171 lines
4.9 KiB
C
171 lines
4.9 KiB
C
/*
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* Copyright 2015-2016, Aneesh Kumar K.V, IBM Corporation.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/sched.h>
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#include <linux/mm_types.h>
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#include <misc/cxl-base.h>
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#include <asm/pgalloc.h>
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#include <asm/tlb.h>
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#include "mmu_decl.h"
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#include <trace/events/thp.h>
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int (*register_process_table)(unsigned long base, unsigned long page_size,
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unsigned long tbl_size);
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#ifdef CONFIG_TRANSPARENT_HUGEPAGE
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/*
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* This is called when relaxing access to a hugepage. It's also called in the page
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* fault path when we don't hit any of the major fault cases, ie, a minor
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* update of _PAGE_ACCESSED, _PAGE_DIRTY, etc... The generic code will have
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* handled those two for us, we additionally deal with missing execute
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* permission here on some processors
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*/
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int pmdp_set_access_flags(struct vm_area_struct *vma, unsigned long address,
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pmd_t *pmdp, pmd_t entry, int dirty)
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{
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int changed;
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#ifdef CONFIG_DEBUG_VM
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WARN_ON(!pmd_trans_huge(*pmdp) && !pmd_devmap(*pmdp));
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assert_spin_locked(&vma->vm_mm->page_table_lock);
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#endif
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changed = !pmd_same(*(pmdp), entry);
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if (changed) {
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__ptep_set_access_flags(vma->vm_mm, pmdp_ptep(pmdp),
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pmd_pte(entry), address);
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flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
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}
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return changed;
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}
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int pmdp_test_and_clear_young(struct vm_area_struct *vma,
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unsigned long address, pmd_t *pmdp)
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{
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return __pmdp_test_and_clear_young(vma->vm_mm, address, pmdp);
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}
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/*
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* set a new huge pmd. We should not be called for updating
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* an existing pmd entry. That should go via pmd_hugepage_update.
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*/
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void set_pmd_at(struct mm_struct *mm, unsigned long addr,
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pmd_t *pmdp, pmd_t pmd)
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{
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#ifdef CONFIG_DEBUG_VM
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WARN_ON(pte_present(pmd_pte(*pmdp)) && !pte_protnone(pmd_pte(*pmdp)));
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assert_spin_locked(&mm->page_table_lock);
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WARN_ON(!(pmd_trans_huge(pmd) || pmd_devmap(pmd)));
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#endif
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trace_hugepage_set_pmd(addr, pmd_val(pmd));
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return set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd));
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}
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static void do_nothing(void *unused)
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{
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}
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/*
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* Serialize against find_current_mm_pte which does lock-less
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* lookup in page tables with local interrupts disabled. For huge pages
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* it casts pmd_t to pte_t. Since format of pte_t is different from
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* pmd_t we want to prevent transit from pmd pointing to page table
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* to pmd pointing to huge page (and back) while interrupts are disabled.
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* We clear pmd to possibly replace it with page table pointer in
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* different code paths. So make sure we wait for the parallel
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* find_current_mm_pte to finish.
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*/
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void serialize_against_pte_lookup(struct mm_struct *mm)
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{
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smp_mb();
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smp_call_function_many(mm_cpumask(mm), do_nothing, NULL, 1);
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}
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/*
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* We use this to invalidate a pmdp entry before switching from a
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* hugepte to regular pmd entry.
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*/
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void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
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pmd_t *pmdp)
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{
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pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT, 0);
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flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
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/*
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* This ensures that generic code that rely on IRQ disabling
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* to prevent a parallel THP split work as expected.
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*/
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serialize_against_pte_lookup(vma->vm_mm);
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}
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static pmd_t pmd_set_protbits(pmd_t pmd, pgprot_t pgprot)
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{
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return __pmd(pmd_val(pmd) | pgprot_val(pgprot));
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}
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pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot)
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{
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unsigned long pmdv;
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pmdv = (pfn << PAGE_SHIFT) & PTE_RPN_MASK;
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return pmd_set_protbits(__pmd(pmdv), pgprot);
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}
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pmd_t mk_pmd(struct page *page, pgprot_t pgprot)
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{
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return pfn_pmd(page_to_pfn(page), pgprot);
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}
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pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
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{
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unsigned long pmdv;
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pmdv = pmd_val(pmd);
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pmdv &= _HPAGE_CHG_MASK;
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return pmd_set_protbits(__pmd(pmdv), newprot);
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}
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/*
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* This is called at the end of handling a user page fault, when the
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* fault has been handled by updating a HUGE PMD entry in the linux page tables.
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* We use it to preload an HPTE into the hash table corresponding to
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* the updated linux HUGE PMD entry.
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*/
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void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr,
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pmd_t *pmd)
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{
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return;
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}
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#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
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/* For use by kexec */
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void mmu_cleanup_all(void)
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{
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if (radix_enabled())
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radix__mmu_cleanup_all();
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else if (mmu_hash_ops.hpte_clear_all)
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mmu_hash_ops.hpte_clear_all();
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}
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#ifdef CONFIG_MEMORY_HOTPLUG
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int create_section_mapping(unsigned long start, unsigned long end)
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{
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if (radix_enabled())
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return radix__create_section_mapping(start, end);
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return hash__create_section_mapping(start, end);
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}
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int remove_section_mapping(unsigned long start, unsigned long end)
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{
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if (radix_enabled())
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return radix__remove_section_mapping(start, end);
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return hash__remove_section_mapping(start, end);
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}
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#endif /* CONFIG_MEMORY_HOTPLUG */
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