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Commit 98219dda authored by Kirill A. Shutemov's avatar Kirill A. Shutemov Committed by Ingo Molnar
Browse files

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: 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/20180214182542.69302-8-kirill.shutemov@linux.intel.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 6f9dd329

arch/x86/include/asm/paravirt.h

+6 −4
Original line number Diff line number Diff line
@@ -569,13 +569,15 @@ 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)

{

	if (pgtable_l5_enabled)

		set_pgd(pgdp, __pgd(0));

}

arch/x86/include/asm/pgalloc.h

+4 −1
Original line number Diff line number Diff line
@@ -167,6 +167,8 @@ static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pud, 
#if CONFIG_PGTABLE_LEVELS > 4

static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, p4d_t *p4d)

{

	if (!pgtable_l5_enabled)

		return;

	paravirt_alloc_p4d(mm, __pa(p4d) >> PAGE_SHIFT);

	set_pgd(pgd, __pgd(_PAGE_TABLE | __pa(p4d)));

}
@@ -191,6 +193,7 @@ extern void ___p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d); 
static inline void __p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d,

				  unsigned long address)

{

	if (pgtable_l5_enabled)

		___p4d_free_tlb(tlb, p4d);

}

arch/x86/include/asm/pgtable.h

+10 −1
Original line number Diff line number Diff line
@@ -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