LXR linux/arch/arm64/include/asm/stage2

   1/* SPDX-License-Identifier: GPL-2.0-only */
   2/*
   3 * Copyright (C) 2016 - ARM Ltd
   4 *
   5 * stage2 page table helpers
   6 */
   7
   8#ifndef __ARM64_S2_PGTABLE_H_
   9#define __ARM64_S2_PGTABLE_H_
  10
  11#include <linux/pgtable.h>
  12
  13/*
  14 * PGDIR_SHIFT determines the size a top-level page table entry can map
  15 * and depends on the number of levels in the page table. Compute the
  16 * PGDIR_SHIFT for a given number of levels.
  17 */
  18#define pt_levels_pgdir_shift(lvls)     ARM64_HW_PGTABLE_LEVEL_SHIFT(4 - (lvls))
  19
  20/*
  21 * The hardware supports concatenation of up to 16 tables at stage2 entry
  22 * level and we use the feature whenever possible, which means we resolve 4
  23 * additional bits of address at the entry level.
  24 *
  25 * This implies, the total number of page table levels required for
  26 * IPA_SHIFT at stage2 expected by the hardware can be calculated using
  27 * the same logic used for the (non-collapsable) stage1 page tables but for
  28 * (IPA_SHIFT - 4).
  29 */
  30#define stage2_pgtable_levels(ipa)      ARM64_HW_PGTABLE_LEVELS((ipa) - 4)
  31#define kvm_stage2_levels(kvm)          VTCR_EL2_LVLS(kvm->arch.vtcr)
  32
  33/* stage2_pgdir_shift() is the size mapped by top-level stage2 entry for the VM */
  34#define stage2_pgdir_shift(kvm)         pt_levels_pgdir_shift(kvm_stage2_levels(kvm))
  35#define stage2_pgdir_size(kvm)          (1ULL << stage2_pgdir_shift(kvm))
  36#define stage2_pgdir_mask(kvm)          ~(stage2_pgdir_size(kvm) - 1)
  37
  38/*
  39 * kvm_mmmu_cache_min_pages() is the number of pages required to install
  40 * a stage-2 translation. We pre-allocate the entry level page table at
  41 * the VM creation.
  42 */
  43#define kvm_mmu_cache_min_pages(kvm)    (kvm_stage2_levels(kvm) - 1)
  44
  45static inline phys_addr_t
  46stage2_pgd_addr_end(struct kvm *kvm, phys_addr_t addr, phys_addr_t end)
  47{
  48        phys_addr_t boundary = (addr + stage2_pgdir_size(kvm)) & stage2_pgdir_mask(kvm);
  49
  50        return (boundary - 1 < end - 1) ? boundary : end;
  51}
  52
  53#endif  /* __ARM64_S2_PGTABLE_H_ */
  54