1 /* 2 * drivers/s390/char/monreader.c 3 * 4 * Character device driver for reading z/VM *MONITOR service records. 5 * 6 * Copyright (C) 2004 IBM Corporation, IBM Deutschland Entwicklung GmbH. 7 * 8 * Author: Gerald Schaefer <geraldsc@de.ibm.com> 9 */ 10 11 #include <linux/module.h> 12 #include <linux/moduleparam.h> 13 #include <linux/init.h> 14 #include <linux/errno.h> 15 #include <linux/types.h> 16 #include <linux/kernel.h> 17 #include <linux/miscdevice.h> 18 #include <linux/ctype.h> 19 #include <linux/spinlock.h> 20 #include <linux/interrupt.h> 21 #include <asm/uaccess.h> 22 #include <asm/ebcdic.h> 23 #include <asm/extmem.h> 24 #include <linux/poll.h> 25 #include "../net/iucv.h" 26 27 28 //#define MON_DEBUG /* Debug messages on/off */ 29 30 #define MON_NAME "monreader" 31 32 #define P_INFO(x...) printk(KERN_INFO MON_NAME " info: " x) 33 #define P_ERROR(x...) printk(KERN_ERR MON_NAME " error: " x) 34 #define P_WARNING(x...) printk(KERN_WARNING MON_NAME " warning: " x) 35 36 #ifdef MON_DEBUG 37 #define P_DEBUG(x...) printk(KERN_DEBUG MON_NAME " debug: " x) 38 #else 39 #define P_DEBUG(x...) do {} while (0) 40 #endif 41 42 #define MON_COLLECT_SAMPLE 0x80 43 #define MON_COLLECT_EVENT 0x40 44 #define MON_SERVICE "*MONITOR" 45 #define MON_IN_USE 0x01 46 #define MON_MSGLIM 255 47 48 static char mon_dcss_name[9] = "MONDCSS\0"; 49 50 struct mon_msg { 51 u32 pos; 52 u32 mca_offset; 53 iucv_MessagePending local_eib; 54 char msglim_reached; 55 char replied_msglim; 56 }; 57 58 struct mon_private { 59 u16 pathid; 60 iucv_handle_t iucv_handle; 61 struct mon_msg *msg_array[MON_MSGLIM]; 62 unsigned int write_index; 63 unsigned int read_index; 64 atomic_t msglim_count; 65 atomic_t read_ready; 66 atomic_t iucv_connected; 67 atomic_t iucv_severed; 68 }; 69 70 static unsigned long mon_in_use = 0; 71 72 static unsigned long mon_dcss_start; 73 static unsigned long mon_dcss_end; 74 75 static DECLARE_WAIT_QUEUE_HEAD(mon_read_wait_queue); 76 static DECLARE_WAIT_QUEUE_HEAD(mon_conn_wait_queue); 77 78 static u8 iucv_host[8] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}; 79 80 static u8 user_data_connect[16] = { 81 /* Version code, must be 0x01 for shared mode */ 82 0x01, 83 /* what to collect */ 84 MON_COLLECT_SAMPLE | MON_COLLECT_EVENT, 85 /* DCSS name in EBCDIC, 8 bytes padded with blanks */ 86 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 87 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 88 }; 89 90 static u8 user_data_sever[16] = { 91 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 92 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 93 }; 94 95 96 /****************************************************************************** 97 * helper functions * 98 *****************************************************************************/ 99 /* 100 * Create the 8 bytes EBCDIC DCSS segment name from 101 * an ASCII name, incl. padding 102 */ 103 static inline void 104 dcss_mkname(char *ascii_name, char *ebcdic_name) 105 { 106 int i; 107 108 for (i = 0; i < 8; i++) { 109 if (ascii_name[i] == '\0') 110 break; 111 ebcdic_name[i] = toupper(ascii_name[i]); 112 }; 113 for (; i < 8; i++) 114 ebcdic_name[i] = ' '; 115 