+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);
+}
+
projects / linux-2.6-microblaze.git / commitdiff