From: Sameeh Jubran <sameehj@amazon.com>
Date: Sun, 3 May 2020 09:52:12 +0000
Subject: net: ena: allow setting the hash function without changing the key
Patch-mainline: v5.8-rc1
Git-commit: f66c2ea3b18a8cc8e45ff32c636aaefb2ac06315
References: bsc#1174852

Current code does not allow setting the hash function without
changing the key. This commit enables it.

To achieve this we separate ena_com_get_hash_function() to 2 functions:
ena_com_get_hash_function() - which gets only the hash function, and
ena_com_get_hash_key() - which gets only the hash key.

Also return 0 instead of rc at the end of ena_get_rxfh() since all
previous operations succeeded.

Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/amazon/ena/ena_com.c     |   13 +++++++++----
 drivers/net/ethernet/amazon/ena/ena_com.h     |   21 +++++++++++++++------
 drivers/net/ethernet/amazon/ena/ena_ethtool.c |   12 ++++++++----
 3 files changed, 32 insertions(+), 14 deletions(-)

--- a/drivers/net/ethernet/amazon/ena/ena_com.c
+++ b/drivers/net/ethernet/amazon/ena/ena_com.c
@@ -2339,13 +2339,10 @@ int ena_com_fill_hash_function(struct en
 }
 
 int ena_com_get_hash_function(struct ena_com_dev *ena_dev,
-			      enum ena_admin_hash_functions *func,
-			      u8 *key)
+			      enum ena_admin_hash_functions *func)
 {
 	struct ena_rss *rss = &ena_dev->rss;
 	struct ena_admin_get_feat_resp get_resp;
-	struct ena_admin_feature_rss_flow_hash_control *hash_key =
-		rss->hash_key;
 	int rc;
 
 	if (unlikely(!func))
@@ -2365,6 +2362,14 @@ int ena_com_get_hash_function(struct ena
 
 	*func = rss->hash_func;
 
+	return 0;
+}
+
+int ena_com_get_hash_key(struct ena_com_dev *ena_dev, u8 *key)
+{
+	struct ena_admin_feature_rss_flow_hash_control *hash_key =
+		ena_dev->rss.hash_key;
+
 	if (key)
 		memcpy(key, hash_key->key, (size_t)(hash_key->keys_num) << 2);
 
--- a/drivers/net/ethernet/amazon/ena/ena_com.h
+++ b/drivers/net/ethernet/amazon/ena/ena_com.h
@@ -695,13 +695,11 @@ int ena_com_fill_hash_function(struct en
  */
 int ena_com_set_hash_function(struct ena_com_dev *ena_dev);
 
-/* ena_com_get_hash_function - Retrieve the hash function and the hash key
- * from the device.
+/* ena_com_get_hash_function - Retrieve the hash function from the device.
  * @ena_dev: ENA communication layer struct
  * @func: hash function
- * @key: hash key
  *
- * Retrieve the hash function and the hash key from the device.
+ * Retrieve the hash function from the device.
  *
  * @note: If the caller called ena_com_fill_hash_function but didn't flash
  * it to the device, the new configuration will be lost.
@@ -709,9 +707,20 @@ int ena_com_set_hash_function(struct ena
  * @return: 0 on Success and negative value otherwise.
  */
 int ena_com_get_hash_function(struct ena_com_dev *ena_dev,
-			      enum ena_admin_hash_functions *func,
-			      u8 *key);
+			      enum ena_admin_hash_functions *func);
 
+/* ena_com_get_hash_key - Retrieve the hash key
+ * @ena_dev: ENA communication layer struct
+ * @key: hash key
+ *
+ * Retrieve the hash key.
+ *
+ * @note: If the caller called ena_com_fill_hash_key but didn't flash
+ * it to the device, the new configuration will be lost.
+ *
+ * @return: 0 on Success and negative value otherwise.
+ */
+int ena_com_get_hash_key(struct ena_com_dev *ena_dev, u8 *key);
 /* ena_com_fill_hash_ctrl - Fill RSS hash control
  * @ena_dev: ENA communication layer struct.
  * @proto: The protocol to configure.
--- a/drivers/net/ethernet/amazon/ena/ena_ethtool.c
+++ b/drivers/net/ethernet/amazon/ena/ena_ethtool.c
@@ -673,7 +673,7 @@ static int ena_get_rxfh(struct net_devic
 	/* We call this function in order to check if the device
 	 * supports getting/setting the hash function.
 	 */
-	rc = ena_com_get_hash_function(adapter->ena_dev, &ena_func, key);
+	rc = ena_com_get_hash_function(adapter->ena_dev, &ena_func);
 	if (rc) {
 		if (rc == -EOPNOTSUPP) {
 			key = NULL;
@@ -684,6 +684,10 @@ static int ena_get_rxfh(struct net_devic
 		return rc;
 	}
 
+	rc = ena_com_get_hash_key(adapter->ena_dev, key);
+	if (rc)
+		return rc;
+
 	switch (ena_func) {
 	case ENA_ADMIN_TOEPLITZ:
 		func = ETH_RSS_HASH_TOP;
@@ -700,7 +704,7 @@ static int ena_get_rxfh(struct net_devic
 	if (hfunc)
 		*hfunc = func;
 
-	return rc;
+	return 0;
 }
 
 static int ena_set_rxfh(struct net_device *netdev, const u32 *indir,
@@ -708,7 +712,7 @@ static int ena_set_rxfh(struct net_devic
 {
 	struct ena_adapter *adapter = netdev_priv(netdev);
 	struct ena_com_dev *ena_dev = adapter->ena_dev;
-	enum ena_admin_hash_functions func;
+	enum ena_admin_hash_functions func = 0;
 	int rc, i;
 
 	if (indir) {
@@ -747,7 +751,7 @@ static int ena_set_rxfh(struct net_devic
 		return -EOPNOTSUPP;
 	}
 
-	if (key) {
+	if (key || func) {
 		rc = ena_com_fill_hash_function(ena_dev, func, key,
 						ENA_HASH_KEY_SIZE,
 						0xFFFFFFFF);