File Index
Files and directories
Sign in
FILE

nandsim.c

File preview with syntax highlighting.

linux-6.19.14/drivers/mtd/nand/raw/nandsim.c 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/partitions.h>
  27#include <linux/delay.h>
  28#include <linux/list.h>
  29#include <linux/random.h>
  30#include <linux/sched.h>
  31#include <linux/sched/mm.h>
  32#include <linux/fs.h>
  33#include <linux/pagemap.h>
  34#include <linux/seq_file.h>
  35#include <linux/debugfs.h>
  36
  37/* Default simulator parameters values */
  38#if !defined(CONFIG_NANDSIM_FIRST_ID_BYTE)  || \
  39    !defined(CONFIG_NANDSIM_SECOND_ID_BYTE) || \
  40    !defined(CONFIG_NANDSIM_THIRD_ID_BYTE)  || \
  41    !defined(CONFIG_NANDSIM_FOURTH_ID_BYTE)
  42#define CONFIG_NANDSIM_FIRST_ID_BYTE  0x98
  43#define CONFIG_NANDSIM_SECOND_ID_BYTE 0x39
  44#define CONFIG_NANDSIM_THIRD_ID_BYTE  0xFF /* No byte */
  45#define CONFIG_NANDSIM_FOURTH_ID_BYTE 0xFF /* No byte */
  46#endif
  47
  48#ifndef CONFIG_NANDSIM_ACCESS_DELAY
  49#define CONFIG_NANDSIM_ACCESS_DELAY 25
  50#endif
  51#ifndef CONFIG_NANDSIM_PROGRAMM_DELAY
  52#define CONFIG_NANDSIM_PROGRAMM_DELAY 200
  53#endif
  54#ifndef CONFIG_NANDSIM_ERASE_DELAY
  55#define CONFIG_NANDSIM_ERASE_DELAY 2
  56#endif
  57#ifndef CONFIG_NANDSIM_OUTPUT_CYCLE
  58#define CONFIG_NANDSIM_OUTPUT_CYCLE 40
  59#endif
  60#ifndef CONFIG_NANDSIM_INPUT_CYCLE
  61#define CONFIG_NANDSIM_INPUT_CYCLE  50
  62#endif
  63#ifndef CONFIG_NANDSIM_BUS_WIDTH
  64#define CONFIG_NANDSIM_BUS_WIDTH  8
  65#endif
  66#ifndef CONFIG_NANDSIM_DO_DELAYS
  67#define CONFIG_NANDSIM_DO_DELAYS  0
  68#endif
  69#ifndef CONFIG_NANDSIM_LOG
  70#define CONFIG_NANDSIM_LOG        0
  71#endif
  72#ifndef CONFIG_NANDSIM_DBG
  73#define CONFIG_NANDSIM_DBG        0
  74#endif
  75#ifndef CONFIG_NANDSIM_MAX_PARTS
  76#define CONFIG_NANDSIM_MAX_PARTS  32
  77#endif
  78
  79static uint access_delay   = CONFIG_NANDSIM_ACCESS_DELAY;
  80static uint programm_delay = CONFIG_NANDSIM_PROGRAMM_DELAY;
  81static uint erase_delay    = CONFIG_NANDSIM_ERASE_DELAY;
  82static uint output_cycle   = CONFIG_NANDSIM_OUTPUT_CYCLE;
  83static uint input_cycle    = CONFIG_NANDSIM_INPUT_CYCLE;
  84static uint bus_width      = CONFIG_NANDSIM_BUS_WIDTH;
  85static uint do_delays      = CONFIG_NANDSIM_DO_DELAYS;
  86static uint log            = CONFIG_NANDSIM_LOG;
  87static uint dbg            = CONFIG_NANDSIM_DBG;
  88static unsigned long parts[CONFIG_NANDSIM_MAX_PARTS];
  89static unsigned int parts_num;
  90static char *badblocks = NULL;
  91static char *weakblocks = NULL;
  92static char *weakpages = NULL;
  93static unsigned int bitflips = 0;
  94static char *gravepages = NULL;
  95static unsigned int overridesize = 0;
  96static char *cache_file = NULL;
  97static unsigned int bbt;
  98static unsigned int bch;
  99static u_char id_bytes[8] = {
 100	[0] = CONFIG_NANDSIM_FIRST_ID_BYTE,
 101	[1] = CONFIG_NANDSIM_SECOND_ID_BYTE,
 102	[2] = CONFIG_NANDSIM_THIRD_ID_BYTE,
 103	[3] = CONFIG_NANDSIM_FOURTH_ID_BYTE,
 104	[4 ... 7] = 0xFF,
 105};
 106
 107module_param_array(id_bytes, byte, NULL, 0400);
 108module_param_named(first_id_byte, id_bytes[0], byte, 0400);
 109module_param_named(second_id_byte, id_bytes[1], byte, 0400);
 110module_param_named(third_id_byte, id_bytes[2], byte, 0400);
 111module_param_named(fourth_id_byte, id_bytes[3], byte, 0400);
 112module_param(access_delay,   uint, 0400);
 113module_param(programm_delay, uint, 0400);
 114module_param(erase_delay,    uint, 0400);
 115module_param(output_cycle,   uint, 0400);
 116module_param(input_cycle,    uint, 0400);
 117module_param(bus_width,      uint, 0400);
 118module_param(do_delays,      uint, 0400);
 119module_param(log,            uint, 0400);
 120module_param(dbg,            uint, 0400);
 121module_param_array(parts, ulong, &parts_num, 0400);
 122module_param(badblocks,      charp, 0400);
 123module_param(weakblocks,     charp, 0400);
 124module_param(weakpages,      charp, 0400);
 125module_param(bitflips,       uint, 0400);
 126module_param(gravepages,     charp, 0400);
 127module_param(overridesize,   uint, 0400);
 128module_param(cache_file,     charp, 0400);
 129module_param(bbt,	     uint, 0400);
 130module_param(bch,	     uint, 0400);
 131
 132MODULE_PARM_DESC(id_bytes,       "The ID bytes returned by NAND Flash 'read ID' command");
 133MODULE_PARM_DESC(first_id_byte,  "The first byte returned by NAND Flash 'read ID' command (manufacturer ID) (obsolete)");
 134MODULE_PARM_DESC(second_id_byte, "The second byte returned by NAND Flash 'read ID' command (chip ID) (obsolete)");
 135MODULE_PARM_DESC(third_id_byte,  "The third byte returned by NAND Flash 'read ID' command (obsolete)");
 136MODULE_PARM_DESC(fourth_id_byte, "The fourth byte returned by NAND Flash 'read ID' command (obsolete)");
 137MODULE_PARM_DESC(access_delay,   "Initial page access delay (microseconds)");
 138MODULE_PARM_DESC(programm_delay, "Page programm delay (microseconds");
 139MODULE_PARM_DESC(erase_delay,    "Sector erase delay (milliseconds)");
 140MODULE_PARM_DESC(output_cycle,   "Word output (from flash) time (nanoseconds)");
 141MODULE_PARM_DESC(input_cycle,    "Word input (to flash) time (nanoseconds)");
 142MODULE_PARM_DESC(bus_width,      "Chip's bus width (8- or 16-bit)");
 143MODULE_PARM_DESC(do_delays,      "Simulate NAND delays using busy-waits if not zero");
 144MODULE_PARM_DESC(log,            "Perform logging if not zero");
 145MODULE_PARM_DESC(dbg,            "Output debug information if not zero");
 146MODULE_PARM_DESC(parts,          "Partition sizes (in erase blocks) separated by commas");
 147/* Page and erase block positions for the following parameters are independent of any partitions */
 148MODULE_PARM_DESC(badblocks,      "Erase blocks that are initially marked bad, separated by commas");
 149MODULE_PARM_DESC(weakblocks,     "Weak erase blocks [: remaining erase cycles (defaults to 3)]"
 150				 " separated by commas e.g. 113:2 means eb 113"
 151				 " can be erased only twice before failing");
 152MODULE_PARM_DESC(weakpages,      "Weak pages [: maximum writes (defaults to 3)]"
 153				 " separated by commas e.g. 1401:2 means page 1401"
 154				 " can be written only twice before failing");
 155MODULE_PARM_DESC(bitflips,       "Maximum number of random bit flips per page (zero by default)");
 156MODULE_PARM_DESC(gravepages,     "Pages that lose data [: maximum reads (defaults to 3)]"
 157				 " separated by commas e.g. 1401:2 means page 1401"
 158				 " can be read only twice before failing");
 159MODULE_PARM_DESC(overridesize,   "Specifies the NAND Flash size overriding the ID bytes. "
 160				 "The size is specified in erase blocks and as the exponent of a power of two"
 161				 " e.g. 5 means a size of 32 erase blocks");
 162MODULE_PARM_DESC(cache_file,     "File to use to cache nand pages instead of memory");
 163MODULE_PARM_DESC(bbt,		 "0 OOB, 1 BBT with marker in OOB, 2 BBT with marker in data area");
 164MODULE_PARM_DESC(bch,		 "Enable BCH ecc and set how many bits should "
 165				 "be correctable in 512-byte blocks");
 166
 167/* The largest possible page size */
 168#define NS_LARGEST_PAGE_SIZE	4096
 169
 170/* Simulator's output macros (logging, debugging, warning, error) */
 171#define NS_LOG(args...) \
 172	do { if (log) pr_debug(" log: " args); } while(0)
 173#define NS_DBG(args...) \
 174	do { if (dbg) pr_debug(" debug: " args); } while(0)
 175#define NS_WARN(args...) \
 176	do { pr_warn(" warning: " args); } while(0)
 177#define NS_ERR(args...) \
 178	do { pr_err(" error: " args); } while(0)
 179#define NS_INFO(args...) \
 180	do { pr_info(" " args); } while(0)
 181
 182/* Busy-wait delay macros (microseconds, milliseconds) */
 183#define NS_UDELAY(us) \
 184        do { if (do_delays) udelay(us); } while(0)
 185#define NS_MDELAY(us) \
 186        do { if (do_delays) mdelay(us); } while(0)
 187
 188/* Is the nandsim structure initialized ? */
 189#define NS_IS_INITIALIZED(ns) ((ns)->geom.totsz != 0)
 190
 191/* Good operation completion status */
 192#define NS_STATUS_OK(ns) (NAND_STATUS_READY | (NAND_STATUS_WP * ((ns)->lines.wp == 0)))
 193
 194/* Operation failed completion status */
 195#define NS_STATUS_FAILED(ns) (NAND_STATUS_FAIL | NS_STATUS_OK(ns))
 196
 197/* Calculate the page offset in flash RAM image by (row, column) address */
 198#define NS_RAW_OFFSET(ns) \
 199	(((ns)->regs.row * (ns)->geom.pgszoob) + (ns)->regs.column)
 200
 201/* Calculate the OOB offset in flash RAM image by (row, column) address */
 202#define NS_RAW_OFFSET_OOB(ns) (NS_RAW_OFFSET(ns) + ns->geom.pgsz)
 203
 204/* Calculate the byte shift in the next page to access */
 205#define NS_PAGE_BYTE_SHIFT(ns) ((ns)->regs.column + (ns)->regs.off)
 206
 207/* After a command is input, the simulator goes to one of the following states */
 208#define STATE_CMD_READ0        0x00000001 /* read data from the beginning of page */
 209#define STATE_CMD_READ1        0x00000002 /* read data from the second half of page */
 210#define STATE_CMD_READSTART    0x00000003 /* read data second command (large page devices) */
 211#define STATE_CMD_PAGEPROG     0x00000004 /* start page program */
 212#define STATE_CMD_READOOB      0x00000005 /* read OOB area */
 213#define STATE_CMD_ERASE1       0x00000006 /* sector erase first command */
 214#define STATE_CMD_STATUS       0x00000007 /* read status */
 215#define STATE_CMD_SEQIN        0x00000009 /* sequential data input */
 216#define STATE_CMD_READID       0x0000000A /* read ID */
 217#define STATE_CMD_ERASE2       0x0000000B /* sector erase second command */
 218#define STATE_CMD_RESET        0x0000000C /* reset */
 219#define STATE_CMD_RNDOUT       0x0000000D /* random output command */
 220#define STATE_CMD_RNDOUTSTART  0x0000000E /* random output start command */
 221#define STATE_CMD_MASK         0x0000000F /* command states mask */
 222
 223/* After an address is input, the simulator goes to one of these states */
 224#define STATE_ADDR_PAGE        0x00000010 /* full (row, column) address is accepted */
 225#define STATE_ADDR_SEC         0x00000020 /* sector address was accepted */
 226#define STATE_ADDR_COLUMN      0x00000030 /* column address was accepted */
 227#define STATE_ADDR_ZERO        0x00000040 /* one byte zero address was accepted */
 228#define STATE_ADDR_MASK        0x00000070 /* address states mask */
 229
 230/* During data input/output the simulator is in these states */
 231#define STATE_DATAIN           0x00000100 /* waiting for data input */
 232#define STATE_DATAIN_MASK      0x00000100 /* data input states mask */
 233
 234#define STATE_DATAOUT          0x00001000 /* waiting for page data output */
 235#define STATE_DATAOUT_ID       0x00002000 /* waiting for ID bytes output */
 236#define STATE_DATAOUT_STATUS   0x00003000 /* waiting for status output */
 237#define STATE_DATAOUT_MASK     0x00007000 /* data output states mask */
 238
 239/* Previous operation is done, ready to accept new requests */
 240#define STATE_READY            0x00000000
 241
 242/* This state is used to mark that the next state isn't known yet */
 243#define STATE_UNKNOWN          0x10000000
 244
 245/* Simulator's actions bit masks */
 246#define ACTION_CPY       0x00100000 /* copy page/OOB to the internal buffer */
 247#define ACTION_PRGPAGE   0x00200000 /* program the internal buffer to flash */
 248#define ACTION_SECERASE  0x00300000 /* erase sector */
 249#define ACTION_ZEROOFF   0x00400000 /* don't add any offset to address */
 250#define ACTION_HALFOFF   0x00500000 /* add to address half of page */
 251#define ACTION_OOBOFF    0x00600000 /* add to address OOB offset */
 252#define ACTION_MASK      0x00700000 /* action mask */
 253
 254#define NS_OPER_NUM      13 /* Number of operations supported by the simulator */
 255#define NS_OPER_STATES   6  /* Maximum number of states in operation */
 256
 257#define OPT_ANY          0xFFFFFFFF /* any chip supports this operation */
 258#define OPT_PAGE512      0x00000002 /* 512-byte  page chips */
 259#define OPT_PAGE2048     0x00000008 /* 2048-byte page chips */
 260#define OPT_PAGE512_8BIT 0x00000040 /* 512-byte page chips with 8-bit bus width */
 261#define OPT_PAGE4096     0x00000080 /* 4096-byte page chips */
 262#define OPT_LARGEPAGE    (OPT_PAGE2048 | OPT_PAGE4096) /* 2048 & 4096-byte page chips */
 263#define OPT_SMALLPAGE    (OPT_PAGE512) /* 512-byte page chips */
 264
 265/* Remove action bits from state */
 266#define NS_STATE(x) ((x) & ~ACTION_MASK)
 267
 268/*
 269 * Maximum previous states which need to be saved. Currently saving is
 270 * only needed for page program operation with preceded read command
 271 * (which is only valid for 512-byte pages).
