drivers/misc/ibmasm/ibmasmfs.c

   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 Asböck <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  *    |       |-- connected
  41  *    |       |-- depth
  42  *    |       |-- events
  43  *    |       |-- height
  44  *    |       `-- width
  45  *    .
  46  *    .
  47  *    .
  48  *    `-- n
  49  *        |-- command
  50  *        |-- event
  51  *        |-- reverse_heartbeat
  52  *        `-- remote_video
  53  *            |-- connected
  54  *            |-- depth
  55  *            |-- events
  56  *            |-- height
  57  *            `-- width
  58  *
  59  * For each service processor the following files are created:
  60  *
  61  * command: execute dot commands
  62  *      write: execute a dot command on the service processor
  63  *      read: return the result of a previously executed dot command
  64  *
  65  * events: listen for service processor events
  66  *      read: sleep (interruptible) until an event occurs
  67  *      write: wakeup sleeping event listener
  68  *
  69  * reverse_heartbeat: send a heartbeat to the service processor
  70  *      read: sleep (interruptible) until the reverse heartbeat fails
  71  *      write: wakeup sleeping heartbeat listener
  72  *
  73  * remote_video/width
  74  * remote_video/height
  75  * remote_video/width: control remote display settings
  76  *      write: set value
  77  *      read: read value
  78  *
  79  * remote_video/connected
  80  *      read: return "1" if web browser VNC java applet is connected,
  81  *              "0" otherwise
  82  *
  83  * remote_video/events
  84  *      read: sleep until a remote mouse or keyboard event occurs, then return
  85  *              then event.
  86  */
  87
  88 #include <linux/fs.h>
  89 #include <linux/pagemap.h>
  90 #include <asm/uaccess.h>
  91 #include <asm/io.h>
  92 #include "ibmasm.h"
  93 #include "remote.h"
  94 #include "dot_command.h"
  95
  96 #define IBMASMFS_MAGIC 0x66726f67
  97
  98 static LIST_HEAD(service_processors);
  99
 100 static struct inode *ibmasmfs_make_inode(struct super_block *sb, int mode);
 101 static void ibmasmfs_create_files (struct super_block *sb, struct dentry *root);
 102 static int ibmasmfs_fill_super (struct super_block *sb, void *data, int silent);
 103
 104
 105 static struct super_block *ibmasmfs_get_super(struct file_system_type *fst,
 106                         int flags, const char *name, void *data)
 107 {
 108         return get_sb_single(fst, flags, data, ibmasmfs_fill_super);
 109 }
 110
 111 static struct super_operations ibmasmfs_s_ops = {
 112         .statfs         = simple_statfs,
 113         .drop_inode     = generic_delete_inode,
 114 };
 115
 116 static struct file_operations *ibmasmfs_dir_ops = &simple_dir_operations;
 117
 118 static struct file_system_type ibmasmfs_type = {
 119         .owner          = THIS_MODULE,
 120         .name           = "ibmasmfs",
 121         .get_sb         = ibmasmfs_get_super,
 122         .kill_sb        = kill_litter_super,
 123 };
 124
 125 static int ibmasmfs_fill_super (struct super_block *sb, void *data, int silent)
 126 {
 127         struct inode *root;
 128         struct dentry *root_dentry;
 129
 130         sb->s_blocksize = PAGE_CACHE_SIZE;
 131         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 132         sb->s_magic = IBMASMFS_MAGIC;
 133         sb->s_op = &ibmasmfs_s_ops;
 134         sb->s_time_gran = 1;
 135
 136         root = ibmasmfs_make_inode (sb, S_IFDIR | 0500);
 137         if (!root)
 138                 return -ENOMEM;
 139
 140         root->i_op = &simple_dir_inode_operations;
 141         root->i_fop = ibmasmfs_dir_ops;
 142
 143         root_dentry = d_alloc_root(root);
 144         if (!root_dentry) {
 145                 iput(root);
 146                 return -ENOMEM;
