[mirror_ubuntu-artful-kernel.git] / arch / x86 / lib / checksum_32.S

/*
 * INET		An implementation of the TCP/IP protocol suite for the LINUX
 *		operating system.  INET is implemented using the  BSD Socket
 *		interface as the means of communication with the user level.
 *
 *		IP/TCP/UDP checksumming routines
 *
 * Authors:	Jorge Cwik, <jorge@laser.satlink.net>
 *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
 *		Tom May, <ftom@netcom.com>
 *              Pentium Pro/II routines:
 *              Alexander Kjeldaas <astor@guardian.no>
 *              Finn Arne Gangstad <finnag@guardian.no>
 *		Lots of code moved from tcp.c and ip.c; see those files
 *		for more names.
 *
 * Changes:     Ingo Molnar, converted csum_partial_copy() to 2.1 exception
 *			     handling.
 *		Andi Kleen,  add zeroing on error
 *                   converted to pure assembler
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 */

#include <linux/linkage.h>
#include <asm/errno.h>
#include <asm/asm.h>
#include <asm/export.h>
				
/*
 * computes a partial checksum, e.g. for TCP/UDP fragments
 */

/*	
unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum)
 */
		
.text
		
#ifndef CONFIG_X86_USE_PPRO_CHECKSUM

	  /*		
	   * Experiments with Ethernet and SLIP connections show that buff
	   * is aligned on either a 2-byte or 4-byte boundary.  We get at
	   * least a twofold speedup on 486 and Pentium if it is 4-byte aligned.
	   * Fortunately, it is easy to convert 2-byte alignment to 4-byte
	   * alignment for the unrolled loop.
	   */		
ENTRY(csum_partial)
	pushl %esi
	pushl %ebx
	movl 20(%esp),%eax	# Function arg: unsigned int sum
	movl 16(%esp),%ecx	# Function arg: int len
	movl 12(%esp),%esi	# Function arg: unsigned char *buff
	testl $3, %esi		# Check alignment.
	jz 2f			# Jump if alignment is ok.
	testl $1, %esi		# Check alignment.
	jz 10f			# Jump if alignment is boundary of 2 bytes.

	# buf is odd
	dec %ecx
	jl 8f
	movzbl (%esi), %ebx
	adcl %ebx, %eax
	roll $8, %eax
	inc %esi
	testl $2, %esi
	jz 2f
10:
	subl $2, %ecx		# Alignment uses up two bytes.
	jae 1f			# Jump if we had at least two bytes.
	addl $2, %ecx		# ecx was < 2.  Deal with it.
	jmp 4f
1:	movw (%esi), %bx
	addl $2, %esi
	addw %bx, %ax
	adcl $0, %eax
2:
	movl %ecx, %edx
	shrl $5, %ecx
	jz 2f
	testl %esi, %esi
1:	movl (%esi), %ebx
	adcl %ebx, %eax
	movl 4(%esi), %ebx
	adcl %ebx, %eax
	movl 8(%esi), %ebx
	adcl %ebx, %eax
	movl 12(%esi), %ebx
	adcl %ebx, %eax
	movl 16(%esi), %ebx
	adcl %ebx, %eax
	movl 20(%esi), %ebx
	adcl %ebx, %eax
	movl 24(%esi), %ebx
	adcl %ebx, %eax
	movl 28(%esi), %ebx
	adcl %ebx, %eax
	lea 32(%esi), %esi
	dec %ecx
	jne 1b
	adcl $0, %eax
2:	movl %edx, %ecx
	andl $0x1c, %edx
	je 4f
	shrl $2, %edx		# This clears CF
3:	adcl (%esi), %eax
	lea 4(%esi), %esi
	dec %edx
	jne 3b
	adcl $0, %eax
4:	andl $3, %ecx
	jz 7f
	cmpl $2, %ecx
	jb 5f
	movw (%esi),%cx
	leal 2(%esi),%esi
	je 6f
	shll $16,%ecx
5:	movb (%esi),%cl
6:	addl %ecx,%eax
	adcl $0, %eax 
7:	
	testb $1, 12(%esp)
	jz 8f
	roll $8, %eax
8:
	popl %ebx
	popl %esi
	ret
ENDPROC(csum_partial)

