xref: /titanic_41/usr/src/uts/common/sys/mdi_impldefs.h (revision 3ee0e49223f178da635734759b9167f924321ff0)
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  *             /  ............
78  *     <vHCI>:/               \
79  *      +-----------+   +-----------+
80  *      | scsi_vhci |   |  pci@1f,0 |
81  *      +-----------+   +-----------+
82  *            /   \               \
83  * <Client>: /     \ :<Client>     \ :parent(pHCI)
84  *  +----------+ +-----------+    +-------------+
85  *  | ssd 1    | | ssd 2     |    | qlc@0,0     |
86  *  +----------+ +-----------+    +-------------+
87  *   |            |                /        \
88  *   |            |       <pHCI>: /          \ :<pHCI>
89  *   |            |      +-------------+   +-------------+
90  *   |            |      | pHCI 1 (fp) |   | pHCI 2 (fp) |
91  *   |            |      +-------------+   +-------------+
92  *   |            |          /        |      /          |
93  *   |            |    +------+       |    +------+     |
94  *   |            |    | ssd 3|       |    | ssd  |     |
95  *   |            |    |!mpxio|       |    | (OBP)|     |
96  *   |            |    +------+       |    +------+     |
97  *   |            |                   |                 |
98  *   |            |       <pathinfo>: |                 |
99  *   |            |               +-------+         +--------+
100  *   |            +-------------->| path  |-------->| path   |
101  *   |                            | info  |         | info   |
102  *   |                            | node 1|         | node 3 |
103  *   |                            +-------+         +--------+
104  *   |                                |               |
105  *   |                                |            +~~~~~~~~+
106  *   |                            +-------+        :+--------+
107  *   +--------------------------->| path  |-------->| path   |
108  *                                | info  |        :| info   |
109  *                                | node 2|        +| node 4 |
110  *                                +-------+         +--------+
111  *
112  * The multipath information nodes (mdi_pathinfo nodes) establish the
113  * relationship between the pseudo client driver instance nodes (children
114  * of the vHCI) and the physical host controller interconnect (pHCI
115  * drivers) forming a matrix structure.
116  *
117  * The mpxio module implements locking at multiple granularity levels to
118  * support the needs of various consumers.  The multipath matrix can be
119  * column locked, or row locked depending on the consumer. The intention
120  * is to balance simplicity and performance.
121  *
122  * Locking:
123  *
124  * The devinfo locking still applies:
125  *
126  *   1) An ndi_devi_enter of a parent protects linkage/state of children.
127  *   2) state >= DS_INITIALIZED adds devi_ref of parent
128  *   3) devi_ref at state >= DS_ATTACHED prevents detach(9E).
129  *
130  * The ordering of 1) is (vHCI, pHCI). For a DEBUG kernel this ordering
131  * is asserted by the ndi_devi_enter() implementation.  There is also an
132  * ndi_devi_enter(Client), which is atypical since the client is a leaf.
133  * This is done to synchronize pathinfo nodes during devinfo snapshot (see
134  * di_register_pip) by pretending that the pathinfo nodes are children
135  * of the client.
136  *
137  * In addition to devinfo locking the current implementation utilizes
138  * the following locks:
139  *
140  *   mdi_mutex: protects the global list of vHCIs.
141  *
142  *   vh_phci_mutex: per-vHCI (mutex) lock: protects list of pHCIs registered
143  *   with vHCI.
144  *
145  *   vh_client_mutex: per-vHCI (mutex) lock: protects list/hash of Clients
146  *   associated with vHCI.
147  *
148  *   ph_mutex: per-pHCI (mutex) lock: protects the column (pHCI-mdi_pathinfo
149  *   node list) and per-pHCI structure fields.  mdi_pathinfo node creation,
150  *   deletion and child mdi_pathinfo node state changes are serialized on per
151  *   pHCI basis (Protection against DR).
152  *
153  *   ct_mutex: per-client (mutex) lock: protects the row (client-mdi_pathinfo
154  *   node list) and per-client structure fields.  The client-mdi_pathinfo node
155  *   list is typically walked to select an optimal path when routing I/O
156  *   requests.
157  *
158  *   pi_mutex: per-mdi_pathinfo (mutex) lock: protects the mdi_pathinfo node
159  *   structure fields.
160  *
161  * Note that per-Client structure and per-pHCI fields are freely readable when
162  * corresponding mdi_pathinfo locks are held, since holding an mdi_pathinfo
163  * node guarantees that its corresponding client and pHCI devices will not be
164  * freed.
165  */
166 
167 /*
168  * MDI Client global unique identifier property name string definition
169  */
170 extern const char			*mdi_client_guid_prop;
171 #define	MDI_CLIENT_GUID_PROP		(char *)mdi_client_guid_prop
172 
173 /*
174  * MDI Client load balancing policy definitions
175  *
176  * Load balancing policies are determined on a per-vHCI basis and are
177  * configurable via the vHCI's driver.conf file.
178  */
179 typedef enum {
180 	LOAD_BALANCE_NONE,		/* Alternate pathing		*/
181 	LOAD_BALANCE_RR,		/* Round Robin			*/
182 	LOAD_BALANCE_LBA		/* Logical Block Addressing	*/
183 } client_lb_t;
184 
185 typedef struct {
186 	int region_size;
187 }client_lb_args_t;
188 
189 /*
190  * MDI client load balancing property name/value string definitions
191  */
192 extern const char			*mdi_load_balance;
193 extern const char			*mdi_load_balance_none;
194 extern const char			*mdi_load_balance_ap;
195 extern const char			*mdi_load_balance_rr;
196 extern const char			*mdi_load_balance_lba;
197 
198 #define	LOAD_BALANCE_PROP		(char *)mdi_load_balance
199 #define	LOAD_BALANCE_PROP_NONE		(char *)mdi_load_balance_none
200 #define	LOAD_BALANCE_PROP_AP		(char *)mdi_load_balance_ap
201 #define	LOAD_BALANCE_PROP_RR		(char *)mdi_load_balance_rr
202 #define	LOAD_BALANCE_PROP_LBA		(char *)mdi_load_balance_lba
203 
204 /* default for region size */
205 #define	LOAD_BALANCE_DEFAULT_REGION_SIZE	18
206 
207 /*
208  * vHCI drivers:
209  *
210  * vHCI drivers are pseudo nexus drivers which implement multipath services
211  * for a specific command set or bus architecture ('class').  There is a
212  * single instance of the vHCI driver for each command set which supports
213  * multipath devices.
214  *
215  * Each vHCI driver registers the following callbacks from attach(9e).
216  */
217 #define	MDI_VHCI_OPS_REV_1		1
218 /*
219  * Change MDI_VHCI_OPS_REV_NAME as per MDI_VHCI_OPS_REV
220  */
221 #define	MDI_VHCI_OPS_REV	MDI_VHCI_OPS_REV_1
222 #define	MDI_VHCI_OPS_REV_NAME	"1"
223 
224 typedef struct mdi_vhci_ops {
225 	/* revision management */
226 	int	vo_revision;
227 
228 	/* mdi_pathinfo node init callback */
229 	int	(*vo_pi_init)(dev_info_t *vdip, mdi_pathinfo_t *pip, int flags);
230 
231 	/* mdi_pathinfo node uninit callback */
232 	int	(*vo_pi_uninit)(dev_info_t *vdip, mdi_pathinfo_t *pip,
233 		    int flags);
234 
235 	/* mdi_pathinfo node state change callback */
236 	int	(*vo_pi_state_change)(dev_info_t *vdip, mdi_pathinfo_t *pip,
237 		    mdi_pathinfo_state_t state, uint32_t, int flags);
238 
239 	/* Client path failover callback */
240 	int	(*vo_failover)(dev_info_t *vdip, dev_info_t *cdip, int flags);
241 } mdi_vhci_ops_t;
242 
243 /*
244  * An mdi_vhci structure is created and bound to the devinfo node of every
245  * registered vHCI class driver; this happens when a vHCI registers itself from
246  * attach(9e).  This structure is unbound and freed when the vHCI unregisters
247  * at detach(9e) time;
248  *
249  * Each vHCI driver is associated with a vHCI class name; this is the handle
250  * used to register and unregister pHCI drivers for a given transport.
251  *
252  * Locking: Different parts of this structure are guarded by different
253  * locks: global threading of multiple vHCIs and initialization is protected
254  * by mdi_mutex, the list of pHCIs associated with a vHCI is protected by
255  * vh_phci_mutex, and Clients are protected by vh_client_mutex.
