Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1500 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c
new file mode 100644
index 000000000..841cb7f31
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/idle.c
@@ -0,0 +1,1500 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * PowerNV cpuidle code
+ *
+ * Copyright 2015 IBM Corp.
+ */
+
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/device.h>
+#include <linux/cpu.h>
+
+#include <asm/firmware.h>
+#include <asm/interrupt.h>
+#include <asm/machdep.h>
+#include <asm/opal.h>
+#include <asm/cputhreads.h>
+#include <asm/cpuidle.h>
+#include <asm/code-patching.h>
+#include <asm/smp.h>
+#include <asm/runlatch.h>
+#include <asm/dbell.h>
+
+#include "powernv.h"
+#include "subcore.h"
+
+/* Power ISA 3.0 allows for stop states 0x0 - 0xF */
+#define MAX_STOP_STATE	0xF
+
+#define P9_STOP_SPR_MSR 2000
+#define P9_STOP_SPR_PSSCR      855
+
+static u32 supported_cpuidle_states;
+struct pnv_idle_states_t *pnv_idle_states;
+int nr_pnv_idle_states;
+
+/*
+ * The default stop state that will be used by ppc_md.power_save
+ * function on platforms that support stop instruction.
+ */
+static u64 pnv_default_stop_val;
+static u64 pnv_default_stop_mask;
+static bool default_stop_found;
+
+/*
+ * First stop state levels when SPR and TB loss can occur.
+ */
+static u64 pnv_first_tb_loss_level = MAX_STOP_STATE + 1;
+static u64 deep_spr_loss_state = MAX_STOP_STATE + 1;
+
+/*
+ * psscr value and mask of the deepest stop idle state.
+ * Used when a cpu is offlined.
+ */
+static u64 pnv_deepest_stop_psscr_val;
+static u64 pnv_deepest_stop_psscr_mask;
+static u64 pnv_deepest_stop_flag;
+static bool deepest_stop_found;
+
+static unsigned long power7_offline_type;
+
+static int __init pnv_save_sprs_for_deep_states(void)
+{
+	int cpu;
+	int rc;
+
+	/*
+	 * hid0, hid1, hid4, hid5, hmeer and lpcr values are symmetric across
+	 * all cpus at boot. Get these reg values of current cpu and use the
+	 * same across all cpus.
+	 */
+	uint64_t lpcr_val	= mfspr(SPRN_LPCR);
+	uint64_t hid0_val	= mfspr(SPRN_HID0);
+	uint64_t hmeer_val	= mfspr(SPRN_HMEER);
+	uint64_t msr_val = MSR_IDLE;
+	uint64_t psscr_val = pnv_deepest_stop_psscr_val;
+
+	for_each_present_cpu(cpu) {
+		uint64_t pir = get_hard_smp_processor_id(cpu);
+		uint64_t hsprg0_val = (uint64_t)paca_ptrs[cpu];
+
+		rc = opal_slw_set_reg(pir, SPRN_HSPRG0, hsprg0_val);
+		if (rc != 0)
+			return rc;
+
+		rc = opal_slw_set_reg(pir, SPRN_LPCR, lpcr_val);
+		if (rc != 0)
+			return rc;
+
+		if (cpu_has_feature(CPU_FTR_ARCH_300)) {
+			rc = opal_slw_set_reg(pir, P9_STOP_SPR_MSR, msr_val);
+			if (rc)
+				return rc;
+
+			rc = opal_slw_set_reg(pir,
+					      P9_STOP_SPR_PSSCR, psscr_val);
+
+			if (rc)
+				return rc;
+		}
+
+		/* HIDs are per core registers */
+		if (cpu_thread_in_core(cpu) == 0) {
+
+			rc = opal_slw_set_reg(pir, SPRN_HMEER, hmeer_val);
+			if (rc != 0)
+				return rc;
+
+			rc = opal_slw_set_reg(pir, SPRN_HID0, hid0_val);
+			if (rc != 0)
+				return rc;
+
+			/* Only p8 needs to set extra HID registers */
+			if (!cpu_has_feature(CPU_FTR_ARCH_300)) {
+				uint64_t hid1_val = mfspr(SPRN_HID1);
+				uint64_t hid4_val = mfspr(SPRN_HID4);
+				uint64_t hid5_val = mfspr(SPRN_HID5);
+
+				rc = opal_slw_set_reg(pir, SPRN_HID1, hid1_val);
+				if (rc != 0)
+					return rc;
+
+				rc = opal_slw_set_reg(pir, SPRN_HID4, hid4_val);
+				if (rc != 0)
+					return rc;
+
+				rc = opal_slw_set_reg(pir, SPRN_HID5, hid5_val);
+				if (rc != 0)
+					return rc;
+			}
+		}
+	}
+
+	return 0;
+}
+
+u32 pnv_get_supported_cpuidle_states(void)
+{
+	return supported_cpuidle_states;
+}
+EXPORT_SYMBOL_GPL(pnv_get_supported_cpuidle_states);
+
+static void pnv_fastsleep_workaround_apply(void *info)
+
+{
+	int cpu = smp_processor_id();
+	int rc;
+	int *err = info;
+
+	if (cpu_first_thread_sibling(cpu) != cpu)
+		return;
+
+	rc = opal_config_cpu_idle_state(OPAL_CONFIG_IDLE_FASTSLEEP,
+					OPAL_CONFIG_IDLE_APPLY);
+	if (rc)
+		*err = 1;
+}
+
+static bool power7_fastsleep_workaround_entry = true;
+static bool power7_fastsleep_workaround_exit = true;
+
+/*
+ * Used to store fastsleep workaround state
+ * 0 - Workaround applied/undone at fastsleep entry/exit path (Default)
+ * 1 - Workaround applied once, never undone.
+ */
+static u8 fastsleep_workaround_applyonce;
+
+static ssize_t show_fastsleep_workaround_applyonce(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%u\n", fastsleep_workaround_applyonce);
+}
+
+static ssize_t store_fastsleep_workaround_applyonce(struct device *dev,
+		struct device_attribute *attr, const char *buf,
+		size_t count)
+{
+	int err;
+	u8 val;
+
+	if (kstrtou8(buf, 0, &val) || val != 1)
+		return -EINVAL;
+
+	if (fastsleep_workaround_applyonce == 1)
+		return count;
+
+	/*
+	 * fastsleep_workaround_applyonce = 1 implies
+	 * fastsleep workaround needs to be left in 'applied' state on all
+	 * the cores. Do this by-
+	 * 1. Disable the 'undo' workaround in fastsleep exit path
+	 * 2. Sendi IPIs to all the cores which have at least one online thread
+	 * 3. Disable the 'apply' workaround in fastsleep entry path
+	 *
+	 * There is no need to send ipi to cores which have all threads
+	 * offlined, as last thread of the core entering fastsleep or deeper
+	 * state would have applied workaround.
