diff mbox series

[Concept,16/19] linux: Add kdev_t.h header with device number macros

Message ID 20260117011448.3007171-17-sjg@u-boot.org
State New
Headers
Series ext4l: Reduce ext4_uboot.h size by moving code to include/linux |

Commit Message

Simon Glass Jan. 17, 2026, 1:14 a.m. UTC 
  From: Simon Glass <simon.glass@canonical.com>

Move device-number-encoding macros to a dedicated header file that
mirrors the Linux kernel organisation.

kdev_t.h provides:
- MINORBITS, MINORMASK - minor number parameters
- MAJOR(), MINOR() - extract major/minor from dev_t
- MKDEV() - create dev_t from major/minor
- old_valid_dev(), old_encode_dev(), old_decode_dev() - old 8:8 format
- new_encode_dev(), new_decode_dev() - new format (pass-through)

Co-developed-by: Claude Opus 4.5 <noreply@anthropic.com>
Signed-off-by: Simon Glass <simon.glass@canonical.com>
---

 fs/ext4l/ext4_uboot.h  | 24 ++----------------
 include/linux/kdev_t.h | 56 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 58 insertions(+), 22 deletions(-)
 create mode 100644 include/linux/kdev_t.h
diff mbox series

Patch

diff --git a/fs/ext4l/ext4_uboot.h b/fs/ext4l/ext4_uboot.h
index f77891835cb..aa357599449 100644
--- a/fs/ext4l/ext4_uboot.h
+++ b/fs/ext4l/ext4_uboot.h
@@ -1086,28 +1086,8 @@  static inline unsigned int i_gid_read(const struct inode *inode)
 #define i_uid_update(m, a, i)			do { } while (0)
 #define i_gid_update(m, a, i)			do { } while (0)
 
-/* Device encoding helpers */
-#ifndef MINORBITS
-#define MINORBITS	20
-#endif
-#ifndef MINORMASK
-#define MINORMASK	((1U << MINORBITS) - 1)
-#endif
-#ifndef MAJOR
-#define MAJOR(dev)	((unsigned int)((dev) >> MINORBITS))
-#endif
-#ifndef MINOR
-#define MINOR(dev)	((unsigned int)((dev) & MINORMASK))
-#endif
-#ifndef MKDEV
-#define MKDEV(ma, mi)	(((ma) << MINORBITS) | (mi))
-#endif
-
-#define old_valid_dev(dev)	(MAJOR(dev) < 256 && MINOR(dev) < 256)
-#define old_encode_dev(dev)	((MAJOR(dev) << 8) | MINOR(dev))
-#define old_decode_dev(dev)	MKDEV((dev) >> 8, (dev) & 0xff)
-#define new_encode_dev(dev)	((unsigned int)(dev))
-#define new_decode_dev(dev)	((dev_t)(dev))
+/* Device encoding helpers are now in linux/kdev_t.h */
+#include <linux/kdev_t.h>
 
 /* UID/GID bit helpers */
 #define low_16_bits(x)		((x) & 0xFFFF)
diff --git a/include/linux/kdev_t.h b/include/linux/kdev_t.h
new file mode 100644
index 00000000000..1aa524b9dca
--- /dev/null
+++ b/include/linux/kdev_t.h
@@ -0,0 +1,56 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Device number macros for U-Boot
+ *
+ * Based on Linux kdev_t.h
+ */
+#ifndef _LINUX_KDEV_T_H
+#define _LINUX_KDEV_T_H
+
+#include <linux/types.h>
+
+/* Number of minor bits */
+#ifndef MINORBITS
+#define MINORBITS	20
+#endif
+
+/* Minor number mask */
+#ifndef MINORMASK
+#define MINORMASK	((1U << MINORBITS) - 1)
+#endif
+
+/**
+ * MAJOR - extract major number from dev_t
+ * @dev: device number
+ */
+#ifndef MAJOR
+#define MAJOR(dev)	((unsigned int)((dev) >> MINORBITS))
+#endif
+
+/**
+ * MINOR - extract minor number from dev_t
+ * @dev: device number
+ */
+#ifndef MINOR
+#define MINOR(dev)	((unsigned int)((dev) & MINORMASK))
+#endif
+
+/**
+ * MKDEV - create dev_t from major and minor numbers
+ * @ma: major number
+ * @mi: minor number
+ */
+#ifndef MKDEV
+#define MKDEV(ma, mi)	(((ma) << MINORBITS) | (mi))
+#endif
+
+/* Old-style device number encoding (8:8) */
+#define old_valid_dev(dev)	(MAJOR(dev) < 256 && MINOR(dev) < 256)
+#define old_encode_dev(dev)	((MAJOR(dev) << 8) | MINOR(dev))
+#define old_decode_dev(dev)	MKDEV((dev) >> 8, (dev) & 0xff)
+
+/* New-style device number encoding (pass-through) */
+#define new_encode_dev(dev)	((unsigned int)(dev))
+#define new_decode_dev(dev)	((dev_t)(dev))
+
+#endif /* _LINUX_KDEV_T_H */