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 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 unsigned long kernstart_virt_addr __ro_after_init = KERNELBASE; 29 EXPORT_SYMBOL_GPL(kernstart_virt_addr); 30 31 static bool disable_kuep = !IS_ENABLED(CONFIG_PPC_KUEP); 32 static bool disable_kuap = !IS_ENABLED(CONFIG_PPC_KUAP); 33 34 static int __init parse_nosmep(char *p) 35 { 36 disable_kuep = true; 37 pr_warn("Disabling Kernel Userspace Execution Prevention\n"); 38 return 0; 39 } 40 early_param("nosmep", parse_nosmep); 41 42 static int __init parse_nosmap(char *p) 43 { 44 disable_kuap = true; 45 pr_warn("Disabling Kernel Userspace Access Protection\n"); 46 return 0; 47 } 48 early_param("nosmap", parse_nosmap); 49 50 void __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 61 CTOR(0); CTOR(1); CTOR(2); CTOR(3); CTOR(4); CTOR(5); CTOR(6); CTOR(7); 62 CTOR(8); CTOR(9); CTOR(10); CTOR(11); CTOR(12); CTOR(13); CTOR(14); CTOR(15); 63 64 static 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 89 struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE + 1]; 90 EXPORT_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 */ 99 void 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; 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 new = kmem_cache_create(name, table_size, align, 0, ctor(shift)); 128 if (!new) 129 panic("Could not allocate pgtable cache for order %d", shift); 130 131 kfree(name); 132 pgtable_cache[shift] = new; 133 134 pr_debug("Allocated pgtable cache for order %d\n", shift); 135 } 136 EXPORT_SYMBOL_GPL(pgtable_cache_add); /* used by kvm_hv module */ 137 138 void pgtable_cache_init(void) 139 { 140 pgtable_cache_add(PGD_INDEX_SIZE); 141 142 if (PMD_CACHE_INDEX) 143 pgtable_cache_add(PMD_CACHE_INDEX); 144 /* 145 * In all current configs, when the PUD index exists it's the 146 * same size as either the pgd or pmd index except with THP enabled 147 * on book3s 64 148 */ 149 if (PUD_CACHE_INDEX) 150 pgtable_cache_add(PUD_CACHE_INDEX); 151 } 152