1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * This file contains the routines setting up the linux page tables.
4 * -- paulus
5 *
6 * Derived from arch/ppc/mm/init.c:
7 * Copyright (C) 1995-1996 Gary Thomas ([email protected])
8 *
9 * Modifications by Paul Mackerras (PowerMac) ([email protected])
10 * and Cort Dougan (PReP) ([email protected])
11 * Copyright (C) 1996 Paul Mackerras
12 *
13 * Derived from "arch/i386/mm/init.c"
14 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
15 */
16
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/types.h>
20 #include <linux/mm.h>
21 #include <linux/vmalloc.h>
22 #include <linux/init.h>
23 #include <linux/highmem.h>
24 #include <linux/memblock.h>
25 #include <linux/slab.h>
26 #include <linux/set_memory.h>
27
28 #include <asm/pgalloc.h>
29 #include <asm/fixmap.h>
30 #include <asm/setup.h>
31 #include <asm/sections.h>
32 #include <asm/early_ioremap.h>
33
34 #include <mm/mmu_decl.h>
35
36 static u8 early_fixmap_pagetable[FIXMAP_PTE_SIZE] __page_aligned_data;
37
early_ioremap_init(void)38 notrace void __init early_ioremap_init(void)
39 {
40 unsigned long addr = ALIGN_DOWN(FIXADDR_START, PGDIR_SIZE);
41 pte_t *ptep = (pte_t *)early_fixmap_pagetable;
42 pmd_t *pmdp = pmd_off_k(addr);
43
44 for (; (s32)(FIXADDR_TOP - addr) > 0;
45 addr += PGDIR_SIZE, ptep += PTRS_PER_PTE, pmdp++)
46 pmd_populate_kernel(&init_mm, pmdp, ptep);
47
48 early_ioremap_setup();
49 }
50
early_alloc_pgtable(unsigned long size)51 void __init *early_alloc_pgtable(unsigned long size)
52 {
53 return memblock_alloc_or_panic(size, size);
54
55 }
56
early_pte_alloc_kernel(pmd_t * pmdp,unsigned long va)57 pte_t __init *early_pte_alloc_kernel(pmd_t *pmdp, unsigned long va)
58 {
59 if (pmd_none(*pmdp)) {
60 pte_t *ptep = early_alloc_pgtable(PTE_FRAG_SIZE);
61
62 pmd_populate_kernel(&init_mm, pmdp, ptep);
63 }
64 return pte_offset_kernel(pmdp, va);
65 }
66
67
map_kernel_page(unsigned long va,phys_addr_t pa,pgprot_t prot)68 int __ref map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot)
69 {
70 pmd_t *pd;
71 pte_t *pg;
72 int err = -ENOMEM;
73
74 /* Use upper 10 bits of VA to index the first level map */
75 pd = pmd_off_k(va);
76 /* Use middle 10 bits of VA to index the second-level map */
77 if (likely(slab_is_available()))
78 pg = pte_alloc_kernel(pd, va);
79 else
80 pg = early_pte_alloc_kernel(pd, va);
81 if (pg) {
82 err = 0;
83 /* The PTE should never be already set nor present in the
84 * hash table
85 */
86 BUG_ON((pte_present(*pg) | pte_hashpte(*pg)) && pgprot_val(prot));
87 set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, prot));
88 }
89 smp_wmb();
90 return err;
91 }
92
93 /*
94 * Map in a chunk of physical memory starting at start.
95 */
__mapin_ram_chunk(unsigned long offset,unsigned long top)96 static void __init __mapin_ram_chunk(unsigned long offset, unsigned long top)
97 {
98 unsigned long v, s;
99 phys_addr_t p;
100 bool ktext;
101
102 s = offset;
103 v = PAGE_OFFSET + s;
104 p = memstart_addr + s;
105 for (; s < top; s += PAGE_SIZE) {
106 ktext = core_kernel_text(v);
107 map_kernel_page(v, p, ktext ? PAGE_KERNEL_TEXT : PAGE_KERNEL);
108 v += PAGE_SIZE;
109 p += PAGE_SIZE;
110 }
111 }
112
mapin_ram(void)113 void __init mapin_ram(void)
114 {
115 phys_addr_t base, end;
116 u64 i;
117
118 for_each_mem_range(i, &base, &end) {
119 phys_addr_t top = min(end, total_lowmem);
120
121 if (base >= top)
122 continue;
123 base = mmu_mapin_ram(base, top);
124 __mapin_ram_chunk(base, top);
125 }
126 }
127
__mark_initmem_nx(void)128 static int __mark_initmem_nx(void)
129 {
130 unsigned long numpages = PFN_UP((unsigned long)_einittext) -
131 PFN_DOWN((unsigned long)_sinittext);
132 int err;
133
134 err = mmu_mark_initmem_nx();
135
136 if (!v_block_mapped((unsigned long)_sinittext)) {
137 err = set_memory_nx((unsigned long)_sinittext, numpages);
138 if (err)
139 return err;
140 err = set_memory_rw((unsigned long)_sinittext, numpages);
141 }
142 return err;
143 }
144
mark_initmem_nx(void)145 void mark_initmem_nx(void)
146 {
147 int err = __mark_initmem_nx();
148
149 if (err)
150 panic("%s() failed, err = %d\n", __func__, err);
151 }
152
153 #ifdef CONFIG_STRICT_KERNEL_RWX
__mark_rodata_ro(void)154 static int __mark_rodata_ro(void)
155 {
156 unsigned long numpages;
157
158 if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX) && mmu_has_feature(MMU_FTR_HPTE_TABLE))
159 pr_warn("This platform has HASH MMU, STRICT_MODULE_RWX won't work\n");
160
161 if (v_block_mapped((unsigned long)_stext + 1))
162 return mmu_mark_rodata_ro();
163
164 /*
165 * mark text and rodata as read only. __end_rodata is set by
166 * powerpc's linker script and includes tables and data
167 * requiring relocation which are not put in RO_DATA.
168 */
169 numpages = PFN_UP((unsigned long)__end_rodata) -
170 PFN_DOWN((unsigned long)_stext);
171
172 return set_memory_ro((unsigned long)_stext, numpages);
173 }
174
mark_rodata_ro(void)175 void mark_rodata_ro(void)
176 {
177 int err = __mark_rodata_ro();
178
179 if (err)
180 panic("%s() failed, err = %d\n", __func__, err);
181 }
182 #endif
183