[PATCH] kernel.h: add IS_PTR_ALIGNED() macro

From	Masahiro Yamada <yamada.masahiro@socionext.com>
Newsgroups	linux.kernel
Subject	[PATCH] kernel.h: add IS_PTR_ALIGNED() macro
Date	2017-03-29 12:30 +0200
Message-ID	<tqj1w-5wl-21@gated-at.bofh.it> (permalink)
Organization	linux.* mail to news gateway

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We often check if a pointer has a specific alignment.  Because the
'&' (bitwise AND) operator cannot take a pointer for the operand,
so we need a cast like, IS_ALIGNED((unsigned long)p, a).

IS_PTR_ALIGNED will be useful as a shorthand.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 include/linux/kernel.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index e5edd55..a810e4b 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -50,6 +50,7 @@
 #define __ALIGN_MASK(x, mask)	__ALIGN_KERNEL_MASK((x), (mask))
 #define PTR_ALIGN(p, a)		((typeof(p))ALIGN((unsigned long)(p), (a)))
 #define IS_ALIGNED(x, a)		(((x) & ((typeof(x))(a) - 1)) == 0)
+#define IS_PTR_ALIGNED(p, a)		(IS_ALIGNED((unsigned long)p, a))
 
 /* generic data direction definitions */
 #define READ			0
-- 
2.7.4

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[PATCH] kernel.h: add IS_PTR_ALIGNED() macro Masahiro Yamada <yamada.masahiro@socionext.com> - 2017-03-29 12:30 +0200
  Re: [PATCH] kernel.h: add IS_PTR_ALIGNED() macro Andrew Morton <akpm@linux-foundation.org> - 2017-03-29 23:40 +0200
  Re: [PATCH] kernel.h: add IS_PTR_ALIGNED() macro "H. Peter Anvin" <hpa@zytor.com> - 2017-03-29 23:40 +0200
    Re: [PATCH] kernel.h: add IS_PTR_ALIGNED() macro Masahiro Yamada <yamada.masahiro@socionext.com> - 2017-03-30 04:00 +0200
      Re: [PATCH] kernel.h: add IS_PTR_ALIGNED() macro "H. Peter Anvin" <hpa@zytor.com> - 2017-03-30 05:50 +0200
        Re: [PATCH] kernel.h: add IS_PTR_ALIGNED() macro Masahiro Yamada <yamada.masahiro@socionext.com> - 2017-03-30 17:30 +0200

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