Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull SMP hotplug notifier removal from Thomas Gleixner:
 "This is the final cleanup of the hotplug notifier infrastructure. The
  series has been reintgrated in the last two days because there came a
  new driver using the old infrastructure via the SCSI tree.

  Summary:

   - convert the last leftover drivers utilizing notifiers

   - fixup for a completely broken hotplug user

   - prevent setup of already used states

   - removal of the notifiers

   - treewide cleanup of hotplug state names

   - consolidation of state space

  There is a sphinx based documentation pending, but that needs review
  from the documentation folks"

* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/armada-xp: Consolidate hotplug state space
  irqchip/gic: Consolidate hotplug state space
  coresight/etm3/4x: Consolidate hotplug state space
  cpu/hotplug: Cleanup state names
  cpu/hotplug: Remove obsolete cpu hotplug register/unregister functions
  staging/lustre/libcfs: Convert to hotplug state machine
  scsi/bnx2i: Convert to hotplug state machine
  scsi/bnx2fc: Convert to hotplug state machine
  cpu/hotplug: Prevent overwriting of callbacks
  x86/msr: Remove bogus cleanup from the error path
  bus: arm-ccn: Prevent hotplug callback leak
  perf/x86/intel/cstate: Prevent hotplug callback leak
  ARM/imx/mmcd: Fix broken cpu hotplug handling
  scsi: qedi: Convert to hotplug state machine

arch/arm/kernel/smp_twd.c

@@ -339,7 +339,7 @@ static int __init twd_local_timer_common_register(struct device_node *np)
 	}
 
 	cpuhp_setup_state_nocalls(CPUHP_AP_ARM_TWD_STARTING,
-				  "AP_ARM_TWD_STARTING",
+				  "arm/timer/twd:starting",
 				  twd_timer_starting_cpu, twd_timer_dying_cpu);
 
 	twd_get_clock(np);

arch/arm/mach-imx/mmdc.c

@@ -60,6 +60,7 @@
 
 #define to_mmdc_pmu(p) container_of(p, struct mmdc_pmu, pmu)
 
+static enum cpuhp_state cpuhp_mmdc_state;
 static int ddr_type;
 
 struct fsl_mmdc_devtype_data {
@@ -451,8 +452,8 @@ static int imx_mmdc_remove(struct platform_device *pdev)
 {
 	struct mmdc_pmu *pmu_mmdc = platform_get_drvdata(pdev);
 
+	cpuhp_state_remove_instance_nocalls(cpuhp_mmdc_state, &pmu_mmdc->node);
 	perf_pmu_unregister(&pmu_mmdc->pmu);
-	cpuhp_remove_state_nocalls(CPUHP_ONLINE);
 	kfree(pmu_mmdc);
 	return 0;
 }
@@ -472,6 +473,18 @@ static int imx_mmdc_perf_init(struct platform_device *pdev, void __iomem *mmdc_b
 		return -ENOMEM;
 	}
 
+	/* The first instance registers the hotplug state */
+	if (!cpuhp_mmdc_state) {
+		ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
+					      "perf/arm/mmdc:online", NULL,
+					      mmdc_pmu_offline_cpu);
+		if (ret < 0) {
+			pr_err("cpuhp_setup_state_multi failed\n");
+			goto pmu_free;
+		}
+		cpuhp_mmdc_state = ret;
+	}
+
 	mmdc_num = mmdc_pmu_init(pmu_mmdc, mmdc_base, &pdev->dev);
 	if (mmdc_num == 0)
 		name = "mmdc";
@@ -485,26 +498,23 @@ static int imx_mmdc_perf_init(struct platform_device *pdev, void __iomem *mmdc_b
 			HRTIMER_MODE_REL);
 	pmu_mmdc->hrtimer.function = mmdc_pmu_timer_handler;
 
-	cpuhp_state_add_instance_nocalls(CPUHP_ONLINE,
-					 &pmu_mmdc->node);
-	cpumask_set_cpu(smp_processor_id(), &pmu_mmdc->cpu);
-	ret = cpuhp_setup_state_multi(CPUHP_AP_NOTIFY_ONLINE,
-				      "MMDC_ONLINE", NULL,
-				      mmdc_pmu_offline_cpu);
-	if (ret) {
-		pr_err("cpuhp_setup_state_multi failure\n");
-		goto pmu_register_err;
-	}
+	cpumask_set_cpu(raw_smp_processor_id(), &pmu_mmdc->cpu);
+
+	/* Register the pmu instance for cpu hotplug */
+	cpuhp_state_add_instance_nocalls(cpuhp_mmdc_state, &pmu_mmdc->node);
 
 	ret = perf_pmu_register(&(pmu_mmdc->pmu), name, -1);
-	platform_set_drvdata(pdev, pmu_mmdc);
 	if (ret)
 		goto pmu_register_err;
+
+	platform_set_drvdata(pdev, pmu_mmdc);
 	return 0;
 
 pmu_register_err:
 	pr_warn("MMDC Perf PMU failed (%d), disabled\n", ret);
+	cpuhp_state_remove_instance_nocalls(cpuhp_mmdc_state, &pmu_mmdc->node);
 	hrtimer_cancel(&pmu_mmdc->hrtimer);
+pmu_free:
 	kfree(pmu_mmdc);
 	return ret;
 }

arch/arm/mach-mvebu/coherency.c

@@ -148,7 +148,7 @@ static void __init armada_370_coherency_init(struct device_node *np)
 	of_node_put(cpu_config_np);
 
 	cpuhp_setup_state_nocalls(CPUHP_AP_ARM_MVEBU_COHERENCY,
-				  "AP_ARM_MVEBU_COHERENCY",
+				  "arm/mvebu/coherency:starting",
 				  armada_xp_clear_l2_starting, NULL);
 exit:
 	set_cpu_coherent();

arch/arm/mm/cache-l2x0-pmu.c

@@ -563,7 +563,7 @@ static __init int l2x0_pmu_init(void)
 
 	cpumask_set_cpu(0, &pmu_cpu);
 	ret = cpuhp_setup_state_nocalls(CPUHP_AP_PERF_ARM_L2X0_ONLINE,
-					"AP_PERF_ARM_L2X0_ONLINE", NULL,
+					"perf/arm/l2x0:online", NULL,
 					l2x0_pmu_offline_cpu);
 	if (ret)
 		goto out_pmu;

arch/arm/mm/cache-l2x0.c

@@ -683,7 +683,7 @@ static void __init l2c310_enable(void __iomem *base, unsigned num_lock)
 
 	if (aux & L310_AUX_CTRL_FULL_LINE_ZERO)
 		cpuhp_setup_state(CPUHP_AP_ARM_L2X0_STARTING,
-				  "AP_ARM_L2X0_STARTING", l2c310_starting_cpu,
+				  "arm/l2x0:starting", l2c310_starting_cpu,
 				  l2c310_dying_cpu);
 }
 

arch/arm/vfp/vfpmodule.c

@@ -799,7 +799,7 @@ static int __init vfp_init(void)
 	}
 
 	cpuhp_setup_state_nocalls(CPUHP_AP_ARM_VFP_STARTING,
-				  "AP_ARM_VFP_STARTING", vfp_starting_cpu,
+				  "arm/vfp:starting", vfp_starting_cpu,
 				  vfp_dying_cpu);
 
 	vfp_vector = vfp_support_entry;

arch/arm/xen/enlighten.c

@@ -412,7 +412,7 @@ static int __init xen_guest_init(void)
 		pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);
 
 	return cpuhp_setup_state(CPUHP_AP_ARM_XEN_STARTING,
-				 "AP_ARM_XEN_STARTING", xen_starting_cpu,
+				 "arm/xen:starting", xen_starting_cpu,
 				 xen_dying_cpu);
 }
 early_initcall(xen_guest_init);

arch/arm64/kernel/armv8_deprecated.c

@@ -640,7 +640,7 @@ static int __init armv8_deprecated_init(void)
 	}
 
 	cpuhp_setup_state_nocalls(CPUHP_AP_ARM64_ISNDEP_STARTING,
-				  "AP_ARM64_ISNDEP_STARTING",
+				  "arm64/isndep:starting",
 				  run_all_insn_set_hw_mode, NULL);
 	register_insn_emulation_sysctl(ctl_abi);
 

arch/arm64/kernel/debug-monitors.c

@@ -140,7 +140,7 @@ static int clear_os_lock(unsigned int cpu)
 static int debug_monitors_init(void)
 {
 	return cpuhp_setup_state(CPUHP_AP_ARM64_DEBUG_MONITORS_STARTING,
-				 "CPUHP_AP_ARM64_DEBUG_MONITORS_STARTING",
+				 "arm64/debug_monitors:starting",
 				 clear_os_lock, NULL);
 }
 postcore_initcall(debug_monitors_init);

arch/arm64/kernel/hw_breakpoint.c

@@ -1001,7 +1001,7 @@ static int __init arch_hw_breakpoint_init(void)
 	 * debugger will leave the world in a nice state for us.
 	 */
 	ret = cpuhp_setup_state(CPUHP_AP_PERF_ARM_HW_BREAKPOINT_STARTING,
-			  "CPUHP_AP_PERF_ARM_HW_BREAKPOINT_STARTING",
+			  "perf/arm64/hw_breakpoint:starting",
 			  hw_breakpoint_reset, NULL);
 	if (ret)
 		pr_err("failed to register CPU hotplug notifier: %d\n", ret);

arch/blackfin/kernel/perf_event.c

@@ -475,7 +475,7 @@ static int __init bfin_pmu_init(void)
 
 	ret = perf_pmu_register(&pmu, "cpu", PERF_TYPE_RAW);
 	if (!ret)
-		cpuhp_setup_state(CPUHP_PERF_BFIN, "PERF_BFIN",
+		cpuhp_setup_state(CPUHP_PERF_BFIN,"perf/bfin:starting",
 				  bfin_pmu_prepare_cpu, NULL);
 	return ret;
 }

arch/metag/kernel/perf/perf_event.c

@@ -868,7 +868,7 @@ static int __init init_hw_perf_events(void)
 	metag_out32(0, PERF_COUNT(1));
 
 	cpuhp_setup_state(CPUHP_AP_PERF_METAG_STARTING,
-			  "AP_PERF_METAG_STARTING", metag_pmu_starting_cpu,
+			  "perf/metag:starting", metag_pmu_starting_cpu,
 			  NULL);
 
 	ret = perf_pmu_register(&pmu, metag_pmu->name, PERF_TYPE_RAW);

arch/mips/kernel/pm-cps.c

@@ -713,7 +713,7 @@ static int __init cps_pm_init(void)
 		pr_warn("pm-cps: no CPC, clock & power gating unavailable\n");
 	}
 