 147         }
 148         sb->s_root = root_dentry;
 149
 150         ibmasmfs_create_files(sb, root_dentry);
 151         return 0;
 152 }
 153
 154 static struct inode *ibmasmfs_make_inode(struct super_block *sb, int mode)
 155 {
 156         struct inode *ret = new_inode(sb);
 157
 158         if (ret) {
 159                 ret->i_mode = mode;
 160                 ret->i_uid = ret->i_gid = 0;
 161                 ret->i_blksize = PAGE_CACHE_SIZE;
 162                 ret->i_blocks = 0;
 163                 ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
 164         }
 165         return ret;
 166 }
 167
 168 static struct dentry *ibmasmfs_create_file (struct super_block *sb,
 169                         struct dentry *parent,
 170                         const char *name,
 171                         struct file_operations *fops,
 172                         void *data,
 173                         int mode)
 174 {
 175         struct dentry *dentry;
 176         struct inode *inode;
 177
 178         dentry = d_alloc_name(parent, name);
 179         if (!dentry)
 180                 return NULL;
 181
 182         inode = ibmasmfs_make_inode(sb, S_IFREG | mode);
 183         if (!inode) {
 184                 dput(dentry);
 185                 return NULL;
 186         }
 187
 188         inode->i_fop = fops;
 189         inode->u.generic_ip = data;
 190
 191         d_add(dentry, inode);
 192         return dentry;
 193 }
 194
 195 static struct dentry *ibmasmfs_create_dir (struct super_block *sb,
 196                                 struct dentry *parent,
 197                                 const char *name)
 198 {
 199         struct dentry *dentry;
 200         struct inode *inode;
 201
 202         dentry = d_alloc_name(parent, name);
 203         if (!dentry)
 204                 return NULL;
 205
 206         inode = ibmasmfs_make_inode(sb, S_IFDIR | 0500);
 207         if (!inode) {
 208                 dput(dentry);
 209                 return NULL;
 210         }
 211
 212         inode->i_op = &simple_dir_inode_operations;
 213         inode->i_fop = ibmasmfs_dir_ops;
 214
 215         d_add(dentry, inode);
 216         return dentry;
 217 }
 218
 219 int ibmasmfs_register(void)
 220 {
 221         return register_filesystem(&ibmasmfs_type);
 222 }
 223
 224 void ibmasmfs_unregister(void)
 225 {
 226         unregister_filesystem(&ibmasmfs_type);
 227 }
 228
 229 void ibmasmfs_add_sp(struct service_processor *sp)
 230 {
 231         list_add(&sp->node, &service_processors);
 232 }
 233
 234 /* struct to save state between command file operations */
 235 struct ibmasmfs_command_data {
 236         struct service_processor        *sp;
 237         struct command                  *command;
 238 };
 239
 240 /* struct to save state between event file operations */
 241 struct ibmasmfs_event_data {
 242         struct service_processor        *sp;
 243         struct event_reader             reader;
 244         int                             active;
 245 };
 246
 247 /* struct to save state between reverse heartbeat file operations */
 248 struct ibmasmfs_heartbeat_data {
 249         struct service_processor        *sp;
 250         struct reverse_heartbeat        heartbeat;
 251         int                             active;
 252 };
 253
 254 static int command_file_open(struct inode *inode, struct file *file)
 255 {
 256         struct ibmasmfs_command_data *command_data;
 257
 258         if (!inode->u.generic_ip)
 259                 return -ENODEV;
 260
 261         command_data = kmalloc(sizeof(struct ibmasmfs_command_data), GFP_KERNEL);
 262         if (!command_data)
 263                 return -ENOMEM;
 264
 265         command_data->command = NULL;
 266         command_data->sp = inode->u.generic_ip;
 267         file->private_data = command_data;
