drivers/block/swim_iop.c

   1 /*
   2  * Driver for the SWIM (Super Woz Integrated Machine) IOP
   3  * floppy controller on the Macintosh IIfx and Quadra 900/950
   4  *
   5  * Written by Joshua M. Thompson (funaho@jurai.org)
   6  * based on the SWIM3 driver (c) 1996 by Paul Mackerras.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * as published by the Free Software Foundation; either version
  11  * 2 of the License, or (at your option) any later version.
  12  *
  13  * 1999-06-12 (jmt) - Initial implementation.
  14  */
  15
  16 /*
  17  * -------------------
  18  * Theory of Operation
  19  * -------------------
  20  *
  21  * Since the SWIM IOP is message-driven we implement a simple request queue
  22  * system.  One outstanding request may be queued at any given time (this is
  23  * an IOP limitation); only when that request has completed can a new request
  24  * be sent.
  25  */
  26
  27 #include <linux/stddef.h>
  28 #include <linux/kernel.h>
  29 #include <linux/sched.h>
  30 #include <linux/timer.h>
  31 #include <linux/delay.h>
  32 #include <linux/fd.h>
  33 #include <linux/ioctl.h>
  34 #include <linux/blkdev.h>
  35 #include <asm/io.h>
  36 #include <asm/uaccess.h>
  37 #include <asm/mac_iop.h>
  38 #include <asm/swim_iop.h>
  39
  40 #define DRIVER_VERSION "Version 0.1 (1999-06-12)"
  41
  42 #define MAX_FLOPPIES    4
  43
  44 enum swim_state {
  45         idle,
  46         available,
  47         revalidating,
  48         transferring,
  49         ejecting
  50 };
  51
  52 struct floppy_state {
  53         enum swim_state state;
  54         int     drive_num;      /* device number */
  55         int     secpercyl;      /* disk geometry information */
  56         int     secpertrack;
  57         int     total_secs;
  58         int     write_prot;     /* 1 if write-protected, 0 if not, -1 dunno */
  59         int     ref_count;
  60         struct timer_list timeout;
  61         int     ejected;
  62         struct wait_queue *wait;
  63         int     wanted;
  64         int     timeout_pending;
  65 };
  66
  67 struct swim_iop_req {
  68         int     sent;
  69         int     complete;
  70         __u8    command[32];
  71         struct floppy_state *fs;
  72         void    (*done)(struct swim_iop_req *);
  73 };
  74
  75 static struct swim_iop_req *current_req;
  76 static int floppy_count;
  77
  78 static struct floppy_state floppy_states[MAX_FLOPPIES];
  79 static DEFINE_SPINLOCK(swim_iop_lock);
  80
  81 #define CURRENT elv_next_request(swim_queue)
  82
  83 static char *drive_names[7] = {
  84         "not installed",        /* DRV_NONE    */
  85         "unknown (1)",          /* DRV_UNKNOWN */
  86         "a 400K drive",         /* DRV_400K    */
  87         "an 800K drive"         /* DRV_800K    */
  88         "unknown (4)",          /* ????        */
  89         "an FDHD",              /* DRV_FDHD    */
  90         "unknown (6)",          /* ????        */
  91         "an Apple HD20"         /* DRV_HD20    */
  92 };
  93
  94 int swimiop_init(void);
  95 static void swimiop_init_request(struct swim_iop_req *);
  96 static int swimiop_send_request(struct swim_iop_req *);
  97 static void swimiop_receive(struct iop_msg *, struct pt_regs *);
  98 static void swimiop_status_update(int, struct swim_drvstatus *);
  99 static int swimiop_eject(struct floppy_state *fs);
 100
 101 static int floppy_ioctl(struct inode *inode, struct file *filp,
 102                         unsigned int cmd, unsigned long param);
 103 static int floppy_open(struct inode *inode, struct file *filp);
 104 static int floppy_release(struct inode *inode, struct file *filp);
 105 static int floppy_check_change(struct gendisk *disk);
 106 static int floppy_revalidate(struct gendisk *disk);
 107 static int grab_drive(struct floppy_state *fs, enum swim_state state,
 108                       int interruptible);
 109 static void release_drive(struct floppy_state *fs);
 110 static void set_timeout(struct floppy_state *fs, int nticks,
 111                         void (*proc)(unsigned long));
 112 static void fd_request_timeout(unsigned long);
 113 static void do_fd_request(request_queue_t * q);
 114 static void start_request(struct floppy_state *fs);
 115
 116 static struct block_device_operations floppy_fops = {
 117         .open           = floppy_open,
 118         .release        = floppy_release,
 119         .ioctl          = floppy_ioctl,
 120         .media_changed  = floppy_check_change,
 121         .revalidate_disk= floppy_revalidate,
 122 };
 123
 124 static struct request_queue *swim_queue;
 125 /*
 126  * SWIM IOP initialization
 127  */