-	return cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "AP_PM_CPS_CPU_ONLINE",
+	return cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "mips/cps_pm:online",
 				 cps_pm_online_cpu, NULL);
 }
 arch_initcall(cps_pm_init);

arch/mips/oprofile/op_model_loongson3.c

@@ -186,7 +186,7 @@ static int __init loongson3_init(void)
 {
 	on_each_cpu(reset_counters, NULL, 1);
 	cpuhp_setup_state_nocalls(CPUHP_AP_MIPS_OP_LOONGSON3_STARTING,
-				  "AP_MIPS_OP_LOONGSON3_STARTING",
+				  "mips/oprofile/loongson3:starting",
 				  loongson3_starting_cpu, loongson3_dying_cpu);
 	save_perf_irq = perf_irq;
 	perf_irq = loongson3_perfcount_handler;

arch/powerpc/mm/numa.c

@@ -944,7 +944,7 @@ void __init initmem_init(void)
 	 * _nocalls() + manual invocation is used because cpuhp is not yet
 	 * initialized for the boot CPU.
 	 */
-	cpuhp_setup_state_nocalls(CPUHP_POWER_NUMA_PREPARE, "POWER_NUMA_PREPARE",
+	cpuhp_setup_state_nocalls(CPUHP_POWER_NUMA_PREPARE, "powerpc/numa:prepare",
 				  ppc_numa_cpu_prepare, ppc_numa_cpu_dead);
 	for_each_present_cpu(cpu)
 		numa_setup_cpu(cpu);

arch/powerpc/perf/core-book3s.c

@@ -2189,7 +2189,7 @@ int register_power_pmu(struct power_pmu *pmu)
 #endif /* CONFIG_PPC64 */
 
 	perf_pmu_register(&power_pmu, "cpu", PERF_TYPE_RAW);
-	cpuhp_setup_state(CPUHP_PERF_POWER, "PERF_POWER",
+	cpuhp_setup_state(CPUHP_PERF_POWER, "perf/powerpc:prepare",
 			  power_pmu_prepare_cpu, NULL);
 	return 0;
 }

arch/s390/kernel/perf_cpum_cf.c

@@ -711,7 +711,7 @@ static int __init cpumf_pmu_init(void)
 		return rc;
 	}
 	return cpuhp_setup_state(CPUHP_AP_PERF_S390_CF_ONLINE,
-				 "AP_PERF_S390_CF_ONLINE",
+				 "perf/s390/cf:online",
 				 s390_pmu_online_cpu, s390_pmu_offline_cpu);
 }
 early_initcall(cpumf_pmu_init);

arch/s390/kernel/perf_cpum_sf.c

@@ -1623,7 +1623,7 @@ static int __init init_cpum_sampling_pmu(void)
 		goto out;
 	}
 
-	cpuhp_setup_state(CPUHP_AP_PERF_S390_SF_ONLINE, "AP_PERF_S390_SF_ONLINE",
+	cpuhp_setup_state(CPUHP_AP_PERF_S390_SF_ONLINE, "perf/s390/sf:online",
 			  s390_pmu_sf_online_cpu, s390_pmu_sf_offline_cpu);
 out:
 	return err;

arch/x86/entry/vdso/vma.c

@@ -371,7 +371,7 @@ static int __init init_vdso(void)
 
 	/* notifier priority > KVM */
 	return cpuhp_setup_state(CPUHP_AP_X86_VDSO_VMA_ONLINE,
-				 "AP_X86_VDSO_VMA_ONLINE", vgetcpu_online, NULL);
+				 "x86/vdso/vma:online", vgetcpu_online, NULL);
 }
 subsys_initcall(init_vdso);
 #endif /* CONFIG_X86_64 */

arch/x86/events/amd/ibs.c

@@ -1010,7 +1010,7 @@ static __init int amd_ibs_init(void)
 	 * all online cpus.
 	 */
 	cpuhp_setup_state(CPUHP_AP_PERF_X86_AMD_IBS_STARTING,
-			  "AP_PERF_X86_AMD_IBS_STARTING",
+			  "perf/x86/amd/ibs:STARTING",
 			  x86_pmu_amd_ibs_starting_cpu,
 			  x86_pmu_amd_ibs_dying_cpu);
 

arch/x86/events/amd/power.c

@@ -291,7 +291,7 @@ static int __init amd_power_pmu_init(void)
 
 
 	cpuhp_setup_state(CPUHP_AP_PERF_X86_AMD_POWER_ONLINE,
-			  "AP_PERF_X86_AMD_POWER_ONLINE",
+			  "perf/x86/amd/power:online",
 			  power_cpu_init, power_cpu_exit);
 
 	ret = perf_pmu_register(&pmu_class, "power", -1);

arch/x86/events/amd/uncore.c

@@ -527,16 +527,16 @@ static int __init amd_uncore_init(void)
 	 * Install callbacks. Core will call them for each online cpu.
 	 */
 	if (cpuhp_setup_state(CPUHP_PERF_X86_AMD_UNCORE_PREP,
-			      "PERF_X86_AMD_UNCORE_PREP",
+			      "perf/x86/amd/uncore:prepare",
 			      amd_uncore_cpu_up_prepare, amd_uncore_cpu_dead))
 		goto fail_l2;
 
 	if (cpuhp_setup_state(CPUHP_AP_PERF_X86_AMD_UNCORE_STARTING,
-			      "AP_PERF_X86_AMD_UNCORE_STARTING",
+			      "perf/x86/amd/uncore:starting",
 			      amd_uncore_cpu_starting, NULL))
 		goto fail_prep;
 	if (cpuhp_setup_state(CPUHP_AP_PERF_X86_AMD_UNCORE_ONLINE,
-			      "AP_PERF_X86_AMD_UNCORE_ONLINE",
+			      "perf/x86/amd/uncore:online",
 			      amd_uncore_cpu_online,
 			      amd_uncore_cpu_down_prepare))
 		goto fail_start;

arch/x86/events/core.c

@@ -1820,18 +1820,18 @@ static int __init init_hw_perf_events(void)
 	 * Install callbacks. Core will call them for each online
 	 * cpu.
 	 */
-	err = cpuhp_setup_state(CPUHP_PERF_X86_PREPARE, "PERF_X86_PREPARE",
+	err = cpuhp_setup_state(CPUHP_PERF_X86_PREPARE, "perf/x86:prepare",
 				x86_pmu_prepare_cpu, x86_pmu_dead_cpu);
 	if (err)
 		return err;
 
 	err = cpuhp_setup_state(CPUHP_AP_PERF_X86_STARTING,
-				"AP_PERF_X86_STARTING", x86_pmu_starting_cpu,
+				"perf/x86:starting", x86_pmu_starting_cpu,
 				x86_pmu_dying_cpu);
 	if (err)
 		goto out;
 
-	err = cpuhp_setup_state(CPUHP_AP_PERF_X86_ONLINE, "AP_PERF_X86_ONLINE",
+	err = cpuhp_setup_state(CPUHP_AP_PERF_X86_ONLINE, "perf/x86:online",
 				x86_pmu_online_cpu, NULL);
 	if (err)
 		goto out1;

arch/x86/events/intel/cqm.c

@@ -1747,9 +1747,9 @@ static int __init intel_cqm_init(void)
 	 * is enabled to avoid notifier leak.
 	 */
 	cpuhp_setup_state(CPUHP_AP_PERF_X86_CQM_STARTING,
-			  "AP_PERF_X86_CQM_STARTING",
+			  "perf/x86/cqm:starting",
 			  intel_cqm_cpu_starting, NULL);
-	cpuhp_setup_state(CPUHP_AP_PERF_X86_CQM_ONLINE, "AP_PERF_X86_CQM_ONLINE",
+	cpuhp_setup_state(CPUHP_AP_PERF_X86_CQM_ONLINE, "perf/x86/cqm:online",
 			  NULL, intel_cqm_cpu_exit);
 
 out:

arch/x86/events/intel/cstate.c

@@ -594,6 +594,9 @@ static int __init cstate_probe(const struct cstate_model *cm)
 
 static inline void cstate_cleanup(void)
 {
+	cpuhp_remove_state_nocalls(CPUHP_AP_PERF_X86_CSTATE_ONLINE);
+	cpuhp_remove_state_nocalls(CPUHP_AP_PERF_X86_CSTATE_STARTING);
+
 	if (has_cstate_core)
 		perf_pmu_unregister(&cstate_core_pmu);
 
@@ -606,16 +609,16 @@ static int __init cstate_init(void)
 	int err;
 
 	cpuhp_setup_state(CPUHP_AP_PERF_X86_CSTATE_STARTING,
-			  "AP_PERF_X86_CSTATE_STARTING", cstate_cpu_init,
-			  NULL);
+			  "perf/x86/cstate:starting", cstate_cpu_init, NULL);
 	cpuhp_setup_state(CPUHP_AP_PERF_X86_CSTATE_ONLINE,
-			  "AP_PERF_X86_CSTATE_ONLINE", NULL, cstate_cpu_exit);
+			  "perf/x86/cstate:online", NULL, cstate_cpu_exit);
 
 	if (has_cstate_core) {
 		err = perf_pmu_register(&cstate_core_pmu, cstate_core_pmu.name, -1);
 		if (err) {
 			has_cstate_core = false;
 			pr_info("Failed to register cstate core pmu\n");
+			cstate_cleanup();
 			return err;
 		}
 	}
@@ -629,8 +632,7 @@ static int __init cstate_init(void)
 			return err;
 		}
 	}
-
-	return err;
+	return 0;
 }
 
 static int __init cstate_pmu_init(void)
@@ -655,8 +657,6 @@ module_init(cstate_pmu_init);
 
 static void __exit cstate_pmu_exit(void)
 {
-	cpuhp_remove_state_nocalls(CPUHP_AP_PERF_X86_CSTATE_ONLINE);
-	cpuhp_remove_state_nocalls(CPUHP_AP_PERF_X86_CSTATE_STARTING);
 	cstate_cleanup();
 }
 module_exit(cstate_pmu_exit);

arch/x86/events/intel/rapl.c

@@ -803,13 +803,13 @@ static int __init rapl_pmu_init(void)
 	 * Install callbacks. Core will call them for each online cpu.
 	 */
 
-	ret = cpuhp_setup_state(CPUHP_PERF_X86_RAPL_PREP, "PERF_X86_RAPL_PREP",
+	ret = cpuhp_setup_state(CPUHP_PERF_X86_RAPL_PREP, "perf/x86/rapl:prepare",
 				rapl_cpu_prepare, NULL);
 	if (ret)
 		goto out;
 
 	ret = cpuhp_setup_state(CPUHP_AP_PERF_X86_RAPL_ONLINE,
-				"AP_PERF_X86_RAPL_ONLINE",
+				"perf/x86/rapl:online",
 				rapl_cpu_online, rapl_cpu_offline);
 	if (ret)
 		goto out1;

arch/x86/events/intel/uncore.c

@@ -1398,22 +1398,22 @@ static int __init intel_uncore_init(void)
 	 */
 	if (!cret) {
 	       ret = cpuhp_setup_state(CPUHP_PERF_X86_UNCORE_PREP,
-					"PERF_X86_UNCORE_PREP",
-					uncore_cpu_prepare, NULL);
+				       "perf/x86/intel/uncore:prepare",
+				       uncore_cpu_prepare, NULL);
 		if (ret)
 			goto err;
 	} else {
 		cpuhp_setup_state_nocalls(CPUHP_PERF_X86_UNCORE_PREP,
-					  "PERF_X86_UNCORE_PREP",
+					  "perf/x86/intel/uncore:prepare",
 					  uncore_cpu_prepare, NULL);
 	}
 	first_init = 1;
 	cpuhp_setup_state(CPUHP_AP_PERF_X86_UNCORE_STARTING,
-			  "AP_PERF_X86_UNCORE_STARTING",
+			  "perf/x86/uncore:starting",
 			  uncore_cpu_starting, uncore_cpu_dying);
 	first_init = 0;
 	cpuhp_setup_state(CPUHP_AP_PERF_X86_UNCORE_ONLINE,
-			  "AP_PERF_X86_UNCORE_ONLINE",
+			  "perf/x86/uncore:online",
 			  uncore_event_cpu_online, uncore_event_cpu_offline);
 	return 0;
 

arch/x86/kernel/apb_timer.c

@@ -234,7 +234,7 @@ static __init int apbt_late_init(void)
 	if (intel_mid_timer_options == INTEL_MID_TIMER_LAPIC_APBT ||
 		!apb_timer_block_enabled)
 		return 0;
-	return cpuhp_setup_state(CPUHP_X86_APB_DEAD, "X86_APB_DEAD", NULL,
+	return cpuhp_setup_state(CPUHP_X86_APB_DEAD, "x86/apb:dead", NULL,
 				 apbt_cpu_dead);
 }
 fs_initcall(apbt_late_init);

arch/x86/kernel/apic/x2apic_cluster.c

@@ -191,7 +191,7 @@ static int x2apic_cluster_probe(void)
 	if (!x2apic_mode)
 		return 0;
 
