xref: /openbmc/linux/drivers/s390/block/dasd_int.h (revision 275876e2)
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 	struct dasd_device *basedev;	/* base device if no block->base */
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 #define DASD_RETRIES	  256
229 #define DASD_RETRIES_MAX  32768
230 
231 /* per dasd_ccw_req flags */
232 #define DASD_CQR_FLAGS_USE_ERP   0	/* use ERP for this request */
233 #define DASD_CQR_FLAGS_FAILFAST  1	/* FAILFAST */
234 #define DASD_CQR_VERIFY_PATH	 2	/* path verification request */
235 #define DASD_CQR_ALLOW_SLOCK	 3	/* Try this request even when lock was
236 					 * stolen. Should not be combined with
237 					 * DASD_CQR_FLAGS_USE_ERP
238 					 */
239 
240 /* Signature for error recovery functions. */
241 typedef struct dasd_ccw_req *(*dasd_erp_fn_t) (struct dasd_ccw_req *);
242 
243 /*
244  * Unique identifier for dasd device.
245  */
246 #define UA_NOT_CONFIGURED  0x00
247 #define UA_BASE_DEVICE	   0x01
248 #define UA_BASE_PAV_ALIAS  0x02
249 #define UA_HYPER_PAV_ALIAS 0x03
250 
251 struct dasd_uid {
252 	__u8 type;
253 	char vendor[4];
254 	char serial[15];
255 	__u16 ssid;
256 	__u8 real_unit_addr;
257 	__u8 base_unit_addr;
258 	char vduit[33];
259 };
260 
261 /*
262  * the struct dasd_discipline is
263  * sth like a table of virtual functions, if you think of dasd_eckd
264  * inheriting dasd...
265  * no, currently we are not planning to reimplement the driver in C++
266  */
267 struct dasd_discipline {
268 	struct module *owner;
269 	char ebcname[8];	/* a name used for tagging and printks */
270 	char name[8];		/* a name used for tagging and printks */
271 	int max_blocks;		/* maximum number of blocks to be chained */
272 
273 	struct list_head list;	/* used for list of disciplines */
274 
275 	/*
276 	 * Device recognition functions. check_device is used to verify
277 	 * the sense data and the information returned by read device
278 	 * characteristics. It returns 0 if the discipline can be used
279 	 * for the device in question. uncheck_device is called during
280 	 * device shutdown to deregister a device from its discipline.
281 	 */
282 	int (*check_device) (struct dasd_device *);
283 	void (*uncheck_device) (struct dasd_device *);
284 
285 	/*
286 	 * do_analysis is used in the step from device state "basic" to
287 	 * state "accept". It returns 0 if the device can be made ready,
288 	 * it returns -EMEDIUMTYPE if the device can't be made ready or
289 	 * -EAGAIN if do_analysis started a ccw that needs to complete
290 	 * before the analysis may be repeated.
291 	 */
292 	int (*do_analysis) (struct dasd_block *);
293 
294 	/*
295 	 * This function is called, when new paths become available.
296 	 * Disciplins may use this callback to do necessary setup work,
297 	 * e.g. verify that new path is compatible with the current
298 	 * configuration.
299 	 */
300 	int (*verify_path)(struct dasd_device *, __u8);
301 
302 	/*
303 	 * Last things to do when a device is set online, and first things
304 	 * when it is set offline.
305 	 */
306 	int (*basic_to_ready) (struct dasd_device *);
307 	int (*online_to_ready) (struct dasd_device *);
308 	int (*basic_to_known)(struct dasd_device *);
309 
310 	/* (struct dasd_device *);
311 	 * Device operation functions. build_cp creates a ccw chain for
312 	 * a block device request, start_io starts the request and
313 	 * term_IO cancels it (e.g. in case of a timeout). format_device
314 	 * returns a ccw chain to be used to format the device.
315 	 * handle_terminated_request allows to examine a cqr and prepare
316 	 * it for retry.
