[PATCH 1/7] byteorder: replace __u16

[Jan Beulich <jbeulich@xxxxxxxx>]

In {big,little}_endian.h the changes are entirely mechanical, except for
dealing with casting away of const from pointers-to-const on lines
touched anyway.

In swab.h the casting of constants is done away with as well - I simply
don't see what the respective comment is concerned about in our
environment (sizeof(int) >= 4, sizeof(long) >= {4,8} depending on
architecture, sizeof(long long) >= 8). The comment is certainly relevant
in more general cases. Excess parentheses are dropped as well,
___swab16()'s local variable is renamed, and __arch__swab16()'s is
dropped as being redundant with ___swab16()'s.

With that no uses of the type remain, so it moves to linux-compat.h.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
---
I'm unconvinced of the need of the separate ___constant_swab16(). I'm
also unconvinced of the need for said constants (that even had casts on
them).

--- a/xen/include/xen/byteorder/big_endian.h
+++ b/xen/include/xen/byteorder/big_endian.h
@@ -16,25 +16,25 @@
 #define __constant_cpu_to_le32(x) ((__force __le32)___constant_swab32((x)))
 #define __constant_le32_to_cpu(x) ___constant_swab32((__force 
__u32)(__le32)(x))
 #define __constant_cpu_to_le16(x) ((__force __le16)___constant_swab16((x)))
-#define __constant_le16_to_cpu(x) ___constant_swab16((__force 
__u16)(__le16)(x))
+#define __constant_le16_to_cpu(x) ___constant_swab16((__force 
uint16_t)(__le16)(x))
 #define __constant_cpu_to_be64(x) ((__force __be64)(__u64)(x))
 #define __constant_be64_to_cpu(x) ((__force __u64)(__be64)(x))
 #define __constant_cpu_to_be32(x) ((__force __be32)(__u32)(x))
 #define __constant_be32_to_cpu(x) ((__force __u32)(__be32)(x))
-#define __constant_cpu_to_be16(x) ((__force __be16)(__u16)(x))
-#define __constant_be16_to_cpu(x) ((__force __u16)(__be16)(x))
+#define __constant_cpu_to_be16(x) ((__force __be16)(uint16_t)(x))
+#define __constant_be16_to_cpu(x) ((__force uint16_t)(__be16)(x))
 #define __cpu_to_le64(x) ((__force __le64)__swab64((x)))
 #define __le64_to_cpu(x) __swab64((__force __u64)(__le64)(x))
 #define __cpu_to_le32(x) ((__force __le32)__swab32((x)))
 #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
 #define __cpu_to_le16(x) ((__force __le16)__swab16((x)))
-#define __le16_to_cpu(x) __swab16((__force __u16)(__le16)(x))
+#define __le16_to_cpu(x) __swab16((__force uint16_t)(__le16)(x))
 #define __cpu_to_be64(x) ((__force __be64)(__u64)(x))
 #define __be64_to_cpu(x) ((__force __u64)(__be64)(x))
 #define __cpu_to_be32(x) ((__force __be32)(__u32)(x))
 #define __be32_to_cpu(x) ((__force __u32)(__be32)(x))
-#define __cpu_to_be16(x) ((__force __be16)(__u16)(x))
-#define __be16_to_cpu(x) ((__force __u16)(__be16)(x))
+#define __cpu_to_be16(x) ((__force __be16)(uint16_t)(x))
+#define __be16_to_cpu(x) ((__force uint16_t)(__be16)(x))
 