256  *
257  * XXX Depending on the context, some of the fields can be freely read without
258  * holding any locks (ex. holding vh_client_mutex lock also guarantees that
259  * the vHCI (parent) cannot be unexpectedly freed).
260  */
261 typedef struct mdi_vhci {
262 	/* protected by mdi_mutex... */
263 	struct mdi_vhci		*vh_next;	/* next vHCI link	*/
264 	struct mdi_vhci		*vh_prev;	/* prev vHCI link	*/
265 	char			*vh_class;	/* vHCI class name	*/
266 	dev_info_t		*vh_dip;	/* vHCI devi handle	*/
267 	int			vh_refcnt;	/* vHCI reference count	*/
268 	struct mdi_vhci_config	*vh_config;	/* vHCI config		*/
269 	client_lb_t		vh_lb;		/* vHCI load-balancing	*/
270 	struct mdi_vhci_ops	*vh_ops;	/* vHCI callback vectors */
271 
272 	/* protected by MDI_VHCI_PHCI_LOCK vh_phci_mutex... */
273 	kmutex_t		vh_phci_mutex;	/* pHCI mutex		*/
274 	int			vh_phci_count;	/* pHCI device count	*/
275 	struct mdi_phci		*vh_phci_head;	/* pHCI list head	*/
276 	struct mdi_phci		*vh_phci_tail;	/* pHCI list tail	*/
277 
278 	/* protected by MDI_VHCI_CLIENT_LOCK vh_client_mutex... */
279 	kmutex_t		vh_client_mutex; /* Client mutex	*/
280 	int			vh_client_count; /* Client count	*/
281 	struct client_hash	*vh_client_table; /* Client hash	*/
282 } mdi_vhci_t;
283 
284 /*
285  * per-vHCI lock macros
286  */
287 #define	MDI_VHCI_PHCI_LOCK(vh)		mutex_enter(&(vh)->vh_phci_mutex)
288 #define	MDI_VHCI_PHCI_TRYLOCK(vh)	mutex_tryenter(&(vh)->vh_phci_mutex)
289 #define	MDI_VHCI_PHCI_UNLOCK(vh)	mutex_exit(&(vh)->vh_phci_mutex)
290 #ifdef	DEBUG
291 #define	MDI_VHCI_PCHI_LOCKED(vh)	MUTEX_HELD(&(vh)->vh_phci_mutex)
292 #endif	/* DEBUG */
293 #define	MDI_VHCI_CLIENT_LOCK(vh)	mutex_enter(&(vh)->vh_client_mutex)
294 #define	MDI_VHCI_CLIENT_TRYLOCK(vh)	mutex_tryenter(&(vh)->vh_client_mutex)
295 #define	MDI_VHCI_CLIENT_UNLOCK(vh)	mutex_exit(&(vh)->vh_client_mutex)
296 #ifdef	DEBUG
297 #define	MDI_VHCI_CLIENT_LOCKED(vh)	MUTEX_HELD(&(vh)->vh_client_mutex)
298 #endif	/* DEBUG */
299 
300 
301 /*
302  * GUID Hash definitions
303  *
304  * Since all the mpxio managed devices for a given class are enumerated under
305  * the single vHCI instance for that class, sequentially walking through the
306  * client device link to find a client would be prohibitively slow.
307  */
308 
309 #define	CLIENT_HASH_TABLE_SIZE	(32)	/* GUID hash */
310 
311 /*
312  * Client hash table structure
313  */
314 struct client_hash {
315 	struct mdi_client	*ct_hash_head;	/* Client hash head	*/
316 	int			ct_hash_count;	/* Client hash count	*/
317 };
318 
319 
320 /*
321  * pHCI Drivers:
322  *
323  * Physical HBA drivers provide transport services for mpxio-managed devices.
324  * As each pHCI instance is attached, it must register itself with the mpxio
325  * framework using mdi_phci_register().  When the pHCI is detached it must
326  * similarly call mdi_phci_unregister().
327  *
328  * The framework maintains a list of registered pHCI device instances for each
329  * vHCI.  This list involves (vh_phci_count, vh_phci_head, vh_phci_tail) and
330  * (ph_next, ph_prev, ph_vhci) and is protected by vh_phci_mutex.
331  *
332  * Locking order:
333  *
334  * _NOTE(LOCK_ORDER(mdi_mutex, mdi_phci::ph_mutex))		XXX
335  * _NOTE(LOCK_ORDER(mdi_phci::ph_mutex devinfo_tree_lock))		XXX
336  */
337 typedef struct mdi_phci {
338 	/* protected by MDI_VHCI_PHCI_LOCK vh_phci_mutex... */
339 	struct mdi_phci		*ph_next;	/* next pHCI link	*/
340 	struct mdi_phci		*ph_prev;	/* prev pHCI link	*/
341 	dev_info_t		*ph_dip;	/* pHCI devi handle	*/
342 	struct mdi_vhci 	*ph_vhci;	/* pHCI back ref. to vHCI */
343 
344 	/* protected by MDI_PHCI_LOCK ph_mutex... */
345 	kmutex_t		ph_mutex;	/* per-pHCI mutex	*/
346 	int			ph_path_count;	/* pi count		*/
347 	mdi_pathinfo_t		*ph_path_head;	/* pi list head		*/
348 	mdi_pathinfo_t		*ph_path_tail;	/* pi list tail		*/
349 	int			ph_flags;	/* pHCI operation flags	*/
350 	int			ph_unstable;	/* Paths in transient state */
351 	kcondvar_t		ph_unstable_cv;	/* Paths in transient state */
352 
353 	/* protected by mdi_phci_[gs]et_vhci_private caller... */
354 	void			*ph_vprivate;	/* vHCI driver private	*/
355 } mdi_phci_t;
356 
357 /*
358  * A pHCI device is 'unstable' while one or more paths are in a transitional
359  * state.  Hotplugging is prevented during this state.
