mtd: kill MTD_NAND_VERIFY_WRITE
[profile/ivi/kernel-adaptation-intel-automotive.git] / drivers / mtd / nand / nandsim.c
1 /*
2  * NAND flash simulator.
3  *
4  * Author: Artem B. Bityuckiy <dedekind@oktetlabs.ru>, <dedekind@infradead.org>
5  *
6  * Copyright (C) 2004 Nokia Corporation
7  *
8  * Note: NS means "NAND Simulator".
9  * Note: Input means input TO flash chip, output means output FROM chip.
10  *
11  * This program is free software; you can redistribute it and/or modify it
12  * under the terms of the GNU General Public License as published by the
13  * Free Software Foundation; either version 2, or (at your option) any later
14  * version.
15  *
16  * This program is distributed in the hope that it will be useful, but
17  * WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
19  * Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program; if not, write to the Free Software
23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA
24  */
25
26 #include <linux/init.h>
27 #include <linux/types.h>
28 #include <linux/module.h>
29 #include <linux/moduleparam.h>
30 #include <linux/vmalloc.h>
31 #include <linux/math64.h>
32 #include <linux/slab.h>
33 #include <linux/errno.h>
34 #include <linux/string.h>
35 #include <linux/mtd/mtd.h>
36 #include <linux/mtd/nand.h>
37 #include <linux/mtd/nand_bch.h>
38 #include <linux/mtd/partitions.h>
39 #include <linux/delay.h>
40 #include <linux/list.h>
41 #include <linux/random.h>
42 #include <linux/sched.h>
43 #include <linux/fs.h>
44 #include <linux/pagemap.h>
45
46 /* Default simulator parameters values */
47 #if !defined(CONFIG_NANDSIM_FIRST_ID_BYTE)  || \
48     !defined(CONFIG_NANDSIM_SECOND_ID_BYTE) || \
49     !defined(CONFIG_NANDSIM_THIRD_ID_BYTE)  || \
50     !defined(CONFIG_NANDSIM_FOURTH_ID_BYTE)
51 #define CONFIG_NANDSIM_FIRST_ID_BYTE  0x98
52 #define CONFIG_NANDSIM_SECOND_ID_BYTE 0x39
53 #define CONFIG_NANDSIM_THIRD_ID_BYTE  0xFF /* No byte */
54 #define CONFIG_NANDSIM_FOURTH_ID_BYTE 0xFF /* No byte */
55 #endif
56
57 #ifndef CONFIG_NANDSIM_ACCESS_DELAY
58 #define CONFIG_NANDSIM_ACCESS_DELAY 25
59 #endif
60 #ifndef CONFIG_NANDSIM_PROGRAMM_DELAY
61 #define CONFIG_NANDSIM_PROGRAMM_DELAY 200
62 #endif
63 #ifndef CONFIG_NANDSIM_ERASE_DELAY
64 #define CONFIG_NANDSIM_ERASE_DELAY 2
65 #endif
66 #ifndef CONFIG_NANDSIM_OUTPUT_CYCLE
67 #define CONFIG_NANDSIM_OUTPUT_CYCLE 40
68 #endif
69 #ifndef CONFIG_NANDSIM_INPUT_CYCLE
70 #define CONFIG_NANDSIM_INPUT_CYCLE  50
71 #endif
72 #ifndef CONFIG_NANDSIM_BUS_WIDTH
73 #define CONFIG_NANDSIM_BUS_WIDTH  8
74 #endif
75 #ifndef CONFIG_NANDSIM_DO_DELAYS
76 #define CONFIG_NANDSIM_DO_DELAYS  0
77 #endif
78 #ifndef CONFIG_NANDSIM_LOG
79 #define CONFIG_NANDSIM_LOG        0
80 #endif
81 #ifndef CONFIG_NANDSIM_DBG
82 #define CONFIG_NANDSIM_DBG        0
83 #endif
84 #ifndef CONFIG_NANDSIM_MAX_PARTS
85 #define CONFIG_NANDSIM_MAX_PARTS  32
86 #endif
87
88 static uint first_id_byte  = CONFIG_NANDSIM_FIRST_ID_BYTE;
89 static uint second_id_byte = CONFIG_NANDSIM_SECOND_ID_BYTE;
90 static uint third_id_byte  = CONFIG_NANDSIM_THIRD_ID_BYTE;
91 static uint fourth_id_byte = CONFIG_NANDSIM_FOURTH_ID_BYTE;
92 static uint access_delay   = CONFIG_NANDSIM_ACCESS_DELAY;
93 static uint programm_delay = CONFIG_NANDSIM_PROGRAMM_DELAY;
94 static uint erase_delay    = CONFIG_NANDSIM_ERASE_DELAY;
95 static uint output_cycle   = CONFIG_NANDSIM_OUTPUT_CYCLE;
96 static uint input_cycle    = CONFIG_NANDSIM_INPUT_CYCLE;
97 static uint bus_width      = CONFIG_NANDSIM_BUS_WIDTH;
98 static uint do_delays      = CONFIG_NANDSIM_DO_DELAYS;
99 static uint log            = CONFIG_NANDSIM_LOG;
100 static uint dbg            = CONFIG_NANDSIM_DBG;
101 static unsigned long parts[CONFIG_NANDSIM_MAX_PARTS];
102 static unsigned int parts_num;
103 static char *badblocks = NULL;
104 static char *weakblocks = NULL;
105 static char *weakpages = NULL;
106 static unsigned int bitflips = 0;
107 static char *gravepages = NULL;
108 static unsigned int rptwear = 0;
109 static unsigned int overridesize = 0;
110 static char *cache_file = NULL;
111 static unsigned int bbt;
112 static unsigned int bch;
113
114 module_param(first_id_byte,  uint, 0400);
115 module_param(second_id_byte, uint, 0400);
116 module_param(third_id_byte,  uint, 0400);
117 module_param(fourth_id_byte, uint, 0400);
118 module_param(access_delay,   uint, 0400);
119 module_param(programm_delay, uint, 0400);
120 module_param(erase_delay,    uint, 0400);
121 module_param(output_cycle,   uint, 0400);
122 module_param(input_cycle,    uint, 0400);
123 module_param(bus_width,      uint, 0400);
124 module_param(do_delays,      uint, 0400);
125 module_param(log,            uint, 0400);
126 module_param(dbg,            uint, 0400);
127 module_param_array(parts, ulong, &parts_num, 0400);
128 module_param(badblocks,      charp, 0400);
129 module_param(weakblocks,     charp, 0400);
130 module_param(weakpages,      charp, 0400);
131 module_param(bitflips,       uint, 0400);
132 module_param(gravepages,     charp, 0400);
133 module_param(rptwear,        uint, 0400);
134 module_param(overridesize,   uint, 0400);
135 module_param(cache_file,     charp, 0400);
136 module_param(bbt,            uint, 0400);
137 module_param(bch,            uint, 0400);
138
139 MODULE_PARM_DESC(first_id_byte,  "The first byte returned by NAND Flash 'read ID' command (manufacturer ID)");
140 MODULE_PARM_DESC(second_id_byte, "The second byte returned by NAND Flash 'read ID' command (chip ID)");
141 MODULE_PARM_DESC(third_id_byte,  "The third byte returned by NAND Flash 'read ID' command");
142 MODULE_PARM_DESC(fourth_id_byte, "The fourth byte returned by NAND Flash 'read ID' command");
143 MODULE_PARM_DESC(access_delay,   "Initial page access delay (microseconds)");
144 MODULE_PARM_DESC(programm_delay, "Page programm delay (microseconds");
145 MODULE_PARM_DESC(erase_delay,    "Sector erase delay (milliseconds)");
146 MODULE_PARM_DESC(output_cycle,   "Word output (from flash) time (nanoseconds)");
147 MODULE_PARM_DESC(input_cycle,    "Word input (to flash) time (nanoseconds)");
148 MODULE_PARM_DESC(bus_width,      "Chip's bus width (8- or 16-bit)");
149 MODULE_PARM_DESC(do_delays,      "Simulate NAND delays using busy-waits if not zero");
150 MODULE_PARM_DESC(log,            "Perform logging if not zero");
151 MODULE_PARM_DESC(dbg,            "Output debug information if not zero");
152 MODULE_PARM_DESC(parts,          "Partition sizes (in erase blocks) separated by commas");
153 /* Page and erase block positions for the following parameters are independent of any partitions */
154 MODULE_PARM_DESC(badblocks,      "Erase blocks that are initially marked bad, separated by commas");
155 MODULE_PARM_DESC(weakblocks,     "Weak erase blocks [: remaining erase cycles (defaults to 3)]"
156                                  " separated by commas e.g. 113:2 means eb 113"
157                                  " can be erased only twice before failing");
158 MODULE_PARM_DESC(weakpages,      "Weak pages [: maximum writes (defaults to 3)]"
159                                  " separated by commas e.g. 1401:2 means page 1401"
160                                  " can be written only twice before failing");
161 MODULE_PARM_DESC(bitflips,       "Maximum number of random bit flips per page (zero by default)");
162 MODULE_PARM_DESC(gravepages,     "Pages that lose data [: maximum reads (defaults to 3)]"
163                                  " separated by commas e.g. 1401:2 means page 1401"
164                                  " can be read only twice before failing");
165 MODULE_PARM_DESC(rptwear,        "Number of erases between reporting wear, if not zero");
166 MODULE_PARM_DESC(overridesize,   "Specifies the NAND Flash size overriding the ID bytes. "
167                                  "The size is specified in erase blocks and as the exponent of a power of two"
168                                  " e.g. 5 means a size of 32 erase blocks");
169 MODULE_PARM_DESC(cache_file,     "File to use to cache nand pages instead of memory");
170 MODULE_PARM_DESC(bbt,            "0 OOB, 1 BBT with marker in OOB, 2 BBT with marker in data area");
171 MODULE_PARM_DESC(bch,            "Enable BCH ecc and set how many bits should "
172                                  "be correctable in 512-byte blocks");
173
174 /* The largest possible page size */
175 #define NS_LARGEST_PAGE_SIZE    4096
176
177 /* The prefix for simulator output */
178 #define NS_OUTPUT_PREFIX "[nandsim]"
179
180 /* Simulator's output macros (logging, debugging, warning, error) */
181 #define NS_LOG(args...) \
182         do { if (log) printk(KERN_DEBUG NS_OUTPUT_PREFIX " log: " args); } while(0)
183 #define NS_DBG(args...) \
184         do { if (dbg) printk(KERN_DEBUG NS_OUTPUT_PREFIX " debug: " args); } while(0)
185 #define NS_WARN(args...) \
186         do { printk(KERN_WARNING NS_OUTPUT_PREFIX " warning: " args); } while(0)
187 #define NS_ERR(args...) \
188         do { printk(KERN_ERR NS_OUTPUT_PREFIX " error: " args); } while(0)
189 #define NS_INFO(args...) \
190         do { printk(KERN_INFO NS_OUTPUT_PREFIX " " args); } while(0)
191
192 /* Busy-wait delay macros (microseconds, milliseconds) */
193 #define NS_UDELAY(us) \
194         do { if (do_delays) udelay(us); } while(0)
195 #define NS_MDELAY(us) \
196         do { if (do_delays) mdelay(us); } while(0)
197
198 /* Is the nandsim structure initialized ? */
199 #define NS_IS_INITIALIZED(ns) ((ns)->geom.totsz != 0)
200
201 /* Good operation completion status */
202 #define NS_STATUS_OK(ns) (NAND_STATUS_READY | (NAND_STATUS_WP * ((ns)->lines.wp == 0)))
203
204 /* Operation failed completion status */
205 #define NS_STATUS_FAILED(ns) (NAND_STATUS_FAIL | NS_STATUS_OK(ns))
206
207 /* Calculate the page offset in flash RAM image by (row, column) address */
208 #define NS_RAW_OFFSET(ns) \
209         (((ns)->regs.row << (ns)->geom.pgshift) + ((ns)->regs.row * (ns)->geom.oobsz) + (ns)->regs.column)
210
211 /* Calculate the OOB offset in flash RAM image by (row, column) address */
212 #define NS_RAW_OFFSET_OOB(ns) (NS_RAW_OFFSET(ns) + ns->geom.pgsz)
213
214 /* After a command is input, the simulator goes to one of the following states */
215 #define STATE_CMD_READ0        0x00000001 /* read data from the beginning of page */
216 #define STATE_CMD_READ1        0x00000002 /* read data from the second half of page */
217 #define STATE_CMD_READSTART    0x00000003 /* read data second command (large page devices) */
218 #define STATE_CMD_PAGEPROG     0x00000004 /* start page program */
219 #define STATE_CMD_READOOB      0x00000005 /* read OOB area */
220 #define STATE_CMD_ERASE1       0x00000006 /* sector erase first command */
221 #define STATE_CMD_STATUS       0x00000007 /* read status */
222 #define STATE_CMD_STATUS_M     0x00000008 /* read multi-plane status (isn't implemented) */
223 #define STATE_CMD_SEQIN        0x00000009 /* sequential data input */
224 #define STATE_CMD_READID       0x0000000A /* read ID */
225 #define STATE_CMD_ERASE2       0x0000000B /* sector erase second command */
226 #define STATE_CMD_RESET        0x0000000C /* reset */
