v4.19.13 snapshot.
diff --git a/arch/arm/mach-ux500/platsmp.c b/arch/arm/mach-ux500/platsmp.c
new file mode 100644
index 0000000..69c2361
--- /dev/null
+++ b/arch/arm/mach-ux500/platsmp.c
@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2002 ARM Ltd.
+ * Copyright (C) 2008 STMicroelctronics.
+ * Copyright (C) 2009 ST-Ericsson.
+ * Author: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
+ *
+ * This file is based on arm realview platform
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/delay.h>
+#include <linux/device.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_plat.h>
+#include <asm/smp_scu.h>
+
+#include "db8500-regs.h"
+
+/* Magic triggers in backup RAM */
+#define UX500_CPU1_JUMPADDR_OFFSET 0x1FF4
+#define UX500_CPU1_WAKEMAGIC_OFFSET 0x1FF0
+
+static void __iomem *backupram;
+
+static void __init ux500_smp_prepare_cpus(unsigned int max_cpus)
+{
+ struct device_node *np;
+ static void __iomem *scu_base;
+ unsigned int ncores;
+ int i;
+
+ np = of_find_compatible_node(NULL, NULL, "ste,dbx500-backupram");
+ if (!np) {
+ pr_err("No backupram base address\n");
+ return;
+ }
+ backupram = of_iomap(np, 0);
+ of_node_put(np);
+ if (!backupram) {
+ pr_err("No backupram remap\n");
+ return;
+ }
+
+ np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
+ if (!np) {
+ pr_err("No SCU base address\n");
+ return;
+ }
+ scu_base = of_iomap(np, 0);
+ of_node_put(np);
+ if (!scu_base) {
+ pr_err("No SCU remap\n");
+ return;
+ }
+
+ scu_enable(scu_base);
+ ncores = scu_get_core_count(scu_base);
+ for (i = 0; i < ncores; i++)
+ set_cpu_possible(i, true);
+ iounmap(scu_base);
+}
+
+static int ux500_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+ /*
+ * write the address of secondary startup into the backup ram register
+ * at offset 0x1FF4, then write the magic number 0xA1FEED01 to the
+ * backup ram register at offset 0x1FF0, which is what boot rom code
+ * is waiting for. This will wake up the secondary core from WFE.
+ */
+ writel(__pa_symbol(secondary_startup),
+ backupram + UX500_CPU1_JUMPADDR_OFFSET);
+ writel(0xA1FEED01,
+ backupram + UX500_CPU1_WAKEMAGIC_OFFSET);
+
+ /* make sure write buffer is drained */
+ mb();
+ arch_send_wakeup_ipi_mask(cpumask_of(cpu));
+ return 0;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+void ux500_cpu_die(unsigned int cpu)
+{
+ wfi();
+}
+#endif
+
+static const struct smp_operations ux500_smp_ops __initconst = {
+ .smp_prepare_cpus = ux500_smp_prepare_cpus,
+ .smp_boot_secondary = ux500_boot_secondary,
+#ifdef CONFIG_HOTPLUG_CPU
+ .cpu_die = ux500_cpu_die,
+#endif
+};
+CPU_METHOD_OF_DECLARE(ux500_smp, "ste,dbx500-smp", &ux500_smp_ops);