 268         return 0;
 269 }
 270
 271 static int command_file_close(struct inode *inode, struct file *file)
 272 {
 273         struct ibmasmfs_command_data *command_data = file->private_data;
 274
 275         if (command_data->command)
 276                 command_put(command_data->command);
 277
 278         kfree(command_data);
 279         return 0;
 280 }
 281
 282 static ssize_t command_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
 283 {
 284         struct ibmasmfs_command_data *command_data = file->private_data;
 285         struct command *cmd;
 286         int len;
 287         unsigned long flags;
 288
 289         if (*offset < 0)
 290                 return -EINVAL;
 291         if (count == 0 || count > IBMASM_CMD_MAX_BUFFER_SIZE)
 292                 return 0;
 293         if (*offset != 0)
 294                 return 0;
 295
 296         spin_lock_irqsave(&command_data->sp->lock, flags);
 297         cmd = command_data->command;
 298         if (cmd == NULL) {
 299                 spin_unlock_irqrestore(&command_data->sp->lock, flags);
 300                 return 0;
 301         }
 302         command_data->command = NULL;
 303         spin_unlock_irqrestore(&command_data->sp->lock, flags);
 304
 305         if (cmd->status != IBMASM_CMD_COMPLETE) {
 306                 command_put(cmd);
 307                 return -EIO;
 308         }
 309         len = min(count, cmd->buffer_size);
 310         if (copy_to_user(buf, cmd->buffer, len)) {
 311                 command_put(cmd);
 312                 return -EFAULT;
 313         }
 314         command_put(cmd);
 315
 316         return len;
 317 }
 318
 319 static ssize_t command_file_write(struct file *file, const char __user *ubuff, size_t count, loff_t *offset)
 320 {
 321         struct ibmasmfs_command_data *command_data = file->private_data;
 322         struct command *cmd;
 323         unsigned long flags;
 324
 325         if (*offset < 0)
 326                 return -EINVAL;
 327         if (count == 0 || count > IBMASM_CMD_MAX_BUFFER_SIZE)
 328                 return 0;
 329         if (*offset != 0)
 330                 return 0;
 331
 332         /* commands are executed sequentially, only one command at a time */
 333         if (command_data->command)
 334                 return -EAGAIN;
 335
 336         cmd = ibmasm_new_command(count);
 337         if (!cmd)
 338                 return -ENOMEM;
 339
 340         if (copy_from_user(cmd->buffer, ubuff, count)) {
 341                 command_put(cmd);
 342                 return -EFAULT;
 343         }
 344
 345         spin_lock_irqsave(&command_data->sp->lock, flags);
 346         if (command_data->command) {
 347                 spin_unlock_irqrestore(&command_data->sp->lock, flags);
 348                 command_put(cmd);
 349                 return -EAGAIN;
 350         }
 351         command_data->command = cmd;
 352         spin_unlock_irqrestore(&command_data->sp->lock, flags);
 353
 354         ibmasm_exec_command(command_data->sp, cmd);
 355         ibmasm_wait_for_response(cmd, get_dot_command_timeout(cmd->buffer));
 356
 357         return count;
 358 }
 359
 360 static int event_file_open(struct inode *inode, struct file *file)
 361 {
 362         struct ibmasmfs_event_data *event_data;
 363         struct service_processor *sp;
 364
 365         if (!inode->u.generic_ip)
 366                 return -ENODEV;
 367
 368         sp = inode->u.generic_ip;
 369
 370         event_data = kmalloc(sizeof(struct ibmasmfs_event_data), GFP_KERNEL);
 371         if (!event_data)
 372                 return -ENOMEM;
 373
 374         ibmasm_event_reader_register(sp, &event_data->reader);
 375
 376         event_data->sp = sp;
 377         file->private_data = event_data;
 378         return 0;
 379 }
 380
