/*
* 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 */