227 #define STATE_CMD_RNDOUT       0x0000000D /* random output command */
228 #define STATE_CMD_RNDOUTSTART  0x0000000E /* random output start command */
229 #define STATE_CMD_MASK         0x0000000F /* command states mask */
230
231 /* After an address is input, the simulator goes to one of these states */
232 #define STATE_ADDR_PAGE        0x00000010 /* full (row, column) address is accepted */
233 #define STATE_ADDR_SEC         0x00000020 /* sector address was accepted */
234 #define STATE_ADDR_COLUMN      0x00000030 /* column address was accepted */
235 #define STATE_ADDR_ZERO        0x00000040 /* one byte zero address was accepted */
236 #define STATE_ADDR_MASK        0x00000070 /* address states mask */
237
238 /* During data input/output the simulator is in these states */
239 #define STATE_DATAIN           0x00000100 /* waiting for data input */
240 #define STATE_DATAIN_MASK      0x00000100 /* data input states mask */
241
242 #define STATE_DATAOUT          0x00001000 /* waiting for page data output */
243 #define STATE_DATAOUT_ID       0x00002000 /* waiting for ID bytes output */
244 #define STATE_DATAOUT_STATUS   0x00003000 /* waiting for status output */
245 #define STATE_DATAOUT_STATUS_M 0x00004000 /* waiting for multi-plane status output */
246 #define STATE_DATAOUT_MASK     0x00007000 /* data output states mask */
247
248 /* Previous operation is done, ready to accept new requests */
249 #define STATE_READY            0x00000000
250
251 /* This state is used to mark that the next state isn't known yet */
252 #define STATE_UNKNOWN          0x10000000
253
254 /* Simulator's actions bit masks */
255 #define ACTION_CPY       0x00100000 /* copy page/OOB to the internal buffer */
256 #define ACTION_PRGPAGE   0x00200000 /* program the internal buffer to flash */
257 #define ACTION_SECERASE  0x00300000 /* erase sector */
258 #define ACTION_ZEROOFF   0x00400000 /* don't add any offset to address */
259 #define ACTION_HALFOFF   0x00500000 /* add to address half of page */
260 #define ACTION_OOBOFF    0x00600000 /* add to address OOB offset */
261 #define ACTION_MASK      0x00700000 /* action mask */
262
263 #define NS_OPER_NUM      13 /* Number of operations supported by the simulator */
264 #define NS_OPER_STATES   6  /* Maximum number of states in operation */
265
266 #define OPT_ANY          0xFFFFFFFF /* any chip supports this operation */
267 #define OPT_PAGE256      0x00000001 /* 256-byte  page chips */
268 #define OPT_PAGE512      0x00000002 /* 512-byte  page chips */
269 #define OPT_PAGE2048     0x00000008 /* 2048-byte page chips */
270 #define OPT_SMARTMEDIA   0x00000010 /* SmartMedia technology chips */
271 #define OPT_PAGE512_8BIT 0x00000040 /* 512-byte page chips with 8-bit bus width */
272 #define OPT_PAGE4096     0x00000080 /* 4096-byte page chips */
273 #define OPT_LARGEPAGE    (OPT_PAGE2048 | OPT_PAGE4096) /* 2048 & 4096-byte page chips */
274 #define OPT_SMALLPAGE    (OPT_PAGE256  | OPT_PAGE512)  /* 256 and 512-byte page chips */
275
276 /* Remove action bits from state */
277 #define NS_STATE(x) ((x) & ~ACTION_MASK)
278
279 /*
280  * Maximum previous states which need to be saved. Currently saving is
281  * only needed for page program operation with preceded read command
282  * (which is only valid for 512-byte pages).
283  */
284 #define NS_MAX_PREVSTATES 1
285
286 /* Maximum page cache pages needed to read or write a NAND page to the cache_file */
287 #define NS_MAX_HELD_PAGES 16
288
289 /*
290  * A union to represent flash memory contents and flash buffer.
291  */
292 union ns_mem {
293         u_char *byte;    /* for byte access */
294         uint16_t *word;  /* for 16-bit word access */
295 };
296
297 /*
298  * The structure which describes all the internal simulator data.
299  */
300 struct nandsim {
301         struct mtd_partition partitions[CONFIG_NANDSIM_MAX_PARTS];
302         unsigned int nbparts;
303
304         uint busw;              /* flash chip bus width (8 or 16) */
305         u_char ids[4];          /* chip's ID bytes */
306         uint32_t options;       /* chip's characteristic bits */
307         uint32_t state;         /* current chip state */
308         uint32_t nxstate;       /* next expected state */
309
310         uint32_t *op;           /* current operation, NULL operations isn't known yet  */
311         uint32_t pstates[NS_MAX_PREVSTATES]; /* previous states */
312         uint16_t npstates;      /* number of previous states saved */
313         uint16_t stateidx;      /* current state index */
314
315         /* The simulated NAND flash pages array */
316         union ns_mem *pages;
317
318         /* Slab allocator for nand pages */
319         struct kmem_cache *nand_pages_slab;
320
321         /* Internal buffer of page + OOB size bytes */
322         union ns_mem buf;
323
324         /* NAND flash "geometry" */
325         struct {
326                 uint64_t totsz;     /* total flash size, bytes */
327                 uint32_t secsz;     /* flash sector (erase block) size, bytes */
328                 uint pgsz;          /* NAND flash page size, bytes */
329                 uint oobsz;         /* page OOB area size, bytes */
330                 uint64_t totszoob;  /* total flash size including OOB, bytes */
331                 uint pgszoob;       /* page size including OOB , bytes*/
332                 uint secszoob;      /* sector size including OOB, bytes */
333                 uint pgnum;         /* total number of pages */
334                 uint pgsec;         /* number of pages per sector */
335                 uint secshift;      /* bits number in sector size */
336                 uint pgshift;       /* bits number in page size */
337                 uint oobshift;      /* bits number in OOB size */
338                 uint pgaddrbytes;   /* bytes per page address */
339                 uint secaddrbytes;  /* bytes per sector address */
340                 uint idbytes;       /* the number ID bytes that this chip outputs */
341         } geom;
342
343         /* NAND flash internal registers */
344         struct {
345                 unsigned command; /* the command register */
346                 u_char   status;  /* the status register */
347                 uint     row;     /* the page number */
348                 uint     column;  /* the offset within page */
349                 uint     count;   /* internal counter */
350                 uint     num;     /* number of bytes which must be processed */
351                 uint     off;     /* fixed page offset */
352         } regs;
353
354         /* NAND flash lines state */
355         struct {
356                 int ce;  /* chip Enable */
357                 int cle; /* command Latch Enable */
358                 int ale; /* address Latch Enable */
359                 int wp;  /* write Protect */
360         } lines;
361
362         /* Fields needed when using a cache file */
363         struct file *cfile; /* Open file */
364         unsigned char *pages_written; /* Which pages have been written */
365         void *file_buf;
366         struct page *held_pages[NS_MAX_HELD_PAGES];
367         int held_cnt;
368 };
369
370 /*
371  * Operations array. To perform any operation the simulator must pass
372  * through the correspondent states chain.
373  */
374 static struct nandsim_operations {
375         uint32_t reqopts;  /* options which are required to perform the operation */
376         uint32_t states[NS_OPER_STATES]; /* operation's states */
377 } ops[NS_OPER_NUM] = {
378         /* Read page + OOB from the beginning */
379         {OPT_SMALLPAGE, {STATE_CMD_READ0 | ACTION_ZEROOFF, STATE_ADDR_PAGE | ACTION_CPY,
380                         STATE_DATAOUT, STATE_READY}},
381         /* Read page + OOB from the second half */
382         {OPT_PAGE512_8BIT, {STATE_CMD_READ1 | ACTION_HALFOFF, STATE_ADDR_PAGE | ACTION_CPY,
383                         STATE_DATAOUT, STATE_READY}},
384         /* Read OOB */
385         {OPT_SMALLPAGE, {STATE_CMD_READOOB | ACTION_OOBOFF, STATE_ADDR_PAGE | ACTION_CPY,
386                         STATE_DATAOUT, STATE_READY}},
387         /* Program page starting from the beginning */
388         {OPT_ANY, {STATE_CMD_SEQIN, STATE_ADDR_PAGE, STATE_DATAIN,
389                         STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
390         /* Program page starting from the beginning */
391         {OPT_SMALLPAGE, {STATE_CMD_READ0, STATE_CMD_SEQIN | ACTION_ZEROOFF, STATE_ADDR_PAGE,
392                               STATE_DATAIN, STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
393         /* Program page starting from the second half */
394         {OPT_PAGE512, {STATE_CMD_READ1, STATE_CMD_SEQIN | ACTION_HALFOFF, STATE_ADDR_PAGE,
395                               STATE_DATAIN, STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
396         /* Program OOB */
397         {OPT_SMALLPAGE, {STATE_CMD_READOOB, STATE_CMD_SEQIN | ACTION_OOBOFF, STATE_ADDR_PAGE,
398                               STATE_DATAIN, STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
399         /* Erase sector */
400         {OPT_ANY, {STATE_CMD_ERASE1, STATE_ADDR_SEC, STATE_CMD_ERASE2 | ACTION_SECERASE, STATE_READY}},
401         /* Read status */
402         {OPT_ANY, {STATE_CMD_STATUS, STATE_DATAOUT_STATUS, STATE_READY}},
403         /* Read multi-plane status */
404         {OPT_SMARTMEDIA, {STATE_CMD_STATUS_M, STATE_DATAOUT_STATUS_M, STATE_READY}},
405         /* Read ID */
406         {OPT_ANY, {STATE_CMD_READID, STATE_ADDR_ZERO, STATE_DATAOUT_ID, STATE_READY}},
407         /* Large page devices read page */
408         {OPT_LARGEPAGE, {STATE_CMD_READ0, STATE_ADDR_PAGE, STATE_CMD_READSTART | ACTION_CPY,
409                                STATE_DATAOUT, STATE_READY}},
410         /* Large page devices random page read */
411         {OPT_LARGEPAGE, {STATE_CMD_RNDOUT, STATE_ADDR_COLUMN, STATE_CMD_RNDOUTSTART | ACTION_CPY,
412                                STATE_DATAOUT, STATE_READY}},
413 };
414
415 struct weak_block {
416         struct list_head list;
417         unsigned int erase_block_no;
418         unsigned int max_erases;
419         unsigned int erases_done;
420 };
421
422 static LIST_HEAD(weak_blocks);
423
424 struct weak_page {
425         struct list_head list;
426         unsigned int page_no;
427         unsigned int max_writes;
428         unsigned int writes_done;
429 };
430
431 static LIST_HEAD(weak_pages);
432
433 struct grave_page {
434         struct list_head list;
435         unsigned int page_no;
436         unsigned int max_reads;
437         unsigned int reads_done;
438 };
439
440 static LIST_HEAD(grave_pages);
441
442 static unsigned long *erase_block_wear = NULL;
443 static unsigned int wear_eb_count = 0;
444 static unsigned long total_wear = 0;
445 static unsigned int rptwear_cnt = 0;
446
447 /* MTD structure for NAND controller */
448 static struct mtd_info *nsmtd;
449
450 /*
451  * Allocate array of page pointers, create slab allocation for an array
452  * and initialize the array by NULL pointers.