#else

/* Version for PentiumII/PPro */

ENTRY(csum_partial)
	pushl %esi
	pushl %ebx
	movl 20(%esp),%eax	# Function arg: unsigned int sum
	movl 16(%esp),%ecx	# Function arg: int len
	movl 12(%esp),%esi	# Function arg:	const unsigned char *buf

	testl $3, %esi         
	jnz 25f                 
10:
	movl %ecx, %edx
	movl %ecx, %ebx
	andl $0x7c, %ebx
	shrl $7, %ecx
	addl %ebx,%esi
	shrl $2, %ebx  
	negl %ebx
	lea 45f(%ebx,%ebx,2), %ebx
	testl %esi, %esi
	jmp *%ebx

	# Handle 2-byte-aligned regions
20:	addw (%esi), %ax
	lea 2(%esi), %esi
	adcl $0, %eax
	jmp 10b
25:
	testl $1, %esi         
	jz 30f                 
	# buf is odd
	dec %ecx
	jl 90f
	movzbl (%esi), %ebx
	addl %ebx, %eax
	adcl $0, %eax
	roll $8, %eax
	inc %esi
	testl $2, %esi
	jz 10b

30:	subl $2, %ecx          
	ja 20b                 
	je 32f
	addl $2, %ecx
	jz 80f
	movzbl (%esi),%ebx	# csumming 1 byte, 2-aligned
	addl %ebx, %eax
	adcl $0, %eax
	jmp 80f
32:
	addw (%esi), %ax	# csumming 2 bytes, 2-aligned
	adcl $0, %eax
	jmp 80f

40: 
	addl -128(%esi), %eax
	adcl -124(%esi), %eax
	adcl -120(%esi), %eax
	adcl -116(%esi), %eax   
	adcl -112(%esi), %eax   
	adcl -108(%esi), %eax
	adcl -104(%esi), %eax
	adcl -100(%esi), %eax
	adcl -96(%esi), %eax
	adcl -92(%esi), %eax
	adcl -88(%esi), %eax
	adcl -84(%esi), %eax
	adcl -80(%esi), %eax
	adcl -76(%esi), %eax
	adcl -72(%esi), %eax
	adcl -68(%esi), %eax
	adcl -64(%esi), %eax     
	adcl -60(%esi), %eax     
	adcl -56(%esi), %eax     
	adcl -52(%esi), %eax   
	adcl -48(%esi), %eax   
	adcl -44(%esi), %eax
	adcl -40(%esi), %eax
	adcl -36(%esi), %eax
	adcl -32(%esi), %eax
	adcl -28(%esi), %eax
	adcl -24(%esi), %eax
	adcl -20(%esi), %eax
	adcl -16(%esi), %eax
	adcl -12(%esi), %eax
	adcl -8(%esi), %eax
	adcl -4(%esi), %eax
45:
	lea 128(%esi), %esi
	adcl $0, %eax
	dec %ecx
	jge 40b
	movl %edx, %ecx
50:	andl $3, %ecx
	jz 80f

	# Handle the last 1-3 bytes without jumping
	notl %ecx		# 1->2, 2->1, 3->0, higher bits are masked
	movl $0xffffff,%ebx	# by the shll and shrl instructions
	shll $3,%ecx
	shrl %cl,%ebx
	andl -128(%esi),%ebx	# esi is 4-aligned so should be ok
	addl %ebx,%eax
	adcl $0,%eax
80: 
	testb $1, 12(%esp)
	jz 90f
	roll $8, %eax
90: 
	popl %ebx
	popl %esi
	ret
ENDPROC(csum_partial)
				
#endif
EXPORT_SYMBOL(csum_partial)

/*
unsigned int csum_partial_copy_generic (const char *src, char *dst,
				  int len, int sum, int *src_err_ptr, int *dst_err_ptr)
 */ 

/*
 * Copy from ds while checksumming, otherwise like csum_partial
 *
 * The macros SRC and DST specify the type of access for the instruction.
 * thus we can call a custom exception handler for all access types.
 *
 * FIXME: could someone double-check whether I haven't mixed up some SRC and
 *	  DST definitions? It's damn hard to trigger all cases.  I hope I got
 *	  them all but there's no guarantee.
 */

#define SRC(y...)			\
	9999: y;			\
	_ASM_EXTABLE(9999b, 6001f)

#define DST(y...)			\
	9999: y;			\
	_ASM_EXTABLE(9999b, 6002f)

