Merge tag 'for-linus-20170510' of git://git.infradead.org/linux-mtd
[muen/linux.git] / drivers / mtd / nand / nandsim.c
1 /*
2  * NAND flash simulator.
3  *
4  * Author: Artem B. Bityuckiy <dedekind@oktetlabs.ru>, <dedekind@infradead.org>
5  *
6  * Copyright (C) 2004 Nokia Corporation
7  *
8  * Note: NS means "NAND Simulator".
9  * Note: Input means input TO flash chip, output means output FROM chip.
10  *
11  * This program is free software; you can redistribute it and/or modify it
12  * under the terms of the GNU General Public License as published by the
13  * Free Software Foundation; either version 2, or (at your option) any later
14  * version.
15  *
16  * This program is distributed in the hope that it will be useful, but
17  * WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
19  * Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program; if not, write to the Free Software
23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA
24  */
25
26 #include <linux/init.h>
27 #include <linux/types.h>
28 #include <linux/module.h>
29 #include <linux/moduleparam.h>
30 #include <linux/vmalloc.h>
31 #include <linux/math64.h>
32 #include <linux/slab.h>
33 #include <linux/errno.h>
34 #include <linux/string.h>
35 #include <linux/mtd/mtd.h>
36 #include <linux/mtd/nand.h>
37 #include <linux/mtd/nand_bch.h>
38 #include <linux/mtd/partitions.h>
39 #include <linux/delay.h>
40 #include <linux/list.h>
41 #include <linux/random.h>
42 #include <linux/sched.h>
43 #include <linux/sched/mm.h>
44 #include <linux/fs.h>
45 #include <linux/pagemap.h>
46 #include <linux/seq_file.h>
47 #include <linux/debugfs.h>
48
49 /* Default simulator parameters values */
50 #if !defined(CONFIG_NANDSIM_FIRST_ID_BYTE)  || \
51     !defined(CONFIG_NANDSIM_SECOND_ID_BYTE) || \
52     !defined(CONFIG_NANDSIM_THIRD_ID_BYTE)  || \
53     !defined(CONFIG_NANDSIM_FOURTH_ID_BYTE)
54 #define CONFIG_NANDSIM_FIRST_ID_BYTE  0x98
55 #define CONFIG_NANDSIM_SECOND_ID_BYTE 0x39
56 #define CONFIG_NANDSIM_THIRD_ID_BYTE  0xFF /* No byte */
57 #define CONFIG_NANDSIM_FOURTH_ID_BYTE 0xFF /* No byte */
58 #endif
59
60 #ifndef CONFIG_NANDSIM_ACCESS_DELAY
61 #define CONFIG_NANDSIM_ACCESS_DELAY 25
62 #endif
63 #ifndef CONFIG_NANDSIM_PROGRAMM_DELAY
64 #define CONFIG_NANDSIM_PROGRAMM_DELAY 200
65 #endif
66 #ifndef CONFIG_NANDSIM_ERASE_DELAY
67 #define CONFIG_NANDSIM_ERASE_DELAY 2
68 #endif
69 #ifndef CONFIG_NANDSIM_OUTPUT_CYCLE
70 #define CONFIG_NANDSIM_OUTPUT_CYCLE 40
71 #endif
72 #ifndef CONFIG_NANDSIM_INPUT_CYCLE
73 #define CONFIG_NANDSIM_INPUT_CYCLE  50
74 #endif
75 #ifndef CONFIG_NANDSIM_BUS_WIDTH
76 #define CONFIG_NANDSIM_BUS_WIDTH  8
77 #endif
78 #ifndef CONFIG_NANDSIM_DO_DELAYS
79 #define CONFIG_NANDSIM_DO_DELAYS  0
80 #endif
81 #ifndef CONFIG_NANDSIM_LOG
82 #define CONFIG_NANDSIM_LOG        0
83 #endif
84 #ifndef CONFIG_NANDSIM_DBG
85 #define CONFIG_NANDSIM_DBG        0
86 #endif
87 #ifndef CONFIG_NANDSIM_MAX_PARTS
88 #define CONFIG_NANDSIM_MAX_PARTS  32
89 #endif
90
91 static uint access_delay   = CONFIG_NANDSIM_ACCESS_DELAY;
92 static uint programm_delay = CONFIG_NANDSIM_PROGRAMM_DELAY;
93 static uint erase_delay    = CONFIG_NANDSIM_ERASE_DELAY;
94 static uint output_cycle   = CONFIG_NANDSIM_OUTPUT_CYCLE;
95 static uint input_cycle    = CONFIG_NANDSIM_INPUT_CYCLE;
96 static uint bus_width      = CONFIG_NANDSIM_BUS_WIDTH;
97 static uint do_delays      = CONFIG_NANDSIM_DO_DELAYS;
98 static uint log            = CONFIG_NANDSIM_LOG;
99 static uint dbg            = CONFIG_NANDSIM_DBG;
100 static unsigned long parts[CONFIG_NANDSIM_MAX_PARTS];
101 static unsigned int parts_num;
102 static char *badblocks = NULL;
103 static char *weakblocks = NULL;
104 static char *weakpages = NULL;
105 static unsigned int bitflips = 0;
106 static char *gravepages = NULL;
107 static unsigned int overridesize = 0;
108 static char *cache_file = NULL;
109 static unsigned int bbt;
110 static unsigned int bch;
111 static u_char id_bytes[8] = {
112         [0] = CONFIG_NANDSIM_FIRST_ID_BYTE,
113         [1] = CONFIG_NANDSIM_SECOND_ID_BYTE,
114         [2] = CONFIG_NANDSIM_THIRD_ID_BYTE,
115         [3] = CONFIG_NANDSIM_FOURTH_ID_BYTE,
116         [4 ... 7] = 0xFF,
117 };
118
119 module_param_array(id_bytes, byte, NULL, 0400);
120 module_param_named(first_id_byte, id_bytes[0], byte, 0400);
121 module_param_named(second_id_byte, id_bytes[1], byte, 0400);
122 module_param_named(third_id_byte, id_bytes[2], byte, 0400);
123 module_param_named(fourth_id_byte, id_bytes[3], byte, 0400);
124 module_param(access_delay,   uint, 0400);
125 module_param(programm_delay, uint, 0400);
126 module_param(erase_delay,    uint, 0400);
127 module_param(output_cycle,   uint, 0400);
128 module_param(input_cycle,    uint, 0400);
129 module_param(bus_width,      uint, 0400);
130 module_param(do_delays,      uint, 0400);
131 module_param(log,            uint, 0400);
132 module_param(dbg,            uint, 0400);
133 module_param_array(parts, ulong, &parts_num, 0400);
134 module_param(badblocks,      charp, 0400);
135 module_param(weakblocks,     charp, 0400);
136 module_param(weakpages,      charp, 0400);
137 module_param(bitflips,       uint, 0400);
138 module_param(gravepages,     charp, 0400);
139 module_param(overridesize,   uint, 0400);
140 module_param(cache_file,     charp, 0400);
141 module_param(bbt,            uint, 0400);
142 module_param(bch,            uint, 0400);
143
144 MODULE_PARM_DESC(id_bytes,       "The ID bytes returned by NAND Flash 'read ID' command");
145 MODULE_PARM_DESC(first_id_byte,  "The first byte returned by NAND Flash 'read ID' command (manufacturer ID) (obsolete)");
146 MODULE_PARM_DESC(second_id_byte, "The second byte returned by NAND Flash 'read ID' command (chip ID) (obsolete)");
147 MODULE_PARM_DESC(third_id_byte,  "The third byte returned by NAND Flash 'read ID' command (obsolete)");
148 MODULE_PARM_DESC(fourth_id_byte, "The fourth byte returned by NAND Flash 'read ID' command (obsolete)");
149 MODULE_PARM_DESC(access_delay,   "Initial page access delay (microseconds)");
150 MODULE_PARM_DESC(programm_delay, "Page programm delay (microseconds");
151 MODULE_PARM_DESC(erase_delay,    "Sector erase delay (milliseconds)");
152 MODULE_PARM_DESC(output_cycle,   "Word output (from flash) time (nanoseconds)");
153 MODULE_PARM_DESC(input_cycle,    "Word input (to flash) time (nanoseconds)");
154 MODULE_PARM_DESC(bus_width,      "Chip's bus width (8- or 16-bit)");
155 MODULE_PARM_DESC(do_delays,      "Simulate NAND delays using busy-waits if not zero");
156 MODULE_PARM_DESC(log,            "Perform logging if not zero");
157 MODULE_PARM_DESC(dbg,            "Output debug information if not zero");
158 MODULE_PARM_DESC(parts,          "Partition sizes (in erase blocks) separated by commas");
159 /* Page and erase block positions for the following parameters are independent of any partitions */
160 MODULE_PARM_DESC(badblocks,      "Erase blocks that are initially marked bad, separated by commas");
161 MODULE_PARM_DESC(weakblocks,     "Weak erase blocks [: remaining erase cycles (defaults to 3)]"
162                                  " separated by commas e.g. 113:2 means eb 113"
163                                  " can be erased only twice before failing");
164 MODULE_PARM_DESC(weakpages,      "Weak pages [: maximum writes (defaults to 3)]"
165                                  " separated by commas e.g. 1401:2 means page 1401"
166                                  " can be written only twice before failing");
167 MODULE_PARM_DESC(bitflips,       "Maximum number of random bit flips per page (zero by default)");
168 MODULE_PARM_DESC(gravepages,     "Pages that lose data [: maximum reads (defaults to 3)]"
169                                  " separated by commas e.g. 1401:2 means page 1401"
170                                  " can be read only twice before failing");
171 MODULE_PARM_DESC(overridesize,   "Specifies the NAND Flash size overriding the ID bytes. "
172                                  "The size is specified in erase blocks and as the exponent of a power of two"
173                                  " e.g. 5 means a size of 32 erase blocks");
174 MODULE_PARM_DESC(cache_file,     "File to use to cache nand pages instead of memory");
175 MODULE_PARM_DESC(bbt,            "0 OOB, 1 BBT with marker in OOB, 2 BBT with marker in data area");
176 MODULE_PARM_DESC(bch,            "Enable BCH ecc and set how many bits should "
177                                  "be correctable in 512-byte blocks");
178
179 /* The largest possible page size */
180 #define NS_LARGEST_PAGE_SIZE    4096
181
182 /* The prefix for simulator output */
183 #define NS_OUTPUT_PREFIX "[nandsim]"
184
185 /* Simulator's output macros (logging, debugging, warning, error) */
186 #define NS_LOG(args...) \
187         do { if (log) printk(KERN_DEBUG NS_OUTPUT_PREFIX " log: " args); } while(0)
188 #define NS_DBG(args...) \
189         do { if (dbg) printk(KERN_DEBUG NS_OUTPUT_PREFIX " debug: " args); } while(0)
190 #define NS_WARN(args...) \
191         do { printk(KERN_WARNING NS_OUTPUT_PREFIX " warning: " args); } while(0)
192 #define NS_ERR(args...) \
193         do { printk(KERN_ERR NS_OUTPUT_PREFIX " error: " args); } while(0)
194 #define NS_INFO(args...) \
195         do { printk(KERN_INFO NS_OUTPUT_PREFIX " " args); } while(0)
196
197 /* Busy-wait delay macros (microseconds, milliseconds) */
198 #define NS_UDELAY(us) \
199         do { if (do_delays) udelay(us); } while(0)
200 #define NS_MDELAY(us) \
201         do { if (do_delays) mdelay(us); } while(0)
202
203 /* Is the nandsim structure initialized ? */
204 #define NS_IS_INITIALIZED(ns) ((ns)->geom.totsz != 0)
205
206 /* Good operation completion status */
207 #define NS_STATUS_OK(ns) (NAND_STATUS_READY | (NAND_STATUS_WP * ((ns)->lines.wp == 0)))
208
209 /* Operation failed completion status */
210 #define NS_STATUS_FAILED(ns) (NAND_STATUS_FAIL | NS_STATUS_OK(ns))
211
212 /* Calculate the page offset in flash RAM image by (row, column) address */
213 #define NS_RAW_OFFSET(ns) \
214         (((ns)->regs.row * (ns)->geom.pgszoob) + (ns)->regs.column)
215
216 /* Calculate the OOB offset in flash RAM image by (row, column) address */
217 #define NS_RAW_OFFSET_OOB(ns) (NS_RAW_OFFSET(ns) + ns->geom.pgsz)
218
219 /* After a command is input, the simulator goes to one of the following states */
220 #define STATE_CMD_READ0        0x00000001 /* read data from the beginning of page */
221 #define STATE_CMD_READ1        0x00000002 /* read data from the second half of page */
222 #define STATE_CMD_READSTART    0x00000003 /* read data second command (large page devices) */
223 #define STATE_CMD_PAGEPROG     0x00000004 /* start page program */
224 #define STATE_CMD_READOOB      0x00000005 /* read OOB area */
225 #define STATE_CMD_ERASE1       0x00000006 /* sector erase first command */
226 #define STATE_CMD_STATUS       0x00000007 /* read status */
227 #define STATE_CMD_SEQIN        0x00000009 /* sequential data input */
228 #define STATE_CMD_READID       0x0000000A /* read ID */
229 #define STATE_CMD_ERASE2       0x0000000B /* sector erase second command */
230 #define STATE_CMD_RESET        0x0000000C /* reset */
231 #define STATE_CMD_RNDOUT       0x0000000D /* random output command */
232 #define STATE_CMD_RNDOUTSTART  0x0000000E /* random output start command */
233 #define STATE_CMD_MASK         0x0000000F /* command states mask */
234
235 /* After an address is input, the simulator goes to one of these states */
236 #define STATE_ADDR_PAGE        0x00000010 /* full (row, column) address is accepted */
237 #define STATE_ADDR_SEC         0x00000020 /* sector address was accepted */
238 #define STATE_ADDR_COLUMN      0x00000030 /* column address was accepted */
239 #define STATE_ADDR_ZERO        0x00000040 /* one byte zero address was accepted */
240 #define STATE_ADDR_MASK        0x00000070 /* address states mask */
241
242 /* During data input/output the simulator is in these states */
243 #define STATE_DATAIN           0x00000100 /* waiting for data input */
244 #define STATE_DATAIN_MASK      0x00000100 /* data input states mask */
245
246 #define STATE_DATAOUT          0x00001000 /* waiting for page data output */
247 #define STATE_DATAOUT_ID       0x00002000 /* waiting for ID bytes output */
