1 files changed, 25 insertions, 0 deletions

diff --git a/arch/x86_64/kernel/pmtimer.c b/arch/x86_64/kernel/pmtimer.c
index feb5f108dd26..5c51d10408a6 100644
--- a/arch/x86_64/kernel/pmtimer.c
+++ b/arch/x86_64/kernel/pmtimer.c
@@ -80,6 +80,31 @@ int pmtimer_mark_offset(void)
         return lost - 1;
 }
 
+static unsigned pmtimer_wait_tick(void)
+{
+        u32 a, b;
+        for (a = b = inl(pmtmr_ioport) & ACPI_PM_MASK;
+             a == b;
+             b = inl(pmtmr_ioport) & ACPI_PM_MASK)
+                ;
+        return b;
+}
+
+/* note: wait time is rounded up to one tick */
+void pmtimer_wait(unsigned us)
+{
+        u32 a, b;
+        a = pmtimer_wait_tick();
+        do {
+                b = inl(pmtmr_ioport);
+        } while (cyc2us(b - a) < us);
+}
+
+void pmtimer_resume(void)
+{
+        last_pmtmr_tick = inl(pmtmr_ioport);
+}
+
 unsigned int do_gettimeoffset_pm(void)
 {
         u32 now, offset, delta = 0;