random32: make prandom_u32() output unpredictable
[platform/kernel/linux-starfive.git] / drivers / block / swim3.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Driver for the SWIM3 (Super Woz Integrated Machine 3)
4  * floppy controller found on Power Macintoshes.
5  *
6  * Copyright (C) 1996 Paul Mackerras.
7  */
8
9 /*
10  * TODO:
11  * handle 2 drives
12  * handle GCR disks
13  */
14
15 #undef DEBUG
16
17 #include <linux/stddef.h>
18 #include <linux/kernel.h>
19 #include <linux/sched/signal.h>
20 #include <linux/timer.h>
21 #include <linux/delay.h>
22 #include <linux/fd.h>
23 #include <linux/ioctl.h>
24 #include <linux/blk-mq.h>
25 #include <linux/interrupt.h>
26 #include <linux/mutex.h>
27 #include <linux/module.h>
28 #include <linux/spinlock.h>
29 #include <linux/wait.h>
30 #include <asm/io.h>
31 #include <asm/dbdma.h>
32 #include <asm/prom.h>
33 #include <linux/uaccess.h>
34 #include <asm/mediabay.h>
35 #include <asm/machdep.h>
36 #include <asm/pmac_feature.h>
37
38 #define MAX_FLOPPIES    2
39
40 static DEFINE_MUTEX(swim3_mutex);
41 static struct gendisk *disks[MAX_FLOPPIES];
42
43 enum swim_state {
44         idle,
45         locating,
46         seeking,
47         settling,
48         do_transfer,
49         jogging,
50         available,
51         revalidating,
52         ejecting
53 };
54
55 #define REG(x)  unsigned char x; char x ## _pad[15];
56
57 /*
58  * The names for these registers mostly represent speculation on my part.
59  * It will be interesting to see how close they are to the names Apple uses.
60  */
61 struct swim3 {
62         REG(data);
63         REG(timer);             /* counts down at 1MHz */
64         REG(error);
65         REG(mode);
66         REG(select);            /* controls CA0, CA1, CA2 and LSTRB signals */
67         REG(setup);
68         REG(control);           /* writing bits clears them */
69         REG(status);            /* writing bits sets them in control */
70         REG(intr);
71         REG(nseek);             /* # tracks to seek */
72         REG(ctrack);            /* current track number */
73         REG(csect);             /* current sector number */
74         REG(gap3);              /* size of gap 3 in track format */
75         REG(sector);            /* sector # to read or write */
76         REG(nsect);             /* # sectors to read or write */
77         REG(intr_enable);
78 };
79
80 #define control_bic     control
81 #define control_bis     status
82
83 /* Bits in select register */
84 #define CA_MASK         7
85 #define LSTRB           8
86
87 /* Bits in control register */
88 #define DO_SEEK         0x80
89 #define FORMAT          0x40
90 #define SELECT          0x20
91 #define WRITE_SECTORS   0x10
92 #define DO_ACTION       0x08
93 #define DRIVE2_ENABLE   0x04
94 #define DRIVE_ENABLE    0x02
95 #define INTR_ENABLE     0x01
96
97 /* Bits in status register */
98 #define FIFO_1BYTE      0x80
99 #define FIFO_2BYTE      0x40
100 #define ERROR           0x20
101 #define DATA            0x08
102 #define RDDATA          0x04
103 #define INTR_PENDING    0x02
104 #define MARK_BYTE       0x01
105
106 /* Bits in intr and intr_enable registers */
107 #define ERROR_INTR      0x20
108 #define DATA_CHANGED    0x10
109 #define TRANSFER_DONE   0x08
110 #define SEEN_SECTOR     0x04
111 #define SEEK_DONE       0x02
112 #define TIMER_DONE      0x01
113
114 /* Bits in error register */
115 #define ERR_DATA_CRC    0x80
116 #define ERR_ADDR_CRC    0x40
117 #define ERR_OVERRUN     0x04
118 #define ERR_UNDERRUN    0x01
119
120 /* Bits in setup register */
121 #define S_SW_RESET      0x80
122 #define S_GCR_WRITE     0x40
123 #define S_IBM_DRIVE     0x20
124 #define S_TEST_MODE     0x10
125 #define S_FCLK_DIV2     0x08
126 #define S_GCR           0x04
127 #define S_COPY_PROT     0x02
128 #define S_INV_WDATA     0x01
129
130 /* Select values for swim3_action */
131 #define SEEK_POSITIVE   0
132 #define SEEK_NEGATIVE   4
133 #define STEP            1
134 #define MOTOR_ON        2
135 #define MOTOR_OFF       6
136 #define INDEX           3
137 #define EJECT           7
138 #define SETMFM          9
139 #define SETGCR          13
140
141 /* Select values for swim3_select and swim3_readbit */
142 #define STEP_DIR        0
143 #define STEPPING        1
144 #define MOTOR_ON        2
145 #define RELAX           3       /* also eject in progress */
146 #define READ_DATA_0     4
147 #define ONEMEG_DRIVE    5
148 #define SINGLE_SIDED    6       /* drive or diskette is 4MB type? */
149 #define DRIVE_PRESENT   7
150 #define DISK_IN         8
151 #define WRITE_PROT      9
152 #define TRACK_ZERO      10
153 #define TACHO           11
154 #define READ_DATA_1     12
155 #define GCR_MODE        13
156 #define SEEK_COMPLETE   14
157 #define TWOMEG_MEDIA    15
158
159 /* Definitions of values used in writing and formatting */
160 #define DATA_ESCAPE     0x99
161 #define GCR_SYNC_EXC    0x3f
162 #define GCR_SYNC_CONV   0x80
163 #define GCR_FIRST_MARK  0xd5
164 #define GCR_SECOND_MARK 0xaa
165 #define GCR_ADDR_MARK   "\xd5\xaa\x00"
166 #define GCR_DATA_MARK   "\xd5\xaa\x0b"
167 #define GCR_SLIP_BYTE   "\x27\xaa"
168 #define GCR_SELF_SYNC   "\x3f\xbf\x1e\x34\x3c\x3f"
169
170 #define DATA_99         "\x99\x99"
171 #define MFM_ADDR_MARK   "\x99\xa1\x99\xa1\x99\xa1\x99\xfe"
172 #define MFM_INDEX_MARK  "\x99\xc2\x99\xc2\x99\xc2\x99\xfc"
173 #define MFM_GAP_LEN     12
174
175 struct floppy_state {
176         enum swim_state state;
177         struct swim3 __iomem *swim3;    /* hardware registers */
178         struct dbdma_regs __iomem *dma; /* DMA controller registers */
179         int     swim3_intr;     /* interrupt number for SWIM3 */
