![Hugh Dickins](/assets/img/avatar_default.png)
Nick Piggin points out that page accounting on MIPS multiple ZERO_PAGEs is not maintained by its move_pte, and could lead to freeing a ZERO_PAGE. Instead of complicating that move_pte, just forget the minor optimization when mremapping, and change the one thing which needed it for correctness - filemap_xip use ZERO_PAGE(0) throughout instead of according to address. [ "There is no block device driver one could use for XIP on mips platforms" - Carsten Otte ] Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Andrew Morton <akpm@osdl.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
408 lines
11 KiB
C
408 lines
11 KiB
C
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 2003 Ralf Baechle
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*/
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#ifndef _ASM_PGTABLE_H
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#define _ASM_PGTABLE_H
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#ifdef CONFIG_32BIT
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#include <asm/pgtable-32.h>
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#endif
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#ifdef CONFIG_64BIT
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#include <asm/pgtable-64.h>
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#endif
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#include <asm/io.h>
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#include <asm/pgtable-bits.h>
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struct mm_struct;
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struct vm_area_struct;
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#define PAGE_NONE __pgprot(_PAGE_PRESENT | _CACHE_CACHABLE_NONCOHERENT)
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#define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
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PAGE_CACHABLE_DEFAULT)
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#define PAGE_COPY __pgprot(_PAGE_PRESENT | _PAGE_READ | \
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PAGE_CACHABLE_DEFAULT)
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#define PAGE_READONLY __pgprot(_PAGE_PRESENT | _PAGE_READ | \
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PAGE_CACHABLE_DEFAULT)
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#define PAGE_KERNEL __pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE | \
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_PAGE_GLOBAL | PAGE_CACHABLE_DEFAULT)
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#define PAGE_USERIO __pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
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PAGE_CACHABLE_DEFAULT)
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#define PAGE_KERNEL_UNCACHED __pgprot(_PAGE_PRESENT | __READABLE | \
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__WRITEABLE | _PAGE_GLOBAL | _CACHE_UNCACHED)
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/*
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* MIPS can't do page protection for execute, and considers that the same like
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* read. Also, write permissions imply read permissions. This is the closest
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* we can get by reasonable means..
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*/
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#define __P000 PAGE_NONE
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#define __P001 PAGE_READONLY
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#define __P010 PAGE_COPY
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#define __P011 PAGE_COPY
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#define __P100 PAGE_READONLY
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#define __P101 PAGE_READONLY
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#define __P110 PAGE_COPY
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#define __P111 PAGE_COPY
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#define __S000 PAGE_NONE
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#define __S001 PAGE_READONLY
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#define __S010 PAGE_SHARED
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#define __S011 PAGE_SHARED
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#define __S100 PAGE_READONLY
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#define __S101 PAGE_READONLY
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#define __S110 PAGE_SHARED
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#define __S111 PAGE_SHARED
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/*
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* ZERO_PAGE is a global shared page that is always zero; used
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* for zero-mapped memory areas etc..
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*/
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extern unsigned long empty_zero_page;
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extern unsigned long zero_page_mask;
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#define ZERO_PAGE(vaddr) \
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(virt_to_page((void *)(empty_zero_page + (((unsigned long)(vaddr)) & zero_page_mask))))
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extern void paging_init(void);
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/*
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* Conversion functions: convert a page and protection to a page entry,
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* and a page entry and page directory to the page they refer to.
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*/
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#define pmd_phys(pmd) (pmd_val(pmd) - PAGE_OFFSET)
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#define pmd_page(pmd) (pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT))
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#define pmd_page_vaddr(pmd) pmd_val(pmd)
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#if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32_R1)
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#define pte_none(pte) (!(((pte).pte_low | (pte).pte_high) & ~_PAGE_GLOBAL))
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#define pte_present(pte) ((pte).pte_low & _PAGE_PRESENT)
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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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//printk("pte_high %x pte_low %x\n", ptep->pte_high, ptep->pte_low);
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if (pte.pte_low & _PAGE_GLOBAL) {
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pte_t *buddy = ptep_buddy(ptep);
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/*
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* Make sure the buddy is global too (if it's !none,
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* it better already be global)
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*/
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if (pte_none(*buddy)) {
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buddy->pte_low |= _PAGE_GLOBAL;
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buddy->pte_high |= _PAGE_GLOBAL;
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}
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}
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}
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#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
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static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
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{
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pte_t null = __pte(0);
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/* Preserve global status for the pair */
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if (ptep_buddy(ptep)->pte_low & _PAGE_GLOBAL)
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null.pte_low = null.pte_high = _PAGE_GLOBAL;
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set_pte_at(mm, addr, ptep, null);
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}
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#else
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#define pte_none(pte) (!(pte_val(pte) & ~_PAGE_GLOBAL))
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#define pte_present(pte) (pte_val(pte) & _PAGE_PRESENT)
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/*
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* Certain architectures need to do special things when pte's
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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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static inline void set_pte(pte_t *ptep, pte_t pteval)
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{
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*ptep = pteval;
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#if !defined(CONFIG_CPU_R3000) && !defined(CONFIG_CPU_TX39XX)
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if (pte_val(pteval) & _PAGE_GLOBAL) {
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pte_t *buddy = ptep_buddy(ptep);
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/*
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* Make sure the buddy is global too (if it's !none,
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* it better already be global)
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*/
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if (pte_none(*buddy))
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pte_val(*buddy) = pte_val(*buddy) | _PAGE_GLOBAL;
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}
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#endif
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}
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#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
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static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
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{
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#if !defined(CONFIG_CPU_R3000) && !defined(CONFIG_CPU_TX39XX)
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/* Preserve global status for the pair */
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if (pte_val(*ptep_buddy(ptep)) & _PAGE_GLOBAL)
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set_pte_at(mm, addr, ptep, __pte(_PAGE_GLOBAL));
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else
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#endif
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set_pte_at(mm, addr, ptep, __pte(0));
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}
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#endif
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/*
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* (pmds are folded into puds so this doesn't get actually called,
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* but the define is needed for a generic inline function.)
