kern

annotate src/vm.c @ 18:096807345aa2

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fixed the stupid mistake. forgot to page-align the page directory
author John Tsiombikas <nuclear@member.fsf.org>
date Sun, 27 Mar 2011 06:28:26 +0300
parents 098b1cb5eeaa
children 8be069e6bb05
rev   line source
nuclear@17 1 #include <stdio.h>
nuclear@17 2 #include <string.h>
nuclear@17 3 #include <inttypes.h>
nuclear@17 4 #include "vm.h"
nuclear@17 5 #include <stdio.h>
nuclear@17 6 #include "intr.h"
nuclear@17 7 #include "mem.h"
nuclear@17 8 #include "panic.h"
nuclear@17 9
nuclear@17 10
nuclear@17 11 /* defined in vm-asm.S */
nuclear@17 12 void enable_paging(void);
nuclear@17 13 void set_pgdir_addr(uint32_t addr);
nuclear@17 14 uint32_t get_fault_addr(void);
nuclear@17 15
nuclear@17 16 static void pgfault(int inum, uint32_t err);
nuclear@17 17
nuclear@17 18 /* page directory */
nuclear@18 19 static uint32_t *pgdir;
nuclear@17 20
nuclear@17 21 #define KMEM_START 0xc0000000
nuclear@17 22 #define IDMAP_START 0xa0000
nuclear@17 23
nuclear@17 24 #define ATTR_PGDIR_MASK 0x3f
nuclear@17 25 #define ATTR_PGTBL_MASK 0x1ff
nuclear@17 26 #define ADDR_PGENT_MASK 0xfffff000
nuclear@17 27
nuclear@17 28 #define PAGEFAULT 14
nuclear@17 29
nuclear@17 30 void init_vm(struct mboot_info *mb)
nuclear@17 31 {
nuclear@17 32 init_mem(mb);
nuclear@17 33
nuclear@18 34 pgdir = (uint32_t*)alloc_phys_page();
nuclear@17 35 memset(pgdir, 0, sizeof pgdir);
nuclear@17 36
nuclear@17 37 /* map the video memory and kernel code 1-1 */
nuclear@17 38 map_mem_range(IDMAP_START, MAX_BRK - IDMAP_START, IDMAP_START, 0);
nuclear@17 39
nuclear@17 40 interrupt(PAGEFAULT, pgfault);
nuclear@17 41
nuclear@17 42 set_pgdir_addr((int32_t)pgdir);
nuclear@17 43 enable_paging();
nuclear@17 44 }
nuclear@17 45
nuclear@17 46 void map_page(int vpage, int ppage, unsigned int attr)
nuclear@17 47 {
nuclear@17 48 uint32_t *pgtbl;
nuclear@17 49 int diridx = PAGE_TO_PGTBL(vpage);
nuclear@17 50 int pgidx = PAGE_TO_PGTBL_PG(vpage);
nuclear@17 51
nuclear@17 52 if(!(pgdir[diridx] & PG_PRESENT)) {
nuclear@17 53 uint32_t addr = alloc_phys_page();
nuclear@17 54 pgtbl = (uint32_t*)addr;
nuclear@18 55 memset(pgtbl, 0, PGSIZE);
nuclear@18 56
nuclear@17 57 pgdir[diridx] = addr | (attr & ATTR_PGDIR_MASK) | PG_PRESENT;
nuclear@17 58 } else {
nuclear@17 59 pgtbl = (uint32_t*)(pgdir[diridx] & ADDR_PGENT_MASK);
nuclear@17 60 }
nuclear@17 61
nuclear@17 62 pgtbl[pgidx] = PAGE_TO_ADDR(ppage) | (attr & ATTR_PGTBL_MASK) | PG_PRESENT;
nuclear@17 63 }
nuclear@17 64
nuclear@17 65 void unmap_page(int vpage)
nuclear@17 66 {
nuclear@17 67 uint32_t *pgtbl;
nuclear@17 68 int diridx = PAGE_TO_PGTBL(vpage);
nuclear@17 69 int pgidx = PAGE_TO_PGTBL_PG(vpage);
nuclear@17 70
nuclear@17 71 if(!(pgdir[diridx] & PG_PRESENT)) {
nuclear@17 72 goto err;
nuclear@17 73 }
nuclear@17 74 pgtbl = (uint32_t*)(pgdir[diridx] & ADDR_PGENT_MASK);
nuclear@17 75
nuclear@17 76 if(!(pgtbl[pgidx] & PG_PRESENT)) {
nuclear@17 77 goto err;
nuclear@17 78 }
nuclear@17 79 pgtbl[pgidx] = 0;
nuclear@17 80
nuclear@17 81 return;
nuclear@17 82 err:
nuclear@17 83 printf("unmap_page(%d): page already not mapped\n", vpage);
nuclear@17 84 }
nuclear@17 85
nuclear@17 86 void map_page_range(int vpg_start, int pgcount, int ppg_start, unsigned int attr)
