ARCv2: Enable unaligned access in early ASM code

commit 252f6e8 upstream. It is currently done in arc_init_IRQ() which might be too late considering gcc 7.3.1 onwards (GNU 2018.03) generates unaligned memory accesses by default Cc: [email protected] exynos-linux-stable#4.4+ Signed-off-by: Eugeniy Paltsev <[email protected]> Signed-off-by: Vineet Gupta <[email protected]> [vgupta: rewrote changelog] Signed-off-by: Greg Kroah-Hartman <[email protected]>
ianmacd · Feb 27, 2019 · 812224d · 812224d
1 parent e9f0613
commit 812224d
Showing 1 changed file with 10 additions and 0 deletions.
diff --git a/arch/arc/kernel/head.S b/arch/arc/kernel/head.S
@@ -17,6 +17,7 @@
 #include <asm/entry.h>
 #include <asm/arcregs.h>
 #include <asm/cache.h>
+#include <asm/irqflags.h>
 
 .macro CPU_EARLY_SETUP
 
@@ -47,6 +48,15 @@
 	sr	r5, [ARC_REG_DC_CTRL]
 
 1:
+
+#ifdef CONFIG_ISA_ARCV2
+	; Unaligned access is disabled at reset, so re-enable early as
+	; gcc 7.3.1 (ARC GNU 2018.03) onwards generates unaligned access
+	; by default
+	lr	r5, [status32]
+	bset	r5, r5, STATUS_AD_BIT
+	kflag	r5
+#endif
 .endm
 
 	.section .init.text, "ax",@progbits