KVM: Fix unlikely kvm_create vs decache_vcpus_on_cpu race
[linux-2.6] / drivers / char / viotape.c
1 /* -*- linux-c -*-
2  *  drivers/char/viotape.c
3  *
4  *  iSeries Virtual Tape
5  *
6  *  Authors: Dave Boutcher <boutcher@us.ibm.com>
7  *           Ryan Arnold <ryanarn@us.ibm.com>
8  *           Colin Devilbiss <devilbis@us.ibm.com>
9  *           Stephen Rothwell <sfr@au1.ibm.com>
10  *
11  * (C) Copyright 2000-2004 IBM Corporation
12  *
13  * This program is free software;  you can redistribute it and/or
14  * modify it under the terms of the GNU General Public License as
15  * published by the Free Software Foundation; either version 2 of the
16  * License, or (at your option) anyu later version.
17  *
18  * This program is distributed in the hope that it will be useful, but
19  * WITHOUT ANY WARRANTY; without even the implied warranty of
20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
21  * General Public License for more details.
22  *
23  * You should have received a copy of the GNU General Public License
24  * along with this program; if not, write to the Free Software Foundation,
25  * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
26  *
27  * This routine provides access to tape drives owned and managed by an OS/400
28  * partition running on the same box as this Linux partition.
29  *
30  * All tape operations are performed by sending messages back and forth to
31  * the OS/400 partition.  The format of the messages is defined in
32  * iseries/vio.h
33  */
34 #include <linux/module.h>
35 #include <linux/kernel.h>
36 #include <linux/errno.h>
37 #include <linux/init.h>
38 #include <linux/wait.h>
39 #include <linux/spinlock.h>
40 #include <linux/mtio.h>
41 #include <linux/device.h>
42 #include <linux/dma-mapping.h>
43 #include <linux/fs.h>
44 #include <linux/cdev.h>
45 #include <linux/major.h>
46 #include <linux/completion.h>
47 #include <linux/proc_fs.h>
48 #include <linux/seq_file.h>
49
50 #include <asm/uaccess.h>
51 #include <asm/ioctls.h>
52 #include <asm/firmware.h>
53 #include <asm/vio.h>
54 #include <asm/iseries/vio.h>
55 #include <asm/iseries/hv_lp_event.h>
56 #include <asm/iseries/hv_call_event.h>
57 #include <asm/iseries/hv_lp_config.h>
58
59 #define VIOTAPE_VERSION         "1.2"
60 #define VIOTAPE_MAXREQ          1
61
62 #define VIOTAPE_KERN_WARN       KERN_WARNING "viotape: "
63 #define VIOTAPE_KERN_INFO       KERN_INFO "viotape: "
64
65 static int viotape_numdev;
66
67 /*
68  * The minor number follows the conventions of the SCSI tape drives.  The
69  * rewind and mode are encoded in the minor #.  We use this struct to break
70  * them out
71  */
72 struct viot_devinfo_struct {
73         int devno;
74         int mode;
75         int rewind;
76 };
77
78 #define VIOTAPOP_RESET          0
79 #define VIOTAPOP_FSF            1
80 #define VIOTAPOP_BSF            2
81 #define VIOTAPOP_FSR            3
82 #define VIOTAPOP_BSR            4
83 #define VIOTAPOP_WEOF           5
84 #define VIOTAPOP_REW            6
85 #define VIOTAPOP_NOP            7
86 #define VIOTAPOP_EOM            8
87 #define VIOTAPOP_ERASE          9
88 #define VIOTAPOP_SETBLK        10
89 #define VIOTAPOP_SETDENSITY    11
90 #define VIOTAPOP_SETPOS        12
91 #define VIOTAPOP_GETPOS        13
92 #define VIOTAPOP_SETPART       14
93 #define VIOTAPOP_UNLOAD        15
94
95 struct viotapelpevent {
96         struct HvLpEvent event;
97         u32 reserved;
98         u16 version;
99         u16 sub_type_result;
100         u16 tape;
101         u16 flags;
102         u32 token;
103         u64 len;
104         union {
105                 struct {
106                         u32 tape_op;
107                         u32 count;
108                 } op;
109                 struct {
110                         u32 type;
111                         u32 resid;
112                         u32 dsreg;
113                         u32 gstat;
114                         u32 erreg;
115                         u32 file_no;
116                         u32 block_no;
117                 } get_status;
118                 struct {
119                         u32 block_no;
120                 } get_pos;
121         } u;
122 };
123
124 enum viotapesubtype {
125         viotapeopen = 0x0001,
126         viotapeclose = 0x0002,
127         viotaperead = 0x0003,
128         viotapewrite = 0x0004,
129         viotapegetinfo = 0x0005,
130         viotapeop = 0x0006,
131         viotapegetpos = 0x0007,
132         viotapesetpos = 0x0008,
133         viotapegetstatus = 0x0009
134 };
135
136 enum viotaperc {
137         viotape_InvalidRange = 0x0601,
138         viotape_InvalidToken = 0x0602,
