v4.19.13 snapshot.
diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
new file mode 100644
index 0000000..d71c777
--- /dev/null
+++ b/arch/powerpc/mm/pgtable.c
@@ -0,0 +1,307 @@
+/*
+ * This file contains common routines for dealing with free of page tables
+ * Along with common page table handling code
+ *
+ * Derived from arch/powerpc/mm/tlb_64.c:
+ * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *
+ * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
+ * and Cort Dougan (PReP) (cort@cs.nmt.edu)
+ * Copyright (C) 1996 Paul Mackerras
+ *
+ * Derived from "arch/i386/mm/init.c"
+ * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
+ *
+ * Dave Engebretsen <engebret@us.ibm.com>
+ * Rework for PPC64 port.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/gfp.h>
+#include <linux/mm.h>
+#include <linux/percpu.h>
+#include <linux/hardirq.h>
+#include <linux/hugetlb.h>
+#include <asm/pgalloc.h>
+#include <asm/tlbflush.h>
+#include <asm/tlb.h>
+
+static inline int is_exec_fault(void)
+{
+ return current->thread.regs && TRAP(current->thread.regs) == 0x400;
+}
+
+/* We only try to do i/d cache coherency on stuff that looks like
+ * reasonably "normal" PTEs. We currently require a PTE to be present
+ * and we avoid _PAGE_SPECIAL and cache inhibited pte. We also only do that
+ * on userspace PTEs
+ */
+static inline int pte_looks_normal(pte_t pte)
+{
+
+#if defined(CONFIG_PPC_BOOK3S_64)
+ if ((pte_val(pte) & (_PAGE_PRESENT | _PAGE_SPECIAL)) == _PAGE_PRESENT) {
+ if (pte_ci(pte))
+ return 0;
+ if (pte_user(pte))
+ return 1;
+ }
+ return 0;
+#else
+ return (pte_val(pte) &
+ (_PAGE_PRESENT | _PAGE_SPECIAL | _PAGE_NO_CACHE | _PAGE_USER |
+ _PAGE_PRIVILEGED)) ==
+ (_PAGE_PRESENT | _PAGE_USER);
+#endif
+}
+
+static struct page *maybe_pte_to_page(pte_t pte)
+{
+ unsigned long pfn = pte_pfn(pte);
+ struct page *page;
+
+ if (unlikely(!pfn_valid(pfn)))
+ return NULL;
+ page = pfn_to_page(pfn);
+ if (PageReserved(page))
+ return NULL;
+ return page;
+}
+
+#if defined(CONFIG_PPC_STD_MMU) || _PAGE_EXEC == 0
+
+/* Server-style MMU handles coherency when hashing if HW exec permission
+ * is supposed per page (currently 64-bit only). If not, then, we always
+ * flush the cache for valid PTEs in set_pte. Embedded CPU without HW exec
+ * support falls into the same category.
+ */
+
+static pte_t set_pte_filter(pte_t pte)
+{
+ if (radix_enabled())
+ return pte;
+
+ pte = __pte(pte_val(pte) & ~_PAGE_HPTEFLAGS);
+ if (pte_looks_normal(pte) && !(cpu_has_feature(CPU_FTR_COHERENT_ICACHE) ||
+ cpu_has_feature(CPU_FTR_NOEXECUTE))) {
+ struct page *pg = maybe_pte_to_page(pte);
+ if (!pg)
+ return pte;
+ if (!test_bit(PG_arch_1, &pg->flags)) {
+ flush_dcache_icache_page(pg);
+ set_bit(PG_arch_1, &pg->flags);
+ }
+ }
+ return pte;
+}
+
+static pte_t set_access_flags_filter(pte_t pte, struct vm_area_struct *vma,
+ int dirty)
+{
+ return pte;
+}
+
+#else /* defined(CONFIG_PPC_STD_MMU) || _PAGE_EXEC == 0 */
+
+/* Embedded type MMU with HW exec support. This is a bit more complicated
+ * as we don't have two bits to spare for _PAGE_EXEC and _PAGE_HWEXEC so
+ * instead we "filter out" the exec permission for non clean pages.
+ */
+static pte_t set_pte_filter(pte_t pte)
+{
+ struct page *pg;
+
+ /* No exec permission in the first place, move on */
+ if (!(pte_val(pte) & _PAGE_EXEC) || !pte_looks_normal(pte))
+ return pte;
+
+ /* If you set _PAGE_EXEC on weird pages you're on your own */
+ pg = maybe_pte_to_page(pte);
+ if (unlikely(!pg))
+ return pte;
+
+ /* If the page clean, we move on */
+ if (test_bit(PG_arch_1, &pg->flags))
+ return pte;
+
+ /* If it's an exec fault, we flush the cache and make it clean */
+ if (is_exec_fault()) {
+ flush_dcache_icache_page(pg);
+ set_bit(PG_arch_1, &pg->flags);
+ return pte;
+ }
+
+ /* Else, we filter out _PAGE_EXEC */
+ return __pte(pte_val(pte) & ~_PAGE_EXEC);
+}
+
+static pte_t set_access_flags_filter(pte_t pte, struct vm_area_struct *vma,
+ int dirty)
+{
+ struct page *pg;
+
+ /* So here, we only care about exec faults, as we use them
+ * to recover lost _PAGE_EXEC and perform I$/D$ coherency
+ * if necessary. Also if _PAGE_EXEC is already set, same deal,
+ * we just bail out
+ */
+ if (dirty || (pte_val(pte) & _PAGE_EXEC) || !is_exec_fault())
+ return pte;
+
+#ifdef CONFIG_DEBUG_VM
+ /* So this is an exec fault, _PAGE_EXEC is not set. If it was
+ * an error we would have bailed out earlier in do_page_fault()
+ * but let's make sure of it
+ */
+ if (WARN_ON(!(vma->vm_flags & VM_EXEC)))
+ return pte;
+#endif /* CONFIG_DEBUG_VM */
+
+ /* If you set _PAGE_EXEC on weird pages you're on your own */
+ pg = maybe_pte_to_page(pte);
+ if (unlikely(!pg))
+ goto bail;
+
+ /* If the page is already clean, we move on */
+ if (test_bit(PG_arch_1, &pg->flags))
+ goto bail;
+
+ /* Clean the page and set PG_arch_1 */
+ flush_dcache_icache_page(pg);
+ set_bit(PG_arch_1, &pg->flags);
+
+ bail:
+ return __pte(pte_val(pte) | _PAGE_EXEC);
+}
+
+#endif /* !(defined(CONFIG_PPC_STD_MMU) || _PAGE_EXEC == 0) */
+
+/*
+ * set_pte stores a linux PTE into the linux page table.
