[Blackfin] arch: Blackfin checksum annotations

FSVOtest in this case, since I don't have the hardware...
However, all changes seen by gcc are actually
 - explicit cast to unsigned short in return expression of functions
    returning unsigned short
 - csum_fold() return type changed from unsigned int to __sum16
   (unsigned short), same as for all other architecture and as net/* expects;
   expression actually returned is ((~(sum << 16)) >> 16) with sum being
   unsigned 32bit, so it's (a) going to fit into the range of unsigned short
   and (b) had been unsigned all along, so no sign expansion mess happened.

Tested-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Miller <davem@davemloft.net>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

arch/blackfin/lib/checksum.c

@@ -72,9 +72,9 @@ static unsigned short do_csum(const unsigned char *buff, int len)
  *	This is a version of ip_compute_csum() optimized for IP headers,
  *	which always checksum on 4 octet boundaries.
  */
-unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl)
+__sum16 ip_fast_csum(unsigned char *iph, unsigned int ihl)
 {
-	return ~do_csum(iph, ihl * 4);
+	return (__force __sum16)~do_csum(iph, ihl * 4);
 }
 
 /*
@@ -89,7 +89,7 @@ unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl)
  *
  * it's best to have buff aligned on a 32-bit boundary
  */
-unsigned int csum_partial(const unsigned char *buff, int len, unsigned int sum)
+__wsum csum_partial(const void *buff, int len, __wsum sum)
 {
 	/*
 	 * Just in case we get nasty checksum data...
@@ -109,31 +109,30 @@ unsigned int csum_partial(const unsigned char *buff, int len, unsigned int sum)
  * this routine is used for miscellaneous IP-like checksums, mainly
  * in icmp.c
  */
-unsigned short ip_compute_csum(const unsigned char *buff, int len)
+__sum16 ip_compute_csum(const void *buff, int len)
 {
-	return ~do_csum(buff, len);
+	return (__force __sum16)~do_csum(buff, len);
 }
 
 /*
  * copy from fs while checksumming, otherwise like csum_partial
  */
 
-unsigned int
-csum_partial_copy_from_user(const unsigned char *src, unsigned char *dst,
-			    int len, int sum, int *csum_err)
+__wsum
+csum_partial_copy_from_user(const void __user *src, void *dst,
+			    int len, __wsum sum, int *csum_err)
 {
 	if (csum_err)
 		*csum_err = 0;
-	memcpy(dst, src, len);
+	memcpy(dst, (__force void *)src, len);
 	return csum_partial(dst, len, sum);
 }
 
 /*
  * copy from ds while checksumming, otherwise like csum_partial
  */
 
-unsigned int csum_partial_copy(const unsigned char *src, unsigned char *dst,
-			       int len, int sum)
+__wsum csum_partial_copy(const void *src, void *dst, int len, __wsum sum)
 {
 	memcpy(dst, src, len);
 	return csum_partial(dst, len, sum);

include/asm-blackfin/checksum.h

@@ -15,7 +15,7 @@
  *
  * it's best to have buff aligned on a 32-bit boundary
  */
-unsigned int csum_partial(const unsigned char *buff, int len, unsigned int sum);
+__wsum csum_partial(const void *buff, int len, __wsum sum);
 
 /*
  * the same as csum_partial, but copies from src while it
@@ -25,8 +25,8 @@ unsigned int csum_partial(const unsigned char *buff, int len, unsigned int sum);
  * better 64-bit) boundary
  */
 
-unsigned int csum_partial_copy(const unsigned char *src, unsigned char *dst,
-			       int len, int sum);
+__wsum csum_partial_copy(const void *src, void *dst,
+			       int len, __wsum sum);
 
 /*
  * the same as csum_partial_copy, but copies from user space.
@@ -35,20 +35,19 @@ unsigned int csum_partial_copy(const unsigned char *src, unsigned char *dst,
  * better 64-bit) boundary
  */
 
-extern unsigned int csum_partial_copy_from_user(const unsigned char *src,
-						unsigned char *dst, int len,
-						int sum, int *csum_err);
+extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
+					  int len, __wsum sum, int *csum_err);
 
 #define csum_partial_copy_nocheck(src, dst, len, sum)	\
 	csum_partial_copy((src), (dst), (len), (sum))
 
-unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl);
+__sum16 ip_fast_csum(unsigned char *iph, unsigned int ihl);
 
 /*
  *	Fold a partial checksum
  */
 
-static inline unsigned int csum_fold(unsigned int sum)
+static inline __sum16 csum_fold(__wsum sum)
 {
 	while (sum >> 16)
 		sum = (sum & 0xffff) + (sum >> 16);
@@ -60,9 +59,9 @@ static inline unsigned int csum_fold(unsigned int sum)
  * returns a 16-bit checksum, already complemented
  */
 
-static inline unsigned int
-csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr, unsigned short len,
-		   unsigned short proto, unsigned int sum)
+static inline __wsum
+csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
+		   unsigned short proto, __wsum sum)
 {
 
 	__asm__ ("%0 = %0 + %1;\n\t"
@@ -84,9 +83,9 @@ csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr, unsigned short len,
 	return (sum);
 }
 
-static inline unsigned short int
-csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, unsigned short len,
-		  unsigned short proto, unsigned int sum)
+static inline __sum16
+csum_tcpudp_magic(__be32 saddr, __be32 daddr, unsigned short len,
+		  unsigned short proto, __wsum sum)
 {
 	return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
 }
@@ -96,6 +95,6 @@ csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, unsigned short len,
  * in icmp.c
  */
 
-extern unsigned short ip_compute_csum(const unsigned char *buff, int len);
+extern __sum16 ip_compute_csum(const void *buff, int len);
 
 #endif				/* _BFIN_CHECKSUM_H */