Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  1 /*
  2  *  drivers/s390/char/tape.h
  3  *    tape device driver for 3480/3490E/3590 tapes.
  4  *
  5  *  S390 and zSeries version
  6  *    Copyright IBM Corp. 2001,2006
  7  *    Author(s): Carsten Otte <cotte@de.ibm.com>
  8  *               Tuan Ngo-Anh <ngoanh@de.ibm.com>
  9  *               Martin Schwidefsky <schwidefsky@de.ibm.com>
 10  *               Stefan Bader <shbader@de.ibm.com>
 11  */
 12 
 13 #ifndef _TAPE_H
 14 #define _TAPE_H
 15 
 16 #include <asm/ccwdev.h>
 17 #include <asm/debug.h>
 18 #include <asm/idals.h>
 19 #include <linux/blkdev.h>
 20 #include <linux/kernel.h>
 21 #include <linux/module.h>
 22 #include <linux/mtio.h>
 23 #include <linux/interrupt.h>
 24 #include <linux/workqueue.h>
 25 
 26 struct gendisk;
 27 
 28 /*
 29  * Define DBF_LIKE_HELL for lots of messages in the debug feature.
 30  */
 31 #define DBF_LIKE_HELL
 32 #ifdef  DBF_LIKE_HELL
 33 #define DBF_LH(level, str, ...) \
 34 do { \
 35         debug_sprintf_event(TAPE_DBF_AREA, level, str, ## __VA_ARGS__); \
 36 } while (0)
 37 #else
 38 #define DBF_LH(level, str, ...) do {} while(0)
 39 #endif
 40 
 41 /*
 42  * macros s390 debug feature (dbf)
 43  */
 44 #define DBF_EVENT(d_level, d_str...) \
 45 do { \
 46         debug_sprintf_event(TAPE_DBF_AREA, d_level, d_str); \
 47 } while (0)
 48 
 49 #define DBF_EXCEPTION(d_level, d_str...) \
 50 do { \
 51         debug_sprintf_exception(TAPE_DBF_AREA, d_level, d_str); \
 52 } while (0)
 53 
 54 #define TAPE_VERSION_MAJOR 2
 55 #define TAPE_VERSION_MINOR 0
 56 #define TAPE_MAGIC "tape"
 57 
 58 #define TAPE_MINORS_PER_DEV 2       /* two minors per device */
 59 #define TAPEBLOCK_HSEC_SIZE     2048
 60 #define TAPEBLOCK_HSEC_S2B      2
 61 #define TAPEBLOCK_RETRIES       5
 62 
 63 enum tape_medium_state {
 64         MS_UNKNOWN,
 65         MS_LOADED,
 66         MS_UNLOADED,
 67         MS_SIZE
 68 };
 69 
 70 enum tape_state {
 71         TS_UNUSED=0,
 72         TS_IN_USE,
 73         TS_BLKUSE,
 74         TS_INIT,
 75         TS_NOT_OPER,
 76         TS_SIZE
 77 };
 78 
 79 enum tape_op {
 80         TO_BLOCK,       /* Block read */
 81         TO_BSB,         /* Backward space block */
 82         TO_BSF,         /* Backward space filemark */
 83         TO_DSE,         /* Data security erase */
 84         TO_FSB,         /* Forward space block */
 85         TO_FSF,         /* Forward space filemark */
 86         TO_LBL,         /* Locate block label */
 87         TO_NOP,         /* No operation */
 88         TO_RBA,         /* Read backward */
 89         TO_RBI,         /* Read block information */
 90         TO_RFO,         /* Read forward */
 91         TO_REW,         /* Rewind tape */
 92         TO_RUN,         /* Rewind and unload tape */
 93         TO_WRI,         /* Write block */
 94         TO_WTM,         /* Write tape mark */
 95         TO_MSEN,        /* Medium sense */
 96         TO_LOAD,        /* Load tape */
 97         TO_READ_CONFIG, /* Read configuration data */
 98         TO_READ_ATTMSG, /* Read attention message */
 99         TO_DIS,         /* Tape display */
100         TO_ASSIGN,      /* Assign tape to channel path */
101         TO_UNASSIGN,    /* Unassign tape from channel path */
102         TO_CRYPT_ON,    /* Enable encrpytion */
103         TO_CRYPT_OFF,   /* Disable encrpytion */
104         TO_KEKL_SET,    /* Set KEK label */
105         TO_KEKL_QUERY,  /* Query KEK label */
106         TO_RDC,         /* Read device characteristics */
107         TO_SIZE,        /* #entries in tape_op_t */
108 };
109 
110 /* Forward declaration */
111 struct tape_device;
112 
113 /* tape_request->status can be: */
114 enum tape_request_status {
115         TAPE_REQUEST_INIT,      /* request is ready to be processed */
