diff options
Diffstat (limited to 'arch/powerpc/include/asm/nohash/32/pgalloc.h')
| -rw-r--r-- | arch/powerpc/include/asm/nohash/32/pgalloc.h | 44 |
1 files changed, 38 insertions, 6 deletions
diff --git a/arch/powerpc/include/asm/nohash/32/pgalloc.h b/arch/powerpc/include/asm/nohash/32/pgalloc.h index 76d6b9e0c8a9..633139291a48 100644 --- a/arch/powerpc/include/asm/nohash/32/pgalloc.h +++ b/arch/powerpc/include/asm/nohash/32/pgalloc.h @@ -2,14 +2,42 @@ #define _ASM_POWERPC_PGALLOC_32_H #include <linux/threads.h> +#include <linux/slab.h> -/* For 32-bit, all levels of page tables are just drawn from get_free_page() */ -#define MAX_PGTABLE_INDEX_SIZE 0 +/* + * Functions that deal with pagetables that could be at any level of + * the table need to be passed an "index_size" so they know how to + * handle allocation. For PTE pages (which are linked to a struct + * page for now, and drawn from the main get_free_pages() pool), the + * allocation size will be (2^index_size * sizeof(pointer)) and + * allocations are drawn from the kmem_cache in PGT_CACHE(index_size). + * + * The maximum index size needs to be big enough to allow any + * pagetable sizes we need, but small enough to fit in the low bits of + * any page table pointer. In other words all pagetables, even tiny + * ones, must be aligned to allow at least enough low 0 bits to + * contain this value. This value is also used as a mask, so it must + * be one less than a power of two. + */ +#define MAX_PGTABLE_INDEX_SIZE 0xf extern void __bad_pte(pmd_t *pmd); -extern pgd_t *pgd_alloc(struct mm_struct *mm); -extern void pgd_free(struct mm_struct *mm, pgd_t *pgd); +extern struct kmem_cache *pgtable_cache[]; +#define PGT_CACHE(shift) ({ \ + BUG_ON(!(shift)); \ + pgtable_cache[(shift) - 1]; \ + }) + +static inline pgd_t *pgd_alloc(struct mm_struct *mm) +{ + return kmem_cache_alloc(PGT_CACHE(PGD_INDEX_SIZE), GFP_KERNEL); +} + +static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd) +{ + kmem_cache_free(PGT_CACHE(PGD_INDEX_SIZE), pgd); +} /* * We don't have any real pmd's, and this code never triggers because @@ -68,8 +96,12 @@ static inline void pte_free(struct mm_struct *mm, pgtable_t ptepage) static inline void pgtable_free(void *table, unsigned index_size) { - BUG_ON(index_size); /* 32-bit doesn't use this */ - free_page((unsigned long)table); + if (!index_size) { + free_page((unsigned long)table); + } else { + BUG_ON(index_size > MAX_PGTABLE_INDEX_SIZE); + kmem_cache_free(PGT_CACHE(index_size), table); + } } #define check_pgt_cache() do { } while (0) |