nuclear@17: #include <stdio.h>
nuclear@17: #include <string.h>
nuclear@17: #include <inttypes.h>
nuclear@17: #include "vm.h"
nuclear@17: #include <stdio.h>
nuclear@17: #include "intr.h"
nuclear@17: #include "mem.h"
nuclear@17: #include "panic.h"
nuclear@17: 
nuclear@17: 
nuclear@17: /* defined in vm-asm.S */
nuclear@17: void enable_paging(void);
nuclear@17: void set_pgdir_addr(uint32_t addr);
nuclear@17: uint32_t get_fault_addr(void);
nuclear@17: 
nuclear@17: static void pgfault(int inum, uint32_t err);
nuclear@17: 
nuclear@17: /* page directory */
nuclear@18: static uint32_t *pgdir;
nuclear@17: 
nuclear@17: #define KMEM_START		0xc0000000
nuclear@17: #define IDMAP_START		0xa0000
nuclear@17: 
nuclear@17: #define ATTR_PGDIR_MASK	0x3f
nuclear@17: #define ATTR_PGTBL_MASK	0x1ff
nuclear@17: #define ADDR_PGENT_MASK	0xfffff000
nuclear@17: 
nuclear@17: #define PAGEFAULT		14
nuclear@17: 
nuclear@17: void init_vm(struct mboot_info *mb)
nuclear@17: {
nuclear@19: 	uint32_t idmap_end;
nuclear@19: 
nuclear@17: 	init_mem(mb);
nuclear@17: 
nuclear@18: 	pgdir = (uint32_t*)alloc_phys_page();
nuclear@17: 	memset(pgdir, 0, sizeof pgdir);
nuclear@17: 
nuclear@17: 	/* map the video memory and kernel code 1-1 */
nuclear@19: 	get_kernel_mem_range(0, &idmap_end);
nuclear@19: 	map_mem_range(IDMAP_START, idmap_end - IDMAP_START, IDMAP_START, 0);
nuclear@17: 
nuclear@17: 	interrupt(PAGEFAULT, pgfault);
nuclear@17: 
nuclear@17: 	set_pgdir_addr((int32_t)pgdir);
nuclear@17: 	enable_paging();
nuclear@17: }
nuclear@17: 
nuclear@17: void map_page(int vpage, int ppage, unsigned int attr)
nuclear@17: {
nuclear@17: 	uint32_t *pgtbl;
nuclear@17: 	int diridx = PAGE_TO_PGTBL(vpage);
nuclear@17: 	int pgidx = PAGE_TO_PGTBL_PG(vpage);
nuclear@17: 
nuclear@17: 	if(!(pgdir[diridx] & PG_PRESENT)) {
nuclear@17: 		uint32_t addr = alloc_phys_page();
nuclear@17: 		pgtbl = (uint32_t*)addr;
nuclear@18: 		memset(pgtbl, 0, PGSIZE);
nuclear@18: 
nuclear@17: 		pgdir[diridx] = addr | (attr & ATTR_PGDIR_MASK) | PG_PRESENT;
nuclear@17: 	} else {
nuclear@17: 		pgtbl = (uint32_t*)(pgdir[diridx] & ADDR_PGENT_MASK);
nuclear@17: 	}
nuclear@17: 
nuclear@17: 	pgtbl[pgidx] = PAGE_TO_ADDR(ppage) | (attr & ATTR_PGTBL_MASK) | PG_PRESENT;
nuclear@17: }
nuclear@17: 
nuclear@17: void unmap_page(int vpage)
nuclear@17: {
nuclear@17: 	uint32_t *pgtbl;
nuclear@17: 	int diridx = PAGE_TO_PGTBL(vpage);
nuclear@17: 	int pgidx = PAGE_TO_PGTBL_PG(vpage);
nuclear@17: 
nuclear@17: 	if(!(pgdir[diridx] & PG_PRESENT)) {
nuclear@17: 		goto err;
nuclear@17: 	}
nuclear@17: 	pgtbl = (uint32_t*)(pgdir[diridx] & ADDR_PGENT_MASK);
nuclear@17: 
