// SPDX-License-Identifier: GPL-2.0-or-later /* * PowerPC version * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) * * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) * and Cort Dougan (PReP) (cort@cs.nmt.edu) * Copyright (C) 1996 Paul Mackerras * * Derived from "arch/i386/mm/init.c" * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds * * Dave Engebretsen <engebret@us.ibm.com> * Rework for PPC64 port. */ #undef DEBUG #include <linux/string.h> #include <linux/pgtable.h> #include <asm/pgalloc.h> #include <asm/kup.h> #include <asm/smp.h> phys_addr_t memstart_addr __ro_after_init = (phys_addr_t)~0ull; EXPORT_SYMBOL_GPL(memstart_addr); phys_addr_t kernstart_addr __ro_after_init; EXPORT_SYMBOL_GPL(kernstart_addr); unsigned long kernstart_virt_addr __ro_after_init = KERNELBASE; EXPORT_SYMBOL_GPL(kernstart_virt_addr); bool disable_kuep = !IS_ENABLED(CONFIG_PPC_KUEP); bool disable_kuap = !IS_ENABLED(CONFIG_PPC_KUAP); static int __init parse_nosmep(char *p) { if (!IS_ENABLED(CONFIG_PPC_BOOK3S_64)) return 0; disable_kuep = true; pr_warn("Disabling Kernel Userspace Execution Prevention\n"); return 0; } early_param("nosmep", parse_nosmep); static int __init parse_nosmap(char *p) { disable_kuap = true; pr_warn("Disabling Kernel Userspace Access Protection\n"); return 0; } early_param("nosmap", parse_nosmap); void __weak setup_kuep(bool disabled) { if (!IS_ENABLED(CONFIG_PPC_KUEP) || disabled) return; if (smp_processor_id() != boot_cpuid) return; pr_info("Activating Kernel Userspace Execution Prevention\n"); } void setup_kup(void) { setup_kuap(disable_kuap); setup_kuep(disable_kuep); } #define CTOR(shift) static void ctor_##shift(void *addr) \ { \ memset(addr, 0, sizeof(void *) << (shift)); \ } CTOR(0); CTOR(1); CTOR(2); CTOR(3); CTOR(4); CTOR(5); CTOR(6); CTOR(7); CTOR(8); CTOR(9); CTOR(10); CTOR(11); CTOR(12); CTOR(13); CTOR(14); CTOR(15); static inline void (*ctor(int shift))(void *) { BUILD_BUG_ON(MAX_PGTABLE_INDEX_SIZE != 15); switch (shift) { case 0: return ctor_0; case 1: return ctor_1; case 2: return ctor_2; case 3: return ctor_3; case 4: return ctor_4; case 5: return ctor_5; case 6: return ctor_6; case 7: return ctor_7; case 8: return ctor_8; case 9: return ctor_9; case 10: return ctor_10; case 11: return ctor_11; case 12: return ctor_12; case 13: return ctor_13; case 14: return ctor_14; case 15: return ctor_15; } return NULL; } struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE + 1]; EXPORT_SYMBOL_GPL(pgtable_cache); /* used by kvm_hv module */ /* * Create a kmem_cache() for pagetables. This is not used for PTE * pages - they're linked to struct page, come from the normal free * pages pool and have a different entry size (see real_pte_t) to * everything else. Caches created by this function are used for all * the higher level pagetables, and for hugepage pagetables. */ void pgtable_cache_add(unsigned int shift) { char *name; unsigned long table_size = sizeof(void *) << shift; unsigned long align = table_size; /* When batching pgtable pointers for RCU freeing, we store * the index size in the low bits. Table alignment must be * big enough to fit it. * * Likewise, hugeapge pagetable pointers contain a (different) * shift value in the low bits. All tables must be aligned so * as to leave enough 0 bits in the address to contain it. */ unsigned long minalign = max(MAX_PGTABLE_INDEX_SIZE + 1, HUGEPD_SHIFT_MASK + 1); struct kmem_cache *new = NULL; /* It would be nice if this was a BUILD_BUG_ON(), but at the * moment, gcc doesn't seem to recognize is_power_of_2 as a * constant expression, so so much for that. */ BUG_ON(!is_power_of_2(minalign)); BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE); if (PGT_CACHE(shift)) return; /* Already have a cache of this size */ align = max_t(unsigned long, align, minalign); name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift); if (name) new = kmem_cache_create(name, table_size, align, 0, ctor(shift)); if (!new) panic("Could not allocate pgtable cache for order %d", shift); kfree(name); pgtable_cache[shift] = new; pr_debug("Allocated pgtable cache for order %d\n", shift); } EXPORT_SYMBOL_GPL(pgtable_cache_add); /* used by kvm_hv module */ void pgtable_cache_init(void) { pgtable_cache_add(PGD_INDEX_SIZE); if (PMD_CACHE_INDEX) pgtable_cache_add(PMD_CACHE_INDEX); /* * In all current configs, when the PUD index exists it's the * same size as either the pgd or pmd index except with THP enabled * on book3s 64 */ if (PUD_CACHE_INDEX) pgtable_cache_add(PUD_CACHE_INDEX); }