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1da177e4 LT |
1 | /* |
2 | * drivers/s390/char/tape_char.c | |
3 | * character device frontend for tape device driver | |
4 | * | |
5 | * S390 and zSeries version | |
6 | * Copyright (C) 2001,2002 IBM Deutschland Entwicklung GmbH, IBM Corporation | |
7 | * Author(s): Carsten Otte <cotte@de.ibm.com> | |
8 | * Michael Holzheu <holzheu@de.ibm.com> | |
9 | * Tuan Ngo-Anh <ngoanh@de.ibm.com> | |
10 | * Martin Schwidefsky <schwidefsky@de.ibm.com> | |
11 | */ | |
12 | ||
13 | #include <linux/config.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/types.h> | |
16 | #include <linux/proc_fs.h> | |
17 | #include <linux/mtio.h> | |
18 | ||
19 | #include <asm/uaccess.h> | |
20 | ||
21 | #define TAPE_DBF_AREA tape_core_dbf | |
22 | ||
23 | #include "tape.h" | |
24 | #include "tape_std.h" | |
25 | #include "tape_class.h" | |
26 | ||
27 | #define PRINTK_HEADER "TAPE_CHAR: " | |
28 | ||
29 | #define TAPECHAR_MAJOR 0 /* get dynamic major */ | |
30 | ||
31 | /* | |
32 | * file operation structure for tape character frontend | |
33 | */ | |
34 | static ssize_t tapechar_read(struct file *, char __user *, size_t, loff_t *); | |
35 | static ssize_t tapechar_write(struct file *, const char __user *, size_t, loff_t *); | |
36 | static int tapechar_open(struct inode *,struct file *); | |
37 | static int tapechar_release(struct inode *,struct file *); | |
38 | static int tapechar_ioctl(struct inode *, struct file *, unsigned int, | |
39 | unsigned long); | |
40 | ||
41 | static struct file_operations tape_fops = | |
42 | { | |
43 | .owner = THIS_MODULE, | |
44 | .read = tapechar_read, | |
45 | .write = tapechar_write, | |
46 | .ioctl = tapechar_ioctl, | |
47 | .open = tapechar_open, | |
48 | .release = tapechar_release, | |
49 | }; | |
50 | ||
51 | static int tapechar_major = TAPECHAR_MAJOR; | |
52 | ||
53 | /* | |
54 | * This function is called for every new tapedevice | |
55 | */ | |
56 | int | |
57 | tapechar_setup_device(struct tape_device * device) | |
58 | { | |
59 | char device_name[20]; | |
60 | ||
61 | sprintf(device_name, "ntibm%i", device->first_minor / 2); | |
62 | device->nt = register_tape_dev( | |
63 | &device->cdev->dev, | |
64 | MKDEV(tapechar_major, device->first_minor), | |
65 | &tape_fops, | |
66 | device_name, | |
67 | "non-rewinding" | |
68 | ); | |
69 | device_name[0] = 'r'; | |
70 | device->rt = register_tape_dev( | |
71 | &device->cdev->dev, | |
72 | MKDEV(tapechar_major, device->first_minor + 1), | |
73 | &tape_fops, | |
74 | device_name, | |
75 | "rewinding" | |
76 | ); | |
77 | ||
78 | return 0; | |
79 | } | |
80 | ||
81 | void | |
82 | tapechar_cleanup_device(struct tape_device *device) | |
83 | { | |
84 | unregister_tape_dev(device->rt); | |
85 | device->rt = NULL; | |
86 | unregister_tape_dev(device->nt); | |
87 | device->nt = NULL; | |
88 | } | |
89 | ||
90 | /* | |
91 | * Terminate write command (we write two TMs and skip backward over last) | |
92 | * This ensures that the tape is always correctly terminated. | |
93 | * When the user writes afterwards a new file, he will overwrite the | |
