1// SPDX-License-Identifier: GPL-2.0
2/*
3 *    SCLP OCF communication parameters sysfs interface
4 *
5 *    Copyright IBM Corp. 2011
6 *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
7 */
8
9#define KMSG_COMPONENT "sclp_ocf"
10#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
11
12#include <linux/kernel.h>
13#include <linux/init.h>
14#include <linux/stat.h>
15#include <linux/device.h>
16#include <linux/string.h>
17#include <linux/ctype.h>
18#include <linux/kmod.h>
19#include <linux/timer.h>
20#include <linux/err.h>
21#include <asm/ebcdic.h>
22#include <asm/sclp.h>
23
24#include "sclp.h"
25
26#define OCF_LENGTH_HMC_NETWORK 8UL
27#define OCF_LENGTH_CPC_NAME 8UL
28
29static char hmc_network[OCF_LENGTH_HMC_NETWORK + 1];
30static char cpc_name[OCF_LENGTH_CPC_NAME]; /* in EBCDIC */
31
32static DEFINE_SPINLOCK(sclp_ocf_lock);
33static struct work_struct sclp_ocf_change_work;
34
35static struct kset *ocf_kset;
36
37static void sclp_ocf_change_notify(struct work_struct *work)
38{
39	kobject_uevent(&ocf_kset->kobj, KOBJ_CHANGE);
40}
41
42/* Handler for OCF event. Look for the CPC image name. */
43static void sclp_ocf_handler(struct evbuf_header *evbuf)
44{
45	struct gds_vector *v;
46	struct gds_subvector *sv, *netid, *cpc;
47	size_t size;
48
49	/* Find the 0x9f00 block. */
50	v = sclp_find_gds_vector(evbuf + 1, (void *) evbuf + evbuf->length,
51				 0x9f00);
52	if (!v)
53		return;
54	/* Find the 0x9f22 block inside the 0x9f00 block. */
55	v = sclp_find_gds_vector(v + 1, (void *) v + v->length, 0x9f22);
56	if (!v)
57		return;
58	/* Find the 0x81 block inside the 0x9f22 block. */
59	sv = sclp_find_gds_subvector(v + 1, (void *) v + v->length, 0x81);
60	if (!sv)
61		return;
62	/* Find the 0x01 block inside the 0x81 block. */
63	netid = sclp_find_gds_subvector(sv + 1, (void *) sv + sv->length, 1);
64	/* Find the 0x02 block inside the 0x81 block. */
65	cpc = sclp_find_gds_subvector(sv + 1, (void *) sv + sv->length, 2);
66	/* Copy network name and cpc name. */
67	spin_lock(&sclp_ocf_lock);
68	if (netid) {
69		size = min(OCF_LENGTH_HMC_NETWORK, (size_t) netid->length);
70		memcpy(hmc_network, netid + 1, size);
71		EBCASC(hmc_network, size);
72		hmc_network[size] = 0;
73	}
74	if (cpc) {
75		size = min(OCF_LENGTH_CPC_NAME, (size_t) cpc->length);
76		memset(cpc_name, 0, OCF_LENGTH_CPC_NAME);
77		memcpy(cpc_name, cpc + 1, size);
78	}
79	spin_unlock(&sclp_ocf_lock);
80	schedule_work(&sclp_ocf_change_work);
81}
82
83static struct sclp_register sclp_ocf_event = {
84	.receive_mask = EVTYP_OCF_MASK,
85	.receiver_fn = sclp_ocf_handler,
86};
87
88void sclp_ocf_cpc_name_copy(char *dst)
89{
90	spin_lock_irq(&sclp_ocf_lock);
91	memcpy(dst, cpc_name, OCF_LENGTH_CPC_NAME);
92	spin_unlock_irq(&sclp_ocf_lock);
93}
94EXPORT_SYMBOL(sclp_ocf_cpc_name_copy);
95
96static ssize_t cpc_name_show(struct kobject *kobj,
97			     struct kobj_attribute *attr, char *page)
98{
99	char name[OCF_LENGTH_CPC_NAME + 1];
100
101	sclp_ocf_cpc_name_copy(name);
102	name[OCF_LENGTH_CPC_NAME] = 0;
103	EBCASC(name, OCF_LENGTH_CPC_NAME);
104	return snprintf(page, PAGE_SIZE, "%s\n", name);
105}
106
107static struct kobj_attribute cpc_name_attr =
108	__ATTR(cpc_name, 0444, cpc_name_show, NULL);
109
110static ssize_t hmc_network_show(struct kobject *kobj,
111				struct kobj_attribute *attr, char *page)
112{
113	int rc;
114
115	spin_lock_irq(&sclp_ocf_lock);
116	rc = snprintf(page, PAGE_SIZE, "%s\n", hmc_network);
117	spin_unlock_irq(&sclp_ocf_lock);
118	return rc;
119}
120
121static struct kobj_attribute hmc_network_attr =
122	__ATTR(hmc_network, 0444, hmc_network_show, NULL);
123
124static struct attribute *ocf_attrs[] = {
125	&cpc_name_attr.attr,
126	&hmc_network_attr.attr,
127	NULL,
128};
129
130static const struct attribute_group ocf_attr_group = {
131	.attrs = ocf_attrs,
132};
133
134static int __init ocf_init(void)
135{
136	int rc;
137
138	INIT_WORK(&sclp_ocf_change_work, sclp_ocf_change_notify);
139	ocf_kset = kset_create_and_add("ocf", NULL, firmware_kobj);
140	if (!ocf_kset)
141		return -ENOMEM;
142
143	rc = sysfs_create_group(&ocf_kset->kobj, &ocf_attr_group);
144	if (rc) {
145		kset_unregister(ocf_kset);
146		return rc;
147	}
148
149	return sclp_register(&sclp_ocf_event);
150}
151
152device_initcall(ocf_init);
153