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authorArnd Bergmann <arnd@arndb.de>2009-05-13 22:56:25 +0000
committerArnd Bergmann <arnd@klappe2.(none)>2009-06-11 21:02:14 +0200
commitc31ae4bb4a9fa4606a74c0a4fb61b74f804e861e (patch)
tree7694b1a05bc1ac660ac26eb9997200556ccd3933 /include/asm-generic/bitsperlong.h
parent63b852a6b67d0820d388b0ecd0da83ccb4048b8d (diff)
downloadlinux-linaro-stable-c31ae4bb4a9fa4606a74c0a4fb61b74f804e861e.tar.gz
asm-generic: introduce asm/bitsperlong.h
This provides a reliable way for asm-generic/types.h and other files to find out if it is running on a 32 or 64 bit platform. We cannot use CONFIG_64BIT for this in headers that are included from user space because CONFIG symbols are not available there. We also cannot do it inside of asm/types.h because some headers need the word size but cannot include types.h. The solution is to introduce a new header <asm/bitsperlong.h> that defines both __BITS_PER_LONG for user space and BITS_PER_LONG for usage in the kernel. The asm-generic version falls back to 32 bit unless the architecture overrides it, which I did for all 64 bit platforms. Signed-off-by: Remis Lima Baima <remis.developer@googlemail.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'include/asm-generic/bitsperlong.h')
-rw-r--r--include/asm-generic/bitsperlong.h32
1 files changed, 32 insertions, 0 deletions
diff --git a/include/asm-generic/bitsperlong.h b/include/asm-generic/bitsperlong.h
new file mode 100644
index 000000000000..4ae54e07de83
--- /dev/null
+++ b/include/asm-generic/bitsperlong.h
@@ -0,0 +1,32 @@
+#ifndef __ASM_GENERIC_BITS_PER_LONG
+#define __ASM_GENERIC_BITS_PER_LONG
+
+/*
+ * There seems to be no way of detecting this automatically from user
+ * space, so 64 bit architectures should override this in their
+ * bitsperlong.h. In particular, an architecture that supports
+ * both 32 and 64 bit user space must not rely on CONFIG_64BIT
+ * to decide it, but rather check a compiler provided macro.
+ */
+#ifndef __BITS_PER_LONG
+#define __BITS_PER_LONG 32
+#endif
+
+#ifdef __KERNEL__
+
+#ifdef CONFIG_64BIT
+#define BITS_PER_LONG 64
+#else
+#define BITS_PER_LONG 32
+#endif /* CONFIG_64BIT */
+
+/*
+ * FIXME: The check currently breaks x86-64 build, so it's
+ * temporarily disabled. Please fix x86-64 and reenable
+ */
+#if 0 && BITS_PER_LONG != __BITS_PER_LONG
+#error Inconsistent word size. Check asm/bitsperlong.h
+#endif
+
+#endif /* __KERNEL__ */
+#endif /* __ASM_GENERIC_BITS_PER_LONG */