1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * PowerPC version |
4 | * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) |
5 | * |
6 | * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) |
7 | * and Cort Dougan (PReP) (cort@cs.nmt.edu) |
8 | * Copyright (C) 1996 Paul Mackerras |
9 | * |
10 | * Derived from "arch/i386/mm/init.c" |
11 | * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds |
12 | * |
13 | * Dave Engebretsen <engebret@us.ibm.com> |
14 | * Rework for PPC64 port. |
15 | */ |
16 | |
17 | #undef DEBUG |
18 | |
19 | #include <linux/string.h> |
20 | #include <linux/pgtable.h> |
21 | #include <asm/pgalloc.h> |
22 | #include <asm/kup.h> |
23 | #include <asm/smp.h> |
24 | |
25 | phys_addr_t memstart_addr __ro_after_init = (phys_addr_t)~0ull; |
26 | EXPORT_SYMBOL_GPL(memstart_addr); |
27 | phys_addr_t kernstart_addr __ro_after_init; |
28 | EXPORT_SYMBOL_GPL(kernstart_addr); |
29 | unsigned long kernstart_virt_addr __ro_after_init = KERNELBASE; |
30 | EXPORT_SYMBOL_GPL(kernstart_virt_addr); |
31 | |
32 | bool disable_kuep = !IS_ENABLED(CONFIG_PPC_KUEP); |
33 | bool disable_kuap = !IS_ENABLED(CONFIG_PPC_KUAP); |
34 | |
35 | static int __init parse_nosmep(char *p) |
36 | { |
37 | if (!IS_ENABLED(CONFIG_PPC_BOOK3S_64)) |
38 | return 0; |
39 | |
40 | disable_kuep = true; |
41 | pr_warn("Disabling Kernel Userspace Execution Prevention\n" ); |
42 | return 0; |
43 | } |
44 | early_param("nosmep" , parse_nosmep); |
45 | |
46 | static int __init parse_nosmap(char *p) |
47 | { |
48 | disable_kuap = true; |
49 | pr_warn("Disabling Kernel Userspace Access Protection\n" ); |
50 | return 0; |
51 | } |
52 | early_param("nosmap" , parse_nosmap); |
53 | |
54 | void __weak setup_kuep(bool disabled) |
55 | { |
56 | if (!IS_ENABLED(CONFIG_PPC_KUEP) || disabled) |
57 | return; |
58 | |
59 | if (smp_processor_id() != boot_cpuid) |
60 | return; |
61 | |
62 | pr_info("Activating Kernel Userspace Execution Prevention\n" ); |
63 | } |
64 | |
65 | void setup_kup(void) |
66 | { |
67 | setup_kuap(disable_kuap); |
68 | setup_kuep(disable_kuep); |
69 | } |
70 | |
71 | #define CTOR(shift) static void ctor_##shift(void *addr) \ |
72 | { \ |
73 | memset(addr, 0, sizeof(void *) << (shift)); \ |
74 | } |
75 | |
76 | CTOR(0); CTOR(1); CTOR(2); CTOR(3); CTOR(4); CTOR(5); CTOR(6); CTOR(7); |
77 | CTOR(8); CTOR(9); CTOR(10); CTOR(11); CTOR(12); CTOR(13); CTOR(14); CTOR(15); |
78 | |
79 | static inline void (*ctor(int shift))(void *) |
80 | { |
81 | BUILD_BUG_ON(MAX_PGTABLE_INDEX_SIZE != 15); |
82 | |
83 | switch (shift) { |
84 | case 0: return ctor_0; |
85 | case 1: return ctor_1; |
86 | case 2: return ctor_2; |
87 | case 3: return ctor_3; |
88 | case 4: return ctor_4; |
89 | case 5: return ctor_5; |
90 | case 6: return ctor_6; |
91 | case 7: return ctor_7; |
92 | case 8: return ctor_8; |
93 | case 9: return ctor_9; |
94 | case 10: return ctor_10; |
95 | case 11: return ctor_11; |
96 | case 12: return ctor_12; |
97 | case 13: return ctor_13; |
98 | case 14: return ctor_14; |
99 | case 15: return ctor_15; |
100 | } |
101 | return NULL; |
102 | } |
103 | |
104 | struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE + 1]; |
105 | EXPORT_SYMBOL_GPL(pgtable_cache); /* used by kvm_hv module */ |
106 | |
107 | /* |
108 | * Create a kmem_cache() for pagetables. This is not used for PTE |
109 | * pages - they're linked to struct page, come from the normal free |
110 | * pages pool and have a different entry size (see real_pte_t) to |
111 | * everything else. Caches created by this function are used for all |
112 | * the higher level pagetables, and for hugepage pagetables. |
113 | */ |
114 | void pgtable_cache_add(unsigned int shift) |
115 | { |
116 | char *name; |
117 | unsigned long table_size = sizeof(void *) << shift; |
118 | unsigned long align = table_size; |
119 | |
120 | /* When batching pgtable pointers for RCU freeing, we store |
121 | * the index size in the low bits. Table alignment must be |
122 | * big enough to fit it. |
123 | * |
124 | * Likewise, hugeapge pagetable pointers contain a (different) |
125 | * shift value in the low bits. All tables must be aligned so |
126 | * as to leave enough 0 bits in the address to contain it. */ |
127 | unsigned long minalign = max(MAX_PGTABLE_INDEX_SIZE + 1, |
128 | HUGEPD_SHIFT_MASK + 1); |
129 | struct kmem_cache *new = NULL; |
130 | |
131 | /* It would be nice if this was a BUILD_BUG_ON(), but at the |
132 | * moment, gcc doesn't seem to recognize is_power_of_2 as a |
133 | * constant expression, so so much for that. */ |
134 | BUG_ON(!is_power_of_2(minalign)); |
135 | BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE); |
136 | |
137 | if (PGT_CACHE(shift)) |
138 | return; /* Already have a cache of this size */ |
139 | |
140 | align = max_t(unsigned long, align, minalign); |
141 | name = kasprintf(GFP_KERNEL, fmt: "pgtable-2^%d" , shift); |
142 | if (name) |
143 | new = kmem_cache_create(name, size: table_size, align, flags: 0, ctor: ctor(shift)); |
144 | if (!new) |
145 | panic(fmt: "Could not allocate pgtable cache for order %d" , shift); |
146 | |
147 | kfree(objp: name); |
148 | pgtable_cache[shift] = new; |
149 | |
150 | pr_debug("Allocated pgtable cache for order %d\n" , shift); |
151 | } |
152 | EXPORT_SYMBOL_GPL(pgtable_cache_add); /* used by kvm_hv module */ |
153 | |
154 | void pgtable_cache_init(void) |
155 | { |
156 | pgtable_cache_add(PGD_INDEX_SIZE); |
157 | |
158 | if (PMD_CACHE_INDEX) |
159 | pgtable_cache_add(PMD_CACHE_INDEX); |
160 | /* |
161 | * In all current configs, when the PUD index exists it's the |
162 | * same size as either the pgd or pmd index except with THP enabled |
163 | * on book3s 64 |
164 | */ |
165 | if (PUD_CACHE_INDEX) |
166 | pgtable_cache_add(PUD_CACHE_INDEX); |
167 | } |
168 | |