#ifndef CONFIG_X86_USE_PPRO_CHECKSUM

#define ARGBASE 16		
#define FP		12
		
ENTRY(csum_partial_copy_generic)
	subl  $4,%esp	
	pushl %edi
	pushl %esi
	pushl %ebx
	movl ARGBASE+16(%esp),%eax	# sum
	movl ARGBASE+12(%esp),%ecx	# len
	movl ARGBASE+4(%esp),%esi	# src
	movl ARGBASE+8(%esp),%edi	# dst

	testl $2, %edi			# Check alignment. 
	jz 2f				# Jump if alignment is ok.
	subl $2, %ecx			# Alignment uses up two bytes.
	jae 1f				# Jump if we had at least two bytes.
	addl $2, %ecx			# ecx was < 2.  Deal with it.
	jmp 4f
SRC(1:	movw (%esi), %bx	)
	addl $2, %esi
DST(	movw %bx, (%edi)	)
	addl $2, %edi
	addw %bx, %ax	
	adcl $0, %eax
2:
	movl %ecx, FP(%esp)
	shrl $5, %ecx
	jz 2f
	testl %esi, %esi
SRC(1:	movl (%esi), %ebx	)
SRC(	movl 4(%esi), %edx	)
	adcl %ebx, %eax
DST(	movl %ebx, (%edi)	)
	adcl %edx, %eax
DST(	movl %edx, 4(%edi)	)

SRC(	movl 8(%esi), %ebx	)
SRC(	movl 12(%esi), %edx	)
	adcl %ebx, %eax
DST(	movl %ebx, 8(%edi)	)
	adcl %edx, %eax
DST(	movl %edx, 12(%edi)	)

SRC(	movl 16(%esi), %ebx 	)
SRC(	movl 20(%esi), %edx	)
	adcl %ebx, %eax
DST(	movl %ebx, 16(%edi)	)
	adcl %edx, %eax
DST(	movl %edx, 20(%edi)	)

SRC(	movl 24(%esi), %ebx	)
SRC(	movl 28(%esi), %edx	)
	adcl %ebx, %eax
DST(	movl %ebx, 24(%edi)	)
	adcl %edx, %eax
DST(	movl %edx, 28(%edi)	)

	lea 32(%esi), %esi
	lea 32(%edi), %edi
	dec %ecx
	jne 1b
	adcl $0, %eax
2:	movl FP(%esp), %edx
	movl %edx, %ecx
	andl $0x1c, %edx
	je 4f
	shrl $2, %edx			# This clears CF
SRC(3:	movl (%esi), %ebx	)
	adcl %ebx, %eax
DST(	movl %ebx, (%edi)	)
	lea 4(%esi), %esi
	lea 4(%edi), %edi
	dec %edx
	jne 3b
	adcl $0, %eax
4:	andl $3, %ecx
	jz 7f
	cmpl $2, %ecx
	jb 5f
SRC(	movw (%esi), %cx	)
	leal 2(%esi), %esi
DST(	movw %cx, (%edi)	)
	leal 2(%edi), %edi
	je 6f
	shll $16,%ecx
SRC(5:	movb (%esi), %cl	)
DST(	movb %cl, (%edi)	)
6:	addl %ecx, %eax
	adcl $0, %eax
7:
5000:

# Exception handler:
.section .fixup, "ax"							

6001:
	movl ARGBASE+20(%esp), %ebx	# src_err_ptr
	movl $-EFAULT, (%ebx)

	# zero the complete destination - computing the rest
	# is too much work 
	movl ARGBASE+8(%esp), %edi	# dst
	movl ARGBASE+12(%esp), %ecx	# len
	xorl %eax,%eax
	rep ; stosb

	jmp 5000b

6002:
	movl ARGBASE+24(%esp), %ebx	# dst_err_ptr
	movl $-EFAULT,(%ebx)
	jmp 5000b

.previous

	popl %ebx
	popl %esi
	popl %edi
	popl %ecx			# equivalent to addl $4,%esp
	ret	
ENDPROC(csum_partial_copy_generic)

#else

/* Version for PentiumII/PPro */

#define ROUND1(x) \
	SRC(movl x(%esi), %ebx	)	;	\
	addl %ebx, %eax			;	\
	DST(movl %ebx, x(%edi)	)	; 

#define ROUND(x) \
	SRC(movl x(%esi), %ebx	)	;	\
	adcl %ebx, %eax			;	\
	DST(movl %ebx, x(%edi)	)	;