248 #define STATE_DATAOUT_STATUS   0x00003000 /* waiting for status output */
249 #define STATE_DATAOUT_MASK     0x00007000 /* data output states mask */
250
251 /* Previous operation is done, ready to accept new requests */
252 #define STATE_READY            0x00000000
253
254 /* This state is used to mark that the next state isn't known yet */
255 #define STATE_UNKNOWN          0x10000000
256
257 /* Simulator's actions bit masks */
258 #define ACTION_CPY       0x00100000 /* copy page/OOB to the internal buffer */
259 #define ACTION_PRGPAGE   0x00200000 /* program the internal buffer to flash */
260 #define ACTION_SECERASE  0x00300000 /* erase sector */
261 #define ACTION_ZEROOFF   0x00400000 /* don't add any offset to address */
262 #define ACTION_HALFOFF   0x00500000 /* add to address half of page */
263 #define ACTION_OOBOFF    0x00600000 /* add to address OOB offset */
264 #define ACTION_MASK      0x00700000 /* action mask */
265
266 #define NS_OPER_NUM      13 /* Number of operations supported by the simulator */
267 #define NS_OPER_STATES   6  /* Maximum number of states in operation */
268
269 #define OPT_ANY          0xFFFFFFFF /* any chip supports this operation */
270 #define OPT_PAGE512      0x00000002 /* 512-byte  page chips */
271 #define OPT_PAGE2048     0x00000008 /* 2048-byte page chips */
272 #define OPT_PAGE512_8BIT 0x00000040 /* 512-byte page chips with 8-bit bus width */
273 #define OPT_PAGE4096     0x00000080 /* 4096-byte page chips */
274 #define OPT_LARGEPAGE    (OPT_PAGE2048 | OPT_PAGE4096) /* 2048 & 4096-byte page chips */
275 #define OPT_SMALLPAGE    (OPT_PAGE512) /* 512-byte page chips */
276
277 /* Remove action bits from state */
278 #define NS_STATE(x) ((x) & ~ACTION_MASK)
279
280 /*
281  * Maximum previous states which need to be saved. Currently saving is
282  * only needed for page program operation with preceded read command
283  * (which is only valid for 512-byte pages).
284  */
285 #define NS_MAX_PREVSTATES 1
286
287 /* Maximum page cache pages needed to read or write a NAND page to the cache_file */
288 #define NS_MAX_HELD_PAGES 16
289
290 struct nandsim_debug_info {
291         struct dentry *dfs_root;
292         struct dentry *dfs_wear_report;
293 };
294
295 /*
296  * A union to represent flash memory contents and flash buffer.
297  */
298 union ns_mem {
299         u_char *byte;    /* for byte access */
300         uint16_t *word;  /* for 16-bit word access */
301 };
302
303 /*
304  * The structure which describes all the internal simulator data.
305  */
306 struct nandsim {
307         struct mtd_partition partitions[CONFIG_NANDSIM_MAX_PARTS];
308         unsigned int nbparts;
309
310         uint busw;              /* flash chip bus width (8 or 16) */
311         u_char ids[8];          /* chip's ID bytes */
312         uint32_t options;       /* chip's characteristic bits */
313         uint32_t state;         /* current chip state */
314         uint32_t nxstate;       /* next expected state */
315
316         uint32_t *op;           /* current operation, NULL operations isn't known yet  */
317         uint32_t pstates[NS_MAX_PREVSTATES]; /* previous states */
318         uint16_t npstates;      /* number of previous states saved */
319         uint16_t stateidx;      /* current state index */
320
321         /* The simulated NAND flash pages array */
322         union ns_mem *pages;
323
324         /* Slab allocator for nand pages */
325         struct kmem_cache *nand_pages_slab;
326
327         /* Internal buffer of page + OOB size bytes */
328         union ns_mem buf;
329
330         /* NAND flash "geometry" */
331         struct {
332                 uint64_t totsz;     /* total flash size, bytes */
333                 uint32_t secsz;     /* flash sector (erase block) size, bytes */
334                 uint pgsz;          /* NAND flash page size, bytes */
335                 uint oobsz;         /* page OOB area size, bytes */
336                 uint64_t totszoob;  /* total flash size including OOB, bytes */
337                 uint pgszoob;       /* page size including OOB , bytes*/
338                 uint secszoob;      /* sector size including OOB, bytes */
339                 uint pgnum;         /* total number of pages */
340                 uint pgsec;         /* number of pages per sector */
341                 uint secshift;      /* bits number in sector size */
342                 uint pgshift;       /* bits number in page size */
343                 uint pgaddrbytes;   /* bytes per page address */
344                 uint secaddrbytes;  /* bytes per sector address */
345                 uint idbytes;       /* the number ID bytes that this chip outputs */
346         } geom;
347
348         /* NAND flash internal registers */
349         struct {
350                 unsigned command; /* the command register */
351                 u_char   status;  /* the status register */
352                 uint     row;     /* the page number */
353                 uint     column;  /* the offset within page */
354                 uint     count;   /* internal counter */
355                 uint     num;     /* number of bytes which must be processed */
356                 uint     off;     /* fixed page offset */
357         } regs;
358
359         /* NAND flash lines state */
360         struct {
361                 int ce;  /* chip Enable */
362                 int cle; /* command Latch Enable */
363                 int ale; /* address Latch Enable */
364                 int wp;  /* write Protect */
365         } lines;
366
367         /* Fields needed when using a cache file */
368         struct file *cfile; /* Open file */
369         unsigned long *pages_written; /* Which pages have been written */
370         void *file_buf;
371         struct page *held_pages[NS_MAX_HELD_PAGES];
372         int held_cnt;
373
374         struct nandsim_debug_info dbg;
375 };
376
377 /*
378  * Operations array. To perform any operation the simulator must pass
379  * through the correspondent states chain.
380  */
381 static struct nandsim_operations {
382         uint32_t reqopts;  /* options which are required to perform the operation */
383         uint32_t states[NS_OPER_STATES]; /* operation's states */
384 } ops[NS_OPER_NUM] = {
385         /* Read page + OOB from the beginning */
386         {OPT_SMALLPAGE, {STATE_CMD_READ0 | ACTION_ZEROOFF, STATE_ADDR_PAGE | ACTION_CPY,
387                         STATE_DATAOUT, STATE_READY}},
388         /* Read page + OOB from the second half */
389         {OPT_PAGE512_8BIT, {STATE_CMD_READ1 | ACTION_HALFOFF, STATE_ADDR_PAGE | ACTION_CPY,
390                         STATE_DATAOUT, STATE_READY}},
391         /* Read OOB */
392         {OPT_SMALLPAGE, {STATE_CMD_READOOB | ACTION_OOBOFF, STATE_ADDR_PAGE | ACTION_CPY,
393                         STATE_DATAOUT, STATE_READY}},
394         /* Program page starting from the beginning */
395         {OPT_ANY, {STATE_CMD_SEQIN, STATE_ADDR_PAGE, STATE_DATAIN,
396                         STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
397         /* Program page starting from the beginning */
398         {OPT_SMALLPAGE, {STATE_CMD_READ0, STATE_CMD_SEQIN | ACTION_ZEROOFF, STATE_ADDR_PAGE,
399                               STATE_DATAIN, STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
400         /* Program page starting from the second half */
401         {OPT_PAGE512, {STATE_CMD_READ1, STATE_CMD_SEQIN | ACTION_HALFOFF, STATE_ADDR_PAGE,
402                               STATE_DATAIN, STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
403         /* Program OOB */
404         {OPT_SMALLPAGE, {STATE_CMD_READOOB, STATE_CMD_SEQIN | ACTION_OOBOFF, STATE_ADDR_PAGE,
405                               STATE_DATAIN, STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
406         /* Erase sector */
407         {OPT_ANY, {STATE_CMD_ERASE1, STATE_ADDR_SEC, STATE_CMD_ERASE2 | ACTION_SECERASE, STATE_READY}},
408         /* Read status */
409         {OPT_ANY, {STATE_CMD_STATUS, STATE_DATAOUT_STATUS, STATE_READY}},
410         /* Read ID */
411         {OPT_ANY, {STATE_CMD_READID, STATE_ADDR_ZERO, STATE_DATAOUT_ID, STATE_READY}},
412         /* Large page devices read page */
413         {OPT_LARGEPAGE, {STATE_CMD_READ0, STATE_ADDR_PAGE, STATE_CMD_READSTART | ACTION_CPY,
414                                STATE_DATAOUT, STATE_READY}},
415         /* Large page devices random page read */
416         {OPT_LARGEPAGE, {STATE_CMD_RNDOUT, STATE_ADDR_COLUMN, STATE_CMD_RNDOUTSTART | ACTION_CPY,
417                                STATE_DATAOUT, STATE_READY}},
418 };
419
420 struct weak_block {
421         struct list_head list;
422         unsigned int erase_block_no;
423         unsigned int max_erases;
424         unsigned int erases_done;
425 };
426
427 static LIST_HEAD(weak_blocks);
428
429 struct weak_page {
430         struct list_head list;
431         unsigned int page_no;
432         unsigned int max_writes;
433         unsigned int writes_done;
434 };
435
436 static LIST_HEAD(weak_pages);
437
438 struct grave_page {
439         struct list_head list;
440         unsigned int page_no;
441         unsigned int max_reads;
442         unsigned int reads_done;
443 };
444
445 static LIST_HEAD(grave_pages);
446
447 static unsigned long *erase_block_wear = NULL;
448 static unsigned int wear_eb_count = 0;
449 static unsigned long total_wear = 0;
450
451 /* MTD structure for NAND controller */
452 static struct mtd_info *nsmtd;
453
454 static int nandsim_debugfs_show(struct seq_file *m, void *private)
455 {
456         unsigned long wmin = -1, wmax = 0, avg;
457         unsigned long deciles[10], decile_max[10], tot = 0;
458         unsigned int i;
459
460         /* Calc wear stats */
461         for (i = 0; i < wear_eb_count; ++i) {
462                 unsigned long wear = erase_block_wear[i];
463                 if (wear < wmin)
464                         wmin = wear;
465                 if (wear > wmax)
466                         wmax = wear;
467                 tot += wear;
468         }
469
470         for (i = 0; i < 9; ++i) {
471                 deciles[i] = 0;
472                 decile_max[i] = (wmax * (i + 1) + 5) / 10;
473         }
474         deciles[9] = 0;
475         decile_max[9] = wmax;
476         for (i = 0; i < wear_eb_count; ++i) {
477                 int d;
478                 unsigned long wear = erase_block_wear[i];
479                 for (d = 0; d < 10; ++d)
480                         if (wear <= decile_max[d]) {
481                                 deciles[d] += 1;
482                                 break;
483                         }
484         }
485         avg = tot / wear_eb_count;
486
487         /* Output wear report */
488         seq_printf(m, "Total numbers of erases:  %lu\n", tot);
489         seq_printf(m, "Number of erase blocks:   %u\n", wear_eb_count);
490         seq_printf(m, "Average number of erases: %lu\n", avg);
491         seq_printf(m, "Maximum number of erases: %lu\n", wmax);
492         seq_printf(m, "Minimum number of erases: %lu\n", wmin);
493         for (i = 0; i < 10; ++i) {
494                 unsigned long from = (i ? decile_max[i - 1] + 1 : 0);
495                 if (from > decile_max[i])
496                         continue;
497                 seq_printf(m, "Number of ebs with erase counts from %lu to %lu : %lu\n",
498                         from,
499                         decile_max[i],
500                         deciles[i]);
501         }
502
503         return 0;
504 }
505
506 static int nandsim_debugfs_open(struct inode *inode, struct file *file)
507 {
508         return single_open(file, nandsim_debugfs_show, inode->i_private);
509 }
510
511 static const struct file_operations dfs_fops = {
512         .open           = nandsim_debugfs_open,
513         .read           = seq_read,
514         .llseek         = seq_lseek,
515         .release        = single_release,
516 };
517
518 /**
519  * nandsim_debugfs_create - initialize debugfs
520  * @dev: nandsim device description object
521  *
522  * This function creates all debugfs files for UBI device @ubi. Returns zero in
523  * case of success and a negative error code in case of failure.