 static inline __le64 __cpu_to_le64p(const __u64 *p)
 {
@@ -52,13 +52,13 @@ static inline __u32 __le32_to_cpup(const
 {
     return __swab32p((__u32 *)p);
 }
-static inline __le16 __cpu_to_le16p(const __u16 *p)
+static inline __le16 __cpu_to_le16p(const uint16_t *p)
 {
     return (__force __le16)__swab16p(p);
 }
-static inline __u16 __le16_to_cpup(const __le16 *p)
+static inline uint16_t __le16_to_cpup(const __le16 *p)
 {
-    return __swab16p((__u16 *)p);
+    return __swab16p((const uint16_t *)p);
 }
 static inline __be64 __cpu_to_be64p(const __u64 *p)
 {
@@ -76,13 +76,13 @@ static inline __u32 __be32_to_cpup(const
 {
     return (__force __u32)*p;
 }
-static inline __be16 __cpu_to_be16p(const __u16 *p)
+static inline __be16 __cpu_to_be16p(const uint16_t *p)
 {
     return (__force __be16)*p;
 }
-static inline __u16 __be16_to_cpup(const __be16 *p)
+static inline uint16_t __be16_to_cpup(const __be16 *p)
 {
-    return (__force __u16)*p;
+    return (__force uint16_t)*p;
 }
 #define __cpu_to_le64s(x) __swab64s((x))
 #define __le64_to_cpus(x) __swab64s((x))
--- a/xen/include/xen/byteorder/little_endian.h
+++ b/xen/include/xen/byteorder/little_endian.h
@@ -15,26 +15,26 @@
 #define __constant_le64_to_cpu(x) ((__force __u64)(__le64)(x))
 #define __constant_cpu_to_le32(x) ((__force __le32)(__u32)(x))
 #define __constant_le32_to_cpu(x) ((__force __u32)(__le32)(x))
-#define __constant_cpu_to_le16(x) ((__force __le16)(__u16)(x))
-#define __constant_le16_to_cpu(x) ((__force __u16)(__le16)(x))
+#define __constant_cpu_to_le16(x) ((__force __le16)(uint16_t)(x))
+#define __constant_le16_to_cpu(x) ((__force uint16_t)(__le16)(x))
 #define __constant_cpu_to_be64(x) ((__force __be64)___constant_swab64((x)))
 #define __constant_be64_to_cpu(x) ___constant_swab64((__force 
__u64)(__be64)(x))
 #define __constant_cpu_to_be32(x) ((__force __be32)___constant_swab32((x)))
 #define __constant_be32_to_cpu(x) ___constant_swab32((__force 
__u32)(__be32)(x))
 #define __constant_cpu_to_be16(x) ((__force __be16)___constant_swab16((x)))
-#define __constant_be16_to_cpu(x) ___constant_swab16((__force 
__u16)(__be16)(x))
+#define __constant_be16_to_cpu(x) ___constant_swab16((__force 
uint16_t)(__be16)(x))
 #define __cpu_to_le64(x) ((__force __le64)(__u64)(x))
 #define __le64_to_cpu(x) ((__force __u64)(__le64)(x))
 #define __cpu_to_le32(x) ((__force __le32)(__u32)(x))
 #define __le32_to_cpu(x) ((__force __u32)(__le32)(x))
-#define __cpu_to_le16(x) ((__force __le16)(__u16)(x))
-#define __le16_to_cpu(x) ((__force __u16)(__le16)(x))
+#define __cpu_to_le16(x) ((__force __le16)(uint16_t)(x))
+#define __le16_to_cpu(x) ((__force uint16_t)(__le16)(x))
 #define __cpu_to_be64(x) ((__force __be64)__swab64((x)))
 #define __be64_to_cpu(x) __swab64((__force __u64)(__be64)(x))
 #define __cpu_to_be32(x) ((__force __be32)__swab32((x)))
 #define __be32_to_cpu(x) __swab32((__force __u32)(__be32)(x))
 #define __cpu_to_be16(x) ((__force __be16)__swab16((x)))
-#define __be16_to_cpu(x) __swab16((__force __u16)(__be16)(x))
+#define __be16_to_cpu(x) __swab16((__force uint16_t)(__be16)(x))
 
 static inline __le64 __cpu_to_le64p(const __u64 *p)
 {
@@ -52,13 +52,13 @@ static inline __u32 __le32_to_cpup(const
 {
     return (__force __u32)*p;
 }
-static inline __le16 __cpu_to_le16p(const __u16 *p)
+static inline __le16 __cpu_to_le16p(const uint16_t *p)
 {
     return (__force __le16)*p;
 }
-static inline __u16 __le16_to_cpup(const __le16 *p)
+static inline uint16_t __le16_to_cpup(const __le16 *p)
 {
-    return (__force __u16)*p;
+    return (__force uint16_t)*p;
 }
 static inline __be64 __cpu_to_be64p(const __u64 *p)
 {
@@ -76,13 +76,13 @@ static inline __u32 __be32_to_cpup(const
 {
     return __swab32p((__u32 *)p);
 }
-static inline __be16 __cpu_to_be16p(const __u16 *p)
+static inline __be16 __cpu_to_be16p(const uint16_t *p)
 {
     return (__force __be16)__swab16p(p);
 }
-static inline __u16 __be16_to_cpup(const __be16 *p)
+static inline uint16_t __be16_to_cpup(const __be16 *p)
 {
-    return __swab16p((__u16 *)p);
+    return __swab16p((const uint16_t *)p);
 }
 #define __cpu_to_le64s(x) do {} while (0)
 #define __le64_to_cpus(x) do {} while (0)
--- a/xen/include/xen/byteorder/swab.h
+++ b/xen/include/xen/byteorder/swab.h
@@ -10,15 +10,16 @@
  *    to clean up support for bizarre-endian architectures.
  */
 
