diff options
Diffstat (limited to 'src/kernel/paging/kheap.c')
| -rw-r--r-- | src/kernel/paging/kheap.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/src/kernel/paging/kheap.c b/src/kernel/paging/kheap.c new file mode 100644 index 0000000..13f8ab2 --- /dev/null +++ b/src/kernel/paging/kheap.c @@ -0,0 +1,168 @@ +#include "kheap.h" +#include "paging.h" +#include "../lib/lib.h" +#include "../system.h" + +unsigned int placement_address; + +heap_header_t *kheap = NULL; +heap_header_t *uheap = NULL; + +void init_kheap() { + end = (unsigned int) &end; + placement_address = end; + + kheap = (heap_header_t *) fmalloc(KHEAP_SIZE); + init_heap(kheap, KHEAP_SIZE); + + uheap = (heap_header_t *) kmalloc_a(UHEAP_SIZE); + init_heap(uheap, UHEAP_SIZE); + vpage_map_user(root_vpage_dir, (unsigned int) &uheap, (unsigned int) &uheap); +} + +void *fmalloc(unsigned int size) { + //assert(placement_address + size < MEM_END); + unsigned int hold = placement_address; + memory_set((void *) hold, 0, size); + placement_address += size; + return (void *) hold; +} + +void *kmalloc_a(unsigned int size) { + //assert(((placement_address & 0xFFFFF000) + 0x1000) + size < MEM_END); + placement_address &= 0xFFFFF000; + placement_address += 0x1000; + + unsigned int hold = placement_address; + placement_address += size; + + return (void *) hold; +} + +heap_header_t *find_sized_heap(heap_header_t *heap, size_t size) { + while ((heap->size < HEAP_FIND_SIZE + size) || (heap->free != 1)) { + assert(heap->magic == KHEAP_MAGIC); + assert(heap->magic2 == KHEAP_MAGIC2); + heap_footer_t *foot = (heap_footer_t *) ((unsigned int) heap + HEAP_S + heap->size); + assert(foot->magic == KHEAP_MAGIC); + assert(foot->magic2 == KHEAP_MAGIC2); + + if (foot->size == KHEAP_END) + panic("out of heap space"); + + if (foot->size != heap->size) + panic("heap footer/header mismatch"); + + heap = (heap_header_t *) ((unsigned int) foot + sizeof(heap_footer_t)); + } + + return heap; +} + +void split_heap(heap_header_t *heap, size_t size) { + heap_footer_t *foot = (heap_footer_t *) ((unsigned int) heap + HEAP_S + size); + foot->magic = KHEAP_MAGIC; + foot->magic2 = KHEAP_MAGIC2; + foot->size = size; + + size_t new_size = heap->size - HEAP_TOTAL - size; + heap->size = size; + + heap = (heap_header_t *) ((unsigned int) foot + sizeof(heap_footer_t)); + heap->size = new_size; + heap->free = 1; + heap->magic = KHEAP_MAGIC; + heap->magic2 = KHEAP_MAGIC2; + + foot = (heap_footer_t *) ((unsigned int) heap + HEAP_S + heap->size); + if ((foot->magic != KHEAP_MAGIC) || (foot->magic2 != KHEAP_MAGIC2)) { + warn("invalid footer in split"); + // dump_struct(foot, sizeof(heap_footer_t)); + } + + if (foot->size != KHEAP_END) + foot->size = new_size; +} + +void free_internal(heap_header_t *heap, void *address) { + heap_header_t *head = (heap_header_t *) ((unsigned int) address - HEAP_S); + if (head == heap) { + warn("can't collapse top of heap"); + head->free = 1; + return; + } + + if ((head->magic != KHEAP_MAGIC) || (head->magic2 != KHEAP_MAGIC2)) { + //warn("invalid header in heap"); + //dump_struct(head, sizeof(heap_header_t)); + return; + } + + heap_footer_t *foot = (heap_footer_t *) ((unsigned int) head + HEAP_S + head->size); + if ((foot->magic != KHEAP_MAGIC) || (foot->magic2 != KHEAP_MAGIC2)) + panic("bad heap in free() call"); + + foot = (heap_footer_t *) ((unsigned int) head - sizeof(heap_footer_t)); + if ((foot->magic != KHEAP_MAGIC) || (foot->magic2 != KHEAP_MAGIC2)) { + //warn("invalid footer in heap"); + return; + } + + if (foot->size == KHEAP_END) + panic("impossible condition for heap"); + + heap = (heap_header_t *) ((unsigned int) foot - foot->size - HEAP_S); + if ((heap->magic != KHEAP_MAGIC) || (heap->magic2 != KHEAP_MAGIC2)) { + warn("invalid parent in heap"); + return; + } + + foot = (heap_footer_t *) ((unsigned int) heap + (heap->size + head->size + HEAP_TOTAL) + HEAP_S); + if ((foot->magic != KHEAP_MAGIC) || (foot->magic2 != KHEAP_MAGIC2)) { + return; + } + + heap->size += head->size + HEAP_TOTAL; + foot->size = heap->size; +} + +void *malloc_internal(heap_header_t *heap, size_t size) { + heap = find_sized_heap(heap, size + 8); + heap->free = 0; + split_heap(heap, size); + return (void *) ((unsigned int) heap + HEAP_S); +} + +void init_heap(heap_header_t *heap, size_t size) { + heap->magic = KHEAP_MAGIC; + heap->magic2 = KHEAP_MAGIC2; + heap->free = 1; + heap->size = size - HEAP_TOTAL; + + heap_footer_t *foot = (heap_footer_t *) ((unsigned int) heap + HEAP_S + heap->size); + foot->magic = KHEAP_MAGIC; + foot->magic2 = KHEAP_MAGIC2; + foot->size = KHEAP_END; +} + +void *kmalloc(unsigned int size) { + if (kheap == NULL) + return fmalloc(size); + + return malloc_internal(kheap, size); +} + +void kfree(void *address) { + if (kheap == NULL) + return; + + free_internal(kheap, address); +} + +void *umalloc(size_t size) { + return malloc_internal(uheap, size); +} + +void ufree(void *address) { + free_internal(uheap, address); +}
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