1 files changed, 121 insertions, 0 deletions

diff --git a/include/asm-generic/unaligned.h b/include/asm-generic/unaligned.h
new file mode 100644
index 000000000000..c856a43e3b45
--- /dev/null
+++ b/include/asm-generic/unaligned.h
@@ -0,0 +1,121 @@
+#ifndef _ASM_GENERIC_UNALIGNED_H_
+#define _ASM_GENERIC_UNALIGNED_H_
+
+/*
+ * 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 <linux/types.h>
+
+/* 
+ * The main single-value unaligned transfer routines.
+ */
+#define get_unaligned(ptr) \
+        ((__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;
+}
+
+static inline unsigned long __get_unaligned(const void *ptr, size_t size)
+{
+        unsigned long val;
+        switch (size) {
+        case 1:
+                val = *(const __u8 *)ptr;
+                break;
+        case 2:
+                val = __uldw((const __u16 *)ptr);
+                break;
+        case 4:
+                val = __uldl((const __u32 *)ptr);
+                break;
+        case 8:
+                val = __uldq((const __u64 *)ptr);
+                break;
+        default:
+                bad_unaligned_access_length();
+        };
+        return val;
+}
+
+static inline void __put_unaligned(unsigned long val, void *ptr, size_t size)
+{
+        switch (size) {
+        case 1:
+                *(__u8 *)ptr = val;
+                break;
+        case 2:
+                __ustw(val, (__u16 *)ptr);
+                break;
+        case 4:
+                __ustl(val, (__u32 *)ptr);
+                break;
+        case 8:
+                __ustq(val, (__u64 *)ptr);
+                break;
+        default:
+                bad_unaligned_access_length();
+        };
+}
+
+#endif /* _ASM_GENERIC_UNALIGNED_H */