[SPARC64]: Fix missing fold at end of checksums.

Both csum_partial() and the csum_partial_copy*() family of routines
forget to do a final fold on the computed checksum value on sparc64.
So do the standard Sparc "add + set condition codes, add carry"
sequence, then make sure the high 32-bits of the return value are
clear.

Based upon some excellent detective work and debugging done by
Richard Braun and Samuel Thibault.

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 6 insertions, 4 deletions

diff --git a/arch/sparc64/lib/checksum.S b/arch/sparc64/lib/checksum.S
index ba9cd3ccc2b2..1d230f693dc4 100644
--- a/arch/sparc64/lib/checksum.S
+++ b/arch/sparc64/lib/checksum.S
@@ -165,8 +165,9 @@ csum_partial_end_cruft:
         sll             %g1, 8, %g1
         or              %o5, %g1, %o4
 
-1:      add             %o2, %o4, %o2
+1:      addcc           %o2, %o4, %o2
+        addc            %g0, %o2, %o2
 
 csum_partial_finish:
         retl
-         mov            %o2, %o0
+         srl            %o2, 0, %o0
diff --git a/arch/sparc64/lib/csum_copy.S b/arch/sparc64/lib/csum_copy.S
index 71af48839064..e566c770a0f6 100644
--- a/arch/sparc64/lib/csum_copy.S
+++ b/arch/sparc64/lib/csum_copy.S
@@ -221,11 +221,12 @@ FUNC_NAME:		/* %o0=src, %o1=dst, %o2=len, %o3=sum */
         sll             %g1, 8, %g1
         or              %o5, %g1, %o4
 
-1:      add             %o3, %o4, %o3
+1:      addcc           %o3, %o4, %o3
+        addc            %g0, %o3, %o3
 
 70:
         retl
-         mov            %o3, %o0
+         srl            %o3, 0, %o0
 
 95:     mov             0, GLOBAL_SPARE
         brlez,pn        %o2, 4f