 272 */
 273#define NS_MAX_PREVSTATES 1
 274
 275/* Maximum page cache pages needed to read or write a NAND page to the cache_file */
 276#define NS_MAX_HELD_PAGES 16
 277
 278/*
 279 * A union to represent flash memory contents and flash buffer.
 280 */
 281union ns_mem {
 282	u_char *byte;    /* for byte access */
 283	uint16_t *word;  /* for 16-bit word access */
 284};
 285
 286/*
 287 * The structure which describes all the internal simulator data.
 288 */
 289struct nandsim {
 290	struct nand_chip chip;
 291	struct nand_controller base;
 292	struct mtd_partition partitions[CONFIG_NANDSIM_MAX_PARTS];
 293	unsigned int nbparts;
 294
 295	uint busw;              /* flash chip bus width (8 or 16) */
 296	u_char ids[8];          /* chip's ID bytes */
 297	uint32_t options;       /* chip's characteristic bits */
 298	uint32_t state;         /* current chip state */
 299	uint32_t nxstate;       /* next expected state */
 300
 301	uint32_t *op;           /* current operation, NULL operations isn't known yet  */
 302	uint32_t pstates[NS_MAX_PREVSTATES]; /* previous states */
 303	uint16_t npstates;      /* number of previous states saved */
 304	uint16_t stateidx;      /* current state index */
 305
 306	/* The simulated NAND flash pages array */
 307	union ns_mem *pages;
 308
 309	/* Slab allocator for nand pages */
 310	struct kmem_cache *nand_pages_slab;
 311
 312	/* Internal buffer of page + OOB size bytes */
 313	union ns_mem buf;
 314
 315	/* NAND flash "geometry" */
 316	struct {
 317		uint64_t totsz;     /* total flash size, bytes */
 318		uint32_t secsz;     /* flash sector (erase block) size, bytes */
 319		uint pgsz;          /* NAND flash page size, bytes */
 320		uint oobsz;         /* page OOB area size, bytes */
 321		uint64_t totszoob;  /* total flash size including OOB, bytes */
 322		uint pgszoob;       /* page size including OOB , bytes*/
 323		uint secszoob;      /* sector size including OOB, bytes */
 324		uint pgnum;         /* total number of pages */
 325		uint pgsec;         /* number of pages per sector */
 326		uint secshift;      /* bits number in sector size */
 327		uint pgshift;       /* bits number in page size */
 328		uint pgaddrbytes;   /* bytes per page address */
 329		uint secaddrbytes;  /* bytes per sector address */
 330		uint idbytes;       /* the number ID bytes that this chip outputs */
 331	} geom;
 332
 333	/* NAND flash internal registers */
 334	struct {
 335		unsigned command; /* the command register */
 336		u_char   status;  /* the status register */
 337		uint     row;     /* the page number */
 338		uint     column;  /* the offset within page */
 339		uint     count;   /* internal counter */
 340		uint     num;     /* number of bytes which must be processed */
 341		uint     off;     /* fixed page offset */
 342	} regs;
 343
 344	/* NAND flash lines state */
 345        struct {
 346                int ce;  /* chip Enable */
 347                int cle; /* command Latch Enable */
 348                int ale; /* address Latch Enable */
 349                int wp;  /* write Protect */
 350        } lines;
 351
 352	/* Fields needed when using a cache file */
 353	struct file *cfile; /* Open file */
 354	unsigned long *pages_written; /* Which pages have been written */
 355	void *file_buf;
 356	struct page *held_pages[NS_MAX_HELD_PAGES];
 357	int held_cnt;
 358
 359	/* debugfs entry */
 360	struct dentry *dent;
 361};
 362
 363/*
 364 * Operations array. To perform any operation the simulator must pass
 365 * through the correspondent states chain.
 366 */
 367static struct nandsim_operations {
 368	uint32_t reqopts;  /* options which are required to perform the operation */
 369	uint32_t states[NS_OPER_STATES]; /* operation's states */
 370} ops[NS_OPER_NUM] = {
 371	/* Read page + OOB from the beginning */
 372	{OPT_SMALLPAGE, {STATE_CMD_READ0 | ACTION_ZEROOFF, STATE_ADDR_PAGE | ACTION_CPY,
 373			STATE_DATAOUT, STATE_READY}},
 374	/* Read page + OOB from the second half */
 375	{OPT_PAGE512_8BIT, {STATE_CMD_READ1 | ACTION_HALFOFF, STATE_ADDR_PAGE | ACTION_CPY,
 376			STATE_DATAOUT, STATE_READY}},
 377	/* Read OOB */
 378	{OPT_SMALLPAGE, {STATE_CMD_READOOB | ACTION_OOBOFF, STATE_ADDR_PAGE | ACTION_CPY,
 379			STATE_DATAOUT, STATE_READY}},
 380	/* Program page starting from the beginning */
 381	{OPT_ANY, {STATE_CMD_SEQIN, STATE_ADDR_PAGE, STATE_DATAIN,
 382			STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
 383	/* Program page starting from the beginning */
 384	{OPT_SMALLPAGE, {STATE_CMD_READ0, STATE_CMD_SEQIN | ACTION_ZEROOFF, STATE_ADDR_PAGE,
 385			      STATE_DATAIN, STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
 386	/* Program page starting from the second half */
 387	{OPT_PAGE512, {STATE_CMD_READ1, STATE_CMD_SEQIN | ACTION_HALFOFF, STATE_ADDR_PAGE,
 388			      STATE_DATAIN, STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
 389	/* Program OOB */
 390	{OPT_SMALLPAGE, {STATE_CMD_READOOB, STATE_CMD_SEQIN | ACTION_OOBOFF, STATE_ADDR_PAGE,
 391			      STATE_DATAIN, STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
 392	/* Erase sector */
 393	{OPT_ANY, {STATE_CMD_ERASE1, STATE_ADDR_SEC, STATE_CMD_ERASE2 | ACTION_SECERASE, STATE_READY}},
 394	/* Read status */
 395	{OPT_ANY, {STATE_CMD_STATUS, STATE_DATAOUT_STATUS, STATE_READY}},
 396	/* Read ID */
 397	{OPT_ANY, {STATE_CMD_READID, STATE_ADDR_ZERO, STATE_DATAOUT_ID, STATE_READY}},
 398	/* Large page devices read page */
 399	{OPT_LARGEPAGE, {STATE_CMD_READ0, STATE_ADDR_PAGE, STATE_CMD_READSTART | ACTION_CPY,
 400			       STATE_DATAOUT, STATE_READY}},
 401	/* Large page devices random page read */
 402	{OPT_LARGEPAGE, {STATE_CMD_RNDOUT, STATE_ADDR_COLUMN, STATE_CMD_RNDOUTSTART | ACTION_CPY,
 403			       STATE_DATAOUT, STATE_READY}},
 404};
 405
 406struct weak_block {
 407	struct list_head list;
 408	unsigned int erase_block_no;
 409	unsigned int max_erases;
 410	unsigned int erases_done;
 411};
 412
 413static LIST_HEAD(weak_blocks);
 414
 415struct weak_page {
 416	struct list_head list;
 417	unsigned int page_no;
 418	unsigned int max_writes;
 419	unsigned int writes_done;
 420};
 421
 422static LIST_HEAD(weak_pages);
 423
 424struct grave_page {
 425	struct list_head list;
 426	unsigned int page_no;
 427	unsigned int max_reads;
 428	unsigned int reads_done;
 429};
 430
 431static LIST_HEAD(grave_pages);
 432
 433static unsigned long *erase_block_wear = NULL;
 434static unsigned int wear_eb_count = 0;
 435static unsigned long total_wear = 0;
 436
 437/* MTD structure for NAND controller */
 438static struct mtd_info *nsmtd;
 439
 440static int ns_show(struct seq_file *m, void *private)
 441{
 442	unsigned long wmin = -1, wmax = 0, avg;
 443	unsigned long deciles[10], decile_max[10], tot = 0;
 444	unsigned int i;
 445
 446	/* Calc wear stats */
 447	for (i = 0; i < wear_eb_count; ++i) {
 448		unsigned long wear = erase_block_wear[i];
 449		if (wear < wmin)
 450			wmin = wear;
 451		if (wear > wmax)
 452			wmax = wear;
 453		tot += wear;
 454	}
 455
 456	for (i = 0; i < 9; ++i) {
 457		deciles[i] = 0;
 458		decile_max[i] = (wmax * (i + 1) + 5) / 10;
 459	}
 460	deciles[9] = 0;
 461	decile_max[9] = wmax;
 462	for (i = 0; i < wear_eb_count; ++i) {
 463		int d;
 464		unsigned long wear = erase_block_wear[i];
 465		for (d = 0; d < 10; ++d)
 466			if (wear <= decile_max[d]) {
 467				deciles[d] += 1;
 468				break;
 469			}
 470	}
 471	avg = tot / wear_eb_count;
 472
 473	/* Output wear report */
 474	seq_printf(m, "Total numbers of erases:  %lu\n", tot);
 475	seq_printf(m, "Number of erase blocks:   %u\n", wear_eb_count);
 476	seq_printf(m, "Average number of erases: %lu\n", avg);
 477	seq_printf(m, "Maximum number of erases: %lu\n", wmax);
 478	seq_printf(m, "Minimum number of erases: %lu\n", wmin);
 479	for (i = 0; i < 10; ++i) {
 480		unsigned long from = (i ? decile_max[i - 1] + 1 : 0);
 481		if (from > decile_max[i])
 482			continue;
 483		seq_printf(m, "Number of ebs with erase counts from %lu to %lu : %lu\n",
 484			from,
 485			decile_max[i],
 486			deciles[i]);
 487	}
 488
 489	return 0;
 490}
 491DEFINE_SHOW_ATTRIBUTE(ns);
 492
 493/**
 494 * ns_debugfs_create - initialize debugfs
 495 * @ns: nandsim device description object
 496 *
 497 * This function creates all debugfs files for UBI device @ubi. Returns zero in
 498 * case of success and a negative error code in case of failure.
