diff options
Diffstat (limited to 'arch/x86/kernel/head64.c')
| -rw-r--r-- | arch/x86/kernel/head64.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 98b0ff49b220..ffb31c50d515 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -40,7 +40,7 @@ static unsigned int __initdata next_early_pgt; pmdval_t early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX); #ifdef CONFIG_X86_5LEVEL -unsigned int pgtable_l5_enabled __ro_after_init = 1; +unsigned int pgtable_l5_enabled __ro_after_init; EXPORT_SYMBOL(pgtable_l5_enabled); unsigned int pgdir_shift __ro_after_init = 48; EXPORT_SYMBOL(pgdir_shift); @@ -64,6 +64,26 @@ static void __head *fixup_pointer(void *ptr, unsigned long physaddr) return ptr - (void *)_text + (void *)physaddr; } +#ifdef CONFIG_X86_5LEVEL +static unsigned int __head *fixup_int(void *ptr, unsigned long physaddr) +{ + return fixup_pointer(ptr, physaddr); +} + +static void __head check_la57_support(unsigned long physaddr) +{ + if (native_cpuid_eax(0) < 7) + return; + + if (!(native_cpuid_ecx(7) & (1 << (X86_FEATURE_LA57 & 31)))) + return; + + *fixup_int(&pgtable_l5_enabled, physaddr) = 1; +} +#else +static void __head check_la57_support(unsigned long physaddr) {} +#endif + unsigned long __head __startup_64(unsigned long physaddr, struct boot_params *bp) { @@ -76,6 +96,8 @@ unsigned long __head __startup_64(unsigned long physaddr, int i; unsigned int *next_pgt_ptr; + check_la57_support(physaddr); + /* Is the address too large? */ if (physaddr >> MAX_PHYSMEM_BITS) for (;;); |