xref: /linux/drivers/s390/block/dasd_int.h (revision 26b0d14106954ae46d2f4f7eec3481828a210f7d)
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  * Copyright IBM Corp. 1999, 2009
8  */
9 
10 #ifndef DASD_INT_H
11 #define DASD_INT_H
12 
13 /* we keep old device allocation scheme; IOW, minors are still in 0..255 */
14 #define DASD_PER_MAJOR (1U << (MINORBITS - DASD_PARTN_BITS))
15 #define DASD_PARTN_MASK ((1 << DASD_PARTN_BITS) - 1)
16 
17 /*
18  * States a dasd device can have:
19  *   new: the dasd_device structure is allocated.
20  *   known: the discipline for the device is identified.
21  *   basic: the device can do basic i/o.
22  *   unfmt: the device could not be analyzed (format is unknown).
23  *   ready: partition detection is done and the device is can do block io.
24  *   online: the device accepts requests from the block device queue.
25  *
26  * Things to do for startup state transitions:
27  *   new -> known: find discipline for the device and create devfs entries.
28  *   known -> basic: request irq line for the device.
29  *   basic -> ready: do the initial analysis, e.g. format detection,
30  *                   do block device setup and detect partitions.
31  *   ready -> online: schedule the device tasklet.
32  * Things to do for shutdown state transitions:
33  *   online -> ready: just set the new device state.
34  *   ready -> basic: flush requests from the block device layer, clear
35  *                   partition information and reset format information.
36  *   basic -> known: terminate all requests and free irq.
37  *   known -> new: remove devfs entries and forget discipline.
38  */
39 
40 #define DASD_STATE_NEW	  0
41 #define DASD_STATE_KNOWN  1
42 #define DASD_STATE_BASIC  2
43 #define DASD_STATE_UNFMT  3
44 #define DASD_STATE_READY  4
45 #define DASD_STATE_ONLINE 5
46 
47 #include <linux/module.h>
48 #include <linux/wait.h>
49 #include <linux/blkdev.h>
50 #include <linux/genhd.h>
51 #include <linux/hdreg.h>
52 #include <linux/interrupt.h>
53 #include <linux/log2.h>
54 #include <asm/ccwdev.h>
55 #include <linux/workqueue.h>
56 #include <asm/debug.h>
57 #include <asm/dasd.h>
58 #include <asm/idals.h>
59 
60 /* DASD discipline magic */
61 #define DASD_ECKD_MAGIC 0xC5C3D2C4
62 #define DASD_DIAG_MAGIC 0xC4C9C1C7
63 #define DASD_FBA_MAGIC 0xC6C2C140
64 
65 /*
66  * SECTION: Type definitions
67  */
68 struct dasd_device;
69 struct dasd_block;
70 
71 /* BIT DEFINITIONS FOR SENSE DATA */
72 #define DASD_SENSE_BIT_0 0x80
73 #define DASD_SENSE_BIT_1 0x40
74 #define DASD_SENSE_BIT_2 0x20
75 #define DASD_SENSE_BIT_3 0x10
76 
77 /* BIT DEFINITIONS FOR SIM SENSE */
78 #define DASD_SIM_SENSE 0x0F
79 #define DASD_SIM_MSG_TO_OP 0x03
80 #define DASD_SIM_LOG 0x0C
81 
82 /* lock class for nested cdev lock */
83 #define CDEV_NESTED_FIRST 1
84 #define CDEV_NESTED_SECOND 2
85 
86 /*
87  * SECTION: MACROs for klogd and s390 debug feature (dbf)
88  */
89 #define DBF_DEV_EVENT(d_level, d_device, d_str, d_data...) \
90 do { \
91 	debug_sprintf_event(d_device->debug_area, \
92 			    d_level, \
93 			    d_str "\n", \
94 			    d_data); \
95 } while(0)
96 
97 #define DBF_DEV_EXC(d_level, d_device, d_str, d_data...) \
98 do { \
99 	debug_sprintf_exception(d_device->debug_area, \
100 				d_level, \
101 				d_str "\n", \
102 				d_data); \
103 } while(0)
104 
105 #define DBF_EVENT(d_level, d_str, d_data...)\
106 do { \
107 	debug_sprintf_event(dasd_debug_area, \
108 			    d_level,\
109 			    d_str "\n", \
110 			    d_data); \
111 } while(0)
112 
113 #define DBF_EVENT_DEVID(d_level, d_cdev, d_str, d_data...)	\
114 do { \
115 	struct ccw_dev_id __dev_id;			\
116 	ccw_device_get_id(d_cdev, &__dev_id);		\