+	 */
+	power7_fastsleep_workaround_exit = false;
+
+	cpus_read_lock();
+	on_each_cpu(pnv_fastsleep_workaround_apply, &err, 1);
+	cpus_read_unlock();
+	if (err) {
+		pr_err("fastsleep_workaround_applyonce change failed while running pnv_fastsleep_workaround_apply");
+		goto fail;
+	}
+
+	power7_fastsleep_workaround_entry = false;
+
+	fastsleep_workaround_applyonce = 1;
+
+	return count;
+fail:
+	return -EIO;
+}
+
+static DEVICE_ATTR(fastsleep_workaround_applyonce, 0600,
+			show_fastsleep_workaround_applyonce,
+			store_fastsleep_workaround_applyonce);
+
+static inline void atomic_start_thread_idle(void)
+{
+	int cpu = raw_smp_processor_id();
+	int first = cpu_first_thread_sibling(cpu);
+	int thread_nr = cpu_thread_in_core(cpu);
+	unsigned long *state = &paca_ptrs[first]->idle_state;
+
+	clear_bit(thread_nr, state);
+}
+
+static inline void atomic_stop_thread_idle(void)
+{
+	int cpu = raw_smp_processor_id();
+	int first = cpu_first_thread_sibling(cpu);
+	int thread_nr = cpu_thread_in_core(cpu);
+	unsigned long *state = &paca_ptrs[first]->idle_state;
+
+	set_bit(thread_nr, state);
+}
+
+static inline void atomic_lock_thread_idle(void)
+{
+	int cpu = raw_smp_processor_id();
+	int first = cpu_first_thread_sibling(cpu);
+	unsigned long *state = &paca_ptrs[first]->idle_state;
+
+	while (unlikely(test_and_set_bit_lock(NR_PNV_CORE_IDLE_LOCK_BIT, state)))
+		barrier();
+}
+
+static inline void atomic_unlock_and_stop_thread_idle(void)
+{
+	int cpu = raw_smp_processor_id();
+	int first = cpu_first_thread_sibling(cpu);
+	unsigned long thread = 1UL << cpu_thread_in_core(cpu);
+	unsigned long *state = &paca_ptrs[first]->idle_state;
+	u64 s = READ_ONCE(*state);
+	u64 new, tmp;
+
+	BUG_ON(!(s & PNV_CORE_IDLE_LOCK_BIT));
+	BUG_ON(s & thread);
+
+again:
+	new = (s | thread) & ~PNV_CORE_IDLE_LOCK_BIT;
+	tmp = cmpxchg(state, s, new);
+	if (unlikely(tmp != s)) {
+		s = tmp;
+		goto again;
+	}
+}
+
+static inline void atomic_unlock_thread_idle(void)
+{
+	int cpu = raw_smp_processor_id();
+	int first = cpu_first_thread_sibling(cpu);
+	unsigned long *state = &paca_ptrs[first]->idle_state;
+
+	BUG_ON(!test_bit(NR_PNV_CORE_IDLE_LOCK_BIT, state));
+	clear_bit_unlock(NR_PNV_CORE_IDLE_LOCK_BIT, state);
+}
+
+/* P7 and P8 */
+struct p7_sprs {
+	/* per core */
+	u64 tscr;
+	u64 worc;
+
+	/* per subcore */
+	u64 sdr1;
+	u64 rpr;
+
+	/* per thread */
+	u64 lpcr;
+	u64 hfscr;
+	u64 fscr;
+	u64 purr;
+	u64 spurr;
+	u64 dscr;
+	u64 wort;
+
+	/* per thread SPRs that get lost in shallow states */
+	u64 amr;
+	u64 iamr;
+	u64 uamor;
+	/* amor is restored to constant ~0 */
+};
+
+static unsigned long power7_idle_insn(unsigned long type)
+{
+	int cpu = raw_smp_processor_id();
+	int first = cpu_first_thread_sibling(cpu);
+	unsigned long *state = &paca_ptrs[first]->idle_state;
+	unsigned long thread = 1UL << cpu_thread_in_core(cpu);
+	unsigned long core_thread_mask = (1UL << threads_per_core) - 1;
+	unsigned long srr1;
+	bool full_winkle;
+	struct p7_sprs sprs = {}; /* avoid false use-uninitialised */
+	bool sprs_saved = false;
+	int rc;
+
+	if (unlikely(type != PNV_THREAD_NAP)) {
+		atomic_lock_thread_idle();
+
+		BUG_ON(!(*state & thread));
+		*state &= ~thread;
+
+		if (power7_fastsleep_workaround_entry) {
+			if ((*state & core_thread_mask) == 0) {
+				rc = opal_config_cpu_idle_state(
+						OPAL_CONFIG_IDLE_FASTSLEEP,
+						OPAL_CONFIG_IDLE_APPLY);
+				BUG_ON(rc);
+			}
+		}
+
+		if (type == PNV_THREAD_WINKLE) {
+			sprs.tscr	= mfspr(SPRN_TSCR);
+			sprs.worc	= mfspr(SPRN_WORC);
+
+			sprs.sdr1	= mfspr(SPRN_SDR1);
+			sprs.rpr	= mfspr(SPRN_RPR);
+
+			sprs.lpcr	= mfspr(SPRN_LPCR);
+			if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
+				sprs.hfscr	= mfspr(SPRN_HFSCR);
+				sprs.fscr	= mfspr(SPRN_FSCR);
+			}
+			sprs.purr	= mfspr(SPRN_PURR);
+			sprs.spurr	= mfspr(SPRN_SPURR);
+			sprs.dscr	= mfspr(SPRN_DSCR);
+			sprs.wort	= mfspr(SPRN_WORT);
+
+			sprs_saved = true;
+
+			/*
+			 * Increment winkle counter and set all winkle bits if
+			 * all threads are winkling. This allows wakeup side to
+			 * distinguish between fast sleep and winkle state
+			 * loss. Fast sleep still has to resync the timebase so
+			 * this may not be a really big win.
+			 */
+			*state += 1 << PNV_CORE_IDLE_WINKLE_COUNT_SHIFT;
+			if ((*state & PNV_CORE_IDLE_WINKLE_COUNT_BITS)
+					>> PNV_CORE_IDLE_WINKLE_COUNT_SHIFT
+					== threads_per_core)
+				*state |= PNV_CORE_IDLE_THREAD_WINKLE_BITS;
+			WARN_ON((*state & PNV_CORE_IDLE_WINKLE_COUNT_BITS) == 0);
+		}
+
+		atomic_unlock_thread_idle();
+	}
+
+	if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
+		sprs.amr	= mfspr(SPRN_AMR);
+		sprs.iamr	= mfspr(SPRN_IAMR);
+		sprs.uamor	= mfspr(SPRN_UAMOR);
+	}
+
+	local_paca->thread_idle_state = type;
+	srr1 = isa206_idle_insn_mayloss(type);		/* go idle */
+	local_paca->thread_idle_state = PNV_THREAD_RUNNING;
+
+	WARN_ON_ONCE(!srr1);
+	WARN_ON_ONCE(mfmsr() & (MSR_IR|MSR_DR));
+
+	if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
+		if ((srr1 & SRR1_WAKESTATE) != SRR1_WS_NOLOSS) {
+			/*
+			 * We don't need an isync after the mtsprs here because
+			 * the upcoming mtmsrd is execution synchronizing.
