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>

arch/sh/include/asm/pgalloc.h

@@ -6,10 +6,13 @@
 
 #define QUICK_PT 1	/* Other page table pages that are zero on free */
 
+extern pgd_t *pgd_alloc(struct mm_struct *);
+extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
+
 #ifdef CONFIG_PGTABLE_LEVELS_3
-#include <asm/pgalloc_pmd.h>
-#else
-#include <asm/pgalloc_nopmd.h>
+extern void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmd);
+extern pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address);
+extern void pmd_free(struct mm_struct *mm, pmd_t *pmd);
 #endif
 
 static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
@@ -67,7 +70,6 @@ do {							\
 
 static inline void check_pgt_cache(void)
 {
-	__check_pgt_cache();
 	quicklist_trim(QUICK_PT, NULL, 25, 16);
 }
 

arch/sh/include/asm/pgtable.h

@@ -141,9 +141,9 @@ typedef pte_t *pte_addr_t;
 #define pte_pfn(x)		((unsigned long)(((x).pte_low >> PAGE_SHIFT)))
 
 /*
- * No page table caches to initialise
+ * Initialise the page table caches
  */
-#define pgtable_cache_init()	do { } while (0)
+extern void pgtable_cache_init(void);
 
 struct vm_area_struct;
 

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

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 */