1// SPDX-License-Identifier: GPL-2.0
2/*
3 *    Copyright IBM Corp. 2007
4 *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
5 */
6
7#define KMSG_COMPONENT "sclp_config"
8#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
9
10#include <linux/init.h>
11#include <linux/errno.h>
12#include <linux/cpu.h>
13#include <linux/device.h>
14#include <linux/workqueue.h>
15#include <linux/slab.h>
16#include <linux/sysfs.h>
17#include <asm/smp.h>
18
19#include "sclp.h"
20
21struct conf_mgm_data {
22	u8 reserved;
23	u8 ev_qualifier;
24} __attribute__((packed));
25
26#define OFB_DATA_MAX 64
27
28struct sclp_ofb_evbuf {
29	struct evbuf_header header;
30	struct conf_mgm_data cm_data;
31	char ev_data[OFB_DATA_MAX];
32} __packed;
33
34struct sclp_ofb_sccb {
35	struct sccb_header header;
36	struct sclp_ofb_evbuf ofb_evbuf;
37} __packed;
38
39#define EV_QUAL_CPU_CHANGE	1
40#define EV_QUAL_CAP_CHANGE	3
41#define EV_QUAL_OPEN4BUSINESS	5
42
43static struct work_struct sclp_cpu_capability_work;
44static struct work_struct sclp_cpu_change_work;
45
46static void sclp_cpu_capability_notify(struct work_struct *work)
47{
48	int cpu;
49	struct device *dev;
50
51	s390_update_cpu_mhz();
52	pr_info("CPU capability may have changed\n");
53	get_online_cpus();
54	for_each_online_cpu(cpu) {
55		dev = get_cpu_device(cpu);
56		kobject_uevent(&dev->kobj, KOBJ_CHANGE);
57	}
58	put_online_cpus();
59}
60
61static void __ref sclp_cpu_change_notify(struct work_struct *work)
62{
63	lock_device_hotplug();
64	smp_rescan_cpus();
65	unlock_device_hotplug();
66}
67
68static void sclp_conf_receiver_fn(struct evbuf_header *evbuf)
69{
70	struct conf_mgm_data *cdata;
71
72	cdata = (struct conf_mgm_data *)(evbuf + 1);
73	switch (cdata->ev_qualifier) {
74	case EV_QUAL_CPU_CHANGE:
75		schedule_work(&sclp_cpu_change_work);
76		break;
77	case EV_QUAL_CAP_CHANGE:
78		schedule_work(&sclp_cpu_capability_work);
79		break;
80	}
81}
82
83static struct sclp_register sclp_conf_register =
84{
85#ifdef CONFIG_SCLP_OFB
86	.send_mask    = EVTYP_CONFMGMDATA_MASK,
87#endif
88	.receive_mask = EVTYP_CONFMGMDATA_MASK,
89	.receiver_fn  = sclp_conf_receiver_fn,
90};
91
92#ifdef CONFIG_SCLP_OFB
93static int sclp_ofb_send_req(char *ev_data, size_t len)
94{
95	static DEFINE_MUTEX(send_mutex);
96	struct sclp_ofb_sccb *sccb;
97	int rc, response;
98
99	if (len > OFB_DATA_MAX)
100		return -EINVAL;
101	sccb = (struct sclp_ofb_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
102	if (!sccb)
103		return -ENOMEM;
104	/* Setup SCCB for Control-Program Identification */
105	sccb->header.length = sizeof(struct sclp_ofb_sccb);
106	sccb->ofb_evbuf.header.length = sizeof(struct sclp_ofb_evbuf);
107	sccb->ofb_evbuf.header.type = EVTYP_CONFMGMDATA;
108	sccb->ofb_evbuf.cm_data.ev_qualifier = EV_QUAL_OPEN4BUSINESS;
109	memcpy(sccb->ofb_evbuf.ev_data, ev_data, len);
110
111	if (!(sclp_conf_register.sclp_receive_mask & EVTYP_CONFMGMDATA_MASK))
112		pr_warn("SCLP receiver did not register to receive "
113			"Configuration Management Data Events.\n");
114
115	mutex_lock(&send_mutex);
116	rc = sclp_sync_request(SCLP_CMDW_WRITE_EVENT_DATA, sccb);
117	mutex_unlock(&send_mutex);
118	if (rc)
119		goto out;
120	response = sccb->header.response_code;
121	if (response != 0x0020) {
122		pr_err("Open for Business request failed with response code "
123		       "0x%04x\n", response);
124		rc = -EIO;
125	}
126out:
127	free_page((unsigned long)sccb);
128	return rc;
129}
130
131static ssize_t sysfs_ofb_data_write(struct file *filp, struct kobject *kobj,
132				    struct bin_attribute *bin_attr,
133				    char *buf, loff_t off, size_t count)
134{
135	int rc;
136
137	rc = sclp_ofb_send_req(buf, count);
138	return rc ?: count;
139}
140
141static const struct bin_attribute ofb_bin_attr = {
142	.attr = {
143		.name = "event_data",
144		.mode = S_IWUSR,
145	},
146	.write = sysfs_ofb_data_write,
147};
148#endif
149
150static int __init sclp_ofb_setup(void)
151{
152#ifdef CONFIG_SCLP_OFB
153	struct kset *ofb_kset;
154	int rc;
155
156	ofb_kset = kset_create_and_add("ofb", NULL, firmware_kobj);
157	if (!ofb_kset)
158		return -ENOMEM;
159	rc = sysfs_create_bin_file(&ofb_kset->kobj, &ofb_bin_attr);
160	if (rc) {
161		kset_unregister(ofb_kset);
162		return rc;
163	}
164#endif
165	return 0;
166}
167
168static int __init sclp_conf_init(void)
169{
170	int rc;
171
172	INIT_WORK(&sclp_cpu_capability_work, sclp_cpu_capability_notify);
173	INIT_WORK(&sclp_cpu_change_work, sclp_cpu_change_notify);
174	rc = sclp_register(&sclp_conf_register);
175	if (rc)
176		return rc;
177	return sclp_ofb_setup();
178}
179
180__initcall(sclp_conf_init);
181