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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>
60 lines
1.7 KiB
C
60 lines
1.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _PGTABLE_NOP4D_H
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#define _PGTABLE_NOP4D_H
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#ifndef __ASSEMBLY__
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#define __PAGETABLE_P4D_FOLDED 1
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typedef struct { pgd_t pgd; } p4d_t;
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#define P4D_SHIFT PGDIR_SHIFT
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#define MAX_PTRS_PER_P4D 1
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#define PTRS_PER_P4D 1
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#define P4D_SIZE (1UL << P4D_SHIFT)
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#define P4D_MASK (~(P4D_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 p4d is never bad, and a p4d 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 p4d_ERROR(p4d) (pgd_ERROR((p4d).pgd))
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#define pgd_populate(mm, pgd, p4d) do { } while (0)
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#define pgd_populate_safe(mm, pgd, p4d) do { } while (0)
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/*
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* (p4ds 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_p4d((p4d_t *)(pgdptr), (p4d_t) { pgdval })
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static inline p4d_t *p4d_offset(pgd_t *pgd, unsigned long address)
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{
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return (p4d_t *)pgd;
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}
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#define p4d_val(x) (pgd_val((x).pgd))
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#define __p4d(x) ((p4d_t) { __pgd(x) })
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#define pgd_page(pgd) (p4d_page((p4d_t){ pgd }))
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#define pgd_page_vaddr(pgd) (p4d_page_vaddr((p4d_t){ pgd }))
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/*
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* allocating and freeing a p4d is trivial: the 1-entry p4d 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 p4d_alloc_one(mm, address) NULL
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#define p4d_free(mm, x) do { } while (0)
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#define __p4d_free_tlb(tlb, x, a) do { } while (0)
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#undef p4d_addr_end
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#define p4d_addr_end(addr, end) (end)
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#endif /* __ASSEMBLY__ */
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#endif /* _PGTABLE_NOP4D_H */
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