xref: /linux/drivers/s390/block/dasd_int.h (revision 20c644680af1ef9a6b36c0873f59498c98b07ab1)
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 /* erp debugging in dasd.c and dasd_3990_erp.c */
17 #define ERP_DEBUG
18 
19 
20 /* we keep old device allocation scheme; IOW, minors are still in 0..255 */
21 #define DASD_PER_MAJOR (1U << (MINORBITS - DASD_PARTN_BITS))
22 #define DASD_PARTN_MASK ((1 << DASD_PARTN_BITS) - 1)
23 
24 /*
25  * States a dasd device can have:
26  *   new: the dasd_device structure is allocated.
27  *   known: the discipline for the device is identified.
28  *   basic: the device can do basic i/o.
29  *   unfmt: the device could not be analyzed (format is unknown).
30  *   ready: partition detection is done and the device is can do block io.
31  *   online: the device accepts requests from the block device queue.
32  *
33  * Things to do for startup state transitions:
34  *   new -> known: find discipline for the device and create devfs entries.
35  *   known -> basic: request irq line for the device.
36  *   basic -> ready: do the initial analysis, e.g. format detection,
37  *                   do block device setup and detect partitions.
38  *   ready -> online: schedule the device tasklet.
39  * Things to do for shutdown state transitions:
40  *   online -> ready: just set the new device state.
41  *   ready -> basic: flush requests from the block device layer, clear
42  *                   partition information and reset format information.
43  *   basic -> known: terminate all requests and free irq.
44  *   known -> new: remove devfs entries and forget discipline.
45  */
46 
47 #define DASD_STATE_NEW	  0
48 #define DASD_STATE_KNOWN  1
49 #define DASD_STATE_BASIC  2
50 #define DASD_STATE_UNFMT  3
51 #define DASD_STATE_READY  4
52 #define DASD_STATE_ONLINE 5
53 
54 #include <linux/module.h>
55 #include <linux/wait.h>
56 #include <linux/blkdev.h>
57 #include <linux/devfs_fs_kernel.h>
58 #include <linux/genhd.h>
59 #include <linux/hdreg.h>
60 #include <linux/interrupt.h>
61 #include <asm/ccwdev.h>
62 #include <linux/workqueue.h>
63 #include <asm/debug.h>
64 #include <asm/dasd.h>
65 #include <asm/idals.h>
66 
67 /*
68  * SECTION: Type definitions
69  */
70 struct dasd_device;
71 
72 typedef enum {
73 	dasd_era_fatal = -1,	/* no chance to recover		     */
74 	dasd_era_none = 0,	/* don't recover, everything alright */
75 	dasd_era_msg = 1,	/* don't recover, just report...     */
76 	dasd_era_recover = 2	/* recovery action recommended	     */
77 } dasd_era_t;
78 
79 /* BIT DEFINITIONS FOR SENSE DATA */
80 #define DASD_SENSE_BIT_0 0x80
81 #define DASD_SENSE_BIT_1 0x40
82 #define DASD_SENSE_BIT_2 0x20
83 #define DASD_SENSE_BIT_3 0x10
84 
85 /*
86  * SECTION: MACROs for klogd and s390 debug feature (dbf)
87  */
88 #define DBF_DEV_EVENT(d_level, d_device, d_str, d_data...) \
89 do { \
90 	debug_sprintf_event(d_device->debug_area, \
91 			    d_level, \
92 			    d_str "\n", \
93 			    d_data); \
94 } while(0)
95 
96 #define DBF_DEV_EXC(d_level, d_device, d_str, d_data...) \
97 do { \
98 	debug_sprintf_exception(d_device->debug_area, \
99 				d_level, \
100 				d_str "\n", \
101 				d_data); \
102 } while(0)
103 
104 #define DBF_EVENT(d_level, d_str, d_data...)\
105 do { \
106 	debug_sprintf_event(dasd_debug_area, \
107 			    d_level,\
108 			    d_str "\n", \
109 			    d_data); \
110 } while(0)
111 
112 #define DBF_EXC(d_level, d_str, d_data...)\
113 do { \
114 	debug_sprintf_exception(dasd_debug_area, \
115 				d_level,\
116 				d_str "\n", \
117 				d_data); \
118 } while(0)
119 
120 /* definition of dbf debug levels */
121 #define	DBF_EMERG	0	/* system is unusable			*/
122 #define	DBF_ALERT	1	/* action must be taken immediately	*/
