drivers/mtd/nand/raw/nandsim.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * NAND flash simulator.
   4  *
   5  * Author: Artem B. Bityuckiy <dedekind@oktetlabs.ru>, <dedekind@infradead.org>
   6  *
   7  * Copyright (C) 2004 Nokia Corporation
   8  *
   9  * Note: NS means "NAND Simulator".
  10  * Note: Input means input TO flash chip, output means output FROM chip.
  11  */
  12
  13 #define pr_fmt(fmt)  "[nandsim]" fmt
  14
  15 #include <linux/init.h>
  16 #include <linux/types.h>
  17 #include <linux/module.h>
  18 #include <linux/moduleparam.h>
  19 #include <linux/vmalloc.h>
  20 #include <linux/math64.h>
  21 #include <linux/slab.h>
  22 #include <linux/errno.h>
  23 #include <linux/string.h>
  24 #include <linux/mtd/mtd.h>
  25 #include <linux/mtd/rawnand.h>
  26 #include <linux/mtd/nand_bch.h>
  27 #include <linux/mtd/partitions.h>
  28 #include <linux/delay.h>
  29 #include <linux/list.h>
  30 #include <linux/random.h>
  31 #include <linux/sched.h>
  32 #include <linux/sched/mm.h>
  33 #include <linux/fs.h>
  34 #include <linux/pagemap.h>
  35 #include <linux/seq_file.h>
  36 #include <linux/debugfs.h>
  37
  38 /* Default simulator parameters values */
  39 #if !defined(CONFIG_NANDSIM_FIRST_ID_BYTE)  || \
  40     !defined(CONFIG_NANDSIM_SECOND_ID_BYTE) || \
  41     !defined(CONFIG_NANDSIM_THIRD_ID_BYTE)  || \
  42     !defined(CONFIG_NANDSIM_FOURTH_ID_BYTE)
  43 #define CONFIG_NANDSIM_FIRST_ID_BYTE  0x98
  44 #define CONFIG_NANDSIM_SECOND_ID_BYTE 0x39
  45 #define CONFIG_NANDSIM_THIRD_ID_BYTE  0xFF /* No byte */
  46 #define CONFIG_NANDSIM_FOURTH_ID_BYTE 0xFF /* No byte */
  47 #endif
  48
  49 #ifndef CONFIG_NANDSIM_ACCESS_DELAY
  50 #define CONFIG_NANDSIM_ACCESS_DELAY 25
  51 #endif
  52 #ifndef CONFIG_NANDSIM_PROGRAMM_DELAY
  53 #define CONFIG_NANDSIM_PROGRAMM_DELAY 200
  54 #endif
  55 #ifndef CONFIG_NANDSIM_ERASE_DELAY
  56 #define CONFIG_NANDSIM_ERASE_DELAY 2
  57 #endif
  58 #ifndef CONFIG_NANDSIM_OUTPUT_CYCLE
  59 #define CONFIG_NANDSIM_OUTPUT_CYCLE 40
  60 #endif
  61 #ifndef CONFIG_NANDSIM_INPUT_CYCLE
  62 #define CONFIG_NANDSIM_INPUT_CYCLE  50
  63 #endif
  64 #ifndef CONFIG_NANDSIM_BUS_WIDTH
  65 #define CONFIG_NANDSIM_BUS_WIDTH  8
  66 #endif
  67 #ifndef CONFIG_NANDSIM_DO_DELAYS
  68 #define CONFIG_NANDSIM_DO_DELAYS  0
  69 #endif
  70 #ifndef CONFIG_NANDSIM_LOG
  71 #define CONFIG_NANDSIM_LOG        0
  72 #endif
  73 #ifndef CONFIG_NANDSIM_DBG
  74 #define CONFIG_NANDSIM_DBG        0
  75 #endif
  76 #ifndef CONFIG_NANDSIM_MAX_PARTS
  77 #define CONFIG_NANDSIM_MAX_PARTS  32
  78 #endif
  79
  80 static uint access_delay   = CONFIG_NANDSIM_ACCESS_DELAY;
  81 static uint programm_delay = CONFIG_NANDSIM_PROGRAMM_DELAY;
  82 static uint erase_delay    = CONFIG_NANDSIM_ERASE_DELAY;
  83 static uint output_cycle   = CONFIG_NANDSIM_OUTPUT_CYCLE;
  84 static uint input_cycle    = CONFIG_NANDSIM_INPUT_CYCLE;
  85 static uint bus_width      = CONFIG_NANDSIM_BUS_WIDTH;
  86 static uint do_delays      = CONFIG_NANDSIM_DO_DELAYS;
  87 static uint log            = CONFIG_NANDSIM_LOG;
  88 static uint dbg            = CONFIG_NANDSIM_DBG;
  89 static unsigned long parts[CONFIG_NANDSIM_MAX_PARTS];
  90 static unsigned int parts_num;
  91 static char *badblocks = NULL;
  92 static char *weakblocks = NULL;
  93 static char *weakpages = NULL;
  94 static unsigned int bitflips = 0;
  95 static char *gravepages = NULL;
  96 static unsigned int overridesize = 0;
  97 static char *cache_file = NULL;
  98 static unsigned int bbt;
  99 static unsigned int bch;
 100 static u_char id_bytes[8] = {
 101         [0] = CONFIG_NANDSIM_FIRST_ID_BYTE,
 102         [1] = CONFIG_NANDSIM_SECOND_ID_BYTE,
 103         [2] = CONFIG_NANDSIM_THIRD_ID_BYTE,
 104         [3] = CONFIG_NANDSIM_FOURTH_ID_BYTE,
 105         [4 ... 7] = 0xFF,
 106 };
 107
 108 module_param_array(id_bytes, byte, NULL, 0400);
 109 module_param_named(first_id_byte, id_bytes[0], byte, 0400);
 110 module_param_named(second_id_byte, id_bytes[1], byte, 0400);
 111 module_param_named(third_id_byte, id_bytes[2], byte, 0400);
 112 module_param_named(fourth_id_byte, id_bytes[3], byte, 0400);
 113 module_param(access_delay,   uint, 0400);
 114 module_param(programm_delay, uint, 0400);
 115 module_param(erase_delay,    uint, 0400);
 116 module_param(output_cycle,   uint, 0400);
 117 module_param(input_cycle,    uint, 0400);
 118 module_param(bus_width,      uint, 0400);
 119 module_param(do_delays,      uint, 0400);
 120 module_param(log,            uint, 0400);
 121 module_param(dbg,            uint, 0400);
 122 module_param_array(parts, ulong, &parts_num, 0400);
 123 module_param(badblocks,      charp, 0400);
 124 module_param(weakblocks,     charp, 0400);
 125 module_param(weakpages,      charp, 0400);
 126 module_param(bitflips,       uint, 0400);
 127 module_param(gravepages,     charp, 0400);
 128 module_param(overridesize,   uint, 0400);
 129 module_param(cache_file,     charp, 0400);
 130 module_param(bbt,            uint, 0400);
 131 module_param(bch,            uint, 0400);
 132
 133 MODULE_PARM_DESC(id_bytes,       "The ID bytes returned by NAND Flash 'read ID' command");
 134 MODULE_PARM_DESC(first_id_byte,  "The first byte returned by NAND Flash 'read ID' command (manufacturer ID) (obsolete)");
 135 MODULE_PARM_DESC(second_id_byte, "The second byte returned by NAND Flash 'read ID' command (chip ID) (obsolete)");
 136 MODULE_PARM_DESC(third_id_byte,  "The third byte returned by NAND Flash 'read ID' command (obsolete)");
 137 MODULE_PARM_DESC(fourth_id_byte, "The fourth byte returned by NAND Flash 'read ID' command (obsolete)");
 138 MODULE_PARM_DESC(access_delay,   "Initial page access delay (microseconds)");
 139 MODULE_PARM_DESC(programm_delay, "Page programm delay (microseconds");
 140 MODULE_PARM_DESC(erase_delay,    "Sector erase delay (milliseconds)");
 141 MODULE_PARM_DESC(output_cycle,   "Word output (from flash) time (nanoseconds)");
 142 MODULE_PARM_DESC(input_cycle,    "Word input (to flash) time (nanoseconds)");
 143 MODULE_PARM_DESC(bus_width,      "Chip's bus width (8- or 16-bit)");
 144 MODULE_PARM_DESC(do_delays,      "Simulate NAND delays using busy-waits if not zero");
 145 MODULE_PARM_DESC(log,            "Perform logging if not zero");
 146 MODULE_PARM_DESC(dbg,            "Output debug information if not zero");
 147 MODULE_PARM_DESC(parts,          "Partition sizes (in erase blocks) separated by commas");
 148 /* Page and erase block positions for the following parameters are independent of any partitions */
 149 MODULE_PARM_DESC(badblocks,      "Erase blocks that are initially marked bad, separated by commas");
 150 MODULE_PARM_DESC(weakblocks,     "Weak erase blocks [: remaining erase cycles (defaults to 3)]"
 151                                  " separated by commas e.g. 113:2 means eb 113"
 152                                  " can be erased only twice before failing");
 153 MODULE_PARM_DESC(weakpages,      "Weak pages [: maximum writes (defaults to 3)]"
 154                                  " separated by commas e.g. 1401:2 means page 1401"
 155                                  " can be written only twice before failing");
 156 MODULE_PARM_DESC(bitflips,       "Maximum number of random bit flips per page (zero by default)");
 157 MODULE_PARM_DESC(gravepages,     "Pages that lose data [: maximum reads (defaults to 3)]"
 158                                  " separated by commas e.g. 1401:2 means page 1401"
 159                                  " can be read only twice before failing");
 160 MODULE_PARM_DESC(overridesize,   "Specifies the NAND Flash size overriding the ID bytes. "
 161                                  "The size is specified in erase blocks and as the exponent of a power of two"
 162                                  " e.g. 5 means a size of 32 erase blocks");
 163 MODULE_PARM_DESC(cache_file,     "File to use to cache nand pages instead of memory");
 164 MODULE_PARM_DESC(bbt,            "0 OOB, 1 BBT with marker in OOB, 2 BBT with marker in data area");
 165 MODULE_PARM_DESC(bch,            "Enable BCH ecc and set how many bits should "
 166                                  "be correctable in 512-byte blocks");
 167
 168 /* The largest possible page size */
 169 #define NS_LARGEST_PAGE_SIZE    4096
 170
 171 /* Simulator's output macros (logging, debugging, warning, error) */
 172 #define NS_LOG(args...) \
 173         do { if (log) pr_debug(" log: " args); } while(0)
 174 #define NS_DBG(args...) \
 175         do { if (dbg) pr_debug(" debug: " args); } while(0)
 176 #define NS_WARN(args...) \
 177         do { pr_warn(" warning: " args); } while(0)
 178 #define NS_ERR(args...) \
 179         do { pr_err(" error: " args); } while(0)
 180 #define NS_INFO(args...) \
 181         do { pr_info(" " args); } while(0)
 182
 183 /* Busy-wait delay macros (microseconds, milliseconds) */
 184 #define NS_UDELAY(us) \
 185         do { if (do_delays) udelay(us); } while(0)
 186 #define NS_MDELAY(us) \
 187         do { if (do_delays) mdelay(us); } while(0)
 188
 189 /* Is the nandsim structure initialized ? */
 190 #define NS_IS_INITIALIZED(ns) ((ns)->geom.totsz != 0)
 191
 192 /* Good operation completion status */
 193 #define NS_STATUS_OK(ns) (NAND_STATUS_READY | (NAND_STATUS_WP * ((ns)->lines.wp == 0)))
 194
 195 /* Operation failed completion status */
 196 #define NS_STATUS_FAILED(ns) (NAND_STATUS_FAIL | NS_STATUS_OK(ns))
 197
 198 /* Calculate the page offset in flash RAM image by (row, column) address */
 199 #define NS_RAW_OFFSET(ns) \
 200         (((ns)->regs.row * (ns)->geom.pgszoob) + (ns)->regs.column)
 201
 202 /* Calculate the OOB offset in flash RAM image by (row, column) address */
 203 #define NS_RAW_OFFSET_OOB(ns) (NS_RAW_OFFSET(ns) + ns->geom.pgsz)
 204
 205 /* After a command is input, the simulator goes to one of the following states */
 206 #define STATE_CMD_READ0        0x00000001 /* read data from the beginning of page */
 207 #define STATE_CMD_READ1        0x00000002 /* read data from the second half of page */
 208 #define STATE_CMD_READSTART    0x00000003 /* read data second command (large page devices) */
 209 #define STATE_CMD_PAGEPROG     0x00000004 /* start page program */
 210 #define STATE_CMD_READOOB      0x00000005 /* read OOB area */
 211 #define STATE_CMD_ERASE1       0x00000006 /* sector erase first command */
 212 #define STATE_CMD_STATUS       0x00000007 /* read status */
 213 #define STATE_CMD_SEQIN        0x00000009 /* sequential data input */
 214 #define STATE_CMD_READID       0x0000000A /* read ID */
 215 #define STATE_CMD_ERASE2       0x0000000B /* sector erase second command */
 216 #define STATE_CMD_RESET        0x0000000C /* reset */
 217 #define STATE_CMD_RNDOUT       0x0000000D /* random output command */
 218 #define STATE_CMD_RNDOUTSTART  0x0000000E /* random output start command */
 219 #define STATE_CMD_MASK         0x0000000F /* command states mask */
 220
 221 /* After an address is input, the simulator goes to one of these states */
 222 #define STATE_ADDR_PAGE        0x00000010 /* full (row, column) address is accepted */
 223 #define STATE_ADDR_SEC         0x00000020 /* sector address was accepted */
 224 #define STATE_ADDR_COLUMN      0x00000030 /* column address was accepted */
 225 #define STATE_ADDR_ZERO        0x00000040 /* one byte zero address was accepted */
 226 #define STATE_ADDR_MASK        0x00000070 /* address states mask */
 227
 228 /* During data input/output the simulator is in these states */
 229 #define STATE_DATAIN           0x00000100 /* waiting for data input */
 230 #define STATE_DATAIN_MASK      0x00000100 /* data input states mask */
 231
 232 #define STATE_DATAOUT          0x00001000 /* waiting for page data output */
 233 #define STATE_DATAOUT_ID       0x00002000 /* waiting for ID bytes output */
 234 #define STATE_DATAOUT_STATUS   0x00003000 /* waiting for status output */
