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 <asm/uaccess.h> 24 #include <asm/ebcdic.h> 25 #include <asm/io.h> 26 #include <asm/appldata.h> 27 #include <asm/monwriter.h> 28 29 #define MONWRITE_MAX_DATALEN 4010 30 31 static int mon_max_bufs = 255; 32 static int mon_buf_count; 33 34 struct mon_buf { 35 struct list_head list; 36 struct monwrite_hdr hdr; 37 int diag_done; 38 char *data; 39 }; 40 41 static LIST_HEAD(mon_priv_list); 42 43 struct mon_private { 44 struct list_head priv_list; 45 struct list_head list; 46 struct monwrite_hdr hdr; 47 size_t hdr_to_read; 48 size_t data_to_read; 49 struct mon_buf *current_buf; 50 struct mutex thread_mutex; 51 }; 52 53 /* 54 * helper functions 55 */ 56 57 static int monwrite_diag(struct monwrite_hdr *myhdr, char *buffer, int fcn) 58 { 59 struct appldata_product_id id; 60 int rc; 61 62 strcpy(id.prod_nr, "LNXAPPL"); 63 id.prod_fn = myhdr->applid; 64 id.record_nr = myhdr->record_num; 65 id.version_nr = myhdr->version; 66 id.release_nr = myhdr->release; 67 id.mod_lvl = myhdr->mod_level; 68 rc = appldata_asm(&id, fcn, (void *) buffer, myhdr->datalen); 69 if (rc <= 0) 70 return rc; 71 pr_err("Writing monitor data failed with rc=%i\n", rc); 72 if (rc == 5) 73 return -EPERM; 74 return -EINVAL; 75 } 76 77 static struct mon_buf *monwrite_find_hdr(struct mon_private *monpriv, 78 struct monwrite_hdr *monhdr) 79 { 80 struct mon_buf *entry, *next; 81 82 list_for_each_entry_safe(entry, next, &monpriv->list, list) 83 if ((entry->hdr.mon_function == monhdr->mon_function || 84 monhdr->mon_function == MONWRITE_STOP_INTERVAL) && 85 entry->hdr.applid == monhdr->applid && 86 entry->hdr.record_num == monhdr->record_num && 87 entry->hdr.version == monhdr->version && 88 entry->hdr.release == monhdr->release && 89 entry->hdr.mod_level == monhdr->mod_level) 90 return entry; 91 92 return NULL; 93 } 94 95 static int monwrite_new_hdr(struct mon_private *monpriv) 96 { 97 struct monwrite_hdr *monhdr = &monpriv->hdr; 98 struct mon_buf *monbuf; 99 int rc; 100 101 if (monhdr->datalen > MONWRITE_MAX_DATALEN || 102 monhdr->mon_function > MONWRITE_START_CONFIG || 103 monhdr->hdrlen != sizeof(struct monwrite_hdr)) 104 return -EINVAL; 105 monbuf = NULL; 106 if (monhdr->mon_function != MONWRITE_GEN_EVENT) 107 monbuf = monwrite_find_hdr(monpriv, monhdr); 108 if (monbuf) { 109 if (monhdr->mon_function == MONWRITE_STOP_INTERVAL) { 110 monhdr->datalen = monbuf->hdr.datalen; 111 rc = monwrite_diag(monhdr, monbuf->data, 112 APPLDATA_STOP_REC); 113 list_del(&monbuf->list); 114 mon_buf_count--; 115 kfree(monbuf->data); 116 kfree(monbuf); 117 monbuf = NULL; 118 } 119 } else if (monhdr->mon_function != MONWRITE_STOP_INTERVAL) { 120 if (mon_buf_count >= mon_max_bufs) 121 return -ENOSPC; 122 monbuf = kzalloc(sizeof(struct mon_buf), GFP_KERNEL); 123 if (!monbuf) 124 return -ENOMEM; 125 monbuf->data = kzalloc(monhdr->datalen, 126 GFP_KERNEL | GFP_DMA); 127 if (!monbuf->data) { 128 kfree(monbuf); 129 return -ENOMEM; 130 } 131 monbuf->hdr = *monhdr; 132 list_add_tail(&monbuf->list, &monpriv->list); 133 if (monhdr->mon_function != MONWRITE_GEN_EVENT) 134 mon_buf_count++; 135 } 136 monpriv->current_buf = monbuf; 137 return 0; 138 } 139 140 static int monwrite_new_data(struct mon_private *monpriv) 141 { 142 struct monwrite_hdr *monhdr = &monpriv->hdr; 143 struct mon_buf *monbuf = monpriv->current_buf; 