mirror of
https://gitlab.com/sortix/sortix.git
synced 2023-02-13 20:55:38 -05:00
124 lines
3.5 KiB
C++
124 lines
3.5 KiB
C++
/*******************************************************************************
|
|
|
|
Copyright(C) Jonas 'Sortie' Termansen 2013.
|
|
|
|
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/>.
|
|
|
|
addralloc.cpp
|
|
Class to keep track of mount points.
|
|
|
|
*******************************************************************************/
|
|
|
|
#include <assert.h>
|
|
#include <errno.h>
|
|
#include <stddef.h>
|
|
|
|
#include <sortix/kernel/addralloc.h>
|
|
#include <sortix/kernel/kernel.h>
|
|
#include <sortix/kernel/kthread.h>
|
|
#include <sortix/kernel/memorymanagement.h>
|
|
|
|
namespace Sortix {
|
|
|
|
size_t aux_allocated = 0;
|
|
size_t heap_allocated = 0;
|
|
kthread_mutex_t alloc_lock = KTHREAD_MUTEX_INITIALIZER;
|
|
|
|
// TODO: Kernel address space is allocated simply by increasing the pointer,
|
|
// with no support for freeing it. This is not that big a problem at this point,
|
|
// since address space is consumed at boot and then used forever. When it
|
|
// becomes normal for devices to come and go, just recode these functions and
|
|
// everyone should do the right thing.
|
|
|
|
bool AllocateKernelAddress(addralloc_t* ret, size_t size)
|
|
{
|
|
size = Page::AlignUp(size);
|
|
ScopedLock lock(&alloc_lock);
|
|
addr_t kmem_from;
|
|
size_t kmem_size;
|
|
Memory::GetKernelVirtualArea(&kmem_from, &kmem_size);
|
|
addr_t aux_reached = kmem_from + kmem_size - aux_allocated;
|
|
size_t heap_reached = kmem_from + heap_allocated;
|
|
size_t unused_left = aux_reached - heap_reached;
|
|
if ( unused_left < size )
|
|
return errno = ENOMEM, false;
|
|
aux_allocated += size;
|
|
ret->from = kmem_from + kmem_size - aux_allocated;
|
|
ret->size = size;
|
|
return true;
|
|
}
|
|
|
|
void FreeKernelAddress(addralloc_t* alloc)
|
|
{
|
|
if ( !alloc->from )
|
|
return;
|
|
// Currently, nothing to do here.
|
|
alloc->from = 0;
|
|
alloc->size = 0;
|
|
}
|
|
|
|
size_t ExpandHeap(size_t increase)
|
|
{
|
|
increase = Page::AlignUp(increase);
|
|
ScopedLock lock(&alloc_lock);
|
|
addr_t kmem_from;
|
|
size_t kmem_size;
|
|
Memory::GetKernelVirtualArea(&kmem_from, &kmem_size);
|
|
addr_t aux_reached = kmem_from + kmem_size - aux_allocated;
|
|
size_t heap_reached = kmem_from + heap_allocated;
|
|
size_t unused_left = aux_reached - heap_reached;
|
|
if ( unused_left < increase )
|
|
return errno = ENOMEM, 0;
|
|
heap_allocated += increase;
|
|
return increase;
|
|
}
|
|
|
|
void ShrinkHeap(size_t decrease)
|
|
{
|
|
assert(decrease == Page::AlignUp(decrease));
|
|
ScopedLock lock(&alloc_lock);
|
|
assert(decrease <= heap_allocated);
|
|
heap_allocated -= decrease;
|
|
}
|
|
|
|
// No need for locks in these three functions, since only the heap calls these
|
|
// and it already uses an internal lock, and heap_allocated will not change
|
|
// unless the heap calls ExpandHeap.
|
|
|
|
addr_t GetHeapLower()
|
|
{
|
|
addr_t kmem_from;
|
|
size_t kmem_size;
|
|
Memory::GetKernelVirtualArea(&kmem_from, &kmem_size);
|
|
(void) kmem_size;
|
|
return kmem_from;
|
|
}
|
|
|
|
addr_t GetHeapUpper()
|
|
{
|
|
addr_t kmem_from;
|
|
size_t kmem_size;
|
|
Memory::GetKernelVirtualArea(&kmem_from, &kmem_size);
|
|
(void) kmem_size;
|
|
return kmem_from + heap_allocated;
|
|
}
|
|
|
|
size_t GetHeapSize()
|
|
{
|
|
return heap_allocated;
|
|
}
|
|
|
|
} // namespace Sortix
|