12 files changed, 164 insertions, 99 deletions

diff --git a/arch/arm/mach-at91/cpuidle.c b/arch/arm/mach-at91/cpuidle.c
index 1cfeac1483d6..4696a0d61e2e 100644
--- a/arch/arm/mach-at91/cpuidle.c
+++ b/arch/arm/mach-at91/cpuidle.c
@@ -33,7 +33,7 @@ static struct cpuidle_driver at91_idle_driver = {
 
 /* Actual code that puts the SoC in different idle states */
 static int at91_enter_idle(struct cpuidle_device *dev,
-                               struct cpuidle_state *state)
+                               int index)
 {
         struct timeval before, after;
         int idle_time;
@@ -41,10 +41,10 @@ static int at91_enter_idle(struct cpuidle_device *dev,
 
         local_irq_disable();
         do_gettimeofday(&before);
-        if (state == &dev->states[0])
+        if (index == 0)
                 /* Wait for interrupt state */
                 cpu_do_idle();
-        else if (state == &dev->states[1]) {
+        else if (index == 1) {
                 asm("b 1f; .align 5; 1:");
                 asm("mcr p15, 0, r0, c7, c10, 4");      /* drain write buffer */
                 saved_lpr = sdram_selfrefresh_enable();
@@ -55,7 +55,9 @@ static int at91_enter_idle(struct cpuidle_device *dev,
         local_irq_enable();
         idle_time = (after.tv_sec - before.tv_sec) * USEC_PER_SEC +
                         (after.tv_usec - before.tv_usec);
-        return idle_time;
+
+        dev->last_residency = idle_time;
+        return index;
 }
 
 /* Initialize CPU idle by registering the idle states */
diff --git a/arch/arm/mach-davinci/cpuidle.c b/arch/arm/mach-davinci/cpuidle.c
index bd59f31b8a95..ca8582a95ad9 100644
--- a/arch/arm/mach-davinci/cpuidle.c
+++ b/arch/arm/mach-davinci/cpuidle.c
@@ -78,9 +78,9 @@ static struct davinci_ops davinci_states[DAVINCI_CPUIDLE_MAX_STATES] = {
 
 /* Actual code that puts the SoC in different idle states */
 static int davinci_enter_idle(struct cpuidle_device *dev,
-                                                struct cpuidle_state *state)
+                                                int index)
 {
-        struct davinci_ops *ops = cpuidle_get_statedata(state);
+        struct davinci_ops *ops = cpuidle_get_statedata(&dev->states[index]);
         struct timeval before, after;
         int idle_time;
 
@@ -98,7 +98,10 @@ static int davinci_enter_idle(struct cpuidle_device *dev,
         local_irq_enable();
         idle_time = (after.tv_sec - before.tv_sec) * USEC_PER_SEC +
                         (after.tv_usec - before.tv_usec);
-        return idle_time;
+
+        dev->last_residency = idle_time;
+
+        return index;
 }
 
 static int __init davinci_cpuidle_probe(struct platform_device *pdev)
diff --git a/arch/arm/mach-exynos4/cpuidle.c b/arch/arm/mach-exynos4/cpuidle.c
index bf7e96f2793a..ea026e72b977 100644
--- a/arch/arm/mach-exynos4/cpuidle.c
+++ b/arch/arm/mach-exynos4/cpuidle.c
@@ -16,7 +16,7 @@
 #include <asm/proc-fns.h>
 
 static int exynos4_enter_idle(struct cpuidle_device *dev,
-                              struct cpuidle_state *state);
+                              int index);
 
 static struct cpuidle_state exynos4_cpuidle_set[] = {
         [0] = {
@@ -37,7 +37,7 @@ static struct cpuidle_driver exynos4_idle_driver = {
 };
 
 static int exynos4_enter_idle(struct cpuidle_device *dev,
-                              struct cpuidle_state *state)
+                              int index)
 {
         struct timeval before, after;
         int idle_time;
@@ -52,7 +52,8 @@ static int exynos4_enter_idle(struct cpuidle_device *dev,
         idle_time = (after.tv_sec - before.tv_sec) * USEC_PER_SEC +
                     (after.tv_usec - before.tv_usec);
 