139         viotape_DMAError = 0x0603,
140         viotape_UseError = 0x0604,
141         viotape_ReleaseError = 0x0605,
142         viotape_InvalidTape = 0x0606,
143         viotape_InvalidOp = 0x0607,
144         viotape_TapeErr = 0x0608,
145
146         viotape_AllocTimedOut = 0x0640,
147         viotape_BOTEnc = 0x0641,
148         viotape_BlankTape = 0x0642,
149         viotape_BufferEmpty = 0x0643,
150         viotape_CleanCartFound = 0x0644,
151         viotape_CmdNotAllowed = 0x0645,
152         viotape_CmdNotSupported = 0x0646,
153         viotape_DataCheck = 0x0647,
154         viotape_DecompressErr = 0x0648,
155         viotape_DeviceTimeout = 0x0649,
156         viotape_DeviceUnavail = 0x064a,
157         viotape_DeviceBusy = 0x064b,
158         viotape_EndOfMedia = 0x064c,
159         viotape_EndOfTape = 0x064d,
160         viotape_EquipCheck = 0x064e,
161         viotape_InsufficientRs = 0x064f,
162         viotape_InvalidLogBlk = 0x0650,
163         viotape_LengthError = 0x0651,
164         viotape_LibDoorOpen = 0x0652,
165         viotape_LoadFailure = 0x0653,
166         viotape_NotCapable = 0x0654,
167         viotape_NotOperational = 0x0655,
168         viotape_NotReady = 0x0656,
169         viotape_OpCancelled = 0x0657,
170         viotape_PhyLinkErr = 0x0658,
171         viotape_RdyNotBOT = 0x0659,
172         viotape_TapeMark = 0x065a,
173         viotape_WriteProt = 0x065b
174 };
175
176 static const struct vio_error_entry viotape_err_table[] = {
177         { viotape_InvalidRange, EIO, "Internal error" },
178         { viotape_InvalidToken, EIO, "Internal error" },
179         { viotape_DMAError, EIO, "DMA error" },
180         { viotape_UseError, EIO, "Internal error" },
181         { viotape_ReleaseError, EIO, "Internal error" },
182         { viotape_InvalidTape, EIO, "Invalid tape device" },
183         { viotape_InvalidOp, EIO, "Invalid operation" },
184         { viotape_TapeErr, EIO, "Tape error" },
185         { viotape_AllocTimedOut, EBUSY, "Allocate timed out" },
186         { viotape_BOTEnc, EIO, "Beginning of tape encountered" },
187         { viotape_BlankTape, EIO, "Blank tape" },
188         { viotape_BufferEmpty, EIO, "Buffer empty" },
189         { viotape_CleanCartFound, ENOMEDIUM, "Cleaning cartridge found" },
190         { viotape_CmdNotAllowed, EIO, "Command not allowed" },
191         { viotape_CmdNotSupported, EIO, "Command not supported" },
192         { viotape_DataCheck, EIO, "Data check" },
193         { viotape_DecompressErr, EIO, "Decompression error" },
194         { viotape_DeviceTimeout, EBUSY, "Device timeout" },
195         { viotape_DeviceUnavail, EIO, "Device unavailable" },
196         { viotape_DeviceBusy, EBUSY, "Device busy" },
197         { viotape_EndOfMedia, ENOSPC, "End of media" },
198         { viotape_EndOfTape, ENOSPC, "End of tape" },
199         { viotape_EquipCheck, EIO, "Equipment check" },
200         { viotape_InsufficientRs, EOVERFLOW, "Insufficient tape resources" },
201         { viotape_InvalidLogBlk, EIO, "Invalid logical block location" },
202         { viotape_LengthError, EOVERFLOW, "Length error" },
203         { viotape_LibDoorOpen, EBUSY, "Door open" },
204         { viotape_LoadFailure, ENOMEDIUM, "Load failure" },
205         { viotape_NotCapable, EIO, "Not capable" },
206         { viotape_NotOperational, EIO, "Not operational" },
207         { viotape_NotReady, EIO, "Not ready" },
208         { viotape_OpCancelled, EIO, "Operation cancelled" },
209         { viotape_PhyLinkErr, EIO, "Physical link error" },
210         { viotape_RdyNotBOT, EIO, "Ready but not beginning of tape" },
211         { viotape_TapeMark, EIO, "Tape mark" },
212         { viotape_WriteProt, EROFS, "Write protection error" },
213         { 0, 0, NULL },
214 };
215
216 /* Maximum number of tapes we support */
217 #define VIOTAPE_MAX_TAPE        HVMAXARCHITECTEDVIRTUALTAPES
218 #define MAX_PARTITIONS          4
219
220 /* defines for current tape state */
221 #define VIOT_IDLE               0
222 #define VIOT_READING            1
223 #define VIOT_WRITING            2
224
225 /* Our info on the tapes */
226 struct tape_descr {
227         char rsrcname[10];
228         char type[4];
229         char model[3];
230 };
231
232 static struct tape_descr *viotape_unitinfo;
233 static dma_addr_t viotape_unitinfo_token;
234
235 static struct mtget viomtget[VIOTAPE_MAX_TAPE];
236
237 static struct class *tape_class;
238
239 static struct device *tape_device[VIOTAPE_MAX_TAPE];
240
241 /*
242  * maintain the current state of each tape (and partition)
243  * so that we know when to write EOF marks.
