[dpdk-dev] [PATCH v1 16/16] common/mlx5: add register access DevX routine

[Viacheslav Ovsiienko <viacheslavo@mellanox.com>]

The DevX routine to read/write NIC registers via DevX API is added.
This is the preparation step to check timestamp modes and units
and gather the extended statistics.

Signed-off-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
---
 drivers/common/mlx5/mlx5_devx_cmds.c            | 57 +++++++++++++++++++++++++
 drivers/common/mlx5/mlx5_devx_cmds.h            |  4 ++
 drivers/common/mlx5/mlx5_prm.h                  | 25 +++++++++++
 drivers/common/mlx5/rte_common_mlx5_version.map |  1 +
 4 files changed, 87 insertions(+)

diff --git a/drivers/common/mlx5/mlx5_devx_cmds.c b/drivers/common/mlx5/mlx5_devx_cmds.c
index 093636c..5b99e11 100644
--- a/drivers/common/mlx5/mlx5_devx_cmds.c
+++ b/drivers/common/mlx5/mlx5_devx_cmds.c
@@ -12,6 +12,63 @@
 
 
 /**
+ * Perform access to the registers. Reads data from and writes data to
+ * the specified register.
+ *
+ * @param[in] ctx
+ *   Context returned from mlx5 open_device() glue function.
+ * @param[in] reg_id
+ *   Register identifier according to the PRM.
+ * @param[in] arg
+ *   Register access auxiliary parameter according to the PRM.
+ * @param[inout] value
+ *   Pointer to the value to be wriiten to the register or
+ *   to the buffer where the read data to be stored.
+ * @param[in] write
+ *   Non-zero value means write to the register should be performed,
+ *   otherwise read access will be performed.
+ *
+ * @return
+ *   0 on success, a negative value otherwise.
+ */
+int
+mlx5_devx_cmd_register_access(void *ctx, uint16_t reg_id,
+			      uint32_t arg, uint32_t *value,
+			      uint32_t write)
+{
+	uint32_t in[MLX5_ST_SZ_DW(access_register_in)]   = {0};
+	uint32_t out[MLX5_ST_SZ_DW(access_register_out)] = {0};
+	int status, rc;
+
+	MLX5_SET(access_register_in, in, opcode, MLX5_CMD_OP_ACCESS_REGISTER);
+	MLX5_SET(access_register_in, in, op_mod, write ?
+					MLX5_ACCESS_REGISTER_IN_OP_MOD_WRITE :
+					MLX5_ACCESS_REGISTER_IN_OP_MOD_READ);
+	MLX5_SET(access_register_in, in, register_id, reg_id);
+	MLX5_SET(access_register_in, in, argument, arg);
+	if (write && value)
+		MLX5_SET(access_register_in, in, register_data, *value);
+	rc = mlx5_glue->devx_general_cmd(ctx, in, sizeof(in), out, sizeof(out));
+	if (rc)
+		goto error;
+	status = MLX5_GET(access_register_out, out, status);
+	if (status) {
+		int syndrome = MLX5_GET(access_register_out, out, syndrome);
+
+		DRV_LOG(DEBUG, "Failed to access NIC register 0x%X, "
+			       "status %x, syndrome = %x",
+			       reg_id, status, syndrome);
+		return -1;
+	}
+	if (value && !write)
+		*value = MLX5_GET(access_register_out, out, register_data);
+	return 0;
+error:
+	rc = (rc > 0) ? -rc : rc;
+	return rc;
+};
+
+/**
  * Allocate flow counters via devx interface.
  *
  * @param[in] ctx
diff --git a/drivers/common/mlx5/mlx5_devx_cmds.h b/drivers/common/mlx5/mlx5_devx_cmds.h
index c79b349..119479d 100644
--- a/drivers/common/mlx5/mlx5_devx_cmds.h
+++ b/drivers/common/mlx5/mlx5_devx_cmds.h
@@ -383,6 +383,10 @@ int mlx5_devx_cmd_modify_qp_state(struct mlx5_devx_obj *qp,
 int mlx5_devx_cmd_modify_rqt(struct mlx5_devx_obj *rqt,
 			     struct mlx5_devx_rqt_attr *rqt_attr);
 
+__rte_internal
+int mlx5_devx_cmd_register_access(void *ctx, uint16_t reg_id,
+				  uint32_t arg, uint32_t *value,
+				  uint32_t write);
 /**
  * Create virtio queue counters object DevX API.
  *
diff --git a/drivers/common/mlx5/mlx5_prm.h b/drivers/common/mlx5/mlx5_prm.h
index 8705b42..6575edc 100644
--- a/drivers/common/mlx5/mlx5_prm.h
+++ b/drivers/common/mlx5/mlx5_prm.h
@@ -776,6 +776,7 @@ enum {
 	MLX5_CMD_OP_SUSPEND_QP = 0x50F,
 	MLX5_CMD_OP_RESUME_QP = 0x510,
 	MLX5_CMD_OP_QUERY_NIC_VPORT_CONTEXT = 0x754,
+	MLX5_CMD_OP_ACCESS_REGISTER = 0x805,
 	MLX5_CMD_OP_ALLOC_TRANSPORT_DOMAIN = 0x816,
 	MLX5_CMD_OP_CREATE_TIR = 0x900,
 	MLX5_CMD_OP_CREATE_SQ = 0X904,
@@ -2545,6 +2546,30 @@ struct mlx5_ifc_set_pp_rate_limit_context_bits {
 	u8 reserved_at_60[0x120];
 };
 
+struct mlx5_ifc_access_register_out_bits {
+	u8 status[0x8];
+	u8 reserved_at_8[0x18];
+	u8 syndrome[0x20];
+	u8 reserved_at_40[0x40];
+	u8 register_data[0][0x20];
+};
+
+enum {
+	MLX5_ACCESS_REGISTER_IN_OP_MOD_WRITE  = 0x0,
+	MLX5_ACCESS_REGISTER_IN_OP_MOD_READ   = 0x1,
+};
+
+struct mlx5_ifc_access_register_in_bits {
+	u8 opcode[0x10];
+	u8 reserved_at_10[0x10];
+	u8 reserved_at_20[0x10];
+	u8 op_mod[0x10];
+	u8 reserved_at_40[0x10];
+	u8 register_id[0x10];
+	u8 argument[0x20];
+	u8 register_data[0][0x20];
+};
+
 /* CQE format mask. */
 #define MLX5E_CQE_FORMAT_MASK 0xc
 
diff --git a/drivers/common/mlx5/rte_common_mlx5_version.map b/drivers/common/mlx5/rte_common_mlx5_version.map
index ae57ebd..123b460 100644
--- a/drivers/common/mlx5/rte_common_mlx5_version.map
+++ b/drivers/common/mlx5/rte_common_mlx5_version.map
@@ -34,6 +34,7 @@ INTERNAL {
 	mlx5_devx_cmd_query_hca_attr;
 	mlx5_devx_cmd_query_virtio_q_counters;
 	mlx5_devx_cmd_query_virtq;
+	mlx5_devx_cmd_register_access;
 	mlx5_devx_get_out_command_status;
 
 	mlx5_get_ifname_sysfs;
-- 
1.8.3.1