-        return idle_time;
+        dev->last_residency = idle_time;
+        return index;
 }
 
 static int __init exynos4_init_cpuidle(void)
diff --git a/arch/arm/mach-kirkwood/cpuidle.c b/arch/arm/mach-kirkwood/cpuidle.c
index f68d33f1f396..358dd80b3a07 100644
--- a/arch/arm/mach-kirkwood/cpuidle.c
+++ b/arch/arm/mach-kirkwood/cpuidle.c
@@ -32,17 +32,17 @@ static DEFINE_PER_CPU(struct cpuidle_device, kirkwood_cpuidle_device);
 
 /* Actual code that puts the SoC in different idle states */
 static int kirkwood_enter_idle(struct cpuidle_device *dev,
-                               struct cpuidle_state *state)
+                               int index)
 {
         struct timeval before, after;
         int idle_time;
 
         local_irq_disable();
         do_gettimeofday(&before);
-        if (state == &dev->states[0])
+        if (index == 0)
                 /* Wait for interrupt state */
                 cpu_do_idle();
-        else if (state == &dev->states[1]) {
+        else if (index == 1) {
                 /*
                  * Following write will put DDR in self refresh.
                  * Note that we have 256 cycles before DDR puts it
@@ -57,7 +57,11 @@ static int kirkwood_enter_idle(struct cpuidle_device *dev,
         local_irq_enable();
         idle_time = (after.tv_sec - before.tv_sec) * USEC_PER_SEC +
                         (after.tv_usec - before.tv_usec);
-        return idle_time;
+
+        /* Update last residency */
+        dev->last_residency = idle_time;
+
+        return index;
 }
 
 /* Initialize CPU idle by registering the idle states */
diff --git a/arch/arm/mach-omap2/cpuidle34xx.c b/arch/arm/mach-omap2/cpuidle34xx.c
index 4bf6e6e8b100..58425c75f1b8 100644
--- a/arch/arm/mach-omap2/cpuidle34xx.c
+++ b/arch/arm/mach-omap2/cpuidle34xx.c
@@ -88,17 +88,19 @@ static int _cpuidle_deny_idle(struct powerdomain *pwrdm,
 /**
  * omap3_enter_idle - Programs OMAP3 to enter the specified state
  * @dev: cpuidle device
- * @state: The target state to be programmed
+ * @index: the index of state to be entered
  *
  * Called from the CPUidle framework to program the device to the
  * specified target state selected by the governor.
  */
 static int omap3_enter_idle(struct cpuidle_device *dev,
-                        struct cpuidle_state *state)
+                                int index)
 {
-        struct omap3_idle_statedata *cx = cpuidle_get_statedata(state);
+        struct omap3_idle_statedata *cx =
+                        cpuidle_get_statedata(&dev->states[index]);
         struct timespec ts_preidle, ts_postidle, ts_idle;
         u32 mpu_state = cx->mpu_state, core_state = cx->core_state;
+        int idle_time;
 
         /* Used to keep track of the total time in idle */
         getnstimeofday(&ts_preidle);
@@ -113,7 +115,7 @@ static int omap3_enter_idle(struct cpuidle_device *dev,
                 goto return_sleep_time;
 
         /* Deny idle for C1 */
-        if (state == &dev->states[0]) {
+        if (index == 0) {
                 pwrdm_for_each_clkdm(mpu_pd, _cpuidle_deny_idle);
                 pwrdm_for_each_clkdm(core_pd, _cpuidle_deny_idle);
         }
@@ -122,7 +124,7 @@ static int omap3_enter_idle(struct cpuidle_device *dev,
         omap_sram_idle();
 
         /* Re-allow idle for C1 */
-        if (state == &dev->states[0]) {
+        if (index == 0) {
                 pwrdm_for_each_clkdm(mpu_pd, _cpuidle_allow_idle);
                 pwrdm_for_each_clkdm(core_pd, _cpuidle_allow_idle);
         }
@@ -134,28 +136,35 @@ return_sleep_time:
         local_irq_enable();
         local_fiq_enable();
 
-        return ts_idle.tv_nsec / NSEC_PER_USEC + ts_idle.tv_sec * USEC_PER_SEC;
+        idle_time = ts_idle.tv_nsec / NSEC_PER_USEC + ts_idle.tv_sec * \
+                                                                USEC_PER_SEC;
+
+        /* Update cpuidle counters */
+        dev->last_residency = idle_time;
+
+        return index;
 }
 
