mirror of
https://github.com/Tom-on64/kern.git
synced 2026-11-03 18:22:22 +00:00
The great 64-bit rewrite
* We did loose tasking and only have a paging skeleton, but hey it took like 4 months so i'm happy that there's something :p
This commit is contained in:
+20
-223
@@ -1,238 +1,35 @@
|
||||
#include "serial.h"
|
||||
#include <bootloader.h>
|
||||
#include <kernel.h>
|
||||
#include <string.h>
|
||||
#include <pmm.h>
|
||||
|
||||
#include <paging.h>
|
||||
|
||||
#define PAGE_DIR_COUNT 256
|
||||
static uint32_t pagedirs[PAGE_DIR_COUNT][1024] __align(4096);
|
||||
static uint8_t pagedir_used[PAGE_DIR_COUNT];
|
||||
size_t* pag_globalpd = NULL;
|
||||
|
||||
// TODO: Should this be initialized? If so, to what?
|
||||
size_t pag_page_count = 0;
|
||||
void pag_invalidate(size_t vaddr) { __asm__ volatile ("invlpg %0" ::"m"(vaddr)); }
|
||||
|
||||
// Invalidates the pagedir entry in the CPUs TLB cache
|
||||
static inline void invalidate(uint32_t vaddr) {
|
||||
__asm__ volatile ("invlpg %0" : : "m"(vaddr));
|
||||
}
|
||||
int pag_init() {
|
||||
size_t pd_phys = 0;
|
||||
__asm__ volatile ("movq %%cr3, %0" : "=r"(pd_phys));
|
||||
if (!pd_phys) return 1;
|
||||
|
||||
// Temp paging thing
|
||||
uint32_t temp_frame_start;
|
||||
void pag_register_temp_frame(uint32_t target) { temp_frame_start = target; }
|
||||
uint32_t pag_temp_frame(void) {
|
||||
uint32_t fin = temp_frame_start;
|
||||
temp_frame_start += PAGE_SIZE;
|
||||
return fin;
|
||||
}
|
||||
size_t pd_virt = pd_phys + bootloader.hhdm_offset;
|
||||
pag_globalpd = (size_t*)pd_virt;
|
||||
|
||||
int pag_init(void) {
|
||||
// Unmap first MB
|
||||
init_pagedir[0] = 0;
|
||||
invalidate(0);
|
||||
|
||||
/*
|
||||
* Recursive table mapping
|
||||
* We map the last pagetab to the pagedir itself, so it acts
|
||||
* as a pagetab even though it's a pagedir. This maps it to
|
||||
* the virtual address 0xFFFFF000.
|
||||
*/
|
||||
init_pagedir[1023] = ((uint32_t)init_pagedir - KERNEL_BASE) |
|
||||
PAGE_FLAG_PRESENT | PAGE_FLAG_WRITE;
|
||||
invalidate(1023 * PAGE_SIZE);
|
||||
|
||||
// TODO: This sometimes causes a #PF
|
||||
memset(pagedirs, 0, PAGE_SIZE * PAGE_DIR_COUNT);
|
||||
memset(pagedir_used, 0, PAGE_DIR_COUNT);
|
||||
|
||||
debugf("[pag] Paging initalized.\n");
|
||||
debugf("[pag] Paging initialized.");
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
void pag_map(uint32_t vaddr, uint32_t paddr, uint32_t flags) {
|
||||
// Save the pagedir we were in
|
||||
uint32_t* prevpd = NULL;
|
||||
|
||||
// Switch to the init pagedir if in kernel memory
|
||||
if (vaddr >= KERNEL_BASE) {
|
||||
prevpd = pag_get_pagedir();
|
||||
if (prevpd != init_pagedir) pag_set_pagedir(init_pagedir);
|
||||
}
|
||||
|
||||
// Extract indecies
|
||||
size_t pdi = vaddr >> 22;
|
||||
size_t pti = vaddr >> 12 & 0x3FF;
|
||||
|
||||
uint32_t* pagedir = PAGEDIR;
|
||||
uint32_t* pagetab = PAGETAB(pdi);
|
||||
|
||||
// Allocate a pagetab if it didn't exist
|
||||
if (!(pagedir[pdi] & PAGE_FLAG_PRESENT)) {
|
||||
uint32_t tabaddr = pmm_bitmap.ready ? pmm_alloc() : pag_temp_frame();
|
||||
|
||||
pagedir[pdi] = tabaddr |
|
||||
PAGE_FLAG_PRESENT | PAGE_FLAG_WRITE | PAGE_FLAG_OWNER | flags;
|
||||
invalidate(vaddr);
|
||||
|
||||
|
||||
for (size_t i = 0; i < 1024; i++) {
|
||||
pagetab[i] = 0;
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
// The actuall mapping
|
||||
pagetab[pti] = paddr | PAGE_FLAG_PRESENT | flags;
|
||||
pag_page_count++;
|
||||
invalidate(vaddr);
|
||||
|
||||
// Do we need to return to the original pagedir?
