diff --git a/drivers/acpi/apei/apei-base.c b/drivers/acpi/apei/apei-base.c
index 00a783661d0b5548b65882f312faa4a116ff5762..46f80e2c92f7da893ff28f5993d89fa01efc323a 100644
--- a/drivers/acpi/apei/apei-base.c
+++ b/drivers/acpi/apei/apei-base.c
@@ -590,6 +590,9 @@ static int apei_check_gar(struct acpi_generic_address *reg, u64 *paddr,
 	if (bit_width == 32 && bit_offset == 0 && (*paddr & 0x03) == 0 &&
 	    *access_bit_width < 32)
 		*access_bit_width = 32;
+	else if (bit_width == 64 && bit_offset == 0 && (*paddr & 0x07) == 0 &&
+	    *access_bit_width < 64)
+		*access_bit_width = 64;
 
 	if ((bit_width + bit_offset) > *access_bit_width) {
 		pr_warning(FW_BUG APEI_PFX
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index f1a5da44591dcd1b415b57e638165318bc13e793..ed9a1cc690be5fa8cd3844394128216350904a7e 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -958,6 +958,9 @@ static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr)
 		return -EINVAL;
 	}
 
+	if (!dev)
+		return -EINVAL;
+
 	dev->cpu = pr->id;
 
 	if (max_cstate == 0)
@@ -1149,6 +1152,7 @@ int acpi_processor_cst_has_changed(struct acpi_processor *pr)
 		}
 
 		/* Populate Updated C-state information */
+		acpi_processor_get_power_info(pr);
 		acpi_processor_setup_cpuidle_states(pr);
 
 		/* Enable all cpuidle devices */
diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c
index 836bfe0690422855c80ecfe41895a4fe667bfd14..53e7ac9403a7dc21502e90a698ef1b27ad668a37 100644
--- a/drivers/acpi/processor_perflib.c
+++ b/drivers/acpi/processor_perflib.c
@@ -340,6 +340,13 @@ static void amd_fixup_frequency(struct acpi_processor_px *px, int i)
 	if ((boot_cpu_data.x86 == 0x10 && boot_cpu_data.x86_model < 10)
 	    || boot_cpu_data.x86 == 0x11) {
 		rdmsr(MSR_AMD_PSTATE_DEF_BASE + index, lo, hi);
+		/*
+		 * MSR C001_0064+:
+		 * Bit 63: PstateEn. Read-write. If set, the P-state is valid.
+		 */
+		if (!(hi & BIT(31)))
+			return;
+
 		fid = lo & 0x3f;
 		did = (lo >> 6) & 7;
 		if (boot_cpu_data.x86 == 0x10)
diff --git a/drivers/cpufreq/Kconfig.x86 b/drivers/cpufreq/Kconfig.x86
index 934854ae5eb4a436205d644c76c8011a5c41de3e..7227cd7340423c595a2a1b29488e864662198634 100644
--- a/drivers/cpufreq/Kconfig.x86
+++ b/drivers/cpufreq/Kconfig.x86
@@ -106,7 +106,7 @@ config X86_POWERNOW_K7_ACPI
 config X86_POWERNOW_K8
 	tristate "AMD Opteron/Athlon64 PowerNow!"
 	select CPU_FREQ_TABLE
-	depends on ACPI && ACPI_PROCESSOR
+	depends on ACPI && ACPI_PROCESSOR && X86_ACPI_CPUFREQ
 	help
 	  This adds the CPUFreq driver for K8/early Opteron/Athlon64 processors.
 	  Support for K10 and newer processors is now in acpi-cpufreq.
diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
index 0d048f6a2b23a3bf9476a658cac846ccd321bd3c..7b0d49d78c61fc6c9fd312b0d05663ad42edf099 100644
--- a/drivers/cpufreq/acpi-cpufreq.c
+++ b/drivers/cpufreq/acpi-cpufreq.c
@@ -1030,4 +1030,11 @@ MODULE_PARM_DESC(acpi_pstate_strict,
 late_initcall(acpi_cpufreq_init);
 module_exit(acpi_cpufreq_exit);
 
