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linux-next/arch/mips/lib/memset.S
Tony Wu e5674ad6ca MIPS: Separate two consecutive loads in memset.S
partial_fixup is used in noreorder block.

Separating two consecutive loads can save one cycle on processors with
GPR intrelock and can fix load-use on processors that need a load delay slot.

Also do so for fwd_fixup.

[Ralf: Only R2000/R3000 class processors are lacking the the load-user
interlock and even some of those got it retrofitted.  With R2000/R3000
being fairly uncommon these days the impact of this bug should be minor.]

Signed-off-by: Tony Wu <tung7970@gmail.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1768/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-12-16 18:10:57 +00:00

181 lines
4.1 KiB
ArmAsm

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1998, 1999, 2000 by Ralf Baechle
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
* Copyright (C) 2007 Maciej W. Rozycki
*/
#include <asm/asm.h>
#include <asm/asm-offsets.h>
#include <asm/regdef.h>
#if LONGSIZE == 4
#define LONG_S_L swl
#define LONG_S_R swr
#else
#define LONG_S_L sdl
#define LONG_S_R sdr
#endif
#define EX(insn,reg,addr,handler) \
9: insn reg, addr; \
.section __ex_table,"a"; \
PTR 9b, handler; \
.previous
.macro f_fill64 dst, offset, val, fixup
EX(LONG_S, \val, (\offset + 0 * LONGSIZE)(\dst), \fixup)
EX(LONG_S, \val, (\offset + 1 * LONGSIZE)(\dst), \fixup)
EX(LONG_S, \val, (\offset + 2 * LONGSIZE)(\dst), \fixup)
EX(LONG_S, \val, (\offset + 3 * LONGSIZE)(\dst), \fixup)
EX(LONG_S, \val, (\offset + 4 * LONGSIZE)(\dst), \fixup)
EX(LONG_S, \val, (\offset + 5 * LONGSIZE)(\dst), \fixup)
EX(LONG_S, \val, (\offset + 6 * LONGSIZE)(\dst), \fixup)
EX(LONG_S, \val, (\offset + 7 * LONGSIZE)(\dst), \fixup)
#if LONGSIZE == 4
EX(LONG_S, \val, (\offset + 8 * LONGSIZE)(\dst), \fixup)
EX(LONG_S, \val, (\offset + 9 * LONGSIZE)(\dst), \fixup)
EX(LONG_S, \val, (\offset + 10 * LONGSIZE)(\dst), \fixup)
EX(LONG_S, \val, (\offset + 11 * LONGSIZE)(\dst), \fixup)
EX(LONG_S, \val, (\offset + 12 * LONGSIZE)(\dst), \fixup)
EX(LONG_S, \val, (\offset + 13 * LONGSIZE)(\dst), \fixup)
EX(LONG_S, \val, (\offset + 14 * LONGSIZE)(\dst), \fixup)
EX(LONG_S, \val, (\offset + 15 * LONGSIZE)(\dst), \fixup)
#endif
.endm
/*
* memset(void *s, int c, size_t n)
*
* a0: start of area to clear
* a1: char to fill with
* a2: size of area to clear
*/
.set noreorder
.align 5
LEAF(memset)
beqz a1, 1f
move v0, a0 /* result */
andi a1, 0xff /* spread fillword */
LONG_SLL t1, a1, 8
or a1, t1
LONG_SLL t1, a1, 16
#if LONGSIZE == 8
or a1, t1
LONG_SLL t1, a1, 32
#endif
or a1, t1
1:
FEXPORT(__bzero)
sltiu t0, a2, LONGSIZE /* very small region? */
bnez t0, .Lsmall_memset
andi t0, a0, LONGMASK /* aligned? */
#ifndef CONFIG_CPU_DADDI_WORKAROUNDS
beqz t0, 1f
PTR_SUBU t0, LONGSIZE /* alignment in bytes */
#else
.set noat
li AT, LONGSIZE
beqz t0, 1f
PTR_SUBU t0, AT /* alignment in bytes */
.set at
#endif
R10KCBARRIER(0(ra))
#ifdef __MIPSEB__
EX(LONG_S_L, a1, (a0), .Lfirst_fixup) /* make word/dword aligned */
#endif
#ifdef __MIPSEL__
EX(LONG_S_R, a1, (a0), .Lfirst_fixup) /* make word/dword aligned */
#endif
PTR_SUBU a0, t0 /* long align ptr */
PTR_ADDU a2, t0 /* correct size */
1: ori t1, a2, 0x3f /* # of full blocks */
xori t1, 0x3f
beqz t1, .Lmemset_partial /* no block to fill */
andi t0, a2, 0x40-LONGSIZE
PTR_ADDU t1, a0 /* end address */
.set reorder
1: PTR_ADDIU a0, 64
R10KCBARRIER(0(ra))
f_fill64 a0, -64, a1, .Lfwd_fixup
bne t1, a0, 1b
.set noreorder
.Lmemset_partial:
R10KCBARRIER(0(ra))
PTR_LA t1, 2f /* where to start */
#if LONGSIZE == 4
PTR_SUBU t1, t0
#else
.set noat
LONG_SRL AT, t0, 1
PTR_SUBU t1, AT
.set at
#endif
jr t1
PTR_ADDU a0, t0 /* dest ptr */
.set push
.set noreorder
.set nomacro
f_fill64 a0, -64, a1, .Lpartial_fixup /* ... but first do longs ... */
2: .set pop
andi a2, LONGMASK /* At most one long to go */
beqz a2, 1f
PTR_ADDU a0, a2 /* What's left */
R10KCBARRIER(0(ra))
#ifdef __MIPSEB__
EX(LONG_S_R, a1, -1(a0), .Llast_fixup)
#endif
#ifdef __MIPSEL__
EX(LONG_S_L, a1, -1(a0), .Llast_fixup)
#endif
1: jr ra
move a2, zero
.Lsmall_memset:
beqz a2, 2f
PTR_ADDU t1, a0, a2
1: PTR_ADDIU a0, 1 /* fill bytewise */
R10KCBARRIER(0(ra))
bne t1, a0, 1b
sb a1, -1(a0)
2: jr ra /* done */
move a2, zero
END(memset)
.Lfirst_fixup:
jr ra
nop
.Lfwd_fixup:
PTR_L t0, TI_TASK($28)
andi a2, 0x3f
LONG_L t0, THREAD_BUADDR(t0)
LONG_ADDU a2, t1
jr ra
LONG_SUBU a2, t0
.Lpartial_fixup:
PTR_L t0, TI_TASK($28)
andi a2, LONGMASK
LONG_L t0, THREAD_BUADDR(t0)
LONG_ADDU a2, t1
jr ra
LONG_SUBU a2, t0
.Llast_fixup:
jr ra
andi v1, a2, LONGMASK