kernel.h: define u8, s8, u32, etc. limits

commit 89a0714106aac7309c7dfa0f004b39e1e89d2942 upstream.

Create constants that define the maximum and minimum values
representable by the kernel types u8, s8, u16, s16, and so on.

Signed-off-by: Alex Elder <elder@linaro.org>
Cc: Sage Weil <sage@inktank.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 672ddc4de4af0511b20a4d269bcae1c517c3d5c4..93bfc3a7e0a33834a43336d6696f4690c2f47b1e 100644 (file)
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -29,6 +29,19 @@
 #define ULLONG_MAX     (~0ULL)
 #define SIZE_MAX       (~(size_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
 
 #define REPEAT_BYTE(x) ((~0ul / 0xff) * (x))