+ */
+void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
+ pte_t pte)
+{
+ /*
+ * When handling numa faults, we already have the pte marked
+ * _PAGE_PRESENT, but we can be sure that it is not in hpte.
+ * Hence we can use set_pte_at for them.
+ */
+ VM_WARN_ON(pte_present(*ptep) && !pte_protnone(*ptep));
+
+ /* Add the pte bit when trying to set a pte */
+ pte = __pte(pte_val(pte) | _PAGE_PTE);
+
+ /* Note: mm->context.id might not yet have been assigned as
+ * this context might not have been activated yet when this
+ * is called.
+ */
+ pte = set_pte_filter(pte);
+
+ /* Perform the setting of the PTE */
+ __set_pte_at(mm, addr, ptep, pte, 0);
+}
+
+/*
+ * This is called when relaxing access to a PTE. It's also called in the page
+ * fault path when we don't hit any of the major fault cases, ie, a minor
+ * update of _PAGE_ACCESSED, _PAGE_DIRTY, etc... The generic code will have
+ * handled those two for us, we additionally deal with missing execute
+ * permission here on some processors
+ */
+int ptep_set_access_flags(struct vm_area_struct *vma, unsigned long address,
+ pte_t *ptep, pte_t entry, int dirty)
+{
+ int changed;
+ entry = set_access_flags_filter(entry, vma, dirty);
+ changed = !pte_same(*(ptep), entry);
+ if (changed) {
+ assert_pte_locked(vma->vm_mm, address);
+ __ptep_set_access_flags(vma, ptep, entry,
+ address, mmu_virtual_psize);
+ }
+ return changed;
+}
+
+#ifdef CONFIG_HUGETLB_PAGE
+extern int huge_ptep_set_access_flags(struct vm_area_struct *vma,
+ unsigned long addr, pte_t *ptep,
+ pte_t pte, int dirty)
+{
+#ifdef HUGETLB_NEED_PRELOAD
+ /*
+ * The "return 1" forces a call of update_mmu_cache, which will write a
+ * TLB entry. Without this, platforms that don't do a write of the TLB
+ * entry in the TLB miss handler asm will fault ad infinitum.
+ */
+ ptep_set_access_flags(vma, addr, ptep, pte, dirty);
+ return 1;
+#else
+ int changed, psize;
+
+ pte = set_access_flags_filter(pte, vma, dirty);
+ changed = !pte_same(*(ptep), pte);
+ if (changed) {
+
+#ifdef CONFIG_PPC_BOOK3S_64
+ struct hstate *h = hstate_vma(vma);
+
+ psize = hstate_get_psize(h);
+#ifdef CONFIG_DEBUG_VM
+ assert_spin_locked(huge_pte_lockptr(h, vma->vm_mm, ptep));
+#endif
+
+#else
+ /*
+ * Not used on non book3s64 platforms. But 8xx
+ * can possibly use tsize derived from hstate.
+ */
+ psize = 0;
+#endif
+ __ptep_set_access_flags(vma, ptep, pte, addr, psize);
+ }
+ return changed;
+#endif
+}
+#endif /* CONFIG_HUGETLB_PAGE */
+
+#ifdef CONFIG_DEBUG_VM
+void assert_pte_locked(struct mm_struct *mm, unsigned long addr)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+
+ if (mm == &init_mm)
+ return;
+ pgd = mm->pgd + pgd_index(addr);
+ BUG_ON(pgd_none(*pgd));
+ pud = pud_offset(pgd, addr);
+ BUG_ON(pud_none(*pud));
+ pmd = pmd_offset(pud, addr);
+ /*
+ * khugepaged to collapse normal pages to hugepage, first set
+ * pmd to none to force page fault/gup to take mmap_sem. After
+ * pmd is set to none, we do a pte_clear which does this assertion
+ * so if we find pmd none, return.
+ */
+ if (pmd_none(*pmd))
+ return;
+ BUG_ON(!pmd_present(*pmd));
+ assert_spin_locked(pte_lockptr(mm, pmd));
+}
+#endif /* CONFIG_DEBUG_VM */
+
+unsigned long vmalloc_to_phys(void *va)
+{
+ unsigned long pfn = vmalloc_to_pfn(va);
+
+ BUG_ON(!pfn);
+ return __pa(pfn_to_kaddr(pfn)) + offset_in_page(va);
+}
+EXPORT_SYMBOL_GPL(vmalloc_to_phys);