Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / 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 #include <linux/seq_file.h>
46 #include <linux/debugfs.h>
47
48 /* Default simulator parameters values */
49 #if !defined(CONFIG_NANDSIM_FIRST_ID_BYTE)  || \
50     !defined(CONFIG_NANDSIM_SECOND_ID_BYTE) || \
51     !defined(CONFIG_NANDSIM_THIRD_ID_BYTE)  || \
52     !defined(CONFIG_NANDSIM_FOURTH_ID_BYTE)
53 #define CONFIG_NANDSIM_FIRST_ID_BYTE  0x98
54 #define CONFIG_NANDSIM_SECOND_ID_BYTE 0x39
55 #define CONFIG_NANDSIM_THIRD_ID_BYTE  0xFF /* No byte */
56 #define CONFIG_NANDSIM_FOURTH_ID_BYTE 0xFF /* No byte */
57 #endif
58
59 #ifndef CONFIG_NANDSIM_ACCESS_DELAY
60 #define CONFIG_NANDSIM_ACCESS_DELAY 25
61 #endif
62 #ifndef CONFIG_NANDSIM_PROGRAMM_DELAY
63 #define CONFIG_NANDSIM_PROGRAMM_DELAY 200
64 #endif
65 #ifndef CONFIG_NANDSIM_ERASE_DELAY
66 #define CONFIG_NANDSIM_ERASE_DELAY 2
67 #endif
68 #ifndef CONFIG_NANDSIM_OUTPUT_CYCLE
69 #define CONFIG_NANDSIM_OUTPUT_CYCLE 40
70 #endif
71 #ifndef CONFIG_NANDSIM_INPUT_CYCLE
72 #define CONFIG_NANDSIM_INPUT_CYCLE  50
73 #endif
74 #ifndef CONFIG_NANDSIM_BUS_WIDTH
75 #define CONFIG_NANDSIM_BUS_WIDTH  8
76 #endif
77 #ifndef CONFIG_NANDSIM_DO_DELAYS
78 #define CONFIG_NANDSIM_DO_DELAYS  0
79 #endif
80 #ifndef CONFIG_NANDSIM_LOG
81 #define CONFIG_NANDSIM_LOG        0
82 #endif
83 #ifndef CONFIG_NANDSIM_DBG
84 #define CONFIG_NANDSIM_DBG        0
85 #endif
86 #ifndef CONFIG_NANDSIM_MAX_PARTS
87 #define CONFIG_NANDSIM_MAX_PARTS  32
88 #endif
89
90 static uint access_delay   = CONFIG_NANDSIM_ACCESS_DELAY;
91 static uint programm_delay = CONFIG_NANDSIM_PROGRAMM_DELAY;
92 static uint erase_delay    = CONFIG_NANDSIM_ERASE_DELAY;
93 static uint output_cycle   = CONFIG_NANDSIM_OUTPUT_CYCLE;
94 static uint input_cycle    = CONFIG_NANDSIM_INPUT_CYCLE;
95 static uint bus_width      = CONFIG_NANDSIM_BUS_WIDTH;
96 static uint do_delays      = CONFIG_NANDSIM_DO_DELAYS;
97 static uint log            = CONFIG_NANDSIM_LOG;
98 static uint dbg            = CONFIG_NANDSIM_DBG;
99 static unsigned long parts[CONFIG_NANDSIM_MAX_PARTS];
100 static unsigned int parts_num;
101 static char *badblocks = NULL;
102 static char *weakblocks = NULL;
103 static char *weakpages = NULL;
104 static unsigned int bitflips = 0;
105 static char *gravepages = NULL;
106 static unsigned int overridesize = 0;
107 static char *cache_file = NULL;
108 static unsigned int bbt;
109 static unsigned int bch;
110 static u_char id_bytes[8] = {
111         [0] = CONFIG_NANDSIM_FIRST_ID_BYTE,
112         [1] = CONFIG_NANDSIM_SECOND_ID_BYTE,
113         [2] = CONFIG_NANDSIM_THIRD_ID_BYTE,
114         [3] = CONFIG_NANDSIM_FOURTH_ID_BYTE,
115         [4 ... 7] = 0xFF,
116 };
117
118 module_param_array(id_bytes, byte, NULL, 0400);
119 module_param_named(first_id_byte, id_bytes[0], byte, 0400);
120 module_param_named(second_id_byte, id_bytes[1], byte, 0400);
121 module_param_named(third_id_byte, id_bytes[2], byte, 0400);
122 module_param_named(fourth_id_byte, id_bytes[3], byte, 0400);
123 module_param(access_delay,   uint, 0400);
124 module_param(programm_delay, uint, 0400);
125 module_param(erase_delay,    uint, 0400);
126 module_param(output_cycle,   uint, 0400);
127 module_param(input_cycle,    uint, 0400);
128 module_param(bus_width,      uint, 0400);
129 module_param(do_delays,      uint, 0400);
130 module_param(log,            uint, 0400);
131 module_param(dbg,            uint, 0400);
132 module_param_array(parts, ulong, &parts_num, 0400);
133 module_param(badblocks,      charp, 0400);
134 module_param(weakblocks,     charp, 0400);
135 module_param(weakpages,      charp, 0400);
136 module_param(bitflips,       uint, 0400);
137 module_param(gravepages,     charp, 0400);
138 module_param(overridesize,   uint, 0400);
139 module_param(cache_file,     charp, 0400);
140 module_param(bbt,            uint, 0400);
141 module_param(bch,            uint, 0400);
142
143 MODULE_PARM_DESC(id_bytes,       "The ID bytes returned by NAND Flash 'read ID' command");
144 MODULE_PARM_DESC(first_id_byte,  "The first byte returned by NAND Flash 'read ID' command (manufacturer ID) (obsolete)");
145 MODULE_PARM_DESC(second_id_byte, "The second byte returned by NAND Flash 'read ID' command (chip ID) (obsolete)");
146 MODULE_PARM_DESC(third_id_byte,  "The third byte returned by NAND Flash 'read ID' command (obsolete)");
147 MODULE_PARM_DESC(fourth_id_byte, "The fourth byte returned by NAND Flash 'read ID' command (obsolete)");
148 MODULE_PARM_DESC(access_delay,   "Initial page access delay (microseconds)");
149 MODULE_PARM_DESC(programm_delay, "Page programm delay (microseconds");
150 MODULE_PARM_DESC(erase_delay,    "Sector erase delay (milliseconds)");
151 MODULE_PARM_DESC(output_cycle,   "Word output (from flash) time (nanoseconds)");
152 MODULE_PARM_DESC(input_cycle,    "Word input (to flash) time (nanoseconds)");
153 MODULE_PARM_DESC(bus_width,      "Chip's bus width (8- or 16-bit)");
154 MODULE_PARM_DESC(do_delays,      "Simulate NAND delays using busy-waits if not zero");
155 MODULE_PARM_DESC(log,            "Perform logging if not zero");
156 MODULE_PARM_DESC(dbg,            "Output debug information if not zero");
157 MODULE_PARM_DESC(parts,          "Partition sizes (in erase blocks) separated by commas");
158 /* Page and erase block positions for the following parameters are independent of any partitions */
159 MODULE_PARM_DESC(badblocks,      "Erase blocks that are initially marked bad, separated by commas");
160 MODULE_PARM_DESC(weakblocks,     "Weak erase blocks [: remaining erase cycles (defaults to 3)]"
161                                  " separated by commas e.g. 113:2 means eb 113"
162                                  " can be erased only twice before failing");
163 MODULE_PARM_DESC(weakpages,      "Weak pages [: maximum writes (defaults to 3)]"
164                                  " separated by commas e.g. 1401:2 means page 1401"
165                                  " can be written only twice before failing");
166 MODULE_PARM_DESC(bitflips,       "Maximum number of random bit flips per page (zero by default)");
167 MODULE_PARM_DESC(gravepages,     "Pages that lose data [: maximum reads (defaults to 3)]"
168                                  " separated by commas e.g. 1401:2 means page 1401"
169                                  " can be read only twice before failing");
170 MODULE_PARM_DESC(overridesize,   "Specifies the NAND Flash size overriding the ID bytes. "
171                                  "The size is specified in erase blocks and as the exponent of a power of two"
172                                  " e.g. 5 means a size of 32 erase blocks");
173 MODULE_PARM_DESC(cache_file,     "File to use to cache nand pages instead of memory");
174 MODULE_PARM_DESC(bbt,            "0 OOB, 1 BBT with marker in OOB, 2 BBT with marker in data area");
175 MODULE_PARM_DESC(bch,            "Enable BCH ecc and set how many bits should "
176                                  "be correctable in 512-byte blocks");
177
178 /* The largest possible page size */
179 #define NS_LARGEST_PAGE_SIZE    4096
180
181 /* The prefix for simulator output */
182 #define NS_OUTPUT_PREFIX "[nandsim]"
183
184 /* Simulator's output macros (logging, debugging, warning, error) */
185 #define NS_LOG(args...) \
186         do { if (log) printk(KERN_DEBUG NS_OUTPUT_PREFIX " log: " args); } while(0)
187 #define NS_DBG(args...) \
188         do { if (dbg) printk(KERN_DEBUG NS_OUTPUT_PREFIX " debug: " args); } while(0)
189 #define NS_WARN(args...) \
190         do { printk(KERN_WARNING NS_OUTPUT_PREFIX " warning: " args); } while(0)
191 #define NS_ERR(args...) \
192         do { printk(KERN_ERR NS_OUTPUT_PREFIX " error: " args); } while(0)
193 #define NS_INFO(args...) \
194         do { printk(KERN_INFO NS_OUTPUT_PREFIX " " args); } while(0)
195
196 /* Busy-wait delay macros (microseconds, milliseconds) */
197 #define NS_UDELAY(us) \
198         do { if (do_delays) udelay(us); } while(0)
199 #define NS_MDELAY(us) \
200         do { if (do_delays) mdelay(us); } while(0)
201
202 /* Is the nandsim structure initialized ? */
203 #define NS_IS_INITIALIZED(ns) ((ns)->geom.totsz != 0)
204
205 /* Good operation completion status */
206 #define NS_STATUS_OK(ns) (NAND_STATUS_READY | (NAND_STATUS_WP * ((ns)->lines.wp == 0)))
207
208 /* Operation failed completion status */
209 #define NS_STATUS_FAILED(ns) (NAND_STATUS_FAIL | NS_STATUS_OK(ns))
210
211 /* Calculate the page offset in flash RAM image by (row, column) address */
212 #define NS_RAW_OFFSET(ns) \
213         (((ns)->regs.row * (ns)->geom.pgszoob) + (ns)->regs.column)
214
215 /* Calculate the OOB offset in flash RAM image by (row, column) address */
216 #define NS_RAW_OFFSET_OOB(ns) (NS_RAW_OFFSET(ns) + ns->geom.pgsz)
217
218 /* After a command is input, the simulator goes to one of the following states */
219 #define STATE_CMD_READ0        0x00000001 /* read data from the beginning of page */
220 #define STATE_CMD_READ1        0x00000002 /* read data from the second half of page */
221 #define STATE_CMD_READSTART    0x00000003 /* read data second command (large page devices) */
222 #define STATE_CMD_PAGEPROG     0x00000004 /* start page program */
223 #define STATE_CMD_READOOB      0x00000005 /* read OOB area */
224 #define STATE_CMD_ERASE1       0x00000006 /* sector erase first command */
225 #define STATE_CMD_STATUS       0x00000007 /* read status */
226 #define STATE_CMD_SEQIN        0x00000009 /* sequential data input */
227 #define STATE_CMD_READID       0x0000000A /* read ID */
228 #define STATE_CMD_ERASE2       0x0000000B /* sector erase second command */
229 #define STATE_CMD_RESET        0x0000000C /* reset */
230 #define STATE_CMD_RNDOUT       0x0000000D /* random output command */
231 #define STATE_CMD_RNDOUTSTART  0x0000000E /* random output start command */
232 #define STATE_CMD_MASK         0x0000000F /* command states mask */
233
234 /* After an address is input, the simulator goes to one of these states */
235 #define STATE_ADDR_PAGE        0x00000010 /* full (row, column) address is accepted */
236 #define STATE_ADDR_SEC         0x00000020 /* sector address was accepted */
237 #define STATE_ADDR_COLUMN      0x00000030 /* column address was accepted */
238 #define STATE_ADDR_ZERO        0x00000040 /* one byte zero address was accepted */
239 #define STATE_ADDR_MASK        0x00000070 /* address states mask */
240
241 /* During data input/output the simulator is in these states */
242 #define STATE_DATAIN           0x00000100 /* waiting for data input */
243 #define STATE_DATAIN_MASK      0x00000100 /* data input states mask */
244
245 #define STATE_DATAOUT          0x00001000 /* waiting for page data output */
246 #define STATE_DATAOUT_ID       0x00002000 /* waiting for ID bytes output */
247 #define STATE_DATAOUT_STATUS   0x00003000 /* waiting for status output */
248 #define STATE_DATAOUT_MASK     0x00007000 /* data output states mask */
249
250 /* Previous operation is done, ready to accept new requests */
251 #define STATE_READY            0x00000000
252
253 /* This state is used to mark that the next state isn't known yet */
254 #define STATE_UNKNOWN          0x10000000
255
256 /* Simulator's actions bit masks */
257 #define ACTION_CPY       0x00100000 /* copy page/OOB to the internal buffer */
258 #define ACTION_PRGPAGE   0x00200000 /* program the internal buffer to flash */
259 #define ACTION_SECERASE  0x00300000 /* erase sector */
260 #define ACTION_ZEROOFF   0x00400000 /* don't add any offset to address */
261 #define ACTION_HALFOFF   0x00500000 /* add to address half of page */
262 #define ACTION_OOBOFF    0x00600000 /* add to address OOB offset */
263 #define ACTION_MASK      0x00700000 /* action mask */
264
265 #define NS_OPER_NUM      13 /* Number of operations supported by the simulator */
266 #define NS_OPER_STATES   6  /* Maximum number of states in operation */
267
268 #define OPT_ANY          0xFFFFFFFF /* any chip supports this operation */
269 #define OPT_PAGE512      0x00000002 /* 512-byte  page chips */
270 #define OPT_PAGE2048     0x00000008 /* 2048-byte page 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_PAGE512) /* 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 struct nandsim_debug_info {
290         struct dentry *dfs_root;
291         struct dentry *dfs_wear_report;
292 };
293
294 /*
295  * A union to represent flash memory contents and flash buffer.
