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>
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index 892df37..3fbaad2 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -569,14 +569,16 @@ static inline p4dval_t p4d_val(p4d_t p4d)
static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
{
- pgdval_t val = native_pgd_val(pgd);
-
- PVOP_VCALL2(pv_mmu_ops.set_pgd, pgdp, val);
+ if (pgtable_l5_enabled)
+ PVOP_VCALL2(pv_mmu_ops.set_pgd, pgdp, native_pgd_val(pgd));
+ else
+ set_p4d((p4d_t *)(pgdp), (p4d_t) { pgd.pgd });
}
static inline void pgd_clear(pgd_t *pgdp)
{
- set_pgd(pgdp, __pgd(0));
+ if (pgtable_l5_enabled)
+ set_pgd(pgdp, __pgd(0));
}
#endif /* CONFIG_PGTABLE_LEVELS == 5 */