[PATCH iwl-next v2 6/9] igc: Add support to set tx-min-frag-size

[Faizal Rahim <faizal.abdul.rahim@linux.intel.com>]

Add support to set tx-min-frag-size via set_mm callback in igc.
Increase the max limit of tx-ming-frag-size in ethtool from 252 to 256
since i225/6 value range is 64, 128, 192 and 256.

Co-developed-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Faizal Rahim <faizal.abdul.rahim@linux.intel.com>
---
 drivers/net/ethernet/intel/igc/igc.h         |  1 +
 drivers/net/ethernet/intel/igc/igc_defines.h |  2 ++
 drivers/net/ethernet/intel/igc/igc_ethtool.c |  5 +++
 drivers/net/ethernet/intel/igc/igc_tsn.c     | 37 ++++++++++++++++++--
 drivers/net/ethernet/intel/igc/igc_tsn.h     |  2 +-
 net/ethtool/mm.c                             |  2 +-
 6 files changed, 44 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h
index 705bd4739e3b..2f3662143589 100644
--- a/drivers/net/ethernet/intel/igc/igc.h
+++ b/drivers/net/ethernet/intel/igc/igc.h
@@ -42,6 +42,7 @@ void igc_ethtool_set_ops(struct net_device *);
 
 struct fpe_t {
 	struct ethtool_mmsv mmsv;
+	u32 tx_min_frag_size;
 };
 
 enum igc_mac_filter_type {
diff --git a/drivers/net/ethernet/intel/igc/igc_defines.h b/drivers/net/ethernet/intel/igc/igc_defines.h
index 563b154c3e94..9d7d903545ed 100644
--- a/drivers/net/ethernet/intel/igc/igc_defines.h
+++ b/drivers/net/ethernet/intel/igc/igc_defines.h
@@ -553,6 +553,8 @@
 #define IGC_TQAVCTRL_PREEMPT_ENA	0x00000002
 #define IGC_TQAVCTRL_ENHANCED_QAV	0x00000008
 #define IGC_TQAVCTRL_FUTSCDDIS		0x00000080
+#define IGC_TQAVCTRL_MIN_FRAG_MASK	0x0000C000
+#define IGC_TQAVCTRL_MIN_FRAG_SHIFT	14
 
 #define IGC_TXQCTL_QUEUE_MODE_LAUNCHT	0x00000001
 #define IGC_TXQCTL_STRICT_CYCLE		0x00000002
diff --git a/drivers/net/ethernet/intel/igc/igc_ethtool.c b/drivers/net/ethernet/intel/igc/igc_ethtool.c
index 41cb03816f92..83da59aec59e 100644
--- a/drivers/net/ethernet/intel/igc/igc_ethtool.c
+++ b/drivers/net/ethernet/intel/igc/igc_ethtool.c
@@ -1789,6 +1789,11 @@ static int igc_ethtool_set_mm(struct net_device *netdev,
 	struct igc_adapter *adapter = netdev_priv(netdev);
 	struct fpe_t *fpe = &adapter->fpe;
 
+	fpe->tx_min_frag_size = igc_fpe_get_supported_frag_size(cmd->tx_min_frag_size);
+	if (fpe->tx_min_frag_size != cmd->tx_min_frag_size)
+		NL_SET_ERR_MSG_MOD(extack,
+				   "tx-min-frag-size value set is unsupported. Rounded up to supported value (64, 128, 192, 256)");
+
 	ethtool_mmsv_set_mm(&fpe->mmsv, cmd);
 
 	if (fpe->mmsv.pmac_enabled)
diff --git a/drivers/net/ethernet/intel/igc/igc_tsn.c b/drivers/net/ethernet/intel/igc/igc_tsn.c
index 52ff6f324d79..50c343c59e29 100644
--- a/drivers/net/ethernet/intel/igc/igc_tsn.c
+++ b/drivers/net/ethernet/intel/igc/igc_tsn.c
@@ -7,6 +7,12 @@
 #include "igc_hw.h"
 #include "igc_tsn.h"
 
+#define MIN_MULTPLIER_TX_MIN_FRAG	0
+#define MAX_MULTPLIER_TX_MIN_FRAG	3
+/* Frag size is based on the Section 8.12.2 of the SW User Manual */
+#define TX_MIN_FRAG_SIZE		64
+#define TX_MAX_FRAG_SIZE	(TX_MIN_FRAG_SIZE * (MAX_MULTPLIER_TX_MIN_FRAG + 1))
+
 DEFINE_STATIC_KEY_FALSE(igc_fpe_enabled);
 
 static int igc_fpe_init_smd_frame(struct igc_ring *ring,
@@ -145,6 +151,7 @@ void igc_fpe_init(struct igc_adapter *adapter)
 {
 	struct fpe_t *fpe = &adapter->fpe;
 
+	fpe->tx_min_frag_size = TX_MIN_FRAG_SIZE;
 	ethtool_mmsv_init(&adapter->fpe.mmsv, adapter->netdev, &igc_mmsv_ops);
 }
 