453  *
454  * RETURNS: 0 if success, -ENOMEM if memory alloc fails.
455  */
456 static int alloc_device(struct nandsim *ns)
457 {
458         struct file *cfile;
459         int i, err;
460
461         if (cache_file) {
462                 cfile = filp_open(cache_file, O_CREAT | O_RDWR | O_LARGEFILE, 0600);
463                 if (IS_ERR(cfile))
464                         return PTR_ERR(cfile);
465                 if (!cfile->f_op || (!cfile->f_op->read && !cfile->f_op->aio_read)) {
466                         NS_ERR("alloc_device: cache file not readable\n");
467                         err = -EINVAL;
468                         goto err_close;
469                 }
470                 if (!cfile->f_op->write && !cfile->f_op->aio_write) {
471                         NS_ERR("alloc_device: cache file not writeable\n");
472                         err = -EINVAL;
473                         goto err_close;
474                 }
475                 ns->pages_written = vzalloc(ns->geom.pgnum);
476                 if (!ns->pages_written) {
477                         NS_ERR("alloc_device: unable to allocate pages written array\n");
478                         err = -ENOMEM;
479                         goto err_close;
480                 }
481                 ns->file_buf = kmalloc(ns->geom.pgszoob, GFP_KERNEL);
482                 if (!ns->file_buf) {
483                         NS_ERR("alloc_device: unable to allocate file buf\n");
484                         err = -ENOMEM;
485                         goto err_free;
486                 }
487                 ns->cfile = cfile;
488                 return 0;
489         }
490
491         ns->pages = vmalloc(ns->geom.pgnum * sizeof(union ns_mem));
492         if (!ns->pages) {
493                 NS_ERR("alloc_device: unable to allocate page array\n");
494                 return -ENOMEM;
495         }
496         for (i = 0; i < ns->geom.pgnum; i++) {
497                 ns->pages[i].byte = NULL;
498         }
499         ns->nand_pages_slab = kmem_cache_create("nandsim",
500                                                 ns->geom.pgszoob, 0, 0, NULL);
501         if (!ns->nand_pages_slab) {
502                 NS_ERR("cache_create: unable to create kmem_cache\n");
503                 return -ENOMEM;
504         }
505
506         return 0;
507
508 err_free:
509         vfree(ns->pages_written);
510 err_close:
511         filp_close(cfile, NULL);
512         return err;
513 }
514
515 /*
516  * Free any allocated pages, and free the array of page pointers.
517  */
518 static void free_device(struct nandsim *ns)
519 {
520         int i;
521
522         if (ns->cfile) {
523                 kfree(ns->file_buf);
524                 vfree(ns->pages_written);
525                 filp_close(ns->cfile, NULL);
526                 return;
527         }
528
529         if (ns->pages) {
530                 for (i = 0; i < ns->geom.pgnum; i++) {
531                         if (ns->pages[i].byte)
532                                 kmem_cache_free(ns->nand_pages_slab,
533                                                 ns->pages[i].byte);
534                 }
535                 kmem_cache_destroy(ns->nand_pages_slab);
536                 vfree(ns->pages);
537         }
538 }
539
540 static char *get_partition_name(int i)
541 {
542         char buf[64];
543         sprintf(buf, "NAND simulator partition %d", i);
544         return kstrdup(buf, GFP_KERNEL);
545 }
546
547 /*
548  * Initialize the nandsim structure.
549  *
550  * RETURNS: 0 if success, -ERRNO if failure.
551  */
552 static int init_nandsim(struct mtd_info *mtd)
553 {
554         struct nand_chip *chip = mtd->priv;
555         struct nandsim   *ns   = chip->priv;
556         int i, ret = 0;
557         uint64_t remains;
558         uint64_t next_offset;
559
560         if (NS_IS_INITIALIZED(ns)) {
561                 NS_ERR("init_nandsim: nandsim is already initialized\n");
562                 return -EIO;
563         }
564
565         /* Force mtd to not do delays */
566         chip->chip_delay = 0;
567
568         /* Initialize the NAND flash parameters */
569         ns->busw = chip->options & NAND_BUSWIDTH_16 ? 16 : 8;
570         ns->geom.totsz    = mtd->size;
571         ns->geom.pgsz     = mtd->writesize;
572         ns->geom.oobsz    = mtd->oobsize;
573         ns->geom.secsz    = mtd->erasesize;
574         ns->geom.pgszoob  = ns->geom.pgsz + ns->geom.oobsz;
575         ns->geom.pgnum    = div_u64(ns->geom.totsz, ns->geom.pgsz);
576         ns->geom.totszoob = ns->geom.totsz + (uint64_t)ns->geom.pgnum * ns->geom.oobsz;
577         ns->geom.secshift = ffs(ns->geom.secsz) - 1;
578         ns->geom.pgshift  = chip->page_shift;
579         ns->geom.oobshift = ffs(ns->geom.oobsz) - 1;
580         ns->geom.pgsec    = ns->geom.secsz / ns->geom.pgsz;
581         ns->geom.secszoob = ns->geom.secsz + ns->geom.oobsz * ns->geom.pgsec;
582         ns->options = 0;
583
584         if (ns->geom.pgsz == 256) {
585                 ns->options |= OPT_PAGE256;
586         }
587         else if (ns->geom.pgsz == 512) {
588                 ns->options |= OPT_PAGE512;
589                 if (ns->busw == 8)
590                         ns->options |= OPT_PAGE512_8BIT;
591         } else if (ns->geom.pgsz == 2048) {
592                 ns->options |= OPT_PAGE2048;
593         } else if (ns->geom.pgsz == 4096) {
594                 ns->options |= OPT_PAGE4096;
595         } else {
596                 NS_ERR("init_nandsim: unknown page size %u\n", ns->geom.pgsz);
597                 return -EIO;
598         }
599
600         if (ns->options & OPT_SMALLPAGE) {
601                 if (ns->geom.totsz <= (32 << 20)) {
602                         ns->geom.pgaddrbytes  = 3;
603                         ns->geom.secaddrbytes = 2;
604                 } else {
605                         ns->geom.pgaddrbytes  = 4;
606                         ns->geom.secaddrbytes = 3;
607                 }
608         } else {
609                 if (ns->geom.totsz <= (128 << 20)) {
610                         ns->geom.pgaddrbytes  = 4;
611                         ns->geom.secaddrbytes = 2;
612                 } else {
613                         ns->geom.pgaddrbytes  = 5;
614                         ns->geom.secaddrbytes = 3;
615                 }
616         }
617
618         /* Fill the partition_info structure */
619         if (parts_num > ARRAY_SIZE(ns->partitions)) {
620                 NS_ERR("too many partitions.\n");
621                 ret = -EINVAL;
622                 goto error;
623         }
624         remains = ns->geom.totsz;
625         next_offset = 0;
626         for (i = 0; i < parts_num; ++i) {
627                 uint64_t part_sz = (uint64_t)parts[i] * ns->geom.secsz;
628
629                 if (!part_sz || part_sz > remains) {
630                         NS_ERR("bad partition size.\n");
631                         ret = -EINVAL;
632                         goto error;
633                 }
634                 ns->partitions[i].name   = get_partition_name(i);
635                 ns->partitions[i].offset = next_offset;
636                 ns->partitions[i].size   = part_sz;
637                 next_offset += ns->partitions[i].size;
638                 remains -= ns->partitions[i].size;
639         }
640         ns->nbparts = parts_num;
641         if (remains) {
642                 if (parts_num + 1 > ARRAY_SIZE(ns->partitions)) {
643                         NS_ERR("too many partitions.\n");
644                         ret = -EINVAL;
645                         goto error;
646                 }
647                 ns->partitions[i].name   = get_partition_name(i);
648                 ns->partitions[i].offset = next_offset;
649                 ns->partitions[i].size   = remains;
650                 ns->nbparts += 1;
651         }
652
653         /* Detect how many ID bytes the NAND chip outputs */
654         for (i = 0; nand_flash_ids[i].name != NULL; i++) {
655                 if (second_id_byte != nand_flash_ids[i].id)
656                         continue;
657         }
658
659         if (ns->busw == 16)
660                 NS_WARN("16-bit flashes support wasn't tested\n");
661
662         printk("flash size: %llu MiB\n",
663                         (unsigned long long)ns->geom.totsz >> 20);
664         printk("page size: %u bytes\n",         ns->geom.pgsz);
665         printk("OOB area size: %u bytes\n",     ns->geom.oobsz);
666         printk("sector size: %u KiB\n",         ns->geom.secsz >> 10);
667         printk("pages number: %u\n",            ns->geom.pgnum);
668         printk("pages per sector: %u\n",        ns->geom.pgsec);
669         printk("bus width: %u\n",               ns->busw);
670         printk("bits in sector size: %u\n",     ns->geom.secshift);
671         printk("bits in page size: %u\n",       ns->geom.pgshift);
672         printk("bits in OOB size: %u\n",        ns->geom.oobshift);
673         printk("flash size with OOB: %llu KiB\n",
674                         (unsigned long long)ns->geom.totszoob >> 10);
675         printk("page address bytes: %u\n",      ns->geom.pgaddrbytes);
676         printk("sector address bytes: %u\n",    ns->geom.secaddrbytes);
677         printk("options: %#x\n",                ns->options);
678
679         if ((ret = alloc_device(ns)) != 0)
680                 goto error;
681
682         /* Allocate / initialize the internal buffer */
683         ns->buf.byte = kmalloc(ns->geom.pgszoob, GFP_KERNEL);
684         if (!ns->buf.byte) {
685                 NS_ERR("init_nandsim: unable to allocate %u bytes for the internal buffer\n",
686                         ns->geom.pgszoob);
687                 ret = -ENOMEM;
688                 goto error;
689         }
690         memset(ns->buf.byte, 0xFF, ns->geom.pgszoob);
691
692         return 0;
693
694 error:
695         free_device(ns);
696
697         return ret;
698 }
699
700 /*
701  * Free the nandsim structure.