117 	debug_sprintf_event(dasd_debug_area,		\
118 			    d_level,					\
119 			    "0.%x.%04x " d_str "\n",			\
120 			    __dev_id.ssid, __dev_id.devno, d_data);	\
121 } while (0)
122 
123 #define DBF_EXC(d_level, d_str, d_data...)\
124 do { \
125 	debug_sprintf_exception(dasd_debug_area, \
126 				d_level,\
127 				d_str "\n", \
128 				d_data); \
129 } while(0)
130 
131 /* limit size for an errorstring */
132 #define ERRORLENGTH 30
133 
134 /* definition of dbf debug levels */
135 #define	DBF_EMERG	0	/* system is unusable			*/
136 #define	DBF_ALERT	1	/* action must be taken immediately	*/
137 #define	DBF_CRIT	2	/* critical conditions			*/
138 #define	DBF_ERR		3	/* error conditions			*/
139 #define	DBF_WARNING	4	/* warning conditions			*/
140 #define	DBF_NOTICE	5	/* normal but significant condition	*/
141 #define	DBF_INFO	6	/* informational			*/
142 #define	DBF_DEBUG	6	/* debug-level messages			*/
143 
144 /* messages to be written via klogd and dbf */
145 #define DEV_MESSAGE(d_loglevel,d_device,d_string,d_args...)\
146 do { \
147 	printk(d_loglevel PRINTK_HEADER " %s: " d_string "\n", \
148 	       dev_name(&d_device->cdev->dev), d_args); \
149 	DBF_DEV_EVENT(DBF_ALERT, d_device, d_string, d_args); \
150 } while(0)
151 
152 #define MESSAGE(d_loglevel,d_string,d_args...)\
153 do { \
154 	printk(d_loglevel PRINTK_HEADER " " d_string "\n", d_args); \
155 	DBF_EVENT(DBF_ALERT, d_string, d_args); \
156 } while(0)
157 
158 /* messages to be written via klogd only */
159 #define DEV_MESSAGE_LOG(d_loglevel,d_device,d_string,d_args...)\
160 do { \
161 	printk(d_loglevel PRINTK_HEADER " %s: " d_string "\n", \
162 	       dev_name(&d_device->cdev->dev), d_args); \
163 } while(0)
164 
165 #define MESSAGE_LOG(d_loglevel,d_string,d_args...)\
166 do { \
167 	printk(d_loglevel PRINTK_HEADER " " d_string "\n", d_args); \
168 } while(0)
169 
170 struct dasd_ccw_req {
171 	unsigned int magic;		/* Eye catcher */
172 	struct list_head devlist;	/* for dasd_device request queue */
173 	struct list_head blocklist;	/* for dasd_block request queue */
174 
175 	/* Where to execute what... */
176 	struct dasd_block *block;	/* the originating block device */
177 	struct dasd_device *memdev;	/* the device used to allocate this */
178 	struct dasd_device *startdev;	/* device the request is started on */
179 	void *cpaddr;			/* address of ccw or tcw */
180 	unsigned char cpmode;		/* 0 = cmd mode, 1 = itcw */
181 	char status;			/* status of this request */
182 	short retries;			/* A retry counter */
183 	unsigned long flags;        	/* flags of this request */
184 
185 	/* ... and how */
186 	unsigned long starttime;	/* jiffies time of request start */
187 	unsigned long expires;		/* expiration period in jiffies */
188 	char lpm;			/* logical path mask */
189 	void *data;			/* pointer to data area */
190 
191 	/* these are important for recovering erroneous requests          */
192 	int intrc;			/* internal error, e.g. from start_IO */
193 	struct irb irb;			/* device status in case of an error */
194 	struct dasd_ccw_req *refers;	/* ERP-chain queueing. */
195 	void *function; 		/* originating ERP action */
196 
197 	/* these are for statistics only */
198 	unsigned long long buildclk;	/* TOD-clock of request generation */
199 	unsigned long long startclk;	/* TOD-clock of request start */
200 	unsigned long long stopclk;	/* TOD-clock of request interrupt */
201 	unsigned long long endclk;	/* TOD-clock of request termination */
202 
203         /* Callback that is called after reaching final status. */
204 	void (*callback)(struct dasd_ccw_req *, void *data);
205 	void *callback_data;
206 };
207 
208 /*
209  * dasd_ccw_req -> status can be:
210  */
211 #define DASD_CQR_FILLED 	0x00	/* request is ready to be processed */
212 #define DASD_CQR_DONE		0x01	/* request is completed successfully */
213 #define DASD_CQR_NEED_ERP	0x02	/* request needs recovery action */
214 #define DASD_CQR_IN_ERP 	0x03	/* request is in recovery */
215 #define DASD_CQR_FAILED 	0x04	/* request is finally failed */
216 #define DASD_CQR_TERMINATED	0x05	/* request was stopped by driver */
217 
218 #define DASD_CQR_QUEUED 	0x80	/* request is queued to be processed */
219 #define DASD_CQR_IN_IO		0x81	/* request is currently in IO */
220 #define DASD_CQR_ERROR		0x82	/* request is completed with error */
221 #define DASD_CQR_CLEAR_PENDING	0x83	/* request is clear pending */
222 #define DASD_CQR_CLEARED	0x84	/* request was cleared */
223 #define DASD_CQR_SUCCESS	0x85	/* request was successful */
224 
225 /* default expiration time*/
226 #define DASD_EXPIRES	  300
227 #define DASD_EXPIRES_MAX  40000000
228 
229 /* per dasd_ccw_req flags */
230 #define DASD_CQR_FLAGS_USE_ERP   0	/* use ERP for this request */
231 #define DASD_CQR_FLAGS_FAILFAST  1	/* FAILFAST */
232 #define DASD_CQR_VERIFY_PATH	 2	/* path verification request */
233 #define DASD_CQR_ALLOW_SLOCK	 3	/* Try this request even when lock was
234 					 * stolen. Should not be combined with
235 					 * DASD_CQR_FLAGS_USE_ERP
236 					 */
237 
238 /* Signature for error recovery functions. */
239 typedef struct dasd_ccw_req *(*dasd_erp_fn_t) (struct dasd_ccw_req *);
240 
241 /*
242  * Unique identifier for dasd device.
243  */
244 #define UA_NOT_CONFIGURED  0x00
245 #define UA_BASE_DEVICE	   0x01
246 #define UA_BASE_PAV_ALIAS  0x02
247 #define UA_HYPER_PAV_ALIAS 0x03
248 
249 struct dasd_uid {
250 	__u8 type;
251 	char vendor[4];
252 	char serial[15];
253 	__u16 ssid;
254 	__u8 real_unit_addr;
255 	__u8 base_unit_addr;
256 	char vduit[33];
257 };
258 
259 /*
260  * the struct dasd_discipline is
261  * sth like a table of virtual functions, if you think of dasd_eckd
262  * inheriting dasd...
263  * no, currently we are not planning to reimplement the driver in C++
264  */
265 struct dasd_discipline {
266 	struct module *owner;
267 	char ebcname[8];	/* a name used for tagging and printks */
268 	char name[8];		/* a name used for tagging and printks */
269 	int max_blocks;		/* maximum number of blocks to be chained */
270 
271 	struct list_head list;	/* used for list of disciplines */
272 
273 	/*
274 	 * Device recognition functions. check_device is used to verify
275 	 * the sense data and the information returned by read device
276 	 * characteristics. It returns 0 if the discipline can be used
277 	 * for the device in question. uncheck_device is called during
278 	 * device shutdown to deregister a device from its discipline.
279 	 */
280 	int (*check_device) (struct dasd_device *);
281 	void (*uncheck_device) (struct dasd_device *);
282 
283 	/*
284 	 * do_analysis is used in the step from device state "basic" to
285 	 * state "accept". It returns 0 if the device can be made ready,
286 	 * it returns -EMEDIUMTYPE if the device can't be made ready or
287 	 * -EAGAIN if do_analysis started a ccw that needs to complete
288 	 * before the analysis may be repeated.
289 	 */
290 	int (*do_analysis) (struct dasd_block *);
291 
292 	/*
293 	 * This function is called, when new paths become available.
294 	 * Disciplins may use this callback to do necessary setup work,
295 	 * e.g. verify that new path is compatible with the current
296 	 * configuration.
297 	 */
298 	int (*verify_path)(struct dasd_device *, __u8);
299 
300 	/*
301 	 * Last things to do when a device is set online, and first things
302 	 * when it is set offline.
