Merge commit 'v2.6.29-rc1' into core/urgent
[linux-2.6] / 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 <asm/div64.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/partitions.h>
38 #include <linux/delay.h>
39 #include <linux/list.h>
40 #include <linux/random.h>
41 #include <linux/sched.h>
42 #include <linux/fs.h>
43 #include <linux/pagemap.h>
44
45 /* Default simulator parameters values */
46 #if !defined(CONFIG_NANDSIM_FIRST_ID_BYTE)  || \
47     !defined(CONFIG_NANDSIM_SECOND_ID_BYTE) || \
48     !defined(CONFIG_NANDSIM_THIRD_ID_BYTE)  || \
49     !defined(CONFIG_NANDSIM_FOURTH_ID_BYTE)
50 #define CONFIG_NANDSIM_FIRST_ID_BYTE  0x98
51 #define CONFIG_NANDSIM_SECOND_ID_BYTE 0x39
52 #define CONFIG_NANDSIM_THIRD_ID_BYTE  0xFF /* No byte */
53 #define CONFIG_NANDSIM_FOURTH_ID_BYTE 0xFF /* No byte */
54 #endif
55
56 #ifndef CONFIG_NANDSIM_ACCESS_DELAY
57 #define CONFIG_NANDSIM_ACCESS_DELAY 25
58 #endif
59 #ifndef CONFIG_NANDSIM_PROGRAMM_DELAY
60 #define CONFIG_NANDSIM_PROGRAMM_DELAY 200
61 #endif
62 #ifndef CONFIG_NANDSIM_ERASE_DELAY
63 #define CONFIG_NANDSIM_ERASE_DELAY 2
64 #endif
65 #ifndef CONFIG_NANDSIM_OUTPUT_CYCLE
66 #define CONFIG_NANDSIM_OUTPUT_CYCLE 40
67 #endif
68 #ifndef CONFIG_NANDSIM_INPUT_CYCLE
69 #define CONFIG_NANDSIM_INPUT_CYCLE  50
70 #endif
71 #ifndef CONFIG_NANDSIM_BUS_WIDTH
72 #define CONFIG_NANDSIM_BUS_WIDTH  8
73 #endif
74 #ifndef CONFIG_NANDSIM_DO_DELAYS
75 #define CONFIG_NANDSIM_DO_DELAYS  0
76 #endif
77 #ifndef CONFIG_NANDSIM_LOG
78 #define CONFIG_NANDSIM_LOG        0
79 #endif
80 #ifndef CONFIG_NANDSIM_DBG
81 #define CONFIG_NANDSIM_DBG        0
82 #endif
83
84 static uint first_id_byte  = CONFIG_NANDSIM_FIRST_ID_BYTE;
85 static uint second_id_byte = CONFIG_NANDSIM_SECOND_ID_BYTE;
86 static uint third_id_byte  = CONFIG_NANDSIM_THIRD_ID_BYTE;
87 static uint fourth_id_byte = CONFIG_NANDSIM_FOURTH_ID_BYTE;
88 static uint access_delay   = CONFIG_NANDSIM_ACCESS_DELAY;
89 static uint programm_delay = CONFIG_NANDSIM_PROGRAMM_DELAY;
90 static uint erase_delay    = CONFIG_NANDSIM_ERASE_DELAY;
91 static uint output_cycle   = CONFIG_NANDSIM_OUTPUT_CYCLE;
92 static uint input_cycle    = CONFIG_NANDSIM_INPUT_CYCLE;
93 static uint bus_width      = CONFIG_NANDSIM_BUS_WIDTH;
94 static uint do_delays      = CONFIG_NANDSIM_DO_DELAYS;
95 static uint log            = CONFIG_NANDSIM_LOG;
96 static uint dbg            = CONFIG_NANDSIM_DBG;
97 static unsigned long parts[MAX_MTD_DEVICES];
98 static unsigned int parts_num;
99 static char *badblocks = NULL;
100 static char *weakblocks = NULL;
101 static char *weakpages = NULL;
102 static unsigned int bitflips = 0;
103 static char *gravepages = NULL;
104 static unsigned int rptwear = 0;
105 static unsigned int overridesize = 0;
106 static char *cache_file = NULL;
107
108 module_param(first_id_byte,  uint, 0400);
109 module_param(second_id_byte, uint, 0400);
110 module_param(third_id_byte,  uint, 0400);
111 module_param(fourth_id_byte, uint, 0400);
112 module_param(access_delay,   uint, 0400);
113 module_param(programm_delay, uint, 0400);
114 module_param(erase_delay,    uint, 0400);
115 module_param(output_cycle,   uint, 0400);
116 module_param(input_cycle,    uint, 0400);
117 module_param(bus_width,      uint, 0400);
118 module_param(do_delays,      uint, 0400);
119 module_param(log,            uint, 0400);
120 module_param(dbg,            uint, 0400);
121 module_param_array(parts, ulong, &parts_num, 0400);
122 module_param(badblocks,      charp, 0400);
123 module_param(weakblocks,     charp, 0400);
124 module_param(weakpages,      charp, 0400);
125 module_param(bitflips,       uint, 0400);
126 module_param(gravepages,     charp, 0400);
127 module_param(rptwear,        uint, 0400);
128 module_param(overridesize,   uint, 0400);
129 module_param(cache_file,     charp, 0400);
130
131 MODULE_PARM_DESC(first_id_byte,  "The first byte returned by NAND Flash 'read ID' command (manufacturer ID)");
132 MODULE_PARM_DESC(second_id_byte, "The second byte returned by NAND Flash 'read ID' command (chip ID)");
133 MODULE_PARM_DESC(third_id_byte,  "The third byte returned by NAND Flash 'read ID' command");
134 MODULE_PARM_DESC(fourth_id_byte, "The fourth byte returned by NAND Flash 'read ID' command");
135 MODULE_PARM_DESC(access_delay,   "Initial page access delay (microseconds)");
136 MODULE_PARM_DESC(programm_delay, "Page programm delay (microseconds");
137 MODULE_PARM_DESC(erase_delay,    "Sector erase delay (milliseconds)");
138 MODULE_PARM_DESC(output_cycle,   "Word output (from flash) time (nanodeconds)");
139 MODULE_PARM_DESC(input_cycle,    "Word input (to flash) time (nanodeconds)");
140 MODULE_PARM_DESC(bus_width,      "Chip's bus width (8- or 16-bit)");
141 MODULE_PARM_DESC(do_delays,      "Simulate NAND delays using busy-waits if not zero");
142 MODULE_PARM_DESC(log,            "Perform logging if not zero");
143 MODULE_PARM_DESC(dbg,            "Output debug information if not zero");
144 MODULE_PARM_DESC(parts,          "Partition sizes (in erase blocks) separated by commas");
145 /* Page and erase block positions for the following parameters are independent of any partitions */
146 MODULE_PARM_DESC(badblocks,      "Erase blocks that are initially marked bad, separated by commas");
147 MODULE_PARM_DESC(weakblocks,     "Weak erase blocks [: remaining erase cycles (defaults to 3)]"
148                                  " separated by commas e.g. 113:2 means eb 113"
149                                  " can be erased only twice before failing");
150 MODULE_PARM_DESC(weakpages,      "Weak pages [: maximum writes (defaults to 3)]"
151                                  " separated by commas e.g. 1401:2 means page 1401"
152                                  " can be written only twice before failing");
153 MODULE_PARM_DESC(bitflips,       "Maximum number of random bit flips per page (zero by default)");
154 MODULE_PARM_DESC(gravepages,     "Pages that lose data [: maximum reads (defaults to 3)]"
155                                  " separated by commas e.g. 1401:2 means page 1401"
156                                  " can be read only twice before failing");
157 MODULE_PARM_DESC(rptwear,        "Number of erases inbetween reporting wear, if not zero");
158 MODULE_PARM_DESC(overridesize,   "Specifies the NAND Flash size overriding the ID bytes. "
159                                  "The size is specified in erase blocks and as the exponent of a power of two"
160                                  " e.g. 5 means a size of 32 erase blocks");
161 MODULE_PARM_DESC(cache_file,     "File to use to cache nand pages instead of memory");
162
163 /* The largest possible page size */
164 #define NS_LARGEST_PAGE_SIZE    2048
165
166 /* The prefix for simulator output */
167 #define NS_OUTPUT_PREFIX "[nandsim]"
168
169 /* Simulator's output macros (logging, debugging, warning, error) */
170 #define NS_LOG(args...) \
171         do { if (log) printk(KERN_DEBUG NS_OUTPUT_PREFIX " log: " args); } while(0)
172 #define NS_DBG(args...) \
173         do { if (dbg) printk(KERN_DEBUG NS_OUTPUT_PREFIX " debug: " args); } while(0)
174 #define NS_WARN(args...) \
175         do { printk(KERN_WARNING NS_OUTPUT_PREFIX " warning: " args); } while(0)
176 #define NS_ERR(args...) \
177         do { printk(KERN_ERR NS_OUTPUT_PREFIX " error: " args); } while(0)
178 #define NS_INFO(args...) \
179         do { printk(KERN_INFO NS_OUTPUT_PREFIX " " args); } while(0)
180
181 /* Busy-wait delay macros (microseconds, milliseconds) */
182 #define NS_UDELAY(us) \
183         do { if (do_delays) udelay(us); } while(0)
184 #define NS_MDELAY(us) \
185         do { if (do_delays) mdelay(us); } while(0)
186
187 /* Is the nandsim structure initialized ? */
188 #define NS_IS_INITIALIZED(ns) ((ns)->geom.totsz != 0)
189
190 /* Good operation completion status */
191 #define NS_STATUS_OK(ns) (NAND_STATUS_READY | (NAND_STATUS_WP * ((ns)->lines.wp == 0)))
192
193 /* Operation failed completion status */
194 #define NS_STATUS_FAILED(ns) (NAND_STATUS_FAIL | NS_STATUS_OK(ns))
195
196 /* Calculate the page offset in flash RAM image by (row, column) address */
197 #define NS_RAW_OFFSET(ns) \
198         (((ns)->regs.row << (ns)->geom.pgshift) + ((ns)->regs.row * (ns)->geom.oobsz) + (ns)->regs.column)
199
200 /* Calculate the OOB offset in flash RAM image by (row, column) address */
201 #define NS_RAW_OFFSET_OOB(ns) (NS_RAW_OFFSET(ns) + ns->geom.pgsz)
202
203 /* After a command is input, the simulator goes to one of the following states */
204 #define STATE_CMD_READ0        0x00000001 /* read data from the beginning of page */
205 #define STATE_CMD_READ1        0x00000002 /* read data from the second half of page */
206 #define STATE_CMD_READSTART    0x00000003 /* read data second command (large page devices) */
207 #define STATE_CMD_PAGEPROG     0x00000004 /* start page programm */
208 #define STATE_CMD_READOOB      0x00000005 /* read OOB area */
209 #define STATE_CMD_ERASE1       0x00000006 /* sector erase first command */
210 #define STATE_CMD_STATUS       0x00000007 /* read status */
211 #define STATE_CMD_STATUS_M     0x00000008 /* read multi-plane status (isn't implemented) */
212 #define STATE_CMD_SEQIN        0x00000009 /* sequential data imput */
213 #define STATE_CMD_READID       0x0000000A /* read ID */
214 #define STATE_CMD_ERASE2       0x0000000B /* sector erase second command */
215 #define STATE_CMD_RESET        0x0000000C /* reset */
216 #define STATE_CMD_RNDOUT       0x0000000D /* random output command */
217 #define STATE_CMD_RNDOUTSTART  0x0000000E /* random output start command */
218 #define STATE_CMD_MASK         0x0000000F /* command states mask */
219
220 /* After an address is input, the simulator goes to one of these states */
221 #define STATE_ADDR_PAGE        0x00000010 /* full (row, column) address is accepted */
222 #define STATE_ADDR_SEC         0x00000020 /* sector address was accepted */
223 #define STATE_ADDR_COLUMN      0x00000030 /* column address was accepted */
224 #define STATE_ADDR_ZERO        0x00000040 /* one byte zero address was accepted */
225 #define STATE_ADDR_MASK        0x00000070 /* address states mask */
226
227 /* Durind data input/output the simulator is in these states */
228 #define STATE_DATAIN           0x00000100 /* waiting for data input */
229 #define STATE_DATAIN_MASK      0x00000100 /* data input states mask */
230
231 #define STATE_DATAOUT          0x00001000 /* waiting for page data output */
232 #define STATE_DATAOUT_ID       0x00002000 /* waiting for ID bytes output */
233 #define STATE_DATAOUT_STATUS   0x00003000 /* waiting for status output */
234 #define STATE_DATAOUT_STATUS_M 0x00004000 /* waiting for multi-plane status output */
235 #define STATE_DATAOUT_MASK     0x00007000 /* data output states mask */
236
237 /* Previous operation is done, ready to accept new requests */
238 #define STATE_READY            0x00000000
239
240 /* This state is used to mark that the next state isn't known yet */
241 #define STATE_UNKNOWN          0x10000000
242
243 /* Simulator's actions bit masks */
244 #define ACTION_CPY       0x00100000 /* copy page/OOB to the internal buffer */
245 #define ACTION_PRGPAGE   0x00200000 /* programm the internal buffer to flash */
246 #define ACTION_SECERASE  0x00300000 /* erase sector */
247 #define ACTION_ZEROOFF   0x00400000 /* don't add any offset to address */
248 #define ACTION_HALFOFF   0x00500000 /* add to address half of page */
249 #define ACTION_OOBOFF    0x00600000 /* add to address OOB offset */
250 #define ACTION_MASK      0x00700000 /* action mask */
251
252 #define NS_OPER_NUM      13 /* Number of operations supported by the simulator */
253 #define NS_OPER_STATES   6  /* Maximum number of states in operation */
254
255 #define OPT_ANY          0xFFFFFFFF /* any chip supports this operation */
256 #define OPT_PAGE256      0x00000001 /* 256-byte  page chips */
257 #define OPT_PAGE512      0x00000002 /* 512-byte  page chips */
258 #define OPT_PAGE2048     0x00000008 /* 2048-byte page chips */
259 #define OPT_SMARTMEDIA   0x00000010 /* SmartMedia technology chips */
260 #define OPT_AUTOINCR     0x00000020 /* page number auto inctimentation is possible */
261 #define OPT_PAGE512_8BIT 0x00000040 /* 512-byte page chips with 8-bit bus width */
262 #define OPT_LARGEPAGE    (OPT_PAGE2048) /* 2048-byte page chips */
263 #define OPT_SMALLPAGE    (OPT_PAGE256  | OPT_PAGE512)  /* 256 and 512-byte page chips */
264
265 /* Remove action bits ftom state */
266 #define NS_STATE(x) ((x) & ~ACTION_MASK)
267
268 /*
269  * Maximum previous states which need to be saved. Currently saving is
270  * only needed for page programm operation with preceeded read command
271  * (which is only valid for 512-byte pages).