+			 */
+			mtspr(SPRN_AMR,		sprs.amr);
+			mtspr(SPRN_IAMR,	sprs.iamr);
+			mtspr(SPRN_AMOR,	~0);
+			mtspr(SPRN_UAMOR,	sprs.uamor);
+		}
+	}
+
+	if (unlikely((srr1 & SRR1_WAKEMASK_P8) == SRR1_WAKEHMI))
+		hmi_exception_realmode(NULL);
+
+	if (likely((srr1 & SRR1_WAKESTATE) != SRR1_WS_HVLOSS)) {
+		if (unlikely(type != PNV_THREAD_NAP)) {
+			atomic_lock_thread_idle();
+			if (type == PNV_THREAD_WINKLE) {
+				WARN_ON((*state & PNV_CORE_IDLE_WINKLE_COUNT_BITS) == 0);
+				*state -= 1 << PNV_CORE_IDLE_WINKLE_COUNT_SHIFT;
+				*state &= ~(thread << PNV_CORE_IDLE_THREAD_WINKLE_BITS_SHIFT);
+			}
+			atomic_unlock_and_stop_thread_idle();
+		}
+		return srr1;
+	}
+
+	/* HV state loss */
+	BUG_ON(type == PNV_THREAD_NAP);
+
+	atomic_lock_thread_idle();
+
+	full_winkle = false;
+	if (type == PNV_THREAD_WINKLE) {
+		WARN_ON((*state & PNV_CORE_IDLE_WINKLE_COUNT_BITS) == 0);
+		*state -= 1 << PNV_CORE_IDLE_WINKLE_COUNT_SHIFT;
+		if (*state & (thread << PNV_CORE_IDLE_THREAD_WINKLE_BITS_SHIFT)) {
+			*state &= ~(thread << PNV_CORE_IDLE_THREAD_WINKLE_BITS_SHIFT);
+			full_winkle = true;
+			BUG_ON(!sprs_saved);
+		}
+	}
+
+	WARN_ON(*state & thread);
+
+	if ((*state & core_thread_mask) != 0)
+		goto core_woken;
+
+	/* Per-core SPRs */
+	if (full_winkle) {
+		mtspr(SPRN_TSCR,	sprs.tscr);
+		mtspr(SPRN_WORC,	sprs.worc);
+	}
+
+	if (power7_fastsleep_workaround_exit) {
+		rc = opal_config_cpu_idle_state(OPAL_CONFIG_IDLE_FASTSLEEP,
+						OPAL_CONFIG_IDLE_UNDO);
+		BUG_ON(rc);
+	}
+
+	/* TB */
+	if (opal_resync_timebase() != OPAL_SUCCESS)
+		BUG();
+
+core_woken:
+	if (!full_winkle)
+		goto subcore_woken;
+
+	if ((*state & local_paca->subcore_sibling_mask) != 0)
+		goto subcore_woken;
+
+	/* Per-subcore SPRs */
+	mtspr(SPRN_SDR1,	sprs.sdr1);
+	mtspr(SPRN_RPR,		sprs.rpr);
+
+subcore_woken:
+	/*
+	 * isync after restoring shared SPRs and before unlocking. Unlock
+	 * only contains hwsync which does not necessarily do the right
+	 * thing for SPRs.
+	 */
+	isync();
+	atomic_unlock_and_stop_thread_idle();
+
+	/* Fast sleep does not lose SPRs */
+	if (!full_winkle)
+		return srr1;
+
+	/* Per-thread SPRs */
+	mtspr(SPRN_LPCR,	sprs.lpcr);
+	if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
+		mtspr(SPRN_HFSCR,	sprs.hfscr);
+		mtspr(SPRN_FSCR,	sprs.fscr);
+	}
+	mtspr(SPRN_PURR,	sprs.purr);
+	mtspr(SPRN_SPURR,	sprs.spurr);
+	mtspr(SPRN_DSCR,	sprs.dscr);
+	mtspr(SPRN_WORT,	sprs.wort);
+
+	mtspr(SPRN_SPRG3,	local_paca->sprg_vdso);
+
+#ifdef CONFIG_PPC_64S_HASH_MMU
+	/*
+	 * The SLB has to be restored here, but it sometimes still
+	 * contains entries, so the __ variant must be used to prevent
+	 * multi hits.
+	 */
+	__slb_restore_bolted_realmode();
+#endif
+
+	return srr1;
+}
+
+extern unsigned long idle_kvm_start_guest(unsigned long srr1);
+
+#ifdef CONFIG_HOTPLUG_CPU
+static unsigned long power7_offline(void)
+{
+	unsigned long srr1;
+
+	mtmsr(MSR_IDLE);
+
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+	/* Tell KVM we're entering idle. */
+	/******************************************************/
+	/*  N O T E   W E L L    ! ! !    N O T E   W E L L   */
+	/* The following store to HSTATE_HWTHREAD_STATE(r13)  */
+	/* MUST occur in real mode, i.e. with the MMU off,    */
+	/* and the MMU must stay off until we clear this flag */
+	/* and test HSTATE_HWTHREAD_REQ(r13) in               */
+	/* pnv_powersave_wakeup in this file.                 */
+	/* The reason is that another thread can switch the   */
+	/* MMU to a guest context whenever this flag is set   */
+	/* to KVM_HWTHREAD_IN_IDLE, and if the MMU was on,    */
+	/* that would potentially cause this thread to start  */
+	/* executing instructions from guest memory in        */
+	/* hypervisor mode, leading to a host crash or data   */
+	/* corruption, or worse.                              */
+	/******************************************************/
+	local_paca->kvm_hstate.hwthread_state = KVM_HWTHREAD_IN_IDLE;
+#endif
+
+	__ppc64_runlatch_off();
+	srr1 = power7_idle_insn(power7_offline_type);
+	__ppc64_runlatch_on();
+
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+	local_paca->kvm_hstate.hwthread_state = KVM_HWTHREAD_IN_KERNEL;
+	/* Order setting hwthread_state vs. testing hwthread_req */
+	smp_mb();
+	if (local_paca->kvm_hstate.hwthread_req)
+		srr1 = idle_kvm_start_guest(srr1);
+#endif
+
+	mtmsr(MSR_KERNEL);
+
+	return srr1;
+}
+#endif
+
+void power7_idle_type(unsigned long type)
+{
+	unsigned long srr1;
+
+	if (!prep_irq_for_idle_irqsoff())
+		return;
+
+	mtmsr(MSR_IDLE);
+	__ppc64_runlatch_off();
+	srr1 = power7_idle_insn(type);
+	__ppc64_runlatch_on();
+	mtmsr(MSR_KERNEL);
+
+	fini_irq_for_idle_irqsoff();
+	irq_set_pending_from_srr1(srr1);
+}
+
+static void power7_idle(void)
+{
+	if (!powersave_nap)
+		return;
+
+	power7_idle_type(PNV_THREAD_NAP);
+}
+
+struct p9_sprs {
+	/* per core */
+	u64 ptcr;
+	u64 rpr;
+	u64 tscr;
+	u64 ldbar;
+
+	/* per thread */
+	u64 lpcr;
+	u64 hfscr;
+	u64 fscr;
+	u64 pid;
+	u64 purr;
+	u64 spurr;
+	u64 dscr;
+	u64 ciabr;
+
+	u64 mmcra;
+	u32 mmcr0;
+	u32 mmcr1;
+	u64 mmcr2;
+
+	/* per thread SPRs that get lost in shallow states */
+	u64 amr;
+	u64 iamr;
+	u64 amor;
+	u64 uamor;
+};
+
+static unsigned long power9_idle_stop(unsigned long psscr)
+{
+	int cpu = raw_smp_processor_id();
+	int first = cpu_first_thread_sibling(cpu);
+	unsigned long *state = &paca_ptrs[first]->idle_state;
+	unsigned long core_thread_mask = (1UL << threads_per_core) - 1;
+	unsigned long srr1;
+	unsigned long pls;
+	unsigned long mmcr0 = 0;
+	unsigned long mmcra = 0;
+	struct p9_sprs sprs = {}; /* avoid false used-uninitialised */
+	bool sprs_saved = false;
+
+	if (!(psscr & (PSSCR_EC|PSSCR_ESL))) {
+		/* EC=ESL=0 case */
+
+		/*
+		 * Wake synchronously. SRESET via xscom may still cause
+		 * a 0x100 powersave wakeup with SRR1 reason!
