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_parameter_list *parm_list;
62 struct appldata_product_id *id;
63 int rc;
64
65 id = kmalloc(sizeof(*id), GFP_KERNEL);
66 parm_list = kmalloc(sizeof(*parm_list), GFP_KERNEL);
67 rc = -ENOMEM;
68 if (!id || !parm_list)
69 goto out;
70 memcpy(id->prod_nr, "LNXAPPL", 7);
71 id->prod_fn = myhdr->applid;
72 id->record_nr = myhdr->record_num;
73 id->version_nr = myhdr->version;
74 id->release_nr = myhdr->release;
75 id->mod_lvl = myhdr->mod_level;
76 rc = appldata_asm(parm_list, id, fcn,
77 (void *) buffer, myhdr->datalen);
78 if (rc <= 0)
79 goto out;
80 pr_err("Writing monitor data failed with rc=%i\n", rc);
81 rc = (rc == 5) ? -EPERM : -EINVAL;
82 out:
83 kfree(id);
84 kfree(parm_list);
85 return rc;
86 }
87
monwrite_find_hdr(struct mon_private * monpriv,struct monwrite_hdr * monhdr)88 static struct mon_buf *monwrite_find_hdr(struct mon_private *monpriv,
89 struct monwrite_hdr *monhdr)
90 {
91 struct mon_buf *entry, *next;
92
93 list_for_each_entry_safe(entry, next, &monpriv->list, list)
94 if ((entry->hdr.mon_function == monhdr->mon_function ||
95 monhdr->mon_function == MONWRITE_STOP_INTERVAL) &&
96 entry->hdr.applid == monhdr->applid &&
97 entry->hdr.record_num == monhdr->record_num &&
98 entry->hdr.version == monhdr->version &&
99 entry->hdr.release == monhdr->release &&
100 entry->hdr.mod_level == monhdr->mod_level)
101 return entry;
102
103 return NULL;
104 }
105
monwrite_new_hdr(struct mon_private * monpriv)106 static int monwrite_new_hdr(struct mon_private *monpriv)
107 {
108 struct monwrite_hdr *monhdr = &monpriv->hdr;
109 struct mon_buf *monbuf;
110 int rc = 0;
111
112 if (monhdr->datalen > MONWRITE_MAX_DATALEN ||
113 monhdr->mon_function > MONWRITE_START_CONFIG ||
114 monhdr->hdrlen != sizeof(struct monwrite_hdr))
115 return -EINVAL;
116 monbuf = NULL;
117 if (monhdr->mon_function != MONWRITE_GEN_EVENT)
118 monbuf = monwrite_find_hdr(monpriv, monhdr);
119 if (monbuf) {
120 if (monhdr->mon_function == MONWRITE_STOP_INTERVAL) {
121 monhdr->datalen = monbuf->hdr.datalen;
122 rc = monwrite_diag(monhdr, monbuf->data,
123 APPLDATA_STOP_REC);
124 list_del(&monbuf->list);
125 mon_buf_count--;
126 kfree(monbuf->data);
127 kfree(monbuf);
128 monbuf = NULL;
129 }
130 } else if (monhdr->mon_function != MONWRITE_STOP_INTERVAL) {
131 if (mon_buf_count >= mon_max_bufs)
132 return -ENOSPC;
133 monbuf = kzalloc(sizeof(struct mon_buf), GFP_KERNEL);
134 if (!monbuf)
135 return -ENOMEM;
136 monbuf->data = kzalloc(monhdr->datalen,
137 GFP_KERNEL | GFP_DMA);
138 if (!monbuf->data) {
139 kfree(monbuf);
140 return -ENOMEM;
141 }
142 monbuf->hdr = *monhdr;
143 list_add_tail(&monbuf->list, &monpriv->list);
144 if (monhdr->mon_function != MONWRITE_GEN_EVENT)
145 mon_buf_count++;
146 }
147 monpriv->current_buf = monbuf;
148 return rc;
149 }
150
monwrite_new_data(struct mon_private * monpriv)151 static int monwrite_new_data(struct mon_private *monpriv)
152 {
