xref: /titanic_50/usr/src/uts/common/sys/mdi_impldefs.h (revision 60c807700988885656502665e0cf8afd4b4346f7)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #ifndef	_SYS_MDI_IMPLDEFS_H
27 #define	_SYS_MDI_IMPLDEFS_H
28 
29 #pragma ident	"%Z%%M%	%I%	%E% SMI"
30 
31 #include <sys/note.h>
32 #include <sys/types.h>
33 #include <sys/sunmdi.h>
34 #include <sys/modhash.h>
35 #include <sys/callb.h>
36 
37 #ifdef	__cplusplus
38 extern "C" {
39 #endif
40 
41 #ifdef _KERNEL
42 
43 /*
44  * Multipath Driver Interfaces
45  *
46  * The multipathing framework is provided in two modules.  The 'mpxio' misc.
47  * module provides the core multipath framework and the 'scsi_vhci' nexus
48  * driver provides the SCSI-III command set driver functionality for
49  * managing Fibre-Channel storage devices.
50  *
51  * As in any multipathing solution there are three major problems to solve:
52  *
53  * 1) Identification and enumeration of multipath client devices.
54  * 2) Optimal path selection when routing I/O requests.
55  * 3) Observability interfaces to snapshot the multipath configuration,
56  *    and infrastructure to provide performance and error statistics.
57  *
58  * The mpxio framework consists of several major components:
59  *
60  * 1) The MDI is the Multiplexed Device Interface; this is the core glue which
61  *    holds the following components together.
62  * 2) vHCI (Virtual Host Controller Interconnect) drivers provide multipathing
63  *    services for a given bus technology (example: 'scsi_vhci' provides
64  *    multipathing support for SCSI-III fibre-channel devices).
65  * 3) pHCI (Physical Host Controller Interconnect) drivers provide transport
66  *    services for a given host controller (example: 'fcp' provides transport
67  *    for fibre-channel devices).
68  * 4) Client Devices are standard Solaris target (or leaf) drivers
69  *    (example: 'ssd' is the standard disk driver for fibre-channel arrays).
70  * 5) Multipath information nodes ('pathinfo' nodes) connect client device
71  *    nodes and pHCI device nodes in the device tree.
72  *
73  * With the scsi_vhci, a QLC card, and mpxio enabled, the device tree might
74  * look like this:
75  *
76  *	+-----------+   +-----------+
77  *      | scsi_vhci |   |  pci@1f,0 |
78  *      +-----------+   +-----------+
79  *         /     \               \
80  * +----------+ +-----------+    +-------------+
81  * | ssd1     | | ssd2	    |    | qlc@0,0     |
82  * +----------+ +-----------+    +-------------+
83  *   |          |                  /        \
84  *   |          |        +-------------+   +------------+
85  *   |          |        | pHCI 1      |   |  pHCI 2    |
86  *   |          |        +-------------+   +------------+
87  *   |          |          /        |      /          |
88  *   |          |    +------+       |    +------+     |
89  *   |          |    |  ssd |       |    |  ssd |     |
90  *   |          |    | (OBP)|       |    | (OBP)|     |
91  *   |          |    +------+       |    +------+     |
92  *   |          |                   |                 |
93  *   |          |               +-------+           +--------+
94  *   |          +-------------->| path  |---------->| path   |
95  *   |                          | info  |           | info   |
96  *   |                          | node 1|           | node 3 |
97  *   |                          +-------+           +--------+
98  *   |                              |                 |
99  *   |                          +-------+           +--------+
100  *   +------------------------->| path  |---------->| path   |
101  *                              | info  |           | info   |
102  *                              | node 2|           | node 4 |
103  *                              +-------+           +--------+
104  *
105  * The multipath information nodes (mdi_pathinfo nodes) establish the
106  * relationship between the pseudo client driver instance nodes and the
107  * physical host controller interconnect (pHCI drivers) forming a matrix
108  * structure.
109  *
110  * The mpxio module implements locking at multiple granularity levels to
111  * support the needs of various consumers.  The multipath matrix can be
112  * globally locked, column locked, or row locked depending on the consumer.
113  * The intention is to balance simplicity and performance.
114  *
115  * Locking:
116  *
117  * The current implementation utilizes the following locks:
118  *
119  *   mdi_mutex: protects the vHCI list, per-vHCI structure and the
120  *   list of pHCIs and Client devices registered against them (protection
121  *   against multi-threaded add/remove).
122  *
123  *   devinfo_tree_lock (rw): protects system wide creation/removal of
124  *   mdi_pathinfo nodes into the multipath matrix.  Consumers (like the devinfo
125  *   driver) can freeze the configuration by acquiring this as a reader.
126  *
127  *   per-pHCI (mutex) lock: protects the column (pHCI-mdi_pathinfo node list)
128  *   and per-pHCI structure fields.  mdi_pathinfo node creation, deletion and
129  *   child mdi_pathinfo node state changes are serialized on per pHCI basis
130  *   (Protection against DR).
131  *
132  *   per-client (mutex) lock: protects the row (client-mdi_pathinfo node list)
133  *   and per-client structure fields.  The client-mdi_pathinfo node list is
134  *   typically walked to select an optimal path when routing I/O requests.
135  *
136  *   per-mdi_pathinfo (mutex) lock: protects the mdi_pathinfo node structure
137  *   fields.
138  *
139  * Note that per-Client structure and per-pHCI fields are freely readable when
140  * corresponding mdi_pathinfo locks are held, since holding an mdi_pathinfo
141  * node guarantees that its corresponding client and pHCI devices will not be
142  * freed.
143  */
144 
145 /*
146  * MDI Client global unique identifier property name string definition
147  */
148 extern const char			*mdi_client_guid_prop;
149 #define	MDI_CLIENT_GUID_PROP		(char *)mdi_client_guid_prop
150 
151 /*
152  * MDI Client load balancing policy definitions
153  *
154  * Load balancing policies are determined on a per-vHCI basis and are
155  * configurable via the vHCI's driver.conf file.
156  */
157 typedef enum {
158 	LOAD_BALANCE_NONE,		/* Alternate pathing		*/
159 	LOAD_BALANCE_RR,		/* Round Robin			*/
160 	LOAD_BALANCE_LBA		/* Logical Block Addressing	*/
161 } client_lb_t;
162 
163 typedef struct {
164 	int region_size;
165 }client_lb_args_t;
166 
167 /*
168  * MDI client load balancing property name/value string definitions
169  */
170 extern const char			*mdi_load_balance;
171 extern const char			*mdi_load_balance_none;
172 extern const char			*mdi_load_balance_ap;
173 extern const char			*mdi_load_balance_rr;
174 extern const char			*mdi_load_balance_lba;
175 
176 #define	LOAD_BALANCE_PROP		(char *)mdi_load_balance
177 #define	LOAD_BALANCE_PROP_NONE		(char *)mdi_load_balance_none
178 #define	LOAD_BALANCE_PROP_AP		(char *)mdi_load_balance_ap
179 #define	LOAD_BALANCE_PROP_RR		(char *)mdi_load_balance_rr
180 #define	LOAD_BALANCE_PROP_LBA		(char *)mdi_load_balance_lba
181 
182 /* default for region size */
183 #define	LOAD_BALANCE_DEFAULT_REGION_SIZE	18
184 
185 /*
186  * vHCI drivers:
187  *
188  * vHCI drivers are pseudo nexus drivers which implement multipath services
189  * for a specific command set or bus architecture ('class').  There is a
190  * single instance of the vHCI driver for each command set which supports
191  * multipath devices.
192  *
193  * Each vHCI driver registers the following callbacks from attach(9e).
