xref: /openbmc/linux/drivers/s390/block/dasd_int.h (revision 12eb4683)
1 /*
2  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
3  *		    Horst Hummel <Horst.Hummel@de.ibm.com>
4  *		    Martin Schwidefsky <schwidefsky@de.ibm.com>
5  * Bugreports.to..: <Linux390@de.ibm.com>
6  * Copyright IBM Corp. 1999, 2009
7  */
8 
9 #ifndef DASD_INT_H
10 #define DASD_INT_H
11 
12 /* we keep old device allocation scheme; IOW, minors are still in 0..255 */
13 #define DASD_PER_MAJOR (1U << (MINORBITS - DASD_PARTN_BITS))
14 #define DASD_PARTN_MASK ((1 << DASD_PARTN_BITS) - 1)
15 
16 /*
17  * States a dasd device can have:
18  *   new: the dasd_device structure is allocated.
19  *   known: the discipline for the device is identified.
20  *   basic: the device can do basic i/o.
21  *   unfmt: the device could not be analyzed (format is unknown).
22  *   ready: partition detection is done and the device is can do block io.
23  *   online: the device accepts requests from the block device queue.
24  *
25  * Things to do for startup state transitions:
26  *   new -> known: find discipline for the device and create devfs entries.
27  *   known -> basic: request irq line for the device.
28  *   basic -> ready: do the initial analysis, e.g. format detection,
29  *                   do block device setup and detect partitions.
30  *   ready -> online: schedule the device tasklet.
31  * Things to do for shutdown state transitions:
32  *   online -> ready: just set the new device state.
33  *   ready -> basic: flush requests from the block device layer, clear
34  *                   partition information and reset format information.
35  *   basic -> known: terminate all requests and free irq.
36  *   known -> new: remove devfs entries and forget discipline.
37  */
38 
39 #define DASD_STATE_NEW	  0
40 #define DASD_STATE_KNOWN  1
41 #define DASD_STATE_BASIC  2
42 #define DASD_STATE_UNFMT  3
43 #define DASD_STATE_READY  4
44 #define DASD_STATE_ONLINE 5
45 
46 #include <linux/module.h>
47 #include <linux/wait.h>
48 #include <linux/blkdev.h>
49 #include <linux/genhd.h>
50 #include <linux/hdreg.h>
51 #include <linux/interrupt.h>
52 #include <linux/log2.h>
53 #include <asm/ccwdev.h>
54 #include <linux/workqueue.h>
55 #include <asm/debug.h>
56 #include <asm/dasd.h>
57 #include <asm/idals.h>
58 
59 /* DASD discipline magic */
60 #define DASD_ECKD_MAGIC 0xC5C3D2C4
61 #define DASD_DIAG_MAGIC 0xC4C9C1C7
62 #define DASD_FBA_MAGIC 0xC6C2C140
63 
64 /*
65  * SECTION: Type definitions
66  */
67 struct dasd_device;
68 struct dasd_block;
69 
70 /* BIT DEFINITIONS FOR SENSE DATA */
71 #define DASD_SENSE_BIT_0 0x80
72 #define DASD_SENSE_BIT_1 0x40
73 #define DASD_SENSE_BIT_2 0x20
74 #define DASD_SENSE_BIT_3 0x10
75 
76 /* BIT DEFINITIONS FOR SIM SENSE */
77 #define DASD_SIM_SENSE 0x0F
78 #define DASD_SIM_MSG_TO_OP 0x03
79 #define DASD_SIM_LOG 0x0C
80 
81 /* lock class for nested cdev lock */
82 #define CDEV_NESTED_FIRST 1
83 #define CDEV_NESTED_SECOND 2
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_EVENT_DEVID(d_level, d_cdev, d_str, d_data...)	\
113 do { \
114 	struct ccw_dev_id __dev_id;			\
115 	ccw_device_get_id(d_cdev, &__dev_id);		\
116 	debug_sprintf_event(dasd_debug_area,		\
117 			    d_level,					\
118 			    "0.%x.%04x " d_str "\n",			\
119 			    __dev_id.ssid, __dev_id.devno, d_data);	\
120 } while (0)
121 
122 #define DBF_EXC(d_level, d_str, d_data...)\
123 do { \
124 	debug_sprintf_exception(dasd_debug_area, \
125 				d_level,\
126 				d_str "\n", \
127 				d_data); \
128 } while(0)
129 
130 /* limit size for an errorstring */
131 #define ERRORLENGTH 30
132 
133 /* definition of dbf debug levels */
134 #define	DBF_EMERG	0	/* system is unusable			*/
