[net-next 04/15] net/mlx5: Add support for devlink region_snapshot parameter

[Saeed Mahameed <saeedm@mellanox.com>]

From: Alex Vesker <valex@mellanox.com>

This parameter enables capturing region snapshot of the crspace
during critical errors. The default value of this parameter is
disabled, it can be enabled using devlink param commands.
It is possible to configure during runtime and also driver init.

Command line examples:

Delete snapshot id 1 from cr-space address region from device pci/0000:00:05.0
$ devlink region del pci/0000:00:05.0/cr-space snapshot 1

Dump the snapshot taken from cr-space address region with ID 1
$ devlink region dump pci/0000:00:05.0/cr-space snapshot 1

Read from address 0x10, 16 Bytes of snapshot ID 1 taken from cr-space address region
$ devlink region read pci/0000:00:05.0/cr-space snapshot 1 address 0x10 length 16

Signed-off-by: Alex Vesker <valex@mellanox.com>
Reviewed-by: Feras Daoud <ferasda@mellanox.com>
Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Reviewed-by: Alex Vesker <valex@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
---
 .../net/ethernet/mellanox/mlx5/core/devlink.c | 60 ++++++++++++++++++-
 .../ethernet/mellanox/mlx5/core/diag/crdump.c | 22 +++++++
 .../ethernet/mellanox/mlx5/core/lib/mlx5.h    |  2 +
 3 files changed, 83 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/devlink.c b/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
index 72ff27f57817..308fe64e7bcd 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
@@ -2,13 +2,71 @@
 /* Copyright (c) 2019 Mellanox Technologies */
 
 #include <devlink.h>
+#include <linux/mlx5/driver.h>
+#include "lib/mlx5.h"
+
+static int mlx5_devlink_get_crdump_snapshot(struct devlink *devlink, u32 id,
+					    struct devlink_param_gset_ctx *ctx)
+{
+	struct mlx5_core_dev *dev = devlink_priv(devlink);
+
+	ctx->val.vbool = mlx5_crdump_is_snapshot_enabled(dev);
+	return 0;
+}
+
+static int mlx5_devlink_set_crdump_snapshot(struct devlink *devlink, u32 id,
+					    struct devlink_param_gset_ctx *ctx)
+{
+	struct mlx5_core_dev *dev = devlink_priv(devlink);
+
+	return mlx5_crdump_set_snapshot_enabled(dev, ctx->val.vbool);
+}
+
+static const struct devlink_param mlx5_devlink_params[] = {
+	DEVLINK_PARAM_GENERIC(REGION_SNAPSHOT,
+			      BIT(DEVLINK_PARAM_CMODE_RUNTIME) |
+			      BIT(DEVLINK_PARAM_CMODE_DRIVERINIT),
+			      mlx5_devlink_get_crdump_snapshot,
+			      mlx5_devlink_set_crdump_snapshot, NULL),
+};
 
 int mlx5_devlink_register(struct devlink *devlink, struct device *dev)
 {
-	return devlink_register(devlink, dev);
+	union devlink_param_value init_val;
+	int err;
+
+	err = devlink_register(devlink, dev);
+	if (err) {
+		dev_warn(dev,
+			 "devlink register failed (err = %d)", err);
+		return err;
+	}
+
+	err = devlink_params_register(devlink, mlx5_devlink_params,
+				      ARRAY_SIZE(mlx5_devlink_params));
+	if (err) {
+		dev_err(dev, "devlink_params_register failed, err = %d\n", err);
+		goto unregister;
+	}
+
+	init_val.vbool = false;
+	err = devlink_param_driverinit_value_set(devlink,
+						 DEVLINK_PARAM_GENERIC_ID_REGION_SNAPSHOT,
+						 init_val);
+	if (err)
+		dev_warn(dev,
+			 "devlink param init failed (err = %d)", err);
+
+	return 0;
+
+unregister:
+	devlink_unregister(devlink);
+	return err;
 }
 
 void mlx5_devlink_unregister(struct devlink *devlink)
 {
+	devlink_params_unregister(devlink, mlx5_devlink_params,
+				  ARRAY_SIZE(mlx5_devlink_params));
 	devlink_unregister(devlink);
 }
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/diag/crdump.c b/drivers/net/ethernet/mellanox/mlx5/core/diag/crdump.c
index 6430ceeefb53..7337a49f2733 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/diag/crdump.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/diag/crdump.c
@@ -16,6 +16,7 @@ static const char *region_cr_space_str = "cr-space";
 
 struct mlx5_fw_crdump {
 	u32			size;
+	bool			snapshot_enable;
 	struct devlink_region	*region_crspace;
 };
 
@@ -103,6 +104,27 @@ int mlx5_crdump_collect(struct mlx5_core_dev *dev,
 	return ret;
 }
 
+bool mlx5_crdump_is_snapshot_enabled(struct mlx5_core_dev *dev)
+{
+	struct mlx5_priv *priv = &dev->priv;
+
+	if (mlx5_crdump_enbaled(dev))
+		return priv->health.crdump->snapshot_enable;
+
+	return false;
+}
+
+int mlx5_crdump_set_snapshot_enabled(struct mlx5_core_dev *dev, bool value)
+{
+	struct mlx5_priv *priv = &dev->priv;
+
+	if (!mlx5_crdump_enbaled(dev))
+		return -ENODEV;
+
+	priv->health.crdump->snapshot_enable = value;
+	return 0;
+}
+
 int mlx5_crdump_init(struct mlx5_core_dev *dev)
 {
 	struct devlink *devlink = priv_to_devlink(dev);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lib/mlx5.h b/drivers/net/ethernet/mellanox/mlx5/core/lib/mlx5.h
index 3c9a6dedccaa..c639f0af29ed 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/lib/mlx5.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/lib/mlx5.h
@@ -45,6 +45,8 @@ int mlx5_crdump_init(struct mlx5_core_dev *dev);
 void mlx5_crdump_cleanup(struct mlx5_core_dev *dev);
 int mlx5_crdump_collect(struct mlx5_core_dev *dev,
 			char *crdump_region, u32 *snapshot_id);
+bool mlx5_crdump_is_snapshot_enabled(struct mlx5_core_dev *dev);
+int mlx5_crdump_set_snapshot_enabled(struct mlx5_core_dev *dev, bool value);
 
 /* TODO move to lib/events.h */
 
-- 
2.20.1