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authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>2018-02-14 21:25:40 +0300
committerIngo Molnar <mingo@kernel.org>2018-02-16 10:48:48 +0100
commit98219dda2ab56ce2a967fdebf81e838d676d9ddc (patch)
treea8c3e987dfd3ad335dd24231e3752801bca92173 /arch/x86/include/asm/pgtable.h
parent6f9dd329717f696f578347c0781a0247db957596 (diff)
x86/mm: Fold p4d page table layer at runtime
Change page table helpers to fold p4d at runtime. The logic is the same as in <asm-generic/pgtable-nop4d.h>. Signed-off-by: Kirill 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/20180214182542.69302-8-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/pgtable.h')
-rw-r--r--arch/x86/include/asm/pgtable.h11
1 files changed, 10 insertions, 1 deletions
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 63c2552b6b65..c8baa7f12d1b 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -65,7 +65,7 @@ extern pmdval_t early_pmd_flags;
#ifndef __PAGETABLE_P4D_FOLDED
#define set_pgd(pgdp, pgd) native_set_pgd(pgdp, pgd)
-#define pgd_clear(pgd) native_pgd_clear(pgd)
+#define pgd_clear(pgd) (pgtable_l5_enabled ? native_pgd_clear(pgd) : 0)
#endif
#ifndef set_p4d
@@ -859,6 +859,8 @@ static inline unsigned long p4d_index(unsigned long address)
#if CONFIG_PGTABLE_LEVELS > 4
static inline int pgd_present(pgd_t pgd)
{
+ if (!pgtable_l5_enabled)
+ return 1;
return pgd_flags(pgd) & _PAGE_PRESENT;
}
@@ -876,6 +878,8 @@ static inline unsigned long pgd_page_vaddr(pgd_t pgd)
/* to find an entry in a page-table-directory. */
static inline p4d_t *p4d_offset(pgd_t *pgd, unsigned long address)
{
+ if (!pgtable_l5_enabled)
+ return (p4d_t *)pgd;
return (p4d_t *)pgd_page_vaddr(*pgd) + p4d_index(address);
}
@@ -883,6 +887,9 @@ static inline int pgd_bad(pgd_t pgd)
{
unsigned long ignore_flags = _PAGE_USER;
+ if (!pgtable_l5_enabled)
+ return 0;
+
if (IS_ENABLED(CONFIG_PAGE_TABLE_ISOLATION))
ignore_flags |= _PAGE_NX;
@@ -891,6 +898,8 @@ static inline int pgd_bad(pgd_t pgd)
static inline int pgd_none(pgd_t pgd)
{
+ if (!pgtable_l5_enabled)
+ return 0;
/*
* There is no need to do a workaround for the KNL stray
* A/D bit erratum here. PGDs only point to page tables