sclp_config.c

  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(&dev->kobj, 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(&sclp_cpu_change_work);
 74		break;
 75	case EV_QUAL_CAP_CHANGE:
 76		schedule_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(&sclp_conf_register);
173	if (rc)
174		return rc;
175	return sclp_ofb_setup();
176}
177
178__initcall(sclp_conf_init);