524  */
525 static int nandsim_debugfs_create(struct nandsim *dev)
526 {
527         struct nandsim_debug_info *dbg = &dev->dbg;
528         struct dentry *dent;
529
530         if (!IS_ENABLED(CONFIG_DEBUG_FS))
531                 return 0;
532
533         dent = debugfs_create_dir("nandsim", NULL);
534         if (!dent) {
535                 NS_ERR("cannot create \"nandsim\" debugfs directory\n");
536                 return -ENODEV;
537         }
538         dbg->dfs_root = dent;
539
540         dent = debugfs_create_file("wear_report", S_IRUSR,
541                                    dbg->dfs_root, dev, &dfs_fops);
542         if (!dent)
543                 goto out_remove;
544         dbg->dfs_wear_report = dent;
545
546         return 0;
547
548 out_remove:
549         debugfs_remove_recursive(dbg->dfs_root);
550         return -ENODEV;
551 }
552
553 /**
554  * nandsim_debugfs_remove - destroy all debugfs files
555  */
556 static void nandsim_debugfs_remove(struct nandsim *ns)
557 {
558         if (IS_ENABLED(CONFIG_DEBUG_FS))
559                 debugfs_remove_recursive(ns->dbg.dfs_root);
560 }
561
562 /*
563  * Allocate array of page pointers, create slab allocation for an array
564  * and initialize the array by NULL pointers.
565  *
566  * RETURNS: 0 if success, -ENOMEM if memory alloc fails.
567  */
568 static int __init alloc_device(struct nandsim *ns)
569 {
570         struct file *cfile;
571         int i, err;
572
573         if (cache_file) {
574                 cfile = filp_open(cache_file, O_CREAT | O_RDWR | O_LARGEFILE, 0600);
575                 if (IS_ERR(cfile))
576                         return PTR_ERR(cfile);
577                 if (!(cfile->f_mode & FMODE_CAN_READ)) {
578                         NS_ERR("alloc_device: cache file not readable\n");
579                         err = -EINVAL;
580                         goto err_close;
581                 }
582                 if (!(cfile->f_mode & FMODE_CAN_WRITE)) {
583                         NS_ERR("alloc_device: cache file not writeable\n");
584                         err = -EINVAL;
585                         goto err_close;
586                 }
587                 ns->pages_written = vzalloc(BITS_TO_LONGS(ns->geom.pgnum) *
588                                             sizeof(unsigned long));
589                 if (!ns->pages_written) {
590                         NS_ERR("alloc_device: unable to allocate pages written array\n");
591                         err = -ENOMEM;
592                         goto err_close;
593                 }
594                 ns->file_buf = kmalloc(ns->geom.pgszoob, GFP_KERNEL);
595                 if (!ns->file_buf) {
596                         NS_ERR("alloc_device: unable to allocate file buf\n");
597                         err = -ENOMEM;
598                         goto err_free;
599                 }
600                 ns->cfile = cfile;
601                 return 0;
602         }
603
604         ns->pages = vmalloc(ns->geom.pgnum * sizeof(union ns_mem));
605         if (!ns->pages) {
606                 NS_ERR("alloc_device: unable to allocate page array\n");
607                 return -ENOMEM;
608         }
609         for (i = 0; i < ns->geom.pgnum; i++) {
610                 ns->pages[i].byte = NULL;
611         }
612         ns->nand_pages_slab = kmem_cache_create("nandsim",
613                                                 ns->geom.pgszoob, 0, 0, NULL);
614         if (!ns->nand_pages_slab) {
615                 NS_ERR("cache_create: unable to create kmem_cache\n");
616                 return -ENOMEM;
617         }
618
619         return 0;
620
621 err_free:
622         vfree(ns->pages_written);
623 err_close:
624         filp_close(cfile, NULL);
625         return err;
626 }
627
628 /*
629  * Free any allocated pages, and free the array of page pointers.
630  */
631 static void free_device(struct nandsim *ns)
632 {
633         int i;
634
635         if (ns->cfile) {
636                 kfree(ns->file_buf);
637                 vfree(ns->pages_written);
638                 filp_close(ns->cfile, NULL);
639                 return;
640         }
641
642         if (ns->pages) {
643                 for (i = 0; i < ns->geom.pgnum; i++) {
644                         if (ns->pages[i].byte)
645                                 kmem_cache_free(ns->nand_pages_slab,
646                                                 ns->pages[i].byte);
647                 }
648                 kmem_cache_destroy(ns->nand_pages_slab);
649                 vfree(ns->pages);
650         }
651 }
652
653 static char __init *get_partition_name(int i)
654 {
655         return kasprintf(GFP_KERNEL, "NAND simulator partition %d", i);
656 }
657
658 /*
659  * Initialize the nandsim structure.
660  *
661  * RETURNS: 0 if success, -ERRNO if failure.
662  */
663 static int __init init_nandsim(struct mtd_info *mtd)
664 {
665         struct nand_chip *chip = mtd_to_nand(mtd);
666         struct nandsim   *ns   = nand_get_controller_data(chip);
667         int i, ret = 0;
668         uint64_t remains;
669         uint64_t next_offset;
670
671         if (NS_IS_INITIALIZED(ns)) {
672                 NS_ERR("init_nandsim: nandsim is already initialized\n");
673                 return -EIO;
674         }
675
676         /* Force mtd to not do delays */
677         chip->chip_delay = 0;
678
679         /* Initialize the NAND flash parameters */
680         ns->busw = chip->options & NAND_BUSWIDTH_16 ? 16 : 8;
681         ns->geom.totsz    = mtd->size;
682         ns->geom.pgsz     = mtd->writesize;
683         ns->geom.oobsz    = mtd->oobsize;
684         ns->geom.secsz    = mtd->erasesize;
685         ns->geom.pgszoob  = ns->geom.pgsz + ns->geom.oobsz;
686         ns->geom.pgnum    = div_u64(ns->geom.totsz, ns->geom.pgsz);
687         ns->geom.totszoob = ns->geom.totsz + (uint64_t)ns->geom.pgnum * ns->geom.oobsz;
688         ns->geom.secshift = ffs(ns->geom.secsz) - 1;
689         ns->geom.pgshift  = chip->page_shift;
690         ns->geom.pgsec    = ns->geom.secsz / ns->geom.pgsz;
691         ns->geom.secszoob = ns->geom.secsz + ns->geom.oobsz * ns->geom.pgsec;
692         ns->options = 0;
693
694         if (ns->geom.pgsz == 512) {
695                 ns->options |= OPT_PAGE512;
696                 if (ns->busw == 8)
697                         ns->options |= OPT_PAGE512_8BIT;
698         } else if (ns->geom.pgsz == 2048) {
699                 ns->options |= OPT_PAGE2048;
700         } else if (ns->geom.pgsz == 4096) {
701                 ns->options |= OPT_PAGE4096;
702         } else {
703                 NS_ERR("init_nandsim: unknown page size %u\n", ns->geom.pgsz);
704                 return -EIO;
705         }
706
707         if (ns->options & OPT_SMALLPAGE) {
708                 if (ns->geom.totsz <= (32 << 20)) {
709                         ns->geom.pgaddrbytes  = 3;
710                         ns->geom.secaddrbytes = 2;
711                 } else {
712                         ns->geom.pgaddrbytes  = 4;
713                         ns->geom.secaddrbytes = 3;
714                 }
715         } else {
716                 if (ns->geom.totsz <= (128 << 20)) {
717                         ns->geom.pgaddrbytes  = 4;
718                         ns->geom.secaddrbytes = 2;
719                 } else {
720                         ns->geom.pgaddrbytes  = 5;
721                         ns->geom.secaddrbytes = 3;
722                 }
723         }
724
725         /* Fill the partition_info structure */
726         if (parts_num > ARRAY_SIZE(ns->partitions)) {
727                 NS_ERR("too many partitions.\n");
728                 return -EINVAL;
729         }
730         remains = ns->geom.totsz;
731         next_offset = 0;
732         for (i = 0; i < parts_num; ++i) {
733                 uint64_t part_sz = (uint64_t)parts[i] * ns->geom.secsz;
734
735                 if (!part_sz || part_sz > remains) {
736                         NS_ERR("bad partition size.\n");
737                         return -EINVAL;
738                 }
739                 ns->partitions[i].name   = get_partition_name(i);
740                 if (!ns->partitions[i].name) {
741                         NS_ERR("unable to allocate memory.\n");
742                         return -ENOMEM;
743                 }
744                 ns->partitions[i].offset = next_offset;
745                 ns->partitions[i].size   = part_sz;
746                 next_offset += ns->partitions[i].size;
747                 remains -= ns->partitions[i].size;
748         }
749         ns->nbparts = parts_num;
750         if (remains) {
751                 if (parts_num + 1 > ARRAY_SIZE(ns->partitions)) {
752                         NS_ERR("too many partitions.\n");
753                         return -EINVAL;
754                 }
755                 ns->partitions[i].name   = get_partition_name(i);
756                 if (!ns->partitions[i].name) {
757                         NS_ERR("unable to allocate memory.\n");
758                         return -ENOMEM;
759                 }
760                 ns->partitions[i].offset = next_offset;
761                 ns->partitions[i].size   = remains;
762                 ns->nbparts += 1;
763         }
764
765         if (ns->busw == 16)
766                 NS_WARN("16-bit flashes support wasn't tested\n");
767
768         printk("flash size: %llu MiB\n",
769                         (unsigned long long)ns->geom.totsz >> 20);
770         printk("page size: %u bytes\n",         ns->geom.pgsz);
771         printk("OOB area size: %u bytes\n",     ns->geom.oobsz);
772         printk("sector size: %u KiB\n",         ns->geom.secsz >> 10);
773         printk("pages number: %u\n",            ns->geom.pgnum);
774         printk("pages per sector: %u\n",        ns->geom.pgsec);
775         printk("bus width: %u\n",               ns->busw);
776         printk("bits in sector size: %u\n",     ns->geom.secshift);
777         printk("bits in page size: %u\n",       ns->geom.pgshift);
778         printk("bits in OOB size: %u\n",        ffs(ns->geom.oobsz) - 1);
779         printk("flash size with OOB: %llu KiB\n",
780                         (unsigned long long)ns->geom.totszoob >> 10);
781         printk("page address bytes: %u\n",      ns->geom.pgaddrbytes);
782         printk("sector address bytes: %u\n",    ns->geom.secaddrbytes);
783         printk("options: %#x\n",                ns->options);
784
785         if ((ret = alloc_device(ns)) != 0)
786                 return ret;
787
788         /* Allocate / initialize the internal buffer */
789         ns->buf.byte = kmalloc(ns->geom.pgszoob, GFP_KERNEL);
790         if (!ns->buf.byte) {
791                 NS_ERR("init_nandsim: unable to allocate %u bytes for the internal buffer\n",
792                         ns->geom.pgszoob);
793                 return -ENOMEM;
794         }
795         memset(ns->buf.byte, 0xFF, ns->geom.pgszoob);
796
797         return 0;
798 }
799
800 /*
801  * Free the nandsim structure.
