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      1 /*	$NetBSD: ebh.h,v 1.5 2025/01/08 11:39:50 andvar Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2010 Department of Software Engineering,
      5  *		      University of Szeged, Hungary
      6  * Copyright (c) 2010 David Tengeri <dtengeri (at) inf.u-szeged.hu>
      7  * Copyright (c) 2010 Adam Hoka <ahoka (at) 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 #ifndef EBH_H_
     36 #define EBH_H_
     37 
     38 #ifdef _KERNEL
     39 #include <sys/param.h>
     40 #include <sys/kernel.h>
     41 #include <sys/cdefs.h>
     42 #include <sys/stdint.h>
     43 #include <sys/types.h>
     44 #include <sys/tree.h>
     45 #include <sys/queue.h>
     46 #include <sys/kmem.h>
     47 #include <sys/endian.h>
     48 #include <sys/rwlock.h>
     49 #include <sys/condvar.h>
     50 #include <sys/mutex.h>
     51 #include <sys/kthread.h>
     52 
     53 #include <dev/flash/flash.h>
     54 #include "debug.h"
     55 #include "ebh_misc.h"
     56 #endif /* _KERNEL */
     57 
     58 #include "ebh_media.h"
     59 
     60 /**
     61  * struct  chfs_eb_hdr - in-memory representation of eraseblock headers
     62  * @ec_hdr: erase counter header ob eraseblock
     63  * @u.nor_hdr: eraseblock header on NOR flash
     64  * @u.nand_hdr: eraseblock header on NAND flash
     65  */
     66 struct  chfs_eb_hdr {
     67 	struct chfs_eb_ec_hdr ec_hdr;
     68 	union {
     69 		struct chfs_nor_eb_hdr  nor_hdr;
     70 		struct chfs_nand_eb_hdr nand_hdr;
     71 	} u;
     72 };
     73 
     74 #ifdef _KERNEL
     75 /* Maximum retries when getting new PEB before exit with failure */
     76 #define CHFS_MAX_GET_PEB_RETRIES 2
     77 
     78 /**
     79  * LEB status
     80  *
     81  */
     82 enum {
     83 	EBH_LEB_UNMAPPED = -1,
     84 	EBH_LEB_MAPPED,
     85 	EBH_LEB_DIRTY,
     86 	EBH_LEB_INVALID,
     87 	EBH_LEB_ERASE,
     88 	EBH_LEB_ERASED,
     89 	EBH_LEB_FREE,
     90 };
     91 
     92 /**
     93  * EB header status
     94  */
     95 enum {
     96 	EBHDR_LEB_OK = 0,
     97 	EBHDR_LEB_DIRTY,
     98 	EBHDR_LEB_INVALIDATED,
     99 	EBHDR_LEB_BADMAGIC,
    100 	EBHDR_LEB_BADCRC,
    101 	EBHDR_LEB_FREE,
    102 	EBHDR_LEB_NO_HDR,
    103 };
    104 
    105 struct chfs_ebh;
    106 
    107 /**
    108  * struct chfs_ltree_entry - an entry in the lock tree
    109  * @rb: RB-node of the tree
    110  * @lnr: logical eraseblock number
    111  * @users: counts the tasks that are using or want to use the eraseblock
    112  * @mutex: read/write mutex to lock the eraseblock
    113  */
    114 struct chfs_ltree_entry {
    115 	RB_ENTRY(chfs_ltree_entry) rb;
    116 	int lnr;
    117 	int users;
    118 	krwlock_t mutex;
    119 };
    120 
    121 /* Generate structure for Lock tree's red-black tree */
    122 RB_HEAD(ltree_rbtree, chfs_ltree_entry);
    123 
    124 
    125 /**
    126  * struct chfs_scan_leb - scanning information about a physical eraseblock
    127  * @erase_cnt: erase counter
    128  * @pebnr: physical eraseblock number
    129  * @info: the status of the PEB's eraseblock header when NOR serial when NAND
    130  * @u.list: link in one of the eraseblock list
    131  * @u.rb: link in the used RB-tree of chfs_scan_info
    132  */
    133 struct chfs_scan_leb {
    134 	int erase_cnt;
    135 	int pebnr;
    136 	int lnr;
    137 	uint64_t info;
    138 	union {
    139 		TAILQ_ENTRY(chfs_scan_leb) queue;
    140 		RB_ENTRY(chfs_scan_leb) rb;
    141 	} u;
    142 };
    143 
    144 TAILQ_HEAD(scan_leb_queue, chfs_scan_leb);
    145 RB_HEAD(scan_leb_used_rbtree, chfs_scan_leb);
    146 
    147 
    148 /**
    149  * struct chfs_scan_info - chfs scanning information
    150  * @corrupted: queue of corrupted physical eraseblocks
    151  * @free: queue of free physical eraseblocks
    152  * @erase: queue of the physical eraseblocks signed to erase
    153  * @erased: queue of physical eraseblocks that contain no header
    154  * @used: RB-tree of used PEBs describing by chfs_scan_leb
    155  * @sum_of_ec: summary of erase counters
    156  * @num_of_eb: number of free and used eraseblocks
    157  * @bad_peb_cnt: counter of bad eraseblocks
    158  *
    159  * This structure contains information about the scanning for further
    160  * processing.
