v4.19.13 snapshot.
diff --git a/drivers/acpi/acpica/hwtimer.c b/drivers/acpi/acpica/hwtimer.c
new file mode 100644
index 0000000..5d5e271
--- /dev/null
+++ b/drivers/acpi/acpica/hwtimer.c
@@ -0,0 +1,175 @@
+// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
+/******************************************************************************
+ *
+ * Name: hwtimer.c - ACPI Power Management Timer Interface
+ *
+ * Copyright (C) 2000 - 2018, Intel Corp.
+ *
+ *****************************************************************************/
+
+#define EXPORT_ACPI_INTERFACES
+
+#include <acpi/acpi.h>
+#include "accommon.h"
+
+#define _COMPONENT ACPI_HARDWARE
+ACPI_MODULE_NAME("hwtimer")
+
+#if (!ACPI_REDUCED_HARDWARE) /* Entire module */
+/******************************************************************************
+ *
+ * FUNCTION: acpi_get_timer_resolution
+ *
+ * PARAMETERS: resolution - Where the resolution is returned
+ *
+ * RETURN: Status and timer resolution
+ *
+ * DESCRIPTION: Obtains resolution of the ACPI PM Timer (24 or 32 bits).
+ *
+ ******************************************************************************/
+acpi_status acpi_get_timer_resolution(u32 * resolution)
+{
+ ACPI_FUNCTION_TRACE(acpi_get_timer_resolution);
+
+ if (!resolution) {
+ return_ACPI_STATUS(AE_BAD_PARAMETER);
+ }
+
+ if ((acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER) == 0) {
+ *resolution = 24;
+ } else {
+ *resolution = 32;
+ }
+
+ return_ACPI_STATUS(AE_OK);
+}
+
+ACPI_EXPORT_SYMBOL(acpi_get_timer_resolution)
+
+/******************************************************************************
+ *
+ * FUNCTION: acpi_get_timer
+ *
+ * PARAMETERS: ticks - Where the timer value is returned
+ *
+ * RETURN: Status and current timer value (ticks)
+ *
+ * DESCRIPTION: Obtains current value of ACPI PM Timer (in ticks).
+ *
+ ******************************************************************************/
+acpi_status acpi_get_timer(u32 * ticks)
+{
+ acpi_status status;
+ u64 timer_value;
+
+ ACPI_FUNCTION_TRACE(acpi_get_timer);
+
+ if (!ticks) {
+ return_ACPI_STATUS(AE_BAD_PARAMETER);
+ }
+
+ /* ACPI 5.0A: PM Timer is optional */
+
+ if (!acpi_gbl_FADT.xpm_timer_block.address) {
+ return_ACPI_STATUS(AE_SUPPORT);
+ }
+
+ status = acpi_hw_read(&timer_value, &acpi_gbl_FADT.xpm_timer_block);
+ if (ACPI_SUCCESS(status)) {
+
+ /* ACPI PM Timer is defined to be 32 bits (PM_TMR_LEN) */
+
+ *ticks = (u32)timer_value;
+ }
+
+ return_ACPI_STATUS(status);
+}
+
+ACPI_EXPORT_SYMBOL(acpi_get_timer)
+
+/******************************************************************************
+ *
+ * FUNCTION: acpi_get_timer_duration
+ *
+ * PARAMETERS: start_ticks - Starting timestamp
+ * end_ticks - End timestamp
+ * time_elapsed - Where the elapsed time is returned
+ *
+ * RETURN: Status and time_elapsed
+ *
+ * DESCRIPTION: Computes the time elapsed (in microseconds) between two
+ * PM Timer time stamps, taking into account the possibility of
+ * rollovers, the timer resolution, and timer frequency.
+ *
+ * The PM Timer's clock ticks at roughly 3.6 times per
+ * _microsecond_, and its clock continues through Cx state
+ * transitions (unlike many CPU timestamp counters) -- making it
+ * a versatile and accurate timer.
+ *
+ * Note that this function accommodates only a single timer
+ * rollover. Thus for 24-bit timers, this function should only
+ * be used for calculating durations less than ~4.6 seconds
+ * (~20 minutes for 32-bit timers) -- calculations below:
+ *
+ * 2**24 Ticks / 3,600,000 Ticks/Sec = 4.66 sec
+ * 2**32 Ticks / 3,600,000 Ticks/Sec = 1193 sec or 19.88 minutes
+ *
+ ******************************************************************************/
+acpi_status
+acpi_get_timer_duration(u32 start_ticks, u32 end_ticks, u32 *time_elapsed)
+{
+ acpi_status status;
+ u64 delta_ticks;
+ u64 quotient;
+
+ ACPI_FUNCTION_TRACE(acpi_get_timer_duration);
+
+ if (!time_elapsed) {
+ return_ACPI_STATUS(AE_BAD_PARAMETER);
+ }
+
+ /* ACPI 5.0A: PM Timer is optional */
+
+ if (!acpi_gbl_FADT.xpm_timer_block.address) {
+ return_ACPI_STATUS(AE_SUPPORT);
+ }
+
+ if (start_ticks == end_ticks) {
+ *time_elapsed = 0;
+ return_ACPI_STATUS(AE_OK);
+ }
+
+ /*
+ * Compute Tick Delta:
+ * Handle (max one) timer rollovers on 24-bit versus 32-bit timers.
+ */
+ delta_ticks = end_ticks;
+ if (start_ticks > end_ticks) {
+ if ((acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER) == 0) {
+
+ /* 24-bit Timer */
+
+ delta_ticks |= (u64)1 << 24;
+ } else {
+ /* 32-bit Timer */
+
+ delta_ticks |= (u64)1 << 32;
+ }
+ }
+ delta_ticks -= start_ticks;
+
+ /*
+ * Compute Duration (Requires a 64-bit multiply and divide):
+ *
+ * time_elapsed (microseconds) =
+ * (delta_ticks * ACPI_USEC_PER_SEC) / ACPI_PM_TIMER_FREQUENCY;
+ */
+ status = acpi_ut_short_divide(delta_ticks * ACPI_USEC_PER_SEC,
+ ACPI_PM_TIMER_FREQUENCY, "ient, NULL);
+
+ *time_elapsed = (u32)quotient;
+ return_ACPI_STATUS(status);
+}
+
+ACPI_EXPORT_SYMBOL(acpi_get_timer_duration)
+#endif /* !ACPI_REDUCED_HARDWARE */