 235 #define STATE_DATAOUT_MASK     0x00007000 /* data output states mask */
 236
 237 /* Previous operation is done, ready to accept new requests */
 238 #define STATE_READY            0x00000000
 239
 240 /* This state is used to mark that the next state isn't known yet */
 241 #define STATE_UNKNOWN          0x10000000
 242
 243 /* Simulator's actions bit masks */
 244 #define ACTION_CPY       0x00100000 /* copy page/OOB to the internal buffer */
 245 #define ACTION_PRGPAGE   0x00200000 /* program the internal buffer to flash */
 246 #define ACTION_SECERASE  0x00300000 /* erase sector */
 247 #define ACTION_ZEROOFF   0x00400000 /* don't add any offset to address */
 248 #define ACTION_HALFOFF   0x00500000 /* add to address half of page */
 249 #define ACTION_OOBOFF    0x00600000 /* add to address OOB offset */
 250 #define ACTION_MASK      0x00700000 /* action mask */
 251
 252 #define NS_OPER_NUM      13 /* Number of operations supported by the simulator */
 253 #define NS_OPER_STATES   6  /* Maximum number of states in operation */
 254
 255 #define OPT_ANY          0xFFFFFFFF /* any chip supports this operation */
 256 #define OPT_PAGE512      0x00000002 /* 512-byte  page chips */
 257 #define OPT_PAGE2048     0x00000008 /* 2048-byte page chips */
 258 #define OPT_PAGE512_8BIT 0x00000040 /* 512-byte page chips with 8-bit bus width */
 259 #define OPT_PAGE4096     0x00000080 /* 4096-byte page chips */
 260 #define OPT_LARGEPAGE    (OPT_PAGE2048 | OPT_PAGE4096) /* 2048 & 4096-byte page chips */
 261 #define OPT_SMALLPAGE    (OPT_PAGE512) /* 512-byte page chips */
 262
 263 /* Remove action bits from state */
 264 #define NS_STATE(x) ((x) & ~ACTION_MASK)
 265
 266 /*
 267  * Maximum previous states which need to be saved. Currently saving is
 268  * only needed for page program operation with preceded read command
 269  * (which is only valid for 512-byte pages).
 270  */
 271 #define NS_MAX_PREVSTATES 1
 272
 273 /* Maximum page cache pages needed to read or write a NAND page to the cache_file */
 274 #define NS_MAX_HELD_PAGES 16
 275
 276 /*
 277  * A union to represent flash memory contents and flash buffer.
 278  */
 279 union ns_mem {
 280         u_char *byte;    /* for byte access */
 281         uint16_t *word;  /* for 16-bit word access */
 282 };
 283
 284 /*
 285  * The structure which describes all the internal simulator data.
 286  */
 287 struct nandsim {
 288         struct nand_chip chip;
 289         struct nand_controller base;
 290         struct mtd_partition partitions[CONFIG_NANDSIM_MAX_PARTS];
 291         unsigned int nbparts;
 292
 293         uint busw;              /* flash chip bus width (8 or 16) */
 294         u_char ids[8];          /* chip's ID bytes */
 295         uint32_t options;       /* chip's characteristic bits */
 296         uint32_t state;         /* current chip state */
 297         uint32_t nxstate;       /* next expected state */
 298
 299         uint32_t *op;           /* current operation, NULL operations isn't known yet  */
 300         uint32_t pstates[NS_MAX_PREVSTATES]; /* previous states */
 301         uint16_t npstates;      /* number of previous states saved */
 302         uint16_t stateidx;      /* current state index */
 303
 304         /* The simulated NAND flash pages array */
 305         union ns_mem *pages;
 306
 307         /* Slab allocator for nand pages */
 308         struct kmem_cache *nand_pages_slab;
 309
 310         /* Internal buffer of page + OOB size bytes */
 311         union ns_mem buf;
 312
 313         /* NAND flash "geometry" */
 314         struct {
 315                 uint64_t totsz;     /* total flash size, bytes */
 316                 uint32_t secsz;     /* flash sector (erase block) size, bytes */
 317                 uint pgsz;          /* NAND flash page size, bytes */
 318                 uint oobsz;         /* page OOB area size, bytes */
 319                 uint64_t totszoob;  /* total flash size including OOB, bytes */
 320                 uint pgszoob;       /* page size including OOB , bytes*/
 321                 uint secszoob;      /* sector size including OOB, bytes */
 322                 uint pgnum;         /* total number of pages */
 323                 uint pgsec;         /* number of pages per sector */
 324                 uint secshift;      /* bits number in sector size */
 325                 uint pgshift;       /* bits number in page size */
 326                 uint pgaddrbytes;   /* bytes per page address */
 327                 uint secaddrbytes;  /* bytes per sector address */
 328                 uint idbytes;       /* the number ID bytes that this chip outputs */
 329         } geom;
 330
 331         /* NAND flash internal registers */
 332         struct {
 333                 unsigned command; /* the command register */
 334                 u_char   status;  /* the status register */
 335                 uint     row;     /* the page number */
 336                 uint     column;  /* the offset within page */
 337                 uint     count;   /* internal counter */
 338                 uint     num;     /* number of bytes which must be processed */
 339                 uint     off;     /* fixed page offset */
 340         } regs;
 341
 342         /* NAND flash lines state */
 343         struct {
 344                 int ce;  /* chip Enable */
 345                 int cle; /* command Latch Enable */
 346                 int ale; /* address Latch Enable */
 347                 int wp;  /* write Protect */
 348         } lines;
 349
 350         /* Fields needed when using a cache file */
 351         struct file *cfile; /* Open file */
 352         unsigned long *pages_written; /* Which pages have been written */
 353         void *file_buf;
 354         struct page *held_pages[NS_MAX_HELD_PAGES];
 355         int held_cnt;
 356 };
 357
 358 /*
 359  * Operations array. To perform any operation the simulator must pass
 360  * through the correspondent states chain.
 361  */
 362 static struct nandsim_operations {
 363         uint32_t reqopts;  /* options which are required to perform the operation */
 364         uint32_t states[NS_OPER_STATES]; /* operation's states */
 365 } ops[NS_OPER_NUM] = {
 366         /* Read page + OOB from the beginning */
 367         {OPT_SMALLPAGE, {STATE_CMD_READ0 | ACTION_ZEROOFF, STATE_ADDR_PAGE | ACTION_CPY,
 368                         STATE_DATAOUT, STATE_READY}},
 369         /* Read page + OOB from the second half */
 370         {OPT_PAGE512_8BIT, {STATE_CMD_READ1 | ACTION_HALFOFF, STATE_ADDR_PAGE | ACTION_CPY,
 371                         STATE_DATAOUT, STATE_READY}},
 372         /* Read OOB */
 373         {OPT_SMALLPAGE, {STATE_CMD_READOOB | ACTION_OOBOFF, STATE_ADDR_PAGE | ACTION_CPY,
 374                         STATE_DATAOUT, STATE_READY}},
 375         /* Program page starting from the beginning */
 376         {OPT_ANY, {STATE_CMD_SEQIN, STATE_ADDR_PAGE, STATE_DATAIN,
 377                         STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
 378         /* Program page starting from the beginning */
 379         {OPT_SMALLPAGE, {STATE_CMD_READ0, STATE_CMD_SEQIN | ACTION_ZEROOFF, STATE_ADDR_PAGE,
 380                               STATE_DATAIN, STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
 381         /* Program page starting from the second half */
 382         {OPT_PAGE512, {STATE_CMD_READ1, STATE_CMD_SEQIN | ACTION_HALFOFF, STATE_ADDR_PAGE,
 383                               STATE_DATAIN, STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
 384         /* Program OOB */
 385         {OPT_SMALLPAGE, {STATE_CMD_READOOB, STATE_CMD_SEQIN | ACTION_OOBOFF, STATE_ADDR_PAGE,
 386                               STATE_DATAIN, STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
 387         /* Erase sector */
 388         {OPT_ANY, {STATE_CMD_ERASE1, STATE_ADDR_SEC, STATE_CMD_ERASE2 | ACTION_SECERASE, STATE_READY}},
 389         /* Read status */
 390         {OPT_ANY, {STATE_CMD_STATUS, STATE_DATAOUT_STATUS, STATE_READY}},
 391         /* Read ID */
 392         {OPT_ANY, {STATE_CMD_READID, STATE_ADDR_ZERO, STATE_DATAOUT_ID, STATE_READY}},
 393         /* Large page devices read page */
 394         {OPT_LARGEPAGE, {STATE_CMD_READ0, STATE_ADDR_PAGE, STATE_CMD_READSTART | ACTION_CPY,
 395                                STATE_DATAOUT, STATE_READY}},
 396         /* Large page devices random page read */
 397         {OPT_LARGEPAGE, {STATE_CMD_RNDOUT, STATE_ADDR_COLUMN, STATE_CMD_RNDOUTSTART | ACTION_CPY,
 398                                STATE_DATAOUT, STATE_READY}},
 399 };
 400
 401 struct weak_block {
 402         struct list_head list;
 403         unsigned int erase_block_no;
 404         unsigned int max_erases;
 405         unsigned int erases_done;
 406 };
 407
 408 static LIST_HEAD(weak_blocks);
 409
 410 struct weak_page {
 411         struct list_head list;
 412         unsigned int page_no;
 413         unsigned int max_writes;
 414         unsigned int writes_done;
 415 };
 416
 417 static LIST_HEAD(weak_pages);
 418
 419 struct grave_page {
 420         struct list_head list;
 421         unsigned int page_no;
 422         unsigned int max_reads;
 423         unsigned int reads_done;
 424 };
 425
 426 static LIST_HEAD(grave_pages);
 427
 428 static unsigned long *erase_block_wear = NULL;
 429 static unsigned int wear_eb_count = 0;
 430 static unsigned long total_wear = 0;
 431
 432 /* MTD structure for NAND controller */
 433 static struct mtd_info *nsmtd;
 434
 435 static int nandsim_show(struct seq_file *m, void *private)
 436 {
 437         unsigned long wmin = -1, wmax = 0, avg;
 438         unsigned long deciles[10], decile_max[10], tot = 0;
 439         unsigned int i;
 440
 441         /* Calc wear stats */
 442         for (i = 0; i < wear_eb_count; ++i) {
 443                 unsigned long wear = erase_block_wear[i];
 444                 if (wear < wmin)
 445                         wmin = wear;
 446                 if (wear > wmax)
 447                         wmax = wear;
 448                 tot += wear;
 449         }
 450
 451         for (i = 0; i < 9; ++i) {
 452                 deciles[i] = 0;
 453                 decile_max[i] = (wmax * (i + 1) + 5) / 10;
 454         }
 455         deciles[9] = 0;
 456         decile_max[9] = wmax;
 457         for (i = 0; i < wear_eb_count; ++i) {
 458                 int d;
 459                 unsigned long wear = erase_block_wear[i];
 460                 for (d = 0; d < 10; ++d)
 461                         if (wear <= decile_max[d]) {
 462                                 deciles[d] += 1;
 463                                 break;
 464                         }
 465         }
 466         avg = tot / wear_eb_count;
 467
 468         /* Output wear report */
 469         seq_printf(m, "Total numbers of erases:  %lu\n", tot);
 470         seq_printf(m, "Number of erase blocks:   %u\n", wear_eb_count);
 471         seq_printf(m, "Average number of erases: %lu\n", avg);
 472         seq_printf(m, "Maximum number of erases: %lu\n", wmax);
 473         seq_printf(m, "Minimum number of erases: %lu\n", wmin);
 474         for (i = 0; i < 10; ++i) {
 475                 unsigned long from = (i ? decile_max[i - 1] + 1 : 0);
 476                 if (from > decile_max[i])
 477                         continue;
 478                 seq_printf(m, "Number of ebs with erase counts from %lu to %lu : %lu\n",
 479                         from,
 480                         decile_max[i],
 481                         deciles[i]);
 482         }
 483
 484         return 0;
 485 }
 486 DEFINE_SHOW_ATTRIBUTE(nandsim);
 487
 488 /**
 489  * nandsim_debugfs_create - initialize debugfs
 490  * @dev: nandsim device description object
 491  *
 492  * This function creates all debugfs files for UBI device @ubi. Returns zero in
 493  * case of success and a negative error code in case of failure.