303 	 */
304 	int (*ready_to_online) (struct dasd_device *);
305 	int (*online_to_ready) (struct dasd_device *);
306 
307 	/*
308 	 * Device operation functions. build_cp creates a ccw chain for
309 	 * a block device request, start_io starts the request and
310 	 * term_IO cancels it (e.g. in case of a timeout). format_device
311 	 * returns a ccw chain to be used to format the device.
312 	 * handle_terminated_request allows to examine a cqr and prepare
313 	 * it for retry.
314 	 */
315 	struct dasd_ccw_req *(*build_cp) (struct dasd_device *,
316 					  struct dasd_block *,
317 					  struct request *);
318 	int (*start_IO) (struct dasd_ccw_req *);
319 	int (*term_IO) (struct dasd_ccw_req *);
320 	void (*handle_terminated_request) (struct dasd_ccw_req *);
321 	struct dasd_ccw_req *(*format_device) (struct dasd_device *,
322 					       struct format_data_t *);
323 	int (*free_cp) (struct dasd_ccw_req *, struct request *);
324 
325 	/*
326 	 * Error recovery functions. examine_error() returns a value that
327 	 * indicates what to do for an error condition. If examine_error()
328 	 * returns 'dasd_era_recover' erp_action() is called to create a
329 	 * special error recovery ccw. erp_postaction() is called after
330 	 * an error recovery ccw has finished its execution. dump_sense
331 	 * is called for every error condition to print the sense data
332 	 * to the console.
333 	 */
334 	dasd_erp_fn_t(*erp_action) (struct dasd_ccw_req *);
335 	dasd_erp_fn_t(*erp_postaction) (struct dasd_ccw_req *);
336 	void (*dump_sense) (struct dasd_device *, struct dasd_ccw_req *,
337 			    struct irb *);
338 	void (*dump_sense_dbf) (struct dasd_device *, struct irb *, char *);
339 	void (*check_for_device_change) (struct dasd_device *,
340 					 struct dasd_ccw_req *,
341 					 struct irb *);
342 
343         /* i/o control functions. */
344 	int (*fill_geometry) (struct dasd_block *, struct hd_geometry *);
345 	int (*fill_info) (struct dasd_device *, struct dasd_information2_t *);
346 	int (*ioctl) (struct dasd_block *, unsigned int, void __user *);
347 
348 	/* suspend/resume functions */
349 	int (*freeze) (struct dasd_device *);
350 	int (*restore) (struct dasd_device *);
351 
352 	/* reload device after state change */
353 	int (*reload) (struct dasd_device *);
354 
355 	int (*get_uid) (struct dasd_device *, struct dasd_uid *);
356 	void (*kick_validate) (struct dasd_device *);
357 };
358 
359 extern struct dasd_discipline *dasd_diag_discipline_pointer;
360 
361 /*
362  * Notification numbers for extended error reporting notifications:
363  * The DASD_EER_DISABLE notification is sent before a dasd_device (and it's
364  * eer pointer) is freed. The error reporting module needs to do all necessary
365  * cleanup steps.
366  * The DASD_EER_TRIGGER notification sends the actual error reports (triggers).
