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/page.h>
  35#include <asm/prom.h>
  36#include <asm/mmu_context.h>
  37#include <asm/mmu.h>
  38#include <asm/smp.h>
  39#include <asm/machdep.h>
  40#include <asm/tlb.h>
  41#include <asm/processor.h>
  42#include <asm/cputable.h>
  43#include <asm/sections.h>
  44#include <asm/firmware.h>
  45#include <asm/dma.h>
  46
  47#include <mm/mmu_decl.h>
  48
  49
  50#ifdef CONFIG_PPC_BOOK3S_64
  51/*
  52 * partition table and process table for ISA 3.0
  53 */
  54struct prtb_entry *process_tb;
  55struct patb_entry *partition_tb;
  56/*
  57 * page table size
  58 */
  59unsigned long __pte_index_size;
  60EXPORT_SYMBOL(__pte_index_size);
  61unsigned long __pmd_index_size;
  62EXPORT_SYMBOL(__pmd_index_size);
  63unsigned long __pud_index_size;
  64EXPORT_SYMBOL(__pud_index_size);
  65unsigned long __pgd_index_size;
  66EXPORT_SYMBOL(__pgd_index_size);
  67unsigned long __pud_cache_index;
  68EXPORT_SYMBOL(__pud_cache_index);
  69unsigned long __pte_table_size;
  70EXPORT_SYMBOL(__pte_table_size);
  71unsigned long __pmd_table_size;
  72EXPORT_SYMBOL(__pmd_table_size);
  73unsigned long __pud_table_size;
  74EXPORT_SYMBOL(__pud_table_size);
  75unsigned long __pgd_table_size;
  76EXPORT_SYMBOL(__pgd_table_size);
  77unsigned long __pmd_val_bits;
  78EXPORT_SYMBOL(__pmd_val_bits);
  79unsigned long __pud_val_bits;
  80EXPORT_SYMBOL(__pud_val_bits);
  81unsigned long __pgd_val_bits;
  82EXPORT_SYMBOL(__pgd_val_bits);
  83unsigned long __kernel_virt_start;
  84EXPORT_SYMBOL(__kernel_virt_start);
  85unsigned long __vmalloc_start;
  86EXPORT_SYMBOL(__vmalloc_start);
  87unsigned long __vmalloc_end;
  88EXPORT_SYMBOL(__vmalloc_end);
  89unsigned long __kernel_io_start;
  90EXPORT_SYMBOL(__kernel_io_start);
  91unsigned long __kernel_io_end;
  92struct page *vmemmap;
  93EXPORT_SYMBOL(vmemmap);
  94unsigned long __pte_frag_nr;
  95EXPORT_SYMBOL(__pte_frag_nr);
  96unsigned long __pte_frag_size_shift;
  97EXPORT_SYMBOL(__pte_frag_size_shift);
  98#endif
  99
 100#ifndef __PAGETABLE_PUD_FOLDED
 101/* 4 level page table */
 102struct page *p4d_page(p4d_t p4d)
 103{
 104        if (p4d_is_leaf(p4d)) {
 105                VM_WARN_ON(!p4d_huge(p4d));
 106                return pte_page(p4d_pte(p4d));
 107        }
 108        return virt_to_page(p4d_pgtable(p4d));
 109}
 110#endif
 111
 112struct page *pud_page(pud_t pud)
 113{
 114        if (pud_is_leaf(pud)) {
 115                VM_WARN_ON(!pud_huge(pud));
 116                return pte_page(pud_pte(pud));
 117        }
 118        return virt_to_page(pud_pgtable(pud));
 119}
 120
 121/*
 122 * For hugepage we have pfn in the pmd, we use PTE_RPN_SHIFT bits for flags
 123 * For PTE page, we have a PTE_FRAG_SIZE (4K) aligned virtual address.
 124 */
 125struct page *pmd_page(pmd_t pmd)
 126{
 127        if (pmd_is_leaf(pmd)) {
 128                VM_WARN_ON(!(pmd_large(pmd) || pmd_huge(pmd)));
 129                return pte_page(pmd_pte(pmd));
 130        }
 131        return virt_to_page(pmd_page_vaddr(pmd));
 132}
 133
 134#ifdef CONFIG_STRICT_KERNEL_RWX
 135void mark_rodata_ro(void)
 136{
 137        if (!mmu_has_feature(MMU_FTR_KERNEL_RO)) {
 138                pr_warn("Warning: Unable to mark rodata read only on this CPU.\n");
 139                return;
 140        }
 141
 142        if (radix_enabled())
 143                radix__mark_rodata_ro();
 144        else
 145                hash__mark_rodata_ro();
 146
 147        // mark_initmem_nx() should have already run by now
 148        ptdump_check_wx();
 149}
 150
 151void mark_initmem_nx(void)
 152{
 153        if (radix_enabled())
 154                radix__mark_initmem_nx();
 155        else
 156                hash__mark_initmem_nx();
 157}
 158#endif
 159