 494  */
 495 static int nandsim_debugfs_create(struct nandsim *dev)
 496 {
 497         struct dentry *root = nsmtd->dbg.dfs_dir;
 498         struct dentry *dent;
 499
 500         /*
 501          * Just skip debugfs initialization when the debugfs directory is
 502          * missing.
 503          */
 504         if (IS_ERR_OR_NULL(root)) {
 505                 if (IS_ENABLED(CONFIG_DEBUG_FS) &&
 506                     !IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
 507                         NS_WARN("CONFIG_MTD_PARTITIONED_MASTER must be enabled to expose debugfs stuff\n");
 508                 return 0;
 509         }
 510
 511         dent = debugfs_create_file("nandsim_wear_report", S_IRUSR,
 512                                    root, dev, &nandsim_fops);
 513         if (IS_ERR_OR_NULL(dent)) {
 514                 NS_ERR("cannot create \"nandsim_wear_report\" debugfs entry\n");
 515                 return -1;
 516         }
 517
 518         return 0;
 519 }
 520
 521 /*
 522  * Allocate array of page pointers, create slab allocation for an array
 523  * and initialize the array by NULL pointers.
 524  *
 525  * RETURNS: 0 if success, -ENOMEM if memory alloc fails.
 526  */
 527 static int __init alloc_device(struct nandsim *ns)
 528 {
 529         struct file *cfile;
 530         int i, err;
 531
 532         if (cache_file) {
 533                 cfile = filp_open(cache_file, O_CREAT | O_RDWR | O_LARGEFILE, 0600);
 534                 if (IS_ERR(cfile))
 535                         return PTR_ERR(cfile);
 536                 if (!(cfile->f_mode & FMODE_CAN_READ)) {
 537                         NS_ERR("alloc_device: cache file not readable\n");
 538                         err = -EINVAL;
 539                         goto err_close;
 540                 }
 541                 if (!(cfile->f_mode & FMODE_CAN_WRITE)) {
 542                         NS_ERR("alloc_device: cache file not writeable\n");
 543                         err = -EINVAL;
 544                         goto err_close;
 545                 }
 546                 ns->pages_written =
 547                         vzalloc(array_size(sizeof(unsigned long),
 548                                            BITS_TO_LONGS(ns->geom.pgnum)));
 549                 if (!ns->pages_written) {
 550                         NS_ERR("alloc_device: unable to allocate pages written array\n");
 551                         err = -ENOMEM;
 552                         goto err_close;
 553                 }
 554                 ns->file_buf = kmalloc(ns->geom.pgszoob, GFP_KERNEL);
 555                 if (!ns->file_buf) {
 556                         NS_ERR("alloc_device: unable to allocate file buf\n");
 557                         err = -ENOMEM;
 558                         goto err_free;
 559                 }
 560                 ns->cfile = cfile;
 561                 return 0;
 562         }
 563
 564         ns->pages = vmalloc(array_size(sizeof(union ns_mem), ns->geom.pgnum));
 565         if (!ns->pages) {
 566                 NS_ERR("alloc_device: unable to allocate page array\n");
 567                 return -ENOMEM;
 568         }
 569         for (i = 0; i < ns->geom.pgnum; i++) {
 570                 ns->pages[i].byte = NULL;
 571         }
 572         ns->nand_pages_slab = kmem_cache_create("nandsim",
 573                                                 ns->geom.pgszoob, 0, 0, NULL);
 574         if (!ns->nand_pages_slab) {
 575                 NS_ERR("cache_create: unable to create kmem_cache\n");
 576                 return -ENOMEM;
 577         }
 578
 579         return 0;
 580
 581 err_free:
 582         vfree(ns->pages_written);
 583 err_close:
 584         filp_close(cfile, NULL);
 585         return err;
 586 }
 587
 588 /*
 589  * Free any allocated pages, and free the array of page pointers.
 590  */
 591 static void free_device(struct nandsim *ns)
 592 {
 593         int i;
 594
 595         if (ns->cfile) {
 596                 kfree(ns->file_buf);
 597                 vfree(ns->pages_written);
 598                 filp_close(ns->cfile, NULL);
 599                 return;
 600         }
 601
 602         if (ns->pages) {
 603                 for (i = 0; i < ns->geom.pgnum; i++) {
 604                         if (ns->pages[i].byte)
 605                                 kmem_cache_free(ns->nand_pages_slab,
 606                                                 ns->pages[i].byte);
 607                 }
 608                 kmem_cache_destroy(ns->nand_pages_slab);
 609                 vfree(ns->pages);
 610         }
 611 }
 612
 613 static char __init *get_partition_name(int i)
 614 {
 615         return kasprintf(GFP_KERNEL, "NAND simulator partition %d", i);
 616 }
 617
 618 /*
 619  * Initialize the nandsim structure.
 620  *
 621  * RETURNS: 0 if success, -ERRNO if failure.
 622  */
 623 static int __init init_nandsim(struct mtd_info *mtd)
 624 {
 625         struct nand_chip *chip = mtd_to_nand(mtd);
 626         struct nandsim   *ns   = nand_get_controller_data(chip);
 627         int i, ret = 0;
 628         uint64_t remains;
 629         uint64_t next_offset;
 630
 631         if (NS_IS_INITIALIZED(ns)) {
 632                 NS_ERR("init_nandsim: nandsim is already initialized\n");
 633                 return -EIO;
 634         }
 635
 636         /* Initialize the NAND flash parameters */
 637         ns->busw = chip->options & NAND_BUSWIDTH_16 ? 16 : 8;
 638         ns->geom.totsz    = mtd->size;
 639         ns->geom.pgsz     = mtd->writesize;
 640         ns->geom.oobsz    = mtd->oobsize;
 641         ns->geom.secsz    = mtd->erasesize;
 642         ns->geom.pgszoob  = ns->geom.pgsz + ns->geom.oobsz;
 643         ns->geom.pgnum    = div_u64(ns->geom.totsz, ns->geom.pgsz);
 644         ns->geom.totszoob = ns->geom.totsz + (uint64_t)ns->geom.pgnum * ns->geom.oobsz;
 645         ns->geom.secshift = ffs(ns->geom.secsz) - 1;
 646         ns->geom.pgshift  = chip->page_shift;
 647         ns->geom.pgsec    = ns->geom.secsz / ns->geom.pgsz;
 648         ns->geom.secszoob = ns->geom.secsz + ns->geom.oobsz * ns->geom.pgsec;
 649         ns->options = 0;
 650
 651         if (ns->geom.pgsz == 512) {
 652                 ns->options |= OPT_PAGE512;
 653                 if (ns->busw == 8)
 654                         ns->options |= OPT_PAGE512_8BIT;
 655         } else if (ns->geom.pgsz == 2048) {
 656                 ns->options |= OPT_PAGE2048;
 657         } else if (ns->geom.pgsz == 4096) {
 658                 ns->options |= OPT_PAGE4096;
 659         } else {
 660                 NS_ERR("init_nandsim: unknown page size %u\n", ns->geom.pgsz);
 661                 return -EIO;
 662         }
 663
 664         if (ns->options & OPT_SMALLPAGE) {
 665                 if (ns->geom.totsz <= (32 << 20)) {
 666                         ns->geom.pgaddrbytes  = 3;
 667                         ns->geom.secaddrbytes = 2;
 668                 } else {
 669                         ns->geom.pgaddrbytes  = 4;
 670                         ns->geom.secaddrbytes = 3;
 671                 }
 672         } else {
 673                 if (ns->geom.totsz <= (128 << 20)) {
 674                         ns->geom.pgaddrbytes  = 4;
 675                         ns->geom.secaddrbytes = 2;
 676                 } else {
 677                         ns->geom.pgaddrbytes  = 5;
 678                         ns->geom.secaddrbytes = 3;
 679                 }
 680         }
 681
 682         /* Fill the partition_info structure */
 683         if (parts_num > ARRAY_SIZE(ns->partitions)) {
 684                 NS_ERR("too many partitions.\n");
 685                 return -EINVAL;
 686         }
 687         remains = ns->geom.totsz;
 688         next_offset = 0;
 689         for (i = 0; i < parts_num; ++i) {
 690                 uint64_t part_sz = (uint64_t)parts[i] * ns->geom.secsz;
 691
 692                 if (!part_sz || part_sz > remains) {
 693                         NS_ERR("bad partition size.\n");
 694                         return -EINVAL;
 695                 }
 696                 ns->partitions[i].name   = get_partition_name(i);
 697                 if (!ns->partitions[i].name) {
 698                         NS_ERR("unable to allocate memory.\n");
 699                         return -ENOMEM;
 700                 }
 701                 ns->partitions[i].offset = next_offset;
 702                 ns->partitions[i].size   = part_sz;
 703                 next_offset += ns->partitions[i].size;
 704                 remains -= ns->partitions[i].size;
 705         }
 706         ns->nbparts = parts_num;
 707         if (remains) {
 708                 if (parts_num + 1 > ARRAY_SIZE(ns->partitions)) {
 709                         NS_ERR("too many partitions.\n");
 710                         return -EINVAL;
 711                 }
 712                 ns->partitions[i].name   = get_partition_name(i);
 713                 if (!ns->partitions[i].name) {
 714                         NS_ERR("unable to allocate memory.\n");
 715                         return -ENOMEM;
 716                 }
 717                 ns->partitions[i].offset = next_offset;
 718                 ns->partitions[i].size   = remains;
 719                 ns->nbparts += 1;
 720         }
 721
 722         if (ns->busw == 16)
 723                 NS_WARN("16-bit flashes support wasn't tested\n");
 724
 725         printk("flash size: %llu MiB\n",
 726                         (unsigned long long)ns->geom.totsz >> 20);
 727         printk("page size: %u bytes\n",         ns->geom.pgsz);
 728         printk("OOB area size: %u bytes\n",     ns->geom.oobsz);
 729         printk("sector size: %u KiB\n",         ns->geom.secsz >> 10);
 730         printk("pages number: %u\n",            ns->geom.pgnum);
 731         printk("pages per sector: %u\n",        ns->geom.pgsec);
 732         printk("bus width: %u\n",               ns->busw);
 733         printk("bits in sector size: %u\n",     ns->geom.secshift);
 734         printk("bits in page size: %u\n",       ns->geom.pgshift);
 735         printk("bits in OOB size: %u\n",        ffs(ns->geom.oobsz) - 1);
 736         printk("flash size with OOB: %llu KiB\n",
 737                         (unsigned long long)ns->geom.totszoob >> 10);
 738         printk("page address bytes: %u\n",      ns->geom.pgaddrbytes);
 739         printk("sector address bytes: %u\n",    ns->geom.secaddrbytes);
 740         printk("options: %#x\n",                ns->options);
 741
 742         if ((ret = alloc_device(ns)) != 0)
 743                 return ret;
 744
 745         /* Allocate / initialize the internal buffer */
 746         ns->buf.byte = kmalloc(ns->geom.pgszoob, GFP_KERNEL);
 747         if (!ns->buf.byte) {
 748                 NS_ERR("init_nandsim: unable to allocate %u bytes for the internal buffer\n",
 749                         ns->geom.pgszoob);
 750                 return -ENOMEM;
 751         }
 752         memset(ns->buf.byte, 0xFF, ns->geom.pgszoob);
 753
 754         return 0;
 755 }
 756
 757 /*
 758  * Free the nandsim structure.