135 #define	DBF_ALERT	1	/* action must be taken immediately	*/
136 #define	DBF_CRIT	2	/* critical conditions			*/
137 #define	DBF_ERR		3	/* error conditions			*/
138 #define	DBF_WARNING	4	/* warning conditions			*/
139 #define	DBF_NOTICE	5	/* normal but significant condition	*/
140 #define	DBF_INFO	6	/* informational			*/
141 #define	DBF_DEBUG	6	/* debug-level messages			*/
142 
143 /* messages to be written via klogd and dbf */
144 #define DEV_MESSAGE(d_loglevel,d_device,d_string,d_args...)\
145 do { \
146 	printk(d_loglevel PRINTK_HEADER " %s: " d_string "\n", \
147 	       dev_name(&d_device->cdev->dev), d_args); \
148 	DBF_DEV_EVENT(DBF_ALERT, d_device, d_string, d_args); \
149 } while(0)
150 
151 #define MESSAGE(d_loglevel,d_string,d_args...)\
152 do { \
153 	printk(d_loglevel PRINTK_HEADER " " d_string "\n", d_args); \
154 	DBF_EVENT(DBF_ALERT, d_string, d_args); \
155 } while(0)
156 
157 /* messages to be written via klogd only */
158 #define DEV_MESSAGE_LOG(d_loglevel,d_device,d_string,d_args...)\
159 do { \
160 	printk(d_loglevel PRINTK_HEADER " %s: " d_string "\n", \
161 	       dev_name(&d_device->cdev->dev), d_args); \
162 } while(0)
163 
164 #define MESSAGE_LOG(d_loglevel,d_string,d_args...)\
165 do { \
166 	printk(d_loglevel PRINTK_HEADER " " d_string "\n", d_args); \
167 } while(0)
168 
169 struct dasd_ccw_req {
170 	unsigned int magic;		/* Eye catcher */
171 	struct list_head devlist;	/* for dasd_device request queue */
172 	struct list_head blocklist;	/* for dasd_block request queue */
173 
174 	/* Where to execute what... */
175 	struct dasd_block *block;	/* the originating block device */
176 	struct dasd_device *memdev;	/* the device used to allocate this */
177 	struct dasd_device *startdev;	/* device the request is started on */
178 	void *cpaddr;			/* address of ccw or tcw */
179 	unsigned char cpmode;		/* 0 = cmd mode, 1 = itcw */
180 	char status;			/* status of this request */
181 	short retries;			/* A retry counter */
182 	unsigned long flags;        	/* flags of this request */
183 
184 	/* ... and how */
185 	unsigned long starttime;	/* jiffies time of request start */
186 	unsigned long expires;		/* expiration period in jiffies */
187 	char lpm;			/* logical path mask */
188 	void *data;			/* pointer to data area */
189 
190 	/* these are important for recovering erroneous requests          */
191 	int intrc;			/* internal error, e.g. from start_IO */
192 	struct irb irb;			/* device status in case of an error */
193 	struct dasd_ccw_req *refers;	/* ERP-chain queueing. */
194 	void *function; 		/* originating ERP action */
195 
196 	/* these are for statistics only */
197 	unsigned long long buildclk;	/* TOD-clock of request generation */
198 	unsigned long long startclk;	/* TOD-clock of request start */
199 	unsigned long long stopclk;	/* TOD-clock of request interrupt */
200 	unsigned long long endclk;	/* TOD-clock of request termination */
201 
202         /* Callback that is called after reaching final status. */
203 	void (*callback)(struct dasd_ccw_req *, void *data);
204 	void *callback_data;
205 };
206 
207 /*
208  * dasd_ccw_req -> status can be:
209  */
210 #define DASD_CQR_FILLED 	0x00	/* request is ready to be processed */
211 #define DASD_CQR_DONE		0x01	/* request is completed successfully */
212 #define DASD_CQR_NEED_ERP	0x02	/* request needs recovery action */
213 #define DASD_CQR_IN_ERP 	0x03	/* request is in recovery */
214 #define DASD_CQR_FAILED 	0x04	/* request is finally failed */
215 #define DASD_CQR_TERMINATED	0x05	/* request was stopped by driver */
216 
217 #define DASD_CQR_QUEUED 	0x80	/* request is queued to be processed */
218 #define DASD_CQR_IN_IO		0x81	/* request is currently in IO */
