slab: Common constants for kmalloc boundaries

[platform/adaptation/renesas_rcar/renesas_kernel.git] / include / linux / slab.h

diff --git a/include/linux/slab.h b/include/linux/slab.h
index c97fe92..c017805 100644 (file)
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -163,7 +163,12 @@ struct kmem_cache {
 #else /* CONFIG_SLOB */
 
 /*
- * The largest kmalloc size supported by the slab allocators is
+ * Kmalloc array related definitions
+ */
+
+#ifdef CONFIG_SLAB
+/*
+ * The largest kmalloc size supported by the SLAB allocators is
  * 32 megabyte (2^25) or the maximum allocatable page order if that is
  * less than 32 MB.
  *
@@ -173,9 +178,24 @@ struct kmem_cache {
  */
 #define KMALLOC_SHIFT_HIGH     ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \
                                (MAX_ORDER + PAGE_SHIFT - 1) : 25)
+#define KMALLOC_SHIFT_MAX      KMALLOC_SHIFT_HIGH
+#define KMALLOC_SHIFT_LOW      5
+#else
+/*
+ * SLUB allocates up to order 2 pages directly and otherwise
+ * passes the request to the page allocator.
+ */
+#define KMALLOC_SHIFT_HIGH     (PAGE_SHIFT + 1)
+#define KMALLOC_SHIFT_MAX      (MAX_ORDER + PAGE_SHIFT)
+#define KMALLOC_SHIFT_LOW      3
+#endif
 
-#define KMALLOC_MAX_SIZE       (1UL << KMALLOC_SHIFT_HIGH)
-#define KMALLOC_MAX_ORDER      (KMALLOC_SHIFT_HIGH - PAGE_SHIFT)
+/* Maximum allocatable size */
+#define KMALLOC_MAX_SIZE       (1UL << KMALLOC_SHIFT_MAX)
+/* Maximum size for which we actually use a slab cache */
+#define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH)
+/* Maximum order allocatable via the slab allocagtor */
+#define KMALLOC_MAX_ORDER      (KMALLOC_SHIFT_MAX - PAGE_SHIFT)
 
 /*
  * Kmalloc subsystem.
@@ -183,15 +203,9 @@ struct kmem_cache {
 #if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8
 #define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN
 #else
-#ifdef CONFIG_SLAB
-#define KMALLOC_MIN_SIZE 32
-#else
-#define KMALLOC_MIN_SIZE 8
-#endif
+#define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW)
 #endif
 
-#define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
-
 /*
  * Figure out which kmalloc slab an allocation of a certain size
  * belongs to.