 381 static int event_file_close(struct inode *inode, struct file *file)
 382 {
 383         struct ibmasmfs_event_data *event_data = file->private_data;
 384
 385         ibmasm_event_reader_unregister(event_data->sp, &event_data->reader);
 386         kfree(event_data);
 387         return 0;
 388 }
 389
 390 static ssize_t event_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
 391 {
 392         struct ibmasmfs_event_data *event_data = file->private_data;
 393         struct event_reader *reader = &event_data->reader;
 394         int ret;
 395
 396         if (*offset < 0)
 397                 return -EINVAL;
 398         if (count == 0 || count > IBMASM_EVENT_MAX_SIZE)
 399                 return 0;
 400         if (*offset != 0)
 401                 return 0;
 402
 403         ret = ibmasm_get_next_event(event_data->sp, reader);
 404         if (ret <= 0)
 405                 return ret;
 406
 407         if (count < reader->data_size)
 408                 return -EINVAL;
 409
 410         if (copy_to_user(buf, reader->data, reader->data_size))
 411                 return -EFAULT;
 412
 413         return reader->data_size;
 414 }
 415
 416 static ssize_t event_file_write(struct file *file, const char __user *buf, size_t count, loff_t *offset)
 417 {
 418         struct ibmasmfs_event_data *event_data = file->private_data;
 419
 420         if (*offset < 0)
 421                 return -EINVAL;
 422         if (count != 1)
 423                 return 0;
 424         if (*offset != 0)
 425                 return 0;
 426
 427         wake_up_interruptible(&event_data->reader.wait);
 428         return 0;
 429 }
 430
 431 static int r_heartbeat_file_open(struct inode *inode, struct file *file)
 432 {
 433         struct ibmasmfs_heartbeat_data *rhbeat;
 434
 435         if (!inode->u.generic_ip)
 436                 return -ENODEV;
 437
 438         rhbeat = kmalloc(sizeof(struct ibmasmfs_heartbeat_data), GFP_KERNEL);
 439         if (!rhbeat)
 440                 return -ENOMEM;
 441
 442         rhbeat->sp = (struct service_processor *)inode->u.generic_ip;
 443         rhbeat->active = 0;
 444         ibmasm_init_reverse_heartbeat(rhbeat->sp, &rhbeat->heartbeat);
 445         file->private_data = rhbeat;
 446         return 0;
 447 }
 448
 449 static int r_heartbeat_file_close(struct inode *inode, struct file *file)
 450 {
 451         struct ibmasmfs_heartbeat_data *rhbeat = file->private_data;
 452
 453         kfree(rhbeat);
 454         return 0;
 455 }
 456
 457 static ssize_t r_heartbeat_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
 458 {
 459         struct ibmasmfs_heartbeat_data *rhbeat = file->private_data;
 460         unsigned long flags;
 461         int result;
 462
 463         if (*offset < 0)
 464                 return -EINVAL;
 465         if (count == 0 || count > 1024)
 466                 return 0;
 467         if (*offset != 0)
 468                 return 0;
 469
 470         /* allow only one reverse heartbeat per process */
 471         spin_lock_irqsave(&rhbeat->sp->lock, flags);
 472         if (rhbeat->active) {
 473                 spin_unlock_irqrestore(&rhbeat->sp->lock, flags);
 474                 return -EBUSY;
 475         }
 476         rhbeat->active = 1;
 477         spin_unlock_irqrestore(&rhbeat->sp->lock, flags);
 478
 479         result = ibmasm_start_reverse_heartbeat(rhbeat->sp, &rhbeat->heartbeat);
 480         rhbeat->active = 0;
 481
 482         return result;
 483 }
 484
 485 static ssize_t r_heartbeat_file_write(struct file *file, const char __user *buf, size_t count, loff_t *offset)
 486 {
 487         struct ibmasmfs_heartbeat_data *rhbeat = file->private_data;
 488
 489         if (*offset < 0)
 490                 return -EINVAL;
 491         if (count != 1)
 492                 return 0;
 493         if (*offset != 0)
