mirror of
https://gitlab.com/sortix/sortix.git
synced 2023-02-13 20:55:38 -05:00
218 lines
7 KiB
C++
218 lines
7 KiB
C++
/*******************************************************************************
|
|
|
|
Copyright(C) Jonas 'Sortie' Termansen 2011, 2012, 2014.
|
|
|
|
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/>.
|
|
|
|
x64/memorymanagement.cpp
|
|
Handles memory for the x64 architecture.
|
|
|
|
*******************************************************************************/
|
|
|
|
#include <string.h>
|
|
|
|
#include <sortix/kernel/interrupt.h>
|
|
#include <sortix/kernel/kernel.h>
|
|
#include <sortix/kernel/memorymanagement.h>
|
|
|
|
#include "multiboot.h"
|
|
#include "x86-family/memorymanagement.h"
|
|
|
|
namespace Sortix {
|
|
namespace Page {
|
|
|
|
extern size_t stackused;
|
|
extern size_t stacklength;
|
|
void ExtendStack();
|
|
|
|
} // namespace Page
|
|
} // namespace Sortix
|
|
|
|
namespace Sortix {
|
|
namespace Memory {
|
|
|
|
extern addr_t currentdir;
|
|
|
|
void InitCPU()
|
|
{
|
|
// The x64 boot code already set up virtual memory and identity
|
|
// mapped the first 2 MiB. This code finishes the job such that
|
|
// virtual memory is fully usable and manageable.
|
|
|
|
// boot.s already initialized everything from 0x21000UL to 0x2F000UL to
|
|
// zeroes. Since these structures are already used, doing it here would
|
|
// destroying the existing data.
|
|
|
|
PML* const BOOTPML4 = (PML* const) 0x21000UL;
|
|
PML* const BOOTPML3 = (PML* const) 0x26000UL;
|
|
PML* const BOOTPML2 = (PML* const) 0x27000UL;
|
|
PML* const BOOTPML1 = (PML* const) 0x28000UL;
|
|
|
|
// First order of business is to map the virtual memory structures
|
|
// to the pre-defined locations in the virtual address space.
|
|
addr_t flags = PML_PRESENT | PML_WRITABLE;
|
|
|
|
// Fractal map the PML1s.
|
|
BOOTPML4->entry[511] = (addr_t) BOOTPML4 | flags;
|
|
|
|
// Fractal map the PML2s.
|
|
BOOTPML4->entry[510] = (addr_t) BOOTPML3 | flags | PML_FORK;
|
|
BOOTPML3->entry[511] = (addr_t) BOOTPML4 | flags;
|
|
|
|
// Fractal map the PML3s.
|
|
BOOTPML3->entry[510] = (addr_t) BOOTPML2 | flags | PML_FORK;
|
|
BOOTPML2->entry[511] = (addr_t) BOOTPML4 | flags;
|
|
|
|
// Fractal map the PML4s.
|
|
BOOTPML2->entry[510] = (addr_t) BOOTPML1 | flags | PML_FORK;
|
|
BOOTPML1->entry[511] = (addr_t) BOOTPML4 | flags;
|
|
|
|
// Add some predefined room for forking address spaces.
|
|
PML* const FORKPML2 = (PML* const) 0x29000UL;
|
|
PML* const FORKPML1 = (PML* const) 0x2A000UL;
|
|
|
|
BOOTPML3->entry[0] = (addr_t) FORKPML2 | flags | PML_FORK;
|
|
FORKPML2->entry[0] = (addr_t) FORKPML1 | flags | PML_FORK;
|
|
|
|
currentdir = (addr_t) BOOTPML4;
|
|
|
|
// The virtual memory structures are now available on the predefined
|
|
// locations. This means the virtual memory code is bootstrapped. Of
|
|
// course, we still have no physical page allocator, so that's the
|
|
// next step.
|
|
|
|
PML* const PHYSPML3 = (PML* const) 0x2B000UL;
|
|
PML* const PHYSPML2 = (PML* const) 0x2C000UL;
|
|
PML* const PHYSPML1 = (PML* const) 0x2D000UL;
|
|
PML* const PHYSPML0 = (PML* const) 0x2E000UL;
|
|
|
|
BOOTPML4->entry[509] = (addr_t) PHYSPML3 | flags;
|
|
PHYSPML3->entry[0] = (addr_t) PHYSPML2 | flags;
|
|
PHYSPML2->entry[0] = (addr_t) PHYSPML1 | flags;
|
|
PHYSPML1->entry[0] = (addr_t) PHYSPML0 | flags;
|
|
|
|
Page::stackused = 0;
|
|
Page::stacklength = 4096UL / sizeof(addr_t);
|
|
|
|
// The physical memory allocator should now be ready for use. Next
|
|
// up, the calling function will fill up the physical allocator with
|
|
// plenty of nice physical pages. (see Page::InitPushRegion)
|
|
}
|
|
|
|
// Please note that even if this function exists, you should still clean
|
|
// up the address space of a process _before_ calling
|
|
// DestroyAddressSpace. This is just a hack because it currently is
|
|
// impossible to clean up PLM1's using the MM api!