 499 */
 500static int ns_debugfs_create(struct nandsim *ns)
 501{
 502	struct dentry *root = nsmtd->dbg.dfs_dir;
 503
 504	/*
 505	 * Just skip debugfs initialization when the debugfs directory is
 506	 * missing.
 507	 */
 508	if (IS_ERR_OR_NULL(root)) {
 509		if (IS_ENABLED(CONFIG_DEBUG_FS) &&
 510		    !IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
 511			NS_WARN("CONFIG_MTD_PARTITIONED_MASTER must be enabled to expose debugfs stuff\n");
 512		return 0;
 513	}
 514
 515	ns->dent = debugfs_create_file("nandsim_wear_report", 0400, root, ns,
 516				       &ns_fops);
 517	if (IS_ERR_OR_NULL(ns->dent)) {
 518		NS_ERR("cannot create \"nandsim_wear_report\" debugfs entry\n");
 519		return -1;
 520	}
 521
 522	return 0;
 523}
 524
 525static void ns_debugfs_remove(struct nandsim *ns)
 526{
 527	debugfs_remove_recursive(ns->dent);
 528}
 529
 530/*
 531 * Allocate array of page pointers, create slab allocation for an array
 532 * and initialize the array by NULL pointers.
 533 *
 534 * RETURNS: 0 if success, -ENOMEM if memory alloc fails.
 535 */
 536static int __init ns_alloc_device(struct nandsim *ns)
 537{
 538	struct file *cfile;
 539	int i, err;
 540
 541	if (cache_file) {
 542		cfile = filp_open(cache_file, O_CREAT | O_RDWR | O_LARGEFILE, 0600);
 543		if (IS_ERR(cfile))
 544			return PTR_ERR(cfile);
 545		if (!(cfile->f_mode & FMODE_CAN_READ)) {
 546			NS_ERR("alloc_device: cache file not readable\n");
 547			err = -EINVAL;
 548			goto err_close_filp;
 549		}
 550		if (!(cfile->f_mode & FMODE_CAN_WRITE)) {
 551			NS_ERR("alloc_device: cache file not writeable\n");
 552			err = -EINVAL;
 553			goto err_close_filp;
 554		}
 555		ns->pages_written = vcalloc(BITS_TO_LONGS(ns->geom.pgnum),
 556					    sizeof(unsigned long));
 557		if (!ns->pages_written) {
 558			NS_ERR("alloc_device: unable to allocate pages written array\n");
 559			err = -ENOMEM;
 560			goto err_close_filp;
 561		}
 562		ns->file_buf = kmalloc(ns->geom.pgszoob, GFP_KERNEL);
 563		if (!ns->file_buf) {
 564			NS_ERR("alloc_device: unable to allocate file buf\n");
 565			err = -ENOMEM;
 566			goto err_free_pw;
 567		}
 568		ns->cfile = cfile;
 569
 570		return 0;
 571
 572err_free_pw:
 573		vfree(ns->pages_written);
 574err_close_filp:
 575		filp_close(cfile, NULL);
 576
 577		return err;
 578	}
 579
 580	ns->pages = vmalloc_array(ns->geom.pgnum, sizeof(union ns_mem));
 581	if (!ns->pages) {
 582		NS_ERR("alloc_device: unable to allocate page array\n");
 583		return -ENOMEM;
 584	}
 585	for (i = 0; i < ns->geom.pgnum; i++) {
 586		ns->pages[i].byte = NULL;
 587	}
 588	ns->nand_pages_slab = kmem_cache_create("nandsim",
 589						ns->geom.pgszoob, 0, 0, NULL);
 590	if (!ns->nand_pages_slab) {
 591		NS_ERR("cache_create: unable to create kmem_cache\n");
 592		err = -ENOMEM;
 593		goto err_free_pg;
 594	}
 595
 596	return 0;
 597
 598err_free_pg:
 599	vfree(ns->pages);
 600
 601	return err;
 602}
 603
 604/*
 605 * Free any allocated pages, and free the array of page pointers.
 606 */
 607static void ns_free_device(struct nandsim *ns)
 608{
 609	int i;
 610
 611	if (ns->cfile) {
 612		kfree(ns->file_buf);
 613		vfree(ns->pages_written);
 614		filp_close(ns->cfile, NULL);
 615		return;
 616	}
 617
 618	if (ns->pages) {
 619		for (i = 0; i < ns->geom.pgnum; i++) {
 620			if (ns->pages[i].byte)
 621				kmem_cache_free(ns->nand_pages_slab,
 622						ns->pages[i].byte);
 623		}
 624		kmem_cache_destroy(ns->nand_pages_slab);
 625		vfree(ns->pages);
 626	}
 627}
 628
 629static char __init *ns_get_partition_name(int i)
 630{
 631	return kasprintf(GFP_KERNEL, "NAND simulator partition %d", i);
 632}
 633
 634/*
 635 * Initialize the nandsim structure.
 636 *
 637 * RETURNS: 0 if success, -ERRNO if failure.
 638 */
 639static int __init ns_init(struct mtd_info *mtd)
 640{
 641	struct nand_chip *chip = mtd_to_nand(mtd);
 642	struct nandsim   *ns   = nand_get_controller_data(chip);
 643	int i, ret = 0;
 644	uint64_t remains;
 645	uint64_t next_offset;
 646
 647	if (NS_IS_INITIALIZED(ns)) {
 648		NS_ERR("init_nandsim: nandsim is already initialized\n");
 649		return -EIO;
 650	}
 651
 652	/* Initialize the NAND flash parameters */
 653	ns->busw = chip->options & NAND_BUSWIDTH_16 ? 16 : 8;
 654	ns->geom.totsz    = mtd->size;
 655	ns->geom.pgsz     = mtd->writesize;
 656	ns->geom.oobsz    = mtd->oobsize;
 657	ns->geom.secsz    = mtd->erasesize;
 658	ns->geom.pgszoob  = ns->geom.pgsz + ns->geom.oobsz;
 659	ns->geom.pgnum    = div_u64(ns->geom.totsz, ns->geom.pgsz);
 660	ns->geom.totszoob = ns->geom.totsz + (uint64_t)ns->geom.pgnum * ns->geom.oobsz;
 661	ns->geom.secshift = ffs(ns->geom.secsz) - 1;
 662	ns->geom.pgshift  = chip->page_shift;
 663	ns->geom.pgsec    = ns->geom.secsz / ns->geom.pgsz;
 664	ns->geom.secszoob = ns->geom.secsz + ns->geom.oobsz * ns->geom.pgsec;
 665	ns->options = 0;
 666
 667	if (ns->geom.pgsz == 512) {
 668		ns->options |= OPT_PAGE512;
 669		if (ns->busw == 8)
 670			ns->options |= OPT_PAGE512_8BIT;
 671	} else if (ns->geom.pgsz == 2048) {
 672		ns->options |= OPT_PAGE2048;
 673	} else if (ns->geom.pgsz == 4096) {
 674		ns->options |= OPT_PAGE4096;
 675	} else {
 676		NS_ERR("init_nandsim: unknown page size %u\n", ns->geom.pgsz);
 677		return -EIO;
 678	}
 679
 680	if (ns->options & OPT_SMALLPAGE) {
 681		if (ns->geom.totsz <= (32 << 20)) {
 682			ns->geom.pgaddrbytes  = 3;
 683			ns->geom.secaddrbytes = 2;
 684		} else {
 685			ns->geom.pgaddrbytes  = 4;
 686			ns->geom.secaddrbytes = 3;
 687		}
 688	} else {
 689		if (ns->geom.totsz <= (128 << 20)) {
 690			ns->geom.pgaddrbytes  = 4;
 691			ns->geom.secaddrbytes = 2;
 692		} else {
 693			ns->geom.pgaddrbytes  = 5;
 694			ns->geom.secaddrbytes = 3;
 695		}
 696	}
 697
 698	/* Fill the partition_info structure */
 699	if (parts_num > ARRAY_SIZE(ns->partitions)) {
 700		NS_ERR("too many partitions.\n");
 701		return -EINVAL;
 702	}
 703	remains = ns->geom.totsz;
 704	next_offset = 0;
 705	for (i = 0; i < parts_num; ++i) {
 706		uint64_t part_sz = (uint64_t)parts[i] * ns->geom.secsz;
 707
 708		if (!part_sz || part_sz > remains) {
 709			NS_ERR("bad partition size.\n");
 710			return -EINVAL;
 711		}
 712		ns->partitions[i].name = ns_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   = part_sz;
 719		next_offset += ns->partitions[i].size;
 720		remains -= ns->partitions[i].size;
 721	}
 722	ns->nbparts = parts_num;
 723	if (remains) {
 724		if (parts_num + 1 > ARRAY_SIZE(ns->partitions)) {
 725			NS_ERR("too many partitions.\n");
 726			ret = -EINVAL;
 727			goto free_partition_names;
 728		}
 729		ns->partitions[i].name = ns_get_partition_name(i);
 730		if (!ns->partitions[i].name) {
 731			NS_ERR("unable to allocate memory.\n");
 732			ret = -ENOMEM;
 733			goto free_partition_names;
 734		}
 735		ns->partitions[i].offset = next_offset;
 736		ns->partitions[i].size   = remains;
 737		ns->nbparts += 1;
 738	}
 739
 740	if (ns->busw == 16)
 741		NS_WARN("16-bit flashes support wasn't tested\n");
 742
 743	printk("flash size: %llu MiB\n",
 744			(unsigned long long)ns->geom.totsz >> 20);
 745	printk("page size: %u bytes\n",         ns->geom.pgsz);
 746	printk("OOB area size: %u bytes\n",     ns->geom.oobsz);
 747	printk("sector size: %u KiB\n",         ns->geom.secsz >> 10);
 748	printk("pages number: %u\n",            ns->geom.pgnum);
 749	printk("pages per sector: %u\n",        ns->geom.pgsec);
 750	printk("bus width: %u\n",               ns->busw);
 751	printk("bits in sector size: %u\n",     ns->geom.secshift);
 752	printk("bits in page size: %u\n",       ns->geom.pgshift);
 753	printk("bits in OOB size: %u\n",	ffs(ns->geom.oobsz) - 1);
 754	printk("flash size with OOB: %llu KiB\n",
 755			(unsigned long long)ns->geom.totszoob >> 10);
 756	printk("page address bytes: %u\n",      ns->geom.pgaddrbytes);
 757	printk("sector address bytes: %u\n",    ns->geom.secaddrbytes);
 758	printk("options: %#x\n",                ns->options);
 759
 760	ret = ns_alloc_device(ns);
 761	if (ret)
 762		goto free_partition_names;
 763
 764	/* Allocate / initialize the internal buffer */
 765	ns->buf.byte = kmalloc(ns->geom.pgszoob, GFP_KERNEL);
 766	if (!ns->buf.byte) {
 767		NS_ERR("init_nandsim: unable to allocate %u bytes for the internal buffer\n",
 768			ns->geom.pgszoob);
 769		ret = -ENOMEM;
 770		goto free_device;
 771	}
 772	memset(ns->buf.byte, 0xFF, ns->geom.pgszoob);
 773
 774	return 0;
 775
 776free_device:
 777	ns_free_device(ns);
 778free_partition_names:
 779	for (i = 0; i < ARRAY_SIZE(ns->partitions); ++i)
 780		kfree(ns->partitions[i].name);
 781
 782	return ret;
 783}
 784
 785/*
 786 * Free the nandsim structure.