317 	 */
318 	struct dasd_ccw_req *(*build_cp) (struct dasd_device *,
319 					  struct dasd_block *,
320 					  struct request *);
321 	int (*start_IO) (struct dasd_ccw_req *);
322 	int (*term_IO) (struct dasd_ccw_req *);
323 	void (*handle_terminated_request) (struct dasd_ccw_req *);
324 	int (*format_device) (struct dasd_device *,
325 			      struct format_data_t *, int enable_pav);
326 	int (*free_cp) (struct dasd_ccw_req *, struct request *);
327 
328 	/*
329 	 * Error recovery functions. examine_error() returns a value that
330 	 * indicates what to do for an error condition. If examine_error()
331 	 * returns 'dasd_era_recover' erp_action() is called to create a
332 	 * special error recovery ccw. erp_postaction() is called after
333 	 * an error recovery ccw has finished its execution. dump_sense
334 	 * is called for every error condition to print the sense data
335 	 * to the console.
336 	 */
337 	dasd_erp_fn_t(*erp_action) (struct dasd_ccw_req *);
338 	dasd_erp_fn_t(*erp_postaction) (struct dasd_ccw_req *);
339 	void (*dump_sense) (struct dasd_device *, struct dasd_ccw_req *,
340 			    struct irb *);
341 	void (*dump_sense_dbf) (struct dasd_device *, struct irb *, char *);
342 	void (*check_for_device_change) (struct dasd_device *,
343 					 struct dasd_ccw_req *,
344 					 struct irb *);
345 
346         /* i/o control functions. */
347 	int (*fill_geometry) (struct dasd_block *, struct hd_geometry *);
348 	int (*fill_info) (struct dasd_device *, struct dasd_information2_t *);
349 	int (*ioctl) (struct dasd_block *, unsigned int, void __user *);
350 
351 	/* suspend/resume functions */
352 	int (*freeze) (struct dasd_device *);
353 	int (*restore) (struct dasd_device *);
354 
355 	/* reload device after state change */
356 	int (*reload) (struct dasd_device *);
357 
358 	int (*get_uid) (struct dasd_device *, struct dasd_uid *);
359 	void (*kick_validate) (struct dasd_device *);
360 };
361 
362 extern struct dasd_discipline *dasd_diag_discipline_pointer;
363 
364 /*
365  * Notification numbers for extended error reporting notifications:
366  * The DASD_EER_DISABLE notification is sent before a dasd_device (and it's
367  * eer pointer) is freed. The error reporting module needs to do all necessary
368  * cleanup steps.
369  * The DASD_EER_TRIGGER notification sends the actual error reports (triggers).
370  */
371 #define DASD_EER_DISABLE 0
372 #define DASD_EER_TRIGGER 1
373 
374 /* Trigger IDs for extended error reporting DASD_EER_TRIGGER notification */
375 #define DASD_EER_FATALERROR  1
376 #define DASD_EER_NOPATH      2
377 #define DASD_EER_STATECHANGE 3
378 #define DASD_EER_PPRCSUSPEND 4
379 
380 struct dasd_path {
381 	__u8 opm;
382 	__u8 tbvpm;
383 	__u8 ppm;
384 	__u8 npm;
385 };
386 
387 struct dasd_profile_info {
388 	/* legacy part of profile data, as in dasd_profile_info_t */
389 	unsigned int dasd_io_reqs;	 /* number of requests processed */
390 	unsigned int dasd_io_sects;	 /* number of sectors processed */
391 	unsigned int dasd_io_secs[32];	 /* histogram of request's sizes */
392 	unsigned int dasd_io_times[32];	 /* histogram of requests's times */
393 	unsigned int dasd_io_timps[32];	 /* h. of requests's times per sector */
394 	unsigned int dasd_io_time1[32];	 /* hist. of time from build to start */
395 	unsigned int dasd_io_time2[32];	 /* hist. of time from start to irq */
396 	unsigned int dasd_io_time2ps[32]; /* hist. of time from start to irq */
397 	unsigned int dasd_io_time3[32];	 /* hist. of time from irq to end */
398 	unsigned int dasd_io_nr_req[32]; /* hist. of # of requests in chanq */
399 
400 	/* new data */
401 	struct timespec starttod;	   /* time of start or last reset */
402 	unsigned int dasd_io_alias;	   /* requests using an alias */
403 	unsigned int dasd_io_tpm;	   /* requests using transport mode */
404 	unsigned int dasd_read_reqs;	   /* total number of read  requests */
405 	unsigned int dasd_read_sects;	   /* total number read sectors */