-	ret = cpuhp_setup_state(CPUHP_X2APIC_PREPARE, "X2APIC_PREPARE",
+	ret = cpuhp_setup_state(CPUHP_X2APIC_PREPARE, "x86/x2apic:prepare",
 				x2apic_prepare_cpu, x2apic_dead_cpu);
 	if (ret < 0) {
 		pr_err("Failed to register X2APIC_PREPARE\n");

arch/x86/kernel/hpet.c

@@ -1051,11 +1051,11 @@ static __init int hpet_late_init(void)
 		return 0;
 
 	/* This notifier should be called after workqueue is ready */
-	ret = cpuhp_setup_state(CPUHP_AP_X86_HPET_ONLINE, "AP_X86_HPET_ONLINE",
+	ret = cpuhp_setup_state(CPUHP_AP_X86_HPET_ONLINE, "x86/hpet:online",
 				hpet_cpuhp_online, NULL);
 	if (ret)
 		return ret;
-	ret = cpuhp_setup_state(CPUHP_X86_HPET_DEAD, "X86_HPET_DEAD", NULL,
+	ret = cpuhp_setup_state(CPUHP_X86_HPET_DEAD, "x86/hpet:dead", NULL,
 				hpet_cpuhp_dead);
 	if (ret)
 		goto err_cpuhp;

arch/x86/kernel/msr.c

@@ -224,7 +224,6 @@ static int __init msr_init(void)
 	return 0;
 
 out_class:
-	cpuhp_remove_state(cpuhp_msr_state);
 	class_destroy(msr_class);
 out_chrdev:
 	__unregister_chrdev(MSR_MAJOR, 0, NR_CPUS, "cpu/msr");

arch/x86/kernel/tboot.c

@@ -408,7 +408,7 @@ static __init int tboot_late_init(void)
 	tboot_create_trampoline();
 
 	atomic_set(&ap_wfs_count, 0);
-	cpuhp_setup_state(CPUHP_AP_X86_TBOOT_DYING, "AP_X86_TBOOT_DYING", NULL,
+	cpuhp_setup_state(CPUHP_AP_X86_TBOOT_DYING, "x86/tboot:dying", NULL,
 			  tboot_dying_cpu);
 #ifdef CONFIG_DEBUG_FS
 	debugfs_create_file("tboot_log", S_IRUSR,

arch/x86/kvm/x86.c

@@ -5855,7 +5855,7 @@ static void kvm_timer_init(void)
 	}
 	pr_debug("kvm: max_tsc_khz = %ld\n", max_tsc_khz);
 
-	cpuhp_setup_state(CPUHP_AP_X86_KVM_CLK_ONLINE, "AP_X86_KVM_CLK_ONLINE",
+	cpuhp_setup_state(CPUHP_AP_X86_KVM_CLK_ONLINE, "x86/kvm/clk:online",
 			  kvmclock_cpu_online, kvmclock_cpu_down_prep);
 }
 

arch/x86/xen/enlighten.c

@@ -1529,11 +1529,11 @@ static int xen_cpuhp_setup(void)
 	int rc;
 
 	rc = cpuhp_setup_state_nocalls(CPUHP_XEN_PREPARE,
-				       "XEN_HVM_GUEST_PREPARE",
+				       "x86/xen/hvm_guest:prepare",
 				       xen_cpu_up_prepare, xen_cpu_dead);
 	if (rc >= 0) {
 		rc = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
-					       "XEN_HVM_GUEST_ONLINE",
+					       "x86/xen/hvm_guest:online",
 					       xen_cpu_up_online, NULL);
 		if (rc < 0)
 			cpuhp_remove_state_nocalls(CPUHP_XEN_PREPARE);

arch/xtensa/kernel/perf_event.c

@@ -422,7 +422,7 @@ static int __init xtensa_pmu_init(void)
 	int irq = irq_create_mapping(NULL, XCHAL_PROFILING_INTERRUPT);
 
 	ret = cpuhp_setup_state(CPUHP_AP_PERF_XTENSA_STARTING,
-				"AP_PERF_XTENSA_STARTING", xtensa_pmu_setup,
+				"perf/xtensa:starting", xtensa_pmu_setup,
 				NULL);
 	if (ret) {
 		pr_err("xtensa_pmu: failed to register CPU-hotplug.\n");

drivers/bus/arm-cci.c

@@ -1796,7 +1796,7 @@ static int __init cci_platform_init(void)
 	int ret;
 
 	ret = cpuhp_setup_state_multi(CPUHP_AP_PERF_ARM_CCI_ONLINE,
-				      "AP_PERF_ARM_CCI_ONLINE", NULL,
+				      "perf/arm/cci:online", NULL,
 				      cci_pmu_offline_cpu);
 	if (ret)
 		return ret;

drivers/bus/arm-ccn.c

@@ -1562,7 +1562,7 @@ static int __init arm_ccn_init(void)
 	int i, ret;
 
 	ret = cpuhp_setup_state_multi(CPUHP_AP_PERF_ARM_CCN_ONLINE,
-				      "AP_PERF_ARM_CCN_ONLINE", NULL,
+				      "perf/arm/ccn:online", NULL,
 				      arm_ccn_pmu_offline_cpu);
 	if (ret)
 		return ret;
@@ -1570,7 +1570,10 @@ static int __init arm_ccn_init(void)
 	for (i = 0; i < ARRAY_SIZE(arm_ccn_pmu_events); i++)
 		arm_ccn_pmu_events_attrs[i] = &arm_ccn_pmu_events[i].attr.attr;
 
-	return platform_driver_register(&arm_ccn_driver);
+	ret = platform_driver_register(&arm_ccn_driver);
+	if (ret)
+		cpuhp_remove_multi_state(CPUHP_AP_PERF_ARM_CCN_ONLINE);
+	return ret;
 }
 
 static void __exit arm_ccn_exit(void)

drivers/clocksource/arc_timer.c

@@ -309,7 +309,7 @@ static int __init arc_clockevent_setup(struct device_node *node)
 	}
 
 	ret = cpuhp_setup_state(CPUHP_AP_ARC_TIMER_STARTING,
-				"AP_ARC_TIMER_STARTING",
+				"clockevents/arc/timer:starting",
 				arc_timer_starting_cpu,
 				arc_timer_dying_cpu);
 	if (ret) {

drivers/clocksource/arm_arch_timer.c

@@ -738,7 +738,7 @@ static int __init arch_timer_register(void)
 
 	/* Register and immediately configure the timer on the boot CPU */
 	err = cpuhp_setup_state(CPUHP_AP_ARM_ARCH_TIMER_STARTING,
-				"AP_ARM_ARCH_TIMER_STARTING",
+				"clockevents/arm/arch_timer:starting",
 				arch_timer_starting_cpu, arch_timer_dying_cpu);
 	if (err)
 		goto out_unreg_cpupm;

drivers/clocksource/arm_global_timer.c

@@ -316,7 +316,7 @@ static int __init global_timer_of_register(struct device_node *np)
 		goto out_irq;
 	
 	err = cpuhp_setup_state(CPUHP_AP_ARM_GLOBAL_TIMER_STARTING,
-				"AP_ARM_GLOBAL_TIMER_STARTING",
+				"clockevents/arm/global_timer:starting",
 				gt_starting_cpu, gt_dying_cpu);
 	if (err)
 		goto out_irq;

drivers/clocksource/dummy_timer.c

@@ -34,7 +34,7 @@ static int dummy_timer_starting_cpu(unsigned int cpu)
 static int __init dummy_timer_register(void)
 {
 	return cpuhp_setup_state(CPUHP_AP_DUMMY_TIMER_STARTING,
-				 "AP_DUMMY_TIMER_STARTING",
+				 "clockevents/dummy_timer:starting",
 				 dummy_timer_starting_cpu, NULL);
 }
 early_initcall(dummy_timer_register);

drivers/clocksource/exynos_mct.c

@@ -552,7 +552,7 @@ static int __init exynos4_timer_resources(struct device_node *np, void __iomem *
 
 	/* Install hotplug callbacks which configure the timer on this CPU */
 	err = cpuhp_setup_state(CPUHP_AP_EXYNOS4_MCT_TIMER_STARTING,
-				"AP_EXYNOS4_MCT_TIMER_STARTING",
+				"clockevents/exynos4/mct_timer:starting",
 				exynos4_mct_starting_cpu,
 				exynos4_mct_dying_cpu);
 	if (err)

drivers/clocksource/jcore-pit.c

@@ -240,7 +240,7 @@ static int __init jcore_pit_init(struct device_node *node)
 	}
 
 	cpuhp_setup_state(CPUHP_AP_JCORE_TIMER_STARTING,
-			  "AP_JCORE_TIMER_STARTING",
+			  "clockevents/jcore:starting",
 			  jcore_pit_local_init, NULL);
 
 	return 0;

drivers/clocksource/metag_generic.c

@@ -154,6 +154,6 @@ int __init metag_generic_timer_init(void)
 
 	/* Hook cpu boot to configure the CPU's timers */
 	return cpuhp_setup_state(CPUHP_AP_METAG_TIMER_STARTING,
-				 "AP_METAG_TIMER_STARTING",
+				 "clockevents/metag:starting",
 				 arch_timer_starting_cpu, NULL);
 }

drivers/clocksource/mips-gic-timer.c

@@ -120,8 +120,8 @@ static int gic_clockevent_init(void)
 	}
 
 	cpuhp_setup_state(CPUHP_AP_MIPS_GIC_TIMER_STARTING,
-			  "AP_MIPS_GIC_TIMER_STARTING", gic_starting_cpu,
-			  gic_dying_cpu);
+			  "clockevents/mips/gic/timer:starting",
+			  gic_starting_cpu, gic_dying_cpu);
 	return 0;
 }
 

drivers/clocksource/qcom-timer.c

@@ -182,7 +182,7 @@ static int __init msm_timer_init(u32 dgt_hz, int sched_bits, int irq,
 	} else {
 		/* Install and invoke hotplug callbacks */
 		res = cpuhp_setup_state(CPUHP_AP_QCOM_TIMER_STARTING,
-					"AP_QCOM_TIMER_STARTING",
+					"clockevents/qcom/timer:starting",
 					msm_local_timer_starting_cpu,
 					msm_local_timer_dying_cpu);
 		if (res) {

drivers/clocksource/time-armada-370-xp.c

@@ -320,7 +320,7 @@ static int __init armada_370_xp_timer_common_init(struct device_node *np)
 	}
 
 	res = cpuhp_setup_state(CPUHP_AP_ARMADA_TIMER_STARTING,
-				"AP_ARMADA_TIMER_STARTING",
+				"clockevents/armada:starting",
 				armada_370_xp_timer_starting_cpu,
 				armada_370_xp_timer_dying_cpu);
 	if (res) {

drivers/clocksource/timer-atlas7.c

@@ -221,7 +221,7 @@ static int __init sirfsoc_clockevent_init(void)
 