 787 */
 788static void ns_free(struct nandsim *ns)
 789{
 790	int i;
 791
 792	for (i = 0; i < ARRAY_SIZE(ns->partitions); ++i)
 793		kfree(ns->partitions[i].name);
 794
 795	kfree(ns->buf.byte);
 796	ns_free_device(ns);
 797
 798	return;
 799}
 800
 801static int ns_parse_badblocks(struct nandsim *ns, struct mtd_info *mtd)
 802{
 803	char *w;
 804	int zero_ok;
 805	unsigned int erase_block_no;
 806	loff_t offset;
 807
 808	if (!badblocks)
 809		return 0;
 810	w = badblocks;
 811	do {
 812		zero_ok = (*w == '0' ? 1 : 0);
 813		erase_block_no = simple_strtoul(w, &w, 0);
 814		if (!zero_ok && !erase_block_no) {
 815			NS_ERR("invalid badblocks.\n");
 816			return -EINVAL;
 817		}
 818		offset = (loff_t)erase_block_no * ns->geom.secsz;
 819		if (mtd_block_markbad(mtd, offset)) {
 820			NS_ERR("invalid badblocks.\n");
 821			return -EINVAL;
 822		}
 823		if (*w == ',')
 824			w += 1;
 825	} while (*w);
 826	return 0;
 827}
 828
 829static int ns_parse_weakblocks(void)
 830{
 831	char *w;
 832	int zero_ok;
 833	unsigned int erase_block_no;
 834	unsigned int max_erases;
 835	struct weak_block *wb;
 836
 837	if (!weakblocks)
 838		return 0;
 839	w = weakblocks;
 840	do {
 841		zero_ok = (*w == '0' ? 1 : 0);
 842		erase_block_no = simple_strtoul(w, &w, 0);
 843		if (!zero_ok && !erase_block_no) {
 844			NS_ERR("invalid weakblocks.\n");
 845			return -EINVAL;
 846		}
 847		max_erases = 3;
 848		if (*w == ':') {
 849			w += 1;
 850			max_erases = simple_strtoul(w, &w, 0);
 851		}
 852		if (*w == ',')
 853			w += 1;
 854		wb = kzalloc(sizeof(*wb), GFP_KERNEL);
 855		if (!wb) {
 856			NS_ERR("unable to allocate memory.\n");
 857			return -ENOMEM;
 858		}
 859		wb->erase_block_no = erase_block_no;
 860		wb->max_erases = max_erases;
 861		list_add(&wb->list, &weak_blocks);
 862	} while (*w);
 863	return 0;
 864}
 865
 866static int ns_erase_error(unsigned int erase_block_no)
 867{
 868	struct weak_block *wb;
 869
 870	list_for_each_entry(wb, &weak_blocks, list)
 871		if (wb->erase_block_no == erase_block_no) {
 872			if (wb->erases_done >= wb->max_erases)
 873				return 1;
 874			wb->erases_done += 1;
 875			return 0;
 876		}
 877	return 0;
 878}
 879
 880static int ns_parse_weakpages(void)
 881{
 882	char *w;
 883	int zero_ok;
 884	unsigned int page_no;
 885	unsigned int max_writes;
 886	struct weak_page *wp;
 887
 888	if (!weakpages)
 889		return 0;
 890	w = weakpages;
 891	do {
 892		zero_ok = (*w == '0' ? 1 : 0);
 893		page_no = simple_strtoul(w, &w, 0);
 894		if (!zero_ok && !page_no) {
 895			NS_ERR("invalid weakpages.\n");
 896			return -EINVAL;
 897		}
 898		max_writes = 3;
 899		if (*w == ':') {
 900			w += 1;
 901			max_writes = simple_strtoul(w, &w, 0);
 902		}
 903		if (*w == ',')
 904			w += 1;
 905		wp = kzalloc(sizeof(*wp), GFP_KERNEL);
 906		if (!wp) {
 907			NS_ERR("unable to allocate memory.\n");
 908			return -ENOMEM;
 909		}
 910		wp->page_no = page_no;
 911		wp->max_writes = max_writes;
 912		list_add(&wp->list, &weak_pages);
 913	} while (*w);
 914	return 0;
 915}
 916
 917static int ns_write_error(unsigned int page_no)
 918{
 919	struct weak_page *wp;
 920
 921	list_for_each_entry(wp, &weak_pages, list)
 922		if (wp->page_no == page_no) {
 923			if (wp->writes_done >= wp->max_writes)
 924				return 1;
 925			wp->writes_done += 1;
 926			return 0;
 927		}
 928	return 0;
 929}
 930
 931static int ns_parse_gravepages(void)
 932{
 933	char *g;
 934	int zero_ok;
 935	unsigned int page_no;
 936	unsigned int max_reads;
 937	struct grave_page *gp;
 938
 939	if (!gravepages)
 940		return 0;
 941	g = gravepages;
 942	do {
 943		zero_ok = (*g == '0' ? 1 : 0);
 944		page_no = simple_strtoul(g, &g, 0);
 945		if (!zero_ok && !page_no) {
 946			NS_ERR("invalid gravepagess.\n");
 947			return -EINVAL;
 948		}
 949		max_reads = 3;
 950		if (*g == ':') {
 951			g += 1;
 952			max_reads = simple_strtoul(g, &g, 0);
 953		}
 954		if (*g == ',')
 955			g += 1;
 956		gp = kzalloc(sizeof(*gp), GFP_KERNEL);
 957		if (!gp) {
 958			NS_ERR("unable to allocate memory.\n");
 959			return -ENOMEM;
 960		}
 961		gp->page_no = page_no;
 962		gp->max_reads = max_reads;
 963		list_add(&gp->list, &grave_pages);
 964	} while (*g);
 965	return 0;
 966}
 967
 968static int ns_read_error(unsigned int page_no)
 969{
 970	struct grave_page *gp;
 971
 972	list_for_each_entry(gp, &grave_pages, list)
 973		if (gp->page_no == page_no) {
 974			if (gp->reads_done >= gp->max_reads)
 975				return 1;
 976			gp->reads_done += 1;
 977			return 0;
 978		}
 979	return 0;
 980}
 981
 982static int ns_setup_wear_reporting(struct mtd_info *mtd)
 983{
 984	wear_eb_count = div_u64(mtd->size, mtd->erasesize);
 985	erase_block_wear = kcalloc(wear_eb_count, sizeof(unsigned long), GFP_KERNEL);
 986	if (!erase_block_wear) {
 987		NS_ERR("Too many erase blocks for wear reporting\n");
 988		return -ENOMEM;
 989	}
 990	return 0;
 991}
 992
 993static void ns_update_wear(unsigned int erase_block_no)
 994{
 995	if (!erase_block_wear)
 996		return;
 997	total_wear += 1;
 998	/*
 999	 * TODO: Notify this through a debugfs entry,
1000	 * instead of showing an error message.
1001	 */
1002	if (total_wear == 0)
1003		NS_ERR("Erase counter total overflow\n");
1004	erase_block_wear[erase_block_no] += 1;
1005	if (erase_block_wear[erase_block_no] == 0)
1006		NS_ERR("Erase counter overflow for erase block %u\n", erase_block_no);
1007}
1008
1009/*
1010 * Returns the string representation of 'state' state.
1011 */
1012static char *ns_get_state_name(uint32_t state)
1013{
1014	switch (NS_STATE(state)) {
1015		case STATE_CMD_READ0:
1016			return "STATE_CMD_READ0";
1017		case STATE_CMD_READ1:
1018			return "STATE_CMD_READ1";
1019		case STATE_CMD_PAGEPROG:
1020			return "STATE_CMD_PAGEPROG";
1021		case STATE_CMD_READOOB:
1022			return "STATE_CMD_READOOB";
1023		case STATE_CMD_READSTART:
1024			return "STATE_CMD_READSTART";
1025		case STATE_CMD_ERASE1:
1026			return "STATE_CMD_ERASE1";
1027		case STATE_CMD_STATUS:
1028			return "STATE_CMD_STATUS";
1029		case STATE_CMD_SEQIN:
1030			return "STATE_CMD_SEQIN";
1031		case STATE_CMD_READID:
1032			return "STATE_CMD_READID";
1033		case STATE_CMD_ERASE2:
1034			return "STATE_CMD_ERASE2";
1035		case STATE_CMD_RESET:
1036			return "STATE_CMD_RESET";
1037		case STATE_CMD_RNDOUT:
1038			return "STATE_CMD_RNDOUT";
1039		case STATE_CMD_RNDOUTSTART:
1040			return "STATE_CMD_RNDOUTSTART";
1041		case STATE_ADDR_PAGE:
1042			return "STATE_ADDR_PAGE";
1043		case STATE_ADDR_SEC:
1044			return "STATE_ADDR_SEC";
1045		case STATE_ADDR_ZERO:
1046			return "STATE_ADDR_ZERO";
1047		case STATE_ADDR_COLUMN:
1048			return "STATE_ADDR_COLUMN";
1049		case STATE_DATAIN:
1050			return "STATE_DATAIN";
1051		case STATE_DATAOUT:
1052			return "STATE_DATAOUT";
1053		case STATE_DATAOUT_ID:
1054			return "STATE_DATAOUT_ID";
1055		case STATE_DATAOUT_STATUS:
1056			return "STATE_DATAOUT_STATUS";
1057		case STATE_READY:
1058			return "STATE_READY";
1059		case STATE_UNKNOWN:
1060			return "STATE_UNKNOWN";
1061	}
1062
1063	NS_ERR("get_state_name: unknown state, BUG\n");
1064	return NULL;
1065}
1066
1067/*
1068 * Check if command is valid.
1069 *
1070 * RETURNS: 1 if wrong command, 0 if right.
1071 */
1072static int ns_check_command(int cmd)
1073{
1074	switch (cmd) {
1075
1076	case NAND_CMD_READ0:
1077	case NAND_CMD_READ1:
1078	case NAND_CMD_READSTART:
1079	case NAND_CMD_PAGEPROG:
1080	case NAND_CMD_READOOB:
1081	case NAND_CMD_ERASE1:
1082	case NAND_CMD_STATUS:
1083	case NAND_CMD_SEQIN:
1084	case NAND_CMD_READID:
1085	case NAND_CMD_ERASE2:
1086	case NAND_CMD_RESET:
1087	case NAND_CMD_RNDOUT:
1088	case NAND_CMD_RNDOUTSTART:
1089		return 0;
1090
1091	default:
1092		return 1;
1093	}
1094}
1095
1096/*
1097 * Returns state after command is accepted by command number.
1098 */
1099static uint32_t ns_get_state_by_command(unsigned command)
1100{
1101	switch (command) {
1102		case NAND_CMD_READ0:
1103			return STATE_CMD_READ0;
1104		case NAND_CMD_READ1:
1105			return STATE_CMD_READ1;
1106		case NAND_CMD_PAGEPROG:
1107			return STATE_CMD_PAGEPROG;
1108		case NAND_CMD_READSTART:
1109			return STATE_CMD_READSTART;
1110		case NAND_CMD_READOOB:
1111			return STATE_CMD_READOOB;
1112		case NAND_CMD_ERASE1:
1113			return STATE_CMD_ERASE1;
1114		case NAND_CMD_STATUS:
1115			return STATE_CMD_STATUS;
1116		case NAND_CMD_SEQIN:
1117			return STATE_CMD_SEQIN;
1118		case NAND_CMD_READID:
1119			return STATE_CMD_READID;
1120		case NAND_CMD_ERASE2:
1121			return STATE_CMD_ERASE2;
1122		case NAND_CMD_RESET:
1123			return STATE_CMD_RESET;
1124		case NAND_CMD_RNDOUT:
1125			return STATE_CMD_RNDOUT;
1126		case NAND_CMD_RNDOUTSTART:
1127			return STATE_CMD_RNDOUTSTART;
1128	}
1129
1130	NS_ERR("get_state_by_command: unknown command, BUG\n");
1131	return 0;
1132}
1133
1134/*
1135 * Move an address byte to the correspondent internal register.
