linux/kernel.h: split *_MAX and *_MIN macros into <linux/limits.h>
<linux/kernel.h> tends to be cluttered because we often put various sort
of unrelated stuff in it. So, we have split out a sensible chunk of
code into a separate header from time to time.
This commit splits out the *_MAX and *_MIN defines.
The standard header <limits.h> contains various MAX, MIN constants
including numerial limits. [1]
I think it makes sense to move in-kernel MAX, MIN constants into
include/linux/limits.h.
We already have include/uapi/linux/limits.h to contain some user-space
constants. I changed its include guard to _UAPI_LINUX_LIMITS_H. This
change has no impact to the user-space because
scripts/headers_install.sh rips off the '_UAPI' prefix from the include
guards of exported headers.
[1] http://pubs.opengroup.org/onlinepubs/009604499/basedefs/limits.h.html
Link: http://lkml.kernel.org/r/1549156242-20806-2-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Alex Elder <elder@linaro.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Zhang Yanmin <yanmin.zhang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/limits.h b/include/linux/limits.h
new file mode 100644
index 0000000..76afcd2
--- /dev/null
+++ b/include/linux/limits.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_LIMITS_H
+#define _LINUX_LIMITS_H
+
+#include <uapi/linux/limits.h>
+#include <linux/types.h>
+
+#define USHRT_MAX ((unsigned short)~0U)
+#define SHRT_MAX ((short)(USHRT_MAX >> 1))
+#define SHRT_MIN ((short)(-SHRT_MAX - 1))
+#define INT_MAX ((int)(~0U >> 1))
+#define INT_MIN (-INT_MAX - 1)
+#define UINT_MAX (~0U)
+#define LONG_MAX ((long)(~0UL >> 1))
+#define LONG_MIN (-LONG_MAX - 1)
+#define ULONG_MAX (~0UL)
+#define LLONG_MAX ((long long)(~0ULL >> 1))
+#define LLONG_MIN (-LLONG_MAX - 1)
+#define ULLONG_MAX (~0ULL)
+#define SIZE_MAX (~(size_t)0)
+#define PHYS_ADDR_MAX (~(phys_addr_t)0)
+
+#define U8_MAX ((u8)~0U)
+#define S8_MAX ((s8)(U8_MAX >> 1))
+#define S8_MIN ((s8)(-S8_MAX - 1))
+#define U16_MAX ((u16)~0U)
+#define S16_MAX ((s16)(U16_MAX >> 1))
+#define S16_MIN ((s16)(-S16_MAX - 1))
+#define U32_MAX ((u32)~0U)
+#define S32_MAX ((s32)(U32_MAX >> 1))
+#define S32_MIN ((s32)(-S32_MAX - 1))
+#define U64_MAX ((u64)~0ULL)
+#define S64_MAX ((s64)(U64_MAX >> 1))
+#define S64_MIN ((s64)(-S64_MAX - 1))
+
+#endif /* _LINUX_LIMITS_H */