ARM: 7150/1: Allow kernel unaligned accesses on ARMv6+ processors

commit 8428e84d42179c2a00f5f6450866e70d802d1d05 upstream.

Recent gcc versions generate unaligned accesses by default on ARMv6 and
later processors. This patch ensures that the SCTLR.A bit is always
cleared on such processors to avoid kernel traping before
alignment_init() is called.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: John Linn <John.Linn@xilinx.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 278c1b0..673151c 100644 (file)
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -348,7 +348,7 @@ __secondary_data:
  *  r13 = *virtual* address to jump to upon completion
  */
 __enable_mmu:
-#ifdef CONFIG_ALIGNMENT_TRAP
+#if defined(CONFIG_ALIGNMENT_TRAP) && __LINUX_ARM_ARCH__ < 6
        orr     r0, r0, #CR_A
 #else
        bic     r0, r0, #CR_A