367  */
368 #define DASD_EER_DISABLE 0
369 #define DASD_EER_TRIGGER 1
370 
371 /* Trigger IDs for extended error reporting DASD_EER_TRIGGER notification */
372 #define DASD_EER_FATALERROR  1
373 #define DASD_EER_NOPATH      2
374 #define DASD_EER_STATECHANGE 3
375 #define DASD_EER_PPRCSUSPEND 4
376 
377 struct dasd_path {
378 	__u8 opm;
379 	__u8 tbvpm;
380 	__u8 ppm;
381 	__u8 npm;
382 };
383 
384 struct dasd_profile_info {
385 	/* legacy part of profile data, as in dasd_profile_info_t */
386 	unsigned int dasd_io_reqs;	 /* number of requests processed */
387 	unsigned int dasd_io_sects;	 /* number of sectors processed */
388 	unsigned int dasd_io_secs[32];	 /* histogram of request's sizes */
389 	unsigned int dasd_io_times[32];	 /* histogram of requests's times */
390 	unsigned int dasd_io_timps[32];	 /* h. of requests's times per sector */
391 	unsigned int dasd_io_time1[32];	 /* hist. of time from build to start */
392 	unsigned int dasd_io_time2[32];	 /* hist. of time from start to irq */
393 	unsigned int dasd_io_time2ps[32]; /* hist. of time from start to irq */
394 	unsigned int dasd_io_time3[32];	 /* hist. of time from irq to end */
395 	unsigned int dasd_io_nr_req[32]; /* hist. of # of requests in chanq */
396 
397 	/* new data */
398 	struct timespec starttod;	   /* time of start or last reset */
399 	unsigned int dasd_io_alias;	   /* requests using an alias */
400 	unsigned int dasd_io_tpm;	   /* requests using transport mode */
401 	unsigned int dasd_read_reqs;	   /* total number of read  requests */
402 	unsigned int dasd_read_sects;	   /* total number read sectors */
403 	unsigned int dasd_read_alias;	   /* read request using an alias */
404 	unsigned int dasd_read_tpm;	   /* read requests in transport mode */
405 	unsigned int dasd_read_secs[32];   /* histogram of request's sizes */
406 	unsigned int dasd_read_times[32];  /* histogram of requests's times */
407 	unsigned int dasd_read_time1[32];  /* hist. time from build to start */
408 	unsigned int dasd_read_time2[32];  /* hist. of time from start to irq */
409 	unsigned int dasd_read_time3[32];  /* hist. of time from irq to end */
410 	unsigned int dasd_read_nr_req[32]; /* hist. of # of requests in chanq */
411 };
412 
413 struct dasd_profile {
414 	struct dentry *dentry;
415 	struct dasd_profile_info *data;
416 	spinlock_t lock;
417 };
418 
419 struct dasd_device {
420 	/* Block device stuff. */
421 	struct dasd_block *block;
422 
423         unsigned int devindex;
424 	unsigned long flags;	   /* per device flags */
425 	unsigned short features;   /* copy of devmap-features (read-only!) */
426 
427 	/* extended error reporting stuff (eer) */
428 	struct dasd_ccw_req *eer_cqr;
429 
430 	/* Device discipline stuff. */
431 	struct dasd_discipline *discipline;
432 	struct dasd_discipline *base_discipline;
433 	char *private;
434 	struct dasd_path path_data;
435 
436 	/* Device state and target state. */
437 	int state, target;
438 	struct mutex state_mutex;
439 	int stopped;		/* device (ccw_device_start) was stopped */
440 
441 	/* reference count. */
442         atomic_t ref_count;
443 
444 	/* ccw queue and memory for static ccw/erp buffers. */
445 	struct list_head ccw_queue;
446 	spinlock_t mem_lock;
447 	void *ccw_mem;
448 	void *erp_mem;
449 	struct list_head ccw_chunks;
450 	struct list_head erp_chunks;
451 
452 	atomic_t tasklet_scheduled;
453         struct tasklet_struct tasklet;
454 	struct work_struct kick_work;
455 	struct work_struct restore_device;
456 	struct work_struct reload_device;
457 	struct work_struct kick_validate;
458 	struct timer_list timer;
459 
460 	debug_info_t *debug_area;
461 
462 	struct ccw_device *cdev;
463 
464 	/* hook for alias management */
465 	struct list_head alias_list;
466 
467 	/* default expiration time in s */
468 	unsigned long default_expires;
469 
470 	struct dentry *debugfs_dentry;
471 	struct dasd_profile profile;
472 };
473 
474 struct dasd_block {
475 	/* Block device stuff. */
476 	struct gendisk *gdp;
477 	struct request_queue *request_queue;
478 	spinlock_t request_queue_lock;
479 	struct block_device *bdev;
480 	atomic_t open_count;
481 
482 	unsigned long long blocks; /* size of volume in blocks */
483 	unsigned int bp_block;	   /* bytes per block */
484 	unsigned int s2b_shift;	   /* log2 (bp_block/512) */
485 
486 	struct dasd_device *base;
487 	struct list_head ccw_queue;
488 	spinlock_t queue_lock;
489 
490 	atomic_t tasklet_scheduled;
491 	struct tasklet_struct tasklet;
492 	struct timer_list timer;
493 
494 	struct dentry *debugfs_dentry;
495 	struct dasd_profile profile;
496 };
497 
498 
499 
500 /* reasons why device (ccw_device_start) was stopped */
501 #define DASD_STOPPED_NOT_ACC 1         /* not accessible */
502 #define DASD_STOPPED_QUIESCE 2         /* Quiesced */
503 #define DASD_STOPPED_PENDING 4         /* long busy */
504 #define DASD_STOPPED_DC_WAIT 8         /* disconnected, wait */
505 #define DASD_STOPPED_SU      16        /* summary unit check handling */
506 #define DASD_STOPPED_PM      32        /* pm state transition */
507 #define DASD_UNRESUMED_PM    64        /* pm resume failed state */
508 
509 /* per device flags */
510 #define DASD_FLAG_OFFLINE	3	/* device is in offline processing */
511 #define DASD_FLAG_EER_SNSS	4	/* A SNSS is required */
512 #define DASD_FLAG_EER_IN_USE	5	/* A SNSS request is running */
513 #define DASD_FLAG_DEVICE_RO	6	/* The device itself is read-only. Don't
514 					 * confuse this with the user specified
515 					 * read-only feature.
