powerpc32: Use kmem_cache memory for PGDIR
When pages are not 4K, PGDIR table is allocated with kmalloc(). In order to
optimise TLB handlers, aligned memory is needed. kmalloc() doesn't provide
aligned memory blocks, so lets use a kmem_cache pool instead.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <scottwood@freescale.com>
diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c
index 8331396..03b1a3b 100644
--- a/arch/powerpc/mm/pgtable_32.c
+++ b/arch/powerpc/mm/pgtable_32.c
@@ -72,13 +72,25 @@
#define PGDIR_ORDER (32 + PGD_T_LOG2 - PGDIR_SHIFT)
+#ifndef CONFIG_PPC_4K_PAGES
+static struct kmem_cache *pgtable_cache;
+
+void pgtable_cache_init(void)
+{
+ pgtable_cache = kmem_cache_create("PGDIR cache", 1 << PGDIR_ORDER,
+ 1 << PGDIR_ORDER, 0, NULL);
+ if (pgtable_cache == NULL)
+ panic("Couldn't allocate pgtable caches");
+}
+#endif
+
pgd_t *pgd_alloc(struct mm_struct *mm)
{
pgd_t *ret;
/* pgdir take page or two with 4K pages and a page fraction otherwise */
#ifndef CONFIG_PPC_4K_PAGES
- ret = kzalloc(1 << PGDIR_ORDER, GFP_KERNEL);
+ ret = kmem_cache_alloc(pgtable_cache, GFP_KERNEL | __GFP_ZERO);
#else
ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
PGDIR_ORDER - PAGE_SHIFT);
@@ -89,7 +101,7 @@
void pgd_free(struct mm_struct *mm, pgd_t *pgd)
{
#ifndef CONFIG_PPC_4K_PAGES
- kfree((void *)pgd);
+ kmem_cache_free(pgtable_cache, (void *)pgd);
#else
free_pages((unsigned long)pgd, PGDIR_ORDER - PAGE_SHIFT);
#endif