116         TAPE_REQUEST_QUEUED,    /* request is queued to be processed */
117         TAPE_REQUEST_IN_IO,     /* request is currently in IO */
118         TAPE_REQUEST_DONE,      /* request is completed. */
119         TAPE_REQUEST_CANCEL,    /* request should be canceled. */
120         TAPE_REQUEST_LONG_BUSY, /* request has to be restarted after long busy */
121 };
122 
123 /* Tape CCW request */
124 struct tape_request {
125         struct list_head list;          /* list head for request queueing. */
126         struct tape_device *device;     /* tape device of this request */
127         struct ccw1 *cpaddr;            /* address of the channel program. */
128         void *cpdata;                   /* pointer to ccw data. */
129         enum tape_request_status status;/* status of this request */
130         int options;                    /* options for execution. */
131         int retries;                    /* retry counter for error recovery. */
132         int rescnt;                     /* residual count from devstat. */
133 
134         /* Callback for delivering final status. */
135         void (*callback)(struct tape_request *, void *);
136         void *callback_data;
137 
138         enum tape_op op;
139         int rc;
140 };
141 
142 /* Function type for magnetic tape commands */
143 typedef int (*tape_mtop_fn)(struct tape_device *, int);
144 
145 /* Size of the array containing the mtops for a discipline */
146 #define TAPE_NR_MTOPS (MTMKPART+1)
147 
148 /* Tape Discipline */
149 struct tape_discipline {
150         struct module *owner;
151         int  (*setup_device)(struct tape_device *);
152         void (*cleanup_device)(struct tape_device *);
153         int (*irq)(struct tape_device *, struct tape_request *, struct irb *);
154         struct tape_request *(*read_block)(struct tape_device *, size_t);
155         struct tape_request *(*write_block)(struct tape_device *, size_t);
156         void (*process_eov)(struct tape_device*);
157 #ifdef CONFIG_S390_TAPE_BLOCK
158         /* Block device stuff. */
159         struct tape_request *(*bread)(struct tape_device *, struct request *);
160         void (*check_locate)(struct tape_device *, struct tape_request *);
161         void (*free_bread)(struct tape_request *);
162 #endif
163         /* ioctl function for additional ioctls. */
164         int (*ioctl_fn)(struct tape_device *, unsigned int, unsigned long);
165         /* Array of tape commands with TAPE_NR_MTOPS entries */
166         tape_mtop_fn *mtop_array;
167 };
168 
169 /*
170  * The discipline irq function either returns an error code (<0) which
171  * means that the request has failed with an error or one of the following:
172  */
173 #define TAPE_IO_SUCCESS         0       /* request successful */
174 #define TAPE_IO_PENDING         1       /* request still running */
175 #define TAPE_IO_RETRY           2       /* retry to current request */
176 #define TAPE_IO_STOP            3       /* stop the running request */
177 #define TAPE_IO_LONG_BUSY       4       /* delay the running request */
178 
179 /* Char Frontend Data */
180 struct tape_char_data {
181         struct idal_buffer *idal_buf;   /* idal buffer for user char data */
182         int block_size;                 /*   of size block_size. */
183 };
184 
185 #ifdef CONFIG_S390_TAPE_BLOCK
186 /* Block Frontend Data */
187 struct tape_blk_data
188 {
189         struct tape_device *    device;
190         /* Block device request queue. */
191         struct request_queue *  request_queue;
192         spinlock_t              request_queue_lock;
193 
194         /* Task to move entries from block request to CCS request queue. */
195         struct work_struct      requeue_task;