244  */
245 static struct {
246         unsigned char   cur_part;
247         unsigned char   part_stat_rwi[MAX_PARTITIONS];
248 } state[VIOTAPE_MAX_TAPE];
249
250 /* We single-thread */
251 static struct semaphore reqSem;
252
253 /*
254  * When we send a request, we use this struct to get the response back
255  * from the interrupt handler
256  */
257 struct op_struct {
258         void                    *buffer;
259         dma_addr_t              dmaaddr;
260         size_t                  count;
261         int                     rc;
262         int                     non_blocking;
263         struct completion       com;
264         struct device           *dev;
265         struct op_struct        *next;
266 };
267
268 static spinlock_t       op_struct_list_lock;
269 static struct op_struct *op_struct_list;
270
271 /* forward declaration to resolve interdependence */
272 static int chg_state(int index, unsigned char new_state, struct file *file);
273
274 /* procfs support */
275 static int proc_viotape_show(struct seq_file *m, void *v)
276 {
277         int i;
278
279         seq_printf(m, "viotape driver version " VIOTAPE_VERSION "\n");
280         for (i = 0; i < viotape_numdev; i++) {
281                 seq_printf(m, "viotape device %d is iSeries resource %10.10s"
282                                 "type %4.4s, model %3.3s\n",
283                                 i, viotape_unitinfo[i].rsrcname,
284                                 viotape_unitinfo[i].type,
285                                 viotape_unitinfo[i].model);
286         }
287         return 0;
288 }
289
290 static int proc_viotape_open(struct inode *inode, struct file *file)
291 {
292         return single_open(file, proc_viotape_show, NULL);
293 }
294
295 static const struct file_operations proc_viotape_operations = {
296         .open           = proc_viotape_open,
297         .read           = seq_read,
298         .llseek         = seq_lseek,
299         .release        = single_release,
300 };
301
302 /* Decode the device minor number into its parts */
303 void get_dev_info(struct inode *ino, struct viot_devinfo_struct *devi)
304 {
305         devi->devno = iminor(ino) & 0x1F;
306         devi->mode = (iminor(ino) & 0x60) >> 5;
307         /* if bit is set in the minor, do _not_ rewind automatically */
308         devi->rewind = (iminor(ino) & 0x80) == 0;
309 }
310
311 /* This is called only from the exit and init paths, so no need for locking */
312 static void clear_op_struct_pool(void)
313 {
314         while (op_struct_list) {
315                 struct op_struct *toFree = op_struct_list;
316                 op_struct_list = op_struct_list->next;
317                 kfree(toFree);
318         }
319 }
320
321 /* Likewise, this is only called from the init path */
322 static int add_op_structs(int structs)
323 {
324         int i;
325
326         for (i = 0; i < structs; ++i) {
327                 struct op_struct *new_struct =
328                         kmalloc(sizeof(*new_struct), GFP_KERNEL);
329                 if (!new_struct) {
330                         clear_op_struct_pool();
331                         return -ENOMEM;
332                 }
333                 new_struct->next = op_struct_list;
334                 op_struct_list = new_struct;
335         }
336         return 0;
337 }
338
339 /* Allocate an op structure from our pool */
340 static struct op_struct *get_op_struct(void)
341 {
342         struct op_struct *retval;
343         unsigned long flags;
344
345         spin_lock_irqsave(&op_struct_list_lock, flags);
346         retval = op_struct_list;
347         if (retval)
348                 op_struct_list = retval->next;
349         spin_unlock_irqrestore(&op_struct_list_lock, flags);
350         if (retval) {
351                 memset(retval, 0, sizeof(*retval));
352                 init_completion(&retval->com);
353         }
354
355         return retval;
356 }
357
358 /* Return an op structure to our pool */
359 static void free_op_struct(struct op_struct *op_struct)
360 {
361         unsigned long flags;
362
363         spin_lock_irqsave(&op_struct_list_lock, flags);
364         op_struct->next = op_struct_list;
365         op_struct_list = op_struct;
366         spin_unlock_irqrestore(&op_struct_list_lock, flags);
367 }
368
369 /* Map our tape return codes to errno values */
370 int tape_rc_to_errno(int tape_rc, char *operation, int tapeno)
371 {
372         const struct vio_error_entry *err;
373
374         if (tape_rc == 0)
375                 return 0;
376
377         err = vio_lookup_rc(viotape_err_table, tape_rc);
378         printk(VIOTAPE_KERN_WARN "error(%s) 0x%04x on Device %d (%-10s): %s\n",
379                         operation, tape_rc, tapeno,
380                         viotape_unitinfo[tapeno].rsrcname, err->msg);
381         return -err->errno;
382 }
383
384 /* Get info on all tapes from OS/400 */
385 static int get_viotape_info(void)
386 {
387         HvLpEvent_Rc hvrc;
388         int i;
389         size_t len = sizeof(*viotape_unitinfo) * VIOTAPE_MAX_TAPE;
390         struct op_struct *op = get_op_struct();
391
392         if (op == NULL)
393                 return -ENOMEM;
394
395         viotape_unitinfo = dma_alloc_coherent(iSeries_vio_dev, len,
396                 &viotape_unitinfo_token, GFP_ATOMIC);
397         if (viotape_unitinfo == NULL) {
398                 free_op_struct(op);
399                 return -ENOMEM;
400         }
401
402         memset(viotape_unitinfo, 0, len);
403
