From c08cfc2d2cf43c443f74549aefd7a7f2ffc3d7de Mon Sep 17 00:00:00 2001
From: Michal Simek <michal.simek@xilinx.com>
Date: Fri, 23 Jan 2015 09:45:12 +0100
Subject: [PATCH] ARM: zynq: Enable the Neon instructions
Added the lowlevel_init to enable the Neon instructions.
Initially the u-boot was causing undefined instruction
exception if loaded through tcl, and working fine if loaded
through FSBL. The exception was causing in convertion formula
of given time to ticks. It was because, the Neon instructions
were disabled and hence causing the undefined exception. In
FSBL case, the FSBL was enabling the Neon instructions. Hence,
added the lowlevel_init to enable the Neon instructions.
Also enable neon instructions for non-xilinx toolchain.
Signed-off-by: Siva Durga Prasad Paladugu <sivadur@xilinx.com>
Acked-by: Radhey Shyam Pandey <radheys@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
---
arch/arm/cpu/armv7/zynq/Makefile | 1 +
arch/arm/cpu/armv7/zynq/config.mk | 7 +++++++
arch/arm/cpu/armv7/zynq/cpu.c | 3 ---
arch/arm/cpu/armv7/zynq/lowlevel_init.S | 26 +++++++++++++++++++++++++
4 files changed, 34 insertions(+), 3 deletions(-)
create mode 100644 arch/arm/cpu/armv7/zynq/config.mk
create mode 100644 arch/arm/cpu/armv7/zynq/lowlevel_init.S
diff --git a/arch/arm/cpu/armv7/zynq/Makefile b/arch/arm/cpu/armv7/zynq/Makefile
index 3363a3c71b..901f2ce4cb 100644
--- a/arch/arm/cpu/armv7/zynq/Makefile
+++ b/arch/arm/cpu/armv7/zynq/Makefile
@@ -13,4 +13,5 @@ obj-y += cpu.o
obj-y += ddrc.o
obj-y += slcr.o
obj-y += clk.o
+obj-y += lowlevel_init.o
obj-$(CONFIG_SPL_BUILD) += spl.o
diff --git a/arch/arm/cpu/armv7/zynq/config.mk b/arch/arm/cpu/armv7/zynq/config.mk
new file mode 100644
index 0000000000..778a377e8a
--- /dev/null
+++ b/arch/arm/cpu/armv7/zynq/config.mk
@@ -0,0 +1,7 @@
+#
+# Copyright (C) 2013 - 2015 Xilinx, Inc. All rights reserved.
+#
+# SPDX-License-Identifier: GPL-2.0
+#
+# Allow NEON instructions (needed for lowlevel_init.S with GNU toolchain)
+PLATFORM_RELFLAGS += -mfpu=neon
diff --git a/arch/arm/cpu/armv7/zynq/cpu.c b/arch/arm/cpu/armv7/zynq/cpu.c
index 816d0c5da7..d1bfec9f71 100644
--- a/arch/arm/cpu/armv7/zynq/cpu.c
+++ b/arch/arm/cpu/armv7/zynq/cpu.c
@@ -10,9 +10,6 @@
#include <asm/arch/sys_proto.h>
#include <asm/arch/hardware.h>
-void lowlevel_init(void)
-{
-}
#define ZYNQ_SILICON_VER_MASK 0xF0000000
#define ZYNQ_SILICON_VER_SHIFT 28
diff --git a/arch/arm/cpu/armv7/zynq/lowlevel_init.S b/arch/arm/cpu/armv7/zynq/lowlevel_init.S
new file mode 100644
index 0000000000..6d714b711c
--- /dev/null
+++ b/arch/arm/cpu/armv7/zynq/lowlevel_init.S
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2013 Xilinx, Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <asm-offsets.h>
+#include <config.h>
+#include <linux/linkage.h>
+
+ENTRY(lowlevel_init)
+
+ /* Enable the the VFP */
+ mrc p15, 0, r1, c1, c0, 2
+ orr r1, r1, #(0x3 << 20)
+ orr r1, r1, #(0x3 << 20)
+ mcr p15, 0, r1, c1, c0, 2
+ isb
+ fmrx r1, FPEXC
+ orr r1,r1, #(1<<30)
+ fmxr FPEXC, r1
+
+ /* Move back to caller */
+ mov pc, lr
+
+ENDPROC(lowlevel_init)
--
2.39.5