[PATCH net-next 07/15] igb: prepare for RSS key get/set support

[Tony Nguyen <anthony.l.nguyen@intel.com>]

From: Takashi Kozu <takkozu@amazon.com>

Store the RSS key inside struct igb_adapter and introduce the
igb_write_rss_key() helper function. This allows the driver to program
the E1000 registers using a persistent RSS key, instead of using a
stack-local buffer in igb_setup_mrqc().

Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Piotr Kwapulinski <piotr.kwapulinski@intel.com>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Signed-off-by: Takashi Kozu <takkozu@amazon.com>
Tested-by: Rinitha S <sx.rinitha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/igb/igb.h         |  3 +++
 drivers/net/ethernet/intel/igb/igb_ethtool.c | 21 ++++++++++++++++++++
 drivers/net/ethernet/intel/igb/igb_main.c    |  8 ++++----
 3 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/intel/igb/igb.h b/drivers/net/ethernet/intel/igb/igb.h
index 0fff1df81b7b..8c9b02058cec 100644
--- a/drivers/net/ethernet/intel/igb/igb.h
+++ b/drivers/net/ethernet/intel/igb/igb.h
@@ -495,6 +495,7 @@ struct hwmon_buff {
 #define IGB_N_PEROUT	2
 #define IGB_N_SDP	4
 #define IGB_RETA_SIZE	128
+#define IGB_RSS_KEY_SIZE	40
 
 enum igb_filter_match_flags {
 	IGB_FILTER_FLAG_ETHER_TYPE = 0x1,
@@ -655,6 +656,7 @@ struct igb_adapter {
 	struct i2c_client *i2c_client;
 	u32 rss_indir_tbl_init;
 	u8 rss_indir_tbl[IGB_RETA_SIZE];
+	u8 rss_key[IGB_RSS_KEY_SIZE];
 
 	unsigned long link_check_timeout;
 	int copper_tries;
@@ -735,6 +737,7 @@ void igb_down(struct igb_adapter *);
 void igb_reinit_locked(struct igb_adapter *);
 void igb_reset(struct igb_adapter *);
 int igb_reinit_queues(struct igb_adapter *);
+void igb_write_rss_key(struct igb_adapter *adapter);
 void igb_write_rss_indir_tbl(struct igb_adapter *);
 int igb_set_spd_dplx(struct igb_adapter *, u32, u8);
 int igb_setup_tx_resources(struct igb_ring *);
diff --git a/drivers/net/ethernet/intel/igb/igb_ethtool.c b/drivers/net/ethernet/intel/igb/igb_ethtool.c
index f7938c1da835..9a105e59f432 100644
--- a/drivers/net/ethernet/intel/igb/igb_ethtool.c
+++ b/drivers/net/ethernet/intel/igb/igb_ethtool.c
@@ -3019,6 +3019,27 @@ static int igb_set_rxnfc(struct net_device *dev, struct ethtool_rxnfc *cmd)
 	return ret;
 }
 
+/**
+ * igb_write_rss_key - Program the RSS key into device registers
+ * @adapter: board private structure
+ *
+ * Write the RSS key stored in adapter->rss_key to the E1000 hardware registers.
+ * Each 32-bit chunk of the key is read using get_unaligned_le32() and written
+ * to the appropriate register.
+ */
+void igb_write_rss_key(struct igb_adapter *adapter)
+{
+	struct e1000_hw *hw = &adapter->hw;
+
+	ASSERT_RTNL();
+
+	for (int i = 0; i < IGB_RSS_KEY_SIZE / 4; i++) {
+		u32 val = get_unaligned_le32(&adapter->rss_key[i * 4]);
+
+		wr32(E1000_RSSRK(i), val);
+	}
+}
+
 static int igb_get_eee(struct net_device *netdev, struct ethtool_keee *edata)
 {
 	struct igb_adapter *adapter = netdev_priv(netdev);
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index ee99fd8fd513..f40fe12419f1 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -4049,6 +4049,9 @@ static int igb_sw_init(struct igb_adapter *adapter)
 
 	pci_read_config_word(pdev, PCI_COMMAND, &hw->bus.pci_cmd_word);
 
+	/* init RSS key */
+	netdev_rss_key_fill(adapter->rss_key, sizeof(adapter->rss_key));
+
 	/* set default ring sizes */
 	adapter->tx_ring_count = IGB_DEFAULT_TXD;
 	adapter->rx_ring_count = IGB_DEFAULT_RXD;
@@ -4523,11 +4526,8 @@ static void igb_setup_mrqc(struct igb_adapter *adapter)
 	struct e1000_hw *hw = &adapter->hw;
 	u32 mrqc, rxcsum;
 	u32 j, num_rx_queues;
-	u32 rss_key[10];
 
-	netdev_rss_key_fill(rss_key, sizeof(rss_key));
-	for (j = 0; j < 10; j++)
-		wr32(E1000_RSSRK(j), rss_key[j]);
+	igb_write_rss_key(adapter);
 
 	num_rx_queues = adapter->rss_queues;
 
-- 
2.47.1