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   1 /*
   2  * NAND flash simulator.
   3  *
   4  * Author: Artem B. Bityuckiy <dedekind@oktetlabs.ru>, <dedekind@infradead.org>
   5  *
   6  * Copyright (C) 2004 Nokia Corporation
   7  *
   8  * Note: NS means "NAND Simulator".
   9  * Note: Input means input TO flash chip, output means output FROM chip.
  10  *
  11  * This program is free software; you can redistribute it and/or modify it
  12  * under the terms of the GNU General Public License as published by the
  13  * Free Software Foundation; either version 2, or (at your option) any later
  14  * version.
  15  *
  16  * This program is distributed in the hope that it will be useful, but
  17  * WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
  19  * Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA
  24  *
  25  * $Id: nandsim.c,v 1.8 2005/03/19 15:33:56 dedekind Exp $
  26  */
  27
  28 #include <linux/init.h>
  29 #include <linux/types.h>
  30 #include <linux/module.h>
  31 #include <linux/moduleparam.h>
  32 #include <linux/vmalloc.h>
  33 #include <linux/slab.h>
  34 #include <linux/errno.h>
  35 #include <linux/string.h>
  36 #include <linux/mtd/mtd.h>
  37 #include <linux/mtd/nand.h>
  38 #include <linux/mtd/partitions.h>
  39 #include <linux/delay.h>
  40 #include <linux/list.h>
  41 #include <linux/random.h>
  42
  43 /* Default simulator parameters values */
  44 #if !defined(CONFIG_NANDSIM_FIRST_ID_BYTE)  || \
  45     !defined(CONFIG_NANDSIM_SECOND_ID_BYTE) || \
  46     !defined(CONFIG_NANDSIM_THIRD_ID_BYTE)  || \
  47     !defined(CONFIG_NANDSIM_FOURTH_ID_BYTE)
  48 #define CONFIG_NANDSIM_FIRST_ID_BYTE  0x98
  49 #define CONFIG_NANDSIM_SECOND_ID_BYTE 0x39
  50 #define CONFIG_NANDSIM_THIRD_ID_BYTE  0xFF /* No byte */
  51 #define CONFIG_NANDSIM_FOURTH_ID_BYTE 0xFF /* No byte */
  52 #endif
  53
  54 #ifndef CONFIG_NANDSIM_ACCESS_DELAY
  55 #define CONFIG_NANDSIM_ACCESS_DELAY 25
  56 #endif
  57 #ifndef CONFIG_NANDSIM_PROGRAMM_DELAY
  58 #define CONFIG_NANDSIM_PROGRAMM_DELAY 200
  59 #endif
  60 #ifndef CONFIG_NANDSIM_ERASE_DELAY
  61 #define CONFIG_NANDSIM_ERASE_DELAY 2
  62 #endif
  63 #ifndef CONFIG_NANDSIM_OUTPUT_CYCLE
  64 #define CONFIG_NANDSIM_OUTPUT_CYCLE 40
  65 #endif
  66 #ifndef CONFIG_NANDSIM_INPUT_CYCLE
  67 #define CONFIG_NANDSIM_INPUT_CYCLE  50
  68 #endif
  69 #ifndef CONFIG_NANDSIM_BUS_WIDTH
  70 #define CONFIG_NANDSIM_BUS_WIDTH  8
  71 #endif
  72 #ifndef CONFIG_NANDSIM_DO_DELAYS
  73 #define CONFIG_NANDSIM_DO_DELAYS  0
  74 #endif
  75 #ifndef CONFIG_NANDSIM_LOG
  76 #define CONFIG_NANDSIM_LOG        0
  77 #endif
  78 #ifndef CONFIG_NANDSIM_DBG
  79 #define CONFIG_NANDSIM_DBG        0
  80 #endif
  81
  82 static uint first_id_byte  = CONFIG_NANDSIM_FIRST_ID_BYTE;
  83 static uint second_id_byte = CONFIG_NANDSIM_SECOND_ID_BYTE;
  84 static uint third_id_byte  = CONFIG_NANDSIM_THIRD_ID_BYTE;
  85 static uint fourth_id_byte = CONFIG_NANDSIM_FOURTH_ID_BYTE;
  86 static uint access_delay   = CONFIG_NANDSIM_ACCESS_DELAY;
  87 static uint programm_delay = CONFIG_NANDSIM_PROGRAMM_DELAY;
  88 static uint erase_delay    = CONFIG_NANDSIM_ERASE_DELAY;
  89 static uint output_cycle   = CONFIG_NANDSIM_OUTPUT_CYCLE;
  90 static uint input_cycle    = CONFIG_NANDSIM_INPUT_CYCLE;
  91 static uint bus_width      = CONFIG_NANDSIM_BUS_WIDTH;
  92 static uint do_delays      = CONFIG_NANDSIM_DO_DELAYS;
  93 static uint log            = CONFIG_NANDSIM_LOG;
  94 static uint dbg            = CONFIG_NANDSIM_DBG;
  95 static unsigned long parts[MAX_MTD_DEVICES];
  96 static unsigned int parts_num;
  97 static char *badblocks = NULL;
  98 static char *weakblocks = NULL;
  99 static char *weakpages = NULL;
 100 static unsigned int bitflips = 0;
 101 static char *gravepages = NULL;
 102 static unsigned int rptwear = 0;
 103 static unsigned int overridesize = 0;
 104
 105 module_param(first_id_byte,  uint, 0400);
 106 module_param(second_id_byte, uint, 0400);
 107 module_param(third_id_byte,  uint, 0400);
 108 module_param(fourth_id_byte, uint, 0400);
 109 module_param(access_delay,   uint, 0400);
 110 module_param(programm_delay, uint, 0400);
 111 module_param(erase_delay,    uint, 0400);
 112 module_param(output_cycle,   uint, 0400);
 113 module_param(input_cycle,    uint, 0400);
 114 module_param(bus_width,      uint, 0400);
 115 module_param(do_delays,      uint, 0400);
 116 module_param(log,            uint, 0400);
 117 module_param(dbg,            uint, 0400);
 118 module_param_array(parts, ulong, &parts_num, 0400);
 119 module_param(badblocks,      charp, 0400);
 120 module_param(weakblocks,     charp, 0400);
 121 module_param(weakpages,      charp, 0400);
 122 module_param(bitflips,       uint, 0400);
 123 module_param(gravepages,     charp, 0400);
 124 module_param(rptwear,        uint, 0400);
 125 module_param(overridesize,   uint, 0400);
 126
 127 MODULE_PARM_DESC(first_id_byte,  "The first byte returned by NAND Flash 'read ID' command (manufacturer ID)");
 128 MODULE_PARM_DESC(second_id_byte, "The second byte returned by NAND Flash 'read ID' command (chip ID)");
 129 MODULE_PARM_DESC(third_id_byte,  "The third byte returned by NAND Flash 'read ID' command");
 130 MODULE_PARM_DESC(fourth_id_byte, "The fourth byte returned by NAND Flash 'read ID' command");
 131 MODULE_PARM_DESC(access_delay,   "Initial page access delay (microiseconds)");
 132 MODULE_PARM_DESC(programm_delay, "Page programm delay (microseconds");
 133 MODULE_PARM_DESC(erase_delay,    "Sector erase delay (milliseconds)");
 134 MODULE_PARM_DESC(output_cycle,   "Word output (from flash) time (nanodeconds)");
 135 MODULE_PARM_DESC(input_cycle,    "Word input (to flash) time (nanodeconds)");
 136 MODULE_PARM_DESC(bus_width,      "Chip's bus width (8- or 16-bit)");
 137 MODULE_PARM_DESC(do_delays,      "Simulate NAND delays using busy-waits if not zero");
 138 MODULE_PARM_DESC(log,            "Perform logging if not zero");
 139 MODULE_PARM_DESC(dbg,            "Output debug information if not zero");
 140 MODULE_PARM_DESC(parts,          "Partition sizes (in erase blocks) separated by commas");
 141 /* Page and erase block positions for the following parameters are independent of any partitions */
 142 MODULE_PARM_DESC(badblocks,      "Erase blocks that are initially marked bad, separated by commas");
 143 MODULE_PARM_DESC(weakblocks,     "Weak erase blocks [: remaining erase cycles (defaults to 3)]"
 144                                  " separated by commas e.g. 113:2 means eb 113"
 145                                  " can be erased only twice before failing");
 146 MODULE_PARM_DESC(weakpages,      "Weak pages [: maximum writes (defaults to 3)]"
 147                                  " separated by commas e.g. 1401:2 means page 1401"
 148                                  " can be written only twice before failing");
 149 MODULE_PARM_DESC(bitflips,       "Maximum number of random bit flips per page (zero by default)");
 150 MODULE_PARM_DESC(gravepages,     "Pages that lose data [: maximum reads (defaults to 3)]"
 151                                  " separated by commas e.g. 1401:2 means page 1401"
 152                                  " can be read only twice before failing");
 153 MODULE_PARM_DESC(rptwear,        "Number of erases inbetween reporting wear, if not zero");
 154 MODULE_PARM_DESC(overridesize,   "Specifies the NAND Flash size overriding the ID bytes. "
 155                                  "The size is specified in erase blocks and as the exponent of a power of two"
 156                                  " e.g. 5 means a size of 32 erase blocks");
 157
 158 /* The largest possible page size */
 159 #define NS_LARGEST_PAGE_SIZE    2048
 160
 161 /* The prefix for simulator output */
 162 #define NS_OUTPUT_PREFIX "[nandsim]"
 163
 164 /* Simulator's output macros (logging, debugging, warning, error) */
 165 #define NS_LOG(args...) \
 166         do { if (log) printk(KERN_DEBUG NS_OUTPUT_PREFIX " log: " args); } while(0)
 167 #define NS_DBG(args...) \
 168         do { if (dbg) printk(KERN_DEBUG NS_OUTPUT_PREFIX " debug: " args); } while(0)
 169 #define NS_WARN(args...) \
 170         do { printk(KERN_WARNING NS_OUTPUT_PREFIX " warning: " args); } while(0)
 171 #define NS_ERR(args...) \
 172         do { printk(KERN_ERR NS_OUTPUT_PREFIX " error: " args); } while(0)
 173 #define NS_INFO(args...) \
 174         do { printk(KERN_INFO NS_OUTPUT_PREFIX " " args); } while(0)
 175
 176 /* Busy-wait delay macros (microseconds, milliseconds) */
 177 #define NS_UDELAY(us) \
 178         do { if (do_delays) udelay(us); } while(0)
 179 #define NS_MDELAY(us) \
 180         do { if (do_delays) mdelay(us); } while(0)
 181
 182 /* Is the nandsim structure initialized ? */
 183 #define NS_IS_INITIALIZED(ns) ((ns)->geom.totsz != 0)
 184
 185 /* Good operation completion status */
 186 #define NS_STATUS_OK(ns) (NAND_STATUS_READY | (NAND_STATUS_WP * ((ns)->lines.wp == 0)))
 187
 188 /* Operation failed completion status */
 189 #define NS_STATUS_FAILED(ns) (NAND_STATUS_FAIL | NS_STATUS_OK(ns))
 190
 191 /* Calculate the page offset in flash RAM image by (row, column) address */
 192 #define NS_RAW_OFFSET(ns) \
 193         (((ns)->regs.row << (ns)->geom.pgshift) + ((ns)->regs.row * (ns)->geom.oobsz) + (ns)->regs.column)
 194
 195 /* Calculate the OOB offset in flash RAM image by (row, column) address */
 196 #define NS_RAW_OFFSET_OOB(ns) (NS_RAW_OFFSET(ns) + ns->geom.pgsz)
 197
 198 /* After a command is input, the simulator goes to one of the following states */
 199 #define STATE_CMD_READ0        0x00000001 /* read data from the beginning of page */
 200 #define STATE_CMD_READ1        0x00000002 /* read data from the second half of page */
 201 #define STATE_CMD_READSTART    0x00000003 /* read data second command (large page devices) */
 202 #define STATE_CMD_PAGEPROG     0x00000004 /* start page programm */
 203 #define STATE_CMD_READOOB      0x00000005 /* read OOB area */
 204 #define STATE_CMD_ERASE1       0x00000006 /* sector erase first command */
 205 #define STATE_CMD_STATUS       0x00000007 /* read status */
 206 #define STATE_CMD_STATUS_M     0x00000008 /* read multi-plane status (isn't implemented) */
 207 #define STATE_CMD_SEQIN        0x00000009 /* sequential data imput */
 208 #define STATE_CMD_READID       0x0000000A /* read ID */
 209 #define STATE_CMD_ERASE2       0x0000000B /* sector erase second command */