    161  */
    162 struct chfs_scan_info {
    163 	struct scan_leb_queue corrupted;
    164 	struct scan_leb_queue free;
    165 	struct scan_leb_queue erase;
    166 	struct scan_leb_queue erased;
    167 	struct scan_leb_used_rbtree used;
    168 	uint64_t sum_of_ec;
    169 	int num_of_eb;
    170 	int bad_peb_cnt;
    171 };
    172 
    173 /**
    174  * struct chfs_peb - PEB information for erasing and wear leveling
    175  * @erase_cnt: erase counter of the physical eraseblock
    176  * @pebnr: physical eraseblock number
    177  * @u.queue: link to the queue of the PEBs waiting for erase
    178  * @u.rb: link to the RB-tree to the free PEBs
    179  */
    180 struct chfs_peb {
    181 	int erase_cnt;
    182 	int pebnr;
    183 	union {
    184 		TAILQ_ENTRY(chfs_peb) queue;
    185 		RB_ENTRY(chfs_peb) rb;
    186 	} u;
    187 };
    188 
    189 /* Generate queue and rb-tree structures. */
    190 TAILQ_HEAD(peb_queue, chfs_peb);
    191 RB_HEAD(peb_free_rbtree, chfs_peb);
    192 RB_HEAD(peb_in_use_rbtree, chfs_peb);
    193 
    194 
    195 /*
    196  * struct chfs_ebh_ops - collection of operations which
    197  * 								 depends on flash type
    198  * *************************************************************************** *
    199  * Direct flash operations:
    200  *
    201  * @read_eb_hdr: read eraseblock header from media
    202  * @write_eb_hdr: write eraseblock header to media
    203  * @check_eb_hdr: validates eraseblock header
    204  * @mark_eb_hdr_dirty_flash: marks eraseblock dirty on flash
    205  * @invalidate_eb_hdr: invalidates eraseblock header
    206  * @mark_eb_hdr_free: marks eraseblock header free (after erase)
    207  * *************************************************************************** *
    208  * Scanning operations:
    209  *
    210  * @process_eb: process an eraseblock information at scan
    211  * *************************************************************************** *
    212  * Misc operations:
    213  *
    214  * @create_eb_hdr: creates an eraseblock header based on flash type
    215  * @calc_data_offs: calculates where the data starts
    216  */
    217 struct chfs_ebh_ops {
    218 	int (*read_eb_hdr)(struct chfs_ebh *ebh, int pebnr,
    219 	    struct chfs_eb_hdr *ebhdr);
    220 	int (*write_eb_hdr)(struct chfs_ebh *ebh, int pebnr,
    221 	    struct chfs_eb_hdr *ebhdr);
    222 	int (*check_eb_hdr)(struct chfs_ebh *ebh, void *buf);
    223 	int (*mark_eb_hdr_dirty_flash)(struct chfs_ebh *ebh, int pebnr, int lid);
    224 	int (*invalidate_eb_hdr)(struct chfs_ebh *ebh, int pebnr);
    225 	int (*mark_eb_hdr_free)(struct chfs_ebh *ebh, int pebnr, int ec);
    226 
    227 	int (*process_eb)(struct chfs_ebh *ebh, struct chfs_scan_info *si,
    228 	    int pebnr, struct chfs_eb_hdr *ebhdr);
    229 
    230 	int (*create_eb_hdr)(struct chfs_eb_hdr *ebhdr, int lnr);
    231 	int (*calc_data_offs)(struct chfs_ebh *ebh, int pebnr, int offset);
    232 };
    233 
    234 /**
    235  * struct erase_thread - background thread for erasing
