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Subject[RFC PATCH] kernel: add byteorder macros with alignment fixups
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A common pattern in the kernel (especially networking) is:

le32_to_cpu(get_unaligned((__le32 *)x));

Repeat for various combinations of le/be and 64/32/16 bit. Add
a variant that operates on possibly unaligned pointers to
byteorder/generic.h

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
---
include/linux/byteorder/generic.h | 16 ++++++++++++++++
1 files changed, 16 insertions(+), 0 deletions(-)
diff --git a/include/linux/byteorder/generic.h b/include/linux/byteorder/generic.h
index d377155..9b1a7a4 100644
--- a/include/linux/byteorder/generic.h
+++ b/include/linux/byteorder/generic.h
@@ -73,6 +73,10 @@
* cpu_to_[bl]eXXp(__uXX x)
* [bl]eXX_to_cpup(__uXX x)
*
+ * The same, but takes a possibly unaligned pointer to the value to convert
+ * cpu_to_[bl]eXXp_un(__uXX x)
+ * [bl]eXX_to_cpup_un(__uXX x)
+ *
* The same, but change in situ
* cpu_to_[bl]eXXs(__uXX x)
* [bl]eXX_to_cpus(__uXX x)
@@ -84,6 +88,8 @@


#if defined(__KERNEL__)
+#include <asm/unaligned.h>
+
/*
* inside the kernel, we can use nicknames;
* outside of it, we must avoid POSIX namespace pollution...
@@ -126,6 +132,16 @@
#define be16_to_cpus __be16_to_cpus

/*
+ * Operates on possibly unaligned pointers
+ */
+#define le64_to_cpup_un(x) __le64_to_cpu(get_unaligned((__le64 *)(x)))
+#define le32_to_cpup_un(x) __le32_to_cpu(get_unaligned((__le32 *)(x)))
+#define le16_to_cpup_un(x) __le16_to_cpu(get_unaligned((__le16 *)(x)))
+#define be64_to_cpup_un(x) __be64_to_cpu(get_unaligned((__be64 *)(x)))
+#define be32_to_cpup_un(x) __be32_to_cpu(get_unaligned((__be32 *)(x)))
+#define be16_to_cpup_un(x) __be16_to_cpu(get_unaligned((__be16 *)(x)))
+
+/*
* They have to be macros in order to do the constant folding
* correctly - if the argument passed into a inline function
* it is no longer constant according to gcc..
--
1.5.4.4.684.g0e08




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