xref: /openbmc/linux/drivers/s390/block/dasd_int.h (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
1 /*
2  * File...........: linux/drivers/s390/block/dasd_int.h
3  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
4  *		    Horst Hummel <Horst.Hummel@de.ibm.com>
5  *		    Martin Schwidefsky <schwidefsky@de.ibm.com>
6  * Bugreports.to..: <Linux390@de.ibm.com>
7  * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000
8  *
9  */
10 
11 #ifndef DASD_INT_H
12 #define DASD_INT_H
13 
14 #ifdef __KERNEL__
15 
16 /* we keep old device allocation scheme; IOW, minors are still in 0..255 */
17 #define DASD_PER_MAJOR (1U << (MINORBITS - DASD_PARTN_BITS))
18 #define DASD_PARTN_MASK ((1 << DASD_PARTN_BITS) - 1)
19 
20 /*
21  * States a dasd device can have:
22  *   new: the dasd_device structure is allocated.
23  *   known: the discipline for the device is identified.
24  *   basic: the device can do basic i/o.
25  *   unfmt: the device could not be analyzed (format is unknown).
26  *   ready: partition detection is done and the device is can do block io.
27  *   online: the device accepts requests from the block device queue.
28  *
29  * Things to do for startup state transitions:
30  *   new -> known: find discipline for the device and create devfs entries.
31  *   known -> basic: request irq line for the device.
32  *   basic -> ready: do the initial analysis, e.g. format detection,
33  *                   do block device setup and detect partitions.
34  *   ready -> online: schedule the device tasklet.
35  * Things to do for shutdown state transitions:
36  *   online -> ready: just set the new device state.
37  *   ready -> basic: flush requests from the block device layer, clear
38  *                   partition information and reset format information.
39  *   basic -> known: terminate all requests and free irq.
40  *   known -> new: remove devfs entries and forget discipline.
41  */
42 
43 #define DASD_STATE_NEW	  0
44 #define DASD_STATE_KNOWN  1
45 #define DASD_STATE_BASIC  2
46 #define DASD_STATE_UNFMT  3
47 #define DASD_STATE_READY  4
48 #define DASD_STATE_ONLINE 5
49 
50 #include <linux/module.h>
51 #include <linux/wait.h>
52 #include <linux/blkdev.h>
53 #include <linux/genhd.h>
54 #include <linux/hdreg.h>
55 #include <linux/interrupt.h>
56 #include <linux/log2.h>
57 #include <asm/ccwdev.h>
58 #include <linux/workqueue.h>
59 #include <asm/debug.h>
60 #include <asm/dasd.h>
61 #include <asm/idals.h>
62 
63 /*
64  * SECTION: Type definitions
65  */
66 struct dasd_device;
67 
68 typedef enum {
69 	dasd_era_fatal = -1,	/* no chance to recover		     */
70 	dasd_era_none = 0,	/* don't recover, everything alright */
71 	dasd_era_msg = 1,	/* don't recover, just report...     */
72 	dasd_era_recover = 2	/* recovery action recommended	     */
73 } dasd_era_t;
74 
75 /* BIT DEFINITIONS FOR SENSE DATA */
76 #define DASD_SENSE_BIT_0 0x80
77 #define DASD_SENSE_BIT_1 0x40
78 #define DASD_SENSE_BIT_2 0x20
79 #define DASD_SENSE_BIT_3 0x10
80 
81 /*
82  * SECTION: MACROs for klogd and s390 debug feature (dbf)
83  */
84 #define DBF_DEV_EVENT(d_level, d_device, d_str, d_data...) \
85 do { \
86 	debug_sprintf_event(d_device->debug_area, \
87 			    d_level, \
88 			    d_str "\n", \
89 			    d_data); \
90 } while(0)
91 
92 #define DBF_DEV_EXC(d_level, d_device, d_str, d_data...) \
93 do { \
94 	debug_sprintf_exception(d_device->debug_area, \
95 				d_level, \
96 				d_str "\n", \
97 				d_data); \
98 } while(0)
99 
100 #define DBF_EVENT(d_level, d_str, d_data...)\
101 do { \
102 	debug_sprintf_event(dasd_debug_area, \
103 			    d_level,\
104 			    d_str "\n", \
105 			    d_data); \
106 } while(0)
107 
108 #define DBF_EXC(d_level, d_str, d_data...)\
109 do { \
110 	debug_sprintf_exception(dasd_debug_area, \
111 				d_level,\
112 				d_str "\n", \
113 				d_data); \
114 } while(0)
115 