#define ARGBASE 12
		
ENTRY(csum_partial_copy_generic)
	pushl %ebx
	pushl %edi
	pushl %esi
	movl ARGBASE+4(%esp),%esi	#src
	movl ARGBASE+8(%esp),%edi	#dst	
	movl ARGBASE+12(%esp),%ecx	#len
	movl ARGBASE+16(%esp),%eax	#sum
#	movl %ecx, %edx  
	movl %ecx, %ebx  
	movl %esi, %edx
	shrl $6, %ecx     
	andl $0x3c, %ebx  
	negl %ebx
	subl %ebx, %esi  
	subl %ebx, %edi  
	lea  -1(%esi),%edx
	andl $-32,%edx
	lea 3f(%ebx,%ebx), %ebx
	testl %esi, %esi 
	jmp *%ebx
1:	addl $64,%esi
	addl $64,%edi 
	SRC(movb -32(%edx),%bl)	; SRC(movb (%edx),%bl)
	ROUND1(-64) ROUND(-60) ROUND(-56) ROUND(-52)	
	ROUND (-48) ROUND(-44) ROUND(-40) ROUND(-36)	
	ROUND (-32) ROUND(-28) ROUND(-24) ROUND(-20)	
	ROUND (-16) ROUND(-12) ROUND(-8)  ROUND(-4)	
3:	adcl $0,%eax
	addl $64, %edx
	dec %ecx
	jge 1b
4:	movl ARGBASE+12(%esp),%edx	#len
	andl $3, %edx
	jz 7f
	cmpl $2, %edx
	jb 5f
SRC(	movw (%esi), %dx         )
	leal 2(%esi), %esi
DST(	movw %dx, (%edi)         )
	leal 2(%edi), %edi
	je 6f
	shll $16,%edx
5:
SRC(	movb (%esi), %dl         )
DST(	movb %dl, (%edi)         )
6:	addl %edx, %eax
	adcl $0, %eax
7:
.section .fixup, "ax"
6001:	movl	ARGBASE+20(%esp), %ebx	# src_err_ptr	
	movl $-EFAULT, (%ebx)
	# zero the complete destination (computing the rest is too much work)
	movl ARGBASE+8(%esp),%edi	# dst
	movl ARGBASE+12(%esp),%ecx	# len
	xorl %eax,%eax
	rep; stosb
	jmp 7b
6002:	movl ARGBASE+24(%esp), %ebx	# dst_err_ptr
	movl $-EFAULT, (%ebx)
	jmp  7b			
.previous				

	popl %esi
	popl %edi
	popl %ebx
	ret
ENDPROC(csum_partial_copy_generic)
				