194  */
195 #define	MDI_VHCI_OPS_REV_1		1
196 /*
197  * Change MDI_VHCI_OPS_REV_NAME as per MDI_VHCI_OPS_REV
198  */
199 #define	MDI_VHCI_OPS_REV	MDI_VHCI_OPS_REV_1
200 #define	MDI_VHCI_OPS_REV_NAME	"1"
201 
202 typedef struct mdi_vhci_ops {
203 	/* revision management */
204 	int	vo_revision;
205 
206 	/* mdi_pathinfo node init callback */
207 	int	(*vo_pi_init)(dev_info_t *vdip, mdi_pathinfo_t *pip, int flags);
208 
209 	/* mdi_pathinfo node uninit callback */
210 	int	(*vo_pi_uninit)(dev_info_t *vdip, mdi_pathinfo_t *pip,
211 		    int flags);
212 
213 	/* mdi_pathinfo node state change callback */
214 	int	(*vo_pi_state_change)(dev_info_t *vdip, mdi_pathinfo_t *pip,
215 		    mdi_pathinfo_state_t state, uint32_t, int flags);
216 
217 	/* Client path failover callback */
218 	int	(*vo_failover)(dev_info_t *vdip, dev_info_t *cdip, int flags);
219 } mdi_vhci_ops_t;
220 
221 /*
222  * An mdi_vhci structure is created and bound to the devinfo node of every
223  * registered vHCI class driver; this happens when a vHCI registers itself from
224  * attach(9e).  This structure is unbound and freed when the vHCI unregisters
225  * at detach(9e) time;
226  *
227  * Each vHCI driver is associated with a vHCI class name; this is the handle
228  * used to register and unregister pHCI drivers for a given transport.
229  *
230  * Locking: This structure is guarded by the mdi_mutex; however, depending
231  * on the context, some of the fields can be freely read without holding any
232  * locks (ex. holding a child's lock also guarantees that the vHCI (parent)
233  * cannot be unexpectedly freed).
234  */
235 typedef struct mdi_vhci {
236 	struct mdi_vhci		*vh_next;	/* next link		*/
237 	struct mdi_vhci		*vh_prev;	/* prev link		*/
238 	int			vh_flags;	/* Operation flags	*/
239 	dev_info_t		*vh_dip;	/* devi handle		*/
240 	char			*vh_class;	/* Class name		*/
241 	struct mdi_vhci_ops	*vh_ops;	/* Callback vectors	*/
242 	client_lb_t		vh_lb;		/* Global cache		*/
243 	int			vh_phci_count;	/* pHCI device count	*/
244 	struct mdi_phci		*vh_phci_head;	/* pHCI list head	*/
245 	struct mdi_phci		*vh_phci_tail;	/* pHCI list tail	*/
246 	int			vh_client_count;	/* Client count	*/
247 	struct client_hash	*vh_client_table;	/* Client hash	*/
248 	int			vh_refcnt;	/* reference count */
249 	struct mdi_vhci_config	*vh_config;	/* vhci config */
250 } mdi_vhci_t;
251 
252 /*
253  * GUID Hash definitions
254  *
255  * Since all the mpxio managed devices for a given class are enumerated under
256  * the single vHCI instance for that class, sequentially walking through the
257  * client device link to find a client would be prohibitively slow.
258  */
259 
260 #define	CLIENT_HASH_TABLE_SIZE	(32)	/* GUID hash */
261 
262 /*
263  * Client hash table structure
264  */
265 struct client_hash {
266 	struct mdi_client	*ct_hash_head;	/* Client hash head	*/
267 	int			ct_hash_count;	/* Client hash count	*/
268 };
269 
270 
271 /*
272  * pHCI Drivers:
273  *
274  * Physical HBA drivers provide transport services for mpxio-managed devices.
275  * As each pHCI instance is attached, it must register itself with the mpxio
276  * framework using mdi_phci_register().  When the pHCI is detached it must
277  * similarly call mdi_phci_unregister().
278  *
279  * The framework maintains a list of registered pHCI device instances for each
280  * vHCI.  This list is vHCI->vh_phci_count, vHCI->vh_phci_head,
281  * vHCI->vh_phci_tail and pHCI->ph_next.  This list is protected by the global
282  * mdi_mutex.
283  *
284  * Locking order:
285  *
286  * _NOTE(LOCK_ORDER(mdi_mutex, mdi_phci::ph_mutex))
287  * _NOTE(LOCK_ORDER(mdi_phci::ph_mutex devinfo_tree_lock))
288  */
289 typedef struct mdi_phci {
290 	kmutex_t		ph_mutex;	/* per-pHCI mutex	*/
291 	struct mdi_phci		*ph_next;	/* next link		*/
292 	struct mdi_phci		*ph_prev;	/* prev link		*/
293 	dev_info_t		*ph_dip;	/* devi handle		*/
294 	struct mdi_vhci 	*ph_vhci;	/* back ref. to vHCI	*/
295 	int			ph_flags;	/* pHCI operation flags	*/
296 	int			ph_path_count;	/* child pi count	*/
297 	mdi_pathinfo_t		*ph_path_head;	/* pi list head		*/
298 	mdi_pathinfo_t		*ph_path_tail;	/* pi list tail		*/
299 	int			ph_unstable;	/* Paths in transient state */
300 	kcondvar_t		ph_unstable_cv;	/* Paths in transient state */
301 	kcondvar_t		ph_powerchange_cv;
302 						/* Paths in transient state */
303 	void			*ph_vprivate;	/* vHCI driver private	*/
304 } mdi_phci_t;
305 
306 /*
307  * A pHCI device is 'unstable' while one or more paths are in a transitional
308  * state.  Hotplugging is prevented during this state.
