1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Character device driver for writing z/VM *MONITOR service records. 4 * 5 * Copyright IBM Corp. 2006, 2009 6 * 7 * Author(s): Melissa Howland <Melissa.Howland@us.ibm.com> 8 */ 9 10 #define KMSG_COMPONENT "monwriter" 11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 12 13 #include <linux/module.h> 14 #include <linux/moduleparam.h> 15 #include <linux/init.h> 16 #include <linux/errno.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 <linux/slab.h> 25 #include <linux/uaccess.h> 26 #include <asm/ebcdic.h> 27 #include <asm/io.h> 28 #include <asm/appldata.h> 29 #include <asm/monwriter.h> 30 31 #define MONWRITE_MAX_DATALEN 4010 32 33 static int mon_max_bufs = 255; 34 static int mon_buf_count; 35 36 struct mon_buf { 37 struct list_head list; 38 struct monwrite_hdr hdr; 39 int diag_done; 40 char *data; 41 }; 42 43 static LIST_HEAD(mon_priv_list); 44 45 struct mon_private { 46 struct list_head priv_list; 47 struct list_head list; 48 struct monwrite_hdr hdr; 49 size_t hdr_to_read; 50 size_t data_to_read; 51 struct mon_buf *current_buf; 52 struct mutex thread_mutex; 53 }; 54 55 /* 56 * helper functions 57 */ 58 59 static int monwrite_diag(struct monwrite_hdr *myhdr, char *buffer, int fcn) 60 { 61 struct appldata_product_id id; 62 int rc; 63 64 strncpy(id.prod_nr, "LNXAPPL", 7); 65 id.prod_fn = myhdr->applid; 66 id.record_nr = myhdr->record_num; 67 id.version_nr = myhdr->version; 68 id.release_nr = myhdr->release; 69 id.mod_lvl = myhdr->mod_level; 70 rc = appldata_asm(&id, fcn, (void *) buffer, myhdr->datalen); 71 if (rc <= 0) 72 return rc; 73 pr_err("Writing monitor data failed with rc=%i\n", rc); 74 if (rc == 5) 75 return -EPERM; 76 return -EINVAL; 77 } 78 79 static struct mon_buf *monwrite_find_hdr(struct mon_private *monpriv, 80 struct monwrite_hdr *monhdr) 81 { 82 struct mon_buf *entry, *next; 83 84 list_for_each_entry_safe(entry, next, &monpriv->list, list) 85 if ((entry->hdr.mon_function == monhdr->mon_function || 86 monhdr->mon_function == MONWRITE_STOP_INTERVAL) && 87 entry->hdr.applid == monhdr->applid && 88 entry->hdr.record_num == monhdr->record_num && 89 entry->hdr.version == monhdr->version && 90 entry->hdr.release == monhdr->release && 91 entry->hdr.mod_level == monhdr->mod_level) 92 return entry; 93 94 return NULL; 95 } 96 97 static int monwrite_new_hdr(struct mon_private *monpriv) 98 { 99 struct monwrite_hdr *monhdr = &monpriv->hdr; 100 struct mon_buf *monbuf; 101 int rc = 0; 102 103 if (monhdr->datalen > MONWRITE_MAX_DATALEN || 104 monhdr->mon_function > MONWRITE_START_CONFIG || 105 monhdr->hdrlen != sizeof(struct monwrite_hdr)) 106 return -EINVAL; 107 monbuf = NULL; 108 if (monhdr->mon_function != MONWRITE_GEN_EVENT) 109 monbuf = monwrite_find_hdr(monpriv, monhdr); 110 if (monbuf) { 111 if (monhdr->mon_function == MONWRITE_STOP_INTERVAL) { 112 monhdr->datalen = monbuf->hdr.datalen; 113 rc = monwrite_diag(monhdr, monbuf->data, 114 APPLDATA_STOP_REC); 115 list_del(&monbuf->list); 116 mon_buf_count--; 117 kfree(monbuf->data); 118 kfree(monbuf); 119 monbuf = NULL; 120 } 121 } else if (monhdr->mon_function != MONWRITE_STOP_INTERVAL) { 122 if (mon_buf_count >= mon_max_bufs) 123 return -ENOSPC; 124 monbuf = kzalloc(sizeof(struct mon_buf), GFP_KERNEL); 125 if (!monbuf) 126 return -ENOMEM; 127 monbuf->data = kzalloc(monhdr->datalen, 128 GFP_KERNEL | GFP_DMA); 129 if (!monbuf->data) { 130 kfree(monbuf); 131 return -ENOMEM; 132 } 133 monbuf->hdr = *monhdr; 134 list_add_tail(&monbuf->list, &monpriv->list); 135 if (monhdr->mon_function != MONWRITE_GEN_EVENT) 136 mon_buf_count++; 137 } 138 monpriv->current_buf = monbuf; 139 return rc; 140 } 141 142 static int monwrite_new_data(struct mon_private *monpriv) 143 { 144 struct monwrite_hdr *monhdr = &monpriv->hdr; 145 struct mon_buf *monbuf = monpriv->current_buf; 146 int rc = 0; 147 148 switch (monhdr->mon_function) { 149 case MONWRITE_START_INTERVAL: 150 if (!monbuf->diag_done) { 151 rc = monwrite_diag(monhdr, monbuf->data, 152 APPLDATA_START_INTERVAL_REC); 153 monbuf->diag_done = 1; 154 } 155 break; 156 case MONWRITE_START_CONFIG: 157 if (!monbuf->diag_done) { 158 rc = monwrite_diag(monhdr, monbuf->data, 159 APPLDATA_START_CONFIG_REC); 160 monbuf->diag_done = 1; 161 } 162 break; 163 case MONWRITE_GEN_EVENT: 164 rc = monwrite_diag(monhdr, monbuf->data, 165 APPLDATA_GEN_EVENT_REC); 166 list_del(&monpriv->current_buf->list); 167 kfree(monpriv->current_buf->data); 168 kfree(monpriv->current_buf); 