360  */
361 #define	MDI_PHCI_UNSTABLE(ph)		(ph)->ph_unstable++;
362 #define	MDI_PHCI_STABLE(ph) { \
363 	(ph)->ph_unstable--; \
364 	if ((ph)->ph_unstable == 0) { \
365 		cv_broadcast(&(ph)->ph_unstable_cv); \
366 	} \
367 }
368 
369 /*
370  * per-pHCI lock macros
371  */
372 #define	MDI_PHCI_LOCK(ph)		mutex_enter(&(ph)->ph_mutex)
373 #define	MDI_PHCI_TRYLOCK(ph)		mutex_tryenter(&(ph)->ph_mutex)
374 #define	MDI_PHCI_UNLOCK(ph)		mutex_exit(&(ph)->ph_mutex)
375 #ifdef	DEBUG
376 #define	MDI_PHCI_LOCKED(vh)		MUTEX_HELD(&(ph)->ph_mutex)
377 #endif	/* DEBUG */
378 
379 /*
380  * pHCI state definitions and macros to track the pHCI driver instance state
381  */
382 #define	MDI_PHCI_FLAGS_OFFLINE		0x1	/* pHCI is offline */
383 #define	MDI_PHCI_FLAGS_SUSPEND		0x2	/* pHCI is suspended */
384 #define	MDI_PHCI_FLAGS_POWER_DOWN	0x4	/* pHCI is power down */
385 #define	MDI_PHCI_FLAGS_DETACH		0x8	/* pHCI is detached */
386 #define	MDI_PHCI_FLAGS_USER_DISABLE	0x10	/* pHCI is disabled,user */
387 #define	MDI_PHCI_FLAGS_D_DISABLE	0x20	/* pHCI is disabled,driver */
388 #define	MDI_PHCI_FLAGS_D_DISABLE_TRANS	0x40	/* pHCI is disabled,transient */
389 #define	MDI_PHCI_FLAGS_POWER_TRANSITION	0x80	/* pHCI is power transition */
390 
391 #define	MDI_PHCI_DISABLE_MASK						\
392 	    (MDI_PHCI_FLAGS_USER_DISABLE | MDI_PHCI_FLAGS_D_DISABLE |	\
393 	    MDI_PHCI_FLAGS_D_DISABLE_TRANS)
394 
395 #define	MDI_PHCI_IS_READY(ph)						\
396 	    (((ph)->ph_flags & MDI_PHCI_DISABLE_MASK) == 0)
397 
398 #define	MDI_PHCI_SET_OFFLINE(ph) 					{\
399 	    ASSERT(MDI_PHCI_LOCKED(ph));				\
400 	    (ph)->ph_flags |= MDI_PHCI_FLAGS_OFFLINE;			}
401 #define	MDI_PHCI_SET_ONLINE(ph)						{\
402 	    ASSERT(MDI_PHCI_LOCKED(ph));				\
403 	    (ph)->ph_flags &= ~MDI_PHCI_FLAGS_OFFLINE;			}
404 #define	MDI_PHCI_IS_OFFLINE(ph)						\
405 	    ((ph)->ph_flags & MDI_PHCI_FLAGS_OFFLINE)
406 
407 #define	MDI_PHCI_SET_SUSPEND(ph) 					{\
408 	    ASSERT(MDI_PHCI_LOCKED(ph));				\
409 	    (ph)->ph_flags |= MDI_PHCI_FLAGS_SUSPEND;			}
410 #define	MDI_PHCI_SET_RESUME(ph)						{\
411 	    ASSERT(MDI_PHCI_LOCKED(ph));				\
412 	    (ph)->ph_flags &= ~MDI_PHCI_FLAGS_SUSPEND;			}
413 #define	MDI_PHCI_IS_SUSPENDED(ph)					\
414 	    ((ph)->ph_flags & MDI_PHCI_FLAGS_SUSPEND)
415 
416 #define	MDI_PHCI_SET_DETACH(ph)						{\
417 	    ASSERT(MDI_PHCI_LOCKED(ph));				\
418 	    (ph)->ph_flags |= MDI_PHCI_FLAGS_DETACH;			}
419 #define	MDI_PHCI_SET_ATTACH(ph)						{\
420 	    ASSERT(MDI_PHCI_LOCKED(ph));				\
421 	    (ph)->ph_flags &= ~MDI_PHCI_FLAGS_DETACH;			}
422 
423 #define	MDI_PHCI_SET_POWER_DOWN(ph)					{\
424 	    ASSERT(MDI_PHCI_LOCKED(ph));				\
425 	    (ph)->ph_flags |= MDI_PHCI_FLAGS_POWER_DOWN;		}
426 #define	MDI_PHCI_SET_POWER_UP(ph)					{\
427 	    ASSERT(MDI_PHCI_LOCKED(ph));				\
428 	    (ph)->ph_flags &= ~MDI_PHCI_FLAGS_POWER_DOWN;		}
429 #define	MDI_PHCI_IS_POWERED_DOWN(ph)					\
430 	    ((ph)->ph_flags & MDI_PHCI_FLAGS_POWER_DOWN)
431 
432 #define	MDI_PHCI_SET_USER_ENABLE(ph)					{\
433 	    ASSERT(MDI_PHCI_LOCKED(ph));				\
434 	    (ph)->ph_flags &= ~MDI_PHCI_FLAGS_USER_DISABLE;		}
435 #define	MDI_PHCI_SET_USER_DISABLE(ph)					{\
436 	    ASSERT(MDI_PHCI_LOCKED(ph));				\
437 	    (ph)->ph_flags |= MDI_PHCI_FLAGS_USER_DISABLE;		}
438 #define	MDI_PHCI_IS_USER_DISABLED(ph)					\
439 	    ((ph)->ph_flags & MDI_PHCI_FLAGS_USER_DISABLE)
440 
441 #define	MDI_PHCI_SET_DRV_ENABLE(ph)					{\
442 	    ASSERT(MDI_PHCI_LOCKED(ph));				\
443 	    (ph)->ph_flags &= ~MDI_PHCI_FLAGS_D_DISABLE;		}
444 #define	MDI_PHCI_SET_DRV_DISABLE(ph)					{\
445 	    ASSERT(MDI_PHCI_LOCKED(ph));				\
446 	    (ph)->ph_flags |= MDI_PHCI_FLAGS_D_DISABLE;			}
447 #define	MDI_PHCI_IS_DRV_DISABLED(ph)					\
448 	    ((ph)->ph_flags & MDI_PHCI_FLAGS_D_DISABLE)
449 
450 #define	MDI_PHCI_SET_DRV_ENABLE_TRANSIENT(ph)				{\
451 	    ASSERT(MDI_PHCI_LOCKED(ph));				\
452 	    (ph)->ph_flags &= ~MDI_PHCI_FLAGS_D_DISABLE_TRANS;		}
453 #define	MDI_PHCI_SET_DRV_DISABLE_TRANSIENT(ph)				{\
454 	    ASSERT(MDI_PHCI_LOCKED(ph));				\
455 	    (ph)->ph_flags |= MDI_PHCI_FLAGS_D_DISABLE_TRANS;		}
456 #define	MDI_PHCI_IS_DRV_DISABLED_TRANSIENT(ph)				\
457 	    ((ph)->ph_flags & MDI_PHCI_FLAGS_D_DISABLE_TRANS)
458 
459 #define	MDI_PHCI_SET_POWER_TRANSITION(ph)				{\
460 	    ASSERT(MDI_PHCI_LOCKED(ph));				\
461 	    (ph)->ph_flags |= MDI_PHCI_FLAGS_POWER_TRANSITION;		}
462 #define	MDI_PHCI_CLEAR_POWER_TRANSITION(ph)				{\
463 	    ASSERT(MDI_PHCI_LOCKED(ph));				\
464 	    (ph)->ph_flags &= ~MDI_PHCI_FLAGS_POWER_TRANSITION;		}
465 #define	MDI_PHCI_IS_POWER_TRANSITION(ph)				\
466 	    ((ph)->ph_flags & MDI_PHCI_FLAGS_POWER_TRANSITION)
467 
468 /*
469  * mpxio Managed Clients:
470  *
471  * This framework creates a struct mdi_client for every client device created
472  * by the framework as a result of self-enumeration of target devices by the
473  * registered pHCI devices.  This structure is bound to client device dev_info
474  * node at the time of client device allocation (ndi_devi_alloc(9e)). This
475  * structure is unbound from the dev_info node when mpxio framework removes a
476  * client device node from the system.
477  *
478  * This structure is created when a first path is enumerated and removed when
479  * last path is de-enumerated from the system.
480  *
481  * Multipath client devices are instantiated as children of corresponding vHCI
482  * driver instance. Each client device is uniquely identified by a GUID
483  * provided by target device itself.  The parent vHCI device also maintains a
484  * hashed list of client devices, protected by vh_client_mutex.
485  *
486  * Typically pHCI devices self-enumerate their child devices using taskq,
487  * resulting in multiple paths to the same client device to be enumerated by
488  * competing threads.
489  *
490  * Currently this framework supports two kinds of load-balancing policy
491  * configurable through the vHCI driver configuration files.
492  *
493  * NONE		- Legacy AP mode
494  * Round Robin	- Balance the pHCI load in a Round Robin fashion.
495  *
496  * This framework identifies the client device in three distinct states:
497  *
498  * OPTIMAL	- Client device has atleast one redundant path.
499  * DEGRADED	- No redundant paths (critical).  Failure in the current active
500  *		  path would result in data access failures.
501  * FAILED 	- No paths are available to access this device.
