1/* $NetBSD: rf_paritymap.h,v 1.1 2009/11/17 18:54:26 jld Exp $ */
2
3/*-
4 * Copyright (c) 2009 Jed Davis.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#include <sys/mutex.h>
30#include <sys/param.h>
31#include <sys/rwlock.h>
32#include <sys/types.h>
33
34#include <dev/raidframe/raidframevar.h>
35
36/* RF_PARITYMAP_N* in raidframevar.h */
37
38#define RF_PMLABEL_VALID 1
39#define RF_PMLABEL_WASUSED 2
40#define RF_PMLABEL_DISABLE 4
41
42/*
43 * On-disk format: a single bit for each region; if the bit is clear,
44 * then the parity is clean.
45 */
46struct rf_paritymap_ondisk
47{
48        /* XXX Do these really need to be volatile? */
49	volatile char bits[RF_PARITYMAP_NBYTE];
50};
51
52/* In-core per-region state: a byte for each, encoded as follows. */
53struct rf_paritymap_current
54{
55	volatile int8_t state[RF_PARITYMAP_NREG];
56	/*
57	 * Values:
58	 * if x == 0, the region may be written out as clean
59	 * if x > 0, then x outstanding IOs to that region
60	 * if x < 0, then there was recently IO; periodically increment x
61	 */
62};
63
64/* The entire state. */
65struct rf_paritymap
66{
67	struct rf_paritymap_ondisk *disk_boot, *disk_now;
68	struct rf_paritymap_current *current;
69
70	/*
71	 * This lock will be held while component disks' caches are
72	 * flushed, which could take many milliseconds, so it should
73	 * not be taken where that kind of delay is unacceptable.
74	 * Contention on this lock is not, however, expected to be a
75	 * performance bottleneck.
76	 */
77	kmutex_t lock;
78	/*
79	 * The flags field, below, has its own lock so that
80	 * inter-thread communication can occur without taking the
81	 * overall lock.  Ordering is lock -> lk_flags.
82	 */
83	kmutex_t lk_flags;
84
85	RF_Raid_t *raid;
86	daddr_t region_size;
87	callout_t ticker;
88	struct rf_pmparams params;
89	volatile int flags;
90	struct rf_pmctrs ctrs;
91};
92
93void rf_paritymap_status(struct rf_paritymap *, struct rf_pmstat *);
94
95int rf_paritymap_test(struct rf_paritymap *, daddr_t);
96void rf_paritymap_begin_region(struct rf_paritymap *, unsigned);
97void rf_paritymap_begin(struct rf_paritymap *, daddr_t, daddr_t);
98void rf_paritymap_end_region(struct rf_paritymap *, unsigned);
99void rf_paritymap_end(struct rf_paritymap *, daddr_t, daddr_t);
100
101void rf_paritymap_checkwork(struct rf_paritymap *);
102void rf_paritymap_invalidate(struct rf_paritymap *);
103void rf_paritymap_forceclean(struct rf_paritymap *);
104void rf_paritymap_write(struct rf_paritymap *);
105
106int rf_paritymap_init(struct rf_paritymap *, RF_Raid_t *,
107    const struct rf_pmparams *);
108void rf_paritymap_destroy(struct rf_paritymap *, int);
109
110int rf_paritymap_rewrite(struct rf_paritymap *);
111
112int rf_paritymap_merge(struct rf_paritymap_ondisk *,
113    struct rf_paritymap_ondisk *);
114
115int rf_paritymap_ineligible(RF_Raid_t *);
116void rf_paritymap_attach(RF_Raid_t *, int);
117void rf_paritymap_detach(RF_Raid_t *); /* Not while the RAID is live! */
118
119int rf_paritymap_get_disable(RF_Raid_t *);
120void rf_paritymap_set_disable(RF_Raid_t *, int);
121
122int rf_paritymap_set_params(struct rf_paritymap *,
123    const struct rf_pmparams *, int);
124
125void rf_paritymap_init_label(struct rf_paritymap *,
126    RF_ComponentLabel_t *);
127