head64.c 5.0 KB

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