arch/powerpc/mm/pgtable-book3s64.c

   1 /*
   2  * Copyright 2015-2016, Aneesh Kumar K.V, IBM Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version
   7  * 2 of the License, or (at your option) any later version.
   8  */
   9
  10 #include <linux/sched.h>
  11 #include <linux/mm_types.h>
  12
  13 #include <asm/pgalloc.h>
  14 #include <asm/tlb.h>
  15
  16 #include "mmu_decl.h"
  17 #include <trace/events/thp.h>
  18
  19 int (*register_process_table)(unsigned long base, unsigned long page_size,
  20                               unsigned long tbl_size);
  21
  22 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
  23 /*
  24  * This is called when relaxing access to a hugepage. It's also called in the page
  25  * fault path when we don't hit any of the major fault cases, ie, a minor
  26  * update of _PAGE_ACCESSED, _PAGE_DIRTY, etc... The generic code will have
  27  * handled those two for us, we additionally deal with missing execute
  28  * permission here on some processors
  29  */
  30 int pmdp_set_access_flags(struct vm_area_struct *vma, unsigned long address,
  31                           pmd_t *pmdp, pmd_t entry, int dirty)
  32 {
  33         int changed;
  34 #ifdef CONFIG_DEBUG_VM
  35         WARN_ON(!pmd_trans_huge(*pmdp));
  36         assert_spin_locked(&vma->vm_mm->page_table_lock);
  37 #endif
  38         changed = !pmd_same(*(pmdp), entry);
  39         if (changed) {
  40                 __ptep_set_access_flags(vma->vm_mm, pmdp_ptep(pmdp),
  41                                         pmd_pte(entry), address);
  42                 flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
  43         }
  44         return changed;
  45 }
  46
  47 int pmdp_test_and_clear_young(struct vm_area_struct *vma,
  48                               unsigned long address, pmd_t *pmdp)
  49 {
  50         return __pmdp_test_and_clear_young(vma->vm_mm, address, pmdp);
  51 }
  52 /*
  53  * set a new huge pmd. We should not be called for updating
  54  * an existing pmd entry. That should go via pmd_hugepage_update.
  55  */
  56 void set_pmd_at(struct mm_struct *mm, unsigned long addr,
  57                 pmd_t *pmdp, pmd_t pmd)
  58 {
  59 #ifdef CONFIG_DEBUG_VM
  60         WARN_ON(pte_present(pmd_pte(*pmdp)) && !pte_protnone(pmd_pte(*pmdp)));
  61         assert_spin_locked(&mm->page_table_lock);
  62         WARN_ON(!pmd_trans_huge(pmd));
  63 #endif
  64         trace_hugepage_set_pmd(addr, pmd_val(pmd));
  65         return set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd));
  66 }
  67 /*
  68  * We use this to invalidate a pmdp entry before switching from a
  69  * hugepte to regular pmd entry.
  70  */
  71 void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
  72                      pmd_t *pmdp)
  73 {
  74         pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT, 0);
  75         flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
  76         /*
  77          * This ensures that generic code that rely on IRQ disabling
  78          * to prevent a parallel THP split work as expected.
  79          */
  80         kick_all_cpus_sync();
  81 }
  82
  83 static pmd_t pmd_set_protbits(pmd_t pmd, pgprot_t pgprot)
  84 {
  85         return __pmd(pmd_val(pmd) | pgprot_val(pgprot));
  86 }
  87
  88 pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot)
  89 {
  90         unsigned long pmdv;
  91
  92         pmdv = (pfn << PAGE_SHIFT) & PTE_RPN_MASK;
  93         return pmd_set_protbits(__pmd(pmdv), pgprot);
  94 }
  95
  96 pmd_t mk_pmd(struct page *page, pgprot_t pgprot)
  97 {
  98         return pfn_pmd(page_to_pfn(page), pgprot);
  99 }
 100
 101 pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
 102 {
 103         unsigned long pmdv;
 104
 105         pmdv = pmd_val(pmd);
 106         pmdv &= _HPAGE_CHG_MASK;
 107         return pmd_set_protbits(__pmd(pmdv), newprot);
 108 }
 109
 110 /*
 111  * This is called at the end of handling a user page fault, when the
 112  * fault has been handled by updating a HUGE PMD entry in the linux page tables.
 113  * We use it to preload an HPTE into the hash table corresponding to
 114  * the updated linux HUGE PMD entry.
 115  */
 116 void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr,
 117                           pmd_t *pmd)
 118 {
 119         return;
 120 }
 121 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 122
 123 /* For use by kexec */
 124 void mmu_cleanup_all(void)
 125 {
 126         if (radix_enabled())
 127                 radix__mmu_cleanup_all();
 128         else if (mmu_hash_ops.hpte_clear_all)
 129                 mmu_hash_ops.hpte_clear_all();
 130 }
 131
 132 #ifdef CONFIG_MEMORY_HOTPLUG
 133 int create_section_mapping(unsigned long start, unsigned long end)
 134 {
 135         if (radix_enabled())
 136                 return radix__create_section_mapping(start, end);
 137
 138         return hash__create_section_mapping(start, end);
 139 }
 140
 141 int remove_section_mapping(unsigned long start, unsigned long end)
 142 {
 143         if (radix_enabled())
 144                 return radix__remove_section_mapping(start, end);
 145
 146         return hash__remove_section_mapping(start, end);
 147 }
 148 #endif /* CONFIG_MEMORY_HOTPLUG */