502  *
503  * Locking order:
504  *
505  * _NOTE(LOCK_ORDER(mdi_mutex, mdi_client::ct_mutex))			XXX
506  * _NOTE(LOCK_ORDER(mdi_client::ct_mutex devinfo_tree_lock))		XXX
507  */
508 typedef struct mdi_client {
509 	/* protected by MDI_VHCI_CLIENT_LOCK vh_client_mutex... */
510 	struct mdi_client	*ct_hnext;	/* next client		*/
511 	struct mdi_client	*ct_hprev;	/* prev client		*/
512 	dev_info_t		*ct_dip;	/* client devi handle	*/
513 	struct mdi_vhci		*ct_vhci;	/* vHCI back ref	*/
514 	char			*ct_drvname;	/* client driver name	*/
515 	char			*ct_guid;	/* client guid		*/
516 	client_lb_t		ct_lb;		/* load balancing scheme */
517 	client_lb_args_t	*ct_lb_args; 	/* load balancing args */
518 
519 
520 	/* protected by MDI_CLIENT_LOCK ct_mutex... */
521 	kmutex_t		ct_mutex;	/* per-client mutex	*/
522 	int			ct_path_count;	/* multi path count	*/
523 	mdi_pathinfo_t		*ct_path_head;	/* multi path list head	*/
524 	mdi_pathinfo_t		*ct_path_tail;	/* multi path list tail	*/
525 	mdi_pathinfo_t		*ct_path_last;	/* last path used for i/o */
526 	int			ct_state;	/* state information	*/
527 	int			ct_flags;	/* Driver op. flags	*/
528 	int			ct_failover_flags;	/* Failover args */
529 	int			ct_failover_status;	/* last fo status */
530 	kcondvar_t		ct_failover_cv;	/* Failover status cv	*/
531 	int			ct_unstable;	/* Paths in transient state */
532 	kcondvar_t		ct_unstable_cv;	/* Paths in transient state */
533 
534 	int			ct_power_cnt;	/* Hold count on parent power */
535 	kcondvar_t		ct_powerchange_cv;
536 					/* Paths in power transient state */
537 	short			ct_powercnt_config;
538 					/* held in pre/post config */
539 	short			ct_powercnt_unconfig;
540 					/* held in pre/post unconfig */
541 	int			ct_powercnt_reset;
542 					/* ct_power_cnt was resetted */
543 
544 	void			*ct_cprivate;	/* client driver private */
545 	void			*ct_vprivate;	/* vHCI driver private	*/
546 } mdi_client_t;
547 
548 /*
549  * per-Client device locking definitions
550  */
551 #define	MDI_CLIENT_LOCK(ct)		mutex_enter(&(ct)->ct_mutex)
552 #define	MDI_CLIENT_TRYLOCK(ct)		mutex_tryenter(&(ct)->ct_mutex)
553 #define	MDI_CLIENT_UNLOCK(ct)		mutex_exit(&(ct)->ct_mutex)
554 #ifdef	DEBUG
555 #define	MDI_CLIENT_LOCKED(ct)		MUTEX_HELD(&(ct)->ct_mutex)
556 #endif	/* DEBUG */
557 
558 /*
559  * A Client device is in unstable while one or more paths are in transitional
560  * state.  We do not allow failover to take place while paths are in transient
561  * state. Similarly we do not allow state transition while client device
562  * failover is in progress.
563  */
564 #define	MDI_CLIENT_UNSTABLE(ct)		(ct)->ct_unstable++;
565 #define	MDI_CLIENT_STABLE(ct) { \
566 	(ct)->ct_unstable--; \
567 	if ((ct)->ct_unstable == 0) { \
568 		cv_broadcast(&(ct)->ct_unstable_cv); \
569 	} \
570 }
571 
572 /*
573  * Client driver instance state definitions:
574  */
575 #define	MDI_CLIENT_FLAGS_OFFLINE		0x00000001
576 #define	MDI_CLIENT_FLAGS_SUSPEND		0x00000002
577 #define	MDI_CLIENT_FLAGS_POWER_DOWN		0x00000004
578 #define	MDI_CLIENT_FLAGS_DETACH			0x00000008
579 #define	MDI_CLIENT_FLAGS_FAILOVER		0x00000010
580 #define	MDI_CLIENT_FLAGS_REPORT_DEV		0x00000020
581 #define	MDI_CLIENT_FLAGS_PATH_FREE_IN_PROGRESS	0x00000040
582 #define	MDI_CLIENT_FLAGS_ASYNC_FREE		0x00000080
583 #define	MDI_CLIENT_FLAGS_DEV_NOT_SUPPORTED	0x00000100
584 #define	MDI_CLIENT_FLAGS_POWER_TRANSITION	0x00000200
585 
586 #define	MDI_CLIENT_SET_OFFLINE(ct)					{\
587 	    ASSERT(MDI_CLIENT_LOCKED(ct));				\
588 	    (ct)->ct_flags |= MDI_CLIENT_FLAGS_OFFLINE;			}
589 #define	MDI_CLIENT_SET_ONLINE(ct)					{\
590 	    ASSERT(MDI_CLIENT_LOCKED(ct));				\
591 	    (ct)->ct_flags &= ~MDI_CLIENT_FLAGS_OFFLINE;		}
592 #define	MDI_CLIENT_IS_OFFLINE(ct) \
593 	    ((ct)->ct_flags & MDI_CLIENT_FLAGS_OFFLINE)
594 
595 #define	MDI_CLIENT_SET_SUSPEND(ct)					{\
596 	    ASSERT(MDI_CLIENT_LOCKED(ct));				\
597 	    (ct)->ct_flags |= MDI_CLIENT_FLAGS_SUSPEND;			}
598 #define	MDI_CLIENT_SET_RESUME(ct)					{\
599 	    ASSERT(MDI_CLIENT_LOCKED(ct));				\
600 	    (ct)->ct_flags &= ~MDI_CLIENT_FLAGS_SUSPEND;		}
601 #define	MDI_CLIENT_IS_SUSPENDED(ct) \
602 	    ((ct)->ct_flags & MDI_CLIENT_FLAGS_SUSPEND)
603 
604 #define	MDI_CLIENT_SET_POWER_DOWN(ct)					{\
605 	    ASSERT(MDI_CLIENT_LOCKED(ct));				\
606 	    (ct)->ct_flags |= MDI_CLIENT_FLAGS_POWER_DOWN;		}
607 #define	MDI_CLIENT_SET_POWER_UP(ct)					{\
608 	    ASSERT(MDI_CLIENT_LOCKED(ct));				\
609 	    (ct)->ct_flags &= ~MDI_CLIENT_FLAGS_POWER_DOWN;		}
610 #define	MDI_CLIENT_IS_POWERED_DOWN(ct) \
611 	    ((ct)->ct_flags & MDI_CLIENT_FLAGS_POWER_DOWN)
612 
613 #define	MDI_CLIENT_SET_POWER_TRANSITION(ct)				{\
614 	    ASSERT(MDI_CLIENT_LOCKED(ct));				\
615 	    (ct)->ct_flags |= MDI_CLIENT_FLAGS_POWER_TRANSITION;	}
616 #define	MDI_CLIENT_CLEAR_POWER_TRANSITION(ct)				{\
617 	    ASSERT(MDI_CLIENT_LOCKED(ct));				\
618 	    (ct)->ct_flags &= ~MDI_CLIENT_FLAGS_POWER_TRANSITION;	}
619 #define	MDI_CLIENT_IS_POWER_TRANSITION(ct) \
620 	    ((ct)->ct_flags & MDI_CLIENT_FLAGS_POWER_TRANSITION)
621 
622 #define	MDI_CLIENT_SET_DETACH(ct)					{\
623 	    ASSERT(MDI_CLIENT_LOCKED(ct));				\
624 	    (ct)->ct_flags |= MDI_CLIENT_FLAGS_DETACH;			}
625 #define	MDI_CLIENT_SET_ATTACH(ct)					{\
626 	    ASSERT(MDI_CLIENT_LOCKED(ct));				\
627 	    (ct)->ct_flags &= ~MDI_CLIENT_FLAGS_DETACH;			}
628 #define	MDI_CLIENT_IS_DETACHED(ct) \
629 	    ((ct)->ct_flags & MDI_CLIENT_FLAGS_DETACH)
630 
631 #define	MDI_CLIENT_SET_FAILOVER_IN_PROGRESS(ct)				{\
632 	    ASSERT(MDI_CLIENT_LOCKED(ct));				\
633 	    (ct)->ct_flags |= MDI_CLIENT_FLAGS_FAILOVER;		}
634 #define	MDI_CLIENT_CLEAR_FAILOVER_IN_PROGRESS(ct)			{\
635 	    ASSERT(MDI_CLIENT_LOCKED(ct));				\
636 	    (ct)->ct_flags &= ~MDI_CLIENT_FLAGS_FAILOVER;		}
637 #define	MDI_CLIENT_IS_FAILOVER_IN_PROGRESS(ct) \
638 	    ((ct)->ct_flags & MDI_CLIENT_FLAGS_FAILOVER)
639 
640 #define	MDI_CLIENT_SET_REPORT_DEV_NEEDED(ct)				{\
641 	    ASSERT(MDI_CLIENT_LOCKED(ct));				\
642 	    (ct)->ct_flags |= MDI_CLIENT_FLAGS_REPORT_DEV;		}
643 #define	MDI_CLIENT_CLEAR_REPORT_DEV_NEEDED(ct)				{\
644 	    ASSERT(MDI_CLIENT_LOCKED(ct));				\
645 	    (ct)->ct_flags &= ~MDI_CLIENT_FLAGS_REPORT_DEV;		}
646 #define	MDI_CLIENT_IS_REPORT_DEV_NEEDED(ct) \
647 	    ((ct)->ct_flags & MDI_CLIENT_FLAGS_REPORT_DEV)
648 
649 #define	MDI_CLIENT_SET_PATH_FREE_IN_PROGRESS(ct)			{\
650 	    ASSERT(MDI_CLIENT_LOCKED(ct));				\
651 	    (ct)->ct_flags |= MDI_CLIENT_FLAGS_PATH_FREE_IN_PROGRESS;	}
652 #define	MDI_CLIENT_CLEAR_PATH_FREE_IN_PROGRESS(ct)			{\
653 	    ASSERT(MDI_CLIENT_LOCKED(ct));				\
654 	    (ct)->ct_flags &= ~MDI_CLIENT_FLAGS_PATH_FREE_IN_PROGRESS;	}
655 #define	MDI_CLIENT_IS_PATH_FREE_IN_PROGRESS(ct) \
656 	    ((ct)->ct_flags & MDI_CLIENT_FLAGS_PATH_FREE_IN_PROGRESS)
657 
658 #define	MDI_CLIENT_SET_DEV_NOT_SUPPORTED(ct)				{\
659 	    ASSERT(MDI_CLIENT_LOCKED(ct));				\
660 	    (ct)->ct_flags |= MDI_CLIENT_FLAGS_DEV_NOT_SUPPORTED;	}
661 #define	MDI_CLIENT_IS_DEV_NOT_SUPPORTED(ct) \
662 	    ((ct)->ct_flags & MDI_CLIENT_FLAGS_DEV_NOT_SUPPORTED)
663 
664 /*
665  * Client operating states.
