70d65cd555
... and get rid of the pointless fallback in the wrappers. On error it used to zero the unwritten area and calculate the csum of the entire thing. Not wanting to do it in assembler part had been very reasonable; doing that in the first place, OTOH... In case of an error the caller discards the data we'd copied, along with whatever checksum it might've had. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
444 lines
8.0 KiB
ArmAsm
444 lines
8.0 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0-or-later */
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/*
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* This file contains assembly-language implementations
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* of IP-style 1's complement checksum routines.
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*
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* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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*
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* Severely hacked about by Paul Mackerras (paulus@cs.anu.edu.au).
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*/
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#include <linux/sys.h>
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#include <asm/processor.h>
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#include <asm/errno.h>
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#include <asm/ppc_asm.h>
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#include <asm/export.h>
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/*
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* Computes the checksum of a memory block at buff, length len,
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* and adds in "sum" (32-bit).
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*
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* __csum_partial(r3=buff, r4=len, r5=sum)
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*/
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_GLOBAL(__csum_partial)
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addic r0,r5,0 /* clear carry */
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srdi. r6,r4,3 /* less than 8 bytes? */
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beq .Lcsum_tail_word
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/*
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* If only halfword aligned, align to a double word. Since odd
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* aligned addresses should be rare and they would require more
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* work to calculate the correct checksum, we ignore that case
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* and take the potential slowdown of unaligned loads.
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*/
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rldicl. r6,r3,64-1,64-2 /* r6 = (r3 >> 1) & 0x3 */
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beq .Lcsum_aligned
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li r7,4
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sub r6,r7,r6
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mtctr r6
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1:
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lhz r6,0(r3) /* align to doubleword */
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subi r4,r4,2
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addi r3,r3,2
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adde r0,r0,r6
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bdnz 1b
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.Lcsum_aligned:
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/*
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* We unroll the loop such that each iteration is 64 bytes with an
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* entry and exit limb of 64 bytes, meaning a minimum size of
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* 128 bytes.
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*/
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srdi. r6,r4,7
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beq .Lcsum_tail_doublewords /* len < 128 */
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srdi r6,r4,6
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subi r6,r6,1
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mtctr r6
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stdu r1,-STACKFRAMESIZE(r1)
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std r14,STK_REG(R14)(r1)
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std r15,STK_REG(R15)(r1)
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std r16,STK_REG(R16)(r1)
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ld r6,0(r3)
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ld r9,8(r3)
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ld r10,16(r3)
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ld r11,24(r3)
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/*
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* On POWER6 and POWER7 back to back adde instructions take 2 cycles
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* because of the XER dependency. This means the fastest this loop can
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* go is 16 cycles per iteration. The scheduling of the loop below has
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* been shown to hit this on both POWER6 and POWER7.
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*/
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.align 5
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2:
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adde r0,r0,r6
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ld r12,32(r3)
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ld r14,40(r3)
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adde r0,r0,r9
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ld r15,48(r3)
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ld r16,56(r3)
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addi r3,r3,64
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adde r0,r0,r10
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adde r0,r0,r11
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adde r0,r0,r12
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adde r0,r0,r14
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adde r0,r0,r15
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ld r6,0(r3)
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ld r9,8(r3)
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adde r0,r0,r16
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ld r10,16(r3)
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ld r11,24(r3)
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bdnz 2b
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adde r0,r0,r6
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ld r12,32(r3)
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ld r14,40(r3)
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adde r0,r0,r9
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ld r15,48(r3)
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ld r16,56(r3)
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addi r3,r3,64
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adde r0,r0,r10
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adde r0,r0,r11
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adde r0,r0,r12
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adde r0,r0,r14
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adde r0,r0,r15
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adde r0,r0,r16
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ld r14,STK_REG(R14)(r1)
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ld r15,STK_REG(R15)(r1)
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ld r16,STK_REG(R16)(r1)
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addi r1,r1,STACKFRAMESIZE
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andi. r4,r4,63
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.Lcsum_tail_doublewords: /* Up to 127 bytes to go */
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srdi. r6,r4,3
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beq .Lcsum_tail_word