219 #define DASD_CQR_ERROR		0x82	/* request is completed with error */
220 #define DASD_CQR_CLEAR_PENDING	0x83	/* request is clear pending */
221 #define DASD_CQR_CLEARED	0x84	/* request was cleared */
222 #define DASD_CQR_SUCCESS	0x85	/* request was successful */
223 
224 /* default expiration time*/
225 #define DASD_EXPIRES	  300
226 #define DASD_EXPIRES_MAX  40000000
227 #define DASD_RETRIES	  256
228 #define DASD_RETRIES_MAX  32768
229 
230 /* per dasd_ccw_req flags */
231 #define DASD_CQR_FLAGS_USE_ERP   0	/* use ERP for this request */
232 #define DASD_CQR_FLAGS_FAILFAST  1	/* FAILFAST */
233 #define DASD_CQR_VERIFY_PATH	 2	/* path verification request */
234 #define DASD_CQR_ALLOW_SLOCK	 3	/* Try this request even when lock was
235 					 * stolen. Should not be combined with
236 					 * DASD_CQR_FLAGS_USE_ERP
237 					 */
238 
239 /* Signature for error recovery functions. */
240 typedef struct dasd_ccw_req *(*dasd_erp_fn_t) (struct dasd_ccw_req *);
241 
242 /*
243  * Unique identifier for dasd device.
244  */
245 #define UA_NOT_CONFIGURED  0x00
246 #define UA_BASE_DEVICE	   0x01
247 #define UA_BASE_PAV_ALIAS  0x02
248 #define UA_HYPER_PAV_ALIAS 0x03
249 
250 struct dasd_uid {
251 	__u8 type;
252 	char vendor[4];
253 	char serial[15];
254 	__u16 ssid;
255 	__u8 real_unit_addr;
256 	__u8 base_unit_addr;
257 	char vduit[33];
258 };
259 
260 /*
261  * the struct dasd_discipline is
262  * sth like a table of virtual functions, if you think of dasd_eckd
263  * inheriting dasd...
264  * no, currently we are not planning to reimplement the driver in C++
265  */
266 struct dasd_discipline {
267 	struct module *owner;
268 	char ebcname[8];	/* a name used for tagging and printks */
269 	char name[8];		/* a name used for tagging and printks */
270 	int max_blocks;		/* maximum number of blocks to be chained */
271 
272 	struct list_head list;	/* used for list of disciplines */
273 
274 	/*
275 	 * Device recognition functions. check_device is used to verify
276 	 * the sense data and the information returned by read device
277 	 * characteristics. It returns 0 if the discipline can be used
278 	 * for the device in question. uncheck_device is called during
279 	 * device shutdown to deregister a device from its discipline.
280 	 */
281 	int (*check_device) (struct dasd_device *);
282 	void (*uncheck_device) (struct dasd_device *);
283 
284 	/*
285 	 * do_analysis is used in the step from device state "basic" to
286 	 * state "accept". It returns 0 if the device can be made ready,
287 	 * it returns -EMEDIUMTYPE if the device can't be made ready or
288 	 * -EAGAIN if do_analysis started a ccw that needs to complete
289 	 * before the analysis may be repeated.
290 	 */
291 	int (*do_analysis) (struct dasd_block *);
292 
293 	/*
294 	 * This function is called, when new paths become available.
295 	 * Disciplins may use this callback to do necessary setup work,
296 	 * e.g. verify that new path is compatible with the current
297 	 * configuration.
298 	 */
299 	int (*verify_path)(struct dasd_device *, __u8);
300 
301 	/*
302 	 * Last things to do when a device is set online, and first things
303 	 * when it is set offline.
304 	 */
305 	int (*basic_to_ready) (struct dasd_device *);
306 	int (*online_to_ready) (struct dasd_device *);
307 	int (*ready_to_basic)  (struct dasd_device *);
308 
309 	/* (struct dasd_device *);
310 	 * Device operation functions. build_cp creates a ccw chain for
311 	 * a block device request, start_io starts the request and
312 	 * term_IO cancels it (e.g. in case of a timeout). format_device
313 	 * returns a ccw chain to be used to format the device.
314 	 * handle_terminated_request allows to examine a cqr and prepare
315 	 * it for retry.