666  */
667 #define	MDI_CLIENT_STATE_OPTIMAL	1
668 #define	MDI_CLIENT_STATE_DEGRADED	2
669 #define	MDI_CLIENT_STATE_FAILED		3
670 
671 #define	MDI_CLIENT_STATE(ct) ((ct)->ct_state)
672 #define	MDI_CLIENT_SET_STATE(ct, state) ((ct)->ct_state = state)
673 
674 #define	MDI_CLIENT_IS_FAILED(ct) \
675 	    ((ct)->ct_state == MDI_CLIENT_STATE_FAILED)
676 
677 /*
678  * mdi_pathinfo nodes:
679  *
680  * From this framework's perspective, a 'path' is a tuple consisting of a
681  * client or end device, a host controller which provides device
682  * identification and transport services (pHCI), and bus specific unit
683  * addressing information.  A path may be decorated with properties which
684  * describe the capabilities of the path; such properties are analogous to
685  * device node and minor node properties.
686  *
687  * The framework maintains link list of mdi_pathinfo nodes created by every
688  * pHCI driver instance via the pi_phci_link linkage; this is used (for example)
689  * to make sure that all relevant pathinfo nodes are freed before the pHCI
690  * is unregistered.
691  *
692  * Locking order:
693  *
694  * _NOTE(LOCK_ORDER(mdi_phci::ph_mutex mdi_pathinfo::pi_mutex))		XXX
695  * _NOTE(LOCK_ORDER(mdi_client::ct_mutex mdi_pathinfo::pi_mutex))	XXX
696  * _NOTE(LOCK_ORDER(mdi_phci::ph_mutex mdi_client::ct_mutex))		XXX
697  * _NOTE(LOCK_ORDER(devinfo_tree_lock mdi_pathinfo::pi_mutex))		XXX
698  *
699  * mdi_pathinfo node structure definition
700  */
701 struct mdi_pathinfo {
702 	/* protected by MDI_PHCI_LOCK ph_mutex... */
703 	struct mdi_pathinfo	*pi_phci_link;	 /* next path in phci list */
704 	mdi_phci_t		*pi_phci;	/* pHCI dev_info node	*/
705 
706 	/* protected by MDI_CLIENT_LOCK ct_mutex... */
707 	struct mdi_pathinfo	*pi_client_link; /* next path in client list */
708 	mdi_client_t		*pi_client;	/* client		*/
709 
710 	/* protected by MDI_VHCI_CLIENT_LOCK vh_client_mutex... */
711 	char			*pi_addr;	/* path unit address	*/
712 
713 	/* protected by MDI_PI_LOCK pi_mutex... */
714 	kmutex_t		pi_mutex;	/* per path mutex	*/
715 	mdi_pathinfo_state_t	pi_state;	/* path state		*/
716 	mdi_pathinfo_state_t	pi_old_state;	/* path state		*/
717 	kcondvar_t		pi_state_cv;	/* path state condvar	*/
718 	nvlist_t		*pi_prop;	/* Properties		*/
719 	void			*pi_cprivate;	/* client private info	*/
720 	void			*pi_pprivate;	/* phci private info	*/
721 	int			pi_ref_cnt;	/* pi reference count	*/
722 	kcondvar_t		pi_ref_cv;	/* condition variable	*/
723 	struct mdi_pi_kstats	*pi_kstats;	/* aggregate kstats */
724 	int			pi_pm_held;	/* phci's kidsup incremented */
725 	int			pi_preferred;	/* Preferred path 	*/
726 	void			*pi_vprivate;	/* vhci private info	*/
727 };
728 
729 /*
730  * pathinfo statistics:
731  *
732  * The mpxio architecture allows for multiple pathinfo nodes for each
733  * client-pHCI combination.  For statistics purposes, these statistics are
734  * aggregated into a single client-pHCI set of kstats.
735  */
736 struct mdi_pi_kstats {
737 	int	pi_kstat_ref;		/* # paths aggregated, also a ref cnt */
738 	kstat_t	*pi_kstat_iostats;	/* mdi:iopath statistic set */
739 	kstat_t *pi_kstat_errstats;	/* error statistics */
740 };
741 
742 /*
743  * pathinfo error kstat
744  */
745 struct pi_errs {
746 	struct kstat_named pi_softerrs;		/* "Soft" Error */
747 	struct kstat_named pi_harderrs;		/* "Hard" Error */
748 	struct kstat_named pi_transerrs;	/* Transport Errors */
749 	struct kstat_named pi_icnt_busy;	/* Interconnect Busy */
750 	struct kstat_named pi_icnt_errors;	/* Interconnect Errors */
751 	struct kstat_named pi_phci_rsrc;	/* pHCI No Resources */
752 	struct kstat_named pi_phci_localerr;	/* pHCI Local Errors */
753 	struct kstat_named pi_phci_invstate;	/* pHCI Invalid State */
754 	struct kstat_named pi_failedfrom;	/* Failover: Failed From */
755 	struct kstat_named pi_failedto;		/* Failover: Failed To */
756 };
757 
758 /*
759  * increment an error counter
760  */
761 #define	MDI_PI_ERRSTAT(pip, x) { \
762 	if (MDI_PI((pip))->pi_kstats != NULL) { \
763 		struct pi_errs *pep; \
764 		pep = MDI_PI(pip)->pi_kstats->pi_kstat_errstats->ks_data; \
765 		pep->x.value.ui32++; \
766 	} \
767 }
768 
769 /*
770  * error codes which can be passed to MDI_PI_ERRSTAT
771  */
772 #define	MDI_PI_SOFTERR	pi_softerrs
773 #define	MDI_PI_HARDERR	pi_harderrs
774 #define	MDI_PI_TRANSERR	pi_transerrs
775 #define	MDI_PI_ICNTBUSY	pi_icnt_busy
776 #define	MDI_PI_ICNTERR	pi_icnt_errors
777 #define	MDI_PI_PHCIRSRC	pi_phci_rsrc
778 #define	MDI_PI_PHCILOCL	pi_phci_localerr
779 #define	MDI_PI_PHCIINVS	pi_phci_invstate
780 #define	MDI_PI_FAILFROM	pi_failedfrom
781 #define	MDI_PI_FAILTO	pi_failedto
782 
783 #define	MDI_PI(type)			((struct mdi_pathinfo *)(type))
784 
785 #define	MDI_PI_LOCK(pip)		mutex_enter(&MDI_PI(pip)->pi_mutex)
786 #define	MDI_PI_TRYLOCK(pip)		mutex_tryenter(&MDI_PI(pip)->pi_mutex)
787 #define	MDI_PI_UNLOCK(pip)		mutex_exit(&MDI_PI(pip)->pi_mutex)
788 #ifdef	DEBUG
789 #define	MDI_PI_LOCKED(pip)		MUTEX_HELD(&MDI_PI(pip)->pi_mutex)
790 #endif	/* DEBUG */
791 
792 #define	MDI_PI_HOLD(pip)		(++MDI_PI(pip)->pi_ref_cnt)
793 #define	MDI_PI_RELE(pip)		(--MDI_PI(pip)->pi_ref_cnt)
