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 #ifdef CONFIG_KFENCE 35 bool __ro_after_init kfence_disabled; 36 #endif 37 parse_nosmep(char * p)38 static int __init parse_nosmep(char *p) 39 { 40 if (!IS_ENABLED(CONFIG_PPC_BOOK3S_64)) 41 return 0; 42 43 disable_kuep = true; 44 pr_warn("Disabling Kernel Userspace Execution Prevention\n"); 45 return 0; 46 } 47 early_param("nosmep", parse_nosmep); 48 parse_nosmap(char * p)49 static int __init parse_nosmap(char *p) 50 { 51 disable_kuap = true; 52 pr_warn("Disabling Kernel Userspace Access Protection\n"); 53 return 0; 54 } 55 early_param("nosmap", parse_nosmap); 56 setup_kuep(bool disabled)57 void __weak setup_kuep(bool disabled) 58 { 59 if (!IS_ENABLED(CONFIG_PPC_KUEP) || disabled) 60 return; 61 62 if (smp_processor_id() != boot_cpuid) 63 return; 64 65 pr_info("Activating Kernel Userspace Execution Prevention\n"); 66 } 67 setup_kup(void)68 void setup_kup(void) 69 { 70 setup_kuap(disable_kuap); 71 setup_kuep(disable_kuep); 72 } 73 74 #define CTOR(shift) static void ctor_##shift(void *addr) \ 75 { \ 76 memset(addr, 0, sizeof(pgd_t) << (shift)); \ 77 } 78 79 CTOR(0); CTOR(1); CTOR(2); CTOR(3); CTOR(4); CTOR(5); CTOR(6); CTOR(7); 80 CTOR(8); CTOR(9); CTOR(10); CTOR(11); CTOR(12); CTOR(13); CTOR(14); CTOR(15); 81 ctor(int shift)82 static inline void (*ctor(int shift))(void *) 83 { 84 BUILD_BUG_ON(MAX_PGTABLE_INDEX_SIZE != 15); 85 86 switch (shift) { 87 case 0: return ctor_0; 88 case 1: return ctor_1; 89 case 2: return ctor_2; 90 case 3: return ctor_3; 91 case 4: return ctor_4; 92 case 5: return ctor_5; 93 case 6: return ctor_6; 94 case 7: return ctor_7; 95 case 8: return ctor_8; 96 case 9: return ctor_9; 97 case 10: return ctor_10; 98 case 11: return ctor_11; 99 case 12: return ctor_12; 100 case 13: return ctor_13; 101 case 14: return ctor_14; 102 case 15: return ctor_15; 103 } 104 return NULL; 105 } 106 107 struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE + 1]; 108 EXPORT_SYMBOL_GPL(pgtable_cache); /* used by kvm_hv module */ 109 110 /* 111 * Create a kmem_cache() for pagetables. This is not used for PTE 112 * pages - they're linked to struct page, come from the normal free 113 * pages pool and have a different entry size (see real_pte_t) to 114 * everything else. Caches created by this function are used for all 115 * the higher level pagetables, and for hugepage pagetables. 116 */ pgtable_cache_add(unsigned int shift)117 void pgtable_cache_add(unsigned int shift) 118 { 119 char *name; 120 unsigned long table_size = sizeof(pgd_t) << shift; 121 unsigned long align = table_size; 122 123 /* When batching pgtable pointers for RCU freeing, we store 124 * the index size in the low bits. Table alignment must be 125 * big enough to fit it. 126 */ 127 unsigned long minalign = MAX_PGTABLE_INDEX_SIZE + 1; 128 struct kmem_cache *new = NULL; 129 130 /* It would be nice if this was a BUILD_BUG_ON(), but at the 131 * moment, gcc doesn't seem to recognize is_power_of_2 as a 132 * constant expression, so so much for that. */ 133 BUG_ON(!is_power_of_2(minalign)); 134 BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE); 135 136 if (PGT_CACHE(shift)) 137 return; /* Already have a cache of this size */ 138 139 align = max_t(unsigned long, align, minalign); 140 name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift); 141 if (name) 142 new = kmem_cache_create(name, table_size, align, 0, ctor(shift)); 143 if (!new) 144 panic("Could not allocate pgtable cache for order %d", shift); 145 146 kfree(name); 147 pgtable_cache[shift] = new; 148 149 pr_debug("Allocated pgtable cache for order %d\n", shift); 150 } 151 EXPORT_SYMBOL_GPL(pgtable_cache_add); /* used by kvm_hv module */ 152 pgtable_cache_init(void)153 void pgtable_cache_init(void) 154 { 155 pgtable_cache_add(PGD_INDEX_SIZE); 156 157 if (PMD_CACHE_INDEX) 158 pgtable_cache_add(PMD_CACHE_INDEX); 159 /* 160 * In all current configs, when the PUD index exists it's the 161 * same size as either the pgd or pmd index except with THP enabled 162 * on book3s 64 163 */ 164 if (PUD_CACHE_INDEX) 165 pgtable_cache_add(PUD_CACHE_INDEX); 166 } 167