144 int rc = 0; 145 146 switch (monhdr->mon_function) { 147 case MONWRITE_START_INTERVAL: 148 if (!monbuf->diag_done) { 149 rc = monwrite_diag(monhdr, monbuf->data, 150 APPLDATA_START_INTERVAL_REC); 151 monbuf->diag_done = 1; 152 } 153 break; 154 case MONWRITE_START_CONFIG: 155 if (!monbuf->diag_done) { 156 rc = monwrite_diag(monhdr, monbuf->data, 157 APPLDATA_START_CONFIG_REC); 158 monbuf->diag_done = 1; 159 } 160 break; 161 case MONWRITE_GEN_EVENT: 162 rc = monwrite_diag(monhdr, monbuf->data, 163 APPLDATA_GEN_EVENT_REC); 164 list_del(&monpriv->current_buf->list); 165 kfree(monpriv->current_buf->data); 166 kfree(monpriv->current_buf); 167 monpriv->current_buf = NULL; 168 break; 169 default: 170 /* monhdr->mon_function is checked in monwrite_new_hdr */ 171 BUG(); 172 } 173 return rc; 174 } 175 176 /* 177 * file operations 178 */ 179 180 static int monwrite_open(struct inode *inode, struct file *filp) 181 { 182 struct mon_private *monpriv; 183 184 monpriv = kzalloc(sizeof(struct mon_private), GFP_KERNEL); 185 if (!monpriv) 186 return -ENOMEM; 187 INIT_LIST_HEAD(&monpriv->list); 188 monpriv->hdr_to_read = sizeof(monpriv->hdr); 189 mutex_init(&monpriv->thread_mutex); 190 filp->private_data = monpriv; 191 list_add_tail(&monpriv->priv_list, &mon_priv_list); 192 return nonseekable_open(inode, filp); 193 } 194 195 static int monwrite_close(struct inode *inode, struct file *filp) 196 { 197 struct mon_private *monpriv = filp->private_data; 198 struct mon_buf *entry, *next; 199 200 list_for_each_entry_safe(entry, next, &monpriv->list, list) { 201 if (entry->hdr.mon_function != MONWRITE_GEN_EVENT) 202 monwrite_diag(&entry->hdr, entry->data, 203 APPLDATA_STOP_REC); 204 mon_buf_count--; 205 list_del(&entry->list); 206 kfree(entry->data); 207 kfree(entry); 208 } 209 list_del(&monpriv->priv_list); 210 kfree(monpriv); 211 return 0; 212 } 213 214 static ssize_t monwrite_write(struct file *filp, const char __user *data, 215 size_t count, loff_t *ppos) 216 { 217 struct mon_private *monpriv = filp->private_data; 218 size_t len, written; 219 void *to; 220 int rc; 221 222 mutex_lock(&monpriv->thread_mutex); 223 for (written = 0; written < count; ) { 224 if (monpriv->hdr_to_read) { 225 len = min(count - written, monpriv->hdr_to_read); 226 to = (char *) &monpriv->hdr + 227 sizeof(monpriv->hdr) - monpriv->hdr_to_read; 228 if (copy_from_user(to, data + written, len)) { 229 rc = -EFAULT; 230 goto out_error; 231 } 232 monpriv->hdr_to_read -= len; 233 written += len; 234 if (monpriv->hdr_to_read > 0) 235 continue; 236 rc = monwrite_new_hdr(monpriv); 237 if (rc) 238 goto out_error; 239 monpriv->data_to_read = monpriv->current_buf ? 240 monpriv->current_buf->hdr.datalen : 0; 241 } 242 243 if (monpriv->data_to_read) { 244 len = min(count - written, monpriv->data_to_read); 245 to = monpriv->current_buf->data + 246 monpriv->hdr.datalen - monpriv->data_to_read; 247 if (copy_from_user(to, data + written, len)) { 248 rc = -EFAULT; 249 goto out_error; 250 } 251 monpriv->data_to_read -= len; 252 written += len; 253 if (monpriv->data_to_read > 0) 254 continue; 255 rc = monwrite_new_data(monpriv); 256 if (rc) 257 goto out_error; 258 } 259 monpriv->hdr_to_read = sizeof(monpriv->hdr); 260 } 261 mutex_unlock(&monpriv->thread_mutex); 262 return written; 263 264 out_error: 265 monpriv->data_to_read = 0; 266 monpriv->hdr_to_read = sizeof(struct monwrite_hdr); 267 mutex_unlock(&monpriv->thread_mutex); 268 return rc; 269 } 270 271 static const struct file_operations monwrite_fops = { 272 .owner = THIS_MODULE, 273 .open = &monwrite_open, 274 .release = &monwrite_close, 275 .write = &monwrite_write, 276 }; 277 278 static struct miscdevice mon_dev = { 279 .name = "monwriter", 280 .fops = &monwrite_fops, 281 .minor = MISC_DYNAMIC_MINOR, 282 }; 283 284 /* 285 * suspend/resume 286 */ 287 288 static int monwriter_freeze(struct device *dev) 289 { 290 struct mon_private *monpriv; 291 struct mon_buf *monbuf; 292 293 list_for_each_entry(monpriv, &mon_priv_list, priv_list) { 294 list_for_each_entry(monbuf, &monpriv->list, list) { 295 if (monbuf->hdr.mon_function != MONWRITE_GEN_EVENT) 296 monwrite_diag(&monbuf->hdr, monbuf->data, 297 APPLDATA_STOP_REC); 298 } 299 } 300 return 0; 301 } 302 303 static int monwriter_restore(struct device *dev) 304 { 305 struct mon_private *monpriv; 306 struct mon_buf *monbuf; 307 308 list_for_each_entry(monpriv, &mon_priv_list, priv_list) { 309 list_for_each_entry(monbuf, &monpriv->list, list) { 310 if (monbuf->hdr.mon_function == MONWRITE_START_INTERVAL) 311 monwrite_diag(&monbuf->hdr, monbuf->data, 312 APPLDATA_START_INTERVAL_REC); 313 if (monbuf->hdr.mon_function == MONWRITE_START_CONFIG) 314 monwrite_diag(&monbuf->hdr, monbuf->data, 315 APPLDATA_START_CONFIG_REC); 316 } 317 } 318 return 0; 319 } 320 321 static int monwriter_thaw(struct device *dev) 322 { 323 return monwriter_restore(dev); 324 } 325 326 static const struct dev_pm_ops monwriter_pm_ops = { 327 .freeze = monwriter_freeze, 328 .thaw = monwriter_thaw, 329 .restore = monwriter_restore, 330 }; 331 332 static struct platform_driver monwriter_pdrv = { 333 .driver = { 334 .name = "monwriter", 335 .owner = THIS_MODULE, 336 .pm = &monwriter_pm_ops, 337 }, 338 }; 339 340 static struct platform_device *monwriter_pdev; 341 342 /* 343 * module init/exit 344 */ 345 346 static int __init mon_init(void) 347 { 348 int rc; 349 350 if (!MACHINE_IS_VM) 351 return -ENODEV; 352 353 rc = platform_driver_register(&monwriter_pdrv); 354 if (rc) 355 return rc; 356 357 monwriter_pdev = platform_device_register_simple("monwriter", -1, NULL, 358 0); 359 if (IS_ERR(monwriter_pdev)) { 360 rc = PTR_ERR(monwriter_pdev); 361 goto out_driver; 362 } 363 364 /* 365 * misc_register() has to be the last action in module_init(), because 366 * file operations will be available right after this. 367 */ 368 rc = misc_register(&mon_dev); 369 if (rc) 370 goto out_device; 371 return 0; 372 373 out_device: 374 platform_device_unregister(monwriter_pdev); 375 out_driver: 376 platform_driver_unregister(&monwriter_pdrv); 377 return rc; 378 } 379 380 static void __exit mon_exit(void) 381 { 382 WARN_ON(misc_deregister(&mon_dev) != 0); 383 platform_device_unregister(monwriter_pdev); 384 platform_driver_unregister(&monwriter_pdrv); 385 } 386 387 module_init(mon_init); 388 module_exit(mon_exit); 389 390 module_param_named(max_bufs, mon_max_bufs, int, 0644); 391 MODULE_PARM_DESC(max_bufs, "Maximum number of sample monitor data buffers " 392 "that can be active at one time"); 393 394 MODULE_AUTHOR("Melissa Howland <Melissa.Howland@us.ibm.com>"); 395 MODULE_DESCRIPTION("Character device driver for writing z/VM " 396 "APPLDATA monitor records."); 397 MODULE_LICENSE("GPL"); 398