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![Kirill A. Shutemov](/assets/img/avatar_default.png)
We are going to introduce <asm-generic/pgtable-nop4d.h> to provide abstraction for properly (in opposite to 5level-fixup.h hack) folded p4d level. The new header will be included from pgtable-nopud.h. If an architecture uses <asm-generic/nop*d.h>, we cannot use 5level-fixup.h directly to quickly convert the architecture to 5-level paging as it would conflict with pgtable-nop4d.h. With this patch an architecture can define __ARCH_USE_5LEVEL_HACK before inclusion <asm-genenric/nop*d.h> to use 5level-fixup.h. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
62 lines
1.8 KiB
C
62 lines
1.8 KiB
C
#ifndef _PGTABLE_NOP4D_HACK_H
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#define _PGTABLE_NOP4D_HACK_H
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#ifndef __ASSEMBLY__
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#include <asm-generic/5level-fixup.h>
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#define __PAGETABLE_PUD_FOLDED
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/*
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* Having the pud type consist of a pgd gets the size right, and allows
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* us to conceptually access the pgd entry that this pud is folded into
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* without casting.
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*/
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typedef struct { pgd_t pgd; } pud_t;
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#define PUD_SHIFT PGDIR_SHIFT
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#define PTRS_PER_PUD 1
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#define PUD_SIZE (1UL << PUD_SHIFT)
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#define PUD_MASK (~(PUD_SIZE-1))
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/*
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* The "pgd_xxx()" functions here are trivial for a folded two-level
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* setup: the pud is never bad, and a pud always exists (as it's folded
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* into the pgd entry)
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*/
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static inline int pgd_none(pgd_t pgd) { return 0; }
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static inline int pgd_bad(pgd_t pgd) { return 0; }
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static inline int pgd_present(pgd_t pgd) { return 1; }
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static inline void pgd_clear(pgd_t *pgd) { }
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#define pud_ERROR(pud) (pgd_ERROR((pud).pgd))
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#define pgd_populate(mm, pgd, pud) do { } while (0)
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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_pgd(pgdptr, pgdval) set_pud((pud_t *)(pgdptr), (pud_t) { pgdval })
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static inline pud_t *pud_offset(pgd_t *pgd, unsigned long address)
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{
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return (pud_t *)pgd;
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}
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#define pud_val(x) (pgd_val((x).pgd))
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#define __pud(x) ((pud_t) { __pgd(x) })
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#define pgd_page(pgd) (pud_page((pud_t){ pgd }))
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#define pgd_page_vaddr(pgd) (pud_page_vaddr((pud_t){ pgd }))
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/*
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* allocating and freeing a pud is trivial: the 1-entry pud is
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* inside the pgd, so has no extra memory associated with it.
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*/
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#define pud_alloc_one(mm, address) NULL
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#define pud_free(mm, x) do { } while (0)
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#define __pud_free_tlb(tlb, x, a) do { } while (0)
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#undef pud_addr_end
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#define pud_addr_end(addr, end) (end)
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#endif /* __ASSEMBLY__ */
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#endif /* _PGTABLE_NOP4D_HACK_H */
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