arch/powerpc/lib/checksum_32.S - pub/scm/linux/kernel/git/jhogan/linux - Git at Google

 /*
  * This file contains assembly-language implementations
  * of IP-style 1's complement checksum routines.
  *
  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
  *
  *  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.
  *
  * Severely hacked about by Paul Mackerras (paulus@cs.anu.edu.au).
  */

 #include <linux/sys.h>
 #include <asm/processor.h>
 #include <asm/cache.h>
 #include <asm/errno.h>
 #include <asm/ppc_asm.h>

 	.text

 /*
  * computes the checksum of a memory block at buff, length len,
  * and adds in "sum" (32-bit)
  *
  * __csum_partial(buff, len, sum)
  */
 _GLOBAL(__csum_partial)
 	subi	r3,r3,4
 	srawi.	r6,r4,2		/* Divide len by 4 and also clear carry */
 	beq	3f		/* if we're doing < 4 bytes */
 	andi.	r0,r3,2		/* Align buffer to longword boundary */
 	beq+	1f
 	lhz	r0,4(r3)	/* do 2 bytes to get aligned */
 	subi	r4,r4,2
 	addi	r3,r3,2
 	srwi.	r6,r4,2		/* # words to do */
 	adde	r5,r5,r0
 	beq	3f
 1:	andi.	r6,r6,3		/* Prepare to handle words 4 by 4 */
 	beq	21f
 	mtctr	r6
 2:	lwzu	r0,4(r3)
 	adde	r5,r5,r0
 	bdnz	2b
 21:	srwi.	r6,r4,4		/* # blocks of 4 words to do */
 	beq	3f
 	mtctr	r6
 22:	lwz	r0,4(r3)
 	lwz	r6,8(r3)
 	lwz	r7,12(r3)
 	lwzu	r8,16(r3)
 	adde	r5,r5,r0
 	adde	r5,r5,r6
 	adde	r5,r5,r7
 	adde	r5,r5,r8
 	bdnz	22b
 3:	andi.	r0,r4,2
 	beq+	4f
 	lhz	r0,4(r3)
 	addi	r3,r3,2
 	adde	r5,r5,r0
 4:	andi.	r0,r4,1
 	beq+	5f
 	lbz	r0,4(r3)
 	slwi	r0,r0,8		/* Upper byte of word */
 	adde	r5,r5,r0
 5:	addze	r3,r5		/* add in final carry */
 	blr

 /*
  * Computes the checksum of a memory block at src, length len,
  * and adds in "sum" (32-bit), while copying the block to dst.
  * If an access exception occurs on src or dst, it stores -EFAULT
  * to *src_err or *dst_err respectively, and (for an error on
  * src) zeroes the rest of dst.
  *
  * csum_partial_copy_generic(src, dst, len, sum, src_err, dst_err)
  */
 #define CSUM_COPY_16_BYTES_WITHEX(n)	\
 8 ## n ## 0:			\
 	lwz	r7,4(r4);	\
 8 ## n ## 1:			\
 	lwz	r8,8(r4);	\
 8 ## n ## 2:			\
 	lwz	r9,12(r4);	\
 8 ## n ## 3:			\
 	lwzu	r10,16(r4);	\
 8 ## n ## 4:			\
 	stw	r7,4(r6);	\
 	adde	r12,r12,r7;	\
 8 ## n ## 5:			\
 	stw	r8,8(r6);	\
 	adde	r12,r12,r8;	\
 8 ## n ## 6:			\
 	stw	r9,12(r6);	\
 	adde	r12,r12,r9;	\
 8 ## n ## 7:			\
 	stwu	r10,16(r6);	\
 	adde	r12,r12,r10

 #define CSUM_COPY_16_BYTES_EXCODE(n)		\
 .section __ex_table,"a";		\
 	.align	2;			\
 	.long	8 ## n ## 0b,src_error;	\
 	.long	8 ## n ## 1b,src_error;	\
 	.long	8 ## n ## 2b,src_error;	\
 	.long	8 ## n ## 3b,src_error;	\
 	.long	8 ## n ## 4b,dst_error;	\
 	.long	8 ## n ## 5b,dst_error;	\
 	.long	8 ## n ## 6b,dst_error;	\
 	.long	8 ## n ## 7b,dst_error;	\
 	.text

