1 files changed, 41 insertions, 6 deletions

diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c
index 1961e3539b57..b4330a01a566 100644
--- a/drivers/clocksource/acpi_pm.c
+++ b/drivers/clocksource/acpi_pm.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * linux/drivers/clocksource/acpi_pm.c
  *
@@ -12,8 +13,6 @@
  *
  * Based on parts of linux/drivers/acpi/hardware/hwtimer.c, timer_pit.c,
  * timer_hpet.c, and on Arjan van de Ven's implementation for 2.4.
- *
- * This file is licensed under the GPL v2.
  */
 
 #include <linux/acpi_pmtmr.h>
@@ -24,6 +23,11 @@
 #include <linux/pci.h>
 #include <linux/delay.h>
 #include <asm/io.h>
+#include <asm/time.h>
+
+static void *suspend_resume_cb_data;
+
+static void (*suspend_resume_callback)(void *data, bool suspend);
 
 /*
  * The I/O port the PMTMR resides at.
@@ -58,6 +62,32 @@ u32 acpi_pm_read_verified(void)
 	return v2;
 }
 
+void acpi_pmtmr_register_suspend_resume_callback(void (*cb)(void *data, bool suspend), void *data)
+{
+	suspend_resume_callback = cb;
+	suspend_resume_cb_data = data;
+}
+EXPORT_SYMBOL_GPL(acpi_pmtmr_register_suspend_resume_callback);
+
+void acpi_pmtmr_unregister_suspend_resume_callback(void)
+{
+	suspend_resume_callback = NULL;
+	suspend_resume_cb_data = NULL;
+}
+EXPORT_SYMBOL_GPL(acpi_pmtmr_unregister_suspend_resume_callback);
+
+static void acpi_pm_suspend(struct clocksource *cs)
+{
+	if (suspend_resume_callback)
+		suspend_resume_callback(suspend_resume_cb_data, true);
+}
+
+static void acpi_pm_resume(struct clocksource *cs)
+{
+	if (suspend_resume_callback)
+		suspend_resume_callback(suspend_resume_cb_data, false);
+}
+
 static u64 acpi_pm_read(struct clocksource *cs)
 {
 	return (u64)read_pmtmr();
@@ -69,6 +99,8 @@ static struct clocksource clocksource_acpi_pm = {
 	.read		= acpi_pm_read,
 	.mask		= (u64)ACPI_PM_MASK,
 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
+	.suspend	= acpi_pm_suspend,
+	.resume		= acpi_pm_resume,
 };
 
 
@@ -211,8 +243,9 @@ static int __init init_acpi_pm_clocksource(void)
 		return -ENODEV;
 	}
 
-	return clocksource_register_hz(&clocksource_acpi_pm,
-						PMTMR_TICKS_PER_SEC);
+	if (tsc_clocksource_watchdog_disabled())
+		clocksource_acpi_pm.flags |= CLOCK_SOURCE_MUST_VERIFY;
+	return clocksource_register_hz(&clocksource_acpi_pm, PMTMR_TICKS_PER_SEC);
 }
 
 /* We use fs_initcall because we want the PCI fixups to have run
@@ -230,8 +263,10 @@ static int __init parse_pmtmr(char *arg)
 	int ret;
 
 	ret = kstrtouint(arg, 16, &base);
-	if (ret)
-		return ret;
+	if (ret) {
+		pr_warn("PMTMR: invalid 'pmtmr=' value: '%s'\n", arg);
+		return 1;
+	}
 
 	pr_info("PMTMR IOPort override: 0x%04x -> 0x%04x\n", pmtmr_ioport,
 		base);