404         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
405                         HvLpEvent_Type_VirtualIo,
406                         viomajorsubtype_tape | viotapegetinfo,
407                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
408                         viopath_sourceinst(viopath_hostLp),
409                         viopath_targetinst(viopath_hostLp),
410                         (u64) (unsigned long) op, VIOVERSION << 16,
411                         viotape_unitinfo_token, len, 0, 0);
412         if (hvrc != HvLpEvent_Rc_Good) {
413                 printk(VIOTAPE_KERN_WARN "hv error on op %d\n",
414                                 (int)hvrc);
415                 free_op_struct(op);
416                 return -EIO;
417         }
418
419         wait_for_completion(&op->com);
420
421         free_op_struct(op);
422
423         for (i = 0;
424              ((i < VIOTAPE_MAX_TAPE) && (viotape_unitinfo[i].rsrcname[0]));
425              i++)
426                 viotape_numdev++;
427         return 0;
428 }
429
430
431 /* Write */
432 static ssize_t viotap_write(struct file *file, const char *buf,
433                 size_t count, loff_t * ppos)
434 {
435         HvLpEvent_Rc hvrc;
436         unsigned short flags = file->f_flags;
437         int noblock = ((flags & O_NONBLOCK) != 0);
438         ssize_t ret;
439         struct viot_devinfo_struct devi;
440         struct op_struct *op = get_op_struct();
441
442         if (op == NULL)
443                 return -ENOMEM;
444
445         get_dev_info(file->f_path.dentry->d_inode, &devi);
446
447         /*
448          * We need to make sure we can send a request.  We use
449          * a semaphore to keep track of # requests in use.  If
450          * we are non-blocking, make sure we don't block on the
451          * semaphore
452          */
453         if (noblock) {
454                 if (down_trylock(&reqSem)) {
455                         ret = -EWOULDBLOCK;
456                         goto free_op;
457                 }
458         } else
459                 down(&reqSem);
460
461         /* Allocate a DMA buffer */
462         op->dev = tape_device[devi.devno];
463         op->buffer = dma_alloc_coherent(op->dev, count, &op->dmaaddr,
464                         GFP_ATOMIC);
465
466         if (op->buffer == NULL) {
467                 printk(VIOTAPE_KERN_WARN
468                                 "error allocating dma buffer for len %ld\n",
469                                 count);
470                 ret = -EFAULT;
471                 goto up_sem;
472         }
473
474         /* Copy the data into the buffer */
475         if (copy_from_user(op->buffer, buf, count)) {
476                 printk(VIOTAPE_KERN_WARN "tape: error on copy from user\n");
477                 ret = -EFAULT;
478                 goto free_dma;
479         }
480
481         op->non_blocking = noblock;
482         init_completion(&op->com);
483         op->count = count;
484
485         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
486                         HvLpEvent_Type_VirtualIo,
487                         viomajorsubtype_tape | viotapewrite,
488                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
489                         viopath_sourceinst(viopath_hostLp),
490                         viopath_targetinst(viopath_hostLp),
491                         (u64)(unsigned long)op, VIOVERSION << 16,
492                         ((u64)devi.devno << 48) | op->dmaaddr, count, 0, 0);
493         if (hvrc != HvLpEvent_Rc_Good) {
494                 printk(VIOTAPE_KERN_WARN "hv error on op %d\n",
495                                 (int)hvrc);
496                 ret = -EIO;
497                 goto free_dma;
498         }
499
500         if (noblock)
501                 return count;
502
503         wait_for_completion(&op->com);
504
505         if (op->rc)
506                 ret = tape_rc_to_errno(op->rc, "write", devi.devno);
507         else {
508                 chg_state(devi.devno, VIOT_WRITING, file);
509                 ret = op->count;
510         }
511
512 free_dma:
513         dma_free_coherent(op->dev, count, op->buffer, op->dmaaddr);
514 up_sem:
515         up(&reqSem);
516 free_op:
517         free_op_struct(op);
518         return ret;
519 }
520
521 /* read */
522 static ssize_t viotap_read(struct file *file, char *buf, size_t count,
523                 loff_t *ptr)
524 {
525         HvLpEvent_Rc hvrc;
526         unsigned short flags = file->f_flags;
527         struct op_struct *op = get_op_struct();
528         int noblock = ((flags & O_NONBLOCK) != 0);
529         ssize_t ret;
530         struct viot_devinfo_struct devi;
531
532         if (op == NULL)
533                 return -ENOMEM;
534
535         get_dev_info(file->f_path.dentry->d_inode, &devi);
536
537         /*
538          * We need to make sure we can send a request.  We use
539          * a semaphore to keep track of # requests in use.  If
540          * we are non-blocking, make sure we don't block on the
541          * semaphore
542          */
543         if (noblock) {
544                 if (down_trylock(&reqSem)) {
545                         ret = -EWOULDBLOCK;
546                         goto free_op;
547                 }
548         } else
549                 down(&reqSem);
550
551         chg_state(devi.devno, VIOT_READING, file);
552
553         /* Allocate a DMA buffer */
554         op->dev = tape_device[devi.devno];
555         op->buffer = dma_alloc_coherent(op->dev, count, &op->dmaaddr,