nuclear@17: 	if(!(pgtbl[pgidx] & PG_PRESENT)) {
nuclear@17: 		goto err;
nuclear@17: 	}
nuclear@17: 	pgtbl[pgidx] = 0;
nuclear@17: 
nuclear@17: 	return;
nuclear@17: err:
nuclear@17: 	printf("unmap_page(%d): page already not mapped\n", vpage);
nuclear@17: }
nuclear@17: 
nuclear@17: void map_page_range(int vpg_start, int pgcount, int ppg_start, unsigned int attr)
nuclear@17: {
nuclear@17: 	int i;
nuclear@17: 
nuclear@17: 	for(i=0; i<pgcount; i++) {
nuclear@17: 		map_page(vpg_start + i, ppg_start + i, attr);
nuclear@17: 	}
nuclear@17: }
nuclear@17: 
nuclear@17: void map_mem_range(uint32_t vaddr, size_t sz, uint32_t paddr, unsigned int attr)
nuclear@17: {
nuclear@17: 	int vpg_start, ppg_start, num_pages;
nuclear@17: 
nuclear@17: 	if(!sz) return;
nuclear@17: 
nuclear@17: 	if(ADDR_TO_PGOFFS(paddr)) {
nuclear@17: 		panic("map_mem_range called with unaligned physical address: %x\n", paddr);
nuclear@17: 	}
nuclear@17: 
nuclear@17: 	vpg_start = ADDR_TO_PAGE(vaddr);
nuclear@17: 	ppg_start = ADDR_TO_PAGE(paddr);
nuclear@17: 	num_pages = ADDR_TO_PAGE(sz) + 1;
nuclear@17: 
nuclear@17: 	map_page_range(vpg_start, num_pages, ppg_start, attr);
nuclear@17: }
nuclear@17: 
nuclear@18: uint32_t virt_to_phys(uint32_t vaddr)
nuclear@18: {
nuclear@18: 	uint32_t pgaddr, *pgtbl;
nuclear@18: 	int diridx = ADDR_TO_PGTBL(vaddr);
nuclear@18: 	int pgidx = ADDR_TO_PGTBL_PG(vaddr);
nuclear@18: 
nuclear@18: 	if(!(pgdir[diridx] & PG_PRESENT)) {
nuclear@18: 		panic("virt_to_phys(%x): page table %d not present\n", vaddr, diridx);
nuclear@18: 	}
nuclear@18: 	pgtbl = (uint32_t*)(pgdir[diridx] & PGENT_ADDR_MASK);
nuclear@18: 
nuclear@18: 	if(!(pgtbl[pgidx] & PG_PRESENT)) {
nuclear@18: 		panic("virt_to_phys(%x): page %d not present\n", vaddr, ADDR_TO_PAGE(vaddr));
nuclear@18: 	}
nuclear@18: 	pgaddr = pgtbl[pgidx] & PGENT_ADDR_MASK;
nuclear@18: 
nuclear@18: 	return pgaddr | ADDR_TO_PGOFFS(vaddr);
nuclear@18: }
nuclear@18: 
nuclear@17: static void pgfault(int inum, uint32_t err)
nuclear@17: {
nuclear@17: 	printf("~~~~ PAGE FAULT ~~~~\n");
nuclear@17: 
nuclear@17: 	printf("fault address: %x\n", get_fault_addr());
nuclear@17: 
nuclear@17: 	if(err & PG_PRESENT) {
nuclear@17: 		if(err & 8) {
nuclear@17: 			printf("reserved bit set in some paging structure\n");
nuclear@17: 		} else {
nuclear@17: 			printf("%s protection violation ", (err & PG_WRITABLE) ? "write" : "read");
nuclear@17: 			printf("in %s mode\n", err & PG_USER ? "user" : "kernel");
nuclear@17: 		}
nuclear@17: 	} else {
nuclear@17: 		printf("page not present\n");
nuclear@17: 	}
nuclear@19: 
nuclear@19: 	panic("unhandled page fault\n");
nuclear@17: }