180         int     dma_intr;       /* interrupt number for DMA channel */
181         int     cur_cyl;        /* cylinder head is on, or -1 */
182         int     cur_sector;     /* last sector we saw go past */
183         int     req_cyl;        /* the cylinder for the current r/w request */
184         int     head;           /* head number ditto */
185         int     req_sector;     /* sector number ditto */
186         int     scount;         /* # sectors we're transferring at present */
187         int     retries;
188         int     settle_time;
189         int     secpercyl;      /* disk geometry information */
190         int     secpertrack;
191         int     total_secs;
192         int     write_prot;     /* 1 if write-protected, 0 if not, -1 dunno */
193         struct dbdma_cmd *dma_cmd;
194         int     ref_count;
195         int     expect_cyl;
196         struct timer_list timeout;
197         int     timeout_pending;
198         int     ejected;
199         wait_queue_head_t wait;
200         int     wanted;
201         struct macio_dev *mdev;
202         char    dbdma_cmd_space[5 * sizeof(struct dbdma_cmd)];
203         int     index;
204         struct request *cur_req;
205         struct blk_mq_tag_set tag_set;
206 };
207
208 #define swim3_err(fmt, arg...)  dev_err(&fs->mdev->ofdev.dev, "[fd%d] " fmt, fs->index, arg)
209 #define swim3_warn(fmt, arg...) dev_warn(&fs->mdev->ofdev.dev, "[fd%d] " fmt, fs->index, arg)
210 #define swim3_info(fmt, arg...) dev_info(&fs->mdev->ofdev.dev, "[fd%d] " fmt, fs->index, arg)
211
212 #ifdef DEBUG
213 #define swim3_dbg(fmt, arg...)  dev_dbg(&fs->mdev->ofdev.dev, "[fd%d] " fmt, fs->index, arg)
214 #else
215 #define swim3_dbg(fmt, arg...)  do { } while(0)
216 #endif
217
218 static struct floppy_state floppy_states[MAX_FLOPPIES];
219 static int floppy_count = 0;
220 static DEFINE_SPINLOCK(swim3_lock);
221
222 static unsigned short write_preamble[] = {
223         0x4e4e, 0x4e4e, 0x4e4e, 0x4e4e, 0x4e4e, /* gap field */
224         0, 0, 0, 0, 0, 0,                       /* sync field */
225         0x99a1, 0x99a1, 0x99a1, 0x99fb,         /* data address mark */
226         0x990f                                  /* no escape for 512 bytes */
227 };
228
229 static unsigned short write_postamble[] = {
230         0x9904,                                 /* insert CRC */
231         0x4e4e, 0x4e4e,
232         0x9908,                                 /* stop writing */
233         0, 0, 0, 0, 0, 0
234 };
235
236 static void seek_track(struct floppy_state *fs, int n);
237 static void init_dma(struct dbdma_cmd *cp, int cmd, void *buf, int count);
238 static void act(struct floppy_state *fs);
239 static void scan_timeout(struct timer_list *t);
240 static void seek_timeout(struct timer_list *t);
241 static void settle_timeout(struct timer_list *t);
242 static void xfer_timeout(struct timer_list *t);
243 static irqreturn_t swim3_interrupt(int irq, void *dev_id);
244 /*static void fd_dma_interrupt(int irq, void *dev_id);*/
245 static int grab_drive(struct floppy_state *fs, enum swim_state state,
246                       int interruptible);
247 static void release_drive(struct floppy_state *fs);
248 static int fd_eject(struct floppy_state *fs);
249 static int floppy_ioctl(struct block_device *bdev, fmode_t mode,
250                         unsigned int cmd, unsigned long param);
251 static int floppy_open(struct block_device *bdev, fmode_t mode);
252 static void floppy_release(struct gendisk *disk, fmode_t mode);
253 static unsigned int floppy_check_events(struct gendisk *disk,
254                                         unsigned int clearing);
255 static int floppy_revalidate(struct gendisk *disk);
256
257 static bool swim3_end_request(struct floppy_state *fs, blk_status_t err, unsigned int nr_bytes)
258 {
259         struct request *req = fs->cur_req;
260
261         swim3_dbg("  end request, err=%d nr_bytes=%d, cur_req=%p\n",
262                   err, nr_bytes, req);
263
264         if (err)
265                 nr_bytes = blk_rq_cur_bytes(req);
266         if (blk_update_request(req, err, nr_bytes))
267                 return true;
268         __blk_mq_end_request(req, err);
269         fs->cur_req = NULL;
270         return false;
271 }
272
273 static void swim3_select(struct floppy_state *fs, int sel)
274 {
275         struct swim3 __iomem *sw = fs->swim3;
276
277         out_8(&sw->select, RELAX);
278         if (sel & 8)
279                 out_8(&sw->control_bis, SELECT);
280         else
281                 out_8(&sw->control_bic, SELECT);
282         out_8(&sw->select, sel & CA_MASK);
283 }
284
285 static void swim3_action(struct floppy_state *fs, int action)
286 {
287         struct swim3 __iomem *sw = fs->swim3;
288
289         swim3_select(fs, action);
290         udelay(1);
291         out_8(&sw->select, sw->select | LSTRB);
292         udelay(2);
293         out_8(&sw->select, sw->select & ~LSTRB);
294         udelay(1);
295 }
296
297 static int swim3_readbit(struct floppy_state *fs, int bit)
298 {
299         struct swim3 __iomem *sw = fs->swim3;
300         int stat;
301
302         swim3_select(fs, bit);
303         udelay(1);
304         stat = in_8(&sw->status);
305         return (stat & DATA) == 0;
306 }
307
308 static blk_status_t swim3_queue_rq(struct blk_mq_hw_ctx *hctx,
309                                    const struct blk_mq_queue_data *bd)
310 {
311         struct floppy_state *fs = hctx->queue->queuedata;
312         struct request *req = bd->rq;
313         unsigned long x;
314
315         spin_lock_irq(&swim3_lock);
316         if (fs->cur_req || fs->state != idle) {
