Subject: [PATCH 14/23] mlxsw: core: Prevent QSFP module initialization for old hardware

From: Vadim Pasternak <[email-masked]>
Date: Sat, 18 May 2019 18:58:28 +0300

[ Upstream commit c52ecff7e6439ca8c9b03282e8869a005aa94831 ]

Old Mellanox silicons, like switchx-2, switch-ib do not support reading
QSFP modules temperature through MTMP register. Attempt to access this
register on systems equipped with the this kind of silicon will cause
initialization flow failure.
Test for hardware resource capability is added in order to distinct
between old and new silicon - old silicons do not have such capability.

Fixes: 6a79507cfe94 ("mlxsw: core: Extend thermal module with per QSFP module thermal zones")
Fixes: 5c42eaa07bd0 ("mlxsw: core: Extend hwmon interface with QSFP module temperature attributes")
Reported-by: Jiri Pirko <[email-masked]>
Signed-off-by: Vadim Pasternak <[email-masked]>
Signed-off-by: Ido Schimmel <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 drivers/net/ethernet/mellanox/mlxsw/core.c         | 6 ++++++
 drivers/net/ethernet/mellanox/mlxsw/core.h         | 2 ++
 drivers/net/ethernet/mellanox/mlxsw/core_hwmon.c   | 3 +++
 drivers/net/ethernet/mellanox/mlxsw/core_thermal.c | 6 ++++++
 4 files changed, 17 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/core.c b/drivers/net/ethernet/mellanox/mlxsw/core.c
index f26a4ca29363..0b56291d22c6 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/core.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/core.c
@@ -122,6 +122,12 @@ void *mlxsw_core_driver_priv(struct mlxsw_core *mlxsw_core)
 }
 EXPORT_SYMBOL(mlxsw_core_driver_priv);
 
+bool mlxsw_core_res_query_enabled(const struct mlxsw_core *mlxsw_core)
+{
+	return mlxsw_core->driver->res_query_enabled;
+}
+EXPORT_SYMBOL(mlxsw_core_res_query_enabled);
+
 struct mlxsw_rx_listener_item {
 	struct list_head list;
 	struct mlxsw_rx_listener rxl;
diff --git a/drivers/net/ethernet/mellanox/mlxsw/core.h b/drivers/net/ethernet/mellanox/mlxsw/core.h
index 8ec53f027575..62b8de9305af 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/core.h
+++ b/drivers/net/ethernet/mellanox/mlxsw/core.h
@@ -28,6 +28,8 @@ unsigned int mlxsw_core_max_ports(const struct mlxsw_core *mlxsw_core);
 
 void *mlxsw_core_driver_priv(struct mlxsw_core *mlxsw_core);
 
+bool mlxsw_core_res_query_enabled(const struct mlxsw_core *mlxsw_core);
+
 int mlxsw_core_driver_register(struct mlxsw_driver *mlxsw_driver);
 void mlxsw_core_driver_unregister(struct mlxsw_driver *mlxsw_driver);
 
diff --git a/drivers/net/ethernet/mellanox/mlxsw/core_hwmon.c b/drivers/net/ethernet/mellanox/mlxsw/core_hwmon.c
index 6956bbebe2f1..496dc904c5ed 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/core_hwmon.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/core_hwmon.c
@@ -518,6 +518,9 @@ static int mlxsw_hwmon_module_init(struct mlxsw_hwmon *mlxsw_hwmon)
 	u8 width;
 	int err;
 
+	if (!mlxsw_core_res_query_enabled(mlxsw_hwmon->core))
+		return 0;
+
 	/* Add extra attributes for module temperature. Sensor index is
 	 * assigned to sensor_count value, while all indexed before
 	 * sensor_count are already utilized by the sensors connected through
diff --git a/drivers/net/ethernet/mellanox/mlxsw/core_thermal.c b/drivers/net/ethernet/mellanox/mlxsw/core_thermal.c
index 472f63f9fac5..d3e851e7ca72 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/core_thermal.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/core_thermal.c
@@ -740,6 +740,9 @@ mlxsw_thermal_modules_init(struct device *dev, struct mlxsw_core *core,
 	struct mlxsw_thermal_module *module_tz;
 	int i, err;
 
+	if (!mlxsw_core_res_query_enabled(core))
+		return 0;
+
 	thermal->tz_module_arr = kcalloc(module_count,
 					 sizeof(*thermal->tz_module_arr),
 					 GFP_KERNEL);
@@ -776,6 +779,9 @@ mlxsw_thermal_modules_fini(struct mlxsw_thermal *thermal)
 	unsigned int module_count = mlxsw_core_max_ports(thermal->core);
 	int i;
 
+	if (!mlxsw_core_res_query_enabled(thermal->core))
+		return;
+
 	for (i = module_count - 1; i >= 0; i--)
 		mlxsw_thermal_module_fini(&thermal->tz_module_arr[i]);
 	kfree(thermal->tz_module_arr);
-- 
2.20.1