 759  */
 760 static void free_nandsim(struct nandsim *ns)
 761 {
 762         kfree(ns->buf.byte);
 763         free_device(ns);
 764
 765         return;
 766 }
 767
 768 static int parse_badblocks(struct nandsim *ns, struct mtd_info *mtd)
 769 {
 770         char *w;
 771         int zero_ok;
 772         unsigned int erase_block_no;
 773         loff_t offset;
 774
 775         if (!badblocks)
 776                 return 0;
 777         w = badblocks;
 778         do {
 779                 zero_ok = (*w == '0' ? 1 : 0);
 780                 erase_block_no = simple_strtoul(w, &w, 0);
 781                 if (!zero_ok && !erase_block_no) {
 782                         NS_ERR("invalid badblocks.\n");
 783                         return -EINVAL;
 784                 }
 785                 offset = (loff_t)erase_block_no * ns->geom.secsz;
 786                 if (mtd_block_markbad(mtd, offset)) {
 787                         NS_ERR("invalid badblocks.\n");
 788                         return -EINVAL;
 789                 }
 790                 if (*w == ',')
 791                         w += 1;
 792         } while (*w);
 793         return 0;
 794 }
 795
 796 static int parse_weakblocks(void)
 797 {
 798         char *w;
 799         int zero_ok;
 800         unsigned int erase_block_no;
 801         unsigned int max_erases;
 802         struct weak_block *wb;
 803
 804         if (!weakblocks)
 805                 return 0;
 806         w = weakblocks;
 807         do {
 808                 zero_ok = (*w == '0' ? 1 : 0);
 809                 erase_block_no = simple_strtoul(w, &w, 0);
 810                 if (!zero_ok && !erase_block_no) {
 811                         NS_ERR("invalid weakblocks.\n");
 812                         return -EINVAL;
 813                 }
 814                 max_erases = 3;
 815                 if (*w == ':') {
 816                         w += 1;
 817                         max_erases = simple_strtoul(w, &w, 0);
 818                 }
 819                 if (*w == ',')
 820                         w += 1;
 821                 wb = kzalloc(sizeof(*wb), GFP_KERNEL);
 822                 if (!wb) {
 823                         NS_ERR("unable to allocate memory.\n");
 824                         return -ENOMEM;
 825                 }
 826                 wb->erase_block_no = erase_block_no;
 827                 wb->max_erases = max_erases;
 828                 list_add(&wb->list, &weak_blocks);
 829         } while (*w);
 830         return 0;
 831 }
 832
 833 static int erase_error(unsigned int erase_block_no)
 834 {
 835         struct weak_block *wb;
 836
 837         list_for_each_entry(wb, &weak_blocks, list)
 838                 if (wb->erase_block_no == erase_block_no) {
 839                         if (wb->erases_done >= wb->max_erases)
 840                                 return 1;
 841                         wb->erases_done += 1;
 842                         return 0;
 843                 }
 844         return 0;
 845 }
 846
 847 static int parse_weakpages(void)
 848 {
 849         char *w;
 850         int zero_ok;
 851         unsigned int page_no;
 852         unsigned int max_writes;
 853         struct weak_page *wp;
 854
 855         if (!weakpages)
 856                 return 0;
 857         w = weakpages;
 858         do {
 859                 zero_ok = (*w == '0' ? 1 : 0);
 860                 page_no = simple_strtoul(w, &w, 0);
 861                 if (!zero_ok && !page_no) {
 862                         NS_ERR("invalid weakpages.\n");
 863                         return -EINVAL;
 864                 }
 865                 max_writes = 3;
 866                 if (*w == ':') {
 867                         w += 1;
 868                         max_writes = simple_strtoul(w, &w, 0);
 869                 }
 870                 if (*w == ',')
 871                         w += 1;
 872                 wp = kzalloc(sizeof(*wp), GFP_KERNEL);
 873                 if (!wp) {
 874                         NS_ERR("unable to allocate memory.\n");
 875                         return -ENOMEM;
 876                 }
 877                 wp->page_no = page_no;
 878                 wp->max_writes = max_writes;
 879                 list_add(&wp->list, &weak_pages);
 880         } while (*w);
 881         return 0;
 882 }
 883
 884 static int write_error(unsigned int page_no)
 885 {
 886         struct weak_page *wp;
 887
 888         list_for_each_entry(wp, &weak_pages, list)
 889                 if (wp->page_no == page_no) {
 890                         if (wp->writes_done >= wp->max_writes)
 891                                 return 1;
 892                         wp->writes_done += 1;
 893                         return 0;
 894                 }
 895         return 0;
 896 }
 897
 898 static int parse_gravepages(void)
 899 {
 900         char *g;
 901         int zero_ok;
 902         unsigned int page_no;
 903         unsigned int max_reads;
 904         struct grave_page *gp;
 905
 906         if (!gravepages)
 907                 return 0;
 908         g = gravepages;
 909         do {
 910                 zero_ok = (*g == '0' ? 1 : 0);
 911                 page_no = simple_strtoul(g, &g, 0);
 912                 if (!zero_ok && !page_no) {
 913                         NS_ERR("invalid gravepagess.\n");
 914                         return -EINVAL;
 915                 }
 916                 max_reads = 3;
 917                 if (*g == ':') {
 918                         g += 1;
 919                         max_reads = simple_strtoul(g, &g, 0);
 920                 }
 921                 if (*g == ',')
 922                         g += 1;
 923                 gp = kzalloc(sizeof(*gp), GFP_KERNEL);
 924                 if (!gp) {
 925                         NS_ERR("unable to allocate memory.\n");
 926                         return -ENOMEM;
 927                 }
 928                 gp->page_no = page_no;
 929                 gp->max_reads = max_reads;
 930                 list_add(&gp->list, &grave_pages);
 931         } while (*g);
 932         return 0;
 933 }
 934
 935 static int read_error(unsigned int page_no)
 936 {
 937         struct grave_page *gp;
 938
 939         list_for_each_entry(gp, &grave_pages, list)
 940                 if (gp->page_no == page_no) {
 941                         if (gp->reads_done >= gp->max_reads)
 942                                 return 1;
 943                         gp->reads_done += 1;
 944                         return 0;
 945                 }
 946         return 0;
 947 }
 948
 949 static void free_lists(void)
 950 {
 951         struct list_head *pos, *n;
 952         list_for_each_safe(pos, n, &weak_blocks) {
 953                 list_del(pos);
 954                 kfree(list_entry(pos, struct weak_block, list));
 955         }
 956         list_for_each_safe(pos, n, &weak_pages) {
 957                 list_del(pos);
 958                 kfree(list_entry(pos, struct weak_page, list));
 959         }
 960         list_for_each_safe(pos, n, &grave_pages) {
 961                 list_del(pos);
 962                 kfree(list_entry(pos, struct grave_page, list));
 963         }
 964         kfree(erase_block_wear);
 965 }
 966
 967 static int setup_wear_reporting(struct mtd_info *mtd)
 968 {
 969         size_t mem;
 970
 971         wear_eb_count = div_u64(mtd->size, mtd->erasesize);
 972         mem = wear_eb_count * sizeof(unsigned long);
 973         if (mem / sizeof(unsigned long) != wear_eb_count) {
 974                 NS_ERR("Too many erase blocks for wear reporting\n");
 975                 return -ENOMEM;
 976         }
 977         erase_block_wear = kzalloc(mem, GFP_KERNEL);
 978         if (!erase_block_wear) {
 979                 NS_ERR("Too many erase blocks for wear reporting\n");
 980                 return -ENOMEM;
 981         }
 982         return 0;
 983 }
 984
 985 static void update_wear(unsigned int erase_block_no)
 986 {
 987         if (!erase_block_wear)
 988                 return;
 989         total_wear += 1;
 990         /*
 991          * TODO: Notify this through a debugfs entry,
 992          * instead of showing an error message.
 993          */
 994         if (total_wear == 0)
 995                 NS_ERR("Erase counter total overflow\n");
 996         erase_block_wear[erase_block_no] += 1;
 997         if (erase_block_wear[erase_block_no] == 0)
 998                 NS_ERR("Erase counter overflow for erase block %u\n", erase_block_no);
 999 }
1000
1001 /*
1002  * Returns the string representation of 'state' state.
1003  */
1004 static char *get_state_name(uint32_t state)
1005 {
1006         switch (NS_STATE(state)) {
1007                 case STATE_CMD_READ0:
1008                         return "STATE_CMD_READ0";
1009                 case STATE_CMD_READ1:
1010                         return "STATE_CMD_READ1";
1011                 case STATE_CMD_PAGEPROG:
1012                         return "STATE_CMD_PAGEPROG";
1013                 case STATE_CMD_READOOB:
1014                         return "STATE_CMD_READOOB";
1015                 case STATE_CMD_READSTART:
1016                         return "STATE_CMD_READSTART";
1017                 case STATE_CMD_ERASE1:
1018                         return "STATE_CMD_ERASE1";
1019                 case STATE_CMD_STATUS:
1020                         return "STATE_CMD_STATUS";
1021                 case STATE_CMD_SEQIN:
1022                         return "STATE_CMD_SEQIN";
1023                 case STATE_CMD_READID:
1024                         return "STATE_CMD_READID";
1025                 case STATE_CMD_ERASE2:
1026                         return "STATE_CMD_ERASE2";
1027                 case STATE_CMD_RESET:
1028                         return "STATE_CMD_RESET";
1029                 case STATE_CMD_RNDOUT:
1030                         return "STATE_CMD_RNDOUT";
1031                 case STATE_CMD_RNDOUTSTART:
1032                         return "STATE_CMD_RNDOUTSTART";
1033                 case STATE_ADDR_PAGE:
1034                         return "STATE_ADDR_PAGE";
1035                 case STATE_ADDR_SEC:
1036                         return "STATE_ADDR_SEC";
1037                 case STATE_ADDR_ZERO:
1038                         return "STATE_ADDR_ZERO";
1039                 case STATE_ADDR_COLUMN:
1040                         return "STATE_ADDR_COLUMN";
1041                 case STATE_DATAIN:
1042                         return "STATE_DATAIN";
1043                 case STATE_DATAOUT:
1044                         return "STATE_DATAOUT";
1045                 case STATE_DATAOUT_ID:
1046                         return "STATE_DATAOUT_ID";
1047                 case STATE_DATAOUT_STATUS:
1048                         return "STATE_DATAOUT_STATUS";
1049                 case STATE_READY:
1050                         return "STATE_READY";
1051                 case STATE_UNKNOWN:
1052                         return "STATE_UNKNOWN";
1053         }
1054
1055         NS_ERR("get_state_name: unknown state, BUG\n");
1056         return NULL;
1057 }
1058
1059 /*
1060  * Check if command is valid.
1061  *
1062  * RETURNS: 1 if wrong command, 0 if right.
1063  */
1064 static int check_command(int cmd)
1065 {
1066         switch (cmd) {
1067
1068         case NAND_CMD_READ0:
1069         case NAND_CMD_READ1:
1070         case NAND_CMD_READSTART:
1071         case NAND_CMD_PAGEPROG:
1072         case NAND_CMD_READOOB:
1073         case NAND_CMD_ERASE1:
1074         case NAND_CMD_STATUS:
1075         case NAND_CMD_SEQIN:
1076         case NAND_CMD_READID:
1077         case NAND_CMD_ERASE2:
1078         case NAND_CMD_RESET:
1079         case NAND_CMD_RNDOUT:
1080         case NAND_CMD_RNDOUTSTART:
1081                 return 0;
1082
1083         default:
1084                 return 1;
1085         }
1086 }
1087
1088 /*
1089  * Returns state after command is accepted by command number.
