xref: /openbmc/linux/drivers/s390/char/sclp_cpi_sys.c (revision 0c6dfa75)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *    SCLP control program identification sysfs interface
4  *
5  *    Copyright IBM Corp. 2001, 2007
6  *    Author(s): Martin Peschke <mpeschke@de.ibm.com>
7  *		 Michael Ernst <mernst@de.ibm.com>
8  */
9 
10 #define KMSG_COMPONENT "sclp_cpi"
11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
12 
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/stat.h>
16 #include <linux/device.h>
17 #include <linux/string.h>
18 #include <linux/ctype.h>
19 #include <linux/kmod.h>
20 #include <linux/timer.h>
21 #include <linux/err.h>
22 #include <linux/slab.h>
23 #include <linux/completion.h>
24 #include <linux/export.h>
25 #include <asm/ebcdic.h>
26 #include <asm/sclp.h>
27 
28 #include "sclp.h"
29 #include "sclp_rw.h"
30 #include "sclp_cpi_sys.h"
31 
32 #define CPI_LENGTH_NAME 8
33 #define CPI_LENGTH_LEVEL 16
34 
35 static DEFINE_MUTEX(sclp_cpi_mutex);
36 
37 struct cpi_evbuf {
38 	struct evbuf_header header;
39 	u8	id_format;
40 	u8	reserved0;
41 	u8	system_type[CPI_LENGTH_NAME];
42 	u64	reserved1;
43 	u8	system_name[CPI_LENGTH_NAME];
44 	u64	reserved2;
45 	u64	system_level;
46 	u64	reserved3;
47 	u8	sysplex_name[CPI_LENGTH_NAME];
48 	u8	reserved4[16];
49 } __attribute__((packed));
50 
51 struct cpi_sccb {
52 	struct sccb_header header;
53 	struct cpi_evbuf cpi_evbuf;
54 } __attribute__((packed));
55 
56 static struct sclp_register sclp_cpi_event = {
57 	.send_mask = EVTYP_CTLPROGIDENT_MASK,
58 };
59 
60 static char system_name[CPI_LENGTH_NAME + 1];
61 static char sysplex_name[CPI_LENGTH_NAME + 1];
62 static char system_type[CPI_LENGTH_NAME + 1];
63 static u64 system_level;
64 
65 static void set_data(char *field, char *data)
66 {
67 	memset(field, ' ', CPI_LENGTH_NAME);
68 	memcpy(field, data, strlen(data));
69 	sclp_ascebc_str(field, CPI_LENGTH_NAME);
70 }
71 
72 static void cpi_callback(struct sclp_req *req, void *data)
73 {
74 	struct completion *completion = data;
75 
76 	complete(completion);
77 }
78 
79 static struct sclp_req *cpi_prepare_req(void)
80 {
81 	struct sclp_req *req;
82 	struct cpi_sccb *sccb;
83 	struct cpi_evbuf *evb;
84 
85 	req = kzalloc(sizeof(struct sclp_req), GFP_KERNEL);
86 	if (!req)
87 		return ERR_PTR(-ENOMEM);
88 	sccb = (struct cpi_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
89 	if (!sccb) {
90 		kfree(req);
91 		return ERR_PTR(-ENOMEM);
92 	}
93 
94 	/* setup SCCB for Control-Program Identification */
95 	sccb->header.length = sizeof(struct cpi_sccb);
96 	sccb->cpi_evbuf.header.length = sizeof(struct cpi_evbuf);
97 	sccb->cpi_evbuf.header.type = EVTYP_CTLPROGIDENT;
98 	evb = &sccb->cpi_evbuf;
99 
100 	/* set system type */
101 	set_data(evb->system_type, system_type);
102 
103 	/* set system name */
104 	set_data(evb->system_name, system_name);
105 
106 	/* set system level */
107 	evb->system_level = system_level;
108 
109 	/* set sysplex name */
110 	set_data(evb->sysplex_name, sysplex_name);
111 
112 	/* prepare request data structure presented to SCLP driver */
113 	req->command = SCLP_CMDW_WRITE_EVENT_DATA;
114 	req->sccb = sccb;
115 	req->status = SCLP_REQ_FILLED;
116 	req->callback = cpi_callback;
117 	return req;
118 }
119 
120 static void cpi_free_req(struct sclp_req *req)
121 {
122 	free_page((unsigned long) req->sccb);
123 	kfree(req);
124 }
125 
126 static int cpi_req(void)
127 {
128 	struct completion completion;
129 	struct sclp_req *req;
130 	int rc;