 128
 129 int swimiop_init(void)
 130 {
 131         volatile struct swim_iop_req req;
 132         struct swimcmd_status *cmd = (struct swimcmd_status *) &req.command[0];
 133         struct swim_drvstatus *ds = &cmd->status;
 134         struct floppy_state *fs;
 135         int i;
 136
 137         current_req = NULL;
 138         floppy_count = 0;
 139
 140         if (!iop_ism_present)
 141                 return -ENODEV;
 142
 143         if (register_blkdev(FLOPPY_MAJOR, "fd"))
 144                 return -EBUSY;
 145
 146         swim_queue = blk_init_queue(do_fd_request, &swim_iop_lock);
 147         if (!swim_queue) {
 148                 unregister_blkdev(FLOPPY_MAJOR, "fd");
 149                 return -ENOMEM;
 150         }
 151
 152         printk("SWIM-IOP: %s by Joshua M. Thompson (funaho@jurai.org)\n",
 153                 DRIVER_VERSION);
 154
 155         if (iop_listen(SWIM_IOP, SWIM_CHAN, swimiop_receive, "SWIM") != 0) {
 156                 printk(KERN_ERR "SWIM-IOP: IOP channel already in use; can't initialize.\n");
 157                 unregister_blkdev(FLOPPY_MAJOR, "fd");
 158                 blk_cleanup_queue(swim_queue);
 159                 return -EBUSY;
 160         }
 161
 162         printk(KERN_ERR "SWIM_IOP: probing for installed drives.\n");
 163
 164         for (i = 0 ; i < MAX_FLOPPIES ; i++) {
 165                 memset(&floppy_states[i], 0, sizeof(struct floppy_state));
 166                 fs = &floppy_states[floppy_count];
 167
 168                 swimiop_init_request(&req);
 169                 cmd->code = CMD_STATUS;
 170                 cmd->drive_num = i + 1;
 171                 if (swimiop_send_request(&req) != 0) continue;
 172                 while (!req.complete);
 173                 if (cmd->error != 0) {
 174                         printk(KERN_ERR "SWIM-IOP: probe on drive %d returned error %d\n", i, (uint) cmd->error);
 175                         continue;
 176                 }
 177                 if (ds->installed != 0x01) continue;
 178                 printk("SWIM-IOP: drive %d is %s (%s, %s, %s, %s)\n", i,
 179                         drive_names[ds->info.type],
 180                         ds->info.external? "ext" : "int",
 181                         ds->info.scsi? "scsi" : "floppy",
 182                         ds->info.fixed? "fixed" : "removable",
 183                         ds->info.secondary? "secondary" : "primary");
 184                 swimiop_status_update(floppy_count, ds);
 185                 fs->state = idle;
 186
 187                 init_timer(&fs->timeout);
 188                 floppy_count++;
 189         }
 190         printk("SWIM-IOP: detected %d installed drives.\n", floppy_count);
 191
 192         for (i = 0; i < floppy_count; i++) {
 193                 struct gendisk *disk = alloc_disk(1);
 194                 if (!disk)
 195                         continue;
 196                 disk->major = FLOPPY_MAJOR;
 197                 disk->first_minor = i;
 198                 disk->fops = &floppy_fops;
 199                 sprintf(disk->disk_name, "fd%d", i);
 200                 disk->private_data = &floppy_states[i];
 201                 disk->queue = swim_queue;
 202                 set_capacity(disk, 2880 * 2);
 203                 add_disk(disk);
 204         }
 205
 206         return 0;
 207 }
 208
 209 static void swimiop_init_request(struct swim_iop_req *req)
 210 {
 211         req->sent = 0;
 212         req->complete = 0;
 213         req->done = NULL;
 214 }
 215
 216 static int swimiop_send_request(struct swim_iop_req *req)
 217 {
 218         unsigned long flags;
 219         int err;
 220
 221         /* It's doubtful an interrupt routine would try to send */
 222         /* a SWIM request, but I'd rather play it safe here.    */
 223
 224         local_irq_save(flags);
 225
 226         if (current_req != NULL) {
 227                 local_irq_restore(flags);
 228                 return -ENOMEM;
 229         }
 230
 231         current_req = req;
 232
 233         /* Interrupts should be back on for iop_send_message() */
 234
 235         local_irq_restore(flags);
 236
 237         err = iop_send_message(SWIM_IOP, SWIM_CHAN, (void *) req,
 238                                 sizeof(req->command), (__u8 *) &req->command[0],
 239                                 swimiop_receive);
 240
 241         /* No race condition here; we own current_req at this point */
 242
 243         if (err) {
 244                 current_req = NULL;
 245         } else {
 246                 req->sent = 1;
 247         }
 248         return err;
 249 }
 250
 251 /*
 252  * Receive a SWIM message from the IOP.
