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