 	/* Install and invoke hotplug callbacks */
 	return cpuhp_setup_state(CPUHP_AP_MARCO_TIMER_STARTING,
-				 "AP_MARCO_TIMER_STARTING",
+				 "clockevents/marco:starting",
 				 sirfsoc_local_timer_starting_cpu,
 				 sirfsoc_local_timer_dying_cpu);
 }

drivers/hwtracing/coresight/coresight-etm3x.c

@@ -804,10 +804,10 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id)
 
 	if (!etm_count++) {
 		cpuhp_setup_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING,
-					  "AP_ARM_CORESIGHT_STARTING",
+					  "arm/coresight:starting",
 					  etm_starting_cpu, etm_dying_cpu);
 		ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
-						"AP_ARM_CORESIGHT_ONLINE",
+						"arm/coresight:online",
 						etm_online_cpu, NULL);
 		if (ret < 0)
 			goto err_arch_supported;

drivers/hwtracing/coresight/coresight-etm4x.c

@@ -986,11 +986,11 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
 		dev_err(dev, "ETM arch init failed\n");
 
 	if (!etm4_count++) {
-		cpuhp_setup_state_nocalls(CPUHP_AP_ARM_CORESIGHT4_STARTING,
-					  "AP_ARM_CORESIGHT4_STARTING",
+		cpuhp_setup_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING,
+					  "arm/coresight4:starting",
 					  etm4_starting_cpu, etm4_dying_cpu);
 		ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
-						"AP_ARM_CORESIGHT4_ONLINE",
+						"arm/coresight4:online",
 						etm4_online_cpu, NULL);
 		if (ret < 0)
 			goto err_arch_supported;
@@ -1037,7 +1037,7 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
 
 err_arch_supported:
 	if (--etm4_count == 0) {
-		cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT4_STARTING);
+		cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING);
 		if (hp_online)
 			cpuhp_remove_state_nocalls(hp_online);
 	}

drivers/irqchip/irq-armada-370-xp.c

@@ -578,13 +578,13 @@ static int __init armada_370_xp_mpic_of_init(struct device_node *node,
 #ifdef CONFIG_SMP
 		set_smp_cross_call(armada_mpic_send_doorbell);
 		cpuhp_setup_state_nocalls(CPUHP_AP_IRQ_ARMADA_XP_STARTING,
-					  "AP_IRQ_ARMADA_XP_STARTING",
+					  "irqchip/armada/ipi:starting",
 					  armada_xp_mpic_starting_cpu, NULL);
 #endif
 	} else {
 #ifdef CONFIG_SMP
-		cpuhp_setup_state_nocalls(CPUHP_AP_IRQ_ARMADA_CASC_STARTING,
-					  "AP_IRQ_ARMADA_CASC_STARTING",
+		cpuhp_setup_state_nocalls(CPUHP_AP_IRQ_ARMADA_XP_STARTING,
+					  "irqchip/armada/cascade:starting",
 					  mpic_cascaded_starting_cpu, NULL);
 #endif
 		irq_set_chained_handler(parent_irq,

drivers/irqchip/irq-bcm2836.c

@@ -245,7 +245,7 @@ bcm2836_arm_irqchip_smp_init(void)
 #ifdef CONFIG_SMP
 	/* Unmask IPIs to the boot CPU. */
 	cpuhp_setup_state(CPUHP_AP_IRQ_BCM2836_STARTING,
-			  "AP_IRQ_BCM2836_STARTING", bcm2836_cpu_starting,
+			  "irqchip/bcm2836:starting", bcm2836_cpu_starting,
 			  bcm2836_cpu_dying);
 
 	set_smp_cross_call(bcm2836_arm_irqchip_send_ipi);

drivers/irqchip/irq-gic-v3.c

@@ -632,9 +632,9 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq)
 static void gic_smp_init(void)
 {
 	set_smp_cross_call(gic_raise_softirq);
-	cpuhp_setup_state_nocalls(CPUHP_AP_IRQ_GICV3_STARTING,
-				  "AP_IRQ_GICV3_STARTING", gic_starting_cpu,
-				  NULL);
+	cpuhp_setup_state_nocalls(CPUHP_AP_IRQ_GIC_STARTING,
+				  "irqchip/arm/gicv3:starting",
+				  gic_starting_cpu, NULL);
 }
 
 static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,

drivers/irqchip/irq-gic.c

@@ -1191,7 +1191,7 @@ static int __init __gic_init_bases(struct gic_chip_data *gic,
 		set_smp_cross_call(gic_raise_softirq);
 #endif
 		cpuhp_setup_state_nocalls(CPUHP_AP_IRQ_GIC_STARTING,
-					  "AP_IRQ_GIC_STARTING",
+					  "irqchip/arm/gic:starting",
 					  gic_starting_cpu, NULL);
 		set_handle_irq(gic_handle_irq);
 		if (static_key_true(&supports_deactivate))

drivers/irqchip/irq-hip04.c

@@ -407,7 +407,7 @@ hip04_of_init(struct device_node *node, struct device_node *parent)
 	set_handle_irq(hip04_handle_irq);
 
 	hip04_irq_dist_init(&hip04_data);
-	cpuhp_setup_state(CPUHP_AP_IRQ_HIP04_STARTING, "AP_IRQ_HIP04_STARTING",
+	cpuhp_setup_state(CPUHP_AP_IRQ_HIP04_STARTING, "irqchip/hip04:starting",
 			  hip04_irq_starting_cpu, NULL);
 	return 0;
 }

drivers/leds/trigger/ledtrig-cpu.c

@@ -127,7 +127,7 @@ static int __init ledtrig_cpu_init(void)
 
 	register_syscore_ops(&ledtrig_cpu_syscore_ops);
 
-	ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "AP_LEDTRIG_STARTING",
+	ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "leds/trigger:starting",
 				ledtrig_online_cpu, ledtrig_prepare_down_cpu);
 	if (ret < 0)
 		pr_err("CPU hotplug notifier for ledtrig-cpu could not be registered: %d\n",

drivers/net/virtio_net.c

@@ -2484,13 +2484,13 @@ static __init int virtio_net_driver_init(void)
 {
 	int ret;
 
-	ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "AP_VIRT_NET_ONLINE",
+	ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "virtio/net:online",
 				      virtnet_cpu_online,
 				      virtnet_cpu_down_prep);
 	if (ret < 0)
 		goto out;
 	virtionet_online = ret;
-	ret = cpuhp_setup_state_multi(CPUHP_VIRT_NET_DEAD, "VIRT_NET_DEAD",
+	ret = cpuhp_setup_state_multi(CPUHP_VIRT_NET_DEAD, "virtio/net:dead",
 				      NULL, virtnet_cpu_dead);
 	if (ret)
 		goto err_dead;

drivers/perf/arm_pmu.c

@@ -1084,7 +1084,7 @@ static int arm_pmu_hp_init(void)
 	int ret;
 
 	ret = cpuhp_setup_state_multi(CPUHP_AP_PERF_ARM_STARTING,
-				      "AP_PERF_ARM_STARTING",
+				      "perf/arm/pmu:starting",
 				      arm_perf_starting_cpu, NULL);
 	if (ret)
 		pr_err("CPU hotplug notifier for ARM PMU could not be registered: %d\n",

drivers/scsi/bnx2fc/bnx2fc_fcoe.c

@@ -127,13 +127,6 @@ module_param_named(log_fka, bnx2fc_log_fka, uint, S_IRUGO|S_IWUSR);
 MODULE_PARM_DESC(log_fka, " Print message to kernel log when fcoe is "
 	"initiating a FIP keep alive when debug logging is enabled.");
 
-static int bnx2fc_cpu_callback(struct notifier_block *nfb,
-			     unsigned long action, void *hcpu);
-/* notification function for CPU hotplug events */
-static struct notifier_block bnx2fc_cpu_notifier = {
-	.notifier_call = bnx2fc_cpu_callback,
-};
-
 static inline struct net_device *bnx2fc_netdev(const struct fc_lport *lport)
 {
 	return ((struct bnx2fc_interface *)
@@ -2622,37 +2615,19 @@ static void bnx2fc_percpu_thread_destroy(unsigned int cpu)
 		kthread_stop(thread);
 }
 
-/**
- * bnx2fc_cpu_callback - Handler for CPU hotplug events
- *
- * @nfb:    The callback data block
- * @action: The event triggering the callback
- * @hcpu:   The index of the CPU that the event is for
- *
- * This creates or destroys per-CPU data for fcoe
- *
- * Returns NOTIFY_OK always.
- */
-static int bnx2fc_cpu_callback(struct notifier_block *nfb,
-			     unsigned long action, void *hcpu)
+
+static int bnx2fc_cpu_online(unsigned int cpu)
 {
-	unsigned cpu = (unsigned long)hcpu;
+	printk(PFX "CPU %x online: Create Rx thread\n", cpu);
+	bnx2fc_percpu_thread_create(cpu);
+	return 0;
+}
 
-	switch (action) {
-	case CPU_ONLINE:
-	case CPU_ONLINE_FROZEN:
-		printk(PFX "CPU %x online: Create Rx thread\n", cpu);
-		bnx2fc_percpu_thread_create(cpu);
-		break;
-	case CPU_DEAD:
-	case CPU_DEAD_FROZEN:
-		printk(PFX "CPU %x offline: Remove Rx thread\n", cpu);
-		bnx2fc_percpu_thread_destroy(cpu);
-		break;
-	default:
-		break;
-	}
-	return NOTIFY_OK;
+static int bnx2fc_cpu_dead(unsigned int cpu)
+{
+	printk(PFX "CPU %x offline: Remove Rx thread\n", cpu);
+	bnx2fc_percpu_thread_destroy(cpu);
+	return 0;
 }
 
 static int bnx2fc_slave_configure(struct scsi_device *sdev)
@@ -2664,6 +2639,8 @@ static int bnx2fc_slave_configure(struct scsi_device *sdev)
 	return 0;
 }
 
+static enum cpuhp_state bnx2fc_online_state;
+
 /**
  * bnx2fc_mod_init - module init entry point
  *
@@ -2724,21 +2701,31 @@ static int __init bnx2fc_mod_init(void)
 		spin_lock_init(&p->fp_work_lock);
 	}
 
-	cpu_notifier_register_begin();
+	get_online_cpus();
 
-	for_each_online_cpu(cpu) {
+	for_each_online_cpu(cpu)
 		bnx2fc_percpu_thread_create(cpu);
-	}
 
-	/* Initialize per CPU interrupt thread */
-	__register_hotcpu_notifier(&bnx2fc_cpu_notifier);
+	rc = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
+				       "scsi/bnx2fc:online",
+				       bnx2fc_cpu_online, NULL);
+	if (rc < 0)
+		goto stop_threads;
+	bnx2fc_online_state = rc;
 
-	cpu_notifier_register_done();
+	cpuhp_setup_state_nocalls(CPUHP_SCSI_BNX2FC_DEAD, "scsi/bnx2fc:dead",
+				  NULL, bnx2fc_cpu_dead);
+	put_online_cpus();
 
 	cnic_register_driver(CNIC_ULP_FCOE, &bnx2fc_cnic_cb);
 
 	return 0;
 
+stop_threads:
+	for_each_online_cpu(cpu)
+		bnx2fc_percpu_thread_destroy(cpu);
+	put_online_cpus();
+	kthread_stop(l2_thread);
 free_wq:
 	destroy_workqueue(bnx2fc_wq);
 release_bt:
@@ -2797,16 +2784,16 @@ static void __exit bnx2fc_mod_exit(void)
 	if (l2_thread)
 		kthread_stop(l2_thread);
 
