Commit 4c2b4058 authored by Kirill A. Shutemov's avatar Kirill A. Shutemov Committed by Ingo Molnar

x86/mm: Initialize 'pgtable_l5_enabled' at boot-time

'pgtable_l5_enabled' indicates which paging mode we are using. We need to
initialize it at boot-time according to machine capability.
Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20180214182542.69302-2-kirill.shutemov@linux.intel.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 09e61a77
...@@ -47,7 +47,7 @@ ...@@ -47,7 +47,7 @@
#include <linux/decompress/mm.h> #include <linux/decompress/mm.h>
#ifdef CONFIG_X86_5LEVEL #ifdef CONFIG_X86_5LEVEL
unsigned int pgtable_l5_enabled __ro_after_init = 1; unsigned int pgtable_l5_enabled __ro_after_init;
unsigned int pgdir_shift __ro_after_init = 48; unsigned int pgdir_shift __ro_after_init = 48;
unsigned int ptrs_per_p4d __ro_after_init = 512; unsigned int ptrs_per_p4d __ro_after_init = 512;
#endif #endif
...@@ -729,6 +729,12 @@ void choose_random_location(unsigned long input, ...@@ -729,6 +729,12 @@ void choose_random_location(unsigned long input,
return; return;
} }
#ifdef CONFIG_X86_5LEVEL
if (__read_cr4() & X86_CR4_LA57) {
pgtable_l5_enabled = 1;
}
#endif
boot_params->hdr.loadflags |= KASLR_FLAG; boot_params->hdr.loadflags |= KASLR_FLAG;
/* Prepare to add new identity pagetables on demand. */ /* Prepare to add new identity pagetables on demand. */
......
...@@ -40,7 +40,7 @@ static unsigned int __initdata next_early_pgt; ...@@ -40,7 +40,7 @@ static unsigned int __initdata next_early_pgt;
pmdval_t early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX); pmdval_t early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX);
#ifdef CONFIG_X86_5LEVEL #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); EXPORT_SYMBOL(pgtable_l5_enabled);
unsigned int pgdir_shift __ro_after_init = 48; unsigned int pgdir_shift __ro_after_init = 48;
EXPORT_SYMBOL(pgdir_shift); EXPORT_SYMBOL(pgdir_shift);
...@@ -64,6 +64,26 @@ static void __head *fixup_pointer(void *ptr, unsigned long physaddr) ...@@ -64,6 +64,26 @@ static void __head *fixup_pointer(void *ptr, unsigned long physaddr)
return ptr - (void *)_text + (void *)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, unsigned long __head __startup_64(unsigned long physaddr,
struct boot_params *bp) struct boot_params *bp)
{ {
...@@ -76,6 +96,8 @@ unsigned long __head __startup_64(unsigned long physaddr, ...@@ -76,6 +96,8 @@ unsigned long __head __startup_64(unsigned long physaddr,
int i; int i;
unsigned int *next_pgt_ptr; unsigned int *next_pgt_ptr;
check_la57_support(physaddr);
/* Is the address too large? */ /* Is the address too large? */
if (physaddr >> MAX_PHYSMEM_BITS) if (physaddr >> MAX_PHYSMEM_BITS)
for (;;); for (;;);
......
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