Merge branches 'x86/urgent', 'x86/amd-iommu', 'x86/apic', 'x86/cleanups', 'x86/core...
[linux-2.6] / drivers / s390 / char / sclp_config.c
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);