Move the timer difference convenience function from acpi_cpu.c to make it

globally available.  acpi_TimerDelta() subtracts two readings from the
ACPI PM timer and returns the difference.  It properly distinguishes between
24-bit and 32-bit timers and handles wraparound.

3 files changed, 17 insertions, 14 deletions

diff --git a/sys/dev/acpica/acpi.c b/sys/dev/acpica/acpi.c
index 2469456..1275129 100644
--- a/sys/dev/acpica/acpi.c
+++ b/sys/dev/acpica/acpi.c
@@ -1372,6 +1372,21 @@ acpi_GetHandleInScope(ACPI_HANDLE parent, char *path, ACPI_HANDLE *result)
     }
 }
 
+/* Find the difference between two PM tick counts. */
+uint32_t
+acpi_TimerDelta(uint32_t end, uint32_t start)
+{
+    uint32_t delta;
+
+    if (end >= start)
+	delta = end - start;
+    else if (AcpiGbl_FADT->TmrValExt == 0)
+	delta = (((0x00FFFFFF - start) + end + 1) & 0x00FFFFFF);
+    else
+	delta = ((0xFFFFFFFF - start) + end + 1);
+    return (delta);
+}
+
 /*
  * Allocate a buffer with a preset data size.
  */
diff --git a/sys/dev/acpica/acpi_cpu.c b/sys/dev/acpica/acpi_cpu.c
index 76b7ad4..f5c2f8a 100644
--- a/sys/dev/acpica/acpi_cpu.c
+++ b/sys/dev/acpica/acpi_cpu.c
@@ -160,7 +160,6 @@ static void	acpi_cpu_startup_cx(void);
 static void	acpi_cpu_throttle_set(uint32_t speed);
 static void	acpi_cpu_idle(void);
 static void	acpi_cpu_c1(void);
-static void	acpi_pm_ticksub(uint32_t *end, const uint32_t *start);
 static void	acpi_cpu_notify(ACPI_HANDLE h, UINT32 notify, void *context);
 static int	acpi_cpu_quirks(struct acpi_cpu_softc *sc);
 static int	acpi_cpu_throttle_sysctl(SYSCTL_HANDLER_ARGS);
@@ -875,7 +874,7 @@ acpi_cpu_idle()
     }
 
     /* Find the actual time asleep in microseconds, minus overhead. */
-    acpi_pm_ticksub(&end_time, &start_time);
+    end_time = acpi_TimerDelta(end_time, start_time);
     asleep = PM_USEC(end_time) - cx_next->trans_lat;
 
     /* Record statistics */
@@ -915,18 +914,6 @@ acpi_cpu_c1()
 #endif
 }
 
-/* Find the difference between two PM tick counts. */
-static void
-acpi_pm_ticksub(uint32_t *end, const uint32_t *start)
-{
-    if (*end >= *start)
-	*end = *end - *start;
-    else if (AcpiGbl_FADT->TmrValExt == 0)
-	*end = (((0x00FFFFFF - *start) + *end + 1) & 0x00FFFFFF);
-    else
-	*end = ((0xFFFFFFFF - *start) + *end + 1);
-}
-
 /*
  * Re-evaluate the _PSS and _CST objects when we are notified that they
  * have changed.
diff --git a/sys/dev/acpica/acpivar.h b/sys/dev/acpica/acpivar.h
index 10fa91a..99b6ac7 100644
--- a/sys/dev/acpica/acpivar.h
+++ b/sys/dev/acpica/acpivar.h
@@ -233,6 +233,7 @@ extern BOOLEAN		acpi_BatteryIsPresent(device_t dev);
 extern BOOLEAN		acpi_MatchHid(device_t dev, char *hid);
 extern ACPI_STATUS	acpi_GetHandleInScope(ACPI_HANDLE parent, char *path,
 					      ACPI_HANDLE *result);
+extern uint32_t		acpi_TimerDelta(uint32_t end, uint32_t start);
 extern ACPI_BUFFER	*acpi_AllocBuffer(int size);
 extern ACPI_STATUS	acpi_ConvertBufferToInteger(ACPI_BUFFER *bufp,
 						    UINT32 *number);