+		 */
+		srr1 = isa300_idle_stop_noloss(psscr);		/* go idle */
+		if (likely(!srr1))
+			return 0;
+
+		/*
+		 * Registers not saved, can't recover!
+		 * This would be a hardware bug
+		 */
+		BUG_ON((srr1 & SRR1_WAKESTATE) != SRR1_WS_NOLOSS);
+
+		goto out;
+	}
+
+	/* EC=ESL=1 case */
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+	if (cpu_has_feature(CPU_FTR_P9_TM_XER_SO_BUG)) {
+		local_paca->requested_psscr = psscr;
+		/* order setting requested_psscr vs testing dont_stop */
+		smp_mb();
+		if (atomic_read(&local_paca->dont_stop)) {
+			local_paca->requested_psscr = 0;
+			return 0;
+		}
+	}
+#endif
+
+	if (!cpu_has_feature(CPU_FTR_POWER9_DD2_1)) {
+		 /*
+		  * POWER9 DD2 can incorrectly set PMAO when waking up
+		  * after a state-loss idle. Saving and restoring MMCR0
+		  * over idle is a workaround.
+		  */
+		mmcr0		= mfspr(SPRN_MMCR0);
+	}
+
+	if ((psscr & PSSCR_RL_MASK) >= deep_spr_loss_state) {
+		sprs.lpcr	= mfspr(SPRN_LPCR);
+		sprs.hfscr	= mfspr(SPRN_HFSCR);
+		sprs.fscr	= mfspr(SPRN_FSCR);
+		sprs.pid	= mfspr(SPRN_PID);
+		sprs.purr	= mfspr(SPRN_PURR);
+		sprs.spurr	= mfspr(SPRN_SPURR);
+		sprs.dscr	= mfspr(SPRN_DSCR);
+		sprs.ciabr	= mfspr(SPRN_CIABR);
+
+		sprs.mmcra	= mfspr(SPRN_MMCRA);
+		sprs.mmcr0	= mfspr(SPRN_MMCR0);
+		sprs.mmcr1	= mfspr(SPRN_MMCR1);
+		sprs.mmcr2	= mfspr(SPRN_MMCR2);
+
+		sprs.ptcr	= mfspr(SPRN_PTCR);
+		sprs.rpr	= mfspr(SPRN_RPR);
+		sprs.tscr	= mfspr(SPRN_TSCR);
+		if (!firmware_has_feature(FW_FEATURE_ULTRAVISOR))
+			sprs.ldbar = mfspr(SPRN_LDBAR);
+
+		sprs_saved = true;
+
+		atomic_start_thread_idle();
+	}
+
+	sprs.amr	= mfspr(SPRN_AMR);
+	sprs.iamr	= mfspr(SPRN_IAMR);
+	sprs.uamor	= mfspr(SPRN_UAMOR);
+
+	srr1 = isa300_idle_stop_mayloss(psscr);		/* go idle */
+
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+	local_paca->requested_psscr = 0;
+#endif
+
+	psscr = mfspr(SPRN_PSSCR);
+
+	WARN_ON_ONCE(!srr1);
+	WARN_ON_ONCE(mfmsr() & (MSR_IR|MSR_DR));
+
+	if ((srr1 & SRR1_WAKESTATE) != SRR1_WS_NOLOSS) {
+		/*
+		 * We don't need an isync after the mtsprs here because the
+		 * upcoming mtmsrd is execution synchronizing.
+		 */
+		mtspr(SPRN_AMR,		sprs.amr);
+		mtspr(SPRN_IAMR,	sprs.iamr);
+		mtspr(SPRN_AMOR,	~0);
+		mtspr(SPRN_UAMOR,	sprs.uamor);
+
+		/*
+		 * Workaround for POWER9 DD2.0, if we lost resources, the ERAT
+		 * might have been corrupted and needs flushing. We also need
+		 * to reload MMCR0 (see mmcr0 comment above).
+		 */
+		if (!cpu_has_feature(CPU_FTR_POWER9_DD2_1)) {
+			asm volatile(PPC_ISA_3_0_INVALIDATE_ERAT);
+			mtspr(SPRN_MMCR0, mmcr0);
+		}
+
+		/*
+		 * DD2.2 and earlier need to set then clear bit 60 in MMCRA
+		 * to ensure the PMU starts running.
+		 */
+		mmcra = mfspr(SPRN_MMCRA);
+		mmcra |= PPC_BIT(60);
+		mtspr(SPRN_MMCRA, mmcra);
+		mmcra &= ~PPC_BIT(60);
+		mtspr(SPRN_MMCRA, mmcra);
+	}
+
+	if (unlikely((srr1 & SRR1_WAKEMASK_P8) == SRR1_WAKEHMI))
+		hmi_exception_realmode(NULL);
+
+	/*
+	 * On POWER9, SRR1 bits do not match exactly as expected.
+	 * SRR1_WS_GPRLOSS (10b) can also result in SPR loss, so
+	 * just always test PSSCR for SPR/TB state loss.
+	 */
+	pls = (psscr & PSSCR_PLS) >> PSSCR_PLS_SHIFT;
+	if (likely(pls < deep_spr_loss_state)) {
+		if (sprs_saved)
+			atomic_stop_thread_idle();
+		goto out;
+	}
+
+	/* HV state loss */
+	BUG_ON(!sprs_saved);
+
+	atomic_lock_thread_idle();
+
+	if ((*state & core_thread_mask) != 0)
+		goto core_woken;
+
+	/* Per-core SPRs */
+	mtspr(SPRN_PTCR,	sprs.ptcr);
+	mtspr(SPRN_RPR,		sprs.rpr);
+	mtspr(SPRN_TSCR,	sprs.tscr);
+
+	if (pls >= pnv_first_tb_loss_level) {
+		/* TB loss */
+		if (opal_resync_timebase() != OPAL_SUCCESS)
+			BUG();
+	}
+
+	/*
+	 * isync after restoring shared SPRs and before unlocking. Unlock
+	 * only contains hwsync which does not necessarily do the right
+	 * thing for SPRs.
