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/smp_lock.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 <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         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
  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;
 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
 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         lock_kernel();
 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         unlock_kernel();
 195         return nonseekable_open(inode, filp);
 196 }
 197
 198 static int monwrite_close(struct inode *inode, struct file *filp)
 199 {
 200         struct mon_private *monpriv = filp->private_data;
 201         struct mon_buf *entry, *next;
 202
 203         list_for_each_entry_safe(entry, next, &monpriv->list, list) {
 204                 if (entry->hdr.mon_function != MONWRITE_GEN_EVENT)
 205                         monwrite_diag(&entry->hdr, entry->data,
 206                                       APPLDATA_STOP_REC);
 207                 mon_buf_count--;
 208                 list_del(&entry->list);
 209                 kfree(entry->data);
 210                 kfree(entry);
 211         }
 212         list_del(&monpriv->priv_list);
 213         kfree(monpriv);
 214         return 0;
 215 }
 216
 217 static ssize_t monwrite_write(struct file *filp, const char __user *data,
 218                               size_t count, loff_t *ppos)
 219 {
 220         struct mon_private *monpriv = filp->private_data;
 221         size_t len, written;
 222         void *to;
 223         int rc;
 224
 225         mutex_lock(&monpriv->thread_mutex);
 226         for (written = 0; written < count; ) {
 227                 if (monpriv->hdr_to_read) {
 228                         len = min(count - written, monpriv->hdr_to_read);
 229                         to = (char *) &monpriv->hdr +
 230                                 sizeof(monpriv->hdr) - monpriv->hdr_to_read;
 231                         if (copy_from_user(to, data + written, len)) {
 232                                 rc = -EFAULT;
 233                                 goto out_error;
 234                         }
 235                         monpriv->hdr_to_read -= len;
 236                         written += len;
 237                         if (monpriv->hdr_to_read > 0)
 238                                 continue;
 239                         rc = monwrite_new_hdr(monpriv);
 240                         if (rc)
 241                                 goto out_error;
 242                         monpriv->data_to_read = monpriv->current_buf ?
 243                                 monpriv->current_buf->hdr.datalen : 0;
 244                 }
 245
 246                 if (monpriv->data_to_read) {
 247                         len = min(count - written, monpriv->data_to_read);
 248                         to = monpriv->current_buf->data +
 249                                 monpriv->hdr.datalen - monpriv->data_to_read;
 250                         if (copy_from_user(to, data + written, len)) {
 251                                 rc = -EFAULT;
 252                                 goto out_error;
 253                         }
 254                         monpriv->data_to_read -= len;
 255                         written += len;
 256                         if (monpriv->data_to_read > 0)
 257                                 continue;
 258                         rc = monwrite_new_data(monpriv);
 259                         if (rc)
 260                                 goto out_error;
 261                 }
 262                 monpriv->hdr_to_read = sizeof(monpriv->hdr);
 263         }
 264         mutex_unlock(&monpriv->thread_mutex);
 265         return written;
 266
 267 out_error:
 268         monpriv->data_to_read = 0;
 269         monpriv->hdr_to_read = sizeof(struct monwrite_hdr);
 270         mutex_unlock(&monpriv->thread_mutex);
 271         return rc;
 272 }
 273
 274 static const struct file_operations monwrite_fops = {
 275         .owner   = THIS_MODULE,
 276         .open    = &monwrite_open,
 277         .release = &monwrite_close,
 278         .write   = &monwrite_write,
 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
 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
 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
 324 static int monwriter_thaw(struct device *dev)
 325 {
 326         return monwriter_restore(dev);
 327 }
 328
 329 static 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                 .owner  = THIS_MODULE,
 339                 .pm     = &monwriter_pm_ops,
 340         },
 341 };
 342
 343 static struct platform_device *monwriter_pdev;
 344
 345 /*
 346  * module init/exit
 347  */
 348
 349 static int __init mon_init(void)
 350 {
 351         int rc;
 352
 353         if (!MACHINE_IS_VM)
 354                 return -ENODEV;
 355
 356         rc = platform_driver_register(&monwriter_pdrv);
 357         if (rc)
 358                 return rc;
 359
 360         monwriter_pdev = platform_device_register_simple("monwriter", -1, NULL,
 361                                                         0);
 362         if (IS_ERR(monwriter_pdev)) {
 363                 rc = PTR_ERR(monwriter_pdev);
 364                 goto out_driver;
 365         }
 366
 367         rc = misc_register(&mon_dev);
 368         if (rc)
 369                 goto out_device;
 370         return 0;
 371
 372 out_device:
 373         platform_device_unregister(monwriter_pdev);
 374 out_driver:
 375         platform_driver_unregister(&monwriter_pdrv);
 376         return rc;
 377 }
 378
 379 static void __exit mon_exit(void)
 380 {
 381         WARN_ON(misc_deregister(&mon_dev) != 0);
 382         platform_device_unregister(monwriter_pdev);
 383         platform_driver_unregister(&monwriter_pdrv);
 384 }
 385
 386 module_init(mon_init);
 387 module_exit(mon_exit);
 388
 389 module_param_named(max_bufs, mon_max_bufs, int, 0644);
 390 MODULE_PARM_DESC(max_bufs, "Maximum number of sample monitor data buffers "
 391                  "that can be active at one time");
 392
 393 MODULE_AUTHOR("Melissa Howland <Melissa.Howland@us.ibm.com>");
 394 MODULE_DESCRIPTION("Character device driver for writing z/VM "
 395                    "APPLDATA monitor records.");
 396 MODULE_LICENSE("GPL");