316 	 */
317 	struct dasd_ccw_req *(*build_cp) (struct dasd_device *,
318 					  struct dasd_block *,
319 					  struct request *);
320 	int (*start_IO) (struct dasd_ccw_req *);
321 	int (*term_IO) (struct dasd_ccw_req *);
322 	void (*handle_terminated_request) (struct dasd_ccw_req *);
323 	int (*format_device) (struct dasd_device *,
324 			      struct format_data_t *);
325 	int (*free_cp) (struct dasd_ccw_req *, struct request *);
326 
327 	/*
328 	 * Error recovery functions. examine_error() returns a value that
329 	 * indicates what to do for an error condition. If examine_error()
330 	 * returns 'dasd_era_recover' erp_action() is called to create a
331 	 * special error recovery ccw. erp_postaction() is called after
332 	 * an error recovery ccw has finished its execution. dump_sense
333 	 * is called for every error condition to print the sense data
334 	 * to the console.
335 	 */
336 	dasd_erp_fn_t(*erp_action) (struct dasd_ccw_req *);
337 	dasd_erp_fn_t(*erp_postaction) (struct dasd_ccw_req *);
338 	void (*dump_sense) (struct dasd_device *, struct dasd_ccw_req *,
339 			    struct irb *);
340 	void (*dump_sense_dbf) (struct dasd_device *, struct irb *, char *);
341 	void (*check_for_device_change) (struct dasd_device *,
342 					 struct dasd_ccw_req *,
343 					 struct irb *);
344 
345         /* i/o control functions. */
346 	int (*fill_geometry) (struct dasd_block *, struct hd_geometry *);
347 	int (*fill_info) (struct dasd_device *, struct dasd_information2_t *);
348 	int (*ioctl) (struct dasd_block *, unsigned int, void __user *);
349 
350 	/* suspend/resume functions */
351 	int (*freeze) (struct dasd_device *);
352 	int (*restore) (struct dasd_device *);
353 
354 	/* reload device after state change */
355 	int (*reload) (struct dasd_device *);
356 
357 	int (*get_uid) (struct dasd_device *, struct dasd_uid *);
358 	void (*kick_validate) (struct dasd_device *);
359 };
360 
361 extern struct dasd_discipline *dasd_diag_discipline_pointer;
362 
363 /*
364  * Notification numbers for extended error reporting notifications:
365  * The DASD_EER_DISABLE notification is sent before a dasd_device (and it's
366  * eer pointer) is freed. The error reporting module needs to do all necessary
367  * cleanup steps.
368  * The DASD_EER_TRIGGER notification sends the actual error reports (triggers).
369  */
370 #define DASD_EER_DISABLE 0
371 #define DASD_EER_TRIGGER 1
372 
373 /* Trigger IDs for extended error reporting DASD_EER_TRIGGER notification */
374 #define DASD_EER_FATALERROR  1
375 #define DASD_EER_NOPATH      2
376 #define DASD_EER_STATECHANGE 3
377 #define DASD_EER_PPRCSUSPEND 4
378 
379 struct dasd_path {
380 	__u8 opm;
381 	__u8 tbvpm;
382 	__u8 ppm;
383 	__u8 npm;
384 };
385 
386 struct dasd_profile_info {
387 	/* legacy part of profile data, as in dasd_profile_info_t */
388 	unsigned int dasd_io_reqs;	 /* number of requests processed */
389 	unsigned int dasd_io_sects;	 /* number of sectors processed */
390 	unsigned int dasd_io_secs[32];	 /* histogram of request's sizes */
391 	unsigned int dasd_io_times[32];	 /* histogram of requests's times */
392 	unsigned int dasd_io_timps[32];	 /* h. of requests's times per sector */
393 	unsigned int dasd_io_time1[32];	 /* hist. of time from build to start */
394 	unsigned int dasd_io_time2[32];	 /* hist. of time from start to irq */
395 	unsigned int dasd_io_time2ps[32]; /* hist. of time from start to irq */
396 	unsigned int dasd_io_time3[32];	 /* hist. of time from irq to end */
397 	unsigned int dasd_io_nr_req[32]; /* hist. of # of requests in chanq */
398 
399 	/* new data */
400 	struct timespec starttod;	   /* time of start or last reset */
401 	unsigned int dasd_io_alias;	   /* requests using an alias */
402 	unsigned int dasd_io_tpm;	   /* requests using transport mode */
403 	unsigned int dasd_read_reqs;	   /* total number of read  requests */
404 	unsigned int dasd_read_sects;	   /* total number read sectors */
