microblaze: clean up checksum.c

This changes the function prototypes in the checksum code
to have the usual prototypes, typically by turning int
arguments into __wsum.

Also change csum_partial_copy_from_user() to operate
on the right address space and export ip_fast_csum,
which is used in modular networking code.

The new version is now sparse-clean including endianess
checks.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michal Simek <monstr@monstr.eu>

arch/microblaze/include/asm/checksum.h

@@ -51,16 +51,17 @@ extern __wsum csum_partial(const void *buff, int len, __wsum sum);
  * here even more important to align src and dst on a 32-bit (or even
  * better 64-bit) boundary
  */
-extern __wsum csum_partial_copy(const char *src, char *dst, int len, int sum);
+extern __wsum csum_partial_copy(const void *src, void *dst, int len,
+								__wsum sum);
 
 /*
  * the same as csum_partial_copy, but copies from user space.
  *
  * here even more important to align src and dst on a 32-bit (or even
  * better 64-bit) boundary
  */
-extern __wsum csum_partial_copy_from_user(const char *src, 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))
@@ -75,11 +76,12 @@ extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
 /*
  *	Fold a partial checksum
  */
-static inline __sum16 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;
 }
 
 static inline __sum16
@@ -93,6 +95,6 @@ csum_tcpudp_magic(__be32 saddr, __be32 daddr, unsigned short len,
  * this routine is used for miscellaneous IP-like checksums, mainly
  * in icmp.c
  */
-extern __sum16 ip_compute_csum(const unsigned char *buff, int len);
+extern __sum16 ip_compute_csum(const void *buff, int len);
 
 #endif /* _ASM_MICROBLAZE_CHECKSUM_H */

arch/microblaze/lib/checksum.c

@@ -32,9 +32,10 @@
 /* Revised by Kenneth Albanowski for m68knommu. Basic problem: unaligned access
  kills, so most of the assembly has to go. */
 
-#include <net/checksum.h>
-#include <asm/checksum.h>
 #include <linux/module.h>
+#include <net/checksum.h>
+
+#include <asm/byteorder.h>
 
 static inline unsigned short from32to16(unsigned long x)
 {
@@ -102,6 +103,7 @@ __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
 {
 	return (__force __sum16)~do_csum(iph, ihl*4);
 }
+EXPORT_SYMBOL(ip_fast_csum);
 
 /*
  * computes the checksum of a memory block at buff, length len,
@@ -115,38 +117,45 @@ __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
  *
  * it's best to have buff aligned on a 32-bit boundary
  */
-__wsum csum_partial(const void *buff, int len, __wsum sum)
+__wsum csum_partial(const void *buff, int len, __wsum wsum)
 {
+	unsigned int sum = (__force unsigned int)wsum;
 	unsigned int result = do_csum(buff, len);
 
 	/* add in old sum, and carry.. */
 	result += sum;
 	if (sum > result)
 		result += 1;
-	return result;
+	return (__force __wsum)result;
 }
 EXPORT_SYMBOL(csum_partial);
 
 /*
  * this routine is used for miscellaneous IP-like checksums, mainly
  * in icmp.c
  */
-__sum16 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);
 }
 EXPORT_SYMBOL(ip_compute_csum);
 
 /*
  * copy from fs while checksumming, otherwise like csum_partial
  */
 __wsum
-csum_partial_copy_from_user(const char __user *src, char *dst, int len,
-						int sum, int *csum_err)
+csum_partial_copy_from_user(const void __user *src, void *dst, int len,
+						__wsum sum, int *csum_err)
 {
-	if (csum_err)
+	int missing;
+
+	missing = __copy_from_user(dst, src, len);
+	if (missing) {
+		memset(dst + len - missing, 0, missing);
+		*csum_err = -EFAULT;
+	} else
 		*csum_err = 0;
-	memcpy(dst, src, len);
+
 	return csum_partial(dst, len, sum);
 }
 EXPORT_SYMBOL(csum_partial_copy_from_user);
@@ -155,7 +164,7 @@ EXPORT_SYMBOL(csum_partial_copy_from_user);
  * copy from ds while checksumming, otherwise like csum_partial
  */
 __wsum
-csum_partial_copy(const char *src, char *dst, int len, int sum)
+csum_partial_copy(const void *src, void *dst, int len, __wsum sum)
 {
 	memcpy(dst, src, len);
 	return csum_partial(dst, len, sum);