309  */
310 #define	MDI_PHCI_UNSTABLE(ph)		(ph)->ph_unstable++;
311 #define	MDI_PHCI_STABLE(ph) { \
312 	(ph)->ph_unstable--; \
313 	if ((ph)->ph_unstable == 0) { \
314 		cv_broadcast(&(ph)->ph_unstable_cv); \
315 	} \
316 }
317 
318 /*
319  * per-pHCI lock macros
320  */
321 #define	MDI_PHCI_LOCK(ph)		mutex_enter(&((ph))->ph_mutex)
322 #define	MDI_PHCI_TRYLOCK(ph)		mutex_tryenter(&((ph))->ph_mutex)
323 #define	MDI_PHCI_UNLOCK(ph)		mutex_exit(&((ph))->ph_mutex)
324 
325 /*
326  * pHCI state definitions and macros to track the pHCI driver instance state
327  */
328 #define	MDI_PHCI_FLAGS_OFFLINE		0x1	/* pHCI is offline */
329 #define	MDI_PHCI_FLAGS_SUSPEND		0x2	/* pHCI is suspended */
330 #define	MDI_PHCI_FLAGS_POWER_DOWN	0x4	/* pHCI is power down */
331 #define	MDI_PHCI_FLAGS_DETACH		0x8	/* pHCI is detached */
332 #define	MDI_PHCI_FLAGS_USER_DISABLE	0x10	/* pHCI is disabled,user */
333 #define	MDI_PHCI_FLAGS_D_DISABLE	0x20	/* pHCI is disabled,driver */
334 #define	MDI_PHCI_FLAGS_D_DISABLE_TRANS	0x40	/* pHCI is disabled,transient */
335 #define	MDI_PHCI_FLAGS_POWER_TRANSITION	0x80	/* pHCI is power transition */
336 
337 #define	MDI_PHCI_DISABLE_MASK	(~(MDI_PHCI_FLAGS_USER_DISABLE | \
338 				MDI_PHCI_FLAGS_D_DISABLE | \
339 				MDI_PHCI_FLAGS_D_DISABLE_TRANS))
340 #define	MDI_PHCI_IS_READY(ph) \
341 	(((ph)->ph_flags &  (MDI_PHCI_DISABLE_MASK)) == 0)
342 
343 #define	MDI_PHCI_SET_OFFLINE(ph) \
344 	    ((ph)->ph_flags |= MDI_PHCI_FLAGS_OFFLINE)
345 
346 #define	MDI_PHCI_SET_ONLINE(ph) \
347 	    ((ph)->ph_flags &= ~MDI_PHCI_FLAGS_OFFLINE)
348 
349 #define	MDI_PHCI_SET_SUSPEND(ph) \
350 	    ((ph)->ph_flags |= MDI_PHCI_FLAGS_SUSPEND)
351 
352 #define	MDI_PHCI_SET_RESUME(ph) \
353 	    ((ph)->ph_flags &= ~MDI_PHCI_FLAGS_SUSPEND)
354 
355 #define	MDI_PHCI_IS_OFFLINE(ph) \
356 	    ((ph)->ph_flags & MDI_PHCI_FLAGS_OFFLINE)
357 
358 #define	MDI_PHCI_IS_SUSPENDED(ph) \
359 	    ((ph)->ph_flags & MDI_PHCI_FLAGS_SUSPEND)
360 
361 #define	MDI_PHCI_SET_DETACH(ph) \
362 	    ((ph)->ph_flags |= MDI_PHCI_FLAGS_DETACH)
363 
364 #define	MDI_PHCI_SET_ATTACH(ph) \
365 	    ((ph)->ph_flags &= ~MDI_PHCI_FLAGS_DETACH)
366 
367 #define	MDI_PHCI_SET_POWER_DOWN(ph) \
368 	    ((ph)->ph_flags |= MDI_PHCI_FLAGS_POWER_DOWN)
369 
370 #define	MDI_PHCI_SET_POWER_UP(ph) \
371 	    ((ph)->ph_flags &= ~MDI_PHCI_FLAGS_POWER_DOWN)
372 
373 #define	MDI_PHCI_SET_USER_ENABLE(ph) \
374 		((ph)->ph_flags &= ~MDI_PHCI_FLAGS_USER_DISABLE)
375 
376 #define	MDI_PHCI_SET_USER_DISABLE(ph) \
377 		((ph)->ph_flags |= MDI_PHCI_FLAGS_USER_DISABLE)
378 
379 #define	MDI_PHCI_SET_DRV_ENABLE(ph)	\
380 		((ph)->ph_flags &= ~MDI_PHCI_FLAGS_D_DISABLE)
381 
382 #define	MDI_PHCI_SET_DRV_DISABLE(ph)	\
383 		((ph)->ph_flags |= MDI_PHCI_FLAGS_D_DISABLE)
384 
385 #define	MDI_PHCI_SET_DRV_ENABLE_TRANSIENT(ph)	\
386 		((ph)->ph_flags &= ~MDI_PHCI_FLAGS_D_DISABLE_TRANS)
387 
388 #define	MDI_PHCI_SET_DRV_DISABLE_TRANSIENT(ph)	\
389 		((ph)->ph_flags |= MDI_PHCI_FLAGS_D_DISABLE_TRANS)
390 
391 #define	MDI_PHCI_IS_USER_DISABLED(ph) \
392 		((ph)->ph_flags & MDI_PHCI_FLAGS_USER_DISABLE)
393 
394 #define	MDI_PHCI_IS_DRV_DISABLED_TRANSIENT(ph)	\
395 		((ph)->ph_flags & MDI_PHCI_FLAGS_D_DISABLE_TRANS)
396 
397 #define	MDI_PHCI_IS_DRV_DISABLED(ph)	\
398 		((ph)->ph_flags & MDI_PHCI_FLAGS_D_DISABLE)
399 
400 #define	MDI_PHCI_IS_POWERED_DOWN(ph) \
401 	    ((ph)->ph_flags & MDI_PHCI_FLAGS_POWER_DOWN)
402 
403 #define	MDI_PHCI_SET_POWER_TRANSITION(ph) \
404 	    ((ph)->ph_flags |= MDI_PHCI_FLAGS_POWER_TRANSITION)
405 
406 #define	MDI_PHCI_CLEAR_POWER_TRANSITION(ph) \
407 	    ((ph)->ph_flags &= ~MDI_PHCI_FLAGS_POWER_TRANSITION)
408 
409 #define	MDI_PHCI_IS_POWER_TRANSITION(ph) \
410 	    ((ph)->ph_flags & MDI_PHCI_FLAGS_POWER_TRANSITION)
411 
412 /*
413  * mpxio Managed Clients:
414  *
415  * This framework creates a struct mdi_client for every client device created
416  * by the framework as a result of self-enumeration of target devices by the
417  * registered pHCI devices.  This structure is bound to client device dev_info
418  * node at the time of client device allocation (ndi_devi_alloc(9e)). This
419  * structure is unbound from the dev_info node when mpxio framework removes a
420  * client device node from the system.
421  *
422  * This structure is created when a first path is enumerated and removed when
423  * last path is de-enumerated from the system.
424  *
425  * Multipath client devices are instantiated as children of corresponding vHCI
426  * driver instance. Each client device is uniquely identified by a GUID
427  * provided by target device itself.  The parent vHCI device also maintains a
428  * hashed list of client devices, protected by the global mdi_mutex.
429  *
430  * Typically pHCI devices self-enumerate their child devices using taskq,
431  * resulting in multiple paths to the same client device to be enumerated by
432  * competing threads.  mdi_mutex is also used to serialize the client device
433  * creation.
434  *
435  * Currently this framework supports two kinds of load-balancing policy
436  * configurable through the vHCI driver configuration files.
437  *
438  * NONE		- Legacy AP mode
439  * Round Robin	- Balance the pHCI load in a Round Robin fashion.
440  *
441  * This framework identifies the client device in three distinct states:
442  *
443  * OPTIMAL	- Client device has atleast one redundant path.
444  * DEGRADED	- No redundant paths (critical).  Failure in the current active
445  *                path would result in data access failures.
446  * FAILED 	- No paths are available to access this device.
447  *
448  * Locking order:
449  *
450  * _NOTE(LOCK_ORDER(mdi_mutex, mdi_client::ct_mutex))
451  * _NOTE(LOCK_ORDER(mdi_client::ct_mutex devinfo_tree_lock))
452  */
453 typedef struct mdi_client {
454 	kmutex_t		ct_mutex;	/* per-client mutex	*/
455 	struct mdi_client	*ct_hnext;	/* next client		*/
456 	struct mdi_client	*ct_hprev;	/* prev client		*/
457 	dev_info_t		*ct_dip;	/* client devi handle	*/
458 	struct mdi_vhci		*ct_vhci;	/* vHCI back ref	*/
459 	char			*ct_drvname;	/* client driver name	*/
460 	char			*ct_guid;	/* client guid		*/
461 	void			*ct_cprivate;	/* client driver private */
462 	client_lb_t		ct_lb;		/* load balancing scheme */
463 	client_lb_args_t	*ct_lb_args; 	/* load balancing args */
464 	int			ct_flags;	/* Driver op. flags	*/
465 	int			ct_state;	/* state information	*/
466 	int			ct_failover_flags;	/* Failover args */
467 	int			ct_failover_status;	/* last fo status */
468 	kcondvar_t		ct_failover_cv;	/* Failover status cv	*/
469 	int			ct_path_count;	/* multi path count	*/
470 	mdi_pathinfo_t		*ct_path_head;	/* multi path list head	*/
471 	mdi_pathinfo_t		*ct_path_tail;	/* multi path list tail	*/
472 	mdi_pathinfo_t		*ct_path_last;	/* last path used for i/o */
473 	int			ct_unstable;	/* Paths in transient state */
474 	kcondvar_t		ct_unstable_cv;	/* Paths in transient state */
475 	int			ct_power_cnt;	/* Hold count on parent power */
476 	kcondvar_t		ct_powerchange_cv;
477 					/* Paths in power transient state */
478 	short			ct_powercnt_config;
479 					/* held in pre/post config */
480 	short			ct_powercnt_unconfig;
481 					/* held in pre/post unconfig */
482 	int			ct_powercnt_reset;
483 					/* ct_power_cnt was resetted */
484 	void			*ct_vprivate;	/* vHCI driver private	*/
485 } mdi_client_t;
486 
487 /*
488  * per-Client device locking definitions
489  */
490 #define	MDI_CLIENT_LOCK(ct)		mutex_enter(&((ct))->ct_mutex)
491 #define	MDI_CLIENT_TRYLOCK(ct)		mutex_tryenter(&((ct))->ct_mutex)
492 #define	MDI_CLIENT_UNLOCK(ct)		mutex_exit(&((ct))->ct_mutex)
493 
494 /*
495  * A Client device is in unstable while one or more paths are in transitional
496  * state.  We do not allow failover to take place while paths are in transient
497  * state. Similarly we do not allow state transition while client device
498  * failover is in progress.
