Linux kernel mirror (for testing)
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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
24phys_addr_t memstart_addr __ro_after_init = (phys_addr_t)~0ull;
25EXPORT_SYMBOL_GPL(memstart_addr);
26phys_addr_t kernstart_addr __ro_after_init;
27EXPORT_SYMBOL_GPL(kernstart_addr);
28unsigned long kernstart_virt_addr __ro_after_init = KERNELBASE;
29EXPORT_SYMBOL_GPL(kernstart_virt_addr);
30
31bool disable_kuep = !IS_ENABLED(CONFIG_PPC_KUEP);
32bool disable_kuap = !IS_ENABLED(CONFIG_PPC_KUAP);
33
34static int __init parse_nosmep(char *p)
35{
36 disable_kuep = true;
37 pr_warn("Disabling Kernel Userspace Execution Prevention\n");
38 return 0;
39}
40early_param("nosmep", parse_nosmep);
41
42static int __init parse_nosmap(char *p)
43{
44 disable_kuap = true;
45 pr_warn("Disabling Kernel Userspace Access Protection\n");
46 return 0;
47}
48early_param("nosmap", parse_nosmap);
49
50#define CTOR(shift) static void ctor_##shift(void *addr) \
51{ \
52 memset(addr, 0, sizeof(void *) << (shift)); \
53}
54
55CTOR(0); CTOR(1); CTOR(2); CTOR(3); CTOR(4); CTOR(5); CTOR(6); CTOR(7);
56CTOR(8); CTOR(9); CTOR(10); CTOR(11); CTOR(12); CTOR(13); CTOR(14); CTOR(15);
57
58static inline void (*ctor(int shift))(void *)
59{
60 BUILD_BUG_ON(MAX_PGTABLE_INDEX_SIZE != 15);
61
62 switch (shift) {
63 case 0: return ctor_0;
64 case 1: return ctor_1;
65 case 2: return ctor_2;
66 case 3: return ctor_3;
67 case 4: return ctor_4;
68 case 5: return ctor_5;
69 case 6: return ctor_6;
70 case 7: return ctor_7;
71 case 8: return ctor_8;
72 case 9: return ctor_9;
73 case 10: return ctor_10;
74 case 11: return ctor_11;
75 case 12: return ctor_12;
76 case 13: return ctor_13;
77 case 14: return ctor_14;
78 case 15: return ctor_15;
79 }
80 return NULL;
81}
82
83struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE + 1];
84EXPORT_SYMBOL_GPL(pgtable_cache); /* used by kvm_hv module */
85
86/*
87 * Create a kmem_cache() for pagetables. This is not used for PTE
88 * pages - they're linked to struct page, come from the normal free
89 * pages pool and have a different entry size (see real_pte_t) to
90 * everything else. Caches created by this function are used for all
91 * the higher level pagetables, and for hugepage pagetables.
92 */
93void pgtable_cache_add(unsigned int shift)
94{
95 char *name;
96 unsigned long table_size = sizeof(void *) << shift;
97 unsigned long align = table_size;
98
99 /* When batching pgtable pointers for RCU freeing, we store
100 * the index size in the low bits. Table alignment must be
101 * big enough to fit it.
102 *
103 * Likewise, hugeapge pagetable pointers contain a (different)
104 * shift value in the low bits. All tables must be aligned so
105 * as to leave enough 0 bits in the address to contain it. */
106 unsigned long minalign = max(MAX_PGTABLE_INDEX_SIZE + 1,
107 HUGEPD_SHIFT_MASK + 1);
108 struct kmem_cache *new;
109
110 /* It would be nice if this was a BUILD_BUG_ON(), but at the
111 * moment, gcc doesn't seem to recognize is_power_of_2 as a
112 * constant expression, so so much for that. */
113 BUG_ON(!is_power_of_2(minalign));
114 BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
115
116 if (PGT_CACHE(shift))
117 return; /* Already have a cache of this size */
118
119 align = max_t(unsigned long, align, minalign);
120 name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift);
121 new = kmem_cache_create(name, table_size, align, 0, ctor(shift));
122 if (!new)
123 panic("Could not allocate pgtable cache for order %d", shift);
124
125 kfree(name);
126 pgtable_cache[shift] = new;
127
128 pr_debug("Allocated pgtable cache for order %d\n", shift);
129}
130EXPORT_SYMBOL_GPL(pgtable_cache_add); /* used by kvm_hv module */
131
132void pgtable_cache_init(void)
133{
134 pgtable_cache_add(PGD_INDEX_SIZE);
135
136 if (PMD_CACHE_INDEX)
137 pgtable_cache_add(PMD_CACHE_INDEX);
138 /*
139 * In all current configs, when the PUD index exists it's the
140 * same size as either the pgd or pmd index except with THP enabled
141 * on book3s 64
142 */
143 if (PUD_CACHE_INDEX)
144 pgtable_cache_add(PUD_CACHE_INDEX);
145}