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Diffstat (limited to 'arch/powerpc/mm/init-common.c')
| -rw-r--r-- | arch/powerpc/mm/init-common.c | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/arch/powerpc/mm/init-common.c b/arch/powerpc/mm/init-common.c new file mode 100644 index 000000000000..a175cd82ae8c --- /dev/null +++ b/arch/powerpc/mm/init-common.c @@ -0,0 +1,107 @@ +/* + * 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> + +static void pgd_ctor(void *addr) +{ + memset(addr, 0, PGD_TABLE_SIZE); +} + +static void pud_ctor(void *addr) +{ + memset(addr, 0, PUD_TABLE_SIZE); +} + +static void pmd_ctor(void *addr) +{ + memset(addr, 0, PMD_TABLE_SIZE); +} + +struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE]; + +/* + * 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 shift, void (*ctor)(void *)) +{ + 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 < 1) || (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); + kfree(name); + pgtable_cache[shift - 1] = new; + pr_debug("Allocated pgtable cache for order %d\n", shift); +} + + +void pgtable_cache_init(void) +{ + pgtable_cache_add(PGD_INDEX_SIZE, pgd_ctor); + + if (PMD_INDEX_SIZE && !PGT_CACHE(PMD_INDEX_SIZE)) + pgtable_cache_add(PMD_CACHE_INDEX, pmd_ctor); + /* + * 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_INDEX_SIZE && !PGT_CACHE(PUD_INDEX_SIZE)) + pgtable_cache_add(PUD_INDEX_SIZE, pud_ctor); + + if (!PGT_CACHE(PGD_INDEX_SIZE)) + panic("Couldn't allocate pgd cache"); + if (PMD_INDEX_SIZE && !PGT_CACHE(PMD_INDEX_SIZE)) + panic("Couldn't allocate pmd pgtable caches"); + if (PUD_INDEX_SIZE && !PGT_CACHE(PUD_INDEX_SIZE)) + panic("Couldn't allocate pud pgtable caches"); +} |