[AVR32] Define ARCH_KMALLOC_MINALIGN to L1_CACHE_BYTES
This allows SLUB debugging to be used without fear of messing up DMA
transfers. SPI is one example that easily breaks without this patch.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
diff --git a/include/asm-avr32/cache.h b/include/asm-avr32/cache.h
index dabb955..d3cf35a 100644
--- a/include/asm-avr32/cache.h
+++ b/include/asm-avr32/cache.h
@@ -4,6 +4,15 @@
#define L1_CACHE_SHIFT 5
#define L1_CACHE_BYTES (1 << L1_CACHE_SHIFT)
+/*
+ * Memory returned by kmalloc() may be used for DMA, so we must make
+ * sure that all such allocations are cache aligned. Otherwise,
+ * unrelated code may cause parts of the buffer to be read into the
+ * cache before the transfer is done, causing old data to be seen by
+ * the CPU.
+ */
+#define ARCH_KMALLOC_MINALIGN L1_CACHE_BYTES
+
#ifndef __ASSEMBLER__
struct cache_info {
unsigned int ways;