406 	unsigned int dasd_read_alias;	   /* read request using an alias */
407 	unsigned int dasd_read_tpm;	   /* read requests in transport mode */
408 	unsigned int dasd_read_secs[32];   /* histogram of request's sizes */
409 	unsigned int dasd_read_times[32];  /* histogram of requests's times */
410 	unsigned int dasd_read_time1[32];  /* hist. time from build to start */
411 	unsigned int dasd_read_time2[32];  /* hist. of time from start to irq */
412 	unsigned int dasd_read_time3[32];  /* hist. of time from irq to end */
413 	unsigned int dasd_read_nr_req[32]; /* hist. of # of requests in chanq */
414 };
415 
416 struct dasd_profile {
417 	struct dentry *dentry;
418 	struct dasd_profile_info *data;
419 	spinlock_t lock;
420 };
421 
422 struct dasd_device {
423 	/* Block device stuff. */
424 	struct dasd_block *block;
425 
426         unsigned int devindex;
427 	unsigned long flags;	   /* per device flags */
428 	unsigned short features;   /* copy of devmap-features (read-only!) */
429 
430 	/* extended error reporting stuff (eer) */
431 	struct dasd_ccw_req *eer_cqr;
432 
433 	/* Device discipline stuff. */
434 	struct dasd_discipline *discipline;
435 	struct dasd_discipline *base_discipline;
436 	char *private;
437 	struct dasd_path path_data;
438 
439 	/* Device state and target state. */
440 	int state, target;
441 	struct mutex state_mutex;
442 	int stopped;		/* device (ccw_device_start) was stopped */
443 
444 	/* reference count. */
445         atomic_t ref_count;
446 
447 	/* ccw queue and memory for static ccw/erp buffers. */
448 	struct list_head ccw_queue;
449 	spinlock_t mem_lock;
450 	void *ccw_mem;
451 	void *erp_mem;
452 	struct list_head ccw_chunks;
453 	struct list_head erp_chunks;
454 
455 	atomic_t tasklet_scheduled;
456         struct tasklet_struct tasklet;
457 	struct work_struct kick_work;
458 	struct work_struct restore_device;
459 	struct work_struct reload_device;
460 	struct work_struct kick_validate;
461 	struct timer_list timer;
462 
463 	debug_info_t *debug_area;
464 
465 	struct ccw_device *cdev;
466 
467 	/* hook for alias management */
468 	struct list_head alias_list;
469 
470 	/* default expiration time in s */
471 	unsigned long default_expires;
472 	unsigned long default_retries;
473 
474 	unsigned long blk_timeout;
475 
476 	struct dentry *debugfs_dentry;
477 	struct dasd_profile profile;
478 };
479 
480 struct dasd_block {
481 	/* Block device stuff. */
482 	struct gendisk *gdp;
483 	struct request_queue *request_queue;
484 	spinlock_t request_queue_lock;
485 	struct block_device *bdev;
486 	atomic_t open_count;
487 
488 	unsigned long long blocks; /* size of volume in blocks */
489 	unsigned int bp_block;	   /* bytes per block */
490 	unsigned int s2b_shift;	   /* log2 (bp_block/512) */
491 
492 	struct dasd_device *base;
493 	struct list_head ccw_queue;
494 	spinlock_t queue_lock;
495 
496 	atomic_t tasklet_scheduled;
497 	struct tasklet_struct tasklet;
498 	struct timer_list timer;
499 
500 	struct dentry *debugfs_dentry;
501 	struct dasd_profile profile;
502 };
503 
504 
505 
506 /* reasons why device (ccw_device_start) was stopped */
507 #define DASD_STOPPED_NOT_ACC 1         /* not accessible */
508 #define DASD_STOPPED_QUIESCE 2         /* Quiesced */
509 #define DASD_STOPPED_PENDING 4         /* long busy */
510 #define DASD_STOPPED_DC_WAIT 8         /* disconnected, wait */
511 #define DASD_STOPPED_SU      16        /* summary unit check handling */
512 #define DASD_STOPPED_PM      32        /* pm state transition */
513 #define DASD_UNRESUMED_PM    64        /* pm resume failed state */
514 
515 /* per device flags */
516 #define DASD_FLAG_OFFLINE	3	/* device is in offline processing */
517 #define DASD_FLAG_EER_SNSS	4	/* A SNSS is required */
518 #define DASD_FLAG_EER_IN_USE	5	/* A SNSS request is running */
519 #define DASD_FLAG_DEVICE_RO	6	/* The device itself is read-only. Don't
520 					 * confuse this with the user specified
521 					 * read-only feature.
