From 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d Mon Sep 17 00:00:00 2001 From: Zeng Chi Date: Mon, 21 Sep 2026 18:24:42 +0800 Subject: KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson Cc: David Ballesteros Signed-off-by: Zeng Chi Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson --- arch/arm/lib/memcpy.S | 66 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) create mode 100644 arch/arm/lib/memcpy.S (limited to 'arch/arm/lib/memcpy.S') diff --git a/arch/arm/lib/memcpy.S b/arch/arm/lib/memcpy.S new file mode 100644 index 000000000..90f2b645a --- /dev/null +++ b/arch/arm/lib/memcpy.S @@ -0,0 +1,66 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * linux/arch/arm/lib/memcpy.S + * + * Author: Nicolas Pitre + * Created: Sep 28, 2005 + * Copyright: MontaVista Software, Inc. + */ + +#include +#include +#include + +#define LDR1W_SHIFT 0 +#define STR1W_SHIFT 0 + + .macro ldr1w ptr reg abort + W(ldr) \reg, [\ptr], #4 + .endm + + .macro ldr4w ptr reg1 reg2 reg3 reg4 abort + ldmia \ptr!, {\reg1, \reg2, \reg3, \reg4} + .endm + + .macro ldr8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort + ldmia \ptr!, {\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8} + .endm + + .macro ldr1b ptr reg cond=al abort + ldrb\cond \reg, [\ptr], #1 + .endm + + .macro str1w ptr reg abort + W(str) \reg, [\ptr], #4 + .endm + + .macro str8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort + stmia \ptr!, {\reg1, \reg2, \reg3, \reg4, \reg5, \reg6, \reg7, \reg8} + .endm + + .macro str1b ptr reg cond=al abort + strb\cond \reg, [\ptr], #1 + .endm + + .macro enter regs:vararg +UNWIND( .save {r0, \regs} ) + stmdb sp!, {r0, \regs} + .endm + + .macro exit regs:vararg + ldmfd sp!, {r0, \regs} + .endm + + .text + +/* Prototype: void *memcpy(void *dest, const void *src, size_t n); */ + +ENTRY(__memcpy) +ENTRY(mmiocpy) +WEAK(memcpy) + +#include "copy_template.S" + +ENDPROC(memcpy) +ENDPROC(mmiocpy) +ENDPROC(__memcpy) -- cgit v1.3.1