[NET]: Alpha checksum annotations and cleanups.

* sanitize prototypes and annotate
* kill useless access_ok() in csum_partial_copy_from_user() (the only
caller checks it already).
* do_csum_partial_copy_from_user() is not needed now
* replace htons(len) with len << 8 - they are the same wrt checksums
on little-endian.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/alpha/lib/checksum.c

@@ -41,28 +41,25 @@ static inline unsigned short from64to16(unsigned long x)
  * computes the checksum of the TCP/UDP pseudo-header
  * returns a 16-bit checksum, already complemented.
  */
-unsigned short int csum_tcpudp_magic(unsigned long saddr,
-				   unsigned long daddr,
+__sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
 				   unsigned short len,
 				   unsigned short proto,
-				   unsigned int sum)
+				   __wsum sum)
 {
-	return ~from64to16(saddr + daddr + sum +
-		((unsigned long) ntohs(len) << 16) +
-		((unsigned long) proto << 8));
+	return (__force __sum16)~from64to16(
+		(__force u64)saddr + (__force u64)daddr +
+		(__force u64)sum + ((len + proto) << 8));
 }
 
-unsigned int csum_tcpudp_nofold(unsigned long saddr,
-				   unsigned long daddr,
+__wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
 				   unsigned short len,
 				   unsigned short proto,
-				   unsigned int sum)
+				   __wsum sum)
 {
 	unsigned long result;
 
-	result = (saddr + daddr + sum +
-		  ((unsigned long) ntohs(len) << 16) +
-		  ((unsigned long) proto << 8));
+	result = (__force u64)saddr + (__force u64)daddr +
+		 (__force u64)sum + ((len + proto) << 8);
 
 	/* Fold down to 32-bits so we don't lose in the typedef-less 
 	   network stack.  */
@@ -70,7 +67,7 @@ unsigned int csum_tcpudp_nofold(unsigned long saddr,
 	result = (result & 0xffffffff) + (result >> 32);
 	/* 33 to 32 */
 	result = (result & 0xffffffff) + (result >> 32);
-	return result;
+	return (__force __wsum)result;
 }
 
 /*
@@ -146,9 +143,9 @@ out:
  *	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(const void *iph, unsigned int ihl)
 {
-	return ~do_csum(iph,ihl*4);
+	return (__force __sum16)~do_csum(iph,ihl*4);
 }
 
 /*
@@ -163,15 +160,15 @@ 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)
 {
 	unsigned long result = do_csum(buff, len);
 
 	/* add in old sum, and carry.. */
-	result += sum;
+	result += (__force u32)sum;
 	/* 32+c bits -> 32 bits */
 	result = (result & 0xffffffff) + (result >> 32);
-	return result;
+	return (__force __wsum)result;
 }
 
 EXPORT_SYMBOL(csum_partial);
@@ -180,7 +177,7 @@ EXPORT_SYMBOL(csum_partial);
  * this routine is used for miscellaneous IP-like checksums, mainly
  * in icmp.c
  */
-unsigned short ip_compute_csum(unsigned char * buff, int len)
+__sum16 ip_compute_csum(const void *buff, int len)
 {
-	return ~from64to16(do_csum(buff,len));
+	return (__force __sum16)~from64to16(do_csum(buff,len));
 }

arch/alpha/lib/csum_partial_copy.c

@@ -329,11 +329,11 @@ csum_partial_cfu_unaligned(const unsigned long __user * src,
 	return checksum;
 }
 
-static unsigned int
-do_csum_partial_copy_from_user(const char __user *src, char *dst, int len,
-			       unsigned int sum, int *errp)
+__wsum
+csum_partial_copy_from_user(const void __user *src, void *dst, int len,
+			       __wsum sum, int *errp)
 {
-	unsigned long checksum = (unsigned) sum;
+	unsigned long checksum = (__force u32) sum;
 	unsigned long soff = 7 & (unsigned long) src;
 	unsigned long doff = 7 & (unsigned long) dst;
 
