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 bool disable_kuep = !IS_ENABLED(CONFIG_PPC_KUEP); 32 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 #define CTOR(shift) static void ctor_##shift(void *addr) \ 51 { \ 52 memset(addr, 0, sizeof(void *) << (shift)); \ 53 } 54 55 CTOR(0); CTOR(1); CTOR(2); CTOR(3); CTOR(4); CTOR(5); CTOR(6); CTOR(7); 56 CTOR(8); CTOR(9); CTOR(10); CTOR(11); CTOR(12); CTOR(13); CTOR(14); CTOR(15); 57 58 static 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 83 struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE + 1]; 84 EXPORT_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 */ 93 void 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 } 130 EXPORT_SYMBOL_GPL(pgtable_cache_add); /* used by kvm_hv module */ 131 132 void 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 } 146