516 					 */
517 #define DASD_FLAG_IS_RESERVED	7	/* The device is reserved */
518 #define DASD_FLAG_LOCK_STOLEN	8	/* The device lock was stolen */
519 #define DASD_FLAG_SUSPENDED	9	/* The device was suspended */
520 
521 
522 void dasd_put_device_wake(struct dasd_device *);
523 
524 /*
525  * Reference count inliners
526  */
527 static inline void
528 dasd_get_device(struct dasd_device *device)
529 {
530 	atomic_inc(&device->ref_count);
531 }
532 
533 static inline void
534 dasd_put_device(struct dasd_device *device)
535 {
536 	if (atomic_dec_return(&device->ref_count) == 0)
537 		dasd_put_device_wake(device);
538 }
539 
540 /*
541  * The static memory in ccw_mem and erp_mem is managed by a sorted
542  * list of free memory chunks.
543  */
544 struct dasd_mchunk
545 {
546 	struct list_head list;
547 	unsigned long size;
548 } __attribute__ ((aligned(8)));
549 
550 static inline void
551 dasd_init_chunklist(struct list_head *chunk_list, void *mem,
552 		    unsigned long size)
553 {
554 	struct dasd_mchunk *chunk;
555 
556 	INIT_LIST_HEAD(chunk_list);
557 	chunk = (struct dasd_mchunk *) mem;
558 	chunk->size = size - sizeof(struct dasd_mchunk);
559 	list_add(&chunk->list, chunk_list);
560 }
561 
562 static inline void *
563 dasd_alloc_chunk(struct list_head *chunk_list, unsigned long size)
564 {
565 	struct dasd_mchunk *chunk, *tmp;
566 
567 	size = (size + 7L) & -8L;
568 	list_for_each_entry(chunk, chunk_list, list) {
569 		if (chunk->size < size)
570 			continue;
571 		if (chunk->size > size + sizeof(struct dasd_mchunk)) {
572 			char *endaddr = (char *) (chunk + 1) + chunk->size;
573 			tmp = (struct dasd_mchunk *) (endaddr - size) - 1;
574 			tmp->size = size;
575 			chunk->size -= size + sizeof(struct dasd_mchunk);
576 			chunk = tmp;
577 		} else
578 			list_del(&chunk->list);
579 		return (void *) (chunk + 1);
580 	}
581 	return NULL;
582 }
583 
584 static inline void
585 dasd_free_chunk(struct list_head *chunk_list, void *mem)
586 {
587 	struct dasd_mchunk *chunk, *tmp;
588 	struct list_head *p, *left;
589 
590 	chunk = (struct dasd_mchunk *)
591 		((char *) mem - sizeof(struct dasd_mchunk));
592 	/* Find out the left neighbour in chunk_list. */
593 	left = chunk_list;
594 	list_for_each(p, chunk_list) {
595 		if (list_entry(p, struct dasd_mchunk, list) > chunk)
596 			break;
597 		left = p;
598 	}
599 	/* Try to merge with right neighbour = next element from left. */
600 	if (left->next != chunk_list) {
601 		tmp = list_entry(left->next, struct dasd_mchunk, list);
602 		if ((char *) (chunk + 1) + chunk->size == (char *) tmp) {
603 			list_del(&tmp->list);
604 			chunk->size += tmp->size + sizeof(struct dasd_mchunk);
605 		}
606 	}
607 	/* Try to merge with left neighbour. */
608 	if (left != chunk_list) {
609 		tmp = list_entry(left, struct dasd_mchunk, list);
610 		if ((char *) (tmp + 1) + tmp->size == (char *) chunk) {
611 			tmp->size += chunk->size + sizeof(struct dasd_mchunk);
612 			return;
613 		}
614 	}
615 	__list_add(&chunk->list, left, left->next);
616 }
617 
618 /*
619  * Check if bsize is in { 512, 1024, 2048, 4096 }
620  */
621 static inline int
622 dasd_check_blocksize(int bsize)
623 {
624 	if (bsize < 512 || bsize > 4096 || !is_power_of_2(bsize))
625 		return -EMEDIUMTYPE;
626 	return 0;
627 }
628 
629 /* externals in dasd.c */
630 #define DASD_PROFILE_OFF	 0
