/* * 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. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * */ #undef DEBUG #include <linux/string.h> #include <asm/pgalloc.h> #include <asm/pgtable.h> #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); }