mirror of
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2025-09-04 20:19:47 +08:00
fd1d362600
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>
150 lines
3.0 KiB
ArmAsm
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)
|