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
31static bool disable_kuep = !IS_ENABLED(CONFIG_PPC_KUEP);
32static bool 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
50void __ref setup_kup(void)
51{
52	setup_kuep(disable_kuep);
53	setup_kuap(disable_kuap);
54}
55
56#define CTOR(shift) static void ctor_##shift(void *addr) \
57{							\
58	memset(addr, 0, sizeof(void *) << (shift));	\
59}
60
61CTOR(0); CTOR(1); CTOR(2); CTOR(3); CTOR(4); CTOR(5); CTOR(6); CTOR(7);
62CTOR(8); CTOR(9); CTOR(10); CTOR(11); CTOR(12); CTOR(13); CTOR(14); CTOR(15);
63
64static inline void (*ctor(int shift))(void *)
65{
66	BUILD_BUG_ON(MAX_PGTABLE_INDEX_SIZE != 15);
67
68	switch (shift) {
69	case 0: return ctor_0;
70	case 1: return ctor_1;
71	case 2: return ctor_2;
72	case 3: return ctor_3;
73	case 4: return ctor_4;
74	case 5: return ctor_5;
75	case 6: return ctor_6;
76	case 7: return ctor_7;
77	case 8: return ctor_8;
78	case 9: return ctor_9;
79	case 10: return ctor_10;
80	case 11: return ctor_11;
81	case 12: return ctor_12;
82	case 13: return ctor_13;
83	case 14: return ctor_14;
84	case 15: return ctor_15;
85	}
86	return NULL;
87}
88
89struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE + 1];
90EXPORT_SYMBOL_GPL(pgtable_cache);	/* used by kvm_hv module */
91
92/*
93 * Create a kmem_cache() for pagetables.  This is not used for PTE
94 * pages - they're linked to struct page, come from the normal free
95 * pages pool and have a different entry size (see real_pte_t) to
96 * everything else.  Caches created by this function are used for all
97 * the higher level pagetables, and for hugepage pagetables.
98 */
99void pgtable_cache_add(unsigned int shift)
100{
101	char *name;
102	unsigned long table_size = sizeof(void *) << shift;
103	unsigned long align = table_size;
104
105	/* When batching pgtable pointers for RCU freeing, we store
106	 * the index size in the low bits.  Table alignment must be
107	 * big enough to fit it.
108	 *
109	 * Likewise, hugeapge pagetable pointers contain a (different)
110	 * shift value in the low bits.  All tables must be aligned so
111	 * as to leave enough 0 bits in the address to contain it. */
112	unsigned long minalign = max(MAX_PGTABLE_INDEX_SIZE + 1,
113				     HUGEPD_SHIFT_MASK + 1);
114	struct kmem_cache *new = NULL;
115
116	/* It would be nice if this was a BUILD_BUG_ON(), but at the
117	 * moment, gcc doesn't seem to recognize is_power_of_2 as a
118	 * constant expression, so so much for that. */
119	BUG_ON(!is_power_of_2(minalign));
120	BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
121
122	if (PGT_CACHE(shift))
123		return; /* Already have a cache of this size */
124
125	align = max_t(unsigned long, align, minalign);
126	name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift);
127	if (name)
128		new = kmem_cache_create(name, table_size, align, 0, ctor(shift));
129	if (!new)
130		panic("Could not allocate pgtable cache for order %d", shift);
131
132	kfree(name);
133	pgtable_cache[shift] = new;
134
135	pr_debug("Allocated pgtable cache for order %d\n", shift);
136}
137EXPORT_SYMBOL_GPL(pgtable_cache_add);	/* used by kvm_hv module */
138
139void pgtable_cache_init(void)
140{
141	pgtable_cache_add(PGD_INDEX_SIZE);
142
143	if (PMD_CACHE_INDEX)
144		pgtable_cache_add(PMD_CACHE_INDEX);
145	/*
146	 * In all current configs, when the PUD index exists it's the
147	 * same size as either the pgd or pmd index except with THP enabled
148	 * on book3s 64
149	 */
150	if (PUD_CACHE_INDEX)
151		pgtable_cache_add(PUD_CACHE_INDEX);
152}
153