116 /* definition of dbf debug levels */
117 #define	DBF_EMERG	0	/* system is unusable			*/
118 #define	DBF_ALERT	1	/* action must be taken immediately	*/
119 #define	DBF_CRIT	2	/* critical conditions			*/
120 #define	DBF_ERR		3	/* error conditions			*/
121 #define	DBF_WARNING	4	/* warning conditions			*/
122 #define	DBF_NOTICE	5	/* normal but significant condition	*/
123 #define	DBF_INFO	6	/* informational			*/
124 #define	DBF_DEBUG	6	/* debug-level messages			*/
125 
126 /* messages to be written via klogd and dbf */
127 #define DEV_MESSAGE(d_loglevel,d_device,d_string,d_args...)\
128 do { \
129 	printk(d_loglevel PRINTK_HEADER " %s: " d_string "\n", \
130 	       d_device->cdev->dev.bus_id, d_args); \
131 	DBF_DEV_EVENT(DBF_ALERT, d_device, d_string, d_args); \
132 } while(0)
133 
134 #define MESSAGE(d_loglevel,d_string,d_args...)\
135 do { \
136 	printk(d_loglevel PRINTK_HEADER " " d_string "\n", d_args); \
137 	DBF_EVENT(DBF_ALERT, d_string, d_args); \
138 } while(0)
139 
140 /* messages to be written via klogd only */
141 #define DEV_MESSAGE_LOG(d_loglevel,d_device,d_string,d_args...)\
142 do { \
143 	printk(d_loglevel PRINTK_HEADER " %s: " d_string "\n", \
144 	       d_device->cdev->dev.bus_id, d_args); \
145 } while(0)
146 
147 #define MESSAGE_LOG(d_loglevel,d_string,d_args...)\
148 do { \
149 	printk(d_loglevel PRINTK_HEADER " " d_string "\n", d_args); \
150 } while(0)
151 
152 struct dasd_ccw_req {
153 	unsigned int magic;		/* Eye catcher */
154         struct list_head list;		/* list_head for request queueing. */
155 
156 	/* Where to execute what... */
157 	struct dasd_device *device;	/* device the request is for */
158 	struct ccw1 *cpaddr;		/* address of channel program */
159 	char status;	        	/* status of this request */
160 	short retries;			/* A retry counter */
161 	unsigned long flags;        	/* flags of this request */
162 
163 	/* ... and how */
164 	unsigned long starttime;	/* jiffies time of request start */
165 	int expires;			/* expiration period in jiffies */
166 	char lpm;               	/* logical path mask */
167 	void *data;			/* pointer to data area */
168 
169 	/* these are important for recovering erroneous requests          */
170 	struct irb irb;			/* device status in case of an error */
171 	struct dasd_ccw_req *refers;	/* ERP-chain queueing. */
172 	void *function; 		/* originating ERP action */
173 
174 	/* these are for statistics only */
175 	unsigned long long buildclk;	/* TOD-clock of request generation */
176 	unsigned long long startclk;	/* TOD-clock of request start */
177 	unsigned long long stopclk;	/* TOD-clock of request interrupt */
178 	unsigned long long endclk;	/* TOD-clock of request termination */
179 
180         /* Callback that is called after reaching final status. */
181         void (*callback)(struct dasd_ccw_req *, void *data);
182         void *callback_data;
183 };
184 
185 /*
186  * dasd_ccw_req -> status can be:
187  */
188 #define DASD_CQR_FILLED   0x00	/* request is ready to be processed */
189 #define DASD_CQR_QUEUED   0x01	/* request is queued to be processed */
190 #define DASD_CQR_IN_IO    0x02	/* request is currently in IO */
191 #define DASD_CQR_DONE     0x03	/* request is completed successfully */
192 #define DASD_CQR_ERROR    0x04	/* request is completed with error */
193 #define DASD_CQR_FAILED   0x05	/* request is finally failed */
194 #define DASD_CQR_CLEAR    0x06	/* request is clear pending */
195 
196 /* per dasd_ccw_req flags */
197 #define DASD_CQR_FLAGS_USE_ERP   0	/* use ERP for this request */
198 #define DASD_CQR_FLAGS_FAILFAST  1	/* FAILFAST */
199 
200 /* Signature for error recovery functions. */
201 typedef struct dasd_ccw_req *(*dasd_erp_fn_t) (struct dasd_ccw_req *);
202 
203 /*
204  * the struct dasd_discipline is
205  * sth like a table of virtual functions, if you think of dasd_eckd
206  * inheriting dasd...