@@ -295,7 +302,7 @@ static int igc_tsn_disable_offload(struct igc_adapter *adapter)
 	tqavctrl = rd32(IGC_TQAVCTRL);
 	tqavctrl &= ~(IGC_TQAVCTRL_TRANSMIT_MODE_TSN |
 		      IGC_TQAVCTRL_ENHANCED_QAV | IGC_TQAVCTRL_FUTSCDDIS |
-		      IGC_TQAVCTRL_PREEMPT_ENA);
+		      IGC_TQAVCTRL_PREEMPT_ENA | IGC_TQAVCTRL_MIN_FRAG_MASK);
 
 	wr32(IGC_TQAVCTRL, tqavctrl);
 
@@ -341,12 +348,34 @@ static void igc_tsn_set_retx_qbvfullthreshold(struct igc_adapter *adapter)
 	wr32(IGC_RETX_CTL, retxctl);
 }
 
+static u8 igc_fpe_get_frag_size_mult(const struct fpe_t *fpe)
+{
+	u8 mult = (fpe->tx_min_frag_size / TX_MIN_FRAG_SIZE) - 1;
+
+	return clamp_t(u8, mult, MIN_MULTPLIER_TX_MIN_FRAG,
+		       MAX_MULTPLIER_TX_MIN_FRAG);
+}
+
+u32 igc_fpe_get_supported_frag_size(u32 frag_size)
+{
+	const u32 supported_sizes[] = {64, 128, 192, 256};
+
+	/* Find the smallest supported size that is >= frag_size */
+	for (int i = 0; i < ARRAY_SIZE(supported_sizes); i++) {
+		if (frag_size <= supported_sizes[i])
+			return supported_sizes[i];
+	}
+
+	return TX_MAX_FRAG_SIZE; /* Should not happen, value > 256 is blocked by ethtool */
+}
+
 static int igc_tsn_enable_offload(struct igc_adapter *adapter)
 {
 	struct igc_hw *hw = &adapter->hw;
 	u32 tqavctrl, baset_l, baset_h;
 	u32 sec, nsec, cycle, rxpbs;
 	ktime_t base_time, systim;
+	u32 frag_size_mult;
 	int i;
 
 	wr32(IGC_TSAUXC, 0);
@@ -518,13 +547,15 @@ static int igc_tsn_enable_offload(struct igc_adapter *adapter)
 	}
 
 	tqavctrl = rd32(IGC_TQAVCTRL) & ~(IGC_TQAVCTRL_FUTSCDDIS |
-		   IGC_TQAVCTRL_PREEMPT_ENA);
-
+		   IGC_TQAVCTRL_PREEMPT_ENA | IGC_TQAVCTRL_MIN_FRAG_MASK);
 	tqavctrl |= IGC_TQAVCTRL_TRANSMIT_MODE_TSN | IGC_TQAVCTRL_ENHANCED_QAV;
 
 	if (adapter->fpe.mmsv.pmac_enabled)
 		tqavctrl |= IGC_TQAVCTRL_PREEMPT_ENA;
 
+	frag_size_mult = igc_fpe_get_frag_size_mult(&adapter->fpe);
+	tqavctrl |= frag_size_mult << IGC_TQAVCTRL_MIN_FRAG_SHIFT;
+
 	adapter->qbv_count++;
 
 	cycle = adapter->cycle_time;
diff --git a/drivers/net/ethernet/intel/igc/igc_tsn.h b/drivers/net/ethernet/intel/igc/igc_tsn.h
index 889d70c6d827..898c4630bc70 100644
--- a/drivers/net/ethernet/intel/igc/igc_tsn.h
+++ b/drivers/net/ethernet/intel/igc/igc_tsn.h
@@ -9,7 +9,7 @@
 DECLARE_STATIC_KEY_FALSE(igc_fpe_enabled);
 
 void igc_fpe_init(struct igc_adapter *adapter);
-u32 igc_fpe_get_supported_frag_size(u32 user_frag_size);
+u32 igc_fpe_get_supported_frag_size(u32 frag_size);
 bool igc_fpe_transmitted_smd_v(union igc_adv_tx_desc *tx_desc);
 int igc_tsn_offload_apply(struct igc_adapter *adapter);
 int igc_tsn_reset(struct igc_adapter *adapter);
diff --git a/net/ethtool/mm.c b/net/ethtool/mm.c
index 2ebb811948ec..1320d26f4bc9 100644
--- a/net/ethtool/mm.c
+++ b/net/ethtool/mm.c
@@ -152,7 +152,7 @@ const struct nla_policy ethnl_mm_set_policy[ETHTOOL_A_MM_MAX + 1] = {
 	[ETHTOOL_A_MM_VERIFY_TIME]	= NLA_POLICY_RANGE(NLA_U32, 1, 128),
 	[ETHTOOL_A_MM_TX_ENABLED]	= NLA_POLICY_MAX(NLA_U8, 1),
 	[ETHTOOL_A_MM_PMAC_ENABLED]	= NLA_POLICY_MAX(NLA_U8, 1),
-	[ETHTOOL_A_MM_TX_MIN_FRAG_SIZE]	= NLA_POLICY_RANGE(NLA_U32, 60, 252),
+	[ETHTOOL_A_MM_TX_MIN_FRAG_SIZE]	= NLA_POLICY_RANGE(NLA_U32, 60, 256),
 };
 
 static void mm_state_to_cfg(const struct ethtool_mm_state *state,
-- 
2.34.1