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The function ptep_get_and_clear uses an atomic instruction sequence to get and clear an active pte. Rather than add such an atomic operator to all virtual machine implementations in paravirt-ops, it is easier to support the raw atomic sequence and use either a trapping writable pagetable approach, or a post-update notification. For the post update notification, we require the pte_update function to be called after the access. Combine the 2-level and 3-level paging operators into one common function which does the post-update notification, and rename the actual atomic sequences to raw_ptep_xxx operators. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Andi Kleen <ak@muc.de> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Andrew Morton <akpm@osdl.org>
72 lines
2.2 KiB
C
72 lines
2.2 KiB
C
#ifndef _I386_PGTABLE_2LEVEL_H
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#define _I386_PGTABLE_2LEVEL_H
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#define pte_ERROR(e) \
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printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, (e).pte_low)
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#define pgd_ERROR(e) \
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printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
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/*
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* Certain architectures need to do special things when PTEs
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* within a page table are directly modified. Thus, the following
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* hook is made available.
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*/
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#ifndef CONFIG_PARAVIRT
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#define set_pte(pteptr, pteval) (*(pteptr) = pteval)
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#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
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#define set_pmd(pmdptr, pmdval) (*(pmdptr) = (pmdval))
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#endif
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#define set_pte_atomic(pteptr, pteval) set_pte(pteptr,pteval)
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#define set_pte_present(mm,addr,ptep,pteval) set_pte_at(mm,addr,ptep,pteval)
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#define pte_clear(mm,addr,xp) do { set_pte_at(mm, addr, xp, __pte(0)); } while (0)
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#define pmd_clear(xp) do { set_pmd(xp, __pmd(0)); } while (0)
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#define raw_ptep_get_and_clear(xp) __pte(xchg(&(xp)->pte_low, 0))
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#define pte_page(x) pfn_to_page(pte_pfn(x))
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#define pte_none(x) (!(x).pte_low)
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#define pte_pfn(x) ((unsigned long)(((x).pte_low >> PAGE_SHIFT)))
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#define pfn_pte(pfn, prot) __pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
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#define pfn_pmd(pfn, prot) __pmd(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
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/*
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* All present user pages 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);
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}
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/*
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* All present pages 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 1;
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}
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/*
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* Bits 0, 6 and 7 are taken, split up the 29 bits of offset
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* into this range:
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*/
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#define PTE_FILE_MAX_BITS 29
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#define pte_to_pgoff(pte) \
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((((pte).pte_low >> 1) & 0x1f ) + (((pte).pte_low >> 8) << 5 ))
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#define pgoff_to_pte(off) \
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((pte_t) { (((off) & 0x1f) << 1) + (((off) >> 5) << 8) + _PAGE_FILE })
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/* Encode and de-code a swap entry */
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#define __swp_type(x) (((x).val >> 1) & 0x1f)
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#define __swp_offset(x) ((x).val >> 8)
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#define __swp_entry(type, offset) ((swp_entry_t) { ((type) << 1) | ((offset) << 8) })
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#define __pte_to_swp_entry(pte) ((swp_entry_t) { (pte).pte_low })
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#define __swp_entry_to_pte(x) ((pte_t) { (x).val })
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void vmalloc_sync_all(void);
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#endif /* _I386_PGTABLE_2LEVEL_H */
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