[PATCH 1/2] armv8: aarch32: Execute 32-bit Linux for LayerScape platforms

[Alison Wang]

The ARMv8 architecture supports:
1. 64-bit execution state, AArch64.
2. 32-bit execution state, AArch32, that is compatible with previous
versions of the ARM architecture.

LayerScape platforms are compliant with ARMv8 architecture. This patch
is to support running 32-bit Linux kernel for LayerScape platforms.

Verified on LayerScape LS1043ARDB, LS1012ARDB, LS1046ARDB boards.

Signed-off-by: Ebony Zhu <ebony.zhu at nxp.com>
Signed-off-by: Alison Wang <alison.wang at nxp.com>
---
 arch/arm/Kconfig                    |  9 +++++++++
 arch/arm/mach-imx/Kconfig           | 14 ++++++++++++++
 arch/arm/mach-imx/Makefile          |  4 +++-
 arch/arm/mach-imx/mach-layerscape.c | 23 +++++++++++++++++++++++
 4 files changed, 49 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm/mach-imx/mach-layerscape.c

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index f0c8068..e8d470e 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -294,6 +294,15 @@ config PGTABLE_LEVELS
 	default 3 if ARM_LPAE
 	default 2
 
+config ARCH_AARCH32_ES_SUPPORT
+	def_bool n
+	help
+	 The ARMv8 architecture supports 64-bit execution state, AArch64
+	 and 32-bit execution state, AArch32, that is compatible with
+	 previous versions of the ARM architecture.
+
+	 Enable AArch32 execution state support for ARMv8 architecture.
+
 source "init/Kconfig"
 
 source "kernel/Kconfig.freezer"
diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig
index 0ac05a0..fda4f5f 100644
--- a/arch/arm/mach-imx/Kconfig
+++ b/arch/arm/mach-imx/Kconfig
@@ -549,6 +549,20 @@ config SOC_LS1021A
 	help
 	  This enables support for Freescale LS1021A processor.
 
+config ARCH_LAYERSCAPE_AARCH32
+	bool "Freescale Layerscape SoC AArch32 ES support"
+	select ARCH_AARCH32_ES_SUPPORT
+	select ARM_AMBA
+	select ARM_GIC
+	select ARM_ARCH_TIMER
+	select ARCH_DMA_ADDR_T_64BIT if ARM_LPAE
+	select PCI_LAYERSCAPE if PCI
+	select PCI_DOMAINS if PCI
+
+	help
+	  This enables support for Freescale Layerscape SoC family in
+	  in AArch32 execution state.
+
 endif
 
 comment "Cortex-A/Cortex-M asymmetric multiprocessing platforms"
diff --git a/arch/arm/mach-imx/Makefile b/arch/arm/mach-imx/Makefile
index 737450f..7ded4fa 100644
--- a/arch/arm/mach-imx/Makefile
+++ b/arch/arm/mach-imx/Makefile
@@ -69,7 +69,7 @@ obj-$(CONFIG_HAVE_IMX_ANATOP) += anatop.o
 obj-$(CONFIG_HAVE_IMX_GPC) += gpc.o
 obj-$(CONFIG_HAVE_IMX_MMDC) += mmdc.o
 obj-$(CONFIG_HAVE_IMX_SRC) += src.o
-ifneq ($(CONFIG_SOC_IMX6)$(CONFIG_SOC_LS1021A),)
+ifneq ($(CONFIG_SOC_IMX6)$(CONFIG_SOC_LS1021A)$(CONFIG_ARCH_LAYERSCAPE_AARCH32),)
 AFLAGS_headsmp.o :=-Wa,-march=armv7-a
 obj-$(CONFIG_SMP) += headsmp.o platsmp.o
 obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
@@ -96,4 +96,6 @@ obj-$(CONFIG_SOC_VF610) += mach-vf610.o
 
 obj-$(CONFIG_SOC_LS1021A) += mach-ls1021a.o
 
+obj-$(CONFIG_ARCH_LAYERSCAPE_AARCH32) += mach-layerscape.o
+
 obj-y += devices/
diff --git a/arch/arm/mach-imx/mach-layerscape.c b/arch/arm/mach-imx/mach-layerscape.c
new file mode 100644
index 0000000..acfb2a2
--- /dev/null
+++ b/arch/arm/mach-imx/mach-layerscape.c
@@ -0,0 +1,23 @@
+/*
+ * Copyright 2015-2016 Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <asm/mach/arch.h>
+
+#include "common.h"
+
+static const char * const layerscape_dt_compat[] __initconst = {
+	"fsl,ls1012a",
+	"fsl,ls1043a",
+	"fsl,ls1046a",
+	NULL,
+};
+
+DT_MACHINE_START(LAYERSCAPE_AARCH32, "Freescale LAYERSCAPE")
+	.dt_compat	= layerscape_dt_compat,
+MACHINE_END
-- 
2.1.0.27.g96db324