207  * no, currently we are not planning to reimplement the driver in C++
208  */
209 struct dasd_discipline {
210 	struct module *owner;
211 	char ebcname[8];	/* a name used for tagging and printks */
212 	char name[8];		/* a name used for tagging and printks */
213 	int max_blocks;		/* maximum number of blocks to be chained */
214 
215 	struct list_head list;	/* used for list of disciplines */
216 
217         /*
218          * Device recognition functions. check_device is used to verify
219          * the sense data and the information returned by read device
220          * characteristics. It returns 0 if the discipline can be used
221          * for the device in question.
222          * do_analysis is used in the step from device state "basic" to
223          * state "accept". It returns 0 if the device can be made ready,
224          * it returns -EMEDIUMTYPE if the device can't be made ready or
225          * -EAGAIN if do_analysis started a ccw that needs to complete
226          * before the analysis may be repeated.
227          */
228         int (*check_device)(struct dasd_device *);
229 	int (*do_analysis) (struct dasd_device *);
230 
231         /*
232          * Device operation functions. build_cp creates a ccw chain for
233          * a block device request, start_io starts the request and
234          * term_IO cancels it (e.g. in case of a timeout). format_device
235          * returns a ccw chain to be used to format the device.
236          */
237 	struct dasd_ccw_req *(*build_cp) (struct dasd_device *,
238 					  struct request *);
239 	int (*start_IO) (struct dasd_ccw_req *);
240 	int (*term_IO) (struct dasd_ccw_req *);
241 	struct dasd_ccw_req *(*format_device) (struct dasd_device *,
242 					       struct format_data_t *);
243 	int (*free_cp) (struct dasd_ccw_req *, struct request *);
244         /*
245          * Error recovery functions. examine_error() returns a value that
246          * indicates what to do for an error condition. If examine_error()
247 	 * returns 'dasd_era_recover' erp_action() is called to create a
248          * special error recovery ccw. erp_postaction() is called after
249          * an error recovery ccw has finished its execution. dump_sense
250          * is called for every error condition to print the sense data
251          * to the console.
252          */
253 	dasd_era_t(*examine_error) (struct dasd_ccw_req *, struct irb *);
254 	dasd_erp_fn_t(*erp_action) (struct dasd_ccw_req *);
255 	dasd_erp_fn_t(*erp_postaction) (struct dasd_ccw_req *);
256 	void (*dump_sense) (struct dasd_device *, struct dasd_ccw_req *,
257 			    struct irb *);
258 
259         /* i/o control functions. */
260 	int (*fill_geometry) (struct dasd_device *, struct hd_geometry *);
261 	int (*fill_info) (struct dasd_device *, struct dasd_information2_t *);
262 	int (*ioctl) (struct dasd_device *, unsigned int, void __user *);
263 };
264 
265 extern struct dasd_discipline *dasd_diag_discipline_pointer;
266 
267 /*
268  * Unique identifier for dasd device.
269  */
270 struct dasd_uid {
271 	__u8 alias;
272 	char vendor[4];
273 	char serial[15];
274 	__u16 ssid;
275 	__u8 unit_addr;
276 };
277 
278 /*
279  * Notification numbers for extended error reporting notifications:
280  * The DASD_EER_DISABLE notification is sent before a dasd_device (and it's
281  * eer pointer) is freed. The error reporting module needs to do all necessary
282  * cleanup steps.
283  * The DASD_EER_TRIGGER notification sends the actual error reports (triggers).
