ixgbe: Check for RSS key before setting value

The RSS key is being repopulated every time the interface is brought up
regardless of whether there is an existing value. If the user sets the RSS
key and the interface is brought up (e.g. reset), the user specified RSS
key will be overwritten.

This patch changes the rss_key to a pointer so we can check to see if the
key has been populated and preserve it accordingly.

Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

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

@@ -769,7 +769,7 @@ struct ixgbe_adapter {
 	u8 rss_indir_tbl[IXGBE_MAX_RETA_ENTRIES];
 
 #define IXGBE_RSS_KEY_SIZE     40  /* size of RSS Hash Key in bytes */
-	u32 rss_key[IXGBE_RSS_KEY_SIZE / sizeof(u32)];
+	u32 *rss_key;
 };
 
 static inline u8 ixgbe_max_rss_indices(struct ixgbe_adapter *adapter)

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

@@ -2967,9 +2967,7 @@ static int ixgbe_rss_indir_tbl_max(struct ixgbe_adapter *adapter)
 
 static u32 ixgbe_get_rxfh_key_size(struct net_device *netdev)
 {
-	struct ixgbe_adapter *adapter = netdev_priv(netdev);
-
-	return sizeof(adapter->rss_key);
+	return IXGBE_RSS_KEY_SIZE;
 }
 
 static u32 ixgbe_rss_indir_size(struct net_device *netdev)

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

@@ -3638,6 +3638,28 @@ void ixgbe_store_key(struct ixgbe_adapter *adapter)
 		IXGBE_WRITE_REG(hw, IXGBE_RSSRK(i), adapter->rss_key[i]);
 }
 
+/**
+ * ixgbe_init_rss_key - Initialize adapter RSS key
+ * @adapter: device handle
+ *
+ * Allocates and initializes the RSS key if it is not allocated.
+ **/
+static inline int ixgbe_init_rss_key(struct ixgbe_adapter *adapter)
+{
+	u32 *rss_key;
+
+	if (!adapter->rss_key) {
+		rss_key = kzalloc(IXGBE_RSS_KEY_SIZE, GFP_KERNEL);
+		if (unlikely(!rss_key))
+			return -ENOMEM;
+
+		netdev_rss_key_fill(rss_key, IXGBE_RSS_KEY_SIZE);
+		adapter->rss_key = rss_key;
+	}
+
+	return 0;
+}
+
 /**
  * ixgbe_store_reta - Write the RETA table to HW
  * @adapter: device handle
@@ -3740,7 +3762,7 @@ static void ixgbe_setup_vfreta(struct ixgbe_adapter *adapter)
 	/* Fill out hash function seeds */
 	for (i = 0; i < 10; i++)
 		IXGBE_WRITE_REG(hw, IXGBE_PFVFRSSRK(i, pf_pool),
-				adapter->rss_key[i]);
+				*(adapter->rss_key + i));
 
 	/* Fill out the redirection table */
 	for (i = 0, j = 0; i < 64; i++, j++) {
@@ -3801,7 +3823,6 @@ static void ixgbe_setup_mrqc(struct ixgbe_adapter *adapter)
 	if (adapter->flags2 & IXGBE_FLAG2_RSS_FIELD_IPV6_UDP)
 		rss_field |= IXGBE_MRQC_RSS_FIELD_IPV6_UDP;
 
-	netdev_rss_key_fill(adapter->rss_key, sizeof(adapter->rss_key));
 	if ((hw->mac.type >= ixgbe_mac_X550) &&
 	    (adapter->flags & IXGBE_FLAG_SRIOV_ENABLED)) {
 		unsigned int pf_pool = adapter->num_vfs;
@@ -6015,6 +6036,9 @@ static int ixgbe_sw_init(struct ixgbe_adapter *adapter,
 	if (!adapter->mac_table)
 		return -ENOMEM;
 
+	if (ixgbe_init_rss_key(adapter))
+		return -ENOMEM;
+
 	/* Set MAC specific capability flags and exceptions */
 	switch (hw->mac.type) {
 	case ixgbe_mac_82598EB:
@@ -10391,6 +10415,7 @@ err_sw_init:
 	iounmap(adapter->io_addr);
 	kfree(adapter->jump_tables[0]);
 	kfree(adapter->mac_table);
+	kfree(adapter->rss_key);
 err_ioremap:
 	disable_dev = !test_and_set_bit(__IXGBE_DISABLED, &adapter->state);
 	free_netdev(netdev);
@@ -10475,6 +10500,7 @@ static void ixgbe_remove(struct pci_dev *pdev)
 	}
 
 	kfree(adapter->mac_table);
+	kfree(adapter->rss_key);
 	disable_dev = !test_and_set_bit(__IXGBE_DISABLED, &adapter->state);
 	free_netdev(netdev);
 

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

@@ -1113,7 +1113,7 @@ static int ixgbe_get_vf_rss_key(struct ixgbe_adapter *adapter,
 		return -EOPNOTSUPP;
 	}
 
-	memcpy(rss_key, adapter->rss_key, sizeof(adapter->rss_key));
+	memcpy(rss_key, adapter->rss_key, IXGBE_RSS_KEY_SIZE);
 
 	return 0;
 }