1
0
Fork 0
mirror of https://gitlab.com/sortix/sortix.git synced 2023-02-13 20:55:38 -05:00
sortix--sortix/kernel/addralloc.cpp
Jonas 'Sortie' Termansen 2b72262b4f Relicense Sortix to the ISC license.
I hereby relicense all my work on Sortix under the ISC license as below.

All Sortix contributions by other people are already under this license,
are not substantial enough to be copyrightable, or have been removed.

All imported code from other projects is compatible with this license.

All GPL licensed code from other projects had previously been removed.

Copyright 2011-2016 Jonas 'Sortie' Termansen and contributors.

Permission to use, copy, modify, and distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
2016-03-05 22:21:50 +01:00

128 lines
3.7 KiB
C++

/*
* Copyright (c) 2013, 2014 Jonas 'Sortie' Termansen.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* 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;
}
// TODO: Proper deallocation support!
void FreeKernelAddress(addralloc_t* alloc)
{
if ( !alloc->from )
return;
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;
if ( alloc->from == aux_reached )
aux_allocated -= alloc->size;
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