+static const struct x86_cpu_id acpi_cpufreq_ids[] = {
+	X86_FEATURE_MATCH(X86_FEATURE_ACPI),
+	X86_FEATURE_MATCH(X86_FEATURE_HW_PSTATE),
+	{}
+};
+MODULE_DEVICE_TABLE(x86cpu, acpi_cpufreq_ids);
+
 MODULE_ALIAS("acpi");
diff --git a/drivers/cpufreq/cpufreq-cpu0.c b/drivers/cpufreq/cpufreq-cpu0.c
index 52bf36d599f575fcdd0bfe4fc3788db0d492e5a8..debc5a7c8db6207feeb9c428ccc44b8fcaed8d2f 100644
--- a/drivers/cpufreq/cpufreq-cpu0.c
+++ b/drivers/cpufreq/cpufreq-cpu0.c
@@ -71,12 +71,15 @@ static int cpu0_set_target(struct cpufreq_policy *policy,
 	}
 
 	if (cpu_reg) {
+		rcu_read_lock();
 		opp = opp_find_freq_ceil(cpu_dev, &freq_Hz);
 		if (IS_ERR(opp)) {
+			rcu_read_unlock();
 			pr_err("failed to find OPP for %ld\n", freq_Hz);
 			return PTR_ERR(opp);
 		}
 		volt = opp_get_voltage(opp);
+		rcu_read_unlock();
 		tol = volt * voltage_tolerance / 100;
 		volt_old = regulator_get_voltage(cpu_reg);
 	}
@@ -236,12 +239,14 @@ static int cpu0_cpufreq_driver_init(void)
 		 */
 		for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++)
 			;
+		rcu_read_lock();
 		opp = opp_find_freq_exact(cpu_dev,
 				freq_table[0].frequency * 1000, true);
 		min_uV = opp_get_voltage(opp);
 		opp = opp_find_freq_exact(cpu_dev,
 				freq_table[i-1].frequency * 1000, true);
 		max_uV = opp_get_voltage(opp);
+		rcu_read_unlock();
 		ret = regulator_set_voltage_time(cpu_reg, min_uV, max_uV);
 		if (ret > 0)
 			transition_latency += ret * 1000;
diff --git a/drivers/cpufreq/omap-cpufreq.c b/drivers/cpufreq/omap-cpufreq.c
index 1f3417a8322dfe8b0ca773873e058f7eb3a6c283..97102b05843fa580435ae0ae5b872d9467b577df 100644
--- a/drivers/cpufreq/omap-cpufreq.c
+++ b/drivers/cpufreq/omap-cpufreq.c
@@ -110,13 +110,16 @@ static int omap_target(struct cpufreq_policy *policy,
 	freq = ret;
 
 	if (mpu_reg) {
+		rcu_read_lock();
 		opp = opp_find_freq_ceil(mpu_dev, &freq);
 		if (IS_ERR(opp)) {
+			rcu_read_unlock();
 			dev_err(mpu_dev, "%s: unable to find MPU OPP for %d\n",
 				__func__, freqs.new);
 			return -EINVAL;
 		}
 		volt = opp_get_voltage(opp);
+		rcu_read_unlock();
 		tol = volt * OPP_TOLERANCE / 100;
 		volt_old = regulator_get_voltage(mpu_reg);
 	}
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 53766f39aaddfd5db9147842b40825fb1399453b..3b367973a8028c5d1cd32bd823bcf9e005d269b6 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -994,6 +994,11 @@ module_exit(devfreq_exit);
  * @freq:	The frequency given to target function
  * @flags:	Flags handed from devfreq framework.
  *
+ * Locking: This function must be called under rcu_read_lock(). opp is a rcu
+ * protected pointer. The reason for the same is that the opp pointer which is
+ * returned will remain valid for use with opp_get_{voltage, freq} only while
+ * under the locked area. The pointer returned must be used prior to unlocking
+ * with rcu_read_unlock() to maintain the integrity of the pointer.
  */
 struct opp *devfreq_recommended_opp(struct device *dev, unsigned long *freq,
 				    u32 flags)
diff --git a/drivers/devfreq/exynos4_bus.c b/drivers/devfreq/exynos4_bus.c
index 80c745e83082bf6d9dade7a81dffbb89931632a7..46d94e9e95b53ae033af012ef745822e0b7f5ccd 100644
--- a/drivers/devfreq/exynos4_bus.c
+++ b/drivers/devfreq/exynos4_bus.c
@@ -73,6 +73,16 @@ enum busclk_level_idx {
 #define EX4210_LV_NUM	(LV_2 + 1)
 #define EX4x12_LV_NUM	(LV_4 + 1)
 