 210 #define STATE_CMD_RESET        0x0000000C /* reset */
 211 #define STATE_CMD_MASK         0x0000000F /* command states mask */
 212
 213 /* After an addres is input, the simulator goes to one of these states */
 214 #define STATE_ADDR_PAGE        0x00000010 /* full (row, column) address is accepted */
 215 #define STATE_ADDR_SEC         0x00000020 /* sector address was accepted */
 216 #define STATE_ADDR_ZERO        0x00000030 /* one byte zero address was accepted */
 217 #define STATE_ADDR_MASK        0x00000030 /* address states mask */
 218
 219 /* Durind data input/output the simulator is in these states */
 220 #define STATE_DATAIN           0x00000100 /* waiting for data input */
 221 #define STATE_DATAIN_MASK      0x00000100 /* data input states mask */
 222
 223 #define STATE_DATAOUT          0x00001000 /* waiting for page data output */
 224 #define STATE_DATAOUT_ID       0x00002000 /* waiting for ID bytes output */
 225 #define STATE_DATAOUT_STATUS   0x00003000 /* waiting for status output */
 226 #define STATE_DATAOUT_STATUS_M 0x00004000 /* waiting for multi-plane status output */
 227 #define STATE_DATAOUT_MASK     0x00007000 /* data output states mask */
 228
 229 /* Previous operation is done, ready to accept new requests */
 230 #define STATE_READY            0x00000000
 231
 232 /* This state is used to mark that the next state isn't known yet */
 233 #define STATE_UNKNOWN          0x10000000
 234
 235 /* Simulator's actions bit masks */
 236 #define ACTION_CPY       0x00100000 /* copy page/OOB to the internal buffer */
 237 #define ACTION_PRGPAGE   0x00200000 /* programm the internal buffer to flash */
 238 #define ACTION_SECERASE  0x00300000 /* erase sector */
 239 #define ACTION_ZEROOFF   0x00400000 /* don't add any offset to address */
 240 #define ACTION_HALFOFF   0x00500000 /* add to address half of page */
 241 #define ACTION_OOBOFF    0x00600000 /* add to address OOB offset */
 242 #define ACTION_MASK      0x00700000 /* action mask */
 243
 244 #define NS_OPER_NUM      12 /* Number of operations supported by the simulator */
 245 #define NS_OPER_STATES   6  /* Maximum number of states in operation */
 246
 247 #define OPT_ANY          0xFFFFFFFF /* any chip supports this operation */
 248 #define OPT_PAGE256      0x00000001 /* 256-byte  page chips */
 249 #define OPT_PAGE512      0x00000002 /* 512-byte  page chips */
 250 #define OPT_PAGE2048     0x00000008 /* 2048-byte page chips */
 251 #define OPT_SMARTMEDIA   0x00000010 /* SmartMedia technology chips */
 252 #define OPT_AUTOINCR     0x00000020 /* page number auto inctimentation is possible */
 253 #define OPT_PAGE512_8BIT 0x00000040 /* 512-byte page chips with 8-bit bus width */
 254 #define OPT_LARGEPAGE    (OPT_PAGE2048) /* 2048-byte page chips */
 255 #define OPT_SMALLPAGE    (OPT_PAGE256  | OPT_PAGE512)  /* 256 and 512-byte page chips */
 256
 257 /* Remove action bits ftom state */
 258 #define NS_STATE(x) ((x) & ~ACTION_MASK)
 259
 260 /*
 261  * Maximum previous states which need to be saved. Currently saving is
 262  * only needed for page programm operation with preceeded read command
 263  * (which is only valid for 512-byte pages).
 264  */
 265 #define NS_MAX_PREVSTATES 1
 266
 267 /*
 268  * A union to represent flash memory contents and flash buffer.
 269  */
 270 union ns_mem {
 271         u_char *byte;    /* for byte access */
 272         uint16_t *word;  /* for 16-bit word access */
 273 };
 274
 275 /*
 276  * The structure which describes all the internal simulator data.
 277  */
 278 struct nandsim {
 279         struct mtd_partition partitions[MAX_MTD_DEVICES];
 280         unsigned int nbparts;
 281
 282         uint busw;              /* flash chip bus width (8 or 16) */
 283         u_char ids[4];          /* chip's ID bytes */
 284         uint32_t options;       /* chip's characteristic bits */
 285         uint32_t state;         /* current chip state */
 286         uint32_t nxstate;       /* next expected state */
 287
 288         uint32_t *op;           /* current operation, NULL operations isn't known yet  */
 289         uint32_t pstates[NS_MAX_PREVSTATES]; /* previous states */
 290         uint16_t npstates;      /* number of previous states saved */
 291         uint16_t stateidx;      /* current state index */
 292
 293         /* The simulated NAND flash pages array */
 294         union ns_mem *pages;
 295
 296         /* Internal buffer of page + OOB size bytes */
 297         union ns_mem buf;
 298
 299         /* NAND flash "geometry" */
 300         struct nandsin_geometry {
 301                 uint32_t totsz;     /* total flash size, bytes */
 302                 uint32_t secsz;     /* flash sector (erase block) size, bytes */
 303                 uint pgsz;          /* NAND flash page size, bytes */
 304                 uint oobsz;         /* page OOB area size, bytes */
 305                 uint32_t totszoob;  /* total flash size including OOB, bytes */
 306                 uint pgszoob;       /* page size including OOB , bytes*/
 307                 uint secszoob;      /* sector size including OOB, bytes */
 308                 uint pgnum;         /* total number of pages */
 309                 uint pgsec;         /* number of pages per sector */
 310                 uint secshift;      /* bits number in sector size */
 311                 uint pgshift;       /* bits number in page size */
 312                 uint oobshift;      /* bits number in OOB size */
 313                 uint pgaddrbytes;   /* bytes per page address */
 314                 uint secaddrbytes;  /* bytes per sector address */
 315                 uint idbytes;       /* the number ID bytes that this chip outputs */
 316         } geom;
 317
 318         /* NAND flash internal registers */
 319         struct nandsim_regs {
 320                 unsigned command; /* the command register */
 321                 u_char   status;  /* the status register */
 322                 uint     row;     /* the page number */
 323                 uint     column;  /* the offset within page */
 324                 uint     count;   /* internal counter */
 325                 uint     num;     /* number of bytes which must be processed */
 326                 uint     off;     /* fixed page offset */
 327         } regs;
 328
 329         /* NAND flash lines state */
 330         struct ns_lines_status {
 331                 int ce;  /* chip Enable */
 332                 int cle; /* command Latch Enable */
 333                 int ale; /* address Latch Enable */
 334                 int wp;  /* write Protect */
 335         } lines;
 336 };
 337
 338 /*
 339  * Operations array. To perform any operation the simulator must pass
 340  * through the correspondent states chain.
 341  */
 342 static struct nandsim_operations {
 343         uint32_t reqopts;  /* options which are required to perform the operation */
 344         uint32_t states[NS_OPER_STATES]; /* operation's states */
 345 } ops[NS_OPER_NUM] = {
 346         /* Read page + OOB from the beginning */
 347         {OPT_SMALLPAGE, {STATE_CMD_READ0 | ACTION_ZEROOFF, STATE_ADDR_PAGE | ACTION_CPY,
 348                         STATE_DATAOUT, STATE_READY}},
 349         /* Read page + OOB from the second half */
 350         {OPT_PAGE512_8BIT, {STATE_CMD_READ1 | ACTION_HALFOFF, STATE_ADDR_PAGE | ACTION_CPY,
 351                         STATE_DATAOUT, STATE_READY}},
 352         /* Read OOB */
 353         {OPT_SMALLPAGE, {STATE_CMD_READOOB | ACTION_OOBOFF, STATE_ADDR_PAGE | ACTION_CPY,
 354                         STATE_DATAOUT, STATE_READY}},
 355         /* Programm page starting from the beginning */
 356         {OPT_ANY, {STATE_CMD_SEQIN, STATE_ADDR_PAGE, STATE_DATAIN,
 357                         STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
 358         /* Programm page starting from the beginning */
 359         {OPT_SMALLPAGE, {STATE_CMD_READ0, STATE_CMD_SEQIN | ACTION_ZEROOFF, STATE_ADDR_PAGE,
 360                               STATE_DATAIN, STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
 361         /* Programm page starting from the second half */
 362         {OPT_PAGE512, {STATE_CMD_READ1, STATE_CMD_SEQIN | ACTION_HALFOFF, STATE_ADDR_PAGE,
 363                               STATE_DATAIN, STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
 364         /* Programm OOB */
 365         {OPT_SMALLPAGE, {STATE_CMD_READOOB, STATE_CMD_SEQIN | ACTION_OOBOFF, STATE_ADDR_PAGE,
 366                               STATE_DATAIN, STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
 367         /* Erase sector */
 368         {OPT_ANY, {STATE_CMD_ERASE1, STATE_ADDR_SEC, STATE_CMD_ERASE2 | ACTION_SECERASE, STATE_READY}},
 369         /* Read status */
 370         {OPT_ANY, {STATE_CMD_STATUS, STATE_DATAOUT_STATUS, STATE_READY}},
 371         /* Read multi-plane status */
 372         {OPT_SMARTMEDIA, {STATE_CMD_STATUS_M, STATE_DATAOUT_STATUS_M, STATE_READY}},
 373         /* Read ID */
 374         {OPT_ANY, {STATE_CMD_READID, STATE_ADDR_ZERO, STATE_DATAOUT_ID, STATE_READY}},
 375         /* Large page devices read page */
 376         {OPT_LARGEPAGE, {STATE_CMD_READ0, STATE_ADDR_PAGE, STATE_CMD_READSTART | ACTION_CPY,
 377                                STATE_DATAOUT, STATE_READY}}
 378 };
 379
 380 struct weak_block {
 381         struct list_head list;
 382         unsigned int erase_block_no;
 383         unsigned int max_erases;
 384         unsigned int erases_done;
 385 };
 386
 387 static LIST_HEAD(weak_blocks);
 388
 389 struct weak_page {
 390         struct list_head list;
 391         unsigned int page_no;
 392         unsigned int max_writes;
 393         unsigned int writes_done;
 394 };
 395
 396 static LIST_HEAD(weak_pages);
 397
 398 struct grave_page {
 399         struct list_head list;
 400         unsigned int page_no;
 401         unsigned int max_reads;
 402         unsigned int reads_done;
 403 };
 404
 405 static LIST_HEAD(grave_pages);
 406
 407 static unsigned long *erase_block_wear = NULL;
 408 static unsigned int wear_eb_count = 0;
 409 static unsigned long total_wear = 0;
 410 static unsigned int rptwear_cnt = 0;
 411
 412 /* MTD structure for NAND controller */
 413 static struct mtd_info *nsmtd;
 414
 415 static u_char ns_verify_buf[NS_LARGEST_PAGE_SIZE];
 416
 417 /*
 418  * Allocate array of page pointers and initialize the array to NULL
 419  * pointers.
