KERNEL);
 
-		/* second pass generates n+1 and n+3 */
-		base += 0x00010001 * rss_i;
-		reta |= (base & 0x3F803F80) << 1;
+	/* generate redirection table using the default kernel policy */
+	for (i = 0; i < fm10k_get_reta_size(netdev); i++)
+		indir[i] = ethtool_rxfh_indir_default(i, rss_i);
 
-		interface->reta[i] = reta;
-	}
+	fm10k_write_reta(interface, indir);
+
+	kfree(indir);
 }
 
 /**