702  */
703 static void free_nandsim(struct nandsim *ns)
704 {
705         kfree(ns->buf.byte);
706         free_device(ns);
707
708         return;
709 }
710
711 static int parse_badblocks(struct nandsim *ns, struct mtd_info *mtd)
712 {
713         char *w;
714         int zero_ok;
715         unsigned int erase_block_no;
716         loff_t offset;
717
718         if (!badblocks)
719                 return 0;
720         w = badblocks;
721         do {
722                 zero_ok = (*w == '0' ? 1 : 0);
723                 erase_block_no = simple_strtoul(w, &w, 0);
724                 if (!zero_ok && !erase_block_no) {
725                         NS_ERR("invalid badblocks.\n");
726                         return -EINVAL;
727                 }
728                 offset = erase_block_no * ns->geom.secsz;
729                 if (mtd_block_markbad(mtd, offset)) {
730                         NS_ERR("invalid badblocks.\n");
731                         return -EINVAL;
732                 }
733                 if (*w == ',')
734                         w += 1;
735         } while (*w);
736         return 0;
737 }
738
739 static int parse_weakblocks(void)
740 {
741         char *w;
742         int zero_ok;
743         unsigned int erase_block_no;
744         unsigned int max_erases;
745         struct weak_block *wb;
746
747         if (!weakblocks)
748                 return 0;
749         w = weakblocks;
750         do {
751                 zero_ok = (*w == '0' ? 1 : 0);
752                 erase_block_no = simple_strtoul(w, &w, 0);
753                 if (!zero_ok && !erase_block_no) {
754                         NS_ERR("invalid weakblocks.\n");
755                         return -EINVAL;
756                 }
757                 max_erases = 3;
758                 if (*w == ':') {
759                         w += 1;
760                         max_erases = simple_strtoul(w, &w, 0);
761                 }
762                 if (*w == ',')
763                         w += 1;
764                 wb = kzalloc(sizeof(*wb), GFP_KERNEL);
765                 if (!wb) {
766                         NS_ERR("unable to allocate memory.\n");
767                         return -ENOMEM;
768                 }
769                 wb->erase_block_no = erase_block_no;
770                 wb->max_erases = max_erases;
771                 list_add(&wb->list, &weak_blocks);
772         } while (*w);
773         return 0;
774 }
775
776 static int erase_error(unsigned int erase_block_no)
777 {
778         struct weak_block *wb;
779
780         list_for_each_entry(wb, &weak_blocks, list)
781                 if (wb->erase_block_no == erase_block_no) {
782                         if (wb->erases_done >= wb->max_erases)
783                                 return 1;
784                         wb->erases_done += 1;
785                         return 0;
786                 }
787         return 0;
788 }
789
790 static int parse_weakpages(void)
791 {
792         char *w;
793         int zero_ok;
794         unsigned int page_no;
795         unsigned int max_writes;
796         struct weak_page *wp;
797
798         if (!weakpages)
799                 return 0;
800         w = weakpages;
801         do {
802                 zero_ok = (*w == '0' ? 1 : 0);
803                 page_no = simple_strtoul(w, &w, 0);
804                 if (!zero_ok && !page_no) {
805                         NS_ERR("invalid weakpagess.\n");
806                         return -EINVAL;
807                 }
808                 max_writes = 3;
809                 if (*w == ':') {
810                         w += 1;
811                         max_writes = simple_strtoul(w, &w, 0);
812                 }
813                 if (*w == ',')
814                         w += 1;
815                 wp = kzalloc(sizeof(*wp), GFP_KERNEL);
816                 if (!wp) {
817                         NS_ERR("unable to allocate memory.\n");
818                         return -ENOMEM;
819                 }
820                 wp->page_no = page_no;
821                 wp->max_writes = max_writes;
822                 list_add(&wp->list, &weak_pages);
823         } while (*w);
824         return 0;
825 }
826
827 static int write_error(unsigned int page_no)
828 {
829         struct weak_page *wp;
830
831         list_for_each_entry(wp, &weak_pages, list)
832                 if (wp->page_no == page_no) {
833                         if (wp->writes_done >= wp->max_writes)
834                                 return 1;
835                         wp->writes_done += 1;
836                         return 0;
837                 }
838         return 0;
839 }
840
841 static int parse_gravepages(void)
842 {
843         char *g;
844         int zero_ok;
845         unsigned int page_no;
846         unsigned int max_reads;
847         struct grave_page *gp;
848
849         if (!gravepages)
850                 return 0;
851         g = gravepages;
852         do {
853                 zero_ok = (*g == '0' ? 1 : 0);
854                 page_no = simple_strtoul(g, &g, 0);
855                 if (!zero_ok && !page_no) {
856                         NS_ERR("invalid gravepagess.\n");
857                         return -EINVAL;
858                 }
859                 max_reads = 3;
860                 if (*g == ':') {
861                         g += 1;
862                         max_reads = simple_strtoul(g, &g, 0);
863                 }
864                 if (*g == ',')
865                         g += 1;
866                 gp = kzalloc(sizeof(*gp), GFP_KERNEL);
867                 if (!gp) {
868                         NS_ERR("unable to allocate memory.\n");
869                         return -ENOMEM;
870                 }
871                 gp->page_no = page_no;
872                 gp->max_reads = max_reads;
873                 list_add(&gp->list, &grave_pages);
874         } while (*g);
875         return 0;
876 }
877
878 static int read_error(unsigned int page_no)
879 {
880         struct grave_page *gp;
881
882         list_for_each_entry(gp, &grave_pages, list)
883                 if (gp->page_no == page_no) {
884                         if (gp->reads_done >= gp->max_reads)
885                                 return 1;
886                         gp->reads_done += 1;
887                         return 0;
888                 }
889         return 0;
890 }
891
892 static void free_lists(void)
893 {
894         struct list_head *pos, *n;
895         list_for_each_safe(pos, n, &weak_blocks) {
896                 list_del(pos);
897                 kfree(list_entry(pos, struct weak_block, list));
898         }
899         list_for_each_safe(pos, n, &weak_pages) {
900                 list_del(pos);
901                 kfree(list_entry(pos, struct weak_page, list));
902         }
903         list_for_each_safe(pos, n, &grave_pages) {
904                 list_del(pos);
905                 kfree(list_entry(pos, struct grave_page, list));
906         }
907         kfree(erase_block_wear);
908 }
909
910 static int setup_wear_reporting(struct mtd_info *mtd)
911 {
912         size_t mem;
913
914         if (!rptwear)
915                 return 0;
916         wear_eb_count = div_u64(mtd->size, mtd->erasesize);
917         mem = wear_eb_count * sizeof(unsigned long);
918         if (mem / sizeof(unsigned long) != wear_eb_count) {
919                 NS_ERR("Too many erase blocks for wear reporting\n");
920                 return -ENOMEM;
921         }
922         erase_block_wear = kzalloc(mem, GFP_KERNEL);
923         if (!erase_block_wear) {
924                 NS_ERR("Too many erase blocks for wear reporting\n");
925                 return -ENOMEM;
926         }
927         return 0;
928 }
929
930 static void update_wear(unsigned int erase_block_no)
931 {
932         unsigned long wmin = -1, wmax = 0, avg;
933         unsigned long deciles[10], decile_max[10], tot = 0;
934         unsigned int i;
935
936         if (!erase_block_wear)
937                 return;
938         total_wear += 1;
939         if (total_wear == 0)
940                 NS_ERR("Erase counter total overflow\n");
941         erase_block_wear[erase_block_no] += 1;
942         if (erase_block_wear[erase_block_no] == 0)
943                 NS_ERR("Erase counter overflow for erase block %u\n", erase_block_no);
944         rptwear_cnt += 1;
945         if (rptwear_cnt < rptwear)
946                 return;
947         rptwear_cnt = 0;
948         /* Calc wear stats */
949         for (i = 0; i < wear_eb_count; ++i) {
950                 unsigned long wear = erase_block_wear[i];
951                 if (wear < wmin)
952                         wmin = wear;
953                 if (wear > wmax)
954                         wmax = wear;
955                 tot += wear;
956         }
957         for (i = 0; i < 9; ++i) {
958                 deciles[i] = 0;
959                 decile_max[i] = (wmax * (i + 1) + 5) / 10;
960         }
961         deciles[9] = 0;
962         decile_max[9] = wmax;
963         for (i = 0; i < wear_eb_count; ++i) {
964                 int d;
965                 unsigned long wear = erase_block_wear[i];
966                 for (d = 0; d < 10; ++d)
967                         if (wear <= decile_max[d]) {
968                                 deciles[d] += 1;
969                                 break;
970                         }
971         }
972         avg = tot / wear_eb_count;
973         /* Output wear report */
974         NS_INFO("*** Wear Report ***\n");
975         NS_INFO("Total numbers of erases:  %lu\n", tot);
976         NS_INFO("Number of erase blocks:   %u\n", wear_eb_count);
977         NS_INFO("Average number of erases: %lu\n", avg);
978         NS_INFO("Maximum number of erases: %lu\n", wmax);
979         NS_INFO("Minimum number of erases: %lu\n", wmin);
980         for (i = 0; i < 10; ++i) {
981                 unsigned long from = (i ? decile_max[i - 1] + 1 : 0);
982                 if (from > decile_max[i])
983                         continue;
984                 NS_INFO("Number of ebs with erase counts from %lu to %lu : %lu\n",
985                         from,
986                         decile_max[i],
987                         deciles[i]);
988         }
989         NS_INFO("*** End of Wear Report ***\n");
990 }
991
992 /*
993  * Returns the string representation of 'state' state.
994  */
995 static char *get_state_name(uint32_t state)
996 {
997         switch (NS_STATE(state)) {
998                 case STATE_CMD_READ0:
999                         return "STATE_CMD_READ0";
1000                 case STATE_CMD_READ1:
1001                         return "STATE_CMD_READ1";
1002                 case STATE_CMD_PAGEPROG:
1003                         return "STATE_CMD_PAGEPROG";
1004                 case STATE_CMD_READOOB:
1005                         return "STATE_CMD_READOOB";
1006                 case STATE_CMD_READSTART:
1007                         return "STATE_CMD_READSTART";
1008                 case STATE_CMD_ERASE1:
1009                         return "STATE_CMD_ERASE1";
1010                 case STATE_CMD_STATUS:
1011                         return "STATE_CMD_STATUS";
1012                 case STATE_CMD_STATUS_M:
1013                         return "STATE_CMD_STATUS_M";
1014                 case STATE_CMD_SEQIN:
1015                         return "STATE_CMD_SEQIN";
1016                 case STATE_CMD_READID:
1017                         return "STATE_CMD_READID";
1018                 case STATE_CMD_ERASE2:
1019                         return "STATE_CMD_ERASE2";
1020                 case STATE_CMD_RESET:
1021                         return "STATE_CMD_RESET";
1022                 case STATE_CMD_RNDOUT:
1023                         return "STATE_CMD_RNDOUT";
1024                 case STATE_CMD_RNDOUTSTART:
1025                         return "STATE_CMD_RNDOUTSTART";
1026                 case STATE_ADDR_PAGE:
1027                         return "STATE_ADDR_PAGE";
1028                 case STATE_ADDR_SEC:
1029                         return "STATE_ADDR_SEC";
1030                 case STATE_ADDR_ZERO:
1031                         return "STATE_ADDR_ZERO";
1032                 case STATE_ADDR_COLUMN:
1033                         return "STATE_ADDR_COLUMN";
1034                 case STATE_DATAIN:
1035                         return "STATE_DATAIN";
1036                 case STATE_DATAOUT:
1037                         return "STATE_DATAOUT";
1038                 case STATE_DATAOUT_ID:
1039                         return "STATE_DATAOUT_ID";
1040                 case STATE_DATAOUT_STATUS:
1041                         return "STATE_DATAOUT_STATUS";
1042                 case STATE_DATAOUT_STATUS_M:
1043                         return "STATE_DATAOUT_STATUS_M";
1044                 case STATE_READY:
1045                         return "STATE_READY";
1046                 case STATE_UNKNOWN:
1047                         return "STATE_UNKNOWN";
1048         }
1049
1050         NS_ERR("get_state_name: unknown state, BUG\n");
1051         return NULL;
1052 }
1053
1054 /*
1055  * Check if command is valid.
1056  *
1057  * RETURNS: 1 if wrong command, 0 if right.
1058  */
1059 static int check_command(int cmd)
1060 {
1061         switch (cmd) {
1062
1063         case NAND_CMD_READ0:
1064         case NAND_CMD_READ1:
1065         case NAND_CMD_READSTART:
1066         case NAND_CMD_PAGEPROG:
1067         case NAND_CMD_READOOB:
1068         case NAND_CMD_ERASE1:
1069         case NAND_CMD_STATUS:
1070         case NAND_CMD_SEQIN:
1071         case NAND_CMD_READID:
1072         case NAND_CMD_ERASE2:
1073         case NAND_CMD_RESET:
1074         case NAND_CMD_RNDOUT:
1075         case NAND_CMD_RNDOUTSTART:
1076                 return 0;
1077
1078         case NAND_CMD_STATUS_MULTI:
1079         default:
1080                 return 1;
1081         }
1082 }
1083
1084 /*
1085  * Returns state after command is accepted by command number.
1086  */
1087 static uint32_t get_state_by_command(unsigned command)
1088 {
1089         switch (command) {
1090                 case NAND_CMD_READ0:
1091                         return STATE_CMD_READ0;
1092                 case NAND_CMD_READ1:
1093                         return STATE_CMD_READ1;
1094                 case NAND_CMD_PAGEPROG:
1095                         return STATE_CMD_PAGEPROG;
1096                 case NAND_CMD_READSTART:
1097                         return STATE_CMD_READSTART;
1098                 case NAND_CMD_READOOB:
1099                         return STATE_CMD_READOOB;
1100                 case NAND_CMD_ERASE1:
1101                         return STATE_CMD_ERASE1;
1102                 case NAND_CMD_STATUS:
1103                         return STATE_CMD_STATUS;
1104                 case NAND_CMD_STATUS_MULTI:
1105                         return STATE_CMD_STATUS_M;
1106                 case NAND_CMD_SEQIN:
1107                         return STATE_CMD_SEQIN;
1108                 case NAND_CMD_READID:
1109                         return STATE_CMD_READID;
1110                 case NAND_CMD_ERASE2:
1111                         return STATE_CMD_ERASE2;
1112                 case NAND_CMD_RESET:
1113                         return STATE_CMD_RESET;
1114                 case NAND_CMD_RNDOUT:
1115                         return STATE_CMD_RNDOUT;
1116                 case NAND_CMD_RNDOUTSTART:
1117                         return STATE_CMD_RNDOUTSTART;
1118         }
1119
1120         NS_ERR("get_state_by_command: unknown command, BUG\n");
1121         return 0;
1122 }
1123
1124 /*
1125  * Move an address byte to the correspondent internal register.
