2b72262b4f
I hereby relicense all my work on Sortix under the ISC license as below. All Sortix contributions by other people are already under this license, are not substantial enough to be copyrightable, or have been removed. All imported code from other projects is compatible with this license. All GPL licensed code from other projects had previously been removed. Copyright 2011-2016 Jonas 'Sortie' Termansen and contributors. Permission to use, copy, modify, and distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies. THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
52 lines
1.6 KiB
C++
52 lines
1.6 KiB
C++
/*
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* Copyright (c) 2012, 2013 Jonas 'Sortie' Termansen.
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*
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* x86-family/pat.cpp
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* Tests whether PAT is available and initializes it.
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*/
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#include <msr.h>
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#include <stdint.h>
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#include <sortix/kernel/cpuid.h>
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#include <sortix/kernel/kernel.h>
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#include <sortix/kernel/pat.h>
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#include "memorymanagement.h"
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namespace Sortix {
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static const uint32_t bit_PAT = 0x00010000U;
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bool IsPATSupported()
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{
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if ( !IsCPUIdSupported() )
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return false;
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uint32_t eax, ebx, ecx, edx;
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cpuid(1, eax, ebx, ecx, edx);
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uint32_t features = edx;
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return features & bit_PAT;
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}
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void InitializePAT()
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{
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using namespace Sortix::Memory;
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const uint32_t LOW = PA[0] << 0 | PA[1] << 8 | PA[2] << 16 | PA[3] << 24;
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const uint32_t HIGH = PA[4] << 0 | PA[5] << 8 | PA[6] << 16 | PA[7] << 24;
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const int PAT_REG = 0x0277;
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wrmsr(PAT_REG, (uint64_t) LOW << 0 | (uint64_t) HIGH << 32);
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}
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} // namespace Sortix
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