sh: Move page table allocation out of line

We also switched away from quicklists and instead moved to slab
caches. After benchmarking both implementations the difference is
negligible. The slab caches suit us better though because the size of a
pgd table is just 4 entries when we're using a 3-level page table layout
and quicklists always deal with pages.

Signed-off-by: Matt Fleming <matt@console-pimps.org>

2 files changed, 58 insertions, 1 deletions

diff --git a/arch/sh/mm/Makefile b/arch/sh/mm/Makefile
index 8a70535..dd5010c 100644
--- a/arch/sh/mm/Makefile
+++ b/arch/sh/mm/Makefile
@@ -15,7 +15,7 @@ obj-y			+= $(cacheops-y)
 
 mmu-y			:= nommu.o extable_32.o
 mmu-$(CONFIG_MMU)	:= extable_$(BITS).o fault_$(BITS).o \
-			   ioremap_$(BITS).o kmap.o tlbflush_$(BITS).o
+			   ioremap_$(BITS).o kmap.o pgtable.o tlbflush_$(BITS).o
 
 obj-y			+= $(mmu-y)
 obj-$(CONFIG_DEBUG_FS)	+= asids-debugfs.o
diff --git a/arch/sh/mm/pgtable.c b/arch/sh/mm/pgtable.c
new file mode 100644
index 0000000..e1bc548
--- /dev/null
+++ b/arch/sh/mm/pgtable.c
@@ -0,0 +1,57 @@
+#include <linux/mm.h>
+
+#define PGALLOC_GFP GFP_KERNEL | __GFP_REPEAT | __GFP_ZERO
+
+static struct kmem_cache *pgd_cachep;
+
+#ifdef CONFIG_PGTABLE_LEVELS_3
+static struct kmem_cache *pmd_cachep;
+#endif
+
+void pgd_ctor(void *x)
+{
+	pgd_t *pgd = x;
+
+	memcpy(pgd + USER_PTRS_PER_PGD,
+	       swapper_pg_dir + USER_PTRS_PER_PGD,
+	       (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
+}
+
+void pgtable_cache_init(void)
+{
+	pgd_cachep = kmem_cache_create("pgd_cache",
+				       PTRS_PER_PGD * (1<<PTE_MAGNITUDE),
+				       PAGE_SIZE, SLAB_PANIC, pgd_ctor);
+#ifdef CONFIG_PGTABLE_LEVELS_3
+	pmd_cachep = kmem_cache_create("pmd_cache",
+				       PTRS_PER_PMD * (1<<PTE_MAGNITUDE),
+				       PAGE_SIZE, SLAB_PANIC, NULL);
+#endif
+}
+
+pgd_t *pgd_alloc(struct mm_struct *mm)
+{
+	return kmem_cache_alloc(pgd_cachep, PGALLOC_GFP);
+}
+
+void pgd_free(struct mm_struct *mm, pgd_t *pgd)
+{
+	kmem_cache_free(pgd_cachep, pgd);
+}
+
+#ifdef CONFIG_PGTABLE_LEVELS_3
+void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
+{
+	set_pud(pud, __pud((unsigned long)pmd));
+}
+
+pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
+{
+	return kmem_cache_alloc(pmd_cachep, PGALLOC_GFP);
+}
+
+void pmd_free(struct mm_struct *mm, pmd_t *pmd)
+{
+	kmem_cache_free(pmd_cachep, pmd);
+}
+#endif /* CONFIG_PGTABLE_LEVELS_3 */