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0a9fe8ca84
The usage of __flush_tlb_all() in the kernel_physical_mapping_init() path is not necessary. In general flushing the TLB is not required when updating an entry from the !present state. However, to give confidence in the future removal of TLB flushing in this path, use the new set_pte_safe() family of helpers to assert that the !present assumption is true in this path. [ mingo: Minor readability edits. ] Suggested-by: Peter Zijlstra <peterz@infradead.org> Suggested-by: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rik van Riel <riel@surriel.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/154395944177.32119.8524957429632012270.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
65 lines
1.9 KiB
C
65 lines
1.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#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 1
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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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#define pgd_populate_safe(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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