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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>
70 lines
2.0 KiB
C
70 lines
2.0 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _PGTABLE_NOPUD_H
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#define _PGTABLE_NOPUD_H
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#ifndef __ASSEMBLY__
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#ifdef __ARCH_USE_5LEVEL_HACK
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#include <asm-generic/pgtable-nop4d-hack.h>
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#else
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#include <asm-generic/pgtable-nop4d.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 p4d gets the size right, and allows
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* us to conceptually access the p4d entry that this pud is folded into
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* without casting.
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*/
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typedef struct { p4d_t p4d; } pud_t;
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#define PUD_SHIFT P4D_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 "p4d_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 p4d entry)
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*/
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static inline int p4d_none(p4d_t p4d) { return 0; }
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static inline int p4d_bad(p4d_t p4d) { return 0; }
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static inline int p4d_present(p4d_t p4d) { return 1; }
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static inline void p4d_clear(p4d_t *p4d) { }
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#define pud_ERROR(pud) (p4d_ERROR((pud).p4d))
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#define p4d_populate(mm, p4d, pud) do { } while (0)
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#define p4d_populate_safe(mm, p4d, pud) do { } while (0)
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/*
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* (puds are folded into p4ds 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_p4d(p4dptr, p4dval) set_pud((pud_t *)(p4dptr), (pud_t) { p4dval })
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static inline pud_t *pud_offset(p4d_t *p4d, unsigned long address)
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{
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return (pud_t *)p4d;
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}
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#define pud_val(x) (p4d_val((x).p4d))
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#define __pud(x) ((pud_t) { __p4d(x) })
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#define p4d_page(p4d) (pud_page((pud_t){ p4d }))
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#define p4d_page_vaddr(p4d) (pud_page_vaddr((pud_t){ p4d }))
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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 p4d, 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 /* !__ARCH_USE_5LEVEL_HACK */
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#endif /* _PGTABLE_NOPUD_H */
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