272  */
273 #define NS_MAX_PREVSTATES 1
274
275 /* Maximum page cache pages needed to read or write a NAND page to the cache_file */
276 #define NS_MAX_HELD_PAGES 16
277
278 /*
279  * A union to represent flash memory contents and flash buffer.
280  */
281 union ns_mem {
282         u_char *byte;    /* for byte access */
283         uint16_t *word;  /* for 16-bit word access */
284 };
285
286 /*
287  * The structure which describes all the internal simulator data.
288  */
289 struct nandsim {
290         struct mtd_partition partitions[MAX_MTD_DEVICES];
291         unsigned int nbparts;
292
293         uint busw;              /* flash chip bus width (8 or 16) */
294         u_char ids[4];          /* chip's ID bytes */
295         uint32_t options;       /* chip's characteristic bits */
296         uint32_t state;         /* current chip state */
297         uint32_t nxstate;       /* next expected state */
298
299         uint32_t *op;           /* current operation, NULL operations isn't known yet  */
300         uint32_t pstates[NS_MAX_PREVSTATES]; /* previous states */
301         uint16_t npstates;      /* number of previous states saved */
302         uint16_t stateidx;      /* current state index */
303
304         /* The simulated NAND flash pages array */
305         union ns_mem *pages;
306
307         /* Slab allocator for nand pages */
308         struct kmem_cache *nand_pages_slab;
309
310         /* Internal buffer of page + OOB size bytes */
311         union ns_mem buf;
312
313         /* NAND flash "geometry" */
314         struct nandsin_geometry {
315                 uint64_t totsz;     /* total flash size, bytes */
316                 uint32_t secsz;     /* flash sector (erase block) size, bytes */
317                 uint pgsz;          /* NAND flash page size, bytes */
318                 uint oobsz;         /* page OOB area size, bytes */
319                 uint64_t totszoob;  /* total flash size including OOB, bytes */
320                 uint pgszoob;       /* page size including OOB , bytes*/
321                 uint secszoob;      /* sector size including OOB, bytes */
322                 uint pgnum;         /* total number of pages */
323                 uint pgsec;         /* number of pages per sector */
324                 uint secshift;      /* bits number in sector size */
325                 uint pgshift;       /* bits number in page size */
326                 uint oobshift;      /* bits number in OOB size */
327                 uint pgaddrbytes;   /* bytes per page address */
328                 uint secaddrbytes;  /* bytes per sector address */
329                 uint idbytes;       /* the number ID bytes that this chip outputs */
330         } geom;
331
332         /* NAND flash internal registers */
333         struct nandsim_regs {
334                 unsigned command; /* the command register */
335                 u_char   status;  /* the status register */
336                 uint     row;     /* the page number */
337                 uint     column;  /* the offset within page */
338                 uint     count;   /* internal counter */
339                 uint     num;     /* number of bytes which must be processed */
340                 uint     off;     /* fixed page offset */
341         } regs;
342
343         /* NAND flash lines state */
344         struct ns_lines_status {
345                 int ce;  /* chip Enable */
346                 int cle; /* command Latch Enable */
347                 int ale; /* address Latch Enable */
348                 int wp;  /* write Protect */
349         } lines;
350
351         /* Fields needed when using a cache file */
352         struct file *cfile; /* Open file */
353         unsigned char *pages_written; /* Which pages have been written */
354         void *file_buf;
355         struct page *held_pages[NS_MAX_HELD_PAGES];
356         int held_cnt;
357 };
358
359 /*
360  * Operations array. To perform any operation the simulator must pass
361  * through the correspondent states chain.
362  */
363 static struct nandsim_operations {
364         uint32_t reqopts;  /* options which are required to perform the operation */
365         uint32_t states[NS_OPER_STATES]; /* operation's states */
366 } ops[NS_OPER_NUM] = {
367         /* Read page + OOB from the beginning */
368         {OPT_SMALLPAGE, {STATE_CMD_READ0 | ACTION_ZEROOFF, STATE_ADDR_PAGE | ACTION_CPY,
369                         STATE_DATAOUT, STATE_READY}},
370         /* Read page + OOB from the second half */
371         {OPT_PAGE512_8BIT, {STATE_CMD_READ1 | ACTION_HALFOFF, STATE_ADDR_PAGE | ACTION_CPY,
372                         STATE_DATAOUT, STATE_READY}},
373         /* Read OOB */
374         {OPT_SMALLPAGE, {STATE_CMD_READOOB | ACTION_OOBOFF, STATE_ADDR_PAGE | ACTION_CPY,
375                         STATE_DATAOUT, STATE_READY}},
376         /* Programm page starting from the beginning */
377         {OPT_ANY, {STATE_CMD_SEQIN, STATE_ADDR_PAGE, STATE_DATAIN,
378                         STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
379         /* Programm page starting from the beginning */
380         {OPT_SMALLPAGE, {STATE_CMD_READ0, STATE_CMD_SEQIN | ACTION_ZEROOFF, STATE_ADDR_PAGE,
381                               STATE_DATAIN, STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
382         /* Programm page starting from the second half */
383         {OPT_PAGE512, {STATE_CMD_READ1, STATE_CMD_SEQIN | ACTION_HALFOFF, STATE_ADDR_PAGE,
384                               STATE_DATAIN, STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
385         /* Programm OOB */
386         {OPT_SMALLPAGE, {STATE_CMD_READOOB, STATE_CMD_SEQIN | ACTION_OOBOFF, STATE_ADDR_PAGE,
387                               STATE_DATAIN, STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
388         /* Erase sector */
389         {OPT_ANY, {STATE_CMD_ERASE1, STATE_ADDR_SEC, STATE_CMD_ERASE2 | ACTION_SECERASE, STATE_READY}},
390         /* Read status */
391         {OPT_ANY, {STATE_CMD_STATUS, STATE_DATAOUT_STATUS, STATE_READY}},
392         /* Read multi-plane status */
393         {OPT_SMARTMEDIA, {STATE_CMD_STATUS_M, STATE_DATAOUT_STATUS_M, STATE_READY}},
394         /* Read ID */
395         {OPT_ANY, {STATE_CMD_READID, STATE_ADDR_ZERO, STATE_DATAOUT_ID, STATE_READY}},
396         /* Large page devices read page */
397         {OPT_LARGEPAGE, {STATE_CMD_READ0, STATE_ADDR_PAGE, STATE_CMD_READSTART | ACTION_CPY,
398                                STATE_DATAOUT, STATE_READY}},
399         /* Large page devices random page read */
400         {OPT_LARGEPAGE, {STATE_CMD_RNDOUT, STATE_ADDR_COLUMN, STATE_CMD_RNDOUTSTART | ACTION_CPY,
401                                STATE_DATAOUT, STATE_READY}},
402 };
403
404 struct weak_block {
405         struct list_head list;
406         unsigned int erase_block_no;
407         unsigned int max_erases;
408         unsigned int erases_done;
409 };
410
411 static LIST_HEAD(weak_blocks);
412
413 struct weak_page {
414         struct list_head list;
415         unsigned int page_no;
416         unsigned int max_writes;
417         unsigned int writes_done;
418 };
419
420 static LIST_HEAD(weak_pages);
421
422 struct grave_page {
423         struct list_head list;
424         unsigned int page_no;
425         unsigned int max_reads;
426         unsigned int reads_done;
427 };
428
429 static LIST_HEAD(grave_pages);
430
431 static unsigned long *erase_block_wear = NULL;
432 static unsigned int wear_eb_count = 0;
433 static unsigned long total_wear = 0;
434 static unsigned int rptwear_cnt = 0;
435
436 /* MTD structure for NAND controller */
437 static struct mtd_info *nsmtd;
438
439 static u_char ns_verify_buf[NS_LARGEST_PAGE_SIZE];
440
441 /*
442  * Allocate array of page pointers, create slab allocation for an array
443  * and initialize the array by NULL pointers.
444  *
445  * RETURNS: 0 if success, -ENOMEM if memory alloc fails.