153 struct monwrite_hdr *monhdr = &monpriv->hdr;
154 struct mon_buf *monbuf = monpriv->current_buf;
155 int rc = 0;
156
157 switch (monhdr->mon_function) {
158 case MONWRITE_START_INTERVAL:
159 if (!monbuf->diag_done) {
160 rc = monwrite_diag(monhdr, monbuf->data,
161 APPLDATA_START_INTERVAL_REC);
162 monbuf->diag_done = 1;
163 }
164 break;
165 case MONWRITE_START_CONFIG:
166 if (!monbuf->diag_done) {
167 rc = monwrite_diag(monhdr, monbuf->data,
168 APPLDATA_START_CONFIG_REC);
169 monbuf->diag_done = 1;
170 }
171 break;
172 case MONWRITE_GEN_EVENT:
173 rc = monwrite_diag(monhdr, monbuf->data,
174 APPLDATA_GEN_EVENT_REC);
175 list_del(&monpriv->current_buf->list);
176 kfree(monpriv->current_buf->data);
177 kfree(monpriv->current_buf);
178 monpriv->current_buf = NULL;
179 break;
180 default:
181 /* monhdr->mon_function is checked in monwrite_new_hdr */
182 BUG();
183 }
184 return rc;
185 }
186
187 /*
188 * file operations
189 */
190
monwrite_open(struct inode * inode,struct file * filp)191 static int monwrite_open(struct inode *inode, struct file *filp)
192 {
193 struct mon_private *monpriv;
194
195 monpriv = kzalloc(sizeof(struct mon_private), GFP_KERNEL);
196 if (!monpriv)
197 return -ENOMEM;
198 INIT_LIST_HEAD(&monpriv->list);
199 monpriv->hdr_to_read = sizeof(monpriv->hdr);
200 mutex_init(&monpriv->thread_mutex);
201 filp->private_data = monpriv;
202 list_add_tail(&monpriv->priv_list, &mon_priv_list);
203 return nonseekable_open(inode, filp);
204 }
205
monwrite_close(struct inode * inode,struct file * filp)206 static int monwrite_close(struct inode *inode, struct file *filp)
207 {
208 struct mon_private *monpriv = filp->private_data;
209 struct mon_buf *entry, *next;
210
211 list_for_each_entry_safe(entry, next, &monpriv->list, list) {
212 if (entry->hdr.mon_function != MONWRITE_GEN_EVENT)
213 monwrite_diag(&entry->hdr, entry->data,
214 APPLDATA_STOP_REC);
215 mon_buf_count--;
216 list_del(&entry->list);
217 kfree(entry->data);
218 kfree(entry);
219 }
220 list_del(&monpriv->priv_list);
221 kfree(monpriv);
222 return 0;
223 }
224
monwrite_write(struct file * filp,const char __user * data,size_t count,loff_t * ppos)225 static ssize_t monwrite_write(struct file *filp, const char __user *data,
226 size_t count, loff_t *ppos)
227 {
228 struct mon_private *monpriv = filp->private_data;
229 size_t len, written;
230 void *to;
231 int rc;
232
233 mutex_lock(&monpriv->thread_mutex);
234 for (written = 0; written < count; ) {
235 if (monpriv->hdr_to_read) {
236 len = min(count - written, monpriv->hdr_to_read);
237 to = (char *) &monpriv->hdr +
238 sizeof(monpriv->hdr) - monpriv->hdr_to_read;
239 if (copy_from_user(to, data + written, len)) {
240 rc = -EFAULT;
241 goto out_error;
242 }
243 monpriv->hdr_to_read -= len;
244 written += len;
245 if (monpriv->hdr_to_read > 0)
246 continue;
247 rc = monwrite_new_hdr(monpriv);
248 if (rc)
249 goto out_error;
250 monpriv->data_to_read = monpriv->current_buf ?