499  */
500 #define	MDI_CLIENT_UNSTABLE(ct)		(ct)->ct_unstable++;
501 #define	MDI_CLIENT_STABLE(ct) { \
502 	(ct)->ct_unstable--; \
503 	if ((ct)->ct_unstable == 0) { \
504 		cv_broadcast(&(ct)->ct_unstable_cv); \
505 	} \
506 }
507 
508 /*
509  * Client driver instance state definitions:
510  */
511 #define	MDI_CLIENT_FLAGS_OFFLINE		0x00000001
512 #define	MDI_CLIENT_FLAGS_SUSPEND		0x00000002
513 #define	MDI_CLIENT_FLAGS_POWER_DOWN		0x00000004
514 #define	MDI_CLIENT_FLAGS_DETACH			0x00000008
515 #define	MDI_CLIENT_FLAGS_FAILOVER		0x00000010
516 #define	MDI_CLIENT_FLAGS_REPORT_DEV		0x00000020
517 #define	MDI_CLIENT_FLAGS_PATH_FREE_IN_PROGRESS	0x00000040
518 #define	MDI_CLIENT_FLAGS_ASYNC_FREE		0x00000080
519 #define	MDI_CLIENT_FLAGS_DEV_NOT_SUPPORTED	0x00000100
520 #define	MDI_CLIENT_FLAGS_POWER_TRANSITION	0x00000200
521 
522 #define	MDI_CLIENT_SET_OFFLINE(ct) \
523 	    ((ct)->ct_flags |= MDI_CLIENT_FLAGS_OFFLINE)
524 
525 #define	MDI_CLIENT_SET_ONLINE(ct) \
526 	    ((ct)->ct_flags &= ~MDI_CLIENT_FLAGS_OFFLINE)
527 
528 #define	MDI_CLIENT_IS_OFFLINE(ct) \
529 	    ((ct)->ct_flags & MDI_CLIENT_FLAGS_OFFLINE)
530 
531 #define	MDI_CLIENT_SET_SUSPEND(ct) \
532 	    ((ct)->ct_flags |= MDI_CLIENT_FLAGS_SUSPEND)
533 
534 #define	MDI_CLIENT_SET_RESUME(ct) \
535 	    ((ct)->ct_flags &= ~MDI_CLIENT_FLAGS_SUSPEND)
536 
537 #define	MDI_CLIENT_IS_SUSPENDED(ct) \
538 	    ((ct)->ct_flags & MDI_CLIENT_FLAGS_SUSPEND)
539 
540 #define	MDI_CLIENT_SET_POWER_DOWN(ct) \
541 	    ((ct)->ct_flags |= MDI_CLIENT_FLAGS_POWER_DOWN)
542 
543 #define	MDI_CLIENT_SET_POWER_UP(ct) \
544 	    ((ct)->ct_flags &= ~MDI_CLIENT_FLAGS_POWER_DOWN)
545 
546 #define	MDI_CLIENT_IS_POWERED_DOWN(ct) \
547 	    ((ct)->ct_flags & MDI_CLIENT_FLAGS_POWER_DOWN)
548 
549 #define	MDI_CLIENT_SET_POWER_TRANSITION(ct) \
550 	    ((ct)->ct_flags |= MDI_CLIENT_FLAGS_POWER_TRANSITION)
551 
552 #define	MDI_CLIENT_CLEAR_POWER_TRANSITION(ct) \
553 	    ((ct)->ct_flags &= ~MDI_CLIENT_FLAGS_POWER_TRANSITION)
554 
555 #define	MDI_CLIENT_IS_POWER_TRANSITION(ct) \
556 	    ((ct)->ct_flags & MDI_CLIENT_FLAGS_POWER_TRANSITION)
557 
558 #define	MDI_CLIENT_SET_DETACH(ct) \
559 	    ((ct)->ct_flags |= MDI_CLIENT_FLAGS_DETACH)
560 
561 #define	MDI_CLIENT_SET_ATTACH(ct) \
562 	    ((ct)->ct_flags &= ~MDI_CLIENT_FLAGS_DETACH)
563 
564 #define	MDI_CLIENT_IS_DETACHED(ct) \
565 	    ((ct)->ct_flags & MDI_CLIENT_FLAGS_DETACH)
566 
567 #define	MDI_CLIENT_SET_FAILOVER_IN_PROGRESS(ct) \
568 	    ((ct)->ct_flags |= MDI_CLIENT_FLAGS_FAILOVER)
569 
570 #define	MDI_CLIENT_CLEAR_FAILOVER_IN_PROGRESS(ct) \
571 	    ((ct)->ct_flags &= ~MDI_CLIENT_FLAGS_FAILOVER)
572 
573 #define	MDI_CLIENT_IS_FAILOVER_IN_PROGRESS(ct) \
574 	    ((ct)->ct_flags & MDI_CLIENT_FLAGS_FAILOVER)
575 
576 #define	MDI_CLIENT_SET_REPORT_DEV_NEEDED(ct) \
577 	    ((ct)->ct_flags |= MDI_CLIENT_FLAGS_REPORT_DEV)
578 
579 #define	MDI_CLIENT_CLEAR_REPORT_DEV_NEEDED(ct) \
580 	    ((ct)->ct_flags &= ~MDI_CLIENT_FLAGS_REPORT_DEV)
581 
582 #define	MDI_CLIENT_IS_REPORT_DEV_NEEDED(ct) \
583 	    ((ct)->ct_flags & MDI_CLIENT_FLAGS_REPORT_DEV)
584 
585 #define	MDI_CLIENT_SET_PATH_FREE_IN_PROGRESS(ct) \
586 	    ((ct)->ct_flags |= MDI_CLIENT_FLAGS_PATH_FREE_IN_PROGRESS)
587 
588 #define	MDI_CLIENT_CLEAR_PATH_FREE_IN_PROGRESS(ct) \
589 	    ((ct)->ct_flags &= ~MDI_CLIENT_FLAGS_PATH_FREE_IN_PROGRESS)
590 
591 #define	MDI_CLIENT_IS_PATH_FREE_IN_PROGRESS(ct) \
592 	    ((ct)->ct_flags & MDI_CLIENT_FLAGS_PATH_FREE_IN_PROGRESS)
593 
594 #define	MDI_CLIENT_SET_DEV_NOT_SUPPORTED(ct) \
595 	    ((ct)->ct_flags |= MDI_CLIENT_FLAGS_DEV_NOT_SUPPORTED)
596 
597 #define	MDI_CLIENT_IS_DEV_NOT_SUPPORTED(ct) \
598 	    ((ct)->ct_flags & MDI_CLIENT_FLAGS_DEV_NOT_SUPPORTED)
599 
600 /*
601  * Client operating states.