 /**
  * next_valid_state - Find next valid C-state
  * @dev: cpuidle device
- * @state: Currently selected C-state
+ * @index: Index of currently selected c-state
  *
- * If the current state is valid, it is returned back to the caller.
- * Else, this function searches for a lower c-state which is still
- * valid.
+ * If the state corresponding to index is valid, index is returned back
+ * to the caller. Else, this function searches for a lower c-state which is
+ * still valid (as defined in omap3_power_states[]) and returns its index.
  *
  * A state is valid if the 'valid' field is enabled and
  * if it satisfies the enable_off_mode condition.
  */
-static struct cpuidle_state *next_valid_state(struct cpuidle_device *dev,
-                                              struct cpuidle_state *curr)
+static int next_valid_state(struct cpuidle_device *dev,
+                                int index)
 {
-        struct cpuidle_state *next = NULL;
+        struct cpuidle_state *curr = &dev->states[index];
         struct omap3_idle_statedata *cx = cpuidle_get_statedata(curr);
         u32 mpu_deepest_state = PWRDM_POWER_RET;
         u32 core_deepest_state = PWRDM_POWER_RET;
+        int next_index = -1;
 
         if (enable_off_mode) {
                 mpu_deepest_state = PWRDM_POWER_OFF;
@@ -172,20 +181,20 @@ static struct cpuidle_state *next_valid_state(struct cpuidle_device *dev,
         if ((cx->valid) &&
             (cx->mpu_state >= mpu_deepest_state) &&
             (cx->core_state >= core_deepest_state)) {
-                return curr;
+                return index;
         } else {
                 int idx = OMAP3_NUM_STATES - 1;
 
                 /* Reach the current state starting at highest C-state */
                 for (; idx >= 0; idx--) {
                         if (&dev->states[idx] == curr) {
-                                next = &dev->states[idx];
+                                next_index = idx;
                                 break;
                         }
                 }
 
                 /* Should never hit this condition */
-                WARN_ON(next == NULL);
+                WARN_ON(next_index == -1);
 
                 /*
                  * Drop to next valid state.
@@ -197,37 +206,39 @@ static struct cpuidle_state *next_valid_state(struct cpuidle_device *dev,
                         if ((cx->valid) &&
                             (cx->mpu_state >= mpu_deepest_state) &&
                             (cx->core_state >= core_deepest_state)) {
-                                next = &dev->states[idx];
+                                next_index = idx;
                                 break;
                         }
                 }
                 /*
                  * C1 is always valid.
-                 * So, no need to check for 'next==NULL' outside this loop.
+                 * So, no need to check for 'next_index == -1' outside
+                 * this loop.
                  */
         }
 
-        return next;
+        return next_index;
 }
 
 /**
  * omap3_enter_idle_bm - Checks for any bus activity
  * @dev: cpuidle device
- * @state: The target state to be programmed
+ * @index: array index of target state to be programmed
  *
  * This function checks for any pending activity and then programs
  * the device to the specified or a safer state.
  */
 static int omap3_enter_idle_bm(struct cpuidle_device *dev,
-                               struct cpuidle_state *state)
+                               int index)
 {
-        struct cpuidle_state *new_state;
+        struct cpuidle_state *state = &dev->states[index];
+        int new_state_idx;
         u32 core_next_state, per_next_state = 0, per_saved_state = 0, cam_state;
         struct omap3_idle_statedata *cx;
         int ret;
 
         if (!omap3_can_sleep()) {
-                new_state = dev->safe_state;
+                new_state_idx = dev->safe_state_index;
                 goto select_state;
         }
 
@@ -237,7 +248,7 @@ static int omap3_enter_idle_bm(struct cpuidle_device *dev,
          */
         cam_state = pwrdm_read_pwrst(cam_pd);
         if (cam_state == PWRDM_POWER_ON) {
-                new_state = dev->safe_state;
+                new_state_idx = dev->safe_state_index;
                 goto select_state;
         }
 
@@ -264,11 +275,10 @@ static int omap3_enter_idle_bm(struct cpuidle_device *dev,
         if (per_next_state != per_saved_state)
                 pwrdm_set_next_pwrst(per_pd, per_next_state);
 
-        new_state = next_valid_state(dev, state);
+        new_state_idx = next_valid_state(dev, index);
 
 select_state:
-        dev->last_state = new_state;
-        ret = omap3_enter_idle(dev, new_state);
+        ret = omap3_enter_idle(dev, new_state_idx);
 
