Commit 007d77d0 authored by Kenneth W Chen's avatar Kenneth W Chen Committed by Tony Luck
Browse files

[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: default avatarKen Chen <kenneth.w.chen@intel.com>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent 5b4d5681

arch/ia64/lib/ip_fast_csum.S

+53 −2
Original line number Diff line number Diff line
@@ -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)

include/asm-ia64/checksum.h

+6 −0
Original line number Diff line number Diff line
@@ -70,4 +70,10 @@ static inline __sum16 csum_fold(__wsum csum) 
	return (__force __sum16)~sum;

}



#define _HAVE_ARCH_IPV6_CSUM	1

struct in6_addr;

extern unsigned short int csum_ipv6_magic(struct in6_addr *saddr,

	struct in6_addr *daddr, __u32 len, unsigned short proto,

	unsigned int csum);



#endif /* _ASM_IA64_CHECKSUM_H */