LXR linux/arch/x86/kernel/head64.c

   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
  16#include <asm/processor.h>
  17#include <asm/proto.h>
  18#include <asm/smp.h>
  19#include <asm/setup.h>
  20#include <asm/desc.h>
  21#include <asm/pgtable.h>
  22#include <asm/tlbflush.h>
  23#include <asm/sections.h>
  24#include <asm/kdebug.h>
  25#include <asm/e820.h>
  26#include <asm/bios_ebda.h>
  27
  28/* boot cpu pda */
  29static struct x8664_pda _boot_cpu_pda;
  30
  31#ifdef CONFIG_SMP
  32/*
  33 * We install an empty cpu_pda pointer table to indicate to early users
  34 * (numa_set_node) that the cpu_pda pointer table for cpus other than
  35 * the boot cpu is not yet setup.
  36 */
  37static struct x8664_pda *__cpu_pda[NR_CPUS] __initdata;
  38#else
  39static struct x8664_pda *__cpu_pda[NR_CPUS] __read_mostly;
  40#endif
  41
  42void __init x86_64_init_pda(void)
  43{
  44        _cpu_pda = __cpu_pda;
  45        cpu_pda(0) = &_boot_cpu_pda;
  46        pda_init(0);
  47}
  48
  49static void __init zap_identity_mappings(void)
  50{
  51        pgd_t *pgd = pgd_offset_k(0UL);
  52        pgd_clear(pgd);
  53        __flush_tlb_all();
  54}
  55
  56/* Don't add a printk in there. printk relies on the PDA which is not initialized 
  57   yet. */
  58static void __init clear_bss(void)
  59{
  60        memset(__bss_start, 0,
  61               (unsigned long) __bss_stop - (unsigned long) __bss_start);
  62}
  63
  64static void __init copy_bootdata(char *real_mode_data)
  65{
  66        char * command_line;
  67
  68        memcpy(&boot_params, real_mode_data, sizeof boot_params);
  69        if (boot_params.hdr.cmd_line_ptr) {
  70                command_line = __va(boot_params.hdr.cmd_line_ptr);
  71                memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
  72        }
  73}
  74
  75void __init x86_64_start_kernel(char * real_mode_data)
  76{
  77        int i;
  78
  79        /*
  80         * Build-time sanity checks on the kernel image and module
  81         * area mappings. (these are purely build-time and produce no code)
  82         */
  83        BUILD_BUG_ON(MODULES_VADDR < KERNEL_IMAGE_START);
  84        BUILD_BUG_ON(MODULES_VADDR-KERNEL_IMAGE_START < KERNEL_IMAGE_SIZE);
  85        BUILD_BUG_ON(MODULES_LEN + KERNEL_IMAGE_SIZE > 2*PUD_SIZE);
  86        BUILD_BUG_ON((KERNEL_IMAGE_START & ~PMD_MASK) != 0);
  87        BUILD_BUG_ON((MODULES_VADDR & ~PMD_MASK) != 0);
  88        BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL));
  89        BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) ==
  90                                (__START_KERNEL & PGDIR_MASK)));
  91        BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) <= MODULES_END);
  92
  93        /* clear bss before set_intr_gate with early_idt_handler */
  94        clear_bss();
  95
  96        /* Make NULL pointers segfault */
  97        zap_identity_mappings();
  98
  99        /* Cleanup the over mapped high alias */
 100        cleanup_highmap();
 101
 102        for (i = 0; i < NUM_EXCEPTION_VECTORS; i++) {
 103#ifdef CONFIG_EARLY_PRINTK
 104                set_intr_gate(i, &early_idt_handlers[i]);
 105#else
 106                set_intr_gate(i, early_idt_handler);
 107#endif
 108        }
 109        load_idt((const struct desc_ptr *)&idt_descr);
 110
 111        if (console_loglevel == 10)
 112                early_printk("Kernel alive\n");
 113
 114        x86_64_init_pda();
 115
 116        x86_64_start_reservations(real_mode_data);
 117}
 118
 119void __init x86_64_start_reservations(char *real_mode_data)
 120{
 121        copy_bootdata(__va(real_mode_data));
 122
 123        reserve_early(__pa_symbol(&_text), __pa_symbol(&_end), "TEXT DATA BSS");
 124
 125#ifdef CONFIG_BLK_DEV_INITRD
 126        /* Reserve INITRD */
 127        if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image) {
 128                unsigned long ramdisk_image = boot_params.hdr.ramdisk_image;
 129                unsigned long ramdisk_size  = boot_params.hdr.ramdisk_size;
 130                unsigned long ramdisk_end   = ramdisk_image + ramdisk_size;
 131                reserve_early(ramdisk_image, ramdisk_end, "RAMDISK");
 132        }
 133#endif
 134
 135        reserve_ebda_region();
 136
 137        /*
 138         * At this point everything still needed from the boot loader
 139         * or BIOS or kernel text should be early reserved or marked not
 140         * RAM in e820. All other memory is free game.
 141         */
 142
 143        start_kernel();
 144}
 145