blob: ea774285bec3b3f2060a2ae0ccea564e9003b634 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
|
#include <libk/kmalloc.h>
#include <kernel/paging.h>
#include <kernel/pmem.h>
#include <kernel/asm.h>
#include <kernel/vmem.h>
#include <kernel/panic.h>
#include <stdint.h>
static uintptr_t heap_start = KEND + 0xC0001000;
static uintptr_t heap_end = 0xFFBFF000;
static void *kbrk = NULL;
static struct mem_block *first = NULL;
void _request_page(void) {
uintptr_t paddr = pfa_alloc(1);
uintptr_t vaddr = PGROUNDDN((uintptr_t)kbrk + PAGE_SIZE);
kbrk += PAGE_SIZE;
map_page(paddr, vaddr, PD_PRES | PD_RW);
}
void kmalloc_init(void) {
kbrk = PGROUNDDN(heap_start);
_request_page();
first = (struct mem_block*)kbrk;
first->start = (uintptr_t)kbrk + sizeof(struct mem_block);
first->size = 0;
first->alloc = 1;
first->next = NULL;
}
void* kmalloc(size_t sz) {
if (kbrk == NULL)
panic("Attmpted to malloc before initialization");
if ((uintptr_t)kbrk >= heap_end)
return NULL;
struct mem_block *temp = first;
while (temp->next != NULL) {
if (temp->next->size <= sz && temp->next->alloc == 0) {
temp->next->alloc = 1;
return (void*)temp->next->start;
}
temp = temp->next;
}
temp->next = (struct mem_block*)((uintptr_t)temp + sizeof(struct mem_block) + temp->size);
if (temp->next > kbrk)
_request_page();
temp->next->prev = temp;
temp->next->start = (uintptr_t)(temp->next + sizeof(struct mem_block));
temp->next->size = sz;
temp->next->alloc = 1;
temp->next->next = NULL;
return (void*)temp->start;
}
void kfree(void *ptr) {
struct mem_block *temp = first;
while (temp != NULL) {
if (temp->start == (uintptr_t)ptr) {
temp->alloc = 0;
return;
}
temp = temp->next;
}
panic("Attempted to free memory not alloc'd");
}
|