446  */
447 static int alloc_device(struct nandsim *ns)
448 {
449         struct file *cfile;
450         int i, err;
451
452         if (cache_file) {
453                 cfile = filp_open(cache_file, O_CREAT | O_RDWR | O_LARGEFILE, 0600);
454                 if (IS_ERR(cfile))
455                         return PTR_ERR(cfile);
456                 if (!cfile->f_op || (!cfile->f_op->read && !cfile->f_op->aio_read)) {
457                         NS_ERR("alloc_device: cache file not readable\n");
458                         err = -EINVAL;
459                         goto err_close;
460                 }
461                 if (!cfile->f_op->write && !cfile->f_op->aio_write) {
462                         NS_ERR("alloc_device: cache file not writeable\n");
463                         err = -EINVAL;
464                         goto err_close;
465                 }
466                 ns->pages_written = vmalloc(ns->geom.pgnum);
467                 if (!ns->pages_written) {
468                         NS_ERR("alloc_device: unable to allocate pages written array\n");
469                         err = -ENOMEM;
470                         goto err_close;
471                 }
472                 ns->file_buf = kmalloc(ns->geom.pgszoob, GFP_KERNEL);
473                 if (!ns->file_buf) {
474                         NS_ERR("alloc_device: unable to allocate file buf\n");
475                         err = -ENOMEM;
476                         goto err_free;
477                 }
478                 ns->cfile = cfile;
479                 memset(ns->pages_written, 0, ns->geom.pgnum);
480                 return 0;
481         }
482
483         ns->pages = vmalloc(ns->geom.pgnum * sizeof(union ns_mem));
484         if (!ns->pages) {
485                 NS_ERR("alloc_device: unable to allocate page array\n");
486                 return -ENOMEM;
487         }
488         for (i = 0; i < ns->geom.pgnum; i++) {
489                 ns->pages[i].byte = NULL;
490         }
491         ns->nand_pages_slab = kmem_cache_create("nandsim",
492                                                 ns->geom.pgszoob, 0, 0, NULL);
493         if (!ns->nand_pages_slab) {
494                 NS_ERR("cache_create: unable to create kmem_cache\n");
495                 return -ENOMEM;
496         }
497
498         return 0;
499
500 err_free:
501         vfree(ns->pages_written);
502 err_close:
503         filp_close(cfile, NULL);
504         return err;
505 }
506
507 /*
508  * Free any allocated pages, and free the array of page pointers.
509  */
510 static void free_device(struct nandsim *ns)
511 {
512         int i;
513
514         if (ns->cfile) {
515                 kfree(ns->file_buf);
516                 vfree(ns->pages_written);
517                 filp_close(ns->cfile, NULL);
518                 return;
519         }
520
521         if (ns->pages) {
522                 for (i = 0; i < ns->geom.pgnum; i++) {
523                         if (ns->pages[i].byte)
524                                 kmem_cache_free(ns->nand_pages_slab,
525                                                 ns->pages[i].byte);
526                 }
527                 kmem_cache_destroy(ns->nand_pages_slab);
528                 vfree(ns->pages);
529         }
530 }
531
532 static char *get_partition_name(int i)
533 {
534         char buf[64];
535         sprintf(buf, "NAND simulator partition %d", i);
536         return kstrdup(buf, GFP_KERNEL);
537 }
538
539 static uint64_t divide(uint64_t n, uint32_t d)
540 {
541         do_div(n, d);
542         return n;
543 }
544
545 /*
546  * Initialize the nandsim structure.
547  *
548  * RETURNS: 0 if success, -ERRNO if failure.
549  */
550 static int init_nandsim(struct mtd_info *mtd)
551 {
552         struct nand_chip *chip = (struct nand_chip *)mtd->priv;
553         struct nandsim   *ns   = (struct nandsim *)(chip->priv);
554         int i, ret = 0;
555         uint64_t remains;
556         uint64_t next_offset;
557
558         if (NS_IS_INITIALIZED(ns)) {
559                 NS_ERR("init_nandsim: nandsim is already initialized\n");
560                 return -EIO;
561         }
562
563         /* Force mtd to not do delays */
564         chip->chip_delay = 0;
565
566         /* Initialize the NAND flash parameters */
567         ns->busw = chip->options & NAND_BUSWIDTH_16 ? 16 : 8;
568         ns->geom.totsz    = mtd->size;
569         ns->geom.pgsz     = mtd->writesize;
570         ns->geom.oobsz    = mtd->oobsize;
571         ns->geom.secsz    = mtd->erasesize;
572         ns->geom.pgszoob  = ns->geom.pgsz + ns->geom.oobsz;
573         ns->geom.pgnum    = divide(ns->geom.totsz, ns->geom.pgsz);
574         ns->geom.totszoob = ns->geom.totsz + (uint64_t)ns->geom.pgnum * ns->geom.oobsz;
575         ns->geom.secshift = ffs(ns->geom.secsz) - 1;
576         ns->geom.pgshift  = chip->page_shift;
577         ns->geom.oobshift = ffs(ns->geom.oobsz) - 1;
578         ns->geom.pgsec    = ns->geom.secsz / ns->geom.pgsz;
579         ns->geom.secszoob = ns->geom.secsz + ns->geom.oobsz * ns->geom.pgsec;
580         ns->options = 0;
581
582         if (ns->geom.pgsz == 256) {
583                 ns->options |= OPT_PAGE256;
584         }
585         else if (ns->geom.pgsz == 512) {
586                 ns->options |= (OPT_PAGE512 | OPT_AUTOINCR);
587                 if (ns->busw == 8)
588                         ns->options |= OPT_PAGE512_8BIT;
589         } else if (ns->geom.pgsz == 2048) {
590                 ns->options |= OPT_PAGE2048;
591         } else {
592                 NS_ERR("init_nandsim: unknown page size %u\n", ns->geom.pgsz);
593                 return -EIO;
594         }
595
596         if (ns->options & OPT_SMALLPAGE) {
597                 if (ns->geom.totsz <= (32 << 20)) {
598                         ns->geom.pgaddrbytes  = 3;
599                         ns->geom.secaddrbytes = 2;
600                 } else {
601                         ns->geom.pgaddrbytes  = 4;
602                         ns->geom.secaddrbytes = 3;
603                 }
604         } else {
605                 if (ns->geom.totsz <= (128 << 20)) {
606                         ns->geom.pgaddrbytes  = 4;
607                         ns->geom.secaddrbytes = 2;
608                 } else {
609                         ns->geom.pgaddrbytes  = 5;
610                         ns->geom.secaddrbytes = 3;
611                 }
612         }
613
614         /* Fill the partition_info structure */
615         if (parts_num > ARRAY_SIZE(ns->partitions)) {
616                 NS_ERR("too many partitions.\n");
617                 ret = -EINVAL;
618                 goto error;
619         }
620         remains = ns->geom.totsz;
621         next_offset = 0;
622         for (i = 0; i < parts_num; ++i) {
623                 uint64_t part_sz = (uint64_t)parts[i] * ns->geom.secsz;
624
625                 if (!part_sz || part_sz > remains) {
626                         NS_ERR("bad partition size.\n");
627                         ret = -EINVAL;
628                         goto error;
629                 }
630                 ns->partitions[i].name   = get_partition_name(i);
631                 ns->partitions[i].offset = next_offset;
632                 ns->partitions[i].size   = part_sz;
633                 next_offset += ns->partitions[i].size;
634                 remains -= ns->partitions[i].size;
635         }
636         ns->nbparts = parts_num;
637         if (remains) {
638                 if (parts_num + 1 > ARRAY_SIZE(ns->partitions)) {
639                         NS_ERR("too many partitions.\n");
640                         ret = -EINVAL;
641                         goto error;
642                 }
643                 ns->partitions[i].name   = get_partition_name(i);
644                 ns->partitions[i].offset = next_offset;
645                 ns->partitions[i].size   = remains;
646                 ns->nbparts += 1;
647         }
648
649         /* Detect how many ID bytes the NAND chip outputs */
650         for (i = 0; nand_flash_ids[i].name != NULL; i++) {
651                 if (second_id_byte != nand_flash_ids[i].id)
652                         continue;
653                 if (!(nand_flash_ids[i].options & NAND_NO_AUTOINCR))
654                         ns->options |= OPT_AUTOINCR;
655         }
656
657         if (ns->busw == 16)
658                 NS_WARN("16-bit flashes support wasn't tested\n");
659
660         printk("flash size: %llu MiB\n",
661                         (unsigned long long)ns->geom.totsz >> 20);
662         printk("page size: %u bytes\n",         ns->geom.pgsz);
663         printk("OOB area size: %u bytes\n",     ns->geom.oobsz);
664         printk("sector size: %u KiB\n",         ns->geom.secsz >> 10);
665         printk("pages number: %u\n",            ns->geom.pgnum);
666         printk("pages per sector: %u\n",        ns->geom.pgsec);
667         printk("bus width: %u\n",               ns->busw);
668         printk("bits in sector size: %u\n",     ns->geom.secshift);
669         printk("bits in page size: %u\n",       ns->geom.pgshift);
670         printk("bits in OOB size: %u\n",        ns->geom.oobshift);
671         printk("flash size with OOB: %llu KiB\n",
672                         (unsigned long long)ns->geom.totszoob >> 10);
673         printk("page address bytes: %u\n",      ns->geom.pgaddrbytes);
674         printk("sector address bytes: %u\n",    ns->geom.secaddrbytes);
675         printk("options: %#x\n",                ns->options);
676
677         if ((ret = alloc_device(ns)) != 0)
678                 goto error;
679
680         /* Allocate / initialize the internal buffer */
681         ns->buf.byte = kmalloc(ns->geom.pgszoob, GFP_KERNEL);
682         if (!ns->buf.byte) {
683                 NS_ERR("init_nandsim: unable to allocate %u bytes for the internal buffer\n",
684                         ns->geom.pgszoob);
685                 ret = -ENOMEM;
686                 goto error;
687         }
688         memset(ns->buf.byte, 0xFF, ns->geom.pgszoob);
689
690         return 0;
691
692 error:
693         free_device(ns);
694
695         return ret;
696 }
697
698 /*
699  * Free the nandsim structure.
