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/mmu_context.h>
36 #include <asm/mmu.h>
37 #include <asm/smp.h>
38 #include <asm/machdep.h>
39 #include <asm/tlb.h>
40 #include <asm/processor.h>
41 #include <asm/cputable.h>
42 #include <asm/sections.h>
43 #include <asm/firmware.h>
44 #include <asm/dma.h>
45
46 #include <mm/mmu_decl.h>
47
48
49 #ifdef CONFIG_PPC_BOOK3S_64
50 /*
51 * partition table and process table for ISA 3.0
52 */
53 struct prtb_entry *process_tb;
54 struct patb_entry *partition_tb;
55 /*
56 * page table size
57 */
58 unsigned long __pte_index_size;
59 EXPORT_SYMBOL(__pte_index_size);
60 unsigned long __pmd_index_size;
61 EXPORT_SYMBOL(__pmd_index_size);
62 unsigned long __pud_index_size;
63 EXPORT_SYMBOL(__pud_index_size);
64 unsigned long __pgd_index_size;
65 EXPORT_SYMBOL(__pgd_index_size);
66 unsigned long __pud_cache_index;
67 EXPORT_SYMBOL(__pud_cache_index);
68 unsigned long __pte_table_size;
69 EXPORT_SYMBOL(__pte_table_size);
70 unsigned long __pmd_table_size;
71 EXPORT_SYMBOL(__pmd_table_size);
72 unsigned long __pud_table_size;
73 EXPORT_SYMBOL(__pud_table_size);
74 unsigned long __pgd_table_size;
75 EXPORT_SYMBOL(__pgd_table_size);
76 unsigned long __pmd_val_bits;
77 EXPORT_SYMBOL(__pmd_val_bits);
78 unsigned long __pud_val_bits;
79 EXPORT_SYMBOL(__pud_val_bits);
80 unsigned long __pgd_val_bits;
81 EXPORT_SYMBOL(__pgd_val_bits);
82 unsigned long __kernel_virt_start;
83 EXPORT_SYMBOL(__kernel_virt_start);
84 unsigned long __vmalloc_start;
85 EXPORT_SYMBOL(__vmalloc_start);
86 unsigned long __vmalloc_end;
87 EXPORT_SYMBOL(__vmalloc_end);
88 unsigned long __kernel_io_start;
89 EXPORT_SYMBOL(__kernel_io_start);
90 unsigned long __kernel_io_end;
91 struct page *vmemmap;
92 EXPORT_SYMBOL(vmemmap);
93 unsigned long __pte_frag_nr;
94 EXPORT_SYMBOL(__pte_frag_nr);
95 unsigned long __pte_frag_size_shift;
96 EXPORT_SYMBOL(__pte_frag_size_shift);
97 #endif
98
99 #ifndef __PAGETABLE_PUD_FOLDED
100 /* 4 level page table */
101 struct page *p4d_page(p4d_t p4d)
102 {
103 if (p4d_leaf(p4d)) {
104 if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMAP))
105 VM_WARN_ON(!p4d_leaf(p4d));
106 return pte_page(p4d_pte(p4d));
107 }
108 return virt_to_page(p4d_pgtable(p4d));
109 }
110 #endif
111
112 struct page *pud_page(pud_t pud)
113 {
114 if (pud_leaf(pud)) {
115 if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMAP))
116 VM_WARN_ON(!pud_leaf(pud));
117 return pte_page(pud_pte(pud));
118 }
119 return virt_to_page(pud_pgtable(pud));
120 }
121
122 /*
123 * For hugepage we have pfn in the pmd, we use PTE_RPN_SHIFT bits for flags
124 * For PTE page, we have a PTE_FRAG_SIZE (4K) aligned virtual address.
125 */
126 struct page *pmd_page(pmd_t pmd)
127 {
128 if (pmd_leaf(pmd)) {
129 /*
130 * vmalloc_to_page may be called on any vmap address (not only
131 * vmalloc), and it uses pmd_page() etc., when huge vmap is
132 * enabled so these checks can't be used.
133 */
134 if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMAP))
135 VM_WARN_ON(!pmd_leaf(pmd));
136 return pte_page(pmd_pte(pmd));
137 }
138 return virt_to_page(pmd_page_vaddr(pmd));
139 }
140
141 #ifdef CONFIG_STRICT_KERNEL_RWX
142 void mark_rodata_ro(void)
143 {
144 if (!mmu_has_feature(MMU_FTR_KERNEL_RO)) {
145 pr_warn("Warning: Unable to mark rodata read only on this CPU.\n");
146 return;
147 }
148
149 if (radix_enabled())
150 radix__mark_rodata_ro();
151 else
152 hash__mark_rodata_ro();
153 }
154
155 void mark_initmem_nx(void)
156 {
157 if (radix_enabled())
158 radix__mark_initmem_nx();
159 else
160 hash__mark_initmem_nx();
161 }
162 #endif
163
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