[net-next 1/9] ixgbe: Refactor the RSS configuration code

[Jeff Kirsher <jeffrey.t.kirsher@intel.com>]

From: Vlad Zolotarov <vladz@cloudius-systems.com>

This patch is a preparation for enablement of ethtool RSS indirection
table and hash key querying. We don't want to read registers every time
the RSS info is queried. Therefore we will store its current content in the
arrays in the adapter struct and will read it from there (instead of from
registers) when requested.

Will change the code that writes the indirection table and hash key into
the HW registers to take its content from these arrays. This will also
simplify the indirection table updating ethtool callback implementation
in the future.

Signed-off-by: Vlad Zolotarov <vladz@cloudius-systems.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      |   9 ++
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 147 ++++++++++++++++++--------
 2 files changed, 112 insertions(+), 44 deletions(-)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe.h b/drivers/net/ethernet/intel/ixgbe/ixgbe.h
index ae5b8b2..d13ab87 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe.h
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe.h
@@ -766,6 +766,15 @@ struct ixgbe_adapter {
 
 	u8 default_up;
 	unsigned long fwd_bitmask; /* Bitmask indicating in use pools */
+
+/* maximum number of RETA entries among all devices supported by ixgbe
+ * driver: currently it's x550 device in non-SRIOV mode
+ */
+#define IXGBE_MAX_RETA_ENTRIES 512
+	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)];
 };
 
 static inline u8 ixgbe_max_rss_indices(struct ixgbe_adapter *adapter)
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index a7acb2d..57a3ec4 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -3228,89 +3228,148 @@ static void ixgbe_configure_srrctl(struct ixgbe_adapter *adapter,
 	IXGBE_WRITE_REG(hw, IXGBE_SRRCTL(reg_idx), srrctl);
 }
 
-static void ixgbe_setup_reta(struct ixgbe_adapter *adapter, const u32 *seed)
+/**
+ * Return a number of entries in the RSS indirection table
+ *
+ * @adapter: device handle
+ *
+ *  - 82598/82599/X540:     128
+ *  - X550(non-SRIOV mode): 512
+ *  - X550(SRIOV mode):     64
+ */
+static u32 ixgbe_rss_indir_tbl_entries(struct ixgbe_adapter *adapter)
+{
+	if (adapter->hw.mac.type < ixgbe_mac_X550)
+		return 128;
+	else if (adapter->flags & IXGBE_FLAG_SRIOV_ENABLED)
+		return 64;
+	else
+		return 512;
+}
+
+/**
+ * Write the RETA table to HW
+ *
+ * @adapter: device handle
+ *
+ * Write the RSS redirection table stored in adapter.rss_indir_tbl[] to HW.
+ */
+static void ixgbe_store_reta(struct ixgbe_adapter *adapter)
 {
+	u32 i, reta_entries = ixgbe_rss_indir_tbl_entries(adapter);
 	struct ixgbe_hw *hw = &adapter->hw;
 	u32 reta = 0;
-	int i, j;
-	int reta_entries = 128;
-	u16 rss_i = adapter->ring_feature[RING_F_RSS].indices;
-	int indices_multi;
-
-	/*
-	 * Program table for at least 2 queues w/ SR-IOV so that VFs can
-	 * make full use of any rings they may have.  We will use the
-	 * PSRTYPE register to control how many rings we use within the PF.
-	 */
-	if ((adapter->flags & IXGBE_FLAG_SRIOV_ENABLED) && (rss_i < 2))
-		rss_i = 2;
-
-	/* Fill out hash function seeds */
-	for (i = 0; i < 10; i++)
-		IXGBE_WRITE_REG(hw, IXGBE_RSSRK(i), seed[i]);
+	u32 indices_multi;
+	u8 *indir_tbl = adapter->rss_indir_tbl;
 
 	/* Fill out the redirection table as follows:
-	 * 82598: 128 (8 bit wide) entries containing pair of 4 bit RSS indices
-	 * 82599/X540: 128 (8 bit wide) entries containing 4 bit RSS index
-	 * X550: 512 (8 bit wide) entries containing 6 bit RSS index
+	 *  - 82598:      8 bit wide entries containing pair of 4 bit RSS
+	 *    indices.
+	 *  - 82599/X540: 8 bit wide entries containing 4 bit RSS index
+	 *  - X550:       8 bit wide entries containing 6 bit RSS index
 	 */
 	if (adapter->hw.mac.type == ixgbe_mac_82598EB)
 		indices_multi = 0x11;
 	else
 		indices_multi = 0x1;
 
-	switch (adapter->hw.mac.type) {
-	case ixgbe_mac_X550:
-	case ixgbe_mac_X550EM_x:
-		if (!(adapter->flags & IXGBE_FLAG_SRIOV_ENABLED))
-			reta_entries = 512;
-	default:
-		break;
-	}
-
-	/* Fill out redirection table */
-	for (i = 0, j = 0; i < reta_entries; i++, j++) {
-		if (j == rss_i)
-			j = 0;
-		reta = (reta << 8) | (j * indices_multi);
+	/* Write redirection table to HW */
+	for (i = 0; i < reta_entries; i++) {
+		reta |= indices_multi * indir_tbl[i] << (i & 0x3) * 8;
 		if ((i & 3) == 3) {
 			if (i < 128)
 				IXGBE_WRITE_REG(hw, IXGBE_RETA(i >> 2), reta);
 			else
 				IXGBE_WRITE_REG(hw, IXGBE_ERETA((i >> 2) - 32),
 						reta);
+			reta = 0;
 		}
 	}
 }
 