 	.text
 	.stabs	"arch/powerpc/lib/",N_SO,0,0,0f
 	.stabs	"checksum_32.S",N_SO,0,0,0f
 0:

 CACHELINE_BYTES = L1_CACHE_BYTES
 LG_CACHELINE_BYTES = L1_CACHE_SHIFT
 CACHELINE_MASK = (L1_CACHE_BYTES-1)

 _GLOBAL(csum_partial_copy_generic)
 	stwu	r1,-16(r1)
 	stw	r7,12(r1)
 	stw	r8,8(r1)

 	rlwinm	r0,r4,3,0x8
 	rlwnm	r6,r6,r0,0,31	/* odd destination address: rotate one byte */
 	cmplwi	cr7,r0,0	/* is destination address even ? */
 	addic	r12,r6,0
 	addi	r6,r4,-4
 	neg	r0,r4
 	addi	r4,r3,-4
 	andi.	r0,r0,CACHELINE_MASK	/* # bytes to start of cache line */
 	beq	58f

 	cmplw	0,r5,r0			/* is this more than total to do? */
 	blt	63f			/* if not much to do */
 	andi.	r8,r0,3			/* get it word-aligned first */
 	mtctr	r8
 	beq+	61f
 	li	r3,0
 70:	lbz	r9,4(r4)		/* do some bytes */
 	addi	r4,r4,1
 	slwi	r3,r3,8
 	rlwimi	r3,r9,0,24,31
 71:	stb	r9,4(r6)
 	addi	r6,r6,1
 	bdnz	70b
 	adde	r12,r12,r3
 61:	subf	r5,r0,r5
 	srwi.	r0,r0,2
 	mtctr	r0
 	beq	58f
 72:	lwzu	r9,4(r4)		/* do some words */
 	adde	r12,r12,r9
 73:	stwu	r9,4(r6)
 	bdnz	72b

 58:	srwi.	r0,r5,LG_CACHELINE_BYTES /* # complete cachelines */
 	clrlwi	r5,r5,32-LG_CACHELINE_BYTES
 	li	r11,4
 	beq	63f

 	/* Here we decide how far ahead to prefetch the source */
 	li	r3,4
 	cmpwi	r0,1
 	li	r7,0
 	ble	114f
 	li	r7,1
 #if MAX_COPY_PREFETCH > 1
 	/* Heuristically, for large transfers we prefetch
 	   MAX_COPY_PREFETCH cachelines ahead.  For small transfers
 	   we prefetch 1 cacheline ahead. */
 	cmpwi	r0,MAX_COPY_PREFETCH
 	ble	112f
 	li	r7,MAX_COPY_PREFETCH
 112:	mtctr	r7
 111:	dcbt	r3,r4
 	addi	r3,r3,CACHELINE_BYTES
 	bdnz	111b
 #else
 	dcbt	r3,r4
 	addi	r3,r3,CACHELINE_BYTES
 #endif /* MAX_COPY_PREFETCH > 1 */

 114:	subf	r8,r7,r0
 	mr	r0,r7
 	mtctr	r8

 53:	dcbt	r3,r4
 54:	dcbz	r11,r6
 /* the main body of the cacheline loop */
 	CSUM_COPY_16_BYTES_WITHEX(0)
 #if L1_CACHE_BYTES >= 32
 	CSUM_COPY_16_BYTES_WITHEX(1)
 #if L1_CACHE_BYTES >= 64
 	CSUM_COPY_16_BYTES_WITHEX(2)
 	CSUM_COPY_16_BYTES_WITHEX(3)
 #if L1_CACHE_BYTES >= 128
 	CSUM_COPY_16_BYTES_WITHEX(4)
 	CSUM_COPY_16_BYTES_WITHEX(5)
 	CSUM_COPY_16_BYTES_WITHEX(6)
 	CSUM_COPY_16_BYTES_WITHEX(7)
 #endif
 #endif
 #endif
 	bdnz	53b
 	cmpwi	r0,0
 	li	r3,4
 	li	r7,0
 	bne	114b