|
|
// ---
|
|
// TODO: This function is duplicated in {x86,x64}/memorymanagement.cpp!
|
|
// ---
|
|
void RecursiveFreeUserspacePages(size_t level, size_t offset)
|
|
{
|
|
PML* pml = PMLS[level] + offset;
|
|
for ( size_t i = 0; i < ENTRIES; i++ )
|
|
{
|
|
addr_t entry = pml->entry[i];
|
|
if ( !(entry & PML_PRESENT) )
|
|
continue;
|
|
if ( !(entry & PML_USERSPACE) )
|
|
continue;
|
|
if ( !(entry & PML_FORK) )
|
|
continue;
|
|
if ( 1 < level )
|
|
RecursiveFreeUserspacePages(level-1, offset * ENTRIES + i);
|
|
addr_t addr = pml->entry[i] & PML_ADDRESS;
|
|
// No need to unmap the page, we just need to mark it as unused.
|
|
Page::PutUnlocked(addr);
|
|
}
|
|
}
|
|
|
|
void DestroyAddressSpace(addr_t fallback, void (*func)(addr_t, void*), void* user)
|
|
{
|
|
// Look up the last few entries used for the fractal mapping. These
|
|
// cannot be unmapped as that would destroy the world. Instead, we
|
|
// will remember them, switch to another adress space, and safely
|
|
// mark them as unused. Also handling the forking related pages.
|
|
addr_t fractal3 = (PMLS[4] + 0)->entry[510UL];
|
|
addr_t fork2 = (PMLS[3] + 510UL)->entry[0];
|
|
addr_t fractal2 = (PMLS[3] + 510UL)->entry[510];
|
|
addr_t fork1 = (PMLS[2] + 510UL * 512UL + 0)->entry[0];
|
|
addr_t fractal1 = (PMLS[2] + 510UL * 512UL + 510UL)->entry[510];
|
|
addr_t dir = currentdir;
|
|
|
|
// We want to free the pages, but we are still using them ourselves,
|
|
// so lock the page allocation structure until we are done.
|
|
Page::Lock();
|
|
|
|
// In case any pages wasn't cleaned at this point.
|
|
// TODO: Page::Put calls may internally Page::Get and then reusing pages we are not done with just yet
|
|
RecursiveFreeUserspacePages(TOPPMLLEVEL, 0);
|
|
|
|
// Switch to the address space from when the world was originally
|
|
// created. It should contain the kernel, the whole kernel, and
|
|
// nothing but the kernel.
|
|
PML* const BOOTPML4 = (PML* const) 0x21000UL;
|
|
if ( !fallback )
|
|
fallback = (addr_t) BOOTPML4;
|
|
|
|
if ( func )
|
|
func(fallback, user);
|
|
else
|
|
SwitchAddressSpace(fallback);
|
|
|
|
// Ok, now we got marked everything left behind as unused, we can
|
|
// now safely let another thread use the pages.
|
|
Page::Unlock();
|
|
|
|
// These are safe to free since we switched address space.
|
|
Page::Put(fractal3 & PML_ADDRESS);
|
|
Page::Put(fractal2 & PML_ADDRESS);
|
|
Page::Put(fractal1 & PML_ADDRESS);
|
|
Page::Put(fork2 & PML_ADDRESS);
|
|
Page::Put(fork1 & PML_ADDRESS);
|
|
Page::Put(dir & PML_ADDRESS);
|
|
}
|
|
|
|
const size_t KERNEL_STACK_SIZE = 256UL * 1024UL;
|
|
const addr_t KERNEL_STACK_END = 0xFFFF800000001000UL;
|
|
const addr_t KERNEL_STACK_START = KERNEL_STACK_END + KERNEL_STACK_SIZE;
|
|
|
|
const addr_t VIRTUAL_AREA_LOWER = KERNEL_STACK_START;
|
|
const addr_t VIRTUAL_AREA_UPPER = 0xFFFFFE8000000000UL;
|
|
|
|
void GetKernelVirtualArea(addr_t* from, size_t* size)
|
|
{
|
|
*from = KERNEL_STACK_END;
|
|
*size = VIRTUAL_AREA_UPPER - VIRTUAL_AREA_LOWER;
|
|
}
|
|
|
|
void GetUserVirtualArea(uintptr_t* from, size_t* size)
|
|
{
|
|
*from = 0x400000; // 4 MiB.
|
|
*size = 0x800000000000 - *from; // 128 TiB - 4 MiB.
|
|
}
|
|
|
|
addr_t GetKernelStack()
|
|
{
|
|
return KERNEL_STACK_START;
|
|
}
|
|
|
|
size_t GetKernelStackSize()
|
|
{
|
|
return KERNEL_STACK_SIZE;
|
|
}
|
|
|
|
} // namespace Memory
|
|
} // namespace Sortix
|