296  */
297 union ns_mem {
298         u_char *byte;    /* for byte access */
299         uint16_t *word;  /* for 16-bit word access */
300 };
301
302 /*
303  * The structure which describes all the internal simulator data.
304  */
305 struct nandsim {
306         struct mtd_partition partitions[CONFIG_NANDSIM_MAX_PARTS];
307         unsigned int nbparts;
308
309         uint busw;              /* flash chip bus width (8 or 16) */
310         u_char ids[8];          /* chip's ID bytes */
311         uint32_t options;       /* chip's characteristic bits */
312         uint32_t state;         /* current chip state */
313         uint32_t nxstate;       /* next expected state */
314
315         uint32_t *op;           /* current operation, NULL operations isn't known yet  */
316         uint32_t pstates[NS_MAX_PREVSTATES]; /* previous states */
317         uint16_t npstates;      /* number of previous states saved */
318         uint16_t stateidx;      /* current state index */
319
320         /* The simulated NAND flash pages array */
321         union ns_mem *pages;
322
323         /* Slab allocator for nand pages */
324         struct kmem_cache *nand_pages_slab;
325
326         /* Internal buffer of page + OOB size bytes */
327         union ns_mem buf;
328
329         /* NAND flash "geometry" */
330         struct {
331                 uint64_t totsz;     /* total flash size, bytes */
332                 uint32_t secsz;     /* flash sector (erase block) size, bytes */
333                 uint pgsz;          /* NAND flash page size, bytes */
334                 uint oobsz;         /* page OOB area size, bytes */
335                 uint64_t totszoob;  /* total flash size including OOB, bytes */
336                 uint pgszoob;       /* page size including OOB , bytes*/
337                 uint secszoob;      /* sector size including OOB, bytes */
338                 uint pgnum;         /* total number of pages */
339                 uint pgsec;         /* number of pages per sector */
340                 uint secshift;      /* bits number in sector size */
341                 uint pgshift;       /* bits number in page size */
342                 uint pgaddrbytes;   /* bytes per page address */
343                 uint secaddrbytes;  /* bytes per sector address */
344                 uint idbytes;       /* the number ID bytes that this chip outputs */
345         } geom;
346
347         /* NAND flash internal registers */
348         struct {
349                 unsigned command; /* the command register */
350                 u_char   status;  /* the status register */
351                 uint     row;     /* the page number */
352                 uint     column;  /* the offset within page */
353                 uint     count;   /* internal counter */
354                 uint     num;     /* number of bytes which must be processed */
355                 uint     off;     /* fixed page offset */
356         } regs;
357
358         /* NAND flash lines state */
359         struct {
360                 int ce;  /* chip Enable */
361                 int cle; /* command Latch Enable */
362                 int ale; /* address Latch Enable */
363                 int wp;  /* write Protect */
364         } lines;
365
366         /* Fields needed when using a cache file */
367         struct file *cfile; /* Open file */
368         unsigned long *pages_written; /* Which pages have been written */
369         void *file_buf;
370         struct page *held_pages[NS_MAX_HELD_PAGES];
371         int held_cnt;
372
373         struct nandsim_debug_info dbg;
374 };
375
376 /*
377  * Operations array. To perform any operation the simulator must pass
378  * through the correspondent states chain.
379  */
380 static struct nandsim_operations {
381         uint32_t reqopts;  /* options which are required to perform the operation */
382         uint32_t states[NS_OPER_STATES]; /* operation's states */
383 } ops[NS_OPER_NUM] = {
384         /* Read page + OOB from the beginning */
385         {OPT_SMALLPAGE, {STATE_CMD_READ0 | ACTION_ZEROOFF, STATE_ADDR_PAGE | ACTION_CPY,
386                         STATE_DATAOUT, STATE_READY}},
387         /* Read page + OOB from the second half */
388         {OPT_PAGE512_8BIT, {STATE_CMD_READ1 | ACTION_HALFOFF, STATE_ADDR_PAGE | ACTION_CPY,
389                         STATE_DATAOUT, STATE_READY}},
390         /* Read OOB */
391         {OPT_SMALLPAGE, {STATE_CMD_READOOB | ACTION_OOBOFF, STATE_ADDR_PAGE | ACTION_CPY,
392                         STATE_DATAOUT, STATE_READY}},
393         /* Program page starting from the beginning */
394         {OPT_ANY, {STATE_CMD_SEQIN, STATE_ADDR_PAGE, STATE_DATAIN,
395                         STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
396         /* Program page starting from the beginning */
397         {OPT_SMALLPAGE, {STATE_CMD_READ0, STATE_CMD_SEQIN | ACTION_ZEROOFF, STATE_ADDR_PAGE,
398                               STATE_DATAIN, STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
399         /* Program page starting from the second half */
400         {OPT_PAGE512, {STATE_CMD_READ1, STATE_CMD_SEQIN | ACTION_HALFOFF, STATE_ADDR_PAGE,
401                               STATE_DATAIN, STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
402         /* Program OOB */
403         {OPT_SMALLPAGE, {STATE_CMD_READOOB, STATE_CMD_SEQIN | ACTION_OOBOFF, STATE_ADDR_PAGE,
404                               STATE_DATAIN, STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
405         /* Erase sector */
406         {OPT_ANY, {STATE_CMD_ERASE1, STATE_ADDR_SEC, STATE_CMD_ERASE2 | ACTION_SECERASE, STATE_READY}},
407         /* Read status */
408         {OPT_ANY, {STATE_CMD_STATUS, STATE_DATAOUT_STATUS, STATE_READY}},
409         /* Read ID */
410         {OPT_ANY, {STATE_CMD_READID, STATE_ADDR_ZERO, STATE_DATAOUT_ID, STATE_READY}},
411         /* Large page devices read page */
412         {OPT_LARGEPAGE, {STATE_CMD_READ0, STATE_ADDR_PAGE, STATE_CMD_READSTART | ACTION_CPY,
413                                STATE_DATAOUT, STATE_READY}},
414         /* Large page devices random page read */
415         {OPT_LARGEPAGE, {STATE_CMD_RNDOUT, STATE_ADDR_COLUMN, STATE_CMD_RNDOUTSTART | ACTION_CPY,
416                                STATE_DATAOUT, STATE_READY}},
417 };
418
419 struct weak_block {
420         struct list_head list;
421         unsigned int erase_block_no;
422         unsigned int max_erases;
423         unsigned int erases_done;
424 };
425
426 static LIST_HEAD(weak_blocks);
427
428 struct weak_page {
429         struct list_head list;
430         unsigned int page_no;
431         unsigned int max_writes;
432         unsigned int writes_done;
433 };
434
435 static LIST_HEAD(weak_pages);
436
437 struct grave_page {
438         struct list_head list;
439         unsigned int page_no;
440         unsigned int max_reads;
441         unsigned int reads_done;
442 };
443
444 static LIST_HEAD(grave_pages);
445
446 static unsigned long *erase_block_wear = NULL;
447 static unsigned int wear_eb_count = 0;
448 static unsigned long total_wear = 0;
449
450 /* MTD structure for NAND controller */
451 static struct mtd_info *nsmtd;
452
453 static int nandsim_debugfs_show(struct seq_file *m, void *private)
454 {
455         unsigned long wmin = -1, wmax = 0, avg;
456         unsigned long deciles[10], decile_max[10], tot = 0;
457         unsigned int i;
458
459         /* Calc wear stats */
460         for (i = 0; i < wear_eb_count; ++i) {
461                 unsigned long wear = erase_block_wear[i];
462                 if (wear < wmin)
463                         wmin = wear;
464                 if (wear > wmax)
465                         wmax = wear;
466                 tot += wear;
467         }
468
469         for (i = 0; i < 9; ++i) {
470                 deciles[i] = 0;
471                 decile_max[i] = (wmax * (i + 1) + 5) / 10;
472         }
473         deciles[9] = 0;
474         decile_max[9] = wmax;
475         for (i = 0; i < wear_eb_count; ++i) {
476                 int d;
477                 unsigned long wear = erase_block_wear[i];
478                 for (d = 0; d < 10; ++d)
479                         if (wear <= decile_max[d]) {
480                                 deciles[d] += 1;
481                                 break;
482                         }
483         }
484         avg = tot / wear_eb_count;
485
486         /* Output wear report */
487         seq_printf(m, "Total numbers of erases:  %lu\n", tot);
488         seq_printf(m, "Number of erase blocks:   %u\n", wear_eb_count);
489         seq_printf(m, "Average number of erases: %lu\n", avg);
490         seq_printf(m, "Maximum number of erases: %lu\n", wmax);
491         seq_printf(m, "Minimum number of erases: %lu\n", wmin);
492         for (i = 0; i < 10; ++i) {
493                 unsigned long from = (i ? decile_max[i - 1] + 1 : 0);
494                 if (from > decile_max[i])
495                         continue;
496                 seq_printf(m, "Number of ebs with erase counts from %lu to %lu : %lu\n",
497                         from,
498                         decile_max[i],
499                         deciles[i]);
500         }
501
502         return 0;
503 }
504
505 static int nandsim_debugfs_open(struct inode *inode, struct file *file)
506 {
507         return single_open(file, nandsim_debugfs_show, inode->i_private);
508 }
509
510 static const struct file_operations dfs_fops = {
511         .open           = nandsim_debugfs_open,
512         .read           = seq_read,
513         .llseek         = seq_lseek,
514         .release        = single_release,
515 };
516
517 /**
518  * nandsim_debugfs_create - initialize debugfs
519  * @dev: nandsim device description object
520  *
521  * This function creates all debugfs files for UBI device @ubi. Returns zero in
522  * case of success and a negative error code in case of failure.
