sortix--sortix/sortix/x86-family/memorymanagement.h

/******************************************************************************

	Copyright(C) Jonas 'Sortie' Termansen 2011, 2012.

	This file is part of Sortix.

	Sortix is free software: you can redistribute it and/or modify it under the
	terms of the GNU General Public License as published by the Free Software
	Foundation, either version 3 of the License, or (at your option) any later
	version.

	Sortix is distributed in the hope that it will be useful, but WITHOUT ANY
	WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
	FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
	details.

	You should have received a copy of the GNU General Public License along
	with Sortix. If not, see <http://www.gnu.org/licenses/>.

	memorymanagement.h
	Handles memory for the x86 family of architectures.

******************************************************************************/

#ifndef SORTIX_X86_FAMILY_MEMORYMANAGEMENT_H
#define SORTIX_X86_FAMILY_MEMORYMANAGEMENT_H

namespace Sortix
{
	struct PML
	{
		addr_t entry[4096 / sizeof(addr_t)];
	};

	namespace Memory
	{
		const addr_t PML_PRESENT    = (1<<0);
		const addr_t PML_WRITABLE   = (1<<1);
		const addr_t PML_USERSPACE  = (1<<2);
		const addr_t PML_WRTHROUGH  = (1<<3);
		const addr_t PML_NOCACHE    = (1<<4);
		const addr_t PML_PAT        = (1<<7);
		const addr_t PML_AVAILABLE1 = (1<<9);
		const addr_t PML_AVAILABLE2 = (1<<10);
		const addr_t PML_AVAILABLE3 = (1<<11);
		const addr_t PML_FORK       = PML_AVAILABLE1;
		const addr_t PML_FLAGS      = (0xFFFUL); // Bits used for the flags.
		const addr_t PML_ADDRESS    = (~0xFFFUL); // Bits used for the address.
		const addr_t PAT_UC = 0x00; // Uncacheable
		const addr_t PAT_WC = 0x01; // Write-Combine
		const addr_t PAT_WT = 0x04; // Writethrough
		const addr_t PAT_WP = 0x05; // Write-Protect
		const addr_t PAT_WB = 0x06; // Writeback
		const addr_t PAT_UCM = 0x07; // Uncacheable, overruled by MTRR.
		const addr_t PAT_NUM = 0x08;
		// Desired PAT-Register PA-Field Indexing (different from BIOS defaults)
		const addr_t PA[PAT_NUM] =
		{
			PAT_WB,
			PAT_WT,
			PAT_UCM,
			PAT_UC,
			PAT_WC,
			PAT_WP,
			0,
			0,
		};
		// Inverse function of the above.
		const addr_t PAINV[PAT_NUM] =
		{
			3, // UC
			4, // WC
			7, // No such
			8, // No such
			1, // WT
			5, // WP,
			0, // WB
			2, // UCM
		};
		static inline addr_t EncodePATAsPMLFlag(addr_t pat)
		{
			pat = PAINV[pat];
			addr_t result = 0;
			if ( pat & 0x1 ) { result |= PML_WRTHROUGH; }
			if ( pat & 0x2 ) { result |= PML_NOCACHE; }
			if ( pat & 0x4 ) { result |= PML_PAT; }
			return result;
		}
		bool MapPAT(addr_t physical, addr_t mapto, int prot, addr_t mtype);
		addr_t ProtectionToPMLFlags(int prot);
		int PMLFlagsToProtection(addr_t flags);
	}
}

#ifdef PLATFORM_X86
#include "../x86/memorymanagement.h"
#endif

#ifdef PLATFORM_X64
#include "../x64/memorymanagement.h"
#endif

#endif