net/mlx5: Add Crdump support

Crdump allows the driver to retrieve a dump of the FW PCI crspace.
This is useful in case of catastrophic issues which may require FW
reset. The crspace dump can be used for later debug.

Signed-off-by: Alex Vesker <valex@mellanox.com>
Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
Reviewed-by: Feras Daoud <ferasda@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

1 files changed, 106 insertions, 0 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/diag/crdump.c b/drivers/net/ethernet/mellanox/mlx5/core/diag/crdump.c
new file mode 100644
index 000000000000..dfb34172c69b
--- /dev/null
+++ b/drivers/net/ethernet/mellanox/mlx5/core/diag/crdump.c
@@ -0,0 +1,106 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+/* Copyright (c) 2019 Mellanox Technologies */
+
+#include <linux/mlx5/driver.h>
+#include "mlx5_core.h"
+#include "lib/pci_vsc.h"
+#include "lib/mlx5.h"
+
+#define BAD_ACCESS			0xBADACCE5
+#define MLX5_PROTECTED_CR_SCAN_CRSPACE	0x7
+
+static bool mlx5_crdump_enabled(struct mlx5_core_dev *dev)
+{
+	return !!dev->priv.health.crdump_size;
+}
+
+static int mlx5_crdump_fill(struct mlx5_core_dev *dev, u32 *cr_data)
+{
+	u32 crdump_size = dev->priv.health.crdump_size;
+	int i, ret;
+
+	for (i = 0; i < (crdump_size / 4); i++)
+		cr_data[i] = BAD_ACCESS;
+
+	ret = mlx5_vsc_gw_read_block_fast(dev, cr_data, crdump_size);
+	if (ret <= 0) {
+		if (ret == 0)
+			return -EIO;
+		return ret;
+	}
+
+	if (crdump_size != ret) {
+		mlx5_core_warn(dev, "failed to read full dump, read %d out of %u\n",
+			       ret, crdump_size);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+int mlx5_crdump_collect(struct mlx5_core_dev *dev, u32 *cr_data)
+{
+	int ret;
+
+	if (!mlx5_crdump_enabled(dev))
+		return -ENODEV;
+
+	ret = mlx5_vsc_gw_lock(dev);
+	if (ret) {
+		mlx5_core_warn(dev, "crdump: failed to lock vsc gw err %d\n",
+			       ret);
+		return ret;
+	}
+
+	ret = mlx5_vsc_gw_set_space(dev, MLX5_VSC_SPACE_SCAN_CRSPACE, NULL);
+	if (ret)
+		goto unlock;
+
+	ret = mlx5_crdump_fill(dev, cr_data);
+
+unlock:
+	mlx5_vsc_gw_unlock(dev);
+	return ret;
+}
+
+int mlx5_crdump_enable(struct mlx5_core_dev *dev)
+{
+	struct mlx5_priv *priv = &dev->priv;
+	u32 space_size;
+	int ret;
+
+	if (!mlx5_core_is_pf(dev) || !mlx5_vsc_accessible(dev) ||
+	    mlx5_crdump_enabled(dev))
+		return 0;
+
+	ret = mlx5_vsc_gw_lock(dev);
+	if (ret)
+		return ret;
+
+	/* Check if space is supported and get space size */
+	ret = mlx5_vsc_gw_set_space(dev, MLX5_VSC_SPACE_SCAN_CRSPACE,
+				    &space_size);
+	if (ret) {
+		/* Unlock and mask error since space is not supported */
+		mlx5_vsc_gw_unlock(dev);
+		return 0;
+	}
+
+	if (!space_size) {
+		mlx5_core_warn(dev, "Invalid Crspace size, zero\n");
+		mlx5_vsc_gw_unlock(dev);
+		return -EINVAL;
+	}
+
+	ret = mlx5_vsc_gw_unlock(dev);
+	if (ret)
+		return ret;
+
+	priv->health.crdump_size = space_size;
+	return 0;
+}
+
+void mlx5_crdump_disable(struct mlx5_core_dev *dev)
+{
+	dev->priv.health.crdump_size = 0;
+}