LXR linux/arch/powerpc/mm/pgtable

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *  This file contains pgtable related functions for 64-bit machines.
   4 *
   5 *  Derived from arch/ppc64/mm/init.c
   6 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   7 *
   8 *  Modifications by Paul Mackerras (PowerMac) (paulus@samba.org)
   9 *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
  10 *    Copyright (C) 1996 Paul Mackerras
  11 *
  12 *  Derived from "arch/i386/mm/init.c"
  13 *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
  14 *
  15 *  Dave Engebretsen <engebret@us.ibm.com>
  16 *      Rework for PPC64 port.
  17 */
  18
  19#include <linux/signal.h>
  20#include <linux/sched.h>
  21#include <linux/kernel.h>
  22#include <linux/errno.h>
  23#include <linux/string.h>
  24#include <linux/export.h>
  25#include <linux/types.h>
  26#include <linux/mman.h>
  27#include <linux/mm.h>
  28#include <linux/swap.h>
  29#include <linux/stddef.h>
  30#include <linux/vmalloc.h>
  31#include <linux/slab.h>
  32#include <linux/hugetlb.h>
  33
  34#include <asm/pgalloc.h>
  35#include <asm/page.h>
  36#include <asm/prom.h>
  37#include <asm/mmu_context.h>
  38#include <asm/pgtable.h>
  39#include <asm/mmu.h>
  40#include <asm/smp.h>
  41#include <asm/machdep.h>
  42#include <asm/tlb.h>
  43#include <asm/processor.h>
  44#include <asm/cputable.h>
  45#include <asm/sections.h>
  46#include <asm/firmware.h>
  47#include <asm/dma.h>
  48
  49#include <mm/mmu_decl.h>
  50
  51
  52#ifdef CONFIG_PPC_BOOK3S_64
  53/*
  54 * partition table and process table for ISA 3.0
  55 */
  56struct prtb_entry *process_tb;
  57struct patb_entry *partition_tb;
  58/*
  59 * page table size
  60 */
  61unsigned long __pte_index_size;
  62EXPORT_SYMBOL(__pte_index_size);
  63unsigned long __pmd_index_size;
  64EXPORT_SYMBOL(__pmd_index_size);
  65unsigned long __pud_index_size;
  66EXPORT_SYMBOL(__pud_index_size);
  67unsigned long __pgd_index_size;
  68EXPORT_SYMBOL(__pgd_index_size);
  69unsigned long __pud_cache_index;
  70EXPORT_SYMBOL(__pud_cache_index);
  71unsigned long __pte_table_size;
  72EXPORT_SYMBOL(__pte_table_size);
  73unsigned long __pmd_table_size;
  74EXPORT_SYMBOL(__pmd_table_size);
  75unsigned long __pud_table_size;
  76EXPORT_SYMBOL(__pud_table_size);
  77unsigned long __pgd_table_size;
  78EXPORT_SYMBOL(__pgd_table_size);
  79unsigned long __pmd_val_bits;
  80EXPORT_SYMBOL(__pmd_val_bits);
  81unsigned long __pud_val_bits;
  82EXPORT_SYMBOL(__pud_val_bits);
  83unsigned long __pgd_val_bits;
  84EXPORT_SYMBOL(__pgd_val_bits);
  85unsigned long __kernel_virt_start;
  86EXPORT_SYMBOL(__kernel_virt_start);
  87unsigned long __vmalloc_start;
  88EXPORT_SYMBOL(__vmalloc_start);
  89unsigned long __vmalloc_end;
  90EXPORT_SYMBOL(__vmalloc_end);
  91unsigned long __kernel_io_start;
  92EXPORT_SYMBOL(__kernel_io_start);
  93unsigned long __kernel_io_end;
  94struct page *vmemmap;
  95EXPORT_SYMBOL(vmemmap);
  96unsigned long __pte_frag_nr;
  97EXPORT_SYMBOL(__pte_frag_nr);
  98unsigned long __pte_frag_size_shift;
  99EXPORT_SYMBOL(__pte_frag_size_shift);
 100#endif
 101
 102#ifndef __PAGETABLE_PUD_FOLDED
 103/* 4 level page table */
 104struct page *pgd_page(pgd_t pgd)
 105{
 106        if (pgd_is_leaf(pgd)) {
 107                VM_WARN_ON(!pgd_huge(pgd));
 108                return pte_page(pgd_pte(pgd));
 109        }
 110        return virt_to_page(pgd_page_vaddr(pgd));
 111}
 112#endif
 113
 114struct page *pud_page(pud_t pud)
 115{
 116        if (pud_is_leaf(pud)) {
 117                VM_WARN_ON(!pud_huge(pud));
 118                return pte_page(pud_pte(pud));
 119        }
 120        return virt_to_page(pud_page_vaddr(pud));
 121}
 122
 123/*
 124 * For hugepage we have pfn in the pmd, we use PTE_RPN_SHIFT bits for flags
 125 * For PTE page, we have a PTE_FRAG_SIZE (4K) aligned virtual address.
 126 */
 127struct page *pmd_page(pmd_t pmd)
 128{
 129        if (pmd_is_leaf(pmd)) {
 130                VM_WARN_ON(!(pmd_large(pmd) || pmd_huge(pmd)));
 131                return pte_page(pmd_pte(pmd));
 132        }
 133        return virt_to_page(pmd_page_vaddr(pmd));
 134}
 135
 136#ifdef CONFIG_STRICT_KERNEL_RWX
 137void mark_rodata_ro(void)
 138{
 139        if (!mmu_has_feature(MMU_FTR_KERNEL_RO)) {
 140                pr_warn("Warning: Unable to mark rodata read only on this CPU.\n");
 141                return;
 142        }
 143
 144        if (radix_enabled())
 145                radix__mark_rodata_ro();
 146        else
 147                hash__mark_rodata_ro();
 148
 149        // mark_initmem_nx() should have already run by now
 150        ptdump_check_wx();
 151}
 152
 153void mark_initmem_nx(void)
 154{
 155        if (radix_enabled())
 156                radix__mark_initmem_nx();
 157        else
 158                hash__mark_initmem_nx();
 159}
 160#endif
 161