 420  *
 421  * RETURNS: 0 if success, -ENOMEM if memory alloc fails.
 422  */
 423 static int alloc_device(struct nandsim *ns)
 424 {
 425         int i;
 426
 427         ns->pages = vmalloc(ns->geom.pgnum * sizeof(union ns_mem));
 428         if (!ns->pages) {
 429                 NS_ERR("alloc_map: unable to allocate page array\n");
 430                 return -ENOMEM;
 431         }
 432         for (i = 0; i < ns->geom.pgnum; i++) {
 433                 ns->pages[i].byte = NULL;
 434         }
 435
 436         return 0;
 437 }
 438
 439 /*
 440  * Free any allocated pages, and free the array of page pointers.
 441  */
 442 static void free_device(struct nandsim *ns)
 443 {
 444         int i;
 445
 446         if (ns->pages) {
 447                 for (i = 0; i < ns->geom.pgnum; i++) {
 448                         if (ns->pages[i].byte)
 449                                 kfree(ns->pages[i].byte);
 450                 }
 451                 vfree(ns->pages);
 452         }
 453 }
 454
 455 static char *get_partition_name(int i)
 456 {
 457         char buf[64];
 458         sprintf(buf, "NAND simulator partition %d", i);
 459         return kstrdup(buf, GFP_KERNEL);
 460 }
 461
 462 /*
 463  * Initialize the nandsim structure.
 464  *
 465  * RETURNS: 0 if success, -ERRNO if failure.
 466  */
 467 static int init_nandsim(struct mtd_info *mtd)
 468 {
 469         struct nand_chip *chip = (struct nand_chip *)mtd->priv;
 470         struct nandsim   *ns   = (struct nandsim *)(chip->priv);
 471         int i, ret = 0;
 472         u_int32_t remains;
 473         u_int32_t next_offset;
 474
 475         if (NS_IS_INITIALIZED(ns)) {
 476                 NS_ERR("init_nandsim: nandsim is already initialized\n");
 477                 return -EIO;
 478         }
 479
 480         /* Force mtd to not do delays */
 481         chip->chip_delay = 0;
 482
 483         /* Initialize the NAND flash parameters */
 484         ns->busw = chip->options & NAND_BUSWIDTH_16 ? 16 : 8;
 485         ns->geom.totsz    = mtd->size;
 486         ns->geom.pgsz     = mtd->writesize;
 487         ns->geom.oobsz    = mtd->oobsize;
 488         ns->geom.secsz    = mtd->erasesize;
 489         ns->geom.pgszoob  = ns->geom.pgsz + ns->geom.oobsz;
 490         ns->geom.pgnum    = ns->geom.totsz / ns->geom.pgsz;
 491         ns->geom.totszoob = ns->geom.totsz + ns->geom.pgnum * ns->geom.oobsz;
 492         ns->geom.secshift = ffs(ns->geom.secsz) - 1;
 493         ns->geom.pgshift  = chip->page_shift;
 494         ns->geom.oobshift = ffs(ns->geom.oobsz) - 1;
 495         ns->geom.pgsec    = ns->geom.secsz / ns->geom.pgsz;
 496         ns->geom.secszoob = ns->geom.secsz + ns->geom.oobsz * ns->geom.pgsec;
 497         ns->options = 0;
 498
 499         if (ns->geom.pgsz == 256) {
 500                 ns->options |= OPT_PAGE256;
 501         }
 502         else if (ns->geom.pgsz == 512) {
 503                 ns->options |= (OPT_PAGE512 | OPT_AUTOINCR);
 504                 if (ns->busw == 8)
 505                         ns->options |= OPT_PAGE512_8BIT;
 506         } else if (ns->geom.pgsz == 2048) {
 507                 ns->options |= OPT_PAGE2048;
 508         } else {
 509                 NS_ERR("init_nandsim: unknown page size %u\n", ns->geom.pgsz);
 510                 return -EIO;
 511         }
 512
 513         if (ns->options & OPT_SMALLPAGE) {
 514                 if (ns->geom.totsz < (32 << 20)) {
 515                         ns->geom.pgaddrbytes  = 3;
 516                         ns->geom.secaddrbytes = 2;
 517                 } else {
 518                         ns->geom.pgaddrbytes  = 4;
 519                         ns->geom.secaddrbytes = 3;
 520                 }
 521         } else {
 522                 if (ns->geom.totsz <= (128 << 20)) {
 523                         ns->geom.pgaddrbytes  = 4;
 524                         ns->geom.secaddrbytes = 2;
 525                 } else {
 526                         ns->geom.pgaddrbytes  = 5;
 527                         ns->geom.secaddrbytes = 3;
 528                 }
 529         }
 530
 531         /* Fill the partition_info structure */
 532         if (parts_num > ARRAY_SIZE(ns->partitions)) {
 533                 NS_ERR("too many partitions.\n");
 534                 ret = -EINVAL;
 535                 goto error;
 536         }
 537         remains = ns->geom.totsz;
 538         next_offset = 0;
 539         for (i = 0; i < parts_num; ++i) {
 540                 unsigned long part = parts[i];
 541                 if (!part || part > remains / ns->geom.secsz) {
 542                         NS_ERR("bad partition size.\n");
 543                         ret = -EINVAL;
 544                         goto error;
 545                 }
 546                 ns->partitions[i].name   = get_partition_name(i);
 547                 ns->partitions[i].offset = next_offset;
 548                 ns->partitions[i].size   = part * ns->geom.secsz;
 549                 next_offset += ns->partitions[i].size;
 550                 remains -= ns->partitions[i].size;
 551         }
 552         ns->nbparts = parts_num;
 553         if (remains) {
 554                 if (parts_num + 1 > ARRAY_SIZE(ns->partitions)) {
 555                         NS_ERR("too many partitions.\n");
 556                         ret = -EINVAL;
 557                         goto error;
 558                 }
 559                 ns->partitions[i].name   = get_partition_name(i);
 560                 ns->partitions[i].offset = next_offset;
 561                 ns->partitions[i].size   = remains;
 562                 ns->nbparts += 1;
 563         }
 564
 565         /* Detect how many ID bytes the NAND chip outputs */
 566         for (i = 0; nand_flash_ids[i].name != NULL; i++) {
 567                 if (second_id_byte != nand_flash_ids[i].id)
 568                         continue;
 569                 if (!(nand_flash_ids[i].options & NAND_NO_AUTOINCR))
 570                         ns->options |= OPT_AUTOINCR;
 571         }
 572
 573         if (ns->busw == 16)
 574                 NS_WARN("16-bit flashes support wasn't tested\n");
 575
 576         printk("flash size: %u MiB\n",          ns->geom.totsz >> 20);
 577         printk("page size: %u bytes\n",         ns->geom.pgsz);
 578         printk("OOB area size: %u bytes\n",     ns->geom.oobsz);
 579         printk("sector size: %u KiB\n",         ns->geom.secsz >> 10);
 580         printk("pages number: %u\n",            ns->geom.pgnum);
 581         printk("pages per sector: %u\n",        ns->geom.pgsec);
 582         printk("bus width: %u\n",               ns->busw);
 583         printk("bits in sector size: %u\n",     ns->geom.secshift);
 584         printk("bits in page size: %u\n",       ns->geom.pgshift);
 585         printk("bits in OOB size: %u\n",        ns->geom.oobshift);
 586         printk("flash size with OOB: %u KiB\n", ns->geom.totszoob >> 10);
 587         printk("page address bytes: %u\n",      ns->geom.pgaddrbytes);
 588         printk("sector address bytes: %u\n",    ns->geom.secaddrbytes);
 589         printk("options: %#x\n",                ns->options);
 590
 591         if ((ret = alloc_device(ns)) != 0)
 592                 goto error;
 593
 594         /* Allocate / initialize the internal buffer */
 595         ns->buf.byte = kmalloc(ns->geom.pgszoob, GFP_KERNEL);
 596         if (!ns->buf.byte) {
 597                 NS_ERR("init_nandsim: unable to allocate %u bytes for the internal buffer\n",
 598                         ns->geom.pgszoob);
 599                 ret = -ENOMEM;
 600                 goto error;
 601         }
 602         memset(ns->buf.byte, 0xFF, ns->geom.pgszoob);
 603
 604         return 0;
 605
 606 error:
 607         free_device(ns);
 608
 609         return ret;
 610 }
 611
 612 /*
 613  * Free the nandsim structure.