123 #define	DBF_CRIT	2	/* critical conditions			*/
124 #define	DBF_ERR		3	/* error conditions			*/
125 #define	DBF_WARNING	4	/* warning conditions			*/
126 #define	DBF_NOTICE	5	/* normal but significant condition	*/
127 #define	DBF_INFO	6	/* informational			*/
128 #define	DBF_DEBUG	6	/* debug-level messages			*/
129 
130 /* messages to be written via klogd and dbf */
131 #define DEV_MESSAGE(d_loglevel,d_device,d_string,d_args...)\
132 do { \
133 	printk(d_loglevel PRINTK_HEADER " %s: " d_string "\n", \
134 	       d_device->cdev->dev.bus_id, d_args); \
135 	DBF_DEV_EVENT(DBF_ALERT, d_device, d_string, d_args); \
136 } while(0)
137 
138 #define MESSAGE(d_loglevel,d_string,d_args...)\
139 do { \
140 	printk(d_loglevel PRINTK_HEADER " " d_string "\n", d_args); \
141 	DBF_EVENT(DBF_ALERT, d_string, d_args); \
142 } while(0)
143 
144 /* messages to be written via klogd only */
145 #define DEV_MESSAGE_LOG(d_loglevel,d_device,d_string,d_args...)\
146 do { \
147 	printk(d_loglevel PRINTK_HEADER " %s: " d_string "\n", \
148 	       d_device->cdev->dev.bus_id, d_args); \
149 } while(0)
150 
151 #define MESSAGE_LOG(d_loglevel,d_string,d_args...)\
152 do { \
153 	printk(d_loglevel PRINTK_HEADER " " d_string "\n", d_args); \
154 } while(0)
155 
156 struct dasd_ccw_req {
157 	unsigned int magic;		/* Eye catcher */
158         struct list_head list;		/* list_head for request queueing. */
159 
160 	/* Where to execute what... */
161 	struct dasd_device *device;	/* device the request is for */
162 	struct ccw1 *cpaddr;		/* address of channel program */
163 	char status;	        	/* status of this request */
164 	short retries;			/* A retry counter */
165 	unsigned long flags;        	/* flags of this request */
166 
167 	/* ... and how */
168 	unsigned long starttime;	/* jiffies time of request start */
169 	int expires;			/* expiration period in jiffies */
170 	char lpm;               	/* logical path mask */
171 	void *data;			/* pointer to data area */
172 
173 	/* these are important for recovering erroneous requests          */
174 	struct irb irb;			/* device status in case of an error */
175 	struct dasd_ccw_req *refers;	/* ERP-chain queueing. */
176 	void *function; 		/* originating ERP action */
177 
178 	/* these are for statistics only */
179 	unsigned long long buildclk;	/* TOD-clock of request generation */
180 	unsigned long long startclk;	/* TOD-clock of request start */
181 	unsigned long long stopclk;	/* TOD-clock of request interrupt */
182 	unsigned long long endclk;	/* TOD-clock of request termination */
183 
184         /* Callback that is called after reaching final status. */
185         void (*callback)(struct dasd_ccw_req *, void *data);
186         void *callback_data;
187 };
188 
189 /*
190  * dasd_ccw_req -> status can be:
191  */
192 #define DASD_CQR_FILLED   0x00	/* request is ready to be processed */
193 #define DASD_CQR_QUEUED   0x01	/* request is queued to be processed */
194 #define DASD_CQR_IN_IO    0x02	/* request is currently in IO */
195 #define DASD_CQR_DONE     0x03	/* request is completed successfully */
196 #define DASD_CQR_ERROR    0x04	/* request is completed with error */
197 #define DASD_CQR_FAILED   0x05	/* request is finally failed */
198 #define DASD_CQR_CLEAR    0x06	/* request is clear pending */
199 
200 /* per dasd_ccw_req flags */
201 #define DASD_CQR_FLAGS_USE_ERP   0	/* use ERP for this request */
202 #define DASD_CQR_FLAGS_FAILFAST  1	/* FAILFAST */
203 
204 /* Signature for error recovery functions. */
205 typedef struct dasd_ccw_req *(*dasd_erp_fn_t) (struct dasd_ccw_req *);
206 
207 /*
208  * the struct dasd_discipline is
209  * sth like a table of virtual functions, if you think of dasd_eckd
210  * inheriting dasd...