 253  *
 254  * This will be called in two cases:
 255  *
 256  * 1. A message has been successfully sent to the IOP.
 257  * 2. An unsolicited message was received from the IOP.
 258  */
 259
 260 void swimiop_receive(struct iop_msg *msg, struct pt_regs *regs)
 261 {
 262         struct swim_iop_req *req;
 263         struct swimmsg_status *sm;
 264         struct swim_drvstatus *ds;
 265
 266         req = current_req;
 267
 268         switch(msg->status) {
 269                 case IOP_MSGSTATUS_COMPLETE:
 270                         memcpy(&req->command[0], &msg->reply[0], sizeof(req->command));
 271                         req->complete = 1;
 272                         if (req->done) (*req->done)(req);
 273                         current_req = NULL;
 274                         break;
 275                 case IOP_MSGSTATUS_UNSOL:
 276                         sm = (struct swimmsg_status *) &msg->message[0];
 277                         ds = &sm->status;
 278                         swimiop_status_update(sm->drive_num, ds);
 279                         iop_complete_message(msg);
 280                         break;
 281         }
 282 }
 283
 284 static void swimiop_status_update(int drive_num, struct swim_drvstatus *ds)
 285 {
 286         struct floppy_state *fs = &floppy_states[drive_num];
 287
 288         fs->write_prot = (ds->write_prot == 0x80);
 289         if ((ds->disk_in_drive != 0x01) && (ds->disk_in_drive != 0x02)) {
 290                 fs->ejected = 1;
 291         } else {
 292                 fs->ejected = 0;
 293         }
 294         switch(ds->info.type) {
 295                 case DRV_400K:
 296                         fs->secpercyl = 10;
 297                         fs->secpertrack = 10;
 298                         fs->total_secs = 800;
 299                         break;
 300                 case DRV_800K:
 301                         fs->secpercyl = 20;
 302                         fs->secpertrack = 10;
 303                         fs->total_secs = 1600;
 304                         break;
 305                 case DRV_FDHD:
 306                         fs->secpercyl = 36;
 307                         fs->secpertrack = 18;
 308                         fs->total_secs = 2880;
 309                         break;
 310                 default:
 311                         fs->secpercyl = 0;
 312                         fs->secpertrack = 0;
 313                         fs->total_secs = 0;
 314                         break;
 315         }
 316 }
 317
 318 static int swimiop_eject(struct floppy_state *fs)
 319 {
 320         int err, n;
 321         struct swim_iop_req req;
 322         struct swimcmd_eject *cmd = (struct swimcmd_eject *) &req.command[0];
 323
 324         err = grab_drive(fs, ejecting, 1);
 325         if (err) return err;
 326
 327         swimiop_init_request(&req);
 328         cmd->code = CMD_EJECT;
 329         cmd->drive_num = fs->drive_num;
 330         err = swimiop_send_request(&req);
 331         if (err) {
 332                 release_drive(fs);
 333                 return err;
 334         }
 335         for (n = 2*HZ; n > 0; --n) {
 336                 if (req.complete) break;
 337                 if (signal_pending(current)) {
 338                         err = -EINTR;
 339                         break;
 340                 }
 341                 current->state = TASK_INTERRUPTIBLE;
 342                 schedule_timeout(1);
 343         }
 344         release_drive(fs);
 345         return cmd->error;
 346 }
 347
 348 static struct floppy_struct floppy_type =
 349         { 2880,18,2,80,0,0x1B,0x00,0xCF,0x6C,NULL };    /*  7 1.44MB 3.5"   */
 350
 351 static int floppy_ioctl(struct inode *inode, struct file *filp,
 352                         unsigned int cmd, unsigned long param)
 353 {
 354         struct floppy_state *fs = inode->i_bdev->bd_disk->private_data;
 355         int err;
 356