794 
795 #define	MDI_EXT_STATE_CHANGE		0x10000000
796 
797 
798 #define	MDI_DISABLE_OP			0x1
799 #define	MDI_ENABLE_OP			0x2
800 #define	MDI_BEFORE_STATE_CHANGE		0x4
801 #define	MDI_AFTER_STATE_CHANGE		0x8
802 #define	MDI_SYNC_FLAG			0x10
803 
804 #define	MDI_PI_STATE(pip)						\
805 	(MDI_PI((pip))->pi_state & MDI_PATHINFO_STATE_MASK)
806 #define	MDI_PI_OLD_STATE(pip)						\
807 	(MDI_PI((pip))->pi_old_state & MDI_PATHINFO_STATE_MASK)
808 
809 #define	MDI_PI_EXT_STATE(pip)						\
810 	(MDI_PI((pip))->pi_state & MDI_PATHINFO_EXT_STATE_MASK)
811 #define	MDI_PI_OLD_EXT_STATE(pip)					\
812 	(MDI_PI((pip))->pi_old_state & MDI_PATHINFO_EXT_STATE_MASK)
813 
814 #define	MDI_PI_SET_TRANSIENT(pip)					{\
815 	ASSERT(MDI_PI_LOCKED(pip));					\
816 	MDI_PI(pip)->pi_state |= MDI_PATHINFO_STATE_TRANSIENT;		}
817 #define	MDI_PI_CLEAR_TRANSIENT(pip)					{\
818 	ASSERT(MDI_PI_LOCKED(pip));					\
819 	MDI_PI(pip)->pi_state &= ~MDI_PATHINFO_STATE_TRANSIENT;		}
820 #define	MDI_PI_IS_TRANSIENT(pip) \
821 	(MDI_PI(pip)->pi_state & MDI_PATHINFO_STATE_TRANSIENT)
822 
823 #define	MDI_PI_SET_USER_DISABLE(pip)					{\
824 	ASSERT(MDI_PI_LOCKED(pip));					\
825 	MDI_PI(pip)->pi_state |= MDI_PATHINFO_STATE_USER_DISABLE;	}
826 #define	MDI_PI_SET_DRV_DISABLE(pip)					{\
827 	ASSERT(MDI_PI_LOCKED(pip));					\
828 	MDI_PI(pip)->pi_state |= MDI_PATHINFO_STATE_DRV_DISABLE;	}
829 #define	MDI_PI_SET_DRV_DISABLE_TRANS(pip)				{\
830 	ASSERT(MDI_PI_LOCKED(pip));					\
831 	MDI_PI(pip)->pi_state |= MDI_PATHINFO_STATE_DRV_DISABLE_TRANSIENT; }
832 
833 #define	MDI_PI_SET_USER_ENABLE(pip)					{\
834 	ASSERT(MDI_PI_LOCKED(pip));					\
835 	MDI_PI(pip)->pi_state &= ~MDI_PATHINFO_STATE_USER_DISABLE;	}
836 #define	MDI_PI_SET_DRV_ENABLE(pip)					{\
837 	ASSERT(MDI_PI_LOCKED(pip));					\
838 	MDI_PI(pip)->pi_state &= ~MDI_PATHINFO_STATE_DRV_DISABLE;	}
839 #define	MDI_PI_SET_DRV_ENABLE_TRANS(pip)				{\
840 	ASSERT(MDI_PI_LOCKED(pip));					\
841 	MDI_PI(pip)->pi_state &= ~MDI_PATHINFO_STATE_DRV_DISABLE_TRANSIENT; }
842 
843 #define	MDI_PI_IS_USER_DISABLE(pip)					\
844 	(MDI_PI(pip)->pi_state & MDI_PATHINFO_STATE_USER_DISABLE)
845 #define	MDI_PI_IS_DRV_DISABLE(pip)					\
846 	(MDI_PI(pip)->pi_state & MDI_PATHINFO_STATE_DRV_DISABLE)
847 #define	MDI_PI_IS_DRV_DISABLE_TRANSIENT(pip)				\
848 	(MDI_PI(pip)->pi_state & MDI_PATHINFO_STATE_DRV_DISABLE_TRANSIENT)
849 
850 #define	MDI_PI_IS_DISABLE(pip)						\
851 	(MDI_PI_IS_USER_DISABLE(pip) ||					\
852 	MDI_PI_IS_DRV_DISABLE(pip) ||					\
853 	MDI_PI_IS_DRV_DISABLE_TRANSIENT(pip))
854 
855 #define	MDI_PI_IS_INIT(pip)						\
856 	((MDI_PI(pip)->pi_state & MDI_PATHINFO_STATE_MASK) ==		\
857 		MDI_PATHINFO_STATE_INIT)
858 
859 #define	MDI_PI_IS_INITING(pip)						\
860 	((MDI_PI(pip)->pi_state & ~MDI_PATHINFO_EXT_STATE_MASK) ==	\
861 		(MDI_PATHINFO_STATE_INIT | MDI_PATHINFO_STATE_TRANSIENT))
862 
863 #define	MDI_PI_SET_INIT(pip)						{\
864 	ASSERT(MDI_PI_LOCKED(pip));					\
865 	MDI_PI(pip)->pi_state = MDI_PATHINFO_STATE_INIT;		}
866 
867 #define	MDI_PI_SET_ONLINING(pip)					{\
868 	uint32_t	ext_state;					\
869 	ASSERT(MDI_PI_LOCKED(pip));					\
870 	ext_state = MDI_PI(pip)->pi_state & MDI_PATHINFO_EXT_STATE_MASK; \
871 	MDI_PI(pip)->pi_old_state = MDI_PI_STATE(pip);			\
872 	MDI_PI(pip)->pi_state =						\
873 	(MDI_PATHINFO_STATE_ONLINE | MDI_PATHINFO_STATE_TRANSIENT);	\
874 	MDI_PI(pip)->pi_state |= ext_state;				}
875 
876 #define	MDI_PI_IS_ONLINING(pip)						\
877 	((MDI_PI(pip)->pi_state & ~MDI_PATHINFO_EXT_STATE_MASK) ==	\
878 	(MDI_PATHINFO_STATE_ONLINE | MDI_PATHINFO_STATE_TRANSIENT))
879 
880 #define	MDI_PI_SET_ONLINE(pip)						{\
881 	uint32_t	ext_state;					\
882 	ASSERT(MDI_PI_LOCKED(pip));					\
883 	ext_state = MDI_PI(pip)->pi_state & MDI_PATHINFO_EXT_STATE_MASK; \
884 	MDI_PI(pip)->pi_state = MDI_PATHINFO_STATE_ONLINE;		\
885 	MDI_PI(pip)->pi_state |= ext_state;				}
886 
887 #define	MDI_PI_IS_ONLINE(pip)						\
888 	((MDI_PI(pip)->pi_state & MDI_PATHINFO_STATE_MASK) ==		\
889 	MDI_PATHINFO_STATE_ONLINE)
890 
891 #define	MDI_PI_SET_OFFLINING(pip)					{\
892 	uint32_t	ext_state;					\
893 	ASSERT(MDI_PI_LOCKED(pip));					\
894 	ext_state = MDI_PI(pip)->pi_state & MDI_PATHINFO_EXT_STATE_MASK; \
895 	MDI_PI(pip)->pi_old_state = MDI_PI_STATE(pip);			\
896 	MDI_PI(pip)->pi_state =						\
897 	(MDI_PATHINFO_STATE_OFFLINE | MDI_PATHINFO_STATE_TRANSIENT);	\
898 	MDI_PI(pip)->pi_state |= ext_state;				}
899 
900 #define	MDI_PI_IS_OFFLINING(pip)					\
901 	((MDI_PI(pip)->pi_state & ~MDI_PATHINFO_EXT_STATE_MASK) ==	\
902 	(MDI_PATHINFO_STATE_OFFLINE | MDI_PATHINFO_STATE_TRANSIENT))
903 
904 #define	MDI_PI_SET_OFFLINE(pip)						{\
905 	uint32_t	ext_state;					\
906 	ASSERT(MDI_PI_LOCKED(pip));					\
907 	ext_state = MDI_PI(pip)->pi_state & MDI_PATHINFO_EXT_STATE_MASK; \
908 	MDI_PI(pip)->pi_state = MDI_PATHINFO_STATE_OFFLINE;		\
909 	MDI_PI(pip)->pi_state |= ext_state;				}
910 
911 #define	MDI_PI_IS_OFFLINE(pip)						\
912 	((MDI_PI(pip)->pi_state & MDI_PATHINFO_STATE_MASK) ==		\
913 	MDI_PATHINFO_STATE_OFFLINE)
914 
915 #define	MDI_PI_SET_STANDBYING(pip)					{\
916 	uint32_t	ext_state;					\
917 	ASSERT(MDI_PI_LOCKED(pip));					\