 614  */
 615 static void free_nandsim(struct nandsim *ns)
 616 {
 617         kfree(ns->buf.byte);
 618         free_device(ns);
 619
 620         return;
 621 }
 622
 623 static int parse_badblocks(struct nandsim *ns, struct mtd_info *mtd)
 624 {
 625         char *w;
 626         int zero_ok;
 627         unsigned int erase_block_no;
 628         loff_t offset;
 629
 630         if (!badblocks)
 631                 return 0;
 632         w = badblocks;
 633         do {
 634                 zero_ok = (*w == '0' ? 1 : 0);
 635                 erase_block_no = simple_strtoul(w, &w, 0);
 636                 if (!zero_ok && !erase_block_no) {
 637                         NS_ERR("invalid badblocks.\n");
 638                         return -EINVAL;
 639                 }
 640                 offset = erase_block_no * ns->geom.secsz;
 641                 if (mtd->block_markbad(mtd, offset)) {
 642                         NS_ERR("invalid badblocks.\n");
 643                         return -EINVAL;
 644                 }
 645                 if (*w == ',')
 646                         w += 1;
 647         } while (*w);
 648         return 0;
 649 }
 650
 651 static int parse_weakblocks(void)
 652 {
 653         char *w;
 654         int zero_ok;
 655         unsigned int erase_block_no;
 656         unsigned int max_erases;
 657         struct weak_block *wb;
 658
 659         if (!weakblocks)
 660                 return 0;
 661         w = weakblocks;
 662         do {
 663                 zero_ok = (*w == '0' ? 1 : 0);
 664                 erase_block_no = simple_strtoul(w, &w, 0);
 665                 if (!zero_ok && !erase_block_no) {
 666                         NS_ERR("invalid weakblocks.\n");
 667                         return -EINVAL;
 668                 }
 669                 max_erases = 3;
 670                 if (*w == ':') {
 671                         w += 1;
 672                         max_erases = simple_strtoul(w, &w, 0);
 673                 }
 674                 if (*w == ',')
 675                         w += 1;
 676                 wb = kzalloc(sizeof(*wb), GFP_KERNEL);
 677                 if (!wb) {
 678                         NS_ERR("unable to allocate memory.\n");
 679                         return -ENOMEM;
 680                 }
 681                 wb->erase_block_no = erase_block_no;
 682                 wb->max_erases = max_erases;
 683                 list_add(&wb->list, &weak_blocks);
 684         } while (*w);
 685         return 0;
 686 }
 687
 688 static int erase_error(unsigned int erase_block_no)
 689 {
 690         struct weak_block *wb;
 691
 692         list_for_each_entry(wb, &weak_blocks, list)
 693                 if (wb->erase_block_no == erase_block_no) {
 694                         if (wb->erases_done >= wb->max_erases)
 695                                 return 1;
 696                         wb->erases_done += 1;
 697                         return 0;
 698                 }
 699         return 0;
 700 }
 701
 702 static int parse_weakpages(void)
 703 {
 704         char *w;
 705         int zero_ok;
 706         unsigned int page_no;
 707         unsigned int max_writes;
 708         struct weak_page *wp;
 709
 710         if (!weakpages)
 711                 return 0;
 712         w = weakpages;
 713         do {
 714                 zero_ok = (*w == '0' ? 1 : 0);
 715                 page_no = simple_strtoul(w, &w, 0);
 716                 if (!zero_ok && !page_no) {
 717                         NS_ERR("invalid weakpagess.\n");
 718                         return -EINVAL;
 719                 }
 720                 max_writes = 3;
 721                 if (*w == ':') {
 722                         w += 1;
 723                         max_writes = simple_strtoul(w, &w, 0);
 724                 }
 725                 if (*w == ',')
 726                         w += 1;
 727                 wp = kzalloc(sizeof(*wp), GFP_KERNEL);
 728                 if (!wp) {
 729                         NS_ERR("unable to allocate memory.\n");
 730                         return -ENOMEM;
 731                 }
 732                 wp->page_no = page_no;
 733                 wp->max_writes = max_writes;
 734                 list_add(&wp->list, &weak_pages);
 735         } while (*w);
 736         return 0;
 737 }
 738
 739 static int write_error(unsigned int page_no)
 740 {
 741         struct weak_page *wp;
 742
 743         list_for_each_entry(wp, &weak_pages, list)
 744                 if (wp->page_no == page_no) {
 745                         if (wp->writes_done >= wp->max_writes)
 746                                 return 1;
 747                         wp->writes_done += 1;
 748                         return 0;
 749                 }
 750         return 0;
 751 }
 752
 753 static int parse_gravepages(void)
 754 {
 755         char *g;
 756         int zero_ok;
 757         unsigned int page_no;
 758         unsigned int max_reads;
 759         struct grave_page *gp;
 760
 761         if (!gravepages)
 762                 return 0;
 763         g = gravepages;
 764         do {
 765                 zero_ok = (*g == '0' ? 1 : 0);
 766                 page_no = simple_strtoul(g, &g, 0);
 767                 if (!zero_ok && !page_no) {
 768                         NS_ERR("invalid gravepagess.\n");
 769                         return -EINVAL;
 770                 }
 771                 max_reads = 3;
 772                 if (*g == ':') {
 773                         g += 1;
 774                         max_reads = simple_strtoul(g, &g, 0);
 775                 }
 776                 if (*g == ',')
 777                         g += 1;
 778                 gp = kzalloc(sizeof(*gp), GFP_KERNEL);
 779                 if (!gp) {
 780                         NS_ERR("unable to allocate memory.\n");
 781                         return -ENOMEM;
 782                 }
 783                 gp->page_no = page_no;
 784                 gp->max_reads = max_reads;
 785                 list_add(&gp->list, &grave_pages);
 786         } while (*g);
 787         return 0;
 788 }
 789
 790 static int read_error(unsigned int page_no)
 791 {
 792         struct grave_page *gp;
 793
 794         list_for_each_entry(gp, &grave_pages, list)
 795                 if (gp->page_no == page_no) {
 796                         if (gp->reads_done >= gp->max_reads)
 797                                 return 1;
 798                         gp->reads_done += 1;
 799                         return 0;
 800                 }
 801         return 0;
 802 }
 803
 804 static void free_lists(void)
 805 {
 806         struct list_head *pos, *n;
 807         list_for_each_safe(pos, n, &weak_blocks) {
 808                 list_del(pos);
 809                 kfree(list_entry(pos, struct weak_block, list));
 810         }
 811         list_for_each_safe(pos, n, &weak_pages) {
 812                 list_del(pos);
 813                 kfree(list_entry(pos, struct weak_page, list));
 814         }
 815         list_for_each_safe(pos, n, &grave_pages) {
 816                 list_del(pos);
 817                 kfree(list_entry(pos, struct grave_page, list));
 818         }
 819         kfree(erase_block_wear);
 820 }
 821
 822 static int setup_wear_reporting(struct mtd_info *mtd)
 823 {
 824         size_t mem;
 825
 826         if (!rptwear)
 827                 return 0;
 828         wear_eb_count = mtd->size / mtd->erasesize;
 829         mem = wear_eb_count * sizeof(unsigned long);
 830         if (mem / sizeof(unsigned long) != wear_eb_count) {
 831                 NS_ERR("Too many erase blocks for wear reporting\n");
 832                 return -ENOMEM;
 833         }
 834         erase_block_wear = kzalloc(mem, GFP_KERNEL);
 835         if (!erase_block_wear) {
 836                 NS_ERR("Too many erase blocks for wear reporting\n");
 837                 return -ENOMEM;
 838         }
 839         return 0;
 840 }
 841
 842 static void update_wear(unsigned int erase_block_no)
 843 {
 844         unsigned long wmin = -1, wmax = 0, avg;
 845         unsigned long deciles[10], decile_max[10], tot = 0;
 846         unsigned int i;
 847
 848         if (!erase_block_wear)
 849                 return;
 850         total_wear += 1;
 851         if (total_wear == 0)
 852                 NS_ERR("Erase counter total overflow\n");
 853         erase_block_wear[erase_block_no] += 1;
 854         if (erase_block_wear[erase_block_no] == 0)
 855                 NS_ERR("Erase counter overflow for erase block %u\n", erase_block_no);
 856         rptwear_cnt += 1;
 857         if (rptwear_cnt < rptwear)
 858                 return;
 859         rptwear_cnt = 0;
 860         /* Calc wear stats */
 861         for (i = 0; i < wear_eb_count; ++i) {
 862                 unsigned long wear = erase_block_wear[i];
 863                 if (wear < wmin)
 864                         wmin = wear;
 865                 if (wear > wmax)
 866                         wmax = wear;
 867                 tot += wear;
 868         }
 869         for (i = 0; i < 9; ++i) {
 870                 deciles[i] = 0;
 871                 decile_max[i] = (wmax * (i + 1) + 5) / 10;
 872         }
 873         deciles[9] = 0;
 874         decile_max[9] = wmax;
 875         for (i = 0; i < wear_eb_count; ++i) {
 876                 int d;
 877                 unsigned long wear = erase_block_wear[i];
 878                 for (d = 0; d < 10; ++d)
 879                         if (wear <= decile_max[d]) {
 880                                 deciles[d] += 1;
 881                                 break;
 882                         }
 883         }
 884         avg = tot / wear_eb_count;
 885         /* Output wear report */
 886         NS_INFO("*** Wear Report ***\n");
 887         NS_INFO("Total numbers of erases:  %lu\n", tot);
 888         NS_INFO("Number of erase blocks:   %u\n", wear_eb_count);
 889         NS_INFO("Average number of erases: %lu\n", avg);
 890         NS_INFO("Maximum number of erases: %lu\n", wmax);
 891         NS_INFO("Minimum number of erases: %lu\n", wmin);
 892         for (i = 0; i < 10; ++i) {
 893                 unsigned long from = (i ? decile_max[i - 1] + 1 : 0);
 894                 if (from > decile_max[i])
 895                         continue;
 896                 NS_INFO("Number of ebs with erase counts from %lu to %lu : %lu\n",
 897                         from,
 898                         decile_max[i],
 899                         deciles[i]);
 900         }
 901         NS_INFO("*** End of Wear Report ***\n");
 902 }
 903
 904 /*
 905  * Returns the string representation of 'state' state.
 906  */
 907 static char *get_state_name(uint32_t state)
 908 {
 909         switch (NS_STATE(state)) {
 910                 case STATE_CMD_READ0:
 911                         return "STATE_CMD_READ0";
 912                 case STATE_CMD_READ1:
 913                         return "STATE_CMD_READ1";
 914                 case STATE_CMD_PAGEPROG:
 915                         return "STATE_CMD_PAGEPROG";
 916                 case STATE_CMD_READOOB:
 917                         return "STATE_CMD_READOOB";
 918                 case STATE_CMD_READSTART:
 919                         return "STATE_CMD_READSTART";
 920                 case STATE_CMD_ERASE1:
 921                         return "STATE_CMD_ERASE1";
 922                 case STATE_CMD_STATUS:
 923                         return "STATE_CMD_STATUS";
 924                 case STATE_CMD_STATUS_M:
 925                         return "STATE_CMD_STATUS_M";
 926                 case STATE_CMD_SEQIN:
 927                         return "STATE_CMD_SEQIN";
 928                 case STATE_CMD_READID:
 929                         return "STATE_CMD_READID";
 930                 case STATE_CMD_ERASE2:
 931                         return "STATE_CMD_ERASE2";
 932                 case STATE_CMD_RESET:
 933                         return "STATE_CMD_RESET";
 934                 case STATE_ADDR_PAGE:
 935                         return "STATE_ADDR_PAGE";
 936                 case STATE_ADDR_SEC:
 937                         return "STATE_ADDR_SEC";
 938                 case STATE_ADDR_ZERO:
 939                         return "STATE_ADDR_ZERO";
 940                 case STATE_DATAIN:
 941                         return "STATE_DATAIN";
 942                 case STATE_DATAOUT:
 943                         return "STATE_DATAOUT";
 944                 case STATE_DATAOUT_ID:
 945                         return "STATE_DATAOUT_ID";
 946                 case STATE_DATAOUT_STATUS:
 947                         return "STATE_DATAOUT_STATUS";
 948                 case STATE_DATAOUT_STATUS_M:
 949                         return "STATE_DATAOUT_STATUS_M";
 950                 case STATE_READY:
 951                         return "STATE_READY";
 952                 case STATE_UNKNOWN:
 953                         return "STATE_UNKNOWN";
 954         }
 955
 956         NS_ERR("get_state_name: unknown state, BUG\n");
 957         return NULL;
 958 }
 959
 960 /*
 961  * Check if command is valid.
