forked from Minki/linux
528a953934
If the pmd is soft dirty we must mark the pte as soft dirty (and not dirty).
This fixes some cases for guest migration with huge page backings.
Cc: <stable@vger.kernel.org> # 4.8
Fixes: bc29b7ac1d ("s390/mm: clean up pte/pmd encoding")
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
354 lines
9.7 KiB
C
354 lines
9.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
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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 IBM Corp. 2007,2020
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* Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
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*/
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#define KMSG_COMPONENT "hugetlb"
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#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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#include <linux/mm.h>
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#include <linux/hugetlb.h>
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#include <linux/mman.h>
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#include <linux/sched/mm.h>
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#include <linux/security.h>
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/*
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* If the bit selected by single-bit bitmask "a" is set within "x", move
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* it to the position indicated by single-bit bitmask "b".
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*/
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#define move_set_bit(x, a, b) (((x) & (a)) >> ilog2(a) << ilog2(b))
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static inline unsigned long __pte_to_rste(pte_t pte)
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{
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unsigned long rste;
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/*
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* Convert encoding pte bits pmd / pud bits
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* lIR.uswrdy.p dy..R...I...wr
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* empty 010.000000.0 -> 00..0...1...00
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* prot-none, clean, old 111.000000.1 -> 00..1...1...00
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* prot-none, clean, young 111.000001.1 -> 01..1...1...00
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* prot-none, dirty, old 111.000010.1 -> 10..1...1...00
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* prot-none, dirty, young 111.000011.1 -> 11..1...1...00
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* read-only, clean, old 111.000100.1 -> 00..1...1...01
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* read-only, clean, young 101.000101.1 -> 01..1...0...01
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* read-only, dirty, old 111.000110.1 -> 10..1...1...01
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* read-only, dirty, young 101.000111.1 -> 11..1...0...01
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* read-write, clean, old 111.001100.1 -> 00..1...1...11
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* read-write, clean, young 101.001101.1 -> 01..1...0...11
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* read-write, dirty, old 110.001110.1 -> 10..0...1...11
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* read-write, dirty, young 100.001111.1 -> 11..0...0...11
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* HW-bits: R read-only, I invalid
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* SW-bits: p present, y young, d dirty, r read, w write, s special,
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* u unused, l large
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*/
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if (pte_present(pte)) {
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rste = pte_val(pte) & PAGE_MASK;
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rste |= move_set_bit(pte_val(pte), _PAGE_READ,
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_SEGMENT_ENTRY_READ);
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rste |= move_set_bit(pte_val(pte), _PAGE_WRITE,
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_SEGMENT_ENTRY_WRITE);
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rste |= move_set_bit(pte_val(pte), _PAGE_INVALID,
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_SEGMENT_ENTRY_INVALID);
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rste |= move_set_bit(pte_val(pte), _PAGE_PROTECT,
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_SEGMENT_ENTRY_PROTECT);
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rste |= move_set_bit(pte_val(pte), _PAGE_DIRTY,
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_SEGMENT_ENTRY_DIRTY);
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rste |= move_set_bit(pte_val(pte), _PAGE_YOUNG,
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_SEGMENT_ENTRY_YOUNG);
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#ifdef CONFIG_MEM_SOFT_DIRTY
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rste |= move_set_bit(pte_val(pte), _PAGE_SOFT_DIRTY,
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_SEGMENT_ENTRY_SOFT_DIRTY);
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#endif
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rste |= move_set_bit(pte_val(pte), _PAGE_NOEXEC,
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_SEGMENT_ENTRY_NOEXEC);
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} else
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rste = _SEGMENT_ENTRY_EMPTY;
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return rste;
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}
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static inline pte_t __rste_to_pte(unsigned long rste)
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{
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int present;
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pte_t pte;
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if ((rste & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
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present = pud_present(__pud(rste));
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else
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present = pmd_present(__pmd(rste));
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/*
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* Convert encoding pmd / pud bits pte bits
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* dy..R...I...wr lIR.uswrdy.p
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* empty 00..0...1...00 -> 010.000000.0
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* prot-none, clean, old 00..1...1...00 -> 111.000000.1
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* prot-none, clean, young 01..1...1...00 -> 111.000001.1
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* prot-none, dirty, old 10..1...1...00 -> 111.000010.1
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* prot-none, dirty, young 11..1...1...00 -> 111.000011.1
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* read-only, clean, old 00..1...1...01 -> 111.000100.1
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* read-only, clean, young 01..1...0...01 -> 101.000101.1
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* read-only, dirty, old 10..1...1...01 -> 111.000110.1
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* read-only, dirty, young 11..1...0...01 -> 101.000111.1
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* read-write, clean, old 00..1...1...11 -> 111.001100.1
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* read-write, clean, young 01..1...0...11 -> 101.001101.1
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* read-write, dirty, old 10..0...1...11 -> 110.001110.1
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* read-write, dirty, young 11..0...0...11 -> 100.001111.1
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* HW-bits: R read-only, I invalid
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* SW-bits: p present, y young, d dirty, r read, w write, s special,
