1 /* 2 * prepare to run common code 3 * 4 * Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE 5 */ 6 7 #include <linux/init.h> 8 #include <linux/linkage.h> 9 #include <linux/types.h> 10 #include <linux/kernel.h> 11 #include <linux/string.h> 12 #include <linux/percpu.h> 13 #include <linux/start_kernel.h> 14 #include <linux/io.h> 15 #include <linux/memblock.h> 16 17 #include <asm/processor.h> 18 #include <asm/proto.h> 19 #include <asm/smp.h> 20 #include <asm/setup.h> 21 #include <asm/desc.h> 22 #include <asm/pgtable.h> 23 #include <asm/tlbflush.h> 24 #include <asm/sections.h> 25 #include <asm/kdebug.h> 26 #include <asm/e820.h> 27 #include <asm/bios_ebda.h> 28 #include <asm/bootparam_utils.h> 29 #include <asm/microcode.h> 30 31 /* 32 * Manage page tables very early on. 33 */ 34 extern pgd_t early_level4_pgt[PTRS_PER_PGD]; 35 extern pmd_t early_dynamic_pgts[EARLY_DYNAMIC_PAGE_TABLES][PTRS_PER_PMD]; 36 static unsigned int __initdata next_early_pgt = 2; 37 38 /* Wipe all early page tables except for the kernel symbol map */ 39 static void __init reset_early_page_tables(void) 40 { 41 unsigned long i; 42 43 for (i = 0; i < PTRS_PER_PGD-1; i++) 44 early_level4_pgt[i].pgd = 0; 45 46 next_early_pgt = 0; 47 48 write_cr3(__pa(early_level4_pgt)); 49 } 50 51 /* Create a new PMD entry */ 52 int __init early_make_pgtable(unsigned long address) 53 { 54 unsigned long physaddr = address - __PAGE_OFFSET; 55 unsigned long i; 56 pgdval_t pgd, *pgd_p; 57 pudval_t pud, *pud_p; 58 pmdval_t pmd, *pmd_p; 59 60 /* Invalid address or early pgt is done ? */ 61 if (physaddr >= MAXMEM || read_cr3() != __pa(early_level4_pgt)) 62 return -1; 63 64 again: 65 pgd_p = &early_level4_pgt[pgd_index(address)].pgd; 66 pgd = *pgd_p; 67 68 /* 69 * The use of __START_KERNEL_map rather than __PAGE_OFFSET here is 70 * critical -- __PAGE_OFFSET would point us back into the dynamic 71 * range and we might end up looping forever... 72 */ 73 if (pgd) 74 pud_p = (pudval_t *)((pgd & PTE_PFN_MASK) + __START_KERNEL_map - phys_base); 75 else { 76 if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) { 77 reset_early_page_tables(); 78 goto again; 79 } 80 81 pud_p = (pudval_t *)early_dynamic_pgts[next_early_pgt++]; 82 for (i = 0; i < PTRS_PER_PUD; i++) 83 pud_p[i] = 0; 84 *pgd_p = (pgdval_t)pud_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE; 85 } 86 pud_p += pud_index(address); 87 pud = *pud_p; 88 89 if (pud) 90 pmd_p = (pmdval_t *)((pud & PTE_PFN_MASK) + __START_KERNEL_map - phys_base); 91 else { 92 if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) { 93 reset_early_page_tables(); 94 goto again; 95 } 96 97 pmd_p = (pmdval_t *)early_dynamic_pgts[next_early_pgt++]; 98 for (i = 0; i < PTRS_PER_PMD; i++) 99 pmd_p[i] = 0; 100 *pud_p = (pudval_t)pmd_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE; 101 } 102 pmd = (physaddr & PMD_MASK) + (__PAGE_KERNEL_LARGE & ~_PAGE_GLOBAL); 103 pmd_p[pmd_index(address)] = pmd; 104 105 return 0; 106 } 107 108 /* Don't add a printk in there. printk relies on the PDA which is not initialized 109 yet. */ 110 static void __init clear_bss(void) 111 { 112 memset(__bss_start, 0, 113 (unsigned long) __bss_stop - (unsigned long) __bss_start); 114 } 115 116 static unsigned long get_cmd_line_ptr(void) 117 { 118 unsigned long cmd_line_ptr = boot_params.hdr.cmd_line_ptr; 119 120 cmd_line_ptr |= (u64)boot_params.ext_cmd_line_ptr << 32; 121 122 return cmd_line_ptr; 123 } 124 125 static void __init copy_bootdata(char *real_mode_data) 126 { 127 char * command_line; 128 unsigned long cmd_line_ptr; 129 130 memcpy(&boot_params, real_mode_data, sizeof boot_params); 131 sanitize_boot_params(&boot_params); 132 cmd_line_ptr = get_cmd_line_ptr(); 133 if (cmd_line_ptr) { 134 command_line = __va(cmd_line_ptr); 135 memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE); 136 } 137 } 138 139 void __init x86_64_start_kernel(char * real_mode_data) 140 { 141 int i; 142 143 /* 144 * Build-time sanity checks on the kernel image and module 145 * area mappings. (these are purely build-time and produce no code) 146 */ 147 BUILD_BUG_ON(MODULES_VADDR < KERNEL_IMAGE_START); 148 BUILD_BUG_ON(MODULES_VADDR-KERNEL_IMAGE_START < KERNEL_IMAGE_SIZE); 149 BUILD_BUG_ON(MODULES_LEN + KERNEL_IMAGE_SIZE > 2*PUD_SIZE); 150 BUILD_BUG_ON((KERNEL_IMAGE_START & ~PMD_MASK) != 0); 151 BUILD_BUG_ON((MODULES_VADDR & ~PMD_MASK) != 0); 152 BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL)); 153 BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) == 154 (__START_KERNEL & PGDIR_MASK))); 155 BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) <= MODULES_END); 156 157 /* Kill off the identity-map trampoline */ 158 reset_early_page_tables(); 159 160 /* clear bss before set_intr_gate with early_idt_handler */ 161 clear_bss(); 162 163 for (i = 0; i < NUM_EXCEPTION_VECTORS; i++) 164 set_intr_gate(i, &early_idt_handlers[i]); 165 load_idt((const struct desc_ptr *)&idt_descr); 166 167 copy_bootdata(__va(real_mode_data)); 168 169 /* 170 * Load microcode early on BSP. 171 */ 172 load_ucode_bsp(); 173 174 if (console_loglevel == 10) 175 early_printk("Kernel alive\n"); 176 177 clear_page(init_level4_pgt); 178 /* set init_level4_pgt kernel high mapping*/ 179 init_level4_pgt[511] = early_level4_pgt[511]; 180 181 x86_64_start_reservations(real_mode_data); 182 } 183 184 void __init x86_64_start_reservations(char *real_mode_data) 185 { 186 /* version is always not zero if it is copied */ 187 if (!boot_params.hdr.version) 188 copy_bootdata(__va(real_mode_data)); 189 190 reserve_ebda_region(); 191 192 start_kernel(); 193 } 194