1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Character device driver for writing z/VM *MONITOR service records.
4 *
5 * Copyright IBM Corp. 2006, 2009
6 *
7 * Author(s): Melissa Howland <Melissa.Howland@us.ibm.com>
8 */
9
10 #define KMSG_COMPONENT "monwriter"
11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
12
13 #include <linux/module.h>
14 #include <linux/moduleparam.h>
15 #include <linux/init.h>
16 #include <linux/errno.h>
17 #include <linux/types.h>
18 #include <linux/kernel.h>
19 #include <linux/miscdevice.h>
20 #include <linux/ctype.h>
21 #include <linux/poll.h>
22 #include <linux/mutex.h>
23 #include <linux/platform_device.h>
24 #include <linux/slab.h>
25 #include <linux/uaccess.h>
26 #include <asm/ebcdic.h>
27 #include <asm/io.h>
28 #include <asm/appldata.h>
29 #include <asm/monwriter.h>
30
31 #define MONWRITE_MAX_DATALEN 4010
32
33 static int mon_max_bufs = 255;
34 static int mon_buf_count;
35
36 struct mon_buf {
37 struct list_head list;
38 struct monwrite_hdr hdr;
39 int diag_done;
40 char *data;
41 };
42
43 static LIST_HEAD(mon_priv_list);
44
45 struct mon_private {
46 struct list_head priv_list;
47 struct list_head list;
48 struct monwrite_hdr hdr;
49 size_t hdr_to_read;
50 size_t data_to_read;
51 struct mon_buf *current_buf;
52 struct mutex thread_mutex;
53 };
54
55 /*
56 * helper functions
57 */
58
monwrite_diag(struct monwrite_hdr * myhdr,char * buffer,int fcn)59 static int monwrite_diag(struct monwrite_hdr *myhdr, char *buffer, int fcn)
60 {
61 struct appldata_product_id id;
62 int rc;
63
64 memcpy(id.prod_nr, "LNXAPPL", 7);
65 id.prod_fn = myhdr->applid;
66 id.record_nr = myhdr->record_num;
67 id.version_nr = myhdr->version;
68 id.release_nr = myhdr->release;
69 id.mod_lvl = myhdr->mod_level;
70 rc = appldata_asm(&id, fcn, (void *) buffer, myhdr->datalen);
71 if (rc <= 0)
72 return rc;
73 pr_err("Writing monitor data failed with rc=%i\n", rc);
74 if (rc == 5)
75 return -EPERM;
76 return -EINVAL;
77 }
78
monwrite_find_hdr(struct mon_private * monpriv,struct monwrite_hdr * monhdr)79 static struct mon_buf *monwrite_find_hdr(struct mon_private *monpriv,
80 struct monwrite_hdr *monhdr)
81 {
82 struct mon_buf *entry, *next;
83
84 list_for_each_entry_safe(entry, next, &monpriv->list, list)
85 if ((entry->hdr.mon_function == monhdr->mon_function ||
86 monhdr->mon_function == MONWRITE_STOP_INTERVAL) &&
87 entry->hdr.applid == monhdr->applid &&
88 entry->hdr.record_num == monhdr->record_num &&
89 entry->hdr.version == monhdr->version &&
90 entry->hdr.release == monhdr->release &&
91 entry->hdr.mod_level == monhdr->mod_level)
92 return entry;
93
94 return NULL;
95 }
96
monwrite_new_hdr(struct mon_private * monpriv)97 static int monwrite_new_hdr(struct mon_private *monpriv)
98 {
99 struct monwrite_hdr *monhdr = &monpriv->hdr;
100 struct mon_buf *monbuf;
101 int rc = 0;
102
103 if (monhdr->datalen > MONWRITE_MAX_DATALEN ||
104 monhdr->mon_function > MONWRITE_START_CONFIG ||
105 monhdr->hdrlen != sizeof(struct monwrite_hdr))
106 return -EINVAL;
107 monbuf = NULL;
108 if (monhdr->mon_function != MONWRITE_GEN_EVENT)
109 monbuf = monwrite_find_hdr(monpriv, monhdr);
110 if (monbuf) {
111 if (monhdr->mon_function == MONWRITE_STOP_INTERVAL) {
112 monhdr->datalen = monbuf->hdr.datalen;
113 rc = monwrite_diag(monhdr, monbuf->data,
114 APPLDATA_STOP_REC);
115 list_del(&monbuf->list);
116 mon_buf_count--;
117 kfree(monbuf->data);
118 kfree(monbuf);
119 monbuf = NULL;
120 }
121 } else if (monhdr->mon_function != MONWRITE_STOP_INTERVAL) {
122 if (mon_buf_count >= mon_max_bufs)