1126  */
1127 static inline void accept_addr_byte(struct nandsim *ns, u_char bt)
1128 {
1129         uint byte = (uint)bt;
1130
1131         if (ns->regs.count < (ns->geom.pgaddrbytes - ns->geom.secaddrbytes))
1132                 ns->regs.column |= (byte << 8 * ns->regs.count);
1133         else {
1134                 ns->regs.row |= (byte << 8 * (ns->regs.count -
1135                                                 ns->geom.pgaddrbytes +
1136                                                 ns->geom.secaddrbytes));
1137         }
1138
1139         return;
1140 }
1141
1142 /*
1143  * Switch to STATE_READY state.
1144  */
1145 static inline void switch_to_ready_state(struct nandsim *ns, u_char status)
1146 {
1147         NS_DBG("switch_to_ready_state: switch to %s state\n", get_state_name(STATE_READY));
1148
1149         ns->state       = STATE_READY;
1150         ns->nxstate     = STATE_UNKNOWN;
1151         ns->op          = NULL;
1152         ns->npstates    = 0;
1153         ns->stateidx    = 0;
1154         ns->regs.num    = 0;
1155         ns->regs.count  = 0;
1156         ns->regs.off    = 0;
1157         ns->regs.row    = 0;
1158         ns->regs.column = 0;
1159         ns->regs.status = status;
1160 }
1161
1162 /*
1163  * If the operation isn't known yet, try to find it in the global array
1164  * of supported operations.
1165  *
1166  * Operation can be unknown because of the following.
1167  *   1. New command was accepted and this is the first call to find the
1168  *      correspondent states chain. In this case ns->npstates = 0;
1169  *   2. There are several operations which begin with the same command(s)
1170  *      (for example program from the second half and read from the
1171  *      second half operations both begin with the READ1 command). In this
1172  *      case the ns->pstates[] array contains previous states.
1173  *
1174  * Thus, the function tries to find operation containing the following
1175  * states (if the 'flag' parameter is 0):
1176  *    ns->pstates[0], ... ns->pstates[ns->npstates], ns->state
1177  *
1178  * If (one and only one) matching operation is found, it is accepted (
1179  * ns->ops, ns->state, ns->nxstate are initialized, ns->npstate is
1180  * zeroed).
1181  *
1182  * If there are several matches, the current state is pushed to the
1183  * ns->pstates.
1184  *
1185  * The operation can be unknown only while commands are input to the chip.
1186  * As soon as address command is accepted, the operation must be known.
1187  * In such situation the function is called with 'flag' != 0, and the
1188  * operation is searched using the following pattern:
1189  *     ns->pstates[0], ... ns->pstates[ns->npstates], <address input>
1190  *
1191  * It is supposed that this pattern must either match one operation or
1192  * none. There can't be ambiguity in that case.
1193  *
1194  * If no matches found, the function does the following:
1195  *   1. if there are saved states present, try to ignore them and search
1196  *      again only using the last command. If nothing was found, switch
1197  *      to the STATE_READY state.
1198  *   2. if there are no saved states, switch to the STATE_READY state.
1199  *
1200  * RETURNS: -2 - no matched operations found.
1201  *          -1 - several matches.
1202  *           0 - operation is found.
1203  */
1204 static int find_operation(struct nandsim *ns, uint32_t flag)
1205 {
1206         int opsfound = 0;
1207         int i, j, idx = 0;
1208
1209         for (i = 0; i < NS_OPER_NUM; i++) {
1210
1211                 int found = 1;
1212
1213                 if (!(ns->options & ops[i].reqopts))
1214                         /* Ignore operations we can't perform */
1215                         continue;
1216
1217                 if (flag) {
1218                         if (!(ops[i].states[ns->npstates] & STATE_ADDR_MASK))
1219                                 continue;
1220                 } else {
1221                         if (NS_STATE(ns->state) != NS_STATE(ops[i].states[ns->npstates]))
1222                                 continue;
1223                 }
1224
1225                 for (j = 0; j < ns->npstates; j++)
1226                         if (NS_STATE(ops[i].states[j]) != NS_STATE(ns->pstates[j])
1227                                 && (ns->options & ops[idx].reqopts)) {
1228                                 found = 0;
1229                                 break;
1230                         }
1231
1232                 if (found) {
1233                         idx = i;
1234                         opsfound += 1;
1235                 }
1236         }
1237
1238         if (opsfound == 1) {
1239                 /* Exact match */
1240                 ns->op = &ops[idx].states[0];
1241                 if (flag) {
1242                         /*
1243                          * In this case the find_operation function was
1244                          * called when address has just began input. But it isn't
1245                          * yet fully input and the current state must
1246                          * not be one of STATE_ADDR_*, but the STATE_ADDR_*
1247                          * state must be the next state (ns->nxstate).
1248                          */
1249                         ns->stateidx = ns->npstates - 1;
1250                 } else {
1251                         ns->stateidx = ns->npstates;
1252                 }
1253                 ns->npstates = 0;
1254                 ns->state = ns->op[ns->stateidx];
1255                 ns->nxstate = ns->op[ns->stateidx + 1];
1256                 NS_DBG("find_operation: operation found, index: %d, state: %s, nxstate %s\n",
1257                                 idx, get_state_name(ns->state), get_state_name(ns->nxstate));
1258                 return 0;
1259         }
1260
1261         if (opsfound == 0) {
1262                 /* Nothing was found. Try to ignore previous commands (if any) and search again */
1263                 if (ns->npstates != 0) {
1264                         NS_DBG("find_operation: no operation found, try again with state %s\n",
1265                                         get_state_name(ns->state));
1266                         ns->npstates = 0;
1267                         return find_operation(ns, 0);
1268
1269                 }
1270                 NS_DBG("find_operation: no operations found\n");
1271                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1272                 return -2;
1273         }
1274
1275         if (flag) {
1276                 /* This shouldn't happen */
1277                 NS_DBG("find_operation: BUG, operation must be known if address is input\n");
1278                 return -2;
1279         }
1280
1281         NS_DBG("find_operation: there is still ambiguity\n");
1282
1283         ns->pstates[ns->npstates++] = ns->state;
1284
1285         return -1;
1286 }
1287
1288 static void put_pages(struct nandsim *ns)
1289 {
1290         int i;
1291
1292         for (i = 0; i < ns->held_cnt; i++)
1293                 page_cache_release(ns->held_pages[i]);
1294 }
1295
1296 /* Get page cache pages in advance to provide NOFS memory allocation */
1297 static int get_pages(struct nandsim *ns, struct file *file, size_t count, loff_t pos)
1298 {
1299         pgoff_t index, start_index, end_index;
1300         struct page *page;
1301         struct address_space *mapping = file->f_mapping;
1302
1303         start_index = pos >> PAGE_CACHE_SHIFT;
1304         end_index = (pos + count - 1) >> PAGE_CACHE_SHIFT;
1305         if (end_index - start_index + 1 > NS_MAX_HELD_PAGES)
1306                 return -EINVAL;
1307         ns->held_cnt = 0;
1308         for (index = start_index; index <= end_index; index++) {
1309                 page = find_get_page(mapping, index);
1310                 if (page == NULL) {
1311                         page = find_or_create_page(mapping, index, GFP_NOFS);
1312                         if (page == NULL) {
1313                                 write_inode_now(mapping->host, 1);
1314                                 page = find_or_create_page(mapping, index, GFP_NOFS);
1315                         }
1316                         if (page == NULL) {
1317                                 put_pages(ns);
1318                                 return -ENOMEM;
1319                         }
1320                         unlock_page(page);
1321                 }
1322                 ns->held_pages[ns->held_cnt++] = page;
1323         }
1324         return 0;
1325 }
1326
1327 static int set_memalloc(void)
1328 {
1329         if (current->flags & PF_MEMALLOC)
1330                 return 0;
1331         current->flags |= PF_MEMALLOC;
1332         return 1;
1333 }
1334
1335 static void clear_memalloc(int memalloc)
1336 {
1337         if (memalloc)
1338                 current->flags &= ~PF_MEMALLOC;
1339 }
1340
1341 static ssize_t read_file(struct nandsim *ns, struct file *file, void *buf, size_t count, loff_t *pos)
1342 {
1343         mm_segment_t old_fs;
1344         ssize_t tx;
1345         int err, memalloc;
1346
1347         err = get_pages(ns, file, count, *pos);
1348         if (err)
1349                 return err;
1350         old_fs = get_fs();
1351         set_fs(get_ds());
1352         memalloc = set_memalloc();
1353         tx = vfs_read(file, (char __user *)buf, count, pos);
1354         clear_memalloc(memalloc);
1355         set_fs(old_fs);
1356         put_pages(ns);
1357         return tx;
1358 }
1359
1360 static ssize_t write_file(struct nandsim *ns, struct file *file, void *buf, size_t count, loff_t *pos)
1361 {
1362         mm_segment_t old_fs;
1363         ssize_t tx;
1364         int err, memalloc;
1365
1366         err = get_pages(ns, file, count, *pos);
1367         if (err)
1368                 return err;
1369         old_fs = get_fs();
1370         set_fs(get_ds());
1371         memalloc = set_memalloc();
1372         tx = vfs_write(file, (char __user *)buf, count, pos);
1373         clear_memalloc(memalloc);
1374         set_fs(old_fs);
1375         put_pages(ns);
1376         return tx;
1377 }
1378
1379 /*
1380  * Returns a pointer to the current page.
1381  */
1382 static inline union ns_mem *NS_GET_PAGE(struct nandsim *ns)
1383 {
1384         return &(ns->pages[ns->regs.row]);
1385 }
1386
1387 /*
1388  * Retuns a pointer to the current byte, within the current page.
1389  */
1390 static inline u_char *NS_PAGE_BYTE_OFF(struct nandsim *ns)
1391 {
1392         return NS_GET_PAGE(ns)->byte + ns->regs.column + ns->regs.off;
1393 }
1394
1395 int do_read_error(struct nandsim *ns, int num)
1396 {
1397         unsigned int page_no = ns->regs.row;
1398
1399         if (read_error(page_no)) {
1400                 int i;
1401                 memset(ns->buf.byte, 0xFF, num);
1402                 for (i = 0; i < num; ++i)
1403                         ns->buf.byte[i] = random32();
1404                 NS_WARN("simulating read error in page %u\n", page_no);
1405                 return 1;
1406         }
1407         return 0;
1408 }
1409
1410 void do_bit_flips(struct nandsim *ns, int num)
1411 {
1412         if (bitflips && random32() < (1 << 22)) {
1413                 int flips = 1;
1414                 if (bitflips > 1)
1415                         flips = (random32() % (int) bitflips) + 1;
1416                 while (flips--) {
1417                         int pos = random32() % (num * 8);
1418                         ns->buf.byte[pos / 8] ^= (1 << (pos % 8));
1419                         NS_WARN("read_page: flipping bit %d in page %d "
1420                                 "reading from %d ecc: corrected=%u failed=%u\n",
1421                                 pos, ns->regs.row, ns->regs.column + ns->regs.off,
1422                                 nsmtd->ecc_stats.corrected, nsmtd->ecc_stats.failed);
1423                 }
1424         }
1425 }
1426
1427 /*
1428  * Fill the NAND buffer with data read from the specified page.
