diff options
Diffstat (limited to 'arch/powerpc/mm/init_64.c')
| -rw-r--r-- | arch/powerpc/mm/init_64.c | 76 |
1 files changed, 55 insertions, 21 deletions
diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c index 335c578b9cc..776f28d02b6 100644 --- a/arch/powerpc/mm/init_64.c +++ b/arch/powerpc/mm/init_64.c @@ -41,6 +41,7 @@ #include <linux/module.h> #include <linux/poison.h> #include <linux/lmb.h> +#include <linux/hugetlb.h> #include <asm/pgalloc.h> #include <asm/page.h> @@ -119,30 +120,63 @@ static void pmd_ctor(void *addr) memset(addr, 0, PMD_TABLE_SIZE); } -static const unsigned int pgtable_cache_size[2] = { - PGD_TABLE_SIZE, PMD_TABLE_SIZE -}; -static const char *pgtable_cache_name[ARRAY_SIZE(pgtable_cache_size)] = { -#ifdef CONFIG_PPC_64K_PAGES - "pgd_cache", "pmd_cache", -#else - "pgd_cache", "pud_pmd_cache", -#endif /* CONFIG_PPC_64K_PAGES */ -}; - -#ifdef CONFIG_HUGETLB_PAGE -/* Hugepages need an extra cache per hugepagesize, initialized in - * hugetlbpage.c. We can't put into the tables above, because HPAGE_SHIFT - * is not compile time constant. */ -struct kmem_cache *pgtable_cache[ARRAY_SIZE(pgtable_cache_size)+MMU_PAGE_COUNT]; -#else -struct kmem_cache *pgtable_cache[ARRAY_SIZE(pgtable_cache_size)]; -#endif +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); + PGT_CACHE(shift) = new; + + pr_debug("Allocated pgtable cache for order %d\n", shift); +} + void pgtable_cache_init(void) { - pgtable_cache[0] = kmem_cache_create(pgtable_cache_name[0], PGD_TABLE_SIZE, PGD_TABLE_SIZE, SLAB_PANIC, pgd_ctor); - pgtable_cache[1] = kmem_cache_create(pgtable_cache_name[1], PMD_TABLE_SIZE, PMD_TABLE_SIZE, SLAB_PANIC, pmd_ctor); + pgtable_cache_add(PGD_INDEX_SIZE, pgd_ctor); + pgtable_cache_add(PMD_INDEX_SIZE, pmd_ctor); + if (!PGT_CACHE(PGD_INDEX_SIZE) || !PGT_CACHE(PMD_INDEX_SIZE)) + panic("Couldn't allocate pgtable caches"); + + /* In all current configs, when the PUD index exists it's the + * same size as either the pgd or pmd index. Verify that the + * initialization above has also created a PUD cache. This + * will need re-examiniation if we add new possibilities for + * the pagetable layout. */ + BUG_ON(PUD_INDEX_SIZE && !PGT_CACHE(PUD_INDEX_SIZE)); } #ifdef CONFIG_SPARSEMEM_VMEMMAP |