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mtctr r6
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3:
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ld r6,0(r3)
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addi r3,r3,8
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adde r0,r0,r6
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bdnz 3b
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andi. r4,r4,7
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.Lcsum_tail_word: /* Up to 7 bytes to go */
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srdi. r6,r4,2
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beq .Lcsum_tail_halfword
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lwz r6,0(r3)
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addi r3,r3,4
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adde r0,r0,r6
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subi r4,r4,4
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.Lcsum_tail_halfword: /* Up to 3 bytes to go */
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srdi. r6,r4,1
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beq .Lcsum_tail_byte
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lhz r6,0(r3)
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addi r3,r3,2
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adde r0,r0,r6
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subi r4,r4,2
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.Lcsum_tail_byte: /* Up to 1 byte to go */
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andi. r6,r4,1
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beq .Lcsum_finish
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lbz r6,0(r3)
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#ifdef __BIG_ENDIAN__
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sldi r9,r6,8 /* Pad the byte out to 16 bits */
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adde r0,r0,r9
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#else
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adde r0,r0,r6
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#endif
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.Lcsum_finish:
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addze r0,r0 /* add in final carry */
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rldicl r4,r0,32,0 /* fold two 32 bit halves together */
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add r3,r4,r0
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srdi r3,r3,32
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blr
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EXPORT_SYMBOL(__csum_partial)
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.macro srcnr
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100:
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EX_TABLE(100b,.Lerror_nr)
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.endm
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.macro source
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150:
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EX_TABLE(150b,.Lerror)
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.endm
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.macro dstnr
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200:
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EX_TABLE(200b,.Lerror_nr)
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.endm
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.macro dest
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250:
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EX_TABLE(250b,.Lerror)
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.endm
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/*
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* Computes the checksum of a memory block at src, length len,
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* and adds in 0xffffffff (32-bit), while copying the block to dst.
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* If an access exception occurs, it returns 0.
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*
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* csum_partial_copy_generic(r3=src, r4=dst, r5=len)
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*/
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_GLOBAL(csum_partial_copy_generic)
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li r6,-1
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addic r0,r6,0 /* clear carry */
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srdi. r6,r5,3 /* less than 8 bytes? */
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beq .Lcopy_tail_word
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/*
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* If only halfword aligned, align to a double word. Since odd
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* aligned addresses should be rare and they would require more
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* work to calculate the correct checksum, we ignore that case
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* and take the potential slowdown of unaligned loads.
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*
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* If the source and destination are relatively unaligned we only
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* align the source. This keeps things simple.
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*/
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rldicl. r6,r3,64-1,64-2 /* r6 = (r3 >> 1) & 0x3 */
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beq .Lcopy_aligned
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li r9,4
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sub r6,r9,r6
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mtctr r6
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1:
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srcnr; lhz r6,0(r3) /* align to doubleword */
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subi r5,r5,2
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addi r3,r3,2
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adde r0,r0,r6
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dstnr; sth r6,0(r4)
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addi r4,r4,2
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bdnz 1b
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.Lcopy_aligned:
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/*
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* We unroll the loop such that each iteration is 64 bytes with an
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* entry and exit limb of 64 bytes, meaning a minimum size of
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* 128 bytes.
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*/
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srdi. r6,r5,7
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beq .Lcopy_tail_doublewords /* len < 128 */
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srdi r6,r5,6
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subi r6,r6,1
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mtctr r6
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stdu r1,-STACKFRAMESIZE(r1)
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std r14,STK_REG(R14)(r1)
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std r15,STK_REG(R15)(r1)
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std r16,STK_REG(R16)(r1)
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source; ld r6,0(r3)
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source; ld r9,8(r3)
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source; ld r10,16(r3)
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source; ld r11,24(r3)
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/*
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* On POWER6 and POWER7 back to back adde instructions take 2 cycles
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* because of the XER dependency. This means the fastest this loop can
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* go is 16 cycles per iteration. The scheduling of the loop below has
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* been shown to hit this on both POWER6 and POWER7.
