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-rw-r--r--arch/powerpc/platforms/powernv/idle.c1535
1 files changed, 1535 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..1ed7c5286
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/idle.c
@@ -0,0 +1,1535 @@
+// 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/asm-prototypes.h>
+#include <asm/firmware.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 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 regiters */
+ 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 rc;
+ int *err = info;
+
+ 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)
+{
+ cpumask_t primary_thread_mask;
+ 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;
+
+ get_online_cpus();
+ primary_thread_mask = cpu_online_cores_map();
+ on_each_cpu_mask(&primary_thread_mask,
+ pnv_fastsleep_workaround_apply,
+ &err, 1);
+ put_online_cpus();
+ 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 amor;
+ u64 uamor;
+};
+
+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.amor = mfspr(SPRN_AMOR);
+ 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, sprs.amor);
+ 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);
+
+ /*
+ * 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();
+
+ 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 wort;
+
+ 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, bool mmu_on)
+{
+ 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 */
+
+ BUG_ON(!mmu_on);
+
+ /*
+ * 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.wort = mfspr(SPRN_WORT);
+
+ 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.amor = mfspr(SPRN_AMOR);
+ 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, sprs.amor);
+ 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_WORT, sprs.wort);
+
+ 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:
+ if (mmu_on)
+ 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, bool mmu_on)
+{
+ 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 */
+
+ BUG_ON(!mmu_on);
+
+ /*
+ * 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:
+ if (mmu_on)
+ mtmsr(MSR_KERNEL);
+
+ return srr1;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static unsigned long arch300_offline_stop(unsigned long psscr)
+{
+ unsigned long srr1;
+
+#ifndef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+ __ppc64_runlatch_off();
+ if (cpu_has_feature(CPU_FTR_ARCH_31))
+ srr1 = power10_idle_stop(psscr, true);
+ else
+ srr1 = power9_idle_stop(psscr, true);
+ __ppc64_runlatch_on();
+#else
+ /*
+ * Tell KVM we're entering idle.
+ * This does not have to be done in real mode because the P9 MMU
+ * is independent per-thread. Some steppings share radix/hash mode
+ * between threads, but in that case KVM has a barrier sync in real
+ * mode before and after switching between radix and hash.
+ *
+ * kvm_start_guest must still be called in real mode though, hence
+ * the false argument.
+ */
+ local_paca->kvm_hstate.hwthread_state = KVM_HWTHREAD_IN_IDLE;
+
+ __ppc64_runlatch_off();
+ if (cpu_has_feature(CPU_FTR_ARCH_31))
+ srr1 = power10_idle_stop(psscr, false);
+ else
+ srr1 = power9_idle_stop(psscr, false);
+ __ppc64_runlatch_on();
+
+ 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);
+ mtmsr(MSR_KERNEL);
+#endif
+
+ 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, true);
+ else
+ srr1 = power9_idle_stop(psscr, true);
+ __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 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 encouter 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 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++)
+ strlcpy(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);
+ 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);