131 	int response;
132 
133 	rc = sclp_register(&sclp_cpi_event);
134 	if (rc)
135 		goto out;
136 	if (!(sclp_cpi_event.sclp_receive_mask & EVTYP_CTLPROGIDENT_MASK)) {
137 		rc = -EOPNOTSUPP;
138 		goto out_unregister;
139 	}
140 
141 	req = cpi_prepare_req();
142 	if (IS_ERR(req)) {
143 		rc = PTR_ERR(req);
144 		goto out_unregister;
145 	}
146 
147 	init_completion(&completion);
148 	req->callback_data = &completion;
149 
150 	/* Add request to sclp queue */
151 	rc = sclp_add_request(req);
152 	if (rc)
153 		goto out_free_req;
154 
155 	wait_for_completion(&completion);
156 
157 	if (req->status != SCLP_REQ_DONE) {
158 		pr_warn("request failed (status=0x%02x)\n", req->status);
159 		rc = -EIO;
160 		goto out_free_req;
161 	}
162 
163 	response = ((struct cpi_sccb *) req->sccb)->header.response_code;
164 	if (response != 0x0020) {
165 		pr_warn("request failed with response code 0x%x\n", response);
166 		rc = -EIO;
167 	}
168 
169 out_free_req:
170 	cpi_free_req(req);
171 
172 out_unregister:
173 	sclp_unregister(&sclp_cpi_event);
174 
175 out:
176 	return rc;
177 }
178 
179 static int check_string(const char *attr, const char *str)
180 {
181 	size_t len;
182 	size_t i;
183 
184 	len = strlen(str);
185 
186 	if ((len > 0) && (str[len - 1] == '\n'))
187 		len--;
188 
189 	if (len > CPI_LENGTH_NAME)
190 		return -EINVAL;
191 
192 	for (i = 0; i < len ; i++) {
193 		if (isalpha(str[i]) || isdigit(str[i]) ||
194 		    strchr("$@# ", str[i]))
195 			continue;
196 		return -EINVAL;
197 	}
198 
199 	return 0;
200 }
201 
202 static void set_string(char *attr, const char *value)
203 {
204 	size_t len;
205 	size_t i;
206 
207 	len = strlen(value);
208 
209 	if ((len > 0) && (value[len - 1] == '\n'))
210 		len--;
211 
212 	for (i = 0; i < CPI_LENGTH_NAME; i++) {
213 		if (i < len)
214 			attr[i] = toupper(value[i]);
215 		else
216 			attr[i] = ' ';
217 	}
218 }
219 
220 static ssize_t system_name_show(struct kobject *kobj,
221 				struct kobj_attribute *attr, char *page)
222 {
223 	int rc;
224 
225 	mutex_lock(&sclp_cpi_mutex);
226 	rc = snprintf(page, PAGE_SIZE, "%s\n", system_name);
227 	mutex_unlock(&sclp_cpi_mutex);
228 	return rc;
229 }
230 
231 static ssize_t system_name_store(struct kobject *kobj,
232 				 struct kobj_attribute *attr,
233 				 const char *buf,
234 	size_t len)
235 {
236 	int rc;
237 
238 	rc = check_string("system_name", buf);
239 	if (rc)
240 		return rc;
241 
242 	mutex_lock(&sclp_cpi_mutex);
243 	set_string(system_name, buf);
244 	mutex_unlock(&sclp_cpi_mutex);
245 
246 	return len;
247 }
248 
249 static struct kobj_attribute system_name_attr =
250 	__ATTR(system_name, 0644, system_name_show, system_name_store);
251 
252 static ssize_t sysplex_name_show(struct kobject *kobj,
253 				 struct kobj_attribute *attr, char *page)
254 {
255 	int rc;
256 
257 	mutex_lock(&sclp_cpi_mutex);
258 	rc = snprintf(page, PAGE_SIZE, "%s\n", sysplex_name);
259 	mutex_unlock(&sclp_cpi_mutex);
260 	return rc;
261 }
262 
263 static ssize_t sysplex_name_store(struct kobject *kobj,
264 				  struct kobj_attribute *attr,
265 				  const char *buf,
266 	size_t len)
267 {
268 	int rc;
269 
270 	rc = check_string("sysplex_name", buf);
271 	if (rc)
272 		return rc;
273 
274 	mutex_lock(&sclp_cpi_mutex);
275 	set_string(sysplex_name, buf);
276 	mutex_unlock(&sclp_cpi_mutex);
277 
278 	return len;
279 }
280 
281 static struct kobj_attribute sysplex_name_attr =
282 	__ATTR(sysplex_name, 0644, sysplex_name_show, sysplex_name_store);
283 