+	 */
+	isync();
+
+core_woken:
+	atomic_unlock_and_stop_thread_idle();
+
+	/* Per-thread SPRs */
+	mtspr(SPRN_LPCR,	sprs.lpcr);
+	mtspr(SPRN_HFSCR,	sprs.hfscr);
+	mtspr(SPRN_FSCR,	sprs.fscr);
+	mtspr(SPRN_PID,		sprs.pid);
+	mtspr(SPRN_PURR,	sprs.purr);
+	mtspr(SPRN_SPURR,	sprs.spurr);
+	mtspr(SPRN_DSCR,	sprs.dscr);
+	mtspr(SPRN_CIABR,	sprs.ciabr);
+
+	mtspr(SPRN_MMCRA,	sprs.mmcra);
+	mtspr(SPRN_MMCR0,	sprs.mmcr0);
+	mtspr(SPRN_MMCR1,	sprs.mmcr1);
+	mtspr(SPRN_MMCR2,	sprs.mmcr2);
+	if (!firmware_has_feature(FW_FEATURE_ULTRAVISOR))
+		mtspr(SPRN_LDBAR, sprs.ldbar);
+
+	mtspr(SPRN_SPRG3,	local_paca->sprg_vdso);
+
+	if (!radix_enabled())
+		__slb_restore_bolted_realmode();
+
+out:
+	mtmsr(MSR_KERNEL);
+
+	return srr1;
+}
+
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+/*
+ * This is used in working around bugs in thread reconfiguration
+ * on POWER9 (at least up to Nimbus DD2.2) relating to transactional
+ * memory and the way that XER[SO] is checkpointed.
+ * This function forces the core into SMT4 in order by asking
+ * all other threads not to stop, and sending a message to any
+ * that are in a stop state.
+ * Must be called with preemption disabled.
+ */
+void pnv_power9_force_smt4_catch(void)
+{
+	int cpu, cpu0, thr;
+	int awake_threads = 1;		/* this thread is awake */
+	int poke_threads = 0;
+	int need_awake = threads_per_core;
+
+	cpu = smp_processor_id();
+	cpu0 = cpu & ~(threads_per_core - 1);
+	for (thr = 0; thr < threads_per_core; ++thr) {
+		if (cpu != cpu0 + thr)
+			atomic_inc(&paca_ptrs[cpu0+thr]->dont_stop);
+	}
+	/* order setting dont_stop vs testing requested_psscr */
+	smp_mb();
+	for (thr = 0; thr < threads_per_core; ++thr) {
+		if (!paca_ptrs[cpu0+thr]->requested_psscr)
+			++awake_threads;
+		else
+			poke_threads |= (1 << thr);
+	}
+
+	/* If at least 3 threads are awake, the core is in SMT4 already */
+	if (awake_threads < need_awake) {
+		/* We have to wake some threads; we'll use msgsnd */
+		for (thr = 0; thr < threads_per_core; ++thr) {
+			if (poke_threads & (1 << thr)) {
+				ppc_msgsnd_sync();
+				ppc_msgsnd(PPC_DBELL_MSGTYPE, 0,
+					   paca_ptrs[cpu0+thr]->hw_cpu_id);
+			}
+		}
+		/* now spin until at least 3 threads are awake */
+		do {
+			for (thr = 0; thr < threads_per_core; ++thr) {
+				if ((poke_threads & (1 << thr)) &&
+				    !paca_ptrs[cpu0+thr]->requested_psscr) {
+					++awake_threads;
+					poke_threads &= ~(1 << thr);
+				}
+			}
+		} while (awake_threads < need_awake);
+	}
+}
+EXPORT_SYMBOL_GPL(pnv_power9_force_smt4_catch);
+
+void pnv_power9_force_smt4_release(void)
+{
+	int cpu, cpu0, thr;
+
+	cpu = smp_processor_id();
+	cpu0 = cpu & ~(threads_per_core - 1);
+
+	/* clear all the dont_stop flags */
+	for (thr = 0; thr < threads_per_core; ++thr) {
+		if (cpu != cpu0 + thr)
+			atomic_dec(&paca_ptrs[cpu0+thr]->dont_stop);
+	}
+}
+EXPORT_SYMBOL_GPL(pnv_power9_force_smt4_release);
+#endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */
+
+struct p10_sprs {
+	/*
+	 * SPRs that get lost in shallow states:
+	 *
+	 * P10 loses CR, LR, CTR, FPSCR, VSCR, XER, TAR, SPRG2, and HSPRG1
+	 * isa300 idle routines restore CR, LR.
+	 * CTR is volatile
+	 * idle thread doesn't use FP or VEC
+	 * kernel doesn't use TAR
+	 * HSPRG1 is only live in HV interrupt entry
+	 * SPRG2 is only live in KVM guests, KVM handles it.
+	 */
+};
+
+static unsigned long power10_idle_stop(unsigned long psscr)
+{
+	int cpu = raw_smp_processor_id();
+	int first = cpu_first_thread_sibling(cpu);
+	unsigned long *state = &paca_ptrs[first]->idle_state;
+	unsigned long core_thread_mask = (1UL << threads_per_core) - 1;
+	unsigned long srr1;
+	unsigned long pls;
+//	struct p10_sprs sprs = {}; /* avoid false used-uninitialised */
+	bool sprs_saved = false;
+
+	if (!(psscr & (PSSCR_EC|PSSCR_ESL))) {
+		/* EC=ESL=0 case */
+
+		/*
+		 * Wake synchronously. SRESET via xscom may still cause
+		 * a 0x100 powersave wakeup with SRR1 reason!
+		 */
+		srr1 = isa300_idle_stop_noloss(psscr);		/* go idle */
+		if (likely(!srr1))
+			return 0;
+
+		/*
+		 * Registers not saved, can't recover!
+		 * This would be a hardware bug
+		 */
+		BUG_ON((srr1 & SRR1_WAKESTATE) != SRR1_WS_NOLOSS);
+
+		goto out;
+	}
+
+	/* EC=ESL=1 case */
+	if ((psscr & PSSCR_RL_MASK) >= deep_spr_loss_state) {
+		/* XXX: save SPRs for deep state loss here. */
+
+		sprs_saved = true;
+
+		atomic_start_thread_idle();
+	}
+
+	srr1 = isa300_idle_stop_mayloss(psscr);		/* go idle */
+
+	psscr = mfspr(SPRN_PSSCR);
+
+	WARN_ON_ONCE(!srr1);
+	WARN_ON_ONCE(mfmsr() & (MSR_IR|MSR_DR));
+
+	if (unlikely((srr1 & SRR1_WAKEMASK_P8) == SRR1_WAKEHMI))
+		hmi_exception_realmode(NULL);
+
+	/*
+	 * On POWER10, SRR1 bits do not match exactly as expected.
+	 * SRR1_WS_GPRLOSS (10b) can also result in SPR loss, so
+	 * just always test PSSCR for SPR/TB state loss.
