Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) /* SPDX-License-Identifier: GPL-2.0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * arch/alpha/lib/ev6-copy_user.S
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  * 21264 version contributed by Rick Gorton <rick.gorton@alpha-processor.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  * Copy to/from user space, handling exceptions as we go..  This
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  * isn't exactly pretty.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10)  * This is essentially the same as "memcpy()", but with a few twists.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11)  * Notably, we have to make sure that $0 is always up-to-date and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12)  * contains the right "bytes left to copy" value (and that it is updated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13)  * only _after_ a successful copy). There is also some rather minor
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14)  * exception setup stuff..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16)  * Much of the information about 21264 scheduling/coding comes from:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17)  *	Compiler Writer's Guide for the Alpha 21264
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18)  *	abbreviated as 'CWG' in other comments here
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19)  *	ftp.digital.com/pub/Digital/info/semiconductor/literature/dsc-library.html
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20)  * Scheduling notation:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21)  *	E	- either cluster
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22)  *	U	- upper subcluster; U0 - subcluster U0; U1 - subcluster U1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23)  *	L	- lower subcluster; L0 - subcluster L0; L1 - subcluster L1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) #include <asm/export.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) /* Allow an exception for an insn; exit if we get one.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) #define EXI(x,y...)			\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) 	99: x,##y;			\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 	.section __ex_table,"a";	\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 	.long 99b - .;			\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 	lda $31, $exitin-99b($31);	\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 	.previous
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) #define EXO(x,y...)			\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 	99: x,##y;			\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 	.section __ex_table,"a";	\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 	.long 99b - .;			\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 	lda $31, $exitout-99b($31);	\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 	.previous
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 	.set noat
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 	.align 4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 	.globl __copy_user
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 	.ent __copy_user
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 				# Pipeline info: Slotting & Comments
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) __copy_user:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 	.prologue 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 	mov $18, $0		# .. .. .. E
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 	subq $18, 32, $1	# .. .. E. ..	: Is this going to be a small copy?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 	nop			# .. E  .. ..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 	beq $18, $zerolength	# U  .. .. ..	: U L U L
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 	and $16,7,$3		# .. .. .. E	: is leading dest misalignment
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 	ble $1, $onebyteloop	# .. .. U  ..	: 1st branch : small amount of data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 	beq $3, $destaligned	# .. U  .. ..	: 2nd (one cycle fetcher stall)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	subq $3, 8, $3		# E  .. .. ..	: L U U L : trip counter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59)  * The fetcher stall also hides the 1 cycle cross-cluster stall for $3 (L --> U)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60)  * This loop aligns the destination a byte at a time
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61)  * We know we have at least one trip through this loop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) $aligndest:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 	EXI( ldbu $1,0($17) )	# .. .. .. L	: Keep loads separate from stores
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	addq $16,1,$16		# .. .. E  ..	: Section 3.8 in the CWG
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 	addq $3,1,$3		# .. E  .. ..	:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 	nop			# E  .. .. ..	: U L U L
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70)  * the -1 is to compensate for the inc($16) done in a previous quadpack
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71)  * which allows us zero dependencies within either quadpack in the loop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 	EXO( stb $1,-1($16) )	# .. .. .. L	:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 	addq $17,1,$17		# .. .. E  ..	: Section 3.8 in the CWG
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 	subq $0,1,$0		# .. E  .. ..	:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	bne $3, $aligndest	# U  .. .. ..	: U L U L
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79)  * If we fell through into here, we have a minimum of 33 - 7 bytes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80)  * If we arrived via branch, we have a minimum of 32 bytes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) $destaligned:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 	and $17,7,$1		# .. .. .. E	: Check _current_ source alignment
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 	bic $0,7,$4		# .. .. E  ..	: number bytes as a quadword loop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 	EXI( ldq_u $3,0($17) )	# .. L  .. ..	: Forward fetch for fallthrough code
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 	beq $1,$quadaligned	# U  .. .. ..	: U L U L
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89)  * In the worst case, we've just executed an ldq_u here from 0($17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90)  * and we'll repeat it once if we take the branch
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) /* Misaligned quadword loop - not unrolled.  Leave it that way. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) $misquad:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 	EXI( ldq_u $2,8($17) )	# .. .. .. L	:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 	subq $4,8,$4		# .. .. E  ..	:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 	extql $3,$17,$3		# .. U  .. ..	:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 	extqh $2,$17,$1		# U  .. .. ..	: U U L L
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 	bis $3,$1,$1		# .. .. .. E	:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 	EXO( stq $1,0($16) )	# .. .. L  ..	:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 	addq $17,8,$17		# .. E  .. ..	:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 	subq $0,8,$0		# E  .. .. ..	: U L L U
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 	addq $16,8,$16		# .. .. .. E	:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 	bis $2,$2,$3		# .. .. E  ..	:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 	nop			# .. E  .. ..	:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 	bne $4,$misquad		# U  .. .. ..	: U L U L
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 	nop			# .. .. .. E
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 	nop			# .. .. E  ..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 	nop			# .. E  .. ..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 	beq $0,$zerolength	# U  .. .. ..	: U L U L
