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#include <cpuid.h>
#include <stdint.h>
#include <lib.h>
#include <memory.h>
#define MEMORY_INTERNAL
#include <memory/physalloc.h>
#include <memory/virtalloc.h>
#include "paging.h"
#include "bindings.h"
// PAGE MAP LEVEL 4 ENTRY
struct pml4e {
uint64_t flags : 6;
uint64_t : 6;
uint64_t address : 40;
uint64_t : 11;
uint64_t execute_disable : 1;
};
// PAGE DIRECTORY POINTER TABLE ENTRY
struct pdpte {
uint64_t flags : 6;
uint64_t : 1;
uint64_t page_size : 1;
uint64_t : 4;
uint64_t address : 40;
uint64_t : 11;
uint64_t execute_disable : 1;
};
// PAGE DIRECTORY ENTRY
struct pde {
uint64_t flags : 6;
uint64_t : 1;
uint64_t page_size : 1;
uint64_t : 4;
uint64_t address : 40;
uint64_t : 11;
uint64_t execute_disable : 1;
};
// PAGE TABLE ENTRY
struct pte {
uint64_t flags : 9;
uint64_t : 3;
uint64_t address : 40;
uint64_t : 7;
uint64_t protection_key : 4;
uint64_t execute_disable : 1;
};
// bss segment, can write to
extern struct pml4e kernel_pml4[512];
extern struct pdpte kernel_pdpt_0[512];
extern struct pde kernel_pd_0[512];
extern struct pte bootstrap_pt[512];
extern struct pte paging_pt[512]; // paging_pt should NEVER be outside of this file, NEVER i say
// paged address to read page tables
// the structures are not gurenteed to be ident mapped
// map them here with map_<type>(phys_addr) before useing structures
static struct pdpte *pdpt_mapped = (void *) (uintptr_t) 0x201000;
static struct pdpte *pd_mapped = (void *) (uintptr_t) 0x202000;
static struct pdpte *pt_mapped = (void *) (uintptr_t) 0x203000;
void *addr_mapped = (void *) (uintptr_t) 0x204000;
static inline void invlpg(void *addr) {
__asm volatile("invlpg (%0)" ::"r" (addr) : "memory");
}
static void map_pdpt(struct pdpte *phys_addr) {
paging_pt[1].address = (((uint64_t)phys_addr) >> 12);
paging_pt[1].flags = F_PRESENT | F_WRITEABLE;
invlpg(pdpt_mapped);
}
static void map_pd(struct pde *phys_addr) {
paging_pt[2].address = (((uint64_t)phys_addr) >> 12);
paging_pt[2].flags = F_PRESENT | F_WRITEABLE;
invlpg(pd_mapped);
}
static void map_pt(struct pte *phys_addr) {
paging_pt[3].address = (((uint64_t)phys_addr) >> 12);
paging_pt[3].flags = F_PRESENT | F_WRITEABLE;
invlpg(pt_mapped);
}
static void map_addr(void *phys_addr) {
paging_pt[4].address = (((uint64_t)phys_addr) >> 12);
paging_pt[4].flags = F_PRESENT | F_WRITEABLE;
invlpg(addr_mapped);
}
//static int get_maxphysaddr() {
// uint32_t eax, ebx, ecx, edx;
// __cpuid(0x80000008, eax, ebx, ecx, edx);
// return eax & 0xFF;
//}
//int find_phys_addr(struct pml4e *pml4, void *virt_addr, void **phys_addr) {
// uint64_t pml4_offset = ((uint64_t)virt_addr) >> 39;
// uint64_t pdpt_offset = (((uint64_t)virt_addr) >> 30) & 0x1FF;
// uint64_t pd_offset = (((uint64_t)virt_addr) >> 21) & 0x1FF;
// uint64_t pt_offset = (((uint64_t)virt_addr) >> 12) & 0x1FF;
// uint64_t page_offset = (((uint64_t)virt_addr) ) & 0xFFF;