 63:	srwi.	r0,r5,2
 	mtctr	r0
 	beq	64f
 30:	lwzu	r0,4(r4)
 	adde	r12,r12,r0
 31:	stwu	r0,4(r6)
 	bdnz	30b

 64:	andi.	r0,r5,2
 	beq+	65f
 40:	lhz	r0,4(r4)
 	addi	r4,r4,2
 41:	sth	r0,4(r6)
 	adde	r12,r12,r0
 	addi	r6,r6,2
 65:	andi.	r0,r5,1
 	beq+	66f
 50:	lbz	r0,4(r4)
 51:	stb	r0,4(r6)
 	slwi	r0,r0,8
 	adde	r12,r12,r0
 66:	addze	r3,r12
 	addi	r1,r1,16
 	beqlr+	cr7
 	rlwinm	r3,r3,8,0,31	/* odd destination address: rotate one byte */
 	blr

 /* read fault */
 src_error:
 	lwz	r7,12(r1)
 	addi	r1,r1,16
 	cmpwi	cr0,r7,0
 	beqlr
 	li	r0,-EFAULT
 	stw	r0,0(r7)
 	blr
 /* write fault */
 dst_error:
 	lwz	r8,8(r1)
 	addi	r1,r1,16
 	cmpwi	cr0,r8,0
 	beqlr
 	li	r0,-EFAULT
 	stw	r0,0(r8)
 	blr

 	.section __ex_table,"a"
 	.align	2
 	.long	70b,src_error
 	.long	71b,dst_error
 	.long	72b,src_error
 	.long	73b,dst_error
 	.long	54b,dst_error
 	.text

 /*
  * this stuff handles faults in the cacheline loop and branches to either
  * src_error (if in read part) or dst_error (if in write part)
  */
 	CSUM_COPY_16_BYTES_EXCODE(0)
 #if L1_CACHE_BYTES >= 32
 	CSUM_COPY_16_BYTES_EXCODE(1)
 #if L1_CACHE_BYTES >= 64
 	CSUM_COPY_16_BYTES_EXCODE(2)
 	CSUM_COPY_16_BYTES_EXCODE(3)
 #if L1_CACHE_BYTES >= 128
 	CSUM_COPY_16_BYTES_EXCODE(4)
 	CSUM_COPY_16_BYTES_EXCODE(5)
 	CSUM_COPY_16_BYTES_EXCODE(6)
 	CSUM_COPY_16_BYTES_EXCODE(7)
 #endif
 #endif
 #endif

 	.section __ex_table,"a"
 	.align	2
 	.long	30b,src_error
 	.long	31b,dst_error
 	.long	40b,src_error
 	.long	41b,dst_error
 	.long	50b,src_error
 	.long	51b,dst_error
	/*
	* This file contains assembly-language implementations
	* of IP-style 1's complement checksum routines.
	*
	* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
	*
	* 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.
	*
	* Severely hacked about by Paul Mackerras (paulus@cs.anu.edu.au).
	*/

	#include <linux/sys.h>
	#include <asm/processor.h>
	#include <asm/cache.h>
	#include <asm/errno.h>
	#include <asm/ppc_asm.h>

	.text

	/*
	* computes the checksum of a memory block at buff, length len,
	* and adds in "sum" (32-bit)
	*
	* __csum_partial(buff, len, sum)
	*/
	_GLOBAL(__csum_partial)
	subi r3,r3,4
	srawi. r6,r4,2 /* Divide len by 4 and also clear carry */
	beq 3f /* if we're doing < 4 bytes */
	andi. r0,r3,2 /* Align buffer to longword boundary */
	beq+ 1f
	lhz r0,4(r3) /* do 2 bytes to get aligned */
	subi r4,r4,2
	addi r3,r3,2
	srwi. r6,r4,2 /* # words to do */
	adde r5,r5,r0
	beq 3f
	1: andi. r6,r6,3 /* Prepare to handle words 4 by 4 */
	beq 21f
	mtctr r6
	2: lwzu r0,4(r3)
	adde r5,r5,r0
	bdnz 2b
	21: srwi. r6,r4,4 /* # blocks of 4 words to do */
	beq 3f
	mtctr r6
	22: lwz r0,4(r3)
	lwz r6,8(r3)
	lwz r7,12(r3)
	lwzu r8,16(r3)
	adde r5,r5,r0
	adde r5,r5,r6
	adde r5,r5,r7
	adde r5,r5,r8
	bdnz 22b
	3: andi. r0,r4,2
	beq+ 4f
	lhz r0,4(r3)
	addi r3,r3,2
	adde r5,r5,r0
	4: andi. r0,r4,1
	beq+ 5f
	lbz r0,4(r3)
	slwi r0,r0,8 /* Upper byte of word */
	adde r5,r5,r0
	5: addze r3,r5 /* add in final carry */
	blr