700  */
701 static void free_nandsim(struct nandsim *ns)
702 {
703         kfree(ns->buf.byte);
704         free_device(ns);
705
706         return;
707 }
708
709 static int parse_badblocks(struct nandsim *ns, struct mtd_info *mtd)
710 {
711         char *w;
712         int zero_ok;
713         unsigned int erase_block_no;
714         loff_t offset;
715
716         if (!badblocks)
717                 return 0;
718         w = badblocks;
719         do {
720                 zero_ok = (*w == '0' ? 1 : 0);
721                 erase_block_no = simple_strtoul(w, &w, 0);
722                 if (!zero_ok && !erase_block_no) {
723                         NS_ERR("invalid badblocks.\n");
724                         return -EINVAL;
725                 }
726                 offset = erase_block_no * ns->geom.secsz;
727                 if (mtd->block_markbad(mtd, offset)) {
728                         NS_ERR("invalid badblocks.\n");
729                         return -EINVAL;
730                 }
731                 if (*w == ',')
732                         w += 1;
733         } while (*w);
734         return 0;
735 }
736
737 static int parse_weakblocks(void)
738 {
739         char *w;
740         int zero_ok;
741         unsigned int erase_block_no;
742         unsigned int max_erases;
743         struct weak_block *wb;
744
745         if (!weakblocks)
746                 return 0;
747         w = weakblocks;
748         do {
749                 zero_ok = (*w == '0' ? 1 : 0);
750                 erase_block_no = simple_strtoul(w, &w, 0);
751                 if (!zero_ok && !erase_block_no) {
752                         NS_ERR("invalid weakblocks.\n");
753                         return -EINVAL;
754                 }
755                 max_erases = 3;
756                 if (*w == ':') {
757                         w += 1;
758                         max_erases = simple_strtoul(w, &w, 0);
759                 }
760                 if (*w == ',')
761                         w += 1;
762                 wb = kzalloc(sizeof(*wb), GFP_KERNEL);
763                 if (!wb) {
764                         NS_ERR("unable to allocate memory.\n");
765                         return -ENOMEM;
766                 }
767                 wb->erase_block_no = erase_block_no;
768                 wb->max_erases = max_erases;
769                 list_add(&wb->list, &weak_blocks);
770         } while (*w);
771         return 0;
772 }
773
774 static int erase_error(unsigned int erase_block_no)
775 {
776         struct weak_block *wb;
777
778         list_for_each_entry(wb, &weak_blocks, list)
779                 if (wb->erase_block_no == erase_block_no) {
780                         if (wb->erases_done >= wb->max_erases)
781                                 return 1;
782                         wb->erases_done += 1;
783                         return 0;
784                 }
785         return 0;
786 }
787
788 static int parse_weakpages(void)
789 {
790         char *w;
791         int zero_ok;
792         unsigned int page_no;
793         unsigned int max_writes;
794         struct weak_page *wp;
795
796         if (!weakpages)
797                 return 0;
798         w = weakpages;
799         do {
800                 zero_ok = (*w == '0' ? 1 : 0);
801                 page_no = simple_strtoul(w, &w, 0);
802                 if (!zero_ok && !page_no) {
803                         NS_ERR("invalid weakpagess.\n");
804                         return -EINVAL;
805                 }
806                 max_writes = 3;
807                 if (*w == ':') {
808                         w += 1;
809                         max_writes = simple_strtoul(w, &w, 0);
810                 }
811                 if (*w == ',')
812                         w += 1;
813                 wp = kzalloc(sizeof(*wp), GFP_KERNEL);
814                 if (!wp) {
815                         NS_ERR("unable to allocate memory.\n");
816                         return -ENOMEM;
817                 }
818                 wp->page_no = page_no;
819                 wp->max_writes = max_writes;
820                 list_add(&wp->list, &weak_pages);
821         } while (*w);
822         return 0;
823 }
824
825 static int write_error(unsigned int page_no)
826 {
827         struct weak_page *wp;
828
829         list_for_each_entry(wp, &weak_pages, list)
830                 if (wp->page_no == page_no) {
831                         if (wp->writes_done >= wp->max_writes)
832                                 return 1;
833                         wp->writes_done += 1;
834                         return 0;
835                 }
836         return 0;
837 }
838
839 static int parse_gravepages(void)
840 {
841         char *g;
842         int zero_ok;
843         unsigned int page_no;
844         unsigned int max_reads;
845         struct grave_page *gp;
846
847         if (!gravepages)
848                 return 0;
849         g = gravepages;
850         do {
851                 zero_ok = (*g == '0' ? 1 : 0);
852                 page_no = simple_strtoul(g, &g, 0);
853                 if (!zero_ok && !page_no) {
854                         NS_ERR("invalid gravepagess.\n");
855                         return -EINVAL;
856                 }
857                 max_reads = 3;
858                 if (*g == ':') {
859                         g += 1;
860                         max_reads = simple_strtoul(g, &g, 0);
861                 }
862                 if (*g == ',')
863                         g += 1;
864                 gp = kzalloc(sizeof(*gp), GFP_KERNEL);
865                 if (!gp) {
866                         NS_ERR("unable to allocate memory.\n");
867                         return -ENOMEM;
868                 }
869                 gp->page_no = page_no;
870                 gp->max_reads = max_reads;
871                 list_add(&gp->list, &grave_pages);
872         } while (*g);
873         return 0;
874 }
875
876 static int read_error(unsigned int page_no)
877 {
878         struct grave_page *gp;
879
880         list_for_each_entry(gp, &grave_pages, list)
881                 if (gp->page_no == page_no) {
882                         if (gp->reads_done >= gp->max_reads)
883                                 return 1;
884                         gp->reads_done += 1;
885                         return 0;
886                 }
887         return 0;
888 }
889
890 static void free_lists(void)
891 {
892         struct list_head *pos, *n;
893         list_for_each_safe(pos, n, &weak_blocks) {
894                 list_del(pos);
895                 kfree(list_entry(pos, struct weak_block, list));
896         }
897         list_for_each_safe(pos, n, &weak_pages) {
898                 list_del(pos);
899                 kfree(list_entry(pos, struct weak_page, list));
900         }
901         list_for_each_safe(pos, n, &grave_pages) {
902                 list_del(pos);
903                 kfree(list_entry(pos, struct grave_page, list));
904         }
905         kfree(erase_block_wear);
906 }
907
908 static int setup_wear_reporting(struct mtd_info *mtd)
909 {
910         size_t mem;
911
912         if (!rptwear)
913                 return 0;
914         wear_eb_count = divide(mtd->size, mtd->erasesize);
915         mem = wear_eb_count * sizeof(unsigned long);
916         if (mem / sizeof(unsigned long) != wear_eb_count) {
917                 NS_ERR("Too many erase blocks for wear reporting\n");
918                 return -ENOMEM;
919         }
920         erase_block_wear = kzalloc(mem, GFP_KERNEL);
921         if (!erase_block_wear) {
922                 NS_ERR("Too many erase blocks for wear reporting\n");
923                 return -ENOMEM;
924         }
925         return 0;
926 }
927
928 static void update_wear(unsigned int erase_block_no)
929 {
930         unsigned long wmin = -1, wmax = 0, avg;
931         unsigned long deciles[10], decile_max[10], tot = 0;
932         unsigned int i;
933
934         if (!erase_block_wear)
935                 return;
936         total_wear += 1;
937         if (total_wear == 0)
938                 NS_ERR("Erase counter total overflow\n");
939         erase_block_wear[erase_block_no] += 1;
940         if (erase_block_wear[erase_block_no] == 0)
941                 NS_ERR("Erase counter overflow for erase block %u\n", erase_block_no);
942         rptwear_cnt += 1;
943         if (rptwear_cnt < rptwear)
944                 return;
945         rptwear_cnt = 0;
946         /* Calc wear stats */
947         for (i = 0; i < wear_eb_count; ++i) {
948                 unsigned long wear = erase_block_wear[i];
949                 if (wear < wmin)
950                         wmin = wear;
951                 if (wear > wmax)
952                         wmax = wear;
953                 tot += wear;
954         }
955         for (i = 0; i < 9; ++i) {
956                 deciles[i] = 0;
957                 decile_max[i] = (wmax * (i + 1) + 5) / 10;
958         }
959         deciles[9] = 0;
960         decile_max[9] = wmax;
961         for (i = 0; i < wear_eb_count; ++i) {
962                 int d;
963                 unsigned long wear = erase_block_wear[i];
964                 for (d = 0; d < 10; ++d)
965                         if (wear <= decile_max[d]) {
966                                 deciles[d] += 1;
967                                 break;
968                         }
969         }
970         avg = tot / wear_eb_count;
971         /* Output wear report */
972         NS_INFO("*** Wear Report ***\n");
973         NS_INFO("Total numbers of erases:  %lu\n", tot);
974         NS_INFO("Number of erase blocks:   %u\n", wear_eb_count);
975         NS_INFO("Average number of erases: %lu\n", avg);
976         NS_INFO("Maximum number of erases: %lu\n", wmax);
977         NS_INFO("Minimum number of erases: %lu\n", wmin);
978         for (i = 0; i < 10; ++i) {
979                 unsigned long from = (i ? decile_max[i - 1] + 1 : 0);
980                 if (from > decile_max[i])
981                         continue;
982                 NS_INFO("Number of ebs with erase counts from %lu to %lu : %lu\n",
983                         from,
984                         decile_max[i],
985                         deciles[i]);
986         }
987         NS_INFO("*** End of Wear Report ***\n");
988 }
989
990 /*
991  * Returns the string representation of 'state' state.
992  */
993 static char *get_state_name(uint32_t state)
994 {
995         switch (NS_STATE(state)) {
996                 case STATE_CMD_READ0:
997                         return "STATE_CMD_READ0";
998                 case STATE_CMD_READ1:
999                         return "STATE_CMD_READ1";
1000                 case STATE_CMD_PAGEPROG:
1001                         return "STATE_CMD_PAGEPROG";
1002                 case STATE_CMD_READOOB:
1003                         return "STATE_CMD_READOOB";
1004                 case STATE_CMD_READSTART:
1005                         return "STATE_CMD_READSTART";
1006                 case STATE_CMD_ERASE1:
1007                         return "STATE_CMD_ERASE1";
1008                 case STATE_CMD_STATUS:
1009                         return "STATE_CMD_STATUS";
1010                 case STATE_CMD_STATUS_M:
1011                         return "STATE_CMD_STATUS_M";
1012                 case STATE_CMD_SEQIN:
1013                         return "STATE_CMD_SEQIN";
1014                 case STATE_CMD_READID:
1015                         return "STATE_CMD_READID";
1016                 case STATE_CMD_ERASE2:
1017                         return "STATE_CMD_ERASE2";
1018                 case STATE_CMD_RESET:
1019                         return "STATE_CMD_RESET";
1020                 case STATE_CMD_RNDOUT:
1021                         return "STATE_CMD_RNDOUT";
1022                 case STATE_CMD_RNDOUTSTART:
1023                         return "STATE_CMD_RNDOUTSTART";
1024                 case STATE_ADDR_PAGE:
1025                         return "STATE_ADDR_PAGE";
1026                 case STATE_ADDR_SEC:
1027                         return "STATE_ADDR_SEC";
1028                 case STATE_ADDR_ZERO:
1029                         return "STATE_ADDR_ZERO";
1030                 case STATE_ADDR_COLUMN:
1031                         return "STATE_ADDR_COLUMN";
1032                 case STATE_DATAIN:
1033                         return "STATE_DATAIN";
1034                 case STATE_DATAOUT:
1035                         return "STATE_DATAOUT";
1036                 case STATE_DATAOUT_ID:
1037                         return "STATE_DATAOUT_ID";
1038                 case STATE_DATAOUT_STATUS:
1039                         return "STATE_DATAOUT_STATUS";
1040                 case STATE_DATAOUT_STATUS_M:
1041                         return "STATE_DATAOUT_STATUS_M";
1042                 case STATE_READY:
1043                         return "STATE_READY";
1044                 case STATE_UNKNOWN:
1045                         return "STATE_UNKNOWN";
1046         }
1047
1048         NS_ERR("get_state_name: unknown state, BUG\n");
1049         return NULL;
1050 }
1051
1052 /*
1053  * Check if command is valid.
1054  *
1055  * RETURNS: 1 if wrong command, 0 if right.
1056  */
1057 static int check_command(int cmd)
1058 {
1059         switch (cmd) {
1060
1061         case NAND_CMD_READ0:
1062         case NAND_CMD_READ1:
1063         case NAND_CMD_READSTART:
1064         case NAND_CMD_PAGEPROG:
1065         case NAND_CMD_READOOB:
1066         case NAND_CMD_ERASE1:
1067         case NAND_CMD_STATUS:
1068         case NAND_CMD_SEQIN:
1069         case NAND_CMD_READID:
1070         case NAND_CMD_ERASE2:
1071         case NAND_CMD_RESET:
1072         case NAND_CMD_RNDOUT:
1073         case NAND_CMD_RNDOUTSTART:
1074                 return 0;
1075
1076         case NAND_CMD_STATUS_MULTI:
1077         default:
1078                 return 1;
1079         }
1080 }
1081
1082 /*
1083  * Returns state after command is accepted by command number.
1084  */
1085 static uint32_t get_state_by_command(unsigned command)
1086 {
1087         switch (command) {
1088                 case NAND_CMD_READ0:
1089                         return STATE_CMD_READ0;
1090                 case NAND_CMD_READ1:
1091                         return STATE_CMD_READ1;
1092                 case NAND_CMD_PAGEPROG:
1093                         return STATE_CMD_PAGEPROG;
1094                 case NAND_CMD_READSTART:
1095                         return STATE_CMD_READSTART;
1096                 case NAND_CMD_READOOB:
1097                         return STATE_CMD_READOOB;
1098                 case NAND_CMD_ERASE1:
1099                         return STATE_CMD_ERASE1;
1100                 case NAND_CMD_STATUS:
1101                         return STATE_CMD_STATUS;
1102                 case NAND_CMD_STATUS_MULTI:
1103                         return STATE_CMD_STATUS_M;
1104                 case NAND_CMD_SEQIN:
1105                         return STATE_CMD_SEQIN;
1106                 case NAND_CMD_READID:
1107                         return STATE_CMD_READID;
1108                 case NAND_CMD_ERASE2:
1109                         return STATE_CMD_ERASE2;
1110                 case NAND_CMD_RESET:
1111                         return STATE_CMD_RESET;
1112                 case NAND_CMD_RNDOUT:
1113                         return STATE_CMD_RNDOUT;
1114                 case NAND_CMD_RNDOUTSTART:
1115                         return STATE_CMD_RNDOUTSTART;
1116         }
1117
1118         NS_ERR("get_state_by_command: unknown command, BUG\n");
1119         return 0;
1120 }
1121
1122 /*
1123  * Move an address byte to the correspondent internal register.