1429  */
1430 static void read_page(struct nandsim *ns, int num)
1431 {
1432         union ns_mem *mypage;
1433
1434         if (ns->cfile) {
1435                 if (!ns->pages_written[ns->regs.row]) {
1436                         NS_DBG("read_page: page %d not written\n", ns->regs.row);
1437                         memset(ns->buf.byte, 0xFF, num);
1438                 } else {
1439                         loff_t pos;
1440                         ssize_t tx;
1441
1442                         NS_DBG("read_page: page %d written, reading from %d\n",
1443                                 ns->regs.row, ns->regs.column + ns->regs.off);
1444                         if (do_read_error(ns, num))
1445                                 return;
1446                         pos = (loff_t)ns->regs.row * ns->geom.pgszoob + ns->regs.column + ns->regs.off;
1447                         tx = read_file(ns, ns->cfile, ns->buf.byte, num, &pos);
1448                         if (tx != num) {
1449                                 NS_ERR("read_page: read error for page %d ret %ld\n", ns->regs.row, (long)tx);
1450                                 return;
1451                         }
1452                         do_bit_flips(ns, num);
1453                 }
1454                 return;
1455         }
1456
1457         mypage = NS_GET_PAGE(ns);
1458         if (mypage->byte == NULL) {
1459                 NS_DBG("read_page: page %d not allocated\n", ns->regs.row);
1460                 memset(ns->buf.byte, 0xFF, num);
1461         } else {
1462                 NS_DBG("read_page: page %d allocated, reading from %d\n",
1463                         ns->regs.row, ns->regs.column + ns->regs.off);
1464                 if (do_read_error(ns, num))
1465                         return;
1466                 memcpy(ns->buf.byte, NS_PAGE_BYTE_OFF(ns), num);
1467                 do_bit_flips(ns, num);
1468         }
1469 }
1470
1471 /*
1472  * Erase all pages in the specified sector.
1473  */
1474 static void erase_sector(struct nandsim *ns)
1475 {
1476         union ns_mem *mypage;
1477         int i;
1478
1479         if (ns->cfile) {
1480                 for (i = 0; i < ns->geom.pgsec; i++)
1481                         if (ns->pages_written[ns->regs.row + i]) {
1482                                 NS_DBG("erase_sector: freeing page %d\n", ns->regs.row + i);
1483                                 ns->pages_written[ns->regs.row + i] = 0;
1484                         }
1485                 return;
1486         }
1487
1488         mypage = NS_GET_PAGE(ns);
1489         for (i = 0; i < ns->geom.pgsec; i++) {
1490                 if (mypage->byte != NULL) {
1491                         NS_DBG("erase_sector: freeing page %d\n", ns->regs.row+i);
1492                         kmem_cache_free(ns->nand_pages_slab, mypage->byte);
1493                         mypage->byte = NULL;
1494                 }
1495                 mypage++;
1496         }
1497 }
1498
1499 /*
1500  * Program the specified page with the contents from the NAND buffer.
1501  */
1502 static int prog_page(struct nandsim *ns, int num)
1503 {
1504         int i;
1505         union ns_mem *mypage;
1506         u_char *pg_off;
1507
1508         if (ns->cfile) {
1509                 loff_t off, pos;
1510                 ssize_t tx;
1511                 int all;
1512
1513                 NS_DBG("prog_page: writing page %d\n", ns->regs.row);
1514                 pg_off = ns->file_buf + ns->regs.column + ns->regs.off;
1515                 off = (loff_t)ns->regs.row * ns->geom.pgszoob + ns->regs.column + ns->regs.off;
1516                 if (!ns->pages_written[ns->regs.row]) {
1517                         all = 1;
1518                         memset(ns->file_buf, 0xff, ns->geom.pgszoob);
1519                 } else {
1520                         all = 0;
1521                         pos = off;
1522                         tx = read_file(ns, ns->cfile, pg_off, num, &pos);
1523                         if (tx != num) {
1524                                 NS_ERR("prog_page: read error for page %d ret %ld\n", ns->regs.row, (long)tx);
1525                                 return -1;
1526                         }
1527                 }
1528                 for (i = 0; i < num; i++)
1529                         pg_off[i] &= ns->buf.byte[i];
1530                 if (all) {
1531                         pos = (loff_t)ns->regs.row * ns->geom.pgszoob;
1532                         tx = write_file(ns, ns->cfile, ns->file_buf, ns->geom.pgszoob, &pos);
1533                         if (tx != ns->geom.pgszoob) {
1534                                 NS_ERR("prog_page: write error for page %d ret %ld\n", ns->regs.row, (long)tx);
1535                                 return -1;
1536                         }
1537                         ns->pages_written[ns->regs.row] = 1;
1538                 } else {
1539                         pos = off;
1540                         tx = write_file(ns, ns->cfile, pg_off, num, &pos);
1541                         if (tx != num) {
1542                                 NS_ERR("prog_page: write error for page %d ret %ld\n", ns->regs.row, (long)tx);
1543                                 return -1;
1544                         }
1545                 }
1546                 return 0;
1547         }
1548
1549         mypage = NS_GET_PAGE(ns);
1550         if (mypage->byte == NULL) {
1551                 NS_DBG("prog_page: allocating page %d\n", ns->regs.row);
1552                 /*
1553                  * We allocate memory with GFP_NOFS because a flash FS may
1554                  * utilize this. If it is holding an FS lock, then gets here,
1555                  * then kernel memory alloc runs writeback which goes to the FS
1556                  * again and deadlocks. This was seen in practice.
1557                  */
1558                 mypage->byte = kmem_cache_alloc(ns->nand_pages_slab, GFP_NOFS);
1559                 if (mypage->byte == NULL) {
1560                         NS_ERR("prog_page: error allocating memory for page %d\n", ns->regs.row);
1561                         return -1;
1562                 }
1563                 memset(mypage->byte, 0xFF, ns->geom.pgszoob);
1564         }
1565
1566         pg_off = NS_PAGE_BYTE_OFF(ns);
1567         for (i = 0; i < num; i++)
1568                 pg_off[i] &= ns->buf.byte[i];
1569
1570         return 0;
1571 }
1572
1573 /*
1574  * If state has any action bit, perform this action.
1575  *
1576  * RETURNS: 0 if success, -1 if error.
1577  */
1578 static int do_state_action(struct nandsim *ns, uint32_t action)
1579 {
1580         int num;
1581         int busdiv = ns->busw == 8 ? 1 : 2;
1582         unsigned int erase_block_no, page_no;
1583
1584         action &= ACTION_MASK;
1585
1586         /* Check that page address input is correct */
1587         if (action != ACTION_SECERASE && ns->regs.row >= ns->geom.pgnum) {
1588                 NS_WARN("do_state_action: wrong page number (%#x)\n", ns->regs.row);
1589                 return -1;
1590         }
1591
1592         switch (action) {
1593
1594         case ACTION_CPY:
1595                 /*
1596                  * Copy page data to the internal buffer.
1597                  */
1598
1599                 /* Column shouldn't be very large */
1600                 if (ns->regs.column >= (ns->geom.pgszoob - ns->regs.off)) {
1601                         NS_ERR("do_state_action: column number is too large\n");
1602                         break;
1603                 }
1604                 num = ns->geom.pgszoob - ns->regs.off - ns->regs.column;
1605                 read_page(ns, num);
1606
1607                 NS_DBG("do_state_action: (ACTION_CPY:) copy %d bytes to int buf, raw offset %d\n",
1608                         num, NS_RAW_OFFSET(ns) + ns->regs.off);
1609
1610                 if (ns->regs.off == 0)
1611                         NS_LOG("read page %d\n", ns->regs.row);
1612                 else if (ns->regs.off < ns->geom.pgsz)
1613                         NS_LOG("read page %d (second half)\n", ns->regs.row);
1614                 else
1615                         NS_LOG("read OOB of page %d\n", ns->regs.row);
1616
1617                 NS_UDELAY(access_delay);
1618                 NS_UDELAY(input_cycle * ns->geom.pgsz / 1000 / busdiv);
1619
1620                 break;
1621
1622         case ACTION_SECERASE:
1623                 /*
1624                  * Erase sector.
1625                  */
1626
1627                 if (ns->lines.wp) {
1628                         NS_ERR("do_state_action: device is write-protected, ignore sector erase\n");
1629                         return -1;
1630                 }
1631
1632                 if (ns->regs.row >= ns->geom.pgnum - ns->geom.pgsec
1633                         || (ns->regs.row & ~(ns->geom.secsz - 1))) {
1634                         NS_ERR("do_state_action: wrong sector address (%#x)\n", ns->regs.row);
1635                         return -1;
1636                 }
1637
1638                 ns->regs.row = (ns->regs.row <<
1639                                 8 * (ns->geom.pgaddrbytes - ns->geom.secaddrbytes)) | ns->regs.column;
1640                 ns->regs.column = 0;
1641
1642                 erase_block_no = ns->regs.row >> (ns->geom.secshift - ns->geom.pgshift);
1643
1644                 NS_DBG("do_state_action: erase sector at address %#x, off = %d\n",
1645                                 ns->regs.row, NS_RAW_OFFSET(ns));
1646                 NS_LOG("erase sector %u\n", erase_block_no);
1647
1648                 erase_sector(ns);
1649
1650                 NS_MDELAY(erase_delay);
1651
1652                 if (erase_block_wear)
1653                         update_wear(erase_block_no);
1654
1655                 if (erase_error(erase_block_no)) {
1656                         NS_WARN("simulating erase failure in erase block %u\n", erase_block_no);
1657                         return -1;
1658                 }
1659
1660                 break;
1661
1662         case ACTION_PRGPAGE:
1663                 /*
1664                  * Program page - move internal buffer data to the page.
1665                  */
1666
1667                 if (ns->lines.wp) {
1668                         NS_WARN("do_state_action: device is write-protected, programm\n");
1669                         return -1;
1670                 }
1671
1672                 num = ns->geom.pgszoob - ns->regs.off - ns->regs.column;
1673                 if (num != ns->regs.count) {
1674                         NS_ERR("do_state_action: too few bytes were input (%d instead of %d)\n",
1675                                         ns->regs.count, num);
1676                         return -1;
1677                 }
1678
1679                 if (prog_page(ns, num) == -1)
1680                         return -1;
1681
1682                 page_no = ns->regs.row;
1683
1684                 NS_DBG("do_state_action: copy %d bytes from int buf to (%#x, %#x), raw off = %d\n",
1685                         num, ns->regs.row, ns->regs.column, NS_RAW_OFFSET(ns) + ns->regs.off);
1686                 NS_LOG("programm page %d\n", ns->regs.row);
1687
1688                 NS_UDELAY(programm_delay);
1689                 NS_UDELAY(output_cycle * ns->geom.pgsz / 1000 / busdiv);
1690
1691                 if (write_error(page_no)) {
1692                         NS_WARN("simulating write failure in page %u\n", page_no);
1693                         return -1;
1694                 }
1695
1696                 break;
1697
1698         case ACTION_ZEROOFF:
1699                 NS_DBG("do_state_action: set internal offset to 0\n");
1700                 ns->regs.off = 0;
1701                 break;
1702
1703         case ACTION_HALFOFF:
1704                 if (!(ns->options & OPT_PAGE512_8BIT)) {
1705                         NS_ERR("do_state_action: BUG! can't skip half of page for non-512"
1706                                 "byte page size 8x chips\n");
1707                         return -1;
1708                 }
1709                 NS_DBG("do_state_action: set internal offset to %d\n", ns->geom.pgsz/2);
1710                 ns->regs.off = ns->geom.pgsz/2;
1711                 break;
1712
1713         case ACTION_OOBOFF:
1714                 NS_DBG("do_state_action: set internal offset to %d\n", ns->geom.pgsz);
1715                 ns->regs.off = ns->geom.pgsz;
1716                 break;
1717
1718         default:
1719                 NS_DBG("do_state_action: BUG! unknown action\n");
1720         }
1721
1722         return 0;
1723 }
1724
1725 /*
1726  * Switch simulator's state.
1727  */
1728 static void switch_state(struct nandsim *ns)
1729 {
1730         if (ns->op) {
1731                 /*
1732                  * The current operation have already been identified.
1733                  * Just follow the states chain.
1734                  */
1735
1736                 ns->stateidx += 1;
1737                 ns->state = ns->nxstate;
1738                 ns->nxstate = ns->op[ns->stateidx + 1];
1739
1740                 NS_DBG("switch_state: operation is known, switch to the next state, "
1741                         "state: %s, nxstate: %s\n",
1742                         get_state_name(ns->state), get_state_name(ns->nxstate));
1743
1744                 /* See, whether we need to do some action */
1745                 if ((ns->state & ACTION_MASK) && do_state_action(ns, ns->state) < 0) {
1746                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1747                         return;
1748                 }
1749
1750         } else {
1751                 /*
1752                  * We don't yet know which operation we perform.