-	cpu_notifier_register_begin();
-
+	get_online_cpus();
 	/* Destroy per cpu threads */
 	for_each_online_cpu(cpu) {
 		bnx2fc_percpu_thread_destroy(cpu);
 	}
 
-	__unregister_hotcpu_notifier(&bnx2fc_cpu_notifier);
+	cpuhp_remove_state_nocalls(bnx2fc_online_state);
+	cpuhp_remove_state_nocalls(CPUHP_SCSI_BNX2FC_DEAD);
 
-	cpu_notifier_register_done();
+	put_online_cpus();
 
 	destroy_workqueue(bnx2fc_wq);
 	/*

drivers/scsi/bnx2i/bnx2i_init.c

@@ -70,14 +70,6 @@ u64 iscsi_error_mask = 0x00;
 
 DEFINE_PER_CPU(struct bnx2i_percpu_s, bnx2i_percpu);
 
-static int bnx2i_cpu_callback(struct notifier_block *nfb,
-			      unsigned long action, void *hcpu);
-/* notification function for CPU hotplug events */
-static struct notifier_block bnx2i_cpu_notifier = {
-	.notifier_call = bnx2i_cpu_callback,
-};
-
-
 /**
  * bnx2i_identify_device - identifies NetXtreme II device type
  * @hba: 		Adapter structure pointer
@@ -461,41 +453,21 @@ static void bnx2i_percpu_thread_destroy(unsigned int cpu)
 		kthread_stop(thread);
 }
 
-
-/**
- * bnx2i_cpu_callback - Handler for CPU hotplug events
- *
- * @nfb:	The callback data block
- * @action:	The event triggering the callback
- * @hcpu:	The index of the CPU that the event is for
- *
- * This creates or destroys per-CPU data for iSCSI
- *
- * Returns NOTIFY_OK always.
- */
-static int bnx2i_cpu_callback(struct notifier_block *nfb,
-			      unsigned long action, void *hcpu)
+static int bnx2i_cpu_online(unsigned int cpu)
 {
-	unsigned cpu = (unsigned long)hcpu;
+	pr_info("bnx2i: CPU %x online: Create Rx thread\n", cpu);
+	bnx2i_percpu_thread_create(cpu);
+	return 0;
+}
 
-	switch (action) {
-	case CPU_ONLINE:
-	case CPU_ONLINE_FROZEN:
-		printk(KERN_INFO "bnx2i: CPU %x online: Create Rx thread\n",
-			cpu);
-		bnx2i_percpu_thread_create(cpu);
-		break;
-	case CPU_DEAD:
-	case CPU_DEAD_FROZEN:
-		printk(KERN_INFO "CPU %x offline: Remove Rx thread\n", cpu);
-		bnx2i_percpu_thread_destroy(cpu);
-		break;
-	default:
-		break;
-	}
-	return NOTIFY_OK;
+static int bnx2i_cpu_dead(unsigned int cpu)
+{
+	pr_info("CPU %x offline: Remove Rx thread\n", cpu);
+	bnx2i_percpu_thread_destroy(cpu);
+	return 0;
 }
 
+static enum cpuhp_state bnx2i_online_state;
 
 /**
  * bnx2i_mod_init - module init entry point
@@ -539,18 +511,28 @@ static int __init bnx2i_mod_init(void)
 		p->iothread = NULL;
 	}
 
-	cpu_notifier_register_begin();
+	get_online_cpus();
 
 	for_each_online_cpu(cpu)
 		bnx2i_percpu_thread_create(cpu);
 
-	/* Initialize per CPU interrupt thread */
-	__register_hotcpu_notifier(&bnx2i_cpu_notifier);
-
-	cpu_notifier_register_done();
+	err = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
+				       "scsi/bnx2i:online",
+				       bnx2i_cpu_online, NULL);
+	if (err < 0)
+		goto remove_threads;
+	bnx2i_online_state = err;
 
+	cpuhp_setup_state_nocalls(CPUHP_SCSI_BNX2I_DEAD, "scsi/bnx2i:dead",
+				  NULL, bnx2i_cpu_dead);
+	put_online_cpus();
 	return 0;
 
+remove_threads:
+	for_each_online_cpu(cpu)
+		bnx2i_percpu_thread_destroy(cpu);
+	put_online_cpus();
+	cnic_unregister_driver(CNIC_ULP_ISCSI);
 unreg_xport:
 	iscsi_unregister_transport(&bnx2i_iscsi_transport);
 out:
@@ -587,14 +569,14 @@ static void __exit bnx2i_mod_exit(void)
 	}
 	mutex_unlock(&bnx2i_dev_lock);
 
-	cpu_notifier_register_begin();
+	get_online_cpus();
 
 	for_each_online_cpu(cpu)
 		bnx2i_percpu_thread_destroy(cpu);
 
-	__unregister_hotcpu_notifier(&bnx2i_cpu_notifier);
-
-	cpu_notifier_register_done();
+	cpuhp_remove_state_nocalls(bnx2i_online_state);
+	cpuhp_remove_state_nocalls(CPUHP_SCSI_BNX2I_DEAD);
+	put_online_cpus();
 
 	iscsi_unregister_transport(&bnx2i_iscsi_transport);
 	cnic_unregister_driver(CNIC_ULP_ISCSI);

drivers/scsi/qedi/qedi_main.c

@@ -1612,30 +1612,29 @@ static int qedi_percpu_io_thread(void *arg)
 	return 0;
 }
 
-static void qedi_percpu_thread_create(unsigned int cpu)
+static int qedi_cpu_online(unsigned int cpu)
 {
-	struct qedi_percpu_s *p;
+	struct qedi_percpu_s *p = this_cpu_ptr(&qedi_percpu);
 	struct task_struct *thread;
 
-	p = &per_cpu(qedi_percpu, cpu);
-
 	thread = kthread_create_on_node(qedi_percpu_io_thread, (void *)p,
 					cpu_to_node(cpu),
 					"qedi_thread/%d", cpu);
-	if (likely(!IS_ERR(thread))) {
-		kthread_bind(thread, cpu);
-		p->iothread = thread;
-		wake_up_process(thread);
-	}
+	if (IS_ERR(thread))
+		return PTR_ERR(thread);
+
+	kthread_bind(thread, cpu);
+	p->iothread = thread;
+	wake_up_process(thread);
+	return 0;
 }
 
-static void qedi_percpu_thread_destroy(unsigned int cpu)
+static int qedi_cpu_offline(unsigned int cpu)
 {
-	struct qedi_percpu_s *p;
-	struct task_struct *thread;
+	struct qedi_percpu_s *p = this_cpu_ptr(&qedi_percpu);
 	struct qedi_work *work, *tmp;
+	struct task_struct *thread;
 
-	p = &per_cpu(qedi_percpu, cpu);
 	spin_lock_bh(&p->p_work_lock);
 	thread = p->iothread;
 	p->iothread = NULL;
@@ -1650,35 +1649,9 @@ static void qedi_percpu_thread_destroy(unsigned int cpu)
 	spin_unlock_bh(&p->p_work_lock);
 	if (thread)
 		kthread_stop(thread);
+	return 0;
 }
 
-static int qedi_cpu_callback(struct notifier_block *nfb,
-			     unsigned long action, void *hcpu)
-{
-	unsigned int cpu = (unsigned long)hcpu;
-
-	switch (action) {
-	case CPU_ONLINE:
-	case CPU_ONLINE_FROZEN:
-		QEDI_ERR(NULL, "CPU %d online.\n", cpu);
-		qedi_percpu_thread_create(cpu);
-		break;
-	case CPU_DEAD:
-	case CPU_DEAD_FROZEN:
-		QEDI_ERR(NULL, "CPU %d offline.\n", cpu);
-		qedi_percpu_thread_destroy(cpu);
-		break;
-	default:
-		break;
-	}
-
-	return NOTIFY_OK;
-}
-
-static struct notifier_block qedi_cpu_notifier = {
-	.notifier_call = qedi_cpu_callback,
-};
-
 void qedi_reset_host_mtu(struct qedi_ctx *qedi, u16 mtu)
 {
 	struct qed_ll2_params params;
@@ -2038,6 +2011,8 @@ static struct pci_device_id qedi_pci_tbl[] = {
 };
 MODULE_DEVICE_TABLE(pci, qedi_pci_tbl);
 
+static enum cpuhp_state qedi_cpuhp_state;
+
 static struct pci_driver qedi_pci_driver = {
 	.name = QEDI_MODULE_NAME,
 	.id_table = qedi_pci_tbl,
@@ -2047,16 +2022,13 @@ static struct pci_driver qedi_pci_driver = {
 
 static int __init qedi_init(void)
 {
-	int rc = 0;
-	int ret;
 	struct qedi_percpu_s *p;
-	unsigned int cpu = 0;
+	int cpu, rc = 0;
 
 	qedi_ops = qed_get_iscsi_ops();
 	if (!qedi_ops) {
 		QEDI_ERR(NULL, "Failed to get qed iSCSI operations\n");
-		rc = -EINVAL;
-		goto exit_qedi_init_0;
+		return -EINVAL;
 	}
 
 #ifdef CONFIG_DEBUG_FS
@@ -2070,15 +2042,6 @@ static int __init qedi_init(void)
 		goto exit_qedi_init_1;
 	}
 
-	register_hotcpu_notifier(&qedi_cpu_notifier);
-
-	ret = pci_register_driver(&qedi_pci_driver);
-	if (ret) {
-		QEDI_ERR(NULL, "Failed to register driver\n");
-		rc = -EINVAL;
-		goto exit_qedi_init_2;
-	}
-
 	for_each_possible_cpu(cpu) {
 		p = &per_cpu(qedi_percpu, cpu);
 		INIT_LIST_HEAD(&p->work_list);
@@ -2086,11 +2049,22 @@ static int __init qedi_init(void)
 		p->iothread = NULL;
 	}
 
-	for_each_online_cpu(cpu)
-		qedi_percpu_thread_create(cpu);
+	rc = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "scsi/qedi:online",
+			       qedi_cpu_online, qedi_cpu_offline);
+	if (rc < 0)
+		goto exit_qedi_init_2;
+	qedi_cpuhp_state = rc;
 
-	return rc;
+	rc = pci_register_driver(&qedi_pci_driver);
+	if (rc) {
+		QEDI_ERR(NULL, "Failed to register driver\n");
+		goto exit_qedi_hp;
+	}
+
+	return 0;
 
+exit_qedi_hp:
+	cpuhp_remove_state(qedi_cpuhp_state);
 exit_qedi_init_2:
 	iscsi_unregister_transport(&qedi_iscsi_transport);
 exit_qedi_init_1:
@@ -2098,19 +2072,13 @@ exit_qedi_init_1:
 	qedi_dbg_exit();
 #endif
 	qed_put_iscsi_ops();
-exit_qedi_init_0:
 	return rc;
 }
 
 static void __exit qedi_cleanup(void)
 {
-	unsigned int cpu = 0;
-
-	for_each_online_cpu(cpu)
-		qedi_percpu_thread_destroy(cpu);
-
 	pci_unregister_driver(&qedi_pci_driver);
-	unregister_hotcpu_notifier(&qedi_cpu_notifier);
+	cpuhp_remove_state(qedi_cpuhp_state);
 	iscsi_unregister_transport(&qedi_iscsi_transport);
 
