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 
29 static char hmc_network[OCF_LENGTH_HMC_NETWORK + 1];
30 static char cpc_name[OCF_LENGTH_CPC_NAME]; /* in EBCDIC */
31 
32 static DEFINE_SPINLOCK(sclp_ocf_lock);
33 static struct work_struct sclp_ocf_change_work;
34 
35 static struct kset *ocf_kset;
36 
sclp_ocf_change_notify(struct work_struct * work)37 static 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. */
sclp_ocf_handler(struct evbuf_header * evbuf)43 static 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 
83 static struct sclp_register sclp_ocf_event = {
84 	.receive_mask = EVTYP_OCF_MASK,
85 	.receiver_fn = sclp_ocf_handler,
86 };
87 
sclp_ocf_cpc_name_copy(char * dst)88 void 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 }
94 EXPORT_SYMBOL(sclp_ocf_cpc_name_copy);
95 
cpc_name_show(struct kobject * kobj,struct kobj_attribute * attr,char * page)96 static 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 
107 static struct kobj_attribute cpc_name_attr =
108 	__ATTR(cpc_name, 0444, cpc_name_show, NULL);
109 
hmc_network_show(struct kobject * kobj,struct kobj_attribute * attr,char * page)110 static 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 
121 static struct kobj_attribute hmc_network_attr =
122 	__ATTR(hmc_network, 0444, hmc_network_show, NULL);
123 
124 static struct attribute *ocf_attrs[] = {
125 	&cpc_name_attr.attr,
126 	&hmc_network_attr.attr,
127 	NULL,
128 };
129 
130 static const struct attribute_group ocf_attr_group = {
131 	.attrs = ocf_attrs,
132 };
133 
ocf_init(void)134 static 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 
152 device_initcall(ocf_init);
153