scsi/bnx2i: Convert to hotplug state machine

Install the callbacks via the state machine. No functional change.

This is the minimal fixup so we can remove the hotplug notifier mess
completely.

The real rework of this driver to use work queues is still stuck in
review/testing on the SCSI mailing list.

Signed-off-by: Sebastian Andrzej Siewior <[e-mail]>
Cc: "James E.J. Bottomley" <[e-mail]>
Cc: [e-mail]
Cc: "Martin K. Petersen" <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Chad Dupuis <[e-mail]>
Cc: [e-mail]
Cc: Johannes Thumshirn <[e-mail]>
Cc: Christoph Hellwig <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Thomas Gleixner <[e-mail]>

drivers/scsi/bnx2i/bnx2i_init.c

···
 
 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
···
 		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;
-
-	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;
+	pr_info("bnx2i: CPU %x online: Create Rx thread\n", cpu);
+	bnx2i_percpu_thread_create(cpu);
+	return 0;
 }
 
+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
···
 		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);
+	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;
 
-	cpu_notifier_register_done();
-
+	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:
···
 	}
 	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);

include/linux/cpuhotplug.h

···
 	CPUHP_PCI_XGENE_DEAD,
 	CPUHP_IOMMU_INTEL_DEAD,
 	CPUHP_SCSI_BNX2FC_DEAD,
+	CPUHP_SCSI_BNX2I_DEAD,
 	CPUHP_WORKQUEUE_PREP,
 	CPUHP_POWER_NUMA_PREPARE,
 	CPUHP_HRTIMERS_PREPARE,