PGD_KERNEL_START 39 arch/x86/include/asm/pgtable-2level_types.h #define PGD_KERNEL_START (CONFIG_PAGE_OFFSET >> PGDIR_SHIFT) PGD_KERNEL_START 49 arch/x86/include/asm/pgtable-3level_types.h #define PGD_KERNEL_START (CONFIG_PAGE_OFFSET >> PGDIR_SHIFT) PGD_KERNEL_START 160 arch/x86/include/asm/pgtable_64_types.h #define PGD_KERNEL_START ((PAGE_SIZE / 2) / sizeof(pgd_t))