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
19 struct conf_mgm_data {
20 u8 reserved;
21 u8 ev_qualifier;
22 } __attribute__((packed));
23
24 #define OFB_DATA_MAX 64
25
26 struct 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
32 struct 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
41 static struct work_struct sclp_cpu_capability_work;
42 static struct work_struct sclp_cpu_change_work;
43
sclp_cpu_capability_notify(struct work_struct * work)44 static 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(&dev->kobj, KOBJ_CHANGE);
55 }
56 cpus_read_unlock();
57 }
58
sclp_cpu_change_notify(struct work_struct * work)59 static 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
sclp_conf_receiver_fn(struct evbuf_header * evbuf)66 static 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(&sclp_cpu_change_work);
74 break;
75 case EV_QUAL_CAP_CHANGE:
76 schedule_work(&sclp_cpu_capability_work);
77 break;
78 }
79 }
80
81 static struct sclp_register sclp_conf_register =
82 {
83 .send_mask = EVTYP_CONFMGMDATA_MASK,
84 .receive_mask = EVTYP_CONFMGMDATA_MASK,
85 .receiver_fn = sclp_conf_receiver_fn,
86 };
87
sclp_ofb_send_req(char * ev_data,size_t len)88 static int sclp_ofb_send_req(char *ev_data, size_t len)
89 {
90 static DEFINE_MUTEX(send_mutex);
91 struct sclp_ofb_sccb *sccb;
92 int rc, response;
93
94 if (len > OFB_DATA_MAX)
95 return -EINVAL;
96 sccb = (struct sclp_ofb_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
97 if (!sccb)
98 return -ENOMEM;
99 /* Setup SCCB for Control-Program Identification */
100 sccb->header.length = sizeof(struct sclp_ofb_sccb);
101 sccb->ofb_evbuf.header.length = sizeof(struct sclp_ofb_evbuf);
102 sccb->ofb_evbuf.header.type = EVTYP_CONFMGMDATA;
103 sccb->ofb_evbuf.cm_data.ev_qualifier = EV_QUAL_OPEN4BUSINESS;
104 memcpy(sccb->ofb_evbuf.ev_data, ev_data, len);
105
106 if (!(sclp_conf_register.sclp_receive_mask & EVTYP_CONFMGMDATA_MASK))
107 pr_warn("SCLP receiver did not register to receive "
108 "Configuration Management Data Events.\n");
109
110 mutex_lock(&send_mutex);
111 rc = sclp_sync_request(SCLP_CMDW_WRITE_EVENT_DATA, sccb);
112 mutex_unlock(&send_mutex);
113 if (rc)
114 goto out;
115 response = sccb->header.response_code;
116 if (response != 0x0020) {
117 pr_err("Open for Business request failed with response code "
118 "0x%04x\n", response);
119 rc = -EIO;
120 }
121 out:
122 free_page((unsigned long)sccb);
123 return rc;
124 }
125
sysfs_ofb_data_write(struct file * filp,struct kobject * kobj,const struct bin_attribute * bin_attr,char * buf,loff_t off,size_t count)126 static ssize_t sysfs_ofb_data_write(struct file *filp, struct kobject *kobj,
127 const struct bin_attribute *bin_attr,
128 char *buf, loff_t off, size_t count)
129 {
130 int rc;
131
132 rc = sclp_ofb_send_req(buf, count);
133 return rc ?: count;
134 }
135
136 static const struct bin_attribute ofb_bin_attr = {
137 .attr = {
138 .name = "event_data",
139 .mode = S_IWUSR,
140 },
141 .write = sysfs_ofb_data_write,
142 };
143
sclp_ofb_setup(void)144 static int __init sclp_ofb_setup(void)
145 {
146 struct kset *ofb_kset;
147 int rc;
148
149 ofb_kset = kset_create_and_add("ofb", NULL, firmware_kobj);
150 if (!ofb_kset)
151 return -ENOMEM;
152 rc = sysfs_create_bin_file(&ofb_kset->kobj, &ofb_bin_attr);
153 if (rc) {
154 kset_unregister(ofb_kset);
155 return rc;
156 }
157 return 0;
158 }
159
sclp_conf_init(void)160 static int __init sclp_conf_init(void)
161 {
162 int rc;
163
164 INIT_WORK(&sclp_cpu_capability_work, sclp_cpu_capability_notify);
165 INIT_WORK(&sclp_cpu_change_work, sclp_cpu_change_notify);
166 rc = sclp_register(&sclp_conf_register);
167 if (rc)
168 return rc;
169 return sclp_ofb_setup();
170 }
171
172 __initcall(sclp_conf_init);
173