1090  */
1091 static uint32_t get_state_by_command(unsigned command)
1092 {
1093         switch (command) {
1094                 case NAND_CMD_READ0:
1095                         return STATE_CMD_READ0;
1096                 case NAND_CMD_READ1:
1097                         return STATE_CMD_READ1;
1098                 case NAND_CMD_PAGEPROG:
1099                         return STATE_CMD_PAGEPROG;
1100                 case NAND_CMD_READSTART:
1101                         return STATE_CMD_READSTART;
1102                 case NAND_CMD_READOOB:
1103                         return STATE_CMD_READOOB;
1104                 case NAND_CMD_ERASE1:
1105                         return STATE_CMD_ERASE1;
1106                 case NAND_CMD_STATUS:
1107                         return STATE_CMD_STATUS;
1108                 case NAND_CMD_SEQIN:
1109                         return STATE_CMD_SEQIN;
1110                 case NAND_CMD_READID:
1111                         return STATE_CMD_READID;
1112                 case NAND_CMD_ERASE2:
1113                         return STATE_CMD_ERASE2;
1114                 case NAND_CMD_RESET:
1115                         return STATE_CMD_RESET;
1116                 case NAND_CMD_RNDOUT:
1117                         return STATE_CMD_RNDOUT;
1118                 case NAND_CMD_RNDOUTSTART:
1119                         return STATE_CMD_RNDOUTSTART;
1120         }
1121
1122         NS_ERR("get_state_by_command: unknown command, BUG\n");
1123         return 0;
1124 }
1125
1126 /*
1127  * Move an address byte to the correspondent internal register.
1128  */
1129 static inline void accept_addr_byte(struct nandsim *ns, u_char bt)
1130 {
1131         uint byte = (uint)bt;
1132
1133         if (ns->regs.count < (ns->geom.pgaddrbytes - ns->geom.secaddrbytes))
1134                 ns->regs.column |= (byte << 8 * ns->regs.count);
1135         else {
1136                 ns->regs.row |= (byte << 8 * (ns->regs.count -
1137                                                 ns->geom.pgaddrbytes +
1138                                                 ns->geom.secaddrbytes));
1139         }
1140
1141         return;
1142 }
1143
1144 /*
1145  * Switch to STATE_READY state.
1146  */
1147 static inline void switch_to_ready_state(struct nandsim *ns, u_char status)
1148 {
1149         NS_DBG("switch_to_ready_state: switch to %s state\n", get_state_name(STATE_READY));
1150
1151         ns->state       = STATE_READY;
1152         ns->nxstate     = STATE_UNKNOWN;
1153         ns->op          = NULL;
1154         ns->npstates    = 0;
1155         ns->stateidx    = 0;
1156         ns->regs.num    = 0;
1157         ns->regs.count  = 0;
1158         ns->regs.off    = 0;
1159         ns->regs.row    = 0;
1160         ns->regs.column = 0;
1161         ns->regs.status = status;
1162 }
1163
1164 /*
1165  * If the operation isn't known yet, try to find it in the global array
1166  * of supported operations.
1167  *
1168  * Operation can be unknown because of the following.
1169  *   1. New command was accepted and this is the first call to find the
1170  *      correspondent states chain. In this case ns->npstates = 0;
1171  *   2. There are several operations which begin with the same command(s)
1172  *      (for example program from the second half and read from the
1173  *      second half operations both begin with the READ1 command). In this
1174  *      case the ns->pstates[] array contains previous states.
1175  *
1176  * Thus, the function tries to find operation containing the following
1177  * states (if the 'flag' parameter is 0):
1178  *    ns->pstates[0], ... ns->pstates[ns->npstates], ns->state
1179  *
1180  * If (one and only one) matching operation is found, it is accepted (
1181  * ns->ops, ns->state, ns->nxstate are initialized, ns->npstate is
1182  * zeroed).
1183  *
1184  * If there are several matches, the current state is pushed to the
1185  * ns->pstates.
1186  *
1187  * The operation can be unknown only while commands are input to the chip.
1188  * As soon as address command is accepted, the operation must be known.
1189  * In such situation the function is called with 'flag' != 0, and the
1190  * operation is searched using the following pattern:
1191  *     ns->pstates[0], ... ns->pstates[ns->npstates], <address input>
1192  *
1193  * It is supposed that this pattern must either match one operation or
1194  * none. There can't be ambiguity in that case.
1195  *
1196  * If no matches found, the function does the following:
1197  *   1. if there are saved states present, try to ignore them and search
1198  *      again only using the last command. If nothing was found, switch
1199  *      to the STATE_READY state.
1200  *   2. if there are no saved states, switch to the STATE_READY state.
1201  *
1202  * RETURNS: -2 - no matched operations found.
1203  *          -1 - several matches.
1204  *           0 - operation is found.
1205  */
1206 static int find_operation(struct nandsim *ns, uint32_t flag)
1207 {
1208         int opsfound = 0;
1209         int i, j, idx = 0;
1210
1211         for (i = 0; i < NS_OPER_NUM; i++) {
1212
1213                 int found = 1;
1214
1215                 if (!(ns->options & ops[i].reqopts))
1216                         /* Ignore operations we can't perform */
1217                         continue;
1218
1219                 if (flag) {
1220                         if (!(ops[i].states[ns->npstates] & STATE_ADDR_MASK))
1221                                 continue;
1222                 } else {
1223                         if (NS_STATE(ns->state) != NS_STATE(ops[i].states[ns->npstates]))
1224                                 continue;
1225                 }
1226
1227                 for (j = 0; j < ns->npstates; j++)
1228                         if (NS_STATE(ops[i].states[j]) != NS_STATE(ns->pstates[j])
1229                                 && (ns->options & ops[idx].reqopts)) {
1230                                 found = 0;
1231                                 break;
1232                         }
1233
1234                 if (found) {
1235                         idx = i;
1236                         opsfound += 1;
1237                 }
1238         }
1239
1240         if (opsfound == 1) {
1241                 /* Exact match */
1242                 ns->op = &ops[idx].states[0];
1243                 if (flag) {
1244                         /*
1245                          * In this case the find_operation function was
1246                          * called when address has just began input. But it isn't
1247                          * yet fully input and the current state must
1248                          * not be one of STATE_ADDR_*, but the STATE_ADDR_*
1249                          * state must be the next state (ns->nxstate).
1250                          */
1251                         ns->stateidx = ns->npstates - 1;
1252                 } else {
1253                         ns->stateidx = ns->npstates;
1254                 }
1255                 ns->npstates = 0;
1256                 ns->state = ns->op[ns->stateidx];
1257                 ns->nxstate = ns->op[ns->stateidx + 1];
1258                 NS_DBG("find_operation: operation found, index: %d, state: %s, nxstate %s\n",
1259                                 idx, get_state_name(ns->state), get_state_name(ns->nxstate));
1260                 return 0;
1261         }
1262
1263         if (opsfound == 0) {
1264                 /* Nothing was found. Try to ignore previous commands (if any) and search again */
1265                 if (ns->npstates != 0) {
1266                         NS_DBG("find_operation: no operation found, try again with state %s\n",
1267                                         get_state_name(ns->state));
1268                         ns->npstates = 0;
1269                         return find_operation(ns, 0);
1270
1271                 }
1272                 NS_DBG("find_operation: no operations found\n");
1273                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1274                 return -2;
1275         }
1276
1277         if (flag) {
1278                 /* This shouldn't happen */
1279                 NS_DBG("find_operation: BUG, operation must be known if address is input\n");
1280                 return -2;
1281         }
1282
1283         NS_DBG("find_operation: there is still ambiguity\n");
1284
1285         ns->pstates[ns->npstates++] = ns->state;
1286
1287         return -1;
1288 }
1289
1290 static void put_pages(struct nandsim *ns)
1291 {
1292         int i;
1293
1294         for (i = 0; i < ns->held_cnt; i++)
1295                 put_page(ns->held_pages[i]);
1296 }
1297
1298 /* Get page cache pages in advance to provide NOFS memory allocation */
1299 static int get_pages(struct nandsim *ns, struct file *file, size_t count, loff_t pos)
1300 {
1301         pgoff_t index, start_index, end_index;
1302         struct page *page;
1303         struct address_space *mapping = file->f_mapping;
1304
1305         start_index = pos >> PAGE_SHIFT;
1306         end_index = (pos + count - 1) >> PAGE_SHIFT;
1307         if (end_index - start_index + 1 > NS_MAX_HELD_PAGES)
1308                 return -EINVAL;
1309         ns->held_cnt = 0;
1310         for (index = start_index; index <= end_index; index++) {
1311                 page = find_get_page(mapping, index);
1312                 if (page == NULL) {
1313                         page = find_or_create_page(mapping, index, GFP_NOFS);
1314                         if (page == NULL) {
1315                                 write_inode_now(mapping->host, 1);
1316                                 page = find_or_create_page(mapping, index, GFP_NOFS);
1317                         }
1318                         if (page == NULL) {
1319                                 put_pages(ns);
1320                                 return -ENOMEM;
1321                         }
1322                         unlock_page(page);
1323                 }
1324                 ns->held_pages[ns->held_cnt++] = page;
1325         }
1326         return 0;
1327 }
1328
1329 static ssize_t read_file(struct nandsim *ns, struct file *file, void *buf, size_t count, loff_t pos)
1330 {
1331         ssize_t tx;
1332         int err;
1333         unsigned int noreclaim_flag;
1334
1335         err = get_pages(ns, file, count, pos);
1336         if (err)
1337                 return err;
1338         noreclaim_flag = memalloc_noreclaim_save();
1339         tx = kernel_read(file, buf, count, &pos);
1340         memalloc_noreclaim_restore(noreclaim_flag);
1341         put_pages(ns);
1342         return tx;
1343 }
1344
1345 static ssize_t write_file(struct nandsim *ns, struct file *file, void *buf, size_t count, loff_t pos)
1346 {
1347         ssize_t tx;
1348         int err;
1349         unsigned int noreclaim_flag;
1350
1351         err = get_pages(ns, file, count, pos);
1352         if (err)
1353                 return err;
1354         noreclaim_flag = memalloc_noreclaim_save();
1355         tx = kernel_write(file, buf, count, &pos);
1356         memalloc_noreclaim_restore(noreclaim_flag);
1357         put_pages(ns);
1358         return tx;
1359 }
1360
1361 /*
1362  * Returns a pointer to the current page.
1363  */
1364 static inline union ns_mem *NS_GET_PAGE(struct nandsim *ns)
1365 {
1366         return &(ns->pages[ns->regs.row]);
1367 }
1368
1369 /*
1370  * Retuns a pointer to the current byte, within the current page.
1371  */
1372 static inline u_char *NS_PAGE_BYTE_OFF(struct nandsim *ns)
1373 {
1374         return NS_GET_PAGE(ns)->byte + ns->regs.column + ns->regs.off;
1375 }
1376
1377 static int do_read_error(struct nandsim *ns, int num)
1378 {
1379         unsigned int page_no = ns->regs.row;
1380
1381         if (read_error(page_no)) {
1382                 prandom_bytes(ns->buf.byte, num);
1383                 NS_WARN("simulating read error in page %u\n", page_no);
1384                 return 1;
1385         }
1386         return 0;
1387 }
1388
1389 static void do_bit_flips(struct nandsim *ns, int num)
1390 {
1391         if (bitflips && prandom_u32() < (1 << 22)) {
1392                 int flips = 1;
1393                 if (bitflips > 1)
1394                         flips = (prandom_u32() % (int) bitflips) + 1;
1395                 while (flips--) {
1396                         int pos = prandom_u32() % (num * 8);
1397                         ns->buf.byte[pos / 8] ^= (1 << (pos % 8));
1398                         NS_WARN("read_page: flipping bit %d in page %d "
1399                                 "reading from %d ecc: corrected=%u failed=%u\n",
1400                                 pos, ns->regs.row, ns->regs.column + ns->regs.off,
1401                                 nsmtd->ecc_stats.corrected, nsmtd->ecc_stats.failed);
1402                 }
1403         }
1404 }
1405
1406 /*
1407  * Fill the NAND buffer with data read from the specified page.
