[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / ia64 / lib / ip_fast_csum.S

/*
 * Optmized version of the ip_fast_csum() function
 * Used for calculating IP header checksum
 *
 * Return: 16bit checksum, complemented
 *
 * Inputs:
 *      in0: address of buffer to checksum (char *)
 *      in1: length of the buffer (int)
 *
 * Copyright (C) 2002, 2006 Intel Corp.
 * Copyright (C) 2002, 2006 Ken Chen <kenneth.w.chen@intel.com>
 */

#include <asm/asmmacro.h>

/*
 * Since we know that most likely this function is called with buf aligned
 * on 4-byte boundary and 20 bytes in length, we can execution rather quickly
 * versus calling generic version of do_csum, which has lots of overhead in
 * handling various alignments and sizes.  However, due to lack of constrains
 * put on the function input argument, cases with alignment not on 4-byte or
 * size not equal to 20 bytes will be handled by the generic do_csum function.
 */

#define in0	r32
#define in1	r33
#define in2	r34
#define in3	r35
#define in4	r36
#define ret0	r8

GLOBAL_ENTRY(ip_fast_csum)
	.prologue
	.body
	cmp.ne	p6,p7=5,in1	// size other than 20 byte?
	and	r14=3,in0	// is it aligned on 4-byte?
	add	r15=4,in0	// second source pointer
	;;
	cmp.ne.or.andcm p6,p7=r14,r0
	;;
(p7)	ld4	r20=[in0],8
(p7)	ld4	r21=[r15],8
(p6)	br.spnt	.generic
	;;
	ld4	r22=[in0],8
	ld4	r23=[r15],8
	;;
	ld4	r24=[in0]
	add	r20=r20,r21
	add	r22=r22,r23
	;;
	add	r20=r20,r22
	;;
	add	r20=r20,r24
	;;
	shr.u	ret0=r20,16	// now need to add the carry
	zxt2	r20=r20
	;;
	add	r20=ret0,r20
	;;
	shr.u	ret0=r20,16	// add carry again
	zxt2	r20=r20
	;;
	add	r20=ret0,r20
	;;
	shr.u	ret0=r20,16
	zxt2	r20=r20
	;;
	add	r20=ret0,r20
	mov	r9=0xffff
	;;
	andcm	ret0=r9,r20
	.restore sp		// reset frame state
	br.ret.sptk.many b0
	;;