631 #define DASD_PROFILE_ON 	 1
632 #define DASD_PROFILE_GLOBAL_ONLY 2
633 
634 extern debug_info_t *dasd_debug_area;
635 extern struct dasd_profile_info dasd_global_profile_data;
636 extern unsigned int dasd_global_profile_level;
637 extern const struct block_device_operations dasd_device_operations;
638 
639 extern struct kmem_cache *dasd_page_cache;
640 
641 struct dasd_ccw_req *
642 dasd_kmalloc_request(int , int, int, struct dasd_device *);
643 struct dasd_ccw_req *
644 dasd_smalloc_request(int , int, int, struct dasd_device *);
645 void dasd_kfree_request(struct dasd_ccw_req *, struct dasd_device *);
646 void dasd_sfree_request(struct dasd_ccw_req *, struct dasd_device *);
647 void dasd_wakeup_cb(struct dasd_ccw_req *, void *);
648 
649 static inline int
650 dasd_kmalloc_set_cda(struct ccw1 *ccw, void *cda, struct dasd_device *device)
651 {
652 	return set_normalized_cda(ccw, cda);
653 }
654 
655 struct dasd_device *dasd_alloc_device(void);
656 void dasd_free_device(struct dasd_device *);
657 
658 struct dasd_block *dasd_alloc_block(void);
659 void dasd_free_block(struct dasd_block *);
660 
661 void dasd_enable_device(struct dasd_device *);
662 void dasd_set_target_state(struct dasd_device *, int);
663 void dasd_kick_device(struct dasd_device *);
664 void dasd_restore_device(struct dasd_device *);
665 void dasd_reload_device(struct dasd_device *);
666 
667 void dasd_add_request_head(struct dasd_ccw_req *);
668 void dasd_add_request_tail(struct dasd_ccw_req *);
669 int  dasd_start_IO(struct dasd_ccw_req *);
670 int  dasd_term_IO(struct dasd_ccw_req *);
671 void dasd_schedule_device_bh(struct dasd_device *);
672 void dasd_schedule_block_bh(struct dasd_block *);
673 int  dasd_sleep_on(struct dasd_ccw_req *);
674 int  dasd_sleep_on_immediatly(struct dasd_ccw_req *);
675 int  dasd_sleep_on_interruptible(struct dasd_ccw_req *);
676 void dasd_device_set_timer(struct dasd_device *, int);
677 void dasd_device_clear_timer(struct dasd_device *);
678 void dasd_block_set_timer(struct dasd_block *, int);
679 void dasd_block_clear_timer(struct dasd_block *);
680 int  dasd_cancel_req(struct dasd_ccw_req *);
681 int dasd_flush_device_queue(struct dasd_device *);
682 int dasd_generic_probe (struct ccw_device *, struct dasd_discipline *);
683 void dasd_generic_remove (struct ccw_device *cdev);
684 int dasd_generic_set_online(struct ccw_device *, struct dasd_discipline *);
685 int dasd_generic_set_offline (struct ccw_device *cdev);
686 int dasd_generic_notify(struct ccw_device *, int);
687 int dasd_generic_last_path_gone(struct dasd_device *);
688 int dasd_generic_path_operational(struct dasd_device *);
689 
690 void dasd_generic_handle_state_change(struct dasd_device *);
691 int dasd_generic_pm_freeze(struct ccw_device *);
692 int dasd_generic_restore_device(struct ccw_device *);
693 enum uc_todo dasd_generic_uc_handler(struct ccw_device *, struct irb *);
694 void dasd_generic_path_event(struct ccw_device *, int *);
695 int dasd_generic_verify_path(struct dasd_device *, __u8);
696 
697 int dasd_generic_read_dev_chars(struct dasd_device *, int, void *, int);
698 char *dasd_get_sense(struct irb *);
699 
700 void dasd_device_set_stop_bits(struct dasd_device *, int);
701 void dasd_device_remove_stop_bits(struct dasd_device *, int);
702 
703 int dasd_device_is_ro(struct dasd_device *);
704 