405 	unsigned int dasd_read_alias;	   /* read request using an alias */
406 	unsigned int dasd_read_tpm;	   /* read requests in transport mode */
407 	unsigned int dasd_read_secs[32];   /* histogram of request's sizes */
408 	unsigned int dasd_read_times[32];  /* histogram of requests's times */
409 	unsigned int dasd_read_time1[32];  /* hist. time from build to start */
410 	unsigned int dasd_read_time2[32];  /* hist. of time from start to irq */
411 	unsigned int dasd_read_time3[32];  /* hist. of time from irq to end */
412 	unsigned int dasd_read_nr_req[32]; /* hist. of # of requests in chanq */
413 };
414 
415 struct dasd_profile {
416 	struct dentry *dentry;
417 	struct dasd_profile_info *data;
418 	spinlock_t lock;
419 };
420 
421 struct dasd_device {
422 	/* Block device stuff. */
423 	struct dasd_block *block;
424 
425         unsigned int devindex;
426 	unsigned long flags;	   /* per device flags */
427 	unsigned short features;   /* copy of devmap-features (read-only!) */
428 
429 	/* extended error reporting stuff (eer) */
430 	struct dasd_ccw_req *eer_cqr;
431 
432 	/* Device discipline stuff. */
433 	struct dasd_discipline *discipline;
434 	struct dasd_discipline *base_discipline;
435 	char *private;
436 	struct dasd_path path_data;
437 
438 	/* Device state and target state. */
439 	int state, target;
440 	struct mutex state_mutex;
441 	int stopped;		/* device (ccw_device_start) was stopped */
442 
443 	/* reference count. */
444         atomic_t ref_count;
445 
446 	/* ccw queue and memory for static ccw/erp buffers. */
447 	struct list_head ccw_queue;
448 	spinlock_t mem_lock;
449 	void *ccw_mem;
450 	void *erp_mem;
451 	struct list_head ccw_chunks;
452 	struct list_head erp_chunks;
453 
454 	atomic_t tasklet_scheduled;
455         struct tasklet_struct tasklet;
456 	struct work_struct kick_work;
457 	struct work_struct restore_device;
458 	struct work_struct reload_device;
459 	struct work_struct kick_validate;
460 	struct timer_list timer;
461 
462 	debug_info_t *debug_area;
463 
464 	struct ccw_device *cdev;
465 
466 	/* hook for alias management */
467 	struct list_head alias_list;
468 
469 	/* default expiration time in s */
470 	unsigned long default_expires;
471 	unsigned long default_retries;
472 
473 	unsigned long blk_timeout;
474 
475 	struct dentry *debugfs_dentry;
476 	struct dasd_profile profile;
477 };
478 
479 struct dasd_block {
480 	/* Block device stuff. */
481 	struct gendisk *gdp;
482 	struct request_queue *request_queue;
483 	spinlock_t request_queue_lock;
484 	struct block_device *bdev;
485 	atomic_t open_count;
486 
487 	unsigned long long blocks; /* size of volume in blocks */
488 	unsigned int bp_block;	   /* bytes per block */
489 	unsigned int s2b_shift;	   /* log2 (bp_block/512) */
490 
491 	struct dasd_device *base;
492 	struct list_head ccw_queue;
493 	spinlock_t queue_lock;
494 
495 	atomic_t tasklet_scheduled;
496 	struct tasklet_struct tasklet;
497 	struct timer_list timer;
498 
499 	struct dentry *debugfs_dentry;
500 	struct dasd_profile profile;
501 };
502 
503 
504 
505 /* reasons why device (ccw_device_start) was stopped */
506 #define DASD_STOPPED_NOT_ACC 1         /* not accessible */
507 #define DASD_STOPPED_QUIESCE 2         /* Quiesced */
508 #define DASD_STOPPED_PENDING 4         /* long busy */
509 #define DASD_STOPPED_DC_WAIT 8         /* disconnected, wait */
510 #define DASD_STOPPED_SU      16        /* summary unit check handling */
511 #define DASD_STOPPED_PM      32        /* pm state transition */
512 #define DASD_UNRESUMED_PM    64        /* pm resume failed state */
513 
514 /* per device flags */
515 #define DASD_FLAG_OFFLINE	3	/* device is in offline processing */
516 #define DASD_FLAG_EER_SNSS	4	/* A SNSS is required */
517 #define DASD_FLAG_EER_IN_USE	5	/* A SNSS request is running */
518 #define DASD_FLAG_DEVICE_RO	6	/* The device itself is read-only. Don't
519 					 * confuse this with the user specified
520 					 * read-only feature.