 494                 return 0;
 495
 496         if (rhbeat->active)
 497                 ibmasm_stop_reverse_heartbeat(&rhbeat->heartbeat);
 498
 499         return 1;
 500 }
 501
 502 static int remote_settings_file_open(struct inode *inode, struct file *file)
 503 {
 504         file->private_data = inode->u.generic_ip;
 505         return 0;
 506 }
 507
 508 static int remote_settings_file_close(struct inode *inode, struct file *file)
 509 {
 510         return 0;
 511 }
 512
 513 static ssize_t remote_settings_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
 514 {
 515         void __iomem *address = (void __iomem *)file->private_data;
 516         unsigned char *page;
 517         int retval;
 518         int len = 0;
 519         unsigned int value;
 520
 521         if (*offset < 0)
 522                 return -EINVAL;
 523         if (count == 0 || count > 1024)
 524                 return 0;
 525         if (*offset != 0)
 526                 return 0;
 527
 528         page = (unsigned char *)__get_free_page(GFP_KERNEL);
 529         if (!page)
 530                 return -ENOMEM;
 531
 532         value = readl(address);
 533         len = sprintf(page, "%d\n", value);
 534
 535         if (copy_to_user(buf, page, len)) {
 536                 retval = -EFAULT;
 537                 goto exit;
 538         }
 539         *offset += len;
 540         retval = len;
 541
 542 exit:
 543         free_page((unsigned long)page);
 544         return retval;
 545 }
 546
 547 static ssize_t remote_settings_file_write(struct file *file, const char __user *ubuff, size_t count, loff_t *offset)
 548 {
 549         void __iomem *address = (void __iomem *)file->private_data;
 550         char *buff;
 551         unsigned int value;
 552
 553         if (*offset < 0)
 554                 return -EINVAL;
 555         if (count == 0 || count > 1024)
 556                 return 0;
 557         if (*offset != 0)
 558                 return 0;
 559
 560         buff = kmalloc (count + 1, GFP_KERNEL);
 561         if (!buff)
 562                 return -ENOMEM;
 563
 564         memset(buff, 0x0, count + 1);
 565
 566         if (copy_from_user(buff, ubuff, count)) {
 567                 kfree(buff);
 568                 return -EFAULT;
 569         }
 570
 571         value = simple_strtoul(buff, NULL, 10);
 572         writel(value, address);
 573         kfree(buff);
 574
 575         return count;
 576 }
 577
 578 static int remote_event_file_open(struct inode *inode, struct file *file)
 579 {
 580         struct service_processor *sp;
 581         unsigned long flags;
 582         struct remote_queue *q;
 583
 584         file->private_data = inode->u.generic_ip;
 585         sp = file->private_data;
 586         q = &sp->remote_queue;
 587
 588         /* allow only one event reader */
 589         spin_lock_irqsave(&sp->lock, flags);
 590         if (q->open) {
 591                 spin_unlock_irqrestore(&sp->lock, flags);
 592                 return -EBUSY;
 593         }
 594         q->open = 1;
 595         spin_unlock_irqrestore(&sp->lock, flags);
 596
 597         enable_mouse_interrupts(sp);
 598
 599         return 0;
 600 }
 601
 602 static int remote_event_file_close(struct inode *inode, struct file *file)
 603 {
 604         struct service_processor *sp = file->private_data;
 605
 606         disable_mouse_interrupts(sp);
 607         wake_up_interruptible(&sp->remote_queue.wait);
 608         sp->remote_queue.open = 0;
 609
 610         return 0;
 611 }
 612
 613 static ssize_t remote_event_file_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
 614 {
 615         struct service_processor *sp = file->private_data;
 616         struct remote_queue *q = &sp->remote_queue;
 617         size_t data_size;
 618         struct remote_event *reader = q->reader;
 619         size_t num_events;