+	 */
+	pls = (psscr & PSSCR_PLS) >> PSSCR_PLS_SHIFT;
+	if (likely(pls < deep_spr_loss_state)) {
+		if (sprs_saved)
+			atomic_stop_thread_idle();
+		goto out;
+	}
+
+	/* HV state loss */
+	BUG_ON(!sprs_saved);
+
+	atomic_lock_thread_idle();
+
+	if ((*state & core_thread_mask) != 0)
+		goto core_woken;
+
+	/* XXX: restore per-core SPRs here */
+
+	if (pls >= pnv_first_tb_loss_level) {
+		/* TB loss */
+		if (opal_resync_timebase() != OPAL_SUCCESS)
+			BUG();
+	}
+
+	/*
+	 * isync after restoring shared SPRs and before unlocking. Unlock
+	 * only contains hwsync which does not necessarily do the right
+	 * thing for SPRs.
+	 */
+	isync();
+
+core_woken:
+	atomic_unlock_and_stop_thread_idle();
+
+	/* XXX: restore per-thread SPRs here */
+
+	if (!radix_enabled())
+		__slb_restore_bolted_realmode();
+
+out:
+	mtmsr(MSR_KERNEL);
+
+	return srr1;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static unsigned long arch300_offline_stop(unsigned long psscr)
+{
+	unsigned long srr1;
+
+	if (cpu_has_feature(CPU_FTR_ARCH_31))
+		srr1 = power10_idle_stop(psscr);
+	else
+		srr1 = power9_idle_stop(psscr);
+
+	return srr1;
+}
+#endif
+
+void arch300_idle_type(unsigned long stop_psscr_val,
+				      unsigned long stop_psscr_mask)
+{
+	unsigned long psscr;
+	unsigned long srr1;
+
+	if (!prep_irq_for_idle_irqsoff())
+		return;
+
+	psscr = mfspr(SPRN_PSSCR);
+	psscr = (psscr & ~stop_psscr_mask) | stop_psscr_val;
+
+	__ppc64_runlatch_off();
+	if (cpu_has_feature(CPU_FTR_ARCH_31))
+		srr1 = power10_idle_stop(psscr);
+	else
+		srr1 = power9_idle_stop(psscr);
+	__ppc64_runlatch_on();
+
+	fini_irq_for_idle_irqsoff();
+
+	irq_set_pending_from_srr1(srr1);
+}
+
+/*
+ * Used for ppc_md.power_save which needs a function with no parameters
+ */
+static void arch300_idle(void)
+{
+	arch300_idle_type(pnv_default_stop_val, pnv_default_stop_mask);
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+void pnv_program_cpu_hotplug_lpcr(unsigned int cpu, u64 lpcr_val)
+{
+	u64 pir = get_hard_smp_processor_id(cpu);
+
+	mtspr(SPRN_LPCR, lpcr_val);
+
+	/*
+	 * Program the LPCR via stop-api only if the deepest stop state
+	 * can lose hypervisor context.
+	 */
+	if (supported_cpuidle_states & OPAL_PM_LOSE_FULL_CONTEXT)
+		opal_slw_set_reg(pir, SPRN_LPCR, lpcr_val);
+}
+
+/*
+ * pnv_cpu_offline: A function that puts the CPU into the deepest
+ * available platform idle state on a CPU-Offline.
+ * interrupts hard disabled and no lazy irq pending.
+ */
+unsigned long pnv_cpu_offline(unsigned int cpu)
+{
+	unsigned long srr1;
+
+	__ppc64_runlatch_off();
+
+	if (cpu_has_feature(CPU_FTR_ARCH_300) && deepest_stop_found) {
+		unsigned long psscr;
+
+		psscr = mfspr(SPRN_PSSCR);
+		psscr = (psscr & ~pnv_deepest_stop_psscr_mask) |
+						pnv_deepest_stop_psscr_val;
+		srr1 = arch300_offline_stop(psscr);
+	} else if (cpu_has_feature(CPU_FTR_ARCH_206) && power7_offline_type) {
+		srr1 = power7_offline();
+	} else {
+		/* This is the fallback method. We emulate snooze */
+		while (!generic_check_cpu_restart(cpu)) {
+			HMT_low();
+			HMT_very_low();
+		}
+		srr1 = 0;
+		HMT_medium();
+	}
+
+	__ppc64_runlatch_on();
+
+	return srr1;
+}
+#endif
+
+/*
+ * Power ISA 3.0 idle initialization.
+ *
+ * POWER ISA 3.0 defines a new SPR Processor stop Status and Control
+ * Register (PSSCR) to control idle behavior.
+ *
+ * PSSCR layout:
+ * ----------------------------------------------------------
+ * | PLS | /// | SD | ESL | EC | PSLL | /// | TR | MTL | RL |
+ * ----------------------------------------------------------
+ * 0      4     41   42    43   44     48    54   56    60
+ *
+ * PSSCR key fields:
+ *	Bits 0:3  - Power-Saving Level Status (PLS). This field indicates the
+ *	lowest power-saving state the thread entered since stop instruction was
+ *	last executed.
+ *
+ *	Bit 41 - Status Disable(SD)
+ *	0 - Shows PLS entries
+ *	1 - PLS entries are all 0
+ *
+ *	Bit 42 - Enable State Loss
+ *	0 - No state is lost irrespective of other fields
+ *	1 - Allows state loss
+ *
+ *	Bit 43 - Exit Criterion
+ *	0 - Exit from power-save mode on any interrupt
+ *	1 - Exit from power-save mode controlled by LPCR's PECE bits
+ *
+ *	Bits 44:47 - Power-Saving Level Limit
+ *	This limits the power-saving level that can be entered into.
+ *
+ *	Bits 60:63 - Requested Level
+ *	Used to specify which power-saving level must be entered on executing
+ *	stop instruction
+ */
+
+int __init validate_psscr_val_mask(u64 *psscr_val, u64 *psscr_mask, u32 flags)
+{
+	int err = 0;
+
+	/*
+	 * psscr_mask == 0xf indicates an older firmware.
+	 * Set remaining fields of psscr to the default values.
+	 * See NOTE above definition of PSSCR_HV_DEFAULT_VAL
+	 */
+	if (*psscr_mask == 0xf) {
+		*psscr_val = *psscr_val | PSSCR_HV_DEFAULT_VAL;
+		*psscr_mask = PSSCR_HV_DEFAULT_MASK;
+		return err;
+	}
+
+	/*
+	 * New firmware is expected to set the psscr_val bits correctly.
+	 * Validate that the following invariants are correctly maintained by
+	 * the new firmware.
+	 * - ESL bit value matches the EC bit value.
+	 * - ESL bit is set for all the deep stop states.
+	 */
+	if (GET_PSSCR_ESL(*psscr_val) != GET_PSSCR_EC(*psscr_val)) {
+		err = ERR_EC_ESL_MISMATCH;
+	} else if ((flags & OPAL_PM_LOSE_FULL_CONTEXT) &&
+		GET_PSSCR_ESL(*psscr_val) == 0) {
+		err = ERR_DEEP_STATE_ESL_MISMATCH;
+	}
+
+	return err;
+}
+
+/*
+ * pnv_arch300_idle_init: Initializes the default idle state, first
+ *                        deep idle state and deepest idle state on
+ *                        ISA 3.0 CPUs.
