1/* 2 * IBM ASM Service Processor Device Driver 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write to the Free Software 16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 17 * 18 * Copyright (C) IBM Corporation, 2004 19 * 20 * Author: Max Asb�ck <amax@us.ibm.com> 21 * 22 */ 23 24/* 25 * Parts of this code are based on an article by Jonathan Corbet 26 * that appeared in Linux Weekly News. 27 */ 28 29 30/* 31 * The IBMASM file virtual filesystem. It creates the following hierarchy 32 * dymamically when mounted from user space: 33 * 34 * /ibmasm 35 * |-- 0 36 * | |-- command 37 * | |-- event 38 * | |-- reverse_heartbeat 39 * | `-- remote_video 40 * | |-- depth 41 * | |-- height 42 * | `-- width 43 * . 44 * . 45 * . 46 * `-- n 47 * |-- command 48 * |-- event 49 * |-- reverse_heartbeat 50 * `-- remote_video 51 * |-- depth 52 * |-- height 53 * `-- width 54 * 55 * For each service processor the following files are created: 56 * 57 * command: execute dot commands 58 * write: execute a dot command on the service processor 59 * read: return the result of a previously executed dot command 60 * 61 * events: listen for service processor events 62 * read: sleep (interruptible) until an event occurs 63 * write: wakeup sleeping event listener 64 * 65 * reverse_heartbeat: send a heartbeat to the service processor 66 * read: sleep (interruptible) until the reverse heartbeat fails 67 * write: wakeup sleeping heartbeat listener 68 * 69 * remote_video/width 70 * remote_video/height 71 * remote_video/width: control remote display settings 72 * write: set value 73 * read: read value 74 */ 75 76#include <linux/fs.h> 77#include <linux/pagemap.h> 78#include <linux/slab.h> 79#include <asm/uaccess.h> 80#include <asm/io.h> 81#include "ibmasm.h" 82#include "remote.h" 83#include "dot_command.h" 84 85#define IBMASMFS_MAGIC 0x66726f67 86 87static LIST_HEAD(service_processors); 88 89static struct inode *ibmasmfs_make_inode(struct super_block *sb, int mode); 90static void ibmasmfs_create_files (struct super_block *sb, struct dentry *root); 91static int ibmasmfs_fill_super (struct super_block *sb, void *data, int silent); 92 93 94static int ibmasmfs_get_super(struct file_system_type *fst, 95 int flags, const char *name, void *data, 96 struct vfsmount *mnt) 97{ 98 return get_sb_single(fst, flags, data, ibmasmfs_fill_super, mnt); 99} 100 101static const struct super_operations ibmasmfs_s_ops = { 102 .statfs = simple_statfs, 103 .drop_inode = generic_delete_inode, 104}; 105 106static const struct file_operations *ibmasmfs_dir_ops = &simple_dir_operations; 107 108static struct file_system_type ibmasmfs_type = { 109 .owner = THIS_MODULE, 110 .name = "ibmasmfs", 111 .get_sb = ibmasmfs_get_super, 112 .kill_sb = kill_litter_super, 113}; 114 115static int ibmasmfs_fill_super (struct super_block *sb, void *data, int silent) 116{ 117 struct inode *root; 118 struct dentry *root_dentry; 119 120 sb->s_blocksize = PAGE_CACHE_SIZE; 121 sb->s_blocksize_bits = PAGE_CACHE_SHIFT; 122 sb->s_magic = IBMASMFS_MAGIC; 123 sb->s_op = &ibmasmfs_s_ops; 124 sb->s_time_gran = 1; 125 126 root = ibmasmfs_make_inode (sb, S_IFDIR | 0500); 127 if (!root) 128 return -ENOMEM; 129 130 root->i_op = &simple_dir_inode_operations; 131 root->i_fop = ibmasmfs_dir_ops; 132 133 root_dentry = d_alloc_root(root); 134 if (!root_dentry) { 135 iput(root); 136 return -ENOMEM; 137 } 138 sb->s_root = root_dentry; 139 140 ibmasmfs_create_files(sb, root_dentry); 141 return 0; 142} 143 144static struct inode *ibmasmfs_make_inode(struct super_block *sb, int mode) 145{ 146 struct inode *ret = new_inode(sb); 147 148 if (ret) { 149 ret->i_mode = mode; 150 ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME; 151 } 152 return ret; 153} 154 155static struct dentry *ibmasmfs_create_file (struct super_block *sb, 156 struct dentry *parent, 157 const char *name, 158 const struct file_operations *fops, 159 void *data, 160 int mode) 161{ 162 struct dentry *dentry; 163 struct inode *inode; 164 165 dentry = d_alloc_name(parent, name); 166 if (!dentry) 167 