317                 spin_unlock_irq(&swim3_lock);
318                 return BLK_STS_DEV_RESOURCE;
319         }
320         blk_mq_start_request(req);
321         fs->cur_req = req;
322         if (fs->mdev->media_bay &&
323             check_media_bay(fs->mdev->media_bay) != MB_FD) {
324                 swim3_dbg("%s", "  media bay absent, dropping req\n");
325                 swim3_end_request(fs, BLK_STS_IOERR, 0);
326                 goto out;
327         }
328         if (fs->ejected) {
329                 swim3_dbg("%s", "  disk ejected\n");
330                 swim3_end_request(fs, BLK_STS_IOERR, 0);
331                 goto out;
332         }
333         if (rq_data_dir(req) == WRITE) {
334                 if (fs->write_prot < 0)
335                         fs->write_prot = swim3_readbit(fs, WRITE_PROT);
336                 if (fs->write_prot) {
337                         swim3_dbg("%s", "  try to write, disk write protected\n");
338                         swim3_end_request(fs, BLK_STS_IOERR, 0);
339                         goto out;
340                 }
341         }
342
343         /*
344          * Do not remove the cast. blk_rq_pos(req) is now a sector_t and can be
345          * 64 bits, but it will never go past 32 bits for this driver anyway, so
346          * we can safely cast it down and not have to do a 64/32 division
347          */
348         fs->req_cyl = ((long)blk_rq_pos(req)) / fs->secpercyl;
349         x = ((long)blk_rq_pos(req)) % fs->secpercyl;
350         fs->head = x / fs->secpertrack;
351         fs->req_sector = x % fs->secpertrack + 1;
352         fs->state = do_transfer;
353         fs->retries = 0;
354
355         act(fs);
356
357 out:
358         spin_unlock_irq(&swim3_lock);
359         return BLK_STS_OK;
360 }
361
362 static void set_timeout(struct floppy_state *fs, int nticks,
363                         void (*proc)(struct timer_list *t))
364 {
365         if (fs->timeout_pending)
366                 del_timer(&fs->timeout);
367         fs->timeout.expires = jiffies + nticks;
368         fs->timeout.function = proc;
369         add_timer(&fs->timeout);
370         fs->timeout_pending = 1;
371 }
372
373 static inline void scan_track(struct floppy_state *fs)
374 {
375         struct swim3 __iomem *sw = fs->swim3;
376
377         swim3_select(fs, READ_DATA_0);
378         in_8(&sw->intr);                /* clear SEEN_SECTOR bit */
379         in_8(&sw->error);
380         out_8(&sw->intr_enable, SEEN_SECTOR);
381         out_8(&sw->control_bis, DO_ACTION);
382         /* enable intr when track found */
383         set_timeout(fs, HZ, scan_timeout);      /* enable timeout */
384 }
385
386 static inline void seek_track(struct floppy_state *fs, int n)
387 {
388         struct swim3 __iomem *sw = fs->swim3;
389
390         if (n >= 0) {
391                 swim3_action(fs, SEEK_POSITIVE);
392                 sw->nseek = n;
393         } else {
394                 swim3_action(fs, SEEK_NEGATIVE);
395                 sw->nseek = -n;
396         }
397         fs->expect_cyl = (fs->cur_cyl >= 0)? fs->cur_cyl + n: -1;
398         swim3_select(fs, STEP);
399         in_8(&sw->error);
400         /* enable intr when seek finished */
401         out_8(&sw->intr_enable, SEEK_DONE);
402         out_8(&sw->control_bis, DO_SEEK);
403         set_timeout(fs, 3*HZ, seek_timeout);    /* enable timeout */
404         fs->settle_time = 0;
405 }
406
407 static inline void init_dma(struct dbdma_cmd *cp, int cmd,
408                             void *buf, int count)
409 {
410         cp->req_count = cpu_to_le16(count);
411         cp->command = cpu_to_le16(cmd);
412         cp->phy_addr = cpu_to_le32(virt_to_bus(buf));
413         cp->xfer_status = 0;
414 }
415
416 static inline void setup_transfer(struct floppy_state *fs)
417 {
418         int n;
419         struct swim3 __iomem *sw = fs->swim3;
420         struct dbdma_cmd *cp = fs->dma_cmd;
421         struct dbdma_regs __iomem *dr = fs->dma;
422         struct request *req = fs->cur_req;
423
424         if (blk_rq_cur_sectors(req) <= 0) {
425                 swim3_warn("%s", "Transfer 0 sectors ?\n");
426                 return;
427         }
428         if (rq_data_dir(req) == WRITE)
429                 n = 1;
430         else {
431                 n = fs->secpertrack - fs->req_sector + 1;
432                 if (n > blk_rq_cur_sectors(req))
433                         n = blk_rq_cur_sectors(req);
434         }
435
436         swim3_dbg("  setup xfer at sect %d (of %d) head %d for %d\n",
437                   fs->req_sector, fs->secpertrack, fs->head, n);
438
439         fs->scount = n;
440         swim3_select(fs, fs->head? READ_DATA_1: READ_DATA_0);
441         out_8(&sw->sector, fs->req_sector);
442         out_8(&sw->nsect, n);
443         out_8(&sw->gap3, 0);
444         out_le32(&dr->cmdptr, virt_to_bus(cp));
445         if (rq_data_dir(req) == WRITE) {
446                 /* Set up 3 dma commands: write preamble, data, postamble */
447                 init_dma(cp, OUTPUT_MORE, write_preamble, sizeof(write_preamble));
448                 ++cp;
449                 init_dma(cp, OUTPUT_MORE, bio_data(req->bio), 512);
450                 ++cp;
451                 init_dma(cp, OUTPUT_LAST, write_postamble, sizeof(write_postamble));
452         } else {
453                 init_dma(cp, INPUT_LAST, bio_data(req->bio), n * 512);
454         }
455         ++cp;
456         out_le16(&cp->command, DBDMA_STOP);
457         out_8(&sw->control_bic, DO_ACTION | WRITE_SECTORS);
458         in_8(&sw->error);
459         out_8(&sw->control_bic, DO_ACTION | WRITE_SECTORS);