1408  */
1409 static void read_page(struct nandsim *ns, int num)
1410 {
1411         union ns_mem *mypage;
1412
1413         if (ns->cfile) {
1414                 if (!test_bit(ns->regs.row, ns->pages_written)) {
1415                         NS_DBG("read_page: page %d not written\n", ns->regs.row);
1416                         memset(ns->buf.byte, 0xFF, num);
1417                 } else {
1418                         loff_t pos;
1419                         ssize_t tx;
1420
1421                         NS_DBG("read_page: page %d written, reading from %d\n",
1422                                 ns->regs.row, ns->regs.column + ns->regs.off);
1423                         if (do_read_error(ns, num))
1424                                 return;
1425                         pos = (loff_t)NS_RAW_OFFSET(ns) + ns->regs.off;
1426                         tx = read_file(ns, ns->cfile, ns->buf.byte, num, pos);
1427                         if (tx != num) {
1428                                 NS_ERR("read_page: read error for page %d ret %ld\n", ns->regs.row, (long)tx);
1429                                 return;
1430                         }
1431                         do_bit_flips(ns, num);
1432                 }
1433                 return;
1434         }
1435
1436         mypage = NS_GET_PAGE(ns);
1437         if (mypage->byte == NULL) {
1438                 NS_DBG("read_page: page %d not allocated\n", ns->regs.row);
1439                 memset(ns->buf.byte, 0xFF, num);
1440         } else {
1441                 NS_DBG("read_page: page %d allocated, reading from %d\n",
1442                         ns->regs.row, ns->regs.column + ns->regs.off);
1443                 if (do_read_error(ns, num))
1444                         return;
1445                 memcpy(ns->buf.byte, NS_PAGE_BYTE_OFF(ns), num);
1446                 do_bit_flips(ns, num);
1447         }
1448 }
1449
1450 /*
1451  * Erase all pages in the specified sector.
1452  */
1453 static void erase_sector(struct nandsim *ns)
1454 {
1455         union ns_mem *mypage;
1456         int i;
1457
1458         if (ns->cfile) {
1459                 for (i = 0; i < ns->geom.pgsec; i++)
1460                         if (__test_and_clear_bit(ns->regs.row + i,
1461                                                  ns->pages_written)) {
1462                                 NS_DBG("erase_sector: freeing page %d\n", ns->regs.row + i);
1463                         }
1464                 return;
1465         }
1466
1467         mypage = NS_GET_PAGE(ns);
1468         for (i = 0; i < ns->geom.pgsec; i++) {
1469                 if (mypage->byte != NULL) {
1470                         NS_DBG("erase_sector: freeing page %d\n", ns->regs.row+i);
1471                         kmem_cache_free(ns->nand_pages_slab, mypage->byte);
1472                         mypage->byte = NULL;
1473                 }
1474                 mypage++;
1475         }
1476 }
1477
1478 /*
1479  * Program the specified page with the contents from the NAND buffer.
1480  */
1481 static int prog_page(struct nandsim *ns, int num)
1482 {
1483         int i;
1484         union ns_mem *mypage;
1485         u_char *pg_off;
1486
1487         if (ns->cfile) {
1488                 loff_t off;
1489                 ssize_t tx;
1490                 int all;
1491
1492                 NS_DBG("prog_page: writing page %d\n", ns->regs.row);
1493                 pg_off = ns->file_buf + ns->regs.column + ns->regs.off;
1494                 off = (loff_t)NS_RAW_OFFSET(ns) + ns->regs.off;
1495                 if (!test_bit(ns->regs.row, ns->pages_written)) {
1496                         all = 1;
1497                         memset(ns->file_buf, 0xff, ns->geom.pgszoob);
1498                 } else {
1499                         all = 0;
1500                         tx = read_file(ns, ns->cfile, pg_off, num, off);
1501                         if (tx != num) {
1502                                 NS_ERR("prog_page: read error for page %d ret %ld\n", ns->regs.row, (long)tx);
1503                                 return -1;
1504                         }
1505                 }
1506                 for (i = 0; i < num; i++)
1507                         pg_off[i] &= ns->buf.byte[i];
1508                 if (all) {
1509                         loff_t pos = (loff_t)ns->regs.row * ns->geom.pgszoob;
1510                         tx = write_file(ns, ns->cfile, ns->file_buf, ns->geom.pgszoob, pos);
1511                         if (tx != ns->geom.pgszoob) {
1512                                 NS_ERR("prog_page: write error for page %d ret %ld\n", ns->regs.row, (long)tx);
1513                                 return -1;
1514                         }
1515                         __set_bit(ns->regs.row, ns->pages_written);
1516                 } else {
1517                         tx = write_file(ns, ns->cfile, pg_off, num, off);
1518                         if (tx != num) {
1519                                 NS_ERR("prog_page: write error for page %d ret %ld\n", ns->regs.row, (long)tx);
1520                                 return -1;
1521                         }
1522                 }
1523                 return 0;
1524         }
1525
1526         mypage = NS_GET_PAGE(ns);
1527         if (mypage->byte == NULL) {
1528                 NS_DBG("prog_page: allocating page %d\n", ns->regs.row);
1529                 /*
1530                  * We allocate memory with GFP_NOFS because a flash FS may
1531                  * utilize this. If it is holding an FS lock, then gets here,
1532                  * then kernel memory alloc runs writeback which goes to the FS
1533                  * again and deadlocks. This was seen in practice.
1534                  */
1535                 mypage->byte = kmem_cache_alloc(ns->nand_pages_slab, GFP_NOFS);
1536                 if (mypage->byte == NULL) {
1537                         NS_ERR("prog_page: error allocating memory for page %d\n", ns->regs.row);
1538                         return -1;
1539                 }
1540                 memset(mypage->byte, 0xFF, ns->geom.pgszoob);
1541         }
1542
1543         pg_off = NS_PAGE_BYTE_OFF(ns);
1544         for (i = 0; i < num; i++)
1545                 pg_off[i] &= ns->buf.byte[i];
1546
1547         return 0;
1548 }
1549
1550 /*
1551  * If state has any action bit, perform this action.
1552  *
1553  * RETURNS: 0 if success, -1 if error.
1554  */
1555 static int do_state_action(struct nandsim *ns, uint32_t action)
1556 {
1557         int num;
1558         int busdiv = ns->busw == 8 ? 1 : 2;
1559         unsigned int erase_block_no, page_no;
1560
1561         action &= ACTION_MASK;
1562
1563         /* Check that page address input is correct */
1564         if (action != ACTION_SECERASE && ns->regs.row >= ns->geom.pgnum) {
1565                 NS_WARN("do_state_action: wrong page number (%#x)\n", ns->regs.row);
1566                 return -1;
1567         }
1568
1569         switch (action) {
1570
1571         case ACTION_CPY:
1572                 /*
1573                  * Copy page data to the internal buffer.
1574                  */
1575
1576                 /* Column shouldn't be very large */
1577                 if (ns->regs.column >= (ns->geom.pgszoob - ns->regs.off)) {
1578                         NS_ERR("do_state_action: column number is too large\n");
1579                         break;
1580                 }
1581                 num = ns->geom.pgszoob - ns->regs.off - ns->regs.column;
1582                 read_page(ns, num);
1583
1584                 NS_DBG("do_state_action: (ACTION_CPY:) copy %d bytes to int buf, raw offset %d\n",
1585                         num, NS_RAW_OFFSET(ns) + ns->regs.off);
1586
1587                 if (ns->regs.off == 0)
1588                         NS_LOG("read page %d\n", ns->regs.row);
1589                 else if (ns->regs.off < ns->geom.pgsz)
1590                         NS_LOG("read page %d (second half)\n", ns->regs.row);
1591                 else
1592                         NS_LOG("read OOB of page %d\n", ns->regs.row);
1593
1594                 NS_UDELAY(access_delay);
1595                 NS_UDELAY(input_cycle * ns->geom.pgsz / 1000 / busdiv);
1596
1597                 break;
1598
1599         case ACTION_SECERASE:
1600                 /*
1601                  * Erase sector.
1602                  */
1603
1604                 if (ns->lines.wp) {
1605                         NS_ERR("do_state_action: device is write-protected, ignore sector erase\n");
1606                         return -1;
1607                 }
1608
1609                 if (ns->regs.row >= ns->geom.pgnum - ns->geom.pgsec
1610                         || (ns->regs.row & ~(ns->geom.secsz - 1))) {
1611                         NS_ERR("do_state_action: wrong sector address (%#x)\n", ns->regs.row);
1612                         return -1;
1613                 }
1614
1615                 ns->regs.row = (ns->regs.row <<
1616                                 8 * (ns->geom.pgaddrbytes - ns->geom.secaddrbytes)) | ns->regs.column;
1617                 ns->regs.column = 0;
1618
1619                 erase_block_no = ns->regs.row >> (ns->geom.secshift - ns->geom.pgshift);
1620
1621                 NS_DBG("do_state_action: erase sector at address %#x, off = %d\n",
1622                                 ns->regs.row, NS_RAW_OFFSET(ns));
1623                 NS_LOG("erase sector %u\n", erase_block_no);
1624
1625                 erase_sector(ns);
1626
1627                 NS_MDELAY(erase_delay);
1628
1629                 if (erase_block_wear)
1630                         update_wear(erase_block_no);
1631
1632                 if (erase_error(erase_block_no)) {
1633                         NS_WARN("simulating erase failure in erase block %u\n", erase_block_no);
1634                         return -1;
1635                 }
1636
1637                 break;
1638
1639         case ACTION_PRGPAGE:
1640                 /*
1641                  * Program page - move internal buffer data to the page.
1642                  */
1643
1644                 if (ns->lines.wp) {
1645                         NS_WARN("do_state_action: device is write-protected, programm\n");
1646                         return -1;
1647                 }
1648
1649                 num = ns->geom.pgszoob - ns->regs.off - ns->regs.column;
1650                 if (num != ns->regs.count) {
1651                         NS_ERR("do_state_action: too few bytes were input (%d instead of %d)\n",
1652                                         ns->regs.count, num);
1653                         return -1;
1654                 }
1655
1656                 if (prog_page(ns, num) == -1)
1657                         return -1;
1658
1659                 page_no = ns->regs.row;
1660
1661                 NS_DBG("do_state_action: copy %d bytes from int buf to (%#x, %#x), raw off = %d\n",
1662                         num, ns->regs.row, ns->regs.column, NS_RAW_OFFSET(ns) + ns->regs.off);
1663                 NS_LOG("programm page %d\n", ns->regs.row);
1664
1665                 NS_UDELAY(programm_delay);
1666                 NS_UDELAY(output_cycle * ns->geom.pgsz / 1000 / busdiv);
1667
1668                 if (write_error(page_no)) {
1669                         NS_WARN("simulating write failure in page %u\n", page_no);
1670                         return -1;
1671                 }
1672
1673                 break;
1674
1675         case ACTION_ZEROOFF:
1676                 NS_DBG("do_state_action: set internal offset to 0\n");
1677                 ns->regs.off = 0;
1678                 break;
1679
1680         case ACTION_HALFOFF:
1681                 if (!(ns->options & OPT_PAGE512_8BIT)) {
1682                         NS_ERR("do_state_action: BUG! can't skip half of page for non-512"
1683                                 "byte page size 8x chips\n");
1684                         return -1;
1685                 }
1686                 NS_DBG("do_state_action: set internal offset to %d\n", ns->geom.pgsz/2);
1687                 ns->regs.off = ns->geom.pgsz/2;
1688                 break;
1689
1690         case ACTION_OOBOFF:
1691                 NS_DBG("do_state_action: set internal offset to %d\n", ns->geom.pgsz);
1692                 ns->regs.off = ns->geom.pgsz;
1693                 break;
1694
1695         default:
1696                 NS_DBG("do_state_action: BUG! unknown action\n");
1697         }
1698
1699         return 0;
1700 }
1701
1702 /*
1703  * Switch simulator's state.
1704  */
1705 static void switch_state(struct nandsim *ns)
1706 {
1707         if (ns->op) {
1708                 /*
1709                  * The current operation have already been identified.
1710                  * Just follow the states chain.
1711                  */
1712
1713                 ns->stateidx += 1;
1714                 ns->state = ns->nxstate;
1715                 ns->nxstate = ns->op[ns->stateidx + 1];
1716
1717                 NS_DBG("switch_state: operation is known, switch to the next state, "
1718                         "state: %s, nxstate: %s\n",
1719                         get_state_name(ns->state), get_state_name(ns->nxstate));
1720
1721                 /* See, whether we need to do some action */
1722                 if ((ns->state & ACTION_MASK) && do_state_action(ns, ns->state) < 0) {
1723                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1724                         return;
1725                 }
1726
1727         } else {
1728                 /*
1729                  * We don't yet know which operation we perform.