523  */
524 static int nandsim_debugfs_create(struct nandsim *dev)
525 {
526         struct nandsim_debug_info *dbg = &dev->dbg;
527         struct dentry *dent;
528         int err;
529
530         if (!IS_ENABLED(CONFIG_DEBUG_FS))
531                 return 0;
532
533         dent = debugfs_create_dir("nandsim", NULL);
534         if (IS_ERR_OR_NULL(dent)) {
535                 int err = dent ? -ENODEV : PTR_ERR(dent);
536
537                 NS_ERR("cannot create \"nandsim\" debugfs directory, err %d\n",
538                         err);
539                 return err;
540         }
541         dbg->dfs_root = dent;
542
543         dent = debugfs_create_file("wear_report", S_IRUSR,
544                                    dbg->dfs_root, dev, &dfs_fops);
545         if (IS_ERR_OR_NULL(dent))
546                 goto out_remove;
547         dbg->dfs_wear_report = dent;
548
549         return 0;
550
551 out_remove:
552         debugfs_remove_recursive(dbg->dfs_root);
553         err = dent ? PTR_ERR(dent) : -ENODEV;
554         return err;
555 }
556
557 /**
558  * nandsim_debugfs_remove - destroy all debugfs files
559  */
560 static void nandsim_debugfs_remove(struct nandsim *ns)
561 {
562         if (IS_ENABLED(CONFIG_DEBUG_FS))
563                 debugfs_remove_recursive(ns->dbg.dfs_root);
564 }
565
566 /*
567  * Allocate array of page pointers, create slab allocation for an array
568  * and initialize the array by NULL pointers.
569  *
570  * RETURNS: 0 if success, -ENOMEM if memory alloc fails.
571  */
572 static int alloc_device(struct nandsim *ns)
573 {
574         struct file *cfile;
575         int i, err;
576
577         if (cache_file) {
578                 cfile = filp_open(cache_file, O_CREAT | O_RDWR | O_LARGEFILE, 0600);
579                 if (IS_ERR(cfile))
580                         return PTR_ERR(cfile);
581                 if (!(cfile->f_mode & FMODE_CAN_READ)) {
582                         NS_ERR("alloc_device: cache file not readable\n");
583                         err = -EINVAL;
584                         goto err_close;
585                 }
586                 if (!(cfile->f_mode & FMODE_CAN_WRITE)) {
587                         NS_ERR("alloc_device: cache file not writeable\n");
588                         err = -EINVAL;
589                         goto err_close;
590                 }
591                 ns->pages_written = vzalloc(BITS_TO_LONGS(ns->geom.pgnum) *
592                                             sizeof(unsigned long));
593                 if (!ns->pages_written) {
594                         NS_ERR("alloc_device: unable to allocate pages written array\n");
595                         err = -ENOMEM;
596                         goto err_close;
597                 }
598                 ns->file_buf = kmalloc(ns->geom.pgszoob, GFP_KERNEL);
599                 if (!ns->file_buf) {
600                         NS_ERR("alloc_device: unable to allocate file buf\n");
601                         err = -ENOMEM;
602                         goto err_free;
603                 }
604                 ns->cfile = cfile;
605                 return 0;
606         }
607
608         ns->pages = vmalloc(ns->geom.pgnum * sizeof(union ns_mem));
609         if (!ns->pages) {
610                 NS_ERR("alloc_device: unable to allocate page array\n");
611                 return -ENOMEM;
612         }
613         for (i = 0; i < ns->geom.pgnum; i++) {
614                 ns->pages[i].byte = NULL;
615         }
616         ns->nand_pages_slab = kmem_cache_create("nandsim",
617                                                 ns->geom.pgszoob, 0, 0, NULL);
618         if (!ns->nand_pages_slab) {
619                 NS_ERR("cache_create: unable to create kmem_cache\n");
620                 return -ENOMEM;
621         }
622
623         return 0;
624
625 err_free:
626         vfree(ns->pages_written);
627 err_close:
628         filp_close(cfile, NULL);
629         return err;
630 }
631
632 /*
633  * Free any allocated pages, and free the array of page pointers.
634  */
635 static void free_device(struct nandsim *ns)
636 {
637         int i;
638
639         if (ns->cfile) {
640                 kfree(ns->file_buf);
641                 vfree(ns->pages_written);
642                 filp_close(ns->cfile, NULL);
643                 return;
644         }
645
646         if (ns->pages) {
647                 for (i = 0; i < ns->geom.pgnum; i++) {
648                         if (ns->pages[i].byte)
649                                 kmem_cache_free(ns->nand_pages_slab,
650                                                 ns->pages[i].byte);
651                 }
652                 kmem_cache_destroy(ns->nand_pages_slab);
653                 vfree(ns->pages);
654         }
655 }
656
657 static char *get_partition_name(int i)
658 {
659         return kasprintf(GFP_KERNEL, "NAND simulator partition %d", i);
660 }
661
662 /*
663  * Initialize the nandsim structure.
664  *
665  * RETURNS: 0 if success, -ERRNO if failure.
666  */
667 static int init_nandsim(struct mtd_info *mtd)
668 {
669         struct nand_chip *chip = mtd->priv;
670         struct nandsim   *ns   = chip->priv;
671         int i, ret = 0;
672         uint64_t remains;
673         uint64_t next_offset;
674
675         if (NS_IS_INITIALIZED(ns)) {
676                 NS_ERR("init_nandsim: nandsim is already initialized\n");
677                 return -EIO;
678         }
679
680         /* Force mtd to not do delays */
681         chip->chip_delay = 0;
682
683         /* Initialize the NAND flash parameters */
684         ns->busw = chip->options & NAND_BUSWIDTH_16 ? 16 : 8;
685         ns->geom.totsz    = mtd->size;
686         ns->geom.pgsz     = mtd->writesize;
687         ns->geom.oobsz    = mtd->oobsize;
688         ns->geom.secsz    = mtd->erasesize;
689         ns->geom.pgszoob  = ns->geom.pgsz + ns->geom.oobsz;
690         ns->geom.pgnum    = div_u64(ns->geom.totsz, ns->geom.pgsz);
691         ns->geom.totszoob = ns->geom.totsz + (uint64_t)ns->geom.pgnum * ns->geom.oobsz;
692         ns->geom.secshift = ffs(ns->geom.secsz) - 1;
693         ns->geom.pgshift  = chip->page_shift;
694         ns->geom.pgsec    = ns->geom.secsz / ns->geom.pgsz;
695         ns->geom.secszoob = ns->geom.secsz + ns->geom.oobsz * ns->geom.pgsec;
696         ns->options = 0;
697
698         if (ns->geom.pgsz == 512) {
699                 ns->options |= OPT_PAGE512;
700                 if (ns->busw == 8)
701                         ns->options |= OPT_PAGE512_8BIT;
702         } else if (ns->geom.pgsz == 2048) {
703                 ns->options |= OPT_PAGE2048;
704         } else if (ns->geom.pgsz == 4096) {
705                 ns->options |= OPT_PAGE4096;
706         } else {
707                 NS_ERR("init_nandsim: unknown page size %u\n", ns->geom.pgsz);
708                 return -EIO;
709         }
710
711         if (ns->options & OPT_SMALLPAGE) {
712                 if (ns->geom.totsz <= (32 << 20)) {
713                         ns->geom.pgaddrbytes  = 3;
714                         ns->geom.secaddrbytes = 2;
715                 } else {
716                         ns->geom.pgaddrbytes  = 4;
717                         ns->geom.secaddrbytes = 3;
718                 }
719         } else {
720                 if (ns->geom.totsz <= (128 << 20)) {
721                         ns->geom.pgaddrbytes  = 4;
722                         ns->geom.secaddrbytes = 2;
723                 } else {
724                         ns->geom.pgaddrbytes  = 5;
725                         ns->geom.secaddrbytes = 3;
726                 }
727         }
728
729         /* Fill the partition_info structure */
730         if (parts_num > ARRAY_SIZE(ns->partitions)) {
731                 NS_ERR("too many partitions.\n");
732                 ret = -EINVAL;
733                 goto error;
734         }
735         remains = ns->geom.totsz;
736         next_offset = 0;
737         for (i = 0; i < parts_num; ++i) {
738                 uint64_t part_sz = (uint64_t)parts[i] * ns->geom.secsz;
739
740                 if (!part_sz || part_sz > remains) {
741                         NS_ERR("bad partition size.\n");
742                         ret = -EINVAL;
743                         goto error;
744                 }
745                 ns->partitions[i].name   = get_partition_name(i);
746                 ns->partitions[i].offset = next_offset;
747                 ns->partitions[i].size   = part_sz;
748                 next_offset += ns->partitions[i].size;
749                 remains -= ns->partitions[i].size;
750         }
751         ns->nbparts = parts_num;
752         if (remains) {
753                 if (parts_num + 1 > ARRAY_SIZE(ns->partitions)) {
754                         NS_ERR("too many partitions.\n");
755                         ret = -EINVAL;
756                         goto error;
757                 }
758                 ns->partitions[i].name   = get_partition_name(i);
759                 ns->partitions[i].offset = next_offset;
760                 ns->partitions[i].size   = remains;
761                 ns->nbparts += 1;
762         }
763
764         if (ns->busw == 16)
765                 NS_WARN("16-bit flashes support wasn't tested\n");
766
767         printk("flash size: %llu MiB\n",
768                         (unsigned long long)ns->geom.totsz >> 20);
769         printk("page size: %u bytes\n",         ns->geom.pgsz);
770         printk("OOB area size: %u bytes\n",     ns->geom.oobsz);
771         printk("sector size: %u KiB\n",         ns->geom.secsz >> 10);
772         printk("pages number: %u\n",            ns->geom.pgnum);
773         printk("pages per sector: %u\n",        ns->geom.pgsec);
774         printk("bus width: %u\n",               ns->busw);
775         printk("bits in sector size: %u\n",     ns->geom.secshift);
776         printk("bits in page size: %u\n",       ns->geom.pgshift);
777         printk("bits in OOB size: %u\n",        ffs(ns->geom.oobsz) - 1);
778         printk("flash size with OOB: %llu KiB\n",
779                         (unsigned long long)ns->geom.totszoob >> 10);
780         printk("page address bytes: %u\n",      ns->geom.pgaddrbytes);
781         printk("sector address bytes: %u\n",    ns->geom.secaddrbytes);
782         printk("options: %#x\n",                ns->options);
783
784         if ((ret = alloc_device(ns)) != 0)
785                 goto error;
786
787         /* Allocate / initialize the internal buffer */
788         ns->buf.byte = kmalloc(ns->geom.pgszoob, GFP_KERNEL);
789         if (!ns->buf.byte) {
790                 NS_ERR("init_nandsim: unable to allocate %u bytes for the internal buffer\n",
791                         ns->geom.pgszoob);
792                 ret = -ENOMEM;
793                 goto error;
794         }
795         memset(ns->buf.byte, 0xFF, ns->geom.pgszoob);
796
797         return 0;
798
799 error:
800         free_device(ns);
801
802         return ret;
803 }
804
805 /*
806  * Free the nandsim structure.
