1 /* 2 * prepare to run common code 3 * 4 * Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE 5 */ 6 7 #define DISABLE_BRANCH_PROFILING 8 #include <linux/init.h> 9 #include <linux/linkage.h> 10 #include <linux/types.h> 11 #include <linux/kernel.h> 12 #include <linux/string.h> 13 #include <linux/percpu.h> 14 #include <linux/start_kernel.h> 15 #include <linux/io.h> 16 #include <linux/memblock.h> 17 18 #include <asm/processor.h> 19 #include <asm/proto.h> 20 #include <asm/smp.h> 21 #include <asm/setup.h> 22 #include <asm/desc.h> 23 #include <asm/pgtable.h> 24 #include <asm/tlbflush.h> 25 #include <asm/sections.h> 26 #include <asm/kdebug.h> 27 #include <asm/e820.h> 28 #include <asm/bios_ebda.h> 29 #include <asm/bootparam_utils.h> 30 #include <asm/microcode.h> 31 #include <asm/kasan.h> 32 33 /* 34 * Manage page tables very early on. 35 */ 36 extern pgd_t early_level4_pgt[PTRS_PER_PGD]; 37 extern pmd_t early_dynamic_pgts[EARLY_DYNAMIC_PAGE_TABLES][PTRS_PER_PMD]; 38 static unsigned int __initdata next_early_pgt = 2; 39 pmdval_t early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX); 40 41 /* Wipe all early page tables except for the kernel symbol map */ 42 static void __init reset_early_page_tables(void) 43 { 44 memset(early_level4_pgt, 0, sizeof(pgd_t)*(PTRS_PER_PGD-1)); 45 next_early_pgt = 0; 46 write_cr3(__pa_nodebug(early_level4_pgt)); 47 } 48 49 /* Create a new PMD entry */ 50 int __init early_make_pgtable(unsigned long address) 51 { 52 unsigned long physaddr = address - __PAGE_OFFSET; 53 pgdval_t pgd, *pgd_p; 54 pudval_t pud, *pud_p; 55 pmdval_t pmd, *pmd_p; 56 57 /* Invalid address or early pgt is done ? */ 58 if (physaddr >= MAXMEM || read_cr3() != __pa_nodebug(early_level4_pgt)) 59 return -1; 60 61 again: 62 pgd_p = &early_level4_pgt[pgd_index(address)].pgd; 63 pgd = *pgd_p; 64 65 /* 66 * The use of __START_KERNEL_map rather than __PAGE_OFFSET here is 67 * critical -- __PAGE_OFFSET would point us back into the dynamic 68 * range and we might end up looping forever... 69 */ 70 if (pgd) 71 pud_p = (pudval_t *)((pgd & PTE_PFN_MASK) + __START_KERNEL_map - phys_base); 72 else { 73 if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) { 74 reset_early_page_tables(); 75 goto again; 76 } 77 78 pud_p = (pudval_t *)early_dynamic_pgts[next_early_pgt++]; 79 memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD); 80 *pgd_p = (pgdval_t)pud_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE; 81 } 82 pud_p += pud_index(address); 83 pud = *pud_p; 84 85 if (pud) 86 pmd_p = (pmdval_t *)((pud & PTE_PFN_MASK) + __START_KERNEL_map - phys_base); 87 else { 88 if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) { 89 reset_early_page_tables(); 90 goto again; 91 } 92 93 pmd_p = (pmdval_t *)early_dynamic_pgts[next_early_pgt++]; 94 memset(pmd_p, 0, sizeof(*pmd_p) * PTRS_PER_PMD); 95 *pud_p = (pudval_t)pmd_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE; 96 } 97 pmd = (physaddr & PMD_MASK) + early_pmd_flags; 98 pmd_p[pmd_index(address)] = pmd; 99 100 return 0; 101 } 102 103 /* Don't add a printk in there. printk relies on the PDA which is not initialized 104 yet. */ 105 static void __init clear_bss(void) 106 { 107 memset(__bss_start, 0, 108 (unsigned long) __bss_stop - (unsigned long) __bss_start); 109 } 110 111 static unsigned long get_cmd_line_ptr(void) 112 { 113 unsigned long cmd_line_ptr = boot_params.hdr.cmd_line_ptr; 114 115 cmd_line_ptr |= (u64)boot_params.ext_cmd_line_ptr << 32; 116 117 return cmd_line_ptr; 118 } 119 120 static void __init copy_bootdata(char *real_mode_data) 121 { 122 char * command_line; 123 unsigned long cmd_line_ptr; 124 125 memcpy(&boot_params, real_mode_data, sizeof boot_params); 126 sanitize_boot_params(&boot_params); 127 cmd_line_ptr = get_cmd_line_ptr(); 128 if (cmd_line_ptr) { 129 command_line = __va(cmd_line_ptr); 130 memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE); 131 } 132 } 133 134 asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data) 135 { 136 int i; 137 138 /* 139 * Build-time sanity checks on the kernel image and module 140 * area mappings. (these are purely build-time and produce no code) 141 */ 142 BUILD_BUG_ON(MODULES_VADDR < __START_KERNEL_map); 143 BUILD_BUG_ON(MODULES_VADDR - __START_KERNEL_map < KERNEL_IMAGE_SIZE); 144 BUILD_BUG_ON(MODULES_LEN + KERNEL_IMAGE_SIZE > 2*PUD_SIZE); 145 BUILD_BUG_ON((__START_KERNEL_map & ~PMD_MASK) != 0); 146 BUILD_BUG_ON((MODULES_VADDR & ~PMD_MASK) != 0); 147 BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL)); 148 BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) == 149 (__START_KERNEL & PGDIR_MASK))); 150 BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) <= MODULES_END); 151 152 cr4_init_shadow(); 153 154 /* Kill off the identity-map trampoline */ 155 reset_early_page_tables(); 156 157 clear_bss(); 158 159 clear_page(init_level4_pgt); 160 161 kasan_early_init(); 162 163 for (i = 0; i < NUM_EXCEPTION_VECTORS; i++) 164 set_intr_gate(i, early_idt_handler_array[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 /* set init_level4_pgt kernel high mapping*/ 175 init_level4_pgt[511] = early_level4_pgt[511]; 176 177 x86_64_start_reservations(real_mode_data); 178 } 179 180 void __init x86_64_start_reservations(char *real_mode_data) 181 { 182 /* version is always not zero if it is copied */ 183 if (!boot_params.hdr.version) 184 copy_bootdata(__va(real_mode_data)); 185 186 x86_early_init_platform_quirks(); 187 188 switch (boot_params.hdr.hardware_subarch) { 189 case X86_SUBARCH_INTEL_MID: 190 x86_intel_mid_early_setup(); 191 break; 192 default: 193 break; 194 } 195 196 start_kernel(); 197 } 198