#undef ROUND
#undef ROUND1		
		
#endif
EXPORT_SYMBOL(csum_partial_copy_generic)
Commit	Line	Data
1da177e4 LT	1	/*
	2	* INET An implementation of the TCP/IP protocol suite for the LINUX
	3	* operating system. INET is implemented using the BSD Socket
	4	* interface as the means of communication with the user level.
	5	*
	6	* IP/TCP/UDP checksumming routines
	7	*
	8	* Authors: Jorge Cwik, <jorge@laser.satlink.net>
	9	* Arnt Gulbrandsen, <agulbra@nvg.unit.no>
	10	* Tom May, <ftom@netcom.com>
	11	* Pentium Pro/II routines:
	12	* Alexander Kjeldaas <astor@guardian.no>
	13	* Finn Arne Gangstad <finnag@guardian.no>
	14	* Lots of code moved from tcp.c and ip.c; see those files
	15	* for more names.
	16	*
	17	* Changes: Ingo Molnar, converted csum_partial_copy() to 2.1 exception
	18	* handling.
	19	* Andi Kleen, add zeroing on error
	20	* converted to pure assembler
	21	*
	22	* This program is free software; you can redistribute it and/or
	23	* modify it under the terms of the GNU General Public License
	24	* as published by the Free Software Foundation; either version
	25	* 2 of the License, or (at your option) any later version.
	26	*/
	27
00e065ea	28	#include <linux/linkage.h>
1da177e4	29	#include <asm/errno.h>
5f2e8a84	30	#include <asm/asm.h>
784d5699	31	#include <asm/export.h>
1da177e4 LT	32
	33	/*
	34	* computes a partial checksum, e.g. for TCP/UDP fragments
	35	*/
	36
	37	/*
	38	unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum)
	39	*/
	40
	41	.text
1da177e4 LT	42
	43	#ifndef CONFIG_X86_USE_PPRO_CHECKSUM
	44
	45	/*
	46	* Experiments with Ethernet and SLIP connections show that buff
	47	* is aligned on either a 2-byte or 4-byte boundary. We get at
	48	* least a twofold speedup on 486 and Pentium if it is 4-byte aligned.
	49	* Fortunately, it is easy to convert 2-byte alignment to 4-byte
	50	* alignment for the unrolled loop.
	51	*/
00e065ea	52	ENTRY(csum_partial)
131484c8 IM	53	pushl %esi
131484c8 IM	54	pushl %ebx
1da177e4 LT	55	movl 20(%esp),%eax # Function arg: unsigned int sum
	56	movl 16(%esp),%ecx # Function arg: int len
	57	movl 12(%esp),%esi # Function arg: unsigned char *buff
	58	testl $3, %esi # Check alignment.
	59	jz 2f # Jump if alignment is ok.
	60	testl $1, %esi # Check alignment.
d50ba368	61	jz 10f # Jump if alignment is boundary of 2 bytes.
1da177e4 LT	62
	63	# buf is odd
	64	dec %ecx
	65	jl 8f
	66	movzbl (%esi), %ebx
	67	adcl %ebx, %eax
	68	roll $8, %eax
	69	inc %esi
	70	testl $2, %esi
	71	jz 2f
	72	10:
	73	subl $2, %ecx # Alignment uses up two bytes.
	74	jae 1f # Jump if we had at least two bytes.
	75	addl $2, %ecx # ecx was < 2. Deal with it.
	76	jmp 4f
	77	1: movw (%esi), %bx
	78	addl $2, %esi
	79	addw %bx, %ax
	80	adcl $0, %eax
	81	2:
	82	movl %ecx, %edx
	83	shrl $5, %ecx
	84	jz 2f
	85	testl %esi, %esi
	86	1: movl (%esi), %ebx
	87	adcl %ebx, %eax
	88	movl 4(%esi), %ebx
	89	adcl %ebx, %eax
	90	movl 8(%esi), %ebx
	91	adcl %ebx, %eax
	92	movl 12(%esi), %ebx
	93	adcl %ebx, %eax
	94	movl 16(%esi), %ebx
	95	adcl %ebx, %eax
	96	movl 20(%esi), %ebx
	97	adcl %ebx, %eax
	98	movl 24(%esi), %ebx
	99	adcl %ebx, %eax
	100	movl 28(%esi), %ebx
