[PATCH] include: sbi: Fix BSWAPx() macros for big-endian host

[Anup Patel]

The BSWAPx() macros won't do any swapping for big-endian host
because the EXTRACT_BYTE() macro will pickup bytes in reverse
order. Also, the EXTRACT_BYTE() will generate compile error
for constants.

To fix this, we get remove the EXTRACT_BYTE() macro and re-write
BSWAPx() using simple mask and shift operations.

Fixes: 09b34d8cca51 ("include: Add support for byteorder/endianness
conversion")
Reported-by: Samuel Holland <samuel at sholland.org>
Signed-off-by: Anup Patel <apatel at ventanamicro.com>
---
 include/sbi/sbi_byteorder.h | 24 ++++++++++++++----------
 1 file changed, 14 insertions(+), 10 deletions(-)

diff --git a/include/sbi/sbi_byteorder.h b/include/sbi/sbi_byteorder.h
index 680710f..15107e1 100644
--- a/include/sbi/sbi_byteorder.h
+++ b/include/sbi/sbi_byteorder.h
@@ -9,16 +9,20 @@
 
 #include <sbi/sbi_types.h>
 
-#define EXTRACT_BYTE(x, n)	((unsigned long long)((uint8_t *)&x)[n])
-
-#define BSWAP16(x)	((EXTRACT_BYTE(x, 0) << 8) | EXTRACT_BYTE(x, 1))
-#define BSWAP32(x)	((EXTRACT_BYTE(x, 0) << 24) | (EXTRACT_BYTE(x, 1) << 16) | \
-			 (EXTRACT_BYTE(x, 2) << 8) | EXTRACT_BYTE(x, 3))
-#define BSWAP64(x)	((EXTRACT_BYTE(x, 0) << 56) | (EXTRACT_BYTE(x, 1) << 48) | \
-			 (EXTRACT_BYTE(x, 2) << 40) | (EXTRACT_BYTE(x, 3) << 32) | \
-			 (EXTRACT_BYTE(x, 4) << 24) | (EXTRACT_BYTE(x, 5) << 16) | \
-			 (EXTRACT_BYTE(x, 6) << 8) | EXTRACT_BYTE(x, 7))
-
+#define BSWAP16(x)	((((x) & 0x00ff) << 8) | \
+			 (((x) & 0xff00) >> 8))
+#define BSWAP32(x)	((((x) & 0x000000ff) << 24) | \
+			 (((x) & 0x0000ff00) << 8) | \
+			 (((x) & 0x00ff0000) >> 8) | \
+			 (((x) & 0xff000000) >> 24))
+#define BSWAP64(x)	((((x) & 0x00000000000000ffULL) << 56) | \
+			 (((x) & 0x000000000000ff00ULL) << 40) | \
+			 (((x) & 0x0000000000ff0000ULL) << 24) | \
+			 (((x) & 0x00000000ff000000ULL) << 8) | \
+			 (((x) & 0x000000ff00000000ULL) >> 8) | \
+			 (((x) & 0x0000ff0000000000ULL) >> 24) | \
+			 (((x) & 0x00ff000000000000ULL) >> 40) | \
+			 (((x) & 0xff00000000000000ULL) >> 56))
 
 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__  /* CPU(little-endian) */
 #define cpu_to_be16(x)		((uint16_t)BSWAP16(x))
-- 
2.34.1