+/**
+ * struct busfreq_opp_info - opp information for bus
+ * @rate:	Frequency in hertz
+ * @volt:	Voltage in microvolts corresponding to this OPP
+ */
+struct busfreq_opp_info {
+	unsigned long rate;
+	unsigned long volt;
+};
+
 struct busfreq_data {
 	enum exynos4_busf_type type;
 	struct device *dev;
@@ -80,7 +90,7 @@ struct busfreq_data {
 	bool disabled;
 	struct regulator *vdd_int;
 	struct regulator *vdd_mif; /* Exynos4412/4212 only */
-	struct opp *curr_opp;
+	struct busfreq_opp_info curr_oppinfo;
 	struct exynos4_ppmu dmc[2];
 
 	struct notifier_block pm_notifier;
@@ -296,13 +306,14 @@ static unsigned int exynos4x12_clkdiv_sclkip[][3] = {
 };
 
 
-static int exynos4210_set_busclk(struct busfreq_data *data, struct opp *opp)
+static int exynos4210_set_busclk(struct busfreq_data *data,
+				 struct busfreq_opp_info *oppi)
 {
 	unsigned int index;
 	unsigned int tmp;
 
 	for (index = LV_0; index < EX4210_LV_NUM; index++)
-		if (opp_get_freq(opp) == exynos4210_busclk_table[index].clk)
+		if (oppi->rate == exynos4210_busclk_table[index].clk)
 			break;
 
 	if (index == EX4210_LV_NUM)
@@ -361,13 +372,14 @@ static int exynos4210_set_busclk(struct busfreq_data *data, struct opp *opp)
 	return 0;
 }
 
-static int exynos4x12_set_busclk(struct busfreq_data *data, struct opp *opp)
+static int exynos4x12_set_busclk(struct busfreq_data *data,
+				 struct busfreq_opp_info *oppi)
 {
 	unsigned int index;
 	unsigned int tmp;
 
 	for (index = LV_0; index < EX4x12_LV_NUM; index++)
-		if (opp_get_freq(opp) == exynos4x12_mifclk_table[index].clk)
+		if (oppi->rate == exynos4x12_mifclk_table[index].clk)
 			break;
 
 	if (index == EX4x12_LV_NUM)
@@ -576,11 +588,12 @@ static int exynos4x12_get_intspec(unsigned long mifclk)
 	return -EINVAL;
 }
 
-static int exynos4_bus_setvolt(struct busfreq_data *data, struct opp *opp,
-			       struct opp *oldopp)
+static int exynos4_bus_setvolt(struct busfreq_data *data,
+			       struct busfreq_opp_info *oppi,
+			       struct busfreq_opp_info *oldoppi)
 {
 	int err = 0, tmp;
-	unsigned long volt = opp_get_voltage(opp);
+	unsigned long volt = oppi->volt;
 
 	switch (data->type) {
 	case TYPE_BUSF_EXYNOS4210:
@@ -595,11 +608,11 @@ static int exynos4_bus_setvolt(struct busfreq_data *data, struct opp *opp,
 		if (err)
 			break;
 
