xref: /linux/drivers/s390/char/sclp_config.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
1 /*
2  *    Copyright IBM Corp. 2007
3  *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
4  */
5 
6 #define KMSG_COMPONENT "sclp_config"
7 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
8 
9 #include <linux/init.h>
10 #include <linux/errno.h>
11 #include <linux/cpu.h>
12 #include <linux/device.h>
13 #include <linux/workqueue.h>
14 #include <linux/slab.h>
15 #include <linux/sysfs.h>
16 #include <asm/smp.h>
17 
18 #include "sclp.h"
19 
20 struct conf_mgm_data {
21 	u8 reserved;
22 	u8 ev_qualifier;
23 } __attribute__((packed));
24 
25 #define OFB_DATA_MAX 64
26 
27 struct sclp_ofb_evbuf {
28 	struct evbuf_header header;
29 	struct conf_mgm_data cm_data;
30 	char ev_data[OFB_DATA_MAX];
31 } __packed;
32 
33 struct sclp_ofb_sccb {
34 	struct sccb_header header;
35 	struct sclp_ofb_evbuf ofb_evbuf;
36 } __packed;
37 
38 #define EV_QUAL_CPU_CHANGE	1
39 #define EV_QUAL_CAP_CHANGE	3
40 #define EV_QUAL_OPEN4BUSINESS	5
41 
42 static struct work_struct sclp_cpu_capability_work;
43 static struct work_struct sclp_cpu_change_work;
44 
45 static void sclp_cpu_capability_notify(struct work_struct *work)
46 {
47 	int cpu;
48 	struct device *dev;
49 
50 	s390_update_cpu_mhz();
51 	pr_info("CPU capability may have changed\n");
52 	get_online_cpus();
53 	for_each_online_cpu(cpu) {
54 		dev = get_cpu_device(cpu);
55 		kobject_uevent(&dev->kobj, KOBJ_CHANGE);
56 	}
57 	put_online_cpus();
58 }
59 
60 static void __ref sclp_cpu_change_notify(struct work_struct *work)
61 {
62 	smp_rescan_cpus();
63 }
64 
65 static void sclp_conf_receiver_fn(struct evbuf_header *evbuf)
66 {
67 	struct conf_mgm_data *cdata;
68 
69 	cdata = (struct conf_mgm_data *)(evbuf + 1);
70 	switch (cdata->ev_qualifier) {
71 	case EV_QUAL_CPU_CHANGE:
72 		schedule_work(&sclp_cpu_change_work);
73 		break;
74 	case EV_QUAL_CAP_CHANGE:
75 		schedule_work(&sclp_cpu_capability_work);
76 		break;
77 	}
78 }
79 
80 static struct sclp_register sclp_conf_register =
81 {
82 #ifdef CONFIG_SCLP_OFB
83 	.send_mask    = EVTYP_CONFMGMDATA_MASK,
84 #endif
85 	.receive_mask = EVTYP_CONFMGMDATA_MASK,
86 	.receiver_fn  = sclp_conf_receiver_fn,
87 };
88 
89 #ifdef CONFIG_SCLP_OFB
90 static int sclp_ofb_send_req(char *ev_data, size_t len)
91 {
92 	static DEFINE_MUTEX(send_mutex);
93 	struct sclp_ofb_sccb *sccb;
94 	int rc, response;
95 
96 	if (len > OFB_DATA_MAX)
97 		return -EINVAL;
98 	sccb = (struct sclp_ofb_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
99 	if (!sccb)
100 		return -ENOMEM;
101 	/* Setup SCCB for Control-Program Identification */
102 	sccb->header.length = sizeof(struct sclp_ofb_sccb);
103 	sccb->ofb_evbuf.header.length = sizeof(struct sclp_ofb_evbuf);
104 	sccb->ofb_evbuf.header.type = EVTYP_CONFMGMDATA;
105 	sccb->ofb_evbuf.cm_data.ev_qualifier = EV_QUAL_OPEN4BUSINESS;
106 	memcpy(sccb->ofb_evbuf.ev_data, ev_data, len);
107 
108 	if (!(sclp_conf_register.sclp_receive_mask & EVTYP_CONFMGMDATA_MASK))
109 		pr_warn("SCLP receiver did not register to receive "
110 			"Configuration Management Data Events.\n");
111 
112 	mutex_lock(&send_mutex);
113 	rc = sclp_sync_request(SCLP_CMDW_WRITE_EVENT_DATA, sccb);
114 	mutex_unlock(&send_mutex);
115 	if (rc)
116 		goto out;
117 	response = sccb->header.response_code;
118 	if (response != 0x0020) {
119 		pr_err("Open for Business request failed with response code "
120 		       "0x%04x\n", response);
121 		rc = -EIO;
122 	}
123 out:
124 	free_page((unsigned long)sccb);
125 	return rc;
126 }
127 
128 static ssize_t sysfs_ofb_data_write(struct file *filp, struct kobject *kobj,
129 				    struct bin_attribute *bin_attr,
130 				    char *buf, loff_t off, size_t count)
131 {
132 	int rc;
133 
134 	rc = sclp_ofb_send_req(buf, count);
135 	return rc ?: count;
136 }
137 
138 static struct bin_attribute ofb_bin_attr = {
139 	.attr = {
140 		.name = "event_data",
141 		.mode = S_IWUSR,
142 	},
143 	.write = sysfs_ofb_data_write,
144 };
145 #endif
146 
147 static int __init sclp_ofb_setup(void)
148 {
149 #ifdef CONFIG_SCLP_OFB
150 	struct kset *ofb_kset;
151 	int rc;
152 
153 	ofb_kset = kset_create_and_add("ofb", NULL, firmware_kobj);
154 	if (!ofb_kset)
155 		return -ENOMEM;
156 	rc = sysfs_create_bin_file(&ofb_kset->kobj, &ofb_bin_attr);
157 	if (rc) {
158 		kset_unregister(ofb_kset);
159 		return rc;
160 	}
161 #endif
162 	return 0;
163 }
164 
165 static int __init sclp_conf_init(void)
166 {
167 	int rc;
168 
169 	INIT_WORK(&sclp_cpu_capability_work, sclp_cpu_capability_notify);
170 	INIT_WORK(&sclp_cpu_change_work, sclp_cpu_change_notify);
171 	rc = sclp_register(&sclp_conf_register);
172 	if (rc)
173 		return rc;
174 	return sclp_ofb_setup();
175 }
176 
177 __initcall(sclp_conf_init);
178