[ARM] 5534/1: kmalloc must return a cache line aligned buffer
Define ARCH_KMALLOC_MINALIGN in asm/cache.h
At the request of Russell also move ARCH_SLAB_MINALIGN to this file.
Signed-off-by: Martin Fuzzey <mfuzzey@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/include/asm/cache.h b/arch/arm/include/asm/cache.h
index cb7a9e9..feaa75f 100644
--- a/arch/arm/include/asm/cache.h
+++ b/arch/arm/include/asm/cache.h
@@ -7,4 +7,20 @@
#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
+
+/*
+ * With EABI on ARMv5 and above we must have 64-bit aligned slab pointers.
+ */
+#if defined(CONFIG_AEABI) && (__LINUX_ARM_ARCH__ >= 5)
+#define ARCH_SLAB_MINALIGN 8
+#endif
+
#endif