-		tmp = exynos4x12_get_intspec(opp_get_freq(opp));
+		tmp = exynos4x12_get_intspec(oppi->rate);
 		if (tmp < 0) {
 			err = tmp;
 			regulator_set_voltage(data->vdd_mif,
-					      opp_get_voltage(oldopp),
+					      oldoppi->volt,
 					      MAX_SAFEVOLT);
 			break;
 		}
@@ -609,7 +622,7 @@ static int exynos4_bus_setvolt(struct busfreq_data *data, struct opp *opp,
 		/*  Try to recover */
 		if (err)
 			regulator_set_voltage(data->vdd_mif,
-					      opp_get_voltage(oldopp),
+					      oldoppi->volt,
 					      MAX_SAFEVOLT);
 		break;
 	default:
@@ -626,17 +639,26 @@ static int exynos4_bus_target(struct device *dev, unsigned long *_freq,
 	struct platform_device *pdev = container_of(dev, struct platform_device,
 						    dev);
 	struct busfreq_data *data = platform_get_drvdata(pdev);
-	struct opp *opp = devfreq_recommended_opp(dev, _freq, flags);
-	unsigned long freq = opp_get_freq(opp);
-	unsigned long old_freq = opp_get_freq(data->curr_opp);
+	struct opp *opp;
+	unsigned long freq;
+	unsigned long old_freq = data->curr_oppinfo.rate;
+	struct busfreq_opp_info	new_oppinfo;
 
-	if (IS_ERR(opp))
+	rcu_read_lock();
+	opp = devfreq_recommended_opp(dev, _freq, flags);
+	if (IS_ERR(opp)) {
+		rcu_read_unlock();
 		return PTR_ERR(opp);
+	}
+	new_oppinfo.rate = opp_get_freq(opp);
+	new_oppinfo.volt = opp_get_voltage(opp);
+	rcu_read_unlock();
+	freq = new_oppinfo.rate;
 
 	if (old_freq == freq)
 		return 0;
 
-	dev_dbg(dev, "targetting %lukHz %luuV\n", freq, opp_get_voltage(opp));
+	dev_dbg(dev, "targetting %lukHz %luuV\n", freq, new_oppinfo.volt);
 
 	mutex_lock(&data->lock);
 
@@ -644,17 +666,18 @@ static int exynos4_bus_target(struct device *dev, unsigned long *_freq,
 		goto out;
 
 	if (old_freq < freq)
-		err = exynos4_bus_setvolt(data, opp, data->curr_opp);
+		err = exynos4_bus_setvolt(data, &new_oppinfo,
+					  &data->curr_oppinfo);
 	if (err)
 		goto out;
 
 	if (old_freq != freq) {
 		switch (data->type) {
 		case TYPE_BUSF_EXYNOS4210:
-			err = exynos4210_set_busclk(data, opp);
+			err = exynos4210_set_busclk(data, &new_oppinfo);
 			break;
 		case TYPE_BUSF_EXYNOS4x12:
-			err = exynos4x12_set_busclk(data, opp);
+			err = exynos4x12_set_busclk(data, &new_oppinfo);
 			break;
 		default:
 			err = -EINVAL;
@@ -664,11 +687,12 @@ static int exynos4_bus_target(struct device *dev, unsigned long *_freq,
 		goto out;
 
 	if (old_freq > freq)
-		err = exynos4_bus_setvolt(data, opp, data->curr_opp);
+		err = exynos4_bus_setvolt(data, &new_oppinfo,
+					  &data->curr_oppinfo);
 	if (err)
 		goto out;
 