|
||||
if (prevpd != NULL) {
|
||||
pag_sync_pagedir(); // Sync it to other pagedirs
|
||||
if (prevpd != init_pagedir) pag_set_pagedir(prevpd);
|
||||
}
|
||||
}
|
||||
|
||||
uint32_t pag_umap(uint32_t vaddr) {
|
||||
// Same saving as in pag_map()
|
||||
uint32_t* prevpd = NULL;
|
||||
|
||||
if (vaddr >= KERNEL_BASE) {
|
||||
prevpd = pag_get_pagedir();
|
||||
if (prevpd != init_pagedir) pag_set_pagedir(init_pagedir);
|
||||
}
|
||||
|
||||
// Extract indecies
|
||||
size_t pdi = vaddr >> 22;
|
||||
size_t pti = vaddr >> 12 & 0x3FF;
|
||||
|
||||
uint32_t* pagedir = PAGEDIR;
|
||||
uint32_t* pagetab = PAGETAB(pdi);
|
||||
|
||||
uint32_t pte = pagetab[pti];
|
||||
pagetab[pti] = 0;
|
||||
pag_page_count--;
|
||||
|
||||
// Look if we can free the pagetab
|
||||
int remove = 1;
|
||||
for (size_t i = 0; i < 1024; i++) {
|
||||
if (!(pagetab[i] & PAGE_FLAG_PRESENT)) continue;
|
||||
remove = 0;
|
||||
break;
|
||||
}
|
||||
|
||||
// Free the pagetab if possible
|
||||
uint32_t pde = pagedir[pdi];
|
||||
if (remove && pde & PAGE_FLAG_OWNER) {
|
||||
uint32_t tabaddr = PHYS_ADDR(pde);
|
||||
pmm_free(tabaddr);
|
||||
pagedir[pdi] = 0;
|
||||
}
|
||||
|
||||
invalidate(vaddr);
|
||||
|
||||
// Free the page frame
|
||||
if (pte & PAGE_FLAG_OWNER) pmm_free(PHYS_ADDR(pte));
|
||||
|
||||
if (prevpd != NULL) {
|
||||
pag_sync_pagedir(); // Sync it to other pagedirs
|
||||
if (prevpd != init_pagedir) pag_set_pagedir(prevpd);
|
||||
}
|
||||
|
||||
return pte;
|
||||
}
|
||||
|
||||
uint32_t pag_virt_to_phys(uint32_t vaddr) {
|
||||
uint32_t pdi = vaddr >> 22;
|
||||
uint32_t pti = vaddr >> 12 & 0x3FF;
|
||||
|
||||
uint32_t* pagetab = PAGETAB(pdi);
|
||||
|
||||
return (pagetab[pti] & ~0xFFF) + ((uint32_t)vaddr & 0xFFF);
|
||||
}
|
||||
|
||||
uint32_t* pag_get_pagedir() {
|
||||
uint32_t pagedir;
|
||||
__asm__ volatile ("mov %%cr3, %0" : "=r"(pagedir));
|
||||
pagedir += KERNEL_BASE;
|
||||
return (uint32_t*)pagedir;
|
||||
}
|
||||
|
||||
void pag_set_pagedir(uint32_t* pagedir) {
|
||||
pagedir = (uint32_t*)((uint32_t)pagedir - KERNEL_BASE);
|
||||
__asm__ volatile (
|
||||
"mov %0, %%eax\n"
|
||||
"mov %%eax, %%cr3"
|
||||
: : "m"(pagedir)
|
||||
);
|
||||
}
|
||||
|
||||
void pag_sync_pagedir() {
|
||||
for (size_t i = 0; i < PAGE_DIR_COUNT; i++) {
|
||||
if (!pagedir_used[i]) continue;
|
||||
|
||||
uint32_t* pagedir = pagedirs[i];
|
||||
