[PATCH v6 05/15] xen/decompressors: Remove use of *_to_cpup() helpers

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

From: Lin Liu <lin.liu@xxxxxxxxxx>

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@xxxxxxxxxx>
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Anthony PERARD <anthony.perard@xxxxxxxxxx>
CC: Michal Orzel <michal.orzel@xxxxxxx>
CC: Jan Beulich <jbeulich@xxxxxxxx>
CC: Julien Grall <julien@xxxxxxx>
CC: Roger Pau Monné <roger.pau@xxxxxxxxxx>
CC: Stefano Stabellini <sstabellini@xxxxxxxxxx>
CC: Volodymyr Babchuk <Volodymyr_Babchuk@xxxxxxxx>
CC: Bertrand Marquis <bertrand.marquis@xxxxxxx>
CC: Shawn Anastasio <sanastasio@xxxxxxxxxxxxxxxxxxxxx>
CC: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
CC: Daniel P. Smith <dpsmith@xxxxxxxxxxxxxxxxxxxx>
CC: Lin Liu <lin.liu@xxxxxxxxxx>

v6:
 * Fix lz4 and lzo1x too.

v5:
 * Rebase
 * Rearranged from other patches
---
 tools/libs/guest/xg_dom_decompress_lz4.c          | 10 ++++++++--
 tools/libs/guest/xg_dom_decompress_unsafe_lzo1x.c | 14 ++++----------
 tools/libs/guest/xg_dom_decompress_unsafe_xz.c    | 13 +++++++------
 xen/common/lz4/defs.h                             |  6 +++++-
 xen/common/unlzo.c                                | 12 ++++++++++--
 xen/common/xz/private.h                           | 12 +++++++++---
 6 files changed, 43 insertions(+), 24 deletions(-)

diff --git a/tools/libs/guest/xg_dom_decompress_lz4.c 
b/tools/libs/guest/xg_dom_decompress_lz4.c
index b26cce3ec532..53ef0bf328ed 100644
--- a/tools/libs/guest/xg_dom_decompress_lz4.c
+++ b/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"
diff --git a/tools/libs/guest/xg_dom_decompress_unsafe_lzo1x.c 
b/tools/libs/guest/xg_dom_decompress_unsafe_lzo1x.c
index e58c1b95ed17..3f6b133ccf9d 100644
--- a/tools/libs/guest/xg_dom_decompress_unsafe_lzo1x.c
+++ b/tools/libs/guest/xg_dom_decompress_unsafe_lzo1x.c
@@ -16,25 +16,19 @@ typedef uint64_t u64;
 #define noinline
 #define unlikely(a) a
 
-static inline u16 be16_to_cpup(const u16 *p)
+static inline u16 be16_to_cpu(const u16 v)
 {
-       u16 v = *p;
 #if BYTE_ORDER == LITTLE_ENDIAN
-       return (((v & 0x00ffU) << 8) |
-                ((v & 0xff00U) >> 8));
+       return __builtin_bswap16(v);
 #else
        return v;
 #endif
 }
 
-static inline u32 be32_to_cpup(const u32 *p)
+static inline u32 be32_to_cpup(const u32 v)
 {
-       u32 v = *p;
 #if BYTE_ORDER == LITTLE_ENDIAN
-       return (((v & 0x000000ffUL) << 24) |
-                ((v & 0x0000ff00UL) <<  8) |
-                ((v & 0x00ff0000UL) >>  8) |
-                ((v & 0xff000000UL) >> 24));
+       return __builtin_bswap32(v);
 #else
        return v;
 #endif
diff --git a/tools/libs/guest/xg_dom_decompress_unsafe_xz.c 
b/tools/libs/guest/xg_dom_decompress_unsafe_xz.c
index 80eed912dd68..7dbd2622c3b8 100644
--- a/tools/libs/guest/xg_dom_decompress_unsafe_xz.c
+++ b/tools/libs/guest/xg_dom_decompress_unsafe_xz.c
@@ -19,18 +19,19 @@ typedef uint32_t __le32;
 static inline u32 cpu_to_le32(const u32 v)
 {
 #if BYTE_ORDER == BIG_ENDIAN
-       return (((v & 0x000000ffUL) << 24) |
-               ((v & 0x0000ff00UL) <<  8) |
-               ((v & 0x00ff0000UL) >>  8) |
-               ((v & 0xff000000UL) >> 24));
+        return __builtin_bswap32(v);
 #else
        return v;
 #endif
 }
 
-static inline u32 le32_to_cpup(const u32 *p)
+static inline u32 le32_to_cpu(const u32 p)
 {
-       return cpu_to_le32(*p);
+#if BYTE_ORDER == BIG_ENDIAN
+        return __builtin_bswap32(v);
+#else
+       return v;
+#endif
 }
 
 #define __force
diff --git a/xen/common/lz4/defs.h b/xen/common/lz4/defs.h
index ecfbf07f8323..e477806634c1 100644
--- a/xen/common/lz4/defs.h
+++ b/xen/common/lz4/defs.h
@@ -18,7 +18,11 @@
 
 static inline u16 get_unaligned_le16(const void *p)
 {
-       return le16_to_cpup(p);
+       u16 v;
+
+       memcpy(&v, p, sizeof(v));
+
+       return le16_to_cpu(v);
 }
 
 #endif
diff --git a/xen/common/unlzo.c b/xen/common/unlzo.c
index acb8dff600fc..17efb1cc8f1d 100644
--- a/xen/common/unlzo.c
+++ b/xen/common/unlzo.c
@@ -39,12 +39,20 @@
 
 static inline u16 get_unaligned_be16(const void *p)
 {
-       return be16_to_cpup(p);
+       u16 v;
+
+       memcpy(&v, p, sizeof(v));
+
+       return be16_to_cpu(v);
 }
 
 static inline u32 get_unaligned_be32(const void *p)
 {
-       return be32_to_cpup(p);
+       u32 v;
+
+       memcpy(&v, p, sizeof(v));
+
+       return be32_to_cpu(v);
 }
 
 #endif
diff --git a/xen/common/xz/private.h b/xen/common/xz/private.h
index 2299705378ac..a63379994fd6 100644
--- a/xen/common/xz/private.h
+++ b/xen/common/xz/private.h
@@ -18,17 +18,23 @@
 
 static inline u32 get_unaligned_le32(const void *p)
 {
-       return le32_to_cpup(p);
+       u32 v;
+
+       memcpy(&v, p, sizeof(v));
+
+       return le32_to_cpu(v);
 }
 
 static inline void put_unaligned_le32(u32 val, void *p)
 {
-       *(__force __le32*)p = cpu_to_le32(val);
+       u32 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
-- 
2.39.5