ebh.h revision 1.2
1/*	$NetBSD: ebh.h,v 1.2 2012/04/13 14:50:35 ttoth Exp $	*/
2
3/*-
4 * Copyright (c) 2010 Department of Software Engineering,
5 *		      University of Szeged, Hungary
6 * Copyright (c) 2010 David Tengeri <dtengeri@inf.u-szeged.hu>
7 * Copyright (c) 2010 Adam Hoka <ahoka@NetBSD.org>
8 * All rights reserved.
9 *
10 * This code is derived from software contributed to The NetBSD Foundation
11 * by the Department of Software Engineering, University of Szeged, Hungary
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 *    notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 *    notice, this list of conditions and the following disclaimer in the
20 *    documentation and/or other materials provided with the distribution.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35/*
36 * ebh.h
37 *
38 *  Created on: 2009.11.03.
39 *      Author: dtengeri
40 */
41
42#ifndef EBH_H_
43#define EBH_H_
44
45#ifdef _KERNEL
46#include <sys/param.h>
47#include <sys/kernel.h>
48#include <sys/cdefs.h>
49#include <sys/stdint.h>
50#include <sys/types.h>
51#include <sys/tree.h>
52#include <sys/queue.h>
53#include <sys/kmem.h>
54#include <sys/endian.h>
55#include <sys/rwlock.h>
56#include <sys/condvar.h>
57#include <sys/mutex.h>
58#include <sys/kthread.h>
59
60#include <dev/flash/flash.h>
61#include "debug.h"
62#include "ebh_misc.h"
63#endif /* _KERNEL */
64
65#include "ebh_media.h"
66
67/**
68 * struct  chfs_eb_hdr - in-memory representation of eraseblock headers
69 * @ec_hdr: erase counter header ob eraseblock
70 * @u.nor_hdr: eraseblock header on NOR flash
71 * @u.nand_hdr: eraseblock header on NAND flash
72 */
73struct  chfs_eb_hdr {
74	struct chfs_eb_ec_hdr ec_hdr;
75	union {
76		struct chfs_nor_eb_hdr  nor_hdr;
77		struct chfs_nand_eb_hdr nand_hdr;
78	} u;
79};
80
81#ifdef _KERNEL
82/* Maximum retries when getting new PEB before exit with failure */
83#define CHFS_MAX_GET_PEB_RETRIES 2
84
85/**
86 * LEB status
87 *
88 */
89enum {
90	EBH_LEB_UNMAPPED = -1,
91	EBH_LEB_MAPPED,
92	EBH_LEB_DIRTY,
93	EBH_LEB_INVALID,
94	EBH_LEB_ERASE,
95	EBH_LEB_ERASED,
96	EBH_LEB_FREE,
97};
98
99/**
100 * EB header status
101 */
102enum {
103	EBHDR_LEB_OK = 0,
104	EBHDR_LEB_DIRTY,
105	EBHDR_LEB_INVALIDATED,
106	EBHDR_LEB_BADMAGIC,
107	EBHDR_LEB_BADCRC,
108	EBHDR_LEB_FREE,
109	EBHDR_LEB_NO_HDR,
110};
111
112struct chfs_ebh;
113
114/**
115 * struct chfs_ltree_entry - an netry in the lock tree
116 * @rb: RB-node of the tree
117 * @lnr: logical eraseblock number
118 * @users: counts the tasks that are using or want to use the eraseblock
119 * @mutex: read/write mutex to lock the eraseblock
120 */
121struct chfs_ltree_entry {
122	RB_ENTRY(chfs_ltree_entry) rb;
123	int lnr;
124	int users;
125	krwlock_t mutex;
126};
127
128/* Generate structure for Lock tree's red-black tree */
129RB_HEAD(ltree_rbtree, chfs_ltree_entry);
130
131
132/**
133 * struct chfs_scan_leb - scanning infomration about a physical eraseblock
134 * @erase_cnt: erase counter
135 * @pebnr: physical eraseblock number
136 * @info: the status of the PEB's eraseblock header when NOR serial when NAND
137 * @u.list: link in one of the eraseblock list
