ASoC: SOF: debug: List the loaded topology files in fw_profile/tplg_name

The fw_profile/tplg_name debugfs file exposes the topology file name
selected for the platform. When function topologies are used, the
selected name is a placeholder (sof-<platform>-dummy.tplg) which does
not tell which topology files have actually been loaded.

Replace the static name with a list of the loaded topology files, one
per line, set by snd_sof_load_topology() after a successful load and
cleared again when the loading fails or when the topology is removed in
sof_pcm_remove(). The topology path prefix is dropped from the names as
it is exposed separately via fw_profile/tplg_path.

The file is backed by a seq_file reader instead of debugfs_create_str()
so that the list can be replaced under a mutex without racing with
concurrent readers. While no topology is loaded the selected topology
name is shown.

For monolithic topologies the content of the file is unchanged.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>

Author: ujfalusi

sound/soc/sof/core.c

@@ -699,6 +699,7 @@ int snd_sof_device_probe(struct device *dev, struct snd_sof_pdata *plat_data)
 	mutex_init(&sdev->ipc_client_mutex);
 	mutex_init(&sdev->client_event_handler_mutex);
 	mutex_init(&sdev->dsp_fw_boot_mutex);
+	mutex_init(&sdev->loaded_tplg_names_mutex);
 
 	/* set default timeouts if none provided */
 	if (plat_data->desc->ipc_timeout == 0)

sound/soc/sof/debug.c

@@ -14,6 +14,7 @@
 #include <linux/debugfs.h>
 #include <linux/io.h>
 #include <linux/pm_runtime.h>
+#include <linux/seq_file.h>
 #include <sound/sof/ext_manifest.h>
 #include <sound/sof/debug.h>
 #include "sof-priv.h"
@@ -313,6 +314,28 @@ int snd_sof_dbg_memory_info_init(struct snd_sof_dev *sdev)
 }
 EXPORT_SYMBOL_GPL(snd_sof_dbg_memory_info_init);
 
+static int sof_dbg_tplg_name_show(struct seq_file *m, void *v)
+{
+	struct snd_sof_dev *sdev = m->private;
+
+	/* fall back to the selected topology name while no topology is loaded */
+	mutex_lock(&sdev->loaded_tplg_names_mutex);
+	seq_printf(m, "%s\n", sdev->loaded_tplg_names ?: sdev->pdata->tplg_filename);
+	mutex_unlock(&sdev->loaded_tplg_names_mutex);
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(sof_dbg_tplg_name);
+
+/* Takes ownership of the devm allocated tplg_names, NULL clears the list */
+void sof_debug_set_tplg_name(struct snd_sof_dev *sdev, char *tplg_names)
+{
+	mutex_lock(&sdev->loaded_tplg_names_mutex);
+	devm_kfree(sdev->dev, sdev->loaded_tplg_names);
+	sdev->loaded_tplg_names = tplg_names;
+	mutex_unlock(&sdev->loaded_tplg_names_mutex);
+}
+
 int snd_sof_dbg_init(struct snd_sof_dev *sdev)
 {
 	const struct snd_sof_dsp_ops *ops = sof_ops(sdev);
@@ -355,8 +378,8 @@ int snd_sof_dbg_init(struct snd_sof_dev *sdev)
 			   (char **)&plat_data->tplg_filename_prefix);
 	debugfs_create_str("fw_name", 0444, fw_profile,
 			   (char **)&plat_data->fw_filename);
-	debugfs_create_str("tplg_name", 0444, fw_profile,
-			   (char **)&plat_data->tplg_filename);
+	debugfs_create_file("tplg_name", 0444, fw_profile, sdev,
+			    &sof_dbg_tplg_name_fops);
 	debugfs_create_u32("ipc_type", 0444, fw_profile,
 			   (u32 *)&plat_data->ipc_type);
 

sound/soc/sof/pcm.c

@@ -808,8 +808,11 @@ static int sof_pcm_probe(struct snd_soc_component *component)
 
 static void sof_pcm_remove(struct snd_soc_component *component)
 {
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+
 	/* remove topology */
 	snd_soc_tplg_component_remove(component);
+	sof_debug_set_tplg_name(sdev, NULL);
 }
 
 static int sof_pcm_ack(struct snd_soc_component *component,

sound/soc/sof/sof-priv.h

@@ -656,6 +656,9 @@ struct snd_sof_dev {
 	struct snd_soc_component *component;
 	u32 enabled_cores_mask; /* keep track of enabled cores */
 	bool led_present;
+	/* newline separated list of the loaded topology files for debugfs */
+	char *loaded_tplg_names;
+	struct mutex loaded_tplg_names_mutex; /* protects loaded_tplg_names */
 