	101	adcl %ebx, %eax
	102	lea 32(%esi), %esi
	103	dec %ecx
	104	jne 1b
	105	adcl $0, %eax
	106	2: movl %edx, %ecx
	107	andl $0x1c, %edx
	108	je 4f
	109	shrl $2, %edx # This clears CF
	110	3: adcl (%esi), %eax
	111	lea 4(%esi), %esi
	112	dec %edx
	113	jne 3b
	114	adcl $0, %eax
	115	4: andl $3, %ecx
	116	jz 7f
	117	cmpl $2, %ecx
	118	jb 5f
	119	movw (%esi),%cx
	120	leal 2(%esi),%esi
	121	je 6f
	122	shll $16,%ecx
	123	5: movb (%esi),%cl
	124	6: addl %ecx,%eax
	125	adcl $0, %eax
126	7:
3e1aa7cb	127	testb $1, 12(%esp)
1da177e4 LT	128	jz 8f
	129	roll $8, %eax
	130	8:
131484c8 IM	131	popl %ebx
131484c8 IM	132	popl %esi
1da177e4	133	ret
00e065ea	134	ENDPROC(csum_partial)
1da177e4 LT	135
	136	#else
	137
	138	/* Version for PentiumII/PPro */
	139
00e065ea	140	ENTRY(csum_partial)
131484c8 IM	141	pushl %esi
131484c8 IM	142	pushl %ebx
1da177e4 LT	143	movl 20(%esp),%eax # Function arg: unsigned int sum
	144	movl 16(%esp),%ecx # Function arg: int len
	145	movl 12(%esp),%esi # Function arg: const unsigned char *buf
	146
	147	testl $3, %esi
	148	jnz 25f
	149	10:
	150	movl %ecx, %edx
	151	movl %ecx, %ebx
	152	andl $0x7c, %ebx
	153	shrl $7, %ecx
	154	addl %ebx,%esi
	155	shrl $2, %ebx
	156	negl %ebx
	157	lea 45f(%ebx,%ebx,2), %ebx
	158	testl %esi, %esi
	159	jmp *%ebx
	160
	161	# Handle 2-byte-aligned regions
	162	20: addw (%esi), %ax
	163	lea 2(%esi), %esi
	164	adcl $0, %eax
	165	jmp 10b
	166	25:
	167	testl $1, %esi
	168	jz 30f
	169	# buf is odd
	170	dec %ecx
	171	jl 90f
	172	movzbl (%esi), %ebx
	173	addl %ebx, %eax
	174	adcl $0, %eax
	175	roll $8, %eax
	176	inc %esi
	177	testl $2, %esi
	178	jz 10b
	179
	180	30: subl $2, %ecx
	181	ja 20b
	182	je 32f
	183	addl $2, %ecx
	184	jz 80f
	185	movzbl (%esi),%ebx # csumming 1 byte, 2-aligned
	186	addl %ebx, %eax
	187	adcl $0, %eax
	188	jmp 80f
	189	32:
	190	addw (%esi), %ax # csumming 2 bytes, 2-aligned
	191	adcl $0, %eax
	192	jmp 80f
	193
	194	40:
	195	addl -128(%esi), %eax
	196	adcl -124(%esi), %eax
	197	adcl -120(%esi), %eax
	198	adcl -116(%esi), %eax
	199	adcl -112(%esi), %eax
	200	adcl -108(%esi), %eax
	201	adcl -104(%esi), %eax
	202	adcl -100(%esi), %eax
	203	adcl -96(%esi), %eax
	204	adcl -92(%esi), %eax
	205	adcl -88(%esi), %eax
	206	adcl -84(%esi), %eax
207	adcl -80(%esi), %eax
208	adcl -76(%esi), %eax
209	adcl -72(%esi), %eax
210	adcl -68(%esi), %eax
211	adcl -64(%esi), %eax
212	adcl -60(%esi), %eax
213	adcl -56(%esi), %eax
214	adcl -52(%esi), %eax
215	adcl -48(%esi), %eax
216	adcl -44(%esi), %eax
217	adcl -40(%esi), %eax
218	adcl -36(%esi), %eax
219	adcl -32(%esi), %eax
220	adcl -28(%esi), %eax
221	adcl -24(%esi), %eax
222	adcl -20(%esi), %eax
223	adcl -16(%esi), %eax
224	adcl -12(%esi), %eax
225	adcl -8(%esi), %eax
226	adcl -4(%esi), %eax
227	45:
228	lea 128(%esi), %esi
229	adcl $0, %eax
230	dec %ecx
231	jge 40b
232	movl %edx, %ecx
233	50: andl $3, %ecx
234	jz 80f
235
236	# Handle the last 1-3 bytes without jumping
237	notl %ecx # 1->2, 2->1, 3->0, higher bits are masked
238	movl $0xffffff,%ebx # by the shll and shrl instructions
239	shll $3,%ecx
240	shrl %cl,%ebx
241	andl -128(%esi),%ebx # esi is 4-aligned so should be ok
242	addl %ebx,%eax
