patch-2.4.20 linux-2.4.20/include/asm-x86_64/unaligned.h

• Lines: 38
• Date: Thu Nov 28 15:53:15 2002
• Orig file: linux-2.4.19/include/asm-x86_64/unaligned.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.19/include/asm-x86_64/unaligned.h linux-2.4.20/include/asm-x86_64/unaligned.h
@@ -0,0 +1,37 @@
+#ifndef __X8664_UNALIGNED_H
+#define __X8664_UNALIGNED_H
+
+/*
+ * The x86-64 can do unaligned accesses itself. 
+ *
+ * The strange macros are there to make sure these can't
+ * be misused in a way that makes them not work on other
+ * architectures where unaligned accesses aren't as simple.
+ */
+
+/**
+ * get_unaligned - get value from possibly mis-aligned location
+ * @ptr: pointer to value
+ *
+ * This macro should be used for accessing values larger in size than 
+ * single bytes at locations that are expected to be improperly aligned, 
+ * e.g. retrieving a u16 value from a location not u16-aligned.
+ *
+ * Note that unaligned accesses can be very expensive on some architectures.
+ */
+#define get_unaligned(ptr) (*(ptr))
+
+/**
+ * put_unaligned - put value to a possibly mis-aligned location
+ * @val: value to place
+ * @ptr: pointer to location
+ *
+ * This macro should be used for placing values larger in size than 
+ * single bytes at locations that are expected to be improperly aligned, 
+ * e.g. writing a u16 value to a location not u16-aligned.
+ *
+ * Note that unaligned accesses can be very expensive on some architectures.
+ */
+#define put_unaligned(val, ptr) ((void)( *(ptr) = (val) ))
+
+#endif