460         if (rq_data_dir(req) == WRITE)
461                 out_8(&sw->control_bis, WRITE_SECTORS);
462         in_8(&sw->intr);
463         out_le32(&dr->control, (RUN << 16) | RUN);
464         /* enable intr when transfer complete */
465         out_8(&sw->intr_enable, TRANSFER_DONE);
466         out_8(&sw->control_bis, DO_ACTION);
467         set_timeout(fs, 2*HZ, xfer_timeout);    /* enable timeout */
468 }
469
470 static void act(struct floppy_state *fs)
471 {
472         for (;;) {
473                 swim3_dbg("  act loop, state=%d, req_cyl=%d, cur_cyl=%d\n",
474                           fs->state, fs->req_cyl, fs->cur_cyl);
475
476                 switch (fs->state) {
477                 case idle:
478                         return;         /* XXX shouldn't get here */
479
480                 case locating:
481                         if (swim3_readbit(fs, TRACK_ZERO)) {
482                                 swim3_dbg("%s", "    locate track 0\n");
483                                 fs->cur_cyl = 0;
484                                 if (fs->req_cyl == 0)
485                                         fs->state = do_transfer;
486                                 else
487                                         fs->state = seeking;
488                                 break;
489                         }
490                         scan_track(fs);
491                         return;
492
493                 case seeking:
494                         if (fs->cur_cyl < 0) {
495                                 fs->expect_cyl = -1;
496                                 fs->state = locating;
497                                 break;
498                         }
499                         if (fs->req_cyl == fs->cur_cyl) {
500                                 swim3_warn("%s", "Whoops, seeking 0\n");
501                                 fs->state = do_transfer;
502                                 break;
503                         }
504                         seek_track(fs, fs->req_cyl - fs->cur_cyl);
505                         return;
506
507                 case settling:
508                         /* check for SEEK_COMPLETE after 30ms */
509                         fs->settle_time = (HZ + 32) / 33;
510                         set_timeout(fs, fs->settle_time, settle_timeout);
511                         return;
512
513                 case do_transfer:
514                         if (fs->cur_cyl != fs->req_cyl) {
515                                 if (fs->retries > 5) {
516                                         swim3_err("Wrong cylinder in transfer, want: %d got %d\n",
517                                                   fs->req_cyl, fs->cur_cyl);
518                                         swim3_end_request(fs, BLK_STS_IOERR, 0);
519                                         fs->state = idle;
520                                         return;
521                                 }
522                                 fs->state = seeking;
523                                 break;
524                         }
525                         setup_transfer(fs);
526                         return;
527
528                 case jogging:
529                         seek_track(fs, -5);
530                         return;
531
532                 default:
533                         swim3_err("Unknown state %d\n", fs->state);
534                         return;
535                 }
536         }
537 }
538
539 static void scan_timeout(struct timer_list *t)
540 {
541         struct floppy_state *fs = from_timer(fs, t, timeout);
542         struct swim3 __iomem *sw = fs->swim3;
543         unsigned long flags;
544
545         swim3_dbg("* scan timeout, state=%d\n", fs->state);
546
547         spin_lock_irqsave(&swim3_lock, flags);
548         fs->timeout_pending = 0;
549         out_8(&sw->control_bic, DO_ACTION | WRITE_SECTORS);
550         out_8(&sw->select, RELAX);
551         out_8(&sw->intr_enable, 0);
552         fs->cur_cyl = -1;
553         if (fs->retries > 5) {
554                 swim3_end_request(fs, BLK_STS_IOERR, 0);
555                 fs->state = idle;
556         } else {
557                 fs->state = jogging;
558                 act(fs);
559         }
560         spin_unlock_irqrestore(&swim3_lock, flags);
561 }
562
563 static void seek_timeout(struct timer_list *t)
564 {
565         struct floppy_state *fs = from_timer(fs, t, timeout);
566         struct swim3 __iomem *sw = fs->swim3;
567         unsigned long flags;
568
569         swim3_dbg("* seek timeout, state=%d\n", fs->state);
570
571         spin_lock_irqsave(&swim3_lock, flags);
572         fs->timeout_pending = 0;
573         out_8(&sw->control_bic, DO_SEEK);
574         out_8(&sw->select, RELAX);
575         out_8(&sw->intr_enable, 0);
576         swim3_err("%s", "Seek timeout\n");
577         swim3_end_request(fs, BLK_STS_IOERR, 0);
578         fs->state = idle;
579         spin_unlock_irqrestore(&swim3_lock, flags);
580 }
581
582 static void settle_timeout(struct timer_list *t)
583 {
584         struct floppy_state *fs = from_timer(fs, t, timeout);
585         struct swim3 __iomem *sw = fs->swim3;
586         unsigned long flags;
587
588         swim3_dbg("* settle timeout, state=%d\n", fs->state);
589
590         spin_lock_irqsave(&swim3_lock, flags);
591         fs->timeout_pending = 0;
592         if (swim3_readbit(fs, SEEK_COMPLETE)) {
593                 out_8(&sw->select, RELAX);
594                 fs->state = locating;
595                 act(fs);
596                 goto unlock;
597         }
598         out_8(&sw->select, RELAX);
599         if (fs->settle_time < 2*HZ) {