802  */
803 static void free_nandsim(struct nandsim *ns)
804 {
805         kfree(ns->buf.byte);
806         free_device(ns);
807
808         return;
809 }
810
811 static int parse_badblocks(struct nandsim *ns, struct mtd_info *mtd)
812 {
813         char *w;
814         int zero_ok;
815         unsigned int erase_block_no;
816         loff_t offset;
817
818         if (!badblocks)
819                 return 0;
820         w = badblocks;
821         do {
822                 zero_ok = (*w == '0' ? 1 : 0);
823                 erase_block_no = simple_strtoul(w, &w, 0);
824                 if (!zero_ok && !erase_block_no) {
825                         NS_ERR("invalid badblocks.\n");
826                         return -EINVAL;
827                 }
828                 offset = (loff_t)erase_block_no * ns->geom.secsz;
829                 if (mtd_block_markbad(mtd, offset)) {
830                         NS_ERR("invalid badblocks.\n");
831                         return -EINVAL;
832                 }
833                 if (*w == ',')
834                         w += 1;
835         } while (*w);
836         return 0;
837 }
838
839 static int parse_weakblocks(void)
840 {
841         char *w;
842         int zero_ok;
843         unsigned int erase_block_no;
844         unsigned int max_erases;
845         struct weak_block *wb;
846
847         if (!weakblocks)
848                 return 0;
849         w = weakblocks;
850         do {
851                 zero_ok = (*w == '0' ? 1 : 0);
852                 erase_block_no = simple_strtoul(w, &w, 0);
853                 if (!zero_ok && !erase_block_no) {
854                         NS_ERR("invalid weakblocks.\n");
855                         return -EINVAL;
856                 }
857                 max_erases = 3;
858                 if (*w == ':') {
859                         w += 1;
860                         max_erases = simple_strtoul(w, &w, 0);
861                 }
862                 if (*w == ',')
863                         w += 1;
864                 wb = kzalloc(sizeof(*wb), GFP_KERNEL);
865                 if (!wb) {
866                         NS_ERR("unable to allocate memory.\n");
867                         return -ENOMEM;
868                 }
869                 wb->erase_block_no = erase_block_no;
870                 wb->max_erases = max_erases;
871                 list_add(&wb->list, &weak_blocks);
872         } while (*w);
873         return 0;
874 }
875
876 static int erase_error(unsigned int erase_block_no)
877 {
878         struct weak_block *wb;
879
880         list_for_each_entry(wb, &weak_blocks, list)
881                 if (wb->erase_block_no == erase_block_no) {
882                         if (wb->erases_done >= wb->max_erases)
883                                 return 1;
884                         wb->erases_done += 1;
885                         return 0;
886                 }
887         return 0;
888 }
889
890 static int parse_weakpages(void)
891 {
892         char *w;
893         int zero_ok;
894         unsigned int page_no;
895         unsigned int max_writes;
896         struct weak_page *wp;
897
898         if (!weakpages)
899                 return 0;
900         w = weakpages;
901         do {
902                 zero_ok = (*w == '0' ? 1 : 0);
903                 page_no = simple_strtoul(w, &w, 0);
904                 if (!zero_ok && !page_no) {
905                         NS_ERR("invalid weakpages.\n");
906                         return -EINVAL;
907                 }
908                 max_writes = 3;
909                 if (*w == ':') {
910                         w += 1;
911                         max_writes = simple_strtoul(w, &w, 0);
912                 }
913                 if (*w == ',')
914                         w += 1;
915                 wp = kzalloc(sizeof(*wp), GFP_KERNEL);
916                 if (!wp) {
917                         NS_ERR("unable to allocate memory.\n");
918                         return -ENOMEM;
919                 }
920                 wp->page_no = page_no;
921                 wp->max_writes = max_writes;
922                 list_add(&wp->list, &weak_pages);
923         } while (*w);
924         return 0;
925 }
926
927 static int write_error(unsigned int page_no)
928 {
929         struct weak_page *wp;
930
931         list_for_each_entry(wp, &weak_pages, list)
932                 if (wp->page_no == page_no) {
933                         if (wp->writes_done >= wp->max_writes)
934                                 return 1;
935                         wp->writes_done += 1;
936                         return 0;
937                 }
938         return 0;
939 }
940
941 static int parse_gravepages(void)
942 {
943         char *g;
944         int zero_ok;
945         unsigned int page_no;
946         unsigned int max_reads;
947         struct grave_page *gp;
948
949         if (!gravepages)
950                 return 0;
951         g = gravepages;
952         do {
953                 zero_ok = (*g == '0' ? 1 : 0);
954                 page_no = simple_strtoul(g, &g, 0);
955                 if (!zero_ok && !page_no) {
956                         NS_ERR("invalid gravepagess.\n");
957                         return -EINVAL;
958                 }
959                 max_reads = 3;
960                 if (*g == ':') {
961                         g += 1;
962                         max_reads = simple_strtoul(g, &g, 0);
963                 }
964                 if (*g == ',')
965                         g += 1;
966                 gp = kzalloc(sizeof(*gp), GFP_KERNEL);
967                 if (!gp) {
968                         NS_ERR("unable to allocate memory.\n");
969                         return -ENOMEM;
970                 }
971                 gp->page_no = page_no;
972                 gp->max_reads = max_reads;
973                 list_add(&gp->list, &grave_pages);
974         } while (*g);
975         return 0;
976 }
977
978 static int read_error(unsigned int page_no)
979 {
980         struct grave_page *gp;
981
982         list_for_each_entry(gp, &grave_pages, list)
983                 if (gp->page_no == page_no) {
984                         if (gp->reads_done >= gp->max_reads)
985                                 return 1;
986                         gp->reads_done += 1;
987                         return 0;
988                 }
989         return 0;
990 }
991
992 static void free_lists(void)
993 {
994         struct list_head *pos, *n;
995         list_for_each_safe(pos, n, &weak_blocks) {
996                 list_del(pos);
997                 kfree(list_entry(pos, struct weak_block, list));
998         }
999         list_for_each_safe(pos, n, &weak_pages) {
1000                 list_del(pos);
1001                 kfree(list_entry(pos, struct weak_page, list));
1002         }
1003         list_for_each_safe(pos, n, &grave_pages) {
1004                 list_del(pos);
1005                 kfree(list_entry(pos, struct grave_page, list));
1006         }
1007         kfree(erase_block_wear);
1008 }
1009
1010 static int setup_wear_reporting(struct mtd_info *mtd)
1011 {
1012         size_t mem;
1013
1014         wear_eb_count = div_u64(mtd->size, mtd->erasesize);
1015         mem = wear_eb_count * sizeof(unsigned long);
1016         if (mem / sizeof(unsigned long) != wear_eb_count) {
1017                 NS_ERR("Too many erase blocks for wear reporting\n");
1018                 return -ENOMEM;
1019         }
1020         erase_block_wear = kzalloc(mem, GFP_KERNEL);
1021         if (!erase_block_wear) {
1022                 NS_ERR("Too many erase blocks for wear reporting\n");
1023                 return -ENOMEM;
1024         }
1025         return 0;
1026 }
1027
1028 static void update_wear(unsigned int erase_block_no)
1029 {
1030         if (!erase_block_wear)
1031                 return;
1032         total_wear += 1;
1033         /*
1034          * TODO: Notify this through a debugfs entry,
1035          * instead of showing an error message.
1036          */
1037         if (total_wear == 0)
1038                 NS_ERR("Erase counter total overflow\n");
1039         erase_block_wear[erase_block_no] += 1;
1040         if (erase_block_wear[erase_block_no] == 0)
1041                 NS_ERR("Erase counter overflow for erase block %u\n", erase_block_no);
1042 }
1043
1044 /*
1045  * Returns the string representation of 'state' state.
1046  */
1047 static char *get_state_name(uint32_t state)
1048 {
1049         switch (NS_STATE(state)) {
1050                 case STATE_CMD_READ0:
1051                         return "STATE_CMD_READ0";
1052                 case STATE_CMD_READ1:
1053                         return "STATE_CMD_READ1";
1054                 case STATE_CMD_PAGEPROG:
1055                         return "STATE_CMD_PAGEPROG";
1056                 case STATE_CMD_READOOB:
1057                         return "STATE_CMD_READOOB";
1058                 case STATE_CMD_READSTART:
1059                         return "STATE_CMD_READSTART";
1060                 case STATE_CMD_ERASE1:
1061                         return "STATE_CMD_ERASE1";
1062                 case STATE_CMD_STATUS:
1063                         return "STATE_CMD_STATUS";
1064                 case STATE_CMD_SEQIN:
1065                         return "STATE_CMD_SEQIN";
1066                 case STATE_CMD_READID:
1067                         return "STATE_CMD_READID";
1068                 case STATE_CMD_ERASE2:
1069                         return "STATE_CMD_ERASE2";
1070                 case STATE_CMD_RESET:
1071                         return "STATE_CMD_RESET";
1072                 case STATE_CMD_RNDOUT:
1073                         return "STATE_CMD_RNDOUT";
1074                 case STATE_CMD_RNDOUTSTART:
1075                         return "STATE_CMD_RNDOUTSTART";
1076                 case STATE_ADDR_PAGE:
1077                         return "STATE_ADDR_PAGE";
1078                 case STATE_ADDR_SEC:
1079                         return "STATE_ADDR_SEC";
1080                 case STATE_ADDR_ZERO:
1081                         return "STATE_ADDR_ZERO";
1082                 case STATE_ADDR_COLUMN:
1083                         return "STATE_ADDR_COLUMN";
1084                 case STATE_DATAIN:
1085                         return "STATE_DATAIN";
1086                 case STATE_DATAOUT:
1087                         return "STATE_DATAOUT";
1088                 case STATE_DATAOUT_ID:
1089                         return "STATE_DATAOUT_ID";
1090                 case STATE_DATAOUT_STATUS:
1091                         return "STATE_DATAOUT_STATUS";
1092                 case STATE_READY:
1093                         return "STATE_READY";
1094                 case STATE_UNKNOWN:
1095                         return "STATE_UNKNOWN";
1096         }
1097
1098         NS_ERR("get_state_name: unknown state, BUG\n");
1099         return NULL;
1100 }
1101
1102 /*
1103  * Check if command is valid.
1104  *
1105  * RETURNS: 1 if wrong command, 0 if right.
1106  */
1107 static int check_command(int cmd)
1108 {
1109         switch (cmd) {
1110
1111         case NAND_CMD_READ0:
1112         case NAND_CMD_READ1:
1113         case NAND_CMD_READSTART:
1114         case NAND_CMD_PAGEPROG:
1115         case NAND_CMD_READOOB:
1116         case NAND_CMD_ERASE1:
1117         case NAND_CMD_STATUS:
1118         case NAND_CMD_SEQIN:
1119         case NAND_CMD_READID:
1120         case NAND_CMD_ERASE2:
1121         case NAND_CMD_RESET:
1122         case NAND_CMD_RNDOUT:
1123         case NAND_CMD_RNDOUTSTART:
1124                 return 0;
1125
1126         default:
1127                 return 1;
1128         }
1129 }
1130
1131 /*
1132  * Returns state after command is accepted by command number.
