Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6
[linux-2.6] / drivers / s390 / char / monwriter.c
1 /*
2  * drivers/s390/char/monwriter.c
3  *
4  * Character device driver for writing z/VM *MONITOR service records.
5  *
6  * Copyright (C) IBM Corp. 2006
7  *
8  * Author(s): Melissa Howland <Melissa.Howland@us.ibm.com>
9  */
10
11 #include <linux/module.h>
12 #include <linux/moduleparam.h>
13 #include <linux/init.h>
14 #include <linux/errno.h>
15 #include <linux/types.h>
16 #include <linux/kernel.h>
17 #include <linux/miscdevice.h>
18 #include <linux/ctype.h>
19 #include <linux/poll.h>
20 #include <asm/uaccess.h>
21 #include <asm/ebcdic.h>
22 #include <asm/io.h>
23 #include <asm/appldata.h>
24 #include <asm/monwriter.h>
25
26 #define MONWRITE_MAX_DATALEN    4024
27
28 static int mon_max_bufs = 255;
29
30 struct mon_buf {
31         struct list_head list;
32         struct monwrite_hdr hdr;
33         int diag_done;
34         char *data;
35 };
36
37 struct mon_private {
38         struct list_head list;
39         struct monwrite_hdr hdr;
40         size_t hdr_to_read;
41         size_t data_to_read;
42         struct mon_buf *current_buf;
43         int mon_buf_count;
44 };
45
46 /*
47  * helper functions
48  */
49
50 static int monwrite_diag(struct monwrite_hdr *myhdr, char *buffer, int fcn)
51 {
52         struct appldata_product_id id;
53         int rc;
54
55         strcpy(id.prod_nr, "LNXAPPL");
56         id.prod_fn = myhdr->applid;
57         id.record_nr = myhdr->record_num;
58         id.version_nr = myhdr->version;
59         id.release_nr = myhdr->release;
60         id.mod_lvl = myhdr->mod_level;
61         rc = appldata_asm(&id, fcn, (void *) buffer, myhdr->datalen);
62         if (rc <= 0)
63                 return rc;
64         if (rc == 5)
65                 return -EPERM;
66         printk("DIAG X'DC' error with return code: %i\n", rc);
67         return -EINVAL;
68 }
69
70 static inline struct mon_buf *monwrite_find_hdr(struct mon_private *monpriv,
71                                                 struct monwrite_hdr *monhdr)
72 {
73         struct mon_buf *entry, *next;
74
75         list_for_each_entry_safe(entry, next, &monpriv->list, list)
76                 if (entry->hdr.applid == monhdr->applid &&
77                     entry->hdr.record_num == monhdr->record_num &&
78                     entry->hdr.version == monhdr->version &&
79                     entry->hdr.release == monhdr->release &&
80                     entry->hdr.mod_level == monhdr->mod_level)
81                         return entry;
82         return NULL;
83 }
84
85 static int monwrite_new_hdr(struct mon_private *monpriv)
86 {
87         struct monwrite_hdr *monhdr = &monpriv->hdr;
88         struct mon_buf *monbuf;
89         int rc;
90
91         if (monhdr->datalen > MONWRITE_MAX_DATALEN ||
92             monhdr->mon_function > MONWRITE_START_CONFIG ||
93             monhdr->hdrlen != sizeof(struct monwrite_hdr))
94                 return -EINVAL;
95         monbuf = monwrite_find_hdr(monpriv, monhdr);
96         if (monbuf) {
97                 if (monhdr->mon_function == MONWRITE_STOP_INTERVAL) {
98                         monhdr->datalen = monbuf->hdr.datalen;
99                         rc = monwrite_diag(monhdr, monbuf->data,
100                                            APPLDATA_STOP_REC);
101                         list_del(&monbuf->list);
102                         monpriv->mon_buf_count--;
103                         kfree(monbuf->data);
104                         kfree(monbuf);
105                         monbuf = NULL;
106                 }
107         } else {
108                 if (monpriv->mon_buf_count >= mon_max_bufs)
109                         return -ENOSPC;
110                 monbuf = kzalloc(sizeof(struct mon_buf), GFP_KERNEL);
111                 if (!monbuf)
112                         return -ENOMEM;
113                 monbuf->data = kzalloc(monbuf->hdr.datalen,
114                                        GFP_KERNEL | GFP_DMA);
115                 if (!monbuf->data) {
116                         kfree(monbuf);
117                         return -ENOMEM;
118                 }
119                 monbuf->hdr = *monhdr;
120                 list_add_tail(&monbuf->list, &monpriv->list);
121                 monpriv->mon_buf_count++;
122         }
123         monpriv->current_buf = monbuf;
124         return 0;
125 }
126
127 static int monwrite_new_data(struct mon_private *monpriv)
128 {
129         struct monwrite_hdr *monhdr = &monpriv->hdr;
130         struct mon_buf *monbuf = monpriv->current_buf;
131         int rc = 0;
132
133         switch (monhdr->mon_function) {
134         case MONWRITE_START_INTERVAL:
135                 if (!monbuf->diag_done) {
136                         rc = monwrite_diag(monhdr, monbuf->data,
137                                            APPLDATA_START_INTERVAL_REC);
138                         monbuf->diag_done = 1;
139                 }
140                 break;
141         case MONWRITE_START_CONFIG:
142                 if (!monbuf->diag_done) {
143                         rc = monwrite_diag(monhdr, monbuf->data,
144                                            APPLDATA_START_CONFIG_REC);
145                         monbuf->diag_done = 1;
146                 }
147                 break;
148         case MONWRITE_GEN_EVENT:
