v4.19.13 snapshot.
diff --git a/arch/arm/mach-socfpga/platsmp.c b/arch/arm/mach-socfpga/platsmp.c
new file mode 100644
index 0000000..0ee7677
--- /dev/null
+++ b/arch/arm/mach-socfpga/platsmp.c
@@ -0,0 +1,141 @@
+/*
+ * Copyright 2010-2011 Calxeda, Inc.
+ * Copyright 2012 Pavel Machek <pavel@denx.de>
+ * Based on platsmp.c, Copyright (C) 2002 ARM Ltd.
+ * Copyright (C) 2012 Altera Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+#include <asm/cacheflush.h>
+#include <asm/smp_scu.h>
+#include <asm/smp_plat.h>
+
+#include "core.h"
+
+static int socfpga_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+	int trampoline_size = &secondary_trampoline_end - &secondary_trampoline;
+
+	if (socfpga_cpu1start_addr) {
+		/* This will put CPU #1 into reset. */
+		writel(RSTMGR_MPUMODRST_CPU1,
+		       rst_manager_base_addr + SOCFPGA_RSTMGR_MODMPURST);
+
+		memcpy(phys_to_virt(0), &secondary_trampoline, trampoline_size);
+
+		writel(__pa_symbol(secondary_startup),
+		       sys_manager_base_addr + (socfpga_cpu1start_addr & 0x000000ff));
+
+		flush_cache_all();
+		smp_wmb();
+		outer_clean_range(0, trampoline_size);
+
+		/* This will release CPU #1 out of reset. */
+		writel(0, rst_manager_base_addr + SOCFPGA_RSTMGR_MODMPURST);
+	}
+
+	return 0;
+}
+
+static int socfpga_a10_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+	int trampoline_size = &secondary_trampoline_end - &secondary_trampoline;
+
+	if (socfpga_cpu1start_addr) {
+		writel(RSTMGR_MPUMODRST_CPU1, rst_manager_base_addr +
+		       SOCFPGA_A10_RSTMGR_MODMPURST);
+		memcpy(phys_to_virt(0), &secondary_trampoline, trampoline_size);
+
+		writel(__pa_symbol(secondary_startup),
+		       sys_manager_base_addr + (socfpga_cpu1start_addr & 0x00000fff));
+
+		flush_cache_all();
+		smp_wmb();
+		outer_clean_range(0, trampoline_size);
+
+		/* This will release CPU #1 out of reset. */
+		writel(0, rst_manager_base_addr + SOCFPGA_A10_RSTMGR_MODMPURST);
+	}
+
+	return 0;
+}
+
+static void __init socfpga_smp_prepare_cpus(unsigned int max_cpus)
+{
+	struct device_node *np;
+	void __iomem *socfpga_scu_base_addr;
+
+	np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
+	if (!np) {
+		pr_err("%s: missing scu\n", __func__);
+		return;
+	}
+
+	socfpga_scu_base_addr = of_iomap(np, 0);
+	if (!socfpga_scu_base_addr)
+		return;
+	scu_enable(socfpga_scu_base_addr);
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+/*
+ * platform-specific code to shutdown a CPU
+ *
+ * Called with IRQs disabled
+ */
+static void socfpga_cpu_die(unsigned int cpu)
+{
+	/* Do WFI. If we wake up early, go back into WFI */
+	while (1)
+		cpu_do_idle();
+}
+
+/*
+ * We need a dummy function so that platform_can_cpu_hotplug() knows
+ * we support CPU hotplug. However, the function does not need to do
+ * anything, because CPUs going offline just do WFI. We could reset
+ * the CPUs but it would increase power consumption.
+ */
+static int socfpga_cpu_kill(unsigned int cpu)
+{
+	return 1;
+}
+#endif
+
+static const struct smp_operations socfpga_smp_ops __initconst = {
+	.smp_prepare_cpus	= socfpga_smp_prepare_cpus,
+	.smp_boot_secondary	= socfpga_boot_secondary,
+#ifdef CONFIG_HOTPLUG_CPU
+	.cpu_die		= socfpga_cpu_die,
+	.cpu_kill		= socfpga_cpu_kill,
+#endif
+};
+
+static const struct smp_operations socfpga_a10_smp_ops __initconst = {
+	.smp_prepare_cpus	= socfpga_smp_prepare_cpus,
+	.smp_boot_secondary	= socfpga_a10_boot_secondary,
+#ifdef CONFIG_HOTPLUG_CPU
+	.cpu_die		= socfpga_cpu_die,
+	.cpu_kill		= socfpga_cpu_kill,
+#endif
+};
+
+CPU_METHOD_OF_DECLARE(socfpga_smp, "altr,socfpga-smp", &socfpga_smp_ops);
+CPU_METHOD_OF_DECLARE(socfpga_a10_smp, "altr,socfpga-a10-smp", &socfpga_a10_smp_ops);