return NULL; 168 169 inode = ibmasmfs_make_inode(sb, S_IFREG | mode); 170 if (!inode) { 171 dput(dentry); 172 return NULL; 173 } 174 175 inode->i_fop = fops; 176 inode->i_private = data; 177 178 d_add(dentry, inode); 179 return dentry; 180} 181 182static struct dentry *ibmasmfs_create_dir (struct super_block *sb, 183 struct dentry *parent, 184 const char *name) 185{ 186 struct dentry *dentry; 187 struct inode *inode; 188 189 dentry = d_alloc_name(parent, name); 190 if (!dentry) 191 return NULL; 192 193 inode = ibmasmfs_make_inode(sb, S_IFDIR | 0500); 194 if (!inode) { 195 dput(dentry); 196 return NULL; 197 } 198 199 inode->i_op = &simple_dir_inode_operations; 200 inode->i_fop = ibmasmfs_dir_ops; 201 202 d_add(dentry, inode); 203 return dentry; 204} 205 206int ibmasmfs_register(void) 207{ 208 return register_filesystem(&ibmasmfs_type); 209} 210 211void ibmasmfs_unregister(void) 212{ 213 unregister_filesystem(&ibmasmfs_type); 214} 215 216void ibmasmfs_add_sp(struct service_processor *sp) 217{ 218 list_add(&sp->node, &service_processors); 219} 220 221/* struct to save state between command file operations */ 222struct ibmasmfs_command_data { 223 struct service_processor *sp; 224 struct command *command; 225}; 226 227/* struct to save state between event file operations */ 228struct ibmasmfs_event_data { 229 struct service_processor *sp; 230 struct event_reader reader; 231 int active; 232}; 233 234/* struct to save state between reverse heartbeat file operations */ 235struct ibmasmfs_heartbeat_data { 236 struct service_processor *sp; 237 struct reverse_heartbeat heartbeat; 238 int active; 239}; 240 241static int command_file_open(struct inode *inode, struct file *file) 242{ 243 struct ibmasmfs_command_data *command_data; 244 245 if (!inode->i_private) 246 return -ENODEV; 247 248 command_data = kmalloc(sizeof(struct ibmasmfs_command_data), GFP_KERNEL); 249 if (!command_data) 250 return -ENOMEM; 251 252 command_data->command = NULL; 253 command_data->sp = inode->i_private; 254 file->private_data = command_data; 255 return 0; 256} 257 258static int command_file_close(struct inode *inode, struct file *file) 259{ 260 struct ibmasmfs_command_data *command_data = file->private_data; 261 262 if (command_data->command) 263 command_put(command_data->command); 264 265 kfree(command_data); 266 return 0; 267} 268 269static ssize_t command_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset) 270{ 271 struct ibmasmfs_command_data *command_data = file->private_data; 272 struct command *cmd; 273 int len; 274 unsigned long flags; 275 276 if (*offset < 0) 277 return -EINVAL; 278 if (count == 0 || count > IBMASM_CMD_MAX_BUFFER_SIZE) 279 return 0; 280 if (*offset != 0) 281 return 0; 282 283 spin_lock_irqsave(&command_data->sp->lock, flags); 284 cmd = command_data->command; 285 if (cmd == NULL) { 286 spin_unlock_irqrestore(&command_data->sp->lock, flags); 287 return 0; 288 } 289 command_data->command = NULL; 290 spin_unlock_irqrestore(&command_data->sp->lock, flags); 291 292 if (cmd->status != IBMASM_CMD_COMPLETE) { 293 command_put(cmd); 294 return -EIO; 295 } 296 len = min(count, cmd->buffer_size); 297 if (copy_to_user(buf, cmd->buffer, len)) { 298 command_put(cmd); 299 return -EFAULT; 300 } 301 command_put(cmd); 302 303 return len; 304} 305 306static ssize_t command_file_write(struct file *file, const char __user *ubuff, size_t count, loff_t *offset) 307{ 308 struct ibmasmfs_command_data *command_data = file->private_data; 309 struct command *cmd; 310 unsigned long flags; 311 312 if (*offset < 0) 313 return -EINVAL; 314 if (count == 0 || count > IBMASM_CMD_MAX_BUFFER_SIZE) 315 return 0; 316 if (*offset != 0) 317 return 0; 318 319 /* commands are executed sequentially, only one command at a time */ 320 if (command_data->command) 321 return -EAGAIN; 322 323 cmd = ibmasm_new_command(command_data->sp, count); 324 if (!cmd) 325 return -ENOMEM; 326 327 if (copy_from_user(cmd->buffer, ubuff, count)) { 328 command_put(cmd); 329 return -EFAULT; 330 } 331 332 spin_lock_irqsave(&command_data->sp->lock, flags); 