1124  */
1125 static inline void accept_addr_byte(struct nandsim *ns, u_char bt)
1126 {
1127         uint byte = (uint)bt;
1128
1129         if (ns->regs.count < (ns->geom.pgaddrbytes - ns->geom.secaddrbytes))
1130                 ns->regs.column |= (byte << 8 * ns->regs.count);
1131         else {
1132                 ns->regs.row |= (byte << 8 * (ns->regs.count -
1133                                                 ns->geom.pgaddrbytes +
1134                                                 ns->geom.secaddrbytes));
1135         }
1136
1137         return;
1138 }
1139
1140 /*
1141  * Switch to STATE_READY state.
1142  */
1143 static inline void switch_to_ready_state(struct nandsim *ns, u_char status)
1144 {
1145         NS_DBG("switch_to_ready_state: switch to %s state\n", get_state_name(STATE_READY));
1146
1147         ns->state       = STATE_READY;
1148         ns->nxstate     = STATE_UNKNOWN;
1149         ns->op          = NULL;
1150         ns->npstates    = 0;
1151         ns->stateidx    = 0;
1152         ns->regs.num    = 0;
1153         ns->regs.count  = 0;
1154         ns->regs.off    = 0;
1155         ns->regs.row    = 0;
1156         ns->regs.column = 0;
1157         ns->regs.status = status;
1158 }
1159
1160 /*
1161  * If the operation isn't known yet, try to find it in the global array
1162  * of supported operations.
1163  *
1164  * Operation can be unknown because of the following.
1165  *   1. New command was accepted and this is the firs call to find the
1166  *      correspondent states chain. In this case ns->npstates = 0;
1167  *   2. There is several operations which begin with the same command(s)
1168  *      (for example program from the second half and read from the
1169  *      second half operations both begin with the READ1 command). In this
1170  *      case the ns->pstates[] array contains previous states.
1171  *
1172  * Thus, the function tries to find operation containing the following
1173  * states (if the 'flag' parameter is 0):
1174  *    ns->pstates[0], ... ns->pstates[ns->npstates], ns->state
1175  *
1176  * If (one and only one) matching operation is found, it is accepted (
1177  * ns->ops, ns->state, ns->nxstate are initialized, ns->npstate is
1178  * zeroed).
1179  *
1180  * If there are several maches, the current state is pushed to the
1181  * ns->pstates.
1182  *
1183  * The operation can be unknown only while commands are input to the chip.
1184  * As soon as address command is accepted, the operation must be known.
1185  * In such situation the function is called with 'flag' != 0, and the
1186  * operation is searched using the following pattern:
1187  *     ns->pstates[0], ... ns->pstates[ns->npstates], <address input>
1188  *
1189  * It is supposed that this pattern must either match one operation on
1190  * none. There can't be ambiguity in that case.
1191  *
1192  * If no matches found, the functions does the following:
1193  *   1. if there are saved states present, try to ignore them and search
1194  *      again only using the last command. If nothing was found, switch
1195  *      to the STATE_READY state.
1196  *   2. if there are no saved states, switch to the STATE_READY state.
1197  *
1198  * RETURNS: -2 - no matched operations found.
1199  *          -1 - several matches.
1200  *           0 - operation is found.
1201  */
1202 static int find_operation(struct nandsim *ns, uint32_t flag)
1203 {
1204         int opsfound = 0;
1205         int i, j, idx = 0;
1206
1207         for (i = 0; i < NS_OPER_NUM; i++) {
1208
1209                 int found = 1;
1210
1211                 if (!(ns->options & ops[i].reqopts))
1212                         /* Ignore operations we can't perform */
1213                         continue;
1214
1215                 if (flag) {
1216                         if (!(ops[i].states[ns->npstates] & STATE_ADDR_MASK))
1217                                 continue;
1218                 } else {
1219                         if (NS_STATE(ns->state) != NS_STATE(ops[i].states[ns->npstates]))
1220                                 continue;
1221                 }
1222
1223                 for (j = 0; j < ns->npstates; j++)
1224                         if (NS_STATE(ops[i].states[j]) != NS_STATE(ns->pstates[j])
1225                                 && (ns->options & ops[idx].reqopts)) {
1226                                 found = 0;
1227                                 break;
1228                         }
1229
1230                 if (found) {
1231                         idx = i;
1232                         opsfound += 1;
1233                 }
1234         }
1235
1236         if (opsfound == 1) {
1237                 /* Exact match */
1238                 ns->op = &ops[idx].states[0];
1239                 if (flag) {
1240                         /*
1241                          * In this case the find_operation function was
1242                          * called when address has just began input. But it isn't
1243                          * yet fully input and the current state must
1244                          * not be one of STATE_ADDR_*, but the STATE_ADDR_*
1245                          * state must be the next state (ns->nxstate).
1246                          */
1247                         ns->stateidx = ns->npstates - 1;
1248                 } else {
1249                         ns->stateidx = ns->npstates;
1250                 }
1251                 ns->npstates = 0;
1252                 ns->state = ns->op[ns->stateidx];
1253                 ns->nxstate = ns->op[ns->stateidx + 1];
1254                 NS_DBG("find_operation: operation found, index: %d, state: %s, nxstate %s\n",
1255                                 idx, get_state_name(ns->state), get_state_name(ns->nxstate));
1256                 return 0;
1257         }
1258
1259         if (opsfound == 0) {
1260                 /* Nothing was found. Try to ignore previous commands (if any) and search again */
1261                 if (ns->npstates != 0) {
1262                         NS_DBG("find_operation: no operation found, try again with state %s\n",
1263                                         get_state_name(ns->state));
1264                         ns->npstates = 0;
1265                         return find_operation(ns, 0);
1266
1267                 }
1268                 NS_DBG("find_operation: no operations found\n");
1269                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1270                 return -2;
1271         }
1272
1273         if (flag) {
1274                 /* This shouldn't happen */
1275                 NS_DBG("find_operation: BUG, operation must be known if address is input\n");
1276                 return -2;
1277         }
1278
1279         NS_DBG("find_operation: there is still ambiguity\n");
1280
1281         ns->pstates[ns->npstates++] = ns->state;
1282
1283         return -1;
1284 }
1285
1286 static void put_pages(struct nandsim *ns)
1287 {
1288         int i;
1289
1290         for (i = 0; i < ns->held_cnt; i++)
1291                 page_cache_release(ns->held_pages[i]);
1292 }
1293
1294 /* Get page cache pages in advance to provide NOFS memory allocation */
1295 static int get_pages(struct nandsim *ns, struct file *file, size_t count, loff_t pos)
1296 {
1297         pgoff_t index, start_index, end_index;
1298         struct page *page;
1299         struct address_space *mapping = file->f_mapping;
1300
1301         start_index = pos >> PAGE_CACHE_SHIFT;
1302         end_index = (pos + count - 1) >> PAGE_CACHE_SHIFT;
1303         if (end_index - start_index + 1 > NS_MAX_HELD_PAGES)
1304                 return -EINVAL;
1305         ns->held_cnt = 0;
1306         for (index = start_index; index <= end_index; index++) {
1307                 page = find_get_page(mapping, index);
1308                 if (page == NULL) {
1309                         page = find_or_create_page(mapping, index, GFP_NOFS);
1310                         if (page == NULL) {
1311                                 write_inode_now(mapping->host, 1);
1312                                 page = find_or_create_page(mapping, index, GFP_NOFS);
1313                         }
1314                         if (page == NULL) {
1315                                 put_pages(ns);
1316                                 return -ENOMEM;
1317                         }
1318                         unlock_page(page);
1319                 }
1320                 ns->held_pages[ns->held_cnt++] = page;
1321         }
1322         return 0;
1323 }
1324
1325 static int set_memalloc(void)
1326 {
1327         if (current->flags & PF_MEMALLOC)
1328                 return 0;
1329         current->flags |= PF_MEMALLOC;
1330         return 1;
1331 }
1332
1333 static void clear_memalloc(int memalloc)
1334 {
1335         if (memalloc)
1336                 current->flags &= ~PF_MEMALLOC;
1337 }
1338
1339 static ssize_t read_file(struct nandsim *ns, struct file *file, void *buf, size_t count, loff_t *pos)
1340 {
1341         mm_segment_t old_fs;
1342         ssize_t tx;
1343         int err, memalloc;
1344
1345         err = get_pages(ns, file, count, *pos);
1346         if (err)
1347                 return err;
1348         old_fs = get_fs();
1349         set_fs(get_ds());
1350         memalloc = set_memalloc();
1351         tx = vfs_read(file, (char __user *)buf, count, pos);
1352         clear_memalloc(memalloc);
1353         set_fs(old_fs);
1354         put_pages(ns);
1355         return tx;
1356 }
1357
1358 static ssize_t write_file(struct nandsim *ns, struct file *file, void *buf, size_t count, loff_t *pos)
1359 {
1360         mm_segment_t old_fs;
1361         ssize_t tx;
1362         int err, memalloc;
1363
1364         err = get_pages(ns, file, count, *pos);
1365         if (err)
1366                 return err;
1367         old_fs = get_fs();
1368         set_fs(get_ds());
1369         memalloc = set_memalloc();
1370         tx = vfs_write(file, (char __user *)buf, count, pos);
1371         clear_memalloc(memalloc);
1372         set_fs(old_fs);
1373         put_pages(ns);
1374         return tx;
1375 }
1376
1377 /*
1378  * Returns a pointer to the current page.
1379  */
1380 static inline union ns_mem *NS_GET_PAGE(struct nandsim *ns)
1381 {
1382         return &(ns->pages[ns->regs.row]);
1383 }
1384
1385 /*
1386  * Retuns a pointer to the current byte, within the current page.
1387  */
1388 static inline u_char *NS_PAGE_BYTE_OFF(struct nandsim *ns)
1389 {
1390         return NS_GET_PAGE(ns)->byte + ns->regs.column + ns->regs.off;
1391 }
1392
1393 int do_read_error(struct nandsim *ns, int num)
1394 {
1395         unsigned int page_no = ns->regs.row;
1396
1397         if (read_error(page_no)) {
1398                 int i;
1399                 memset(ns->buf.byte, 0xFF, num);
1400                 for (i = 0; i < num; ++i)
1401                         ns->buf.byte[i] = random32();
1402                 NS_WARN("simulating read error in page %u\n", page_no);
1403                 return 1;
1404         }
1405         return 0;
1406 }
1407
1408 void do_bit_flips(struct nandsim *ns, int num)
1409 {
1410         if (bitflips && random32() < (1 << 22)) {
1411                 int flips = 1;
1412                 if (bitflips > 1)
1413                         flips = (random32() % (int) bitflips) + 1;
1414                 while (flips--) {
1415                         int pos = random32() % (num * 8);
1416                         ns->buf.byte[pos / 8] ^= (1 << (pos % 8));
1417                         NS_WARN("read_page: flipping bit %d in page %d "
1418                                 "reading from %d ecc: corrected=%u failed=%u\n",
1419                                 pos, ns->regs.row, ns->regs.column + ns->regs.off,
1420                                 nsmtd->ecc_stats.corrected, nsmtd->ecc_stats.failed);
1421                 }
1422         }
1423 }
1424
1425 /*
1426  * Fill the NAND buffer with data read from the specified page.