1136 */
1137static inline void ns_accept_addr_byte(struct nandsim *ns, u_char bt)
1138{
1139	uint byte = (uint)bt;
1140
1141	if (ns->regs.count < (ns->geom.pgaddrbytes - ns->geom.secaddrbytes))
1142		ns->regs.column |= (byte << 8 * ns->regs.count);
1143	else {
1144		ns->regs.row |= (byte << 8 * (ns->regs.count -
1145						ns->geom.pgaddrbytes +
1146						ns->geom.secaddrbytes));
1147	}
1148
1149	return;
1150}
1151
1152/*
1153 * Switch to STATE_READY state.
1154 */
1155static inline void ns_switch_to_ready_state(struct nandsim *ns, u_char status)
1156{
1157	NS_DBG("switch_to_ready_state: switch to %s state\n",
1158	       ns_get_state_name(STATE_READY));
1159
1160	ns->state       = STATE_READY;
1161	ns->nxstate     = STATE_UNKNOWN;
1162	ns->op          = NULL;
1163	ns->npstates    = 0;
1164	ns->stateidx    = 0;
1165	ns->regs.num    = 0;
1166	ns->regs.count  = 0;
1167	ns->regs.off    = 0;
1168	ns->regs.row    = 0;
1169	ns->regs.column = 0;
1170	ns->regs.status = status;
1171}
1172
1173/*
1174 * If the operation isn't known yet, try to find it in the global array
1175 * of supported operations.
1176 *
1177 * Operation can be unknown because of the following.
1178 *   1. New command was accepted and this is the first call to find the
1179 *      correspondent states chain. In this case ns->npstates = 0;
1180 *   2. There are several operations which begin with the same command(s)
1181 *      (for example program from the second half and read from the
1182 *      second half operations both begin with the READ1 command). In this
1183 *      case the ns->pstates[] array contains previous states.
1184 *
1185 * Thus, the function tries to find operation containing the following
1186 * states (if the 'flag' parameter is 0):
1187 *    ns->pstates[0], ... ns->pstates[ns->npstates], ns->state
1188 *
1189 * If (one and only one) matching operation is found, it is accepted (
1190 * ns->ops, ns->state, ns->nxstate are initialized, ns->npstate is
1191 * zeroed).
1192 *
1193 * If there are several matches, the current state is pushed to the
1194 * ns->pstates.
1195 *
1196 * The operation can be unknown only while commands are input to the chip.
1197 * As soon as address command is accepted, the operation must be known.
1198 * In such situation the function is called with 'flag' != 0, and the
1199 * operation is searched using the following pattern:
1200 *     ns->pstates[0], ... ns->pstates[ns->npstates], <address input>
1201 *
1202 * It is supposed that this pattern must either match one operation or
1203 * none. There can't be ambiguity in that case.
1204 *
1205 * If no matches found, the function does the following:
1206 *   1. if there are saved states present, try to ignore them and search
1207 *      again only using the last command. If nothing was found, switch
1208 *      to the STATE_READY state.
1209 *   2. if there are no saved states, switch to the STATE_READY state.
1210 *
1211 * RETURNS: -2 - no matched operations found.
1212 *          -1 - several matches.
1213 *           0 - operation is found.
1214 */
1215static int ns_find_operation(struct nandsim *ns, uint32_t flag)
1216{
1217	int opsfound = 0;
1218	int i, j, idx = 0;
1219
1220	for (i = 0; i < NS_OPER_NUM; i++) {
1221
1222		int found = 1;
1223
1224		if (!(ns->options & ops[i].reqopts))
1225			/* Ignore operations we can't perform */
1226			continue;
1227
1228		if (flag) {
1229			if (!(ops[i].states[ns->npstates] & STATE_ADDR_MASK))
1230				continue;
1231		} else {
1232			if (NS_STATE(ns->state) != NS_STATE(ops[i].states[ns->npstates]))
1233				continue;
1234		}
1235
1236		for (j = 0; j < ns->npstates; j++)
1237			if (NS_STATE(ops[i].states[j]) != NS_STATE(ns->pstates[j])
1238				&& (ns->options & ops[idx].reqopts)) {
1239				found = 0;
1240				break;
1241			}
1242
1243		if (found) {
1244			idx = i;
1245			opsfound += 1;
1246		}
1247	}
1248
1249	if (opsfound == 1) {
1250		/* Exact match */
1251		ns->op = &ops[idx].states[0];
1252		if (flag) {
1253			/*
1254			 * In this case the find_operation function was
1255			 * called when address has just began input. But it isn't
1256			 * yet fully input and the current state must
1257			 * not be one of STATE_ADDR_*, but the STATE_ADDR_*
1258			 * state must be the next state (ns->nxstate).
1259			 */
1260			ns->stateidx = ns->npstates - 1;
1261		} else {
1262			ns->stateidx = ns->npstates;
1263		}
1264		ns->npstates = 0;
1265		ns->state = ns->op[ns->stateidx];
1266		ns->nxstate = ns->op[ns->stateidx + 1];
1267		NS_DBG("find_operation: operation found, index: %d, state: %s, nxstate %s\n",
1268		       idx, ns_get_state_name(ns->state),
1269		       ns_get_state_name(ns->nxstate));
1270		return 0;
1271	}
1272
1273	if (opsfound == 0) {
1274		/* Nothing was found. Try to ignore previous commands (if any) and search again */
1275		if (ns->npstates != 0) {
1276			NS_DBG("find_operation: no operation found, try again with state %s\n",
1277			       ns_get_state_name(ns->state));
1278			ns->npstates = 0;
1279			return ns_find_operation(ns, 0);
1280
1281		}
1282		NS_DBG("find_operation: no operations found\n");
1283		ns_switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1284		return -2;
1285	}
1286
1287	if (flag) {
1288		/* This shouldn't happen */
1289		NS_DBG("find_operation: BUG, operation must be known if address is input\n");
1290		return -2;
1291	}
1292
1293	NS_DBG("find_operation: there is still ambiguity\n");
1294
1295	ns->pstates[ns->npstates++] = ns->state;
1296
1297	return -1;
1298}
1299
1300static void ns_put_pages(struct nandsim *ns)
1301{
1302	int i;
1303
1304	for (i = 0; i < ns->held_cnt; i++)
1305		put_page(ns->held_pages[i]);
1306}
1307
1308/* Get page cache pages in advance to provide NOFS memory allocation */
1309static int ns_get_pages(struct nandsim *ns, struct file *file, size_t count,
1310			loff_t pos)
1311{
1312	pgoff_t index, start_index, end_index;
1313	struct page *page;
1314	struct address_space *mapping = file->f_mapping;
1315
1316	start_index = pos >> PAGE_SHIFT;
1317	end_index = (pos + count - 1) >> PAGE_SHIFT;
1318	if (end_index - start_index + 1 > NS_MAX_HELD_PAGES)
1319		return -EINVAL;
1320	ns->held_cnt = 0;
1321	for (index = start_index; index <= end_index; index++) {
1322		page = find_get_page(mapping, index);
1323		if (page == NULL) {
1324			page = find_or_create_page(mapping, index, GFP_NOFS);
1325			if (page == NULL) {
1326				write_inode_now(mapping->host, 1);
1327				page = find_or_create_page(mapping, index, GFP_NOFS);
1328			}
1329			if (page == NULL) {
1330				ns_put_pages(ns);
1331				return -ENOMEM;
1332			}
1333			unlock_page(page);
1334		}
1335		ns->held_pages[ns->held_cnt++] = page;
1336	}
1337	return 0;
1338}
1339
1340static ssize_t ns_read_file(struct nandsim *ns, struct file *file, void *buf,
1341			    size_t count, loff_t pos)
1342{
1343	ssize_t tx;
1344	int err;
1345	unsigned int noreclaim_flag;
1346
1347	err = ns_get_pages(ns, file, count, pos);
1348	if (err)
1349		return err;
1350	noreclaim_flag = memalloc_noreclaim_save();
1351	tx = kernel_read(file, buf, count, &pos);
1352	memalloc_noreclaim_restore(noreclaim_flag);
1353	ns_put_pages(ns);
1354	return tx;
1355}
1356
1357static ssize_t ns_write_file(struct nandsim *ns, struct file *file, void *buf,
1358			     size_t count, loff_t pos)
1359{
1360	ssize_t tx;
1361	int err;
1362	unsigned int noreclaim_flag;
1363
1364	err = ns_get_pages(ns, file, count, pos);
1365	if (err)
1366		return err;
1367	noreclaim_flag = memalloc_noreclaim_save();
1368	tx = kernel_write(file, buf, count, &pos);
1369	memalloc_noreclaim_restore(noreclaim_flag);
1370	ns_put_pages(ns);
1371	return tx;
1372}
1373
1374/*
1375 * Returns a pointer to the current page.
1376 */
1377static inline union ns_mem *NS_GET_PAGE(struct nandsim *ns)
1378{
1379	return &(ns->pages[ns->regs.row]);
1380}
1381
1382/*
1383 * Returns a pointer to the current byte, within the current page.
1384 */
1385static inline u_char *NS_PAGE_BYTE_OFF(struct nandsim *ns)
1386{
1387	return NS_GET_PAGE(ns)->byte + NS_PAGE_BYTE_SHIFT(ns);
1388}
1389
1390static int ns_do_read_error(struct nandsim *ns, int num)
1391{
1392	unsigned int page_no = ns->regs.row;
1393
1394	if (ns_read_error(page_no)) {
1395		get_random_bytes(ns->buf.byte, num);
1396		NS_WARN("simulating read error in page %u\n", page_no);
1397		return 1;
1398	}
1399	return 0;
1400}
1401
1402static void ns_do_bit_flips(struct nandsim *ns, int num)
1403{
1404	if (bitflips && get_random_u16() < (1 << 6)) {
1405		int flips = 1;
1406		if (bitflips > 1)
1407			flips = get_random_u32_inclusive(1, bitflips);
1408		while (flips--) {
1409			int pos = get_random_u32_below(num * 8);
1410			ns->buf.byte[pos / 8] ^= (1 << (pos % 8));
1411			NS_WARN("read_page: flipping bit %d in page %d "
1412				"reading from %d ecc: corrected=%u failed=%u\n",
1413				pos, ns->regs.row, NS_PAGE_BYTE_SHIFT(ns),
1414				nsmtd->ecc_stats.corrected, nsmtd->ecc_stats.failed);
1415		}
1416	}
1417}
1418
1419/*
1420 * Fill the NAND buffer with data read from the specified page.
1421 */
1422static void ns_read_page(struct nandsim *ns, int num)
1423{
1424	union ns_mem *mypage;
1425
1426	if (ns->cfile) {
1427		if (!test_bit(ns->regs.row, ns->pages_written)) {
1428			NS_DBG("read_page: page %d not written\n", ns->regs.row);
1429			memset(ns->buf.byte, 0xFF, num);
1430		} else {
1431			loff_t pos;
1432			ssize_t tx;
1433
1434			NS_DBG("read_page: page %d written, reading from %d\n",
1435				ns->regs.row, NS_PAGE_BYTE_SHIFT(ns));
1436			if (ns_do_read_error(ns, num))
1437				return;
1438			pos = (loff_t)NS_RAW_OFFSET(ns) + ns->regs.off;
1439			tx = ns_read_file(ns, ns->cfile, ns->buf.byte, num,
1440					  pos);
1441			if (tx != num) {
1442				NS_ERR("read_page: read error for page %d ret %ld\n", ns->regs.row, (long)tx);
1443				return;
1444			}
1445			ns_do_bit_flips(ns, num);
1446		}
1447		return;
1448	}
1449
1450	mypage = NS_GET_PAGE(ns);
1451	if (mypage->byte == NULL) {
1452		NS_DBG("read_page: page %d not allocated\n", ns->regs.row);
1453		memset(ns->buf.byte, 0xFF, num);
1454	} else {
1455		NS_DBG("read_page: page %d allocated, reading from %d\n",
1456			ns->regs.row, NS_PAGE_BYTE_SHIFT(ns));
1457		if (ns_do_read_error(ns, num))
1458			return;
1459		memcpy(ns->buf.byte, NS_PAGE_BYTE_OFF(ns), num);
1460		ns_do_bit_flips(ns, num);
1461	}
1462}
1463
1464/*
1465 * Erase all pages in the specified sector.