 357         if ((cmd & 0x80) && !capable(CAP_SYS_ADMIN))
 358                 return -EPERM;
 359
 360         switch (cmd) {
 361         case FDEJECT:
 362                 if (fs->ref_count != 1)
 363                         return -EBUSY;
 364                 err = swimiop_eject(fs);
 365                 return err;
 366         case FDGETPRM:
 367                 if (copy_to_user((void *) param, (void *) &floppy_type,
 368                                  sizeof(struct floppy_struct)))
 369                         return -EFAULT;
 370                 return 0;
 371         }
 372         return -ENOTTY;
 373 }
 374
 375 static int floppy_open(struct inode *inode, struct file *filp)
 376 {
 377         struct floppy_state *fs = inode->i_bdev->bd_disk->private_data;
 378
 379         if (fs->ref_count == -1 || filp->f_flags & O_EXCL)
 380                 return -EBUSY;
 381
 382         if ((filp->f_flags & O_NDELAY) == 0 && (filp->f_mode & 3)) {
 383                 check_disk_change(inode->i_bdev);
 384                 if (fs->ejected)
 385                         return -ENXIO;
 386         }
 387
 388         if ((filp->f_mode & 2) && fs->write_prot)
 389                 return -EROFS;
 390
 391         if (filp->f_flags & O_EXCL)
 392                 fs->ref_count = -1;
 393         else
 394                 ++fs->ref_count;
 395
 396         return 0;
 397 }
 398
 399 static int floppy_release(struct inode *inode, struct file *filp)
 400 {
 401         struct floppy_state *fs = inode->i_bdev->bd_disk->private_data;
 402         if (fs->ref_count > 0)
 403                 fs->ref_count--;
 404         return 0;
 405 }
 406
 407 static int floppy_check_change(struct gendisk *disk)
 408 {
 409         struct floppy_state *fs = disk->private_data;
 410         return fs->ejected;
 411 }
 412
 413 static int floppy_revalidate(struct gendisk *disk)
 414 {
 415         struct floppy_state *fs = disk->private_data;
 416         grab_drive(fs, revalidating, 0);
 417         /* yadda, yadda */
 418         release_drive(fs);
 419         return 0;
 420 }
 421
 422 static void floppy_off(unsigned int nr)
 423 {
 424 }
 425
 426 static int grab_drive(struct floppy_state *fs, enum swim_state state,
 427                       int interruptible)
 428 {
 429         unsigned long flags;
 430
 431         local_irq_save(flags);
 432         if (fs->state != idle) {
 433                 ++fs->wanted;
 434                 while (fs->state != available) {
 435                         if (interruptible && signal_pending(current)) {
 436                                 --fs->wanted;
 437                                 local_irq_restore(flags);
 438                                 return -EINTR;
 439                         }
 440                         interruptible_sleep_on(&fs->wait);
 441                 }
 442                 --fs->wanted;
 443         }
 444         fs->state = state;
 445         local_irq_restore(flags);
 446         return 0;
 447 }
 448
 449 static void release_drive(struct floppy_state *fs)
 450 {
 451         unsigned long flags;
 452
 453         local_irq_save(flags);
 454         fs->state = idle;
 455         start_request(fs);
 456         local_irq_restore(flags);
 457 }
 458
 459 static void set_timeout(struct floppy_state *fs, int nticks,
 460                         void (*proc)(unsigned long))
 461 {
 462         unsigned long flags;
 463
 464         local_irq_save(flags);
 465         if (fs->timeout_pending)
 466                 del_timer(&fs->timeout);
 467         init_timer(&fs->timeout);
 468         fs->timeout.expires = jiffies + nticks;
 469         fs->timeout.function = proc;
 470         fs->timeout.data = (unsigned long) fs;
 471         add_timer(&fs->timeout);
 472         fs->timeout_pending = 1;
 473         local_irq_restore(flags);
 474 }
 475
 476 static void do_fd_request(request_queue_t * q)
 477 {
 478         int i;
 479
