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>

diff --git a/arch/arm/cpu/armv7/zynq/Makefile b/arch/arm/cpu/armv7/zynq/Makefile
index 3363a3c..901f2ce 100644 (file)
--- 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 (file)
index 0000000..778a377
--- /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 816d0c5..d1bfec9 100644 (file)
--- 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 (file)
index 0000000..6d714b7
--- /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)