807  */
808 static void free_nandsim(struct nandsim *ns)
809 {
810         kfree(ns->buf.byte);
811         free_device(ns);
812
813         return;
814 }
815
816 static int parse_badblocks(struct nandsim *ns, struct mtd_info *mtd)
817 {
818         char *w;
819         int zero_ok;
820         unsigned int erase_block_no;
821         loff_t offset;
822
823         if (!badblocks)
824                 return 0;
825         w = badblocks;
826         do {
827                 zero_ok = (*w == '0' ? 1 : 0);
828                 erase_block_no = simple_strtoul(w, &w, 0);
829                 if (!zero_ok && !erase_block_no) {
830                         NS_ERR("invalid badblocks.\n");
831                         return -EINVAL;
832                 }
833                 offset = (loff_t)erase_block_no * ns->geom.secsz;
834                 if (mtd_block_markbad(mtd, offset)) {
835                         NS_ERR("invalid badblocks.\n");
836                         return -EINVAL;
837                 }
838                 if (*w == ',')
839                         w += 1;
840         } while (*w);
841         return 0;
842 }
843
844 static int parse_weakblocks(void)
845 {
846         char *w;
847         int zero_ok;
848         unsigned int erase_block_no;
849         unsigned int max_erases;
850         struct weak_block *wb;
851
852         if (!weakblocks)
853                 return 0;
854         w = weakblocks;
855         do {
856                 zero_ok = (*w == '0' ? 1 : 0);
857                 erase_block_no = simple_strtoul(w, &w, 0);
858                 if (!zero_ok && !erase_block_no) {
859                         NS_ERR("invalid weakblocks.\n");
860                         return -EINVAL;
861                 }
862                 max_erases = 3;
863                 if (*w == ':') {
864                         w += 1;
865                         max_erases = simple_strtoul(w, &w, 0);
866                 }
867                 if (*w == ',')
868                         w += 1;
869                 wb = kzalloc(sizeof(*wb), GFP_KERNEL);
870                 if (!wb) {
871                         NS_ERR("unable to allocate memory.\n");
872                         return -ENOMEM;
873                 }
874                 wb->erase_block_no = erase_block_no;
875                 wb->max_erases = max_erases;
876                 list_add(&wb->list, &weak_blocks);
877         } while (*w);
878         return 0;
879 }
880
881 static int erase_error(unsigned int erase_block_no)
882 {
883         struct weak_block *wb;
884
885         list_for_each_entry(wb, &weak_blocks, list)
886                 if (wb->erase_block_no == erase_block_no) {
887                         if (wb->erases_done >= wb->max_erases)
888                                 return 1;
889                         wb->erases_done += 1;
890                         return 0;
891                 }
892         return 0;
893 }
894
895 static int parse_weakpages(void)
896 {
897         char *w;
898         int zero_ok;
899         unsigned int page_no;
900         unsigned int max_writes;
901         struct weak_page *wp;
902
903         if (!weakpages)
904                 return 0;
905         w = weakpages;
906         do {
907                 zero_ok = (*w == '0' ? 1 : 0);
908                 page_no = simple_strtoul(w, &w, 0);
909                 if (!zero_ok && !page_no) {
910                         NS_ERR("invalid weakpagess.\n");
911                         return -EINVAL;
912                 }
913                 max_writes = 3;
914                 if (*w == ':') {
915                         w += 1;
916                         max_writes = simple_strtoul(w, &w, 0);
917                 }
918                 if (*w == ',')
919                         w += 1;
920                 wp = kzalloc(sizeof(*wp), GFP_KERNEL);
921                 if (!wp) {
922                         NS_ERR("unable to allocate memory.\n");
923                         return -ENOMEM;
924                 }
925                 wp->page_no = page_no;
926                 wp->max_writes = max_writes;
927                 list_add(&wp->list, &weak_pages);
928         } while (*w);
929         return 0;
930 }
931
932 static int write_error(unsigned int page_no)
933 {
934         struct weak_page *wp;
935
936         list_for_each_entry(wp, &weak_pages, list)
937                 if (wp->page_no == page_no) {
938                         if (wp->writes_done >= wp->max_writes)
939                                 return 1;
940                         wp->writes_done += 1;
941                         return 0;
942                 }
943         return 0;
944 }
945
946 static int parse_gravepages(void)
947 {
948         char *g;
949         int zero_ok;
950         unsigned int page_no;
951         unsigned int max_reads;
952         struct grave_page *gp;
953
954         if (!gravepages)
955                 return 0;
956         g = gravepages;
957         do {
958                 zero_ok = (*g == '0' ? 1 : 0);
959                 page_no = simple_strtoul(g, &g, 0);
960                 if (!zero_ok && !page_no) {
961                         NS_ERR("invalid gravepagess.\n");
962                         return -EINVAL;
963                 }
964                 max_reads = 3;
965                 if (*g == ':') {
966                         g += 1;
967                         max_reads = simple_strtoul(g, &g, 0);
968                 }
969                 if (*g == ',')
970                         g += 1;
971                 gp = kzalloc(sizeof(*gp), GFP_KERNEL);
972                 if (!gp) {
973                         NS_ERR("unable to allocate memory.\n");
974                         return -ENOMEM;
975                 }
976                 gp->page_no = page_no;
977                 gp->max_reads = max_reads;
978                 list_add(&gp->list, &grave_pages);
979         } while (*g);
980         return 0;
981 }
982
983 static int read_error(unsigned int page_no)
984 {
985         struct grave_page *gp;
986
987         list_for_each_entry(gp, &grave_pages, list)
988                 if (gp->page_no == page_no) {
989                         if (gp->reads_done >= gp->max_reads)
990                                 return 1;
991                         gp->reads_done += 1;
992                         return 0;
993                 }
994         return 0;
995 }
996
997 static void free_lists(void)
998 {
999         struct list_head *pos, *n;
1000         list_for_each_safe(pos, n, &weak_blocks) {
1001                 list_del(pos);
1002                 kfree(list_entry(pos, struct weak_block, list));
1003         }
1004         list_for_each_safe(pos, n, &weak_pages) {
1005                 list_del(pos);
1006                 kfree(list_entry(pos, struct weak_page, list));
1007         }
1008         list_for_each_safe(pos, n, &grave_pages) {
1009                 list_del(pos);
1010                 kfree(list_entry(pos, struct grave_page, list));
1011         }
1012         kfree(erase_block_wear);
1013 }
1014
1015 static int setup_wear_reporting(struct mtd_info *mtd)
1016 {
1017         size_t mem;
1018
1019         wear_eb_count = div_u64(mtd->size, mtd->erasesize);
1020         mem = wear_eb_count * sizeof(unsigned long);
1021         if (mem / sizeof(unsigned long) != wear_eb_count) {
1022                 NS_ERR("Too many erase blocks for wear reporting\n");
1023                 return -ENOMEM;
1024         }
1025         erase_block_wear = kzalloc(mem, GFP_KERNEL);
1026         if (!erase_block_wear) {
1027                 NS_ERR("Too many erase blocks for wear reporting\n");
1028                 return -ENOMEM;
1029         }
1030         return 0;
1031 }
1032
1033 static void update_wear(unsigned int erase_block_no)
1034 {
1035         if (!erase_block_wear)
1036                 return;
1037         total_wear += 1;
1038         /*
1039          * TODO: Notify this through a debugfs entry,
1040          * instead of showing an error message.
1041          */
1042         if (total_wear == 0)
1043                 NS_ERR("Erase counter total overflow\n");
1044         erase_block_wear[erase_block_no] += 1;
1045         if (erase_block_wear[erase_block_no] == 0)
1046                 NS_ERR("Erase counter overflow for erase block %u\n", erase_block_no);
1047 }
1048
1049 /*
1050  * Returns the string representation of 'state' state.
1051  */
1052 static char *get_state_name(uint32_t state)
1053 {
1054         switch (NS_STATE(state)) {
1055                 case STATE_CMD_READ0:
1056                         return "STATE_CMD_READ0";
1057                 case STATE_CMD_READ1:
1058                         return "STATE_CMD_READ1";
1059                 case STATE_CMD_PAGEPROG:
1060                         return "STATE_CMD_PAGEPROG";
1061                 case STATE_CMD_READOOB:
1062                         return "STATE_CMD_READOOB";
1063                 case STATE_CMD_READSTART:
1064                         return "STATE_CMD_READSTART";
1065                 case STATE_CMD_ERASE1:
1066                         return "STATE_CMD_ERASE1";
1067                 case STATE_CMD_STATUS:
1068                         return "STATE_CMD_STATUS";
1069                 case STATE_CMD_SEQIN:
1070                         return "STATE_CMD_SEQIN";
1071                 case STATE_CMD_READID:
1072                         return "STATE_CMD_READID";
1073                 case STATE_CMD_ERASE2:
1074                         return "STATE_CMD_ERASE2";
1075                 case STATE_CMD_RESET:
1076                         return "STATE_CMD_RESET";
1077                 case STATE_CMD_RNDOUT:
1078                         return "STATE_CMD_RNDOUT";
1079                 case STATE_CMD_RNDOUTSTART:
1080                         return "STATE_CMD_RNDOUTSTART";
1081                 case STATE_ADDR_PAGE:
1082                         return "STATE_ADDR_PAGE";
1083                 case STATE_ADDR_SEC:
1084                         return "STATE_ADDR_SEC";
1085                 case STATE_ADDR_ZERO:
1086                         return "STATE_ADDR_ZERO";
1087                 case STATE_ADDR_COLUMN:
1088                         return "STATE_ADDR_COLUMN";
1089                 case STATE_DATAIN:
1090                         return "STATE_DATAIN";
1091                 case STATE_DATAOUT:
1092                         return "STATE_DATAOUT";
1093                 case STATE_DATAOUT_ID:
1094                         return "STATE_DATAOUT_ID";
1095                 case STATE_DATAOUT_STATUS:
1096                         return "STATE_DATAOUT_STATUS";
1097                 case STATE_READY:
1098                         return "STATE_READY";
1099                 case STATE_UNKNOWN:
1100                         return "STATE_UNKNOWN";
1101         }
1102
1103         NS_ERR("get_state_name: unknown state, BUG\n");
1104         return NULL;
1105 }
1106
1107 /*
1108  * Check if command is valid.
1109  *
1110  * RETURNS: 1 if wrong command, 0 if right.
1111  */
1112 static int check_command(int cmd)
1113 {
1114         switch (cmd) {
1115
1116         case NAND_CMD_READ0:
1117         case NAND_CMD_READ1:
1118         case NAND_CMD_READSTART:
1119         case NAND_CMD_PAGEPROG:
1120         case NAND_CMD_READOOB:
1121         case NAND_CMD_ERASE1:
1122         case NAND_CMD_STATUS:
1123         case NAND_CMD_SEQIN:
1124         case NAND_CMD_READID:
1125         case NAND_CMD_ERASE2:
1126         case NAND_CMD_RESET:
1127         case NAND_CMD_RNDOUT:
1128         case NAND_CMD_RNDOUTSTART:
1129                 return 0;
1130
1131         default:
1132                 return 1;
1133         }
1134 }
1135
1136 /*
1137  * Returns state after command is accepted by command number.
1138  */
1139 static uint32_t get_state_by_command(unsigned command)
1140 {
1141         switch (command) {
1142                 case NAND_CMD_READ0:
1143                         return STATE_CMD_READ0;
1144                 case NAND_CMD_READ1:
1145                         return STATE_CMD_READ1;
1146                 case NAND_CMD_PAGEPROG:
1147                         return STATE_CMD_PAGEPROG;
1148                 case NAND_CMD_READSTART:
1149                         return STATE_CMD_READSTART;
1150                 case NAND_CMD_READOOB:
1151                         return STATE_CMD_READOOB;
1152                 case NAND_CMD_ERASE1:
1153                         return STATE_CMD_ERASE1;
1154                 case NAND_CMD_STATUS:
1155                         return STATE_CMD_STATUS;
1156                 case NAND_CMD_SEQIN:
1157                         return STATE_CMD_SEQIN;
1158                 case NAND_CMD_READID:
1159                         return STATE_CMD_READID;
1160                 case NAND_CMD_ERASE2:
1161                         return STATE_CMD_ERASE2;
1162                 case NAND_CMD_RESET:
1163                         return STATE_CMD_RESET;
1164                 case NAND_CMD_RNDOUT:
1165                         return STATE_CMD_RNDOUT;
1166                 case NAND_CMD_RNDOUTSTART:
1167                         return STATE_CMD_RNDOUTSTART;
1168         }
1169
1170         NS_ERR("get_state_by_command: unknown command, BUG\n");
1171         return 0;
1172 }
1173
1174 /*
1175  * Move an address byte to the correspondent internal register.