94 | * second TM and therefore one TM will remain to separate the | |
95 | * two files on the tape... | |
96 | */ | |
97 | static inline void | |
98 | tapechar_terminate_write(struct tape_device *device) | |
99 | { | |
100 | if (tape_mtop(device, MTWEOF, 1) == 0 && | |
101 | tape_mtop(device, MTWEOF, 1) == 0) | |
102 | tape_mtop(device, MTBSR, 1); | |
103 | } | |
104 | ||
105 | static inline int | |
106 | tapechar_check_idalbuffer(struct tape_device *device, size_t block_size) | |
107 | { | |
108 | struct idal_buffer *new; | |
109 | ||
110 | if (device->char_data.idal_buf != NULL && | |
111 | device->char_data.idal_buf->size == block_size) | |
112 | return 0; | |
113 | ||
114 | if (block_size > MAX_BLOCKSIZE) { | |
115 | DBF_EVENT(3, "Invalid blocksize (%zd > %d)\n", | |
116 | block_size, MAX_BLOCKSIZE); | |
117 | PRINT_ERR("Invalid blocksize (%zd> %d)\n", | |
118 | block_size, MAX_BLOCKSIZE); | |
119 | return -EINVAL; | |
120 | } | |
121 | ||
122 | /* The current idal buffer is not correct. Allocate a new one. */ | |
123 | new = idal_buffer_alloc(block_size, 0); | |
124 | if (new == NULL) | |
125 | return -ENOMEM; | |
126 | ||
127 | if (device->char_data.idal_buf != NULL) | |
128 | idal_buffer_free(device->char_data.idal_buf); | |
129 | ||
130 | device->char_data.idal_buf = new; | |
131 | ||
132 | return 0; | |
133 | } | |
134 | ||
135 | /* | |
136 | * Tape device read function | |
137 | */ | |
138 | ssize_t | |
139 | tapechar_read(struct file *filp, char __user *data, size_t count, loff_t *ppos) | |
140 | { | |
141 | struct tape_device *device; | |
142 | struct tape_request *request; | |
143 | size_t block_size; | |
144 | int rc; | |
145 | ||
146 | DBF_EVENT(6, "TCHAR:read\n"); | |
147 | device = (struct tape_device *) filp->private_data; | |
148 | ||
149 | /* | |
150 | * If the tape isn't terminated yet, do it now. And since we then | |
151 | * are at the end of the tape there wouldn't be anything to read | |
152 | * anyways. So we return immediatly. | |
153 | */ | |
154 | if(device->required_tapemarks) { | |
155 | return tape_std_terminate_write(device); | |
156 | } | |
157 | ||
158 | /* Find out block size to use */ | |
159 | if (device->char_data.block_size != 0) { | |
160 | if (count < device->char_data.block_size) { | |
161 | DBF_EVENT(3, "TCHAR:read smaller than block " | |
162 | "size was requested\n"); | |
163 | return -EINVAL; | |
164 | } | |
165 | block_size = device->char_data.block_size; | |
166 | } else { | |
167 | block_size = count; | |
168 | } | |
169 | ||
170 | rc = tapechar_check_idalbuffer(device, block_size); | |
171 | if (rc) | |
172 | return rc; | |
173 | ||
174 | #ifdef CONFIG_S390_TAPE_BLOCK | |
175 | /* Changes position. */ | |
176 | device->blk_data.medium_changed = 1; | |
177 | #endif | |
178 | ||
179 | DBF_EVENT(6, "TCHAR:nbytes: %lx\n", block_size); | |
180 | /* Let the discipline build the ccw chain. */ | |
181 | request = device->discipline->read_block(device, block_size); | |
182 | if (IS_ERR(request)) | |
183 | return PTR_ERR(request); | |
184 | /* Execute it. */ | |
185 | rc = tape_do_io(device, request); | |
186 | if (rc == 0) { | |
187 | rc = block_size - request->rescnt; | |