602  */
603 #define	MDI_CLIENT_STATE_OPTIMAL	1
604 #define	MDI_CLIENT_STATE_DEGRADED	2
605 #define	MDI_CLIENT_STATE_FAILED		3
606 
607 #define	MDI_CLIENT_STATE(ct) ((ct)->ct_state)
608 #define	MDI_CLIENT_SET_STATE(ct, state) ((ct)->ct_state = state)
609 
610 #define	MDI_CLIENT_IS_FAILED(ct) \
611 	    ((ct)->ct_state == MDI_CLIENT_STATE_FAILED)
612 
613 /*
614  * mdi_pathinfo nodes:
615  *
616  * From this framework's perspective, a 'path' is a tuple consisting of a
617  * client or end device, a host controller which provides device
618  * identification and transport services (pHCI), and bus specific unit
619  * addressing information.  A path may be decorated with properties which
620  * describe the capabilities of the path; such properties are analogous to
621  * device node and minor node properties.
622  *
623  * The framework maintains link list of mdi_pathinfo nodes created by every
624  * pHCI driver instance via the pi_phci_link linkage; this is used (for example)
625  * to make sure that all relevant pathinfo nodes are freed before the pHCI
626  * is unregistered.
627  *
628  * Locking order:
629  *
630  * _NOTE(LOCK_ORDER(mdi_phci::ph_mutex mdi_pathinfo::pi_mutex))
631  * _NOTE(LOCK_ORDER(mdi_client::ct_mutex mdi_pathinfo::pi_mutex))
632  * _NOTE(LOCK_ORDER(mdi_phci::ph_mutex mdi_client::ct_mutex))
633  * _NOTE(LOCK_ORDER(devinfo_tree_lock mdi_pathinfo::pi_mutex))
634  *
635  * mdi_pathinfo node structure definition
636  */
637 struct mdi_pathinfo {
638 	kmutex_t		pi_mutex;	/* per path mutex	*/
639 	mdi_pathinfo_state_t	pi_state;	/* path state		*/
640 	mdi_pathinfo_state_t	pi_old_state;	/* path state		*/
641 	kcondvar_t		pi_state_cv;	/* path state condvar	*/
642 	mdi_client_t		*pi_client;	/* client		*/
643 	mdi_phci_t		*pi_phci;	/* pHCI dev_info node	*/
644 	char			*pi_addr;	/* path unit address	*/
645 	nvlist_t		*pi_prop;	/* Properties		*/
646 	void			*pi_cprivate;	/* client private info	*/
647 	void			*pi_pprivate;	/* phci private info	*/
648 	struct mdi_pathinfo	*pi_client_link; /* next path in client list */
649 	struct mdi_pathinfo	*pi_phci_link;	 /* next path in phci list */
650 	int			pi_ref_cnt;	/* pi reference count	*/
651 	kcondvar_t		pi_ref_cv;	/* condition variable	*/
652 	struct mdi_pi_kstats	*pi_kstats;	/* aggregate kstats */
653 	int			pi_pm_held;	/* phci's kidsup incremented */
654 	int			pi_preferred;	/* Preferred path 	*/
655 	void			*pi_vprivate;	/* vhci private info	*/
656 };
657 
658 /*
659  * pathinfo statistics:
660  *
661  * The mpxio architecture allows for multiple pathinfo nodes for each
662  * client-pHCI combination.  For statistics purposes, these statistics are
663  * aggregated into a single client-pHCI set of kstats.
664  */
665 struct mdi_pi_kstats {
666 	int	pi_kstat_ref;		/* # paths aggregated, also a ref cnt */
667 	kstat_t	*pi_kstat_iostats;	/* mdi:iopath statistic set */
668 	kstat_t *pi_kstat_errstats;	/* error statistics */
669 };
670 
671 /*
672  * pathinfo error kstat
673  */
674 struct pi_errs {
675 	struct kstat_named pi_softerrs;		/* "Soft" Error */
676 	struct kstat_named pi_harderrs;		/* "Hard" Error */
677 	struct kstat_named pi_transerrs;	/* Transport Errors */
678 	struct kstat_named pi_icnt_busy;	/* Interconnect Busy */
679 	struct kstat_named pi_icnt_errors;	/* Interconnect Errors */
680 	struct kstat_named pi_phci_rsrc;	/* pHCI No Resources */
681 	struct kstat_named pi_phci_localerr;	/* pHCI Local Errors */
682 	struct kstat_named pi_phci_invstate;	/* pHCI Invalid State */
683 	struct kstat_named pi_failedfrom;	/* Failover: Failed From */
684 	struct kstat_named pi_failedto;		/* Failover: Failed To */
685 };
686 
687 /*
688  * increment an error counter
689  */
690 #define	MDI_PI_ERRSTAT(pip, x) { \
691 	if (MDI_PI((pip))->pi_kstats != NULL) { \
692 		struct pi_errs *pep; \
693 		pep = MDI_PI(pip)->pi_kstats->pi_kstat_errstats->ks_data; \
694 		pep->x.value.ui32++; \
695 	} \
696 }
697 
698 /*
699  * error codes which can be passed to MDI_PI_ERRSTAT
700  */
701 #define	MDI_PI_SOFTERR	pi_softerrs
702 #define	MDI_PI_HARDERR	pi_harderrs
703 #define	MDI_PI_TRANSERR	pi_transerrs
704 #define	MDI_PI_ICNTBUSY	pi_icnt_busy
705 #define	MDI_PI_ICNTERR	pi_icnt_errors
706 #define	MDI_PI_PHCIRSRC	pi_phci_rsrc
707 #define	MDI_PI_PHCILOCL	pi_phci_localerr
708 #define	MDI_PI_PHCIINVS	pi_phci_invstate
709 #define	MDI_PI_FAILFROM	pi_failedfrom
710 #define	MDI_PI_FAILTO	pi_failedto
711 
712 #define	MDI_PI(type)			((struct mdi_pathinfo *)(type))
713 
714 #define	MDI_PI_LOCK(pip)		mutex_enter(&MDI_PI((pip))->pi_mutex)
715 #define	MDI_PI_UNLOCK(pip)		mutex_exit(&MDI_PI((pip))->pi_mutex)
716 #define	MDI_PI_HOLD(pip)		(++MDI_PI((pip))->pi_ref_cnt)
717 #define	MDI_PI_RELE(pip)		(--MDI_PI((pip))->pi_ref_cnt)
718 
719 #define	MDI_EXT_STATE_CHANGE		0x10000000
720 
721 
722 #define	MDI_DISABLE_OP			0x1
723 #define	MDI_ENABLE_OP			0x2
724 #define	MDI_BEFORE_STATE_CHANGE		0x4
725 #define	MDI_AFTER_STATE_CHANGE		0x8
726 #define	MDI_SYNC_FLAG			0x10
727 
728 #define	MDI_PI_STATE(pip) \
729 	    (MDI_PI((pip))->pi_state & MDI_PATHINFO_STATE_MASK)
730 
731 #define	MDI_PI_OLD_STATE(pip) \
732 	    (MDI_PI((pip))->pi_old_state & MDI_PATHINFO_STATE_MASK)
733 
734 #define	MDI_PI_EXT_STATE(pip) \
735 		(MDI_PI((pip))->pi_state & MDI_PATHINFO_EXT_STATE_MASK)
736 
737 #define	MDI_PI_OLD_EXT_STATE(pip) \
738 		(MDI_PI((pip))->pi_old_state & MDI_PATHINFO_EXT_STATE_MASK)
739 
740 #define	MDI_PI_SET_TRANSIENT(pip) \
