63 lines
1.3 KiB
C
63 lines
1.3 KiB
C
/**
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* PROJECT: ExectOS
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* COPYRIGHT: See COPYING.md in the top level directory
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* FILE: xtoskrnl/mm/pages.c
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* DESCRIPTION: Low level page management support
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* DEVELOPERS: Rafal Kupiec <belliash@codingworkshop.eu.org>
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*/
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#include <xtos.h>
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/**
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* Flushes current Translation Lookaside Buffer (TLB)
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*
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* @return This routine does not return any value.
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*
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* @since XT 1.0
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*/
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XTAPI
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VOID
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MmFlushTlb(VOID)
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{
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CPUID_REGISTERS CpuRegisters;
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BOOLEAN Interrupts;
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ULONG_PTR Cr4;
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/* Save interrupts state and disable them */
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Interrupts = ArInterruptsEnabled();
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ArClearInterruptFlag();
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/* Get CPU features */
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CpuRegisters.Leaf = CPUID_GET_CPU_FEATURES;
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ArCpuId(&CpuRegisters);
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/* Check if Paging Global Extensions (PGE) is supported */
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if(CpuRegisters.Edx & CPUID_FEATURES_EDX_PGE)
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{
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/* Read CR4 */
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Cr4 = ArReadControlRegister(4);
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/* Disable PGE */
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ArWriteControlRegister(4, Cr4 & ~CR4_PGE);
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/* Flush the TLB */
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ArFlushTlb();
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/* Restore CR4 */
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ArWriteControlRegister(4, Cr4);
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}
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else
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{
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/* Simply flush the TLB */
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ArFlushTlb();
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}
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/* Check if interrupts should be enabled */
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if(Interrupts)
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{
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/* Re-enable interrupts */
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ArSetInterruptFlag();
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}
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}
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