188 | DBF_EVENT(6, "TCHAR:rbytes: %x\n", rc); | |
189 | filp->f_pos += rc; | |
190 | /* Copy data from idal buffer to user space. */ | |
191 | if (idal_buffer_to_user(device->char_data.idal_buf, | |
192 | data, rc) != 0) | |
193 | rc = -EFAULT; | |
194 | } | |
195 | tape_free_request(request); | |
196 | return rc; | |
197 | } | |
198 | ||
199 | /* | |
200 | * Tape device write function | |
201 | */ | |
202 | ssize_t | |
203 | tapechar_write(struct file *filp, const char __user *data, size_t count, loff_t *ppos) | |
204 | { | |
205 | struct tape_device *device; | |
206 | struct tape_request *request; | |
207 | size_t block_size; | |
208 | size_t written; | |
209 | int nblocks; | |
210 | int i, rc; | |
211 | ||
212 | DBF_EVENT(6, "TCHAR:write\n"); | |
213 | device = (struct tape_device *) filp->private_data; | |
214 | /* Find out block size and number of blocks */ | |
215 | if (device->char_data.block_size != 0) { | |
216 | if (count < device->char_data.block_size) { | |
217 | DBF_EVENT(3, "TCHAR:write smaller than block " | |
218 | "size was requested\n"); | |
219 | return -EINVAL; | |
220 | } | |
221 | block_size = device->char_data.block_size; | |
222 | nblocks = count / block_size; | |
223 | } else { | |
224 | block_size = count; | |
225 | nblocks = 1; | |
226 | } | |
227 | ||
228 | rc = tapechar_check_idalbuffer(device, block_size); | |
229 | if (rc) | |
230 | return rc; | |
231 | ||
232 | #ifdef CONFIG_S390_TAPE_BLOCK | |
233 | /* Changes position. */ | |
234 | device->blk_data.medium_changed = 1; | |
235 | #endif | |
236 | ||
237 | DBF_EVENT(6,"TCHAR:nbytes: %lx\n", block_size); | |
238 | DBF_EVENT(6, "TCHAR:nblocks: %x\n", nblocks); | |
239 | /* Let the discipline build the ccw chain. */ | |
240 | request = device->discipline->write_block(device, block_size); | |
241 | if (IS_ERR(request)) | |
242 | return PTR_ERR(request); | |
243 | rc = 0; | |
244 | written = 0; | |
245 | for (i = 0; i < nblocks; i++) { | |
246 | /* Copy data from user space to idal buffer. */ | |
247 | if (idal_buffer_from_user(device->char_data.idal_buf, | |
248 | data, block_size)) { | |
249 | rc = -EFAULT; | |
250 | break; | |
251 | } | |
252 | rc = tape_do_io(device, request); | |
253 | if (rc) | |
254 | break; | |
255 | DBF_EVENT(6, "TCHAR:wbytes: %lx\n", | |
256 | block_size - request->rescnt); | |
257 | filp->f_pos += block_size - request->rescnt; | |
258 | written += block_size - request->rescnt; | |
259 | if (request->rescnt != 0) | |
260 | break; | |
261 | data += block_size; | |
262 | } | |
263 | tape_free_request(request); | |
264 | if (rc == -ENOSPC) { | |
265 | /* | |
266 | * Ok, the device has no more space. It has NOT written | |
267 | * the block. | |
268 | */ | |
269 | if (device->discipline->process_eov) | |
270 | device->discipline->process_eov(device); | |
271 | if (written > 0) | |
272 | rc = 0; | |
273 | ||
274 | } | |
275 | ||
276 | /* | |
277 | * After doing a write we always need two tapemarks to correctly | |
278 | * terminate the tape (one to terminate the file, the second to | |
279 | * flag the end of recorded data. | |