         /* Restore original PER state if it was modified */
         if (per_next_state != per_saved_state)
@@ -339,11 +349,12 @@ int __init omap3_idle_init(void)
 
         cpuidle_register_driver(&omap3_idle_driver);
         dev = &per_cpu(omap3_idle_dev, smp_processor_id());
+        dev->safe_state_index = -1;
 
         /* C1 . MPU WFI + Core active */
         cx = _fill_cstate(dev, 0, "MPU ON + CORE ON");
         (&dev->states[0])->enter = omap3_enter_idle;
-        dev->safe_state = &dev->states[0];
+        dev->safe_state_index = 0;
         cx->valid = 1;  /* C1 is always valid */
         cx->mpu_state = PWRDM_POWER_ON;
         cx->core_state = PWRDM_POWER_ON;
diff --git a/arch/sh/kernel/cpu/shmobile/cpuidle.c b/arch/sh/kernel/cpu/shmobile/cpuidle.c
index e4469e7233cb..7be50d4c4268 100644
--- a/arch/sh/kernel/cpu/shmobile/cpuidle.c
+++ b/arch/sh/kernel/cpu/shmobile/cpuidle.c
@@ -25,11 +25,11 @@ static unsigned long cpuidle_mode[] = {
 };
 
 static int cpuidle_sleep_enter(struct cpuidle_device *dev,
-                               struct cpuidle_state *state)
+                                int index)
 {
         unsigned long allowed_mode = arch_hwblk_sleep_mode();
         ktime_t before, after;
-        int requested_state = state - &dev->states[0];
+        int requested_state = index;
         int allowed_state;
         int k;
 
@@ -46,11 +46,13 @@ static int cpuidle_sleep_enter(struct cpuidle_device *dev,
          */
         k = min_t(int, allowed_state, requested_state);
 
-        dev->last_state = &dev->states[k];
         before = ktime_get();
         sh_mobile_call_standby(cpuidle_mode[k]);
         after = ktime_get();
-        return ktime_to_ns(ktime_sub(after, before)) >> 10;
+
+        dev->last_residency = (int)ktime_to_ns(ktime_sub(after, before)) >> 10;
+
+        return k;
 }
 
 static struct cpuidle_device cpuidle_dev;
@@ -84,7 +86,7 @@ void sh_mobile_setup_cpuidle(void)
         state->flags |= CPUIDLE_FLAG_TIME_VALID;
         state->enter = cpuidle_sleep_enter;
 
-        dev->safe_state = state;
+        dev->safe_state_index = i-1;
 
         if (sh_mobile_sleep_supported & SUSP_SH_SF) {
                 state = &dev->states[i++];
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 431ab11c8c1b..9cd08cecb347 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -741,22 +741,24 @@ static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
 /**
  * acpi_idle_enter_c1 - enters an ACPI C1 state-type
  * @dev: the target CPU
- * @state: the state data
+ * @index: index of target state
  *
  * This is equivalent to the HALT instruction.
  */
 static int acpi_idle_enter_c1(struct cpuidle_device *dev,
-                              struct cpuidle_state *state)
+                                int index)
 {
         ktime_t  kt1, kt2;
         s64 idle_time;
         struct acpi_processor *pr;
+        struct cpuidle_state *state = &dev->states[index];
         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
 
         pr = __this_cpu_read(processors);
+        dev->last_residency = 0;
 
         if (unlikely(!pr))
-                return 0;
+                return -EINVAL;
 
         local_irq_disable();
 
@@ -764,7 +766,7 @@ static int acpi_idle_enter_c1(struct cpuidle_device *dev,
         if (acpi_idle_suspend) {
                 local_irq_enable();
                 cpu_relax();
-                return 0;
+                return -EINVAL;
         }
 
         lapic_timer_state_broadcast(pr, cx, 1);
@@ -773,37 +775,46 @@ static int acpi_idle_enter_c1(struct cpuidle_device *dev,
         kt2 = ktime_get_real();
         idle_time =  ktime_to_us(ktime_sub(kt2, kt1));
 
+        /* Update device last_residency*/
+        dev->last_residency = (int)idle_time;
+
         local_irq_enable();
         cx->usage++;
         lapic_timer_state_broadcast(pr, cx, 0);
 
