diff options
Diffstat (limited to 'arch/x86/boot/compressed/pgtable_64.c')
| -rw-r--r-- | arch/x86/boot/compressed/pgtable_64.c | 27 |
1 files changed, 17 insertions, 10 deletions
diff --git a/arch/x86/boot/compressed/pgtable_64.c b/arch/x86/boot/compressed/pgtable_64.c index c8862696a47b..2a78746f5a4c 100644 --- a/arch/x86/boot/compressed/pgtable_64.c +++ b/arch/x86/boot/compressed/pgtable_64.c @@ -5,18 +5,16 @@ #include "pgtable.h" #include "../string.h" -/* - * __force_order is used by special_insns.h asm code to force instruction - * serialization. - * - * It is not referenced from the code, but GCC < 5 with -fPIE would fail - * due to an undefined symbol. Define it to make these ancient GCCs work. - */ -unsigned long __force_order; - #define BIOS_START_MIN 0x20000U /* 128K, less than this is insane */ #define BIOS_START_MAX 0x9f000U /* 640K, absolute maximum */ +#ifdef CONFIG_X86_5LEVEL +/* __pgtable_l5_enabled needs to be in .data to avoid being cleared along with .bss */ +unsigned int __section(".data") __pgtable_l5_enabled; +unsigned int __section(".data") pgdir_shift = 39; +unsigned int __section(".data") ptrs_per_p4d = 1; +#endif + struct paging_config { unsigned long trampoline_start; unsigned long l5_required; @@ -32,7 +30,7 @@ static char trampoline_save[TRAMPOLINE_32BIT_SIZE]; * Avoid putting the pointer into .bss as it will be cleared between * paging_prepare() and extract_kernel(). */ -unsigned long *trampoline_32bit __section(.data); +unsigned long *trampoline_32bit __section(".data"); extern struct boot_params *boot_params; int cmdline_find_option_bool(const char *option); @@ -207,4 +205,13 @@ void cleanup_trampoline(void *pgtable) /* Restore trampoline memory */ memcpy(trampoline_32bit, trampoline_save, TRAMPOLINE_32BIT_SIZE); + + /* Initialize variables for 5-level paging */ +#ifdef CONFIG_X86_5LEVEL + if (__read_cr4() & X86_CR4_LA57) { + __pgtable_l5_enabled = 1; + pgdir_shift = 48; + ptrs_per_p4d = 512; + } +#endif } |