Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) /* SPDX-License-Identifier: GPL-2.0-only */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * Copyright (C) 2013 ARM Ltd.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  * Copyright (C) 2013 Linaro.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  * This code is based on glibc cortex strings work originally authored by Linaro
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  * be found @
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9)  * http://bazaar.launchpad.net/~linaro-toolchain-dev/cortex-strings/trunk/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10)  * files/head:/src/aarch64/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <linux/linkage.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <asm/assembler.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17)  * compare two strings
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19)  * Parameters:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20)  *	x0 - const string 1 pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21)  *    x1 - const string 2 pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22)  * Returns:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23)  * x0 - an integer less than, equal to, or greater than zero
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24)  * if  s1  is  found, respectively, to be less than, to match,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25)  * or be greater than s2.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) #define REP8_01 0x0101010101010101
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) #define REP8_7f 0x7f7f7f7f7f7f7f7f
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) #define REP8_80 0x8080808080808080
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) /* Parameters and result.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) src1		.req	x0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) src2		.req	x1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) result		.req	x0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) /* Internal variables.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) data1		.req	x2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) data1w		.req	w2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) data2		.req	x3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) data2w		.req	w3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) has_nul		.req	x4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) diff		.req	x5
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) syndrome	.req	x6
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) tmp1		.req	x7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) tmp2		.req	x8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) tmp3		.req	x9
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) zeroones	.req	x10
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) pos		.req	x11
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) SYM_FUNC_START_WEAK_PI(strcmp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 	eor	tmp1, src1, src2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 	mov	zeroones, #REP8_01
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 	tst	tmp1, #7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 	b.ne	.Lmisaligned8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 	ands	tmp1, src1, #7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	b.ne	.Lmutual_align
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	* NUL detection works on the principle that (X - 1) & (~X) & 0x80
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 	* (=> (X - 1) & ~(X | 0x7f)) is non-zero iff a byte is zero, and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 	* can be done in parallel across the entire word.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 	*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) .Lloop_aligned:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	ldr	data1, [src1], #8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 	ldr	data2, [src2], #8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) .Lstart_realigned:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 	sub	tmp1, data1, zeroones
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 	orr	tmp2, data1, #REP8_7f
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 	eor	diff, data1, data2	/* Non-zero if differences found.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 	bic	has_nul, tmp1, tmp2	/* Non-zero if NUL terminator.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 	orr	syndrome, diff, has_nul
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 	cbz	syndrome, .Lloop_aligned
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 	b	.Lcal_cmpresult
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) .Lmutual_align:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 	* Sources are mutually aligned, but are not currently at an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	* alignment boundary.  Round down the addresses and then mask off
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 	* the bytes that preceed the start point.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 	bic	src1, src1, #7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 	bic	src2, src2, #7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 	lsl	tmp1, tmp1, #3		/* Bytes beyond alignment -> bits.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 	ldr	data1, [src1], #8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 	neg	tmp1, tmp1		/* Bits to alignment -64.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 	ldr	data2, [src2], #8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 	mov	tmp2, #~0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	/* Big-endian.  Early bytes are at MSB.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) CPU_BE( lsl	tmp2, tmp2, tmp1 )	/* Shift (tmp1 & 63).  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 	/* Little-endian.  Early bytes are at LSB.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) CPU_LE( lsr	tmp2, tmp2, tmp1 )	/* Shift (tmp1 & 63).  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 	orr	data1, data1, tmp2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 	orr	data2, data2, tmp2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 	b	.Lstart_realigned
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) .Lmisaligned8:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 	* Get the align offset length to compare per byte first.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 	* After this process, one string's address will be aligned.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 	*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 	and	tmp1, src1, #7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 	neg	tmp1, tmp1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 	add	tmp1, tmp1, #8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 	and	tmp2, src2, #7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 	neg	tmp2, tmp2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 	add	tmp2, tmp2, #8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 	subs	tmp3, tmp1, tmp2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 	csel	pos, tmp1, tmp2, hi /*Choose the maximum. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) .Ltinycmp:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 	ldrb	data1w, [src1], #1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 	ldrb	data2w, [src2], #1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 	subs	pos, pos, #1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 	ccmp	data1w, #1, #0, ne  /* NZCV = 0b0000.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 	ccmp	data1w, data2w, #0, cs  /* NZCV = 0b0000.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 	b.eq	.Ltinycmp