521 					 */
522 #define DASD_FLAG_IS_RESERVED	7	/* The device is reserved */
523 #define DASD_FLAG_LOCK_STOLEN	8	/* The device lock was stolen */
524 #define DASD_FLAG_SUSPENDED	9	/* The device was suspended */
525 #define DASD_FLAG_SAFE_OFFLINE	10	/* safe offline processing requested*/
526 #define DASD_FLAG_SAFE_OFFLINE_RUNNING	11	/* safe offline running */
527 #define DASD_FLAG_ABORTALL	12	/* Abort all noretry requests */
528 
529 #define DASD_SLEEPON_START_TAG	((void *) 1)
530 #define DASD_SLEEPON_END_TAG	((void *) 2)
531 
532 void dasd_put_device_wake(struct dasd_device *);
533 
534 /*
535  * Reference count inliners
536  */
537 static inline void
538 dasd_get_device(struct dasd_device *device)
539 {
540 	atomic_inc(&device->ref_count);
541 }
542 
543 static inline void
544 dasd_put_device(struct dasd_device *device)
545 {
546 	if (atomic_dec_return(&device->ref_count) == 0)
547 		dasd_put_device_wake(device);
548 }
549 
550 /*
551  * The static memory in ccw_mem and erp_mem is managed by a sorted
552  * list of free memory chunks.
553  */
554 struct dasd_mchunk
555 {
556 	struct list_head list;
557 	unsigned long size;
558 } __attribute__ ((aligned(8)));
559 
560 static inline void
561 dasd_init_chunklist(struct list_head *chunk_list, void *mem,
562 		    unsigned long size)
563 {
564 	struct dasd_mchunk *chunk;
565 
566 	INIT_LIST_HEAD(chunk_list);
567 	chunk = (struct dasd_mchunk *) mem;
568 	chunk->size = size - sizeof(struct dasd_mchunk);
569 	list_add(&chunk->list, chunk_list);
570 }
571 
572 static inline void *
573 dasd_alloc_chunk(struct list_head *chunk_list, unsigned long size)
574 {
575 	struct dasd_mchunk *chunk, *tmp;
576 
577 	size = (size + 7L) & -8L;
578 	list_for_each_entry(chunk, chunk_list, list) {
579 		if (chunk->size < size)
580 			continue;
581 		if (chunk->size > size + sizeof(struct dasd_mchunk)) {
582 			char *endaddr = (char *) (chunk + 1) + chunk->size;
583 			tmp = (struct dasd_mchunk *) (endaddr - size) - 1;
584 			tmp->size = size;
585 			chunk->size -= size + sizeof(struct dasd_mchunk);
586 			chunk = tmp;
587 		} else
588 			list_del(&chunk->list);
589 		return (void *) (chunk + 1);
590 	}
591 	return NULL;
592 }
593 
594 static inline void
595 dasd_free_chunk(struct list_head *chunk_list, void *mem)
596 {
597 	struct dasd_mchunk *chunk, *tmp;
598 	struct list_head *p, *left;
599 
600 	chunk = (struct dasd_mchunk *)
601 		((char *) mem - sizeof(struct dasd_mchunk));
602 	/* Find out the left neighbour in chunk_list. */
603 	left = chunk_list;
604 	list_for_each(p, chunk_list) {
605 		if (list_entry(p, struct dasd_mchunk, list) > chunk)
606 			break;
607 		left = p;
608 	}
609 	/* Try to merge with right neighbour = next element from left. */
610 	if (left->next != chunk_list) {
611 		tmp = list_entry(left->next, struct dasd_mchunk, list);
612 		if ((char *) (chunk + 1) + chunk->size == (char *) tmp) {
613 			list_del(&tmp->list);
614 			chunk->size += tmp->size + sizeof(struct dasd_mchunk);
615 		}
616 	}
617 	/* Try to merge with left neighbour. */
618 	if (left != chunk_list) {
619 		tmp = list_entry(left, struct dasd_mchunk, list);
620 		if ((char *) (tmp + 1) + tmp->size == (char *) chunk) {
621 			tmp->size += chunk->size + sizeof(struct dasd_mchunk);
622 			return;
623 		}
624 	}
625 	__list_add(&chunk->list, left, left->next);
626 }
627 
628 /*
629  * Check if bsize is in { 512, 1024, 2048, 4096 }
630  */
631 static inline int
632 dasd_check_blocksize(int bsize)
633 {
634 	if (bsize < 512 || bsize > 4096 || !is_power_of_2(bsize))
