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

source code of linux/drivers/s390/char/sclp_config.c