741 	    (MDI_PI(pip)->pi_state |= MDI_PATHINFO_STATE_TRANSIENT)
742 
743 #define	MDI_PI_CLEAR_TRANSIENT(pip) \
744 	    (MDI_PI(pip)->pi_state &= ~MDI_PATHINFO_STATE_TRANSIENT)
745 
746 #define	MDI_PI_IS_TRANSIENT(pip) \
747 	(MDI_PI(pip)->pi_state & MDI_PATHINFO_STATE_TRANSIENT)
748 
749 #define	MDI_PI_SET_USER_DISABLE(pip) \
750 	(MDI_PI(pip)->pi_state |= MDI_PATHINFO_STATE_USER_DISABLE)
751 
752 #define	MDI_PI_SET_DRV_DISABLE(pip) \
753 	(MDI_PI(pip)->pi_state |= MDI_PATHINFO_STATE_DRV_DISABLE)
754 
755 #define	MDI_PI_SET_DRV_DISABLE_TRANS(pip) \
756 	(MDI_PI(pip)->pi_state |= MDI_PATHINFO_STATE_DRV_DISABLE_TRANSIENT)
757 
758 #define	MDI_PI_SET_USER_ENABLE(pip) \
759 	(MDI_PI(pip)->pi_state &= ~MDI_PATHINFO_STATE_USER_DISABLE)
760 
761 #define	MDI_PI_SET_DRV_ENABLE(pip) \
762 	(MDI_PI(pip)->pi_state &= ~MDI_PATHINFO_STATE_DRV_DISABLE)
763 
764 #define	MDI_PI_SET_DRV_ENABLE_TRANS(pip) \
765 	(MDI_PI(pip)->pi_state &= ~MDI_PATHINFO_STATE_DRV_DISABLE_TRANSIENT)
766 
767 #define	MDI_PI_IS_USER_DISABLE(pip)	\
768 	(MDI_PI(pip)->pi_state & MDI_PATHINFO_STATE_USER_DISABLE)
769 
770 #define	MDI_PI_IS_DRV_DISABLE(pip)	\
771 	(MDI_PI(pip)->pi_state & MDI_PATHINFO_STATE_DRV_DISABLE)
772 
773 #define	MDI_PI_IS_DRV_DISABLE_TRANSIENT(pip)	\
774 	(MDI_PI(pip)->pi_state & MDI_PATHINFO_STATE_DRV_DISABLE_TRANSIENT)
775 
776 #define	MDI_PI_IS_DISABLE(pip)	\
777 	(MDI_PI_IS_USER_DISABLE(pip) || \
778 	MDI_PI_IS_DRV_DISABLE(pip) || \
779 	MDI_PI_IS_DRV_DISABLE_TRANSIENT(pip))
780 
781 #define	MDI_PI_IS_INIT(pip) \
782 	    ((MDI_PI(pip)->pi_state & MDI_PATHINFO_STATE_MASK) == \
783 		MDI_PATHINFO_STATE_INIT)
784 
785 #define	MDI_PI_IS_INITING(pip) \
786 	    ((MDI_PI(pip)->pi_state & ~MDI_PATHINFO_EXT_STATE_MASK) == \
787 		(MDI_PATHINFO_STATE_INIT | MDI_PATHINFO_STATE_TRANSIENT))
788 
789 #define	MDI_PI_SET_INIT(pip) \
790 	    (MDI_PI(pip)->pi_state = MDI_PATHINFO_STATE_INIT)
791 
792 #define	MDI_PI_SET_ONLINING(pip) { \
793 	uint32_t	ext_state; \
794 	ext_state = MDI_PI(pip)->pi_state & MDI_PATHINFO_EXT_STATE_MASK; \
795 	MDI_PI(pip)->pi_old_state = MDI_PI_STATE(pip); \
796 	MDI_PI(pip)->pi_state = \
797 	(MDI_PATHINFO_STATE_ONLINE | MDI_PATHINFO_STATE_TRANSIENT); \
798 	MDI_PI(pip)->pi_state |= ext_state; \
799 }
800 
801 #define	MDI_PI_IS_ONLINING(pip) \
802 	((MDI_PI(pip)->pi_state & ~MDI_PATHINFO_EXT_STATE_MASK) == \
803 	(MDI_PATHINFO_STATE_ONLINE | MDI_PATHINFO_STATE_TRANSIENT))
804 
805 #define	MDI_PI_SET_ONLINE(pip) { \
806 	uint32_t	ext_state; \
807 	ext_state = MDI_PI(pip)->pi_state & MDI_PATHINFO_EXT_STATE_MASK; \
808 	MDI_PI(pip)->pi_state = MDI_PATHINFO_STATE_ONLINE; \
809 	MDI_PI(pip)->pi_state |= ext_state; \
810 }
811 
812 
813 #define	MDI_PI_IS_ONLINE(pip) \
814 	((MDI_PI(pip)->pi_state & MDI_PATHINFO_STATE_MASK) == \
815 	MDI_PATHINFO_STATE_ONLINE)
816 
817 #define	MDI_PI_SET_OFFLINING(pip) { \
818 	uint32_t	ext_state; \
819 	ext_state = MDI_PI(pip)->pi_state & MDI_PATHINFO_EXT_STATE_MASK; \
820 	MDI_PI(pip)->pi_old_state = MDI_PI_STATE(pip); \
821 	MDI_PI(pip)->pi_state = \
822 	(MDI_PATHINFO_STATE_OFFLINE | MDI_PATHINFO_STATE_TRANSIENT); \
823 	MDI_PI(pip)->pi_state |= ext_state; \
824 }
825 
826 #define	MDI_PI_IS_OFFLINING(pip) \
827 	    ((MDI_PI(pip)->pi_state & ~MDI_PATHINFO_EXT_STATE_MASK) == \
828 	    (MDI_PATHINFO_STATE_OFFLINE | MDI_PATHINFO_STATE_TRANSIENT))
829 
830 #define	MDI_PI_SET_OFFLINE(pip) { \
831 	uint32_t	ext_state; \
832 	ext_state = MDI_PI(pip)->pi_state & MDI_PATHINFO_EXT_STATE_MASK; \
833 	MDI_PI(pip)->pi_state = MDI_PATHINFO_STATE_OFFLINE; \
834 	MDI_PI(pip)->pi_state |= ext_state; \
835 }
836 
837 #define	MDI_PI_IS_OFFLINE(pip) \
838 	    ((MDI_PI(pip)->pi_state & MDI_PATHINFO_STATE_MASK) == \
839 		MDI_PATHINFO_STATE_OFFLINE)
840 
841 #define	MDI_PI_SET_STANDBYING(pip) { \
842 	uint32_t	ext_state; \
843 	ext_state = MDI_PI(pip)->pi_state & MDI_PATHINFO_EXT_STATE_MASK; \
844 	MDI_PI(pip)->pi_old_state = MDI_PI_STATE(pip); \
845 	MDI_PI(pip)->pi_state = \
846 	(MDI_PATHINFO_STATE_STANDBY | MDI_PATHINFO_STATE_TRANSIENT); \
847 	MDI_PI(pip)->pi_state |= ext_state; \
848 }
849 
850 #define	MDI_PI_SET_STANDBY(pip) { \
851 	uint32_t	ext_state; \
852 	ext_state = MDI_PI(pip)->pi_state & MDI_PATHINFO_EXT_STATE_MASK; \
853 	MDI_PI(pip)->pi_state = MDI_PATHINFO_STATE_STANDBY; \
854 	MDI_PI(pip)->pi_state |= ext_state; \
855 }
856 
857 #define	MDI_PI_IS_STANDBY(pip) \
858 	((MDI_PI(pip)->pi_state & MDI_PATHINFO_STATE_MASK) == \
859 	MDI_PATHINFO_STATE_STANDBY)
860 
861 #define	MDI_PI_SET_FAULTING(pip) { \
862 	uint32_t	ext_state; \
863 	ext_state = MDI_PI(pip)->pi_state & MDI_PATHINFO_EXT_STATE_MASK; \
864 	MDI_PI(pip)->pi_old_state = MDI_PI_STATE(pip); \
865 	MDI_PI(pip)->pi_state = \
866 	    (MDI_PATHINFO_STATE_FAULT | MDI_PATHINFO_STATE_TRANSIENT); \
867 	MDI_PI(pip)->pi_state |= ext_state; \
868 }
869 
870 #define	MDI_PI_SET_FAULT(pip) { \
871 	uint32_t	ext_state; \
872 	ext_state = MDI_PI(pip)->pi_state & MDI_PATHINFO_EXT_STATE_MASK; \
873 	MDI_PI(pip)->pi_state = MDI_PATHINFO_STATE_FAULT; \
874 	MDI_PI(pip)->pi_state |= ext_state; \
875 }
876 
877 #define	MDI_PI_IS_FAULT(pip) \
878 	((MDI_PI(pip)->pi_state & MDI_PATHINFO_STATE_MASK) == \
879 	MDI_PATHINFO_STATE_FAULT)
880 
881 #define	MDI_PI_IS_SUSPENDED(pip) \
882 	    ((MDI_PI(pip))->pi_phci->ph_flags & MDI_PHCI_FLAGS_SUSPEND)
883 
884 /*
885  * mdi_vhcache_client, mdi_vhcache_pathinfo, and mdi_vhcache_phci structures
886  * hold the vhci to phci client mappings of the on-disk vhci busconfig cache.
