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