| // 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); |
| #ifdef CONFIG_KFENCE |
| bool __ro_after_init kfence_disabled; |
| #endif |
| |
| 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. |
| */ |
| unsigned long minalign = MAX_PGTABLE_INDEX_SIZE + 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); |
| } |