1753                  * Try to identify it.
1754                  */
1755
1756                 /*
1757                  *  The only event causing the switch_state function to
1758                  *  be called with yet unknown operation is new command.
1759                  */
1760                 ns->state = get_state_by_command(ns->regs.command);
1761
1762                 NS_DBG("switch_state: operation is unknown, try to find it\n");
1763
1764                 if (find_operation(ns, 0) != 0)
1765                         return;
1766
1767                 if ((ns->state & ACTION_MASK) && do_state_action(ns, ns->state) < 0) {
1768                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1769                         return;
1770                 }
1771         }
1772
1773         /* For 16x devices column means the page offset in words */
1774         if ((ns->nxstate & STATE_ADDR_MASK) && ns->busw == 16) {
1775                 NS_DBG("switch_state: double the column number for 16x device\n");
1776                 ns->regs.column <<= 1;
1777         }
1778
1779         if (NS_STATE(ns->nxstate) == STATE_READY) {
1780                 /*
1781                  * The current state is the last. Return to STATE_READY
1782                  */
1783
1784                 u_char status = NS_STATUS_OK(ns);
1785
1786                 /* In case of data states, see if all bytes were input/output */
1787                 if ((ns->state & (STATE_DATAIN_MASK | STATE_DATAOUT_MASK))
1788                         && ns->regs.count != ns->regs.num) {
1789                         NS_WARN("switch_state: not all bytes were processed, %d left\n",
1790                                         ns->regs.num - ns->regs.count);
1791                         status = NS_STATUS_FAILED(ns);
1792                 }
1793
1794                 NS_DBG("switch_state: operation complete, switch to STATE_READY state\n");
1795
1796                 switch_to_ready_state(ns, status);
1797
1798                 return;
1799         } else if (ns->nxstate & (STATE_DATAIN_MASK | STATE_DATAOUT_MASK)) {
1800                 /*
1801                  * If the next state is data input/output, switch to it now
1802                  */
1803
1804                 ns->state      = ns->nxstate;
1805                 ns->nxstate    = ns->op[++ns->stateidx + 1];
1806                 ns->regs.num   = ns->regs.count = 0;
1807
1808                 NS_DBG("switch_state: the next state is data I/O, switch, "
1809                         "state: %s, nxstate: %s\n",
1810                         get_state_name(ns->state), get_state_name(ns->nxstate));
1811
1812                 /*
1813                  * Set the internal register to the count of bytes which
1814                  * are expected to be input or output
1815                  */
1816                 switch (NS_STATE(ns->state)) {
1817                         case STATE_DATAIN:
1818                         case STATE_DATAOUT:
1819                                 ns->regs.num = ns->geom.pgszoob - ns->regs.off - ns->regs.column;
1820                                 break;
1821
1822                         case STATE_DATAOUT_ID:
1823                                 ns->regs.num = ns->geom.idbytes;
1824                                 break;
1825
1826                         case STATE_DATAOUT_STATUS:
1827                         case STATE_DATAOUT_STATUS_M:
1828                                 ns->regs.count = ns->regs.num = 0;
1829                                 break;
1830
1831                         default:
1832                                 NS_ERR("switch_state: BUG! unknown data state\n");
1833                 }
1834
1835         } else if (ns->nxstate & STATE_ADDR_MASK) {
1836                 /*
1837                  * If the next state is address input, set the internal
1838                  * register to the number of expected address bytes
1839                  */
1840
1841                 ns->regs.count = 0;
1842
1843                 switch (NS_STATE(ns->nxstate)) {
1844                         case STATE_ADDR_PAGE:
1845                                 ns->regs.num = ns->geom.pgaddrbytes;
1846
1847                                 break;
1848                         case STATE_ADDR_SEC:
1849                                 ns->regs.num = ns->geom.secaddrbytes;
1850                                 break;
1851
1852                         case STATE_ADDR_ZERO:
1853                                 ns->regs.num = 1;
1854                                 break;
1855
1856                         case STATE_ADDR_COLUMN:
1857                                 /* Column address is always 2 bytes */
1858                                 ns->regs.num = ns->geom.pgaddrbytes - ns->geom.secaddrbytes;
1859                                 break;
1860
1861                         default:
1862                                 NS_ERR("switch_state: BUG! unknown address state\n");
1863                 }
1864         } else {
1865                 /*
1866                  * Just reset internal counters.
1867                  */
1868
1869                 ns->regs.num = 0;
1870                 ns->regs.count = 0;
1871         }
1872 }
1873
1874 static u_char ns_nand_read_byte(struct mtd_info *mtd)
1875 {
1876         struct nandsim *ns = ((struct nand_chip *)mtd->priv)->priv;
1877         u_char outb = 0x00;
1878
1879         /* Sanity and correctness checks */
1880         if (!ns->lines.ce) {
1881                 NS_ERR("read_byte: chip is disabled, return %#x\n", (uint)outb);
1882                 return outb;
1883         }
1884         if (ns->lines.ale || ns->lines.cle) {
1885                 NS_ERR("read_byte: ALE or CLE pin is high, return %#x\n", (uint)outb);
1886                 return outb;
1887         }
1888         if (!(ns->state & STATE_DATAOUT_MASK)) {
1889                 NS_WARN("read_byte: unexpected data output cycle, state is %s "
1890                         "return %#x\n", get_state_name(ns->state), (uint)outb);
1891                 return outb;
1892         }
1893
1894         /* Status register may be read as many times as it is wanted */
1895         if (NS_STATE(ns->state) == STATE_DATAOUT_STATUS) {
1896                 NS_DBG("read_byte: return %#x status\n", ns->regs.status);
1897                 return ns->regs.status;
1898         }
1899
1900         /* Check if there is any data in the internal buffer which may be read */
1901         if (ns->regs.count == ns->regs.num) {
1902                 NS_WARN("read_byte: no more data to output, return %#x\n", (uint)outb);
1903                 return outb;
1904         }
1905
1906         switch (NS_STATE(ns->state)) {
1907                 case STATE_DATAOUT:
1908                         if (ns->busw == 8) {
1909                                 outb = ns->buf.byte[ns->regs.count];
1910                                 ns->regs.count += 1;
1911                         } else {
1912                                 outb = (u_char)cpu_to_le16(ns->buf.word[ns->regs.count >> 1]);
1913                                 ns->regs.count += 2;
1914                         }
1915                         break;
1916                 case STATE_DATAOUT_ID:
1917                         NS_DBG("read_byte: read ID byte %d, total = %d\n", ns->regs.count, ns->regs.num);
1918                         outb = ns->ids[ns->regs.count];
1919                         ns->regs.count += 1;
1920                         break;
1921                 default:
1922                         BUG();
1923         }
1924
1925         if (ns->regs.count == ns->regs.num) {
1926                 NS_DBG("read_byte: all bytes were read\n");
1927
1928                 if (NS_STATE(ns->nxstate) == STATE_READY)
1929                         switch_state(ns);
1930         }
1931
1932         return outb;
1933 }
1934
1935 static void ns_nand_write_byte(struct mtd_info *mtd, u_char byte)
1936 {
1937         struct nandsim *ns = ((struct nand_chip *)mtd->priv)->priv;
1938
1939         /* Sanity and correctness checks */
1940         if (!ns->lines.ce) {
1941                 NS_ERR("write_byte: chip is disabled, ignore write\n");
1942                 return;
1943         }
1944         if (ns->lines.ale && ns->lines.cle) {
1945                 NS_ERR("write_byte: ALE and CLE pins are high simultaneously, ignore write\n");
1946                 return;
1947         }
1948
1949         if (ns->lines.cle == 1) {
1950                 /*
1951                  * The byte written is a command.
1952                  */
1953
1954                 if (byte == NAND_CMD_RESET) {
1955                         NS_LOG("reset chip\n");
1956                         switch_to_ready_state(ns, NS_STATUS_OK(ns));
1957                         return;
1958                 }
1959
1960                 /* Check that the command byte is correct */
1961                 if (check_command(byte)) {
1962                         NS_ERR("write_byte: unknown command %#x\n", (uint)byte);
1963                         return;
1964                 }
1965
1966                 if (NS_STATE(ns->state) == STATE_DATAOUT_STATUS
1967                         || NS_STATE(ns->state) == STATE_DATAOUT_STATUS_M
1968                         || NS_STATE(ns->state) == STATE_DATAOUT) {
1969                         int row = ns->regs.row;
1970
1971                         switch_state(ns);
1972                         if (byte == NAND_CMD_RNDOUT)
1973                                 ns->regs.row = row;
1974                 }
1975
1976                 /* Check if chip is expecting command */
1977                 if (NS_STATE(ns->nxstate) != STATE_UNKNOWN && !(ns->nxstate & STATE_CMD_MASK)) {
1978                         /* Do not warn if only 2 id bytes are read */
1979                         if (!(ns->regs.command == NAND_CMD_READID &&
1980                             NS_STATE(ns->state) == STATE_DATAOUT_ID && ns->regs.count == 2)) {
1981                                 /*
1982                                  * We are in situation when something else (not command)
1983                                  * was expected but command was input. In this case ignore
1984                                  * previous command(s)/state(s) and accept the last one.
1985                                  */
1986                                 NS_WARN("write_byte: command (%#x) wasn't expected, expected state is %s, "
1987                                         "ignore previous states\n", (uint)byte, get_state_name(ns->nxstate));
1988                         }
1989                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1990                 }
1991
1992                 NS_DBG("command byte corresponding to %s state accepted\n",
1993                         get_state_name(get_state_by_command(byte)));
1994                 ns->regs.command = byte;
1995                 switch_state(ns);
1996
1997         } else if (ns->lines.ale == 1) {
1998                 /*
1999                  * The byte written is an address.
2000                  */
2001
2002                 if (NS_STATE(ns->nxstate) == STATE_UNKNOWN) {
2003
2004                         NS_DBG("write_byte: operation isn't known yet, identify it\n");
2005
2006                         if (find_operation(ns, 1) < 0)
2007                                 return;
2008
2009                         if ((ns->state & ACTION_MASK) && do_state_action(ns, ns->state) < 0) {
2010                                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2011                                 return;
2012                         }
2013
2014                         ns->regs.count = 0;
2015                         switch (NS_STATE(ns->nxstate)) {
2016                                 case STATE_ADDR_PAGE:
2017                                         ns->regs.num = ns->geom.pgaddrbytes;
2018                                         break;
2019                                 case STATE_ADDR_SEC:
2020                                         ns->regs.num = ns->geom.secaddrbytes;
2021                                         break;
2022                                 case STATE_ADDR_ZERO:
2023                                         ns->regs.num = 1;
2024                                         break;
2025                                 default:
2026                                         BUG();
2027                         }
2028                 }
2029
2030                 /* Check that chip is expecting address */
2031                 if (!(ns->nxstate & STATE_ADDR_MASK)) {
2032                         NS_ERR("write_byte: address (%#x) isn't expected, expected state is %s, "
2033                                 "switch to STATE_READY\n", (uint)byte, get_state_name(ns->nxstate));
2034                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2035                         return;
2036                 }
2037
2038                 /* Check if this is expected byte */
2039                 if (ns->regs.count == ns->regs.num) {
2040                         NS_ERR("write_byte: no more address bytes expected\n");
2041                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2042                         return;
2043                 }
2044
2045                 accept_addr_byte(ns, byte);
2046
2047                 ns->regs.count += 1;
2048
2049                 NS_DBG("write_byte: address byte %#x was accepted (%d bytes input, %d expected)\n",
2050                                 (uint)byte, ns->regs.count, ns->regs.num);
2051
2052                 if (ns->regs.count == ns->regs.num) {
2053                         NS_DBG("address (%#x, %#x) is accepted\n", ns->regs.row, ns->regs.column);
2054                         switch_state(ns);
2055                 }
2056
2057         } else {
2058                 /*
2059                  * The byte written is an input data.