1133  */
1134 static uint32_t get_state_by_command(unsigned command)
1135 {
1136         switch (command) {
1137                 case NAND_CMD_READ0:
1138                         return STATE_CMD_READ0;
1139                 case NAND_CMD_READ1:
1140                         return STATE_CMD_READ1;
1141                 case NAND_CMD_PAGEPROG:
1142                         return STATE_CMD_PAGEPROG;
1143                 case NAND_CMD_READSTART:
1144                         return STATE_CMD_READSTART;
1145                 case NAND_CMD_READOOB:
1146                         return STATE_CMD_READOOB;
1147                 case NAND_CMD_ERASE1:
1148                         return STATE_CMD_ERASE1;
1149                 case NAND_CMD_STATUS:
1150                         return STATE_CMD_STATUS;
1151                 case NAND_CMD_SEQIN:
1152                         return STATE_CMD_SEQIN;
1153                 case NAND_CMD_READID:
1154                         return STATE_CMD_READID;
1155                 case NAND_CMD_ERASE2:
1156                         return STATE_CMD_ERASE2;
1157                 case NAND_CMD_RESET:
1158                         return STATE_CMD_RESET;
1159                 case NAND_CMD_RNDOUT:
1160                         return STATE_CMD_RNDOUT;
1161                 case NAND_CMD_RNDOUTSTART:
1162                         return STATE_CMD_RNDOUTSTART;
1163         }
1164
1165         NS_ERR("get_state_by_command: unknown command, BUG\n");
1166         return 0;
1167 }
1168
1169 /*
1170  * Move an address byte to the correspondent internal register.
1171  */
1172 static inline void accept_addr_byte(struct nandsim *ns, u_char bt)
1173 {
1174         uint byte = (uint)bt;
1175
1176         if (ns->regs.count < (ns->geom.pgaddrbytes - ns->geom.secaddrbytes))
1177                 ns->regs.column |= (byte << 8 * ns->regs.count);
1178         else {
1179                 ns->regs.row |= (byte << 8 * (ns->regs.count -
1180                                                 ns->geom.pgaddrbytes +
1181                                                 ns->geom.secaddrbytes));
1182         }
1183
1184         return;
1185 }
1186
1187 /*
1188  * Switch to STATE_READY state.
1189  */
1190 static inline void switch_to_ready_state(struct nandsim *ns, u_char status)
1191 {
1192         NS_DBG("switch_to_ready_state: switch to %s state\n", get_state_name(STATE_READY));
1193
1194         ns->state       = STATE_READY;
1195         ns->nxstate     = STATE_UNKNOWN;
1196         ns->op          = NULL;
1197         ns->npstates    = 0;
1198         ns->stateidx    = 0;
1199         ns->regs.num    = 0;
1200         ns->regs.count  = 0;
1201         ns->regs.off    = 0;
1202         ns->regs.row    = 0;
1203         ns->regs.column = 0;
1204         ns->regs.status = status;
1205 }
1206
1207 /*
1208  * If the operation isn't known yet, try to find it in the global array
1209  * of supported operations.
1210  *
1211  * Operation can be unknown because of the following.
1212  *   1. New command was accepted and this is the first call to find the
1213  *      correspondent states chain. In this case ns->npstates = 0;
1214  *   2. There are several operations which begin with the same command(s)
1215  *      (for example program from the second half and read from the
1216  *      second half operations both begin with the READ1 command). In this
1217  *      case the ns->pstates[] array contains previous states.
1218  *
1219  * Thus, the function tries to find operation containing the following
1220  * states (if the 'flag' parameter is 0):
1221  *    ns->pstates[0], ... ns->pstates[ns->npstates], ns->state
1222  *
1223  * If (one and only one) matching operation is found, it is accepted (
1224  * ns->ops, ns->state, ns->nxstate are initialized, ns->npstate is
1225  * zeroed).
1226  *
1227  * If there are several matches, the current state is pushed to the
1228  * ns->pstates.
1229  *
1230  * The operation can be unknown only while commands are input to the chip.
1231  * As soon as address command is accepted, the operation must be known.
1232  * In such situation the function is called with 'flag' != 0, and the
1233  * operation is searched using the following pattern:
1234  *     ns->pstates[0], ... ns->pstates[ns->npstates], <address input>
1235  *
1236  * It is supposed that this pattern must either match one operation or
1237  * none. There can't be ambiguity in that case.
1238  *
1239  * If no matches found, the function does the following:
1240  *   1. if there are saved states present, try to ignore them and search
1241  *      again only using the last command. If nothing was found, switch
1242  *      to the STATE_READY state.
1243  *   2. if there are no saved states, switch to the STATE_READY state.
1244  *
1245  * RETURNS: -2 - no matched operations found.
1246  *          -1 - several matches.
1247  *           0 - operation is found.
1248  */
1249 static int find_operation(struct nandsim *ns, uint32_t flag)
1250 {
1251         int opsfound = 0;
1252         int i, j, idx = 0;
1253
1254         for (i = 0; i < NS_OPER_NUM; i++) {
1255
1256                 int found = 1;
1257
1258                 if (!(ns->options & ops[i].reqopts))
1259                         /* Ignore operations we can't perform */
1260                         continue;
1261
1262                 if (flag) {
1263                         if (!(ops[i].states[ns->npstates] & STATE_ADDR_MASK))
1264                                 continue;
1265                 } else {
1266                         if (NS_STATE(ns->state) != NS_STATE(ops[i].states[ns->npstates]))
1267                                 continue;
1268                 }
1269
1270                 for (j = 0; j < ns->npstates; j++)
1271                         if (NS_STATE(ops[i].states[j]) != NS_STATE(ns->pstates[j])
1272                                 && (ns->options & ops[idx].reqopts)) {
1273                                 found = 0;
1274                                 break;
1275                         }
1276
1277                 if (found) {
1278                         idx = i;
1279                         opsfound += 1;
1280                 }
1281         }
1282
1283         if (opsfound == 1) {
1284                 /* Exact match */
1285                 ns->op = &ops[idx].states[0];
1286                 if (flag) {
1287                         /*
1288                          * In this case the find_operation function was
1289                          * called when address has just began input. But it isn't
1290                          * yet fully input and the current state must
1291                          * not be one of STATE_ADDR_*, but the STATE_ADDR_*
1292                          * state must be the next state (ns->nxstate).
1293                          */
1294                         ns->stateidx = ns->npstates - 1;
1295                 } else {
1296                         ns->stateidx = ns->npstates;
1297                 }
1298                 ns->npstates = 0;
1299                 ns->state = ns->op[ns->stateidx];
1300                 ns->nxstate = ns->op[ns->stateidx + 1];
1301                 NS_DBG("find_operation: operation found, index: %d, state: %s, nxstate %s\n",
1302                                 idx, get_state_name(ns->state), get_state_name(ns->nxstate));
1303                 return 0;
1304         }
1305
1306         if (opsfound == 0) {
1307                 /* Nothing was found. Try to ignore previous commands (if any) and search again */
1308                 if (ns->npstates != 0) {
1309                         NS_DBG("find_operation: no operation found, try again with state %s\n",
1310                                         get_state_name(ns->state));
1311                         ns->npstates = 0;
1312                         return find_operation(ns, 0);
1313
1314                 }
1315                 NS_DBG("find_operation: no operations found\n");
1316                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1317                 return -2;
1318         }
1319
1320         if (flag) {
1321                 /* This shouldn't happen */
1322                 NS_DBG("find_operation: BUG, operation must be known if address is input\n");
1323                 return -2;
1324         }
1325
1326         NS_DBG("find_operation: there is still ambiguity\n");
1327
1328         ns->pstates[ns->npstates++] = ns->state;
1329
1330         return -1;
1331 }
1332
1333 static void put_pages(struct nandsim *ns)
1334 {
1335         int i;
1336
1337         for (i = 0; i < ns->held_cnt; i++)
1338                 put_page(ns->held_pages[i]);
1339 }
1340
1341 /* Get page cache pages in advance to provide NOFS memory allocation */
1342 static int get_pages(struct nandsim *ns, struct file *file, size_t count, loff_t pos)
1343 {
1344         pgoff_t index, start_index, end_index;
1345         struct page *page;
1346         struct address_space *mapping = file->f_mapping;
1347
1348         start_index = pos >> PAGE_SHIFT;
1349         end_index = (pos + count - 1) >> PAGE_SHIFT;
1350         if (end_index - start_index + 1 > NS_MAX_HELD_PAGES)
1351                 return -EINVAL;
1352         ns->held_cnt = 0;
1353         for (index = start_index; index <= end_index; index++) {
1354                 page = find_get_page(mapping, index);
1355                 if (page == NULL) {
1356                         page = find_or_create_page(mapping, index, GFP_NOFS);
1357                         if (page == NULL) {
1358                                 write_inode_now(mapping->host, 1);
1359                                 page = find_or_create_page(mapping, index, GFP_NOFS);
1360                         }
1361                         if (page == NULL) {
1362                                 put_pages(ns);
1363                                 return -ENOMEM;
1364                         }
1365                         unlock_page(page);
1366                 }
1367                 ns->held_pages[ns->held_cnt++] = page;
1368         }
1369         return 0;
1370 }
1371
1372 static ssize_t read_file(struct nandsim *ns, struct file *file, void *buf, size_t count, loff_t pos)
1373 {
1374         ssize_t tx;
1375         int err;
1376         unsigned int noreclaim_flag;
1377
1378         err = get_pages(ns, file, count, pos);
1379         if (err)
1380                 return err;
1381         noreclaim_flag = memalloc_noreclaim_save();
1382         tx = kernel_read(file, pos, buf, count);
1383         memalloc_noreclaim_restore(noreclaim_flag);
1384         put_pages(ns);
1385         return tx;
1386 }
1387
1388 static ssize_t write_file(struct nandsim *ns, struct file *file, void *buf, size_t count, loff_t pos)
1389 {
1390         ssize_t tx;
1391         int err;
1392         unsigned int noreclaim_flag;
1393
1394         err = get_pages(ns, file, count, pos);
1395         if (err)
1396                 return err;
1397         noreclaim_flag = memalloc_noreclaim_save();
1398         tx = kernel_write(file, buf, count, pos);
1399         memalloc_noreclaim_restore(noreclaim_flag);
1400         put_pages(ns);
1401         return tx;
1402 }
1403
1404 /*
1405  * Returns a pointer to the current page.
1406  */
1407 static inline union ns_mem *NS_GET_PAGE(struct nandsim *ns)
1408 {
1409         return &(ns->pages[ns->regs.row]);
1410 }
1411
1412 /*
1413  * Retuns a pointer to the current byte, within the current page.
1414  */
1415 static inline u_char *NS_PAGE_BYTE_OFF(struct nandsim *ns)
1416 {
1417         return NS_GET_PAGE(ns)->byte + ns->regs.column + ns->regs.off;
1418 }
1419
1420 static int do_read_error(struct nandsim *ns, int num)
1421 {
1422         unsigned int page_no = ns->regs.row;
1423
1424         if (read_error(page_no)) {
1425                 prandom_bytes(ns->buf.byte, num);
1426                 NS_WARN("simulating read error in page %u\n", page_no);
1427                 return 1;
1428         }
1429         return 0;
1430 }
1431
1432 static void do_bit_flips(struct nandsim *ns, int num)
1433 {
1434         if (bitflips && prandom_u32() < (1 << 22)) {
1435                 int flips = 1;
1436                 if (bitflips > 1)
1437                         flips = (prandom_u32() % (int) bitflips) + 1;
1438                 while (flips--) {
1439                         int pos = prandom_u32() % (num * 8);
1440                         ns->buf.byte[pos / 8] ^= (1 << (pos % 8));
1441                         NS_WARN("read_page: flipping bit %d in page %d "
1442                                 "reading from %d ecc: corrected=%u failed=%u\n",
1443                                 pos, ns->regs.row, ns->regs.column + ns->regs.off,
1444                                 nsmtd->ecc_stats.corrected, nsmtd->ecc_stats.failed);
1445                 }
1446         }
1447 }
1448
1449 /*
1450  * Fill the NAND buffer with data read from the specified page.
