linux_dsm_epyc7002/arch/arm/lib/memset.S
Matthew Wilcox fd1d362600 ARM: implement memset32 & memset64
Reuse the existing optimised memset implementation to implement an
optimised memset32 and memset64.

Link: http://lkml.kernel.org/r/20170720184539.31609-5-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: Russell King <rmk+kernel@armlinux.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: David Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:48 -07:00

150 lines
3.0 KiB
ArmAsm

/*
* linux/arch/arm/lib/memset.S
*
* Copyright (C) 1995-2000 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* ASM optimised string functions
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/unwind.h>
.text
.align 5
ENTRY(mmioset)
ENTRY(memset)
UNWIND( .fnstart )
ands r3, r0, #3 @ 1 unaligned?
mov ip, r0 @ preserve r0 as return value
bne 6f @ 1
/*
* we know that the pointer in ip is aligned to a word boundary.
*/
1: orr r1, r1, r1, lsl #8
orr r1, r1, r1, lsl #16
mov r3, r1
7: cmp r2, #16
blt 4f
#if ! CALGN(1)+0
/*
* We need 2 extra registers for this loop - use r8 and the LR
*/
stmfd sp!, {r8, lr}
UNWIND( .fnend )
UNWIND( .fnstart )
UNWIND( .save {r8, lr} )
mov r8, r1
mov lr, r3
2: subs r2, r2, #64
stmgeia ip!, {r1, r3, r8, lr} @ 64 bytes at a time.
stmgeia ip!, {r1, r3, r8, lr}
stmgeia ip!, {r1, r3, r8, lr}
stmgeia ip!, {r1, r3, r8, lr}
bgt 2b
ldmeqfd sp!, {r8, pc} @ Now <64 bytes to go.
/*
* No need to correct the count; we're only testing bits from now on
*/
tst r2, #32
stmneia ip!, {r1, r3, r8, lr}
stmneia ip!, {r1, r3, r8, lr}
tst r2, #16
stmneia ip!, {r1, r3, r8, lr}
ldmfd sp!, {r8, lr}
UNWIND( .fnend )
#else
/*
* This version aligns the destination pointer in order to write
* whole cache lines at once.
*/
stmfd sp!, {r4-r8, lr}
UNWIND( .fnend )
UNWIND( .fnstart )
UNWIND( .save {r4-r8, lr} )
mov r4, r1
mov r5, r3
mov r6, r1
mov r7, r3
mov r8, r1
mov lr, r3
cmp r2, #96
tstgt ip, #31
ble 3f
and r8, ip, #31
rsb r8, r8, #32
sub r2, r2, r8
movs r8, r8, lsl #(32 - 4)
stmcsia ip!, {r4, r5, r6, r7}
stmmiia ip!, {r4, r5}
tst r8, #(1 << 30)
mov r8, r1
strne r1, [ip], #4
3: subs r2, r2, #64
stmgeia ip!, {r1, r3-r8, lr}
stmgeia ip!, {r1, r3-r8, lr}
bgt 3b
ldmeqfd sp!, {r4-r8, pc}
tst r2, #32
stmneia ip!, {r1, r3-r8, lr}
tst r2, #16
stmneia ip!, {r4-r7}
ldmfd sp!, {r4-r8, lr}
UNWIND( .fnend )
#endif
UNWIND( .fnstart )
4: tst r2, #8
stmneia ip!, {r1, r3}
tst r2, #4
strne r1, [ip], #4
/*
* When we get here, we've got less than 4 bytes to set. We
* may have an unaligned pointer as well.
*/
5: tst r2, #2
strneb r1, [ip], #1
strneb r1, [ip], #1
tst r2, #1
strneb r1, [ip], #1
ret lr
6: subs r2, r2, #4 @ 1 do we have enough
blt 5b @ 1 bytes to align with?
cmp r3, #2 @ 1
strltb r1, [ip], #1 @ 1
strleb r1, [ip], #1 @ 1
strb r1, [ip], #1 @ 1
add r2, r2, r3 @ 1 (r2 = r2 - (4 - r3))
b 1b
UNWIND( .fnend )
ENDPROC(memset)
ENDPROC(mmioset)
ENTRY(__memset32)
UNWIND( .fnstart )
mov r3, r1 @ copy r1 to r3 and fall into memset64
UNWIND( .fnend )
ENDPROC(__memset32)
ENTRY(__memset64)
UNWIND( .fnstart )
mov ip, r0 @ preserve r0 as return value
b 7b @ jump into the middle of memset
UNWIND( .fnend )
ENDPROC(__memset64)