xref: /openbmc/qemu/hw/s390x/sclpcpu.c (revision b074e622)
1 /*
2  * SCLP event type
3  *    Signal CPU - Trigger SCLP interrupt for system CPU configure or
4  *    de-configure
5  *
6  * Copyright IBM, Corp. 2013
7  *
8  * Authors:
9  *  Thang Pham <thang.pham@us.ibm.com>
10  *
11  * This work is licensed under the terms of the GNU GPL, version 2 or (at your
12  * option) any later version.  See the COPYING file in the top-level directory.
13  *
14  */
15 #include "sysemu/sysemu.h"
16 #include "hw/s390x/sclp.h"
17 #include "hw/s390x/event-facility.h"
18 #include "cpu.h"
19 #include "sysemu/cpus.h"
20 #include "sysemu/kvm.h"
21 
22 typedef struct ConfigMgtData {
23     EventBufferHeader ebh;
24     uint8_t reserved;
25     uint8_t event_qualifier;
26 } QEMU_PACKED ConfigMgtData;
27 
28 static qemu_irq *irq_cpu_hotplug; /* Only used in this file */
29 
30 #define EVENT_QUAL_CPU_CHANGE  1
31 
32 void raise_irq_cpu_hotplug(void)
33 {
34     qemu_irq_raise(*irq_cpu_hotplug);
35 }
36 
37 static unsigned int send_mask(void)
38 {
39     return SCLP_EVENT_MASK_CONFIG_MGT_DATA;
40 }
41 
42 static unsigned int receive_mask(void)
43 {
44     return 0;
45 }
46 
47 static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
48                            int *slen)
49 {
50     ConfigMgtData *cdata = (ConfigMgtData *) evt_buf_hdr;
51     if (*slen < sizeof(ConfigMgtData)) {
52         return 0;
53     }
54 
55     /* Event is no longer pending */
56     if (!event->event_pending) {
57         return 0;
58     }
59     event->event_pending = false;
60 
61     /* Event header data */
62     cdata->ebh.length = cpu_to_be16(sizeof(ConfigMgtData));
63     cdata->ebh.type = SCLP_EVENT_CONFIG_MGT_DATA;
64     cdata->ebh.flags |= SCLP_EVENT_BUFFER_ACCEPTED;
65 
66     /* Trigger a rescan of CPUs by setting event qualifier */
67     cdata->event_qualifier = EVENT_QUAL_CPU_CHANGE;
68     *slen -= sizeof(ConfigMgtData);
69 
70     return 1;
71 }
72 
73 static void trigger_signal(void *opaque, int n, int level)
74 {
75     SCLPEvent *event = opaque;
76     event->event_pending = true;
77 
78     /* Trigger SCLP read operation */
79     sclp_service_interrupt(0);
80 }
81 
82 static int irq_cpu_hotplug_init(SCLPEvent *event)
83 {
84     irq_cpu_hotplug = qemu_allocate_irqs(trigger_signal, event, 1);
85     return 0;
86 }
87 
88 static void cpu_class_init(ObjectClass *oc, void *data)
89 {
90     SCLPEventClass *k = SCLP_EVENT_CLASS(oc);
91 
92     k->init = irq_cpu_hotplug_init;
93     k->get_send_mask = send_mask;
94     k->get_receive_mask = receive_mask;
95     k->read_event_data = read_event_data;
96     k->write_event_data = NULL;
97 }
98 
99 static const TypeInfo sclp_cpu_info = {
100     .name          = "sclp-cpu-hotplug",
101     .parent        = TYPE_SCLP_EVENT,
102     .instance_size = sizeof(SCLPEvent),
103     .class_init    = cpu_class_init,
104     .class_size    = sizeof(SCLPEventClass),
105 };
106 
107 static void sclp_cpu_register_types(void)
108 {
109     type_register_static(&sclp_cpu_info);
110 }
111 
112 type_init(sclp_cpu_register_types)
113