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		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
113struct 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 */
127struct 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
143void 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
159void 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