1427  */
1428 static void read_page(struct nandsim *ns, int num)
1429 {
1430         union ns_mem *mypage;
1431
1432         if (ns->cfile) {
1433                 if (!ns->pages_written[ns->regs.row]) {
1434                         NS_DBG("read_page: page %d not written\n", ns->regs.row);
1435                         memset(ns->buf.byte, 0xFF, num);
1436                 } else {
1437                         loff_t pos;
1438                         ssize_t tx;
1439
1440                         NS_DBG("read_page: page %d written, reading from %d\n",
1441                                 ns->regs.row, ns->regs.column + ns->regs.off);
1442                         if (do_read_error(ns, num))
1443                                 return;
1444                         pos = (loff_t)ns->regs.row * ns->geom.pgszoob + ns->regs.column + ns->regs.off;
1445                         tx = read_file(ns, ns->cfile, ns->buf.byte, num, &pos);
1446                         if (tx != num) {
1447                                 NS_ERR("read_page: read error for page %d ret %ld\n", ns->regs.row, (long)tx);
1448                                 return;
1449                         }
1450                         do_bit_flips(ns, num);
1451                 }
1452                 return;
1453         }
1454
1455         mypage = NS_GET_PAGE(ns);
1456         if (mypage->byte == NULL) {
1457                 NS_DBG("read_page: page %d not allocated\n", ns->regs.row);
1458                 memset(ns->buf.byte, 0xFF, num);
1459         } else {
1460                 NS_DBG("read_page: page %d allocated, reading from %d\n",
1461                         ns->regs.row, ns->regs.column + ns->regs.off);
1462                 if (do_read_error(ns, num))
1463                         return;
1464                 memcpy(ns->buf.byte, NS_PAGE_BYTE_OFF(ns), num);
1465                 do_bit_flips(ns, num);
1466         }
1467 }
1468
1469 /*
1470  * Erase all pages in the specified sector.
1471  */
1472 static void erase_sector(struct nandsim *ns)
1473 {
1474         union ns_mem *mypage;
1475         int i;
1476
1477         if (ns->cfile) {
1478                 for (i = 0; i < ns->geom.pgsec; i++)
1479                         if (ns->pages_written[ns->regs.row + i]) {
1480                                 NS_DBG("erase_sector: freeing page %d\n", ns->regs.row + i);
1481                                 ns->pages_written[ns->regs.row + i] = 0;
1482                         }
1483                 return;
1484         }
1485
1486         mypage = NS_GET_PAGE(ns);
1487         for (i = 0; i < ns->geom.pgsec; i++) {
1488                 if (mypage->byte != NULL) {
1489                         NS_DBG("erase_sector: freeing page %d\n", ns->regs.row+i);
1490                         kmem_cache_free(ns->nand_pages_slab, mypage->byte);
1491                         mypage->byte = NULL;
1492                 }
1493                 mypage++;
1494         }
1495 }
1496
1497 /*
1498  * Program the specified page with the contents from the NAND buffer.
1499  */
1500 static int prog_page(struct nandsim *ns, int num)
1501 {
1502         int i;
1503         union ns_mem *mypage;
1504         u_char *pg_off;
1505
1506         if (ns->cfile) {
1507                 loff_t off, pos;
1508                 ssize_t tx;
1509                 int all;
1510
1511                 NS_DBG("prog_page: writing page %d\n", ns->regs.row);
1512                 pg_off = ns->file_buf + ns->regs.column + ns->regs.off;
1513                 off = (loff_t)ns->regs.row * ns->geom.pgszoob + ns->regs.column + ns->regs.off;
1514                 if (!ns->pages_written[ns->regs.row]) {
1515                         all = 1;
1516                         memset(ns->file_buf, 0xff, ns->geom.pgszoob);
1517                 } else {
1518                         all = 0;
1519                         pos = off;
1520                         tx = read_file(ns, ns->cfile, pg_off, num, &pos);
1521                         if (tx != num) {
1522                                 NS_ERR("prog_page: read error for page %d ret %ld\n", ns->regs.row, (long)tx);
1523                                 return -1;
1524                         }
1525                 }
1526                 for (i = 0; i < num; i++)
1527                         pg_off[i] &= ns->buf.byte[i];
1528                 if (all) {
1529                         pos = (loff_t)ns->regs.row * ns->geom.pgszoob;
1530                         tx = write_file(ns, ns->cfile, ns->file_buf, ns->geom.pgszoob, &pos);
1531                         if (tx != ns->geom.pgszoob) {
1532                                 NS_ERR("prog_page: write error for page %d ret %ld\n", ns->regs.row, (long)tx);
1533                                 return -1;
1534                         }
1535                         ns->pages_written[ns->regs.row] = 1;
1536                 } else {
1537                         pos = off;
1538                         tx = write_file(ns, ns->cfile, pg_off, num, &pos);
1539                         if (tx != num) {
1540                                 NS_ERR("prog_page: write error for page %d ret %ld\n", ns->regs.row, (long)tx);
1541                                 return -1;
1542                         }
1543                 }
1544                 return 0;
1545         }
1546
1547         mypage = NS_GET_PAGE(ns);
1548         if (mypage->byte == NULL) {
1549                 NS_DBG("prog_page: allocating page %d\n", ns->regs.row);
1550                 /*
1551                  * We allocate memory with GFP_NOFS because a flash FS may
1552                  * utilize this. If it is holding an FS lock, then gets here,
1553                  * then kernel memory alloc runs writeback which goes to the FS
1554                  * again and deadlocks. This was seen in practice.
1555                  */
1556                 mypage->byte = kmem_cache_alloc(ns->nand_pages_slab, GFP_NOFS);
1557                 if (mypage->byte == NULL) {
1558                         NS_ERR("prog_page: error allocating memory for page %d\n", ns->regs.row);
1559                         return -1;
1560                 }
1561                 memset(mypage->byte, 0xFF, ns->geom.pgszoob);
1562         }
1563
1564         pg_off = NS_PAGE_BYTE_OFF(ns);
1565         for (i = 0; i < num; i++)
1566                 pg_off[i] &= ns->buf.byte[i];
1567
1568         return 0;
1569 }
1570
1571 /*
1572  * If state has any action bit, perform this action.
1573  *
1574  * RETURNS: 0 if success, -1 if error.
1575  */
1576 static int do_state_action(struct nandsim *ns, uint32_t action)
1577 {
1578         int num;
1579         int busdiv = ns->busw == 8 ? 1 : 2;
1580         unsigned int erase_block_no, page_no;
1581
1582         action &= ACTION_MASK;
1583
1584         /* Check that page address input is correct */
1585         if (action != ACTION_SECERASE && ns->regs.row >= ns->geom.pgnum) {
1586                 NS_WARN("do_state_action: wrong page number (%#x)\n", ns->regs.row);
1587                 return -1;
1588         }
1589
1590         switch (action) {
1591
1592         case ACTION_CPY:
1593                 /*
1594                  * Copy page data to the internal buffer.
1595                  */
1596
1597                 /* Column shouldn't be very large */
1598                 if (ns->regs.column >= (ns->geom.pgszoob - ns->regs.off)) {
1599                         NS_ERR("do_state_action: column number is too large\n");
1600                         break;
1601                 }
1602                 num = ns->geom.pgszoob - ns->regs.off - ns->regs.column;
1603                 read_page(ns, num);
1604
1605                 NS_DBG("do_state_action: (ACTION_CPY:) copy %d bytes to int buf, raw offset %d\n",
1606                         num, NS_RAW_OFFSET(ns) + ns->regs.off);
1607
1608                 if (ns->regs.off == 0)
1609                         NS_LOG("read page %d\n", ns->regs.row);
1610                 else if (ns->regs.off < ns->geom.pgsz)
1611                         NS_LOG("read page %d (second half)\n", ns->regs.row);
1612                 else
1613                         NS_LOG("read OOB of page %d\n", ns->regs.row);
1614
1615                 NS_UDELAY(access_delay);
1616                 NS_UDELAY(input_cycle * ns->geom.pgsz / 1000 / busdiv);
1617
1618                 break;
1619
1620         case ACTION_SECERASE:
1621                 /*
1622                  * Erase sector.
1623                  */
1624
1625                 if (ns->lines.wp) {
1626                         NS_ERR("do_state_action: device is write-protected, ignore sector erase\n");
1627                         return -1;
1628                 }
1629
1630                 if (ns->regs.row >= ns->geom.pgnum - ns->geom.pgsec
1631                         || (ns->regs.row & ~(ns->geom.secsz - 1))) {
1632                         NS_ERR("do_state_action: wrong sector address (%#x)\n", ns->regs.row);
1633                         return -1;
1634                 }
1635
1636                 ns->regs.row = (ns->regs.row <<
1637                                 8 * (ns->geom.pgaddrbytes - ns->geom.secaddrbytes)) | ns->regs.column;
1638                 ns->regs.column = 0;
1639
1640                 erase_block_no = ns->regs.row >> (ns->geom.secshift - ns->geom.pgshift);
1641
1642                 NS_DBG("do_state_action: erase sector at address %#x, off = %d\n",
1643                                 ns->regs.row, NS_RAW_OFFSET(ns));
1644                 NS_LOG("erase sector %u\n", erase_block_no);
1645
1646                 erase_sector(ns);
1647
1648                 NS_MDELAY(erase_delay);
1649
1650                 if (erase_block_wear)
1651                         update_wear(erase_block_no);
1652
1653                 if (erase_error(erase_block_no)) {
1654                         NS_WARN("simulating erase failure in erase block %u\n", erase_block_no);
1655                         return -1;
1656                 }
1657
1658                 break;
1659
1660         case ACTION_PRGPAGE:
1661                 /*
1662                  * Programm page - move internal buffer data to the page.
1663                  */
1664
1665                 if (ns->lines.wp) {
1666                         NS_WARN("do_state_action: device is write-protected, programm\n");
1667                         return -1;
1668                 }
1669
1670                 num = ns->geom.pgszoob - ns->regs.off - ns->regs.column;
1671                 if (num != ns->regs.count) {
1672                         NS_ERR("do_state_action: too few bytes were input (%d instead of %d)\n",
1673                                         ns->regs.count, num);
1674                         return -1;
1675                 }
1676
1677                 if (prog_page(ns, num) == -1)
1678                         return -1;
1679
1680                 page_no = ns->regs.row;
1681
1682                 NS_DBG("do_state_action: copy %d bytes from int buf to (%#x, %#x), raw off = %d\n",
1683                         num, ns->regs.row, ns->regs.column, NS_RAW_OFFSET(ns) + ns->regs.off);
1684                 NS_LOG("programm page %d\n", ns->regs.row);
1685
1686                 NS_UDELAY(programm_delay);
1687                 NS_UDELAY(output_cycle * ns->geom.pgsz / 1000 / busdiv);
1688
1689                 if (write_error(page_no)) {
1690                         NS_WARN("simulating write failure in page %u\n", page_no);
1691                         return -1;
1692                 }
1693
1694                 break;
1695
1696         case ACTION_ZEROOFF:
1697                 NS_DBG("do_state_action: set internal offset to 0\n");
1698                 ns->regs.off = 0;
1699                 break;
1700
1701         case ACTION_HALFOFF:
1702                 if (!(ns->options & OPT_PAGE512_8BIT)) {
1703                         NS_ERR("do_state_action: BUG! can't skip half of page for non-512"
1704                                 "byte page size 8x chips\n");
1705                         return -1;
1706                 }
1707                 NS_DBG("do_state_action: set internal offset to %d\n", ns->geom.pgsz/2);
1708                 ns->regs.off = ns->geom.pgsz/2;
1709                 break;
1710
1711         case ACTION_OOBOFF:
1712                 NS_DBG("do_state_action: set internal offset to %d\n", ns->geom.pgsz);
1713                 ns->regs.off = ns->geom.pgsz;
1714                 break;
1715
1716         default:
1717                 NS_DBG("do_state_action: BUG! unknown action\n");
1718         }
1719
1720         return 0;
1721 }
1722
1723 /*
1724  * Switch simulator's state.
1725  */
1726 static void switch_state(struct nandsim *ns)
1727 {
1728         if (ns->op) {
1729                 /*
1730                  * The current operation have already been identified.
1731                  * Just follow the states chain.
1732                  */
1733
1734                 ns->stateidx += 1;
1735                 ns->state = ns->nxstate;
1736                 ns->nxstate = ns->op[ns->stateidx + 1];
1737
1738                 NS_DBG("switch_state: operation is known, switch to the next state, "
1739                         "state: %s, nxstate: %s\n",
1740                         get_state_name(ns->state), get_state_name(ns->nxstate));
1741
1742                 /* See, whether we need to do some action */
1743                 if ((ns->state & ACTION_MASK) && do_state_action(ns, ns->state) < 0) {
1744                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1745                         return;
1746                 }
1747
1748         } else {
1749                 /*
1750                  * We don't yet know which operation we perform.
