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/*
* Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Types.h>
#include <Kernel/Arch/x86/ASM_wrapper.h>
#include <Kernel/Arch/x86/Processor.h>
#include <Kernel/Sections.h>
namespace Kernel {
#define XCR_XFEATURE_ENABLED_MASK 0
UNMAP_AFTER_INIT u64 read_xcr0()
{
u32 eax, edx;
asm volatile("xgetbv"
: "=a"(eax), "=d"(edx)
: "c"(XCR_XFEATURE_ENABLED_MASK));
return eax + ((u64)edx << 32);
}
UNMAP_AFTER_INIT void write_xcr0(u64 value)
{
u32 eax = value;
u32 edx = value >> 32;
asm volatile("xsetbv" ::"a"(eax), "d"(edx), "c"(XCR_XFEATURE_ENABLED_MASK));
}
void stac()
{
if (!Processor::current().has_feature(CPUFeature::SMAP))
return;
asm volatile("stac" ::
: "cc");
}
void clac()
{
if (!Processor::current().has_feature(CPUFeature::SMAP))
return;
asm volatile("clac" ::
: "cc");
}
}
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