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* u unused, l large
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*/
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if (present) {
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pte_val(pte) = rste & _SEGMENT_ENTRY_ORIGIN_LARGE;
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pte_val(pte) |= _PAGE_LARGE | _PAGE_PRESENT;
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pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_READ,
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_PAGE_READ);
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pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_WRITE,
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_PAGE_WRITE);
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pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_INVALID,
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_PAGE_INVALID);
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pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_PROTECT,
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_PAGE_PROTECT);
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pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_DIRTY,
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_PAGE_DIRTY);
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pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_YOUNG,
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_PAGE_YOUNG);
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#ifdef CONFIG_MEM_SOFT_DIRTY
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pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_SOFT_DIRTY,
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_PAGE_SOFT_DIRTY);
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#endif
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pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_NOEXEC,
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_PAGE_NOEXEC);
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} else
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pte_val(pte) = _PAGE_INVALID;
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return pte;
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}
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static void clear_huge_pte_skeys(struct mm_struct *mm, unsigned long rste)
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{
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struct page *page;
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unsigned long size, paddr;
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if (!mm_uses_skeys(mm) ||
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rste & _SEGMENT_ENTRY_INVALID)
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return;
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if ((rste & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3) {
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page = pud_page(__pud(rste));
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size = PUD_SIZE;
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paddr = rste & PUD_MASK;
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} else {
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page = pmd_page(__pmd(rste));
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size = PMD_SIZE;
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paddr = rste & PMD_MASK;
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}
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if (!test_and_set_bit(PG_arch_1, &page->flags))
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__storage_key_init_range(paddr, paddr + size - 1);
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}
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void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
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pte_t *ptep, pte_t pte)
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{
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unsigned long rste;
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rste = __pte_to_rste(pte);
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if (!MACHINE_HAS_NX)
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rste &= ~_SEGMENT_ENTRY_NOEXEC;
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/* Set correct table type for 2G hugepages */
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if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3) {
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if (likely(pte_present(pte)))
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rste |= _REGION3_ENTRY_LARGE;
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rste |= _REGION_ENTRY_TYPE_R3;
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} else if (likely(pte_present(pte)))
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rste |= _SEGMENT_ENTRY_LARGE;
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clear_huge_pte_skeys(mm, rste);
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pte_val(*ptep) = rste;
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}
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pte_t huge_ptep_get(pte_t *ptep)
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{
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return __rste_to_pte(pte_val(*ptep));
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}
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pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
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unsigned long addr, pte_t *ptep)
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{
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pte_t pte = huge_ptep_get(ptep);
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pmd_t *pmdp = (pmd_t *) ptep;
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pud_t *pudp = (pud_t *) ptep;
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if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
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pudp_xchg_direct(mm, addr, pudp, __pud(_REGION3_ENTRY_EMPTY));
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else
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pmdp_xchg_direct(mm, addr, pmdp, __pmd(_SEGMENT_ENTRY_EMPTY));
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return pte;
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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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p4d_t *p4dp;
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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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p4dp = p4d_alloc(mm, pgdp, addr);
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if (p4dp) {
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pudp = pud_alloc(mm, p4dp, addr);
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if (pudp) {
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if (sz == PUD_SIZE)
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return (pte_t *) pudp;
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else if (sz == PMD_SIZE)
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pmdp = pmd_alloc(mm, pudp, addr);
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}
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}
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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,
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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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p4d_t *p4dp;
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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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p4dp = p4d_offset(pgdp, addr);
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if (p4d_present(*p4dp)) {
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pudp = pud_offset(p4dp, addr);
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if (pud_present(*pudp)) {
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if (pud_large(*pudp))
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return (pte_t *) pudp;
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pmdp = pmd_offset(pudp, addr);