 #ifdef CONFIG_DEBUG_FS

drivers/staging/lustre/lnet/libcfs/linux/linux-cpu.c

@@ -967,48 +967,38 @@ cfs_cpt_table_create_pattern(char *pattern)
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
-static int
-cfs_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu)
-{
-	unsigned int cpu = (unsigned long)hcpu;
-	bool warn;
-
-	switch (action) {
-	case CPU_DEAD:
-	case CPU_DEAD_FROZEN:
-	case CPU_ONLINE:
-	case CPU_ONLINE_FROZEN:
-		spin_lock(&cpt_data.cpt_lock);
-		cpt_data.cpt_version++;
-		spin_unlock(&cpt_data.cpt_lock);
-		/* Fall through */
-	default:
-		if (action != CPU_DEAD && action != CPU_DEAD_FROZEN) {
-			CDEBUG(D_INFO, "CPU changed [cpu %u action %lx]\n",
-			       cpu, action);
-			break;
-		}
+static enum cpuhp_state lustre_cpu_online;
 
-		mutex_lock(&cpt_data.cpt_mutex);
-		/* if all HTs in a core are offline, it may break affinity */
-		cpumask_copy(cpt_data.cpt_cpumask,
-			     topology_sibling_cpumask(cpu));
-		warn = cpumask_any_and(cpt_data.cpt_cpumask,
-				       cpu_online_mask) >= nr_cpu_ids;
-		mutex_unlock(&cpt_data.cpt_mutex);
-		CDEBUG(warn ? D_WARNING : D_INFO,
-		       "Lustre: can't support CPU plug-out well now, performance and stability could be impacted [CPU %u action: %lx]\n",
-		       cpu, action);
-	}
+static void cfs_cpu_incr_cpt_version(void)
+{
+	spin_lock(&cpt_data.cpt_lock);
+	cpt_data.cpt_version++;
+	spin_unlock(&cpt_data.cpt_lock);
+}
 
-	return NOTIFY_OK;
+static int cfs_cpu_online(unsigned int cpu)
+{
+	cfs_cpu_incr_cpt_version();
+	return 0;
 }
 
-static struct notifier_block cfs_cpu_notifier = {
-	.notifier_call	= cfs_cpu_notify,
-	.priority	= 0
-};
+static int cfs_cpu_dead(unsigned int cpu)
+{
+	bool warn;
+
+	cfs_cpu_incr_cpt_version();
 
+	mutex_lock(&cpt_data.cpt_mutex);
+	/* if all HTs in a core are offline, it may break affinity */
+	cpumask_copy(cpt_data.cpt_cpumask, topology_sibling_cpumask(cpu));
+	warn = cpumask_any_and(cpt_data.cpt_cpumask,
+			       cpu_online_mask) >= nr_cpu_ids;
+	mutex_unlock(&cpt_data.cpt_mutex);
+	CDEBUG(warn ? D_WARNING : D_INFO,
+	       "Lustre: can't support CPU plug-out well now, performance and stability could be impacted [CPU %u]\n",
+	       cpu);
+	return 0;
+}
 #endif
 
 void
@@ -1018,7 +1008,9 @@ cfs_cpu_fini(void)
 		cfs_cpt_table_free(cfs_cpt_table);
 
 #ifdef CONFIG_HOTPLUG_CPU
-	unregister_hotcpu_notifier(&cfs_cpu_notifier);
+	if (lustre_cpu_online > 0)
+		cpuhp_remove_state_nocalls(lustre_cpu_online);
+	cpuhp_remove_state_nocalls(CPUHP_LUSTRE_CFS_DEAD);
 #endif
 	if (cpt_data.cpt_cpumask)
 		LIBCFS_FREE(cpt_data.cpt_cpumask, cpumask_size());
@@ -1027,6 +1019,8 @@ cfs_cpu_fini(void)
 int
 cfs_cpu_init(void)
 {
+	int ret = 0;
+
 	LASSERT(!cfs_cpt_table);
 
 	memset(&cpt_data, 0, sizeof(cpt_data));
@@ -1041,8 +1035,19 @@ cfs_cpu_init(void)
 	mutex_init(&cpt_data.cpt_mutex);
 
 #ifdef CONFIG_HOTPLUG_CPU
-	register_hotcpu_notifier(&cfs_cpu_notifier);
+	ret = cpuhp_setup_state_nocalls(CPUHP_LUSTRE_CFS_DEAD,
+					"staging/lustre/cfe:dead", NULL,
+					cfs_cpu_dead);
+	if (ret < 0)
+		goto failed;
+	ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
+					"staging/lustre/cfe:online",
+					cfs_cpu_online, NULL);
+	if (ret < 0)
+		goto failed;
+	lustre_cpu_online = ret;
 #endif
+	ret = -EINVAL;
 
 	if (*cpu_pattern) {
 		cfs_cpt_table = cfs_cpt_table_create_pattern(cpu_pattern);
@@ -1075,7 +1080,7 @@ cfs_cpu_init(void)
 
  failed:
 	cfs_cpu_fini();
-	return -1;
+	return ret;
 }
 
 #endif

drivers/xen/events/events_fifo.c

@@ -445,7 +445,7 @@ int __init xen_evtchn_fifo_init(void)
 	evtchn_ops = &evtchn_ops_fifo;
 
 	cpuhp_setup_state_nocalls(CPUHP_XEN_EVTCHN_PREPARE,
-				  "CPUHP_XEN_EVTCHN_PREPARE",
+				  "xen/evtchn:prepare",
 				  xen_evtchn_cpu_prepare, xen_evtchn_cpu_dead);
 out:
 	put_cpu();

include/linux/cpu.h

@@ -57,9 +57,6 @@ struct notifier_block;
 
 #define CPU_ONLINE		0x0002 /* CPU (unsigned)v is up */
 #define CPU_UP_PREPARE		0x0003 /* CPU (unsigned)v coming up */
-#define CPU_UP_CANCELED		0x0004 /* CPU (unsigned)v NOT coming up */
-#define CPU_DOWN_PREPARE	0x0005 /* CPU (unsigned)v going down */
-#define CPU_DOWN_FAILED		0x0006 /* CPU (unsigned)v NOT going down */
 #define CPU_DEAD		0x0007 /* CPU (unsigned)v dead */
 #define CPU_POST_DEAD		0x0009 /* CPU (unsigned)v dead, cpu_hotplug
 					* lock is dropped */
@@ -80,80 +77,14 @@ struct notifier_block;
 
 #ifdef CONFIG_SMP
 extern bool cpuhp_tasks_frozen;
-/* Need to know about CPUs going up/down? */
-#if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
-#define cpu_notifier(fn, pri) {					\
-	static struct notifier_block fn##_nb =			\
-		{ .notifier_call = fn, .priority = pri };	\
-	register_cpu_notifier(&fn##_nb);			\
-}
-
-#define __cpu_notifier(fn, pri) {				\
-	static struct notifier_block fn##_nb =			\
-		{ .notifier_call = fn, .priority = pri };	\
-	__register_cpu_notifier(&fn##_nb);			\
-}
-
-extern int register_cpu_notifier(struct notifier_block *nb);
-extern int __register_cpu_notifier(struct notifier_block *nb);
-extern void unregister_cpu_notifier(struct notifier_block *nb);
-extern void __unregister_cpu_notifier(struct notifier_block *nb);
-
-#else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
-#define cpu_notifier(fn, pri)	do { (void)(fn); } while (0)
-#define __cpu_notifier(fn, pri)	do { (void)(fn); } while (0)
-
-static inline int register_cpu_notifier(struct notifier_block *nb)
-{
-	return 0;
-}
-
-static inline int __register_cpu_notifier(struct notifier_block *nb)
-{
-	return 0;
-}
-
-static inline void unregister_cpu_notifier(struct notifier_block *nb)
-{
-}
-
-static inline void __unregister_cpu_notifier(struct notifier_block *nb)
-{
-}
-#endif
-
 int cpu_up(unsigned int cpu);
 void notify_cpu_starting(unsigned int cpu);
 extern void cpu_maps_update_begin(void);
 extern void cpu_maps_update_done(void);
 
-#define cpu_notifier_register_begin	cpu_maps_update_begin
-#define cpu_notifier_register_done	cpu_maps_update_done
-
 #else	/* CONFIG_SMP */
 #define cpuhp_tasks_frozen	0
 
-#define cpu_notifier(fn, pri)	do { (void)(fn); } while (0)
-#define __cpu_notifier(fn, pri)	do { (void)(fn); } while (0)
-
-static inline int register_cpu_notifier(struct notifier_block *nb)
-{
-	return 0;
-}
-
-static inline int __register_cpu_notifier(struct notifier_block *nb)
-{
-	return 0;
-}
-
-static inline void unregister_cpu_notifier(struct notifier_block *nb)
-{
-}
-
-static inline void __unregister_cpu_notifier(struct notifier_block *nb)
-{
-}
-
 static inline void cpu_maps_update_begin(void)
 {
 }
@@ -162,14 +93,6 @@ static inline void cpu_maps_update_done(void)
 {
 }
 
-static inline void cpu_notifier_register_begin(void)
-{
-}
-
-static inline void cpu_notifier_register_done(void)
-{
-}
-
 #endif /* CONFIG_SMP */
 extern struct bus_type cpu_subsys;
 
@@ -182,12 +105,6 @@ extern void get_online_cpus(void);
 extern void put_online_cpus(void);
 extern void cpu_hotplug_disable(void);
 extern void cpu_hotplug_enable(void);
-#define hotcpu_notifier(fn, pri)	cpu_notifier(fn, pri)
-#define __hotcpu_notifier(fn, pri)	__cpu_notifier(fn, pri)
-#define register_hotcpu_notifier(nb)	register_cpu_notifier(nb)
-#define __register_hotcpu_notifier(nb)	__register_cpu_notifier(nb)
-#define unregister_hotcpu_notifier(nb)	unregister_cpu_notifier(nb)
-#define __unregister_hotcpu_notifier(nb)	__unregister_cpu_notifier(nb)
 void clear_tasks_mm_cpumask(int cpu);
 int cpu_down(unsigned int cpu);
 
@@ -199,13 +116,6 @@ static inline void cpu_hotplug_done(void) {}
 #define put_online_cpus()	do { } while (0)
 #define cpu_hotplug_disable()	do { } while (0)
 #define cpu_hotplug_enable()	do { } while (0)
-#define hotcpu_notifier(fn, pri)	do { (void)(fn); } while (0)
-#define __hotcpu_notifier(fn, pri)	do { (void)(fn); } while (0)
-/* These aren't inline functions due to a GCC bug. */
-#define register_hotcpu_notifier(nb)	({ (void)(nb); 0; })
-#define __register_hotcpu_notifier(nb)	({ (void)(nb); 0; })
-#define unregister_hotcpu_notifier(nb)	({ (void)(nb); })
-#define __unregister_hotcpu_notifier(nb)	({ (void)(nb); })
 #endif		/* CONFIG_HOTPLUG_CPU */
 