635 		return -EMEDIUMTYPE;
636 	return 0;
637 }
638 
639 /* externals in dasd.c */
640 #define DASD_PROFILE_OFF	 0
641 #define DASD_PROFILE_ON 	 1
642 #define DASD_PROFILE_GLOBAL_ONLY 2
643 
644 extern debug_info_t *dasd_debug_area;
645 extern struct dasd_profile_info dasd_global_profile_data;
646 extern unsigned int dasd_global_profile_level;
647 extern const struct block_device_operations dasd_device_operations;
648 
649 extern struct kmem_cache *dasd_page_cache;
650 
651 struct dasd_ccw_req *
652 dasd_kmalloc_request(int , int, int, struct dasd_device *);
653 struct dasd_ccw_req *
654 dasd_smalloc_request(int , int, int, struct dasd_device *);
655 void dasd_kfree_request(struct dasd_ccw_req *, struct dasd_device *);
656 void dasd_sfree_request(struct dasd_ccw_req *, struct dasd_device *);
657 void dasd_wakeup_cb(struct dasd_ccw_req *, void *);
658 
659 static inline int
660 dasd_kmalloc_set_cda(struct ccw1 *ccw, void *cda, struct dasd_device *device)
661 {
662 	return set_normalized_cda(ccw, cda);
663 }
664 
665 struct dasd_device *dasd_alloc_device(void);
666 void dasd_free_device(struct dasd_device *);
667 
668 struct dasd_block *dasd_alloc_block(void);
669 void dasd_free_block(struct dasd_block *);
670 
671 enum blk_eh_timer_return dasd_times_out(struct request *req);
672 
673 void dasd_enable_device(struct dasd_device *);
674 void dasd_set_target_state(struct dasd_device *, int);
675 void dasd_kick_device(struct dasd_device *);
676 void dasd_restore_device(struct dasd_device *);
677 void dasd_reload_device(struct dasd_device *);
678 
679 void dasd_add_request_head(struct dasd_ccw_req *);
680 void dasd_add_request_tail(struct dasd_ccw_req *);
681 int  dasd_start_IO(struct dasd_ccw_req *);
682 int  dasd_term_IO(struct dasd_ccw_req *);
683 void dasd_schedule_device_bh(struct dasd_device *);
684 void dasd_schedule_block_bh(struct dasd_block *);
685 int  dasd_sleep_on(struct dasd_ccw_req *);
686 int  dasd_sleep_on_queue(struct list_head *);
687 int  dasd_sleep_on_immediatly(struct dasd_ccw_req *);
688 int  dasd_sleep_on_interruptible(struct dasd_ccw_req *);
689 void dasd_device_set_timer(struct dasd_device *, int);
690 void dasd_device_clear_timer(struct dasd_device *);
691 void dasd_block_set_timer(struct dasd_block *, int);
692 void dasd_block_clear_timer(struct dasd_block *);
693 int  dasd_cancel_req(struct dasd_ccw_req *);
694 int dasd_flush_device_queue(struct dasd_device *);
695 int dasd_generic_probe (struct ccw_device *, struct dasd_discipline *);
696 void dasd_generic_remove (struct ccw_device *cdev);
697 int dasd_generic_set_online(struct ccw_device *, struct dasd_discipline *);
698 int dasd_generic_set_offline (struct ccw_device *cdev);
699 int dasd_generic_notify(struct ccw_device *, int);
700 int dasd_generic_last_path_gone(struct dasd_device *);
701 int dasd_generic_path_operational(struct dasd_device *);
702 void dasd_generic_shutdown(struct ccw_device *);
703 
704 void dasd_generic_handle_state_change(struct dasd_device *);
705 int dasd_generic_pm_freeze(struct ccw_device *);
706 int dasd_generic_restore_device(struct ccw_device *);
707 enum uc_todo dasd_generic_uc_handler(struct ccw_device *, struct irb *);
708 void dasd_generic_path_event(struct ccw_device *, int *);
709 int dasd_generic_verify_path(struct dasd_device *, __u8);
710 
711 int dasd_generic_read_dev_chars(struct dasd_device *, int, void *, int);
712 char *dasd_get_sense(struct irb *);
713 
714 void dasd_device_set_stop_bits(struct dasd_device *, int);