1730                  * Try to identify it.
1731                  */
1732
1733                 /*
1734                  *  The only event causing the switch_state function to
1735                  *  be called with yet unknown operation is new command.
1736                  */
1737                 ns->state = get_state_by_command(ns->regs.command);
1738
1739                 NS_DBG("switch_state: operation is unknown, try to find it\n");
1740
1741                 if (find_operation(ns, 0) != 0)
1742                         return;
1743
1744                 if ((ns->state & ACTION_MASK) && do_state_action(ns, ns->state) < 0) {
1745                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1746                         return;
1747                 }
1748         }
1749
1750         /* For 16x devices column means the page offset in words */
1751         if ((ns->nxstate & STATE_ADDR_MASK) && ns->busw == 16) {
1752                 NS_DBG("switch_state: double the column number for 16x device\n");
1753                 ns->regs.column <<= 1;
1754         }
1755
1756         if (NS_STATE(ns->nxstate) == STATE_READY) {
1757                 /*
1758                  * The current state is the last. Return to STATE_READY
1759                  */
1760
1761                 u_char status = NS_STATUS_OK(ns);
1762
1763                 /* In case of data states, see if all bytes were input/output */
1764                 if ((ns->state & (STATE_DATAIN_MASK | STATE_DATAOUT_MASK))
1765                         && ns->regs.count != ns->regs.num) {
1766                         NS_WARN("switch_state: not all bytes were processed, %d left\n",
1767                                         ns->regs.num - ns->regs.count);
1768                         status = NS_STATUS_FAILED(ns);
1769                 }
1770
1771                 NS_DBG("switch_state: operation complete, switch to STATE_READY state\n");
1772
1773                 switch_to_ready_state(ns, status);
1774
1775                 return;
1776         } else if (ns->nxstate & (STATE_DATAIN_MASK | STATE_DATAOUT_MASK)) {
1777                 /*
1778                  * If the next state is data input/output, switch to it now
1779                  */
1780
1781                 ns->state      = ns->nxstate;
1782                 ns->nxstate    = ns->op[++ns->stateidx + 1];
1783                 ns->regs.num   = ns->regs.count = 0;
1784
1785                 NS_DBG("switch_state: the next state is data I/O, switch, "
1786                         "state: %s, nxstate: %s\n",
1787                         get_state_name(ns->state), get_state_name(ns->nxstate));
1788
1789                 /*
1790                  * Set the internal register to the count of bytes which
1791                  * are expected to be input or output
1792                  */
1793                 switch (NS_STATE(ns->state)) {
1794                         case STATE_DATAIN:
1795                         case STATE_DATAOUT:
1796                                 ns->regs.num = ns->geom.pgszoob - ns->regs.off - ns->regs.column;
1797                                 break;
1798
1799                         case STATE_DATAOUT_ID:
1800                                 ns->regs.num = ns->geom.idbytes;
1801                                 break;
1802
1803                         case STATE_DATAOUT_STATUS:
1804                                 ns->regs.count = ns->regs.num = 0;
1805                                 break;
1806
1807                         default:
1808                                 NS_ERR("switch_state: BUG! unknown data state\n");
1809                 }
1810
1811         } else if (ns->nxstate & STATE_ADDR_MASK) {
1812                 /*
1813                  * If the next state is address input, set the internal
1814                  * register to the number of expected address bytes
1815                  */
1816
1817                 ns->regs.count = 0;
1818
1819                 switch (NS_STATE(ns->nxstate)) {
1820                         case STATE_ADDR_PAGE:
1821                                 ns->regs.num = ns->geom.pgaddrbytes;
1822
1823                                 break;
1824                         case STATE_ADDR_SEC:
1825                                 ns->regs.num = ns->geom.secaddrbytes;
1826                                 break;
1827
1828                         case STATE_ADDR_ZERO:
1829                                 ns->regs.num = 1;
1830                                 break;
1831
1832                         case STATE_ADDR_COLUMN:
1833                                 /* Column address is always 2 bytes */
1834                                 ns->regs.num = ns->geom.pgaddrbytes - ns->geom.secaddrbytes;
1835                                 break;
1836
1837                         default:
1838                                 NS_ERR("switch_state: BUG! unknown address state\n");
1839                 }
1840         } else {
1841                 /*
1842                  * Just reset internal counters.
1843                  */
1844
1845                 ns->regs.num = 0;
1846                 ns->regs.count = 0;
1847         }
1848 }
1849
1850 static u_char ns_nand_read_byte(struct nand_chip *chip)
1851 {
1852         struct nandsim *ns = nand_get_controller_data(chip);
1853         u_char outb = 0x00;
1854
1855         /* Sanity and correctness checks */
1856         if (!ns->lines.ce) {
1857                 NS_ERR("read_byte: chip is disabled, return %#x\n", (uint)outb);
1858                 return outb;
1859         }
1860         if (ns->lines.ale || ns->lines.cle) {
1861                 NS_ERR("read_byte: ALE or CLE pin is high, return %#x\n", (uint)outb);
1862                 return outb;
1863         }
1864         if (!(ns->state & STATE_DATAOUT_MASK)) {
1865                 NS_WARN("read_byte: unexpected data output cycle, state is %s "
1866                         "return %#x\n", get_state_name(ns->state), (uint)outb);
1867                 return outb;
1868         }
1869
1870         /* Status register may be read as many times as it is wanted */
1871         if (NS_STATE(ns->state) == STATE_DATAOUT_STATUS) {
1872                 NS_DBG("read_byte: return %#x status\n", ns->regs.status);
1873                 return ns->regs.status;
1874         }
1875
1876         /* Check if there is any data in the internal buffer which may be read */
1877         if (ns->regs.count == ns->regs.num) {
1878                 NS_WARN("read_byte: no more data to output, return %#x\n", (uint)outb);
1879                 return outb;
1880         }
1881
1882         switch (NS_STATE(ns->state)) {
1883                 case STATE_DATAOUT:
1884                         if (ns->busw == 8) {
1885                                 outb = ns->buf.byte[ns->regs.count];
1886                                 ns->regs.count += 1;
1887                         } else {
1888                                 outb = (u_char)cpu_to_le16(ns->buf.word[ns->regs.count >> 1]);
1889                                 ns->regs.count += 2;
1890                         }
1891                         break;
1892                 case STATE_DATAOUT_ID:
1893                         NS_DBG("read_byte: read ID byte %d, total = %d\n", ns->regs.count, ns->regs.num);
1894                         outb = ns->ids[ns->regs.count];
1895                         ns->regs.count += 1;
1896                         break;
1897                 default:
1898                         BUG();
1899         }
1900
1901         if (ns->regs.count == ns->regs.num) {
1902                 NS_DBG("read_byte: all bytes were read\n");
1903
1904                 if (NS_STATE(ns->nxstate) == STATE_READY)
1905                         switch_state(ns);
1906         }
1907
1908         return outb;
1909 }
1910
1911 static void ns_nand_write_byte(struct nand_chip *chip, u_char byte)
1912 {
1913         struct nandsim *ns = nand_get_controller_data(chip);
1914
1915         /* Sanity and correctness checks */
1916         if (!ns->lines.ce) {
1917                 NS_ERR("write_byte: chip is disabled, ignore write\n");
1918                 return;
1919         }
1920         if (ns->lines.ale && ns->lines.cle) {
1921                 NS_ERR("write_byte: ALE and CLE pins are high simultaneously, ignore write\n");
1922                 return;
1923         }
1924
1925         if (ns->lines.cle == 1) {
1926                 /*
1927                  * The byte written is a command.
1928                  */
1929
1930                 if (byte == NAND_CMD_RESET) {
1931                         NS_LOG("reset chip\n");
1932                         switch_to_ready_state(ns, NS_STATUS_OK(ns));
1933                         return;
1934                 }
1935
1936                 /* Check that the command byte is correct */
1937                 if (check_command(byte)) {
1938                         NS_ERR("write_byte: unknown command %#x\n", (uint)byte);
1939                         return;
1940                 }
1941
1942                 if (NS_STATE(ns->state) == STATE_DATAOUT_STATUS
1943                         || NS_STATE(ns->state) == STATE_DATAOUT) {
1944                         int row = ns->regs.row;
1945
1946                         switch_state(ns);
1947                         if (byte == NAND_CMD_RNDOUT)
1948                                 ns->regs.row = row;
1949                 }
1950
1951                 /* Check if chip is expecting command */
1952                 if (NS_STATE(ns->nxstate) != STATE_UNKNOWN && !(ns->nxstate & STATE_CMD_MASK)) {
1953                         /* Do not warn if only 2 id bytes are read */
1954                         if (!(ns->regs.command == NAND_CMD_READID &&
1955                             NS_STATE(ns->state) == STATE_DATAOUT_ID && ns->regs.count == 2)) {
1956                                 /*
1957                                  * We are in situation when something else (not command)
1958                                  * was expected but command was input. In this case ignore
1959                                  * previous command(s)/state(s) and accept the last one.
1960                                  */
1961                                 NS_WARN("write_byte: command (%#x) wasn't expected, expected state is %s, "
1962                                         "ignore previous states\n", (uint)byte, get_state_name(ns->nxstate));
1963                         }
1964                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1965                 }
1966
1967                 NS_DBG("command byte corresponding to %s state accepted\n",
1968                         get_state_name(get_state_by_command(byte)));
1969                 ns->regs.command = byte;
1970                 switch_state(ns);
1971
1972         } else if (ns->lines.ale == 1) {
1973                 /*
1974                  * The byte written is an address.
1975                  */
1976
1977                 if (NS_STATE(ns->nxstate) == STATE_UNKNOWN) {
1978
1979                         NS_DBG("write_byte: operation isn't known yet, identify it\n");
1980
1981                         if (find_operation(ns, 1) < 0)
1982                                 return;
1983
1984                         if ((ns->state & ACTION_MASK) && do_state_action(ns, ns->state) < 0) {
1985                                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1986                                 return;
1987                         }
1988
1989                         ns->regs.count = 0;
1990                         switch (NS_STATE(ns->nxstate)) {
1991                                 case STATE_ADDR_PAGE:
1992                                         ns->regs.num = ns->geom.pgaddrbytes;
1993                                         break;
1994                                 case STATE_ADDR_SEC:
1995                                         ns->regs.num = ns->geom.secaddrbytes;
1996                                         break;
1997                                 case STATE_ADDR_ZERO:
1998                                         ns->regs.num = 1;
1999                                         break;
2000                                 default:
2001                                         BUG();
2002                         }
2003                 }
2004
2005                 /* Check that chip is expecting address */
2006                 if (!(ns->nxstate & STATE_ADDR_MASK)) {
2007                         NS_ERR("write_byte: address (%#x) isn't expected, expected state is %s, "
2008                                 "switch to STATE_READY\n", (uint)byte, get_state_name(ns->nxstate));
2009                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2010                         return;
2011                 }
2012
2013                 /* Check if this is expected byte */
2014                 if (ns->regs.count == ns->regs.num) {
2015                         NS_ERR("write_byte: no more address bytes expected\n");
2016                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2017                         return;
2018                 }
2019
2020                 accept_addr_byte(ns, byte);
2021
2022                 ns->regs.count += 1;
2023
2024                 NS_DBG("write_byte: address byte %#x was accepted (%d bytes input, %d expected)\n",
2025                                 (uint)byte, ns->regs.count, ns->regs.num);
2026
2027                 if (ns->regs.count == ns->regs.num) {
2028                         NS_DBG("address (%#x, %#x) is accepted\n", ns->regs.row, ns->regs.column);
2029                         switch_state(ns);
2030                 }
2031
2032         } else {
2033                 /*
2034                  * The byte written is an input data.