	/*
	* Computes the checksum of a memory block at src, length len,
	* and adds in "sum" (32-bit), while copying the block to dst.
	* If an access exception occurs on src or dst, it stores -EFAULT
	* to src_err or dst_err respectively, and (for an error on
	* src) zeroes the rest of dst.
	*
	* csum_partial_copy_generic(src, dst, len, sum, src_err, dst_err)
	*/
	#define CSUM_COPY_16_BYTES_WITHEX(n) \
	8 ## n ## 0: \
	lwz r7,4(r4); \
	8 ## n ## 1: \
	lwz r8,8(r4); \
	8 ## n ## 2: \
	lwz r9,12(r4); \
	8 ## n ## 3: \
	lwzu r10,16(r4); \
	8 ## n ## 4: \
	stw r7,4(r6); \
	adde r12,r12,r7; \
	8 ## n ## 5: \
	stw r8,8(r6); \
	adde r12,r12,r8; \
	8 ## n ## 6: \
	stw r9,12(r6); \
	adde r12,r12,r9; \
	8 ## n ## 7: \
	stwu r10,16(r6); \
	adde r12,r12,r10

	#define CSUM_COPY_16_BYTES_EXCODE(n) \
	.section __ex_table,"a"; \
	.align 2; \
	.long 8 ## n ## 0b,src_error; \
	.long 8 ## n ## 1b,src_error; \
	.long 8 ## n ## 2b,src_error; \
	.long 8 ## n ## 3b,src_error; \
	.long 8 ## n ## 4b,dst_error; \
	.long 8 ## n ## 5b,dst_error; \
	.long 8 ## n ## 6b,dst_error; \
	.long 8 ## n ## 7b,dst_error; \
	.text

	.text
	.stabs "arch/powerpc/lib/",N_SO,0,0,0f
	.stabs "checksum_32.S",N_SO,0,0,0f
	0:

	CACHELINE_BYTES = L1_CACHE_BYTES
	LG_CACHELINE_BYTES = L1_CACHE_SHIFT
	CACHELINE_MASK = (L1_CACHE_BYTES-1)

	_GLOBAL(csum_partial_copy_generic)
	stwu r1,-16(r1)
	stw r7,12(r1)
	stw r8,8(r1)

	rlwinm r0,r4,3,0x8
	rlwnm r6,r6,r0,0,31 /* odd destination address: rotate one byte */
	cmplwi cr7,r0,0 /* is destination address even ? */
	addic r12,r6,0
	addi r6,r4,-4
	neg r0,r4
	addi r4,r3,-4
	andi. r0,r0,CACHELINE_MASK /* # bytes to start of cache line */
	beq 58f

	cmplw 0,r5,r0 /* is this more than total to do? */
	blt 63f /* if not much to do */
	andi. r8,r0,3 /* get it word-aligned first */
	mtctr r8
	beq+ 61f
	li r3,0
	70: lbz r9,4(r4) /* do some bytes */
	addi r4,r4,1
	slwi r3,r3,8
	rlwimi r3,r9,0,24,31
	71: stb r9,4(r6)
	addi r6,r6,1
	bdnz 70b
	adde r12,r12,r3
	61: subf r5,r0,r5
	srwi. r0,r0,2
	mtctr r0
	beq 58f
	72: lwzu r9,4(r4) /* do some words */
	adde r12,r12,r9
	73: stwu r9,4(r6)
	bdnz 72b

	58: srwi. r0,r5,LG_CACHELINE_BYTES /* # complete cachelines */
	clrlwi r5,r5,32-LG_CACHELINE_BYTES
	li r11,4
	beq 63f