284  */
285 #define DASD_EER_DISABLE 0
286 #define DASD_EER_TRIGGER 1
287 
288 /* Trigger IDs for extended error reporting DASD_EER_TRIGGER notification */
289 #define DASD_EER_FATALERROR  1
290 #define DASD_EER_NOPATH      2
291 #define DASD_EER_STATECHANGE 3
292 #define DASD_EER_PPRCSUSPEND 4
293 
294 struct dasd_device {
295 	/* Block device stuff. */
296 	struct gendisk *gdp;
297 	struct request_queue *request_queue;
298 	spinlock_t request_queue_lock;
299 	struct block_device *bdev;
300         unsigned int devindex;
301 	unsigned long blocks;	   /* size of volume in blocks */
302 	unsigned int bp_block;	   /* bytes per block */
303 	unsigned int s2b_shift;	   /* log2 (bp_block/512) */
304 	unsigned long flags;	   /* per device flags */
305 	unsigned short features;   /* copy of devmap-features (read-only!) */
306 
307 	/* extended error reporting stuff (eer) */
308 	struct dasd_ccw_req *eer_cqr;
309 
310 	/* Device discipline stuff. */
311 	struct dasd_discipline *discipline;
312 	struct dasd_discipline *base_discipline;
313 	char *private;
314 
315 	/* Device state and target state. */
316 	int state, target;
317 	int stopped;		/* device (ccw_device_start) was stopped */
318 
319 	/* Open and reference count. */
320         atomic_t ref_count;
321 	atomic_t open_count;
322 
323 	/* ccw queue and memory for static ccw/erp buffers. */
324 	struct list_head ccw_queue;
325 	spinlock_t mem_lock;
326 	void *ccw_mem;
327 	void *erp_mem;
328 	struct list_head ccw_chunks;
329 	struct list_head erp_chunks;
330 
331 	atomic_t tasklet_scheduled;
332         struct tasklet_struct tasklet;
333 	struct work_struct kick_work;
334 	struct timer_list timer;
335 
336 	debug_info_t *debug_area;
337 
338 	struct ccw_device *cdev;
339 
340 #ifdef CONFIG_DASD_PROFILE
341 	struct dasd_profile_info_t profile;
342 #endif
343 };
344 
345 /* reasons why device (ccw_device_start) was stopped */
346 #define DASD_STOPPED_NOT_ACC 1         /* not accessible */
347 #define DASD_STOPPED_QUIESCE 2         /* Quiesced */
348 #define DASD_STOPPED_PENDING 4         /* long busy */
349 #define DASD_STOPPED_DC_WAIT 8         /* disconnected, wait */
350 #define DASD_STOPPED_DC_EIO  16        /* disconnected, return -EIO */
351 
352 /* per device flags */
353 #define DASD_FLAG_DSC_ERROR	2	/* return -EIO when disconnected */
354 #define DASD_FLAG_OFFLINE	3	/* device is in offline processing */
355 #define DASD_FLAG_EER_SNSS	4	/* A SNSS is required */
356 #define DASD_FLAG_EER_IN_USE	5	/* A SNSS request is running */
357 
358 void dasd_put_device_wake(struct dasd_device *);
359 
360 /*
361  * Reference count inliners
362  */
363 static inline void
364 dasd_get_device(struct dasd_device *device)
365 {
366 	atomic_inc(&device->ref_count);
367 }
368 
369 static inline void
370 dasd_put_device(struct dasd_device *device)
371 {
372 	if (atomic_dec_return(&device->ref_count) == 0)
373 		dasd_put_device_wake(device);
374 }
375 
376 /*
377  * The static memory in ccw_mem and erp_mem is managed by a sorted
378  * list of free memory chunks.
379  */
380 struct dasd_mchunk
381 {
382 	struct list_head list;
383 	unsigned long size;
384 } __attribute__ ((aligned(8)));
385 
386 static inline void
387 dasd_init_chunklist(struct list_head *chunk_list, void *mem,
388 		    unsigned long size)
389 {
390 	struct dasd_mchunk *chunk;
391 
392 	INIT_LIST_HEAD(chunk_list);
393 	chunk = (struct dasd_mchunk *) mem;
394 	chunk->size = size - sizeof(struct dasd_mchunk);
395 	list_add(&chunk->list, chunk_list);
396 }
397 
398 static inline void *
399 dasd_alloc_chunk(struct list_head *chunk_list, unsigned long size)
400 {
401 	struct dasd_mchunk *chunk, *tmp;
402 
403 	size = (size + 7L) & -8L;
404 	list_for_each_entry(chunk, chunk_list, list) {
