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