1751                  * Try to identify it.
1752                  */
1753
1754                 /*
1755                  *  The only event causing the switch_state function to
1756                  *  be called with yet unknown operation is new command.
1757                  */
1758                 ns->state = get_state_by_command(ns->regs.command);
1759
1760                 NS_DBG("switch_state: operation is unknown, try to find it\n");
1761
1762                 if (find_operation(ns, 0) != 0)
1763                         return;
1764
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
1771         /* For 16x devices column means the page offset in words */
1772         if ((ns->nxstate & STATE_ADDR_MASK) && ns->busw == 16) {
1773                 NS_DBG("switch_state: double the column number for 16x device\n");
1774                 ns->regs.column <<= 1;
1775         }
1776
1777         if (NS_STATE(ns->nxstate) == STATE_READY) {
1778                 /*
1779                  * The current state is the last. Return to STATE_READY
1780                  */
1781
1782                 u_char status = NS_STATUS_OK(ns);
1783
1784                 /* In case of data states, see if all bytes were input/output */
1785                 if ((ns->state & (STATE_DATAIN_MASK | STATE_DATAOUT_MASK))
1786                         && ns->regs.count != ns->regs.num) {
1787                         NS_WARN("switch_state: not all bytes were processed, %d left\n",
1788                                         ns->regs.num - ns->regs.count);
1789                         status = NS_STATUS_FAILED(ns);
1790                 }
1791
1792                 NS_DBG("switch_state: operation complete, switch to STATE_READY state\n");
1793
1794                 switch_to_ready_state(ns, status);
1795
1796                 return;
1797         } else if (ns->nxstate & (STATE_DATAIN_MASK | STATE_DATAOUT_MASK)) {
1798                 /*
1799                  * If the next state is data input/output, switch to it now
1800                  */
1801
1802                 ns->state      = ns->nxstate;
1803                 ns->nxstate    = ns->op[++ns->stateidx + 1];
1804                 ns->regs.num   = ns->regs.count = 0;
1805
1806                 NS_DBG("switch_state: the next state is data I/O, switch, "
1807                         "state: %s, nxstate: %s\n",
1808                         get_state_name(ns->state), get_state_name(ns->nxstate));
1809
1810                 /*
1811                  * Set the internal register to the count of bytes which
1812                  * are expected to be input or output
1813                  */
1814                 switch (NS_STATE(ns->state)) {
1815                         case STATE_DATAIN:
1816                         case STATE_DATAOUT:
1817                                 ns->regs.num = ns->geom.pgszoob - ns->regs.off - ns->regs.column;
1818                                 break;
1819
1820                         case STATE_DATAOUT_ID:
1821                                 ns->regs.num = ns->geom.idbytes;
1822                                 break;
1823
1824                         case STATE_DATAOUT_STATUS:
1825                         case STATE_DATAOUT_STATUS_M:
1826                                 ns->regs.count = ns->regs.num = 0;
1827                                 break;
1828
1829                         default:
1830                                 NS_ERR("switch_state: BUG! unknown data state\n");
1831                 }
1832
1833         } else if (ns->nxstate & STATE_ADDR_MASK) {
1834                 /*
1835                  * If the next state is address input, set the internal
1836                  * register to the number of expected address bytes
1837                  */
1838
1839                 ns->regs.count = 0;
1840
1841                 switch (NS_STATE(ns->nxstate)) {
1842                         case STATE_ADDR_PAGE:
1843                                 ns->regs.num = ns->geom.pgaddrbytes;
1844
1845                                 break;
1846                         case STATE_ADDR_SEC:
1847                                 ns->regs.num = ns->geom.secaddrbytes;
1848                                 break;
1849
1850                         case STATE_ADDR_ZERO:
1851                                 ns->regs.num = 1;
1852                                 break;
1853
1854                         case STATE_ADDR_COLUMN:
1855                                 /* Column address is always 2 bytes */
1856                                 ns->regs.num = ns->geom.pgaddrbytes - ns->geom.secaddrbytes;
1857                                 break;
1858
1859                         default:
1860                                 NS_ERR("switch_state: BUG! unknown address state\n");
1861                 }
1862         } else {
1863                 /*
1864                  * Just reset internal counters.
1865                  */
1866
1867                 ns->regs.num = 0;
1868                 ns->regs.count = 0;
1869         }
1870 }
1871
1872 static u_char ns_nand_read_byte(struct mtd_info *mtd)
1873 {
1874         struct nandsim *ns = (struct nandsim *)((struct nand_chip *)mtd->priv)->priv;
1875         u_char outb = 0x00;
1876
1877         /* Sanity and correctness checks */
1878         if (!ns->lines.ce) {
1879                 NS_ERR("read_byte: chip is disabled, return %#x\n", (uint)outb);
1880                 return outb;
1881         }
1882         if (ns->lines.ale || ns->lines.cle) {
1883                 NS_ERR("read_byte: ALE or CLE pin is high, return %#x\n", (uint)outb);
1884                 return outb;
1885         }
1886         if (!(ns->state & STATE_DATAOUT_MASK)) {
1887                 NS_WARN("read_byte: unexpected data output cycle, state is %s "
1888                         "return %#x\n", get_state_name(ns->state), (uint)outb);
1889                 return outb;
1890         }
1891
1892         /* Status register may be read as many times as it is wanted */
1893         if (NS_STATE(ns->state) == STATE_DATAOUT_STATUS) {
1894                 NS_DBG("read_byte: return %#x status\n", ns->regs.status);
1895                 return ns->regs.status;
1896         }
1897
1898         /* Check if there is any data in the internal buffer which may be read */
1899         if (ns->regs.count == ns->regs.num) {
1900                 NS_WARN("read_byte: no more data to output, return %#x\n", (uint)outb);
1901                 return outb;
1902         }
1903
1904         switch (NS_STATE(ns->state)) {
1905                 case STATE_DATAOUT:
1906                         if (ns->busw == 8) {
1907                                 outb = ns->buf.byte[ns->regs.count];
1908                                 ns->regs.count += 1;
1909                         } else {
1910                                 outb = (u_char)cpu_to_le16(ns->buf.word[ns->regs.count >> 1]);
1911                                 ns->regs.count += 2;
1912                         }
1913                         break;
1914                 case STATE_DATAOUT_ID:
1915                         NS_DBG("read_byte: read ID byte %d, total = %d\n", ns->regs.count, ns->regs.num);
1916                         outb = ns->ids[ns->regs.count];
1917                         ns->regs.count += 1;
1918                         break;
1919                 default:
1920                         BUG();
1921         }
1922
1923         if (ns->regs.count == ns->regs.num) {
1924                 NS_DBG("read_byte: all bytes were read\n");
1925
1926                 /*
1927                  * The OPT_AUTOINCR allows to read next conseqitive pages without
1928                  * new read operation cycle.
1929                  */
1930                 if ((ns->options & OPT_AUTOINCR) && NS_STATE(ns->state) == STATE_DATAOUT) {
1931                         ns->regs.count = 0;
1932                         if (ns->regs.row + 1 < ns->geom.pgnum)
1933                                 ns->regs.row += 1;
1934                         NS_DBG("read_byte: switch to the next page (%#x)\n", ns->regs.row);
1935                         do_state_action(ns, ACTION_CPY);
1936                 }
1937                 else if (NS_STATE(ns->nxstate) == STATE_READY)
1938                         switch_state(ns);
1939
1940         }
1941
1942         return outb;
1943 }
1944
1945 static void ns_nand_write_byte(struct mtd_info *mtd, u_char byte)
1946 {
1947         struct nandsim *ns = (struct nandsim *)((struct nand_chip *)mtd->priv)->priv;
1948
1949         /* Sanity and correctness checks */
1950         if (!ns->lines.ce) {
1951                 NS_ERR("write_byte: chip is disabled, ignore write\n");
1952                 return;
1953         }
1954         if (ns->lines.ale && ns->lines.cle) {
1955                 NS_ERR("write_byte: ALE and CLE pins are high simultaneously, ignore write\n");
1956                 return;
1957         }
1958
1959         if (ns->lines.cle == 1) {
1960                 /*
1961                  * The byte written is a command.
1962                  */
1963
1964                 if (byte == NAND_CMD_RESET) {
1965                         NS_LOG("reset chip\n");
1966                         switch_to_ready_state(ns, NS_STATUS_OK(ns));
1967                         return;
1968                 }
1969
1970                 /* Check that the command byte is correct */
1971                 if (check_command(byte)) {
1972                         NS_ERR("write_byte: unknown command %#x\n", (uint)byte);
1973                         return;
1974                 }
1975
1976                 if (NS_STATE(ns->state) == STATE_DATAOUT_STATUS
1977                         || NS_STATE(ns->state) == STATE_DATAOUT_STATUS_M
1978                         || NS_STATE(ns->state) == STATE_DATAOUT) {
1979                         int row = ns->regs.row;
1980
1981                         switch_state(ns);
1982                         if (byte == NAND_CMD_RNDOUT)
1983                                 ns->regs.row = row;
1984                 }
1985
1986                 /* Check if chip is expecting command */
1987                 if (NS_STATE(ns->nxstate) != STATE_UNKNOWN && !(ns->nxstate & STATE_CMD_MASK)) {
1988                         /* Do not warn if only 2 id bytes are read */
1989                         if (!(ns->regs.command == NAND_CMD_READID &&
1990                             NS_STATE(ns->state) == STATE_DATAOUT_ID && ns->regs.count == 2)) {
1991                                 /*
1992                                  * We are in situation when something else (not command)
1993                                  * was expected but command was input. In this case ignore
1994                                  * previous command(s)/state(s) and accept the last one.
1995                                  */
1996                                 NS_WARN("write_byte: command (%#x) wasn't expected, expected state is %s, "
1997                                         "ignore previous states\n", (uint)byte, get_state_name(ns->nxstate));
1998                         }
1999                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2000                 }
2001
2002                 NS_DBG("command byte corresponding to %s state accepted\n",
2003                         get_state_name(get_state_by_command(byte)));
2004                 ns->regs.command = byte;
2005                 switch_state(ns);
2006
2007         } else if (ns->lines.ale == 1) {
2008                 /*
2009                  * The byte written is an address.
2010                  */
2011
2012                 if (NS_STATE(ns->nxstate) == STATE_UNKNOWN) {
2013
2014                         NS_DBG("write_byte: operation isn't known yet, identify it\n");
2015
2016                         if (find_operation(ns, 1) < 0)
2017                                 return;
2018
2019                         if ((ns->state & ACTION_MASK) && do_state_action(ns, ns->state) < 0) {
2020                                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2021                                 return;
2022                         }
2023
2024                         ns->regs.count = 0;
2025                         switch (NS_STATE(ns->nxstate)) {
2026                                 case STATE_ADDR_PAGE:
2027                                         ns->regs.num = ns->geom.pgaddrbytes;
2028                                         break;
2029                                 case STATE_ADDR_SEC:
2030                                         ns->regs.num = ns->geom.secaddrbytes;
2031                                         break;
2032                                 case STATE_ADDR_ZERO:
2033                                         ns->regs.num = 1;
2034                                         break;
2035                                 default:
2036                                         BUG();
2037                         }
2038                 }
2039
2040                 /* Check that chip is expecting address */
2041                 if (!(ns->nxstate & STATE_ADDR_MASK)) {
2042                         NS_ERR("write_byte: address (%#x) isn't expected, expected state is %s, "
2043                                 "switch to STATE_READY\n", (uint)byte, get_state_name(ns->nxstate));
2044                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2045                         return;
2046                 }
2047
2048                 /* Check if this is expected byte */
2049                 if (ns->regs.count == ns->regs.num) {
2050                         NS_ERR("write_byte: no more address bytes expected\n");
2051                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2052                         return;
2053                 }
2054
2055                 accept_addr_byte(ns, byte);
2056
2057                 ns->regs.count += 1;
2058
2059                 NS_DBG("write_byte: address byte %#x was accepted (%d bytes input, %d expected)\n",
2060                                 (uint)byte, ns->regs.count, ns->regs.num);
2061
2062                 if (ns->regs.count == ns->regs.num) {
2063                         NS_DBG("address (%#x, %#x) is accepted\n", ns->regs.row, ns->regs.column);
2064                         switch_state(ns);
2065                 }
2066
2067         } else {
2068                 /*
2069                  * The byte written is an input data.