-/* casts are necessary for constants, because we never know how for sure
- * how U/UL/ULL map to __u16, __u32, __u64. At least not in a portable way.
+/*
+ * Casts are necessary for constants, because we never know for sure how
+ * U/UL/ULL map to __u32, __u64. At least not in a portable way.
  */
 #define ___swab16(x)                                    \
 ({                                                      \
-    __u16 __x = (x);                                    \
-    ((__u16)(                                           \
-        (((__u16)(__x) & (__u16)0x00ffU) << 8) |        \
-        (((__u16)(__x) & (__u16)0xff00U) >> 8) ));      \
+    uint16_t x_ = (x);                                  \
+    (uint16_t)(                                         \
+        (((uint16_t)(x_) & 0x00ffU) << 8) |             \
+        (((uint16_t)(x_) & 0xff00U) >> 8));             \
 })
 
 #define ___swab32(x)                                            \
@@ -46,9 +47,9 @@
 })
 
 #define ___constant_swab16(x)                   \
-    ((__u16)(                                   \
-        (((__u16)(x) & (__u16)0x00ffU) << 8) |  \
-        (((__u16)(x) & (__u16)0xff00U) >> 8) ))
+    ((uint16_t)(                                \
+        (((uint16_t)(x) & 0x00ffU) << 8) |      \
+        (((uint16_t)(x) & 0xff00U) >> 8)))
 #define ___constant_swab32(x)                           \
     ((__u32)(                                           \
         (((__u32)(x) & (__u32)0x000000ffUL) << 24) |    \
@@ -70,7 +71,7 @@
  * provide defaults when no architecture-specific optimization is detected
  */
 #ifndef __arch__swab16
-#  define __arch__swab16(x) ({ __u16 __tmp = (x) ; ___swab16(__tmp); })
+#  define __arch__swab16(x) ___swab16(x)
 #endif
 #ifndef __arch__swab32
 #  define __arch__swab32(x) ({ __u32 __tmp = (x) ; ___swab32(__tmp); })
@@ -105,7 +106,7 @@
  */
 #if defined(__GNUC__) && defined(__OPTIMIZE__)
 #  define __swab16(x) \
-(__builtin_constant_p((__u16)(x)) ? \
+(__builtin_constant_p((uint16_t)(x)) ? \
  ___swab16((x)) : \
  __fswab16((x)))
 #  define __swab32(x) \
@@ -123,15 +124,15 @@
 #endif /* OPTIMIZE */
 
 
-static inline attr_const __u16 __fswab16(__u16 x)
+static inline attr_const uint16_t __fswab16(uint16_t x)
 {
     return __arch__swab16(x);
 }
-static inline __u16 __swab16p(const __u16 *x)
+static inline uint16_t __swab16p(const uint16_t *x)
 {
     return __arch__swab16p(x);
 }
-static inline void __swab16s(__u16 *addr)
+static inline void __swab16s(uint16_t *addr)
 {
     __arch__swab16s(addr);
 }
--- a/xen/include/xen/linux-compat.h
+++ b/xen/include/xen/linux-compat.h
@@ -14,6 +14,7 @@
 typedef int8_t  s8, __s8;
 typedef uint8_t __u8;
 typedef int16_t s16, __s16;
+typedef uint16_t __u16;
 typedef int32_t s32, __s32;
 typedef int64_t s64, __s64;
 
--- a/xen/include/xen/types.h
+++ b/xen/include/xen/types.h
@@ -6,7 +6,7 @@
 
 /* Linux inherited types which are being phased out */
 typedef uint8_t u8;
-typedef uint16_t u16, __u16;
+typedef uint16_t u16;
 typedef uint32_t u32, __u32;
 typedef uint64_t u64, __u64;
 
@@ -51,8 +51,8 @@ typedef __PTRDIFF_TYPE__ ptrdiff_t;
 #define LONG_MIN        (-LONG_MAX - 1)
 #define ULONG_MAX       (~0UL)
 
-typedef __u16 __le16;
-typedef __u16 __be16;
+typedef uint16_t __le16;
+typedef uint16_t __be16;
 typedef __u32 __le32;
 typedef __u32 __be32;
 typedef __u64 __le64;