vserver 2.0 rc7

[linux-2.6.git] / include / asm-generic / unaligned.h

diff --git a/include/asm-generic/unaligned.h b/include/asm-generic/unaligned.h
index 57b1402..6c90f0f 100644 (file)
--- 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 */