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*/
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#define set_pmd(pmdptr, pmdval) do { *(pmdptr) = (pmdval); } while(0)
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#ifdef CONFIG_64BIT
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/*
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* (puds are folded into pgds so this doesn't get actually called,
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* but the define is needed for a generic inline function.)
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*/
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#define set_pud(pudptr, pudval) do { *(pudptr) = (pudval); } while(0)
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#endif
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#define PGD_T_LOG2 ffz(~sizeof(pgd_t))
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#define PMD_T_LOG2 ffz(~sizeof(pmd_t))
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#define PTE_T_LOG2 ffz(~sizeof(pte_t))
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extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
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/*
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* The following only work if pte_present() is true.
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* Undefined behaviour if not..
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*/
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static inline int pte_user(pte_t pte) { BUG(); return 0; }
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#if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32_R1)
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static inline int pte_read(pte_t pte) { return pte.pte_low & _PAGE_READ; }
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static inline int pte_write(pte_t pte) { return pte.pte_low & _PAGE_WRITE; }
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static inline int pte_dirty(pte_t pte) { return pte.pte_low & _PAGE_MODIFIED; }
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static inline int pte_young(pte_t pte) { return pte.pte_low & _PAGE_ACCESSED; }
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static inline int pte_file(pte_t pte) { return pte.pte_low & _PAGE_FILE; }
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static inline pte_t pte_wrprotect(pte_t pte)
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{
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pte.pte_low &= ~(_PAGE_WRITE | _PAGE_SILENT_WRITE);
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pte.pte_high &= ~_PAGE_SILENT_WRITE;
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return pte;
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}
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static inline pte_t pte_rdprotect(pte_t pte)
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{
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pte.pte_low &= ~(_PAGE_READ | _PAGE_SILENT_READ);
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pte.pte_high &= ~_PAGE_SILENT_READ;
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return pte;
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}
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static inline pte_t pte_mkclean(pte_t pte)
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{
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pte.pte_low &= ~(_PAGE_MODIFIED | _PAGE_SILENT_WRITE);
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pte.pte_high &= ~_PAGE_SILENT_WRITE;
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return pte;
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}
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static inline pte_t pte_mkold(pte_t pte)
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{
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pte.pte_low &= ~(_PAGE_ACCESSED | _PAGE_SILENT_READ);
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pte.pte_high &= ~_PAGE_SILENT_READ;
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return pte;
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}
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static inline pte_t pte_mkwrite(pte_t pte)
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{
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pte.pte_low |= _PAGE_WRITE;
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if (pte.pte_low & _PAGE_MODIFIED) {
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pte.pte_low |= _PAGE_SILENT_WRITE;
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pte.pte_high |= _PAGE_SILENT_WRITE;
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}
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return pte;
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}
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static inline pte_t pte_mkread(pte_t pte)
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{
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pte.pte_low |= _PAGE_READ;
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if (pte.pte_low & _PAGE_ACCESSED) {
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pte.pte_low |= _PAGE_SILENT_READ;
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pte.pte_high |= _PAGE_SILENT_READ;
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}
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return pte;
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}
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static inline pte_t pte_mkdirty(pte_t pte)
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{
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pte.pte_low |= _PAGE_MODIFIED;
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if (pte.pte_low & _PAGE_WRITE) {
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pte.pte_low |= _PAGE_SILENT_WRITE;
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pte.pte_high |= _PAGE_SILENT_WRITE;
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}
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return pte;
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}
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static inline pte_t pte_mkyoung(pte_t pte)
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{
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pte.pte_low |= _PAGE_ACCESSED;
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if (pte.pte_low & _PAGE_READ)
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pte.pte_low |= _PAGE_SILENT_READ;
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pte.pte_high |= _PAGE_SILENT_READ;
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return pte;
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}
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#else
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static inline int pte_read(pte_t pte) { return pte_val(pte) & _PAGE_READ; }
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static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_WRITE; }
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static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_MODIFIED; }
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static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; }
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static inline int pte_file(pte_t pte) { return pte_val(pte) & _PAGE_FILE; }
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static inline pte_t pte_wrprotect(pte_t pte)
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{
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pte_val(pte) &= ~(_PAGE_WRITE | _PAGE_SILENT_WRITE);
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return pte;
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}
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static inline pte_t pte_rdprotect(pte_t pte)
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{
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pte_val(pte) &= ~(_PAGE_READ | _PAGE_SILENT_READ);
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return pte;
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}
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static inline pte_t pte_mkclean(pte_t pte)
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{
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pte_val(pte) &= ~(_PAGE_MODIFIED|_PAGE_SILENT_WRITE);
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return pte;
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}
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static inline pte_t pte_mkold(pte_t pte)
