ice: Implement driver functionality to dump fec statistics

To debug link issues in the field, it is paramount to
dump fec corrected/uncorrected block counts from firmware.
Firmware requires PCS quad number and PCS port number to
read FEC statistics. Current driver implementation does
not maintain above physical properties of a port.

Add new driver API to derive physical properties of an input
port.These properties include PCS quad number, PCS port number,
serdes lane count, primary serdes lane number.
Extend ethtool option '--show-fec' to support fec statistics.
The IEEE standard mandates two sets of counters:
 - 30.5.1.1.17 aFECCorrectedBlocks
 - 30.5.1.1.18 aFECUncorrectableBlocks

Standard defines above statistics per lane but current
implementation supports total FEC statistics per port
i.e. sum of all lane per port. Find sample output below

FEC parameters for ens21f0np0:
Supported/Configured FEC encodings: Auto RS BaseR
Active FEC encoding: RS
Statistics:
  corrected_blocks: 0
  uncorrectable_blocks: 0

Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Anil Samal <anil.samal@intel.com>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://patch.msgid.link/20240709202951.2103115-3-anthony.l.nguyen@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 57 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/ice/ice_common.c b/drivers/net/ethernet/intel/ice/ice_common.c
index 9fa9d914ae46..a4f175cf5c61 100644
--- a/drivers/net/ethernet/intel/ice/ice_common.c
+++ b/drivers/net/ethernet/intel/ice/ice_common.c
@@ -3371,6 +3371,63 @@ int ice_update_link_info(struct ice_port_info *pi)
 	return status;
 }
 
+#define FEC_REG_PORT(port) {	\
+	FEC_CORR_LOW_REG_PORT##port,		\
+	FEC_CORR_HIGH_REG_PORT##port,	\
+	FEC_UNCORR_LOW_REG_PORT##port,	\
+	FEC_UNCORR_HIGH_REG_PORT##port,	\
+}
+
+static const u32 fec_reg[][ICE_FEC_MAX] = {
+	FEC_REG_PORT(0),
+	FEC_REG_PORT(1),
+	FEC_REG_PORT(2),
+	FEC_REG_PORT(3)
+};
+
+/**
+ * ice_aq_get_fec_stats - reads fec stats from phy
+ * @hw: pointer to the HW struct
+ * @pcs_quad: represents pcsquad of user input serdes
+ * @pcs_port: represents the pcs port number part of above pcs quad
+ * @fec_type: represents FEC stats type
+ * @output: pointer to the caller-supplied buffer to return requested fec stats
+ *
+ * Return: non-zero status on error and 0 on success.
+ */
+int ice_aq_get_fec_stats(struct ice_hw *hw, u16 pcs_quad, u16 pcs_port,
+			 enum ice_fec_stats_types fec_type, u32 *output)
+{
+	u16 flag = (ICE_AQ_FLAG_RD | ICE_AQ_FLAG_BUF | ICE_AQ_FLAG_SI);
+	struct ice_sbq_msg_input msg = {};
+	u32 receiver_id, reg_offset;
+	int err;
+
+	if (pcs_port > 3)
+		return -EINVAL;
+
+	reg_offset = fec_reg[pcs_port][fec_type];
+
+	if (pcs_quad == 0)
+		receiver_id = FEC_RECEIVER_ID_PCS0;
+	else if (pcs_quad == 1)
+		receiver_id = FEC_RECEIVER_ID_PCS1;
+	else
+		return -EINVAL;
+
+	msg.msg_addr_low = lower_16_bits(reg_offset);
+	msg.msg_addr_high = receiver_id;
+	msg.opcode = ice_sbq_msg_rd;
+	msg.dest_dev = rmn_0;
+
+	err = ice_sbq_rw_reg(hw, &msg, flag);
+	if (err)
+		return err;
+
+	*output = msg.data;
+	return 0;
+}
+
 /**
  * ice_cache_phy_user_req
  * @pi: port information structure