149                 rc = monwrite_diag(monhdr, monbuf->data,
150                                    APPLDATA_GEN_EVENT_REC);
151                 list_del(&monpriv->current_buf->list);
152                 kfree(monpriv->current_buf->data);
153                 kfree(monpriv->current_buf);
154                 monpriv->current_buf = NULL;
155                 break;
156         default:
157                 /* monhdr->mon_function is checked in monwrite_new_hdr */
158                 BUG();
159         }
160         return rc;
161 }
162
163 /*
164  * file operations
165  */
166
167 static int monwrite_open(struct inode *inode, struct file *filp)
168 {
169         struct mon_private *monpriv;
170
171         monpriv = kzalloc(sizeof(struct mon_private), GFP_KERNEL);
172         if (!monpriv)
173                 return -ENOMEM;
174         INIT_LIST_HEAD(&monpriv->list);
175         monpriv->hdr_to_read = sizeof(monpriv->hdr);
176         filp->private_data = monpriv;
177         return nonseekable_open(inode, filp);
178 }
179
180 static int monwrite_close(struct inode *inode, struct file *filp)
181 {
182         struct mon_private *monpriv = filp->private_data;
183         struct mon_buf *entry, *next;
184
185         list_for_each_entry_safe(entry, next, &monpriv->list, list) {
186                 if (entry->hdr.mon_function != MONWRITE_GEN_EVENT)
187                         monwrite_diag(&entry->hdr, entry->data,
188                                       APPLDATA_STOP_REC);
189                 monpriv->mon_buf_count--;
190                 list_del(&entry->list);
191                 kfree(entry->data);
192                 kfree(entry);
193         }
194         kfree(monpriv);
195         return 0;
196 }
197
198 static ssize_t monwrite_write(struct file *filp, const char __user *data,
199                               size_t count, loff_t *ppos)
200 {
201         struct mon_private *monpriv = filp->private_data;
202         size_t len, written;
203         void *to;
204         int rc;
205
206         for (written = 0; written < count; ) {
207                 if (monpriv->hdr_to_read) {
208                         len = min(count - written, monpriv->hdr_to_read);
209                         to = (char *) &monpriv->hdr +
210                                 sizeof(monpriv->hdr) - monpriv->hdr_to_read;
211                         if (copy_from_user(to, data + written, len)) {
212                                 rc = -EFAULT;
213                                 goto out_error;
214                         }
215                         monpriv->hdr_to_read -= len;
216                         written += len;
217                         if (monpriv->hdr_to_read > 0)
218                                 continue;
219                         rc = monwrite_new_hdr(monpriv);
220                         if (rc)
221                                 goto out_error;
222                         monpriv->data_to_read = monpriv->current_buf ?
223                                 monpriv->current_buf->hdr.datalen : 0;
224                 }
225
226                 if (monpriv->data_to_read) {
227                         len = min(count - written, monpriv->data_to_read);
228                         to = monpriv->current_buf->data +
229                                 monpriv->hdr.datalen - monpriv->data_to_read;
230                         if (copy_from_user(to, data + written, len)) {
231                                 rc = -EFAULT;
232                                 goto out_error;
233                         }
234                         monpriv->data_to_read -= len;
235                         written += len;
236                         if (monpriv->data_to_read > 0)
237                                 continue;
238                         rc = monwrite_new_data(monpriv);
239                         if (rc)
240                                 goto out_error;
241                 }
242                 monpriv->hdr_to_read = sizeof(monpriv->hdr);
243         }
244         return written;
245
246 out_error:
247         monpriv->data_to_read = 0;
248         monpriv->hdr_to_read = sizeof(struct monwrite_hdr);
249         return rc;
250 }
251
252 static struct file_operations monwrite_fops = {
253         .owner   = THIS_MODULE,
254         .open    = &monwrite_open,
255         .release = &monwrite_close,
256         .write   = &monwrite_write,
257 };
258
259 static struct miscdevice mon_dev = {
260         .name   = "monwriter",
261         .fops   = &monwrite_fops,
262         .minor  = MISC_DYNAMIC_MINOR,
263 };
264
265 /*
266  * module init/exit
267  */
268
269 static int __init mon_init(void)
270 {
271         if (MACHINE_IS_VM)
272                 return misc_register(&mon_dev);
273         else
274                 return -ENODEV;
275 }
276
277 static void __exit mon_exit(void)
278 {
279         WARN_ON(misc_deregister(&mon_dev) != 0);
280 }
281
282 module_init(mon_init);
283 module_exit(mon_exit);
284
285 module_param_named(max_bufs, mon_max_bufs, int, 0644);
286 MODULE_PARM_DESC(max_bufs, "Maximum number of sample monitor data buffers"
287                  "that can be active at one time");
288
289 MODULE_AUTHOR("Melissa Howland <Melissa.Howland@us.ibm.com>");
290 MODULE_DESCRIPTION("Character device driver for writing z/VM "
291                    "APPLDATA monitor records.");
292 MODULE_LICENSE("GPL");