-        return idle_time;
+        return index;
 }
 
 /**
  * acpi_idle_enter_simple - enters an ACPI state without BM handling
  * @dev: the target CPU
- * @state: the state data
+ * @index: the index of suggested state
  */
 static int acpi_idle_enter_simple(struct cpuidle_device *dev,
-                                  struct cpuidle_state *state)
+                                int index)
 {
         struct acpi_processor *pr;
+        struct cpuidle_state *state = &dev->states[index];
         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
         ktime_t  kt1, kt2;
         s64 idle_time_ns;
         s64 idle_time;
 
         pr = __this_cpu_read(processors);
+        dev->last_residency = 0;
 
         if (unlikely(!pr))
-                return 0;
-
-        if (acpi_idle_suspend)
-                return(acpi_idle_enter_c1(dev, state));
+                return -EINVAL;
 
         local_irq_disable();
 
+        if (acpi_idle_suspend) {
+                local_irq_enable();
+                cpu_relax();
+                return -EINVAL;
+        }
+
+
         if (cx->entry_method != ACPI_CSTATE_FFH) {
                 current_thread_info()->status &= ~TS_POLLING;
                 /*
@@ -815,7 +826,7 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev,
                 if (unlikely(need_resched())) {
                         current_thread_info()->status |= TS_POLLING;
                         local_irq_enable();
-                        return 0;
+                        return -EINVAL;
                 }
         }
 
@@ -837,6 +848,9 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev,
         idle_time = idle_time_ns;
         do_div(idle_time, NSEC_PER_USEC);
 
+        /* Update device last_residency*/
+        dev->last_residency = (int)idle_time;
+
         /* Tell the scheduler how much we idled: */
         sched_clock_idle_wakeup_event(idle_time_ns);
 
@@ -848,7 +862,7 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev,
 
         lapic_timer_state_broadcast(pr, cx, 0);
         cx->time += idle_time;
-        return idle_time;
+        return index;
 }
 
 static int c3_cpu_count;
@@ -857,14 +871,15 @@ static DEFINE_SPINLOCK(c3_lock);
 /**
  * acpi_idle_enter_bm - enters C3 with proper BM handling
  * @dev: the target CPU
- * @state: the state data
+ * @index: the index of suggested state
  *
  * If BM is detected, the deepest non-C3 idle state is entered instead.
  */
 static int acpi_idle_enter_bm(struct cpuidle_device *dev,
-                              struct cpuidle_state *state)
+                                int index)
 {
         struct acpi_processor *pr;
+        struct cpuidle_state *state = &dev->states[index];
         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
         ktime_t  kt1, kt2;
         s64 idle_time_ns;
@@ -872,22 +887,26 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 
 
         pr = __this_cpu_read(processors);
+        dev->last_residency = 0;
 
         if (unlikely(!pr))
-                return 0;
+                return -EINVAL;
 
-        if (acpi_idle_suspend)
-                return(acpi_idle_enter_c1(dev, state));
+
+        if (acpi_idle_suspend) {
+                cpu_relax();
+                return -EINVAL;
+        }
 
         if (!cx->bm_sts_skip && acpi_idle_bm_check()) {
-                if (dev->safe_state) {
-                        dev->last_state = dev->safe_state;
-                        return dev->safe_state->enter(dev, dev->safe_state);
+                if (dev->safe_state_index >= 0) {
+                        return dev->states[dev->safe_state_index].enter(dev,
+                                                dev->safe_state_index);
                 } else {
                         local_irq_disable();
                         acpi_safe_halt();
                         local_irq_enable();
-                        return 0;
+                        return -EINVAL;
                 }
         }
 
@@ -904,7 +923,7 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
                 if (unlikely(need_resched())) {
                         current_thread_info()->status |= TS_POLLING;
                         local_irq_enable();
-                        return 0;
+                        return -EINVAL;
                 }
         }
 
@@ -954,6 +973,9 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
         idle_time = idle_time_ns;
         do_div(idle_time, NSEC_PER_USEC);
 
+        /* Update device last_residency*/
+        dev->last_residency = (int)idle_time;
+
         /* Tell the scheduler how much we idled: */
         sched_clock_idle_wakeup_event(idle_time_ns);
 
