130 lines
3.5 KiB
C
130 lines
3.5 KiB
C
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//----------------------------------------------------------------------------//
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// GNU GPL OS/K //
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// //
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// Desc: Early and very dumb heap managment //
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// //
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// //
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// Copyright © 2018-2019 The OS/K Team //
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// //
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// This file is part of OS/K. //
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// //
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// OS/K is free software: you can redistribute it and/or modify //
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// it under the terms of the GNU General Public License as published by //
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// the Free Software Foundation, either version 3 of the License, or //
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// any later version. //
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// //
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// OS/K is distributed in the hope that it will be useful, //
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// but WITHOUT ANY WARRANTY//without even the implied warranty of //
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the //
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// GNU General Public License for more details. //
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// //
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// You should have received a copy of the GNU General Public License //
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// along with OS/K. If not, see <https://www.gnu.org/licenses/>. //
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//----------------------------------------------------------------------------//
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#include <kernel/heap.h>
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// Least address out of the heap
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static void *_heap_end;
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// Maximal value of the heap
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static size_t _heap_max;
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// Lock NOT used internally, but used by KalAllocMemory() & co.
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static Lock_t _heap_lock = INITLOCK(KLOCK_SPINLOCK);
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// Debugging stub
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size_t GetAvailZoneSize(void *x) { (void)x; return 8 * MB; }
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//
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// Initializes heap managment
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//
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void InitHeap(void)
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{
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assert(_heap_end == NULL);
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_heap_end = (void *)_HEAP_START;
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_heap_max = lmin(8 * MB, GetAvailZoneSize((void *)_HEAP_START));
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}
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//
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// Aquires control of the heap's lock
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//
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void LockHeap(void)
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{
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AquireLock(&_heap_lock);
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}
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//
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// Releases control of the heap's lock
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//
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void UnlockHeap(void)
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{
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ReleaseLock(&_heap_lock);
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}
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//
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// Returns the heap's current size
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//
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size_t GetHeapSize(void)
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{
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return (size_t)_heap_end - _HEAP_START;
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}
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//
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// Returns the heap's maximum size
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//
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size_t GetMaxHeapSize(void)
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{
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return _heap_max;
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}
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//
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// Changes the heap's maximal size
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//
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error_t SetMaxHeapSize(size_t new)
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{
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if (new > GetAvailZoneSize((void *)_HEAP_START)) {
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return ENOMEM;
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}
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if (new < (size_t)_heap_end - _HEAP_START) {
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return EADDRINUSE;
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}
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_heap_max = new;
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return EOK;
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}
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//
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// Extends the heap's size
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//
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error_t GrowHeap(size_t req)
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{
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assert(req % alignof(QWORD));
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if ((size_t)_heap_end + req > _HEAP_START + _heap_max) {
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return ENOMEM;
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}
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_heap_end += req;
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return EOK;
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}
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//
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// Reduces the heap's size
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//
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error_t ShrinkHeap(size_t req)
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{
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assert(req % alignof(QWORD));
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if (req > (size_t)_heap_end - _HEAP_START) {
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return EADDRINUSE;
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}
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_heap_end -= req;
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return EOK;
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}
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