123 return -ENOSPC;
124 monbuf = kzalloc(sizeof(struct mon_buf), GFP_KERNEL);
125 if (!monbuf)
126 return -ENOMEM;
127 monbuf->data = kzalloc(monhdr->datalen,
128 GFP_KERNEL | GFP_DMA);
129 if (!monbuf->data) {
130 kfree(monbuf);
131 return -ENOMEM;
132 }
133 monbuf->hdr = *monhdr;
134 list_add_tail(&monbuf->list, &monpriv->list);
135 if (monhdr->mon_function != MONWRITE_GEN_EVENT)
136 mon_buf_count++;
137 }
138 monpriv->current_buf = monbuf;
139 return rc;
140 }
141
monwrite_new_data(struct mon_private * monpriv)142 static int monwrite_new_data(struct mon_private *monpriv)
143 {
144 struct monwrite_hdr *monhdr = &monpriv->hdr;
145 struct mon_buf *monbuf = monpriv->current_buf;
146 int rc = 0;
147
148 switch (monhdr->mon_function) {
149 case MONWRITE_START_INTERVAL:
150 if (!monbuf->diag_done) {
151 rc = monwrite_diag(monhdr, monbuf->data,
152 APPLDATA_START_INTERVAL_REC);
153 monbuf->diag_done = 1;
154 }
155 break;
156 case MONWRITE_START_CONFIG:
157 if (!monbuf->diag_done) {
158 rc = monwrite_diag(monhdr, monbuf->data,
159 APPLDATA_START_CONFIG_REC);
160 monbuf->diag_done = 1;
161 }
162 break;
163 case MONWRITE_GEN_EVENT:
164 rc = monwrite_diag(monhdr, monbuf->data,
165 APPLDATA_GEN_EVENT_REC);
166 list_del(&monpriv->current_buf->list);
167 kfree(monpriv->current_buf->data);
168 kfree(monpriv->current_buf);
169 monpriv->current_buf = NULL;
170 break;
171 default:
172 /* monhdr->mon_function is checked in monwrite_new_hdr */
173 BUG();
174 }
175 return rc;
176 }
177
178 /*
179 * file operations
180 */
181
monwrite_open(struct inode * inode,struct file * filp)182 static int monwrite_open(struct inode *inode, struct file *filp)
183 {
184 struct mon_private *monpriv;
185
186 monpriv = kzalloc(sizeof(struct mon_private), GFP_KERNEL);
187 if (!monpriv)
188 return -ENOMEM;
189 INIT_LIST_HEAD(&monpriv->list);
190 monpriv->hdr_to_read = sizeof(monpriv->hdr);
191 mutex_init(&monpriv->thread_mutex);
192 filp->private_data = monpriv;
193 list_add_tail(&monpriv->priv_list, &mon_priv_list);
194 return nonseekable_open(inode, filp);
195 }
196
monwrite_close(struct inode * inode,struct file * filp)197 static int monwrite_close(struct inode *inode, struct file *filp)
198 {
199 struct mon_private *monpriv = filp->private_data;
200 struct mon_buf *entry, *next;
201
202 list_for_each_entry_safe(entry, next, &monpriv->list, list) {
203 if (entry->hdr.mon_function != MONWRITE_GEN_EVENT)
204 monwrite_diag(&entry->hdr, entry->data,
205 APPLDATA_STOP_REC);
206 mon_buf_count--;
207 list_del(&entry->list);
208 kfree(entry->data);
209 kfree(entry);
210 }
211 list_del(&monpriv->priv_list);
212 kfree(monpriv);
213 return 0;
214 }
215
monwrite_write(struct file * filp,const char __user * data,size_t count,loff_t * ppos)216 static ssize_t monwrite_write(struct file *filp, const char __user *data,
217 size_t count, loff_t *ppos)
218 {
219 struct mon_private *monpriv = filp->private_data;
220 size_t len, written;
221 void *to;
222 int rc;
223
224 mutex_lock(&monpriv->thread_mutex);
225 for (written = 0; written < count; ) {
226 if (monpriv->hdr_to_read) {
227 len = min(count - written, monpriv->hdr_to_read);
228 to = (char *) &monpriv->hdr +
229 sizeof(monpriv->hdr) - monpriv->hdr_to_read;
230 if (copy_from_user(to, data + written, len)) {
231 rc = -EFAULT;
232 goto out_error;
233 }
234 monpriv->hdr_to_read -= len;
235 written += len;
236 if (monpriv->hdr_to_read > 0)
237 continue;
238 rc = monwrite_new_hdr(monpriv);
239 if (rc)
240 goto out_error;
241 monpriv->data_to_read = monpriv->current_buf ?