405 		if (chunk->size < size)
406 			continue;
407 		if (chunk->size > size + sizeof(struct dasd_mchunk)) {
408 			char *endaddr = (char *) (chunk + 1) + chunk->size;
409 			tmp = (struct dasd_mchunk *) (endaddr - size) - 1;
410 			tmp->size = size;
411 			chunk->size -= size + sizeof(struct dasd_mchunk);
412 			chunk = tmp;
413 		} else
414 			list_del(&chunk->list);
415 		return (void *) (chunk + 1);
416 	}
417 	return NULL;
418 }
419 
420 static inline void
421 dasd_free_chunk(struct list_head *chunk_list, void *mem)
422 {
423 	struct dasd_mchunk *chunk, *tmp;
424 	struct list_head *p, *left;
425 
426 	chunk = (struct dasd_mchunk *)
427 		((char *) mem - sizeof(struct dasd_mchunk));
428 	/* Find out the left neighbour in chunk_list. */
429 	left = chunk_list;
430 	list_for_each(p, chunk_list) {
431 		if (list_entry(p, struct dasd_mchunk, list) > chunk)
432 			break;
433 		left = p;
434 	}
435 	/* Try to merge with right neighbour = next element from left. */
436 	if (left->next != chunk_list) {
437 		tmp = list_entry(left->next, struct dasd_mchunk, list);
438 		if ((char *) (chunk + 1) + chunk->size == (char *) tmp) {
439 			list_del(&tmp->list);
440 			chunk->size += tmp->size + sizeof(struct dasd_mchunk);
441 		}
442 	}
443 	/* Try to merge with left neighbour. */
444 	if (left != chunk_list) {
445 		tmp = list_entry(left, struct dasd_mchunk, list);
446 		if ((char *) (tmp + 1) + tmp->size == (char *) chunk) {
447 			tmp->size += chunk->size + sizeof(struct dasd_mchunk);
448 			return;
449 		}
450 	}
451 	__list_add(&chunk->list, left, left->next);
452 }
453 
454 /*
455  * Check if bsize is in { 512, 1024, 2048, 4096 }
456  */
457 static inline int
458 dasd_check_blocksize(int bsize)
459 {
460 	if (bsize < 512 || bsize > 4096 || !is_power_of_2(bsize))
461 		return -EMEDIUMTYPE;
462 	return 0;
463 }
464 
465 /* externals in dasd.c */
466 #define DASD_PROFILE_ON	 1
467 #define DASD_PROFILE_OFF 0
468 
469 extern debug_info_t *dasd_debug_area;
470 extern struct dasd_profile_info_t dasd_global_profile;
471 extern unsigned int dasd_profile_level;
472 extern struct block_device_operations dasd_device_operations;
473 
474 extern struct kmem_cache *dasd_page_cache;
475 
476 struct dasd_ccw_req *
477 dasd_kmalloc_request(char *, int, int, struct dasd_device *);
478 struct dasd_ccw_req *
479 dasd_smalloc_request(char *, int, int, struct dasd_device *);
480 void dasd_kfree_request(struct dasd_ccw_req *, struct dasd_device *);
481 void dasd_sfree_request(struct dasd_ccw_req *, struct dasd_device *);
482 
483 static inline int
484 dasd_kmalloc_set_cda(struct ccw1 *ccw, void *cda, struct dasd_device *device)
485 {
486 	return set_normalized_cda(ccw, cda);
487 }
488 
489 struct dasd_device *dasd_alloc_device(void);
490 void dasd_free_device(struct dasd_device *);
491 
492 void dasd_enable_device(struct dasd_device *);
493 void dasd_set_target_state(struct dasd_device *, int);
494 void dasd_kick_device(struct dasd_device *);
495 
496 void dasd_add_request_head(struct dasd_ccw_req *);
497 void dasd_add_request_tail(struct dasd_ccw_req *);
498 int  dasd_start_IO(struct dasd_ccw_req *);
499 int  dasd_term_IO(struct dasd_ccw_req *);
500 void dasd_schedule_bh(struct dasd_device *);
501 int  dasd_sleep_on(struct dasd_ccw_req *);
502 int  dasd_sleep_on_immediatly(struct dasd_ccw_req *);
503 int  dasd_sleep_on_interruptible(struct dasd_ccw_req *);
504 void dasd_set_timer(struct dasd_device *, int);
505 void dasd_clear_timer(struct dasd_device *);
506 int  dasd_cancel_req(struct dasd_ccw_req *);
507 int dasd_generic_probe (struct ccw_device *, struct dasd_discipline *);
508 void dasd_generic_remove (struct ccw_device *cdev);
509 int dasd_generic_set_online(struct ccw_device *, struct dasd_discipline *);