1176  */
1177 static inline void accept_addr_byte(struct nandsim *ns, u_char bt)
1178 {
1179         uint byte = (uint)bt;
1180
1181         if (ns->regs.count < (ns->geom.pgaddrbytes - ns->geom.secaddrbytes))
1182                 ns->regs.column |= (byte << 8 * ns->regs.count);
1183         else {
1184                 ns->regs.row |= (byte << 8 * (ns->regs.count -
1185                                                 ns->geom.pgaddrbytes +
1186                                                 ns->geom.secaddrbytes));
1187         }
1188
1189         return;
1190 }
1191
1192 /*
1193  * Switch to STATE_READY state.
1194  */
1195 static inline void switch_to_ready_state(struct nandsim *ns, u_char status)
1196 {
1197         NS_DBG("switch_to_ready_state: switch to %s state\n", get_state_name(STATE_READY));
1198
1199         ns->state       = STATE_READY;
1200         ns->nxstate     = STATE_UNKNOWN;
1201         ns->op          = NULL;
1202         ns->npstates    = 0;
1203         ns->stateidx    = 0;
1204         ns->regs.num    = 0;
1205         ns->regs.count  = 0;
1206         ns->regs.off    = 0;
1207         ns->regs.row    = 0;
1208         ns->regs.column = 0;
1209         ns->regs.status = status;
1210 }
1211
1212 /*
1213  * If the operation isn't known yet, try to find it in the global array
1214  * of supported operations.
1215  *
1216  * Operation can be unknown because of the following.
1217  *   1. New command was accepted and this is the first call to find the
1218  *      correspondent states chain. In this case ns->npstates = 0;
1219  *   2. There are several operations which begin with the same command(s)
1220  *      (for example program from the second half and read from the
1221  *      second half operations both begin with the READ1 command). In this
1222  *      case the ns->pstates[] array contains previous states.
1223  *
1224  * Thus, the function tries to find operation containing the following
1225  * states (if the 'flag' parameter is 0):
1226  *    ns->pstates[0], ... ns->pstates[ns->npstates], ns->state
1227  *
1228  * If (one and only one) matching operation is found, it is accepted (
1229  * ns->ops, ns->state, ns->nxstate are initialized, ns->npstate is
1230  * zeroed).
1231  *
1232  * If there are several matches, the current state is pushed to the
1233  * ns->pstates.
1234  *
1235  * The operation can be unknown only while commands are input to the chip.
1236  * As soon as address command is accepted, the operation must be known.
1237  * In such situation the function is called with 'flag' != 0, and the
1238  * operation is searched using the following pattern:
1239  *     ns->pstates[0], ... ns->pstates[ns->npstates], <address input>
1240  *
1241  * It is supposed that this pattern must either match one operation or
1242  * none. There can't be ambiguity in that case.
1243  *
1244  * If no matches found, the function does the following:
1245  *   1. if there are saved states present, try to ignore them and search
1246  *      again only using the last command. If nothing was found, switch
1247  *      to the STATE_READY state.
1248  *   2. if there are no saved states, switch to the STATE_READY state.
1249  *
1250  * RETURNS: -2 - no matched operations found.
1251  *          -1 - several matches.
1252  *           0 - operation is found.
1253  */
1254 static int find_operation(struct nandsim *ns, uint32_t flag)
1255 {
1256         int opsfound = 0;
1257         int i, j, idx = 0;
1258
1259         for (i = 0; i < NS_OPER_NUM; i++) {
1260
1261                 int found = 1;
1262
1263                 if (!(ns->options & ops[i].reqopts))
1264                         /* Ignore operations we can't perform */
1265                         continue;
1266
1267                 if (flag) {
1268                         if (!(ops[i].states[ns->npstates] & STATE_ADDR_MASK))
1269                                 continue;
1270                 } else {
1271                         if (NS_STATE(ns->state) != NS_STATE(ops[i].states[ns->npstates]))
1272                                 continue;
1273                 }
1274
1275                 for (j = 0; j < ns->npstates; j++)
1276                         if (NS_STATE(ops[i].states[j]) != NS_STATE(ns->pstates[j])
1277                                 && (ns->options & ops[idx].reqopts)) {
1278                                 found = 0;
1279                                 break;
1280                         }
1281
1282                 if (found) {
1283                         idx = i;
1284                         opsfound += 1;
1285                 }
1286         }
1287
1288         if (opsfound == 1) {
1289                 /* Exact match */
1290                 ns->op = &ops[idx].states[0];
1291                 if (flag) {
1292                         /*
1293                          * In this case the find_operation function was
1294                          * called when address has just began input. But it isn't
1295                          * yet fully input and the current state must
1296                          * not be one of STATE_ADDR_*, but the STATE_ADDR_*
1297                          * state must be the next state (ns->nxstate).
1298                          */
1299                         ns->stateidx = ns->npstates - 1;
1300                 } else {
1301                         ns->stateidx = ns->npstates;
1302                 }
1303                 ns->npstates = 0;
1304                 ns->state = ns->op[ns->stateidx];
1305                 ns->nxstate = ns->op[ns->stateidx + 1];
1306                 NS_DBG("find_operation: operation found, index: %d, state: %s, nxstate %s\n",
1307                                 idx, get_state_name(ns->state), get_state_name(ns->nxstate));
1308                 return 0;
1309         }
1310
1311         if (opsfound == 0) {
1312                 /* Nothing was found. Try to ignore previous commands (if any) and search again */
1313                 if (ns->npstates != 0) {
1314                         NS_DBG("find_operation: no operation found, try again with state %s\n",
1315                                         get_state_name(ns->state));
1316                         ns->npstates = 0;
1317                         return find_operation(ns, 0);
1318
1319                 }
1320                 NS_DBG("find_operation: no operations found\n");
1321                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1322                 return -2;
1323         }
1324
1325         if (flag) {
1326                 /* This shouldn't happen */
1327                 NS_DBG("find_operation: BUG, operation must be known if address is input\n");
1328                 return -2;
1329         }
1330
1331         NS_DBG("find_operation: there is still ambiguity\n");
1332
1333         ns->pstates[ns->npstates++] = ns->state;
1334
1335         return -1;
1336 }
1337
1338 static void put_pages(struct nandsim *ns)
1339 {
1340         int i;
1341
1342         for (i = 0; i < ns->held_cnt; i++)
1343                 page_cache_release(ns->held_pages[i]);
1344 }
1345
1346 /* Get page cache pages in advance to provide NOFS memory allocation */
1347 static int get_pages(struct nandsim *ns, struct file *file, size_t count, loff_t pos)
1348 {
1349         pgoff_t index, start_index, end_index;
1350         struct page *page;
1351         struct address_space *mapping = file->f_mapping;
1352
1353         start_index = pos >> PAGE_CACHE_SHIFT;
1354         end_index = (pos + count - 1) >> PAGE_CACHE_SHIFT;
1355         if (end_index - start_index + 1 > NS_MAX_HELD_PAGES)
1356                 return -EINVAL;
1357         ns->held_cnt = 0;
1358         for (index = start_index; index <= end_index; index++) {
1359                 page = find_get_page(mapping, index);
1360                 if (page == NULL) {
1361                         page = find_or_create_page(mapping, index, GFP_NOFS);
1362                         if (page == NULL) {
1363                                 write_inode_now(mapping->host, 1);
1364                                 page = find_or_create_page(mapping, index, GFP_NOFS);
1365                         }
1366                         if (page == NULL) {
1367                                 put_pages(ns);
1368                                 return -ENOMEM;
1369                         }
1370                         unlock_page(page);
1371                 }
1372                 ns->held_pages[ns->held_cnt++] = page;
1373         }
1374         return 0;
1375 }
1376
1377 static int set_memalloc(void)
1378 {
1379         if (current->flags & PF_MEMALLOC)
1380                 return 0;
1381         current->flags |= PF_MEMALLOC;
1382         return 1;
1383 }
1384
1385 static void clear_memalloc(int memalloc)
1386 {
1387         if (memalloc)
1388                 current->flags &= ~PF_MEMALLOC;
1389 }
1390
1391 static ssize_t read_file(struct nandsim *ns, struct file *file, void *buf, size_t count, loff_t pos)
1392 {
1393         ssize_t tx;
1394         int err, memalloc;
1395
1396         err = get_pages(ns, file, count, pos);
1397         if (err)
1398                 return err;
1399         memalloc = set_memalloc();
1400         tx = kernel_read(file, pos, buf, count);
1401         clear_memalloc(memalloc);
1402         put_pages(ns);
1403         return tx;
1404 }
1405
1406 static ssize_t write_file(struct nandsim *ns, struct file *file, void *buf, size_t count, loff_t pos)
1407 {
1408         ssize_t tx;
1409         int err, memalloc;
1410
1411         err = get_pages(ns, file, count, pos);
1412         if (err)
1413                 return err;
1414         memalloc = set_memalloc();
1415         tx = kernel_write(file, buf, count, pos);
1416         clear_memalloc(memalloc);
1417         put_pages(ns);
1418         return tx;
1419 }
1420
1421 /*
1422  * Returns a pointer to the current page.
1423  */
1424 static inline union ns_mem *NS_GET_PAGE(struct nandsim *ns)
1425 {
1426         return &(ns->pages[ns->regs.row]);
1427 }
1428
1429 /*
1430  * Retuns a pointer to the current byte, within the current page.
1431  */
1432 static inline u_char *NS_PAGE_BYTE_OFF(struct nandsim *ns)
1433 {
1434         return NS_GET_PAGE(ns)->byte + ns->regs.column + ns->regs.off;
1435 }
1436
1437 static int do_read_error(struct nandsim *ns, int num)
1438 {
1439         unsigned int page_no = ns->regs.row;
1440
1441         if (read_error(page_no)) {
1442                 prandom_bytes(ns->buf.byte, num);
1443                 NS_WARN("simulating read error in page %u\n", page_no);
1444                 return 1;
1445         }
1446         return 0;
1447 }
1448
1449 static void do_bit_flips(struct nandsim *ns, int num)
1450 {
1451         if (bitflips && prandom_u32() < (1 << 22)) {
1452                 int flips = 1;
1453                 if (bitflips > 1)
1454                         flips = (prandom_u32() % (int) bitflips) + 1;
1455                 while (flips--) {
1456                         int pos = prandom_u32() % (num * 8);
1457                         ns->buf.byte[pos / 8] ^= (1 << (pos % 8));
1458                         NS_WARN("read_page: flipping bit %d in page %d "
1459                                 "reading from %d ecc: corrected=%u failed=%u\n",
1460                                 pos, ns->regs.row, ns->regs.column + ns->regs.off,
1461                                 nsmtd->ecc_stats.corrected, nsmtd->ecc_stats.failed);
1462                 }
1463         }
1464 }
1465
1466 /*
1467  * Fill the NAND buffer with data read from the specified page.
1468  */
1469 static void read_page(struct nandsim *ns, int num)
1470 {
1471         union ns_mem *mypage;
1472
1473         if (ns->cfile) {
1474                 if (!test_bit(ns->regs.row, ns->pages_written)) {
1475                         NS_DBG("read_page: page %d not written\n", ns->regs.row);
1476                         memset(ns->buf.byte, 0xFF, num);
1477                 } else {
1478                         loff_t pos;
1479                         ssize_t tx;
1480
1481                         NS_DBG("read_page: page %d written, reading from %d\n",
1482                                 ns->regs.row, ns->regs.column + ns->regs.off);
1483                         if (do_read_error(ns, num))
1484                                 return;
1485                         pos = (loff_t)NS_RAW_OFFSET(ns) + ns->regs.off;
1486                         tx = read_file(ns, ns->cfile, ns->buf.byte, num, pos);
1487                         if (tx != num) {
1488                                 NS_ERR("read_page: read error for page %d ret %ld\n", ns->regs.row, (long)tx);
1489                                 return;
1490                         }
1491                         do_bit_flips(ns, num);
1492                 }
1493                 return;
1494         }
1495
1496         mypage = NS_GET_PAGE(ns);
1497         if (mypage->byte == NULL) {
1498                 NS_DBG("read_page: page %d not allocated\n", ns->regs.row);
1499                 memset(ns->buf.byte, 0xFF, num);
1500         } else {
1501                 NS_DBG("read_page: page %d allocated, reading from %d\n",
1502                         ns->regs.row, ns->regs.column + ns->regs.off);
1503                 if (do_read_error(ns, num))
1504                         return;
1505                 memcpy(ns->buf.byte, NS_PAGE_BYTE_OFF(ns), num);
1506                 do_bit_flips(ns, num);
1507         }
1508 }
1509
1510 /*
1511  * Erase all pages in the specified sector.