 962  *
 963  * RETURNS: 1 if wrong command, 0 if right.
 964  */
 965 static int check_command(int cmd)
 966 {
 967         switch (cmd) {
 968
 969         case NAND_CMD_READ0:
 970         case NAND_CMD_READSTART:
 971         case NAND_CMD_PAGEPROG:
 972         case NAND_CMD_READOOB:
 973         case NAND_CMD_ERASE1:
 974         case NAND_CMD_STATUS:
 975         case NAND_CMD_SEQIN:
 976         case NAND_CMD_READID:
 977         case NAND_CMD_ERASE2:
 978         case NAND_CMD_RESET:
 979         case NAND_CMD_READ1:
 980                 return 0;
 981
 982         case NAND_CMD_STATUS_MULTI:
 983         default:
 984                 return 1;
 985         }
 986 }
 987
 988 /*
 989  * Returns state after command is accepted by command number.
 990  */
 991 static uint32_t get_state_by_command(unsigned command)
 992 {
 993         switch (command) {
 994                 case NAND_CMD_READ0:
 995                         return STATE_CMD_READ0;
 996                 case NAND_CMD_READ1:
 997                         return STATE_CMD_READ1;
 998                 case NAND_CMD_PAGEPROG:
 999                         return STATE_CMD_PAGEPROG;
1000                 case NAND_CMD_READSTART:
1001                         return STATE_CMD_READSTART;
1002                 case NAND_CMD_READOOB:
1003                         return STATE_CMD_READOOB;
1004                 case NAND_CMD_ERASE1:
1005                         return STATE_CMD_ERASE1;
1006                 case NAND_CMD_STATUS:
1007                         return STATE_CMD_STATUS;
1008                 case NAND_CMD_STATUS_MULTI:
1009                         return STATE_CMD_STATUS_M;
1010                 case NAND_CMD_SEQIN:
1011                         return STATE_CMD_SEQIN;
1012                 case NAND_CMD_READID:
1013                         return STATE_CMD_READID;
1014                 case NAND_CMD_ERASE2:
1015                         return STATE_CMD_ERASE2;
1016                 case NAND_CMD_RESET:
1017                         return STATE_CMD_RESET;
1018         }
1019
1020         NS_ERR("get_state_by_command: unknown command, BUG\n");
1021         return 0;
1022 }
1023
1024 /*
1025  * Move an address byte to the correspondent internal register.
1026  */
1027 static inline void accept_addr_byte(struct nandsim *ns, u_char bt)
1028 {
1029         uint byte = (uint)bt;
1030
1031         if (ns->regs.count < (ns->geom.pgaddrbytes - ns->geom.secaddrbytes))
1032                 ns->regs.column |= (byte << 8 * ns->regs.count);
1033         else {
1034                 ns->regs.row |= (byte << 8 * (ns->regs.count -
1035                                                 ns->geom.pgaddrbytes +
1036                                                 ns->geom.secaddrbytes));
1037         }
1038
1039         return;
1040 }
1041
1042 /*
1043  * Switch to STATE_READY state.
1044  */
1045 static inline void switch_to_ready_state(struct nandsim *ns, u_char status)
1046 {
1047         NS_DBG("switch_to_ready_state: switch to %s state\n", get_state_name(STATE_READY));
1048
1049         ns->state       = STATE_READY;
1050         ns->nxstate     = STATE_UNKNOWN;
1051         ns->op          = NULL;
1052         ns->npstates    = 0;
1053         ns->stateidx    = 0;
1054         ns->regs.num    = 0;
1055         ns->regs.count  = 0;
1056         ns->regs.off    = 0;
1057         ns->regs.row    = 0;
1058         ns->regs.column = 0;
1059         ns->regs.status = status;
1060 }
1061
1062 /*
1063  * If the operation isn't known yet, try to find it in the global array
1064  * of supported operations.
1065  *
1066  * Operation can be unknown because of the following.
1067  *   1. New command was accepted and this is the firs call to find the
1068  *      correspondent states chain. In this case ns->npstates = 0;
1069  *   2. There is several operations which begin with the same command(s)
1070  *      (for example program from the second half and read from the
1071  *      second half operations both begin with the READ1 command). In this
1072  *      case the ns->pstates[] array contains previous states.
1073  *
1074  * Thus, the function tries to find operation containing the following
1075  * states (if the 'flag' parameter is 0):
1076  *    ns->pstates[0], ... ns->pstates[ns->npstates], ns->state
1077  *
1078  * If (one and only one) matching operation is found, it is accepted (
1079  * ns->ops, ns->state, ns->nxstate are initialized, ns->npstate is
1080  * zeroed).
1081  *
1082  * If there are several maches, the current state is pushed to the
1083  * ns->pstates.
1084  *
1085  * The operation can be unknown only while commands are input to the chip.
1086  * As soon as address command is accepted, the operation must be known.
1087  * In such situation the function is called with 'flag' != 0, and the
1088  * operation is searched using the following pattern:
1089  *     ns->pstates[0], ... ns->pstates[ns->npstates], <address input>
1090  *
1091  * It is supposed that this pattern must either match one operation on
1092  * none. There can't be ambiguity in that case.
1093  *
1094  * If no matches found, the functions does the following:
1095  *   1. if there are saved states present, try to ignore them and search
1096  *      again only using the last command. If nothing was found, switch
1097  *      to the STATE_READY state.
1098  *   2. if there are no saved states, switch to the STATE_READY state.
1099  *
1100  * RETURNS: -2 - no matched operations found.
1101  *          -1 - several matches.
1102  *           0 - operation is found.
1103  */
1104 static int find_operation(struct nandsim *ns, uint32_t flag)
1105 {
1106         int opsfound = 0;
1107         int i, j, idx = 0;
1108
1109         for (i = 0; i < NS_OPER_NUM; i++) {
1110
1111                 int found = 1;
1112
1113                 if (!(ns->options & ops[i].reqopts))
1114                         /* Ignore operations we can't perform */
1115                         continue;
1116
1117                 if (flag) {
1118                         if (!(ops[i].states[ns->npstates] & STATE_ADDR_MASK))
1119                                 continue;
1120                 } else {
1121                         if (NS_STATE(ns->state) != NS_STATE(ops[i].states[ns->npstates]))
1122                                 continue;
1123                 }
1124
1125                 for (j = 0; j < ns->npstates; j++)
1126                         if (NS_STATE(ops[i].states[j]) != NS_STATE(ns->pstates[j])
1127                                 && (ns->options & ops[idx].reqopts)) {
1128                                 found = 0;
1129                                 break;
1130                         }
1131
1132                 if (found) {
1133                         idx = i;
1134                         opsfound += 1;
1135                 }
1136         }
1137
1138         if (opsfound == 1) {
1139                 /* Exact match */
1140                 ns->op = &ops[idx].states[0];
1141                 if (flag) {
1142                         /*
1143                          * In this case the find_operation function was
1144                          * called when address has just began input. But it isn't
1145                          * yet fully input and the current state must
1146                          * not be one of STATE_ADDR_*, but the STATE_ADDR_*
1147                          * state must be the next state (ns->nxstate).
1148                          */
1149                         ns->stateidx = ns->npstates - 1;
1150                 } else {
1151                         ns->stateidx = ns->npstates;
1152                 }
1153                 ns->npstates = 0;
1154                 ns->state = ns->op[ns->stateidx];
1155                 ns->nxstate = ns->op[ns->stateidx + 1];
1156                 NS_DBG("find_operation: operation found, index: %d, state: %s, nxstate %s\n",
1157                                 idx, get_state_name(ns->state), get_state_name(ns->nxstate));
1158                 return 0;
1159         }
1160
1161         if (opsfound == 0) {
1162                 /* Nothing was found. Try to ignore previous commands (if any) and search again */
1163                 if (ns->npstates != 0) {
1164                         NS_DBG("find_operation: no operation found, try again with state %s\n",
1165                                         get_state_name(ns->state));
1166                         ns->npstates = 0;
1167                         return find_operation(ns, 0);
1168
1169                 }
1170                 NS_DBG("find_operation: no operations found\n");
1171                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1172                 return -2;
1173         }
1174
1175         if (flag) {
1176                 /* This shouldn't happen */
1177                 NS_DBG("find_operation: BUG, operation must be known if address is input\n");
1178                 return -2;
1179         }
1180
1181         NS_DBG("find_operation: there is still ambiguity\n");
1182
1183         ns->pstates[ns->npstates++] = ns->state;
1184
1185         return -1;
1186 }
1187
1188 /*
1189  * Returns a pointer to the current page.
1190  */
1191 static inline union ns_mem *NS_GET_PAGE(struct nandsim *ns)
1192 {
1193         return &(ns->pages[ns->regs.row]);
1194 }
1195
1196 /*
1197  * Retuns a pointer to the current byte, within the current page.
1198  */
1199 static inline u_char *NS_PAGE_BYTE_OFF(struct nandsim *ns)
1200 {
1201         return NS_GET_PAGE(ns)->byte + ns->regs.column + ns->regs.off;
1202 }
1203
1204 /*
1205  * Fill the NAND buffer with data read from the specified page.
1206  */
1207 static void read_page(struct nandsim *ns, int num)
1208 {
1209         union ns_mem *mypage;
1210
1211         mypage = NS_GET_PAGE(ns);
1212         if (mypage->byte == NULL) {
1213                 NS_DBG("read_page: page %d not allocated\n", ns->regs.row);
1214                 memset(ns->buf.byte, 0xFF, num);
1215         } else {
1216                 unsigned int page_no = ns->regs.row;
1217                 NS_DBG("read_page: page %d allocated, reading from %d\n",
1218                         ns->regs.row, ns->regs.column + ns->regs.off);
1219                 if (read_error(page_no)) {
1220                         int i;
1221                         memset(ns->buf.byte, 0xFF, num);
1222                         for (i = 0; i < num; ++i)
1223                                 ns->buf.byte[i] = random32();
1224                         NS_WARN("simulating read error in page %u\n", page_no);
1225                         return;
1226                 }
1227                 memcpy(ns->buf.byte, NS_PAGE_BYTE_OFF(ns), num);
1228                 if (bitflips && random32() < (1 << 22)) {
1229                         int flips = 1;
1230                         if (bitflips > 1)
1231                                 flips = (random32() % (int) bitflips) + 1;
1232                         while (flips--) {
1233                                 int pos = random32() % (num * 8);
1234                                 ns->buf.byte[pos / 8] ^= (1 << (pos % 8));
1235                                 NS_WARN("read_page: flipping bit %d in page %d "
1236                                         "reading from %d ecc: corrected=%u failed=%u\n",
1237                                         pos, ns->regs.row, ns->regs.column + ns->regs.off,
1238                                         nsmtd->ecc_stats.corrected, nsmtd->ecc_stats.failed);
1239                         }
1240                 }
1241         }
1242 }
1243
1244 /*
1245  * Erase all pages in the specified sector.
