[PATCH iwl-next v9 11/14] igc: add support to set tx-min-frag-size

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

Add support for setting tx-min-frag-size via the set_mm callback in igc.
If the requested value is unsupported, round it up to the smallest
supported i226 size (64, 128, 192, 256) and send a netlink message to
inform the user.

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 |  1 +
 drivers/net/ethernet/intel/igc/igc_ethtool.c |  5 +++
 drivers/net/ethernet/intel/igc/igc_tsn.c     | 38 ++++++++++++++++++--
 drivers/net/ethernet/intel/igc/igc_tsn.h     |  1 +
 5 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h
index d970968f3233..d61e2915ccb4 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 igc_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 542c7c8802a0..80e0b5ed8b1a 100644
--- a/drivers/net/ethernet/intel/igc/igc_defines.h
+++ b/drivers/net/ethernet/intel/igc/igc_defines.h
@@ -583,6 +583,7 @@
 #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_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 b64d5c6c1d20..529654ccd83f 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 igc_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)");
+
 	if (fpe->mmsv.pmac_enabled != cmd->pmac_enabled) {
 		if (cmd->pmac_enabled)
 			static_branch_inc(&igc_fpe_enabled);
diff --git a/drivers/net/ethernet/intel/igc/igc_tsn.c b/drivers/net/ethernet/intel/igc/igc_tsn.c
index 8a1725688381..215bf8e38328 100644
--- a/drivers/net/ethernet/intel/igc/igc_tsn.c
+++ b/drivers/net/ethernet/intel/igc/igc_tsn.c
@@ -6,6 +6,12 @@
 #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,
@@ -128,6 +134,7 @@ static const struct ethtool_mmsv_ops igc_mmsv_ops = {
 
 void igc_fpe_init(struct igc_adapter *adapter)
 {
+	adapter->fpe.tx_min_frag_size = TX_MIN_FRAG_SIZE;
 	ethtool_mmsv_init(&adapter->fpe.mmsv, adapter->netdev, &igc_mmsv_ops);
 }
 
@@ -297,7 +304,7 @@ 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);
 
@@ -343,12 +350,35 @@ 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 igc_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];
+	}
+
+	/* Should not happen */
+	return TX_MAX_FRAG_SIZE;
+}
+
 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;
 	ktime_t base_time, systim;
+	u32 frag_size_mult;
 	int i;
 
 	wr32(IGC_TSAUXC, 0);
@@ -517,13 +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 |= FIELD_PREP(IGC_TQAVCTRL_MIN_FRAG_MASK, frag_size_mult);
+
 	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 bb30d15cec76..58fe5f0773d7 100644
--- a/drivers/net/ethernet/intel/igc/igc_tsn.h
+++ b/drivers/net/ethernet/intel/igc/igc_tsn.h
@@ -14,6 +14,7 @@ enum igc_txd_popts_type {
 DECLARE_STATIC_KEY_FALSE(igc_fpe_enabled);
 
 void igc_fpe_init(struct igc_adapter *adapter);
+u32 igc_fpe_get_supported_frag_size(u32 frag_size);
 int igc_tsn_offload_apply(struct igc_adapter *adapter);
 int igc_tsn_reset(struct igc_adapter *adapter);
 void igc_tsn_adjust_txtime_offset(struct igc_adapter *adapter);
-- 
2.34.1