@@ -965,7 +987,7 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 
         lapic_timer_state_broadcast(pr, cx, 0);
         cx->time += idle_time;
-        return idle_time;
+        return index;
 }
 
 struct cpuidle_driver acpi_idle_driver = {
@@ -992,6 +1014,7 @@ static int acpi_processor_setup_cpuidle(struct acpi_processor *pr)
         }
 
         dev->cpu = pr->id;
+        dev->safe_state_index = -1;
         for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
                 dev->states[i].name[0] = '\0';
                 dev->states[i].desc[0] = '\0';
@@ -1027,13 +1050,13 @@ static int acpi_processor_setup_cpuidle(struct acpi_processor *pr)
                                 state->flags |= CPUIDLE_FLAG_TIME_VALID;
 
                         state->enter = acpi_idle_enter_c1;
-                        dev->safe_state = state;
+                        dev->safe_state_index = count;
                         break;
 
                         case ACPI_STATE_C2:
                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
                         state->enter = acpi_idle_enter_simple;
-                        dev->safe_state = state;
+                        dev->safe_state_index = count;
                         break;
 
                         case ACPI_STATE_C3:
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index d4c542372886..88bd12104396 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -62,7 +62,7 @@ int cpuidle_idle_call(void)
 {
         struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices);
         struct cpuidle_state *target_state;
-        int next_state;
+        int next_state, entered_state;
 
         if (off)
                 return -ENODEV;
@@ -102,26 +102,27 @@ int cpuidle_idle_call(void)
 
         target_state = &dev->states[next_state];
 
-        /* enter the state and update stats */
-        dev->last_state = target_state;
-
         trace_power_start(POWER_CSTATE, next_state, dev->cpu);
         trace_cpu_idle(next_state, dev->cpu);
 
-        dev->last_residency = target_state->enter(dev, target_state);
+        entered_state = target_state->enter(dev, next_state);
 
         trace_power_end(dev->cpu);
         trace_cpu_idle(PWR_EVENT_EXIT, dev->cpu);
 
-        if (dev->last_state)
-                target_state = dev->last_state;
-
-        target_state->time += (unsigned long long)dev->last_residency;
-        target_state->usage++;
+        if (entered_state >= 0) {
+                /* Update cpuidle counters */
+                /* This can be moved to within driver enter routine
+                 * but that results in multiple copies of same code.
+                 */
+                dev->states[entered_state].time +=
+                                (unsigned long long)dev->last_residency;
+                dev->states[entered_state].usage++;
+        }
 
         /* give the governor an opportunity to reflect on the outcome */
         if (cpuidle_curr_governor->reflect)
-                cpuidle_curr_governor->reflect(dev);
+                cpuidle_curr_governor->reflect(dev, entered_state);
 
         return 0;
 }
@@ -172,11 +173,10 @@ void cpuidle_resume_and_unlock(void)
 EXPORT_SYMBOL_GPL(cpuidle_resume_and_unlock);
 
 #ifdef CONFIG_ARCH_HAS_CPU_RELAX
-static int poll_idle(struct cpuidle_device *dev, struct cpuidle_state *st)
+static int poll_idle(struct cpuidle_device *dev, int index)
 {
         ktime_t t1, t2;
         s64 diff;
-        int ret;
 
         t1 = ktime_get();
         local_irq_enable();
@@ -188,8 +188,9 @@ static int poll_idle(struct cpuidle_device *dev, struct cpuidle_state *st)
         if (diff > INT_MAX)
                 diff = INT_MAX;
 
-        ret = (int) diff;
-        return ret;
+        dev->last_residency = (int) diff;
+
+        return index;
 }
 
 static void poll_idle_init(struct cpuidle_device *dev)
@@ -248,7 +249,6 @@ int cpuidle_enable_device(struct cpuidle_device *dev)
                 dev->states[i].time = 0;
         }
         dev->last_residency = 0;
-        dev->last_state = NULL;
 
         smp_wmb();
 
diff --git a/drivers/cpuidle/governors/ladder.c b/drivers/cpuidle/governors/ladder.c
index 12c98900dcf8..6a686a76711f 100644
--- a/drivers/cpuidle/governors/ladder.c
+++ b/drivers/cpuidle/governors/ladder.c
@@ -153,11 +153,24 @@ static int ladder_enable_device(struct cpuidle_device *dev)
         return 0;
 }
 