2070                  */
2071
2072                 /* Check that chip is expecting data input */
2073                 if (!(ns->state & STATE_DATAIN_MASK)) {
2074                         NS_ERR("write_byte: data input (%#x) isn't expected, state is %s, "
2075                                 "switch to %s\n", (uint)byte,
2076                                 get_state_name(ns->state), get_state_name(STATE_READY));
2077                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2078                         return;
2079                 }
2080
2081                 /* Check if this is expected byte */
2082                 if (ns->regs.count == ns->regs.num) {
2083                         NS_WARN("write_byte: %u input bytes has already been accepted, ignore write\n",
2084                                         ns->regs.num);
2085                         return;
2086                 }
2087
2088                 if (ns->busw == 8) {
2089                         ns->buf.byte[ns->regs.count] = byte;
2090                         ns->regs.count += 1;
2091                 } else {
2092                         ns->buf.word[ns->regs.count >> 1] = cpu_to_le16((uint16_t)byte);
2093                         ns->regs.count += 2;
2094                 }
2095         }
2096
2097         return;
2098 }
2099
2100 static void ns_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int bitmask)
2101 {
2102         struct nandsim *ns = ((struct nand_chip *)mtd->priv)->priv;
2103
2104         ns->lines.cle = bitmask & NAND_CLE ? 1 : 0;
2105         ns->lines.ale = bitmask & NAND_ALE ? 1 : 0;
2106         ns->lines.ce = bitmask & NAND_NCE ? 1 : 0;
2107
2108         if (cmd != NAND_CMD_NONE)
2109                 ns_nand_write_byte(mtd, cmd);
2110 }
2111
2112 static int ns_device_ready(struct mtd_info *mtd)
2113 {
2114         NS_DBG("device_ready\n");
2115         return 1;
2116 }
2117
2118 static uint16_t ns_nand_read_word(struct mtd_info *mtd)
2119 {
2120         struct nand_chip *chip = (struct nand_chip *)mtd->priv;
2121
2122         NS_DBG("read_word\n");
2123
2124         return chip->read_byte(mtd) | (chip->read_byte(mtd) << 8);
2125 }
2126
2127 static void ns_nand_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
2128 {
2129         struct nandsim *ns = (struct nandsim *)((struct nand_chip *)mtd->priv)->priv;
2130
2131         /* Check that chip is expecting data input */
2132         if (!(ns->state & STATE_DATAIN_MASK)) {
2133                 NS_ERR("write_buf: data input isn't expected, state is %s, "
2134                         "switch to STATE_READY\n", get_state_name(ns->state));
2135                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2136                 return;
2137         }
2138
2139         /* Check if these are expected bytes */
2140         if (ns->regs.count + len > ns->regs.num) {
2141                 NS_ERR("write_buf: too many input bytes\n");
2142                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2143                 return;
2144         }
2145
2146         memcpy(ns->buf.byte + ns->regs.count, buf, len);
2147         ns->regs.count += len;
2148
2149         if (ns->regs.count == ns->regs.num) {
2150                 NS_DBG("write_buf: %d bytes were written\n", ns->regs.count);
2151         }
2152 }
2153
2154 static void ns_nand_read_buf(struct mtd_info *mtd, u_char *buf, int len)
2155 {
2156         struct nandsim *ns = (struct nandsim *)((struct nand_chip *)mtd->priv)->priv;
2157
2158         /* Sanity and correctness checks */
2159         if (!ns->lines.ce) {
2160                 NS_ERR("read_buf: chip is disabled\n");
2161                 return;
2162         }
2163         if (ns->lines.ale || ns->lines.cle) {
2164                 NS_ERR("read_buf: ALE or CLE pin is high\n");
2165                 return;
2166         }
2167         if (!(ns->state & STATE_DATAOUT_MASK)) {
2168                 NS_WARN("read_buf: unexpected data output cycle, current state is %s\n",
2169                         get_state_name(ns->state));
2170                 return;
2171         }
2172
2173         if (NS_STATE(ns->state) != STATE_DATAOUT) {
2174                 int i;
2175
2176                 for (i = 0; i < len; i++)
2177                         buf[i] = ((struct nand_chip *)mtd->priv)->read_byte(mtd);
2178
2179                 return;
2180         }
2181
2182         /* Check if these are expected bytes */
2183         if (ns->regs.count + len > ns->regs.num) {
2184                 NS_ERR("read_buf: too many bytes to read\n");
2185                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
2186                 return;
2187         }
2188
2189         memcpy(buf, ns->buf.byte + ns->regs.count, len);
2190         ns->regs.count += len;
2191
2192         if (ns->regs.count == ns->regs.num) {
2193                 if ((ns->options & OPT_AUTOINCR) && NS_STATE(ns->state) == STATE_DATAOUT) {
2194                         ns->regs.count = 0;
2195                         if (ns->regs.row + 1 < ns->geom.pgnum)
2196                                 ns->regs.row += 1;
2197                         NS_DBG("read_buf: switch to the next page (%#x)\n", ns->regs.row);
2198                         do_state_action(ns, ACTION_CPY);
2199                 }
2200                 else if (NS_STATE(ns->nxstate) == STATE_READY)
2201                         switch_state(ns);
2202         }
2203
2204         return;
2205 }
2206
2207 static int ns_nand_verify_buf(struct mtd_info *mtd, const u_char *buf, int len)
2208 {
2209         ns_nand_read_buf(mtd, (u_char *)&ns_verify_buf[0], len);
2210
2211         if (!memcmp(buf, &ns_verify_buf[0], len)) {
2212                 NS_DBG("verify_buf: the buffer is OK\n");
2213                 return 0;
2214         } else {
2215                 NS_DBG("verify_buf: the buffer is wrong\n");
2216                 return -EFAULT;
2217         }
2218 }
2219
2220 /*
2221  * Module initialization function
2222  */
2223 static int __init ns_init_module(void)
2224 {
2225         struct nand_chip *chip;
2226         struct nandsim *nand;
2227         int retval = -ENOMEM, i;
2228
2229         if (bus_width != 8 && bus_width != 16) {
2230                 NS_ERR("wrong bus width (%d), use only 8 or 16\n", bus_width);
2231                 return -EINVAL;
2232         }
2233
2234         /* Allocate and initialize mtd_info, nand_chip and nandsim structures */
2235         nsmtd = kzalloc(sizeof(struct mtd_info) + sizeof(struct nand_chip)
2236                                 + sizeof(struct nandsim), GFP_KERNEL);
2237         if (!nsmtd) {
2238                 NS_ERR("unable to allocate core structures.\n");
2239                 return -ENOMEM;
2240         }
2241         chip        = (struct nand_chip *)(nsmtd + 1);
2242         nsmtd->priv = (void *)chip;
2243         nand        = (struct nandsim *)(chip + 1);
2244         chip->priv  = (void *)nand;
2245
2246         /*
2247          * Register simulator's callbacks.
2248          */
2249         chip->cmd_ctrl   = ns_hwcontrol;
2250         chip->read_byte  = ns_nand_read_byte;
2251         chip->dev_ready  = ns_device_ready;
2252         chip->write_buf  = ns_nand_write_buf;
2253         chip->read_buf   = ns_nand_read_buf;
2254         chip->verify_buf = ns_nand_verify_buf;
2255         chip->read_word  = ns_nand_read_word;
2256         chip->ecc.mode   = NAND_ECC_SOFT;
2257         /* The NAND_SKIP_BBTSCAN option is necessary for 'overridesize' */
2258         /* and 'badblocks' parameters to work */
2259         chip->options   |= NAND_SKIP_BBTSCAN;
2260
2261         /*
2262          * Perform minimum nandsim structure initialization to handle
2263          * the initial ID read command correctly
2264          */
2265         if (third_id_byte != 0xFF || fourth_id_byte != 0xFF)
2266                 nand->geom.idbytes = 4;
2267         else
2268                 nand->geom.idbytes = 2;
2269         nand->regs.status = NS_STATUS_OK(nand);
2270         nand->nxstate = STATE_UNKNOWN;
2271         nand->options |= OPT_PAGE256; /* temporary value */
2272         nand->ids[0] = first_id_byte;
2273         nand->ids[1] = second_id_byte;
2274         nand->ids[2] = third_id_byte;
2275         nand->ids[3] = fourth_id_byte;
2276         if (bus_width == 16) {
2277                 nand->busw = 16;
2278                 chip->options |= NAND_BUSWIDTH_16;
2279         }
2280
2281         nsmtd->owner = THIS_MODULE;
2282
2283         if ((retval = parse_weakblocks()) != 0)
2284                 goto error;
2285
2286         if ((retval = parse_weakpages()) != 0)
2287                 goto error;
2288
2289         if ((retval = parse_gravepages()) != 0)
2290                 goto error;
2291
2292         if ((retval = nand_scan(nsmtd, 1)) != 0) {
2293                 NS_ERR("can't register NAND Simulator\n");
2294                 if (retval > 0)
2295                         retval = -ENXIO;
2296                 goto error;
2297         }
2298
2299         if (overridesize) {
2300                 uint64_t new_size = (uint64_t)nsmtd->erasesize << overridesize;
2301                 if (new_size >> overridesize != nsmtd->erasesize) {
2302                         NS_ERR("overridesize is too big\n");
2303                         goto err_exit;
2304                 }
2305                 /* N.B. This relies on nand_scan not doing anything with the size before we change it */
2306                 nsmtd->size = new_size;
2307                 chip->chipsize = new_size;
2308                 chip->chip_shift = ffs(nsmtd->erasesize) + overridesize - 1;
2309                 chip->pagemask = (chip->chipsize >> chip->page_shift) - 1;
2310         }
2311
2312         if ((retval = setup_wear_reporting(nsmtd)) != 0)
2313                 goto err_exit;
2314
2315         if ((retval = init_nandsim(nsmtd)) != 0)
2316                 goto err_exit;
2317
2318         if ((retval = parse_badblocks(nand, nsmtd)) != 0)
2319                 goto err_exit;
2320
2321         if ((retval = nand_default_bbt(nsmtd)) != 0)
2322                 goto err_exit;
2323
2324         /* Register NAND partitions */
2325         if ((retval = add_mtd_partitions(nsmtd, &nand->partitions[0], nand->nbparts)) != 0)
2326                 goto err_exit;
2327
2328         return 0;
2329
2330 err_exit:
2331         free_nandsim(nand);
2332         nand_release(nsmtd);
2333         for (i = 0;i < ARRAY_SIZE(nand->partitions); ++i)
2334                 kfree(nand->partitions[i].name);
2335 error:
2336         kfree(nsmtd);
2337         free_lists();
2338
2339         return retval;
2340 }
2341
2342 module_init(ns_init_module);
2343
2344 /*
2345  * Module clean-up function
2346  */
2347 static void __exit ns_cleanup_module(void)
2348 {
2349         struct nandsim *ns = (struct nandsim *)(((struct nand_chip *)nsmtd->priv)->priv);
2350         int i;
2351
2352         free_nandsim(ns);    /* Free nandsim private resources */
2353         nand_release(nsmtd); /* Unregister driver */
2354         for (i = 0;i < ARRAY_SIZE(ns->partitions); ++i)
2355                 kfree(ns->partitions[i].name);
2356         kfree(nsmtd);        /* Free other structures */
2357         free_lists();
2358 }
2359
2360 module_exit(ns_cleanup_module);
2361
2362 MODULE_LICENSE ("GPL");
2363 MODULE_AUTHOR ("Artem B. Bityuckiy");
2364 MODULE_DESCRIPTION ("The NAND flash simulator");