169 monpriv->current_buf = NULL; 170 break; 171 default: 172 /* monhdr->mon_function is checked in monwrite_new_hdr */ 173 BUG(); 174 } 175 return rc; 176 } 177 178 /* 179 * file operations 180 */ 181 182 static int monwrite_open(struct inode *inode, struct file *filp) 183 { 184 struct mon_private *monpriv; 185 186 monpriv = kzalloc(sizeof(struct mon_private), GFP_KERNEL); 187 if (!monpriv) 188 return -ENOMEM; 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 return nonseekable_open(inode, filp); 195 } 196 197 static int monwrite_close(struct inode *inode, struct file *filp) 198 { 199 struct mon_private *monpriv = filp->private_data; 200 struct mon_buf *entry, *next; 201 202 list_for_each_entry_safe(entry, next, &monpriv->list, list) { 203 if (entry->hdr.mon_function != MONWRITE_GEN_EVENT) 204 monwrite_diag(&entry->hdr, entry->data, 205 APPLDATA_STOP_REC); 206 mon_buf_count--; 207 list_del(&entry->list); 208 kfree(entry->data); 209 kfree(entry); 210 } 211 list_del(&monpriv->priv_list); 212 kfree(monpriv); 213 return 0; 214 } 215 216 static ssize_t monwrite_write(struct file *filp, const char __user *data, 217 size_t count, loff_t *ppos) 218 { 219 struct mon_private *monpriv = filp->private_data; 220 size_t len, written; 221 void *to; 222 int rc; 223 224 mutex_lock(&monpriv->thread_mutex); 225 for (written = 0; written < count; ) { 226 if (monpriv->hdr_to_read) { 227 len = min(count - written, monpriv->hdr_to_read); 228 to = (char *) &monpriv->hdr + 229 sizeof(monpriv->hdr) - monpriv->hdr_to_read; 230 if (copy_from_user(to, data + written, len)) { 231 rc = -EFAULT; 232 goto out_error; 233 } 234 monpriv->hdr_to_read -= len; 235 written += len; 236 if (monpriv->hdr_to_read > 0) 237 continue; 238 rc = monwrite_new_hdr(monpriv); 239 if (rc) 240 goto out_error; 241 monpriv->data_to_read = monpriv->current_buf ? 242 monpriv->current_buf->hdr.datalen : 0; 243 } 244 245 if (monpriv->data_to_read) { 246 len = min(count - written, monpriv->data_to_read); 247 to = monpriv->current_buf->data + 248 monpriv->hdr.datalen - monpriv->data_to_read; 249 if (copy_from_user(to, data + written, len)) { 250 rc = -EFAULT; 251 goto out_error; 252 } 253 monpriv->data_to_read -= len; 254 written += len; 255 if (monpriv->data_to_read > 0) 256 continue; 257 rc = monwrite_new_data(monpriv); 258 if (rc) 259 goto out_error; 260 } 261 monpriv->hdr_to_read = sizeof(monpriv->hdr); 262 } 263 mutex_unlock(&monpriv->thread_mutex); 264 return written; 265 266 out_error: 267 monpriv->data_to_read = 0; 268 monpriv->hdr_to_read = sizeof(struct monwrite_hdr); 269 mutex_unlock(&monpriv->thread_mutex); 270 return rc; 271 } 272 273 static const struct file_operations monwrite_fops = { 274 .owner = THIS_MODULE, 275 .open = &monwrite_open, 276 .release = &monwrite_close, 277 .write = &monwrite_write, 278 .llseek = noop_llseek, 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 const 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 .pm = &monwriter_pm_ops, 339 }, 340 }; 341 342 static struct platform_device *monwriter_pdev; 343 344 /* 345 * module init/exit 346 */ 347 348 static int __init mon_init(void) 349 { 350 int rc; 351 352 if (!MACHINE_IS_VM) 353 return -ENODEV; 354 355 rc = platform_driver_register(&monwriter_pdrv); 356 if (rc) 357 return rc; 358 359 monwriter_pdev = platform_device_register_simple("monwriter", -1, NULL, 360 0); 361 if (IS_ERR(monwriter_pdev)) { 362 rc = PTR_ERR(monwriter_pdev); 363 goto out_driver; 364 } 365 366 /* 367 * misc_register() has to be the last action in module_init(), because 368 * file operations will be available right after this. 369 */ 370 rc = misc_register(&mon_dev); 371 if (rc) 372 goto out_device; 373 return 0; 374 375 out_device: 376 platform_device_unregister(monwriter_pdev); 377 out_driver: 378 platform_driver_unregister(&monwriter_pdrv); 379 return rc; 380 } 381 382 static void __exit mon_exit(void) 383 { 384 misc_deregister(&mon_dev); 385 platform_device_unregister(monwriter_pdev); 386 platform_driver_unregister(&monwriter_pdrv); 387 } 388 389 module_init(mon_init); 390 module_exit(mon_exit); 391 392 module_param_named(max_bufs, mon_max_bufs, int, 0644); 393 MODULE_PARM_DESC(max_bufs, "Maximum number of sample monitor data buffers " 394 "that can be active at one time"); 395 396 MODULE_AUTHOR("Melissa Howland <Melissa.Howland@us.ibm.com>"); 397 MODULE_DESCRIPTION("Character device driver for writing z/VM " 398 "APPLDATA monitor records."); 399 MODULE_LICENSE("GPL"); 400