+ *
+ * @np: /ibm,opal/power-mgt device node
+ * @flags: cpu-idle-state-flags array
+ * @dt_idle_states: Number of idle state entries
+ * Returns 0 on success
+ */
+static void __init pnv_arch300_idle_init(void)
+{
+	u64 max_residency_ns = 0;
+	int i;
+
+	/* stop is not really architected, we only have p9,p10 drivers */
+	if (!pvr_version_is(PVR_POWER10) && !pvr_version_is(PVR_POWER9))
+		return;
+
+	/*
+	 * pnv_deepest_stop_{val,mask} should be set to values corresponding to
+	 * the deepest stop state.
+	 *
+	 * pnv_default_stop_{val,mask} should be set to values corresponding to
+	 * the deepest loss-less (OPAL_PM_STOP_INST_FAST) stop state.
+	 */
+	pnv_first_tb_loss_level = MAX_STOP_STATE + 1;
+	deep_spr_loss_state = MAX_STOP_STATE + 1;
+	for (i = 0; i < nr_pnv_idle_states; i++) {
+		int err;
+		struct pnv_idle_states_t *state = &pnv_idle_states[i];
+		u64 psscr_rl = state->psscr_val & PSSCR_RL_MASK;
+
+		/* No deep loss driver implemented for POWER10 yet */
+		if (pvr_version_is(PVR_POWER10) &&
+				state->flags & (OPAL_PM_TIMEBASE_STOP|OPAL_PM_LOSE_FULL_CONTEXT))
+			continue;
+
+		if ((state->flags & OPAL_PM_TIMEBASE_STOP) &&
+		     (pnv_first_tb_loss_level > psscr_rl))
+			pnv_first_tb_loss_level = psscr_rl;
+
+		if ((state->flags & OPAL_PM_LOSE_FULL_CONTEXT) &&
+		     (deep_spr_loss_state > psscr_rl))
+			deep_spr_loss_state = psscr_rl;
+
+		/*
+		 * The idle code does not deal with TB loss occurring
+		 * in a shallower state than SPR loss, so force it to
+		 * behave like SPRs are lost if TB is lost. POWER9 would
+		 * never encounter this, but a POWER8 core would if it
+		 * implemented the stop instruction. So this is for forward
+		 * compatibility.
+		 */
+		if ((state->flags & OPAL_PM_TIMEBASE_STOP) &&
+		     (deep_spr_loss_state > psscr_rl))
+			deep_spr_loss_state = psscr_rl;
+
+		err = validate_psscr_val_mask(&state->psscr_val,
+					      &state->psscr_mask,
+					      state->flags);
+		if (err) {
+			report_invalid_psscr_val(state->psscr_val, err);
+			continue;
+		}
+
+		state->valid = true;
+
+		if (max_residency_ns < state->residency_ns) {
+			max_residency_ns = state->residency_ns;
+			pnv_deepest_stop_psscr_val = state->psscr_val;
+			pnv_deepest_stop_psscr_mask = state->psscr_mask;
+			pnv_deepest_stop_flag = state->flags;
+			deepest_stop_found = true;
+		}
+
+		if (!default_stop_found &&
+		    (state->flags & OPAL_PM_STOP_INST_FAST)) {
+			pnv_default_stop_val = state->psscr_val;
+			pnv_default_stop_mask = state->psscr_mask;
+			default_stop_found = true;
+			WARN_ON(state->flags & OPAL_PM_LOSE_FULL_CONTEXT);
+		}
+	}
+
+	if (unlikely(!default_stop_found)) {
+		pr_warn("cpuidle-powernv: No suitable default stop state found. Disabling platform idle.\n");
+	} else {
+		ppc_md.power_save = arch300_idle;
+		pr_info("cpuidle-powernv: Default stop: psscr = 0x%016llx,mask=0x%016llx\n",
+			pnv_default_stop_val, pnv_default_stop_mask);
+	}
+
+	if (unlikely(!deepest_stop_found)) {
+		pr_warn("cpuidle-powernv: No suitable stop state for CPU-Hotplug. Offlined CPUs will busy wait");
+	} else {
+		pr_info("cpuidle-powernv: Deepest stop: psscr = 0x%016llx,mask=0x%016llx\n",
+			pnv_deepest_stop_psscr_val,
+			pnv_deepest_stop_psscr_mask);
+	}
+
+	pr_info("cpuidle-powernv: First stop level that may lose SPRs = 0x%llx\n",
+		deep_spr_loss_state);
+
+	pr_info("cpuidle-powernv: First stop level that may lose timebase = 0x%llx\n",
+		pnv_first_tb_loss_level);
+}
+
+static void __init pnv_disable_deep_states(void)
+{
+	/*
+	 * The stop-api is unable to restore hypervisor
+	 * resources on wakeup from platform idle states which
+	 * lose full context. So disable such states.
+	 */
+	supported_cpuidle_states &= ~OPAL_PM_LOSE_FULL_CONTEXT;
+	pr_warn("cpuidle-powernv: Disabling idle states that lose full context\n");
+	pr_warn("cpuidle-powernv: Idle power-savings, CPU-Hotplug affected\n");
+
+	if (cpu_has_feature(CPU_FTR_ARCH_300) &&
+	    (pnv_deepest_stop_flag & OPAL_PM_LOSE_FULL_CONTEXT)) {
+		/*
+		 * Use the default stop state for CPU-Hotplug
+		 * if available.
+		 */
+		if (default_stop_found) {
+			pnv_deepest_stop_psscr_val = pnv_default_stop_val;
+			pnv_deepest_stop_psscr_mask = pnv_default_stop_mask;
+			pr_warn("cpuidle-powernv: Offlined CPUs will stop with psscr = 0x%016llx\n",
+				pnv_deepest_stop_psscr_val);
+		} else { /* Fallback to snooze loop for CPU-Hotplug */
+			deepest_stop_found = false;
+			pr_warn("cpuidle-powernv: Offlined CPUs will busy wait\n");
+		}
+	}
+}
+
+/*
+ * Probe device tree for supported idle states
+ */
+static void __init pnv_probe_idle_states(void)
+{
+	int i;
+
+	if (nr_pnv_idle_states < 0) {
+		pr_warn("cpuidle-powernv: no idle states found in the DT\n");
+		return;
+	}
+
+	if (cpu_has_feature(CPU_FTR_ARCH_300))
+		pnv_arch300_idle_init();
+
+	for (i = 0; i < nr_pnv_idle_states; i++)
+		supported_cpuidle_states |= pnv_idle_states[i].flags;
+}
+
+/*
+ * This function parses device-tree and populates all the information
+ * into pnv_idle_states structure. It also sets up nr_pnv_idle_states
+ * which is the number of cpuidle states discovered through device-tree.