600                 ++fs->settle_time;
601                 set_timeout(fs, 1, settle_timeout);
602                 goto unlock;
603         }
604         swim3_err("%s", "Seek settle timeout\n");
605         swim3_end_request(fs, BLK_STS_IOERR, 0);
606         fs->state = idle;
607  unlock:
608         spin_unlock_irqrestore(&swim3_lock, flags);
609 }
610
611 static void xfer_timeout(struct timer_list *t)
612 {
613         struct floppy_state *fs = from_timer(fs, t, timeout);
614         struct swim3 __iomem *sw = fs->swim3;
615         struct dbdma_regs __iomem *dr = fs->dma;
616         unsigned long flags;
617         int n;
618
619         swim3_dbg("* xfer timeout, state=%d\n", fs->state);
620
621         spin_lock_irqsave(&swim3_lock, flags);
622         fs->timeout_pending = 0;
623         out_le32(&dr->control, RUN << 16);
624         /* We must wait a bit for dbdma to stop */
625         for (n = 0; (in_le32(&dr->status) & ACTIVE) && n < 1000; n++)
626                 udelay(1);
627         out_8(&sw->intr_enable, 0);
628         out_8(&sw->control_bic, WRITE_SECTORS | DO_ACTION);
629         out_8(&sw->select, RELAX);
630         swim3_err("Timeout %sing sector %ld\n",
631                (rq_data_dir(fs->cur_req)==WRITE? "writ": "read"),
632                (long)blk_rq_pos(fs->cur_req));
633         swim3_end_request(fs, BLK_STS_IOERR, 0);
634         fs->state = idle;
635         spin_unlock_irqrestore(&swim3_lock, flags);
636 }
637
638 static irqreturn_t swim3_interrupt(int irq, void *dev_id)
639 {
640         struct floppy_state *fs = (struct floppy_state *) dev_id;
641         struct swim3 __iomem *sw = fs->swim3;
642         int intr, err, n;
643         int stat, resid;
644         struct dbdma_regs __iomem *dr;
645         struct dbdma_cmd *cp;
646         unsigned long flags;
647         struct request *req = fs->cur_req;
648
649         swim3_dbg("* interrupt, state=%d\n", fs->state);
650
651         spin_lock_irqsave(&swim3_lock, flags);
652         intr = in_8(&sw->intr);
653         err = (intr & ERROR_INTR)? in_8(&sw->error): 0;
654         if ((intr & ERROR_INTR) && fs->state != do_transfer)
655                 swim3_err("Non-transfer error interrupt: state=%d, dir=%x, intr=%x, err=%x\n",
656                           fs->state, rq_data_dir(req), intr, err);
657         switch (fs->state) {
658         case locating:
659                 if (intr & SEEN_SECTOR) {
660                         out_8(&sw->control_bic, DO_ACTION | WRITE_SECTORS);
661                         out_8(&sw->select, RELAX);
662                         out_8(&sw->intr_enable, 0);
663                         del_timer(&fs->timeout);
664                         fs->timeout_pending = 0;
665                         if (sw->ctrack == 0xff) {
666                                 swim3_err("%s", "Seen sector but cyl=ff?\n");
667                                 fs->cur_cyl = -1;
668                                 if (fs->retries > 5) {
669                                         swim3_end_request(fs, BLK_STS_IOERR, 0);
670                                         fs->state = idle;
671                                 } else {
672                                         fs->state = jogging;
673                                         act(fs);
674                                 }
675                                 break;
676                         }
677                         fs->cur_cyl = sw->ctrack;
678                         fs->cur_sector = sw->csect;
679                         if (fs->expect_cyl != -1 && fs->expect_cyl != fs->cur_cyl)
680                                 swim3_err("Expected cyl %d, got %d\n",
681                                           fs->expect_cyl, fs->cur_cyl);
682                         fs->state = do_transfer;
683                         act(fs);
684                 }
685                 break;
686         case seeking:
687         case jogging:
688                 if (sw->nseek == 0) {
689                         out_8(&sw->control_bic, DO_SEEK);
690                         out_8(&sw->select, RELAX);
691                         out_8(&sw->intr_enable, 0);
692                         del_timer(&fs->timeout);
693                         fs->timeout_pending = 0;
694                         if (fs->state == seeking)
695                                 ++fs->retries;
696                         fs->state = settling;
697                         act(fs);
698                 }
699                 break;
700         case settling:
701                 out_8(&sw->intr_enable, 0);
702                 del_timer(&fs->timeout);
703                 fs->timeout_pending = 0;
704                 act(fs);
705                 break;
706         case do_transfer:
707                 if ((intr & (ERROR_INTR | TRANSFER_DONE)) == 0)
708                         break;
709                 out_8(&sw->intr_enable, 0);
710                 out_8(&sw->control_bic, WRITE_SECTORS | DO_ACTION);
711                 out_8(&sw->select, RELAX);
712                 del_timer(&fs->timeout);
713                 fs->timeout_pending = 0;
714                 dr = fs->dma;
715                 cp = fs->dma_cmd;
716                 if (rq_data_dir(req) == WRITE)
717                         ++cp;
718                 /*
719                  * Check that the main data transfer has finished.
720                  * On writing, the swim3 sometimes doesn't use
721                  * up all the bytes of the postamble, so we can still
722                  * see DMA active here.  That doesn't matter as long
723                  * as all the sector data has been transferred.