    236  * @thread: pointer to thread structure
    237  * @wakeup: conditional variable for sleeping if there isn't any job to do
    238  * @running: flag to signal a thread shutdown
    239  */
    240 struct erase_thread {
    241 	lwp_t *eth_thread;
    242 	kcondvar_t eth_wakeup;
    243 	bool eth_running;
    244 };
    245 
    246 
    247 /**
    248  * struct chfs_ebh - eraseblock handler descriptor
    249  * @mtd: mtd device descriptor
    250  * @eb_size: eraseblock size
    251  * @peb_nr: number of PEBs
    252  * @lmap: LEB to PEB mapping
    253  * @layout_map: the LEBs layout (NOT USED YET)
    254  * @ltree: the lock tree
    255  * @ltree_lock: protects the tree
    256  * @alc_mutex: serializes "atomic LEB change" operation
    257  * @free: RB-tree of the free eraseblocks
    258  * @in_use: RB-tree of PEBs are in use
    259  * @to_erase: list of the PEBs waiting for erase
    260  * @fully_erased: list of PEBs that have been erased but don't have header
    261  * @erase_lock: list and tree lock for fully_erased and to_erase lists and
    262  *		for the free RB-tree
    263  * @bg_erase: background thread for erasing PEBs.
    264  * @ops: collection of operations which depends on flash type
    265  * @max_serial: max serial number of eraseblocks, only used on NAND
    266  */
    267 struct chfs_ebh {
    268 	struct peb_free_rbtree free;
    269 	struct peb_in_use_rbtree in_use;
    270 	struct peb_queue to_erase;
    271 	struct peb_queue fully_erased;
    272 	struct erase_thread bg_erase;
    273 	device_t flash_dev;
    274 	const struct flash_interface *flash_if;
    275 	struct chfs_ebh_ops *ops;
    276 	uint64_t *max_serial;
    277 	int *lmap;
    278 	//int *layout_map;
    279 	struct ltree_rbtree ltree;
    280 	//struct mutex alc_mutex;
    281 	kmutex_t ltree_lock;
    282 	kmutex_t alc_mutex;
    283 	kmutex_t erase_lock;
    284 	size_t eb_size;
    285 	size_t peb_nr;
    286 	flash_size_t flash_size;
    287 };
    288 
    289 /**
    290  * struct chfs_erase_info_priv - private information for erase
    291  * @ebh: eraseblock handler
    292  * @peb: physical eraseblock information
    293  */
    294 struct chfs_erase_info_priv {
    295 	struct chfs_ebh *ebh;
    296 	struct chfs_peb *peb;
    297 };
    298 
    299 /* ebh.c */
    300 
    301 int ebh_open(struct chfs_ebh *ebh, dev_t dev);
    302 int ebh_close(struct chfs_ebh *ebh);
    303 int ebh_read_leb(struct chfs_ebh *ebh, int lnr, char *buf,
    304     uint32_t offset, size_t len, size_t *retlen);
    305 int ebh_write_leb(struct chfs_ebh *ebh, int lnr, char *buf,
    306     uint32_t offset, size_t len, size_t *retlen);
    307 int ebh_erase_leb(struct chfs_ebh *ebh, int lnr);
    308 int ebh_map_leb(struct chfs_ebh *ebh, int lnr);
    309 int ebh_unmap_leb(struct chfs_ebh *ebh, int lnr);
    310 int ebh_is_mapped(struct chfs_ebh *ebh, int lnr);
    311 int ebh_change_leb(struct chfs_ebh *ebh, int lnr, char *buf,
    312     size_t len, size_t *retlen);
    313 
    314 #endif /* _KERNEL */
    315 
    316 #endif /* EBH_H_ */
    317