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[karo-tx-linux.git] / drivers / s390 / char / monwriter.c
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
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         strncpy(id.prod_nr, "LNXAPPL", 7);
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
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
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 = 0;
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 rc;
139 }
140
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
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
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
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
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
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
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                 .pm     = &monwriter_pm_ops,
338         },
339 };
340
341 static struct platform_device *monwriter_pdev;
342
343 /*
344  * module init/exit
345  */
346
347 static int __init mon_init(void)
348 {
349         int rc;
350
351         if (!MACHINE_IS_VM)
352                 return -ENODEV;
353
354         rc = platform_driver_register(&monwriter_pdrv);
355         if (rc)
356                 return rc;
357
358         monwriter_pdev = platform_device_register_simple("monwriter", -1, NULL,
359                                                         0);
360         if (IS_ERR(monwriter_pdev)) {
361                 rc = PTR_ERR(monwriter_pdev);
362                 goto out_driver;
363         }
364
365         /*
366          * misc_register() has to be the last action in module_init(), because
367          * file operations will be available right after this.
368          */
369         rc = misc_register(&mon_dev);
370         if (rc)
371                 goto out_device;
372         return 0;
373
374 out_device:
375         platform_device_unregister(monwriter_pdev);
376 out_driver:
377         platform_driver_unregister(&monwriter_pdrv);
378         return rc;
379 }
380
381 static void __exit mon_exit(void)
382 {
383         misc_deregister(&mon_dev);
384         platform_device_unregister(monwriter_pdev);
385         platform_driver_unregister(&monwriter_pdrv);
386 }
387
388 module_init(mon_init);
389 module_exit(mon_exit);
390
391 module_param_named(max_bufs, mon_max_bufs, int, 0644);
392 MODULE_PARM_DESC(max_bufs, "Maximum number of sample monitor data buffers "
393                  "that can be active at one time");
394
395 MODULE_AUTHOR("Melissa Howland <Melissa.Howland@us.ibm.com>");
396 MODULE_DESCRIPTION("Character device driver for writing z/VM "
397                    "APPLDATA monitor records.");
398 MODULE_LICENSE("GPL");