Used to bring up the second core on MMP3.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
---
 arch/arm/mach-mmp/Makefile  |  3 +++
 arch/arm/mach-mmp/platsmp.c | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+)
 create mode 100644 arch/arm/mach-mmp/platsmp.c

diff --git a/arch/arm/mach-mmp/Makefile b/arch/arm/mach-mmp/Makefile
index 322c1c97dc900..7b3a7f979eece 100644
--- a/arch/arm/mach-mmp/Makefile
+++ b/arch/arm/mach-mmp/Makefile

@@ -22,6 +22,9 @@ ifeq ($(CONFIG_PM),y)
 obj-$(CONFIG_CPU_PXA910)	+= pm-pxa910.o
 obj-$(CONFIG_CPU_MMP2)		+= pm-mmp2.o
 endif
+ifeq ($(CONFIG_SMP),y)
+obj-$(CONFIG_MACH_MMP3_DT)	+= platsmp.o
+endif
 
 # board support
 obj-$(CONFIG_MACH_ASPENITE)	+= aspenite.o

diff --git a/arch/arm/mach-mmp/platsmp.c b/arch/arm/mach-mmp/platsmp.c
new file mode 100644
index 0000000000000..255df640b5bc1
--- /dev/null
+++ b/arch/arm/mach-mmp/platsmp.c

@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2019 Lubomir Rintel <lkundrak@v3.sk>
+ */
+#include <linux/io.h>
+#include <asm/smp_scu.h>
+#include <asm/smp.h>
+#include "addr-map.h"
+
+#define SW_BRANCH_VIRT_ADDR	CIU_REG(0x24)
+
+static int mmp3_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+	/*
+	 * Apparently, the boot ROM on the second core spins on this
+	 * register becoming non-zero and then jumps to the address written
+	 * there. No IPIs involved.
+	 */
+	__raw_writel(virt_to_phys(secondary_startup), SW_BRANCH_VIRT_ADDR);