v4.19.13 snapshot.
diff --git a/include/clocksource/arm_arch_timer.h b/include/clocksource/arm_arch_timer.h
new file mode 100644
index 0000000..349e595
--- /dev/null
+++ b/include/clocksource/arm_arch_timer.h
@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * 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.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef __CLKSOURCE_ARM_ARCH_TIMER_H
+#define __CLKSOURCE_ARM_ARCH_TIMER_H
+
+#include <linux/bitops.h>
+#include <linux/timecounter.h>
+#include <linux/types.h>
+
+#define ARCH_TIMER_TYPE_CP15		BIT(0)
+#define ARCH_TIMER_TYPE_MEM		BIT(1)
+
+#define ARCH_TIMER_CTRL_ENABLE		(1 << 0)
+#define ARCH_TIMER_CTRL_IT_MASK		(1 << 1)
+#define ARCH_TIMER_CTRL_IT_STAT		(1 << 2)
+
+#define CNTHCTL_EL1PCTEN		(1 << 0)
+#define CNTHCTL_EL1PCEN			(1 << 1)
+#define CNTHCTL_EVNTEN			(1 << 2)
+#define CNTHCTL_EVNTDIR			(1 << 3)
+#define CNTHCTL_EVNTI			(0xF << 4)
+
+enum arch_timer_reg {
+	ARCH_TIMER_REG_CTRL,
+	ARCH_TIMER_REG_TVAL,
+};
+
+enum arch_timer_ppi_nr {
+	ARCH_TIMER_PHYS_SECURE_PPI,
+	ARCH_TIMER_PHYS_NONSECURE_PPI,
+	ARCH_TIMER_VIRT_PPI,
+	ARCH_TIMER_HYP_PPI,
+	ARCH_TIMER_MAX_TIMER_PPI
+};
+
+enum arch_timer_spi_nr {
+	ARCH_TIMER_PHYS_SPI,
+	ARCH_TIMER_VIRT_SPI,
+	ARCH_TIMER_MAX_TIMER_SPI
+};
+
+#define ARCH_TIMER_PHYS_ACCESS		0
+#define ARCH_TIMER_VIRT_ACCESS		1
+#define ARCH_TIMER_MEM_PHYS_ACCESS	2
+#define ARCH_TIMER_MEM_VIRT_ACCESS	3
+
+#define ARCH_TIMER_MEM_MAX_FRAMES	8
+
+#define ARCH_TIMER_USR_PCT_ACCESS_EN	(1 << 0) /* physical counter */
+#define ARCH_TIMER_USR_VCT_ACCESS_EN	(1 << 1) /* virtual counter */
+#define ARCH_TIMER_VIRT_EVT_EN		(1 << 2)
+#define ARCH_TIMER_EVT_TRIGGER_SHIFT	(4)
+#define ARCH_TIMER_EVT_TRIGGER_MASK	(0xF << ARCH_TIMER_EVT_TRIGGER_SHIFT)
+#define ARCH_TIMER_USR_VT_ACCESS_EN	(1 << 8) /* virtual timer registers */
+#define ARCH_TIMER_USR_PT_ACCESS_EN	(1 << 9) /* physical timer registers */
+
+#define ARCH_TIMER_EVT_STREAM_PERIOD_US	100
+#define ARCH_TIMER_EVT_STREAM_FREQ				\
+	(USEC_PER_SEC / ARCH_TIMER_EVT_STREAM_PERIOD_US)
+
+struct arch_timer_kvm_info {
+	struct timecounter timecounter;
+	int virtual_irq;
+};
+
+struct arch_timer_mem_frame {
+	bool valid;
+	phys_addr_t cntbase;
+	size_t size;
+	int phys_irq;
+	int virt_irq;
+};
+
+struct arch_timer_mem {
+	phys_addr_t cntctlbase;
+	size_t size;
+	struct arch_timer_mem_frame frame[ARCH_TIMER_MEM_MAX_FRAMES];
+};
+
+#ifdef CONFIG_ARM_ARCH_TIMER
+
+extern u32 arch_timer_get_rate(void);
+extern u64 (*arch_timer_read_counter)(void);
+extern struct arch_timer_kvm_info *arch_timer_get_kvm_info(void);
+extern bool arch_timer_evtstrm_available(void);
+
+#else
+
+static inline u32 arch_timer_get_rate(void)
+{
+	return 0;
+}
+
+static inline u64 arch_timer_read_counter(void)
+{
+	return 0;
+}
+
+static inline bool arch_timer_evtstrm_available(void)
+{
+	return false;
+}
+
+#endif
+
+#endif