1246  */
1247 static void erase_sector(struct nandsim *ns)
1248 {
1249         union ns_mem *mypage;
1250         int i;
1251
1252         mypage = NS_GET_PAGE(ns);
1253         for (i = 0; i < ns->geom.pgsec; i++) {
1254                 if (mypage->byte != NULL) {
1255                         NS_DBG("erase_sector: freeing page %d\n", ns->regs.row+i);
1256                         kfree(mypage->byte);
1257                         mypage->byte = NULL;
1258                 }
1259                 mypage++;
1260         }
1261 }
1262
1263 /*
1264  * Program the specified page with the contents from the NAND buffer.
1265  */
1266 static int prog_page(struct nandsim *ns, int num)
1267 {
1268         int i;
1269         union ns_mem *mypage;
1270         u_char *pg_off;
1271
1272         mypage = NS_GET_PAGE(ns);
1273         if (mypage->byte == NULL) {
1274                 NS_DBG("prog_page: allocating page %d\n", ns->regs.row);
1275                 /*
1276                  * We allocate memory with GFP_NOFS because a flash FS may
1277                  * utilize this. If it is holding an FS lock, then gets here,
1278                  * then kmalloc runs writeback which goes to the FS again
1279                  * and deadlocks. This was seen in practice.
1280                  */
1281                 mypage->byte = kmalloc(ns->geom.pgszoob, GFP_NOFS);
1282                 if (mypage->byte == NULL) {
1283                         NS_ERR("prog_page: error allocating memory for page %d\n", ns->regs.row);
1284                         return -1;
1285                 }
1286                 memset(mypage->byte, 0xFF, ns->geom.pgszoob);
1287         }
1288
1289         pg_off = NS_PAGE_BYTE_OFF(ns);
1290         for (i = 0; i < num; i++)
1291                 pg_off[i] &= ns->buf.byte[i];
1292
1293         return 0;
1294 }
1295
1296 /*
1297  * If state has any action bit, perform this action.
1298  *
1299  * RETURNS: 0 if success, -1 if error.
1300  */
1301 static int do_state_action(struct nandsim *ns, uint32_t action)
1302 {
1303         int num;
1304         int busdiv = ns->busw == 8 ? 1 : 2;
1305         unsigned int erase_block_no, page_no;
1306
1307         action &= ACTION_MASK;
1308
1309         /* Check that page address input is correct */
1310         if (action != ACTION_SECERASE && ns->regs.row >= ns->geom.pgnum) {
1311                 NS_WARN("do_state_action: wrong page number (%#x)\n", ns->regs.row);
1312                 return -1;
1313         }
1314
1315         switch (action) {
1316
1317         case ACTION_CPY:
1318                 /*
1319                  * Copy page data to the internal buffer.
1320                  */
1321
1322                 /* Column shouldn't be very large */
1323                 if (ns->regs.column >= (ns->geom.pgszoob - ns->regs.off)) {
1324                         NS_ERR("do_state_action: column number is too large\n");
1325                         break;
1326                 }
1327                 num = ns->geom.pgszoob - ns->regs.off - ns->regs.column;
1328                 read_page(ns, num);
1329
1330                 NS_DBG("do_state_action: (ACTION_CPY:) copy %d bytes to int buf, raw offset %d\n",
1331                         num, NS_RAW_OFFSET(ns) + ns->regs.off);
1332
1333                 if (ns->regs.off == 0)
1334                         NS_LOG("read page %d\n", ns->regs.row);
1335                 else if (ns->regs.off < ns->geom.pgsz)
1336                         NS_LOG("read page %d (second half)\n", ns->regs.row);
1337                 else
1338                         NS_LOG("read OOB of page %d\n", ns->regs.row);
1339
1340                 NS_UDELAY(access_delay);
1341                 NS_UDELAY(input_cycle * ns->geom.pgsz / 1000 / busdiv);
1342
1343                 break;
1344
1345         case ACTION_SECERASE:
1346                 /*
1347                  * Erase sector.
1348                  */
1349
1350                 if (ns->lines.wp) {
1351                         NS_ERR("do_state_action: device is write-protected, ignore sector erase\n");
1352                         return -1;
1353                 }
1354
1355                 if (ns->regs.row >= ns->geom.pgnum - ns->geom.pgsec
1356                         || (ns->regs.row & ~(ns->geom.secsz - 1))) {
1357                         NS_ERR("do_state_action: wrong sector address (%#x)\n", ns->regs.row);
1358                         return -1;
1359                 }
1360
1361                 ns->regs.row = (ns->regs.row <<
1362                                 8 * (ns->geom.pgaddrbytes - ns->geom.secaddrbytes)) | ns->regs.column;
1363                 ns->regs.column = 0;
1364
1365                 erase_block_no = ns->regs.row >> (ns->geom.secshift - ns->geom.pgshift);
1366
1367                 NS_DBG("do_state_action: erase sector at address %#x, off = %d\n",
1368                                 ns->regs.row, NS_RAW_OFFSET(ns));
1369                 NS_LOG("erase sector %u\n", erase_block_no);
1370
1371                 erase_sector(ns);
1372
1373                 NS_MDELAY(erase_delay);
1374
1375                 if (erase_block_wear)
1376                         update_wear(erase_block_no);
1377
1378                 if (erase_error(erase_block_no)) {
1379                         NS_WARN("simulating erase failure in erase block %u\n", erase_block_no);
1380                         return -1;
1381                 }
1382
1383                 break;
1384
1385         case ACTION_PRGPAGE:
1386                 /*
1387                  * Programm page - move internal buffer data to the page.
1388                  */
1389
1390                 if (ns->lines.wp) {
1391                         NS_WARN("do_state_action: device is write-protected, programm\n");
1392                         return -1;
1393                 }
1394
1395                 num = ns->geom.pgszoob - ns->regs.off - ns->regs.column;
1396                 if (num != ns->regs.count) {
1397                         NS_ERR("do_state_action: too few bytes were input (%d instead of %d)\n",
1398                                         ns->regs.count, num);
1399                         return -1;
1400                 }
1401
1402                 if (prog_page(ns, num) == -1)
1403                         return -1;
1404
1405                 page_no = ns->regs.row;
1406
1407                 NS_DBG("do_state_action: copy %d bytes from int buf to (%#x, %#x), raw off = %d\n",
1408                         num, ns->regs.row, ns->regs.column, NS_RAW_OFFSET(ns) + ns->regs.off);
1409                 NS_LOG("programm page %d\n", ns->regs.row);
1410
1411                 NS_UDELAY(programm_delay);
1412                 NS_UDELAY(output_cycle * ns->geom.pgsz / 1000 / busdiv);
1413
1414                 if (write_error(page_no)) {
1415                         NS_WARN("simulating write failure in page %u\n", page_no);
1416                         return -1;
1417                 }
1418
1419                 break;
1420
1421         case ACTION_ZEROOFF:
1422                 NS_DBG("do_state_action: set internal offset to 0\n");
1423                 ns->regs.off = 0;
1424                 break;
1425
1426         case ACTION_HALFOFF:
1427                 if (!(ns->options & OPT_PAGE512_8BIT)) {
1428                         NS_ERR("do_state_action: BUG! can't skip half of page for non-512"
1429                                 "byte page size 8x chips\n");
1430                         return -1;
1431                 }
1432                 NS_DBG("do_state_action: set internal offset to %d\n", ns->geom.pgsz/2);
1433                 ns->regs.off = ns->geom.pgsz/2;
1434                 break;
1435
1436         case ACTION_OOBOFF:
1437                 NS_DBG("do_state_action: set internal offset to %d\n", ns->geom.pgsz);
1438                 ns->regs.off = ns->geom.pgsz;
1439                 break;
1440
1441         default:
1442                 NS_DBG("do_state_action: BUG! unknown action\n");
1443         }
1444
1445         return 0;
1446 }
1447
1448 /*
1449  * Switch simulator's state.
1450  */
1451 static void switch_state(struct nandsim *ns)
1452 {
1453         if (ns->op) {
1454                 /*
1455                  * The current operation have already been identified.
1456                  * Just follow the states chain.
1457                  */
1458
1459                 ns->stateidx += 1;
1460                 ns->state = ns->nxstate;
1461                 ns->nxstate = ns->op[ns->stateidx + 1];
1462
1463                 NS_DBG("switch_state: operation is known, switch to the next state, "
1464                         "state: %s, nxstate: %s\n",
1465                         get_state_name(ns->state), get_state_name(ns->nxstate));
1466
1467                 /* See, whether we need to do some action */
1468                 if ((ns->state & ACTION_MASK) && do_state_action(ns, ns->state) < 0) {
1469                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1470                         return;
1471                 }
1472
1473         } else {
1474                 /*
1475                  * We don't yet know which operation we perform.
1476                  * Try to identify it.
1477                  */
1478
1479                 /*
1480                  *  The only event causing the switch_state function to
1481                  *  be called with yet unknown operation is new command.