243	adcl $0,%eax
244	80:
3e1aa7cb	245	testb $1, 12(%esp)
1da177e4 LT	246	jz 90f
	247	roll $8, %eax
	248	90:
131484c8 IM	249	popl %ebx
131484c8 IM	250	popl %esi
1da177e4	251	ret
00e065ea	252	ENDPROC(csum_partial)
1da177e4 LT	253
1da177e4 LT	254	#endif
784d5699	255	EXPORT_SYMBOL(csum_partial)
1da177e4 LT	256
	257	/*
	258	unsigned int csum_partial_copy_generic (const char src, char dst,
	259	int len, int sum, int src_err_ptr, int dst_err_ptr)
	260	*/
	261
	262	/*
	263	* Copy from ds while checksumming, otherwise like csum_partial
	264	*
	265	* The macros SRC and DST specify the type of access for the instruction.
	266	* thus we can call a custom exception handler for all access types.
	267	*
	268	* FIXME: could someone double-check whether I haven't mixed up some SRC and
	269	* DST definitions? It's damn hard to trigger all cases. I hope I got
	270	* them all but there's no guarantee.
	271	*/
	272
	273	#define SRC(y...) \
	274	9999: y; \
5f2e8a84	275	_ASM_EXTABLE(9999b, 6001f)
1da177e4 LT	276
	277	#define DST(y...) \
	278	9999: y; \
5f2e8a84	279	_ASM_EXTABLE(9999b, 6002f)
1da177e4	280
1da177e4 LT	281	#ifndef CONFIG_X86_USE_PPRO_CHECKSUM
	282
	283	#define ARGBASE 16
	284	#define FP 12
	285
00e065ea	286	ENTRY(csum_partial_copy_generic)
1da177e4	287	subl $4,%esp
131484c8 IM	288	pushl %edi
	289	pushl %esi
	290	pushl %ebx
1da177e4 LT	291	movl ARGBASE+16(%esp),%eax # sum
	292	movl ARGBASE+12(%esp),%ecx # len
	293	movl ARGBASE+4(%esp),%esi # src
	294	movl ARGBASE+8(%esp),%edi # dst
	295
	296	testl $2, %edi # Check alignment.
	297	jz 2f # Jump if alignment is ok.
	298	subl $2, %ecx # Alignment uses up two bytes.
	299	jae 1f # Jump if we had at least two bytes.
	300	addl $2, %ecx # ecx was < 2. Deal with it.
	301	jmp 4f
	302	SRC(1: movw (%esi), %bx )
	303	addl $2, %esi
	304	DST( movw %bx, (%edi) )
	305	addl $2, %edi
	306	addw %bx, %ax
	307	adcl $0, %eax
	308	2:
	309	movl %ecx, FP(%esp)
	310	shrl $5, %ecx
	311	jz 2f
	312	testl %esi, %esi
	313	SRC(1: movl (%esi), %ebx )
	314	SRC( movl 4(%esi), %edx )
	315	adcl %ebx, %eax
	316	DST( movl %ebx, (%edi) )
	317	adcl %edx, %eax
	318	DST( movl %edx, 4(%edi) )
	319
	320	SRC( movl 8(%esi), %ebx )
	321	SRC( movl 12(%esi), %edx )
	322	adcl %ebx, %eax
	323	DST( movl %ebx, 8(%edi) )
	324	adcl %edx, %eax
	325	DST( movl %edx, 12(%edi) )
	326
	327	SRC( movl 16(%esi), %ebx )
	328	SRC( movl 20(%esi), %edx )
	329	adcl %ebx, %eax
	330	DST( movl %ebx, 16(%edi) )
	331	adcl %edx, %eax
	332	DST( movl %edx, 20(%edi) )
	333
	334	SRC( movl 24(%esi), %ebx )
	335	SRC( movl 28(%esi), %edx )
	336	adcl %ebx, %eax
	337	DST( movl %ebx, 24(%edi) )
	338	adcl %edx, %eax
	339	DST( movl %edx, 28(%edi) )
	340
	341	lea 32(%esi), %esi
	342	lea 32(%edi), %edi
	343	dec %ecx
	344	jne 1b
	345	adcl $0, %eax
	346	2: movl FP(%esp), %edx
	347	movl %edx, %ecx
	348	andl $0x1c, %edx
	349	je 4f
	350	shrl $2, %edx # This clears CF
	351	SRC(3: movl (%esi), %ebx )
	352	adcl %ebx, %eax
	353	DST( movl %ebx, (%edi) )
	354	lea 4(%esi), %esi
355	lea 4(%edi), %edi
356	dec %edx
357	jne 3b
358	adcl $0, %eax
359	4: andl $3, %ecx
360	jz 7f
361	cmpl $2, %ecx
362	jb 5f
363	SRC( movw (%esi), %cx )