284 static ssize_t system_type_show(struct kobject *kobj,
285 				struct kobj_attribute *attr, char *page)
286 {
287 	int rc;
288 
289 	mutex_lock(&sclp_cpi_mutex);
290 	rc = snprintf(page, PAGE_SIZE, "%s\n", system_type);
291 	mutex_unlock(&sclp_cpi_mutex);
292 	return rc;
293 }
294 
295 static ssize_t system_type_store(struct kobject *kobj,
296 				 struct kobj_attribute *attr,
297 				 const char *buf,
298 	size_t len)
299 {
300 	int rc;
301 
302 	rc = check_string("system_type", buf);
303 	if (rc)
304 		return rc;
305 
306 	mutex_lock(&sclp_cpi_mutex);
307 	set_string(system_type, buf);
308 	mutex_unlock(&sclp_cpi_mutex);
309 
310 	return len;
311 }
312 
313 static struct kobj_attribute system_type_attr =
314 	__ATTR(system_type, 0644, system_type_show, system_type_store);
315 
316 static ssize_t system_level_show(struct kobject *kobj,
317 				 struct kobj_attribute *attr, char *page)
318 {
319 	unsigned long long level;
320 
321 	mutex_lock(&sclp_cpi_mutex);
322 	level = system_level;
323 	mutex_unlock(&sclp_cpi_mutex);
324 	return snprintf(page, PAGE_SIZE, "%#018llx\n", level);
325 }
326 
327 static ssize_t system_level_store(struct kobject *kobj,
328 				  struct kobj_attribute *attr,
329 				  const char *buf,
330 	size_t len)
331 {
332 	unsigned long long level;
333 	char *endp;
334 
335 	level = simple_strtoull(buf, &endp, 16);
336 
337 	if (endp == buf)
338 		return -EINVAL;
339 	if (*endp == '\n')
340 		endp++;
341 	if (*endp)
342 		return -EINVAL;
343 
344 	mutex_lock(&sclp_cpi_mutex);
345 	system_level = level;
346 	mutex_unlock(&sclp_cpi_mutex);
347 	return len;
348 }
349 
350 static struct kobj_attribute system_level_attr =
351 	__ATTR(system_level, 0644, system_level_show, system_level_store);
352 
353 static ssize_t set_store(struct kobject *kobj,
354 			 struct kobj_attribute *attr,
355 			 const char *buf, size_t len)
356 {
357 	int rc;
358 
359 	mutex_lock(&sclp_cpi_mutex);
360 	rc = cpi_req();
361 	mutex_unlock(&sclp_cpi_mutex);
362 	if (rc)
363 		return rc;
364 
365 	return len;
366 }
367 
368 static struct kobj_attribute set_attr = __ATTR(set, 0200, NULL, set_store);
369 
370 static struct attribute *cpi_attrs[] = {
371 	&system_name_attr.attr,
372 	&sysplex_name_attr.attr,
373 	&system_type_attr.attr,
374 	&system_level_attr.attr,
375 	&set_attr.attr,
376 	NULL,
377 };
378 
379 static struct attribute_group cpi_attr_group = {
380 	.attrs = cpi_attrs,
381 };
382 
383 static struct kset *cpi_kset;
384 
385 int sclp_cpi_set_data(const char *system, const char *sysplex, const char *type,
386 		      const u64 level)
387 {
388 	int rc;
389 
390 	rc = check_string("system_name", system);
391 	if (rc)
392 		return rc;
393 	rc = check_string("sysplex_name", sysplex);
394 	if (rc)
395 		return rc;
396 	rc = check_string("system_type", type);
397 	if (rc)
398 		return rc;
399 
400 	mutex_lock(&sclp_cpi_mutex);
401 	set_string(system_name, system);
402 	set_string(sysplex_name, sysplex);
403 	set_string(system_type, type);
404 	system_level = level;
405 
406 	rc = cpi_req();
407 	mutex_unlock(&sclp_cpi_mutex);
408 
409 	return rc;
410 }
411 EXPORT_SYMBOL(sclp_cpi_set_data);
412 
413 static int __init cpi_init(void)
414 {
415 	int rc;
416 
417 	cpi_kset = kset_create_and_add("cpi", NULL, firmware_kobj);
418 	if (!cpi_kset)
419 		return -ENOMEM;
420 
421 	rc = sysfs_create_group(&cpi_kset->kobj, &cpi_attr_group);
422 	if (rc)
423 		kset_unregister(cpi_kset);
424 
425 	return rc;
426 }
427 
428 __initcall(cpi_init);
429