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"); 397