xen/decompressors: Remove use of *_to_cpup() helpers

These wrappers simply hide a deference, which adds to the cognitive complexity
of reading the code.  As such, they're not going to be included in the new
byteswap infrastructure.

No functional change.

Signed-off-by: Lin Liu <lin.liu@citrix.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

tools/libs/guest/xg_dom_decompress_lz4.c

@@ -3,6 +3,8 @@
 #include <inttypes.h>
 #include <stdint.h>
 
+#include INCLUDE_ENDIAN_H
+
 #define XG_NEED_UNALIGNED
 #include "xg_private.h"
 #include "xg_dom_decompress.h"
@@ -17,9 +19,13 @@ typedef uint64_t u64;
 #define likely(a) a
 #define unlikely(a) a
 
-static inline uint_fast16_t le16_to_cpup(const unsigned char *buf)
+static inline uint16_t le16_to_cpu(uint16_t v)
 {
-    return buf[0] | (buf[1] << 8);
+#if BYTE_ORDER == BIG_ENDIAN
+    return __builtin_bswap16(v);
+#else
+    return v;
+#endif
 }
 
 #include "../../xen/include/xen/lz4.h"

tools/libs/guest/xg_dom_decompress_unsafe_lzo1x.c

@@ -16,25 +16,10 @@ typedef uint64_t u64;
 #define noinline
 #define unlikely(a) a
 
-static inline u16 be16_to_cpup(const u16 *p)
+static inline uint16_t be16_to_cpu(const uint16_t v)
 {
-	u16 v = *p;
 #if BYTE_ORDER == LITTLE_ENDIAN
-	return (((v & 0x00ffU) << 8) |
+	return __builtin_bswap16(v);
-                ((v & 0xff00U) >> 8));
-#else
-	return v;
-#endif
-}
-
-static inline u32 be32_to_cpup(const u32 *p)
-{
-	u32 v = *p;
-#if BYTE_ORDER == LITTLE_ENDIAN
-	return (((v & 0x000000ffUL) << 24) |
-                ((v & 0x0000ff00UL) <<  8) |
-                ((v & 0x00ff0000UL) >>  8) |
-                ((v & 0xff000000UL) >> 24));
 #else
 	return v;
 #endif

tools/libs/guest/xg_dom_decompress_unsafe_xz.c

@@ -16,21 +16,22 @@ typedef uint16_t u16;
 typedef uint32_t u32;
 typedef uint32_t __le32;
 
-static inline u32 cpu_to_le32(const u32 v)
+static inline uint32_t cpu_to_le32(const uint32_t v)
 {
 #if BYTE_ORDER == BIG_ENDIAN
-	return (((v & 0x000000ffUL) << 24) |
+	return __builtin_bswap32(v);
-	        ((v & 0x0000ff00UL) <<  8) |
-	        ((v & 0x00ff0000UL) >>  8) |
-	        ((v & 0xff000000UL) >> 24));
 #else
 	return v;
 #endif
 }
 
-static inline u32 le32_to_cpup(const u32 *p)
+static inline uint32_t le32_to_cpu(const uint32_t p)
 {
-	return cpu_to_le32(*p);
+#if BYTE_ORDER == BIG_ENDIAN
+	return __builtin_bswap32(v);
+#else
+	return v;
+#endif
 }
 
 #define __force

xen/common/lz4/defs.h

@@ -16,9 +16,13 @@
 #include <xen/unaligned.h>
 #else
 
-static inline u16 get_unaligned_le16(const void *p)
+static inline uint16_t get_unaligned_le16(const void *p)
 {
-	return le16_to_cpup(p);
+	uint16_t v;
+
+	memcpy(&v, p, sizeof(v));
+
+	return le16_to_cpu(v);
 }
 
 #endif

xen/common/unlzo.c

@@ -37,14 +37,22 @@
 #include <xen/unaligned.h>
 #else
 
-static inline u16 get_unaligned_be16(const void *p)
+static inline uint16_t get_unaligned_be16(const void *p)
 {
-	return be16_to_cpup(p);
+	uint16_t v;
+
+	memcpy(&v, p, sizeof(v));
+
+	return be16_to_cpu(v);
 }
 
-static inline u32 get_unaligned_be32(const void *p)
+static inline uint32_t get_unaligned_be32(const void *p)
 {
-	return be32_to_cpup(p);
+	uint32_t v;
+
+	memcpy(&v, p, sizeof(v));
+
+	return be32_to_cpu(v);
 }
 
 #endif

xen/common/xz/private.h

@@ -16,19 +16,25 @@
 #include <xen/unaligned.h>
 #else
 
-static inline u32 get_unaligned_le32(const void *p)
+static inline uint32_t get_unaligned_le32(const void *p)
 {
-	return le32_to_cpup(p);
+	uint32_t v;
+
+	memcpy(&v, p, sizeof(v));
+
+	return le32_to_cpu(v);
 }
 
-static inline void put_unaligned_le32(u32 val, void *p)
+static inline void put_unaligned_le32(uint32_t val, void *p)
 {
-	*(__force __le32*)p = cpu_to_le32(val);
+	uint32_t v = cpu_to_le32(val);
+
+	memcpy(p, &v, sizeof(v));
 }
 
 #endif
 
-#define get_le32(p) le32_to_cpup((const uint32_t *)(p))
+#define get_le32(p) le32_to_cpu(*(const uint32_t *)(p))
 
 #define false 0
 #define true 1