ASCEBC(ebcdic_name, 8); 116 } 117 118 /* 119 * print appropriate error message for segment_load()/segment_type() 120 * return code 121 */ 122 static void 123 mon_segment_warn(int rc, char* seg_name) 124 { 125 switch (rc) { 126 case -ENOENT: 127 P_WARNING("cannot load/query segment %s, does not exist\n", 128 seg_name); 129 break; 130 case -ENOSYS: 131 P_WARNING("cannot load/query segment %s, not running on VM\n", 132 seg_name); 133 break; 134 case -EIO: 135 P_WARNING("cannot load/query segment %s, hardware error\n", 136 seg_name); 137 break; 138 case -ENOTSUPP: 139 P_WARNING("cannot load/query segment %s, is a multi-part " 140 "segment\n", seg_name); 141 break; 142 case -ENOSPC: 143 P_WARNING("cannot load/query segment %s, overlaps with " 144 "storage\n", seg_name); 145 break; 146 case -EBUSY: 147 P_WARNING("cannot load/query segment %s, overlaps with " 148 "already loaded dcss\n", seg_name); 149 break; 150 case -EPERM: 151 P_WARNING("cannot load/query segment %s, already loaded in " 152 "incompatible mode\n", seg_name); 153 break; 154 case -ENOMEM: 155 P_WARNING("cannot load/query segment %s, out of memory\n", 156 seg_name); 157 break; 158 case -ERANGE: 159 P_WARNING("cannot load/query segment %s, exceeds kernel " 160 "mapping range\n", seg_name); 161 break; 162 default: 163 P_WARNING("cannot load/query segment %s, return value %i\n", 164 seg_name, rc); 165 break; 166 } 167 } 168 169 static inline unsigned long 170 mon_mca_start(struct mon_msg *monmsg) 171 { 172 return monmsg->local_eib.ln1msg1.iprmmsg1_u32; 173 } 174 175 static inline unsigned long 176 mon_mca_end(struct mon_msg *monmsg) 177 { 178 return monmsg->local_eib.ln1msg2.ipbfln1f; 179 } 180 181 static inline u8 182 mon_mca_type(struct mon_msg *monmsg, u8 index) 183 { 184 return *((u8 *) mon_mca_start(monmsg) + monmsg->mca_offset + index); 185 } 186 187 static inline u32 188 mon_mca_size(struct mon_msg *monmsg) 189 { 190 return mon_mca_end(monmsg) - mon_mca_start(monmsg) + 1; 191 } 192 193 static inline u32 194 mon_rec_start(struct mon_msg *monmsg) 195 { 196 return *((u32 *) (mon_mca_start(monmsg) + monmsg->mca_offset + 4)); 197 } 198 199 static inline u32 200 mon_rec_end(struct mon_msg *monmsg) 201 { 202 return *((u32 *) (mon_mca_start(monmsg) + monmsg->mca_offset + 8)); 203 } 204 205 static inline int 206 mon_check_mca(struct mon_msg *monmsg) 207 { 208 if ((mon_rec_end(monmsg) <= mon_rec_start(monmsg)) || 209 (mon_rec_start(monmsg) < mon_dcss_start) || 210 (mon_rec_end(monmsg) > mon_dcss_end) || 211 (mon_mca_type(monmsg, 0) == 0) || 212 (mon_mca_size(monmsg) % 12 != 0) || 213 (mon_mca_end(monmsg) <= mon_mca_start(monmsg)) || 214 (mon_mca_end(monmsg) > mon_dcss_end) || 215 (mon_mca_start(monmsg) < mon_dcss_start) || 216 ((mon_mca_type(monmsg, 1) == 0) && (mon_mca_type(monmsg, 2) == 0))) 217 { 218 P_DEBUG("READ, IGNORED INVALID MCA\n\n"); 219 return -EINVAL; 220 } 221 return 0; 222 } 223 224 static inline int 225 mon_send_reply(struct mon_msg *monmsg, struct mon_private *monpriv) 226 { 227 u8 prmmsg[8]; 228 int rc; 229 230 P_DEBUG("read, REPLY: pathid = 0x%04X, msgid = 0x%08X, trgcls = " 231 "0x%08X\n\n", 232 monmsg->local_eib.ippathid, monmsg->local_eib.ipmsgid, 