211  * no, currently we are not planning to reimplement the driver in C++
212  */
213 struct dasd_discipline {
214 	struct module *owner;
215 	char ebcname[8];	/* a name used for tagging and printks */
216 	char name[8];		/* a name used for tagging and printks */
217 	int max_blocks;		/* maximum number of blocks to be chained */
218 
219 	struct list_head list;	/* used for list of disciplines */
220 
221         /*
222          * Device recognition functions. check_device is used to verify
223          * the sense data and the information returned by read device
224          * characteristics. It returns 0 if the discipline can be used
225          * for the device in question.
226          * do_analysis is used in the step from device state "basic" to
227          * state "accept". It returns 0 if the device can be made ready,
228          * it returns -EMEDIUMTYPE if the device can't be made ready or
229          * -EAGAIN if do_analysis started a ccw that needs to complete
230          * before the analysis may be repeated.
231          */
232         int (*check_device)(struct dasd_device *);
233 	int (*do_analysis) (struct dasd_device *);
234 
235         /*
236          * Device operation functions. build_cp creates a ccw chain for
237          * a block device request, start_io starts the request and
238          * term_IO cancels it (e.g. in case of a timeout). format_device
239          * returns a ccw chain to be used to format the device.
240          */
241 	struct dasd_ccw_req *(*build_cp) (struct dasd_device *,
242 					  struct request *);
243 	int (*start_IO) (struct dasd_ccw_req *);
244 	int (*term_IO) (struct dasd_ccw_req *);
245 	struct dasd_ccw_req *(*format_device) (struct dasd_device *,
246 					       struct format_data_t *);
247 	int (*free_cp) (struct dasd_ccw_req *, struct request *);
248         /*
249          * Error recovery functions. examine_error() returns a value that
250          * indicates what to do for an error condition. If examine_error()
251          * returns 'dasd_era_recover' erp_action() is called to create a
252          * special error recovery ccw. erp_postaction() is called after
253          * an error recovery ccw has finished its execution. dump_sense
254          * is called for every error condition to print the sense data
255          * to the console.
256          */
257 	dasd_era_t(*examine_error) (struct dasd_ccw_req *, struct irb *);
258 	dasd_erp_fn_t(*erp_action) (struct dasd_ccw_req *);
259 	dasd_erp_fn_t(*erp_postaction) (struct dasd_ccw_req *);
260 	void (*dump_sense) (struct dasd_device *, struct dasd_ccw_req *,
261 			    struct irb *);
262 
263         /* i/o control functions. */
264 	int (*fill_geometry) (struct dasd_device *, struct hd_geometry *);
265 	int (*fill_info) (struct dasd_device *, struct dasd_information2_t *);
266 	int (*ioctl) (struct dasd_device *, unsigned int, void __user *);
267 };
268 
269 extern struct dasd_discipline *dasd_diag_discipline_pointer;
270 
271 
272 /*
273  * Notification numbers for extended error reporting notifications:
274  * The DASD_EER_DISABLE notification is sent before a dasd_device (and it's
275  * eer pointer) is freed. The error reporting module needs to do all necessary
276  * cleanup steps.
277  * The DASD_EER_TRIGGER notification sends the actual error reports (triggers).
