X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=include%2Fasm-generic%2Funaligned.h;h=6c90f0f36eec9990dc9f00f87454215c2acfe9c4;hb=f7f1b0f1e2fbadeab12d24236000e778aa9b1ead;hp=57b14024ca579abcb2add8a66e2cbfabaefa8028;hpb=5273a3df6485dc2ad6aa7ddd441b9a21970f003b;p=linux-2.6.git

diff --git a/include/asm-generic/unaligned.h b/include/asm-generic/unaligned.h
index 57b14024c..6c90f0f36 100644
--- a/include/asm-generic/unaligned.h
+++ b/include/asm-generic/unaligned.h
@@ -4,17 +4,119 @@
 /*
  * For the benefit of those who are trying to port Linux to another
  * architecture, here are some C-language equivalents. 
+ *
+ * This is based almost entirely upon Richard Henderson's
+ * asm-alpha/unaligned.h implementation.  Some comments were
+ * taken from David Mosberger's asm-ia64/unaligned.h header.
  */
 
-#include <asm/string.h>
-
+#include <linux/types.h>
 
+/* 
+ * The main single-value unaligned transfer routines.
+ */
 #define get_unaligned(ptr) \
-  ({ __typeof__(*(ptr)) __tmp; memcpy(&__tmp, (ptr), sizeof(*(ptr))); __tmp; })
+	((__typeof__(*(ptr)))__get_unaligned((ptr), sizeof(*(ptr))))
+#define put_unaligned(x,ptr) \
+	__put_unaligned((unsigned long)(x), (ptr), sizeof(*(ptr)))
+
+/*
+ * This function doesn't actually exist.  The idea is that when
+ * someone uses the macros below with an unsupported size (datatype),
+ * the linker will alert us to the problem via an unresolved reference
+ * error.
+ */
+extern void bad_unaligned_access_length(void) __attribute__((noreturn));
+
+struct __una_u64 { __u64 x __attribute__((packed)); };
+struct __una_u32 { __u32 x __attribute__((packed)); };
+struct __una_u16 { __u16 x __attribute__((packed)); };
+
+/*
+ * Elemental unaligned loads 
+ */
+
+static inline unsigned long __uldq(const __u64 *addr)
+{
+	const struct __una_u64 *ptr = (const struct __una_u64 *) addr;
+	return ptr->x;
+}
+
+static inline unsigned long __uldl(const __u32 *addr)
+{
+	const struct __una_u32 *ptr = (const struct __una_u32 *) addr;
+	return ptr->x;
+}
+
+static inline unsigned long __uldw(const __u16 *addr)
+{
+	const struct __una_u16 *ptr = (const struct __una_u16 *) addr;
+	return ptr->x;
+}
+
+/*
+ * Elemental unaligned stores 
+ */
+
+static inline void __ustq(__u64 val, __u64 *addr)
+{
+	struct __una_u64 *ptr = (struct __una_u64 *) addr;
+	ptr->x = val;
+}
+
+static inline void __ustl(__u32 val, __u32 *addr)
+{
+	struct __una_u32 *ptr = (struct __una_u32 *) addr;
+	ptr->x = val;
+}
+
+static inline void __ustw(__u16 val, __u16 *addr)
+{
+	struct __una_u16 *ptr = (struct __una_u16 *) addr;
+	ptr->x = val;
+}
+
+#define __get_unaligned(ptr, size) ({		\
+	const void *__gu_p = ptr;		\
+	unsigned long val;			\
+	switch (size) {				\
+	case 1:					\
+		val = *(const __u8 *)__gu_p;	\
+		break;				\
+	case 2:					\
+		val = __uldw(__gu_p);		\
+		break;				\
+	case 4:					\
+		val = __uldl(__gu_p);		\
+		break;				\
+	case 8:					\
+		val = __uldq(__gu_p);		\
+		break;				\
+	default:				\
+		bad_unaligned_access_length();	\
+	};					\
+	val;					\
+})
 
-#define put_unaligned(val, ptr)				\
-  ({ __typeof__(*(ptr)) __tmp = (val);			\
-     memcpy((ptr), &__tmp, sizeof(*(ptr)));		\
-     (void)0; })
+#define __put_unaligned(val, ptr, size)		\
+do {						\
+	void *__gu_p = ptr;			\
+	switch (size) {				\
+	case 1:					\
+		*(__u8 *)__gu_p = val;		\
+	        break;				\
+	case 2:					\
+		__ustw(val, __gu_p);		\
+		break;				\
+	case 4:					\
+		__ustl(val, __gu_p);		\
+		break;				\
+	case 8:					\
+		__ustq(val, __gu_p);		\
+		break;				\
+	default:				\
+	    	bad_unaligned_access_length();	\
+	};					\
+} while(0)
 
 #endif /* _ASM_GENERIC_UNALIGNED_H */