net/mlx5: Add support for FW fatal reporter dump

Add support of dump callback for mlx5 FW fatal reporter.
The FW fatal dump uses cr-dump functionality to gather cr-space data for
debug. The cr-dump uses vsc interface which is valid even if the FW
command interface is not functional, which is the case in most FW fatal
errors.

Command example and output:
$ devlink health dump show pci/0000:82:00.0 reporter fw_fatal
 crdump_data:
  00 20 00 01 00 00 00 00 03 00 00 00 00 00 00 00
  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 80
  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  00 00 00 00 00 00 00 00 00 00 00 00 ba 82 00 00
  0c 00 00 00 00 00 00 00 00 00 00 00 00 00 00 20
  00 00 00 00 00 00 00 00 00 00 00 00 00 00 fa 00
  a4 0e 00 00 00 00 00 00 80 c7 fe ff 50 0a 00 00
...
...
Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

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

@@ -565,9 +565,59 @@ mlx5_fw_fatal_reporter_recover(struct devlink_health_reporter *reporter,
 	return mlx5_health_try_recover(dev);
 }
 
+#define MLX5_CR_DUMP_CHUNK_SIZE 256
+static int
+mlx5_fw_fatal_reporter_dump(struct devlink_health_reporter *reporter,
+			    struct devlink_fmsg *fmsg, void *priv_ctx)
+{
+	struct mlx5_core_dev *dev = devlink_health_reporter_priv(reporter);
+	u32 crdump_size = dev->priv.health.crdump_size;
+	u32 *cr_data;
+	u32 data_size;
+	u32 offset;
+	int err;
+
+	if (!mlx5_core_is_pf(dev))
+		return -EPERM;
+
+	cr_data = kvmalloc(crdump_size, GFP_KERNEL);
+	if (!cr_data)
+		return -ENOMEM;
+	err = mlx5_crdump_collect(dev, cr_data);
+	if (err)
+		return err;
+
+	if (priv_ctx) {
+		struct mlx5_fw_reporter_ctx *fw_reporter_ctx = priv_ctx;
+
+		err = mlx5_fw_reporter_ctx_pairs_put(fmsg, fw_reporter_ctx);
+		if (err)
+			goto free_data;
+	}
+
+	err = devlink_fmsg_arr_pair_nest_start(fmsg, "crdump_data");
+	if (err)
+		goto free_data;
+	for (offset = 0; offset < crdump_size; offset += data_size) {
+		if (crdump_size - offset < MLX5_CR_DUMP_CHUNK_SIZE)
+			data_size = crdump_size - offset;
+		else
+			data_size = MLX5_CR_DUMP_CHUNK_SIZE;
+		err = devlink_fmsg_binary_put(fmsg, cr_data, data_size);
+		if (err)
+			goto free_data;
+	}
+	err = devlink_fmsg_arr_pair_nest_end(fmsg);
+
+free_data:
+	kfree(cr_data);
+	return err;
+}
+
 static const struct devlink_health_reporter_ops mlx5_fw_fatal_reporter_ops = {
 		.name = "fw_fatal",
 		.recover = mlx5_fw_fatal_reporter_recover,
+		.dump = mlx5_fw_fatal_reporter_dump,
 };
 
 #define MLX5_REPORTER_FW_GRACEFUL_PERIOD 1200000