278  */
279 #define DASD_EER_DISABLE 0
280 #define DASD_EER_TRIGGER 1
281 
282 /* Trigger IDs for extended error reporting DASD_EER_TRIGGER notification */
283 #define DASD_EER_FATALERROR  1
284 #define DASD_EER_NOPATH      2
285 #define DASD_EER_STATECHANGE 3
286 #define DASD_EER_PPRCSUSPEND 4
287 
288 struct dasd_device {
289 	/* Block device stuff. */
290 	struct gendisk *gdp;
291 	request_queue_t *request_queue;
292 	spinlock_t request_queue_lock;
293 	struct block_device *bdev;
294         unsigned int devindex;
295 	unsigned long blocks;		/* size of volume in blocks */
296 	unsigned int bp_block;		/* bytes per block */
297 	unsigned int s2b_shift;		/* log2 (bp_block/512) */
298 	unsigned long flags;		/* per device flags */
299 	unsigned short features;        /* copy of devmap-features (read-only!) */
300 
301 	/* extended error reporting stuff (eer) */
302 	struct dasd_ccw_req *eer_cqr;
303 
304 	/* Device discipline stuff. */
305 	struct dasd_discipline *discipline;
306 	struct dasd_discipline *base_discipline;
307 	char *private;
308 
309 	/* Device state and target state. */
310 	int state, target;
311 	int stopped;		/* device (ccw_device_start) was stopped */
312 
313 	/* Open and reference count. */
314         atomic_t ref_count;
315 	atomic_t open_count;
316 
317 	/* ccw queue and memory for static ccw/erp buffers. */
318 	struct list_head ccw_queue;
319 	spinlock_t mem_lock;
320 	void *ccw_mem;
321 	void *erp_mem;
322 	struct list_head ccw_chunks;
323 	struct list_head erp_chunks;
324 
325 	atomic_t tasklet_scheduled;
326         struct tasklet_struct tasklet;
327 	struct work_struct kick_work;
328 	struct timer_list timer;
329 
330 	debug_info_t *debug_area;
331 
332 	struct ccw_device *cdev;
333 
334 #ifdef CONFIG_DASD_PROFILE
335 	struct dasd_profile_info_t profile;
336 #endif
337 };
338 
339 /* reasons why device (ccw_device_start) was stopped */
340 #define DASD_STOPPED_NOT_ACC 1         /* not accessible */
341 #define DASD_STOPPED_QUIESCE 2         /* Quiesced */
342 #define DASD_STOPPED_PENDING 4         /* long busy */
343 #define DASD_STOPPED_DC_WAIT 8         /* disconnected, wait */
344 #define DASD_STOPPED_DC_EIO  16        /* disconnected, return -EIO */
345 
346 /* per device flags */
347 #define DASD_FLAG_DSC_ERROR	2	/* return -EIO when disconnected */
348 #define DASD_FLAG_OFFLINE	3	/* device is in offline processing */
349 #define DASD_FLAG_EER_SNSS	4	/* A SNSS is required */
350 #define DASD_FLAG_EER_IN_USE	5	/* A SNSS request is running */
351 
352 void dasd_put_device_wake(struct dasd_device *);
353 
354 /*
355  * Reference count inliners
356  */
357 static inline void
358 dasd_get_device(struct dasd_device *device)
359 {
360 	atomic_inc(&device->ref_count);
361 }
362 
363 static inline void
364 dasd_put_device(struct dasd_device *device)
365 {
366 	if (atomic_dec_return(&device->ref_count) == 0)
367 		dasd_put_device_wake(device);
368 }
369 
370 /*
371  * The static memory in ccw_mem and erp_mem is managed by a sorted
372  * list of free memory chunks.
373  */
374 struct dasd_mchunk
375 {
376 	struct list_head list;
377 	unsigned long size;
378 } __attribute__ ((aligned(8)));
379 
380 static inline void
381 dasd_init_chunklist(struct list_head *chunk_list, void *mem,
382 		    unsigned long size)
383 {
384 	struct dasd_mchunk *chunk;
385 
386 	INIT_LIST_HEAD(chunk_list);
387 	chunk = (struct dasd_mchunk *) mem;
388 	chunk->size = size - sizeof(struct dasd_mchunk);
389 	list_add(&chunk->list, chunk_list);
390 }
391 
392 static inline void *
393 dasd_alloc_chunk(struct list_head *chunk_list, unsigned long size)
394 {
395 	struct dasd_mchunk *chunk, *tmp;
396 
397 	size = (size + 7L) & -8L;
398 	list_for_each_entry(chunk, chunk_list, list) {
399 		if (chunk->size < size)
400 			continue;
401 		if (chunk->size > size + sizeof(struct dasd_mchunk)) {
402 			char *endaddr = (char *) (chunk + 1) + chunk->size;