242 monpriv->current_buf->hdr.datalen : 0;
243 }
244
245 if (monpriv->data_to_read) {
246 len = min(count - written, monpriv->data_to_read);
247 to = monpriv->current_buf->data +
248 monpriv->hdr.datalen - monpriv->data_to_read;
249 if (copy_from_user(to, data + written, len)) {
250 rc = -EFAULT;
251 goto out_error;
252 }
253 monpriv->data_to_read -= len;
254 written += len;
255 if (monpriv->data_to_read > 0)
256 continue;
257 rc = monwrite_new_data(monpriv);
258 if (rc)
259 goto out_error;
260 }
261 monpriv->hdr_to_read = sizeof(monpriv->hdr);
262 }
263 mutex_unlock(&monpriv->thread_mutex);
264 return written;
265
266 out_error:
267 monpriv->data_to_read = 0;
268 monpriv->hdr_to_read = sizeof(struct monwrite_hdr);
269 mutex_unlock(&monpriv->thread_mutex);
270 return rc;
271 }
272
273 static const struct file_operations monwrite_fops = {
274 .owner = THIS_MODULE,
275 .open = &monwrite_open,
276 .release = &monwrite_close,
277 .write = &monwrite_write,
278 .llseek = noop_llseek,
279 };
280
281 static struct miscdevice mon_dev = {
282 .name = "monwriter",
283 .fops = &monwrite_fops,
284 .minor = MISC_DYNAMIC_MINOR,
285 };
286
287 /*
288 * suspend/resume
289 */
290
monwriter_freeze(struct device * dev)291 static int monwriter_freeze(struct device *dev)
292 {
293 struct mon_private *monpriv;
294 struct mon_buf *monbuf;
295
296 list_for_each_entry(monpriv, &mon_priv_list, priv_list) {
297 list_for_each_entry(monbuf, &monpriv->list, list) {
298 if (monbuf->hdr.mon_function != MONWRITE_GEN_EVENT)
299 monwrite_diag(&monbuf->hdr, monbuf->data,
300 APPLDATA_STOP_REC);
301 }
302 }
303 return 0;
304 }
305
monwriter_restore(struct device * dev)306 static int monwriter_restore(struct device *dev)
307 {
308 struct mon_private *monpriv;
309 struct mon_buf *monbuf;
310
311 list_for_each_entry(monpriv, &mon_priv_list, priv_list) {
312 list_for_each_entry(monbuf, &monpriv->list, list) {
313 if (monbuf->hdr.mon_function == MONWRITE_START_INTERVAL)
314 monwrite_diag(&monbuf->hdr, monbuf->data,
315 APPLDATA_START_INTERVAL_REC);
316 if (monbuf->hdr.mon_function == MONWRITE_START_CONFIG)
317 monwrite_diag(&monbuf->hdr, monbuf->data,
318 APPLDATA_START_CONFIG_REC);
319 }
320 }
321 return 0;
322 }
323
monwriter_thaw(struct device * dev)324 static int monwriter_thaw(struct device *dev)
325 {
326 return monwriter_restore(dev);
327 }
328
329 static const struct dev_pm_ops monwriter_pm_ops = {
330 .freeze = monwriter_freeze,
331 .thaw = monwriter_thaw,
332 .restore = monwriter_restore,
333 };
334
335 static struct platform_driver monwriter_pdrv = {
336 .driver = {
337 .name = "monwriter",
338 .pm = &monwriter_pm_ops,
339 },
340 };
341
342 static struct platform_device *monwriter_pdev;
343
344 /*
345 * module init/exit
346 */
347
mon_init(void)348 static int __init mon_init(void)
349 {
350 int rc;
351
352 if (!MACHINE_IS_VM)
353 return -ENODEV;
354
355 rc = platform_driver_register(&monwriter_pdrv);
356 if (rc)
357 return rc;
358
359 monwriter_pdev = platform_device_register_simple("monwriter", -1, NULL,
360 0);
361 if (IS_ERR(monwriter_pdev)) {
362 rc = PTR_ERR(monwriter_pdev);
363 goto out_driver;
364 }
365
366 /*
367 * misc_register() has to be the last action in module_init(), because
368 * file operations will be available right after this.
369 */
370 rc = misc_register(&mon_dev);
371 if (rc)
372 goto out_device;
373 return 0;
374
375 out_device:
376 platform_device_unregister(monwriter_pdev);
377 out_driver:
378 platform_driver_unregister(&monwriter_pdrv);
379 return rc;
380 }
381
mon_exit(void)382 static void __exit mon_exit(void)
383 {
384 misc_deregister(&mon_dev);
385 platform_device_unregister(monwriter_pdev);
386 platform_driver_unregister(&monwriter_pdrv);
387 }
388
389 module_init(mon_init);
390 module_exit(mon_exit);
391
392 module_param_named(max_bufs, mon_max_bufs, int, 0644);
393 MODULE_PARM_DESC(max_bufs, "Maximum number of sample monitor data buffers "
394 "that can be active at one time");
395
396 MODULE_AUTHOR("Melissa Howland <Melissa.Howland@us.ibm.com>");
397 MODULE_DESCRIPTION("Character device driver for writing z/VM "
398 "APPLDATA monitor records.");
399 MODULE_LICENSE("GPL");
400
