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#include <kernel/pmem.h>
#include <kernel/asm.h>
#include <kernel/panic.h>
#include <kernel/paging.h>
#include <libk/io.h>
#include <libk/string.h>
struct pfa_page freelist;
void pfa_init(struct mboot_info *header) {
struct mboot_mmap_entry *mme;
struct mboot_mmap_entry *temp_map;
for (uintptr_t i = 0; i < header->mmap_length; i += sizeof(struct mboot_mmap_entry)) {
mme = (struct mboot_mmap_entry*)(header->mmap_addr + i);
temp_map = (struct mboot_mmap_entry*)GET_VADDR(mme);
map_page(NULL, (uintptr_t)mme, (uintptr_t)temp_map, PD_PRES);
if (temp_map->type == MBOOT_MEM_AVAILABLE)
pfa_free_range(temp_map->addr_low, temp_map->addr_low + temp_map->len_low);
unmap_page(NULL, (uintptr_t)temp_map);
}
}
uintptr_t pfa_alloc(void) {
struct pfa_page *ret = freelist.next;
if (ret == NULL)
return PFA_ALLOC_ERR;
struct pfa_page *temp_map = (struct pfa_page*)0x1000;
map_page(NULL, (uintptr_t)ret, (uintptr_t)temp_map, PD_PRES | PD_RW);
memset((char*)temp_map, 0, PAGE_SIZE);
unmap_page(NULL, (uintptr_t)temp_map);
return (uintptr_t)ret;
}
void pfa_free(uintptr_t paddr) {
if (paddr % PAGE_SIZE != 0)
panic("Task attempted to free non-aligned memory");
if (paddr == 0)
return;
if (paddr >= KSTART && paddr < KEND)
return;
if (paddr >= 0x80000 && paddr < 0x100000)
return;
struct pfa_page *temp_map = (struct pfa_page*)0x1000;
map_page(NULL, paddr, (uintptr_t)temp_map, PD_PRES | PD_RW);
memset(temp_map, 1, 32);
temp_map->next = freelist.next;
freelist.next = (struct pfa_page*)paddr;
unmap_page(NULL, (uintptr_t)temp_map);
}
void pfa_free_range(uintptr_t start, uintptr_t end) {
for (uintptr_t i = start; i < end; i += PAGE_SIZE)
pfa_free(i);
}
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