[PATCH 06/10] include: add definitions for UID/GID/DEV

[Ahmad Fatoum <a.fatoum@barebox.org>]

We do not care for these fields, but they simplify porting kernel file
systems, so add helpers for them.

Signed-off-by: Ahmad Fatoum <a.fatoum@barebox.org>
---
 include/linux/kdev_t.h       | 22 ++++++++++++++
 include/linux/uidgid.h       | 59 ++++++++++++++++++++++++++++++++++++
 include/linux/uidgid_types.h | 15 +++++++++
 3 files changed, 96 insertions(+)
 create mode 100644 include/linux/kdev_t.h
 create mode 100644 include/linux/uidgid.h
 create mode 100644 include/linux/uidgid_types.h

diff --git a/include/linux/kdev_t.h b/include/linux/kdev_t.h
new file mode 100644
index 000000000000..2919eb6bde82
--- /dev/null
+++ b/include/linux/kdev_t.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_KDEV_T_H
+#define _LINUX_KDEV_T_H
+
+#include <linux/compiler.h>
+
+#define MINORBITS	20
+#define MINORMASK	((1U << MINORBITS) - 1)
+
+#define MAJOR(dev)	((unsigned int) ((dev) >> MINORBITS))
+#define MINOR(dev)	((unsigned int) ((dev) & MINORMASK))
+#define MKDEV(ma,mi)	(((ma) << MINORBITS) | (mi))
+
+static __always_inline dev_t new_decode_dev(u32 dev)
+{
+	unsigned major = (dev & 0xfff00) >> 8;
+	unsigned minor = (dev & 0xff) | ((dev >> 12) & 0xfff00);
+	return MKDEV(major, minor);
+}
+
+
+#endif
diff --git a/include/linux/uidgid.h b/include/linux/uidgid.h
new file mode 100644
index 000000000000..7589e77b325f
--- /dev/null
+++ b/include/linux/uidgid.h
@@ -0,0 +1,59 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_UIDGID_H
+#define _LINUX_UIDGID_H
+
+/*
+ * A set of types for the internal kernel types representing uids and gids.
+ *
+ * The types defined in this header allow distinguishing which uids and gids in
+ * the kernel are values used by userspace and which uid and gid values are
+ * the internal kernel values.  With the addition of user namespaces the values
+ * can be different.  Using the type system makes it possible for the compiler
+ * to detect when we overlook these differences.
+ *
+ */
+#include <linux/uidgid_types.h>
+
+#define KUIDT_INIT(value) (kuid_t){ value }
+#define KGIDT_INIT(value) (kgid_t){ value }
+
+#define make_kuid(uid) KUIDT_INIT(uid)
+#define make_kgid(gid) KGIDT_INIT(gid)
+
+#define GLOBAL_ROOT_UID KUIDT_INIT(0)
+#define GLOBAL_ROOT_GID KGIDT_INIT(0)
+
+#define INVALID_UID KUIDT_INIT(-1)
+#define INVALID_GID KGIDT_INIT(-1)
+
+static inline uid_t __kuid_val(kuid_t uid)
+{
+	return 0;
+}
+
+static inline gid_t __kgid_val(kgid_t gid)
+{
+	return 0;
+}
+
+static inline uid_t from_kuid(kuid_t kuid)
+{
+	return __kuid_val(kuid);
+}
+
+static inline gid_t from_kgid(kgid_t kgid)
+{
+	return __kgid_val(kgid);
+}
+
+static inline bool uid_eq(kuid_t left, kuid_t right)
+{
+	return __kuid_val(left) == __kuid_val(right);
+}
+
+static inline bool gid_eq(kgid_t left, kgid_t right)
+{
+	return __kgid_val(left) == __kgid_val(right);
+}
+
+#endif /* _LINUX_UIDGID_H */
diff --git a/include/linux/uidgid_types.h b/include/linux/uidgid_types.h
new file mode 100644
index 000000000000..b35ac4955a33
--- /dev/null
+++ b/include/linux/uidgid_types.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_UIDGID_TYPES_H
+#define _LINUX_UIDGID_TYPES_H
+
+#include <linux/types.h>
+
+typedef struct {
+	uid_t val;
+} kuid_t;
+
+typedef struct {
+	gid_t val;
+} kgid_t;
+
+#endif /* _LINUX_UIDGID_TYPES_H */
-- 
2.39.5