-static void ixgbe_setup_vfreta(struct ixgbe_adapter *adapter, const u32 *seed)
+/**
+ * Write the RETA table to HW (for x550 devices in SRIOV mode)
+ *
+ * @adapter: device handle
+ *
+ * Write the RSS redirection table stored in adapter.rss_indir_tbl[] to HW.
+ */
+static void ixgbe_store_vfreta(struct ixgbe_adapter *adapter)
 {
+	u32 i, reta_entries = ixgbe_rss_indir_tbl_entries(adapter);
 	struct ixgbe_hw *hw = &adapter->hw;
 	u32 vfreta = 0;
+	unsigned int pf_pool = adapter->num_vfs;
+
+	/* Write redirection table to HW */
+	for (i = 0; i < reta_entries; i++) {
+		vfreta |= (u32)adapter->rss_indir_tbl[i] << (i & 0x3) * 8;
+		if ((i & 3) == 3) {
+			IXGBE_WRITE_REG(hw, IXGBE_PFVFRETA(i >> 2, pf_pool),
+					vfreta);
+			vfreta = 0;
+		}
+	}
+}
+
+static void ixgbe_setup_reta(struct ixgbe_adapter *adapter)
+{
+	struct ixgbe_hw *hw = &adapter->hw;
+	u32 i, j;
+	u32 reta_entries = ixgbe_rss_indir_tbl_entries(adapter);
+	u16 rss_i = adapter->ring_feature[RING_F_RSS].indices;
+
+	/* Program table for at least 2 queues w/ SR-IOV so that VFs can
+	 * make full use of any rings they may have.  We will use the
+	 * PSRTYPE register to control how many rings we use within the PF.
+	 */
+	if ((adapter->flags & IXGBE_FLAG_SRIOV_ENABLED) && (rss_i < 2))
+		rss_i = 2;
+
+	/* Fill out hash function seeds */
+	for (i = 0; i < 10; i++)
+		IXGBE_WRITE_REG(hw, IXGBE_RSSRK(i), adapter->rss_key[i]);
+
+	/* Fill out redirection table */
+	memset(adapter->rss_indir_tbl, 0, sizeof(adapter->rss_indir_tbl));
+
+	for (i = 0, j = 0; i < reta_entries; i++, j++) {
+		if (j == rss_i)
+			j = 0;
+
+		adapter->rss_indir_tbl[i] = j;
+	}
+
+	ixgbe_store_reta(adapter);
+}
+
+static void ixgbe_setup_vfreta(struct ixgbe_adapter *adapter)
+{
+	struct ixgbe_hw *hw = &adapter->hw;
 	u16 rss_i = adapter->ring_feature[RING_F_RSS].indices;
 	unsigned int pf_pool = adapter->num_vfs;
 	int i, j;
 
 	/* Fill out hash function seeds */
 	for (i = 0; i < 10; i++)
-		IXGBE_WRITE_REG(hw, IXGBE_PFVFRSSRK(i, pf_pool), seed[i]);
+		IXGBE_WRITE_REG(hw, IXGBE_PFVFRSSRK(i, pf_pool),
+				adapter->rss_key[i]);
 
 	/* Fill out the redirection table */
 	for (i = 0, j = 0; i < 64; i++, j++) {
 		if (j == rss_i)
 			j = 0;
-		vfreta = (vfreta << 8) | j;
-		if ((i & 3) == 3)
-			IXGBE_WRITE_REG(hw, IXGBE_PFVFRETA(i >> 2, pf_pool),
-					vfreta);
+
+		adapter->rss_indir_tbl[i] = j;
 	}
+
+	ixgbe_store_vfreta(adapter);
 }
 
 static void ixgbe_setup_mrqc(struct ixgbe_adapter *adapter)
 {
 	struct ixgbe_hw *hw = &adapter->hw;
 	u32 mrqc = 0, rss_field = 0, vfmrqc = 0;
-	u32 rss_key[10];
 	u32 rxcsum;
 
 	/* Disable indicating checksum in descriptor, enables RSS hash */
@@ -3354,7 +3413,7 @@ 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(rss_key, sizeof(rss_key));
+	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;
@@ -3364,12 +3423,12 @@ static void ixgbe_setup_mrqc(struct ixgbe_adapter *adapter)
 		IXGBE_WRITE_REG(hw, IXGBE_MRQC, mrqc);
 
 		/* Setup RSS through the VF registers */
-		ixgbe_setup_vfreta(adapter, rss_key);
+		ixgbe_setup_vfreta(adapter);
 		vfmrqc = IXGBE_MRQC_RSSEN;
 		vfmrqc |= rss_field;
 		IXGBE_WRITE_REG(hw, IXGBE_PFVFMRQC(pf_pool), vfmrqc);
 	} else {
-		ixgbe_setup_reta(adapter, rss_key);
+		ixgbe_setup_reta(adapter);
 		mrqc |= rss_field;
 		IXGBE_WRITE_REG(hw, IXGBE_MRQC, mrqc);
 	}
-- 
1.9.3