[PATCH i-g-t 1/2] lib/igt_configfs: Add library for configfs

[Riana Tauro <riana.tauro@intel.com>]

Add library functions to open configfs and create
and remove configfs directories.

Signed-off-by: Riana Tauro <riana.tauro@intel.com>
---
 lib/igt_configfs.c | 88 ++++++++++++++++++++++++++++++++++++++++++++++
 lib/igt_configfs.h | 13 +++++++
 lib/meson.build    |  1 +
 3 files changed, 102 insertions(+)
 create mode 100644 lib/igt_configfs.c
 create mode 100644 lib/igt_configfs.h

diff --git a/lib/igt_configfs.c b/lib/igt_configfs.c
new file mode 100644
index 000000000..57d59f1c4
--- /dev/null
+++ b/lib/igt_configfs.c
@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2025 Intel Corporation
+ */
+#include <sys/mount.h>
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+
+#include "igt_configfs.h"
+#include "igt_core.h"
+
+static const char *igt_configfs_mount(void)
+{
+	struct stat st;
+
+	if (stat("/sys/kernel/debug", &st) == 0)
+		return "/sys/kernel/config";
+
+	if (mount("none", "/sys/kernel/config", "configfs", 0, 0))
+		return NULL;
+
+	return "/sys/kernel/config";
+}
+
+/**
+ * igt_configfs_open: open configfs path
+ * @name: name of the configfs directory
+ *
+ * Opens the configfs directory corresponding to the name
+ *
+ * Returns:
+ * The directory fd, or -1 on failure.
+ */
+int igt_configfs_open(const char *name)
+{
+	char path[PATH_MAX];
+	const char *configfs_path;
+
+	configfs_path = igt_configfs_mount();
+	igt_assert(configfs_path);
+
+	snprintf(path, sizeof(path), "%s/%s", configfs_path, name);
+
+	return open(path, O_RDONLY);
+}
+
+/**
+ * igt_configfs_create_directory: creates configfs group
+ * @fd: fd of configfs parent directory
+ * @name: name of the directory to create
+ *
+ * creates a directory under configfs parent directory
+ *
+ * Returns: 0 on success, -errno otherwise
+ */
+int igt_configfs_create_directory(int fd, const char *name)
+{
+	int ret;
+	int dirfd;
+
+	ret = mkdirat(fd, name, 0755);
+	if (ret)
+		return -errno;
+
+	dirfd = openat(fd, name, O_DIRECTORY);
+	if (dirfd < 0)
+		return -errno;
+
+	return dirfd;
+}
+
+/**
+ * igt_configfs_remove_directory: removes configfs group
+ * @fd: fd of configfs parent directory
+ * @name: name of directory to create
+ *
+ * removes directory under configfs parent directory
+ */
+void igt_configfs_remove_directory(int fd, const char *name)
+{
+	int ret = unlinkat(fd, name, AT_REMOVEDIR);
+
+	if (ret)
+		igt_warn("Unable to remove %s directory: %s\n", name, strerror(errno));
+}
diff --git a/lib/igt_configfs.h b/lib/igt_configfs.h
new file mode 100644
index 000000000..d839db49a
--- /dev/null
+++ b/lib/igt_configfs.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2025 Intel Corporation
+ */
+
+#ifndef IGT_CONFIGFS_H
+#define IGT_CONFIGFS_H
+
+int igt_configfs_open(const char *name);
+int igt_configfs_create_directory(int fd, const char *name);
+void igt_configfs_remove_directory(int fd, const char *name);
+
+#endif /* IGT_CONFIGFS_H */
diff --git a/lib/meson.build b/lib/meson.build
index d7bb72c57..f087947e7 100644
--- a/lib/meson.build
+++ b/lib/meson.build
@@ -19,6 +19,7 @@ lib_sources = [
 	'igt_collection.c',
 	'igt_color_encoding.c',
 	'igt_facts.c',
+	'igt_configfs.c',
 	'igt_crc.c',
 	'igt_debugfs.c',
 	'igt_device.c',
-- 
2.47.1