918 	ext_state = MDI_PI(pip)->pi_state & MDI_PATHINFO_EXT_STATE_MASK; \
919 	MDI_PI(pip)->pi_old_state = MDI_PI_STATE(pip);			\
920 	MDI_PI(pip)->pi_state =						\
921 	(MDI_PATHINFO_STATE_STANDBY | MDI_PATHINFO_STATE_TRANSIENT);	\
922 	MDI_PI(pip)->pi_state |= ext_state;				}
923 
924 #define	MDI_PI_SET_STANDBY(pip)						{\
925 	uint32_t	ext_state;					\
926 	ASSERT(MDI_PI_LOCKED(pip));					\
927 	ext_state = MDI_PI(pip)->pi_state & MDI_PATHINFO_EXT_STATE_MASK; \
928 	MDI_PI(pip)->pi_state = MDI_PATHINFO_STATE_STANDBY;		\
929 	MDI_PI(pip)->pi_state |= ext_state;				}
930 
931 #define	MDI_PI_IS_STANDBY(pip)						\
932 	((MDI_PI(pip)->pi_state & MDI_PATHINFO_STATE_MASK) ==		\
933 	MDI_PATHINFO_STATE_STANDBY)
934 
935 #define	MDI_PI_SET_FAULTING(pip)					{\
936 	uint32_t	ext_state;					\
937 	ASSERT(MDI_PI_LOCKED(pip));					\
938 	ext_state = MDI_PI(pip)->pi_state & MDI_PATHINFO_EXT_STATE_MASK; \
939 	MDI_PI(pip)->pi_old_state = MDI_PI_STATE(pip);			\
940 	MDI_PI(pip)->pi_state =						\
941 	    (MDI_PATHINFO_STATE_FAULT | MDI_PATHINFO_STATE_TRANSIENT);	\
942 	MDI_PI(pip)->pi_state |= ext_state;				}
943 
944 #define	MDI_PI_SET_FAULT(pip)						{\
945 	uint32_t	ext_state;					\
946 	ASSERT(MDI_PI_LOCKED(pip));					\
947 	ext_state = MDI_PI(pip)->pi_state & MDI_PATHINFO_EXT_STATE_MASK; \
948 	MDI_PI(pip)->pi_state = MDI_PATHINFO_STATE_FAULT;		\
949 	MDI_PI(pip)->pi_state |= ext_state;				}
950 
951 #define	MDI_PI_IS_FAULT(pip)						\
952 	((MDI_PI(pip)->pi_state & MDI_PATHINFO_STATE_MASK) ==		\
953 	MDI_PATHINFO_STATE_FAULT)
954 
955 #define	MDI_PI_IS_SUSPENDED(pip)					\
956 	((MDI_PI(pip))->pi_phci->ph_flags & MDI_PHCI_FLAGS_SUSPEND)
957 
958 /*
959  * mdi_vhcache_client, mdi_vhcache_pathinfo, and mdi_vhcache_phci structures
960  * hold the vhci to phci client mappings of the on-disk vhci busconfig cache.
961  */
962 
963 /* phci structure of vhci cache */
964 typedef struct mdi_vhcache_phci {
965 	char			*cphci_path;	/* phci path name */
966 	uint32_t		cphci_id;	/* used when building nvlist */
967 	mdi_phci_t		*cphci_phci;	/* pointer to actual phci */
968 	struct mdi_vhcache_phci	*cphci_next;	/* next in vhci phci list */
969 } mdi_vhcache_phci_t;
970 
971 /* pathinfo structure of vhci cache */
972 typedef struct mdi_vhcache_pathinfo {
973 	char			*cpi_addr;	/* path address */
974 	mdi_vhcache_phci_t	*cpi_cphci;	/* phci the path belongs to */
975 	struct mdi_pathinfo	*cpi_pip;	/* ptr to actual pathinfo */
976 	uint32_t		cpi_flags;	/* see below */
977 	struct mdi_vhcache_pathinfo *cpi_next;	/* next path for the client */
978 } mdi_vhcache_pathinfo_t;
979 
980 /*
981  * cpi_flags
982  *
983  * MDI_CPI_HINT_PATH_DOES_NOT_EXIST - set when configuration of the path has
984  * failed.
985  */
986 #define	MDI_CPI_HINT_PATH_DOES_NOT_EXIST	0x0001
987 
988 /* client structure of vhci cache */
989 typedef struct mdi_vhcache_client {
990 	char			*cct_name_addr;	/* client address */
991 	mdi_vhcache_pathinfo_t	*cct_cpi_head;	/* client's path list head */
992 	mdi_vhcache_pathinfo_t	*cct_cpi_tail;	/* client's path list tail */
993 	struct mdi_vhcache_client *cct_next;	/* next in vhci client list */
994 } mdi_vhcache_client_t;
995 
996 /* vhci cache structure - one for vhci instance */
997 typedef struct mdi_vhci_cache {
998 	mdi_vhcache_phci_t	*vhcache_phci_head;	/* phci list head */
999 	mdi_vhcache_phci_t	*vhcache_phci_tail;	/* phci list tail */
1000 	mdi_vhcache_client_t	*vhcache_client_head;	/* client list head */
1001 	mdi_vhcache_client_t	*vhcache_client_tail;	/* client list tail */
1002 	mod_hash_t		*vhcache_client_hash;	/* client hash */
1003 	int			vhcache_flags;		/* see below */
1004 	int64_t			vhcache_clean_time;	/* last clean time */
1005 	krwlock_t		vhcache_lock;		/* cache lock */
1006 } mdi_vhci_cache_t;
1007 
1008 /* vhcache_flags */
1009 #define	MDI_VHCI_CACHE_SETUP_DONE	0x0001	/* cache setup completed */
1010 
1011 /* vhci bus config structure - one for vhci instance */
1012 typedef struct mdi_vhci_config {
1013 	char			*vhc_vhcache_filename;	/* on-disk file name */
1014 	mdi_vhci_cache_t	vhc_vhcache;		/* vhci cache */
1015 	kmutex_t		vhc_lock;		/* vhci config lock */
1016 	kcondvar_t		vhc_cv;
1017 	int			vhc_flags;		/* see below */
1018 
1019 	/* flush vhci cache when lbolt reaches vhc_flush_at_ticks */
1020 	clock_t			vhc_flush_at_ticks;
1021 
1022 	/*
1023 	 * Head and tail of the client list whose paths are being configured
1024 	 * asynchronously. vhc_acc_count is the number of clients on this list.
1025 	 * vhc_acc_thrcount is the number threads running to configure
1026 	 * the paths for these clients.
1027 	 */
1028 	struct mdi_async_client_config *vhc_acc_list_head;
1029 	struct mdi_async_client_config *vhc_acc_list_tail;
1030 	int			vhc_acc_count;
1031 	int			vhc_acc_thrcount;
1032 
1033 	/* callback id - for flushing the cache during system shutdown */
1034 	callb_id_t		vhc_cbid;
1035 
1036 	/*
1037 	 * vhc_path_discovery_boot -	number of times path discovery will be
1038 	 *				attempted during early boot.
1039 	 * vhc_path_discovery_postboot	number of times path discovery will be
1040 	 *				attempted during late boot.
