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exectos/xtoskrnl/mm/amd64/paging.cc

131 lines
3.2 KiB
C++

/**
* PROJECT: ExectOS
* COPYRIGHT: See COPYING.md in the top level directory
* FILE: xtoskrnl/mm/amd64/paging.cc
* DESCRIPTION: Architecture dependent paging support
* DEVELOPERS: Rafal Kupiec <belliash@codingworkshop.eu.org>
* Aiken Harris <harraiken91@gmail.com>
*/
#include <xtos.hh>
/**
* Checks if eXtended Physical Addressing (XPA) is enabled.
*
* @return This routine returns TRUE if LA57 is enabled, or FALSE otherwise.
*
* @since XT 1.0
*/
XTAPI
BOOLEAN
MM::Paging::GetExtendedPhysicalAddressingStatus(VOID)
{
/* Check if LA57 is enabled */
return ((AR::CpuFunc::ReadControlRegister(4) & CR4_LA57) != 0) ? TRUE : FALSE;
}
/**
* Gets the address of the P5E (Page Map Level 5 Entry), that maps given address.
*
* @param Address
* Specifies the virtual address for which to retrieve the corresponding P5E.
*
* @return This routine returns the address of the P5E, or NULLPTR if LA57 is not enabled.
*
* @since XT 1.0
*/
XTAPI
PMMPDE
MM::Paging::GetP5eAddress(IN PVOID Address)
{
/* Return PDE address */
return PmlRoutines->GetP5eAddress(Address);
}
/**
* Gets the virtual address that is mapped by a given Page Map Level 5 Entry.
*
* @param P5ePointer
* Specifies the address of the P5E.
*
* @return This routine returns the virtual address mapped by the P5E, or NULLPTR if LA57 is not enabled.
*
* @since XT 1.0
*/
XTAPI
PVOID
MM::Paging::GetP5eVirtualAddress(IN PMMPTE P5ePointer)
{
/* Return PTE virtual address */
return PmlRoutines->GetP5eVirtualAddress(P5ePointer);
}
/**
* Gets the address of the PXE (Extended Page Entry), that maps given address.
*
* @param Address
* Specifies the virtual address for which to retrieve the corresponding PXE.
*
* @return This routine returns the address of the PXE.
*
* @since XT 1.0
*/
XTAPI
PMMPXE
MM::Paging::GetPxeAddress(IN PVOID Address)
{
/* Return PXE address */
return PmlRoutines->GetPxeAddress(Address);
}
/**
* Gets the virtual address that is mapped by a given Extended Page Entry.
*
* @param PxePointer
* Specifies the address of the PXE.
*
* @return This routine returns the virtual address mapped by the PXE.
*
* @since XT 1.0
*/
XTAPI
PVOID
MM::Paging::GetPxeVirtualAddress(IN PMMPXE PxePointer)
{
/* Return PXE virtual address */
return PmlRoutines->GetPxeVirtualAddress(PxePointer);
}
/**
* Fills a section of memory with zeroes like RtlZeroMemory(), but in more efficient way.
*
* @param Address
* Supplies an address of the page to be filled with zeroes.
*
* @param Size
* Number of bytes to be filled with zeros. This always should be a multiply of page size.
*
* @return This routine does not return any value.
*
* @since XT 1.0
*/
XTFASTCALL
VOID
MM::Paging::ZeroPages(IN PVOID Address,
IN ULONG Size)
{
__asm__ volatile("xor %%rax, %%rax\n"
"mov %0, %%rdi\n"
"mov %1, %%ecx\n"
"shr $3, %%ecx\n"
"rep stosq\n"
:
: "m" (Address),
"m" (Size)
: "rax",
"rdi",
"ecx",
"memory");
}