.generic:
	.prologue
	.save ar.pfs, r35
	alloc	r35=ar.pfs,2,2,2,0
	.save rp, r34
	mov	r34=b0
	.body
	dep.z	out1=in1,2,30
	mov	out0=in0
	;;
	br.call.sptk.many b0=do_csum
	;;
	andcm	ret0=-1,ret0
	mov	ar.pfs=r35
	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
	zxt4	in2=in2
	;;
	ld4	r22=[in0],4
	ld4	r23=[in1],4
	dep	r15=in3,in2,32,16
	;;
	ld4	r24=[in0],4
	ld4	r25=[in1],4
	mux1	r15=r15,@rev
	add	r16=r20,r21
	add	r17=r22,r23
	zxt4	in4=in4
	;;
	ld4	r26=[in0],4
	ld4	r27=[in1],4
	shr.u	r15=r15,16
	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)
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Optmized version of the ip_fast_csum() function
	3	* Used for calculating IP header checksum
	4	*
	5	* Return: 16bit checksum, complemented
	6	*
	7	* Inputs:
	8	* in0: address of buffer to checksum (char *)
	9	* in1: length of the buffer (int)
	10	*
007d77d0 KC	11	* Copyright (C) 2002, 2006 Intel Corp.
007d77d0 KC	12	* Copyright (C) 2002, 2006 Ken Chen <kenneth.w.chen@intel.com>
1da177e4 LT	13	*/
	14
	15	#include <asm/asmmacro.h>
	16
	17	/*
	18	* Since we know that most likely this function is called with buf aligned
	19	* on 4-byte boundary and 20 bytes in length, we can execution rather quickly
	20	* versus calling generic version of do_csum, which has lots of overhead in
	21	* handling various alignments and sizes. However, due to lack of constrains
	22	* put on the function input argument, cases with alignment not on 4-byte or
	23	* size not equal to 20 bytes will be handled by the generic do_csum function.
	24	*/
	25
	26	#define in0 r32
	27	#define in1 r33
007d77d0 KC	28	#define in2 r34
	29	#define in3 r35
	30	#define in4 r36
1da177e4 LT	31	#define ret0 r8
	32
	33	GLOBAL_ENTRY(ip_fast_csum)
	34	.prologue
	35	.body
	36	cmp.ne p6,p7=5,in1 // size other than 20 byte?
	37	and r14=3,in0 // is it aligned on 4-byte?
	38	add r15=4,in0 // second source pointer
	39	;;
	40	cmp.ne.or.andcm p6,p7=r14,r0
	41	;;
	42	(p7) ld4 r20=[in0],8
	43	(p7) ld4 r21=[r15],8
	44	(p6) br.spnt .generic
	45	;;
	46	ld4 r22=[in0],8
	47	ld4 r23=[r15],8
	48	;;
	49	ld4 r24=[in0]
	50	add r20=r20,r21
	51	add r22=r22,r23
	52	;;
	53	add r20=r20,r22
	54	;;
	55	add r20=r20,r24
	56	;;
	57	shr.u ret0=r20,16 // now need to add the carry
	58	zxt2 r20=r20
	59	;;
	60	add r20=ret0,r20
	61	;;
	62	shr.u ret0=r20,16 // add carry again
	63	zxt2 r20=r20
	64	;;
	65	add r20=ret0,r20
	66	;;
	67	shr.u ret0=r20,16
	68	zxt2 r20=r20
	69	;;
	70	add r20=ret0,r20
6dbfc19b	71	mov r9=0xffff
1da177e4	72	;;
6dbfc19b	73	andcm ret0=r9,r20
1da177e4 LT	74	.restore sp // reset frame state
	75	br.ret.sptk.many b0
	76	;;
	77
	78	.generic:
	79	.prologue
	80	.save ar.pfs, r35
	81	alloc r35=ar.pfs,2,2,2,0
	82	.save rp, r34
	83	mov r34=b0
	84	.body
	85	dep.z out1=in1,2,30
	86	mov out0=in0
	87	;;
	88	br.call.sptk.many b0=do_csum
	89	;;
	90	andcm ret0=-1,ret0
	91	mov ar.pfs=r35
	92	mov b0=r34
	93	br.ret.sptk.many b0
	94	END(ip_fast_csum)
007d77d0 KC	95
	96	GLOBAL_ENTRY(csum_ipv6_magic)
	97	ld4 r20=[in0],4
	98	ld4 r21=[in1],4
5afe18d2	99	zxt4 in2=in2
007d77d0 KC	100	;;
	101	ld4 r22=[in0],4
	102	ld4 r23=[in1],4
5afe18d2	103	dep r15=in3,in2,32,16
007d77d0 KC	104	;;
	105	ld4 r24=[in0],4
	106	ld4 r25=[in1],4
5afe18d2	107	mux1 r15=r15,@rev
007d77d0 KC	108	add r16=r20,r21
007d77d0 KC	109	add r17=r22,r23
5afe18d2	110	zxt4 in4=in4
007d77d0 KC	111	;;
	112	ld4 r26=[in0],4
	113	ld4 r27=[in1],4
5afe18d2	114	shr.u r15=r15,16
007d77d0 KC	115	add r18=r24,r25
	116	add r8=r16,r17
	117	;;
	118	add r19=r26,r27
	119	add r8=r8,r18
	120	;;
	121	add r8=r8,r19
	122	add r15=r15,in4
	123	;;
	124	add r8=r8,r15
	125	;;
	126	shr.u r10=r8,32 // now fold sum into short
	127	zxt4 r11=r8
	128	;;
	129	add r8=r10,r11
	130	;;
	131	shr.u r10=r8,16 // yeah, keep it rolling
	132	zxt2 r11=r8
	133	;;
	134	add r8=r10,r11
	135	;;
	136	shr.u r10=r8,16 // three times lucky
	137	zxt2 r11=r8
	138	;;
	139	add r8=r10,r11
	140	mov r9=0xffff
	141	;;
	142	andcm r8=r9,r8
	143	br.ret.sptk.many b0
	144	END(csum_ipv6_magic)