From 2fb4706057bcf8261b3b0521ec7a62b54b82ce48 Mon Sep 17 00:00:00 2001 From: Mike Rapoport Date: Thu, 4 Jun 2020 16:46:44 -0700 Subject: powerpc: add support for folded p4d page tables Implement primitives necessary for the 4th level folding, add walks of p4d level where appropriate and replace 5level-fixup.h with pgtable-nop4d.h. [rppt@linux.ibm.com: powerpc/xmon: drop unused pgdir varialble in show_pte() function] Link: http://lkml.kernel.org/r/20200519181454.GI1059226@linux.ibm.com [rppt@linux.ibm.com; build fix] Link: http://lkml.kernel.org/r/20200423141845.GI13521@linux.ibm.com Signed-off-by: Mike Rapoport Signed-off-by: Andrew Morton Tested-by: Christophe Leroy # 8xx and 83xx Cc: Arnd Bergmann Cc: Benjamin Herrenschmidt Cc: Brian Cain Cc: Catalin Marinas Cc: Fenghua Yu Cc: Geert Uytterhoeven Cc: Guan Xuetao Cc: James Morse Cc: Jonas Bonn Cc: Julien Thierry Cc: Ley Foon Tan Cc: Marc Zyngier Cc: Michael Ellerman Cc: Paul Mackerras Cc: Rich Felker Cc: Russell King Cc: Stafford Horne Cc: Stefan Kristiansson Cc: Suzuki K Poulose Cc: Tony Luck Cc: Will Deacon Cc: Yoshinori Sato Link: http://lkml.kernel.org/r/20200414153455.21744-9-rppt@kernel.org Signed-off-by: Linus Torvalds --- arch/powerpc/mm/pgtable.c | 30 +++++++++++++++++++----------- 1 file changed, 19 insertions(+), 11 deletions(-) (limited to 'arch/powerpc/mm/pgtable.c') diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c index e3759b69f81b..c2499271f6c1 100644 --- a/arch/powerpc/mm/pgtable.c +++ b/arch/powerpc/mm/pgtable.c @@ -265,6 +265,7 @@ int huge_ptep_set_access_flags(struct vm_area_struct *vma, void assert_pte_locked(struct mm_struct *mm, unsigned long addr) { pgd_t *pgd; + p4d_t *p4d; pud_t *pud; pmd_t *pmd; @@ -272,7 +273,9 @@ void assert_pte_locked(struct mm_struct *mm, unsigned long addr) return; pgd = mm->pgd + pgd_index(addr); BUG_ON(pgd_none(*pgd)); - pud = pud_offset(pgd, addr); + p4d = p4d_offset(pgd, addr); + BUG_ON(p4d_none(*p4d)); + pud = pud_offset(p4d, addr); BUG_ON(pud_none(*pud)); pmd = pmd_offset(pud, addr); /* @@ -312,12 +315,13 @@ EXPORT_SYMBOL_GPL(vmalloc_to_phys); pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea, bool *is_thp, unsigned *hpage_shift) { - pgd_t pgd, *pgdp; + pgd_t *pgdp; + p4d_t p4d, *p4dp; pud_t pud, *pudp; pmd_t pmd, *pmdp; pte_t *ret_pte; hugepd_t *hpdp = NULL; - unsigned pdshift = PGDIR_SHIFT; + unsigned pdshift; if (hpage_shift) *hpage_shift = 0; @@ -325,24 +329,28 @@ pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea, if (is_thp) *is_thp = false; - pgdp = pgdir + pgd_index(ea); - pgd = READ_ONCE(*pgdp); /* * Always operate on the local stack value. This make sure the * value don't get updated by a parallel THP split/collapse, * page fault or a page unmap. The return pte_t * is still not * stable. So should be checked there for above conditions. + * Top level is an exception because it is folded into p4d. */ - if (pgd_none(pgd)) + pgdp = pgdir + pgd_index(ea); + p4dp = p4d_offset(pgdp, ea); + p4d = READ_ONCE(*p4dp); + pdshift = P4D_SHIFT; + + if (p4d_none(p4d)) return NULL; - if (pgd_is_leaf(pgd)) { - ret_pte = (pte_t *)pgdp; + if (p4d_is_leaf(p4d)) { + ret_pte = (pte_t *)p4dp; goto out; } - if (is_hugepd(__hugepd(pgd_val(pgd)))) { - hpdp = (hugepd_t *)&pgd; + if (is_hugepd(__hugepd(p4d_val(p4d)))) { + hpdp = (hugepd_t *)&p4d; goto out_huge; } @@ -352,7 +360,7 @@ pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea, * irq disabled */ pdshift = PUD_SHIFT; - pudp = pud_offset(&pgd, ea); + pudp = pud_offset(&p4d, ea); pud = READ_ONCE(*pudp); if (pud_none(pud)) -- cgit v1.2.3