2060                  */
2061
2062                 /* Check that chip is expecting data input */
2063                 if (!(ns->state & STATE_DATAIN_MASK)) {
2064                         NS_ERR("write_byte: data input (%#x) isn't expected, state is %s, "
2065                                 "switch to %s\n", (uint)byte,
2066                                 get_state_name(ns->state), get_state_name(STATE_READY));
2067                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2068                         return;
2069                 }
2070
2071                 /* Check if this is expected byte */
2072                 if (ns->regs.count == ns->regs.num) {
2073                         NS_WARN("write_byte: %u input bytes has already been accepted, ignore write\n",
2074                                         ns->regs.num);
2075                         return;
2076                 }
2077
2078                 if (ns->busw == 8) {
2079                         ns->buf.byte[ns->regs.count] = byte;
2080                         ns->regs.count += 1;
2081                 } else {
2082                         ns->buf.word[ns->regs.count >> 1] = cpu_to_le16((uint16_t)byte);
2083                         ns->regs.count += 2;
2084                 }
2085         }
2086
2087         return;
2088 }
2089
2090 static void ns_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int bitmask)
2091 {
2092         struct nandsim *ns = ((struct nand_chip *)mtd->priv)->priv;
2093
2094         ns->lines.cle = bitmask & NAND_CLE ? 1 : 0;
2095         ns->lines.ale = bitmask & NAND_ALE ? 1 : 0;
2096         ns->lines.ce = bitmask & NAND_NCE ? 1 : 0;
2097
2098         if (cmd != NAND_CMD_NONE)
2099                 ns_nand_write_byte(mtd, cmd);
2100 }
2101
2102 static int ns_device_ready(struct mtd_info *mtd)
2103 {
2104         NS_DBG("device_ready\n");
2105         return 1;
2106 }
2107
2108 static uint16_t ns_nand_read_word(struct mtd_info *mtd)
2109 {
2110         struct nand_chip *chip = (struct nand_chip *)mtd->priv;
2111
2112         NS_DBG("read_word\n");
2113
2114         return chip->read_byte(mtd) | (chip->read_byte(mtd) << 8);
2115 }
2116
2117 static void ns_nand_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
2118 {
2119         struct nandsim *ns = ((struct nand_chip *)mtd->priv)->priv;
2120
2121         /* Check that chip is expecting data input */
2122         if (!(ns->state & STATE_DATAIN_MASK)) {
2123                 NS_ERR("write_buf: data input isn't expected, state is %s, "
2124                         "switch to STATE_READY\n", get_state_name(ns->state));
2125                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2126                 return;
2127         }
2128
2129         /* Check if these are expected bytes */
2130         if (ns->regs.count + len > ns->regs.num) {
2131                 NS_ERR("write_buf: too many input bytes\n");
2132                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2133                 return;
2134         }
2135
2136         memcpy(ns->buf.byte + ns->regs.count, buf, len);
2137         ns->regs.count += len;
2138
2139         if (ns->regs.count == ns->regs.num) {
2140                 NS_DBG("write_buf: %d bytes were written\n", ns->regs.count);
2141         }
2142 }
2143
2144 static void ns_nand_read_buf(struct mtd_info *mtd, u_char *buf, int len)
2145 {
2146         struct nandsim *ns = ((struct nand_chip *)mtd->priv)->priv;
2147
2148         /* Sanity and correctness checks */
2149         if (!ns->lines.ce) {
2150                 NS_ERR("read_buf: chip is disabled\n");
2151                 return;
2152         }
2153         if (ns->lines.ale || ns->lines.cle) {
2154                 NS_ERR("read_buf: ALE or CLE pin is high\n");
2155                 return;
2156         }
2157         if (!(ns->state & STATE_DATAOUT_MASK)) {
2158                 NS_WARN("read_buf: unexpected data output cycle, current state is %s\n",
2159                         get_state_name(ns->state));
2160                 return;
2161         }
2162
2163         if (NS_STATE(ns->state) != STATE_DATAOUT) {
2164                 int i;
2165
2166                 for (i = 0; i < len; i++)
2167                         buf[i] = ((struct nand_chip *)mtd->priv)->read_byte(mtd);
2168
2169                 return;
2170         }
2171
2172         /* Check if these are expected bytes */
2173         if (ns->regs.count + len > ns->regs.num) {
2174                 NS_ERR("read_buf: too many bytes to read\n");
2175                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2176                 return;
2177         }
2178
2179         memcpy(buf, ns->buf.byte + ns->regs.count, len);
2180         ns->regs.count += len;
2181
2182         if (ns->regs.count == ns->regs.num) {
2183                 if (NS_STATE(ns->nxstate) == STATE_READY)
2184                         switch_state(ns);
2185         }
2186
2187         return;
2188 }
2189
2190 /*
2191  * Module initialization function
2192  */
2193 static int __init ns_init_module(void)
2194 {
2195         struct nand_chip *chip;
2196         struct nandsim *nand;
2197         int retval = -ENOMEM, i;
2198
2199         if (bus_width != 8 && bus_width != 16) {
2200                 NS_ERR("wrong bus width (%d), use only 8 or 16\n", bus_width);
2201                 return -EINVAL;
2202         }
2203
2204         /* Allocate and initialize mtd_info, nand_chip and nandsim structures */
2205         nsmtd = kzalloc(sizeof(struct mtd_info) + sizeof(struct nand_chip)
2206                                 + sizeof(struct nandsim), GFP_KERNEL);
2207         if (!nsmtd) {
2208                 NS_ERR("unable to allocate core structures.\n");
2209                 return -ENOMEM;
2210         }
2211         chip        = (struct nand_chip *)(nsmtd + 1);
2212         nsmtd->priv = (void *)chip;
2213         nand        = (struct nandsim *)(chip + 1);
2214         chip->priv  = (void *)nand;
2215
2216         /*
2217          * Register simulator's callbacks.
2218          */
2219         chip->cmd_ctrl   = ns_hwcontrol;
2220         chip->read_byte  = ns_nand_read_byte;
2221         chip->dev_ready  = ns_device_ready;
2222         chip->write_buf  = ns_nand_write_buf;
2223         chip->read_buf   = ns_nand_read_buf;
2224         chip->read_word  = ns_nand_read_word;
2225         chip->ecc.mode   = NAND_ECC_SOFT;
2226         /* The NAND_SKIP_BBTSCAN option is necessary for 'overridesize' */
2227         /* and 'badblocks' parameters to work */
2228         chip->options   |= NAND_SKIP_BBTSCAN;
2229
2230         switch (bbt) {
2231         case 2:
2232                  chip->bbt_options |= NAND_BBT_NO_OOB;
2233         case 1:
2234                  chip->bbt_options |= NAND_BBT_USE_FLASH;
2235         case 0:
2236                 break;
2237         default:
2238                 NS_ERR("bbt has to be 0..2\n");
2239                 retval = -EINVAL;
2240                 goto error;
2241         }
2242         /*
2243          * Perform minimum nandsim structure initialization to handle
2244          * the initial ID read command correctly
2245          */
2246         if (third_id_byte != 0xFF || fourth_id_byte != 0xFF)
2247                 nand->geom.idbytes = 4;
2248         else
2249                 nand->geom.idbytes = 2;
2250         nand->regs.status = NS_STATUS_OK(nand);
2251         nand->nxstate = STATE_UNKNOWN;
2252         nand->options |= OPT_PAGE256; /* temporary value */
2253         nand->ids[0] = first_id_byte;
2254         nand->ids[1] = second_id_byte;
2255         nand->ids[2] = third_id_byte;
2256         nand->ids[3] = fourth_id_byte;
2257         if (bus_width == 16) {
2258                 nand->busw = 16;
2259                 chip->options |= NAND_BUSWIDTH_16;
2260         }
2261
2262         nsmtd->owner = THIS_MODULE;
2263
2264         if ((retval = parse_weakblocks()) != 0)
2265                 goto error;
2266
2267         if ((retval = parse_weakpages()) != 0)
2268                 goto error;
2269
2270         if ((retval = parse_gravepages()) != 0)
2271                 goto error;
2272
2273         retval = nand_scan_ident(nsmtd, 1, NULL);
2274         if (retval) {
2275                 NS_ERR("cannot scan NAND Simulator device\n");
2276                 if (retval > 0)
2277                         retval = -ENXIO;
2278                 goto error;
2279         }
2280
2281         if (bch) {
2282                 unsigned int eccsteps, eccbytes;
2283                 if (!mtd_nand_has_bch()) {
2284                         NS_ERR("BCH ECC support is disabled\n");
2285                         retval = -EINVAL;
2286                         goto error;
2287                 }
2288                 /* use 512-byte ecc blocks */
2289                 eccsteps = nsmtd->writesize/512;
2290                 eccbytes = (bch*13+7)/8;
2291                 /* do not bother supporting small page devices */
2292                 if ((nsmtd->oobsize < 64) || !eccsteps) {
2293                         NS_ERR("bch not available on small page devices\n");
2294                         retval = -EINVAL;
2295                         goto error;
2296                 }
2297                 if ((eccbytes*eccsteps+2) > nsmtd->oobsize) {
2298                         NS_ERR("invalid bch value %u\n", bch);
2299                         retval = -EINVAL;
2300                         goto error;
2301                 }
2302                 chip->ecc.mode = NAND_ECC_SOFT_BCH;
2303                 chip->ecc.size = 512;
2304                 chip->ecc.bytes = eccbytes;
2305                 NS_INFO("using %u-bit/%u bytes BCH ECC\n", bch, chip->ecc.size);
2306         }
2307
2308         retval = nand_scan_tail(nsmtd);
2309         if (retval) {
2310                 NS_ERR("can't register NAND Simulator\n");
2311                 if (retval > 0)
2312                         retval = -ENXIO;
2313                 goto error;
2314         }
2315
2316         if (overridesize) {
2317                 uint64_t new_size = (uint64_t)nsmtd->erasesize << overridesize;
2318                 if (new_size >> overridesize != nsmtd->erasesize) {
2319                         NS_ERR("overridesize is too big\n");
2320                         goto err_exit;
2321                 }
2322                 /* N.B. This relies on nand_scan not doing anything with the size before we change it */
2323                 nsmtd->size = new_size;
2324                 chip->chipsize = new_size;
2325                 chip->chip_shift = ffs(nsmtd->erasesize) + overridesize - 1;
2326                 chip->pagemask = (chip->chipsize >> chip->page_shift) - 1;
2327         }
2328
2329         if ((retval = setup_wear_reporting(nsmtd)) != 0)
2330                 goto err_exit;
2331
2332         if ((retval = init_nandsim(nsmtd)) != 0)
2333                 goto err_exit;
2334
2335         if ((retval = nand_default_bbt(nsmtd)) != 0)
2336                 goto err_exit;
2337
2338         if ((retval = parse_badblocks(nand, nsmtd)) != 0)
2339                 goto err_exit;
2340
2341         /* Register NAND partitions */
2342         retval = mtd_device_register(nsmtd, &nand->partitions[0],
2343                                      nand->nbparts);
2344         if (retval != 0)
2345                 goto err_exit;
2346
2347         return 0;
2348
2349 err_exit:
2350         free_nandsim(nand);
2351         nand_release(nsmtd);
2352         for (i = 0;i < ARRAY_SIZE(nand->partitions); ++i)
2353                 kfree(nand->partitions[i].name);
2354 error:
2355         kfree(nsmtd);
2356         free_lists();
2357
2358         return retval;
2359 }
2360
2361 module_init(ns_init_module);
2362
2363 /*
2364  * Module clean-up function
2365  */
2366 static void __exit ns_cleanup_module(void)
2367 {
2368         struct nandsim *ns = ((struct nand_chip *)nsmtd->priv)->priv;
2369         int i;
2370
2371         free_nandsim(ns);    /* Free nandsim private resources */
2372         nand_release(nsmtd); /* Unregister driver */
2373         for (i = 0;i < ARRAY_SIZE(ns->partitions); ++i)
2374                 kfree(ns->partitions[i].name);
2375         kfree(nsmtd);        /* Free other structures */
2376         free_lists();
2377 }
2378
2379 module_exit(ns_cleanup_module);
2380
2381 MODULE_LICENSE ("GPL");
2382 MODULE_AUTHOR ("Artem B. Bityuckiy");
2383 MODULE_DESCRIPTION ("The NAND flash simulator");