138 * @u.rb: link in the used RB-tree of chfs_scan_info
139 */
140struct chfs_scan_leb {
141	int erase_cnt;
142	int pebnr;
143	int lnr;
144	uint64_t info;
145	union {
146		TAILQ_ENTRY(chfs_scan_leb) queue;
147		RB_ENTRY(chfs_scan_leb) rb;
148	} u;
149};
150
151TAILQ_HEAD(scan_leb_queue, chfs_scan_leb);
152RB_HEAD(scan_leb_used_rbtree, chfs_scan_leb);
153
154
155/**
156 * struct chfs_scan_info - chfs scanning information
157 * @corrupted: queue of corrupted physical eraseblocks
158 * @free: queue of free physical eraseblocks
159 * @erase: queue of the physical eraseblocks signed to erase
160 * @erased: queue of physical eraseblocks that contain no header
161 * @used: RB-tree of used PEBs describing by chfs_scan_leb
162 * @sum_of_ec: summary of erase counters
163 * @num_of_eb: number of free and used eraseblocks
164 * @bad_peb_cnt: counter of bad eraseblocks
165 *
166 * This structure contains information about the scanning for further
167 * processing.
168 */
169struct chfs_scan_info {
170	struct scan_leb_queue corrupted;
171	struct scan_leb_queue free;
172	struct scan_leb_queue erase;
173	struct scan_leb_queue erased;
174	struct scan_leb_used_rbtree used;
175	uint64_t sum_of_ec;
176	int num_of_eb;
177	int bad_peb_cnt;
178};
179
180/**
181 * struct chfs_peb - PEB information for erasing and wear leveling
182 * @erase_cnt: erase counter of the physical eraseblock
183 * @pebnr: physical eraseblock number
184 * @u.queue: link to the queue of the PEBs waiting for erase
185 * @u.rb: link to the RB-tree to the free PEBs
186 */
187struct chfs_peb {
188	int erase_cnt;
189	int pebnr;
190	union {
191		TAILQ_ENTRY(chfs_peb) queue;
192		RB_ENTRY(chfs_peb) rb;
193	} u;
194};
195
196/* Generate queue and rb-tree structures. */
197TAILQ_HEAD(peb_queue, chfs_peb);
198RB_HEAD(peb_free_rbtree, chfs_peb);
199RB_HEAD(peb_in_use_rbtree, chfs_peb);
200
201
202/*
203 * struct chfs_ebh_ops - collection of operations which
204 * 								 depends on flash type
205 * *************************************************************************** *
206 * Direct flash operations:
207 *
208 * @read_eb_hdr: read eraseblock header from media
209 * @write_eb_hdr: write eraseblock header to media
210 * @check_eb_hdr: validates eraseblock header
211 * @mark_eb_hdr_dirty_flash: marks eraseblock dirty on flash
212 * @invalidate_eb_hdr: invalidates eraseblock header
213 * @mark_eb_hdr_free: marks eraseblock header free (after erase)
214 * *************************************************************************** *
215 * Scanning operations:
216 *
217 * @process_eb: process an eraseblock information at scan
218 * *************************************************************************** *
219 * Misc operations:
220 *
221 * @create_eb_hdr: creates an eraseblock header based on flash type
222 * @calc_data_offs: calculates where the data starts
223 */
224struct chfs_ebh_ops {
225	int (*read_eb_hdr)(struct chfs_ebh *ebh, int pebnr,
226	    struct chfs_eb_hdr *ebhdr);
227	int (*write_eb_hdr)(struct chfs_ebh *ebh, int pebnr,
228	    struct chfs_eb_hdr *ebhdr);
229	int (*check_eb_hdr)(struct chfs_ebh *ebh, void *buf);
230	int (*mark_eb_hdr_dirty_flash)(struct chfs_ebh *ebh, int pebnr, int lid);