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{
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pte_val(pte) &= ~(_PAGE_ACCESSED|_PAGE_SILENT_READ);
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return pte;
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}
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static inline pte_t pte_mkwrite(pte_t pte)
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{
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pte_val(pte) |= _PAGE_WRITE;
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if (pte_val(pte) & _PAGE_MODIFIED)
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pte_val(pte) |= _PAGE_SILENT_WRITE;
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return pte;
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}
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static inline pte_t pte_mkread(pte_t pte)
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{
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pte_val(pte) |= _PAGE_READ;
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if (pte_val(pte) & _PAGE_ACCESSED)
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pte_val(pte) |= _PAGE_SILENT_READ;
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return pte;
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}
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static inline pte_t pte_mkdirty(pte_t pte)
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{
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pte_val(pte) |= _PAGE_MODIFIED;
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if (pte_val(pte) & _PAGE_WRITE)
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pte_val(pte) |= _PAGE_SILENT_WRITE;
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return pte;
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}
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static inline pte_t pte_mkyoung(pte_t pte)
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{
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pte_val(pte) |= _PAGE_ACCESSED;
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if (pte_val(pte) & _PAGE_READ)
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pte_val(pte) |= _PAGE_SILENT_READ;
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return pte;
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}
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#endif
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/*
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* Macro to make mark a page protection value as "uncacheable". Note
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* that "protection" is really a misnomer here as the protection value
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* contains the memory attribute bits, dirty bits, and various other
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* bits as well.
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*/
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#define pgprot_noncached pgprot_noncached
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static inline pgprot_t pgprot_noncached(pgprot_t _prot)
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{
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unsigned long prot = pgprot_val(_prot);
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prot = (prot & ~_CACHE_MASK) | _CACHE_UNCACHED;
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return __pgprot(prot);
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}
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/*
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* Conversion functions: convert a page and protection to a page entry,
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* and a page entry and page directory to the page they refer to.
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*/
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#define mk_pte(page, pgprot) pfn_pte(page_to_pfn(page), (pgprot))
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#if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32_R1)
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static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
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{
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pte.pte_low &= _PAGE_CHG_MASK;
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pte.pte_high &= ~0x3f;
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pte.pte_low |= pgprot_val(newprot);
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pte.pte_high |= pgprot_val(newprot) & 0x3f;
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return pte;
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}
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#else
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static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
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{
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return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
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}
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#endif
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extern void __update_tlb(struct vm_area_struct *vma, unsigned long address,
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pte_t pte);
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extern void __update_cache(struct vm_area_struct *vma, unsigned long address,
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pte_t pte);
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static inline void update_mmu_cache(struct vm_area_struct *vma,
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unsigned long address, pte_t pte)
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{
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__update_tlb(vma, address, pte);
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__update_cache(vma, address, pte);
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}
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#define kern_addr_valid(addr) (1)
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#ifdef CONFIG_64BIT_PHYS_ADDR
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extern int remap_pfn_range(struct vm_area_struct *vma, unsigned long from, unsigned long pfn, unsigned long size, pgprot_t prot);
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static inline int io_remap_pfn_range(struct vm_area_struct *vma,
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unsigned long vaddr,
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unsigned long pfn,
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unsigned long size,
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pgprot_t prot)
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{
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phys_t phys_addr_high = fixup_bigphys_addr(pfn << PAGE_SHIFT, size);
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return remap_pfn_range(vma, vaddr, phys_addr_high >> PAGE_SHIFT, size, prot);
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}
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#else
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#define io_remap_pfn_range(vma, vaddr, pfn, size, prot) \
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remap_pfn_range(vma, vaddr, pfn, size, prot)
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#endif
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#define MK_IOSPACE_PFN(space, pfn) (pfn)
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#define GET_IOSPACE(pfn) 0
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#define GET_PFN(pfn) (pfn)
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#include <asm-generic/pgtable.h>
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/*
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* We provide our own get_unmapped area to cope with the virtual aliasing
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* constraints placed on us by the cache architecture.
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*/
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#define HAVE_ARCH_UNMAPPED_AREA
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/*
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* No page table caches to initialise
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*/
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#define pgtable_cache_init() do { } while (0)
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#endif /* _ASM_PGTABLE_H */
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