The new flag would indicate what paging mode we are in.
Signed-off-by: Kirill A. Shutemov <kirill.shute...@linux.intel.com>
---
arch/x86/boot/compressed/kaslr.c | 4 ++++
arch/x86/include/asm/pgtable_32_types.h | 2 ++
arch/x86/include/asm/pgtable_64_types.h | 6 ++++++
arch/x86/kernel/head64.c | 5 +++++
4 files changed, 17 insertions(+)
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index 8199a6187251..bd69e1830fbe 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -46,6 +46,10 @@
#define STATIC
#include <linux/decompress/mm.h>
+#ifdef CONFIG_X86_5LEVEL
+unsigned int pgtable_l5_enabled __ro_after_init = 1;
+#endif
+
extern unsigned long get_cmd_line_ptr(void);
/* Simplified build-specific string for starting entropy. */
diff --git a/arch/x86/include/asm/pgtable_32_types.h
b/arch/x86/include/asm/pgtable_32_types.h
index 0777e18a1d23..e3225e83db7d 100644
--- a/arch/x86/include/asm/pgtable_32_types.h
+++ b/arch/x86/include/asm/pgtable_32_types.h
@@ -15,6 +15,8 @@
# include <asm/pgtable-2level_types.h>
#endif
+#define pgtable_l5_enabled 0
+
#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
#define PGDIR_MASK (~(PGDIR_SIZE - 1))
diff --git a/arch/x86/include/asm/pgtable_64_types.h
b/arch/x86/include/asm/pgtable_64_types.h
index a0db91ab63b8..5e2d724f8f47 100644
--- a/arch/x86/include/asm/pgtable_64_types.h
+++ b/arch/x86/include/asm/pgtable_64_types.h
@@ -20,6 +20,12 @@ typedef unsigned long pgprotval_t;
typedef struct { pteval_t pte; } pte_t;
+#ifdef CONFIG_X86_5LEVEL
+extern unsigned int pgtable_l5_enabled;
+#else
+#define pgtable_l5_enabled 0
+#endif
+
#endif /* !__ASSEMBLY__ */
#define SHARED_KERNEL_PMD 0
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index bf5c9ba63ba1..17d00d1886de 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -39,6 +39,11 @@ extern pmd_t
early_dynamic_pgts[EARLY_DYNAMIC_PAGE_TABLES][PTRS_PER_PMD];
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;
+EXPORT_SYMBOL(pgtable_l5_enabled);
+#endif
+
#ifdef CONFIG_DYNAMIC_MEMORY_LAYOUT
unsigned long page_offset_base __ro_after_init = __PAGE_OFFSET_BASE;
EXPORT_SYMBOL(page_offset_base);
--
2.15.1