556                         GFP_ATOMIC);
557         if (op->buffer == NULL) {
558                 ret = -EFAULT;
559                 goto up_sem;
560         }
561
562         op->count = count;
563         init_completion(&op->com);
564
565         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
566                         HvLpEvent_Type_VirtualIo,
567                         viomajorsubtype_tape | viotaperead,
568                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
569                         viopath_sourceinst(viopath_hostLp),
570                         viopath_targetinst(viopath_hostLp),
571                         (u64)(unsigned long)op, VIOVERSION << 16,
572                         ((u64)devi.devno << 48) | op->dmaaddr, count, 0, 0);
573         if (hvrc != HvLpEvent_Rc_Good) {
574                 printk(VIOTAPE_KERN_WARN "tape hv error on op %d\n",
575                                 (int)hvrc);
576                 ret = -EIO;
577                 goto free_dma;
578         }
579
580         wait_for_completion(&op->com);
581
582         if (op->rc)
583                 ret = tape_rc_to_errno(op->rc, "read", devi.devno);
584         else {
585                 ret = op->count;
586                 if (ret && copy_to_user(buf, op->buffer, ret)) {
587                         printk(VIOTAPE_KERN_WARN "error on copy_to_user\n");
588                         ret = -EFAULT;
589                 }
590         }
591
592 free_dma:
593         dma_free_coherent(op->dev, count, op->buffer, op->dmaaddr);
594 up_sem:
595         up(&reqSem);
596 free_op:
597         free_op_struct(op);
598         return ret;
599 }
600
601 /* ioctl */
602 static int viotap_ioctl(struct inode *inode, struct file *file,
603                 unsigned int cmd, unsigned long arg)
604 {
605         HvLpEvent_Rc hvrc;
606         int ret;
607         struct viot_devinfo_struct devi;
608         struct mtop mtc;
609         u32 myOp;
610         struct op_struct *op = get_op_struct();
611
612         if (op == NULL)
613                 return -ENOMEM;
614
615         get_dev_info(file->f_path.dentry->d_inode, &devi);
616
617         down(&reqSem);
618
619         ret = -EINVAL;
620
621         switch (cmd) {
622         case MTIOCTOP:
623                 ret = -EFAULT;
624                 /*
625                  * inode is null if and only if we (the kernel)
626                  * made the request
627                  */
628                 if (inode == NULL)
629                         memcpy(&mtc, (void *) arg, sizeof(struct mtop));
630                 else if (copy_from_user((char *)&mtc, (char *)arg,
631                                         sizeof(struct mtop)))
632                         goto free_op;
633
634                 ret = -EIO;
635                 switch (mtc.mt_op) {
636                 case MTRESET:
637                         myOp = VIOTAPOP_RESET;
638                         break;
639                 case MTFSF:
640                         myOp = VIOTAPOP_FSF;
641                         break;
642                 case MTBSF:
643                         myOp = VIOTAPOP_BSF;
644                         break;
645                 case MTFSR:
646                         myOp = VIOTAPOP_FSR;
647                         break;
648                 case MTBSR:
649                         myOp = VIOTAPOP_BSR;
650                         break;
651                 case MTWEOF:
652                         myOp = VIOTAPOP_WEOF;
653                         break;
654                 case MTREW:
655                         myOp = VIOTAPOP_REW;
656                         break;
657                 case MTNOP:
658                         myOp = VIOTAPOP_NOP;
659                         break;
660                 case MTEOM:
661                         myOp = VIOTAPOP_EOM;
662                         break;
663                 case MTERASE:
664                         myOp = VIOTAPOP_ERASE;
665                         break;
666                 case MTSETBLK:
667                         myOp = VIOTAPOP_SETBLK;
668                         break;
669                 case MTSETDENSITY:
670                         myOp = VIOTAPOP_SETDENSITY;
671                         break;
672                 case MTTELL:
673                         myOp = VIOTAPOP_GETPOS;
674                         break;
675                 case MTSEEK:
676                         myOp = VIOTAPOP_SETPOS;
677                         break;
678                 case MTSETPART:
679                         myOp = VIOTAPOP_SETPART;
680                         break;
681                 case MTOFFL:
682                         myOp = VIOTAPOP_UNLOAD;
683                         break;
684                 default:
685                         printk(VIOTAPE_KERN_WARN "MTIOCTOP called "
686                                         "with invalid op 0x%x\n", mtc.mt_op);
687                         goto free_op;
688                 }
689
690                 /*
691                  * if we moved the head, we are no longer
692                  * reading or writing
693                  */
694                 switch (mtc.mt_op) {
695                 case MTFSF:
696                 case MTBSF:
697                 case MTFSR:
698                 case MTBSR:
699                 case MTTELL:
700                 case MTSEEK:
701                 case MTREW:
702                         chg_state(devi.devno, VIOT_IDLE, file);
703                 }
704