510 int dasd_generic_set_offline (struct ccw_device *cdev);
511 int dasd_generic_notify(struct ccw_device *, int);
512 
513 int dasd_generic_read_dev_chars(struct dasd_device *, char *, void **, int);
514 
515 /* externals in dasd_devmap.c */
516 extern int dasd_max_devindex;
517 extern int dasd_probeonly;
518 extern int dasd_autodetect;
519 extern int dasd_nopav;
520 
521 int dasd_devmap_init(void);
522 void dasd_devmap_exit(void);
523 
524 struct dasd_device *dasd_create_device(struct ccw_device *);
525 void dasd_delete_device(struct dasd_device *);
526 
527 int dasd_get_uid(struct ccw_device *, struct dasd_uid *);
528 int dasd_set_uid(struct ccw_device *, struct dasd_uid *);
529 int dasd_get_feature(struct ccw_device *, int);
530 int dasd_set_feature(struct ccw_device *, int, int);
531 
532 int dasd_add_sysfs_files(struct ccw_device *);
533 void dasd_remove_sysfs_files(struct ccw_device *);
534 
535 struct dasd_device *dasd_device_from_cdev(struct ccw_device *);
536 struct dasd_device *dasd_device_from_cdev_locked(struct ccw_device *);
537 struct dasd_device *dasd_device_from_devindex(int);
538 
539 int dasd_parse(void);
540 int dasd_busid_known(char *);
541 
542 /* externals in dasd_gendisk.c */
543 int  dasd_gendisk_init(void);
544 void dasd_gendisk_exit(void);
545 int dasd_gendisk_alloc(struct dasd_device *);
546 void dasd_gendisk_free(struct dasd_device *);
547 int dasd_scan_partitions(struct dasd_device *);
548 void dasd_destroy_partitions(struct dasd_device *);
549 
550 /* externals in dasd_ioctl.c */
551 int  dasd_ioctl(struct inode *, struct file *, unsigned int, unsigned long);
552 long dasd_compat_ioctl(struct file *, unsigned int, unsigned long);
553 
554 /* externals in dasd_proc.c */
555 int dasd_proc_init(void);
556 void dasd_proc_exit(void);
557 
558 /* externals in dasd_erp.c */
559 struct dasd_ccw_req *dasd_default_erp_action(struct dasd_ccw_req *);
560 struct dasd_ccw_req *dasd_default_erp_postaction(struct dasd_ccw_req *);
561 struct dasd_ccw_req *dasd_alloc_erp_request(char *, int, int,
562 					    struct dasd_device *);
563 void dasd_free_erp_request(struct dasd_ccw_req *, struct dasd_device *);
564 void dasd_log_sense(struct dasd_ccw_req *, struct irb *);
565 
566 /* externals in dasd_3370_erp.c */
567 dasd_era_t dasd_3370_erp_examine(struct dasd_ccw_req *, struct irb *);
568 
569 /* externals in dasd_3990_erp.c */
570 dasd_era_t dasd_3990_erp_examine(struct dasd_ccw_req *, struct irb *);
571 struct dasd_ccw_req *dasd_3990_erp_action(struct dasd_ccw_req *);
572 
573 /* externals in dasd_9336_erp.c */
574 dasd_era_t dasd_9336_erp_examine(struct dasd_ccw_req *, struct irb *);
575 
576 /* externals in dasd_9336_erp.c */
577 dasd_era_t dasd_9343_erp_examine(struct dasd_ccw_req *, struct irb *);
578 struct dasd_ccw_req *dasd_9343_erp_action(struct dasd_ccw_req *);
579 
580 /* externals in dasd_eer.c */
581 #ifdef CONFIG_DASD_EER
582 int dasd_eer_init(void);
583 void dasd_eer_exit(void);
584 int dasd_eer_enable(struct dasd_device *);
585 void dasd_eer_disable(struct dasd_device *);
586 void dasd_eer_write(struct dasd_device *, struct dasd_ccw_req *cqr,
587 		    unsigned int id);
588 void dasd_eer_snss(struct dasd_device *);
589 
590 static inline int dasd_eer_enabled(struct dasd_device *device)
591 {
592 	return device->eer_cqr != NULL;
593 }
594 #else
595 #define dasd_eer_init()		(0)
596 #define dasd_eer_exit()		do { } while (0)
597 #define dasd_eer_enable(d)	(0)
598 #define dasd_eer_disable(d)	do { } while (0)
599 #define dasd_eer_write(d,c,i)	do { } while (0)
600 #define dasd_eer_snss(d)	do { } while (0)
601 #define dasd_eer_enabled(d)	(0)
602 #endif	/* CONFIG_DASD_ERR */
603 
604 #endif				/* __KERNEL__ */
605 
606 #endif				/* DASD_H */
607