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*/
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.align 5
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2:
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adde r0,r0,r6
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source; ld r12,32(r3)
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source; ld r14,40(r3)
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adde r0,r0,r9
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source; ld r15,48(r3)
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source; ld r16,56(r3)
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addi r3,r3,64
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adde r0,r0,r10
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dest; std r6,0(r4)
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dest; std r9,8(r4)
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adde r0,r0,r11
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dest; std r10,16(r4)
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dest; std r11,24(r4)
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adde r0,r0,r12
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dest; std r12,32(r4)
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dest; std r14,40(r4)
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adde r0,r0,r14
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dest; std r15,48(r4)
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dest; std r16,56(r4)
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addi r4,r4,64
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adde r0,r0,r15
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source; ld r6,0(r3)
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source; ld r9,8(r3)
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adde r0,r0,r16
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source; ld r10,16(r3)
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source; ld r11,24(r3)
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bdnz 2b
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adde r0,r0,r6
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source; ld r12,32(r3)
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source; ld r14,40(r3)
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adde r0,r0,r9
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source; ld r15,48(r3)
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source; ld r16,56(r3)
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addi r3,r3,64
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adde r0,r0,r10
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dest; std r6,0(r4)
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dest; std r9,8(r4)
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adde r0,r0,r11
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dest; std r10,16(r4)
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dest; std r11,24(r4)
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adde r0,r0,r12
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dest; std r12,32(r4)
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dest; std r14,40(r4)
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adde r0,r0,r14
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dest; std r15,48(r4)
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dest; std r16,56(r4)
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addi r4,r4,64
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adde r0,r0,r15
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adde r0,r0,r16
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ld r14,STK_REG(R14)(r1)
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ld r15,STK_REG(R15)(r1)
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ld r16,STK_REG(R16)(r1)
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addi r1,r1,STACKFRAMESIZE
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andi. r5,r5,63
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.Lcopy_tail_doublewords: /* Up to 127 bytes to go */
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srdi. r6,r5,3
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beq .Lcopy_tail_word
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mtctr r6
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3:
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srcnr; ld r6,0(r3)
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addi r3,r3,8
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adde r0,r0,r6
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dstnr; std r6,0(r4)
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addi r4,r4,8
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bdnz 3b
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andi. r5,r5,7
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.Lcopy_tail_word: /* Up to 7 bytes to go */
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srdi. r6,r5,2
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beq .Lcopy_tail_halfword
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srcnr; lwz r6,0(r3)
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addi r3,r3,4
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adde r0,r0,r6
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dstnr; stw r6,0(r4)
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addi r4,r4,4
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subi r5,r5,4
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.Lcopy_tail_halfword: /* Up to 3 bytes to go */
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srdi. r6,r5,1
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beq .Lcopy_tail_byte
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srcnr; lhz r6,0(r3)
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addi r3,r3,2
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adde r0,r0,r6
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dstnr; sth r6,0(r4)
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addi r4,r4,2
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subi r5,r5,2
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.Lcopy_tail_byte: /* Up to 1 byte to go */
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andi. r6,r5,1
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beq .Lcopy_finish
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srcnr; lbz r6,0(r3)
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#ifdef __BIG_ENDIAN__
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sldi r9,r6,8 /* Pad the byte out to 16 bits */
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adde r0,r0,r9
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#else
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adde r0,r0,r6
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#endif
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dstnr; stb r6,0(r4)
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.Lcopy_finish:
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addze r0,r0 /* add in final carry */
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rldicl r4,r0,32,0 /* fold two 32 bit halves together */
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add r3,r4,r0
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srdi r3,r3,32
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blr
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.Lerror:
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ld r14,STK_REG(R14)(r1)
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ld r15,STK_REG(R15)(r1)
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ld r16,STK_REG(R16)(r1)
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addi r1,r1,STACKFRAMESIZE
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.Lerror_nr:
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li r3,0
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blr
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EXPORT_SYMBOL(csum_partial_copy_generic)
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/*
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* __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
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* const struct in6_addr *daddr,
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* __u32 len, __u8 proto, __wsum sum)
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*/
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_GLOBAL(csum_ipv6_magic)
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ld r8, 0(r3)
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ld r9, 8(r3)
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add r5, r5, r6
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addc r0, r8, r9
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ld r10, 0(r4)
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ld r11, 8(r4)
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#ifdef CONFIG_CPU_LITTLE_ENDIAN
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rotldi r5, r5, 8
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#endif
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adde r0, r0, r10
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add r5, r5, r7
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adde r0, r0, r11
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adde r0, r0, r5
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addze r0, r0
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rotldi r3, r0, 32 /* fold two 32 bit halves together */
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add r3, r0, r3
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srdi r0, r3, 32
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rotlwi r3, r0, 16 /* fold two 16 bit halves together */
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add r3, r0, r3
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not r3, r3
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rlwinm r3, r3, 16, 16, 31
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blr
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EXPORT_SYMBOL(csum_ipv6_magic)
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