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c9b02a2413
Also, setting PDPEs in PAE mode does not require atomic operations, since the PDPEs are cached by the processor, and only reloaded on an explicit or implicit reload of CR3. Since the four PDPEs must always be present in an active root, and the kernel PDPE is never updated, we are safe even from SMIs and interrupts / NMIs using task gates (which reload CR3). Actually, much of this is moot, since the user PDPEs are never updated either, and the only usage of task gates is by the doublefault handler. It appears the only place PGDs get updated in PAE mode is in init_low_mappings() / zap_low_mapping() for initial page table creation and recovery from ACPI sleep state, and these sites are safe by inspection. Getting rid of the cmpxchg8b saves code space and 720 cycles in pgd_alloc on P4. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
161 lines
4.3 KiB
C
161 lines
4.3 KiB
C
#ifndef _I386_PGTABLE_3LEVEL_H
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#define _I386_PGTABLE_3LEVEL_H
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#include <asm-generic/pgtable-nopud.h>
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/*
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* Intel Physical Address Extension (PAE) Mode - three-level page
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* tables on PPro+ CPUs.
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*
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* Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
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*/
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#define pte_ERROR(e) \
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printk("%s:%d: bad pte %p(%08lx%08lx).\n", __FILE__, __LINE__, &(e), (e).pte_high, (e).pte_low)
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#define pmd_ERROR(e) \
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printk("%s:%d: bad pmd %p(%016Lx).\n", __FILE__, __LINE__, &(e), pmd_val(e))
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#define pgd_ERROR(e) \
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printk("%s:%d: bad pgd %p(%016Lx).\n", __FILE__, __LINE__, &(e), pgd_val(e))
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#define pud_none(pud) 0
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#define pud_bad(pud) 0
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#define pud_present(pud) 1
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/*
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* Is the pte executable?
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*/
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static inline int pte_x(pte_t pte)
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{
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return !(pte_val(pte) & _PAGE_NX);
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}
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/*
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* All present user-pages with !NX bit are user-executable:
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*/
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static inline int pte_exec(pte_t pte)
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{
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return pte_user(pte) && pte_x(pte);
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}
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/*
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* All present pages with !NX bit are kernel-executable:
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*/
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static inline int pte_exec_kernel(pte_t pte)
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{
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return pte_x(pte);
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}
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/* Rules for using set_pte: the pte being assigned *must* be
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* either not present or in a state where the hardware will
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* not attempt to update the pte. In places where this is
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* not possible, use pte_get_and_clear to obtain the old pte
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* value and then use set_pte to update it. -ben
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*/
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static inline void set_pte(pte_t *ptep, pte_t pte)
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{
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ptep->pte_high = pte.pte_high;
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smp_wmb();
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ptep->pte_low = pte.pte_low;
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}
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#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
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#define __HAVE_ARCH_SET_PTE_ATOMIC
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#define set_pte_atomic(pteptr,pteval) \
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set_64bit((unsigned long long *)(pteptr),pte_val(pteval))
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#define set_pmd(pmdptr,pmdval) \
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set_64bit((unsigned long long *)(pmdptr),pmd_val(pmdval))
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#define set_pud(pudptr,pudval) \
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(*(pudptr) = (pudval))
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/*
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* Pentium-II erratum A13: in PAE mode we explicitly have to flush
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* the TLB via cr3 if the top-level pgd is changed...
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* We do not let the generic code free and clear pgd entries due to
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* this erratum.
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*/
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static inline void pud_clear (pud_t * pud) { }
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#define pmd_page(pmd) (pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT))
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#define pmd_page_kernel(pmd) \
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((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
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#define pud_page(pud) \
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((struct page *) __va(pud_val(pud) & PAGE_MASK))
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#define pud_page_kernel(pud) \
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((unsigned long) __va(pud_val(pud) & PAGE_MASK))
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/* Find an entry in the second-level page table.. */
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#define pmd_offset(pud, address) ((pmd_t *) pud_page(*(pud)) + \
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pmd_index(address))
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static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
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{
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pte_t res;
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/* xchg acts as a barrier before the setting of the high bits */
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res.pte_low = xchg(&ptep->pte_low, 0);
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res.pte_high = ptep->pte_high;
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ptep->pte_high = 0;
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return res;
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}
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static inline int pte_same(pte_t a, pte_t b)
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{
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return a.pte_low == b.pte_low && a.pte_high == b.pte_high;
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}
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#define pte_page(x) pfn_to_page(pte_pfn(x))
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static inline int pte_none(pte_t pte)
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{
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return !pte.pte_low && !pte.pte_high;
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}
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static inline unsigned long pte_pfn(pte_t pte)
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{
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return (pte.pte_low >> PAGE_SHIFT) |
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(pte.pte_high << (32 - PAGE_SHIFT));
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}
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extern unsigned long long __supported_pte_mask;
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static inline pte_t pfn_pte(unsigned long page_nr, pgprot_t pgprot)
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{
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pte_t pte;
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pte.pte_high = (page_nr >> (32 - PAGE_SHIFT)) | \
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(pgprot_val(pgprot) >> 32);
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pte.pte_high &= (__supported_pte_mask >> 32);
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pte.pte_low = ((page_nr << PAGE_SHIFT) | pgprot_val(pgprot)) & \
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__supported_pte_mask;
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return pte;
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}
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static inline pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot)
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{
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return __pmd((((unsigned long long)page_nr << PAGE_SHIFT) | \
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pgprot_val(pgprot)) & __supported_pte_mask);
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}
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/*
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* Bits 0, 6 and 7 are taken in the low part of the pte,
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* put the 32 bits of offset into the high part.
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*/
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#define pte_to_pgoff(pte) ((pte).pte_high)
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#define pgoff_to_pte(off) ((pte_t) { _PAGE_FILE, (off) })
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#define PTE_FILE_MAX_BITS 32
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/* Encode and de-code a swap entry */
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#define __swp_type(x) (((x).val) & 0x1f)
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#define __swp_offset(x) ((x).val >> 5)
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#define __swp_entry(type, offset) ((swp_entry_t){(type) | (offset) << 5})
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#define __pte_to_swp_entry(pte) ((swp_entry_t){ (pte).pte_high })
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#define __swp_entry_to_pte(x) ((pte_t){ 0, (x).val })
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#define __pmd_free_tlb(tlb, x) do { } while (0)
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#endif /* _I386_PGTABLE_3LEVEL_H */
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