|
||||
// Sync ONLY the kernel pages so 768 has base at 0xC0000000
|
||||
// Also don't sync the recursive mapping in the last page
|
||||
for (size_t i = 768; i < 1023; i++) {
|
||||
pagedir[i] = init_pagedir[i] & ~PAGE_FLAG_OWNER;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
uint32_t* pag_alloc_pagedir() {
|
||||
// Find the first unused page
|
||||
for (size_t i = 0; i < PAGE_DIR_COUNT; i++) {
|
||||
if (pagedir_used[i]) continue;
|
||||
pagedir_used[i] = 1;
|
||||
|
||||
uint32_t* pagedir = pagedirs[i];
|
||||
memset(pagedir, 0, PAGE_SIZE);
|
||||
|
||||
// First 768 entries are user pagetabs (3:1 memory split)
|
||||
for (size_t i = 0; i < 768; i++) pagedir[i] = 0;
|
||||
|
||||
// Next 255 are kernel space
|
||||
for (size_t i = 768; i < 1023; i++) pagedir[i] = init_pagedir[i] & ~PAGE_FLAG_OWNER;
|
||||
|
||||
// Last page is the recursive table mapping
|
||||
pagedir[1023] = ((uint32_t)pagedir - KERNEL_BASE) |
|
||||
PAGE_FLAG_PRESENT | PAGE_FLAG_WRITE;
|
||||
|
||||
return pagedir;
|
||||
}
|
||||
|
||||
// No pages left - out of memory
|
||||
return NULL;
|
||||
}
|
||||
|
||||
void pag_free_pagedir(uint32_t* pagedir) {
|
||||
uint32_t* prevpd = pag_get_pagedir();
|
||||
pag_set_pagedir(pagedir);
|
||||
|
||||
uint32_t pdi = (uint32_t)pagedir - (uint32_t)pagedirs;
|
||||
pdi /= PAGE_SIZE;
|
||||
|
||||
// Free all allocated page frames & pagetabs
|
||||
uint32_t* pd = PAGEDIR;
|
||||
for (int i = 0; i < 768; i++) {
|
||||
uint32_t pde = pd[i];
|
||||
if (pde == 0) continue;
|
||||
|
||||
uint32_t* pagetab = PAGETAB(i);
|
||||
for (size_t j = 0; j < 1024; j++) {
|
||||
uint32_t pte = pagetab[j];
|
||||
|
||||
if (pte & PAGE_FLAG_OWNER) pmm_free(PHYS_ADDR(pte));
|
||||
}
|
||||
memset(pagetab, 0, PAGE_SIZE);
|
||||
|
||||
if (pde & PAGE_FLAG_OWNER) pmm_free(PHYS_ADDR(pde));
|
||||
pd[i] = 0;
|
||||
}
|
||||
|
||||
pagedir_used[pdi] = 0;
|
||||
pag_set_pagedir(prevpd);
|
||||
}
|
||||
void pag_map(size_t vaddr, size_t paddr, size_t flags);
|
||||
size_t pag_umap(size_t vaddr);
|
||||
size_t pag_virt_to_phys(size_t vaddr);
|
||||
size_t* pag_get_pagedir();
|
||||
size_t* pag_get_task_pagedir(void* task);
|
||||
void pag_set_pagedir(size_t* pagedir);
|
||||
size_t* pag_alloc_pagedir();
|
||||
void pag_free_pagedir(size_t* pagedir);
|
||||
void pag_invalidate(size_t vaddr);
|
||||
|
||||
|
||||
Reference in New Issue
Block a user