//
// if (!(pml4[pml4_offset].flags & F_PRESENT))
// return -1;
// struct pdpte *pdpt = (struct pdpte *)(pml4[pml4_offset].address << 12);
// if (!(pdpt[pdpt_offset].flags & F_PRESENT))
// return -1;
// struct pde *pd = (struct pde *)(pdpt[pdpt_offset].address << 12);
// if (!(pd[pd_offset].flags & F_PRESENT))
// return -1;
// struct pte *pt = (struct pte *)(pd[pd_offset].address << 12);
// if (!(pt[pt_offset].flags & F_PRESENT))
// return -1;
// *phys_addr = (void *)((pt[pt_offset].address << 12) + page_offset);
// return 0;
//}
char *curr_alloc = (void *) 0x5000;
int map_page(struct pml4e *pml4, void *virt_addr, void *phys_addr, unsigned int flags) {
uint64_t pml4_offset = ((uint64_t)virt_addr) >> 39;
uint64_t pdpt_offset = (((uint64_t)virt_addr) >> 30) & 0x1FF;
uint64_t pd_offset = (((uint64_t)virt_addr) >> 21) & 0x1FF;
uint64_t pt_offset = (((uint64_t)virt_addr) >> 12) & 0x1FF;
//uint64_t page_offset = (((uint64_t)virt_addr) ) & 0xFFF;
if (!(pml4[pml4_offset].flags & F_PRESENT)) {
void *new_page = alloc_phys_page();
map_addr(new_page);
memset(addr_mapped, 0, 4096);
pml4[pml4_offset].address = ((uint64_t)new_page) >> 12;
}
pml4[pml4_offset].flags = F_PRESENT | flags;
struct pdpte *__pdpt = (struct pdpte *)(uintptr_t)(pml4[pml4_offset].address << 12);
map_pdpt(__pdpt);
if (!(pdpt_mapped[pdpt_offset].flags & F_PRESENT)) {
void *new_page = alloc_phys_page();
map_addr(new_page);
memset(addr_mapped, 0, 4096);
pdpt_mapped[pdpt_offset].address = ((uint64_t)new_page) >> 12;
}
pdpt_mapped[pdpt_offset].flags = F_PRESENT | flags;
struct pde *__pd = (struct pde *)(uintptr_t)(pdpt_mapped[pdpt_offset].address << 12);
map_pd(__pd);
if (!(pd_mapped[pd_offset].flags & F_PRESENT)) {
void *new_page = alloc_phys_page();
map_addr(new_page);
memset(addr_mapped, 0, 4096);
pd_mapped[pd_offset].address = ((uint64_t)new_page) >> 12;
}
pd_mapped[pd_offset].flags = F_PRESENT | flags;
struct pte *__pt = (struct pte *)(uintptr_t)(pd_mapped[pd_offset].address << 12);
map_pt(__pt);
pt_mapped[pt_offset].flags = F_PRESENT | flags;
pt_mapped[pt_offset].address = (((uint64_t)phys_addr) >> 12);
invlpg(virt_addr);
return 0;
}
int unmap_page(struct pml4e *pml4, void *virt_addr) {
uint64_t pml4_offset = ((uint64_t)virt_addr) >> 39;
uint64_t pdpt_offset = (((uint64_t)virt_addr) >> 30) & 0x1FF;
uint64_t pd_offset = (((uint64_t)virt_addr) >> 21) & 0x1FF;
uint64_t pt_offset = (((uint64_t)virt_addr) >> 12) & 0x1FF;
//uint64_t page_offset = (((uint64_t)virt_addr) ) & 0xFFF;
if (!(pml4[pml4_offset].flags & F_PRESENT))
return -1;
struct pdpte *__pdpt = (struct pdpte *)(uintptr_t)(pml4[pml4_offset].address << 12);
map_pdpt(__pdpt);
if (!(pdpt_mapped[pdpt_offset].flags & F_PRESENT))
return -1;
struct pde *__pd = (struct pde *)(uintptr_t)(pdpt_mapped[pdpt_offset].address << 12);
map_pd(__pd);
if (!(pd_mapped[pd_offset].flags & F_PRESENT))
return -1;