705                 init_completion(&op->com);
706                 hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
707                                 HvLpEvent_Type_VirtualIo,
708                                 viomajorsubtype_tape | viotapeop,
709                                 HvLpEvent_AckInd_DoAck,
710                                 HvLpEvent_AckType_ImmediateAck,
711                                 viopath_sourceinst(viopath_hostLp),
712                                 viopath_targetinst(viopath_hostLp),
713                                 (u64)(unsigned long)op,
714                                 VIOVERSION << 16,
715                                 ((u64)devi.devno << 48), 0,
716                                 (((u64)myOp) << 32) | mtc.mt_count, 0);
717                 if (hvrc != HvLpEvent_Rc_Good) {
718                         printk(VIOTAPE_KERN_WARN "hv error on op %d\n",
719                                         (int)hvrc);
720                         goto free_op;
721                 }
722                 wait_for_completion(&op->com);
723                 ret = tape_rc_to_errno(op->rc, "tape operation", devi.devno);
724                 goto free_op;
725
726         case MTIOCGET:
727                 ret = -EIO;
728                 init_completion(&op->com);
729                 hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
730                                 HvLpEvent_Type_VirtualIo,
731                                 viomajorsubtype_tape | viotapegetstatus,
732                                 HvLpEvent_AckInd_DoAck,
733                                 HvLpEvent_AckType_ImmediateAck,
734                                 viopath_sourceinst(viopath_hostLp),
735                                 viopath_targetinst(viopath_hostLp),
736                                 (u64)(unsigned long)op, VIOVERSION << 16,
737                                 ((u64)devi.devno << 48), 0, 0, 0);
738                 if (hvrc != HvLpEvent_Rc_Good) {
739                         printk(VIOTAPE_KERN_WARN "hv error on op %d\n",
740                                         (int)hvrc);
741                         goto free_op;
742                 }
743                 wait_for_completion(&op->com);
744
745                 /* Operation is complete - grab the error code */
746                 ret = tape_rc_to_errno(op->rc, "get status", devi.devno);
747                 free_op_struct(op);
748                 up(&reqSem);
749
750                 if ((ret == 0) && copy_to_user((void *)arg,
751                                         &viomtget[devi.devno],
752                                         sizeof(viomtget[0])))
753                         ret = -EFAULT;
754                 return ret;
755         case MTIOCPOS:
756                 printk(VIOTAPE_KERN_WARN "Got an (unsupported) MTIOCPOS\n");
757                 break;
758         default:
759                 printk(VIOTAPE_KERN_WARN "got an unsupported ioctl 0x%0x\n",
760                                 cmd);
761                 break;
762         }
763
764 free_op:
765         free_op_struct(op);
766         up(&reqSem);
767         return ret;
768 }
769
770 static int viotap_open(struct inode *inode, struct file *file)
771 {
772         HvLpEvent_Rc hvrc;
773         struct viot_devinfo_struct devi;
774         int ret;
775         struct op_struct *op = get_op_struct();
776
777         if (op == NULL)
778                 return -ENOMEM;
779
780         get_dev_info(file->f_path.dentry->d_inode, &devi);
781
782         /* Note: We currently only support one mode! */
783         if ((devi.devno >= viotape_numdev) || (devi.mode)) {
784                 ret = -ENODEV;
785                 goto free_op;
786         }
787
788         init_completion(&op->com);
789
790         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
791                         HvLpEvent_Type_VirtualIo,
792                         viomajorsubtype_tape | viotapeopen,
793                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
794                         viopath_sourceinst(viopath_hostLp),
795                         viopath_targetinst(viopath_hostLp),
796                         (u64)(unsigned long)op, VIOVERSION << 16,
797                         ((u64)devi.devno << 48), 0, 0, 0);
798         if (hvrc != 0) {
799                 printk(VIOTAPE_KERN_WARN "bad rc on signalLpEvent %d\n",
800                                 (int) hvrc);
801                 ret = -EIO;
802                 goto free_op;
803         }
804
805         wait_for_completion(&op->com);
806         ret = tape_rc_to_errno(op->rc, "open", devi.devno);
807
808 free_op:
809         free_op_struct(op);
810         return ret;
811 }
812
813
814 static int viotap_release(struct inode *inode, struct file *file)
815 {
816         HvLpEvent_Rc hvrc;
817         struct viot_devinfo_struct devi;
818         int ret = 0;
819         struct op_struct *op = get_op_struct();
820
821         if (op == NULL)
822                 return -ENOMEM;
823         init_completion(&op->com);
824
825         get_dev_info(file->f_path.dentry->d_inode, &devi);
826
827         if (devi.devno >= viotape_numdev) {
828                 ret = -ENODEV;
829                 goto free_op;
830         }
831
832         chg_state(devi.devno, VIOT_IDLE, file);
833
834         if (devi.rewind) {
835                 hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
836                                 HvLpEvent_Type_VirtualIo,
