[IA64] implement csum_ipv6_magic for ia64.

The asm version is 4.4 times faster than the generic C version and
10X smaller in code size.

Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 53 insertions, 2 deletions

diff --git a/arch/ia64/lib/ip_fast_csum.S b/arch/ia64/lib/ip_fast_csum.S
index 19674ca2acf..4fb132ee207 100644
--- a/arch/ia64/lib/ip_fast_csum.S
+++ b/arch/ia64/lib/ip_fast_csum.S
@@ -8,8 +8,8 @@
  *      in0: address of buffer to checksum (char *)
  *      in1: length of the buffer (int)
  *
- * Copyright (C) 2002 Intel Corp.
- * Copyright (C) 2002 Ken Chen <kenneth.w.chen@intel.com>
+ * Copyright (C) 2002, 2006 Intel Corp.
+ * Copyright (C) 2002, 2006 Ken Chen <kenneth.w.chen@intel.com>
  */
 
 #include <asm/asmmacro.h>
@@ -25,6 +25,9 @@
 
 #define in0     r32
 #define in1     r33
+#define in2     r34
+#define in3     r35
+#define in4     r36
 #define ret0    r8
 
 GLOBAL_ENTRY(ip_fast_csum)
@@ -88,3 +91,51 @@ GLOBAL_ENTRY(ip_fast_csum)
         mov     b0=r34
         br.ret.sptk.many b0
 END(ip_fast_csum)
+
+GLOBAL_ENTRY(csum_ipv6_magic)
+        ld4     r20=[in0],4
+        ld4     r21=[in1],4
+        dep     r15=in3,in2,32,16
+        ;;
+        ld4     r22=[in0],4
+        ld4     r23=[in1],4
+        mux1    r15=r15,@rev
+        ;;
+        ld4     r24=[in0],4
+        ld4     r25=[in1],4
+        shr.u   r15=r15,16
+        add     r16=r20,r21
+        add     r17=r22,r23
+        ;;
+        ld4     r26=[in0],4
+        ld4     r27=[in1],4
+        add     r18=r24,r25
+        add     r8=r16,r17
+        ;;
+        add     r19=r26,r27
+        add     r8=r8,r18
+        ;;
+        add     r8=r8,r19
+        add     r15=r15,in4
+        ;;
+        add     r8=r8,r15
+        ;;
+        shr.u   r10=r8,32       // now fold sum into short
+        zxt4    r11=r8
+        ;;
+        add     r8=r10,r11
+        ;;
+        shr.u   r10=r8,16       // yeah, keep it rolling
+        zxt2    r11=r8
+        ;;
+        add     r8=r10,r11
+        ;;
+        shr.u   r10=r8,16       // three times lucky
+        zxt2    r11=r8
+        ;;
+        add     r8=r10,r11
+        mov     r9=0xffff
+        ;;
+        andcm   r8=r9,r8
+        br.ret.sptk.many b0
+END(csum_ipv6_magic)