diff options
Diffstat (limited to 'arch/x86/kernel/head64.c')
| -rw-r--r-- | arch/x86/kernel/head64.c | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c new file mode 100644 index 000000000..5a4668136 --- /dev/null +++ b/arch/x86/kernel/head64.c @@ -0,0 +1,198 @@ +/* + * prepare to run common code + * + * Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE + */ + +#include <linux/init.h> +#include <linux/linkage.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/string.h> +#include <linux/percpu.h> +#include <linux/start_kernel.h> +#include <linux/io.h> +#include <linux/memblock.h> + +#include <asm/processor.h> +#include <asm/proto.h> +#include <asm/smp.h> +#include <asm/setup.h> +#include <asm/desc.h> +#include <asm/pgtable.h> +#include <asm/tlbflush.h> +#include <asm/sections.h> +#include <asm/kdebug.h> +#include <asm/e820.h> +#include <asm/bios_ebda.h> +#include <asm/bootparam_utils.h> +#include <asm/microcode.h> +#include <asm/kasan.h> + +/* + * Manage page tables very early on. + */ +extern pgd_t early_level4_pgt[PTRS_PER_PGD]; +extern pmd_t early_dynamic_pgts[EARLY_DYNAMIC_PAGE_TABLES][PTRS_PER_PMD]; +static unsigned int __initdata next_early_pgt = 2; +pmdval_t early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX); + +/* Wipe all early page tables except for the kernel symbol map */ +static void __init reset_early_page_tables(void) +{ + unsigned long i; + + for (i = 0; i < PTRS_PER_PGD-1; i++) + early_level4_pgt[i].pgd = 0; + + next_early_pgt = 0; + + write_cr3(__pa_nodebug(early_level4_pgt)); +} + +/* Create a new PMD entry */ +int __init early_make_pgtable(unsigned long address) +{ + unsigned long physaddr = address - __PAGE_OFFSET; + unsigned long i; + pgdval_t pgd, *pgd_p; + pudval_t pud, *pud_p; + pmdval_t pmd, *pmd_p; + + /* Invalid address or early pgt is done ? */ + if (physaddr >= MAXMEM || read_cr3() != __pa_nodebug(early_level4_pgt)) + return -1; + +again: + pgd_p = &early_level4_pgt[pgd_index(address)].pgd; + pgd = *pgd_p; + + /* + * The use of __START_KERNEL_map rather than __PAGE_OFFSET here is + * critical -- __PAGE_OFFSET would point us back into the dynamic + * range and we might end up looping forever... + */ + if (pgd) + pud_p = (pudval_t *)((pgd & PTE_PFN_MASK) + __START_KERNEL_map - phys_base); + else { + if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) { + reset_early_page_tables(); + goto again; + } + + pud_p = (pudval_t *)early_dynamic_pgts[next_early_pgt++]; + for (i = 0; i < PTRS_PER_PUD; i++) + pud_p[i] = 0; + *pgd_p = (pgdval_t)pud_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE; + } + pud_p += pud_index(address); + pud = *pud_p; + + if (pud) + pmd_p = (pmdval_t *)((pud & PTE_PFN_MASK) + __START_KERNEL_map - phys_base); + else { + if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) { + reset_early_page_tables(); + goto again; + } + + pmd_p = (pmdval_t *)early_dynamic_pgts[next_early_pgt++]; + for (i = 0; i < PTRS_PER_PMD; i++) + pmd_p[i] = 0; + *pud_p = (pudval_t)pmd_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE; + } + pmd = (physaddr & PMD_MASK) + early_pmd_flags; + pmd_p[pmd_index(address)] = pmd; + + return 0; +} + +/* Don't add a printk in there. printk relies on the PDA which is not initialized + yet. */ +static void __init clear_bss(void) +{ + memset(__bss_start, 0, + (unsigned long) __bss_stop - (unsigned long) __bss_start); +} + +static unsigned long get_cmd_line_ptr(void) +{ + unsigned long cmd_line_ptr = boot_params.hdr.cmd_line_ptr; + + cmd_line_ptr |= (u64)boot_params.ext_cmd_line_ptr << 32; + + return cmd_line_ptr; +} + +static void __init copy_bootdata(char *real_mode_data) +{ + char * command_line; + unsigned long cmd_line_ptr; + + memcpy(&boot_params, real_mode_data, sizeof boot_params); + sanitize_boot_params(&boot_params); + cmd_line_ptr = get_cmd_line_ptr(); + if (cmd_line_ptr) { + command_line = __va(cmd_line_ptr); + memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE); + } +} + +asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data) +{ + int i; + + /* + * Build-time sanity checks on the kernel image and module + * area mappings. (these are purely build-time and produce no code) + */ + BUILD_BUG_ON(MODULES_VADDR < __START_KERNEL_map); + BUILD_BUG_ON(MODULES_VADDR - __START_KERNEL_map < KERNEL_IMAGE_SIZE); + BUILD_BUG_ON(MODULES_LEN + KERNEL_IMAGE_SIZE > 2*PUD_SIZE); + BUILD_BUG_ON((__START_KERNEL_map & ~PMD_MASK) != 0); + BUILD_BUG_ON((MODULES_VADDR & ~PMD_MASK) != 0); + BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL)); + BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) == + (__START_KERNEL & PGDIR_MASK))); + BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) <= MODULES_END); + + cr4_init_shadow(); + + /* Kill off the identity-map trampoline */ + reset_early_page_tables(); + + kasan_map_early_shadow(early_level4_pgt); + + /* clear bss before set_intr_gate with early_idt_handler */ + clear_bss(); + + for (i = 0; i < NUM_EXCEPTION_VECTORS; i++) + set_intr_gate(i, early_idt_handler_array[i]); + load_idt((const struct desc_ptr *)&idt_descr); + + copy_bootdata(__va(real_mode_data)); + + /* + * Load microcode early on BSP. + */ + load_ucode_bsp(); + + clear_page(init_level4_pgt); + /* set init_level4_pgt kernel high mapping*/ + init_level4_pgt[511] = early_level4_pgt[511]; + + kasan_map_early_shadow(init_level4_pgt); + + x86_64_start_reservations(real_mode_data); +} + +void __init x86_64_start_reservations(char *real_mode_data) +{ + /* version is always not zero if it is copied */ + if (!boot_params.hdr.version) + copy_bootdata(__va(real_mode_data)); + + reserve_ebda_region(); + + start_kernel(); +} |