	/* Here we decide how far ahead to prefetch the source */
	li r3,4
	cmpwi r0,1
	li r7,0
	ble 114f
	li r7,1
	#if MAX_COPY_PREFETCH > 1
	/* Heuristically, for large transfers we prefetch
	MAX_COPY_PREFETCH cachelines ahead. For small transfers
	we prefetch 1 cacheline ahead. */
	cmpwi r0,MAX_COPY_PREFETCH
	ble 112f
	li r7,MAX_COPY_PREFETCH
	112: mtctr r7
	111: dcbt r3,r4
	addi r3,r3,CACHELINE_BYTES
	bdnz 111b
	#else
	dcbt r3,r4
	addi r3,r3,CACHELINE_BYTES
	#endif /* MAX_COPY_PREFETCH > 1 */

	114: subf r8,r7,r0
	mr r0,r7
	mtctr r8

	53: dcbt r3,r4
	54: dcbz r11,r6
	/* the main body of the cacheline loop */
	CSUM_COPY_16_BYTES_WITHEX(0)
	#if L1_CACHE_BYTES >= 32
	CSUM_COPY_16_BYTES_WITHEX(1)
	#if L1_CACHE_BYTES >= 64
	CSUM_COPY_16_BYTES_WITHEX(2)
	CSUM_COPY_16_BYTES_WITHEX(3)
	#if L1_CACHE_BYTES >= 128
	CSUM_COPY_16_BYTES_WITHEX(4)
	CSUM_COPY_16_BYTES_WITHEX(5)
	CSUM_COPY_16_BYTES_WITHEX(6)
	CSUM_COPY_16_BYTES_WITHEX(7)
	#endif
	#endif
	#endif
	bdnz 53b
	cmpwi r0,0
	li r3,4
	li r7,0
	bne 114b

	63: srwi. r0,r5,2
	mtctr r0
	beq 64f
	30: lwzu r0,4(r4)
	adde r12,r12,r0
	31: stwu r0,4(r6)
	bdnz 30b

	64: andi. r0,r5,2
	beq+ 65f
	40: lhz r0,4(r4)
	addi r4,r4,2
	41: sth r0,4(r6)
	adde r12,r12,r0
	addi r6,r6,2
	65: andi. r0,r5,1
	beq+ 66f
	50: lbz r0,4(r4)
	51: stb r0,4(r6)
	slwi r0,r0,8
	adde r12,r12,r0
	66: addze r3,r12
	addi r1,r1,16
	beqlr+ cr7
	rlwinm r3,r3,8,0,31 /* odd destination address: rotate one byte */
	blr

	/* read fault */
	src_error:
	lwz r7,12(r1)
	addi r1,r1,16
	cmpwi cr0,r7,0
	beqlr
	li r0,-EFAULT
	stw r0,0(r7)
	blr
	/* write fault */
	dst_error:
	lwz r8,8(r1)
	addi r1,r1,16
	cmpwi cr0,r8,0
	beqlr
	li r0,-EFAULT
	stw r0,0(r8)
	blr

	.section __ex_table,"a"
	.align 2
	.long 70b,src_error
	.long 71b,dst_error
	.long 72b,src_error
	.long 73b,dst_error
	.long 54b,dst_error
	.text

	/*
	* this stuff handles faults in the cacheline loop and branches to either
	* src_error (if in read part) or dst_error (if in write part)
	*/
	CSUM_COPY_16_BYTES_EXCODE(0)
	#if L1_CACHE_BYTES >= 32
	CSUM_COPY_16_BYTES_EXCODE(1)
	#if L1_CACHE_BYTES >= 64
	CSUM_COPY_16_BYTES_EXCODE(2)
	CSUM_COPY_16_BYTES_EXCODE(3)
	#if L1_CACHE_BYTES >= 128
	CSUM_COPY_16_BYTES_EXCODE(4)
	CSUM_COPY_16_BYTES_EXCODE(5)
	CSUM_COPY_16_BYTES_EXCODE(6)
	CSUM_COPY_16_BYTES_EXCODE(7)
	#endif
	#endif
	#endif

	.section __ex_table,"a"
	.align 2
	.long 30b,src_error
	.long 31b,dst_error
	.long 40b,src_error
	.long 41b,dst_error
	.long 50b,src_error
	.long 51b,dst_error