724                  */
725                 if ((intr & ERROR_INTR) == 0 && cp->xfer_status == 0) {
726                         /* wait a little while for DMA to complete */
727                         for (n = 0; n < 100; ++n) {
728                                 if (cp->xfer_status != 0)
729                                         break;
730                                 udelay(1);
731                                 barrier();
732                         }
733                 }
734                 /* turn off DMA */
735                 out_le32(&dr->control, (RUN | PAUSE) << 16);
736                 stat = le16_to_cpu(cp->xfer_status);
737                 resid = le16_to_cpu(cp->res_count);
738                 if (intr & ERROR_INTR) {
739                         n = fs->scount - 1 - resid / 512;
740                         if (n > 0) {
741                                 blk_update_request(req, 0, n << 9);
742                                 fs->req_sector += n;
743                         }
744                         if (fs->retries < 5) {
745                                 ++fs->retries;
746                                 act(fs);
747                         } else {
748                                 swim3_err("Error %sing block %ld (err=%x)\n",
749                                        rq_data_dir(req) == WRITE? "writ": "read",
750                                        (long)blk_rq_pos(req), err);
751                                 swim3_end_request(fs, BLK_STS_IOERR, 0);
752                                 fs->state = idle;
753                         }
754                 } else {
755                         if ((stat & ACTIVE) == 0 || resid != 0) {
756                                 /* musta been an error */
757                                 swim3_err("fd dma error: stat=%x resid=%d\n", stat, resid);
758                                 swim3_err("  state=%d, dir=%x, intr=%x, err=%x\n",
759                                           fs->state, rq_data_dir(req), intr, err);
760                                 swim3_end_request(fs, BLK_STS_IOERR, 0);
761                                 fs->state = idle;
762                                 break;
763                         }
764                         fs->retries = 0;
765                         if (swim3_end_request(fs, 0, fs->scount << 9)) {
766                                 fs->req_sector += fs->scount;
767                                 if (fs->req_sector > fs->secpertrack) {
768                                         fs->req_sector -= fs->secpertrack;
769                                         if (++fs->head > 1) {
770                                                 fs->head = 0;
771                                                 ++fs->req_cyl;
772                                         }
773                                 }
774                                 act(fs);
775                         } else
776                                 fs->state = idle;
777                 }
778                 break;
779         default:
780                 swim3_err("Don't know what to do in state %d\n", fs->state);
781         }
782         spin_unlock_irqrestore(&swim3_lock, flags);
783         return IRQ_HANDLED;
784 }
785
786 /*
787 static void fd_dma_interrupt(int irq, void *dev_id)
788 {
789 }
790 */
791
792 /* Called under the mutex to grab exclusive access to a drive */
793 static int grab_drive(struct floppy_state *fs, enum swim_state state,
794                       int interruptible)
795 {
796         unsigned long flags;
797
798         swim3_dbg("%s", "-> grab drive\n");
799
800         spin_lock_irqsave(&swim3_lock, flags);
801         if (fs->state != idle && fs->state != available) {
802                 ++fs->wanted;
803                 /* this will enable irqs in order to sleep */
804                 if (!interruptible)
805                         wait_event_lock_irq(fs->wait,
806                                         fs->state == available,
807                                         swim3_lock);
808                 else if (wait_event_interruptible_lock_irq(fs->wait,
809                                         fs->state == available,
810                                         swim3_lock)) {
811                         --fs->wanted;
812                         spin_unlock_irqrestore(&swim3_lock, flags);
813                         return -EINTR;
814                 }
815                 --fs->wanted;
816         }
817         fs->state = state;
818         spin_unlock_irqrestore(&swim3_lock, flags);
819
820         return 0;
821 }
822
823 static void release_drive(struct floppy_state *fs)
824 {
825         struct request_queue *q = disks[fs->index]->queue;
826         unsigned long flags;
827
828         swim3_dbg("%s", "-> release drive\n");
829
830         spin_lock_irqsave(&swim3_lock, flags);
831         fs->state = idle;
832         spin_unlock_irqrestore(&swim3_lock, flags);
833
834         blk_mq_freeze_queue(q);
835         blk_mq_quiesce_queue(q);
836         blk_mq_unquiesce_queue(q);
837         blk_mq_unfreeze_queue(q);
838 }
839
840 static int fd_eject(struct floppy_state *fs)
841 {
842         int err, n;
843
844         err = grab_drive(fs, ejecting, 1);
845         if (err)
846                 return err;
847         swim3_action(fs, EJECT);
848         for (n = 20; n > 0; --n) {
849                 if (signal_pending(current)) {
850                         err = -EINTR;
851                         break;
852                 }
853                 swim3_select(fs, RELAX);
854                 schedule_timeout_interruptible(1);
855                 if (swim3_readbit(fs, DISK_IN) == 0)
856                         break;
857         }
858         swim3_select(fs, RELAX);
859         udelay(150);
860         fs->ejected = 1;
861         release_drive(fs);
862         return err;
863 }
864
865 static struct floppy_struct floppy_type =
866         { 2880,18,2,80,0,0x1B,0x00,0xCF,0x6C,NULL };    /*  7 1.44MB 3.5"   */
867
868 static int floppy_locked_ioctl(struct block_device *bdev, fmode_t mode,
869                         unsigned int cmd, unsigned long param)
870 {
871         struct floppy_state *fs = bdev->bd_disk->private_data;
872         int err;
873                 
874         if ((cmd & 0x80) && !capable(CAP_SYS_ADMIN))
875                 return -EPERM;
876
877         if (fs->mdev->media_bay &&
878             check_media_bay(fs->mdev->media_bay) != MB_FD)
879                 return -ENXIO;
880
881         switch (cmd) {
882         case FDEJECT:
883                 if (fs->ref_count != 1)
884                         return -EBUSY;
885                 err = fd_eject(fs);
886                 return err;
887         case FDGETPRM:
888                 if (copy_to_user((void __user *) param, &floppy_type,
889                                  sizeof(struct floppy_struct)))
890                         return -EFAULT;
891                 return 0;
892         }
893         return -ENOTTY;
894 }
895
896 static int floppy_ioctl(struct block_device *bdev, fmode_t mode,
897                                  unsigned int cmd, unsigned long param)
898 {
899         int ret;
900
901         mutex_lock(&swim3_mutex);
902         ret = floppy_locked_ioctl(bdev, mode, cmd, param);
903         mutex_unlock(&swim3_mutex);
904
905         return ret;
906 }
907
908 static int floppy_open(struct block_device *bdev, fmode_t mode)
909 {
910         struct floppy_state *fs = bdev->bd_disk->private_data;
911         struct swim3 __iomem *sw = fs->swim3;
912         int n, err = 0;
913
914         if (fs->ref_count == 0) {
915                 if (fs->mdev->media_bay &&
916                     check_media_bay(fs->mdev->media_bay) != MB_FD)
917                         return -ENXIO;
918                 out_8(&sw->setup, S_IBM_DRIVE | S_FCLK_DIV2);
919                 out_8(&sw->control_bic, 0xff);
920                 out_8(&sw->mode, 0x95);
921                 udelay(10);
922                 out_8(&sw->intr_enable, 0);
923                 out_8(&sw->control_bis, DRIVE_ENABLE | INTR_ENABLE);
924                 swim3_action(fs, MOTOR_ON);
925                 fs->write_prot = -1;
926                 fs->cur_cyl = -1;
927                 for (n = 0; n < 2 * HZ; ++n) {
928                         if (n >= HZ/30 && swim3_readbit(fs, SEEK_COMPLETE))
929                                 break;
930                         if (signal_pending(current)) {
931                                 err = -EINTR;
932                                 break;
933                         }
934                         swim3_select(fs, RELAX);
935                         schedule_timeout_interruptible(1);
936                 }
937                 if (err == 0 && (swim3_readbit(fs, SEEK_COMPLETE) == 0
938                                  || swim3_readbit(fs, DISK_IN) == 0))
939                         err = -ENXIO;
940                 swim3_action(fs, SETMFM);
941                 swim3_select(fs, RELAX);
942
943         } else if (fs->ref_count == -1 || mode & FMODE_EXCL)
944                 return -EBUSY;
945
946         if (err == 0 && (mode & FMODE_NDELAY) == 0
947             && (mode & (FMODE_READ|FMODE_WRITE))) {
948                 if (bdev_check_media_change(bdev))
949                         floppy_revalidate(bdev->bd_disk);
950                 if (fs->ejected)
951                         err = -ENXIO;
952         }
953
954         if (err == 0 && (mode & FMODE_WRITE)) {
955                 if (fs->write_prot < 0)
956                         fs->write_prot = swim3_readbit(fs, WRITE_PROT);
957                 if (fs->write_prot)
958                         err = -EROFS;
959         }
960
961         if (err) {
962                 if (fs->ref_count == 0) {
963                         swim3_action(fs, MOTOR_OFF);
964                         out_8(&sw->control_bic, DRIVE_ENABLE | INTR_ENABLE);
965                         swim3_select(fs, RELAX);
966                 }
967                 return err;
968         }
969
970         if (mode & FMODE_EXCL)
971                 fs->ref_count = -1;
972         else
973                 ++fs->ref_count;
974
975         return 0;
976 }
977
978 static int floppy_unlocked_open(struct block_device *bdev, fmode_t mode)
979 {
980         int ret;
981
982         mutex_lock(&swim3_mutex);
983         ret = floppy_open(bdev, mode);
984         mutex_unlock(&swim3_mutex);
985
986         return ret;
987 }
988
989 static void floppy_release(struct gendisk *disk, fmode_t mode)
990 {
991         struct floppy_state *fs = disk->private_data;
992         struct swim3 __iomem *sw = fs->swim3;
993
994         mutex_lock(&swim3_mutex);
995         if (fs->ref_count > 0)
996                 --fs->ref_count;
997         else if (fs->ref_count == -1)
998                 fs->ref_count = 0;
999         if (fs->ref_count == 0) {
1000                 swim3_action(fs, MOTOR_OFF);
1001                 out_8(&sw->control_bic, 0xff);
1002                 swim3_select(fs, RELAX);
1003         }
1004         mutex_unlock(&swim3_mutex);
1005 }
1006
1007 static unsigned int floppy_check_events(struct gendisk *disk,
1008                                         unsigned int clearing)
1009 {
1010         struct floppy_state *fs = disk->private_data;
1011         return fs->ejected ? DISK_EVENT_MEDIA_CHANGE : 0;
1012 }
1013
1014 static int floppy_revalidate(struct gendisk *disk)
1015 {
1016         struct floppy_state *fs = disk->private_data;
1017         struct swim3 __iomem *sw;
1018         int ret, n;
1019
1020         if (fs->mdev->media_bay &&
1021             check_media_bay(fs->mdev->media_bay) != MB_FD)
1022                 return -ENXIO;
1023
1024         sw = fs->swim3;
1025         grab_drive(fs, revalidating, 0);
1026         out_8(&sw->intr_enable, 0);
1027         out_8(&sw->control_bis, DRIVE_ENABLE);
1028         swim3_action(fs, MOTOR_ON);     /* necessary? */
1029         fs->write_prot = -1;
1030         fs->cur_cyl = -1;
1031         mdelay(1);
1032         for (n = HZ; n > 0; --n) {
1033                 if (swim3_readbit(fs, SEEK_COMPLETE))
1034                         break;
1035                 if (signal_pending(current))
1036                         break;
1037                 swim3_select(fs, RELAX);
1038                 schedule_timeout_interruptible(1);
1039         }
1040         ret = swim3_readbit(fs, SEEK_COMPLETE) == 0
1041                 || swim3_readbit(fs, DISK_IN) == 0;
1042         if (ret)
1043                 swim3_action(fs, MOTOR_OFF);
1044         else {
1045                 fs->ejected = 0;
1046                 swim3_action(fs, SETMFM);
1047         }
1048         swim3_select(fs, RELAX);
1049
1050         release_drive(fs);
1051         return ret;
1052 }
1053
1054 static const struct block_device_operations floppy_fops = {
1055         .open           = floppy_unlocked_open,
1056         .release        = floppy_release,
1057         .ioctl          = floppy_ioctl,
1058         .check_events   = floppy_check_events,
1059 };
1060
1061 static const struct blk_mq_ops swim3_mq_ops = {
1062         .queue_rq = swim3_queue_rq,
1063 };
1064
1065 static void swim3_mb_event(struct macio_dev* mdev, int mb_state)
1066 {
1067         struct floppy_state *fs = macio_get_drvdata(mdev);
1068         struct swim3 __iomem *sw;
1069
1070         if (!fs)
1071                 return;
1072
1073         sw = fs->swim3;
1074
1075         if (mb_state != MB_FD)
1076                 return;
1077