 #ifdef CONFIG_PM_SLEEP_SMP

include/linux/cpuhotplug.h

@@ -41,6 +41,9 @@ enum cpuhp_state {
 	CPUHP_NET_DEV_DEAD,
 	CPUHP_PCI_XGENE_DEAD,
 	CPUHP_IOMMU_INTEL_DEAD,
+	CPUHP_LUSTRE_CFS_DEAD,
+	CPUHP_SCSI_BNX2FC_DEAD,
+	CPUHP_SCSI_BNX2I_DEAD,
 	CPUHP_WORKQUEUE_PREP,
 	CPUHP_POWER_NUMA_PREPARE,
 	CPUHP_HRTIMERS_PREPARE,
@@ -56,7 +59,6 @@ enum cpuhp_state {
 	CPUHP_POWERPC_MMU_CTX_PREPARE,
 	CPUHP_XEN_PREPARE,
 	CPUHP_XEN_EVTCHN_PREPARE,
-	CPUHP_NOTIFY_PREPARE,
 	CPUHP_ARM_SHMOBILE_SCU_PREPARE,
 	CPUHP_SH_SH3X_PREPARE,
 	CPUHP_BLK_MQ_PREPARE,
@@ -71,7 +73,6 @@ enum cpuhp_state {
 	CPUHP_KVM_PPC_BOOK3S_PREPARE,
 	CPUHP_ZCOMP_PREPARE,
 	CPUHP_TIMERS_DEAD,
-	CPUHP_NOTF_ERR_INJ_PREPARE,
 	CPUHP_MIPS_SOC_PREPARE,
 	CPUHP_BRINGUP_CPU,
 	CPUHP_AP_IDLE_DEAD,
@@ -79,10 +80,8 @@ enum cpuhp_state {
 	CPUHP_AP_SCHED_STARTING,
 	CPUHP_AP_RCUTREE_DYING,
 	CPUHP_AP_IRQ_GIC_STARTING,
-	CPUHP_AP_IRQ_GICV3_STARTING,
 	CPUHP_AP_IRQ_HIP04_STARTING,
 	CPUHP_AP_IRQ_ARMADA_XP_STARTING,
-	CPUHP_AP_IRQ_ARMADA_CASC_STARTING,
 	CPUHP_AP_IRQ_BCM2836_STARTING,
 	CPUHP_AP_ARM_MVEBU_COHERENCY,
 	CPUHP_AP_PERF_X86_UNCORE_STARTING,
@@ -118,7 +117,6 @@ enum cpuhp_state {
 	CPUHP_AP_DUMMY_TIMER_STARTING,
 	CPUHP_AP_ARM_XEN_STARTING,
 	CPUHP_AP_ARM_CORESIGHT_STARTING,
-	CPUHP_AP_ARM_CORESIGHT4_STARTING,
 	CPUHP_AP_ARM64_ISNDEP_STARTING,
 	CPUHP_AP_SMPCFD_DYING,
 	CPUHP_AP_X86_TBOOT_DYING,
@@ -142,7 +140,6 @@ enum cpuhp_state {
 	CPUHP_AP_PERF_ARM_L2X0_ONLINE,
 	CPUHP_AP_WORKQUEUE_ONLINE,
 	CPUHP_AP_RCUTREE_ONLINE,
-	CPUHP_AP_NOTIFY_ONLINE,
 	CPUHP_AP_ONLINE_DYN,
 	CPUHP_AP_ONLINE_DYN_END		= CPUHP_AP_ONLINE_DYN + 30,
 	CPUHP_AP_X86_HPET_ONLINE,

kernel/cpu.c

@@ -183,23 +183,16 @@ EXPORT_SYMBOL_GPL(cpuhp_tasks_frozen);
 /*
  * The following two APIs (cpu_maps_update_begin/done) must be used when
  * attempting to serialize the updates to cpu_online_mask & cpu_present_mask.
- * The APIs cpu_notifier_register_begin/done() must be used to protect CPU
- * hotplug callback (un)registration performed using __register_cpu_notifier()
- * or __unregister_cpu_notifier().
  */
 void cpu_maps_update_begin(void)
 {
 	mutex_lock(&cpu_add_remove_lock);
 }
-EXPORT_SYMBOL(cpu_notifier_register_begin);
 
 void cpu_maps_update_done(void)
 {
 	mutex_unlock(&cpu_add_remove_lock);
 }
-EXPORT_SYMBOL(cpu_notifier_register_done);
-
-static RAW_NOTIFIER_HEAD(cpu_chain);
 
 /* If set, cpu_up and cpu_down will return -EBUSY and do nothing.
  * Should always be manipulated under cpu_add_remove_lock
@@ -349,66 +342,7 @@ void cpu_hotplug_enable(void)
 EXPORT_SYMBOL_GPL(cpu_hotplug_enable);
 #endif	/* CONFIG_HOTPLUG_CPU */
 
-/* Need to know about CPUs going up/down? */
-int register_cpu_notifier(struct notifier_block *nb)
-{
-	int ret;
-	cpu_maps_update_begin();
-	ret = raw_notifier_chain_register(&cpu_chain, nb);
-	cpu_maps_update_done();
-	return ret;
-}
-
-int __register_cpu_notifier(struct notifier_block *nb)
-{
-	return raw_notifier_chain_register(&cpu_chain, nb);
-}
-
-static int __cpu_notify(unsigned long val, unsigned int cpu, int nr_to_call,
-			int *nr_calls)
-{
-	unsigned long mod = cpuhp_tasks_frozen ? CPU_TASKS_FROZEN : 0;
-	void *hcpu = (void *)(long)cpu;
-
-	int ret;
-
-	ret = __raw_notifier_call_chain(&cpu_chain, val | mod, hcpu, nr_to_call,
-					nr_calls);
-
-	return notifier_to_errno(ret);
-}
-
-static int cpu_notify(unsigned long val, unsigned int cpu)
-{
-	return __cpu_notify(val, cpu, -1, NULL);
-}
-
-static void cpu_notify_nofail(unsigned long val, unsigned int cpu)
-{
-	BUG_ON(cpu_notify(val, cpu));
-}
-
 /* Notifier wrappers for transitioning to state machine */
-static int notify_prepare(unsigned int cpu)
-{
-	int nr_calls = 0;
-	int ret;
-
-	ret = __cpu_notify(CPU_UP_PREPARE, cpu, -1, &nr_calls);
-	if (ret) {
-		nr_calls--;
-		printk(KERN_WARNING "%s: attempt to bring up CPU %u failed\n",
-				__func__, cpu);
-		__cpu_notify(CPU_UP_CANCELED, cpu, nr_calls, NULL);
-	}
-	return ret;
-}
-
-static int notify_online(unsigned int cpu)
-{
-	cpu_notify(CPU_ONLINE, cpu);
-	return 0;
-}
 
 static int bringup_wait_for_ap(unsigned int cpu)
 {
@@ -433,10 +367,8 @@ static int bringup_cpu(unsigned int cpu)
 	/* Arch-specific enabling code. */
 	ret = __cpu_up(cpu, idle);
 	irq_unlock_sparse();
-	if (ret) {
-		cpu_notify(CPU_UP_CANCELED, cpu);
+	if (ret)
 		return ret;
-	}
 	ret = bringup_wait_for_ap(cpu);
 	BUG_ON(!cpu_online(cpu));
 	return ret;
@@ -565,11 +497,6 @@ static void cpuhp_thread_fun(unsigned int cpu)
 		BUG_ON(st->state < CPUHP_AP_ONLINE_IDLE);
 
 		undo_cpu_down(cpu, st);
-		/*
-		 * This is a momentary workaround to keep the notifier users
-		 * happy. Will go away once we got rid of the notifiers.
-		 */
-		cpu_notify_nofail(CPU_DOWN_FAILED, cpu);
 		st->rollback = false;
 	} else {
 		/* Cannot happen .... */
@@ -659,22 +586,6 @@ void __init cpuhp_threads_init(void)
 	kthread_unpark(this_cpu_read(cpuhp_state.thread));
 }
 
-EXPORT_SYMBOL(register_cpu_notifier);
-EXPORT_SYMBOL(__register_cpu_notifier);
-void unregister_cpu_notifier(struct notifier_block *nb)
-{
-	cpu_maps_update_begin();
-	raw_notifier_chain_unregister(&cpu_chain, nb);
-	cpu_maps_update_done();
-}
-EXPORT_SYMBOL(unregister_cpu_notifier);
-
-void __unregister_cpu_notifier(struct notifier_block *nb)
-{
-	raw_notifier_chain_unregister(&cpu_chain, nb);
-}
-EXPORT_SYMBOL(__unregister_cpu_notifier);
-
 #ifdef CONFIG_HOTPLUG_CPU
 /**
  * clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU
@@ -741,20 +652,6 @@ static inline void check_for_tasks(int dead_cpu)
 	read_unlock(&tasklist_lock);
 }
 
-static int notify_down_prepare(unsigned int cpu)
-{
-	int err, nr_calls = 0;
-
-	err = __cpu_notify(CPU_DOWN_PREPARE, cpu, -1, &nr_calls);
-	if (err) {
-		nr_calls--;
-		__cpu_notify(CPU_DOWN_FAILED, cpu, nr_calls, NULL);
-		pr_warn("%s: attempt to take down CPU %u failed\n",
-				__func__, cpu);
-	}
-	return err;
-}
-
 /* Take this CPU down. */
 static int take_cpu_down(void *_param)
 {
@@ -833,13 +730,6 @@ static int takedown_cpu(unsigned int cpu)
 	return 0;
 }
 
-static int notify_dead(unsigned int cpu)
-{
-	cpu_notify_nofail(CPU_DEAD, cpu);
-	check_for_tasks(cpu);
-	return 0;
-}
-
 static void cpuhp_complete_idle_dead(void *arg)
 {
 	struct cpuhp_cpu_state *st = arg;
@@ -863,9 +753,7 @@ void cpuhp_report_idle_dead(void)
 }
 
 #else
-#define notify_down_prepare	NULL
 #define takedown_cpu		NULL
-#define notify_dead		NULL
 #endif
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -924,9 +812,6 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen,
 	hasdied = prev_state != st->state && st->state == CPUHP_OFFLINE;
 out:
 	cpu_hotplug_done();
-	/* This post dead nonsense must die */
-	if (!ret && hasdied)
-		cpu_notify_nofail(CPU_POST_DEAD, cpu);
 	return ret;
 }
 
@@ -1291,17 +1176,6 @@ static struct cpuhp_step cpuhp_bp_states[] = {
 		.startup.single		= rcutree_prepare_cpu,
 		.teardown.single	= rcutree_dead_cpu,
 	},
-	/*
-	 * Preparatory and dead notifiers. Will be replaced once the notifiers
-	 * are converted to states.
-	 */
-	[CPUHP_NOTIFY_PREPARE] = {
-		.name			= "notify:prepare",
-		.startup.single		= notify_prepare,
-		.teardown.single	= notify_dead,
-		.skip_onerr		= true,
-		.cant_stop		= true,
-	},
 	/*
 	 * On the tear-down path, timers_dead_cpu() must be invoked
 	 * before blk_mq_queue_reinit_notify() from notify_dead(),
@@ -1391,17 +1265,6 @@ static struct cpuhp_step cpuhp_ap_states[] = {
 		.startup.single		= rcutree_online_cpu,
 		.teardown.single	= rcutree_offline_cpu,
 	},
-
-	/*
-	 * Online/down_prepare notifiers. Will be removed once the notifiers
-	 * are converted to states.
-	 */
-	[CPUHP_AP_NOTIFY_ONLINE] = {
-		.name			= "notify:online",
-		.startup.single		= notify_online,
-		.teardown.single	= notify_down_prepare,
-		.skip_onerr		= true,
-	},
 #endif
 	/*
 	 * The dynamically registered state space is here
@@ -1432,23 +1295,53 @@ static int cpuhp_cb_check(enum cpuhp_state state)
 	return 0;
 }
 
