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/api.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 || 59 read_cr3_pa() != __pa_nodebug(early_level4_pgt)) 60 return -1; 61 62 again: 63 pgd_p = &early_level4_pgt[pgd_index(address)].pgd; 64 pgd = *pgd_p; 65 66 /* 67 * The use of __START_KERNEL_map rather than __PAGE_OFFSET here is 68 * critical -- __PAGE_OFFSET would point us back into the dynamic 69 * range and we might end up looping forever... 70 */ 71 if (pgd) 72 pud_p = (pudval_t *)((pgd & PTE_PFN_MASK) + __START_KERNEL_map - phys_base); 73 else { 74 if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) { 75 reset_early_page_tables(); 76 goto again; 77 } 78 79 pud_p = (pudval_t *)early_dynamic_pgts[next_early_pgt++]; 80 memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD); 81 *pgd_p = (pgdval_t)pud_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE; 82 } 83 pud_p += pud_index(address); 84 pud = *pud_p; 85 86 if (pud) 87 pmd_p = (pmdval_t *)((pud & PTE_PFN_MASK) + __START_KERNEL_map - phys_base); 88 else { 89 if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) { 90 reset_early_page_tables(); 91 goto again; 92 } 93 94 pmd_p = (pmdval_t *)early_dynamic_pgts[next_early_pgt++]; 95 memset(pmd_p, 0, sizeof(*pmd_p) * PTRS_PER_PMD); 96 *pud_p = (pudval_t)pmd_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE; 97 } 98 pmd = (physaddr & PMD_MASK) + early_pmd_flags; 99 pmd_p[pmd_index(address)] = pmd; 100 101 return 0; 102 } 103 104 /* Don't add a printk in there. printk relies on the PDA which is not initialized 105 yet. */ 106 static void __init clear_bss(void) 107 { 108 memset(__bss_start, 0, 109 (unsigned long) __bss_stop - (unsigned long) __bss_start); 110 } 111 112 static unsigned long get_cmd_line_ptr(void) 113 { 114 unsigned long cmd_line_ptr = boot_params.hdr.cmd_line_ptr; 115 116 cmd_line_ptr |= (u64)boot_params.ext_cmd_line_ptr << 32; 117 118 return cmd_line_ptr; 119 } 120 121 static void __init copy_bootdata(char *real_mode_data) 122 { 123 char * command_line; 124 unsigned long cmd_line_ptr; 125 126 memcpy(&boot_params, real_mode_data, sizeof boot_params); 127 sanitize_boot_params(&boot_params); 128 cmd_line_ptr = get_cmd_line_ptr(); 129 if (cmd_line_ptr) { 130 command_line = __va(cmd_line_ptr); 131 memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE); 132 } 133 } 134 135 asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data) 136 { 137 int i; 138 139 /* 140 * Build-time sanity checks on the kernel image and module 141 * area mappings. (these are purely build-time and produce no code) 142 */ 143 BUILD_BUG_ON(MODULES_VADDR < __START_KERNEL_map); 144 BUILD_BUG_ON(MODULES_VADDR - __START_KERNEL_map < KERNEL_IMAGE_SIZE); 145 BUILD_BUG_ON(MODULES_LEN + KERNEL_IMAGE_SIZE > 2*PUD_SIZE); 146 BUILD_BUG_ON((__START_KERNEL_map & ~PMD_MASK) != 0); 147 BUILD_BUG_ON((MODULES_VADDR & ~PMD_MASK) != 0); 148 BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL)); 149 BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) == 150 (__START_KERNEL & PGDIR_MASK))); 151 BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) <= MODULES_END); 152 153 cr4_init_shadow(); 154 155 /* Kill off the identity-map trampoline */ 156 reset_early_page_tables(); 157 158 clear_bss(); 159 160 clear_page(init_level4_pgt); 161 162 kasan_early_init(); 163 164 for (i = 0; i < NUM_EXCEPTION_VECTORS; i++) 165 set_intr_gate(i, early_idt_handler_array[i]); 166 load_idt((const struct desc_ptr *)&idt_descr); 167 168 copy_bootdata(__va(real_mode_data)); 169 170 /* 171 * Load microcode early on BSP. 172 */ 173 load_ucode_bsp(); 174 175 /* set init_level4_pgt kernel high mapping*/ 176 init_level4_pgt[511] = early_level4_pgt[511]; 177 178 x86_64_start_reservations(real_mode_data); 179 } 180 181 void __init x86_64_start_reservations(char *real_mode_data) 182 { 183 /* version is always not zero if it is copied */ 184 if (!boot_params.hdr.version) 185 copy_bootdata(__va(real_mode_data)); 186 187 x86_early_init_platform_quirks(); 188 189 switch (boot_params.hdr.hardware_subarch) { 190 case X86_SUBARCH_INTEL_MID: 191 x86_intel_mid_early_setup(); 192 break; 193 default: 194 break; 195 } 196 197 start_kernel(); 198 } 199