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 <linux/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"); 399