 	/* FW configuration */
 	struct sof_ipc_window *info_window;
@@ -798,6 +801,7 @@ static inline void snd_sof_ipc_process_reply(struct snd_sof_dev *sdev, u32 msg_i
  */
 int snd_sof_dbg_init(struct snd_sof_dev *sdev);
 void snd_sof_free_debug(struct snd_sof_dev *sdev);
+void sof_debug_set_tplg_name(struct snd_sof_dev *sdev, char *tplg_names);
 int snd_sof_debugfs_buf_item(struct snd_sof_dev *sdev,
 			     void *base, size_t size,
 			     const char *name, mode_t mode);

sound/soc/sof/topology.c

@@ -2509,11 +2509,40 @@ static const struct snd_soc_tplg_ops sof_dspless_tplg_ops = {
 	.bytes_ext_ops_count = ARRAY_SIZE(sof_dspless_bytes_ext_ops),
 };
 
+/*
+ * Append the name of a loaded topology file to the list exposed via debugfs.
+ * The topology path prefix is dropped as it is exposed separately.
+ */
+static int sof_tplg_names_append(struct snd_sof_dev *sdev, char **names,
+				 const char *file)
+{
+	const char *prefix = sdev->pdata->tplg_filename_prefix;
+	size_t prefix_len = strlen(prefix);
+	char *new_names;
+
+	if (!strncmp(file, prefix, prefix_len) && file[prefix_len] == '/')
+		file += prefix_len + 1;
+
+	if (*names)
+		new_names = devm_kasprintf(sdev->dev, GFP_KERNEL, "%s\n%s",
+					   *names, file);
+	else
+		new_names = devm_kstrdup(sdev->dev, file, GFP_KERNEL);
+	if (!new_names)
+		return -ENOMEM;
+
+	devm_kfree(sdev->dev, *names);
+	*names = new_names;
+
+	return 0;
+}
+
 int snd_sof_load_topology(struct snd_soc_component *scomp, const char *file)
 {
 	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(scomp);
 	struct snd_sof_pdata *sof_pdata = sdev->pdata;
 	const char *tplg_filename_prefix = sof_pdata->tplg_filename_prefix;
+	char *tplg_names = NULL;
 	int tplg_cnt = 0;
 	int ret;
 	int i;
@@ -2590,6 +2619,10 @@ int snd_sof_load_topology(struct snd_soc_component *scomp, const char *file)
 				tplg_files[i], ret);
 			goto out;
 		}
+
+		ret = sof_tplg_names_append(sdev, &tplg_names, tplg_files[i]);
+		if (ret < 0)
+			goto out;
 	}
 
 	/* Loading user defined topologies */
@@ -2632,12 +2665,24 @@ int snd_sof_load_topology(struct snd_soc_component *scomp, const char *file)
 			 */
 			goto out;
 		}
+
+		ret = sof_tplg_names_append(sdev, &tplg_names, feature_topology);
+		if (ret < 0)
+			goto out;
 	}
 
 	/* call sof_complete when topologies are loaded successfully */
 	ret = sof_complete(scomp);
+	if (ret < 0)
+		goto out;
+
+	/* Update the list of loaded topologies exposed via debugfs */
+	sof_debug_set_tplg_name(sdev, tplg_names);
+	tplg_names = NULL;
 
 out:
+	devm_kfree(sdev->dev, tplg_names);
+
 	if (ret >= 0 && sdev->led_present)
 		ret = snd_ctl_led_request();
 
@@ -2646,8 +2691,10 @@ int snd_sof_load_topology(struct snd_soc_component *scomp, const char *file)
 	 * component probe fails. If snd_soc_tplg_component_load() failed, it
 	 * has removed it already and this call is a no-op.
 	 */
-	if (ret < 0)
+	if (ret < 0) {
 		snd_soc_tplg_component_remove(scomp);
+		sof_debug_set_tplg_name(sdev, NULL);
+	}
 
 	return ret;
 }