233 monmsg->local_eib.iptrgcls); 234 rc = iucv_reply_prmmsg(monmsg->local_eib.ippathid, 235 monmsg->local_eib.ipmsgid, 236 monmsg->local_eib.iptrgcls, 237 0, prmmsg); 238 atomic_dec(&monpriv->msglim_count); 239 if (likely(!monmsg->msglim_reached)) { 240 monmsg->pos = 0; 241 monmsg->mca_offset = 0; 242 monpriv->read_index = (monpriv->read_index + 1) % 243 MON_MSGLIM; 244 atomic_dec(&monpriv->read_ready); 245 } else 246 monmsg->replied_msglim = 1; 247 if (rc) { 248 P_ERROR("read, IUCV reply failed with rc = %i\n\n", rc); 249 return -EIO; 250 } 251 return 0; 252 } 253 254 static inline struct mon_private * 255 mon_alloc_mem(void) 256 { 257 int i,j; 258 struct mon_private *monpriv; 259 260 monpriv = kmalloc(sizeof(struct mon_private), GFP_KERNEL); 261 if (!monpriv) { 262 P_ERROR("no memory for monpriv\n"); 263 return NULL; 264 } 265 memset(monpriv, 0, sizeof(struct mon_private)); 266 for (i = 0; i < MON_MSGLIM; i++) { 267 monpriv->msg_array[i] = kmalloc(sizeof(struct mon_msg), 268 GFP_KERNEL); 269 if (!monpriv->msg_array[i]) { 270 P_ERROR("open, no memory for msg_array\n"); 271 for (j = 0; j < i; j++) 272 kfree(monpriv->msg_array[j]); 273 return NULL; 274 } 275 memset(monpriv->msg_array[i], 0, sizeof(struct mon_msg)); 276 } 277 return monpriv; 278 } 279 280 static inline void 281 mon_read_debug(struct mon_msg *monmsg, struct mon_private *monpriv) 282 { 283 #ifdef MON_DEBUG 284 u8 msg_type[2], mca_type; 285 unsigned long records_len; 286 287 records_len = mon_rec_end(monmsg) - mon_rec_start(monmsg) + 1; 288 289 memcpy(msg_type, &monmsg->local_eib.iptrgcls, 2); 290 EBCASC(msg_type, 2); 291 mca_type = mon_mca_type(monmsg, 0); 292 EBCASC(&mca_type, 1); 293 294 P_DEBUG("read, mon_read_index = %i, mon_write_index = %i\n", 295 monpriv->read_index, monpriv->write_index); 296 P_DEBUG("read, pathid = 0x%04X, msgid = 0x%08X, trgcls = 0x%08X\n", 297 monmsg->local_eib.ippathid, monmsg->local_eib.ipmsgid, 298 monmsg->local_eib.iptrgcls); 299 P_DEBUG("read, msg_type = '%c%c', mca_type = '%c' / 0x%X / 0x%X\n", 300 msg_type[0], msg_type[1], mca_type ? mca_type : 'X', 301 mon_mca_type(monmsg, 1), mon_mca_type(monmsg, 2)); 302 P_DEBUG("read, MCA: start = 0x%lX, end = 0x%lX\n", 303 mon_mca_start(monmsg), mon_mca_end(monmsg)); 304 P_DEBUG("read, REC: start = 0x%X, end = 0x%X, len = %lu\n\n", 305 mon_rec_start(monmsg), mon_rec_end(monmsg), records_len); 306 if (mon_mca_size(monmsg) > 12) 307 P_DEBUG("READ, MORE THAN ONE MCA\n\n"); 308 #endif 309 } 310 311 static inline void 312 mon_next_mca(struct mon_msg *monmsg) 313 { 314 if (likely((mon_mca_size(monmsg) - monmsg->mca_offset) == 12)) 315 return; 316 P_DEBUG("READ, NEXT MCA\n\n"); 317 monmsg->mca_offset += 12; 318 monmsg->pos = 0; 319 } 320 321 static inline struct mon_msg * 322 mon_next_message(struct mon_private *monpriv) 323 { 324 struct mon_msg *monmsg; 325 326 if (!atomic_read(&monpriv->read_ready)) 327 return NULL; 328 monmsg = monpriv->msg_array[monpriv->read_index]; 329 if (unlikely(monmsg->replied_msglim)) { 330 monmsg->replied_msglim = 0; 331 monmsg->msglim_reached = 0; 332 monmsg->pos = 0; 333 monmsg->mca_offset = 0; 334 P_WARNING("read, message limit