141 lines
2.7 KiB
C
141 lines
2.7 KiB
C
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/*
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* IBM System z Huge TLB Page Support for Kernel.
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*
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* Copyright 2007 IBM Corp.
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* Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
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*/
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#include <linux/mm.h>
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#include <linux/hugetlb.h>
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void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
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pte_t *pteptr, pte_t pteval)
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{
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pmd_t *pmdp = (pmd_t *) pteptr;
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pte_t shadow_pteval = pteval;
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unsigned long mask;
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if (!MACHINE_HAS_HPAGE) {
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pteptr = (pte_t *) pte_page(pteval)[1].index;
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mask = pte_val(pteval) &
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(_SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO);
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pte_val(pteval) = (_SEGMENT_ENTRY + __pa(pteptr)) | mask;
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if (mm->context.noexec) {
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pteptr += PTRS_PER_PTE;
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pte_val(shadow_pteval) =
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(_SEGMENT_ENTRY + __pa(pteptr)) | mask;
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}
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}
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pmd_val(*pmdp) = pte_val(pteval);
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if (mm->context.noexec) {
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pmdp = get_shadow_table(pmdp);
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pmd_val(*pmdp) = pte_val(shadow_pteval);
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}
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}
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int arch_prepare_hugepage(struct page *page)
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{
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unsigned long addr = page_to_phys(page);
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pte_t pte;
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pte_t *ptep;
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int i;
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if (MACHINE_HAS_HPAGE)
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return 0;
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ptep = (pte_t *) pte_alloc_one(&init_mm, address);
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if (!ptep)
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return -ENOMEM;
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pte = mk_pte(page, PAGE_RW);
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for (i = 0; i < PTRS_PER_PTE; i++) {
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set_pte_at(&init_mm, addr + i * PAGE_SIZE, ptep + i, pte);
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pte_val(pte) += PAGE_SIZE;
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}
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page[1].index = (unsigned long) ptep;
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return 0;
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}
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void arch_release_hugepage(struct page *page)
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{
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pte_t *ptep;
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if (MACHINE_HAS_HPAGE)
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return;
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ptep = (pte_t *) page[1].index;
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if (!ptep)
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return;
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pte_free(&init_mm, ptep);
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page[1].index = 0;
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}
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pte_t *huge_pte_alloc(struct mm_struct *mm,
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unsigned long addr, unsigned long sz)
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{
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pgd_t *pgdp;
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pud_t *pudp;
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pmd_t *pmdp = NULL;
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pgdp = pgd_offset(mm, addr);
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pudp = pud_alloc(mm, pgdp, addr);
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if (pudp)
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pmdp = pmd_alloc(mm, pudp, addr);
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return (pte_t *) pmdp;
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}
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pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
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{
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pgd_t *pgdp;
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pud_t *pudp;
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pmd_t *pmdp = NULL;
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pgdp = pgd_offset(mm, addr);
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if (pgd_present(*pgdp)) {
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pudp = pud_offset(pgdp, addr);
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if (pud_present(*pudp))
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pmdp = pmd_offset(pudp, addr);
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}
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return (pte_t *) pmdp;
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}
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int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
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{
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return 0;
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}
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struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
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int write)
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{
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return ERR_PTR(-EINVAL);
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}
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int pmd_huge(pmd_t pmd)
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{
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if (!MACHINE_HAS_HPAGE)
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return 0;
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return !!(pmd_val(pmd) & _SEGMENT_ENTRY_LARGE);
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}
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int pud_huge(pud_t pud)
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{
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return 0;
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}
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struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
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pmd_t *pmdp, int write)
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{
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struct page *page;
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if (!MACHINE_HAS_HPAGE)
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return NULL;
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page = pmd_page(*pmdp);
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if (page)
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page += ((address & ~HPAGE_MASK) >> PAGE_SHIFT);
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return page;
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}
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