403 			tmp = (struct dasd_mchunk *) (endaddr - size) - 1;
404 			tmp->size = size;
405 			chunk->size -= size + sizeof(struct dasd_mchunk);
406 			chunk = tmp;
407 		} else
408 			list_del(&chunk->list);
409 		return (void *) (chunk + 1);
410 	}
411 	return NULL;
412 }
413 
414 static inline void
415 dasd_free_chunk(struct list_head *chunk_list, void *mem)
416 {
417 	struct dasd_mchunk *chunk, *tmp;
418 	struct list_head *p, *left;
419 
420 	chunk = (struct dasd_mchunk *)
421 		((char *) mem - sizeof(struct dasd_mchunk));
422 	/* Find out the left neighbour in chunk_list. */
423 	left = chunk_list;
424 	list_for_each(p, chunk_list) {
425 		if (list_entry(p, struct dasd_mchunk, list) > chunk)
426 			break;
427 		left = p;
428 	}
429 	/* Try to merge with right neighbour = next element from left. */
430 	if (left->next != chunk_list) {
431 		tmp = list_entry(left->next, struct dasd_mchunk, list);
432 		if ((char *) (chunk + 1) + chunk->size == (char *) tmp) {
433 			list_del(&tmp->list);
434 			chunk->size += tmp->size + sizeof(struct dasd_mchunk);
435 		}
436 	}
437 	/* Try to merge with left neighbour. */
438 	if (left != chunk_list) {
439 		tmp = list_entry(left, struct dasd_mchunk, list);
440 		if ((char *) (tmp + 1) + tmp->size == (char *) chunk) {
441 			tmp->size += chunk->size + sizeof(struct dasd_mchunk);
442 			return;
443 		}
444 	}
445 	__list_add(&chunk->list, left, left->next);
446 }
447 
448 /*
449  * Check if bsize is in { 512, 1024, 2048, 4096 }
450  */
451 static inline int
452 dasd_check_blocksize(int bsize)
453 {
454 	if (bsize < 512 || bsize > 4096 || (bsize & (bsize - 1)) != 0)
455 		return -EMEDIUMTYPE;
456 	return 0;
457 }
458 
459 /* externals in dasd.c */
460 #define DASD_PROFILE_ON	 1
461 #define DASD_PROFILE_OFF 0
462 
463 extern debug_info_t *dasd_debug_area;
464 extern struct dasd_profile_info_t dasd_global_profile;
465 extern unsigned int dasd_profile_level;
466 extern struct block_device_operations dasd_device_operations;
467 
468 extern kmem_cache_t *dasd_page_cache;
469 
470 struct dasd_ccw_req *
471 dasd_kmalloc_request(char *, int, int, struct dasd_device *);
472 struct dasd_ccw_req *
473 dasd_smalloc_request(char *, int, int, struct dasd_device *);
474 void dasd_kfree_request(struct dasd_ccw_req *, struct dasd_device *);
475 void dasd_sfree_request(struct dasd_ccw_req *, struct dasd_device *);
476 
477 static inline int
478 dasd_kmalloc_set_cda(struct ccw1 *ccw, void *cda, struct dasd_device *device)
479 {
480 	return set_normalized_cda(ccw, cda);
481 }
482 
483 struct dasd_device *dasd_alloc_device(void);
484 void dasd_free_device(struct dasd_device *);
485 
486 void dasd_enable_device(struct dasd_device *);
487 void dasd_set_target_state(struct dasd_device *, int);
488 void dasd_kick_device(struct dasd_device *);
489 
490 void dasd_add_request_head(struct dasd_ccw_req *);
491 void dasd_add_request_tail(struct dasd_ccw_req *);
492 int  dasd_start_IO(struct dasd_ccw_req *);
493 int  dasd_term_IO(struct dasd_ccw_req *);
494 void dasd_schedule_bh(struct dasd_device *);
495 int  dasd_sleep_on(struct dasd_ccw_req *);
496 int  dasd_sleep_on_immediatly(struct dasd_ccw_req *);
497 int  dasd_sleep_on_interruptible(struct dasd_ccw_req *);
498 void dasd_set_timer(struct dasd_device *, int);
499 void dasd_clear_timer(struct dasd_device *);
500 int  dasd_cancel_req(struct dasd_ccw_req *);
501 int dasd_generic_probe (struct ccw_device *, struct dasd_discipline *);
502 void dasd_generic_remove (struct ccw_device *cdev);
503 int dasd_generic_set_online(struct ccw_device *, struct dasd_discipline *);
504 int dasd_generic_set_offline (struct ccw_device *cdev);
505 int dasd_generic_notify(struct ccw_device *, int);
506 void dasd_generic_auto_online (struct ccw_driver *);
507 
508 /* externals in dasd_devmap.c */
509 extern int dasd_max_devindex;
510 extern int dasd_probeonly;