nuclear@17 87 {
nuclear@17 88 int i;
nuclear@17 89
nuclear@17 90 for(i=0; i<pgcount; i++) {
nuclear@17 91 map_page(vpg_start + i, ppg_start + i, attr);
nuclear@17 92 }
nuclear@17 93 }
nuclear@17 94
nuclear@17 95 void map_mem_range(uint32_t vaddr, size_t sz, uint32_t paddr, unsigned int attr)
nuclear@17 96 {
nuclear@17 97 int vpg_start, ppg_start, num_pages;
nuclear@17 98
nuclear@17 99 if(!sz) return;
nuclear@17 100
nuclear@17 101 if(ADDR_TO_PGOFFS(paddr)) {
nuclear@17 102 panic("map_mem_range called with unaligned physical address: %x\n", paddr);
nuclear@17 103 }
nuclear@17 104
nuclear@17 105 vpg_start = ADDR_TO_PAGE(vaddr);
nuclear@17 106 ppg_start = ADDR_TO_PAGE(paddr);
nuclear@17 107 num_pages = ADDR_TO_PAGE(sz) + 1;
nuclear@17 108
nuclear@17 109 map_page_range(vpg_start, num_pages, ppg_start, attr);
nuclear@17 110 }
nuclear@17 111
nuclear@17 112
nuclear@17 113 /* if(mb->flags & MB_MMAP) {
nuclear@17 114 struct mboot_mmap *mem, *mmap_end;
nuclear@17 115
nuclear@17 116 mem = mb->mmap;
nuclear@17 117 mmap_end = (struct mboot_mmap*)((char*)mb->mmap + mb->mmap_len);
nuclear@17 118
nuclear@17 119 printf("memory map:\n");
nuclear@17 120 while(mem < mmap_end) {
nuclear@17 121 unsigned int end = mem->base_low + mem->length_low;
nuclear@17 122 char *type = mem->type == MB_MEM_VALID ? "free:" : "hole:";
nuclear@17 123
nuclear@17 124 printf(" %s %x - %x (%u bytes)\n", type, mem->base_low, end, mem->length_low);
nuclear@17 125 mem = (struct mboot_mmap*)((char*)mem + mem->skip + sizeof mem->skip);
nuclear@17 126 }
nuclear@17 127 }
nuclear@17 128
nuclear@17 129 if(mb->flags & MB_MEM) {
nuclear@17 130 printf("lower memory: %ukb, upper mem: %ukb\n", mb->mem_lower, mb->mem_upper);
nuclear@17 131 }
nuclear@17 132 */
nuclear@17 133
nuclear@18 134 uint32_t virt_to_phys(uint32_t vaddr)
nuclear@18 135 {
nuclear@18 136 uint32_t pgaddr, *pgtbl;
nuclear@18 137 int diridx = ADDR_TO_PGTBL(vaddr);
nuclear@18 138 int pgidx = ADDR_TO_PGTBL_PG(vaddr);
nuclear@18 139
nuclear@18 140 if(!(pgdir[diridx] & PG_PRESENT)) {
nuclear@18 141 panic("virt_to_phys(%x): page table %d not present\n", vaddr, diridx);
nuclear@18 142 }
nuclear@18 143 pgtbl = (uint32_t*)(pgdir[diridx] & PGENT_ADDR_MASK);
nuclear@18 144
nuclear@18 145 if(!(pgtbl[pgidx] & PG_PRESENT)) {
nuclear@18 146 panic("virt_to_phys(%x): page %d not present\n", vaddr, ADDR_TO_PAGE(vaddr));
nuclear@18 147 }
nuclear@18 148 pgaddr = pgtbl[pgidx] & PGENT_ADDR_MASK;
nuclear@18 149
nuclear@18 150 return pgaddr | ADDR_TO_PGOFFS(vaddr);
nuclear@18 151 }
nuclear@18 152
nuclear@17 153 static void pgfault(int inum, uint32_t err)
nuclear@17 154 {
nuclear@17 155 printf("~~~~ PAGE FAULT ~~~~\n");
nuclear@17 156
nuclear@17 157 printf("fault address: %x\n", get_fault_addr());
nuclear@17 158
nuclear@17 159 if(err & PG_PRESENT) {
nuclear@17 160 if(err & 8) {
nuclear@17 161 printf("reserved bit set in some paging structure\n");
nuclear@17 162 } else {
nuclear@17 163 printf("%s protection violation ", (err & PG_WRITABLE) ? "write" : "read");
nuclear@17 164 printf("in %s mode\n", err & PG_USER ? "user" : "kernel");
nuclear@17 165 }
nuclear@17 166 } else {
nuclear@17 167 printf("page not present\n");
nuclear@17 168 }
nuclear@17 169 }