[PATCH v2 1/2] linux/kernel.h: use 'short' to define USHRT_MAX, SHRT_MAX, SHRT_MIN

[PATCH v2 1/2] linux/kernel.h: use 'short' to define USHRT_MAX, SHRT_MAX, SHRT_MIN

[Masahiro Yamada]

The commit log of 44f564a4bf6a ("ipc: add definitions of USHORT_MAX
and others") did not explain why it used (s16) and (u16) instead of
(short) and (unsigned short).

Let's use (short) and (unsigned short), which is more sensible, and
more consistent with the other MAX/MIN defines.

As you see in include/uapi/asm-generic/int-ll64.h, s16/u16 are
typedef'ed as signed/unsigned short. So, this commit does not have
a functional change.

Remove the unneeded parentheses around ~0U while we are here.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Zhang Yanmin <yanmin.zhang@intel.com>
---

Changes in v2:
  - Remove unneeded parentheses

 include/linux/kernel.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 8f0e68e..afc19d9 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -16,9 +16,9 @@
 #include <asm/byteorder.h>
 #include <uapi/linux/kernel.h>
 
-#define USHRT_MAX	((u16)(~0U))
-#define SHRT_MAX	((s16)(USHRT_MAX>>1))
-#define SHRT_MIN	((s16)(-SHRT_MAX - 1))
+#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)
-- 
2.7.4

[PATCH v2 2/2] linux/kernel.h: split *_MAX and *_MIN macros into <linux/limits.h>

[Masahiro Yamada]

<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

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>
---

Changes in v2: None

 include/linux/kernel.h      | 29 +----------------------------
 include/linux/limits.h      | 36 ++++++++++++++++++++++++++++++++++++
 include/uapi/linux/limits.h |  4 ++--
 3 files changed, 39 insertions(+), 30 deletions(-)
 create mode 100644 include/linux/limits.h

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index afc19d9..b80b965 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -4,6 +4,7 @@
 
 
 #include <stdarg.h>
+#include <linux/limits.h>
 #include <linux/linkage.h>
 #include <linux/stddef.h>
 #include <linux/types.h>
@@ -16,34 +17,6 @@
 #include <asm/byteorder.h>
 #include <uapi/linux/kernel.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))
-
 #define STACK_MAGIC	0xdeadbeef
 
 /**
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 */
diff --git a/include/uapi/linux/limits.h b/include/uapi/linux/limits.h
index c3547f0..6bcbe30 100644
--- a/include/uapi/linux/limits.h
+++ b/include/uapi/linux/limits.h
@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef _LINUX_LIMITS_H
-#define _LINUX_LIMITS_H
+#ifndef _UAPI_LINUX_LIMITS_H
+#define _UAPI_LINUX_LIMITS_H
 
 #define NR_OPEN	        1024
 
-- 
2.7.4