196         atomic_t                requeue_scheduled;
197 
198         /* Current position on the tape. */
199         long                    block_position;
200         int                     medium_changed;
201         struct gendisk *        disk;
202 };
203 #endif
204 
205 /* Tape Info */
206 struct tape_device {
207         /* entry in tape_device_list */
208         struct list_head                node;
209 
210         int                             cdev_id;
211         struct ccw_device *             cdev;
212         struct tape_class_device *      nt;
213         struct tape_class_device *      rt;
214 
215         /* Device discipline information. */
216         struct tape_discipline *        discipline;
217         void *                          discdata;
218 
219         /* Generic status flags */
220         long                            tape_generic_status;
221 
222         /* Device state information. */
223         wait_queue_head_t               state_change_wq;
224         enum tape_state                 tape_state;
225         enum tape_medium_state          medium_state;
226         unsigned char *                 modeset_byte;
227 
228         /* Reference count. */
229         atomic_t                        ref_count;
230 
231         /* Request queue. */
232         struct list_head                req_queue;
233 
234         /* Each tape device has (currently) two minor numbers. */
235         int                             first_minor;
236 
237         /* Number of tapemarks required for correct termination. */
238         int                             required_tapemarks;
239 
240         /* Block ID of the BOF */
241         unsigned int                    bof;
242 
243         /* Character device frontend data */
244         struct tape_char_data           char_data;
245 #ifdef CONFIG_S390_TAPE_BLOCK
246         /* Block dev frontend data */
247         struct tape_blk_data            blk_data;
248 #endif
249 
250         /* Function to start or stop the next request later. */
251         struct delayed_work             tape_dnr;
252 
253         /* Timer for long busy */
254         struct timer_list               lb_timeout;
255 
256 };
257 
258 /* Externals from tape_core.c */
259 extern struct tape_request *tape_alloc_request(int cplength, int datasize);
260 extern void tape_free_request(struct tape_request *);
261 extern int tape_do_io(struct tape_device *, struct tape_request *);
262 extern int tape_do_io_async(struct tape_device *, struct tape_request *);
263 extern int tape_do_io_interruptible(struct tape_device *, struct tape_request *);
264 extern int tape_cancel_io(struct tape_device *, struct tape_request *);
265 void tape_hotplug_event(struct tape_device *, int major, int action);
266 
267 static inline int
268 tape_do_io_free(struct tape_device *device, struct tape_request *request)
269 {
270         int rc;
271 
272         rc = tape_do_io(device, request);
273         tape_free_request(request);
274         return rc;
275 }
276 
277 extern int tape_oper_handler(int irq, int status);
278 extern void tape_noper_handler(int irq, int status);
279 extern int tape_open(struct tape_device *);
280 extern int tape_release(struct tape_device *);
281 extern int tape_mtop(struct tape_device *, int, int);
282 extern void tape_state_set(struct tape_device *, enum tape_state);
283 
284 extern int tape_generic_online(struct tape_device *, struct tape_discipline *);
285 extern int tape_generic_offline(struct tape_device *device);
286 
287 /* Externals from tape_devmap.c */
288 extern int tape_generic_probe(struct ccw_device *);
289 extern void tape_generic_remove(struct ccw_device *);
290 
291 extern struct tape_device *tape_get_device(int devindex);
292 extern struct tape_device *tape_get_device_reference(struct tape_device *);