 480         for (i = 0 ; i < floppy_count ; i++) {
 481                 start_request(&floppy_states[i]);
 482         }
 483 }
 484
 485 static void fd_request_complete(struct swim_iop_req *req)
 486 {
 487         struct floppy_state *fs = req->fs;
 488         struct swimcmd_rw *cmd = (struct swimcmd_rw *) &req->command[0];
 489
 490         del_timer(&fs->timeout);
 491         fs->timeout_pending = 0;
 492         fs->state = idle;
 493         if (cmd->error) {
 494                 printk(KERN_ERR "SWIM-IOP: error %d on read/write request.\n", cmd->error);
 495                 end_request(CURRENT, 0);
 496         } else {
 497                 CURRENT->sector += cmd->num_blocks;
 498                 CURRENT->current_nr_sectors -= cmd->num_blocks;
 499                 if (CURRENT->current_nr_sectors <= 0) {
 500                         end_request(CURRENT, 1);
 501                         return;
 502                 }
 503         }
 504         start_request(fs);
 505 }
 506
 507 static void fd_request_timeout(unsigned long data)
 508 {
 509         struct floppy_state *fs = (struct floppy_state *) data;
 510
 511         fs->timeout_pending = 0;
 512         end_request(CURRENT, 0);
 513         fs->state = idle;
 514 }
 515
 516 static void start_request(struct floppy_state *fs)
 517 {
 518         volatile struct swim_iop_req req;
 519         struct swimcmd_rw *cmd = (struct swimcmd_rw *) &req.command[0];
 520
 521         if (fs->state == idle && fs->wanted) {
 522                 fs->state = available;
 523                 wake_up(&fs->wait);
 524                 return;
 525         }
 526         while (CURRENT && fs->state == idle) {
 527                 if (CURRENT->bh && !buffer_locked(CURRENT->bh))
 528                         panic("floppy: block not locked");
 529 #if 0
 530                 printk("do_fd_req: dev=%s cmd=%d sec=%ld nr_sec=%ld buf=%p\n",
 531                        CURRENT->rq_disk->disk_name, CURRENT->cmd,
 532                        CURRENT->sector, CURRENT->nr_sectors, CURRENT->buffer);
 533                 printk("           rq_status=%d errors=%d current_nr_sectors=%ld\n",
 534                        CURRENT->rq_status, CURRENT->errors, CURRENT->current_nr_sectors);
 535 #endif
 536
 537                 if (CURRENT->sector < 0 || CURRENT->sector >= fs->total_secs) {
 538                         end_request(CURRENT, 0);
 539                         continue;
 540                 }
 541                 if (CURRENT->current_nr_sectors == 0) {
 542                         end_request(CURRENT, 1);
 543                         continue;
 544                 }
 545                 if (fs->ejected) {
 546                         end_request(CURRENT, 0);
 547                         continue;
 548                 }
 549
 550                 swimiop_init_request(&req);
 551                 req.fs = fs;
 552                 req.done = fd_request_complete;
 553
 554                 if (CURRENT->cmd == WRITE) {
 555                         if (fs->write_prot) {
 556                                 end_request(CURRENT, 0);
 557                                 continue;
 558                         }
 559                         cmd->code = CMD_WRITE;
 560                 } else {
 561                         cmd->code = CMD_READ;
 562
 563                 }
 564                 cmd->drive_num = fs->drive_num;
 565                 cmd->buffer = CURRENT->buffer;
 566                 cmd->first_block = CURRENT->sector;
 567                 cmd->num_blocks = CURRENT->current_nr_sectors;
 568
 569                 if (swimiop_send_request(&req)) {
 570                         end_request(CURRENT, 0);
 571                         continue;
 572                 }
 573
 574                 set_timeout(fs, HZ*CURRENT->current_nr_sectors,
 575                                 fd_request_timeout);
 576
 577                 fs->state = transferring;
 578         }
 579 }