1466 */
1467static void ns_erase_sector(struct nandsim *ns)
1468{
1469	union ns_mem *mypage;
1470	int i;
1471
1472	if (ns->cfile) {
1473		for (i = 0; i < ns->geom.pgsec; i++)
1474			if (__test_and_clear_bit(ns->regs.row + i,
1475						 ns->pages_written)) {
1476				NS_DBG("erase_sector: freeing page %d\n", ns->regs.row + i);
1477			}
1478		return;
1479	}
1480
1481	mypage = NS_GET_PAGE(ns);
1482	for (i = 0; i < ns->geom.pgsec; i++) {
1483		if (mypage->byte != NULL) {
1484			NS_DBG("erase_sector: freeing page %d\n", ns->regs.row+i);
1485			kmem_cache_free(ns->nand_pages_slab, mypage->byte);
1486			mypage->byte = NULL;
1487		}
1488		mypage++;
1489	}
1490}
1491
1492/*
1493 * Program the specified page with the contents from the NAND buffer.
1494 */
1495static int ns_prog_page(struct nandsim *ns, int num)
1496{
1497	int i;
1498	union ns_mem *mypage;
1499	u_char *pg_off;
1500
1501	if (ns->cfile) {
1502		loff_t off;
1503		ssize_t tx;
1504		int all;
1505
1506		NS_DBG("prog_page: writing page %d\n", ns->regs.row);
1507		pg_off = ns->file_buf + NS_PAGE_BYTE_SHIFT(ns);
1508		off = (loff_t)NS_RAW_OFFSET(ns) + ns->regs.off;
1509		if (!test_bit(ns->regs.row, ns->pages_written)) {
1510			all = 1;
1511			memset(ns->file_buf, 0xff, ns->geom.pgszoob);
1512		} else {
1513			all = 0;
1514			tx = ns_read_file(ns, ns->cfile, pg_off, num, off);
1515			if (tx != num) {
1516				NS_ERR("prog_page: read error for page %d ret %ld\n", ns->regs.row, (long)tx);
1517				return -1;
1518			}
1519		}
1520		for (i = 0; i < num; i++)
1521			pg_off[i] &= ns->buf.byte[i];
1522		if (all) {
1523			loff_t pos = (loff_t)ns->regs.row * ns->geom.pgszoob;
1524			tx = ns_write_file(ns, ns->cfile, ns->file_buf,
1525					   ns->geom.pgszoob, pos);
1526			if (tx != ns->geom.pgszoob) {
1527				NS_ERR("prog_page: write error for page %d ret %ld\n", ns->regs.row, (long)tx);
1528				return -1;
1529			}
1530			__set_bit(ns->regs.row, ns->pages_written);
1531		} else {
1532			tx = ns_write_file(ns, ns->cfile, pg_off, num, off);
1533			if (tx != num) {
1534				NS_ERR("prog_page: write error for page %d ret %ld\n", ns->regs.row, (long)tx);
1535				return -1;
1536			}
1537		}
1538		return 0;
1539	}
1540
1541	mypage = NS_GET_PAGE(ns);
1542	if (mypage->byte == NULL) {
1543		NS_DBG("prog_page: allocating page %d\n", ns->regs.row);
1544		/*
1545		 * We allocate memory with GFP_NOFS because a flash FS may
1546		 * utilize this. If it is holding an FS lock, then gets here,
1547		 * then kernel memory alloc runs writeback which goes to the FS
1548		 * again and deadlocks. This was seen in practice.
1549		 */
1550		mypage->byte = kmem_cache_alloc(ns->nand_pages_slab, GFP_NOFS);
1551		if (mypage->byte == NULL) {
1552			NS_ERR("prog_page: error allocating memory for page %d\n", ns->regs.row);
1553			return -1;
1554		}
1555		memset(mypage->byte, 0xFF, ns->geom.pgszoob);
1556	}
1557
1558	pg_off = NS_PAGE_BYTE_OFF(ns);
1559	for (i = 0; i < num; i++)
1560		pg_off[i] &= ns->buf.byte[i];
1561
1562	return 0;
1563}
1564
1565/*
1566 * If state has any action bit, perform this action.
1567 *
1568 * RETURNS: 0 if success, -1 if error.
1569 */
1570static int ns_do_state_action(struct nandsim *ns, uint32_t action)
1571{
1572	int num;
1573	int busdiv = ns->busw == 8 ? 1 : 2;
1574	unsigned int erase_block_no, page_no;
1575
1576	action &= ACTION_MASK;
1577
1578	/* Check that page address input is correct */
1579	if (action != ACTION_SECERASE && ns->regs.row >= ns->geom.pgnum) {
1580		NS_WARN("do_state_action: wrong page number (%#x)\n", ns->regs.row);
1581		return -1;
1582	}
1583
1584	switch (action) {
1585
1586	case ACTION_CPY:
1587		/*
1588		 * Copy page data to the internal buffer.
1589		 */
1590
1591		/* Column shouldn't be very large */
1592		if (ns->regs.column >= (ns->geom.pgszoob - ns->regs.off)) {
1593			NS_ERR("do_state_action: column number is too large\n");
1594			break;
1595		}
1596		num = ns->geom.pgszoob - NS_PAGE_BYTE_SHIFT(ns);
1597		ns_read_page(ns, num);
1598
1599		NS_DBG("do_state_action: (ACTION_CPY:) copy %d bytes to int buf, raw offset %d\n",
1600			num, NS_RAW_OFFSET(ns) + ns->regs.off);
1601
1602		if (ns->regs.off == 0)
1603			NS_LOG("read page %d\n", ns->regs.row);
1604		else if (ns->regs.off < ns->geom.pgsz)
1605			NS_LOG("read page %d (second half)\n", ns->regs.row);
1606		else
1607			NS_LOG("read OOB of page %d\n", ns->regs.row);
1608
1609		NS_UDELAY(access_delay);
1610		NS_UDELAY(input_cycle * ns->geom.pgsz / 1000 / busdiv);
1611
1612		break;
1613
1614	case ACTION_SECERASE:
1615		/*
1616		 * Erase sector.
1617		 */
1618
1619		if (ns->lines.wp) {
1620			NS_ERR("do_state_action: device is write-protected, ignore sector erase\n");
1621			return -1;
1622		}
1623
1624		if (ns->regs.row >= ns->geom.pgnum - ns->geom.pgsec
1625			|| (ns->regs.row & ~(ns->geom.secsz - 1))) {
1626			NS_ERR("do_state_action: wrong sector address (%#x)\n", ns->regs.row);
1627			return -1;
1628		}
1629
1630		ns->regs.row = (ns->regs.row <<
1631				8 * (ns->geom.pgaddrbytes - ns->geom.secaddrbytes)) | ns->regs.column;
1632		ns->regs.column = 0;
1633
1634		erase_block_no = ns->regs.row >> (ns->geom.secshift - ns->geom.pgshift);
1635
1636		NS_DBG("do_state_action: erase sector at address %#x, off = %d\n",
1637				ns->regs.row, NS_RAW_OFFSET(ns));
1638		NS_LOG("erase sector %u\n", erase_block_no);
1639
1640		ns_erase_sector(ns);
1641
1642		NS_MDELAY(erase_delay);
1643
1644		if (erase_block_wear)
1645			ns_update_wear(erase_block_no);
1646
1647		if (ns_erase_error(erase_block_no)) {
1648			NS_WARN("simulating erase failure in erase block %u\n", erase_block_no);
1649			return -1;
1650		}
1651
1652		break;
1653
1654	case ACTION_PRGPAGE:
1655		/*
1656		 * Program page - move internal buffer data to the page.
1657		 */
1658
1659		if (ns->lines.wp) {
1660			NS_WARN("do_state_action: device is write-protected, programm\n");
1661			return -1;
1662		}
1663
1664		num = ns->geom.pgszoob - NS_PAGE_BYTE_SHIFT(ns);
1665		if (num != ns->regs.count) {
1666			NS_ERR("do_state_action: too few bytes were input (%d instead of %d)\n",
1667					ns->regs.count, num);
1668			return -1;
1669		}
1670
1671		if (ns_prog_page(ns, num) == -1)
1672			return -1;
1673
1674		page_no = ns->regs.row;
1675
1676		NS_DBG("do_state_action: copy %d bytes from int buf to (%#x, %#x), raw off = %d\n",
1677			num, ns->regs.row, ns->regs.column, NS_RAW_OFFSET(ns) + ns->regs.off);
1678		NS_LOG("programm page %d\n", ns->regs.row);
1679
1680		NS_UDELAY(programm_delay);
1681		NS_UDELAY(output_cycle * ns->geom.pgsz / 1000 / busdiv);
1682
1683		if (ns_write_error(page_no)) {
1684			NS_WARN("simulating write failure in page %u\n", page_no);
1685			return -1;
1686		}
1687
1688		break;
1689
1690	case ACTION_ZEROOFF:
1691		NS_DBG("do_state_action: set internal offset to 0\n");
1692		ns->regs.off = 0;
1693		break;
1694
1695	case ACTION_HALFOFF:
1696		if (!(ns->options & OPT_PAGE512_8BIT)) {
1697			NS_ERR("do_state_action: BUG! can't skip half of page for non-512"
1698				"byte page size 8x chips\n");
1699			return -1;
1700		}
1701		NS_DBG("do_state_action: set internal offset to %d\n", ns->geom.pgsz/2);
1702		ns->regs.off = ns->geom.pgsz/2;
1703		break;
1704
1705	case ACTION_OOBOFF:
1706		NS_DBG("do_state_action: set internal offset to %d\n", ns->geom.pgsz);
1707		ns->regs.off = ns->geom.pgsz;
1708		break;
1709
1710	default:
1711		NS_DBG("do_state_action: BUG! unknown action\n");
1712	}
1713
1714	return 0;
1715}
1716
1717/*
1718 * Switch simulator's state.
1719 */
1720static void ns_switch_state(struct nandsim *ns)
1721{
1722	if (ns->op) {
1723		/*
1724		 * The current operation have already been identified.
1725		 * Just follow the states chain.
1726		 */
1727
1728		ns->stateidx += 1;
1729		ns->state = ns->nxstate;
1730		ns->nxstate = ns->op[ns->stateidx + 1];
1731
1732		NS_DBG("switch_state: operation is known, switch to the next state, "
1733			"state: %s, nxstate: %s\n",
1734		       ns_get_state_name(ns->state),
1735		       ns_get_state_name(ns->nxstate));
1736	} else {
1737		/*
1738		 * We don't yet know which operation we perform.
1739		 * Try to identify it.
1740		 */
1741
1742		/*
1743		 *  The only event causing the switch_state function to
1744		 *  be called with yet unknown operation is new command.
