From bbc38aa49830c9377e5087a2294c9378448d5ca5 Mon Sep 17 00:00:00 2001
From: Eric Andersen <andersen@codepoet.org>
Date: Mon, 26 Jul 2004 12:36:24 +0000
Subject: Support linux 2.6.x wide device major/minor numbers

---
 include/sys/sysmacros.h | 68 ++++++++++++++++++++++++++++++++-----------------
 1 file changed, 44 insertions(+), 24 deletions(-)

(limited to 'include/sys/sysmacros.h')

diff --git a/include/sys/sysmacros.h b/include/sys/sysmacros.h
index e482aab17..a9bfa78d3 100644
--- a/include/sys/sysmacros.h
+++ b/include/sys/sysmacros.h
@@ -1,5 +1,5 @@
 /* Definitions of macros to access `dev_t' values.
-   Copyright (C) 1996, 1997, 1999 Free Software Foundation, Inc.
+   Copyright (C) 1996, 1997, 1999, 2003 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -20,30 +20,50 @@
 #ifndef _SYS_SYSMACROS_H
 #define _SYS_SYSMACROS_H	1
 
-/* For compatibility we provide alternative names.
-
-   The problem here is that compilers other than GCC probably don't
-   have the `long long' type and so `dev_t' is actually an array.  */
-#if defined __GNUC__ && __GNUC__ >= 2
-# define major(dev) ((int)(((dev) >> 8) & 0xff))
-# define minor(dev) ((int)((dev) & 0xff))
-# define makedev(major, minor) ((((unsigned int) (major)) << 8) \
-				| ((unsigned int) (minor)))
-#else
-/* We need to know the word order here.  This assumes that the word order
-   is consistent with the byte order.  */
-# include <endian.h>
-# if __BYTE_ORDER == __BIG_ENDIAN
-#  define major(dev) (((dev).__val[1] >> 8) & 0xff)
-#  define minor(dev) ((dev).__val[1] & 0xff)
-#  define makedev(major, minor) { 0, ((((unsigned int) (major)) << 8) \
-				      | ((unsigned int) (minor))) }
-# else
-#  define major(dev) (((dev).__val[0] >> 8) & 0xff)
-#  define minor(dev) ((dev).__val[0] & 0xff)
-#  define makedev(major, minor) { ((((unsigned int) (major)) << 8) \
-				   | ((unsigned int) (minor))), 0 }
+#include <features.h>
+
+/* If the compiler does not know long long it is out of luck.  We are
+   not going to hack weird hacks to support the dev_t representation
+   they need.  */
+#ifdef __GLIBC_HAVE_LONG_LONG
+__extension__
+extern __inline unsigned int gnu_dev_major (unsigned long long int __dev)
+     __THROW;
+__extension__
+extern __inline unsigned int gnu_dev_minor (unsigned long long int __dev)
+     __THROW;
+__extension__
+extern __inline unsigned long long int gnu_dev_makedev (unsigned int __major,
+							unsigned int __minor)
+     __THROW;
+
+# if defined __GNUC__ && __GNUC__ >= 2
+__extension__ extern __inline unsigned int
+gnu_dev_major (unsigned long long int __dev) __THROW
+{
+  return ((__dev >> 8) & 0xfff) | ((unsigned int) (__dev >> 32) & ~0xfff);
+}
+
+__extension__ extern __inline unsigned int
+gnu_dev_minor (unsigned long long int __dev) __THROW
+{
+  return (__dev & 0xff) | ((unsigned int) (__dev >> 12) & ~0xff);
+}
+
+__extension__ extern __inline unsigned long long int
+gnu_dev_makedev (unsigned int __major, unsigned int __minor) __THROW
+{
+  return ((__minor & 0xff) | ((__major & 0xfff) << 8)
+	  | (((unsigned long long int) (__minor & ~0xff)) << 12)
+	  | (((unsigned long long int) (__major & ~0xfff)) << 32));
+}
 # endif
+
+
+/* Access the functions with their traditional names.  */
+# define major(dev) gnu_dev_major (dev)
+# define minor(dev) gnu_dev_minor (dev)
+# define makedev(maj, min) gnu_dev_makedev (maj, min)
 #endif
 
 #endif /* sys/sysmacros.h */
-- 
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