522 					 */
523 #define DASD_FLAG_IS_RESERVED	7	/* The device is reserved */
524 #define DASD_FLAG_LOCK_STOLEN	8	/* The device lock was stolen */
525 #define DASD_FLAG_SUSPENDED	9	/* The device was suspended */
526 #define DASD_FLAG_SAFE_OFFLINE	10	/* safe offline processing requested*/
527 #define DASD_FLAG_SAFE_OFFLINE_RUNNING	11	/* safe offline running */
528 #define DASD_FLAG_ABORTALL	12	/* Abort all noretry requests */
529 
530 #define DASD_SLEEPON_START_TAG	((void *) 1)
531 #define DASD_SLEEPON_END_TAG	((void *) 2)
532 
533 void dasd_put_device_wake(struct dasd_device *);
534 
535 /*
536  * Reference count inliners
537  */
538 static inline void
539 dasd_get_device(struct dasd_device *device)
540 {
541 	atomic_inc(&device->ref_count);
542 }
543 
544 static inline void
545 dasd_put_device(struct dasd_device *device)
546 {
547 	if (atomic_dec_return(&device->ref_count) == 0)
548 		dasd_put_device_wake(device);
549 }
550 
551 /*
552  * The static memory in ccw_mem and erp_mem is managed by a sorted
553  * list of free memory chunks.
554  */
555 struct dasd_mchunk
556 {
557 	struct list_head list;
558 	unsigned long size;
559 } __attribute__ ((aligned(8)));
560 
561 static inline void
562 dasd_init_chunklist(struct list_head *chunk_list, void *mem,
563 		    unsigned long size)
564 {
565 	struct dasd_mchunk *chunk;
566 
567 	INIT_LIST_HEAD(chunk_list);
568 	chunk = (struct dasd_mchunk *) mem;
569 	chunk->size = size - sizeof(struct dasd_mchunk);
570 	list_add(&chunk->list, chunk_list);
571 }
572 
573 static inline void *
574 dasd_alloc_chunk(struct list_head *chunk_list, unsigned long size)
575 {
576 	struct dasd_mchunk *chunk, *tmp;
577 
578 	size = (size + 7L) & -8L;
579 	list_for_each_entry(chunk, chunk_list, list) {
580 		if (chunk->size < size)
581 			continue;
582 		if (chunk->size > size + sizeof(struct dasd_mchunk)) {
583 			char *endaddr = (char *) (chunk + 1) + chunk->size;
584 			tmp = (struct dasd_mchunk *) (endaddr - size) - 1;
585 			tmp->size = size;
586 			chunk->size -= size + sizeof(struct dasd_mchunk);
587 			chunk = tmp;
588 		} else
589 			list_del(&chunk->list);
590 		return (void *) (chunk + 1);
591 	}
592 	return NULL;
593 }
594 
595 static inline void
596 dasd_free_chunk(struct list_head *chunk_list, void *mem)
597 {
598 	struct dasd_mchunk *chunk, *tmp;
599 	struct list_head *p, *left;
600 
601 	chunk = (struct dasd_mchunk *)
602 		((char *) mem - sizeof(struct dasd_mchunk));
603 	/* Find out the left neighbour in chunk_list. */
604 	left = chunk_list;
605 	list_for_each(p, chunk_list) {
606 		if (list_entry(p, struct dasd_mchunk, list) > chunk)
607 			break;
608 		left = p;
609 	}
610 	/* Try to merge with right neighbour = next element from left. */
611 	if (left->next != chunk_list) {
612 		tmp = list_entry(left->next, struct dasd_mchunk, list);
613 		if ((char *) (chunk + 1) + chunk->size == (char *) tmp) {
614 			list_del(&tmp->list);
615 			chunk->size += tmp->size + sizeof(struct dasd_mchunk);
616 		}
617 	}
618 	/* Try to merge with left neighbour. */
619 	if (left != chunk_list) {
620 		tmp = list_entry(left, struct dasd_mchunk, list);
621 		if ((char *) (tmp + 1) + tmp->size == (char *) chunk) {
622 			tmp->size += chunk->size + sizeof(struct dasd_mchunk);
623 			return;
624 		}
625 	}
626 	__list_add(&chunk->list, left, left->next);
627 }
628 
629 /*
630  * Check if bsize is in { 512, 1024, 2048, 4096 }
631  */
632 static inline int
633 dasd_check_blocksize(int bsize)
634 {
635 	if (bsize < 512 || bsize > 4096 || !is_power_of_2(bsize))