reached\n"); 335 monpriv->read_index = (monpriv->read_index + 1) % 336 MON_MSGLIM; 337 atomic_dec(&monpriv->read_ready); 338 return ERR_PTR(-EOVERFLOW); 339 } 340 return monmsg; 341 } 342 343 344 /****************************************************************************** 345 * IUCV handler * 346 *****************************************************************************/ 347 static void 348 mon_iucv_ConnectionComplete(iucv_ConnectionComplete *eib, void *pgm_data) 349 { 350 struct mon_private *monpriv = (struct mon_private *) pgm_data; 351 352 P_DEBUG("IUCV connection completed\n"); 353 P_DEBUG("IUCV ACCEPT (from *MONITOR): Version = 0x%02X, Event = " 354 "0x%02X, Sample = 0x%02X\n", 355 eib->ipuser[0], eib->ipuser[1], eib->ipuser[2]); 356 atomic_set(&monpriv->iucv_connected, 1); 357 wake_up(&mon_conn_wait_queue); 358 } 359 360 static void 361 mon_iucv_ConnectionSevered(iucv_ConnectionSevered *eib, void *pgm_data) 362 { 363 struct mon_private *monpriv = (struct mon_private *) pgm_data; 364 365 P_ERROR("IUCV connection severed with rc = 0x%X\n", 366 (u8) eib->ipuser[0]); 367 atomic_set(&monpriv->iucv_severed, 1); 368 wake_up(&mon_conn_wait_queue); 369 wake_up_interruptible(&mon_read_wait_queue); 370 } 371 372 static void 373 mon_iucv_MessagePending(iucv_MessagePending *eib, void *pgm_data) 374 { 375 struct mon_private *monpriv = (struct mon_private *) pgm_data; 376 377 P_DEBUG("IUCV message pending\n"); 378 memcpy(&monpriv->msg_array[monpriv->write_index]->local_eib, eib, 379 sizeof(iucv_MessagePending)); 380 if (atomic_inc_return(&monpriv->msglim_count) == MON_MSGLIM) { 381 P_WARNING("IUCV message pending, message limit (%i) reached\n", 382 MON_MSGLIM); 383 monpriv->msg_array[monpriv->write_index]->msglim_reached = 1; 384 } 385 monpriv->write_index = (monpriv->write_index + 1) % MON_MSGLIM; 386 atomic_inc(&monpriv->read_ready); 387 wake_up_interruptible(&mon_read_wait_queue); 388 } 389 390 static iucv_interrupt_ops_t mon_iucvops = { 391 .ConnectionComplete = mon_iucv_ConnectionComplete, 392 .ConnectionSevered = mon_iucv_ConnectionSevered, 393 .MessagePending = mon_iucv_MessagePending, 394 }; 395 396 /****************************************************************************** 397 * file operations * 398 *****************************************************************************/ 399 static int 400 mon_open(struct inode *inode, struct file *filp) 401 { 402 int rc, i; 403 struct mon_private *monpriv; 404 405 /* 406 * only one user allowed 407 */ 408 if (test_and_set_bit(MON_IN_USE, &mon_in_use)) 409 return -EBUSY; 410 411 monpriv = mon_alloc_mem(); 412 if (!monpriv) 413 return -ENOMEM; 414 415 /* 416 * Register with IUCV and connect to *MONITOR service 417 */ 418 monpriv->iucv_handle = iucv_register_program("my_monreader ", 419 MON_SERVICE, 420 NULL, 421 &mon_iucvops, 422 monpriv); 423 if (!monpriv->iucv_handle) { 424 P_ERROR("failed to register with iucv driver\n"); 425 rc = -EIO; 426 goto out_error; 427 } 428 P_INFO("open, registered with IUCV\n"); 429 430 rc = iucv_connect(&monpriv->pathid, MON_MSGLIM, user_data_connect, 431 MON_SERVICE, iucv_host, IPRMDATA, NULL, NULL, 432 monpriv->iucv_handle, NULL); 433 