1482                  */
1483                 ns->state = get_state_by_command(ns->regs.command);
1484
1485                 NS_DBG("switch_state: operation is unknown, try to find it\n");
1486
1487                 if (find_operation(ns, 0) != 0)
1488                         return;
1489
1490                 if ((ns->state & ACTION_MASK) && do_state_action(ns, ns->state) < 0) {
1491                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1492                         return;
1493                 }
1494         }
1495
1496         /* For 16x devices column means the page offset in words */
1497         if ((ns->nxstate & STATE_ADDR_MASK) && ns->busw == 16) {
1498                 NS_DBG("switch_state: double the column number for 16x device\n");
1499                 ns->regs.column <<= 1;
1500         }
1501
1502         if (NS_STATE(ns->nxstate) == STATE_READY) {
1503                 /*
1504                  * The current state is the last. Return to STATE_READY
1505                  */
1506
1507                 u_char status = NS_STATUS_OK(ns);
1508
1509                 /* In case of data states, see if all bytes were input/output */
1510                 if ((ns->state & (STATE_DATAIN_MASK | STATE_DATAOUT_MASK))
1511                         && ns->regs.count != ns->regs.num) {
1512                         NS_WARN("switch_state: not all bytes were processed, %d left\n",
1513                                         ns->regs.num - ns->regs.count);
1514                         status = NS_STATUS_FAILED(ns);
1515                 }
1516
1517                 NS_DBG("switch_state: operation complete, switch to STATE_READY state\n");
1518
1519                 switch_to_ready_state(ns, status);
1520
1521                 return;
1522         } else if (ns->nxstate & (STATE_DATAIN_MASK | STATE_DATAOUT_MASK)) {
1523                 /*
1524                  * If the next state is data input/output, switch to it now
1525                  */
1526
1527                 ns->state      = ns->nxstate;
1528                 ns->nxstate    = ns->op[++ns->stateidx + 1];
1529                 ns->regs.num   = ns->regs.count = 0;
1530
1531                 NS_DBG("switch_state: the next state is data I/O, switch, "
1532                         "state: %s, nxstate: %s\n",
1533                         get_state_name(ns->state), get_state_name(ns->nxstate));
1534
1535                 /*
1536                  * Set the internal register to the count of bytes which
1537                  * are expected to be input or output
1538                  */
1539                 switch (NS_STATE(ns->state)) {
1540                         case STATE_DATAIN:
1541                         case STATE_DATAOUT:
1542                                 ns->regs.num = ns->geom.pgszoob - ns->regs.off - ns->regs.column;
1543                                 break;
1544
1545                         case STATE_DATAOUT_ID:
1546                                 ns->regs.num = ns->geom.idbytes;
1547                                 break;
1548
1549                         case STATE_DATAOUT_STATUS:
1550                         case STATE_DATAOUT_STATUS_M:
1551                                 ns->regs.count = ns->regs.num = 0;
1552                                 break;
1553
1554                         default:
1555                                 NS_ERR("switch_state: BUG! unknown data state\n");
1556                 }
1557
1558         } else if (ns->nxstate & STATE_ADDR_MASK) {
1559                 /*
1560                  * If the next state is address input, set the internal
1561                  * register to the number of expected address bytes
1562                  */
1563
1564                 ns->regs.count = 0;
1565
1566                 switch (NS_STATE(ns->nxstate)) {
1567                         case STATE_ADDR_PAGE:
1568                                 ns->regs.num = ns->geom.pgaddrbytes;
1569
1570                                 break;
1571                         case STATE_ADDR_SEC:
1572                                 ns->regs.num = ns->geom.secaddrbytes;
1573                                 break;
1574
1575                         case STATE_ADDR_ZERO:
1576                                 ns->regs.num = 1;
1577                                 break;
1578
1579                         default:
1580                                 NS_ERR("switch_state: BUG! unknown address state\n");
1581                 }
1582         } else {
1583                 /*
1584                  * Just reset internal counters.
1585                  */
1586
1587                 ns->regs.num = 0;
1588                 ns->regs.count = 0;
1589         }
1590 }
1591
1592 static u_char ns_nand_read_byte(struct mtd_info *mtd)
1593 {
1594         struct nandsim *ns = (struct nandsim *)((struct nand_chip *)mtd->priv)->priv;
1595         u_char outb = 0x00;
1596
1597         /* Sanity and correctness checks */
1598         if (!ns->lines.ce) {
1599                 NS_ERR("read_byte: chip is disabled, return %#x\n", (uint)outb);
1600                 return outb;
1601         }
1602         if (ns->lines.ale || ns->lines.cle) {
1603                 NS_ERR("read_byte: ALE or CLE pin is high, return %#x\n", (uint)outb);
1604                 return outb;
1605         }
1606         if (!(ns->state & STATE_DATAOUT_MASK)) {
1607                 NS_WARN("read_byte: unexpected data output cycle, state is %s "
1608                         "return %#x\n", get_state_name(ns->state), (uint)outb);
1609                 return outb;
1610         }
1611
1612         /* Status register may be read as many times as it is wanted */
1613         if (NS_STATE(ns->state) == STATE_DATAOUT_STATUS) {
1614                 NS_DBG("read_byte: return %#x status\n", ns->regs.status);
1615                 return ns->regs.status;
1616         }
1617
1618         /* Check if there is any data in the internal buffer which may be read */
1619         if (ns->regs.count == ns->regs.num) {
1620                 NS_WARN("read_byte: no more data to output, return %#x\n", (uint)outb);
1621                 return outb;
1622         }
1623
1624         switch (NS_STATE(ns->state)) {
1625                 case STATE_DATAOUT:
1626                         if (ns->busw == 8) {
1627                                 outb = ns->buf.byte[ns->regs.count];
1628                                 ns->regs.count += 1;
1629                         } else {
1630                                 outb = (u_char)cpu_to_le16(ns->buf.word[ns->regs.count >> 1]);
1631                                 ns->regs.count += 2;
1632                         }
1633                         break;
1634                 case STATE_DATAOUT_ID:
1635                         NS_DBG("read_byte: read ID byte %d, total = %d\n", ns->regs.count, ns->regs.num);
1636                         outb = ns->ids[ns->regs.count];
1637                         ns->regs.count += 1;
1638                         break;
1639                 default:
1640                         BUG();
1641         }
1642
1643         if (ns->regs.count == ns->regs.num) {
1644                 NS_DBG("read_byte: all bytes were read\n");
1645
1646                 /*
1647                  * The OPT_AUTOINCR allows to read next conseqitive pages without
1648                  * new read operation cycle.
1649                  */
1650                 if ((ns->options & OPT_AUTOINCR) && NS_STATE(ns->state) == STATE_DATAOUT) {
1651                         ns->regs.count = 0;
1652                         if (ns->regs.row + 1 < ns->geom.pgnum)
1653                                 ns->regs.row += 1;
1654                         NS_DBG("read_byte: switch to the next page (%#x)\n", ns->regs.row);
1655                         do_state_action(ns, ACTION_CPY);
1656                 }
1657                 else if (NS_STATE(ns->nxstate) == STATE_READY)
1658                         switch_state(ns);
1659
1660         }
1661
1662         return outb;
1663 }
1664
1665 static void ns_nand_write_byte(struct mtd_info *mtd, u_char byte)
1666 {
1667         struct nandsim *ns = (struct nandsim *)((struct nand_chip *)mtd->priv)->priv;
1668
1669         /* Sanity and correctness checks */
1670         if (!ns->lines.ce) {
1671                 NS_ERR("write_byte: chip is disabled, ignore write\n");
1672                 return;
1673         }
1674         if (ns->lines.ale && ns->lines.cle) {
1675                 NS_ERR("write_byte: ALE and CLE pins are high simultaneously, ignore write\n");
1676                 return;
1677         }
1678
1679         if (ns->lines.cle == 1) {
1680                 /*
1681                  * The byte written is a command.
1682                  */
1683
1684                 if (byte == NAND_CMD_RESET) {
1685                         NS_LOG("reset chip\n");
1686                         switch_to_ready_state(ns, NS_STATUS_OK(ns));
1687                         return;
1688                 }
1689
1690                 /*
1691                  * Chip might still be in STATE_DATAOUT
1692                  * (if OPT_AUTOINCR feature is supported), STATE_DATAOUT_STATUS or
1693                  * STATE_DATAOUT_STATUS_M state. If so, switch state.
1694                  */
1695                 if (NS_STATE(ns->state) == STATE_DATAOUT_STATUS
1696                         || NS_STATE(ns->state) == STATE_DATAOUT_STATUS_M
1697                         || ((ns->options & OPT_AUTOINCR) && NS_STATE(ns->state) == STATE_DATAOUT))
1698                         switch_state(ns);
1699
1700                 /* Check if chip is expecting command */
1701                 if (NS_STATE(ns->nxstate) != STATE_UNKNOWN && !(ns->nxstate & STATE_CMD_MASK)) {
1702                         /*
1703                          * We are in situation when something else (not command)
1704                          * was expected but command was input. In this case ignore
1705                          * previous command(s)/state(s) and accept the last one.
1706                          */
1707                         NS_WARN("write_byte: command (%#x) wasn't expected, expected state is %s, "
1708                                 "ignore previous states\n", (uint)byte, get_state_name(ns->nxstate));
1709                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1710                 }
1711
1712                 /* Check that the command byte is correct */
1713                 if (check_command(byte)) {
1714                         NS_ERR("write_byte: unknown command %#x\n", (uint)byte);
1715                         return;
1716                 }
1717
1718                 NS_DBG("command byte corresponding to %s state accepted\n",
1719                         get_state_name(get_state_by_command(byte)));
1720                 ns->regs.command = byte;
1721                 switch_state(ns);
1722
1723         } else if (ns->lines.ale == 1) {
1724                 /*
1725                  * The byte written is an address.
1726                  */
1727
1728                 if (NS_STATE(ns->nxstate) == STATE_UNKNOWN) {
1729
1730                         NS_DBG("write_byte: operation isn't known yet, identify it\n");
1731
1732                         if (find_operation(ns, 1) < 0)
1733                                 return;
1734
1735                         if ((ns->state & ACTION_MASK) && do_state_action(ns, ns->state) < 0) {
1736                                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1737                                 return;
1738                         }
1739
1740                         ns->regs.count = 0;
1741                         switch (NS_STATE(ns->nxstate)) {
1742                                 case STATE_ADDR_PAGE:
1743                                         ns->regs.num = ns->geom.pgaddrbytes;
1744                                         break;
1745                                 case STATE_ADDR_SEC:
1746                                         ns->regs.num = ns->geom.secaddrbytes;
1747                                         break;
1748                                 case STATE_ADDR_ZERO:
1749                                         ns->regs.num = 1;
1750                                         break;
1751                                 default:
1752                                         BUG();
1753                         }
1754                 }
1755
1756                 /* Check that chip is expecting address */
1757                 if (!(ns->nxstate & STATE_ADDR_MASK)) {
1758                         NS_ERR("write_byte: address (%#x) isn't expected, expected state is %s, "
1759                                 "switch to STATE_READY\n", (uint)byte, get_state_name(ns->nxstate));
1760                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1761                         return;
1762                 }
1763
1764                 /* Check if this is expected byte */
1765                 if (ns->regs.count == ns->regs.num) {
1766                         NS_ERR("write_byte: no more address bytes expected\n");
1767                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1768                         return;
1769                 }
1770
1771                 accept_addr_byte(ns, byte);
1772
1773                 ns->regs.count += 1;
1774
1775                 NS_DBG("write_byte: address byte %#x was accepted (%d bytes input, %d expected)\n",
1776                                 (uint)byte, ns->regs.count, ns->regs.num);
1777
1778                 if (ns->regs.count == ns->regs.num) {
1779                         NS_DBG("address (%#x, %#x) is accepted\n", ns->regs.row, ns->regs.column);
1780                         switch_state(ns);
1781                 }
1782
1783         } else {
1784                 /*
1785                  * The byte written is an input data.