1512  */
1513 static void erase_sector(struct nandsim *ns)
1514 {
1515         union ns_mem *mypage;
1516         int i;
1517
1518         if (ns->cfile) {
1519                 for (i = 0; i < ns->geom.pgsec; i++)
1520                         if (__test_and_clear_bit(ns->regs.row + i,
1521                                                  ns->pages_written)) {
1522                                 NS_DBG("erase_sector: freeing page %d\n", ns->regs.row + i);
1523                         }
1524                 return;
1525         }
1526
1527         mypage = NS_GET_PAGE(ns);
1528         for (i = 0; i < ns->geom.pgsec; i++) {
1529                 if (mypage->byte != NULL) {
1530                         NS_DBG("erase_sector: freeing page %d\n", ns->regs.row+i);
1531                         kmem_cache_free(ns->nand_pages_slab, mypage->byte);
1532                         mypage->byte = NULL;
1533                 }
1534                 mypage++;
1535         }
1536 }
1537
1538 /*
1539  * Program the specified page with the contents from the NAND buffer.
1540  */
1541 static int prog_page(struct nandsim *ns, int num)
1542 {
1543         int i;
1544         union ns_mem *mypage;
1545         u_char *pg_off;
1546
1547         if (ns->cfile) {
1548                 loff_t off;
1549                 ssize_t tx;
1550                 int all;
1551
1552                 NS_DBG("prog_page: writing page %d\n", ns->regs.row);
1553                 pg_off = ns->file_buf + ns->regs.column + ns->regs.off;
1554                 off = (loff_t)NS_RAW_OFFSET(ns) + ns->regs.off;
1555                 if (!test_bit(ns->regs.row, ns->pages_written)) {
1556                         all = 1;
1557                         memset(ns->file_buf, 0xff, ns->geom.pgszoob);
1558                 } else {
1559                         all = 0;
1560                         tx = read_file(ns, ns->cfile, pg_off, num, off);
1561                         if (tx != num) {
1562                                 NS_ERR("prog_page: read error for page %d ret %ld\n", ns->regs.row, (long)tx);
1563                                 return -1;
1564                         }
1565                 }
1566                 for (i = 0; i < num; i++)
1567                         pg_off[i] &= ns->buf.byte[i];
1568                 if (all) {
1569                         loff_t pos = (loff_t)ns->regs.row * ns->geom.pgszoob;
1570                         tx = write_file(ns, ns->cfile, ns->file_buf, ns->geom.pgszoob, pos);
1571                         if (tx != ns->geom.pgszoob) {
1572                                 NS_ERR("prog_page: write error for page %d ret %ld\n", ns->regs.row, (long)tx);
1573                                 return -1;
1574                         }
1575                         __set_bit(ns->regs.row, ns->pages_written);
1576                 } else {
1577                         tx = write_file(ns, ns->cfile, pg_off, num, off);
1578                         if (tx != num) {
1579                                 NS_ERR("prog_page: write error for page %d ret %ld\n", ns->regs.row, (long)tx);
1580                                 return -1;
1581                         }
1582                 }
1583                 return 0;
1584         }
1585
1586         mypage = NS_GET_PAGE(ns);
1587         if (mypage->byte == NULL) {
1588                 NS_DBG("prog_page: allocating page %d\n", ns->regs.row);
1589                 /*
1590                  * We allocate memory with GFP_NOFS because a flash FS may
1591                  * utilize this. If it is holding an FS lock, then gets here,
1592                  * then kernel memory alloc runs writeback which goes to the FS
1593                  * again and deadlocks. This was seen in practice.
1594                  */
1595                 mypage->byte = kmem_cache_alloc(ns->nand_pages_slab, GFP_NOFS);
1596                 if (mypage->byte == NULL) {
1597                         NS_ERR("prog_page: error allocating memory for page %d\n", ns->regs.row);
1598                         return -1;
1599                 }
1600                 memset(mypage->byte, 0xFF, ns->geom.pgszoob);
1601         }
1602
1603         pg_off = NS_PAGE_BYTE_OFF(ns);
1604         for (i = 0; i < num; i++)
1605                 pg_off[i] &= ns->buf.byte[i];
1606
1607         return 0;
1608 }
1609
1610 /*
1611  * If state has any action bit, perform this action.
1612  *
1613  * RETURNS: 0 if success, -1 if error.
1614  */
1615 static int do_state_action(struct nandsim *ns, uint32_t action)
1616 {
1617         int num;
1618         int busdiv = ns->busw == 8 ? 1 : 2;
1619         unsigned int erase_block_no, page_no;
1620
1621         action &= ACTION_MASK;
1622
1623         /* Check that page address input is correct */
1624         if (action != ACTION_SECERASE && ns->regs.row >= ns->geom.pgnum) {
1625                 NS_WARN("do_state_action: wrong page number (%#x)\n", ns->regs.row);
1626                 return -1;
1627         }
1628
1629         switch (action) {
1630
1631         case ACTION_CPY:
1632                 /*
1633                  * Copy page data to the internal buffer.
1634                  */
1635
1636                 /* Column shouldn't be very large */
1637                 if (ns->regs.column >= (ns->geom.pgszoob - ns->regs.off)) {
1638                         NS_ERR("do_state_action: column number is too large\n");
1639                         break;
1640                 }
1641                 num = ns->geom.pgszoob - ns->regs.off - ns->regs.column;
1642                 read_page(ns, num);
1643
1644                 NS_DBG("do_state_action: (ACTION_CPY:) copy %d bytes to int buf, raw offset %d\n",
1645                         num, NS_RAW_OFFSET(ns) + ns->regs.off);
1646
1647                 if (ns->regs.off == 0)
1648                         NS_LOG("read page %d\n", ns->regs.row);
1649                 else if (ns->regs.off < ns->geom.pgsz)
1650                         NS_LOG("read page %d (second half)\n", ns->regs.row);
1651                 else
1652                         NS_LOG("read OOB of page %d\n", ns->regs.row);
1653
1654                 NS_UDELAY(access_delay);
1655                 NS_UDELAY(input_cycle * ns->geom.pgsz / 1000 / busdiv);
1656
1657                 break;
1658
1659         case ACTION_SECERASE:
1660                 /*
1661                  * Erase sector.
1662                  */
1663
1664                 if (ns->lines.wp) {
1665                         NS_ERR("do_state_action: device is write-protected, ignore sector erase\n");
1666                         return -1;
1667                 }
1668
1669                 if (ns->regs.row >= ns->geom.pgnum - ns->geom.pgsec
1670                         || (ns->regs.row & ~(ns->geom.secsz - 1))) {
1671                         NS_ERR("do_state_action: wrong sector address (%#x)\n", ns->regs.row);
1672                         return -1;
1673                 }
1674
1675                 ns->regs.row = (ns->regs.row <<
1676                                 8 * (ns->geom.pgaddrbytes - ns->geom.secaddrbytes)) | ns->regs.column;
1677                 ns->regs.column = 0;
1678
1679                 erase_block_no = ns->regs.row >> (ns->geom.secshift - ns->geom.pgshift);
1680
1681                 NS_DBG("do_state_action: erase sector at address %#x, off = %d\n",
1682                                 ns->regs.row, NS_RAW_OFFSET(ns));
1683                 NS_LOG("erase sector %u\n", erase_block_no);
1684
1685                 erase_sector(ns);
1686
1687                 NS_MDELAY(erase_delay);
1688
1689                 if (erase_block_wear)
1690                         update_wear(erase_block_no);
1691
1692                 if (erase_error(erase_block_no)) {
1693                         NS_WARN("simulating erase failure in erase block %u\n", erase_block_no);
1694                         return -1;
1695                 }
1696
1697                 break;
1698
1699         case ACTION_PRGPAGE:
1700                 /*
1701                  * Program page - move internal buffer data to the page.
1702                  */
1703
1704                 if (ns->lines.wp) {
1705                         NS_WARN("do_state_action: device is write-protected, programm\n");
1706                         return -1;
1707                 }
1708
1709                 num = ns->geom.pgszoob - ns->regs.off - ns->regs.column;
1710                 if (num != ns->regs.count) {
1711                         NS_ERR("do_state_action: too few bytes were input (%d instead of %d)\n",
1712                                         ns->regs.count, num);
1713                         return -1;
1714                 }
1715
1716                 if (prog_page(ns, num) == -1)
1717                         return -1;
1718
1719                 page_no = ns->regs.row;
1720
1721                 NS_DBG("do_state_action: copy %d bytes from int buf to (%#x, %#x), raw off = %d\n",
1722                         num, ns->regs.row, ns->regs.column, NS_RAW_OFFSET(ns) + ns->regs.off);
1723                 NS_LOG("programm page %d\n", ns->regs.row);
1724
1725                 NS_UDELAY(programm_delay);
1726                 NS_UDELAY(output_cycle * ns->geom.pgsz / 1000 / busdiv);
1727
1728                 if (write_error(page_no)) {
1729                         NS_WARN("simulating write failure in page %u\n", page_no);
1730                         return -1;
1731                 }
1732
1733                 break;
1734
1735         case ACTION_ZEROOFF:
1736                 NS_DBG("do_state_action: set internal offset to 0\n");
1737                 ns->regs.off = 0;
1738                 break;
1739
1740         case ACTION_HALFOFF:
1741                 if (!(ns->options & OPT_PAGE512_8BIT)) {
1742                         NS_ERR("do_state_action: BUG! can't skip half of page for non-512"
1743                                 "byte page size 8x chips\n");
1744                         return -1;
1745                 }
1746                 NS_DBG("do_state_action: set internal offset to %d\n", ns->geom.pgsz/2);
1747                 ns->regs.off = ns->geom.pgsz/2;
1748                 break;
1749
1750         case ACTION_OOBOFF:
1751                 NS_DBG("do_state_action: set internal offset to %d\n", ns->geom.pgsz);
1752                 ns->regs.off = ns->geom.pgsz;
1753                 break;
1754
1755         default:
1756                 NS_DBG("do_state_action: BUG! unknown action\n");
1757         }
1758
1759         return 0;
1760 }
1761
1762 /*
1763  * Switch simulator's state.
1764  */
1765 static void switch_state(struct nandsim *ns)
1766 {
1767         if (ns->op) {
1768                 /*
1769                  * The current operation have already been identified.
1770                  * Just follow the states chain.
1771                  */
1772
1773                 ns->stateidx += 1;
1774                 ns->state = ns->nxstate;
1775                 ns->nxstate = ns->op[ns->stateidx + 1];
1776
1777                 NS_DBG("switch_state: operation is known, switch to the next state, "
1778                         "state: %s, nxstate: %s\n",
1779                         get_state_name(ns->state), get_state_name(ns->nxstate));
1780
1781                 /* See, whether we need to do some action */
1782                 if ((ns->state & ACTION_MASK) && do_state_action(ns, ns->state) < 0) {
1783                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1784                         return;
1785                 }
1786
1787         } else {
1788                 /*
1789                  * We don't yet know which operation we perform.
1790                  * Try to identify it.
1791                  */
1792
1793                 /*
1794                  *  The only event causing the switch_state function to
1795                  *  be called with yet unknown operation is new command.