1451  */
1452 static void read_page(struct nandsim *ns, int num)
1453 {
1454         union ns_mem *mypage;
1455
1456         if (ns->cfile) {
1457                 if (!test_bit(ns->regs.row, ns->pages_written)) {
1458                         NS_DBG("read_page: page %d not written\n", ns->regs.row);
1459                         memset(ns->buf.byte, 0xFF, num);
1460                 } else {
1461                         loff_t pos;
1462                         ssize_t tx;
1463
1464                         NS_DBG("read_page: page %d written, reading from %d\n",
1465                                 ns->regs.row, ns->regs.column + ns->regs.off);
1466                         if (do_read_error(ns, num))
1467                                 return;
1468                         pos = (loff_t)NS_RAW_OFFSET(ns) + ns->regs.off;
1469                         tx = read_file(ns, ns->cfile, ns->buf.byte, num, pos);
1470                         if (tx != num) {
1471                                 NS_ERR("read_page: read error for page %d ret %ld\n", ns->regs.row, (long)tx);
1472                                 return;
1473                         }
1474                         do_bit_flips(ns, num);
1475                 }
1476                 return;
1477         }
1478
1479         mypage = NS_GET_PAGE(ns);
1480         if (mypage->byte == NULL) {
1481                 NS_DBG("read_page: page %d not allocated\n", ns->regs.row);
1482                 memset(ns->buf.byte, 0xFF, num);
1483         } else {
1484                 NS_DBG("read_page: page %d allocated, reading from %d\n",
1485                         ns->regs.row, ns->regs.column + ns->regs.off);
1486                 if (do_read_error(ns, num))
1487                         return;
1488                 memcpy(ns->buf.byte, NS_PAGE_BYTE_OFF(ns), num);
1489                 do_bit_flips(ns, num);
1490         }
1491 }
1492
1493 /*
1494  * Erase all pages in the specified sector.
1495  */
1496 static void erase_sector(struct nandsim *ns)
1497 {
1498         union ns_mem *mypage;
1499         int i;
1500
1501         if (ns->cfile) {
1502                 for (i = 0; i < ns->geom.pgsec; i++)
1503                         if (__test_and_clear_bit(ns->regs.row + i,
1504                                                  ns->pages_written)) {
1505                                 NS_DBG("erase_sector: freeing page %d\n", ns->regs.row + i);
1506                         }
1507                 return;
1508         }
1509
1510         mypage = NS_GET_PAGE(ns);
1511         for (i = 0; i < ns->geom.pgsec; i++) {
1512                 if (mypage->byte != NULL) {
1513                         NS_DBG("erase_sector: freeing page %d\n", ns->regs.row+i);
1514                         kmem_cache_free(ns->nand_pages_slab, mypage->byte);
1515                         mypage->byte = NULL;
1516                 }
1517                 mypage++;
1518         }
1519 }
1520
1521 /*
1522  * Program the specified page with the contents from the NAND buffer.
1523  */
1524 static int prog_page(struct nandsim *ns, int num)
1525 {
1526         int i;
1527         union ns_mem *mypage;
1528         u_char *pg_off;
1529
1530         if (ns->cfile) {
1531                 loff_t off;
1532                 ssize_t tx;
1533                 int all;
1534
1535                 NS_DBG("prog_page: writing page %d\n", ns->regs.row);
1536                 pg_off = ns->file_buf + ns->regs.column + ns->regs.off;
1537                 off = (loff_t)NS_RAW_OFFSET(ns) + ns->regs.off;
1538                 if (!test_bit(ns->regs.row, ns->pages_written)) {
1539                         all = 1;
1540                         memset(ns->file_buf, 0xff, ns->geom.pgszoob);
1541                 } else {
1542                         all = 0;
1543                         tx = read_file(ns, ns->cfile, pg_off, num, off);
1544                         if (tx != num) {
1545                                 NS_ERR("prog_page: read error for page %d ret %ld\n", ns->regs.row, (long)tx);
1546                                 return -1;
1547                         }
1548                 }
1549                 for (i = 0; i < num; i++)
1550                         pg_off[i] &= ns->buf.byte[i];
1551                 if (all) {
1552                         loff_t pos = (loff_t)ns->regs.row * ns->geom.pgszoob;
1553                         tx = write_file(ns, ns->cfile, ns->file_buf, ns->geom.pgszoob, pos);
1554                         if (tx != ns->geom.pgszoob) {
1555                                 NS_ERR("prog_page: write error for page %d ret %ld\n", ns->regs.row, (long)tx);
1556                                 return -1;
1557                         }
1558                         __set_bit(ns->regs.row, ns->pages_written);
1559                 } else {
1560                         tx = write_file(ns, ns->cfile, pg_off, num, off);
1561                         if (tx != num) {
1562                                 NS_ERR("prog_page: write error for page %d ret %ld\n", ns->regs.row, (long)tx);
1563                                 return -1;
1564                         }
1565                 }
1566                 return 0;
1567         }
1568
1569         mypage = NS_GET_PAGE(ns);
1570         if (mypage->byte == NULL) {
1571                 NS_DBG("prog_page: allocating page %d\n", ns->regs.row);
1572                 /*
1573                  * We allocate memory with GFP_NOFS because a flash FS may
1574                  * utilize this. If it is holding an FS lock, then gets here,
1575                  * then kernel memory alloc runs writeback which goes to the FS
1576                  * again and deadlocks. This was seen in practice.
1577                  */
1578                 mypage->byte = kmem_cache_alloc(ns->nand_pages_slab, GFP_NOFS);
1579                 if (mypage->byte == NULL) {
1580                         NS_ERR("prog_page: error allocating memory for page %d\n", ns->regs.row);
1581                         return -1;
1582                 }
1583                 memset(mypage->byte, 0xFF, ns->geom.pgszoob);
1584         }
1585
1586         pg_off = NS_PAGE_BYTE_OFF(ns);
1587         for (i = 0; i < num; i++)
1588                 pg_off[i] &= ns->buf.byte[i];
1589
1590         return 0;
1591 }
1592
1593 /*
1594  * If state has any action bit, perform this action.
1595  *
1596  * RETURNS: 0 if success, -1 if error.
1597  */
1598 static int do_state_action(struct nandsim *ns, uint32_t action)
1599 {
1600         int num;
1601         int busdiv = ns->busw == 8 ? 1 : 2;
1602         unsigned int erase_block_no, page_no;
1603
1604         action &= ACTION_MASK;
1605
1606         /* Check that page address input is correct */
1607         if (action != ACTION_SECERASE && ns->regs.row >= ns->geom.pgnum) {
1608                 NS_WARN("do_state_action: wrong page number (%#x)\n", ns->regs.row);
1609                 return -1;
1610         }
1611
1612         switch (action) {
1613
1614         case ACTION_CPY:
1615                 /*
1616                  * Copy page data to the internal buffer.
1617                  */
1618
1619                 /* Column shouldn't be very large */
1620                 if (ns->regs.column >= (ns->geom.pgszoob - ns->regs.off)) {
1621                         NS_ERR("do_state_action: column number is too large\n");
1622                         break;
1623                 }
1624                 num = ns->geom.pgszoob - ns->regs.off - ns->regs.column;
1625                 read_page(ns, num);
1626
1627                 NS_DBG("do_state_action: (ACTION_CPY:) copy %d bytes to int buf, raw offset %d\n",
1628                         num, NS_RAW_OFFSET(ns) + ns->regs.off);
1629
1630                 if (ns->regs.off == 0)
1631                         NS_LOG("read page %d\n", ns->regs.row);
1632                 else if (ns->regs.off < ns->geom.pgsz)
1633                         NS_LOG("read page %d (second half)\n", ns->regs.row);
1634                 else
1635                         NS_LOG("read OOB of page %d\n", ns->regs.row);
1636
1637                 NS_UDELAY(access_delay);
1638                 NS_UDELAY(input_cycle * ns->geom.pgsz / 1000 / busdiv);
1639
1640                 break;
1641
1642         case ACTION_SECERASE:
1643                 /*
1644                  * Erase sector.
1645                  */
1646
1647                 if (ns->lines.wp) {
1648                         NS_ERR("do_state_action: device is write-protected, ignore sector erase\n");
1649                         return -1;
1650                 }
1651
1652                 if (ns->regs.row >= ns->geom.pgnum - ns->geom.pgsec
1653                         || (ns->regs.row & ~(ns->geom.secsz - 1))) {
1654                         NS_ERR("do_state_action: wrong sector address (%#x)\n", ns->regs.row);
1655                         return -1;
1656                 }
1657
1658                 ns->regs.row = (ns->regs.row <<
1659                                 8 * (ns->geom.pgaddrbytes - ns->geom.secaddrbytes)) | ns->regs.column;
1660                 ns->regs.column = 0;
1661
1662                 erase_block_no = ns->regs.row >> (ns->geom.secshift - ns->geom.pgshift);
1663
1664                 NS_DBG("do_state_action: erase sector at address %#x, off = %d\n",
1665                                 ns->regs.row, NS_RAW_OFFSET(ns));
1666                 NS_LOG("erase sector %u\n", erase_block_no);
1667
1668                 erase_sector(ns);
1669
1670                 NS_MDELAY(erase_delay);
1671
1672                 if (erase_block_wear)
1673                         update_wear(erase_block_no);
1674
1675                 if (erase_error(erase_block_no)) {
1676                         NS_WARN("simulating erase failure in erase block %u\n", erase_block_no);
1677                         return -1;
1678                 }
1679
1680                 break;
1681
1682         case ACTION_PRGPAGE:
1683                 /*
1684                  * Program page - move internal buffer data to the page.
1685                  */
1686
1687                 if (ns->lines.wp) {
1688                         NS_WARN("do_state_action: device is write-protected, programm\n");
1689                         return -1;
1690                 }
1691
1692                 num = ns->geom.pgszoob - ns->regs.off - ns->regs.column;
1693                 if (num != ns->regs.count) {
1694                         NS_ERR("do_state_action: too few bytes were input (%d instead of %d)\n",
1695                                         ns->regs.count, num);
1696                         return -1;
1697                 }
1698
1699                 if (prog_page(ns, num) == -1)
1700                         return -1;
1701
1702                 page_no = ns->regs.row;
1703
1704                 NS_DBG("do_state_action: copy %d bytes from int buf to (%#x, %#x), raw off = %d\n",
1705                         num, ns->regs.row, ns->regs.column, NS_RAW_OFFSET(ns) + ns->regs.off);
1706                 NS_LOG("programm page %d\n", ns->regs.row);
1707
1708                 NS_UDELAY(programm_delay);
1709                 NS_UDELAY(output_cycle * ns->geom.pgsz / 1000 / busdiv);
1710
1711                 if (write_error(page_no)) {
1712                         NS_WARN("simulating write failure in page %u\n", page_no);
1713                         return -1;
1714                 }
1715
1716                 break;
1717
1718         case ACTION_ZEROOFF:
1719                 NS_DBG("do_state_action: set internal offset to 0\n");
1720                 ns->regs.off = 0;
1721                 break;
1722
1723         case ACTION_HALFOFF:
1724                 if (!(ns->options & OPT_PAGE512_8BIT)) {
1725                         NS_ERR("do_state_action: BUG! can't skip half of page for non-512"
1726                                 "byte page size 8x chips\n");
1727                         return -1;
1728                 }
1729                 NS_DBG("do_state_action: set internal offset to %d\n", ns->geom.pgsz/2);
1730                 ns->regs.off = ns->geom.pgsz/2;
1731                 break;
1732
1733         case ACTION_OOBOFF:
1734                 NS_DBG("do_state_action: set internal offset to %d\n", ns->geom.pgsz);
1735                 ns->regs.off = ns->geom.pgsz;
1736                 break;
1737
1738         default:
1739                 NS_DBG("do_state_action: BUG! unknown action\n");
1740         }
1741
1742         return 0;
1743 }
1744
1745 /*
1746  * Switch simulator's state.
1747  */
1748 static void switch_state(struct nandsim *ns)
1749 {
1750         if (ns->op) {
1751                 /*
1752                  * The current operation have already been identified.
1753                  * Just follow the states chain.
1754                  */
1755
1756                 ns->stateidx += 1;
1757                 ns->state = ns->nxstate;
1758                 ns->nxstate = ns->op[ns->stateidx + 1];
1759
1760                 NS_DBG("switch_state: operation is known, switch to the next state, "
1761                         "state: %s, nxstate: %s\n",
1762                         get_state_name(ns->state), get_state_name(ns->nxstate));
1763
1764                 /* See, whether we need to do some action */
1765                 if ((ns->state & ACTION_MASK) && do_state_action(ns, ns->state) < 0) {
1766                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1767                         return;
1768                 }
1769
1770         } else {
1771                 /*
1772                  * We don't yet know which operation we perform.
1773                  * Try to identify it.