1786                  */
1787
1788                 /* Check that chip is expecting data input */
1789                 if (!(ns->state & STATE_DATAIN_MASK)) {
1790                         NS_ERR("write_byte: data input (%#x) isn't expected, state is %s, "
1791                                 "switch to %s\n", (uint)byte,
1792                                 get_state_name(ns->state), get_state_name(STATE_READY));
1793                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1794                         return;
1795                 }
1796
1797                 /* Check if this is expected byte */
1798                 if (ns->regs.count == ns->regs.num) {
1799                         NS_WARN("write_byte: %u input bytes has already been accepted, ignore write\n",
1800                                         ns->regs.num);
1801                         return;
1802                 }
1803
1804                 if (ns->busw == 8) {
1805                         ns->buf.byte[ns->regs.count] = byte;
1806                         ns->regs.count += 1;
1807                 } else {
1808                         ns->buf.word[ns->regs.count >> 1] = cpu_to_le16((uint16_t)byte);
1809                         ns->regs.count += 2;
1810                 }
1811         }
1812
1813         return;
1814 }
1815
1816 static void ns_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int bitmask)
1817 {
1818         struct nandsim *ns = ((struct nand_chip *)mtd->priv)->priv;
1819
1820         ns->lines.cle = bitmask & NAND_CLE ? 1 : 0;
1821         ns->lines.ale = bitmask & NAND_ALE ? 1 : 0;
1822         ns->lines.ce = bitmask & NAND_NCE ? 1 : 0;
1823
1824         if (cmd != NAND_CMD_NONE)
1825                 ns_nand_write_byte(mtd, cmd);
1826 }
1827
1828 static int ns_device_ready(struct mtd_info *mtd)
1829 {
1830         NS_DBG("device_ready\n");
1831         return 1;
1832 }
1833
1834 static uint16_t ns_nand_read_word(struct mtd_info *mtd)
1835 {
1836         struct nand_chip *chip = (struct nand_chip *)mtd->priv;
1837
1838         NS_DBG("read_word\n");
1839
1840         return chip->read_byte(mtd) | (chip->read_byte(mtd) << 8);
1841 }
1842
1843 static void ns_nand_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
1844 {
1845         struct nandsim *ns = (struct nandsim *)((struct nand_chip *)mtd->priv)->priv;
1846
1847         /* Check that chip is expecting data input */
1848         if (!(ns->state & STATE_DATAIN_MASK)) {
1849                 NS_ERR("write_buf: data input isn't expected, state is %s, "
1850                         "switch to STATE_READY\n", get_state_name(ns->state));
1851                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1852                 return;
1853         }
1854
1855         /* Check if these are expected bytes */
1856         if (ns->regs.count + len > ns->regs.num) {
1857                 NS_ERR("write_buf: too many input bytes\n");
1858                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1859                 return;
1860         }
1861
1862         memcpy(ns->buf.byte + ns->regs.count, buf, len);
1863         ns->regs.count += len;
1864
1865         if (ns->regs.count == ns->regs.num) {
1866                 NS_DBG("write_buf: %d bytes were written\n", ns->regs.count);
1867         }
1868 }
1869
1870 static void ns_nand_read_buf(struct mtd_info *mtd, u_char *buf, int len)
1871 {
1872         struct nandsim *ns = (struct nandsim *)((struct nand_chip *)mtd->priv)->priv;
1873
1874         /* Sanity and correctness checks */
1875         if (!ns->lines.ce) {
1876                 NS_ERR("read_buf: chip is disabled\n");
1877                 return;
1878         }
1879         if (ns->lines.ale || ns->lines.cle) {
1880                 NS_ERR("read_buf: ALE or CLE pin is high\n");
1881                 return;
1882         }
1883         if (!(ns->state & STATE_DATAOUT_MASK)) {
1884                 NS_WARN("read_buf: unexpected data output cycle, current state is %s\n",
1885                         get_state_name(ns->state));
1886                 return;
1887         }
1888
1889         if (NS_STATE(ns->state) != STATE_DATAOUT) {
1890                 int i;
1891
1892                 for (i = 0; i < len; i++)
1893                         buf[i] = ((struct nand_chip *)mtd->priv)->read_byte(mtd);
1894
1895                 return;
1896         }
1897
1898         /* Check if these are expected bytes */
1899         if (ns->regs.count + len > ns->regs.num) {
1900                 NS_ERR("read_buf: too many bytes to read\n");
1901                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1902                 return;
1903         }
1904
1905         memcpy(buf, ns->buf.byte + ns->regs.count, len);
1906         ns->regs.count += len;
1907
1908         if (ns->regs.count == ns->regs.num) {
1909                 if ((ns->options & OPT_AUTOINCR) && NS_STATE(ns->state) == STATE_DATAOUT) {
1910                         ns->regs.count = 0;
1911                         if (ns->regs.row + 1 < ns->geom.pgnum)
1912                                 ns->regs.row += 1;
1913                         NS_DBG("read_buf: switch to the next page (%#x)\n", ns->regs.row);
1914                         do_state_action(ns, ACTION_CPY);
1915                 }
1916                 else if (NS_STATE(ns->nxstate) == STATE_READY)
1917                         switch_state(ns);
1918         }
1919
1920         return;
1921 }
1922
1923 static int ns_nand_verify_buf(struct mtd_info *mtd, const u_char *buf, int len)
1924 {
1925         ns_nand_read_buf(mtd, (u_char *)&ns_verify_buf[0], len);
1926
1927         if (!memcmp(buf, &ns_verify_buf[0], len)) {
1928                 NS_DBG("verify_buf: the buffer is OK\n");
1929                 return 0;
1930         } else {
1931                 NS_DBG("verify_buf: the buffer is wrong\n");
1932                 return -EFAULT;
1933         }
1934 }
1935
1936 /*
1937  * Module initialization function
1938  */
1939 static int __init ns_init_module(void)
1940 {
1941         struct nand_chip *chip;
1942         struct nandsim *nand;
1943         int retval = -ENOMEM, i;
1944
1945         if (bus_width != 8 && bus_width != 16) {
1946                 NS_ERR("wrong bus width (%d), use only 8 or 16\n", bus_width);
1947                 return -EINVAL;
1948         }
1949
1950         /* Allocate and initialize mtd_info, nand_chip and nandsim structures */
1951         nsmtd = kzalloc(sizeof(struct mtd_info) + sizeof(struct nand_chip)
1952                                 + sizeof(struct nandsim), GFP_KERNEL);
1953         if (!nsmtd) {
1954                 NS_ERR("unable to allocate core structures.\n");
1955                 return -ENOMEM;
1956         }
1957         chip        = (struct nand_chip *)(nsmtd + 1);
1958         nsmtd->priv = (void *)chip;
1959         nand        = (struct nandsim *)(chip + 1);
1960         chip->priv  = (void *)nand;
1961
1962         /*
1963          * Register simulator's callbacks.
1964          */
1965         chip->cmd_ctrl   = ns_hwcontrol;
1966         chip->read_byte  = ns_nand_read_byte;
1967         chip->dev_ready  = ns_device_ready;
1968         chip->write_buf  = ns_nand_write_buf;
1969         chip->read_buf   = ns_nand_read_buf;
1970         chip->verify_buf = ns_nand_verify_buf;
1971         chip->read_word  = ns_nand_read_word;
1972         chip->ecc.mode   = NAND_ECC_SOFT;
1973         /* The NAND_SKIP_BBTSCAN option is necessary for 'overridesize' */
1974         /* and 'badblocks' parameters to work */
1975         chip->options   |= NAND_SKIP_BBTSCAN;
1976
1977         /*
1978          * Perform minimum nandsim structure initialization to handle
1979          * the initial ID read command correctly
1980          */
1981         if (third_id_byte != 0xFF || fourth_id_byte != 0xFF)
1982                 nand->geom.idbytes = 4;
1983         else
1984                 nand->geom.idbytes = 2;
1985         nand->regs.status = NS_STATUS_OK(nand);
1986         nand->nxstate = STATE_UNKNOWN;
1987         nand->options |= OPT_PAGE256; /* temporary value */
1988         nand->ids[0] = first_id_byte;
1989         nand->ids[1] = second_id_byte;
1990         nand->ids[2] = third_id_byte;
1991         nand->ids[3] = fourth_id_byte;
1992         if (bus_width == 16) {
1993                 nand->busw = 16;
1994                 chip->options |= NAND_BUSWIDTH_16;
1995         }
1996
1997         nsmtd->owner = THIS_MODULE;
1998
1999         if ((retval = parse_weakblocks()) != 0)
2000                 goto error;
2001
2002         if ((retval = parse_weakpages()) != 0)
2003                 goto error;
2004
2005         if ((retval = parse_gravepages()) != 0)
2006                 goto error;
2007
2008         if ((retval = nand_scan(nsmtd, 1)) != 0) {
2009                 NS_ERR("can't register NAND Simulator\n");
2010                 if (retval > 0)
2011                         retval = -ENXIO;
2012                 goto error;
2013         }
2014
2015         if (overridesize) {
2016                 u_int32_t new_size = nsmtd->erasesize << overridesize;
2017                 if (new_size >> overridesize != nsmtd->erasesize) {
2018                         NS_ERR("overridesize is too big\n");
2019                         goto err_exit;
2020                 }
2021                 /* N.B. This relies on nand_scan not doing anything with the size before we change it */
2022                 nsmtd->size = new_size;
2023                 chip->chipsize = new_size;
2024                 chip->chip_shift = ffs(new_size) - 1;
2025         }
2026
2027         if ((retval = setup_wear_reporting(nsmtd)) != 0)
2028                 goto err_exit;
2029
2030         if ((retval = init_nandsim(nsmtd)) != 0)
2031                 goto err_exit;
2032
2033         if ((retval = parse_badblocks(nand, nsmtd)) != 0)
2034                 goto err_exit;
2035
2036         if ((retval = nand_default_bbt(nsmtd)) != 0)
2037                 goto err_exit;
2038
2039         /* Register NAND partitions */
2040         if ((retval = add_mtd_partitions(nsmtd, &nand->partitions[0], nand->nbparts)) != 0)
2041                 goto err_exit;
2042
2043         return 0;
2044
2045 err_exit:
2046         free_nandsim(nand);
2047         nand_release(nsmtd);
2048         for (i = 0;i < ARRAY_SIZE(nand->partitions); ++i)
2049                 kfree(nand->partitions[i].name);
2050 error:
2051         kfree(nsmtd);
2052         free_lists();
2053
2054         return retval;
2055 }
2056
2057 module_init(ns_init_module);
2058
2059 /*
2060  * Module clean-up function
2061  */
2062 static void __exit ns_cleanup_module(void)
2063 {
2064         struct nandsim *ns = (struct nandsim *)(((struct nand_chip *)nsmtd->priv)->priv);
2065         int i;
2066
2067         free_nandsim(ns);    /* Free nandsim private resources */
2068         nand_release(nsmtd); /* Unregister driver */
2069         for (i = 0;i < ARRAY_SIZE(ns->partitions); ++i)
2070                 kfree(ns->partitions[i].name);
2071         kfree(nsmtd);        /* Free other structures */
2072         free_lists();
2073 }
2074
2075 module_exit(ns_cleanup_module);
2076
2077 MODULE_LICENSE ("GPL");
2078 MODULE_AUTHOR ("Artem B. Bityuckiy");
2079 MODULE_DESCRIPTION ("The NAND flash simulator");