tile: set ARCH_KMALLOC_MINALIGN

Architectures that handle DMA-non-coherent memory need to set
ARCH_KMALLOC_MINALIGN to make sure that kmalloc'ed buffer is DMA-safe:
the buffer doesn't share a cache with the others.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>

arch/tile/include/asm/cache.h

@@ -31,6 +31,14 @@
 #define L2_CACHE_BYTES		(1 << L2_CACHE_SHIFT)
 #define L2_CACHE_ALIGN(x)	(((x)+(L2_CACHE_BYTES-1)) & -L2_CACHE_BYTES)
 
+/*
+ * TILE-Gx is fully coherents so we don't need to define
+ * ARCH_KMALLOC_MINALIGN.
+ */
+#ifndef __tilegx__
+#define ARCH_KMALLOC_MINALIGN	L2_CACHE_BYTES
+#endif
+
 /* use the cache line size for the L2, which is where it counts */
 #define SMP_CACHE_BYTES_SHIFT	L2_CACHE_SHIFT
 #define SMP_CACHE_BYTES		L2_CACHE_BYTES