1796                  */
1797                 ns->state = get_state_by_command(ns->regs.command);
1798
1799                 NS_DBG("switch_state: operation is unknown, try to find it\n");
1800
1801                 if (find_operation(ns, 0) != 0)
1802                         return;
1803
1804                 if ((ns->state & ACTION_MASK) && do_state_action(ns, ns->state) < 0) {
1805                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1806                         return;
1807                 }
1808         }
1809
1810         /* For 16x devices column means the page offset in words */
1811         if ((ns->nxstate & STATE_ADDR_MASK) && ns->busw == 16) {
1812                 NS_DBG("switch_state: double the column number for 16x device\n");
1813                 ns->regs.column <<= 1;
1814         }
1815
1816         if (NS_STATE(ns->nxstate) == STATE_READY) {
1817                 /*
1818                  * The current state is the last. Return to STATE_READY
1819                  */
1820
1821                 u_char status = NS_STATUS_OK(ns);
1822
1823                 /* In case of data states, see if all bytes were input/output */
1824                 if ((ns->state & (STATE_DATAIN_MASK | STATE_DATAOUT_MASK))
1825                         && ns->regs.count != ns->regs.num) {
1826                         NS_WARN("switch_state: not all bytes were processed, %d left\n",
1827                                         ns->regs.num - ns->regs.count);
1828                         status = NS_STATUS_FAILED(ns);
1829                 }
1830
1831                 NS_DBG("switch_state: operation complete, switch to STATE_READY state\n");
1832
1833                 switch_to_ready_state(ns, status);
1834
1835                 return;
1836         } else if (ns->nxstate & (STATE_DATAIN_MASK | STATE_DATAOUT_MASK)) {
1837                 /*
1838                  * If the next state is data input/output, switch to it now
1839                  */
1840
1841                 ns->state      = ns->nxstate;
1842                 ns->nxstate    = ns->op[++ns->stateidx + 1];
1843                 ns->regs.num   = ns->regs.count = 0;
1844
1845                 NS_DBG("switch_state: the next state is data I/O, switch, "
1846                         "state: %s, nxstate: %s\n",
1847                         get_state_name(ns->state), get_state_name(ns->nxstate));
1848
1849                 /*
1850                  * Set the internal register to the count of bytes which
1851                  * are expected to be input or output
1852                  */
1853                 switch (NS_STATE(ns->state)) {
1854                         case STATE_DATAIN:
1855                         case STATE_DATAOUT:
1856                                 ns->regs.num = ns->geom.pgszoob - ns->regs.off - ns->regs.column;
1857                                 break;
1858
1859                         case STATE_DATAOUT_ID:
1860                                 ns->regs.num = ns->geom.idbytes;
1861                                 break;
1862
1863                         case STATE_DATAOUT_STATUS:
1864                                 ns->regs.count = ns->regs.num = 0;
1865                                 break;
1866
1867                         default:
1868                                 NS_ERR("switch_state: BUG! unknown data state\n");
1869                 }
1870
1871         } else if (ns->nxstate & STATE_ADDR_MASK) {
1872                 /*
1873                  * If the next state is address input, set the internal
1874                  * register to the number of expected address bytes
1875                  */
1876
1877                 ns->regs.count = 0;
1878
1879                 switch (NS_STATE(ns->nxstate)) {
1880                         case STATE_ADDR_PAGE:
1881                                 ns->regs.num = ns->geom.pgaddrbytes;
1882
1883                                 break;
1884                         case STATE_ADDR_SEC:
1885                                 ns->regs.num = ns->geom.secaddrbytes;
1886                                 break;
1887
1888                         case STATE_ADDR_ZERO:
1889                                 ns->regs.num = 1;
1890                                 break;
1891
1892                         case STATE_ADDR_COLUMN:
1893                                 /* Column address is always 2 bytes */
1894                                 ns->regs.num = ns->geom.pgaddrbytes - ns->geom.secaddrbytes;
1895                                 break;
1896
1897                         default:
1898                                 NS_ERR("switch_state: BUG! unknown address state\n");
1899                 }
1900         } else {
1901                 /*
1902                  * Just reset internal counters.
1903                  */
1904
1905                 ns->regs.num = 0;
1906                 ns->regs.count = 0;
1907         }
1908 }
1909
1910 static u_char ns_nand_read_byte(struct mtd_info *mtd)
1911 {
1912         struct nandsim *ns = ((struct nand_chip *)mtd->priv)->priv;
1913         u_char outb = 0x00;
1914
1915         /* Sanity and correctness checks */
1916         if (!ns->lines.ce) {
1917                 NS_ERR("read_byte: chip is disabled, return %#x\n", (uint)outb);
1918                 return outb;
1919         }
1920         if (ns->lines.ale || ns->lines.cle) {
1921                 NS_ERR("read_byte: ALE or CLE pin is high, return %#x\n", (uint)outb);
1922                 return outb;
1923         }
1924         if (!(ns->state & STATE_DATAOUT_MASK)) {
1925                 NS_WARN("read_byte: unexpected data output cycle, state is %s "
1926                         "return %#x\n", get_state_name(ns->state), (uint)outb);
1927                 return outb;
1928         }
1929
1930         /* Status register may be read as many times as it is wanted */
1931         if (NS_STATE(ns->state) == STATE_DATAOUT_STATUS) {
1932                 NS_DBG("read_byte: return %#x status\n", ns->regs.status);
1933                 return ns->regs.status;
1934         }
1935
1936         /* Check if there is any data in the internal buffer which may be read */
1937         if (ns->regs.count == ns->regs.num) {
1938                 NS_WARN("read_byte: no more data to output, return %#x\n", (uint)outb);
1939                 return outb;
1940         }
1941
1942         switch (NS_STATE(ns->state)) {
1943                 case STATE_DATAOUT:
1944                         if (ns->busw == 8) {
1945                                 outb = ns->buf.byte[ns->regs.count];
1946                                 ns->regs.count += 1;
1947                         } else {
1948                                 outb = (u_char)cpu_to_le16(ns->buf.word[ns->regs.count >> 1]);
1949                                 ns->regs.count += 2;
1950                         }
1951                         break;
1952                 case STATE_DATAOUT_ID:
1953                         NS_DBG("read_byte: read ID byte %d, total = %d\n", ns->regs.count, ns->regs.num);
1954                         outb = ns->ids[ns->regs.count];
1955                         ns->regs.count += 1;
1956                         break;
1957                 default:
1958                         BUG();
1959         }
1960
1961         if (ns->regs.count == ns->regs.num) {
1962                 NS_DBG("read_byte: all bytes were read\n");
1963
1964                 if (NS_STATE(ns->nxstate) == STATE_READY)
1965                         switch_state(ns);
1966         }
1967
1968         return outb;
1969 }
1970
1971 static void ns_nand_write_byte(struct mtd_info *mtd, u_char byte)
1972 {
1973         struct nandsim *ns = ((struct nand_chip *)mtd->priv)->priv;
1974
1975         /* Sanity and correctness checks */
1976         if (!ns->lines.ce) {
1977                 NS_ERR("write_byte: chip is disabled, ignore write\n");
1978                 return;
1979         }
1980         if (ns->lines.ale && ns->lines.cle) {
1981                 NS_ERR("write_byte: ALE and CLE pins are high simultaneously, ignore write\n");
1982                 return;
1983         }
1984
1985         if (ns->lines.cle == 1) {
1986                 /*
1987                  * The byte written is a command.
1988                  */
1989
1990                 if (byte == NAND_CMD_RESET) {
1991                         NS_LOG("reset chip\n");
1992                         switch_to_ready_state(ns, NS_STATUS_OK(ns));
1993                         return;
1994                 }
1995
1996                 /* Check that the command byte is correct */
1997                 if (check_command(byte)) {
1998                         NS_ERR("write_byte: unknown command %#x\n", (uint)byte);
1999                         return;
2000                 }
2001
2002                 if (NS_STATE(ns->state) == STATE_DATAOUT_STATUS
2003                         || NS_STATE(ns->state) == STATE_DATAOUT) {
2004                         int row = ns->regs.row;
2005
2006                         switch_state(ns);
2007                         if (byte == NAND_CMD_RNDOUT)
2008                                 ns->regs.row = row;
2009                 }
2010
2011                 /* Check if chip is expecting command */
2012                 if (NS_STATE(ns->nxstate) != STATE_UNKNOWN && !(ns->nxstate & STATE_CMD_MASK)) {
2013                         /* Do not warn if only 2 id bytes are read */
2014                         if (!(ns->regs.command == NAND_CMD_READID &&
2015                             NS_STATE(ns->state) == STATE_DATAOUT_ID && ns->regs.count == 2)) {
2016                                 /*
2017                                  * We are in situation when something else (not command)
2018                                  * was expected but command was input. In this case ignore
2019                                  * previous command(s)/state(s) and accept the last one.
2020                                  */
2021                                 NS_WARN("write_byte: command (%#x) wasn't expected, expected state is %s, "
2022                                         "ignore previous states\n", (uint)byte, get_state_name(ns->nxstate));
2023                         }
2024                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2025                 }
2026
2027                 NS_DBG("command byte corresponding to %s state accepted\n",
2028                         get_state_name(get_state_by_command(byte)));
2029                 ns->regs.command = byte;
2030                 switch_state(ns);
2031
2032         } else if (ns->lines.ale == 1) {
2033                 /*
2034                  * The byte written is an address.
2035                  */
2036
2037                 if (NS_STATE(ns->nxstate) == STATE_UNKNOWN) {
2038
2039                         NS_DBG("write_byte: operation isn't known yet, identify it\n");
2040
2041                         if (find_operation(ns, 1) < 0)
2042                                 return;
2043
2044                         if ((ns->state & ACTION_MASK) && do_state_action(ns, ns->state) < 0) {
2045                                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2046                                 return;
2047                         }
2048
2049                         ns->regs.count = 0;
2050                         switch (NS_STATE(ns->nxstate)) {
2051                                 case STATE_ADDR_PAGE:
2052                                         ns->regs.num = ns->geom.pgaddrbytes;
2053                                         break;
2054                                 case STATE_ADDR_SEC:
2055                                         ns->regs.num = ns->geom.secaddrbytes;
2056                                         break;
2057                                 case STATE_ADDR_ZERO:
2058                                         ns->regs.num = 1;
2059                                         break;
2060                                 default:
2061                                         BUG();
2062                         }
2063                 }
2064
2065                 /* Check that chip is expecting address */
2066                 if (!(ns->nxstate & STATE_ADDR_MASK)) {
2067                         NS_ERR("write_byte: address (%#x) isn't expected, expected state is %s, "
2068                                 "switch to STATE_READY\n", (uint)byte, get_state_name(ns->nxstate));
2069                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2070                         return;
2071                 }
2072
2073                 /* Check if this is expected byte */
2074                 if (ns->regs.count == ns->regs.num) {
2075                         NS_ERR("write_byte: no more address bytes expected\n");
2076                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2077                         return;
2078                 }
2079
2080                 accept_addr_byte(ns, byte);
2081
2082                 ns->regs.count += 1;
2083
2084                 NS_DBG("write_byte: address byte %#x was accepted (%d bytes input, %d expected)\n",
2085                                 (uint)byte, ns->regs.count, ns->regs.num);
2086
2087                 if (ns->regs.count == ns->regs.num) {
2088                         NS_DBG("address (%#x, %#x) is accepted\n", ns->regs.row, ns->regs.column);
2089                         switch_state(ns);
2090                 }
2091
2092         } else {
2093                 /*
2094                  * The byte written is an input data.
