slab: Use common kmalloc_index/kmalloc_size functions

Make slab use the common functions. We can get rid of a lot
of old ugly stuff as a results. Among them the sizes
array and the weird include/linux/kmalloc_sizes file and
some pretty bad #include statements in slab_def.h.

The one thing that is different in slab is that the 32 byte
cache will also be created for arches that have page sizes
larger than 4K. There are numerous smaller allocations that
SLOB and SLUB can handle better because of their support for
smaller allocation sizes so lets keep the 32 byte slab also
for arches with > 4K pages.

Reviewed-by: Glauber Costa <glommer@parallels.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

include/linux/slab_def.h

@@ -11,8 +11,6 @@
  */
 
 #include <linux/init.h>
-#include <asm/page.h>		/* kmalloc_sizes.h needs PAGE_SIZE */
-#include <asm/cache.h>		/* kmalloc_sizes.h needs L1_CACHE_BYTES */
 #include <linux/compiler.h>
 
 /*
@@ -104,15 +102,8 @@ struct kmem_cache {
 	 */
 };
 
-/* Size description struct for general caches. */
-struct cache_sizes {
-	size_t		 	cs_size;
-	struct kmem_cache	*cs_cachep;
-#ifdef CONFIG_ZONE_DMA
-	struct kmem_cache	*cs_dmacachep;
-#endif
-};
-extern struct cache_sizes malloc_sizes[];
+extern struct kmem_cache *kmalloc_caches[PAGE_SHIFT + MAX_ORDER];
+extern struct kmem_cache *kmalloc_dma_caches[PAGE_SHIFT + MAX_ORDER];
 
 void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
 void *__kmalloc(size_t size, gfp_t flags);
@@ -133,26 +124,19 @@ static __always_inline void *kmalloc(size_t size, gfp_t flags)
 	void *ret;
 
 	if (__builtin_constant_p(size)) {
-		int i = 0;
+		int i;
 
 		if (!size)
 			return ZERO_SIZE_PTR;
 
-#define CACHE(x) \
-		if (size <= x) \
-			goto found; \
-		else \
-			i++;
-#include <linux/kmalloc_sizes.h>
-#undef CACHE
-		return NULL;
-found:
+		i = kmalloc_index(size);
+
 #ifdef CONFIG_ZONE_DMA
 		if (flags & GFP_DMA)
-			cachep = malloc_sizes[i].cs_dmacachep;
+			cachep = kmalloc_dma_caches[i];
 		else
 #endif
-			cachep = malloc_sizes[i].cs_cachep;
+			cachep = kmalloc_caches[i];
 
 		ret = kmem_cache_alloc_trace(cachep, flags, size);
 
@@ -186,26 +170,19 @@ static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
 	struct kmem_cache *cachep;
 
 	if (__builtin_constant_p(size)) {
-		int i = 0;
+		int i;
 
 		if (!size)
 			return ZERO_SIZE_PTR;
 
-#define CACHE(x) \
-		if (size <= x) \
-			goto found; \
-		else \
-			i++;
-#include <linux/kmalloc_sizes.h>
-#undef CACHE
-		return NULL;
-found:
+		i = kmalloc_index(size);
+
 #ifdef CONFIG_ZONE_DMA
 		if (flags & GFP_DMA)
-			cachep = malloc_sizes[i].cs_dmacachep;
+			cachep = kmalloc_dma_caches[i];
 		else
 #endif
-			cachep = malloc_sizes[i].cs_cachep;
+			cachep = kmalloc_caches[i];
 
 		return kmem_cache_alloc_node_trace(cachep, flags, node, size);
 	}