1041 	 * vhc_path_discovery_cutoff_time - time at which paths were last
1042 	 *				discovered  + some timeout
1043 	 */
1044 	int			vhc_path_discovery_boot;
1045 	int			vhc_path_discovery_postboot;
1046 	int64_t			vhc_path_discovery_cutoff_time;
1047 } mdi_vhci_config_t;
1048 
1049 /* vhc_flags */
1050 #define	MDI_VHC_SINGLE_THREADED		0x0001	/* config single threaded */
1051 #define	MDI_VHC_EXIT			0x0002	/* exit all config activity */
1052 #define	MDI_VHC_VHCACHE_DIRTY		0x0004	/* cache dirty */
1053 #define	MDI_VHC_VHCACHE_FLUSH_THREAD	0x0008	/* cache flush thead running */
1054 #define	MDI_VHC_VHCACHE_FLUSH_ERROR	0x0010	/* failed to flush cache */
1055 #define	MDI_VHC_READONLY_FS		0x0020	/* filesys is readonly */
1056 
1057 typedef struct mdi_phys_path {
1058 	char			*phys_path;
1059 	struct mdi_phys_path	*phys_path_next;
1060 } mdi_phys_path_t;
1061 
1062 /*
1063  * Lookup tokens are used to cache the result of the vhci cache client lookup
1064  * operations (to reduce the number of real lookup operations).
1065  */
1066 typedef struct mdi_vhcache_lookup_token {
1067 	mdi_vhcache_client_t	*lt_cct;		/* vhcache client */
1068 	int64_t			lt_cct_lookup_time;	/* last lookup time */
1069 } mdi_vhcache_lookup_token_t;
1070 
1071 /* asynchronous configuration of client paths */
1072 typedef struct mdi_async_client_config {
1073 	char			*acc_ct_name;	/* client name */
1074 	char			*acc_ct_addr;	/* client address */
1075 	mdi_phys_path_t		*acc_phclient_path_list_head;	/* path head */
1076 	mdi_vhcache_lookup_token_t acc_token;	/* lookup token */
1077 	struct mdi_async_client_config *acc_next; /* next in vhci acc list */
1078 } mdi_async_client_config_t;
1079 
1080 /*
1081  * vHCI driver instance registration/unregistration
1082  *
1083  * mdi_vhci_register() is called by a vHCI driver to register itself as the
1084  * manager of devices from a particular 'class'.  This should be called from
1085  * attach(9e).
1086  *
1087  * mdi_vhci_unregister() is called from detach(9E) to unregister a vHCI
1088  * instance from the framework.
1089  */
1090 int		mdi_vhci_register(char *, dev_info_t *, mdi_vhci_ops_t *, int);
1091 int		mdi_vhci_unregister(dev_info_t *, int);
1092 
1093 /*
1094  * Utility functions
1095  */
1096 int		mdi_phci_get_path_count(dev_info_t *);
1097 dev_info_t	*mdi_phci_path2devinfo(dev_info_t *, caddr_t);
1098 
1099 
1100 /*
1101  * Path Selection Functions:
1102  *
1103  * mdi_select_path() is called by a vHCI driver to select to which path an
1104  * I/O request should be routed.  The caller passes the 'buf' structure as
1105  * one of the parameters.  The mpxio framework uses the buf's contents to
1106  * maintain per path statistics (total I/O size / count pending).  If more
1107  * than one online path is available, the framework automatically selects
1108  * a suitable one.  If a failover operation is active for this client device
1109  * the call fails, returning MDI_BUSY.
1110  *
1111  * By default this function returns a suitable path in the 'online' state,
1112  * based on the current load balancing policy.  Currently we support
1113  * LOAD_BALANCE_NONE (Previously selected online path will continue to be
1114  * used as long as the path is usable) and LOAD_BALANCE_RR (Online paths
1115  * will be selected in a round robin fashion).  The load balancing scheme
1116  * can be configured in the vHCI driver's configuration file (driver.conf).
1117  *
1118  * vHCI drivers may override this default behaviour by specifying appropriate
1119  * flags.  If start_pip is specified (non NULL), it is used as the routine's
1120  * starting point; it starts walking from there to find the next appropriate
1121  * path.
1122  *
1123  * The following values for 'flags' are currently defined:
1124  *
1125  * 	MDI_SELECT_ONLINE_PATH: select an ONLINE path
1126  *	MDI_SELECT_STANDBY_PATH: select a STANDBY path
1127  * 	MDI_SELECT_USER_DISABLE_PATH: select user disable for failover and
1128  *		auto_failback
1129  *
1130  * The selected paths are returned in an mdi_hold_path() state (pi_ref_cnt),
1131  * caller should release the hold by calling mdi_rele_path() at the end of
1132  * operation.
1133  */
1134 int		mdi_select_path(dev_info_t *, struct buf *, int,
1135 		    mdi_pathinfo_t *, mdi_pathinfo_t **);
1136 int		mdi_set_lb_policy(dev_info_t *, client_lb_t);
1137 int		mdi_set_lb_region_size(dev_info_t *, int);
1138 client_lb_t	mdi_get_lb_policy(dev_info_t *);
1139 
1140 /*
1141  * flags for mdi_select_path() routine
1142  */
1143 #define	MDI_SELECT_ONLINE_PATH		0x0001
1144 #define	MDI_SELECT_STANDBY_PATH		0x0002
1145 #define	MDI_SELECT_USER_DISABLE_PATH	0x0004
1146 
1147 /*
1148  * MDI client device utility functions
1149  */
1150 int		mdi_client_get_path_count(dev_info_t *);
1151 dev_info_t	*mdi_client_path2devinfo(dev_info_t *, caddr_t);
1152 
1153 /*
1154  * Failover:
1155  *
1156  * The vHCI driver calls mdi_failover() to initiate a failover operation.
1157  * mdi_failover() calls back into the vHCI driver's vo_failover()
1158  * entry point to perform the actual failover operation.  The reason
1159  * for requiring the vHCI driver to initiate failover by calling
1160  * mdi_failover(), instead of directly executing vo_failover() itself,
1161  * is to ensure that the mdi framework can keep track of the client
1162  * state properly.  Additionally, mdi_failover() provides as a
1163  * convenience the option of performing the failover operation
1164  * synchronously or asynchronously
1165  *
1166  * Upon successful completion of the failover operation, the paths that were
1167  * previously ONLINE will be in the STANDBY state, and the newly activated
1168  * paths will be in the ONLINE state.
1169  *
1170  * The flags modifier determines whether the activation is done synchronously
1171  */
1172 int mdi_failover(dev_info_t *, dev_info_t *, int);
1173 
1174 /*
1175  * Client device failover mode of operation
1176  */
1177 #define	MDI_FAILOVER_SYNC	1	/* Syncronous Failover		*/
1178 #define	MDI_FAILOVER_ASYNC	2	/* Asyncronous Failover		*/
1179 
1180 /*
1181  * mdi_pathinfo node state change functions.
1182  */
1183 void mdi_pi_kstat_iosupdate(mdi_pathinfo_t *, struct buf *);
1184 
1185 /*
1186  * mdi_pathinfo node extended state change functions.
1187  */
1188 int mdi_pi_get_state2(mdi_pathinfo_t *, mdi_pathinfo_state_t *, uint32_t *);
1189 int mdi_pi_get_preferred(mdi_pathinfo_t *);
1190 
1191 /*
1192  * mdi_pathinfo node member functions
1193  */
1194 void *mdi_pi_get_client_private(mdi_pathinfo_t *);
1195 void mdi_pi_set_client_private(mdi_pathinfo_t *, void *);
1196 void mdi_pi_set_state(mdi_pathinfo_t *, mdi_pathinfo_state_t);
1197 void mdi_pi_set_preferred(mdi_pathinfo_t *, int);
1198 
1199 /* get/set vhci private data */
1200 void *mdi_client_get_vhci_private(dev_info_t *);
1201 void mdi_client_set_vhci_private(dev_info_t *, void *);
1202 void *mdi_phci_get_vhci_private(dev_info_t *);
1203 void mdi_phci_set_vhci_private(dev_info_t *, void *);
1204 void *mdi_pi_get_vhci_private(mdi_pathinfo_t *);
1205 void mdi_pi_set_vhci_private(mdi_pathinfo_t *, void *);
1206 
1207 /*
1208  * mdi_pathinfo Property utilities
1209  */
1210 int mdi_prop_size(mdi_pathinfo_t *, size_t *);
1211 int mdi_prop_pack(mdi_pathinfo_t *, char **, uint_t);
1212 
1213 /* obsolete interface, to be removed */
1214 void mdi_get_next_path(dev_info_t *, mdi_pathinfo_t *, mdi_pathinfo_t **);
1215 int mdi_get_component_type(dev_info_t *);
1216 
1217 #endif	/* _KERNEL */
1218 
1219 #ifdef	__cplusplus
1220 }
1221 #endif
1222 
1223 #endif	/* _SYS_MDI_IMPLDEFS_H */
1224