511 extern int dasd_autodetect;
512 
513 int dasd_devmap_init(void);
514 void dasd_devmap_exit(void);
515 
516 struct dasd_device *dasd_create_device(struct ccw_device *);
517 void dasd_delete_device(struct dasd_device *);
518 
519 int dasd_get_feature(struct ccw_device *, int);
520 int dasd_set_feature(struct ccw_device *, int, int);
521 
522 int dasd_add_sysfs_files(struct ccw_device *);
523 void dasd_remove_sysfs_files(struct ccw_device *);
524 
525 struct dasd_device *dasd_device_from_cdev(struct ccw_device *);
526 struct dasd_device *dasd_device_from_devindex(int);
527 
528 int dasd_parse(void);
529 int dasd_busid_known(char *);
530 
531 /* externals in dasd_gendisk.c */
532 int  dasd_gendisk_init(void);
533 void dasd_gendisk_exit(void);
534 int dasd_gendisk_alloc(struct dasd_device *);
535 void dasd_gendisk_free(struct dasd_device *);
536 int dasd_scan_partitions(struct dasd_device *);
537 void dasd_destroy_partitions(struct dasd_device *);
538 
539 /* externals in dasd_ioctl.c */
540 int  dasd_ioctl(struct inode *, struct file *, unsigned int, unsigned long);
541 long dasd_compat_ioctl(struct file *, unsigned int, unsigned long);
542 
543 /* externals in dasd_proc.c */
544 int dasd_proc_init(void);
545 void dasd_proc_exit(void);
546 
547 /* externals in dasd_erp.c */
548 struct dasd_ccw_req *dasd_default_erp_action(struct dasd_ccw_req *);
549 struct dasd_ccw_req *dasd_default_erp_postaction(struct dasd_ccw_req *);
550 struct dasd_ccw_req *dasd_alloc_erp_request(char *, int, int,
551 					    struct dasd_device *);
552 void dasd_free_erp_request(struct dasd_ccw_req *, struct dasd_device *);
553 void dasd_log_sense(struct dasd_ccw_req *, struct irb *);
554 void dasd_log_ccw(struct dasd_ccw_req *, int, __u32);
555 
556 /* externals in dasd_3370_erp.c */
557 dasd_era_t dasd_3370_erp_examine(struct dasd_ccw_req *, struct irb *);
558 
559 /* externals in dasd_3990_erp.c */
560 dasd_era_t dasd_3990_erp_examine(struct dasd_ccw_req *, struct irb *);
561 struct dasd_ccw_req *dasd_3990_erp_action(struct dasd_ccw_req *);
562 
563 /* externals in dasd_9336_erp.c */
564 dasd_era_t dasd_9336_erp_examine(struct dasd_ccw_req *, struct irb *);
565 
566 /* externals in dasd_9336_erp.c */
567 dasd_era_t dasd_9343_erp_examine(struct dasd_ccw_req *, struct irb *);
568 struct dasd_ccw_req *dasd_9343_erp_action(struct dasd_ccw_req *);
569 
570 /* externals in dasd_eer.c */
571 #ifdef CONFIG_DASD_EER
572 int dasd_eer_init(void);
573 void dasd_eer_exit(void);
574 int dasd_eer_enable(struct dasd_device *);
575 void dasd_eer_disable(struct dasd_device *);
576 void dasd_eer_write(struct dasd_device *, struct dasd_ccw_req *cqr,
577 		    unsigned int id);
578 void dasd_eer_snss(struct dasd_device *);
579 
580 static inline int dasd_eer_enabled(struct dasd_device *device)
581 {
582 	return device->eer_cqr != NULL;
583 }
584 #else
585 #define dasd_eer_init()		(0)
586 #define dasd_eer_exit()		do { } while (0)
587 #define dasd_eer_enable(d)	(0)
588 #define dasd_eer_disable(d)	do { } while (0)
589 #define dasd_eer_write(d,c,i)	do { } while (0)
590 #define dasd_eer_snss(d)	do { } while (0)
591 #define dasd_eer_enabled(d)	(0)
592 #endif	/* CONFIG_DASD_ERR */
593 
594 #endif				/* __KERNEL__ */
595 
596 #endif				/* DASD_H */
597 
598 /*
599  * Overrides for Emacs so that we follow Linus's tabbing style.
600  * Emacs will notice this stuff at the end of the file and automatically
601  * adjust the settings for this buffer only.  This must remain at the end
602  * of the file.
603  * ---------------------------------------------------------------------------
604  * Local variables:
605  * c-indent-level: 4
606  * c-brace-imaginary-offset: 0
607  * c-brace-offset: -4
608  * c-argdecl-indent: 4
609  * c-label-offset: -4
610  * c-continued-statement-offset: 4
611  * c-continued-brace-offset: 0
612  * indent-tabs-mode: 1
613  * tab-width: 8
614  * End:
615  */
616