2035                  */
2036
2037                 /* Check that chip is expecting data input */
2038                 if (!(ns->state & STATE_DATAIN_MASK)) {
2039                         NS_ERR("write_byte: data input (%#x) isn't expected, state is %s, "
2040                                 "switch to %s\n", (uint)byte,
2041                                 get_state_name(ns->state), get_state_name(STATE_READY));
2042                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2043                         return;
2044                 }
2045
2046                 /* Check if this is expected byte */
2047                 if (ns->regs.count == ns->regs.num) {
2048                         NS_WARN("write_byte: %u input bytes has already been accepted, ignore write\n",
2049                                         ns->regs.num);
2050                         return;
2051                 }
2052
2053                 if (ns->busw == 8) {
2054                         ns->buf.byte[ns->regs.count] = byte;
2055                         ns->regs.count += 1;
2056                 } else {
2057                         ns->buf.word[ns->regs.count >> 1] = cpu_to_le16((uint16_t)byte);
2058                         ns->regs.count += 2;
2059                 }
2060         }
2061
2062         return;
2063 }
2064
2065 static void ns_nand_write_buf(struct nand_chip *chip, const u_char *buf,
2066                               int len)
2067 {
2068         struct nandsim *ns = nand_get_controller_data(chip);
2069
2070         /* Check that chip is expecting data input */
2071         if (!(ns->state & STATE_DATAIN_MASK)) {
2072                 NS_ERR("write_buf: data input isn't expected, state is %s, "
2073                         "switch to STATE_READY\n", get_state_name(ns->state));
2074                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2075                 return;
2076         }
2077
2078         /* Check if these are expected bytes */
2079         if (ns->regs.count + len > ns->regs.num) {
2080                 NS_ERR("write_buf: too many input bytes\n");
2081                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2082                 return;
2083         }
2084
2085         memcpy(ns->buf.byte + ns->regs.count, buf, len);
2086         ns->regs.count += len;
2087
2088         if (ns->regs.count == ns->regs.num) {
2089                 NS_DBG("write_buf: %d bytes were written\n", ns->regs.count);
2090         }
2091 }
2092
2093 static void ns_nand_read_buf(struct nand_chip *chip, u_char *buf, int len)
2094 {
2095         struct nandsim *ns = nand_get_controller_data(chip);
2096
2097         /* Sanity and correctness checks */
2098         if (!ns->lines.ce) {
2099                 NS_ERR("read_buf: chip is disabled\n");
2100                 return;
2101         }
2102         if (ns->lines.ale || ns->lines.cle) {
2103                 NS_ERR("read_buf: ALE or CLE pin is high\n");
2104                 return;
2105         }
2106         if (!(ns->state & STATE_DATAOUT_MASK)) {
2107                 NS_WARN("read_buf: unexpected data output cycle, current state is %s\n",
2108                         get_state_name(ns->state));
2109                 return;
2110         }
2111
2112         if (NS_STATE(ns->state) != STATE_DATAOUT) {
2113                 int i;
2114
2115                 for (i = 0; i < len; i++)
2116                         buf[i] = ns_nand_read_byte(chip);
2117
2118                 return;
2119         }
2120
2121         /* Check if these are expected bytes */
2122         if (ns->regs.count + len > ns->regs.num) {
2123                 NS_ERR("read_buf: too many bytes to read\n");
2124                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2125                 return;
2126         }
2127
2128         memcpy(buf, ns->buf.byte + ns->regs.count, len);
2129         ns->regs.count += len;
2130
2131         if (ns->regs.count == ns->regs.num) {
2132                 if (NS_STATE(ns->nxstate) == STATE_READY)
2133                         switch_state(ns);
2134         }
2135
2136         return;
2137 }
2138
2139 static int ns_exec_op(struct nand_chip *chip, const struct nand_operation *op,
2140                       bool check_only)
2141 {
2142         int i;
2143         unsigned int op_id;
2144         const struct nand_op_instr *instr = NULL;
2145         struct nandsim *ns = nand_get_controller_data(chip);
2146
2147         ns->lines.ce = 1;
2148
2149         for (op_id = 0; op_id < op->ninstrs; op_id++) {
2150                 instr = &op->instrs[op_id];
2151                 ns->lines.cle = 0;
2152                 ns->lines.ale = 0;
2153
2154                 switch (instr->type) {
2155                 case NAND_OP_CMD_INSTR:
2156                         ns->lines.cle = 1;
2157                         ns_nand_write_byte(chip, instr->ctx.cmd.opcode);
2158                         break;
2159                 case NAND_OP_ADDR_INSTR:
2160                         ns->lines.ale = 1;
2161                         for (i = 0; i < instr->ctx.addr.naddrs; i++)
2162                                 ns_nand_write_byte(chip, instr->ctx.addr.addrs[i]);
2163                         break;
2164                 case NAND_OP_DATA_IN_INSTR:
2165                         ns_nand_read_buf(chip, instr->ctx.data.buf.in, instr->ctx.data.len);
2166                         break;
2167                 case NAND_OP_DATA_OUT_INSTR:
2168                         ns_nand_write_buf(chip, instr->ctx.data.buf.out, instr->ctx.data.len);
2169                         break;
2170                 case NAND_OP_WAITRDY_INSTR:
2171                         /* we are always ready */
2172                         break;
2173                 }
2174         }
2175
2176         return 0;
2177 }
2178
2179 static int ns_attach_chip(struct nand_chip *chip)
2180 {
2181         unsigned int eccsteps, eccbytes;
2182
2183         if (!bch)
2184                 return 0;
2185
2186         if (!mtd_nand_has_bch()) {
2187                 NS_ERR("BCH ECC support is disabled\n");
2188                 return -EINVAL;
2189         }
2190
2191         /* Use 512-byte ecc blocks */
2192         eccsteps = nsmtd->writesize / 512;
2193         eccbytes = ((bch * 13) + 7) / 8;
2194
2195         /* Do not bother supporting small page devices */
2196         if (nsmtd->oobsize < 64 || !eccsteps) {
2197                 NS_ERR("BCH not available on small page devices\n");
2198                 return -EINVAL;
2199         }
2200
2201         if (((eccbytes * eccsteps) + 2) > nsmtd->oobsize) {
2202                 NS_ERR("Invalid BCH value %u\n", bch);
2203                 return -EINVAL;
2204         }
2205
2206         chip->ecc.mode = NAND_ECC_SOFT;
2207         chip->ecc.algo = NAND_ECC_BCH;
2208         chip->ecc.size = 512;
2209         chip->ecc.strength = bch;
2210         chip->ecc.bytes = eccbytes;
2211
2212         NS_INFO("Using %u-bit/%u bytes BCH ECC\n", bch, chip->ecc.size);
2213
2214         return 0;
2215 }
2216
2217 static const struct nand_controller_ops ns_controller_ops = {
2218         .attach_chip = ns_attach_chip,
2219         .exec_op = ns_exec_op,
2220 };
2221
2222 /*
2223  * Module initialization function
2224  */
2225 static int __init ns_init_module(void)
2226 {
2227         struct nand_chip *chip;
2228         struct nandsim *ns;
2229         int retval = -ENOMEM, i;
2230
2231         if (bus_width != 8 && bus_width != 16) {
2232                 NS_ERR("wrong bus width (%d), use only 8 or 16\n", bus_width);
2233                 return -EINVAL;
2234         }
2235
2236         ns = kzalloc(sizeof(struct nandsim), GFP_KERNEL);
2237         if (!ns) {
2238                 NS_ERR("unable to allocate core structures.\n");
2239                 return -ENOMEM;
2240         }
2241         chip        = &ns->chip;
2242         nsmtd       = nand_to_mtd(chip);
2243         nand_set_controller_data(chip, (void *)ns);
2244
2245         chip->ecc.mode   = NAND_ECC_SOFT;
2246         chip->ecc.algo   = NAND_ECC_HAMMING;
2247         /* The NAND_SKIP_BBTSCAN option is necessary for 'overridesize' */
2248         /* and 'badblocks' parameters to work */
2249         chip->options   |= NAND_SKIP_BBTSCAN;
2250
2251         switch (bbt) {
2252         case 2:
2253                 chip->bbt_options |= NAND_BBT_NO_OOB;
2254                 /* fall through */
2255         case 1:
2256                 chip->bbt_options |= NAND_BBT_USE_FLASH;
2257                 /* fall through */
2258         case 0:
2259                 break;
2260         default:
2261                 NS_ERR("bbt has to be 0..2\n");
2262                 retval = -EINVAL;
2263                 goto error;
2264         }
2265         /*
2266          * Perform minimum nandsim structure initialization to handle
2267          * the initial ID read command correctly
2268          */
2269         if (id_bytes[6] != 0xFF || id_bytes[7] != 0xFF)
2270                 ns->geom.idbytes = 8;
2271         else if (id_bytes[4] != 0xFF || id_bytes[5] != 0xFF)
2272                 ns->geom.idbytes = 6;
2273         else if (id_bytes[2] != 0xFF || id_bytes[3] != 0xFF)
2274                 ns->geom.idbytes = 4;
2275         else
2276                 ns->geom.idbytes = 2;
2277         ns->regs.status = NS_STATUS_OK(ns);
2278         ns->nxstate = STATE_UNKNOWN;
2279         ns->options |= OPT_PAGE512; /* temporary value */
2280         memcpy(ns->ids, id_bytes, sizeof(ns->ids));
2281         if (bus_width == 16) {
2282                 ns->busw = 16;
2283                 chip->options |= NAND_BUSWIDTH_16;
2284         }
2285
2286         nsmtd->owner = THIS_MODULE;
2287
2288         if ((retval = parse_weakblocks()) != 0)
2289                 goto error;
2290
2291         if ((retval = parse_weakpages()) != 0)
2292                 goto error;
2293
2294         if ((retval = parse_gravepages()) != 0)
2295                 goto error;
2296
2297         nand_controller_init(&ns->base);
2298         ns->base.ops = &ns_controller_ops;
2299         chip->controller = &ns->base;
2300
2301         retval = nand_scan(chip, 1);
2302         if (retval) {
2303                 NS_ERR("Could not scan NAND Simulator device\n");
2304                 goto error;
2305         }
2306
2307         if (overridesize) {
2308                 uint64_t new_size = (uint64_t)nsmtd->erasesize << overridesize;
2309                 struct nand_memory_organization *memorg;
2310                 u64 targetsize;
2311
2312                 memorg = nanddev_get_memorg(&chip->base);
2313
2314                 if (new_size >> overridesize != nsmtd->erasesize) {
2315                         NS_ERR("overridesize is too big\n");
2316                         retval = -EINVAL;
2317                         goto err_exit;
2318                 }
2319
2320                 /* N.B. This relies on nand_scan not doing anything with the size before we change it */
2321                 nsmtd->size = new_size;
2322                 memorg->eraseblocks_per_lun = 1 << overridesize;
2323                 targetsize = nanddev_target_size(&chip->base);
2324                 chip->chip_shift = ffs(nsmtd->erasesize) + overridesize - 1;
2325                 chip->pagemask = (targetsize >> chip->page_shift) - 1;
2326         }
2327
2328         if ((retval = setup_wear_reporting(nsmtd)) != 0)
2329                 goto err_exit;
2330
2331         if ((retval = init_nandsim(nsmtd)) != 0)
2332                 goto err_exit;
2333
2334         if ((retval = nand_create_bbt(chip)) != 0)
2335                 goto err_exit;
2336
2337         if ((retval = parse_badblocks(ns, nsmtd)) != 0)
2338                 goto err_exit;
2339
2340         /* Register NAND partitions */
2341         retval = mtd_device_register(nsmtd, &ns->partitions[0],
2342                                      ns->nbparts);
2343         if (retval != 0)
2344                 goto err_exit;
2345
2346         if ((retval = nandsim_debugfs_create(ns)) != 0)
2347                 goto err_exit;
2348
2349         return 0;
2350
2351 err_exit:
2352         free_nandsim(ns);
2353         nand_release(chip);
2354         for (i = 0;i < ARRAY_SIZE(ns->partitions); ++i)
2355                 kfree(ns->partitions[i].name);
2356 error:
2357         kfree(ns);
2358         free_lists();
2359
2360         return retval;
2361 }
2362
2363 module_init(ns_init_module);
2364
2365 /*
2366  * Module clean-up function
2367  */
2368 static void __exit ns_cleanup_module(void)
2369 {
2370         struct nand_chip *chip = mtd_to_nand(nsmtd);
2371         struct nandsim *ns = nand_get_controller_data(chip);
2372         int i;
2373
2374         free_nandsim(ns);    /* Free nandsim private resources */
2375         nand_release(chip); /* Unregister driver */
2376         for (i = 0;i < ARRAY_SIZE(ns->partitions); ++i)
2377                 kfree(ns->partitions[i].name);
2378         kfree(ns);        /* Free other structures */
2379         free_lists();
2380 }
2381
2382 module_exit(ns_cleanup_module);
2383
2384 MODULE_LICENSE ("GPL");
2385 MODULE_AUTHOR ("Artem B. Bityuckiy");
2386 MODULE_DESCRIPTION ("The NAND flash simulator");