837                                 viomajorsubtype_tape | viotapeop,
838                                 HvLpEvent_AckInd_DoAck,
839                                 HvLpEvent_AckType_ImmediateAck,
840                                 viopath_sourceinst(viopath_hostLp),
841                                 viopath_targetinst(viopath_hostLp),
842                                 (u64)(unsigned long)op, VIOVERSION << 16,
843                                 ((u64)devi.devno << 48), 0,
844                                 ((u64)VIOTAPOP_REW) << 32, 0);
845                 wait_for_completion(&op->com);
846
847                 tape_rc_to_errno(op->rc, "rewind", devi.devno);
848         }
849
850         hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
851                         HvLpEvent_Type_VirtualIo,
852                         viomajorsubtype_tape | viotapeclose,
853                         HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
854                         viopath_sourceinst(viopath_hostLp),
855                         viopath_targetinst(viopath_hostLp),
856                         (u64)(unsigned long)op, VIOVERSION << 16,
857                         ((u64)devi.devno << 48), 0, 0, 0);
858         if (hvrc != 0) {
859                 printk(VIOTAPE_KERN_WARN "bad rc on signalLpEvent %d\n",
860                                 (int) hvrc);
861                 ret = -EIO;
862                 goto free_op;
863         }
864
865         wait_for_completion(&op->com);
866
867         if (op->rc)
868                 printk(VIOTAPE_KERN_WARN "close failed\n");
869
870 free_op:
871         free_op_struct(op);
872         return ret;
873 }
874
875 const struct file_operations viotap_fops = {
876         .owner =        THIS_MODULE,
877         .read =         viotap_read,
878         .write =        viotap_write,
879         .ioctl =        viotap_ioctl,
880         .open =         viotap_open,
881         .release =      viotap_release,
882 };
883
884 /* Handle interrupt events for tape */
885 static void vioHandleTapeEvent(struct HvLpEvent *event)
886 {
887         int tapeminor;
888         struct op_struct *op;
889         struct viotapelpevent *tevent = (struct viotapelpevent *)event;
890
891         if (event == NULL) {
892                 /* Notification that a partition went away! */
893                 if (!viopath_isactive(viopath_hostLp)) {
894                         /* TODO! Clean up */
895                 }
896                 return;
897         }
898
899         tapeminor = event->xSubtype & VIOMINOR_SUBTYPE_MASK;
900         op = (struct op_struct *)event->xCorrelationToken;
901         switch (tapeminor) {
902         case viotapegetinfo:
903         case viotapeopen:
904         case viotapeclose:
905                 op->rc = tevent->sub_type_result;
906                 complete(&op->com);
907                 break;
908         case viotaperead:
909                 op->rc = tevent->sub_type_result;
910                 op->count = tevent->len;
911                 complete(&op->com);
912                 break;
913         case viotapewrite:
914                 if (op->non_blocking) {
915                         dma_free_coherent(op->dev, op->count,
916                                         op->buffer, op->dmaaddr);
917                         free_op_struct(op);
918                         up(&reqSem);
919                 } else {
920                         op->rc = tevent->sub_type_result;
921                         op->count = tevent->len;
922                         complete(&op->com);
923                 }
924                 break;
925         case viotapeop:
926         case viotapegetpos:
927         case viotapesetpos:
928         case viotapegetstatus:
929                 if (op) {
930                         op->count = tevent->u.op.count;
931                         op->rc = tevent->sub_type_result;
932                         if (!op->non_blocking)
933                                 complete(&op->com);
934                 }
935                 break;
936         default:
937                 printk(VIOTAPE_KERN_WARN "weird ack\n");
938         }
939 }
940
941 static int viotape_probe(struct vio_dev *vdev, const struct vio_device_id *id)
942 {
943         int i = vdev->unit_address;
944         int j;
945
946         if (i >= viotape_numdev)
947                 return -ENODEV;
948
949         tape_device[i] = &vdev->dev;
950
951         state[i].cur_part = 0;
952         for (j = 0; j < MAX_PARTITIONS; ++j)
953                 state[i].part_stat_rwi[j] = VIOT_IDLE;
954         class_device_create(tape_class, NULL, MKDEV(VIOTAPE_MAJOR, i), NULL,
955                         "iseries!vt%d", i);
956         class_device_create(tape_class, NULL, MKDEV(VIOTAPE_MAJOR, i | 0x80),
957                         NULL, "iseries!nvt%d", i);
958         printk(VIOTAPE_KERN_INFO "tape iseries/vt%d is iSeries "
959                         "resource %10.10s type %4.4s, model %3.3s\n",
960                         i, viotape_unitinfo[i].rsrcname,
961                         viotape_unitinfo[i].type, viotape_unitinfo[i].model);
962         return 0;
963 }
964
965 static int viotape_remove(struct vio_dev *vdev)
966 {
967         int i = vdev->unit_address;
968
969         class_device_destroy(tape_class, MKDEV(VIOTAPE_MAJOR, i | 0x80));
970         class_device_destroy(tape_class, MKDEV(VIOTAPE_MAJOR, i));
971         return 0;
972 }
973
974 /**
975  * viotape_device_table: Used by vio.c to match devices that we
976  * support.