333 if (command_data->command) { 334 spin_unlock_irqrestore(&command_data->sp->lock, flags); 335 command_put(cmd); 336 return -EAGAIN; 337 } 338 command_data->command = cmd; 339 spin_unlock_irqrestore(&command_data->sp->lock, flags); 340 341 ibmasm_exec_command(command_data->sp, cmd); 342 ibmasm_wait_for_response(cmd, get_dot_command_timeout(cmd->buffer)); 343 344 return count; 345} 346 347static int event_file_open(struct inode *inode, struct file *file) 348{ 349 struct ibmasmfs_event_data *event_data; 350 struct service_processor *sp; 351 352 if (!inode->i_private) 353 return -ENODEV; 354 355 sp = inode->i_private; 356 357 event_data = kmalloc(sizeof(struct ibmasmfs_event_data), GFP_KERNEL); 358 if (!event_data) 359 return -ENOMEM; 360 361 ibmasm_event_reader_register(sp, &event_data->reader); 362 363 event_data->sp = sp; 364 event_data->active = 0; 365 file->private_data = event_data; 366 return 0; 367} 368 369static int event_file_close(struct inode *inode, struct file *file) 370{ 371 struct ibmasmfs_event_data *event_data = file->private_data; 372 373 ibmasm_event_reader_unregister(event_data->sp, &event_data->reader); 374 kfree(event_data); 375 return 0; 376} 377 378static ssize_t event_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset) 379{ 380 struct ibmasmfs_event_data *event_data = file->private_data; 381 struct event_reader *reader = &event_data->reader; 382 struct service_processor *sp = event_data->sp; 383 int ret; 384 unsigned long flags; 385 386 if (*offset < 0) 387 return -EINVAL; 388 if (count == 0 || count > IBMASM_EVENT_MAX_SIZE) 389 return 0; 390 if (*offset != 0) 391 return 0; 392 393 spin_lock_irqsave(&sp->lock, flags); 394 if (event_data->active) { 395 spin_unlock_irqrestore(&sp->lock, flags); 396 return -EBUSY; 397 } 398 event_data->active = 1; 399 spin_unlock_irqrestore(&sp->lock, flags); 400 401 ret = ibmasm_get_next_event(sp, reader); 402 if (ret <= 0) 403 goto out; 404 405 if (count < reader->data_size) { 406 ret = -EINVAL; 407 goto out; 408 } 409 410 if (copy_to_user(buf, reader->data, reader->data_size)) { 411 ret = -EFAULT; 412 goto out; 413 } 414 ret = reader->data_size; 415 416out: 417 event_data->active = 0; 418 return ret; 419} 420 421static ssize_t event_file_write(struct file *file, const char __user *buf, size_t count, loff_t *offset) 422{ 423 struct ibmasmfs_event_data *event_data = file->private_data; 424 425 if (*offset < 0) 426 return -EINVAL; 427 if (count != 1) 428 return 0; 429 if (*offset != 0) 430 return 0; 431 432 ibmasm_cancel_next_event(&event_data->reader); 433 return 0; 434} 435 436static int r_heartbeat_file_open(struct inode *inode, struct file *file) 437{ 438 struct ibmasmfs_heartbeat_data *rhbeat; 439 440 if (!inode->i_private) 441 return -ENODEV; 442 443 rhbeat = kmalloc(sizeof(struct ibmasmfs_heartbeat_data), GFP_KERNEL); 444 if (!rhbeat) 445 return -ENOMEM; 446 447 rhbeat->sp = inode->i_private; 448 rhbeat->active = 0; 449 ibmasm_init_reverse_heartbeat(rhbeat->sp, &rhbeat->heartbeat); 450 file->private_data = rhbeat; 451 return 0; 452} 453 454static int r_heartbeat_file_close(struct inode *inode, struct file *file) 455{ 456 struct ibmasmfs_heartbeat_data *rhbeat = file->private_data; 457 458 kfree(rhbeat); 459 return 0; 460} 461 462static ssize_t r_heartbeat_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset) 463{ 464 struct ibmasmfs_heartbeat_data *rhbeat = file->private_data; 465 unsigned long flags; 466 int result; 467 468 if (*offset < 0) 469 return -EINVAL; 470 if (count == 0 || count > 1024) 471 return 0; 472 if (*offset != 0) 473 return 0; 474 475 /* allow only one reverse heartbeat per process */ 476 spin_lock_irqsave(&rhbeat->sp->lock, flags); 477 if (rhbeat->active) { 478 spin_unlock_irqrestore(&rhbeat->sp->lock, flags); 479 return -EBUSY; 480 } 481 rhbeat->active = 1; 482 spin_unlock_irqrestore(&rhbeat->sp->lock, flags); 483 484 result = ibmasm_start_reverse_heartbeat(rhbeat->sp, &rhbeat->heartbeat); 485 rhbeat->active = 0; 486 487 return result; 488} 489 490static