293 extern struct tape_device *tape_put_device(struct tape_device *);
294 
295 /* Externals from tape_char.c */
296 extern int tapechar_init(void);
297 extern void tapechar_exit(void);
298 extern int  tapechar_setup_device(struct tape_device *);
299 extern void tapechar_cleanup_device(struct tape_device *);
300 
301 /* Externals from tape_block.c */
302 #ifdef CONFIG_S390_TAPE_BLOCK
303 extern int tapeblock_init (void);
304 extern void tapeblock_exit(void);
305 extern int tapeblock_setup_device(struct tape_device *);
306 extern void tapeblock_cleanup_device(struct tape_device *);
307 #else
308 static inline int tapeblock_init (void) {return 0;}
309 static inline void tapeblock_exit (void) {;}
310 static inline int tapeblock_setup_device(struct tape_device *t) {return 0;}
311 static inline void tapeblock_cleanup_device (struct tape_device *t) {;}
312 #endif
313 
314 /* tape initialisation functions */
315 #ifdef CONFIG_PROC_FS
316 extern void tape_proc_init (void);
317 extern void tape_proc_cleanup (void);
318 #else
319 static inline void tape_proc_init (void) {;}
320 static inline void tape_proc_cleanup (void) {;}
321 #endif
322 
323 /* a function for dumping device sense info */
324 extern void tape_dump_sense(struct tape_device *, struct tape_request *,
325                             struct irb *);
326 extern void tape_dump_sense_dbf(struct tape_device *, struct tape_request *,
327                                 struct irb *);
328 
329 /* functions for handling the status of a device */
330 extern void tape_med_state_set(struct tape_device *, enum tape_medium_state);
331 
332 /* The debug area */
333 extern debug_info_t *TAPE_DBF_AREA;
334 
335 /* functions for building ccws */
336 static inline struct ccw1 *
337 tape_ccw_cc(struct ccw1 *ccw, __u8 cmd_code, __u16 memsize, void *cda)
338 {
339         ccw->cmd_code = cmd_code;
340         ccw->flags = CCW_FLAG_CC;
341         ccw->count = memsize;
342         ccw->cda = (__u32)(addr_t) cda;
343         return ccw + 1;
344 }
345 
346 static inline struct ccw1 *
347 tape_ccw_end(struct ccw1 *ccw, __u8 cmd_code, __u16 memsize, void *cda)
348 {
349         ccw->cmd_code = cmd_code;
350         ccw->flags = 0;
351         ccw->count = memsize;
352         ccw->cda = (__u32)(addr_t) cda;
353         return ccw + 1;
354 }
355 
356 static inline struct ccw1 *
357 tape_ccw_cmd(struct ccw1 *ccw, __u8 cmd_code)
358 {
359         ccw->cmd_code = cmd_code;
360         ccw->flags = 0;
361         ccw->count = 0;
362         ccw->cda = (__u32)(addr_t) &ccw->cmd_code;
363         return ccw + 1;
364 }
365 
366 static inline struct ccw1 *
367 tape_ccw_repeat(struct ccw1 *ccw, __u8 cmd_code, int count)
368 {
369         while (count-- > 0) {
370                 ccw->cmd_code = cmd_code;
371                 ccw->flags = CCW_FLAG_CC;
372                 ccw->count = 0;
373                 ccw->cda = (__u32)(addr_t) &ccw->cmd_code;
374                 ccw++;
375         }
376         return ccw;
377 }
378 
379 static inline struct ccw1 *
380 tape_ccw_cc_idal(struct ccw1 *ccw, __u8 cmd_code, struct idal_buffer *idal)
381 {
382         ccw->cmd_code = cmd_code;
383         ccw->flags    = CCW_FLAG_CC;
384         idal_buffer_set_cda(idal, ccw);
385         return ccw++;
386 }
387 
388 static inline struct ccw1 *
389 tape_ccw_end_idal(struct ccw1 *ccw, __u8 cmd_code, struct idal_buffer *idal)
390 {
391         ccw->cmd_code = cmd_code;
392         ccw->flags    = 0;
393         idal_buffer_set_cda(idal, ccw);
394         return ccw++;
395 }
396 
397 /* Global vars */
398 extern const char *tape_state_verbose[];
399 extern const char *tape_op_verbose[];
400 
401 #endif /* for ifdef tape.h */
402 
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