1078         /* Clear state */
1079         out_8(&sw->intr_enable, 0);
1080         in_8(&sw->intr);
1081         in_8(&sw->error);
1082 }
1083
1084 static int swim3_add_device(struct macio_dev *mdev, int index)
1085 {
1086         struct device_node *swim = mdev->ofdev.dev.of_node;
1087         struct floppy_state *fs = &floppy_states[index];
1088         int rc = -EBUSY;
1089
1090         fs->mdev = mdev;
1091         fs->index = index;
1092
1093         /* Check & Request resources */
1094         if (macio_resource_count(mdev) < 2) {
1095                 swim3_err("%s", "No address in device-tree\n");
1096                 return -ENXIO;
1097         }
1098         if (macio_irq_count(mdev) < 1) {
1099                 swim3_err("%s", "No interrupt in device-tree\n");
1100                 return -ENXIO;
1101         }
1102         if (macio_request_resource(mdev, 0, "swim3 (mmio)")) {
1103                 swim3_err("%s", "Can't request mmio resource\n");
1104                 return -EBUSY;
1105         }
1106         if (macio_request_resource(mdev, 1, "swim3 (dma)")) {
1107                 swim3_err("%s", "Can't request dma resource\n");
1108                 macio_release_resource(mdev, 0);
1109                 return -EBUSY;
1110         }
1111         dev_set_drvdata(&mdev->ofdev.dev, fs);
1112
1113         if (mdev->media_bay == NULL)
1114                 pmac_call_feature(PMAC_FTR_SWIM3_ENABLE, swim, 0, 1);
1115         
1116         fs->state = idle;
1117         fs->swim3 = (struct swim3 __iomem *)
1118                 ioremap(macio_resource_start(mdev, 0), 0x200);
1119         if (fs->swim3 == NULL) {
1120                 swim3_err("%s", "Couldn't map mmio registers\n");
1121                 rc = -ENOMEM;
1122                 goto out_release;
1123         }
1124         fs->dma = (struct dbdma_regs __iomem *)
1125                 ioremap(macio_resource_start(mdev, 1), 0x200);
1126         if (fs->dma == NULL) {
1127                 swim3_err("%s", "Couldn't map dma registers\n");
1128                 iounmap(fs->swim3);
1129                 rc = -ENOMEM;
1130                 goto out_release;
1131         }
1132         fs->swim3_intr = macio_irq(mdev, 0);
1133         fs->dma_intr = macio_irq(mdev, 1);
1134         fs->cur_cyl = -1;
1135         fs->cur_sector = -1;
1136         fs->secpercyl = 36;
1137         fs->secpertrack = 18;
1138         fs->total_secs = 2880;
1139         init_waitqueue_head(&fs->wait);
1140
1141         fs->dma_cmd = (struct dbdma_cmd *) DBDMA_ALIGN(fs->dbdma_cmd_space);
1142         memset(fs->dma_cmd, 0, 2 * sizeof(struct dbdma_cmd));
1143         fs->dma_cmd[1].command = cpu_to_le16(DBDMA_STOP);
1144
1145         if (mdev->media_bay == NULL || check_media_bay(mdev->media_bay) == MB_FD)
1146                 swim3_mb_event(mdev, MB_FD);
1147
1148         if (request_irq(fs->swim3_intr, swim3_interrupt, 0, "SWIM3", fs)) {
1149                 swim3_err("%s", "Couldn't request interrupt\n");
1150                 pmac_call_feature(PMAC_FTR_SWIM3_ENABLE, swim, 0, 0);
1151                 goto out_unmap;
1152         }
1153
1154         timer_setup(&fs->timeout, NULL, 0);
1155
1156         swim3_info("SWIM3 floppy controller %s\n",
1157                 mdev->media_bay ? "in media bay" : "");
1158
1159         return 0;
1160
1161  out_unmap:
1162         iounmap(fs->dma);
1163         iounmap(fs->swim3);
1164
1165  out_release:
1166         macio_release_resource(mdev, 0);
1167         macio_release_resource(mdev, 1);
1168
1169         return rc;
1170 }
1171
1172 static int swim3_attach(struct macio_dev *mdev,
1173                         const struct of_device_id *match)
1174 {
1175         struct floppy_state *fs;
1176         struct gendisk *disk;
1177         int rc;
1178
1179         if (floppy_count >= MAX_FLOPPIES)
1180                 return -ENXIO;
1181
1182         if (floppy_count == 0) {
1183                 rc = register_blkdev(FLOPPY_MAJOR, "fd");
1184                 if (rc)
1185                         return rc;
1186         }
1187
1188         disk = alloc_disk(1);
1189         if (disk == NULL) {
1190                 rc = -ENOMEM;
1191                 goto out_unregister;
1192         }
1193
1194         fs = &floppy_states[floppy_count];
1195         memset(fs, 0, sizeof(*fs));
1196
1197         disk->queue = blk_mq_init_sq_queue(&fs->tag_set, &swim3_mq_ops, 2,
1198                                                 BLK_MQ_F_SHOULD_MERGE);
1199         if (IS_ERR(disk->queue)) {
1200                 rc = PTR_ERR(disk->queue);
1201                 disk->queue = NULL;
1202                 goto out_put_disk;
1203         }
1204         blk_queue_bounce_limit(disk->queue, BLK_BOUNCE_HIGH);
1205         disk->queue->queuedata = fs;
1206
1207         rc = swim3_add_device(mdev, floppy_count);
1208         if (rc)
1209                 goto out_cleanup_queue;
1210
1211         disk->major = FLOPPY_MAJOR;
1212         disk->first_minor = floppy_count;
1213         disk->fops = &floppy_fops;
1214         disk->private_data = fs;
1215         disk->events = DISK_EVENT_MEDIA_CHANGE;
1216         disk->flags |= GENHD_FL_REMOVABLE;
1217         sprintf(disk->disk_name, "fd%d", floppy_count);
1218         set_capacity(disk, 2880);
1219         add_disk(disk);
1220
1221         disks[floppy_count++] = disk;
1222         return 0;
1223
1224 out_cleanup_queue:
1225         blk_cleanup_queue(disk->queue);
1226         disk->queue = NULL;
1227         blk_mq_free_tag_set(&fs->tag_set);
1228 out_put_disk:
1229         put_disk(disk);
1230 out_unregister:
1231         if (floppy_count == 0)
1232                 unregister_blkdev(FLOPPY_MAJOR, "fd");
1233         return rc;
1234 }
1235
1236 static const struct of_device_id swim3_match[] =
1237 {
1238         {
1239         .name           = "swim3",
1240         },
1241         {
1242         .compatible     = "ohare-swim3"
1243         },
1244         {
1245         .compatible     = "swim3"
1246         },
1247         { /* end of list */ }
1248 };
1249
1250 static struct macio_driver swim3_driver =
1251 {
1252         .driver = {
1253                 .name           = "swim3",
1254                 .of_match_table = swim3_match,
1255         },
1256         .probe          = swim3_attach,
1257 #ifdef CONFIG_PMAC_MEDIABAY
1258         .mediabay_event = swim3_mb_event,
1259 #endif
1260 #if 0
1261         .suspend        = swim3_suspend,
1262         .resume         = swim3_resume,
1263 #endif
1264 };
1265
1266
1267 int swim3_init(void)
1268 {
1269         macio_register_driver(&swim3_driver);
1270         return 0;
1271 }
1272
1273 module_init(swim3_init)
1274
1275 MODULE_LICENSE("GPL");
1276 MODULE_AUTHOR("Paul Mackerras");
1277 MODULE_ALIAS_BLOCKDEV_MAJOR(FLOPPY_MAJOR);