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 */ 54 struct prtb_entry *process_tb; 55 struct patb_entry *partition_tb; 56 /* 57 * page table size 58 */ 59 unsigned long __pte_index_size; 60 EXPORT_SYMBOL(__pte_index_size); 61 unsigned long __pmd_index_size; 62 EXPORT_SYMBOL(__pmd_index_size); 63 unsigned long __pud_index_size; 64 EXPORT_SYMBOL(__pud_index_size); 65 unsigned long __pgd_index_size; 66 EXPORT_SYMBOL(__pgd_index_size); 67 unsigned long __pud_cache_index; 68 EXPORT_SYMBOL(__pud_cache_index); 69 unsigned long __pte_table_size; 70 EXPORT_SYMBOL(__pte_table_size); 71 unsigned long __pmd_table_size; 72 EXPORT_SYMBOL(__pmd_table_size); 73 unsigned long __pud_table_size; 74 EXPORT_SYMBOL(__pud_table_size); 75 unsigned long __pgd_table_size; 76 EXPORT_SYMBOL(__pgd_table_size); 77 unsigned long __pmd_val_bits; 78 EXPORT_SYMBOL(__pmd_val_bits); 79 unsigned long __pud_val_bits; 80 EXPORT_SYMBOL(__pud_val_bits); 81 unsigned long __pgd_val_bits; 82 EXPORT_SYMBOL(__pgd_val_bits); 83 unsigned long __kernel_virt_start; 84 EXPORT_SYMBOL(__kernel_virt_start); 85 unsigned long __vmalloc_start; 86 EXPORT_SYMBOL(__vmalloc_start); 87 unsigned long __vmalloc_end; 88 EXPORT_SYMBOL(__vmalloc_end); 89 unsigned long __kernel_io_start; 90 EXPORT_SYMBOL(__kernel_io_start); 91 unsigned long __kernel_io_end; 92 struct page *vmemmap; 93 EXPORT_SYMBOL(vmemmap); 94 unsigned long __pte_frag_nr; 95 EXPORT_SYMBOL(__pte_frag_nr); 96 unsigned long __pte_frag_size_shift; 97 EXPORT_SYMBOL(__pte_frag_size_shift); 98 #endif 99 100 #ifndef __PAGETABLE_PUD_FOLDED 101 /* 4 level page table */ 102 struct page *p4d_page(p4d_t p4d) 103 { 104 if (p4d_is_leaf(p4d)) { 105 if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMAP)) 106 VM_WARN_ON(!p4d_huge(p4d)); 107 return pte_page(p4d_pte(p4d)); 108 } 109 return virt_to_page(p4d_pgtable(p4d)); 110 } 111 #endif 112 113 struct page *pud_page(pud_t pud) 114 { 115 if (pud_is_leaf(pud)) { 116 if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMAP)) 117 VM_WARN_ON(!pud_huge(pud)); 118 return pte_page(pud_pte(pud)); 119 } 120 return virt_to_page(pud_pgtable(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 */ 127 struct page *pmd_page(pmd_t pmd) 128 { 129 if (pmd_is_leaf(pmd)) { 130 /* 131 * vmalloc_to_page may be called on any vmap address (not only 132 * vmalloc), and it uses pmd_page() etc., when huge vmap is 133 * enabled so these checks can't be used. 134 */ 135 if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMAP)) 136 VM_WARN_ON(!(pmd_large(pmd) || pmd_huge(pmd))); 137 return pte_page(pmd_pte(pmd)); 138 } 139 return virt_to_page(pmd_page_vaddr(pmd)); 140 } 141 142 #ifdef CONFIG_STRICT_KERNEL_RWX 143 void mark_rodata_ro(void) 144 { 145 if (!mmu_has_feature(MMU_FTR_KERNEL_RO)) { 146 pr_warn("Warning: Unable to mark rodata read only on this CPU.\n"); 147 return; 148 } 149 150 if (radix_enabled()) 151 radix__mark_rodata_ro(); 152 else 153 hash__mark_rodata_ro(); 154 155 // mark_initmem_nx() should have already run by now 156 ptdump_check_wx(); 157 } 158 159 void mark_initmem_nx(void) 160 { 161 if (radix_enabled()) 162 radix__mark_initmem_nx(); 163 else 164 hash__mark_initmem_nx(); 165 } 166 #endif 167