705 void dasd_profile_reset(struct dasd_profile *);
706 int dasd_profile_on(struct dasd_profile *);
707 void dasd_profile_off(struct dasd_profile *);
708 void dasd_global_profile_reset(void);
709 char *dasd_get_user_string(const char __user *, size_t);
710 
711 /* externals in dasd_devmap.c */
712 extern int dasd_max_devindex;
713 extern int dasd_probeonly;
714 extern int dasd_autodetect;
715 extern int dasd_nopav;
716 extern int dasd_nofcx;
717 
718 int dasd_devmap_init(void);
719 void dasd_devmap_exit(void);
720 
721 struct dasd_device *dasd_create_device(struct ccw_device *);
722 void dasd_delete_device(struct dasd_device *);
723 
724 int dasd_get_feature(struct ccw_device *, int);
725 int dasd_set_feature(struct ccw_device *, int, int);
726 
727 int dasd_add_sysfs_files(struct ccw_device *);
728 void dasd_remove_sysfs_files(struct ccw_device *);
729 
730 struct dasd_device *dasd_device_from_cdev(struct ccw_device *);
731 struct dasd_device *dasd_device_from_cdev_locked(struct ccw_device *);
732 struct dasd_device *dasd_device_from_devindex(int);
733 
734 void dasd_add_link_to_gendisk(struct gendisk *, struct dasd_device *);
735 struct dasd_device *dasd_device_from_gendisk(struct gendisk *);
736 
737 int dasd_parse(void);
738 int dasd_busid_known(const char *);
739 
740 /* externals in dasd_gendisk.c */
741 int  dasd_gendisk_init(void);
742 void dasd_gendisk_exit(void);
743 int dasd_gendisk_alloc(struct dasd_block *);
744 void dasd_gendisk_free(struct dasd_block *);
745 int dasd_scan_partitions(struct dasd_block *);
746 void dasd_destroy_partitions(struct dasd_block *);
747 
748 /* externals in dasd_ioctl.c */
749 int  dasd_ioctl(struct block_device *, fmode_t, unsigned int, unsigned long);
750 
751 /* externals in dasd_proc.c */
752 int dasd_proc_init(void);
753 void dasd_proc_exit(void);
754 
755 /* externals in dasd_erp.c */
756 struct dasd_ccw_req *dasd_default_erp_action(struct dasd_ccw_req *);
757 struct dasd_ccw_req *dasd_default_erp_postaction(struct dasd_ccw_req *);
758 struct dasd_ccw_req *dasd_alloc_erp_request(char *, int, int,
759 					    struct dasd_device *);
760 void dasd_free_erp_request(struct dasd_ccw_req *, struct dasd_device *);
761 void dasd_log_sense(struct dasd_ccw_req *, struct irb *);
762 void dasd_log_sense_dbf(struct dasd_ccw_req *cqr, struct irb *irb);
763 
764 /* externals in dasd_3990_erp.c */
765 struct dasd_ccw_req *dasd_3990_erp_action(struct dasd_ccw_req *);
766 void dasd_3990_erp_handle_sim(struct dasd_device *, char *);
767 
768 /* externals in dasd_eer.c */
769 #ifdef CONFIG_DASD_EER
770 int dasd_eer_init(void);
771 void dasd_eer_exit(void);
772 int dasd_eer_enable(struct dasd_device *);
773 void dasd_eer_disable(struct dasd_device *);
774 void dasd_eer_write(struct dasd_device *, struct dasd_ccw_req *cqr,
775 		    unsigned int id);
776 void dasd_eer_snss(struct dasd_device *);
777 
778 static inline int dasd_eer_enabled(struct dasd_device *device)
779 {
780 	return device->eer_cqr != NULL;
781 }
782 #else
783 #define dasd_eer_init()		(0)
784 #define dasd_eer_exit()		do { } while (0)
785 #define dasd_eer_enable(d)	(0)
786 #define dasd_eer_disable(d)	do { } while (0)
787 #define dasd_eer_write(d,c,i)	do { } while (0)
788 #define dasd_eer_snss(d)	do { } while (0)
789 #define dasd_eer_enabled(d)	(0)
790 #endif	/* CONFIG_DASD_ERR */
791 
792 #endif				/* DASD_H */
793