 620
 621         if (*offset < 0)
 622                 return -EINVAL;
 623         if (count == 0 || count > 1024)
 624                 return 0;
 625         if (*offset != 0)
 626                 return 0;
 627
 628         if (wait_event_interruptible(q->wait, q->reader != q->writer))
 629                 return -ERESTARTSYS;
 630
 631         /* only get multiples of struct remote_event */
 632         num_events = min((count/sizeof(struct remote_event)), ibmasm_events_available(q));
 633         if (!num_events)
 634                 return 0;
 635
 636         data_size = num_events * sizeof(struct remote_event);
 637
 638         if (copy_to_user(buf, reader, data_size))
 639                 return -EFAULT;
 640
 641         ibmasm_advance_reader(q, num_events);
 642
 643         return data_size;
 644 }
 645
 646
 647 static struct file_operations command_fops = {
 648         .open =         command_file_open,
 649         .release =      command_file_close,
 650         .read =         command_file_read,
 651         .write =        command_file_write,
 652 };
 653
 654 static struct file_operations event_fops = {
 655         .open =         event_file_open,
 656         .release =      event_file_close,
 657         .read =         event_file_read,
 658         .write =        event_file_write,
 659 };
 660
 661 static struct file_operations r_heartbeat_fops = {
 662         .open =         r_heartbeat_file_open,
 663         .release =      r_heartbeat_file_close,
 664         .read =         r_heartbeat_file_read,
 665         .write =        r_heartbeat_file_write,
 666 };
 667
 668 static struct file_operations remote_settings_fops = {
 669         .open =         remote_settings_file_open,
 670         .release =      remote_settings_file_close,
 671         .read =         remote_settings_file_read,
 672         .write =        remote_settings_file_write,
 673 };
 674
 675 static struct file_operations remote_event_fops = {
 676         .open =         remote_event_file_open,
 677         .release =      remote_event_file_close,
 678         .read =         remote_event_file_read,
 679 };
 680
 681
 682 static void ibmasmfs_create_files (struct super_block *sb, struct dentry *root)
 683 {
 684         struct list_head *entry;
 685         struct service_processor *sp;
 686
 687         list_for_each(entry, &service_processors) {
 688                 struct dentry *dir;
 689                 struct dentry *remote_dir;
 690                 sp = list_entry(entry, struct service_processor, node);
 691                 dir = ibmasmfs_create_dir(sb, root, sp->dirname);
 692                 if (!dir)
 693                         continue;
 694
 695                 ibmasmfs_create_file(sb, dir, "command", &command_fops, sp, S_IRUSR|S_IWUSR);
 696                 ibmasmfs_create_file(sb, dir, "event", &event_fops, sp, S_IRUSR|S_IWUSR);
 697                 ibmasmfs_create_file(sb, dir, "reverse_heartbeat", &r_heartbeat_fops, sp, S_IRUSR|S_IWUSR);
 698
 699                 remote_dir = ibmasmfs_create_dir(sb, dir, "remote_video");
 700                 if (!remote_dir)
 701                         continue;
 702
 703                 ibmasmfs_create_file(sb, remote_dir, "width", &remote_settings_fops, (void *)display_width(sp), S_IRUSR|S_IWUSR);
 704                 ibmasmfs_create_file(sb, remote_dir, "height", &remote_settings_fops, (void *)display_height(sp), S_IRUSR|S_IWUSR);
 705                 ibmasmfs_create_file(sb, remote_dir, "depth", &remote_settings_fops, (void *)display_depth(sp), S_IRUSR|S_IWUSR);
 706                 ibmasmfs_create_file(sb, remote_dir, "connected", &remote_settings_fops, (void *)vnc_status(sp), S_IRUSR);
 707                 ibmasmfs_create_file(sb, remote_dir, "events", &remote_event_fops, (void *)sp, S_IRUSR);
 708         }
 709 }