231	int (*invalidate_eb_hdr)(struct chfs_ebh *ebh, int pebnr);
232	int (*mark_eb_hdr_free)(struct chfs_ebh *ebh, int pebnr, int ec);
233
234	int (*process_eb)(struct chfs_ebh *ebh, struct chfs_scan_info *si,
235	    int pebnr, struct chfs_eb_hdr *ebhdr);
236
237	int (*create_eb_hdr)(struct chfs_eb_hdr *ebhdr, int lnr);
238	int (*calc_data_offs)(struct chfs_ebh *ebh, int pebnr, int offset);
239};
240
241/**
242 * struct erase_thread - background thread for erasing
243 * @thread: pointer to thread structure
244 * @wakeup: conditional variable for sleeping if there isn't any job to do
245 * @running: flag to signal a thread shutdown
246 */
247struct erase_thread {
248	lwp_t *eth_thread;
249	kcondvar_t eth_wakeup;
250	bool eth_running;
251};
252
253
254/**
255 * struct chfs_ebh - eraseblock handler descriptor
256 * @mtd: mtd device descriptor
257 * @eb_size: eraseblock size
258 * @peb_nr: number of PEBs
259 * @lmap: LEB to PEB mapping
260 * @layout_map: the LEBs layout (NOT USED YET)
261 * @ltree: the lock tree
262 * @ltree_lock: protects the tree
263 * @alc_mutex: serializes "atomic LEB change" operation
264 * @free: RB-tree of the free easeblocks
265 * @in_use: RB-tree of PEBs are in use
266 * @to_erase: list of the PEBs waiting for erase
267 * @fully_erased: list of PEBs that have been erased but don't have header
268 * @erase_lock: list and tree lock for fully_erased and to_erase lists and
269 *		for the free RB-tree
270 * @bg_erase: background thread for eraseing PEBs.
271 * @ops: collection of operations which depends on flash type
272 * @max_serial: max serial number of eraseblocks, only used on NAND
273 */
274struct chfs_ebh {
275	struct peb_free_rbtree free;
276	struct peb_in_use_rbtree in_use;
277	struct peb_queue to_erase;
278	struct peb_queue fully_erased;
279	struct erase_thread bg_erase;
280	device_t flash_dev;
281	const struct flash_interface *flash_if;
282	struct chfs_ebh_ops *ops;
283	uint64_t *max_serial;
284	int *lmap;
285	//int *layout_map;
286	struct ltree_rbtree ltree;
287	//struct mutex alc_mutex;
288	kmutex_t ltree_lock;
289	kmutex_t alc_mutex;
290	kmutex_t erase_lock;
291	size_t eb_size;
292	size_t peb_nr;
293	flash_size_t flash_size;
294};
295
296/**
297 * struct chfs_erase_info_priv - private information for erase
298 * @ebh: eraseblock handler
299 * @peb: physical eraseblock information
300 */
301struct chfs_erase_info_priv {
302	struct chfs_ebh *ebh;
303	struct chfs_peb *peb;
304};
305
306/* ebh.c */
307
308int ebh_open(struct chfs_ebh *ebh, dev_t dev);
309int ebh_close(struct chfs_ebh *ebh);
310int ebh_read_leb(struct chfs_ebh *ebh, int lnr, char *buf,
311    uint32_t offset, size_t len, size_t *retlen);
312int ebh_write_leb(struct chfs_ebh *ebh, int lnr, char *buf,
313    uint32_t offset, size_t len, size_t *retlen);
314int ebh_erase_leb(struct chfs_ebh *ebh, int lnr);
315int ebh_map_leb(struct chfs_ebh *ebh, int lnr);
316int ebh_unmap_leb(struct chfs_ebh *ebh, int lnr);
317int ebh_is_mapped(struct chfs_ebh *ebh, int lnr);
318int ebh_change_leb(struct chfs_ebh *ebh, int lnr, char *buf,
319    size_t len, size_t *retlen);
320
321#endif /* _KERNEL */
322
323#endif /* EBH_H_ */
324