diff options
Diffstat (limited to '')
| -rw-r--r-- | arch/powerpc/mm/init-common.c | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/arch/powerpc/mm/init-common.c b/arch/powerpc/mm/init-common.c new file mode 100644 index 000000000..119ef491f --- /dev/null +++ b/arch/powerpc/mm/init-common.c @@ -0,0 +1,166 @@ +// 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; + + /* 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); + 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); +} |