ssize_t r_heartbeat_file_write(struct file *file, const char __user *buf, size_t count, loff_t *offset) 491{ 492 struct ibmasmfs_heartbeat_data *rhbeat = file->private_data; 493 494 if (*offset < 0) 495 return -EINVAL; 496 if (count != 1) 497 return 0; 498 if (*offset != 0) 499 return 0; 500 501 if (rhbeat->active) 502 ibmasm_stop_reverse_heartbeat(&rhbeat->heartbeat); 503 504 return 1; 505} 506 507static int remote_settings_file_open(struct inode *inode, struct file *file) 508{ 509 file->private_data = inode->i_private; 510 return 0; 511} 512 513static int remote_settings_file_close(struct inode *inode, struct file *file) 514{ 515 return 0; 516} 517 518static ssize_t remote_settings_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset) 519{ 520 void __iomem *address = (void __iomem *)file->private_data; 521 unsigned char *page; 522 int retval; 523 int len = 0; 524 unsigned int value; 525 526 if (*offset < 0) 527 return -EINVAL; 528 if (count == 0 || count > 1024) 529 return 0; 530 if (*offset != 0) 531 return 0; 532 533 page = (unsigned char *)__get_free_page(GFP_KERNEL); 534 if (!page) 535 return -ENOMEM; 536 537 value = readl(address); 538 len = sprintf(page, "%d\n", value); 539 540 if (copy_to_user(buf, page, len)) { 541 retval = -EFAULT; 542 goto exit; 543 } 544 *offset += len; 545 retval = len; 546 547exit: 548 free_page((unsigned long)page); 549 return retval; 550} 551 552static ssize_t remote_settings_file_write(struct file *file, const char __user *ubuff, size_t count, loff_t *offset) 553{ 554 void __iomem *address = (void __iomem *)file->private_data; 555 char *buff; 556 unsigned int value; 557 558 if (*offset < 0) 559 return -EINVAL; 560 if (count == 0 || count > 1024) 561 return 0; 562 if (*offset != 0) 563 return 0; 564 565 buff = kzalloc (count + 1, GFP_KERNEL); 566 if (!buff) 567 return -ENOMEM; 568 569 570 if (copy_from_user(buff, ubuff, count)) { 571 kfree(buff); 572 return -EFAULT; 573 } 574 575 value = simple_strtoul(buff, NULL, 10); 576 writel(value, address); 577 kfree(buff); 578 579 return count; 580} 581 582static const struct file_operations command_fops = { 583 .open = command_file_open, 584 .release = command_file_close, 585 .read = command_file_read, 586 .write = command_file_write, 587}; 588 589static const struct file_operations event_fops = { 590 .open = event_file_open, 591 .release = event_file_close, 592 .read = event_file_read, 593 .write = event_file_write, 594}; 595 596static const struct file_operations r_heartbeat_fops = { 597 .open = r_heartbeat_file_open, 598 .release = r_heartbeat_file_close, 599 .read = r_heartbeat_file_read, 600 .write = r_heartbeat_file_write, 601}; 602 603static const struct file_operations remote_settings_fops = { 604 .open = remote_settings_file_open, 605 .release = remote_settings_file_close, 606 .read = remote_settings_file_read, 607 .write = remote_settings_file_write, 608}; 609 610 611static void ibmasmfs_create_files (struct super_block *sb, struct dentry *root) 612{ 613 struct list_head *entry; 614 struct service_processor *sp; 615 616 list_for_each(entry, &service_processors) { 617 struct dentry *dir; 618 struct dentry *remote_dir; 619 sp = list_entry(entry, struct service_processor, node); 620 dir = ibmasmfs_create_dir(sb, root, sp->dirname); 621 if (!dir) 622 continue; 623 624 ibmasmfs_create_file(sb, dir, "command", &command_fops, sp, S_IRUSR|S_IWUSR); 625 ibmasmfs_create_file(sb, dir, "event", &event_fops, sp, S_IRUSR|S_IWUSR); 626 ibmasmfs_create_file(sb, dir, "reverse_heartbeat", &r_heartbeat_fops, sp, S_IRUSR|S_IWUSR); 627 628 remote_dir = ibmasmfs_create_dir(sb, dir, "remote_video"); 629 if (!remote_dir) 630 continue; 631 632 ibmasmfs_create_file(sb, remote_dir, "width", &remote_settings_fops, (void *)display_width(sp), S_IRUSR|S_IWUSR); 633 ibmasmfs_create_file(sb, remote_dir, "height", &remote_settings_fops, (void *)display_height(sp), S_IRUSR|S_IWUSR); 634 ibmasmfs_create_file(sb, remote_dir, "depth", &remote_settings_fops, (void *)display_depth(sp), S_IRUSR|S_IWUSR); 635 } 636} 637