1 /* $NetBSD: dm_table.c,v 1.5 2010/01/04 00:19:08 haad Exp $ */
4 * Copyright (c) 2010-2011 Alex Hornung <alex@alexhornung.com>
5 * Copyright (c) 2008 The NetBSD Foundation, Inc.
8 * This code is derived from software contributed to The NetBSD Foundation
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
33 #include <sys/malloc.h>
34 #include <cpu/atomic.h>
35 #include <dev/disk/dm/dm.h>
38 * There are two types of users of this interface:
41 * dmstrategy, dmgetdisklabel, dmsize, dm_dev_status_ioctl,
42 * dm_table_deps_ioctl, dm_table_status_ioctl, dm_table_reload_ioctl
45 * dm_dev_remove_ioctl, dm_dev_resume_ioctl, dm_table_clear_ioctl
47 * Writers can work with table_head only when there are no readers. We
48 * simply use shared/exclusive locking to ensure this.
52 * Function to increment table user reference counter. Return id
54 * DM_TABLE_ACTIVE will return active table id.
55 * DM_TABLE_INACTIVE will return inactive table id.
58 dm_table_busy(dm_table_head_t
*head
, uint8_t table_id
)
64 lockmgr(&head
->table_mtx
, LK_SHARED
);
66 if (table_id
== DM_TABLE_ACTIVE
)
67 id
= head
->cur_active_table
;
69 id
= 1 - head
->cur_active_table
;
71 atomic_add_int(&head
->io_cnt
, 1);
77 * Function release table lock and eventually wakeup all waiters.
80 dm_table_unbusy(dm_table_head_t
*head
)
82 KKASSERT(head
->io_cnt
!= 0);
84 atomic_subtract_int(&head
->io_cnt
, 1);
86 lockmgr(&head
->table_mtx
, LK_RELEASE
);
90 * Return current active table to caller, increment io_cnt reference counter.
93 dm_table_get_entry(dm_table_head_t
*head
, uint8_t table_id
)
97 id
= dm_table_busy(head
, table_id
);
99 return &head
->tables
[id
];
103 * Decrement io reference counter and release shared lock.
106 dm_table_release(dm_table_head_t
*head
, uint8_t table_id
)
108 dm_table_unbusy(head
);
112 * Switch table from inactive to active mode. Have to wait until io_cnt is 0.
115 dm_table_switch_tables(dm_table_head_t
*head
)
117 lockmgr(&head
->table_mtx
, LK_EXCLUSIVE
);
119 head
->cur_active_table
= 1 - head
->cur_active_table
;
121 lockmgr(&head
->table_mtx
, LK_RELEASE
);
125 * Destroy all table data. This function can run when there are no
126 * readers on table lists.
129 dm_table_destroy(dm_table_head_t
*head
, uint8_t table_id
)
132 dm_table_entry_t
*table_en
;
135 lockmgr(&head
->table_mtx
, LK_EXCLUSIVE
);
137 dmdebug("table_id=%d io_cnt=%d\n", table_id
, head
->io_cnt
);
139 if (table_id
== DM_TABLE_ACTIVE
)
140 id
= head
->cur_active_table
;
142 id
= 1 - head
->cur_active_table
;
144 tbl
= &head
->tables
[id
];
146 while ((table_en
= TAILQ_FIRST(tbl
)) != NULL
) {
147 TAILQ_REMOVE(tbl
, table_en
, next
);
149 if (table_en
->target
->destroy
)
150 table_en
->target
->destroy(table_en
);
151 table_en
->target_config
= NULL
;
153 dm_table_free_deps(table_en
);
155 /* decrement the refcount for the target */
156 dm_target_unbusy(table_en
->target
);
158 kfree(table_en
, M_DM
);
160 KKASSERT(TAILQ_EMPTY(tbl
));
162 lockmgr(&head
->table_mtx
, LK_RELEASE
);
168 * Return length of active or inactive table in device.
171 _dm_table_size(dm_table_head_t
*head
, int table
)
174 dm_table_entry_t
*table_en
;
179 /* Select active table */
180 tbl
= dm_table_get_entry(head
, table
);
183 * Find out what tables I want to select.
184 * if length => rawblkno then we should used that table.
186 TAILQ_FOREACH(table_en
, tbl
, next
) {
187 length
+= table_en
->length
;
190 dm_table_unbusy(head
);
196 dm_table_size(dm_table_head_t
*head
)
198 return _dm_table_size(head
, DM_TABLE_ACTIVE
);
202 dm_inactive_table_size(dm_table_head_t
*head
)
204 return _dm_table_size(head
, DM_TABLE_INACTIVE
);
208 * Return > 0 if table is at least one table entry (returns number of entries)
209 * and return 0 if there is not. Target count returned from this function
210 * doesn't need to be true when userspace user receive it (after return
211 * there can be dm_dev_resume_ioctl), therefore this is only informative.
214 dm_table_get_target_count(dm_table_head_t
*head
, uint8_t table_id
)
216 dm_table_entry_t
*table_en
;
218 uint32_t target_count
;
222 tbl
= dm_table_get_entry(head
, table_id
);
224 TAILQ_FOREACH(table_en
, tbl
, next
)
227 dm_table_unbusy(head
);
233 * Initialize dm_table_head_t structures, I'm trying to keep this structure as
234 * opaque as possible.
237 dm_table_head_init(dm_table_head_t
*head
)
239 head
->cur_active_table
= 0;
242 /* Initialize tables. */
243 TAILQ_INIT(&head
->tables
[0]);
244 TAILQ_INIT(&head
->tables
[1]);
246 lockinit(&head
->table_mtx
, "dmtbl", 0, LK_CANRECURSE
);
250 * Destroy all variables in table_head
253 dm_table_head_destroy(dm_table_head_t
*head
)
255 KKASSERT(lockcount(&head
->table_mtx
) == 0);
257 /* tables don't exist when I call this routine, therefore it
258 * doesn't make sense to have io_cnt != 0 */
259 KKASSERT(head
->io_cnt
== 0);
261 lockuninit(&head
->table_mtx
);
265 dm_table_init_target(dm_table_entry_t
*table_en
, void *cfg
)
267 table_en
->target_config
= cfg
;
271 dm_table_add_deps(dm_table_entry_t
*table_en
, dm_pdev_t
*pdev
)
273 dm_table_head_t
*head
;
278 head
= &table_en
->dev
->table_head
;
279 lockmgr(&head
->table_mtx
, LK_SHARED
);
281 TAILQ_FOREACH(map
, &table_en
->pdev_maps
, next
) {
282 if (map
->data
.pdev
->udev
== pdev
->udev
) {
283 lockmgr(&head
->table_mtx
, LK_RELEASE
);
288 map
= kmalloc(sizeof(*map
), M_DM
, M_WAITOK
| M_ZERO
);
289 map
->data
.pdev
= pdev
;
290 TAILQ_INSERT_TAIL(&table_en
->pdev_maps
, map
, next
);
292 lockmgr(&head
->table_mtx
, LK_RELEASE
);
298 dm_table_free_deps(dm_table_entry_t
*table_en
)
300 dm_table_head_t
*head
;
303 head
= &table_en
->dev
->table_head
;
304 lockmgr(&head
->table_mtx
, LK_SHARED
);
306 while ((map
= TAILQ_FIRST(&table_en
->pdev_maps
)) != NULL
) {
307 TAILQ_REMOVE(&table_en
->pdev_maps
, map
, next
);
310 KKASSERT(TAILQ_EMPTY(&table_en
->pdev_maps
));
312 lockmgr(&head
->table_mtx
, LK_RELEASE
);