887  */
888 
889 /* phci structure of vhci cache */
890 typedef struct mdi_vhcache_phci {
891 	char			*cphci_path;	/* phci path name */
892 	uint32_t		cphci_id;	/* used when building nvlist */
893 	mdi_phci_t		*cphci_phci;	/* pointer to actual phci */
894 	struct mdi_vhcache_phci	*cphci_next;	/* next in vhci phci list */
895 } mdi_vhcache_phci_t;
896 
897 /* pathinfo structure of vhci cache */
898 typedef struct mdi_vhcache_pathinfo {
899 	char			*cpi_addr;	/* path address */
900 	mdi_vhcache_phci_t	*cpi_cphci;	/* phci the path belongs to */
901 	struct mdi_pathinfo	*cpi_pip;	/* ptr to actual pathinfo */
902 	uint32_t		cpi_flags;	/* see below */
903 	struct mdi_vhcache_pathinfo *cpi_next;	/* next path for the client */
904 } mdi_vhcache_pathinfo_t;
905 
906 /*
907  * cpi_flags
908  *
909  * MDI_CPI_HINT_PATH_DOES_NOT_EXIST - set when configuration of the path has
910  * failed.
911  */
912 #define	MDI_CPI_HINT_PATH_DOES_NOT_EXIST	0x0001
913 
914 /* client structure of vhci cache */
915 typedef struct mdi_vhcache_client {
916 	char			*cct_name_addr;	/* client address */
917 	mdi_vhcache_pathinfo_t	*cct_cpi_head;	/* client's path list head */
918 	mdi_vhcache_pathinfo_t	*cct_cpi_tail;	/* client's path list tail */
919 	struct mdi_vhcache_client *cct_next;	/* next in vhci client list */
920 } mdi_vhcache_client_t;
921 
922 /* vhci cache structure - one for vhci instance */
923 typedef struct mdi_vhci_cache {
924 	mdi_vhcache_phci_t	*vhcache_phci_head;	/* phci list head */
925 	mdi_vhcache_phci_t	*vhcache_phci_tail;	/* phci list tail */
926 	mdi_vhcache_client_t	*vhcache_client_head;	/* client list head */
927 	mdi_vhcache_client_t	*vhcache_client_tail;	/* client list tail */
928 	mod_hash_t		*vhcache_client_hash;	/* client hash */
929 	int			vhcache_flags;		/* see below */
930 	int64_t			vhcache_clean_time;	/* last clean time */
931 	krwlock_t		vhcache_lock;		/* cache lock */
932 } mdi_vhci_cache_t;
933 
934 /* vhcache_flags */
935 #define	MDI_VHCI_CACHE_SETUP_DONE	0x0001	/* cache setup completed */
936 
937 /* vhci bus config structure - one for vhci instance */
938 typedef struct mdi_vhci_config {
939 	char			*vhc_vhcache_filename;	/* on-disk file name */
940 	mdi_vhci_cache_t	vhc_vhcache;		/* vhci cache */
941 	kmutex_t		vhc_lock;		/* vhci config lock */
942 	kcondvar_t		vhc_cv;
943 	int			vhc_flags;		/* see below */
944 
945 	/* flush vhci cache when lbolt reaches vhc_flush_at_ticks */
946 	clock_t			vhc_flush_at_ticks;
947 
948 	/*
949 	 * Head and tail of the client list whose paths are being configured
950 	 * asynchronously. vhc_acc_count is the number of clients on this list.
951 	 * vhc_acc_thrcount is the number threads running to configure
952 	 * the paths for these clients.
953 	 */
954 	struct mdi_async_client_config *vhc_acc_list_head;
955 	struct mdi_async_client_config *vhc_acc_list_tail;
956 	int			vhc_acc_count;
957 	int			vhc_acc_thrcount;
958 
959 	/* callback id - for flushing the cache during system shutdown */
960 	callb_id_t		vhc_cbid;
961 
962 	/*
963 	 * vhc_path_discovery_boot -	number of times path discovery will be
964 	 *				attempted during early boot.
965 	 * vhc_path_discovery_postboot	number of times path discovery will be
966 	 *				attempted during late boot.
967 	 * vhc_path_discovery_cutoff_time - time at which paths were last
968 	 *				discovered  + some timeout
969 	 */
970 	int			vhc_path_discovery_boot;
971 	int			vhc_path_discovery_postboot;
972 	int64_t			vhc_path_discovery_cutoff_time;
973 } mdi_vhci_config_t;
974 
975 /* vhc_flags */
976 #define	MDI_VHC_SINGLE_THREADED		0x0001	/* config single threaded */
977 #define	MDI_VHC_EXIT			0x0002	/* exit all config activity */
978 #define	MDI_VHC_VHCACHE_DIRTY		0x0004	/* cache dirty */
979 #define	MDI_VHC_VHCACHE_FLUSH_THREAD	0x0008	/* cache flush thead running */
980 #define	MDI_VHC_VHCACHE_FLUSH_ERROR	0x0010	/* failed to flush cache */
981 #define	MDI_VHC_READONLY_FS		0x0020	/* filesys is readonly */
982 
983 typedef struct mdi_phys_path {
984 	char			*phys_path;
985 	struct mdi_phys_path	*phys_path_next;
986 } mdi_phys_path_t;
987 
988 /*
989  * Lookup tokens are used to cache the result of the vhci cache client lookup
990  * operations (to reduce the number of real lookup operations).
