xnu-4570.1.46.tar.gz

[apple/xnu.git] / libkern / libkern / arm / OSByteOrder.h

diff --git a/libkern/libkern/arm/OSByteOrder.h b/libkern/libkern/arm/OSByteOrder.h
new file mode 100644 (file)
index 0000000..81279a1
--- /dev/null
+++ b/libkern/libkern/arm/OSByteOrder.h
@@ -0,0 +1,147 @@
+/*
+ * Copyright (c) 1999-2007 Apple Inc. All rights reserved.
+ */
+
+#ifndef _OS_OSBYTEORDERARM_H
+#define _OS_OSBYTEORDERARM_H
+
+#include <stdint.h>
+#include <arm/arch.h> /* for _ARM_ARCH_6 */
+#include <sys/_types/_os_inline.h>
+
+/* Generic byte swapping functions. */
+
+OS_INLINE
+uint16_t
+_OSSwapInt16(
+    uint16_t        data
+)
+{
+  /* Reduces to 'rev16' with clang */
+  return (uint16_t)(data << 8 | data >> 8);
+}
+
+OS_INLINE
+uint32_t
+_OSSwapInt32(
+    uint32_t        data
+)
+{
+#if defined(__llvm__)
+  data = __builtin_bswap32(data);
+#else
+  /* This actually generates the best code */
+  data = (((data ^ (data >> 16 | (data << 16))) & 0xFF00FFFF) >> 8) ^ (data >> 8 | data << 24);
+#endif
+  
+  return data;
+}
+
+OS_INLINE
+uint64_t
+_OSSwapInt64(
+    uint64_t        data
+)
+{
+#if defined(__llvm__)
+    return __builtin_bswap64(data);
+#else
+    union {
+        uint64_t ull;
+        uint32_t ul[2];
+    } u;
+
+    /* This actually generates the best code */
+    u.ul[0] = (uint32_t)(data >> 32);
+    u.ul[1] = (uint32_t)(data & 0xffffffff);
+    u.ul[0] = _OSSwapInt32(u.ul[0]);
+    u.ul[1] = _OSSwapInt32(u.ul[1]);
+    return u.ull;
+#endif
+}
+
+/* Functions for byte reversed loads. */
+
+OS_INLINE
+uint16_t
+OSReadSwapInt16(
+    const volatile void   * base,
+    uintptr_t       offset
+)
+{
+    uint16_t result;
+
+    result = *(volatile uint16_t *)((volatile uintptr_t)base + offset);
+    return _OSSwapInt16(result);
+}
+
+OS_INLINE
+uint32_t
+OSReadSwapInt32(
+    const volatile void   * base,
+    uintptr_t       offset
+)
+{
+    uint32_t result;
+
+    result = *(volatile uint32_t *)((volatile uintptr_t)base + offset);
+    return _OSSwapInt32(result);
+}
+
+OS_INLINE
+uint64_t
+OSReadSwapInt64(
+    const volatile void   * base,
+    uintptr_t       offset
+)
+{
+    volatile uint32_t * inp;
+    union ullc {
+        uint64_t     ull;
+        uint32_t     ul[2];
+    } outv;
+
+    inp = (volatile uint32_t *)((volatile uintptr_t)base + offset);
+    outv.ul[0] = inp[1];
+    outv.ul[1] = inp[0];
+    outv.ul[0] = _OSSwapInt32(outv.ul[0]);
+    outv.ul[1] = _OSSwapInt32(outv.ul[1]);
+    return outv.ull;
+}
+
+/* Functions for byte reversed stores. */
+
+OS_INLINE
+void
+OSWriteSwapInt16(
+    volatile void   * base,
+    uintptr_t       offset,
+    uint16_t        data
+)
+{
+    *(volatile uint16_t *)((volatile uintptr_t)base + offset) = _OSSwapInt16(data);
+}
+
+OS_INLINE
+void
+OSWriteSwapInt32(
+    volatile void   * base,
+    uintptr_t       offset,
+    uint32_t        data
+)
+{
+    *(volatile uint32_t *)((volatile uintptr_t)base + offset) = _OSSwapInt32(data);
+}
+
+OS_INLINE
+void
+OSWriteSwapInt64(
+    volatile void    * base,
+    uintptr_t        offset,
+    uint64_t         data
+)
+{
+    *(volatile uint64_t *)((volatile uintptr_t)base + offset) = _OSSwapInt64(data);
+}
+
+#endif /* ! _OS_OSBYTEORDERARM_H */