280 | * Since process_eov positions the tape in front of the written | |
281 | * tapemark it doesn't hurt to write two marks again. | |
282 | */ | |
283 | if (!rc) | |
284 | device->required_tapemarks = 2; | |
285 | ||
286 | return rc ? rc : written; | |
287 | } | |
288 | ||
289 | /* | |
290 | * Character frontend tape device open function. | |
291 | */ | |
292 | int | |
293 | tapechar_open (struct inode *inode, struct file *filp) | |
294 | { | |
295 | struct tape_device *device; | |
296 | int minor, rc; | |
297 | ||
298 | DBF_EVENT(6, "TCHAR:open: %i:%i\n", | |
299 | imajor(filp->f_dentry->d_inode), | |
300 | iminor(filp->f_dentry->d_inode)); | |
301 | ||
302 | if (imajor(filp->f_dentry->d_inode) != tapechar_major) | |
303 | return -ENODEV; | |
304 | ||
305 | minor = iminor(filp->f_dentry->d_inode); | |
306 | device = tape_get_device(minor / TAPE_MINORS_PER_DEV); | |
307 | if (IS_ERR(device)) { | |
308 | DBF_EVENT(3, "TCHAR:open: tape_get_device() failed\n"); | |
309 | return PTR_ERR(device); | |
310 | } | |
311 | ||
312 | ||
313 | rc = tape_open(device); | |
314 | if (rc == 0) { | |
315 | filp->private_data = device; | |
316 | return nonseekable_open(inode, filp); | |
317 | } | |
318 | tape_put_device(device); | |
319 | ||
320 | return rc; | |
321 | } | |
322 | ||
323 | /* | |
324 | * Character frontend tape device release function. | |
325 | */ | |
326 | ||
327 | int | |
328 | tapechar_release(struct inode *inode, struct file *filp) | |
329 | { | |
330 | struct tape_device *device; | |
331 | ||
332 | DBF_EVENT(6, "TCHAR:release: %x\n", iminor(inode)); | |
333 | device = (struct tape_device *) filp->private_data; | |
334 | ||
335 | /* | |
336 | * If this is the rewinding tape minor then rewind. In that case we | |
337 | * write all required tapemarks. Otherwise only one to terminate the | |
338 | * file. | |
339 | */ | |
340 | if ((iminor(inode) & 1) != 0) { | |
341 | if (device->required_tapemarks) | |
342 | tape_std_terminate_write(device); | |
343 | tape_mtop(device, MTREW, 1); | |
344 | } else { | |
345 | if (device->required_tapemarks > 1) { | |
346 | if (tape_mtop(device, MTWEOF, 1) == 0) | |
347 | device->required_tapemarks--; | |
348 | } | |
349 | } | |
350 | ||
351 | if (device->char_data.idal_buf != NULL) { | |
352 | idal_buffer_free(device->char_data.idal_buf); | |
353 | device->char_data.idal_buf = NULL; | |
354 | } | |
355 | tape_release(device); | |
356 | filp->private_data = tape_put_device(device); | |
357 | ||
358 | return 0; | |
359 | } | |
360 | ||
361 | /* | |
362 | * Tape device io controls. | |
363 | */ | |
364 | static int | |
365 | tapechar_ioctl(struct inode *inp, struct file *filp, | |
366 | unsigned int no, unsigned long data) | |
367 | { | |
368 | struct tape_device *device; | |
369 | int rc; | |
370 | ||
371 | DBF_EVENT(6, "TCHAR:ioct\n"); | |
372 | ||
373 | device = (struct tape_device *) filp->private_data; | |
374 | ||
375 | if (no == MTIOCTOP) { | |
376 | struct mtop op; | |
377 | ||
378 | if (copy_from_user(&op, (char __user *) data, sizeof(op)) != 0) | |
379 | return -EFAULT; | |
380 | if (op.mt_count < 0) | |
381 | return -EINVAL; | |
382 | ||
383 | /* | |