+/**
+ * ladder_reflect - update the correct last_state_idx
+ * @dev: the CPU
+ * @index: the index of actual state entered
+ */
+static void ladder_reflect(struct cpuidle_device *dev, int index)
+{
+        struct ladder_device *ldev = &__get_cpu_var(ladder_devices);
+        if (index > 0)
+                ldev->last_state_idx = index;
+}
+
 static struct cpuidle_governor ladder_governor = {
         .name =         "ladder",
         .rating =       10,
         .enable =       ladder_enable_device,
         .select =       ladder_select_state,
+        .reflect =      ladder_reflect,
         .owner =        THIS_MODULE,
 };
 
diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index c47f3d09c1ee..e4b200c5b441 100644
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -310,14 +310,17 @@ static int menu_select(struct cpuidle_device *dev)
 /**
  * menu_reflect - records that data structures need update
  * @dev: the CPU
+ * @index: the index of actual entered state
  *
  * NOTE: it's important to be fast here because this operation will add to
  *       the overall exit latency.
  */
-static void menu_reflect(struct cpuidle_device *dev)
+static void menu_reflect(struct cpuidle_device *dev, int index)
 {
         struct menu_device *data = &__get_cpu_var(menu_devices);
-        data->needs_update = 1;
+        data->last_state_idx = index;
+        if (index >= 0)
+                data->needs_update = 1;
 }
 
 /**
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index a46dddf61078..a1c888d2216a 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -81,7 +81,7 @@ static unsigned int mwait_substates;
 static unsigned int lapic_timer_reliable_states = (1 << 1);      /* Default to only C1 */
 
 static struct cpuidle_device __percpu *intel_idle_cpuidle_devices;
-static int intel_idle(struct cpuidle_device *dev, struct cpuidle_state *state);
+static int intel_idle(struct cpuidle_device *dev, int index);
 
 static struct cpuidle_state *cpuidle_state_table;
 
@@ -209,12 +209,13 @@ static struct cpuidle_state atom_cstates[MWAIT_MAX_NUM_CSTATES] = {
 /**
  * intel_idle
  * @dev: cpuidle_device
- * @state: cpuidle state
+ * @index: index of cpuidle state
  *
  */
-static int intel_idle(struct cpuidle_device *dev, struct cpuidle_state *state)
+static int intel_idle(struct cpuidle_device *dev, int index)
 {
         unsigned long ecx = 1; /* break on interrupt flag */
+        struct cpuidle_state *state = &dev->states[index];
         unsigned long eax = (unsigned long)cpuidle_get_statedata(state);
         unsigned int cstate;
         ktime_t kt_before, kt_after;
@@ -256,7 +257,10 @@ static int intel_idle(struct cpuidle_device *dev, struct cpuidle_state *state)
         if (!(lapic_timer_reliable_states & (1 << (cstate))))
                 clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu);
 
-        return usec_delta;
+        /* Update cpuidle counters */
+        dev->last_residency = (int)usec_delta;
+
+        return index;
 }
 
 static void __setup_broadcast_timer(void *arg)
diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
index b51629e15cfc..8da811bcdbdb 100644
--- a/include/linux/cpuidle.h
+++ b/include/linux/cpuidle.h
@@ -42,7 +42,7 @@ struct cpuidle_state {
         unsigned long long      time; /* in US */
 
         int (*enter)    (struct cpuidle_device *dev,
-                         struct cpuidle_state *state);
+                        int index);
 };
 
 /* Idle State Flags */
@@ -87,13 +87,12 @@ struct cpuidle_device {
         int                     state_count;
         struct cpuidle_state    states[CPUIDLE_STATE_MAX];
         struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
-        struct cpuidle_state    *last_state;
 
         struct list_head        device_list;
         struct kobject          kobj;
         struct completion       kobj_unregister;
         void                    *governor_data;
-        struct cpuidle_state    *safe_state;
+        int                     safe_state_index;
 
         int (*prepare)          (struct cpuidle_device *dev);
 };
@@ -169,7 +168,7 @@ struct cpuidle_governor {
         void (*disable)         (struct cpuidle_device *dev);
 
         int  (*select)          (struct cpuidle_device *dev);
-        void (*reflect)         (struct cpuidle_device *dev);
+        void (*reflect)         (struct cpuidle_device *dev, int index);
 
         struct module           *owner;
 };