@@ -367,25 +367,12 @@ do_csum_partial_copy_from_user(const char __user *src, char *dst, int len,
 		}
 		checksum = from64to16 (checksum);
 	}
-	return checksum;
-}
-
-unsigned int
-csum_partial_copy_from_user(const char __user *src, char *dst, int len,
-			    unsigned int sum, int *errp)
-{
-	if (!access_ok(VERIFY_READ, src, len)) {
-		*errp = -EFAULT;
-		memset(dst, 0, len);
-		return sum;
-	}
-
-	return do_csum_partial_copy_from_user(src, dst, len, sum, errp);
+	return (__force __wsum)checksum;
 }
 
-unsigned int
-csum_partial_copy_nocheck(const char __user *src, char *dst, int len,
-			  unsigned int sum)
+__wsum
+csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
 {
-	return do_csum_partial_copy_from_user(src, dst, len, sum, NULL);
+	return csum_partial_copy_from_user((__force const void __user *)src,
+			dst, len, sum, NULL);
 }

include/asm-alpha/checksum.h

@@ -7,21 +7,20 @@
  *	This is a version of ip_compute_csum() optimized for IP headers,
  *	which always checksum on 4 octet boundaries.
  */
-extern unsigned short ip_fast_csum(unsigned char * iph, unsigned int ihl);
+extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
 
 /*
  * computes the checksum of the TCP/UDP pseudo-header
  * returns a 16-bit checksum, already complemented
  */
-extern unsigned short int csum_tcpudp_magic(unsigned long saddr,
-					   unsigned long daddr,
+extern __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
 					   unsigned short len,
 					   unsigned short proto,
-					   unsigned int sum);
+					   __wsum sum);
 
-unsigned int csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr,
+__wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
 				unsigned short len, unsigned short proto,
-				unsigned int sum);
+				__wsum sum);
 
 /*
  * computes the checksum of a memory block at buff, length len,
@@ -35,7 +34,7 @@ unsigned int csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr,
  *
  * it's best to have buff aligned on a 32-bit boundary
  */
-extern unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum);
+extern __wsum csum_partial(const void *buff, int len, __wsum sum);
 
 /*
  * the same as csum_partial, but copies from src while it
@@ -44,9 +43,9 @@ extern unsigned int csum_partial(const unsigned char * buff, int len, unsigned i
  * here even more important to align src and dst on a 32-bit (or even
  * better 64-bit) boundary
  */
-unsigned int csum_partial_copy_from_user(const char __user *src, char *dst, int len, unsigned int sum, int *errp);
+__wsum csum_partial_copy_from_user(const void __user *src, void *dst, int len, __wsum sum, int *errp);
 
-unsigned int csum_partial_copy_nocheck(const char *src, char *dst, int len, unsigned int sum);
+__wsum csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum);
 
 
 /*
@@ -54,24 +53,23 @@ unsigned int csum_partial_copy_nocheck(const char *src, char *dst, int len, unsi
  * in icmp.c
  */
 
-extern unsigned short ip_compute_csum(unsigned char * buff, int len);
+extern __sum16 ip_compute_csum(const void *buff, int len);
 
 /*
  *	Fold a partial checksum without adding pseudo headers
  */
 
-static inline unsigned short csum_fold(unsigned int sum)
+static inline __sum16 csum_fold(__wsum csum)
 {
+	u32 sum = (__force u32)csum;
 	sum = (sum & 0xffff) + (sum >> 16);
 	sum = (sum & 0xffff) + (sum >> 16);
-	return ~sum;
+	return (__force __sum16)~sum;
 }
 
 #define _HAVE_ARCH_IPV6_CSUM
-extern unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
-                                          struct in6_addr *daddr,
-                                          __u32 len,
-                                          unsigned short proto,
-                                          unsigned int sum);
-
+extern __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
+			       const struct in6_addr *daddr,
+			       __u32 len, unsigned short proto,
+			       __wsum sum);
 #endif