715 void dasd_device_remove_stop_bits(struct dasd_device *, int);
716 
717 int dasd_device_is_ro(struct dasd_device *);
718 
719 void dasd_profile_reset(struct dasd_profile *);
720 int dasd_profile_on(struct dasd_profile *);
721 void dasd_profile_off(struct dasd_profile *);
722 void dasd_global_profile_reset(void);
723 char *dasd_get_user_string(const char __user *, size_t);
724 
725 /* externals in dasd_devmap.c */
726 extern int dasd_max_devindex;
727 extern int dasd_probeonly;
728 extern int dasd_autodetect;
729 extern int dasd_nopav;
730 extern int dasd_nofcx;
731 
732 int dasd_devmap_init(void);
733 void dasd_devmap_exit(void);
734 
735 struct dasd_device *dasd_create_device(struct ccw_device *);
736 void dasd_delete_device(struct dasd_device *);
737 
738 int dasd_get_feature(struct ccw_device *, int);
739 int dasd_set_feature(struct ccw_device *, int, int);
740 
741 int dasd_add_sysfs_files(struct ccw_device *);
742 void dasd_remove_sysfs_files(struct ccw_device *);
743 
744 struct dasd_device *dasd_device_from_cdev(struct ccw_device *);
745 struct dasd_device *dasd_device_from_cdev_locked(struct ccw_device *);
746 struct dasd_device *dasd_device_from_devindex(int);
747 
748 void dasd_add_link_to_gendisk(struct gendisk *, struct dasd_device *);
749 struct dasd_device *dasd_device_from_gendisk(struct gendisk *);
750 
751 int dasd_parse(void);
752 int dasd_busid_known(const char *);
753 
754 /* externals in dasd_gendisk.c */
755 int  dasd_gendisk_init(void);
756 void dasd_gendisk_exit(void);
757 int dasd_gendisk_alloc(struct dasd_block *);
758 void dasd_gendisk_free(struct dasd_block *);
759 int dasd_scan_partitions(struct dasd_block *);
760 void dasd_destroy_partitions(struct dasd_block *);
761 
762 /* externals in dasd_ioctl.c */
763 int  dasd_ioctl(struct block_device *, fmode_t, unsigned int, unsigned long);
764 
765 /* externals in dasd_proc.c */
766 int dasd_proc_init(void);
767 void dasd_proc_exit(void);
768 
769 /* externals in dasd_erp.c */
770 struct dasd_ccw_req *dasd_default_erp_action(struct dasd_ccw_req *);
771 struct dasd_ccw_req *dasd_default_erp_postaction(struct dasd_ccw_req *);
772 struct dasd_ccw_req *dasd_alloc_erp_request(char *, int, int,
773 					    struct dasd_device *);
774 void dasd_free_erp_request(struct dasd_ccw_req *, struct dasd_device *);
775 void dasd_log_sense(struct dasd_ccw_req *, struct irb *);
776 void dasd_log_sense_dbf(struct dasd_ccw_req *cqr, struct irb *irb);
777 
778 /* externals in dasd_3990_erp.c */
779 struct dasd_ccw_req *dasd_3990_erp_action(struct dasd_ccw_req *);
780 void dasd_3990_erp_handle_sim(struct dasd_device *, char *);
781 
782 /* externals in dasd_eer.c */
783 #ifdef CONFIG_DASD_EER
784 int dasd_eer_init(void);
785 void dasd_eer_exit(void);
786 int dasd_eer_enable(struct dasd_device *);
787 void dasd_eer_disable(struct dasd_device *);
788 void dasd_eer_write(struct dasd_device *, struct dasd_ccw_req *cqr,
789 		    unsigned int id);
790 void dasd_eer_snss(struct dasd_device *);
791 
792 static inline int dasd_eer_enabled(struct dasd_device *device)
793 {
794 	return device->eer_cqr != NULL;
795 }
796 #else
797 #define dasd_eer_init()		(0)
798 #define dasd_eer_exit()		do { } while (0)
799 #define dasd_eer_enable(d)	(0)
800 #define dasd_eer_disable(d)	do { } while (0)
801 #define dasd_eer_write(d,c,i)	do { } while (0)
802 #define dasd_eer_snss(d)	do { } while (0)
803 #define dasd_eer_enabled(d)	(0)
804 #endif	/* CONFIG_DASD_ERR */
805 
806 #endif				/* DASD_H */
807