1774                  */
1775
1776                 /*
1777                  *  The only event causing the switch_state function to
1778                  *  be called with yet unknown operation is new command.
1779                  */
1780                 ns->state = get_state_by_command(ns->regs.command);
1781
1782                 NS_DBG("switch_state: operation is unknown, try to find it\n");
1783
1784                 if (find_operation(ns, 0) != 0)
1785                         return;
1786
1787                 if ((ns->state & ACTION_MASK) && do_state_action(ns, ns->state) < 0) {
1788                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1789                         return;
1790                 }
1791         }
1792
1793         /* For 16x devices column means the page offset in words */
1794         if ((ns->nxstate & STATE_ADDR_MASK) && ns->busw == 16) {
1795                 NS_DBG("switch_state: double the column number for 16x device\n");
1796                 ns->regs.column <<= 1;
1797         }
1798
1799         if (NS_STATE(ns->nxstate) == STATE_READY) {
1800                 /*
1801                  * The current state is the last. Return to STATE_READY
1802                  */
1803
1804                 u_char status = NS_STATUS_OK(ns);
1805
1806                 /* In case of data states, see if all bytes were input/output */
1807                 if ((ns->state & (STATE_DATAIN_MASK | STATE_DATAOUT_MASK))
1808                         && ns->regs.count != ns->regs.num) {
1809                         NS_WARN("switch_state: not all bytes were processed, %d left\n",
1810                                         ns->regs.num - ns->regs.count);
1811                         status = NS_STATUS_FAILED(ns);
1812                 }
1813
1814                 NS_DBG("switch_state: operation complete, switch to STATE_READY state\n");
1815
1816                 switch_to_ready_state(ns, status);
1817
1818                 return;
1819         } else if (ns->nxstate & (STATE_DATAIN_MASK | STATE_DATAOUT_MASK)) {
1820                 /*
1821                  * If the next state is data input/output, switch to it now
1822                  */
1823
1824                 ns->state      = ns->nxstate;
1825                 ns->nxstate    = ns->op[++ns->stateidx + 1];
1826                 ns->regs.num   = ns->regs.count = 0;
1827
1828                 NS_DBG("switch_state: the next state is data I/O, switch, "
1829                         "state: %s, nxstate: %s\n",
1830                         get_state_name(ns->state), get_state_name(ns->nxstate));
1831
1832                 /*
1833                  * Set the internal register to the count of bytes which
1834                  * are expected to be input or output
1835                  */
1836                 switch (NS_STATE(ns->state)) {
1837                         case STATE_DATAIN:
1838                         case STATE_DATAOUT:
1839                                 ns->regs.num = ns->geom.pgszoob - ns->regs.off - ns->regs.column;
1840                                 break;
1841
1842                         case STATE_DATAOUT_ID:
1843                                 ns->regs.num = ns->geom.idbytes;
1844                                 break;
1845
1846                         case STATE_DATAOUT_STATUS:
1847                                 ns->regs.count = ns->regs.num = 0;
1848                                 break;
1849
1850                         default:
1851                                 NS_ERR("switch_state: BUG! unknown data state\n");
1852                 }
1853
1854         } else if (ns->nxstate & STATE_ADDR_MASK) {
1855                 /*
1856                  * If the next state is address input, set the internal
1857                  * register to the number of expected address bytes
1858                  */
1859
1860                 ns->regs.count = 0;
1861
1862                 switch (NS_STATE(ns->nxstate)) {
1863                         case STATE_ADDR_PAGE:
1864                                 ns->regs.num = ns->geom.pgaddrbytes;
1865
1866                                 break;
1867                         case STATE_ADDR_SEC:
1868                                 ns->regs.num = ns->geom.secaddrbytes;
1869                                 break;
1870
1871                         case STATE_ADDR_ZERO:
1872                                 ns->regs.num = 1;
1873                                 break;
1874
1875                         case STATE_ADDR_COLUMN:
1876                                 /* Column address is always 2 bytes */
1877                                 ns->regs.num = ns->geom.pgaddrbytes - ns->geom.secaddrbytes;
1878                                 break;
1879
1880                         default:
1881                                 NS_ERR("switch_state: BUG! unknown address state\n");
1882                 }
1883         } else {
1884                 /*
1885                  * Just reset internal counters.
1886                  */
1887
1888                 ns->regs.num = 0;
1889                 ns->regs.count = 0;
1890         }
1891 }
1892
1893 static u_char ns_nand_read_byte(struct mtd_info *mtd)
1894 {
1895         struct nand_chip *chip = mtd_to_nand(mtd);
1896         struct nandsim *ns = nand_get_controller_data(chip);
1897         u_char outb = 0x00;
1898
1899         /* Sanity and correctness checks */
1900         if (!ns->lines.ce) {
1901                 NS_ERR("read_byte: chip is disabled, return %#x\n", (uint)outb);
1902                 return outb;
1903         }
1904         if (ns->lines.ale || ns->lines.cle) {
1905                 NS_ERR("read_byte: ALE or CLE pin is high, return %#x\n", (uint)outb);
1906                 return outb;
1907         }
1908         if (!(ns->state & STATE_DATAOUT_MASK)) {
1909                 NS_WARN("read_byte: unexpected data output cycle, state is %s "
1910                         "return %#x\n", get_state_name(ns->state), (uint)outb);
1911                 return outb;
1912         }
1913
1914         /* Status register may be read as many times as it is wanted */
1915         if (NS_STATE(ns->state) == STATE_DATAOUT_STATUS) {
1916                 NS_DBG("read_byte: return %#x status\n", ns->regs.status);
1917                 return ns->regs.status;
1918         }
1919
1920         /* Check if there is any data in the internal buffer which may be read */
1921         if (ns->regs.count == ns->regs.num) {
1922                 NS_WARN("read_byte: no more data to output, return %#x\n", (uint)outb);
1923                 return outb;
1924         }
1925
1926         switch (NS_STATE(ns->state)) {
1927                 case STATE_DATAOUT:
1928                         if (ns->busw == 8) {
1929                                 outb = ns->buf.byte[ns->regs.count];
1930                                 ns->regs.count += 1;
1931                         } else {
1932                                 outb = (u_char)cpu_to_le16(ns->buf.word[ns->regs.count >> 1]);
1933                                 ns->regs.count += 2;
1934                         }
1935                         break;
1936                 case STATE_DATAOUT_ID:
1937                         NS_DBG("read_byte: read ID byte %d, total = %d\n", ns->regs.count, ns->regs.num);
1938                         outb = ns->ids[ns->regs.count];
1939                         ns->regs.count += 1;
1940                         break;
1941                 default:
1942                         BUG();
1943         }
1944
1945         if (ns->regs.count == ns->regs.num) {
1946                 NS_DBG("read_byte: all bytes were read\n");
1947
1948                 if (NS_STATE(ns->nxstate) == STATE_READY)
1949                         switch_state(ns);
1950         }
1951
1952         return outb;
1953 }
1954
1955 static void ns_nand_write_byte(struct mtd_info *mtd, u_char byte)
1956 {
1957         struct nand_chip *chip = mtd_to_nand(mtd);
1958         struct nandsim *ns = nand_get_controller_data(chip);
1959
1960         /* Sanity and correctness checks */
1961         if (!ns->lines.ce) {
1962                 NS_ERR("write_byte: chip is disabled, ignore write\n");
1963                 return;
1964         }
1965         if (ns->lines.ale && ns->lines.cle) {
1966                 NS_ERR("write_byte: ALE and CLE pins are high simultaneously, ignore write\n");
1967                 return;
1968         }
1969
1970         if (ns->lines.cle == 1) {
1971                 /*
1972                  * The byte written is a command.
1973                  */
1974
1975                 if (byte == NAND_CMD_RESET) {
1976                         NS_LOG("reset chip\n");
1977                         switch_to_ready_state(ns, NS_STATUS_OK(ns));
1978                         return;
1979                 }
1980
1981                 /* Check that the command byte is correct */
1982                 if (check_command(byte)) {
1983                         NS_ERR("write_byte: unknown command %#x\n", (uint)byte);
1984                         return;
1985                 }
1986
1987                 if (NS_STATE(ns->state) == STATE_DATAOUT_STATUS
1988                         || NS_STATE(ns->state) == STATE_DATAOUT) {
1989                         int row = ns->regs.row;
1990
1991                         switch_state(ns);
1992                         if (byte == NAND_CMD_RNDOUT)
1993                                 ns->regs.row = row;
1994                 }
1995
1996                 /* Check if chip is expecting command */
1997                 if (NS_STATE(ns->nxstate) != STATE_UNKNOWN && !(ns->nxstate & STATE_CMD_MASK)) {
1998                         /* Do not warn if only 2 id bytes are read */
1999                         if (!(ns->regs.command == NAND_CMD_READID &&
2000                             NS_STATE(ns->state) == STATE_DATAOUT_ID && ns->regs.count == 2)) {
2001                                 /*
2002                                  * We are in situation when something else (not command)
2003                                  * was expected but command was input. In this case ignore
2004                                  * previous command(s)/state(s) and accept the last one.
2005                                  */
2006                                 NS_WARN("write_byte: command (%#x) wasn't expected, expected state is %s, "
2007                                         "ignore previous states\n", (uint)byte, get_state_name(ns->nxstate));
2008                         }
2009                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2010                 }
2011
2012                 NS_DBG("command byte corresponding to %s state accepted\n",
2013                         get_state_name(get_state_by_command(byte)));
2014                 ns->regs.command = byte;
2015                 switch_state(ns);
2016
2017         } else if (ns->lines.ale == 1) {
2018                 /*
2019                  * The byte written is an address.
2020                  */
2021
2022                 if (NS_STATE(ns->nxstate) == STATE_UNKNOWN) {
2023
2024                         NS_DBG("write_byte: operation isn't known yet, identify it\n");
2025
2026                         if (find_operation(ns, 1) < 0)
2027                                 return;
2028
2029                         if ((ns->state & ACTION_MASK) && do_state_action(ns, ns->state) < 0) {
2030                                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2031                                 return;
2032                         }
2033
2034                         ns->regs.count = 0;
2035                         switch (NS_STATE(ns->nxstate)) {
2036                                 case STATE_ADDR_PAGE:
2037                                         ns->regs.num = ns->geom.pgaddrbytes;
2038                                         break;
2039                                 case STATE_ADDR_SEC:
2040                                         ns->regs.num = ns->geom.secaddrbytes;
2041                                         break;
2042                                 case STATE_ADDR_ZERO:
2043                                         ns->regs.num = 1;
2044                                         break;
2045                                 default:
2046                                         BUG();
2047                         }
2048                 }
2049
2050                 /* Check that chip is expecting address */
2051                 if (!(ns->nxstate & STATE_ADDR_MASK)) {
2052                         NS_ERR("write_byte: address (%#x) isn't expected, expected state is %s, "
2053                                 "switch to STATE_READY\n", (uint)byte, get_state_name(ns->nxstate));
2054                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2055                         return;
2056                 }
2057
2058                 /* Check if this is expected byte */
2059                 if (ns->regs.count == ns->regs.num) {
2060                         NS_ERR("write_byte: no more address bytes expected\n");
2061                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2062                         return;
2063                 }
2064
2065                 accept_addr_byte(ns, byte);
2066
2067                 ns->regs.count += 1;
2068
2069                 NS_DBG("write_byte: address byte %#x was accepted (%d bytes input, %d expected)\n",
2070                                 (uint)byte, ns->regs.count, ns->regs.num);
2071
2072                 if (ns->regs.count == ns->regs.num) {
2073                         NS_DBG("address (%#x, %#x) is accepted\n", ns->regs.row, ns->regs.column);
2074                         switch_state(ns);
2075                 }
2076
2077         } else {
2078                 /*
2079                  * The byte written is an input data.