991  */
992 typedef struct mdi_vhcache_lookup_token {
993 	mdi_vhcache_client_t	*lt_cct;		/* vhcache client */
994 	int64_t			lt_cct_lookup_time;	/* last lookup time */
995 } mdi_vhcache_lookup_token_t;
996 
997 /* asynchronous configuration of client paths */
998 typedef struct mdi_async_client_config {
999 	char			*acc_ct_name;	/* client name */
1000 	char			*acc_ct_addr;	/* client address */
1001 	mdi_phys_path_t		*acc_phclient_path_list_head;	/* path head */
1002 	mdi_vhcache_lookup_token_t acc_token;	/* lookup token */
1003 	struct mdi_async_client_config *acc_next; /* next in vhci acc list */
1004 } mdi_async_client_config_t;
1005 
1006 /*
1007  * vHCI driver instance registration/unregistration
1008  *
1009  * mdi_vhci_register() is called by a vHCI driver to register itself as the
1010  * manager of devices from a particular 'class'.  This should be called from
1011  * attach(9e).
1012  *
1013  * mdi_vhci_unregister() is called from detach(9E) to unregister a vHCI
1014  * instance from the framework.
1015  */
1016 int		mdi_vhci_register(char *, dev_info_t *, mdi_vhci_ops_t *, int);
1017 int		mdi_vhci_unregister(dev_info_t *, int);
1018 
1019 /*
1020  * Utility functions
1021  */
1022 int		mdi_phci_get_path_count(dev_info_t *);
1023 dev_info_t	*mdi_phci_path2devinfo(dev_info_t *, caddr_t);
1024 
1025 
1026 /*
1027  * Path Selection Functions:
1028  *
1029  * mdi_select_path() is called by a vHCI driver to select to which path an
1030  * I/O request should be routed.  The caller passes the 'buf' structure as
1031  * one of the parameters.  The mpxio framework uses the buf's contents to
1032  * maintain per path statistics (total I/O size / count pending).  If more
1033  * than one online path is available, the framework automatically selects
1034  * a suitable one.  If a failover operation is active for this client device
1035  * the call fails, returning MDI_BUSY.
1036  *
1037  * By default this function returns a suitable path in the 'online' state,
1038  * based on the current load balancing policy.  Currently we support
1039  * LOAD_BALANCE_NONE (Previously selected online path will continue to be
1040  * used as long as the path is usable) and LOAD_BALANCE_RR (Online paths
1041  * will be selected in a round robin fashion).  The load balancing scheme
1042  * can be configured in the vHCI driver's configuration file (driver.conf).
1043  *
1044  * vHCI drivers may override this default behaviour by specifying appropriate
1045  * flags.  If start_pip is specified (non NULL), it is used as the routine's
1046  * starting point; it starts walking from there to find the next appropriate
1047  * path.
1048  *
1049  * The following values for 'flags' are currently defined:
1050  *
1051  * 	MDI_SELECT_ONLINE_PATH: select an ONLINE path
1052  *	MDI_SELECT_STANDBY_PATH: select a STANDBY path
1053  * 	MDI_SELECT_USER_DISABLE_PATH: select user disable for failover and
1054  *		auto_failback
1055  *
1056  * The selected paths are returned in a held state (ref_cnt) and caller should
1057  * release the hold by calling mdi_rele_path() at the end of operation.
1058  */
1059 int		mdi_select_path(dev_info_t *, struct buf *, int,
1060 		    mdi_pathinfo_t *, mdi_pathinfo_t **);
1061 void		mdi_hold_path(mdi_pathinfo_t *);
1062 void		mdi_rele_path(mdi_pathinfo_t *);
1063 int		mdi_set_lb_policy(dev_info_t *, client_lb_t);
1064 int		mdi_set_lb_region_size(dev_info_t *, int);
1065 client_lb_t	mdi_get_lb_policy(dev_info_t *);
1066 
1067 /*
1068  * flags for mdi_select_path() routine
1069  */
1070 #define	MDI_SELECT_ONLINE_PATH		0x0001
1071 #define	MDI_SELECT_STANDBY_PATH		0x0002
1072 #define	MDI_SELECT_USER_DISABLE_PATH	0x0004
1073 
1074 /*
1075  * MDI client device utility functions
1076  */
1077 int		mdi_client_get_path_count(dev_info_t *);
1078 dev_info_t	*mdi_client_path2devinfo(dev_info_t *, caddr_t);
1079 
1080 /*
1081  * Failover:
1082  *
1083  * The vHCI driver calls mdi_failover() to initiate a failover operation.
1084  * mdi_failover() calls back into the vHCI driver's vo_failover()
1085  * entry point to perform the actual failover operation.  The reason
1086  * for requiring the vHCI driver to initiate failover by calling
1087  * mdi_failover(), instead of directly executing vo_failover() itself,
1088  * is to ensure that the mdi framework can keep track of the client
1089  * state properly.  Additionally, mdi_failover() provides as a
1090  * convenience the option of performing the failover operation
1091  * synchronously or asynchronously
1092  *
1093  * Upon successful completion of the failover operation, the paths that were
1094  * previously ONLINE will be in the STANDBY state, and the newly activated
1095  * paths will be in the ONLINE state.
1096  *
1097  * The flags modifier determines whether the activation is done synchronously
1098  */
1099 int mdi_failover(dev_info_t *, dev_info_t *, int);
1100 
1101 /*
1102  * Client device failover mode of operation
1103  */
1104 #define	MDI_FAILOVER_SYNC	1	/* Syncronous Failover		*/
1105 #define	MDI_FAILOVER_ASYNC	2	/* Asyncronous Failover		*/
1106 
1107 /*
1108  * mdi_pathinfo node state change functions.
1109  */
1110 void mdi_pi_kstat_iosupdate(mdi_pathinfo_t *, struct buf *);
1111 
1112 /*
1113  * mdi_pathinfo node extended state change functions.
1114  */
1115 int mdi_pi_get_state2(mdi_pathinfo_t *, mdi_pathinfo_state_t *, uint32_t *);
1116 int mdi_pi_get_preferred(mdi_pathinfo_t *);
1117 
1118 /*
1119  * mdi_pathinfo node member functions
1120  */
1121 void *mdi_pi_get_client_private(mdi_pathinfo_t *);
1122 void mdi_pi_set_client_private(mdi_pathinfo_t *, void *);
1123 void mdi_pi_set_state(mdi_pathinfo_t *, mdi_pathinfo_state_t);
1124 void mdi_pi_set_preferred(mdi_pathinfo_t *, int);
1125 
1126 /* get/set vhci private data */
1127 void *mdi_client_get_vhci_private(dev_info_t *);
1128 void mdi_client_set_vhci_private(dev_info_t *, void *);
1129 void *mdi_phci_get_vhci_private(dev_info_t *);
1130 void mdi_phci_set_vhci_private(dev_info_t *, void *);
1131 void *mdi_pi_get_vhci_private(mdi_pathinfo_t *);
1132 void mdi_pi_set_vhci_private(mdi_pathinfo_t *, void *);
1133 
1134 /*
1135  * mdi_pathinfo Property utilities
1136  */
1137 int mdi_prop_size(mdi_pathinfo_t *, size_t *);
1138 int mdi_prop_pack(mdi_pathinfo_t *, char **, uint_t);
1139 
1140 /* obsolete interface, to be removed */
1141 void mdi_get_next_path(dev_info_t *, mdi_pathinfo_t *, mdi_pathinfo_t **);
1142 int mdi_get_component_type(dev_info_t *);
1143 
1144 #endif	/* _KERNEL */
1145 
1146 #ifdef	__cplusplus
1147 }
1148 #endif
1149 
1150 #endif	/* _SYS_MDI_IMPLDEFS_H */
1151