net/mlx5e: Support MACsec offload extended packet number (EPN)

MACsec EPN splits the packet number (PN) into two 32-bits fields,
epn_lsb (32 least significant bits (LSBs) of PN) and epn_msb (32
most significant bits (MSBs) of PN).
Epn_msb bits are managed by SW and for that HW is required to send
an object change event of type EPN event notifying the SW to update
the epn_msb in addition, once epn_msb is updated SW update HW with
the new epn_msb value for HW to perform replay protection.
To prevent HW from stopping while handling the event, SW manages
another bit for HW called epn_overlap, HW uses the latter to get
an indication regarding how to read the epn_msb value correctly
while still receiving packets.
Add epn event handling that updates the epn_overlap and epn_msb for
every 2^31 packets according to the following logic:
if epn_lsb crosses 2^31 (half sequence number wraparound) upon HW
relevant event, SW updates the esn_overlap value to OLD (value = 1).
When the epn_lsb crosses 2^32 (full sequence number wraparound)
upon HW relevant event, SW updates the esn_overlap to NEW
(value = 0) and increment the esn_msb.
When using MACsec EPN a salt and short secure channel id (ssci)
needs to be provided by the user, when offloading EPN need to pass
this salt and ssci to the HW to be used in the initial vector (IV)
calculations.
Reviewed-by: Raed Salem <raeds@nvidia.com>
Signed-off-by: Emeel Hakim <ehakim@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/mellanox/mlx5/core/en_accel/macsec.h

@@ -66,7 +66,6 @@ static inline void mlx5e_macsec_offload_handle_rx_skb(struct net_device *netdev,
 						      struct mlx5_cqe64 *cqe)
 {}
 static inline bool mlx5e_is_macsec_device(const struct mlx5_core_dev *mdev) { return false; }
-
 #endif  /* CONFIG_MLX5_EN_MACSEC */
 
 #endif	/* __MLX5_ACCEL_EN_MACSEC_H__ */

drivers/net/ethernet/mellanox/mlx5/core/eq.c

@@ -575,6 +575,9 @@ static void gather_async_events_mask(struct mlx5_core_dev *dev, u64 mask[4])
 	if (MLX5_CAP_GEN_MAX(dev, vhca_state))
 		async_event_mask |= (1ull << MLX5_EVENT_TYPE_VHCA_STATE_CHANGE);
 
+	if (MLX5_CAP_MACSEC(dev, log_max_macsec_offload))
+		async_event_mask |= (1ull << MLX5_EVENT_TYPE_OBJECT_CHANGE);
+
 	mask[0] = async_event_mask;
 
 	if (MLX5_CAP_GEN(dev, event_cap))

drivers/net/ethernet/mellanox/mlx5/core/events.c

@@ -36,6 +36,7 @@ static struct mlx5_nb events_nbs_ref[] = {
 	/* Events to be forwarded (as is) to mlx5 core interfaces (mlx5e/mlx5_ib) */
 	{.nb.notifier_call = forward_event,   .event_type = MLX5_EVENT_TYPE_PORT_CHANGE },
 	{.nb.notifier_call = forward_event,   .event_type = MLX5_EVENT_TYPE_GENERAL_EVENT },
+	{.nb.notifier_call = forward_event,   .event_type = MLX5_EVENT_TYPE_OBJECT_CHANGE },
 	/* QP/WQ resource events to forward */
 	{.nb.notifier_call = forward_event,   .event_type = MLX5_EVENT_TYPE_DCT_DRAINED },
 	{.nb.notifier_call = forward_event,   .event_type = MLX5_EVENT_TYPE_PATH_MIG },
@@ -132,6 +133,8 @@ static const char *eqe_type_str(u8 type)
 		return "MLX5_EVENT_TYPE_MONITOR_COUNTER";
 	case MLX5_EVENT_TYPE_DEVICE_TRACER:
 		return "MLX5_EVENT_TYPE_DEVICE_TRACER";
+	case MLX5_EVENT_TYPE_OBJECT_CHANGE:
+		return "MLX5_EVENT_TYPE_OBJECT_CHANGE";
 	default:
 		return "Unrecognized event";
 	}

drivers/net/ethernet/mellanox/mlx5/core/lib/aso.h

@@ -11,7 +11,9 @@
 	(DIV_ROUND_UP(sizeof(struct mlx5_aso_wqe), MLX5_SEND_WQE_BB))
 #define MLX5_ASO_WQEBBS_DATA \
 	(DIV_ROUND_UP(sizeof(struct mlx5_aso_wqe_data), MLX5_SEND_WQE_BB))
+#define ASO_CTRL_READ_EN BIT(0)
 #define MLX5_WQE_CTRL_WQE_OPC_MOD_SHIFT 24
+#define MLX5_MACSEC_ASO_DS_CNT (DIV_ROUND_UP(sizeof(struct mlx5_aso_wqe), MLX5_SEND_WQE_DS))
 
 struct mlx5_wqe_aso_ctrl_seg {
 	__be32  va_h;
@@ -70,6 +72,7 @@ enum {
 
 enum {
 	MLX5_ACCESS_ASO_OPC_MOD_FLOW_METER = 0x2,
+	MLX5_ACCESS_ASO_OPC_MOD_MACSEC = 0x5,
 };
 
 struct mlx5_aso;

include/linux/mlx5/device.h

@@ -325,6 +325,7 @@ enum mlx5_event {
 	MLX5_EVENT_TYPE_WQ_INVAL_REQ_ERROR = 0x10,
 	MLX5_EVENT_TYPE_WQ_ACCESS_ERROR	   = 0x11,
 	MLX5_EVENT_TYPE_SRQ_CATAS_ERROR	   = 0x12,
+	MLX5_EVENT_TYPE_OBJECT_CHANGE	   = 0x27,
 
 	MLX5_EVENT_TYPE_INTERNAL_ERROR	   = 0x08,
 	MLX5_EVENT_TYPE_PORT_CHANGE	   = 0x09,
@@ -699,6 +700,12 @@ struct mlx5_eqe_temp_warning {
 	__be64 sensor_warning_lsb;
 } __packed;
 
+struct mlx5_eqe_obj_change {
+	u8      rsvd0[2];
+	__be16  obj_type;
+	__be32  obj_id;
+} __packed;
+
 #define SYNC_RST_STATE_MASK    0xf
 
 enum sync_rst_state_type {
@@ -737,6 +744,7 @@ union ev_data {
 	struct mlx5_eqe_xrq_err		xrq_err;
 	struct mlx5_eqe_sync_fw_update	sync_fw_update;
 	struct mlx5_eqe_vhca_state	vhca_state;
+	struct mlx5_eqe_obj_change	obj_change;
 } __packed;
 
 struct mlx5_eqe {