if (rc) { 434 P_ERROR("iucv connection to *MONITOR failed with " 435 "IPUSER SEVER code = %i\n", rc); 436 rc = -EIO; 437 goto out_unregister; 438 } 439 /* 440 * Wait for connection confirmation 441 */ 442 wait_event(mon_conn_wait_queue, 443 atomic_read(&monpriv->iucv_connected) || 444 atomic_read(&monpriv->iucv_severed)); 445 if (atomic_read(&monpriv->iucv_severed)) { 446 atomic_set(&monpriv->iucv_severed, 0); 447 atomic_set(&monpriv->iucv_connected, 0); 448 rc = -EIO; 449 goto out_unregister; 450 } 451 P_INFO("open, established connection to *MONITOR service\n\n"); 452 filp->private_data = monpriv; 453 return nonseekable_open(inode, filp); 454 455 out_unregister: 456 iucv_unregister_program(monpriv->iucv_handle); 457 out_error: 458 for (i = 0; i < MON_MSGLIM; i++) 459 kfree(monpriv->msg_array[i]); 460 kfree(monpriv); 461 clear_bit(MON_IN_USE, &mon_in_use); 462 return rc; 463 } 464 465 static int 466 mon_close(struct inode *inode, struct file *filp) 467 { 468 int rc, i; 469 struct mon_private *monpriv = filp->private_data; 470 471 /* 472 * Close IUCV connection and unregister 473 */ 474 rc = iucv_sever(monpriv->pathid, user_data_sever); 475 if (rc) 476 P_ERROR("close, iucv_sever failed with rc = %i\n", rc); 477 else 478 P_INFO("close, terminated connection to *MONITOR service\n"); 479 480 rc = iucv_unregister_program(monpriv->iucv_handle); 481 if (rc) 482 P_ERROR("close, iucv_unregister failed with rc = %i\n", rc); 483 else 484 P_INFO("close, unregistered with IUCV\n"); 485 486 atomic_set(&monpriv->iucv_severed, 0); 487 atomic_set(&monpriv->iucv_connected, 0); 488 atomic_set(&monpriv->read_ready, 0); 489 atomic_set(&monpriv->msglim_count, 0); 490 monpriv->write_index = 0; 491 monpriv->read_index = 0; 492 493 for (i = 0; i < MON_MSGLIM; i++) 494 kfree(monpriv->msg_array[i]); 495 kfree(monpriv); 496 clear_bit(MON_IN_USE, &mon_in_use); 497 return 0; 498 } 499 500 static ssize_t 501 mon_read(struct file *filp, char __user *data, size_t count, loff_t *ppos) 502 { 503 struct mon_private *monpriv = filp->private_data; 504 struct mon_msg *monmsg; 505 int ret; 506 u32 mce_start; 507 508 monmsg = mon_next_message(monpriv); 509 if (IS_ERR(monmsg)) 510 return PTR_ERR(monmsg); 511 512 if (!monmsg) { 513 if (filp->f_flags & O_NONBLOCK) 514 return -EAGAIN; 515 ret = wait_event_interruptible(mon_read_wait_queue, 516 atomic_read(&monpriv->read_ready) || 517 atomic_read(&monpriv->iucv_severed)); 518 if (ret) 519 return ret; 520 if (unlikely(atomic_read(&monpriv->iucv_severed))) 521 return -EIO; 522 monmsg = monpriv->msg_array[monpriv->read_index]; 523 } 524 525 if (!monmsg->pos) { 526 monmsg->pos = mon_mca_start(monmsg) + monmsg->mca_offset; 527 mon_read_debug(monmsg, monpriv); 528 } 529 if (mon_check_mca(monmsg)) 530 goto reply; 531 532 /* read monitor control element (12 bytes) first */ 533 mce_start = mon_mca_start(monmsg) + monmsg->mca_offset; 534 if ((monmsg->pos >= mce_start) && (monmsg->pos < mce_start + 12)) { 535 count = min(count, (size_t) mce_start + 12 - monmsg->pos); 536 ret = copy_to_user(data, (void *) (unsigned long) monmsg->pos, 537 count); 538 if (ret) 539 return -EFAULT; 540 monmsg->pos += count; 541 if (monmsg->pos == mce_start + 12) 542 monmsg->pos = mon_rec_start(monmsg); 543 goto out_copy; 544 } 545 546 /* read records */ 547 if (monmsg->pos <= mon_rec_end(monmsg)) { 548 count = min(count, (size_t) mon_rec_end(monmsg) - monmsg->pos 549 + 1); 550 ret = copy_to_user(data, (void *) (unsigned long) monmsg->pos, 551 count); 552 if (ret) 553 return -EFAULT; 554 monmsg->pos += count; 555 if (monmsg->pos > mon_rec_end(monmsg)) 556 mon_next_mca(monmsg); 557 goto out_copy; 558 } 559 reply: 560 ret = mon_send_reply(monmsg, monpriv); 561 return ret; 562 563 out_copy: 564 *ppos += count; 565 return count; 566 } 567 568 static unsigned int 569 mon_poll(struct file *filp, struct poll_table_struct *p) 570 { 571 struct mon_private *monpriv = filp->private_data; 572 573 poll_wait(filp, &mon_read_wait_queue, p); 574 if (unlikely(atomic_read(&monpriv->iucv_severed))) 575 return POLLERR; 576 if (atomic_read(&monpriv->read_ready)) 577 return POLLIN | POLLRDNORM; 578 return 0; 579 } 580 581 static struct file_operations mon_fops = { 582 .owner = THIS_MODULE, 583 .open = &mon_open, 584 .release = &mon_close, 585 .read = &mon_read, 586 .poll = &mon_poll, 587 }; 588 589 static struct miscdevice mon_dev = { 590 .name = "monreader", 591 .devfs_name = "monreader", 592 .fops = &mon_fops, 593 .minor = MISC_DYNAMIC_MINOR, 594 }; 595 596 /****************************************************************************** 597 * module init/exit * 598 *****************************************************************************/ 599 static int __init 600 mon_init(void) 601 { 602 int rc; 603 604 if (!MACHINE_IS_VM) { 605 P_ERROR("not running under z/VM, driver not loaded\n"); 606 return -ENODEV; 607 } 608 609 rc = segment_type(mon_dcss_name); 610 if (rc < 0) { 611 mon_segment_warn(rc, mon_dcss_name); 612 return rc; 613 } 614 if (rc != SEG_TYPE_SC) { 615 P_ERROR("segment %s has unsupported type, should be SC\n", 616 mon_dcss_name); 617 return -EINVAL; 618 } 619 620 rc = segment_load(mon_dcss_name, SEGMENT_SHARED, 621 &mon_dcss_start, &mon_dcss_end); 622 if (rc < 0) { 623 mon_segment_warn(rc, mon_dcss_name); 624 return -EINVAL; 625 } 626 dcss_mkname(mon_dcss_name, &user_data_connect[8]); 627 628 rc = misc_register(&mon_dev); 629 if (rc < 0 ) { 630 P_ERROR("misc_register failed, rc = %i\n", rc); 631 goto out; 632 } 633 P_INFO("Loaded segment %s from %p to %p, size = %lu Byte\n", 634 mon_dcss_name, (void *) mon_dcss_start, (void *) mon_dcss_end, 635 mon_dcss_end - mon_dcss_start + 1); 636 return 0; 637 638 out: 639 segment_unload(mon_dcss_name); 640 return rc; 641 } 642 643 static void __exit 644 mon_exit(void) 645 { 646 segment_unload(mon_dcss_name); 647 WARN_ON(misc_deregister(&mon_dev) != 0); 648 return; 649 } 650 651 652 module_init(mon_init); 653 module_exit(mon_exit); 654 655 module_param_string(mondcss, mon_dcss_name, 9, 0444); 656 MODULE_PARM_DESC(mondcss, "Name of DCSS segment to be used for *MONITOR " 657 "service, max. 8 chars. Default is MONDCSS"); 658 659 MODULE_AUTHOR("Gerald Schaefer <geraldsc@de.ibm.com>"); 660 MODULE_DESCRIPTION("Character device driver for reading z/VM " 661 "monitor service records."); 662 MODULE_LICENSE("GPL"); 663