1 files changed, 27 insertions, 36 deletions

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 397f2a7fee48..4e6e758bd397 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -64,7 +64,6 @@
 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
 ACPI_MODULE_NAME("processor_idle");
 #define ACPI_PROCESSOR_FILE_POWER       "power"
-#define US_TO_PM_TIMER_TICKS(t)         ((t * (PM_TIMER_FREQUENCY/1000)) / 1000)
 #define PM_TIMER_TICK_NS                (1000000000ULL/PM_TIMER_FREQUENCY)
 #define C2_OVERHEAD                     1       /* 1us */
 #define C3_OVERHEAD                     1       /* 1us */
@@ -78,6 +77,10 @@ module_param(nocst, uint, 0000);
 static unsigned int latency_factor __read_mostly = 2;
 module_param(latency_factor, uint, 0644);
 
+static s64 us_to_pm_timer_ticks(s64 t)
+{
+        return div64_u64(t * PM_TIMER_FREQUENCY, 1000000);
+}
 /*
  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
  * For now disable this. Probably a bug somewhere else.
@@ -108,25 +111,6 @@ static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = {
         {},
 };
 
-static inline u32 ticks_elapsed(u32 t1, u32 t2)
-{
-        if (t2 >= t1)
-                return (t2 - t1);
-        else if (!(acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER))
-                return (((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
-        else
-                return ((0xFFFFFFFF - t1) + t2);
-}
-
-static inline u32 ticks_elapsed_in_us(u32 t1, u32 t2)
-{
-        if (t2 >= t1)
-                return PM_TIMER_TICKS_TO_US(t2 - t1);
-        else if (!(acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER))
-                return PM_TIMER_TICKS_TO_US(((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
-        else
-                return PM_TIMER_TICKS_TO_US((0xFFFFFFFF - t1) + t2);
-}
 
 /*
  * Callers should disable interrupts before the call and enable
@@ -802,7 +786,8 @@ static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
 static int acpi_idle_enter_c1(struct cpuidle_device *dev,
                               struct cpuidle_state *state)
 {
-        u32 t1, t2;
+        ktime_t  kt1, kt2;
+        s64 idle_time;
         struct acpi_processor *pr;
         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
 
@@ -820,14 +805,15 @@ static int acpi_idle_enter_c1(struct cpuidle_device *dev,
                 return 0;
         }
 
-        t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
+        kt1 = ktime_get_real();
         acpi_idle_do_entry(cx);
-        t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
+        kt2 = ktime_get_real();
+        idle_time =  ktime_to_us(ktime_sub(kt2, kt1));
 
         local_irq_enable();
         cx->usage++;
 
-        return ticks_elapsed_in_us(t1, t2);
+        return idle_time;
 }
 
 /**
@@ -840,8 +826,9 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev,
 {
         struct acpi_processor *pr;
         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
-        u32 t1, t2;
-        int sleep_ticks = 0;
+        ktime_t  kt1, kt2;
+        s64 idle_time;
+        s64 sleep_ticks = 0;
 
         pr = __get_cpu_var(processors);
 
@@ -874,18 +861,19 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev,
         if (cx->type == ACPI_STATE_C3)
                 ACPI_FLUSH_CPU_CACHE();
 
-        t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
+        kt1 = ktime_get_real();
         /* Tell the scheduler that we are going deep-idle: */
         sched_clock_idle_sleep_event();
         acpi_idle_do_entry(cx);
-        t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
+        kt2 = ktime_get_real();
+        idle_time =  ktime_to_us(ktime_sub(kt2, kt1));
 
 #if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86)
         /* TSC could halt in idle, so notify users */
         if (tsc_halts_in_c(cx->type))
                 mark_tsc_unstable("TSC halts in idle");;
 #endif
-        sleep_ticks = ticks_elapsed(t1, t2);
+        sleep_ticks = us_to_pm_timer_ticks(idle_time);
 
         /* Tell the scheduler how much we idled: */
         sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
@@ -897,7 +885,7 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev,
 
         acpi_state_timer_broadcast(pr, cx, 0);
         cx->time += sleep_ticks;
-        return ticks_elapsed_in_us(t1, t2);
+        return idle_time;
 }
 
 static int c3_cpu_count;
@@ -915,8 +903,10 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 {
         struct acpi_processor *pr;
         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
-        u32 t1, t2;
-        int sleep_ticks = 0;
+        ktime_t  kt1, kt2;
+        s64 idle_time;
+        s64 sleep_ticks = 0;
+
 
         pr = __get_cpu_var(processors);
 
@@ -983,9 +973,10 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
                 ACPI_FLUSH_CPU_CACHE();
         }
 
-        t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
+        kt1 = ktime_get_real();
         acpi_idle_do_entry(cx);
-        t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
+        kt2 = ktime_get_real();
+        idle_time =  ktime_to_us(ktime_sub(kt2, kt1));
 
         /* Re-enable bus master arbitration */
         if (pr->flags.bm_check && pr->flags.bm_control) {
@@ -1000,7 +991,7 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
         if (tsc_halts_in_c(ACPI_STATE_C3))
                 mark_tsc_unstable("TSC halts in idle");
 #endif
-        sleep_ticks = ticks_elapsed(t1, t2);
+        sleep_ticks = us_to_pm_timer_ticks(idle_time);
         /* Tell the scheduler how much we idled: */
         sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
 
@@ -1011,7 +1002,7 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 
         acpi_state_timer_broadcast(pr, cx, 0);
         cx->time += sleep_ticks;
-        return ticks_elapsed_in_us(t1, t2);
+        return idle_time;
 }
 
 struct cpuidle_driver acpi_idle_driver = {