2080                  */
2081
2082                 /* Check that chip is expecting data input */
2083                 if (!(ns->state & STATE_DATAIN_MASK)) {
2084                         NS_ERR("write_byte: data input (%#x) isn't expected, state is %s, "
2085                                 "switch to %s\n", (uint)byte,
2086                                 get_state_name(ns->state), get_state_name(STATE_READY));
2087                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2088                         return;
2089                 }
2090
2091                 /* Check if this is expected byte */
2092                 if (ns->regs.count == ns->regs.num) {
2093                         NS_WARN("write_byte: %u input bytes has already been accepted, ignore write\n",
2094                                         ns->regs.num);
2095                         return;
2096                 }
2097
2098                 if (ns->busw == 8) {
2099                         ns->buf.byte[ns->regs.count] = byte;
2100                         ns->regs.count += 1;
2101                 } else {
2102                         ns->buf.word[ns->regs.count >> 1] = cpu_to_le16((uint16_t)byte);
2103                         ns->regs.count += 2;
2104                 }
2105         }
2106
2107         return;
2108 }
2109
2110 static void ns_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int bitmask)
2111 {
2112         struct nand_chip *chip = mtd_to_nand(mtd);
2113         struct nandsim *ns = nand_get_controller_data(chip);
2114
2115         ns->lines.cle = bitmask & NAND_CLE ? 1 : 0;
2116         ns->lines.ale = bitmask & NAND_ALE ? 1 : 0;
2117         ns->lines.ce = bitmask & NAND_NCE ? 1 : 0;
2118
2119         if (cmd != NAND_CMD_NONE)
2120                 ns_nand_write_byte(mtd, cmd);
2121 }
2122
2123 static int ns_device_ready(struct mtd_info *mtd)
2124 {
2125         NS_DBG("device_ready\n");
2126         return 1;
2127 }
2128
2129 static uint16_t ns_nand_read_word(struct mtd_info *mtd)
2130 {
2131         struct nand_chip *chip = mtd_to_nand(mtd);
2132
2133         NS_DBG("read_word\n");
2134
2135         return chip->read_byte(mtd) | (chip->read_byte(mtd) << 8);
2136 }
2137
2138 static void ns_nand_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
2139 {
2140         struct nand_chip *chip = mtd_to_nand(mtd);
2141         struct nandsim *ns = nand_get_controller_data(chip);
2142
2143         /* Check that chip is expecting data input */
2144         if (!(ns->state & STATE_DATAIN_MASK)) {
2145                 NS_ERR("write_buf: data input isn't expected, state is %s, "
2146                         "switch to STATE_READY\n", get_state_name(ns->state));
2147                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2148                 return;
2149         }
2150
2151         /* Check if these are expected bytes */
2152         if (ns->regs.count + len > ns->regs.num) {
2153                 NS_ERR("write_buf: too many input bytes\n");
2154                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2155                 return;
2156         }
2157
2158         memcpy(ns->buf.byte + ns->regs.count, buf, len);
2159         ns->regs.count += len;
2160
2161         if (ns->regs.count == ns->regs.num) {
2162                 NS_DBG("write_buf: %d bytes were written\n", ns->regs.count);
2163         }
2164 }
2165
2166 static void ns_nand_read_buf(struct mtd_info *mtd, u_char *buf, int len)
2167 {
2168         struct nand_chip *chip = mtd_to_nand(mtd);
2169         struct nandsim *ns = nand_get_controller_data(chip);
2170
2171         /* Sanity and correctness checks */
2172         if (!ns->lines.ce) {
2173                 NS_ERR("read_buf: chip is disabled\n");
2174                 return;
2175         }
2176         if (ns->lines.ale || ns->lines.cle) {
2177                 NS_ERR("read_buf: ALE or CLE pin is high\n");
2178                 return;
2179         }
2180         if (!(ns->state & STATE_DATAOUT_MASK)) {
2181                 NS_WARN("read_buf: unexpected data output cycle, current state is %s\n",
2182                         get_state_name(ns->state));
2183                 return;
2184         }
2185
2186         if (NS_STATE(ns->state) != STATE_DATAOUT) {
2187                 int i;
2188
2189                 for (i = 0; i < len; i++)
2190                         buf[i] = mtd_to_nand(mtd)->read_byte(mtd);
2191
2192                 return;
2193         }
2194
2195         /* Check if these are expected bytes */
2196         if (ns->regs.count + len > ns->regs.num) {
2197                 NS_ERR("read_buf: too many bytes to read\n");
2198                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2199                 return;
2200         }
2201
2202         memcpy(buf, ns->buf.byte + ns->regs.count, len);
2203         ns->regs.count += len;
2204
2205         if (ns->regs.count == ns->regs.num) {
2206                 if (NS_STATE(ns->nxstate) == STATE_READY)
2207                         switch_state(ns);
2208         }
2209
2210         return;
2211 }
2212
2213 /*
2214  * Module initialization function
2215  */
2216 static int __init ns_init_module(void)
2217 {
2218         struct nand_chip *chip;
2219         struct nandsim *nand;
2220         int retval = -ENOMEM, i;
2221
2222         if (bus_width != 8 && bus_width != 16) {
2223                 NS_ERR("wrong bus width (%d), use only 8 or 16\n", bus_width);
2224                 return -EINVAL;
2225         }
2226
2227         /* Allocate and initialize mtd_info, nand_chip and nandsim structures */
2228         chip = kzalloc(sizeof(struct nand_chip) + sizeof(struct nandsim),
2229                        GFP_KERNEL);
2230         if (!chip) {
2231                 NS_ERR("unable to allocate core structures.\n");
2232                 return -ENOMEM;
2233         }
2234         nsmtd       = nand_to_mtd(chip);
2235         nand        = (struct nandsim *)(chip + 1);
2236         nand_set_controller_data(chip, (void *)nand);
2237
2238         /*
2239          * Register simulator's callbacks.
2240          */
2241         chip->cmd_ctrl   = ns_hwcontrol;
2242         chip->read_byte  = ns_nand_read_byte;
2243         chip->dev_ready  = ns_device_ready;
2244         chip->write_buf  = ns_nand_write_buf;
2245         chip->read_buf   = ns_nand_read_buf;
2246         chip->read_word  = ns_nand_read_word;
2247         chip->ecc.mode   = NAND_ECC_SOFT;
2248         chip->ecc.algo   = NAND_ECC_HAMMING;
2249         /* The NAND_SKIP_BBTSCAN option is necessary for 'overridesize' */
2250         /* and 'badblocks' parameters to work */
2251         chip->options   |= NAND_SKIP_BBTSCAN;
2252
2253         switch (bbt) {
2254         case 2:
2255                  chip->bbt_options |= NAND_BBT_NO_OOB;
2256         case 1:
2257                  chip->bbt_options |= NAND_BBT_USE_FLASH;
2258         case 0:
2259                 break;
2260         default:
2261                 NS_ERR("bbt has to be 0..2\n");
2262                 retval = -EINVAL;
2263                 goto error;
2264         }
2265         /*
2266          * Perform minimum nandsim structure initialization to handle
2267          * the initial ID read command correctly
2268          */
2269         if (id_bytes[6] != 0xFF || id_bytes[7] != 0xFF)
2270                 nand->geom.idbytes = 8;
2271         else if (id_bytes[4] != 0xFF || id_bytes[5] != 0xFF)
2272                 nand->geom.idbytes = 6;
2273         else if (id_bytes[2] != 0xFF || id_bytes[3] != 0xFF)
2274                 nand->geom.idbytes = 4;
2275         else
2276                 nand->geom.idbytes = 2;
2277         nand->regs.status = NS_STATUS_OK(nand);
2278         nand->nxstate = STATE_UNKNOWN;
2279         nand->options |= OPT_PAGE512; /* temporary value */
2280         memcpy(nand->ids, id_bytes, sizeof(nand->ids));
2281         if (bus_width == 16) {
2282                 nand->busw = 16;
2283                 chip->options |= NAND_BUSWIDTH_16;
2284         }
2285
2286         nsmtd->owner = THIS_MODULE;
2287
2288         if ((retval = parse_weakblocks()) != 0)
2289                 goto error;
2290
2291         if ((retval = parse_weakpages()) != 0)
2292                 goto error;
2293
2294         if ((retval = parse_gravepages()) != 0)
2295                 goto error;
2296
2297         retval = nand_scan_ident(nsmtd, 1, NULL);
2298         if (retval) {
2299                 NS_ERR("cannot scan NAND Simulator device\n");
2300                 goto error;
2301         }
2302
2303         if (bch) {
2304                 unsigned int eccsteps, eccbytes;
2305                 if (!mtd_nand_has_bch()) {
2306                         NS_ERR("BCH ECC support is disabled\n");
2307                         retval = -EINVAL;
2308                         goto error;
2309                 }
2310                 /* use 512-byte ecc blocks */
2311                 eccsteps = nsmtd->writesize/512;
2312                 eccbytes = (bch*13+7)/8;
2313                 /* do not bother supporting small page devices */
2314                 if ((nsmtd->oobsize < 64) || !eccsteps) {
2315                         NS_ERR("bch not available on small page devices\n");
2316                         retval = -EINVAL;
2317                         goto error;
2318                 }
2319                 if ((eccbytes*eccsteps+2) > nsmtd->oobsize) {
2320                         NS_ERR("invalid bch value %u\n", bch);
2321                         retval = -EINVAL;
2322                         goto error;
2323                 }
2324                 chip->ecc.mode = NAND_ECC_SOFT;
2325                 chip->ecc.algo = NAND_ECC_BCH;
2326                 chip->ecc.size = 512;
2327                 chip->ecc.strength = bch;
2328                 chip->ecc.bytes = eccbytes;
2329                 NS_INFO("using %u-bit/%u bytes BCH ECC\n", bch, chip->ecc.size);
2330         }
2331
2332         retval = nand_scan_tail(nsmtd);
2333         if (retval) {
2334                 NS_ERR("can't register NAND Simulator\n");
2335                 goto error;
2336         }
2337
2338         if (overridesize) {
2339                 uint64_t new_size = (uint64_t)nsmtd->erasesize << overridesize;
2340                 if (new_size >> overridesize != nsmtd->erasesize) {
2341                         NS_ERR("overridesize is too big\n");
2342                         retval = -EINVAL;
2343                         goto err_exit;
2344                 }
2345                 /* N.B. This relies on nand_scan not doing anything with the size before we change it */
2346                 nsmtd->size = new_size;
2347                 chip->chipsize = new_size;
2348                 chip->chip_shift = ffs(nsmtd->erasesize) + overridesize - 1;
2349                 chip->pagemask = (chip->chipsize >> chip->page_shift) - 1;
2350         }
2351
2352         if ((retval = setup_wear_reporting(nsmtd)) != 0)
2353                 goto err_exit;
2354
2355         if ((retval = nandsim_debugfs_create(nand)) != 0)
2356                 goto err_exit;
2357
2358         if ((retval = init_nandsim(nsmtd)) != 0)
2359                 goto err_exit;
2360
2361         if ((retval = chip->scan_bbt(nsmtd)) != 0)
2362                 goto err_exit;
2363
2364         if ((retval = parse_badblocks(nand, nsmtd)) != 0)
2365                 goto err_exit;
2366
2367         /* Register NAND partitions */
2368         retval = mtd_device_register(nsmtd, &nand->partitions[0],
2369                                      nand->nbparts);
2370         if (retval != 0)
2371                 goto err_exit;
2372
2373         return 0;
2374
2375 err_exit:
2376         free_nandsim(nand);
2377         nand_release(nsmtd);
2378         for (i = 0;i < ARRAY_SIZE(nand->partitions); ++i)
2379                 kfree(nand->partitions[i].name);
2380 error:
2381         kfree(chip);
2382         free_lists();
2383
2384         return retval;
2385 }
2386
2387 module_init(ns_init_module);
2388
2389 /*
2390  * Module clean-up function
2391  */
2392 static void __exit ns_cleanup_module(void)
2393 {
2394         struct nand_chip *chip = mtd_to_nand(nsmtd);
2395         struct nandsim *ns = nand_get_controller_data(chip);
2396         int i;
2397
2398         nandsim_debugfs_remove(ns);
2399         free_nandsim(ns);    /* Free nandsim private resources */
2400         nand_release(nsmtd); /* Unregister driver */
2401         for (i = 0;i < ARRAY_SIZE(ns->partitions); ++i)
2402                 kfree(ns->partitions[i].name);
2403         kfree(mtd_to_nand(nsmtd));        /* Free other structures */
2404         free_lists();
2405 }
2406
2407 module_exit(ns_cleanup_module);
2408
2409 MODULE_LICENSE ("GPL");
2410 MODULE_AUTHOR ("Artem B. Bityuckiy");
2411 MODULE_DESCRIPTION ("The NAND flash simulator");