384 | * Operations that change tape position should write final | |
385 | * tapemarks. | |
386 | */ | |
387 | switch (op.mt_op) { | |
388 | case MTFSF: | |
389 | case MTBSF: | |
390 | case MTFSR: | |
391 | case MTBSR: | |
392 | case MTREW: | |
393 | case MTOFFL: | |
394 | case MTEOM: | |
395 | case MTRETEN: | |
396 | case MTBSFM: | |
397 | case MTFSFM: | |
398 | case MTSEEK: | |
399 | #ifdef CONFIG_S390_TAPE_BLOCK | |
400 | device->blk_data.medium_changed = 1; | |
401 | #endif | |
402 | if (device->required_tapemarks) | |
403 | tape_std_terminate_write(device); | |
404 | default: | |
405 | ; | |
406 | } | |
407 | rc = tape_mtop(device, op.mt_op, op.mt_count); | |
408 | ||
409 | if (op.mt_op == MTWEOF && rc == 0) { | |
410 | if (op.mt_count > device->required_tapemarks) | |
411 | device->required_tapemarks = 0; | |
412 | else | |
413 | device->required_tapemarks -= op.mt_count; | |
414 | } | |
415 | return rc; | |
416 | } | |
417 | if (no == MTIOCPOS) { | |
418 | /* MTIOCPOS: query the tape position. */ | |
419 | struct mtpos pos; | |
420 | ||
421 | rc = tape_mtop(device, MTTELL, 1); | |
422 | if (rc < 0) | |
423 | return rc; | |
424 | pos.mt_blkno = rc; | |
425 | if (copy_to_user((char __user *) data, &pos, sizeof(pos)) != 0) | |
426 | return -EFAULT; | |
427 | return 0; | |
428 | } | |
429 | if (no == MTIOCGET) { | |
430 | /* MTIOCGET: query the tape drive status. */ | |
431 | struct mtget get; | |
432 | ||
433 | memset(&get, 0, sizeof(get)); | |
434 | get.mt_type = MT_ISUNKNOWN; | |
435 | get.mt_resid = 0 /* device->devstat.rescnt */; | |
436 | get.mt_dsreg = device->tape_state; | |
437 | /* FIXME: mt_gstat, mt_erreg, mt_fileno */ | |
438 | get.mt_gstat = 0; | |
439 | get.mt_erreg = 0; | |
440 | get.mt_fileno = 0; | |
441 | get.mt_gstat = device->tape_generic_status; | |
442 | ||
443 | if (device->medium_state == MS_LOADED) { | |
444 | rc = tape_mtop(device, MTTELL, 1); | |
445 | ||
446 | if (rc < 0) | |
447 | return rc; | |
448 | ||
449 | if (rc == 0) | |
450 | get.mt_gstat |= GMT_BOT(~0); | |
451 | ||
452 | get.mt_blkno = rc; | |
453 | } | |
454 | ||
455 | if (copy_to_user((char __user *) data, &get, sizeof(get)) != 0) | |
456 | return -EFAULT; | |
457 | ||
458 | return 0; | |
459 | } | |
460 | /* Try the discipline ioctl function. */ | |
461 | if (device->discipline->ioctl_fn == NULL) | |
462 | return -EINVAL; | |
463 | return device->discipline->ioctl_fn(device, no, data); | |
464 | } | |
465 | ||
466 | /* | |
467 | * Initialize character device frontend. | |
468 | */ | |
469 | int | |
470 | tapechar_init (void) | |
471 | { | |
472 | dev_t dev; | |
473 | ||
474 | if (alloc_chrdev_region(&dev, 0, 256, "tape") != 0) | |
475 | return -1; | |
476 | ||
477 | tapechar_major = MAJOR(dev); | |
478 | PRINT_INFO("tape gets major %d for character devices\n", MAJOR(dev)); | |
479 | ||
480 | return 0; | |
481 | } | |
482 | ||
483 | /* | |
484 | * cleanup | |
485 | */ | |
486 | void | |
487 | tapechar_exit(void) | |
488 | { | |
489 | PRINT_INFO("tape releases major %d for character devices\n", | |
490 | tapechar_major); | |
491 | unregister_chrdev_region(MKDEV(tapechar_major, 0), 256); | |
492 | } |