-static void cpuhp_store_callbacks(enum cpuhp_state state,
-				  const char *name,
-				  int (*startup)(unsigned int cpu),
-				  int (*teardown)(unsigned int cpu),
-				  bool multi_instance)
+/*
+ * Returns a free for dynamic slot assignment of the Online state. The states
+ * are protected by the cpuhp_slot_states mutex and an empty slot is identified
+ * by having no name assigned.
+ */
+static int cpuhp_reserve_state(enum cpuhp_state state)
+{
+	enum cpuhp_state i;
+
+	for (i = CPUHP_AP_ONLINE_DYN; i <= CPUHP_AP_ONLINE_DYN_END; i++) {
+		if (!cpuhp_ap_states[i].name)
+			return i;
+	}
+	WARN(1, "No more dynamic states available for CPU hotplug\n");
+	return -ENOSPC;
+}
+
+static int cpuhp_store_callbacks(enum cpuhp_state state, const char *name,
+				 int (*startup)(unsigned int cpu),
+				 int (*teardown)(unsigned int cpu),
+				 bool multi_instance)
 {
 	/* (Un)Install the callbacks for further cpu hotplug operations */
 	struct cpuhp_step *sp;
+	int ret = 0;
 
 	mutex_lock(&cpuhp_state_mutex);
+
+	if (state == CPUHP_AP_ONLINE_DYN) {
+		ret = cpuhp_reserve_state(state);
+		if (ret < 0)
+			goto out;
+		state = ret;
+	}
 	sp = cpuhp_get_step(state);
+	if (name && sp->name) {
+		ret = -EBUSY;
+		goto out;
+	}
 	sp->startup.single = startup;
 	sp->teardown.single = teardown;
 	sp->name = name;
 	sp->multi_instance = multi_instance;
 	INIT_HLIST_HEAD(&sp->list);
+out:
 	mutex_unlock(&cpuhp_state_mutex);
+	return ret;
 }
 
 static void *cpuhp_get_teardown_cb(enum cpuhp_state state)
@@ -1509,29 +1402,6 @@ static void cpuhp_rollback_install(int failedcpu, enum cpuhp_state state,
 	}
 }
 
-/*
- * Returns a free for dynamic slot assignment of the Online state. The states
- * are protected by the cpuhp_slot_states mutex and an empty slot is identified
- * by having no name assigned.
- */
-static int cpuhp_reserve_state(enum cpuhp_state state)
-{
-	enum cpuhp_state i;
-
-	mutex_lock(&cpuhp_state_mutex);
-	for (i = CPUHP_AP_ONLINE_DYN; i <= CPUHP_AP_ONLINE_DYN_END; i++) {
-		if (cpuhp_ap_states[i].name)
-			continue;
-
-		cpuhp_ap_states[i].name = "Reserved";
-		mutex_unlock(&cpuhp_state_mutex);
-		return i;
-	}
-	mutex_unlock(&cpuhp_state_mutex);
-	WARN(1, "No more dynamic states available for CPU hotplug\n");
-	return -ENOSPC;
-}
-
 int __cpuhp_state_add_instance(enum cpuhp_state state, struct hlist_node *node,
 			       bool invoke)
 {
@@ -1580,11 +1450,13 @@ EXPORT_SYMBOL_GPL(__cpuhp_state_add_instance);
 
 /**
  * __cpuhp_setup_state - Setup the callbacks for an hotplug machine state
- * @state:	The state to setup
- * @invoke:	If true, the startup function is invoked for cpus where
- *		cpu state >= @state
- * @startup:	startup callback function
- * @teardown:	teardown callback function
+ * @state:		The state to setup
+ * @invoke:		If true, the startup function is invoked for cpus where
+ *			cpu state >= @state
+ * @startup:		startup callback function
+ * @teardown:		teardown callback function
+ * @multi_instance:	State is set up for multiple instances which get
+ *			added afterwards.
  *
  * Returns:
  *   On success:
@@ -1599,25 +1471,16 @@ int __cpuhp_setup_state(enum cpuhp_state state,
 			bool multi_instance)
 {
 	int cpu, ret = 0;
-	int dyn_state = 0;
 
 	if (cpuhp_cb_check(state) || !name)
 		return -EINVAL;
 
 	get_online_cpus();
 
-	/* currently assignments for the ONLINE state are possible */
-	if (state == CPUHP_AP_ONLINE_DYN) {
-		dyn_state = 1;
-		ret = cpuhp_reserve_state(state);
-		if (ret < 0)
-			goto out;
-		state = ret;
-	}
+	ret = cpuhp_store_callbacks(state, name, startup, teardown,
+				    multi_instance);
 
-	cpuhp_store_callbacks(state, name, startup, teardown, multi_instance);
-
-	if (!invoke || !startup)
+	if (ret || !invoke || !startup)
 		goto out;
 
 	/*
@@ -1641,7 +1504,11 @@ int __cpuhp_setup_state(enum cpuhp_state state,
 	}
 out:
 	put_online_cpus();
-	if (!ret && dyn_state)
+	/*
+	 * If the requested state is CPUHP_AP_ONLINE_DYN, return the
+	 * dynamically allocated state in case of success.
+	 */
+	if (!ret && state == CPUHP_AP_ONLINE_DYN)
 		return state;
 	return ret;
 }

lib/Kconfig.debug

@@ -1538,30 +1538,6 @@ config NOTIFIER_ERROR_INJECTION
 
 	  Say N if unsure.
 
-config CPU_NOTIFIER_ERROR_INJECT
-	tristate "CPU notifier error injection module"
-	depends on HOTPLUG_CPU && NOTIFIER_ERROR_INJECTION
-	help
-	  This option provides a kernel module that can be used to test
-	  the error handling of the cpu notifiers by injecting artificial
-	  errors to CPU notifier chain callbacks.  It is controlled through
-	  debugfs interface under /sys/kernel/debug/notifier-error-inject/cpu
-
-	  If the notifier call chain should be failed with some events
-	  notified, write the error code to "actions/<notifier event>/error".
-
-	  Example: Inject CPU offline error (-1 == -EPERM)
-
-	  # cd /sys/kernel/debug/notifier-error-inject/cpu
-	  # echo -1 > actions/CPU_DOWN_PREPARE/error
-	  # echo 0 > /sys/devices/system/cpu/cpu1/online
-	  bash: echo: write error: Operation not permitted
-
-	  To compile this code as a module, choose M here: the module will
-	  be called cpu-notifier-error-inject.
-
-	  If unsure, say N.
-
 config PM_NOTIFIER_ERROR_INJECT
 	tristate "PM notifier error injection module"
 	depends on PM && NOTIFIER_ERROR_INJECTION

lib/Makefile

@@ -128,7 +128,6 @@ obj-$(CONFIG_SWIOTLB) += swiotlb.o
 obj-$(CONFIG_IOMMU_HELPER) += iommu-helper.o iommu-common.o
 obj-$(CONFIG_FAULT_INJECTION) += fault-inject.o
 obj-$(CONFIG_NOTIFIER_ERROR_INJECTION) += notifier-error-inject.o
-obj-$(CONFIG_CPU_NOTIFIER_ERROR_INJECT) += cpu-notifier-error-inject.o
 obj-$(CONFIG_PM_NOTIFIER_ERROR_INJECT) += pm-notifier-error-inject.o
 obj-$(CONFIG_NETDEV_NOTIFIER_ERROR_INJECT) += netdev-notifier-error-inject.o
 obj-$(CONFIG_MEMORY_NOTIFIER_ERROR_INJECT) += memory-notifier-error-inject.o

lib/cpu-notifier-error-inject.c

@@ -1,84 +0,0 @@
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/cpu.h>
-
-#include "notifier-error-inject.h"
-
-static int priority;
-module_param(priority, int, 0);
-MODULE_PARM_DESC(priority, "specify cpu notifier priority");
-
-#define UP_PREPARE 0
-#define UP_PREPARE_FROZEN 0
-#define DOWN_PREPARE 0
-#define DOWN_PREPARE_FROZEN 0
-
-static struct notifier_err_inject cpu_notifier_err_inject = {
-	.actions = {
-		{ NOTIFIER_ERR_INJECT_ACTION(UP_PREPARE) },
-		{ NOTIFIER_ERR_INJECT_ACTION(UP_PREPARE_FROZEN) },
-		{ NOTIFIER_ERR_INJECT_ACTION(DOWN_PREPARE) },
-		{ NOTIFIER_ERR_INJECT_ACTION(DOWN_PREPARE_FROZEN) },
-		{}
-	}
-};
-
-static int notf_err_handle(struct notifier_err_inject_action *action)
-{
-	int ret;
-
-	ret = action->error;
-	if (ret)
-		pr_info("Injecting error (%d) to %s\n", ret, action->name);
-	return ret;
-}
-
-static int notf_err_inj_up_prepare(unsigned int cpu)
-{
-	if (!cpuhp_tasks_frozen)
-		return notf_err_handle(&cpu_notifier_err_inject.actions[0]);
-	else
-		return notf_err_handle(&cpu_notifier_err_inject.actions[1]);
-}
-
-static int notf_err_inj_dead(unsigned int cpu)
-{
-	if (!cpuhp_tasks_frozen)
-		return notf_err_handle(&cpu_notifier_err_inject.actions[2]);
-	else
-		return notf_err_handle(&cpu_notifier_err_inject.actions[3]);
-}
-
-static struct dentry *dir;
-
-static int err_inject_init(void)
-{
-	int err;
-
-	dir = notifier_err_inject_init("cpu", notifier_err_inject_dir,
-					&cpu_notifier_err_inject, priority);
-	if (IS_ERR(dir))
-		return PTR_ERR(dir);
-
-	err = cpuhp_setup_state_nocalls(CPUHP_NOTF_ERR_INJ_PREPARE,
-					"cpu-err-notif:prepare",
-					notf_err_inj_up_prepare,
-					notf_err_inj_dead);
-	if (err)
-		debugfs_remove_recursive(dir);
-
-	return err;
-}
-
-static void err_inject_exit(void)
-{
-	cpuhp_remove_state_nocalls(CPUHP_NOTF_ERR_INJ_PREPARE);
-	debugfs_remove_recursive(dir);
-}
-
-module_init(err_inject_init);
-module_exit(err_inject_exit);
-
-MODULE_DESCRIPTION("CPU notifier error injection module");
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");

virt/kvm/arm/arch_timer.c

@@ -456,7 +456,7 @@ int kvm_timer_hyp_init(void)
 	kvm_info("virtual timer IRQ%d\n", host_vtimer_irq);
 
 	cpuhp_setup_state(CPUHP_AP_KVM_ARM_TIMER_STARTING,
-			  "AP_KVM_ARM_TIMER_STARTING", kvm_timer_starting_cpu,
+			  "kvm/arm/timer:starting", kvm_timer_starting_cpu,
 			  kvm_timer_dying_cpu);
 	return err;
 }

virt/kvm/arm/vgic/vgic-init.c

@@ -428,7 +428,7 @@ int kvm_vgic_hyp_init(void)
 	}
 
 	ret = cpuhp_setup_state(CPUHP_AP_KVM_ARM_VGIC_INIT_STARTING,
-				"AP_KVM_ARM_VGIC_INIT_STARTING",
+				"kvm/arm/vgic:starting",
 				vgic_init_cpu_starting, vgic_init_cpu_dying);
 	if (ret) {
 		kvm_err("Cannot register vgic CPU notifier\n");

virt/kvm/kvm_main.c

@@ -3944,7 +3944,7 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
 			goto out_free_1;
 	}
 
-	r = cpuhp_setup_state_nocalls(CPUHP_AP_KVM_STARTING, "AP_KVM_STARTING",
+	r = cpuhp_setup_state_nocalls(CPUHP_AP_KVM_STARTING, "kvm/cpu:starting",
 				      kvm_starting_cpu, kvm_dying_cpu);
 	if (r)
 		goto out_free_2;