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}
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}
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}
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return (pte_t *) pmdp;
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}
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int pmd_huge(pmd_t pmd)
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{
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return pmd_large(pmd);
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}
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int pud_huge(pud_t pud)
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{
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return pud_large(pud);
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}
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struct page *
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follow_huge_pud(struct mm_struct *mm, unsigned long address,
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pud_t *pud, int flags)
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{
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if (flags & FOLL_GET)
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return NULL;
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return pud_page(*pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT);
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}
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bool __init arch_hugetlb_valid_size(unsigned long size)
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{
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if (MACHINE_HAS_EDAT1 && size == PMD_SIZE)
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return true;
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else if (MACHINE_HAS_EDAT2 && size == PUD_SIZE)
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return true;
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else
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return false;
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}
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static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file,
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unsigned long addr, unsigned long len,
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unsigned long pgoff, unsigned long flags)
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{
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struct hstate *h = hstate_file(file);
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struct vm_unmapped_area_info info;
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info.flags = 0;
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info.length = len;
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info.low_limit = current->mm->mmap_base;
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info.high_limit = TASK_SIZE;
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info.align_mask = PAGE_MASK & ~huge_page_mask(h);
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info.align_offset = 0;
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return vm_unmapped_area(&info);
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}
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static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
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unsigned long addr0, unsigned long len,
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unsigned long pgoff, unsigned long flags)
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{
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struct hstate *h = hstate_file(file);
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struct vm_unmapped_area_info info;
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unsigned long addr;
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info.flags = VM_UNMAPPED_AREA_TOPDOWN;
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info.length = len;
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info.low_limit = max(PAGE_SIZE, mmap_min_addr);
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info.high_limit = current->mm->mmap_base;
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info.align_mask = PAGE_MASK & ~huge_page_mask(h);
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info.align_offset = 0;
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addr = vm_unmapped_area(&info);
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/*
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* A failed mmap() very likely causes application failure,
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* so fall back to the bottom-up function here. This scenario
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* can happen with large stack limits and large mmap()
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* allocations.
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*/
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if (addr & ~PAGE_MASK) {
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VM_BUG_ON(addr != -ENOMEM);
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info.flags = 0;
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info.low_limit = TASK_UNMAPPED_BASE;
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info.high_limit = TASK_SIZE;
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addr = vm_unmapped_area(&info);
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}
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return addr;
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}
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unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
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unsigned long len, unsigned long pgoff, unsigned long flags)
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{
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struct hstate *h = hstate_file(file);
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struct mm_struct *mm = current->mm;
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struct vm_area_struct *vma;
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if (len & ~huge_page_mask(h))
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return -EINVAL;
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if (len > TASK_SIZE - mmap_min_addr)
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return -ENOMEM;
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if (flags & MAP_FIXED) {
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if (prepare_hugepage_range(file, addr, len))
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return -EINVAL;
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goto check_asce_limit;
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}
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if (addr) {
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addr = ALIGN(addr, huge_page_size(h));
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vma = find_vma(mm, addr);
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if (TASK_SIZE - len >= addr && addr >= mmap_min_addr &&
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(!vma || addr + len <= vm_start_gap(vma)))
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goto check_asce_limit;
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}
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if (mm->get_unmapped_area == arch_get_unmapped_area)
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addr = hugetlb_get_unmapped_area_bottomup(file, addr, len,
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pgoff, flags);
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else
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addr = hugetlb_get_unmapped_area_topdown(file, addr, len,
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pgoff, flags);
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if (offset_in_page(addr))
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return addr;
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check_asce_limit:
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return check_asce_limit(mm, addr, len);
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}
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