636 		return -EMEDIUMTYPE;
637 	return 0;
638 }
639 
640 /* externals in dasd.c */
641 #define DASD_PROFILE_OFF	 0
642 #define DASD_PROFILE_ON 	 1
643 #define DASD_PROFILE_GLOBAL_ONLY 2
644 
645 extern debug_info_t *dasd_debug_area;
646 extern struct dasd_profile_info dasd_global_profile_data;
647 extern unsigned int dasd_global_profile_level;
648 extern const struct block_device_operations dasd_device_operations;
649 
650 extern struct kmem_cache *dasd_page_cache;
651 
652 struct dasd_ccw_req *
653 dasd_kmalloc_request(int , int, int, struct dasd_device *);
654 struct dasd_ccw_req *
655 dasd_smalloc_request(int , int, int, struct dasd_device *);
656 void dasd_kfree_request(struct dasd_ccw_req *, struct dasd_device *);
657 void dasd_sfree_request(struct dasd_ccw_req *, struct dasd_device *);
658 void dasd_wakeup_cb(struct dasd_ccw_req *, void *);
659 
660 static inline int
661 dasd_kmalloc_set_cda(struct ccw1 *ccw, void *cda, struct dasd_device *device)
662 {
663 	return set_normalized_cda(ccw, cda);
664 }
665 
666 struct dasd_device *dasd_alloc_device(void);
667 void dasd_free_device(struct dasd_device *);
668 
669 struct dasd_block *dasd_alloc_block(void);
670 void dasd_free_block(struct dasd_block *);
671 
672 enum blk_eh_timer_return dasd_times_out(struct request *req);
673 
674 void dasd_enable_device(struct dasd_device *);
675 void dasd_set_target_state(struct dasd_device *, int);
676 void dasd_kick_device(struct dasd_device *);
677 void dasd_restore_device(struct dasd_device *);
678 void dasd_reload_device(struct dasd_device *);
679 
680 void dasd_add_request_head(struct dasd_ccw_req *);
681 void dasd_add_request_tail(struct dasd_ccw_req *);
682 int  dasd_start_IO(struct dasd_ccw_req *);
683 int  dasd_term_IO(struct dasd_ccw_req *);
684 void dasd_schedule_device_bh(struct dasd_device *);
685 void dasd_schedule_block_bh(struct dasd_block *);
686 int  dasd_sleep_on(struct dasd_ccw_req *);
687 int  dasd_sleep_on_queue(struct list_head *);
688 int  dasd_sleep_on_immediatly(struct dasd_ccw_req *);
689 int  dasd_sleep_on_interruptible(struct dasd_ccw_req *);
690 void dasd_device_set_timer(struct dasd_device *, int);
691 void dasd_device_clear_timer(struct dasd_device *);
692 void dasd_block_set_timer(struct dasd_block *, int);
693 void dasd_block_clear_timer(struct dasd_block *);
694 int  dasd_cancel_req(struct dasd_ccw_req *);
695 int dasd_flush_device_queue(struct dasd_device *);
696 int dasd_generic_probe (struct ccw_device *, struct dasd_discipline *);
697 void dasd_generic_remove (struct ccw_device *cdev);
698 int dasd_generic_set_online(struct ccw_device *, struct dasd_discipline *);
699 int dasd_generic_set_offline (struct ccw_device *cdev);
700 int dasd_generic_notify(struct ccw_device *, int);
701 int dasd_generic_last_path_gone(struct dasd_device *);
702 int dasd_generic_path_operational(struct dasd_device *);
703 void dasd_generic_shutdown(struct ccw_device *);
704 
705 void dasd_generic_handle_state_change(struct dasd_device *);
706 int dasd_generic_pm_freeze(struct ccw_device *);
707 int dasd_generic_restore_device(struct ccw_device *);
708 enum uc_todo dasd_generic_uc_handler(struct ccw_device *, struct irb *);
709 void dasd_generic_path_event(struct ccw_device *, int *);
710 int dasd_generic_verify_path(struct dasd_device *, __u8);
711 
712 int dasd_generic_read_dev_chars(struct dasd_device *, int, void *, int);
713 char *dasd_get_sense(struct irb *);
714 
715 void dasd_device_set_stop_bits(struct dasd_device *, int);
