1 /* 2 * drivers/s390/char/sclp_config.c 3 * 4 * Copyright IBM Corp. 2007 5 * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com> 6 */ 7 8 #include <linux/init.h> 9 #include <linux/errno.h> 10 #include <linux/cpu.h> 11 #include <linux/kthread.h> 12 #include <linux/sysdev.h> 13 #include <linux/workqueue.h> 14 #include <asm/smp.h> 15 #include "sclp.h" 16 17 #define TAG "sclp_config: " 18 19 struct conf_mgm_data { 20 u8 reserved; 21 u8 ev_qualifier; 22 } __attribute__((packed)); 23 24 #define EV_QUAL_CPU_CHANGE 1 25 #define EV_QUAL_CAP_CHANGE 3 26 27 static struct work_struct sclp_cpu_capability_work; 28 static struct work_struct sclp_cpu_change_work; 29 30 static void sclp_cpu_capability_notify(struct work_struct *work) 31 { 32 int cpu; 33 struct sys_device *sysdev; 34 35 printk(KERN_WARNING TAG "cpu capability changed.\n"); 36 get_online_cpus(); 37 for_each_online_cpu(cpu) { 38 sysdev = get_cpu_sysdev(cpu); 39 kobject_uevent(&sysdev->kobj, KOBJ_CHANGE); 40 } 41 put_online_cpus(); 42 } 43 44 static int sclp_cpu_kthread(void *data) 45 { 46 smp_rescan_cpus(); 47 return 0; 48 } 49 50 static void __ref sclp_cpu_change_notify(struct work_struct *work) 51 { 52 /* Can't call smp_rescan_cpus() from workqueue context since it may 53 * deadlock in case of cpu hotplug. So we have to create a kernel 54 * thread in order to call it. 55 */ 56 kthread_run(sclp_cpu_kthread, NULL, "cpu_rescan"); 57 } 58 59 static void sclp_conf_receiver_fn(struct evbuf_header *evbuf) 60 { 61 struct conf_mgm_data *cdata; 62 63 cdata = (struct conf_mgm_data *)(evbuf + 1); 64 switch (cdata->ev_qualifier) { 65 case EV_QUAL_CPU_CHANGE: 66 schedule_work(&sclp_cpu_change_work); 67 break; 68 case EV_QUAL_CAP_CHANGE: 69 schedule_work(&sclp_cpu_capability_work); 70 break; 71 } 72 } 73 74 static struct sclp_register sclp_conf_register = 75 { 76 .receive_mask = EVTYP_CONFMGMDATA_MASK, 77 .receiver_fn = sclp_conf_receiver_fn, 78 }; 79 80 static int __init sclp_conf_init(void) 81 { 82 int rc; 83 84 INIT_WORK(&sclp_cpu_capability_work, sclp_cpu_capability_notify); 85 INIT_WORK(&sclp_cpu_change_work, sclp_cpu_change_notify); 86 87 rc = sclp_register(&sclp_conf_register); 88 if (rc) 89 return rc; 90 91 if (!(sclp_conf_register.sclp_send_mask & EVTYP_CONFMGMDATA_MASK)) { 92 printk(KERN_WARNING TAG "no configuration management.\n"); 93 sclp_unregister(&sclp_conf_register); 94 rc = -ENOSYS; 95 } 96 return rc; 97 } 98 99 __initcall(sclp_conf_init); 100