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 	cbnz	pos, 1f /*find the null or unequal...*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 	cmp	data1w, #1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 	ccmp	data1w, data2w, #0, cs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 	b.eq	.Lstart_align /*the last bytes are equal....*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 1:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 	sub	result, data1, data2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 	ret
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) .Lstart_align:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 	ands	xzr, src1, #7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 	b.eq	.Lrecal_offset
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 	/*process more leading bytes to make str1 aligned...*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 	add	src1, src1, tmp3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 	add	src2, src2, tmp3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 	/*load 8 bytes from aligned str1 and non-aligned str2..*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 	ldr	data1, [src1], #8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	ldr	data2, [src2], #8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 	sub	tmp1, data1, zeroones
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 	orr	tmp2, data1, #REP8_7f
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 	bic	has_nul, tmp1, tmp2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 	eor	diff, data1, data2 /* Non-zero if differences found.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 	orr	syndrome, diff, has_nul
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 	cbnz	syndrome, .Lcal_cmpresult
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 	/*How far is the current str2 from the alignment boundary...*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 	and	tmp3, tmp3, #7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) .Lrecal_offset:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 	neg	pos, tmp3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) .Lloopcmp_proc:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 	* Divide the eight bytes into two parts. First,backwards the src2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 	* to an alignment boundary,load eight bytes from the SRC2 alignment
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 	* boundary,then compare with the relative bytes from SRC1.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 	* If all 8 bytes are equal,then start the second part's comparison.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 	* Otherwise finish the comparison.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 	* This special handle can garantee all the accesses are in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 	* thread/task space in avoid to overrange access.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 	*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 	ldr	data1, [src1,pos]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	ldr	data2, [src2,pos]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 	sub	tmp1, data1, zeroones
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 	orr	tmp2, data1, #REP8_7f
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 	bic	has_nul, tmp1, tmp2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 	eor	diff, data1, data2  /* Non-zero if differences found.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	orr	syndrome, diff, has_nul
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 	cbnz	syndrome, .Lcal_cmpresult
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	/*The second part process*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 	ldr	data1, [src1], #8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 	ldr	data2, [src2], #8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 	sub	tmp1, data1, zeroones
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 	orr	tmp2, data1, #REP8_7f
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 	bic	has_nul, tmp1, tmp2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 	eor	diff, data1, data2  /* Non-zero if differences found.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 	orr	syndrome, diff, has_nul
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 	cbz	syndrome, .Lloopcmp_proc
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) .Lcal_cmpresult:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 	* reversed the byte-order as big-endian,then CLZ can find the most
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 	* significant zero bits.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 	*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) CPU_LE( rev	syndrome, syndrome )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) CPU_LE( rev	data1, data1 )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) CPU_LE( rev	data2, data2 )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 	* For big-endian we cannot use the trick with the syndrome value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 	* as carry-propagation can corrupt the upper bits if the trailing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 	* bytes in the string contain 0x01.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 	* However, if there is no NUL byte in the dword, we can generate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 	* the result directly.  We cannot just subtract the bytes as the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 	* MSB might be significant.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 	*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) CPU_BE( cbnz	has_nul, 1f )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) CPU_BE( cmp	data1, data2 )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) CPU_BE( cset	result, ne )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) CPU_BE( cneg	result, result, lo )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) CPU_BE( ret )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) CPU_BE( 1: )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 	/*Re-compute the NUL-byte detection, using a byte-reversed value. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) CPU_BE(	rev	tmp3, data1 )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) CPU_BE(	sub	tmp1, tmp3, zeroones )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) CPU_BE(	orr	tmp2, tmp3, #REP8_7f )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) CPU_BE(	bic	has_nul, tmp1, tmp2 )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) CPU_BE(	rev	has_nul, has_nul )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) CPU_BE(	orr	syndrome, diff, has_nul )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 	clz	pos, syndrome
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 	* The MS-non-zero bit of the syndrome marks either the first bit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 	* that is different, or the top bit of the first zero byte.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 	* Shifting left now will bring the critical information into the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 	* top bits.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 	*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 	lsl	data1, data1, pos
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 	lsl	data2, data2, pos
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 	* But we need to zero-extend (char is unsigned) the value and then
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 	* perform a signed 32-bit subtraction.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 	*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 	lsr	data1, data1, #56
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 	sub	result, data1, data2, lsr #56
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 	ret
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) SYM_FUNC_END_PI(strcmp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) EXPORT_SYMBOL_NOKASAN(strcmp)