+ */
+
+static int __init pnv_parse_cpuidle_dt(void)
+{
+	struct device_node *np;
+	int nr_idle_states, i;
+	int rc = 0;
+	u32 *temp_u32;
+	u64 *temp_u64;
+	const char **temp_string;
+
+	np = of_find_node_by_path("/ibm,opal/power-mgt");
+	if (!np) {
+		pr_warn("opal: PowerMgmt Node not found\n");
+		return -ENODEV;
+	}
+	nr_idle_states = of_property_count_u32_elems(np,
+						"ibm,cpu-idle-state-flags");
+
+	pnv_idle_states = kcalloc(nr_idle_states, sizeof(*pnv_idle_states),
+				  GFP_KERNEL);
+	temp_u32 = kcalloc(nr_idle_states, sizeof(u32),  GFP_KERNEL);
+	temp_u64 = kcalloc(nr_idle_states, sizeof(u64),  GFP_KERNEL);
+	temp_string = kcalloc(nr_idle_states, sizeof(char *),  GFP_KERNEL);
+
+	if (!(pnv_idle_states && temp_u32 && temp_u64 && temp_string)) {
+		pr_err("Could not allocate memory for dt parsing\n");
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	/* Read flags */
+	if (of_property_read_u32_array(np, "ibm,cpu-idle-state-flags",
+				       temp_u32, nr_idle_states)) {
+		pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-flags in DT\n");
+		rc = -EINVAL;
+		goto out;
+	}
+	for (i = 0; i < nr_idle_states; i++)
+		pnv_idle_states[i].flags = temp_u32[i];
+
+	/* Read latencies */
+	if (of_property_read_u32_array(np, "ibm,cpu-idle-state-latencies-ns",
+				       temp_u32, nr_idle_states)) {
+		pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-latencies-ns in DT\n");
+		rc = -EINVAL;
+		goto out;
+	}
+	for (i = 0; i < nr_idle_states; i++)
+		pnv_idle_states[i].latency_ns = temp_u32[i];
+
+	/* Read residencies */
+	if (of_property_read_u32_array(np, "ibm,cpu-idle-state-residency-ns",
+				       temp_u32, nr_idle_states)) {
+		pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-residency-ns in DT\n");
+		rc = -EINVAL;
+		goto out;
+	}
+	for (i = 0; i < nr_idle_states; i++)
+		pnv_idle_states[i].residency_ns = temp_u32[i];
+
+	/* For power9 and later */
+	if (cpu_has_feature(CPU_FTR_ARCH_300)) {
+		/* Read pm_crtl_val */
+		if (of_property_read_u64_array(np, "ibm,cpu-idle-state-psscr",
+					       temp_u64, nr_idle_states)) {
+			pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-psscr in DT\n");
+			rc = -EINVAL;
+			goto out;
+		}
+		for (i = 0; i < nr_idle_states; i++)
+			pnv_idle_states[i].psscr_val = temp_u64[i];
+
+		/* Read pm_crtl_mask */
+		if (of_property_read_u64_array(np, "ibm,cpu-idle-state-psscr-mask",
+					       temp_u64, nr_idle_states)) {
+			pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-psscr-mask in DT\n");
+			rc = -EINVAL;
+			goto out;
+		}
+		for (i = 0; i < nr_idle_states; i++)
+			pnv_idle_states[i].psscr_mask = temp_u64[i];
+	}
+
+	/*
+	 * power8 specific properties ibm,cpu-idle-state-pmicr-mask and
+	 * ibm,cpu-idle-state-pmicr-val were never used and there is no
+	 * plan to use it in near future. Hence, not parsing these properties
+	 */
+
+	if (of_property_read_string_array(np, "ibm,cpu-idle-state-names",
+					  temp_string, nr_idle_states) < 0) {
+		pr_warn("cpuidle-powernv: missing ibm,cpu-idle-state-names in DT\n");
+		rc = -EINVAL;
+		goto out;
+	}
+	for (i = 0; i < nr_idle_states; i++)
+		strscpy(pnv_idle_states[i].name, temp_string[i],
+			PNV_IDLE_NAME_LEN);
+	nr_pnv_idle_states = nr_idle_states;
+	rc = 0;
+out:
+	kfree(temp_u32);
+	kfree(temp_u64);
+	kfree(temp_string);
+	of_node_put(np);
+	return rc;
+}
+
+static int __init pnv_init_idle_states(void)
+{
+	int cpu;
+	int rc = 0;
+
+	/* Set up PACA fields */
+	for_each_present_cpu(cpu) {
+		struct paca_struct *p = paca_ptrs[cpu];
+
+		p->idle_state = 0;
+		if (cpu == cpu_first_thread_sibling(cpu))
+			p->idle_state = (1 << threads_per_core) - 1;
+
+		if (!cpu_has_feature(CPU_FTR_ARCH_300)) {
+			/* P7/P8 nap */
+			p->thread_idle_state = PNV_THREAD_RUNNING;
+		} else if (pvr_version_is(PVR_POWER9)) {
+			/* P9 stop workarounds */
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+			p->requested_psscr = 0;
+			atomic_set(&p->dont_stop, 0);
+#endif
+		}
+	}
+
+	/* In case we error out nr_pnv_idle_states will be zero */
+	nr_pnv_idle_states = 0;
+	supported_cpuidle_states = 0;
+
+	if (cpuidle_disable != IDLE_NO_OVERRIDE)
+		goto out;
+	rc = pnv_parse_cpuidle_dt();
+	if (rc)
+		return rc;
+	pnv_probe_idle_states();
+
+	if (!cpu_has_feature(CPU_FTR_ARCH_300)) {
+		if (!(supported_cpuidle_states & OPAL_PM_SLEEP_ENABLED_ER1)) {
+			power7_fastsleep_workaround_entry = false;
+			power7_fastsleep_workaround_exit = false;
+		} else {
+			/*
+			 * OPAL_PM_SLEEP_ENABLED_ER1 is set. It indicates that
+			 * workaround is needed to use fastsleep. Provide sysfs
+			 * control to choose how this workaround has to be
+			 * applied.
+			 */
+			device_create_file(cpu_subsys.dev_root,
+				&dev_attr_fastsleep_workaround_applyonce);
+		}
+
+		update_subcore_sibling_mask();
+
+		if (supported_cpuidle_states & OPAL_PM_NAP_ENABLED) {
+			ppc_md.power_save = power7_idle;
+			power7_offline_type = PNV_THREAD_NAP;
+		}
+
+		if ((supported_cpuidle_states & OPAL_PM_WINKLE_ENABLED) &&
+			   (supported_cpuidle_states & OPAL_PM_LOSE_FULL_CONTEXT))
+			power7_offline_type = PNV_THREAD_WINKLE;
+		else if ((supported_cpuidle_states & OPAL_PM_SLEEP_ENABLED) ||
+			   (supported_cpuidle_states & OPAL_PM_SLEEP_ENABLED_ER1))
+			power7_offline_type = PNV_THREAD_SLEEP;
+	}
+
+	if (supported_cpuidle_states & OPAL_PM_LOSE_FULL_CONTEXT) {
+		if (pnv_save_sprs_for_deep_states())
+			pnv_disable_deep_states();
+	}
+
+out:
+	return 0;
+}
+machine_subsys_initcall(powernv, pnv_init_idle_states);