v4.19.13 snapshot.
diff --git a/arch/arm/plat-versatile/Kconfig b/arch/arm/plat-versatile/Kconfig
new file mode 100644
index 0000000..98b9b8e
--- /dev/null
+++ b/arch/arm/plat-versatile/Kconfig
@@ -0,0 +1,6 @@
+if PLAT_VERSATILE
+
+config PLAT_VERSATILE_SCHED_CLOCK
+ bool
+
+endif
diff --git a/arch/arm/plat-versatile/Makefile b/arch/arm/plat-versatile/Makefile
new file mode 100644
index 0000000..bff3ba8
--- /dev/null
+++ b/arch/arm/plat-versatile/Makefile
@@ -0,0 +1,4 @@
+ccflags-$(CONFIG_ARCH_MULTIPLATFORM) := -I$(srctree)/$(src)/include
+
+obj-$(CONFIG_PLAT_VERSATILE_SCHED_CLOCK) += sched-clock.o
+obj-$(CONFIG_SMP) += headsmp.o platsmp.o
diff --git a/arch/arm/plat-versatile/headsmp.S b/arch/arm/plat-versatile/headsmp.S
new file mode 100644
index 0000000..40f27e5
--- /dev/null
+++ b/arch/arm/plat-versatile/headsmp.S
@@ -0,0 +1,41 @@
+/*
+ * linux/arch/arm/plat-versatile/headsmp.S
+ *
+ * Copyright (c) 2003 ARM Limited
+ * All Rights Reserved
+ *
+ * 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/linkage.h>
+#include <linux/init.h>
+#include <asm/assembler.h>
+
+/*
+ * Realview/Versatile Express specific entry point for secondary CPUs.
+ * This provides a "holding pen" into which all secondary cores are held
+ * until we're ready for them to initialise.
+ */
+ENTRY(versatile_secondary_startup)
+ ARM_BE8(setend be)
+ mrc p15, 0, r0, c0, c0, 5
+ bic r0, #0xff000000
+ adr r4, 1f
+ ldmia r4, {r5, r6}
+ sub r4, r4, r5
+ add r6, r6, r4
+pen: ldr r7, [r6]
+ cmp r7, r0
+ bne pen
+
+ /*
+ * we've been released from the holding pen: secondary_stack
+ * should now contain the SVC stack for this core
+ */
+ b secondary_startup
+
+ .align
+1: .long .
+ .long pen_release
+ENDPROC(versatile_secondary_startup)
diff --git a/arch/arm/plat-versatile/include/plat/platsmp.h b/arch/arm/plat-versatile/include/plat/platsmp.h
new file mode 100644
index 0000000..50fb830
--- /dev/null
+++ b/arch/arm/plat-versatile/include/plat/platsmp.h
@@ -0,0 +1,14 @@
+/*
+ * linux/arch/arm/plat-versatile/include/plat/platsmp.h
+ *
+ * Copyright (C) 2011 ARM Ltd.
+ * All Rights Reserved
+ *
+ * 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.
+ */
+
+extern void versatile_secondary_startup(void);
+extern void versatile_secondary_init(unsigned int cpu);
+extern int versatile_boot_secondary(unsigned int cpu, struct task_struct *idle);
diff --git a/arch/arm/plat-versatile/include/plat/sched_clock.h b/arch/arm/plat-versatile/include/plat/sched_clock.h
new file mode 100644
index 0000000..83fdaef
--- /dev/null
+++ b/arch/arm/plat-versatile/include/plat/sched_clock.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef ARM_PLAT_SCHED_CLOCK_H
+#define ARM_PLAT_SCHED_CLOCK_H
+
+void versatile_sched_clock_init(void __iomem *, unsigned long);
+
+#endif
diff --git a/arch/arm/plat-versatile/platsmp.c b/arch/arm/plat-versatile/platsmp.c
new file mode 100644
index 0000000..c236651
--- /dev/null
+++ b/arch/arm/plat-versatile/platsmp.c
@@ -0,0 +1,93 @@
+/*
+ * linux/arch/arm/plat-versatile/platsmp.c
+ *
+ * Copyright (C) 2002 ARM Ltd.
+ * All Rights Reserved
+ *
+ * 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/jiffies.h>
+#include <linux/smp.h>
+
+#include <asm/cacheflush.h>
+#include <asm/smp_plat.h>
+
+#include <plat/platsmp.h>
+
+/*
+ * Write pen_release in a way that is guaranteed to be visible to all
+ * observers, irrespective of whether they're taking part in coherency
+ * or not. This is necessary for the hotplug code to work reliably.
+ */
+static void write_pen_release(int val)
+{
+ pen_release = val;
+ smp_wmb();
+ sync_cache_w(&pen_release);
+}
+
+static DEFINE_SPINLOCK(boot_lock);
+
+void versatile_secondary_init(unsigned int cpu)
+{
+ /*
+ * let the primary processor know we're out of the
+ * pen, then head off into the C entry point
+ */
+ write_pen_release(-1);
+
+ /*
+ * Synchronise with the boot thread.
+ */
+ spin_lock(&boot_lock);
+ spin_unlock(&boot_lock);
+}
+
+int versatile_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+ unsigned long timeout;
+
+ /*
+ * Set synchronisation state between this boot processor
+ * and the secondary one
+ */
+ spin_lock(&boot_lock);
+
+ /*
+ * This is really belt and braces; we hold unintended secondary
+ * CPUs in the holding pen until we're ready for them. However,
+ * since we haven't sent them a soft interrupt, they shouldn't
+ * be there.
+ */
+ write_pen_release(cpu_logical_map(cpu));
+
+ /*
+ * Send the secondary CPU a soft interrupt, thereby causing
+ * the boot monitor to read the system wide flags register,
+ * and branch to the address found there.
+ */
+ arch_send_wakeup_ipi_mask(cpumask_of(cpu));
+
+ timeout = jiffies + (1 * HZ);
+ while (time_before(jiffies, timeout)) {
+ smp_rmb();
+ if (pen_release == -1)
+ break;
+
+ udelay(10);
+ }
+
+ /*
+ * now the secondary core is starting up let it run its
+ * calibrations, then wait for it to finish
+ */
+ spin_unlock(&boot_lock);
+
+ return pen_release != -1 ? -ENOSYS : 0;
+}
diff --git a/arch/arm/plat-versatile/sched-clock.c b/arch/arm/plat-versatile/sched-clock.c
new file mode 100644
index 0000000..c966ae9
--- /dev/null
+++ b/arch/arm/plat-versatile/sched-clock.c
@@ -0,0 +1,41 @@
+/*
+ * linux/arch/arm/plat-versatile/sched-clock.c
+ *
+ * Copyright (C) 1999 - 2003 ARM Limited
+ * Copyright (C) 2000 Deep Blue Solutions Ltd
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#include <linux/kernel.h>
+#include <linux/io.h>
+#include <linux/sched_clock.h>
+
+#include <plat/sched_clock.h>
+
+static void __iomem *ctr;
+
+static u64 notrace versatile_read_sched_clock(void)
+{
+ if (ctr)
+ return readl(ctr);
+
+ return 0;
+}
+
+void __init versatile_sched_clock_init(void __iomem *reg, unsigned long rate)
+{
+ ctr = reg;
+ sched_clock_register(versatile_read_sched_clock, 32, rate);
+}