716 void dasd_device_remove_stop_bits(struct dasd_device *, int);
717 
718 int dasd_device_is_ro(struct dasd_device *);
719 
720 void dasd_profile_reset(struct dasd_profile *);
721 int dasd_profile_on(struct dasd_profile *);
722 void dasd_profile_off(struct dasd_profile *);
723 void dasd_global_profile_reset(void);
724 char *dasd_get_user_string(const char __user *, size_t);
725 
726 /* externals in dasd_devmap.c */
727 extern int dasd_max_devindex;
728 extern int dasd_probeonly;
729 extern int dasd_autodetect;
730 extern int dasd_nopav;
731 extern int dasd_nofcx;
732 
733 int dasd_devmap_init(void);
734 void dasd_devmap_exit(void);
735 
736 struct dasd_device *dasd_create_device(struct ccw_device *);
737 void dasd_delete_device(struct dasd_device *);
738 
739 int dasd_get_feature(struct ccw_device *, int);
740 int dasd_set_feature(struct ccw_device *, int, int);
741 
742 int dasd_add_sysfs_files(struct ccw_device *);
743 void dasd_remove_sysfs_files(struct ccw_device *);
744 
745 struct dasd_device *dasd_device_from_cdev(struct ccw_device *);
746 struct dasd_device *dasd_device_from_cdev_locked(struct ccw_device *);
747 struct dasd_device *dasd_device_from_devindex(int);
748 
749 void dasd_add_link_to_gendisk(struct gendisk *, struct dasd_device *);
750 struct dasd_device *dasd_device_from_gendisk(struct gendisk *);
751 
752 int dasd_parse(void);
753 int dasd_busid_known(const char *);
754 
755 /* externals in dasd_gendisk.c */
756 int  dasd_gendisk_init(void);
757 void dasd_gendisk_exit(void);
758 int dasd_gendisk_alloc(struct dasd_block *);
759 void dasd_gendisk_free(struct dasd_block *);
760 int dasd_scan_partitions(struct dasd_block *);
761 void dasd_destroy_partitions(struct dasd_block *);
762 
763 /* externals in dasd_ioctl.c */
764 int  dasd_ioctl(struct block_device *, fmode_t, unsigned int, unsigned long);
765 
766 /* externals in dasd_proc.c */
767 int dasd_proc_init(void);
768 void dasd_proc_exit(void);
769 
770 /* externals in dasd_erp.c */
771 struct dasd_ccw_req *dasd_default_erp_action(struct dasd_ccw_req *);
772 struct dasd_ccw_req *dasd_default_erp_postaction(struct dasd_ccw_req *);
773 struct dasd_ccw_req *dasd_alloc_erp_request(char *, int, int,
774 					    struct dasd_device *);
775 void dasd_free_erp_request(struct dasd_ccw_req *, struct dasd_device *);
776 void dasd_log_sense(struct dasd_ccw_req *, struct irb *);
777 void dasd_log_sense_dbf(struct dasd_ccw_req *cqr, struct irb *irb);
778 
779 /* externals in dasd_3990_erp.c */
780 struct dasd_ccw_req *dasd_3990_erp_action(struct dasd_ccw_req *);
781 void dasd_3990_erp_handle_sim(struct dasd_device *, char *);
782 
783 /* externals in dasd_eer.c */
784 #ifdef CONFIG_DASD_EER
785 int dasd_eer_init(void);
786 void dasd_eer_exit(void);
787 int dasd_eer_enable(struct dasd_device *);
788 void dasd_eer_disable(struct dasd_device *);
789 void dasd_eer_write(struct dasd_device *, struct dasd_ccw_req *cqr,
790 		    unsigned int id);
791 void dasd_eer_snss(struct dasd_device *);
792 
793 static inline int dasd_eer_enabled(struct dasd_device *device)
794 {
795 	return device->eer_cqr != NULL;
796 }
797 #else
798 #define dasd_eer_init()		(0)
799 #define dasd_eer_exit()		do { } while (0)
800 #define dasd_eer_enable(d)	(0)
801 #define dasd_eer_disable(d)	do { } while (0)
802 #define dasd_eer_write(d,c,i)	do { } while (0)
803 #define dasd_eer_snss(d)	do { } while (0)
804 #define dasd_eer_enabled(d)	(0)
805 #endif	/* CONFIG_DASD_ERR */
806 
807 #endif				/* DASD_H */
808