struct pte *__pt = (struct pte *)(uintptr_t)(pd_mapped[pd_offset].address << 12);
map_pt(__pt);
if (!(pt_mapped[pt_offset].flags & F_PRESENT))
return -1;
pt_mapped[pt_offset].flags = 0;
int i = 0;
for(; i < 512; i++) {
if (pt_mapped[i].flags & F_PRESENT)
break;
}
if (i == 512)
goto done;
pd_mapped[pd_offset].flags = 0;
for(i = 0; i < 512; i++) {
if (pd_mapped[i].flags & F_PRESENT)
break;
}
if (i == 512)
goto done;
pdpt_mapped[pdpt_offset].flags = 0;
for(i = 0; i < 512; i++) {
if(pdpt_mapped[i].flags & F_PRESENT)
break;
}
if (i == 512)
goto done;
pml4[pml4_offset].flags = 0;
//TODO: Return memory used for page structures
done:
invlpg(virt_addr);
return 0;
}
void paging_init(void) {
kernel_pml4[0].flags = F_PRESENT | F_WRITEABLE;
kernel_pml4[0].address = (uint64_t)(&kernel_pdpt_0) >> 12;
kernel_pdpt_0[0].flags = F_PRESENT | F_WRITEABLE;
kernel_pdpt_0[0].address = (uint64_t)(&kernel_pd_0) >> 12;
kernel_pd_0[1].flags = F_PRESENT | F_WRITEABLE;
kernel_pd_0[1].address = (uint64_t)(&paging_pt) >> 12;
kernel_pd_0[2].flags = F_PRESENT | F_WRITEABLE;
kernel_pd_0[2].address = (uint64_t)(&bootstrap_pt) >> 12;
memset(&paging_pt, 0, 4096);
memset(&bootstrap_pt, 0, 4096);
}
static inline void *page_align(void *addr) {
uintptr_t a = (uintptr_t) addr;
a += PAGE_SIZE - 1;
a /= PAGE_SIZE;
a *= PAGE_SIZE;
return (void *) a;
}
void *mmap(void *addr, size_t len) {
len += (long)addr % PAGE_SIZE;
long pages = (len + PAGE_SIZE - 1) / PAGE_SIZE;
void *virt = virtaddr_alloc(pages);
if (virt == NULL) {
return NULL;
}
void *phys = page_align(addr);
for (long i = 0; i < pages; i++) {
void *virt_temp = (char *)virt + (i * PAGE_SIZE);
void *phys_temp = (char *)phys + (i * PAGE_SIZE);
map_page(kernel_pml4, virt_temp, phys_temp, F_WRITEABLE);
}
map_page(kernel_pml4, virt, (void*)0x23443, F_WRITEABLE);
return virt;
}
void unmap(void *addr) {
long pages = virtaddr_free(addr);
for (long i = 0; i < pages; i++) {
void *virt = (char *)addr + (i * PAGE_SIZE);
unmap_page(kernel_pml4, virt);
}
}
void *alloc_pages(int count) {
void *virt = virtaddr_alloc(count);
if (virt == NULL)
return NULL;
void *phys = alloc_phys_pages(count);
if (phys == NULL) {
virtaddr_free(virt);
return NULL;
}
for (int i = 0; i < count; i++) {
void *virt_temp = (char *)virt + (i * PAGE_SIZE);
void *phys_temp = (char *)phys + (i * PAGE_SIZE);
map_page(kernel_pml4, virt_temp, phys_temp, F_WRITEABLE);
}
return virt;
}
void free_page(void *virt) {
long pages = virtaddr_free(virt);
if (pages < 1)
return;
for (long i = 0; i < pages; i++) {
void *virt_temp = (char *)virt + (i * PAGE_SIZE);
unmap_page(kernel_pml4, virt_temp);
}
}
void memory_lock(void) {
cli();
}
void memory_unlock(void) {
sti();
}
int kmap_page(void *virt_addr, void *phys_addr, unsigned int flags) {
return map_page(kernel_pml4, virt_addr, phys_addr, flags);
}
int kunmap_page(void *virt_addr) {
return unmap_page(kernel_pml4, virt_addr);
}
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