977  */
978 static struct vio_device_id viotape_device_table[] __devinitdata = {
979         { "byte", "IBM,iSeries-viotape" },
980         { "", "" }
981 };
982 MODULE_DEVICE_TABLE(vio, viotape_device_table);
983
984 static struct vio_driver viotape_driver = {
985         .id_table = viotape_device_table,
986         .probe = viotape_probe,
987         .remove = viotape_remove,
988         .driver = {
989                 .name = "viotape",
990                 .owner = THIS_MODULE,
991         }
992 };
993
994
995 int __init viotap_init(void)
996 {
997         int ret;
998         struct proc_dir_entry *e;
999
1000         if (!firmware_has_feature(FW_FEATURE_ISERIES))
1001                 return -ENODEV;
1002
1003         op_struct_list = NULL;
1004         if ((ret = add_op_structs(VIOTAPE_MAXREQ)) < 0) {
1005                 printk(VIOTAPE_KERN_WARN "couldn't allocate op structs\n");
1006                 return ret;
1007         }
1008         spin_lock_init(&op_struct_list_lock);
1009
1010         sema_init(&reqSem, VIOTAPE_MAXREQ);
1011
1012         if (viopath_hostLp == HvLpIndexInvalid) {
1013                 vio_set_hostlp();
1014                 if (viopath_hostLp == HvLpIndexInvalid) {
1015                         ret = -ENODEV;
1016                         goto clear_op;
1017                 }
1018         }
1019
1020         ret = viopath_open(viopath_hostLp, viomajorsubtype_tape,
1021                         VIOTAPE_MAXREQ + 2);
1022         if (ret) {
1023                 printk(VIOTAPE_KERN_WARN
1024                                 "error on viopath_open to hostlp %d\n", ret);
1025                 ret = -EIO;
1026                 goto clear_op;
1027         }
1028
1029         printk(VIOTAPE_KERN_INFO "vers " VIOTAPE_VERSION
1030                         ", hosting partition %d\n", viopath_hostLp);
1031
1032         vio_setHandler(viomajorsubtype_tape, vioHandleTapeEvent);
1033
1034         ret = register_chrdev(VIOTAPE_MAJOR, "viotape", &viotap_fops);
1035         if (ret < 0) {
1036                 printk(VIOTAPE_KERN_WARN "Error registering viotape device\n");
1037                 goto clear_handler;
1038         }
1039
1040         tape_class = class_create(THIS_MODULE, "tape");
1041         if (IS_ERR(tape_class)) {
1042                 printk(VIOTAPE_KERN_WARN "Unable to allocat class\n");
1043                 ret = PTR_ERR(tape_class);
1044                 goto unreg_chrdev;
1045         }
1046
1047         if ((ret = get_viotape_info()) < 0) {
1048                 printk(VIOTAPE_KERN_WARN "Unable to obtain virtual device information");
1049                 goto unreg_class;
1050         }
1051
1052         ret = vio_register_driver(&viotape_driver);
1053         if (ret)
1054                 goto unreg_class;
1055
1056         e = create_proc_entry("iSeries/viotape", S_IFREG|S_IRUGO, NULL);
1057         if (e) {
1058                 e->owner = THIS_MODULE;
1059                 e->proc_fops = &proc_viotape_operations;
1060         }
1061
1062         return 0;
1063
1064 unreg_class:
1065         class_destroy(tape_class);
1066 unreg_chrdev:
1067         unregister_chrdev(VIOTAPE_MAJOR, "viotape");
1068 clear_handler:
1069         vio_clearHandler(viomajorsubtype_tape);
1070         viopath_close(viopath_hostLp, viomajorsubtype_tape, VIOTAPE_MAXREQ + 2);
1071 clear_op:
1072         clear_op_struct_pool();
1073         return ret;
1074 }
1075
1076 /* Give a new state to the tape object */
1077 static int chg_state(int index, unsigned char new_state, struct file *file)
1078 {
1079         unsigned char *cur_state =
1080             &state[index].part_stat_rwi[state[index].cur_part];
1081         int rc = 0;
1082
1083         /* if the same state, don't bother */
1084         if (*cur_state == new_state)
1085                 return 0;
1086
1087         /* write an EOF if changing from writing to some other state */
1088         if (*cur_state == VIOT_WRITING) {
1089                 struct mtop write_eof = { MTWEOF, 1 };
1090
1091                 rc = viotap_ioctl(NULL, file, MTIOCTOP,
1092                                   (unsigned long)&write_eof);
1093         }
1094         *cur_state = new_state;
1095         return rc;
1096 }
1097
1098 /* Cleanup */
1099 static void __exit viotap_exit(void)
1100 {
1101         remove_proc_entry("iSeries/viotape", NULL);
1102         vio_unregister_driver(&viotape_driver);
1103         class_destroy(tape_class);
1104         unregister_chrdev(VIOTAPE_MAJOR, "viotape");
1105         if (viotape_unitinfo)
1106                 dma_free_coherent(iSeries_vio_dev,
1107                                 sizeof(viotape_unitinfo[0]) * VIOTAPE_MAX_TAPE,
1108                                 viotape_unitinfo, viotape_unitinfo_token);
1109         viopath_close(viopath_hostLp, viomajorsubtype_tape, VIOTAPE_MAXREQ + 2);
1110         vio_clearHandler(viomajorsubtype_tape);
1111         clear_op_struct_pool();
1112 }
1113
1114 MODULE_LICENSE("GPL");
1115 module_init(viotap_init);
1116 module_exit(viotap_exit);