251 monpriv->current_buf->hdr.datalen : 0;
252 }
253
254 if (monpriv->data_to_read) {
255 len = min(count - written, monpriv->data_to_read);
256 to = monpriv->current_buf->data +
257 monpriv->hdr.datalen - monpriv->data_to_read;
258 if (copy_from_user(to, data + written, len)) {
259 rc = -EFAULT;
260 goto out_error;
261 }
262 monpriv->data_to_read -= len;
263 written += len;
264 if (monpriv->data_to_read > 0)
265 continue;
266 rc = monwrite_new_data(monpriv);
267 if (rc)
268 goto out_error;
269 }
270 monpriv->hdr_to_read = sizeof(monpriv->hdr);
271 }
272 mutex_unlock(&monpriv->thread_mutex);
273 return written;
274
275 out_error:
276 monpriv->data_to_read = 0;
277 monpriv->hdr_to_read = sizeof(struct monwrite_hdr);
278 mutex_unlock(&monpriv->thread_mutex);
279 return rc;
280 }
281
282 static const struct file_operations monwrite_fops = {
283 .owner = THIS_MODULE,
284 .open = &monwrite_open,
285 .release = &monwrite_close,
286 .write = &monwrite_write,
287 .llseek = noop_llseek,
288 };
289
290 static struct miscdevice mon_dev = {
291 .name = "monwriter",
292 .fops = &monwrite_fops,
293 .minor = MISC_DYNAMIC_MINOR,
294 };
295
296 /*
297 * suspend/resume
298 */
299
monwriter_freeze(struct device * dev)300 static int monwriter_freeze(struct device *dev)
301 {
302 struct mon_private *monpriv;
303 struct mon_buf *monbuf;
304
305 list_for_each_entry(monpriv, &mon_priv_list, priv_list) {
306 list_for_each_entry(monbuf, &monpriv->list, list) {
307 if (monbuf->hdr.mon_function != MONWRITE_GEN_EVENT)
308 monwrite_diag(&monbuf->hdr, monbuf->data,
309 APPLDATA_STOP_REC);
310 }
311 }
312 return 0;
313 }
314
monwriter_restore(struct device * dev)315 static int monwriter_restore(struct device *dev)
316 {
317 struct mon_private *monpriv;
318 struct mon_buf *monbuf;
319
320 list_for_each_entry(monpriv, &mon_priv_list, priv_list) {
321 list_for_each_entry(monbuf, &monpriv->list, list) {
322 if (monbuf->hdr.mon_function == MONWRITE_START_INTERVAL)
323 monwrite_diag(&monbuf->hdr, monbuf->data,
324 APPLDATA_START_INTERVAL_REC);
325 if (monbuf->hdr.mon_function == MONWRITE_START_CONFIG)
326 monwrite_diag(&monbuf->hdr, monbuf->data,
327 APPLDATA_START_CONFIG_REC);
328 }
329 }
330 return 0;
331 }
332
monwriter_thaw(struct device * dev)333 static int monwriter_thaw(struct device *dev)
334 {
335 return monwriter_restore(dev);
336 }
337
338 static const struct dev_pm_ops monwriter_pm_ops = {
339 .freeze = monwriter_freeze,
340 .thaw = monwriter_thaw,
341 .restore = monwriter_restore,
342 };
343
344 static struct platform_driver monwriter_pdrv = {
345 .driver = {
346 .name = "monwriter",
347 .pm = &monwriter_pm_ops,
348 },
349 };
350
351 static struct platform_device *monwriter_pdev;
352
353 /*
354 * module init/exit
355 */
356
mon_init(void)357 static int __init mon_init(void)
358 {
359 int rc;
360
361 if (!MACHINE_IS_VM)
362 return -ENODEV;
363
364 rc = platform_driver_register(&monwriter_pdrv);
365 if (rc)
366 return rc;
367
368 monwriter_pdev = platform_device_register_simple("monwriter", -1, NULL,
369 0);
370 if (IS_ERR(monwriter_pdev)) {
371 rc = PTR_ERR(monwriter_pdev);
372 goto out_driver;
373 }
374
375 /*
376 * misc_register() has to be the last action in module_init(), because
377 * file operations will be available right after this.
378 */
379 rc = misc_register(&mon_dev);
380 if (rc)
381 goto out_device;
382 return 0;
383
384 out_device:
385 platform_device_unregister(monwriter_pdev);
386 out_driver:
387 platform_driver_unregister(&monwriter_pdrv);
388 return rc;
389 }
390
mon_exit(void)391 static void __exit mon_exit(void)
392 {
393 misc_deregister(&mon_dev);
394 platform_device_unregister(monwriter_pdev);
395 platform_driver_unregister(&monwriter_pdrv);
396 }
397
398 module_init(mon_init);
399 module_exit(mon_exit);
400
401 module_param_named(max_bufs, mon_max_bufs, int, 0644);
402 MODULE_PARM_DESC(max_bufs, "Maximum number of sample monitor data buffers "
403 "that can be active at one time");
404
405 MODULE_AUTHOR("Melissa Howland <Melissa.Howland@us.ibm.com>");
406 MODULE_DESCRIPTION("Character device driver for writing z/VM "
407 "APPLDATA monitor records.");
408 MODULE_LICENSE("GPL");
409