2095                  */
2096
2097                 /* Check that chip is expecting data input */
2098                 if (!(ns->state & STATE_DATAIN_MASK)) {
2099                         NS_ERR("write_byte: data input (%#x) isn't expected, state is %s, "
2100                                 "switch to %s\n", (uint)byte,
2101                                 get_state_name(ns->state), get_state_name(STATE_READY));
2102                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2103                         return;
2104                 }
2105
2106                 /* Check if this is expected byte */
2107                 if (ns->regs.count == ns->regs.num) {
2108                         NS_WARN("write_byte: %u input bytes has already been accepted, ignore write\n",
2109                                         ns->regs.num);
2110                         return;
2111                 }
2112
2113                 if (ns->busw == 8) {
2114                         ns->buf.byte[ns->regs.count] = byte;
2115                         ns->regs.count += 1;
2116                 } else {
2117                         ns->buf.word[ns->regs.count >> 1] = cpu_to_le16((uint16_t)byte);
2118                         ns->regs.count += 2;
2119                 }
2120         }
2121
2122         return;
2123 }
2124
2125 static void ns_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int bitmask)
2126 {
2127         struct nandsim *ns = ((struct nand_chip *)mtd->priv)->priv;
2128
2129         ns->lines.cle = bitmask & NAND_CLE ? 1 : 0;
2130         ns->lines.ale = bitmask & NAND_ALE ? 1 : 0;
2131         ns->lines.ce = bitmask & NAND_NCE ? 1 : 0;
2132
2133         if (cmd != NAND_CMD_NONE)
2134                 ns_nand_write_byte(mtd, cmd);
2135 }
2136
2137 static int ns_device_ready(struct mtd_info *mtd)
2138 {
2139         NS_DBG("device_ready\n");
2140         return 1;
2141 }
2142
2143 static uint16_t ns_nand_read_word(struct mtd_info *mtd)
2144 {
2145         struct nand_chip *chip = (struct nand_chip *)mtd->priv;
2146
2147         NS_DBG("read_word\n");
2148
2149         return chip->read_byte(mtd) | (chip->read_byte(mtd) << 8);
2150 }
2151
2152 static void ns_nand_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
2153 {
2154         struct nandsim *ns = ((struct nand_chip *)mtd->priv)->priv;
2155
2156         /* Check that chip is expecting data input */
2157         if (!(ns->state & STATE_DATAIN_MASK)) {
2158                 NS_ERR("write_buf: data input isn't expected, state is %s, "
2159                         "switch to STATE_READY\n", get_state_name(ns->state));
2160                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2161                 return;
2162         }
2163
2164         /* Check if these are expected bytes */
2165         if (ns->regs.count + len > ns->regs.num) {
2166                 NS_ERR("write_buf: too many input bytes\n");
2167                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2168                 return;
2169         }
2170
2171         memcpy(ns->buf.byte + ns->regs.count, buf, len);
2172         ns->regs.count += len;
2173
2174         if (ns->regs.count == ns->regs.num) {
2175                 NS_DBG("write_buf: %d bytes were written\n", ns->regs.count);
2176         }
2177 }
2178
2179 static void ns_nand_read_buf(struct mtd_info *mtd, u_char *buf, int len)
2180 {
2181         struct nandsim *ns = ((struct nand_chip *)mtd->priv)->priv;
2182
2183         /* Sanity and correctness checks */
2184         if (!ns->lines.ce) {
2185                 NS_ERR("read_buf: chip is disabled\n");
2186                 return;
2187         }
2188         if (ns->lines.ale || ns->lines.cle) {
2189                 NS_ERR("read_buf: ALE or CLE pin is high\n");
2190                 return;
2191         }
2192         if (!(ns->state & STATE_DATAOUT_MASK)) {
2193                 NS_WARN("read_buf: unexpected data output cycle, current state is %s\n",
2194                         get_state_name(ns->state));
2195                 return;
2196         }
2197
2198         if (NS_STATE(ns->state) != STATE_DATAOUT) {
2199                 int i;
2200
2201                 for (i = 0; i < len; i++)
2202                         buf[i] = ((struct nand_chip *)mtd->priv)->read_byte(mtd);
2203
2204                 return;
2205         }
2206
2207         /* Check if these are expected bytes */
2208         if (ns->regs.count + len > ns->regs.num) {
2209                 NS_ERR("read_buf: too many bytes to read\n");
2210                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2211                 return;
2212         }
2213
2214         memcpy(buf, ns->buf.byte + ns->regs.count, len);
2215         ns->regs.count += len;
2216
2217         if (ns->regs.count == ns->regs.num) {
2218                 if (NS_STATE(ns->nxstate) == STATE_READY)
2219                         switch_state(ns);
2220         }
2221
2222         return;
2223 }
2224
2225 /*
2226  * Module initialization function
2227  */
2228 static int __init ns_init_module(void)
2229 {
2230         struct nand_chip *chip;
2231         struct nandsim *nand;
2232         int retval = -ENOMEM, i;
2233
2234         if (bus_width != 8 && bus_width != 16) {
2235                 NS_ERR("wrong bus width (%d), use only 8 or 16\n", bus_width);
2236                 return -EINVAL;
2237         }
2238
2239         /* Allocate and initialize mtd_info, nand_chip and nandsim structures */
2240         nsmtd = kzalloc(sizeof(struct mtd_info) + sizeof(struct nand_chip)
2241                                 + sizeof(struct nandsim), GFP_KERNEL);
2242         if (!nsmtd) {
2243                 NS_ERR("unable to allocate core structures.\n");
2244                 return -ENOMEM;
2245         }
2246         chip        = (struct nand_chip *)(nsmtd + 1);
2247         nsmtd->priv = (void *)chip;
2248         nand        = (struct nandsim *)(chip + 1);
2249         chip->priv  = (void *)nand;
2250
2251         /*
2252          * Register simulator's callbacks.
2253          */
2254         chip->cmd_ctrl   = ns_hwcontrol;
2255         chip->read_byte  = ns_nand_read_byte;
2256         chip->dev_ready  = ns_device_ready;
2257         chip->write_buf  = ns_nand_write_buf;
2258         chip->read_buf   = ns_nand_read_buf;
2259         chip->read_word  = ns_nand_read_word;
2260         chip->ecc.mode   = NAND_ECC_SOFT;
2261         /* The NAND_SKIP_BBTSCAN option is necessary for 'overridesize' */
2262         /* and 'badblocks' parameters to work */
2263         chip->options   |= NAND_SKIP_BBTSCAN;
2264
2265         switch (bbt) {
2266         case 2:
2267                  chip->bbt_options |= NAND_BBT_NO_OOB;
2268         case 1:
2269                  chip->bbt_options |= NAND_BBT_USE_FLASH;
2270         case 0:
2271                 break;
2272         default:
2273                 NS_ERR("bbt has to be 0..2\n");
2274                 retval = -EINVAL;
2275                 goto error;
2276         }
2277         /*
2278          * Perform minimum nandsim structure initialization to handle
2279          * the initial ID read command correctly
2280          */
2281         if (id_bytes[6] != 0xFF || id_bytes[7] != 0xFF)
2282                 nand->geom.idbytes = 8;
2283         else if (id_bytes[4] != 0xFF || id_bytes[5] != 0xFF)
2284                 nand->geom.idbytes = 6;
2285         else if (id_bytes[2] != 0xFF || id_bytes[3] != 0xFF)
2286                 nand->geom.idbytes = 4;
2287         else
2288                 nand->geom.idbytes = 2;
2289         nand->regs.status = NS_STATUS_OK(nand);
2290         nand->nxstate = STATE_UNKNOWN;
2291         nand->options |= OPT_PAGE512; /* temporary value */
2292         memcpy(nand->ids, id_bytes, sizeof(nand->ids));
2293         if (bus_width == 16) {
2294                 nand->busw = 16;
2295                 chip->options |= NAND_BUSWIDTH_16;
2296         }
2297
2298         nsmtd->owner = THIS_MODULE;
2299
2300         if ((retval = parse_weakblocks()) != 0)
2301                 goto error;
2302
2303         if ((retval = parse_weakpages()) != 0)
2304                 goto error;
2305
2306         if ((retval = parse_gravepages()) != 0)
2307                 goto error;
2308
2309         retval = nand_scan_ident(nsmtd, 1, NULL);
2310         if (retval) {
2311                 NS_ERR("cannot scan NAND Simulator device\n");
2312                 if (retval > 0)
2313                         retval = -ENXIO;
2314                 goto error;
2315         }
2316
2317         if (bch) {
2318                 unsigned int eccsteps, eccbytes;
2319                 if (!mtd_nand_has_bch()) {
2320                         NS_ERR("BCH ECC support is disabled\n");
2321                         retval = -EINVAL;
2322                         goto error;
2323                 }
2324                 /* use 512-byte ecc blocks */
2325                 eccsteps = nsmtd->writesize/512;
2326                 eccbytes = (bch*13+7)/8;
2327                 /* do not bother supporting small page devices */
2328                 if ((nsmtd->oobsize < 64) || !eccsteps) {
2329                         NS_ERR("bch not available on small page devices\n");
2330                         retval = -EINVAL;
2331                         goto error;
2332                 }
2333                 if ((eccbytes*eccsteps+2) > nsmtd->oobsize) {
2334                         NS_ERR("invalid bch value %u\n", bch);
2335                         retval = -EINVAL;
2336                         goto error;
2337                 }
2338                 chip->ecc.mode = NAND_ECC_SOFT_BCH;
2339                 chip->ecc.size = 512;
2340                 chip->ecc.strength = bch;
2341                 chip->ecc.bytes = eccbytes;
2342                 NS_INFO("using %u-bit/%u bytes BCH ECC\n", bch, chip->ecc.size);
2343         }
2344
2345         retval = nand_scan_tail(nsmtd);
2346         if (retval) {
2347                 NS_ERR("can't register NAND Simulator\n");
2348                 if (retval > 0)
2349                         retval = -ENXIO;
2350                 goto error;
2351         }
2352
2353         if (overridesize) {
2354                 uint64_t new_size = (uint64_t)nsmtd->erasesize << overridesize;
2355                 if (new_size >> overridesize != nsmtd->erasesize) {
2356                         NS_ERR("overridesize is too big\n");
2357                         retval = -EINVAL;
2358                         goto err_exit;
2359                 }
2360                 /* N.B. This relies on nand_scan not doing anything with the size before we change it */
2361                 nsmtd->size = new_size;
2362                 chip->chipsize = new_size;
2363                 chip->chip_shift = ffs(nsmtd->erasesize) + overridesize - 1;
2364                 chip->pagemask = (chip->chipsize >> chip->page_shift) - 1;
2365         }
2366
2367         if ((retval = setup_wear_reporting(nsmtd)) != 0)
2368                 goto err_exit;
2369
2370         if ((retval = nandsim_debugfs_create(nand)) != 0)
2371                 goto err_exit;
2372
2373         if ((retval = init_nandsim(nsmtd)) != 0)
2374                 goto err_exit;
2375
2376         if ((retval = chip->scan_bbt(nsmtd)) != 0)
2377                 goto err_exit;
2378
2379         if ((retval = parse_badblocks(nand, nsmtd)) != 0)
2380                 goto err_exit;
2381
2382         /* Register NAND partitions */
2383         retval = mtd_device_register(nsmtd, &nand->partitions[0],
2384                                      nand->nbparts);
2385         if (retval != 0)
2386                 goto err_exit;
2387
2388         return 0;
2389
2390 err_exit:
2391         free_nandsim(nand);
2392         nand_release(nsmtd);
2393         for (i = 0;i < ARRAY_SIZE(nand->partitions); ++i)
2394                 kfree(nand->partitions[i].name);
2395 error:
2396         kfree(nsmtd);
2397         free_lists();
2398
2399         return retval;
2400 }
2401
2402 module_init(ns_init_module);
2403
2404 /*
2405  * Module clean-up function
2406  */
2407 static void __exit ns_cleanup_module(void)
2408 {
2409         struct nandsim *ns = ((struct nand_chip *)nsmtd->priv)->priv;
2410         int i;
2411
2412         nandsim_debugfs_remove(ns);
2413         free_nandsim(ns);    /* Free nandsim private resources */
2414         nand_release(nsmtd); /* Unregister driver */
2415         for (i = 0;i < ARRAY_SIZE(ns->partitions); ++i)
2416                 kfree(ns->partitions[i].name);
2417         kfree(nsmtd);        /* Free other structures */
2418         free_lists();
2419 }
2420
2421 module_exit(ns_cleanup_module);
2422
2423 MODULE_LICENSE ("GPL");
2424 MODULE_AUTHOR ("Artem B. Bityuckiy");
2425 MODULE_DESCRIPTION ("The NAND flash simulator");