1745		 */
1746		ns->state = ns_get_state_by_command(ns->regs.command);
1747
1748		NS_DBG("switch_state: operation is unknown, try to find it\n");
1749
1750		if (ns_find_operation(ns, 0))
1751			return;
1752	}
1753
1754	/* See, whether we need to do some action */
1755	if ((ns->state & ACTION_MASK) &&
1756	    ns_do_state_action(ns, ns->state) < 0) {
1757		ns_switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1758		return;
1759	}
1760
1761	/* For 16x devices column means the page offset in words */
1762	if ((ns->nxstate & STATE_ADDR_MASK) && ns->busw == 16) {
1763		NS_DBG("switch_state: double the column number for 16x device\n");
1764		ns->regs.column <<= 1;
1765	}
1766
1767	if (NS_STATE(ns->nxstate) == STATE_READY) {
1768		/*
1769		 * The current state is the last. Return to STATE_READY
1770		 */
1771
1772		u_char status = NS_STATUS_OK(ns);
1773
1774		/* In case of data states, see if all bytes were input/output */
1775		if ((ns->state & (STATE_DATAIN_MASK | STATE_DATAOUT_MASK))
1776			&& ns->regs.count != ns->regs.num) {
1777			NS_WARN("switch_state: not all bytes were processed, %d left\n",
1778					ns->regs.num - ns->regs.count);
1779			status = NS_STATUS_FAILED(ns);
1780		}
1781
1782		NS_DBG("switch_state: operation complete, switch to STATE_READY state\n");
1783
1784		ns_switch_to_ready_state(ns, status);
1785
1786		return;
1787	} else if (ns->nxstate & (STATE_DATAIN_MASK | STATE_DATAOUT_MASK)) {
1788		/*
1789		 * If the next state is data input/output, switch to it now
1790		 */
1791
1792		ns->state      = ns->nxstate;
1793		ns->nxstate    = ns->op[++ns->stateidx + 1];
1794		ns->regs.num   = ns->regs.count = 0;
1795
1796		NS_DBG("switch_state: the next state is data I/O, switch, "
1797			"state: %s, nxstate: %s\n",
1798		       ns_get_state_name(ns->state),
1799		       ns_get_state_name(ns->nxstate));
1800
1801		/*
1802		 * Set the internal register to the count of bytes which
1803		 * are expected to be input or output
1804		 */
1805		switch (NS_STATE(ns->state)) {
1806			case STATE_DATAIN:
1807			case STATE_DATAOUT:
1808				ns->regs.num = ns->geom.pgszoob - NS_PAGE_BYTE_SHIFT(ns);
1809				break;
1810
1811			case STATE_DATAOUT_ID:
1812				ns->regs.num = ns->geom.idbytes;
1813				break;
1814
1815			case STATE_DATAOUT_STATUS:
1816				ns->regs.count = ns->regs.num = 0;
1817				break;
1818
1819			default:
1820				NS_ERR("switch_state: BUG! unknown data state\n");
1821		}
1822
1823	} else if (ns->nxstate & STATE_ADDR_MASK) {
1824		/*
1825		 * If the next state is address input, set the internal
1826		 * register to the number of expected address bytes
1827		 */
1828
1829		ns->regs.count = 0;
1830
1831		switch (NS_STATE(ns->nxstate)) {
1832			case STATE_ADDR_PAGE:
1833				ns->regs.num = ns->geom.pgaddrbytes;
1834
1835				break;
1836			case STATE_ADDR_SEC:
1837				ns->regs.num = ns->geom.secaddrbytes;
1838				break;
1839
1840			case STATE_ADDR_ZERO:
1841				ns->regs.num = 1;
1842				break;
1843
1844			case STATE_ADDR_COLUMN:
1845				/* Column address is always 2 bytes */
1846				ns->regs.num = ns->geom.pgaddrbytes - ns->geom.secaddrbytes;
1847				break;
1848
1849			default:
1850				NS_ERR("switch_state: BUG! unknown address state\n");
1851		}
1852	} else {
1853		/*
1854		 * Just reset internal counters.
1855		 */
1856
1857		ns->regs.num = 0;
1858		ns->regs.count = 0;
1859	}
1860}
1861
1862static u_char ns_nand_read_byte(struct nand_chip *chip)
1863{
1864	struct nandsim *ns = nand_get_controller_data(chip);
1865	u_char outb = 0x00;
1866
1867	/* Sanity and correctness checks */
1868	if (!ns->lines.ce) {
1869		NS_ERR("read_byte: chip is disabled, return %#x\n", (uint)outb);
1870		return outb;
1871	}
1872	if (ns->lines.ale || ns->lines.cle) {
1873		NS_ERR("read_byte: ALE or CLE pin is high, return %#x\n", (uint)outb);
1874		return outb;
1875	}
1876	if (!(ns->state & STATE_DATAOUT_MASK)) {
1877		NS_WARN("read_byte: unexpected data output cycle, state is %s return %#x\n",
1878			ns_get_state_name(ns->state), (uint)outb);
1879		return outb;
1880	}
1881
1882	/* Status register may be read as many times as it is wanted */
1883	if (NS_STATE(ns->state) == STATE_DATAOUT_STATUS) {
1884		NS_DBG("read_byte: return %#x status\n", ns->regs.status);
1885		return ns->regs.status;
1886	}
1887
1888	/* Check if there is any data in the internal buffer which may be read */
1889	if (ns->regs.count == ns->regs.num) {
1890		NS_WARN("read_byte: no more data to output, return %#x\n", (uint)outb);
1891		return outb;
1892	}
1893
1894	switch (NS_STATE(ns->state)) {
1895		case STATE_DATAOUT:
1896			if (ns->busw == 8) {
1897				outb = ns->buf.byte[ns->regs.count];
1898				ns->regs.count += 1;
1899			} else {
1900				outb = (u_char)cpu_to_le16(ns->buf.word[ns->regs.count >> 1]);
1901				ns->regs.count += 2;
1902			}
1903			break;
1904		case STATE_DATAOUT_ID:
1905			NS_DBG("read_byte: read ID byte %d, total = %d\n", ns->regs.count, ns->regs.num);
1906			outb = ns->ids[ns->regs.count];
1907			ns->regs.count += 1;
1908			break;
1909		default:
1910			BUG();
1911	}
1912
1913	if (ns->regs.count == ns->regs.num) {
1914		NS_DBG("read_byte: all bytes were read\n");
1915
1916		if (NS_STATE(ns->nxstate) == STATE_READY)
1917			ns_switch_state(ns);
1918	}
1919
1920	return outb;
1921}
1922
1923static void ns_nand_write_byte(struct nand_chip *chip, u_char byte)
1924{
1925	struct nandsim *ns = nand_get_controller_data(chip);
1926
1927	/* Sanity and correctness checks */
1928	if (!ns->lines.ce) {
1929		NS_ERR("write_byte: chip is disabled, ignore write\n");
1930		return;
1931	}
1932	if (ns->lines.ale && ns->lines.cle) {
1933		NS_ERR("write_byte: ALE and CLE pins are high simultaneously, ignore write\n");
1934		return;
1935	}
1936
1937	if (ns->lines.cle == 1) {
1938		/*
1939		 * The byte written is a command.
1940		 */
1941
1942		if (byte == NAND_CMD_RESET) {
1943			NS_LOG("reset chip\n");
1944			ns_switch_to_ready_state(ns, NS_STATUS_OK(ns));
1945			return;
1946		}
1947
1948		/* Check that the command byte is correct */
1949		if (ns_check_command(byte)) {
1950			NS_ERR("write_byte: unknown command %#x\n", (uint)byte);
1951			return;
1952		}
1953
1954		if (NS_STATE(ns->state) == STATE_DATAOUT_STATUS
1955			|| NS_STATE(ns->state) == STATE_DATAOUT) {
1956			int row = ns->regs.row;
1957
1958			ns_switch_state(ns);
1959			if (byte == NAND_CMD_RNDOUT)
1960				ns->regs.row = row;
1961		}
1962
1963		/* Check if chip is expecting command */
1964		if (NS_STATE(ns->nxstate) != STATE_UNKNOWN && !(ns->nxstate & STATE_CMD_MASK)) {
1965			/* Do not warn if only 2 id bytes are read */
1966			if (!(ns->regs.command == NAND_CMD_READID &&
1967			    NS_STATE(ns->state) == STATE_DATAOUT_ID && ns->regs.count == 2)) {
1968				/*
1969				 * We are in situation when something else (not command)
1970				 * was expected but command was input. In this case ignore
1971				 * previous command(s)/state(s) and accept the last one.
1972				 */
1973				NS_WARN("write_byte: command (%#x) wasn't expected, expected state is %s, ignore previous states\n",
1974					(uint)byte,
1975					ns_get_state_name(ns->nxstate));
1976			}
1977			ns_switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1978		}
1979
1980		NS_DBG("command byte corresponding to %s state accepted\n",
1981			ns_get_state_name(ns_get_state_by_command(byte)));
1982		ns->regs.command = byte;
1983		ns_switch_state(ns);
1984
1985	} else if (ns->lines.ale == 1) {
1986		/*
1987		 * The byte written is an address.
1988		 */
1989
1990		if (NS_STATE(ns->nxstate) == STATE_UNKNOWN) {
1991
1992			NS_DBG("write_byte: operation isn't known yet, identify it\n");
1993
1994			if (ns_find_operation(ns, 1) < 0)
1995				return;
1996
1997			if ((ns->state & ACTION_MASK) &&
1998			    ns_do_state_action(ns, ns->state) < 0) {
1999				ns_switch_to_ready_state(ns,
2000							 NS_STATUS_FAILED(ns));
2001				return;
2002			}
2003
2004			ns->regs.count = 0;
2005			switch (NS_STATE(ns->nxstate)) {
2006				case STATE_ADDR_PAGE:
2007					ns->regs.num = ns->geom.pgaddrbytes;
2008					break;
2009				case STATE_ADDR_SEC:
2010					ns->regs.num = ns->geom.secaddrbytes;
2011					break;
2012				case STATE_ADDR_ZERO:
2013					ns->regs.num = 1;
2014					break;
2015				default:
2016					BUG();
2017			}
2018		}
2019
2020		/* Check that chip is expecting address */
2021		if (!(ns->nxstate & STATE_ADDR_MASK)) {
2022			NS_ERR("write_byte: address (%#x) isn't expected, expected state is %s, switch to STATE_READY\n",
2023			       (uint)byte, ns_get_state_name(ns->nxstate));
2024			ns_switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2025			return;
2026		}
2027
2028		/* Check if this is expected byte */
2029		if (ns->regs.count == ns->regs.num) {
2030			NS_ERR("write_byte: no more address bytes expected\n");
2031			ns_switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2032			return;
2033		}
2034
2035		ns_accept_addr_byte(ns, byte);
2036
2037		ns->regs.count += 1;
2038
2039		NS_DBG("write_byte: address byte %#x was accepted (%d bytes input, %d expected)\n",
2040				(uint)byte, ns->regs.count, ns->regs.num);
2041
2042		if (ns->regs.count == ns->regs.num) {
2043			NS_DBG("address (%#x, %#x) is accepted\n", ns->regs.row, ns->regs.column);
2044			ns_switch_state(ns);
2045		}
2046
2047	} else {
2048		/*
2049		 * The byte written is an input data.
2050		 */
2051
2052		/* Check that chip is expecting data input */
2053		if (!(ns->state & STATE_DATAIN_MASK)) {
2054			NS_ERR("write_byte: data input (%#x) isn't expected, state is %s, switch to %s\n",
2055			       (uint)byte, ns_get_state_name(ns->state),
2056			       ns_get_state_name(STATE_READY));
2057			ns_switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2058			return;
2059		}
2060
2061		/* Check if this is expected byte */
2062		if (ns->regs.count == ns->regs.num) {
2063			NS_WARN("write_byte: %u input bytes has already been accepted, ignore write\n",
2064					ns->regs.num);
2065			return;
2066		}
2067
2068		if (ns->busw == 8) {
2069			ns->buf.byte[ns->regs.count] = byte;
2070			ns->regs.count += 1;
2071		} else {
2072			ns->buf.word[ns->regs.count >> 1] = cpu_to_le16((uint16_t)byte);
2073			ns->regs.count += 2;
2074		}
2075	}
2076
2077	return;
2078}
2079
2080static void ns_nand_write_buf(struct nand_chip *chip, const u_char *buf,
2081			      int len)
2082{
2083	struct nandsim *ns = nand_get_controller_data(chip);
2084
2085	/* Check that chip is expecting data input */
2086	if (!(ns->state & STATE_DATAIN_MASK)) {
2087		NS_ERR("write_buf: data input isn't expected, state is %s, switch to STATE_READY\n",
2088		       ns_get_state_name(ns->state));
2089		ns_switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2090		return;
2091	}
2092
2093	/* Check if these are expected bytes */
2094	if (ns->regs.count + len > ns->regs.num) {
2095		NS_ERR("write_buf: too many input bytes\n");
2096		ns_switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2097		return;
2098	}
2099
2100	memcpy(ns->buf.byte + ns->regs.count, buf, len);
2101	ns->regs.count += len;
2102
2103	if (ns->regs.count == ns->regs.num) {
2104		NS_DBG("write_buf: %d bytes were written\n", ns->regs.count);
2105	}
2106}
2107
2108static void ns_nand_read_buf(struct nand_chip *chip, u_char *buf, int len)
2109{
2110	struct nandsim *ns = nand_get_controller_data(chip);
2111
2112	/* Sanity and correctness checks */
2113	if (!ns->lines.ce) {
2114		NS_ERR("read_buf: chip is disabled\n");
2115		return;
2116	}
2117	if (ns->lines.ale || ns->lines.cle) {
2118		NS_ERR("read_buf: ALE or CLE pin is high\n");
2119		return;
2120	}
2121	if (!(ns->state & STATE_DATAOUT_MASK)) {
2122		NS_WARN("read_buf: unexpected data output cycle, current state is %s\n",
2123			ns_get_state_name(ns->state));
2124		return;
2125	}
2126
2127	if (NS_STATE(ns->state) != STATE_DATAOUT) {
2128		int i;
2129
2130		for (i = 0; i < len; i++)
2131			buf[i] = ns_nand_read_byte(chip);
2132
2133		return;
2134	}
2135
2136	/* Check if these are expected bytes */
2137	if (ns->regs.count + len > ns->regs.num) {
2138		NS_ERR("read_buf: too many bytes to read\n");
2139		ns_switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2140		return;
2141	}
2142
2143	memcpy(buf, ns->buf.byte + ns->regs.count, len);
2144	ns->regs.count += len;
2145
2146	if (ns->regs.count == ns->regs.num) {
2147		if (NS_STATE(ns->nxstate) == STATE_READY)
2148			ns_switch_state(ns);
2149	}
2150
2151	return;
2152}
2153
2154static int ns_exec_op(struct nand_chip *chip, const struct nand_operation *op,
2155		      bool check_only)
2156{
2157	int i;
2158	unsigned int op_id;
2159	const struct nand_op_instr *instr = NULL;
2160	struct nandsim *ns = nand_get_controller_data(chip);
2161
2162	if (check_only) {
2163		/* The current implementation of nandsim needs to know the
2164		 * ongoing operation when performing the address cycles. This
2165		 * means it cannot make the difference between a regular read
2166		 * and a continuous read. Hence, this hack to manually refuse
2167		 * supporting sequential cached operations.
