[PATCH] include: sbi: fix swap errors with newer gcc -Werror=sequence-point

[Ben Dooks]

The BSWAPxx() macros are now throwing the following warnings with
newer gcc versions. This is due to throwing an argument in that may
be evaluated more than one (I think) and therefore things like the
example below should be avoided.

Fix by making a set of BSWAPxx() wrappers which specifically onlt
evaluate 'x' once.

In file included lib/sbi/sbi_mpxy.c:21:
lib/sbi/sbi_mpxy.c: In function ‘sbi_mpxy_write_attrs’:
ib/sbi/sbi_mpxy.c:632:63: error: operation on ‘mem_idx’ may be undefined [-Werror=sequence-point]
  632 |                         attr_val = le32_to_cpu(mem_ptr[mem_idx++]);
      |                                                        ~~~~~~~^~

Signed-off-by: Ben Dooks <ben.dooks at codethink.co.uk>
---
 include/sbi/sbi_byteorder.h | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/include/sbi/sbi_byteorder.h b/include/sbi/sbi_byteorder.h
index 2b4981e..ed7cad1 100644
--- a/include/sbi/sbi_byteorder.h
+++ b/include/sbi/sbi_byteorder.h
@@ -14,13 +14,13 @@
 # define _conv_cast(type, val) ((type)(val))
 #endif
 
-#define BSWAP16(x)	((((x) & 0x00ff) << 8) | \
+#define __BSWAP16(x)	((((x) & 0x00ff) << 8) | \
 			 (((x) & 0xff00) >> 8))
-#define BSWAP32(x)	((((x) & 0x000000ff) << 24) | \
+#define __BSWAP32(x)	((((x) & 0x000000ff) << 24) | \
 			 (((x) & 0x0000ff00) << 8) | \
 			 (((x) & 0x00ff0000) >> 8) | \
 			 (((x) & 0xff000000) >> 24))
-#define BSWAP64(x)	((((x) & 0x00000000000000ffULL) << 56) | \
+#define __BSWAP64(x)	((((x) & 0x00000000000000ffULL) << 56) | \
 			 (((x) & 0x000000000000ff00ULL) << 40) | \
 			 (((x) & 0x0000000000ff0000ULL) << 24) | \
 			 (((x) & 0x00000000ff000000ULL) << 8) | \
@@ -29,6 +29,10 @@
 			 (((x) & 0x00ff000000000000ULL) >> 40) | \
 			 (((x) & 0xff00000000000000ULL) >> 56))
 
+#define BSWAP64(x) ({ uint64_t _sv = (x); __BSWAP64(_sv); })
+#define BSWAP32(x) ({ uint32_t _sv = (x); __BSWAP32(_sv); })
+#define BSWAP16(x) ({ uint16_t _sv = (x); __BSWAP16(_sv); })
+
 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__  /* CPU(little-endian) */
 #define cpu_to_be16(x)		_conv_cast(uint16_t, BSWAP16(x))
 #define cpu_to_be32(x)		_conv_cast(uint32_t, BSWAP32(x))
-- 
2.37.2.352.g3c44437643