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) /* We know we have at least one trip through the byte loop */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 	EXI ( ldbu $2,0($17) )	# .. .. .. L	: No loads in the same quad
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 	addq $16,1,$16		# .. .. E  ..	: as the store (Section 3.8 in CWG)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 	nop			# .. E  .. ..	:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 	br $31, $dirtyentry	# L0 .. .. ..	: L U U L
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) /* Do the trailing byte loop load, then hop into the store part of the loop */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123)  * A minimum of (33 - 7) bytes to do a quad at a time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)  * Based upon the usage context, it's worth the effort to unroll this loop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125)  * $0 - number of bytes to be moved
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126)  * $4 - number of bytes to move as quadwords
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)  * $16 is current destination address
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)  * $17 is current source address
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) $quadaligned:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 	subq	$4, 32, $2	# .. .. .. E	: do not unroll for small stuff
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 	nop			# .. .. E  ..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 	nop			# .. E  .. ..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	blt	$2, $onequad	# U  .. .. ..	: U L U L
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137)  * There is a significant assumption here that the source and destination
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138)  * addresses differ by more than 32 bytes.  In this particular case, a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139)  * sparsity of registers further bounds this to be a minimum of 8 bytes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140)  * But if this isn't met, then the output result will be incorrect.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141)  * Furthermore, due to a lack of available registers, we really can't
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142)  * unroll this to be an 8x loop (which would enable us to use the wh64
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143)  * instruction memory hint instruction).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) $unroll4:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 	EXI( ldq $1,0($17) )	# .. .. .. L
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 	EXI( ldq $2,8($17) )	# .. .. L  ..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 	subq	$4,32,$4	# .. E  .. ..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 	nop			# E  .. .. ..	: U U L L
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 	addq	$17,16,$17	# .. .. .. E
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 	EXO( stq $1,0($16) )	# .. .. L  ..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 	EXO( stq $2,8($16) )	# .. L  .. ..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 	subq	$0,16,$0	# E  .. .. ..	: U L L U
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 	addq	$16,16,$16	# .. .. .. E
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	EXI( ldq $1,0($17) )	# .. .. L  ..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 	EXI( ldq $2,8($17) )	# .. L  .. ..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 	subq	$4, 32, $3	# E  .. .. ..	: U U L L : is there enough for another trip?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 	EXO( stq $1,0($16) )	# .. .. .. L
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	EXO( stq $2,8($16) )	# .. .. L  ..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 	subq	$0,16,$0	# .. E  .. ..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 	addq	$17,16,$17	# E  .. .. ..	: U L L U
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 	nop			# .. .. .. E
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 	nop			# .. .. E  ..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 	addq	$16,16,$16	# .. E  .. ..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 	bgt	$3,$unroll4	# U  .. .. ..	: U L U L
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 	nop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 	nop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 	nop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 	beq	$4, $noquads
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) $onequad:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 	EXI( ldq $1,0($17) )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 	subq	$4,8,$4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 	addq	$17,8,$17
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 	nop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 	EXO( stq $1,0($16) )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 	subq	$0,8,$0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 	addq	$16,8,$16
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 	bne	$4,$onequad
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) $noquads:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 	nop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 	nop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 	nop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 	beq $0,$zerolength
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194)  * For small copies (or the tail of a larger copy), do a very simple byte loop.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195)  * There's no point in doing a lot of complex alignment calculations to try to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196)  * to quadword stuff for a small amount of data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197)  *	$0 - remaining number of bytes left to copy
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198)  *	$16 - current dest addr
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199)  *	$17 - current source addr
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) $onebyteloop:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 	EXI ( ldbu $2,0($17) )	# .. .. .. L	: No loads in the same quad
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 	addq $16,1,$16		# .. .. E  ..	: as the store (Section 3.8 in CWG)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 	nop			# .. E  .. ..	:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 	nop			# E  .. .. ..	: U L U L
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) $dirtyentry:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210)  * the -1 is to compensate for the inc($16) done in a previous quadpack
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211)  * which allows us zero dependencies within either quadpack in the loop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 	EXO ( stb $2,-1($16) )	# .. .. .. L	:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 	addq $17,1,$17		# .. .. E  ..	: quadpack as the load
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 	subq $0,1,$0		# .. E  .. ..	: change count _after_ copy
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 	bgt $0,$onebyteloop	# U  .. .. ..	: U L U L
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) $zerolength:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) $exitin:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) $exitout:			# Destination for exception recovery(?)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 	nop			# .. .. .. E
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 	nop			# .. .. E  ..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 	nop			# .. E  .. ..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 	ret $31,($26),1		# L0 .. .. ..	: L U L U
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 	.end __copy_user
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 	EXPORT_SYMBOL(__copy_user)