2168		 */
2169		for (op_id = 0; op_id < op->ninstrs; op_id++) {
2170			instr = &op->instrs[op_id];
2171			if (instr->type == NAND_OP_CMD_INSTR &&
2172			    (instr->ctx.cmd.opcode == NAND_CMD_READCACHEEND ||
2173			     instr->ctx.cmd.opcode == NAND_CMD_READCACHESEQ))
2174				return -EOPNOTSUPP;
2175		}
2176
2177		return 0;
2178	}
2179
2180	ns->lines.ce = 1;
2181
2182	for (op_id = 0; op_id < op->ninstrs; op_id++) {
2183		instr = &op->instrs[op_id];
2184		ns->lines.cle = 0;
2185		ns->lines.ale = 0;
2186
2187		switch (instr->type) {
2188		case NAND_OP_CMD_INSTR:
2189			ns->lines.cle = 1;
2190			ns_nand_write_byte(chip, instr->ctx.cmd.opcode);
2191			break;
2192		case NAND_OP_ADDR_INSTR:
2193			ns->lines.ale = 1;
2194			for (i = 0; i < instr->ctx.addr.naddrs; i++)
2195				ns_nand_write_byte(chip, instr->ctx.addr.addrs[i]);
2196			break;
2197		case NAND_OP_DATA_IN_INSTR:
2198			ns_nand_read_buf(chip, instr->ctx.data.buf.in, instr->ctx.data.len);
2199			break;
2200		case NAND_OP_DATA_OUT_INSTR:
2201			ns_nand_write_buf(chip, instr->ctx.data.buf.out, instr->ctx.data.len);
2202			break;
2203		case NAND_OP_WAITRDY_INSTR:
2204			/* we are always ready */
2205			break;
2206		}
2207	}
2208
2209	return 0;
2210}
2211
2212static int ns_attach_chip(struct nand_chip *chip)
2213{
2214	unsigned int eccsteps, eccbytes;
2215
2216	chip->ecc.engine_type = NAND_ECC_ENGINE_TYPE_SOFT;
2217	chip->ecc.algo = bch ? NAND_ECC_ALGO_BCH : NAND_ECC_ALGO_HAMMING;
2218
2219	if (!bch)
2220		return 0;
2221
2222	if (!IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_BCH)) {
2223		NS_ERR("BCH ECC support is disabled\n");
2224		return -EINVAL;
2225	}
2226
2227	/* Use 512-byte ecc blocks */
2228	eccsteps = nsmtd->writesize / 512;
2229	eccbytes = ((bch * 13) + 7) / 8;
2230
2231	/* Do not bother supporting small page devices */
2232	if (nsmtd->oobsize < 64 || !eccsteps) {
2233		NS_ERR("BCH not available on small page devices\n");
2234		return -EINVAL;
2235	}
2236
2237	if (((eccbytes * eccsteps) + 2) > nsmtd->oobsize) {
2238		NS_ERR("Invalid BCH value %u\n", bch);
2239		return -EINVAL;
2240	}
2241
2242	chip->ecc.size = 512;
2243	chip->ecc.strength = bch;
2244	chip->ecc.bytes = eccbytes;
2245
2246	NS_INFO("Using %u-bit/%u bytes BCH ECC\n", bch, chip->ecc.size);
2247
2248	return 0;
2249}
2250
2251static const struct nand_controller_ops ns_controller_ops = {
2252	.attach_chip = ns_attach_chip,
2253	.exec_op = ns_exec_op,
2254};
2255
2256/*
2257 * Module initialization function
2258 */
2259static int __init ns_init_module(void)
2260{
2261	struct list_head *pos, *n;
2262	struct nand_chip *chip;
2263	struct nandsim *ns;
2264	int ret;
2265
2266	if (bus_width != 8 && bus_width != 16) {
2267		NS_ERR("wrong bus width (%d), use only 8 or 16\n", bus_width);
2268		return -EINVAL;
2269	}
2270
2271	ns = kzalloc(sizeof(struct nandsim), GFP_KERNEL);
2272	if (!ns) {
2273		NS_ERR("unable to allocate core structures.\n");
2274		return -ENOMEM;
2275	}
2276	chip	    = &ns->chip;
2277	nsmtd       = nand_to_mtd(chip);
2278	nand_set_controller_data(chip, (void *)ns);
2279
2280	/* The NAND_SKIP_BBTSCAN option is necessary for 'overridesize' */
2281	/* and 'badblocks' parameters to work */
2282	chip->options   |= NAND_SKIP_BBTSCAN;
2283
2284	switch (bbt) {
2285	case 2:
2286		chip->bbt_options |= NAND_BBT_NO_OOB;
2287		fallthrough;
2288	case 1:
2289		chip->bbt_options |= NAND_BBT_USE_FLASH;
2290		fallthrough;
2291	case 0:
2292		break;
2293	default:
2294		NS_ERR("bbt has to be 0..2\n");
2295		ret = -EINVAL;
2296		goto free_ns_struct;
2297	}
2298	/*
2299	 * Perform minimum nandsim structure initialization to handle
2300	 * the initial ID read command correctly
2301	 */
2302	if (id_bytes[6] != 0xFF || id_bytes[7] != 0xFF)
2303		ns->geom.idbytes = 8;
2304	else if (id_bytes[4] != 0xFF || id_bytes[5] != 0xFF)
2305		ns->geom.idbytes = 6;
2306	else if (id_bytes[2] != 0xFF || id_bytes[3] != 0xFF)
2307		ns->geom.idbytes = 4;
2308	else
2309		ns->geom.idbytes = 2;
2310	ns->regs.status = NS_STATUS_OK(ns);
2311	ns->nxstate = STATE_UNKNOWN;
2312	ns->options |= OPT_PAGE512; /* temporary value */
2313	memcpy(ns->ids, id_bytes, sizeof(ns->ids));
2314	if (bus_width == 16) {
2315		ns->busw = 16;
2316		chip->options |= NAND_BUSWIDTH_16;
2317	}
2318
2319	nsmtd->owner = THIS_MODULE;
2320
2321	ret = ns_parse_weakblocks();
2322	if (ret)
2323		goto free_ns_struct;
2324
2325	ret = ns_parse_weakpages();
2326	if (ret)
2327		goto free_wb_list;
2328
2329	ret = ns_parse_gravepages();
2330	if (ret)
2331		goto free_wp_list;
2332
2333	nand_controller_init(&ns->base);
2334	ns->base.ops = &ns_controller_ops;
2335	chip->controller = &ns->base;
2336
2337	ret = nand_scan(chip, 1);
2338	if (ret) {
2339		NS_ERR("Could not scan NAND Simulator device\n");
2340		goto free_gp_list;
2341	}
2342
2343	if (overridesize) {
2344		uint64_t new_size = (uint64_t)nsmtd->erasesize << overridesize;
2345		struct nand_memory_organization *memorg;
2346		u64 targetsize;
2347
2348		memorg = nanddev_get_memorg(&chip->base);
2349
2350		if (new_size >> overridesize != nsmtd->erasesize) {
2351			NS_ERR("overridesize is too big\n");
2352			ret = -EINVAL;
2353			goto cleanup_nand;
2354		}
2355
2356		/* N.B. This relies on nand_scan not doing anything with the size before we change it */
2357		nsmtd->size = new_size;
2358		memorg->eraseblocks_per_lun = 1 << overridesize;
2359		targetsize = nanddev_target_size(&chip->base);
2360		chip->chip_shift = ffs(nsmtd->erasesize) + overridesize - 1;
2361		chip->pagemask = (targetsize >> chip->page_shift) - 1;
2362	}
2363
2364	ret = ns_setup_wear_reporting(nsmtd);
2365	if (ret)
2366		goto cleanup_nand;
2367
2368	ret = ns_init(nsmtd);
2369	if (ret)
2370		goto free_ebw;
2371
2372	ret = nand_create_bbt(chip);
2373	if (ret)
2374		goto free_ns_object;
2375
2376	ret = ns_parse_badblocks(ns, nsmtd);
2377	if (ret)
2378		goto free_ns_object;
2379
2380	/* Register NAND partitions */
2381	ret = mtd_device_register(nsmtd, &ns->partitions[0], ns->nbparts);
2382	if (ret)
2383		goto free_ns_object;
2384
2385	ret = ns_debugfs_create(ns);
2386	if (ret)
2387		goto unregister_mtd;
2388
2389        return 0;
2390
2391unregister_mtd:
2392	WARN_ON(mtd_device_unregister(nsmtd));
2393free_ns_object:
2394	ns_free(ns);
2395free_ebw:
2396	kfree(erase_block_wear);
2397cleanup_nand:
2398	nand_cleanup(chip);
2399free_gp_list:
2400	list_for_each_safe(pos, n, &grave_pages) {
2401		list_del(pos);
2402		kfree(list_entry(pos, struct grave_page, list));
2403	}
2404free_wp_list:
2405	list_for_each_safe(pos, n, &weak_pages) {
2406		list_del(pos);
2407		kfree(list_entry(pos, struct weak_page, list));
2408	}
2409free_wb_list:
2410	list_for_each_safe(pos, n, &weak_blocks) {
2411		list_del(pos);
2412		kfree(list_entry(pos, struct weak_block, list));
2413	}
2414free_ns_struct:
2415	kfree(ns);
2416
2417	return ret;
2418}
2419
2420module_init(ns_init_module);
2421
2422/*
2423 * Module clean-up function
2424 */
2425static void __exit ns_cleanup_module(void)
2426{
2427	struct nand_chip *chip = mtd_to_nand(nsmtd);
2428	struct nandsim *ns = nand_get_controller_data(chip);
2429	struct list_head *pos, *n;
2430
2431	ns_debugfs_remove(ns);
2432	WARN_ON(mtd_device_unregister(nsmtd));
2433	ns_free(ns);
2434	kfree(erase_block_wear);
2435	nand_cleanup(chip);
2436
2437	list_for_each_safe(pos, n, &grave_pages) {
2438		list_del(pos);
2439		kfree(list_entry(pos, struct grave_page, list));
2440	}
2441
2442	list_for_each_safe(pos, n, &weak_pages) {
2443		list_del(pos);
2444		kfree(list_entry(pos, struct weak_page, list));
2445	}
2446
2447	list_for_each_safe(pos, n, &weak_blocks) {
2448		list_del(pos);
2449		kfree(list_entry(pos, struct weak_block, list));
2450	}
2451
2452	kfree(ns);
2453}
2454
2455module_exit(ns_cleanup_module);
2456
2457MODULE_LICENSE ("GPL");
2458MODULE_AUTHOR ("Artem B. Bityuckiy");
2459MODULE_DESCRIPTION ("The NAND flash simulator");
~/ Read-only file preview.