lkml.org 
[lkml]   [2018]   [Apr]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v5 07/13] ARM: smp: Add initialization of CNTVOFF
Date
The CNTVOFF register from arch timer is uninitialized.
It should be done by the bootloader but it is currently not the case,
even for boot CPU because this SoC is booting in secure mode.
It leads to an random offset value meaning that each CPU will have a
different time, which isn't working very well.

Add assembly code used for boot CPU and secondary CPU cores to make
sure that the CNTVOFF register is initialized. Because this code can
be used by different platforms, add this assembly file in ARM's common
folder.

Signed-off-by: Mylène Josserand <mylene.josserand@bootlin.com>
---
arch/arm/common/Makefile | 1 +
arch/arm/common/smp_cntvoff.S | 35 +++++++++++++++++++++++++++++++++++
arch/arm/include/asm/smp_cntvoff.h | 8 ++++++++
3 files changed, 44 insertions(+)
create mode 100644 arch/arm/common/smp_cntvoff.S
create mode 100644 arch/arm/include/asm/smp_cntvoff.h

diff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile
index 70b4a14ed993..83117deb86c8 100644
--- a/arch/arm/common/Makefile
+++ b/arch/arm/common/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_DMABOUNCE) += dmabounce.o
obj-$(CONFIG_SHARP_LOCOMO) += locomo.o
obj-$(CONFIG_SHARP_PARAM) += sharpsl_param.o
obj-$(CONFIG_SHARP_SCOOP) += scoop.o
+obj-$(CONFIG_SMP) += smp_cntvoff.o
obj-$(CONFIG_PCI_HOST_ITE8152) += it8152.o
obj-$(CONFIG_MCPM) += mcpm_head.o mcpm_entry.o mcpm_platsmp.o vlock.o
CFLAGS_REMOVE_mcpm_entry.o = -pg
diff --git a/arch/arm/common/smp_cntvoff.S b/arch/arm/common/smp_cntvoff.S
new file mode 100644
index 000000000000..65ed199a50fe
--- /dev/null
+++ b/arch/arm/common/smp_cntvoff.S
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018 Chen-Yu Tsai
+ * Copyright (c) 2018 Bootlin
+ *
+ * Chen-Yu Tsai <wens@csie.org>
+ * Mylène Josserand <mylene.josserand@bootlin.com>
+ *
+ * SMP support for sunxi based systems with Cortex A7/A15
+ *
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+
+ENTRY(smp_init_cntvoff)
+ .arch armv7-a
+ /*
+ * CNTVOFF has to be initialized either from non-secure Hypervisor
+ * mode or secure Monitor mode with SCR.NS==1. If TrustZone is enabled
+ * then it should be handled by the secure code
+ */
+ cps #MON_MODE
+ mrc p15, 0, r1, c1, c1, 0 /* Get Secure Config */
+ orr r0, r1, #1
+ mcr p15, 0, r0, c1, c1, 0 /* Set Non Secure bit */
+ isb
+ mov r0, #0
+ mcrr p15, 4, r0, r0, c14 /* CNTVOFF = 0 */
+ isb
+ mcr p15, 0, r1, c1, c1, 0 /* Set Secure bit */
+ isb
+ cps #SVC_MODE
+ ret lr
+ENDPROC(smp_init_cntvoff)
diff --git a/arch/arm/include/asm/smp_cntvoff.h b/arch/arm/include/asm/smp_cntvoff.h
new file mode 100644
index 000000000000..59a95f7604ee
--- /dev/null
+++ b/arch/arm/include/asm/smp_cntvoff.h
@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#ifndef __ASMARM_ARCH_CNTVOFF_H
+#define __ASMARM_ARCH_CNTVOFF_H
+
+extern void smp_init_cntvoff(void);
+
+#endif
--
2.11.0
\
 
 \ /
  Last update: 2018-04-03 08:23    [W:0.939 / U:0.164 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site