[PATCH] crypto: crc32: add big endian CRC implementation

[Ahmad Fatoum]

This implementation is a straight copy of the tableless
implementation inside Linux' lib/crc32.c

Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 crypto/crc32.c | 12 ++++++++++++
 include/crc.h  |  1 +
 2 files changed, 13 insertions(+)

diff --git a/crypto/crc32.c b/crypto/crc32.c
index 232c023adb88..998cbc9de297 100644
--- a/crypto/crc32.c
+++ b/crypto/crc32.c
@@ -187,6 +187,18 @@ STATIC uint32_t crc32_no_comp(uint32_t crc, const void *_buf, unsigned int len)
     return crc;
 }
 
+STATIC uint32_t crc32_be(uint32_t crc, const void *_buf, unsigned int len)
+{
+	const unsigned char *buf = _buf;
+	int i;
+	while (len--) {
+		crc ^= *buf++ << 24;
+		for (i = 0; i < 8; i++)
+			crc = (crc << 1) ^ ((crc & 0x80000000) ? 0x04c11db7 : 0);
+	}
+	return crc;
+}
+
 STATIC int file_crc(char *filename, ulong start, ulong size, ulong *crc,
 		    ulong *total)
 {
diff --git a/include/crc.h b/include/crc.h
index eb972705c21a..a5204aaabb9c 100644
--- a/include/crc.h
+++ b/include/crc.h
@@ -36,6 +36,7 @@ static inline u16 crc_itu_t_byte(u16 crc, const u8 data)
 #endif
 
 uint32_t crc32(uint32_t, const void *, unsigned int);
+uint32_t crc32_be(uint32_t, const void *, unsigned int);
 uint32_t crc32_no_comp(uint32_t, const void *, unsigned int);
 int file_crc(char *filename, unsigned long start, unsigned long size,
 	     unsigned long *crc, unsigned long *total);
-- 
2.30.2