-	data->curr_opp = opp;
+	data->curr_oppinfo = new_oppinfo;
 out:
 	mutex_unlock(&data->lock);
 	return err;
@@ -702,7 +726,7 @@ static int exynos4_bus_get_dev_status(struct device *dev,
 
 	exynos4_read_ppmu(data);
 	busier_dmc = exynos4_get_busier_dmc(data);
-	stat->current_frequency = opp_get_freq(data->curr_opp);
+	stat->current_frequency = data->curr_oppinfo.rate;
 
 	if (busier_dmc)
 		addr = S5P_VA_DMC1;
@@ -933,6 +957,7 @@ static int exynos4_busfreq_pm_notifier_event(struct notifier_block *this,
 	struct busfreq_data *data = container_of(this, struct busfreq_data,
 						 pm_notifier);
 	struct opp *opp;
+	struct busfreq_opp_info	new_oppinfo;
 	unsigned long maxfreq = ULONG_MAX;
 	int err = 0;
 
@@ -943,18 +968,29 @@ static int exynos4_busfreq_pm_notifier_event(struct notifier_block *this,
 
 		data->disabled = true;
 
+		rcu_read_lock();
 		opp = opp_find_freq_floor(data->dev, &maxfreq);
+		if (IS_ERR(opp)) {
+			rcu_read_unlock();
+			dev_err(data->dev, "%s: unable to find a min freq\n",
+				__func__);
+			return PTR_ERR(opp);
+		}
+		new_oppinfo.rate = opp_get_freq(opp);
+		new_oppinfo.volt = opp_get_voltage(opp);
+		rcu_read_unlock();
 
-		err = exynos4_bus_setvolt(data, opp, data->curr_opp);
+		err = exynos4_bus_setvolt(data, &new_oppinfo,
+					  &data->curr_oppinfo);
 		if (err)
 			goto unlock;
 
 		switch (data->type) {
 		case TYPE_BUSF_EXYNOS4210:
-			err = exynos4210_set_busclk(data, opp);
+			err = exynos4210_set_busclk(data, &new_oppinfo);
 			break;
 		case TYPE_BUSF_EXYNOS4x12:
-			err = exynos4x12_set_busclk(data, opp);
+			err = exynos4x12_set_busclk(data, &new_oppinfo);
 			break;
 		default:
 			err = -EINVAL;
@@ -962,7 +998,7 @@ static int exynos4_busfreq_pm_notifier_event(struct notifier_block *this,
 		if (err)
 			goto unlock;
 
-		data->curr_opp = opp;
+		data->curr_oppinfo = new_oppinfo;
 unlock:
 		mutex_unlock(&data->lock);
 		if (err)
@@ -1027,13 +1063,17 @@ static int exynos4_busfreq_probe(struct platform_device *pdev)
 		}
 	}
 
+	rcu_read_lock();
 	opp = opp_find_freq_floor(dev, &exynos4_devfreq_profile.initial_freq);
 	if (IS_ERR(opp)) {
+		rcu_read_unlock();
 		dev_err(dev, "Invalid initial frequency %lu kHz.\n",
 			exynos4_devfreq_profile.initial_freq);
 		return PTR_ERR(opp);
 	}
-	data->curr_opp = opp;
+	data->curr_oppinfo.rate = opp_get_freq(opp);
+	data->curr_oppinfo.volt = opp_get_voltage(opp);
+	rcu_read_unlock();
 
 	platform_set_drvdata(pdev, data);
 
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index 4ba384f1ab544976621e6dc48c46dd0453687fef..2df9414a72f7169fe1fccaec285c633ca45f75d1 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -448,8 +448,6 @@ static int intel_idle_probe(void)
 	else
 		on_each_cpu(__setup_broadcast_timer, (void *)true, 1);
 
-	register_cpu_notifier(&cpu_hotplug_notifier);
-
 	pr_debug(PREFIX "v" INTEL_IDLE_VERSION
 		" model 0x%X\n", boot_cpu_data.x86_model);
 
@@ -612,6 +610,7 @@ static int __init intel_idle_init(void)
 			return retval;
 		}
 	}
+	register_cpu_notifier(&cpu_hotplug_notifier);
 
 	return 0;
 }