364	leal 2(%esi), %esi
365	DST( movw %cx, (%edi) )
366	leal 2(%edi), %edi
367	je 6f
368	shll $16,%ecx
369	SRC(5: movb (%esi), %cl )
370	DST( movb %cl, (%edi) )
371	6: addl %ecx, %eax
372	adcl $0, %eax
373	7:
374	5000:
375
376	# Exception handler:
377	.section .fixup, "ax"
378
379	6001:
380	movl ARGBASE+20(%esp), %ebx # src_err_ptr
381	movl $-EFAULT, (%ebx)
382
383	# zero the complete destination - computing the rest
384	# is too much work
385	movl ARGBASE+8(%esp), %edi # dst
386	movl ARGBASE+12(%esp), %ecx # len
387	xorl %eax,%eax
388	rep ; stosb
389
390	jmp 5000b
391
392	6002:
393	movl ARGBASE+24(%esp), %ebx # dst_err_ptr
394	movl $-EFAULT,(%ebx)
395	jmp 5000b
396
397	.previous
398
131484c8 IM	399	popl %ebx
	400	popl %esi
	401	popl %edi
	402	popl %ecx # equivalent to addl $4,%esp
1da177e4	403	ret
00e065ea	404	ENDPROC(csum_partial_copy_generic)
1da177e4 LT	405
	406	#else
	407
	408	/* Version for PentiumII/PPro */
	409
	410	#define ROUND1(x) \
	411	SRC(movl x(%esi), %ebx ) ; \
	412	addl %ebx, %eax ; \
	413	DST(movl %ebx, x(%edi) ) ;
	414
	415	#define ROUND(x) \
	416	SRC(movl x(%esi), %ebx ) ; \
	417	adcl %ebx, %eax ; \
	418	DST(movl %ebx, x(%edi) ) ;
	419
	420	#define ARGBASE 12
	421
00e065ea	422	ENTRY(csum_partial_copy_generic)
131484c8 IM	423	pushl %ebx
	424	pushl %edi
	425	pushl %esi
1da177e4 LT	426	movl ARGBASE+4(%esp),%esi #src
	427	movl ARGBASE+8(%esp),%edi #dst
	428	movl ARGBASE+12(%esp),%ecx #len
	429	movl ARGBASE+16(%esp),%eax #sum
	430	# movl %ecx, %edx
	431	movl %ecx, %ebx
	432	movl %esi, %edx
	433	shrl $6, %ecx
	434	andl $0x3c, %ebx
	435	negl %ebx
	436	subl %ebx, %esi
	437	subl %ebx, %edi
	438	lea -1(%esi),%edx
	439	andl $-32,%edx
	440	lea 3f(%ebx,%ebx), %ebx
	441	testl %esi, %esi
	442	jmp *%ebx
	443	1: addl $64,%esi
	444	addl $64,%edi
	445	SRC(movb -32(%edx),%bl) ; SRC(movb (%edx),%bl)
	446	ROUND1(-64) ROUND(-60) ROUND(-56) ROUND(-52)
	447	ROUND (-48) ROUND(-44) ROUND(-40) ROUND(-36)
	448	ROUND (-32) ROUND(-28) ROUND(-24) ROUND(-20)
	449	ROUND (-16) ROUND(-12) ROUND(-8) ROUND(-4)
	450	3: adcl $0,%eax
	451	addl $64, %edx
	452	dec %ecx
	453	jge 1b
	454	4: movl ARGBASE+12(%esp),%edx #len
	455	andl $3, %edx
	456	jz 7f
	457	cmpl $2, %edx
	458	jb 5f
	459	SRC( movw (%esi), %dx )
	460	leal 2(%esi), %esi
	461	DST( movw %dx, (%edi) )
	462	leal 2(%edi), %edi
	463	je 6f
	464	shll $16,%edx
	465	5:
	466	SRC( movb (%esi), %dl )
	467	DST( movb %dl, (%edi) )
	468	6: addl %edx, %eax
	469	adcl $0, %eax
	470	7:
	471	.section .fixup, "ax"
	472	6001: movl ARGBASE+20(%esp), %ebx # src_err_ptr
	473	movl $-EFAULT, (%ebx)
	474	# zero the complete destination (computing the rest is too much work)
	475	movl ARGBASE+8(%esp),%edi # dst
	476	movl ARGBASE+12(%esp),%ecx # len
	477	xorl %eax,%eax
	478	rep; stosb
	479	jmp 7b
	480	6002: movl ARGBASE+24(%esp), %ebx # dst_err_ptr
	481	movl $-EFAULT, (%ebx)
	482	jmp 7b
	483	.previous
	484
131484c8 IM	485	popl %esi
	486	popl %edi
	487	popl %ebx
1da177e4	488	ret
00e065ea	489	ENDPROC(csum_partial_copy_generic)
1da177e4 LT	490
	491	#undef ROUND
	492	#undef ROUND1
	493
	494	#endif
784d5699	495	EXPORT_SYMBOL(csum_partial_copy_generic)