1 /*
2 * Physical mapping layer for MTD using the Axis partitiontable format
3 *
4 * Copyright (c) 2001-2007 Axis Communications AB
5 *
6 * This file is under the GPL.
7 *
8 * First partition is always sector 0 regardless of if we find a partitiontable
9 * or not. In the start of the next sector, there can be a partitiontable that
10 * tells us what other partitions to define. If there isn't, we use a default
11 * partition split defined below.
12 *
13 */
14
15 #include <linux/module.h>
16 #include <linux/types.h>
17 #include <linux/kernel.h>
18 #include <linux/init.h>
19 #include <linux/slab.h>
20
21 #include <linux/mtd/concat.h>
22 #include <linux/mtd/map.h>
23 #include <linux/mtd/mtd.h>
24 #include <linux/mtd/mtdram.h>
25 #include <linux/mtd/partitions.h>
26
27 #include <asm/axisflashmap.h>
28 #include <asm/mmu.h>
29
30 #define MEM_CSE0_SIZE (0x04000000)
31 #define MEM_CSE1_SIZE (0x04000000)
32
33 #define FLASH_UNCACHED_ADDR KSEG_E
34 #define FLASH_CACHED_ADDR KSEG_F
35
36 #define PAGESIZE (512)
37
38 #if CONFIG_ETRAX_FLASH_BUSWIDTH==1
39 #define flash_data __u8
40 #elif CONFIG_ETRAX_FLASH_BUSWIDTH==2
41 #define flash_data __u16
42 #elif CONFIG_ETRAX_FLASH_BUSWIDTH==4
43 #define flash_data __u32
44 #endif
45
46 /* From head.S */
47 extern unsigned long romfs_in_flash; /* 1 when romfs_start, _length in flash */
48 extern unsigned long romfs_start, romfs_length;
49 extern unsigned long nand_boot; /* 1 when booted from nand flash */
50
51 struct partition_name {
52 char name[6];
53 };
54
55 /* The master mtd for the entire flash. */
56 struct mtd_info* axisflash_mtd = NULL;
57
58 /* Map driver functions. */
59
flash_read(struct map_info * map,unsigned long ofs)60 static map_word flash_read(struct map_info *map, unsigned long ofs)
61 {
62 map_word tmp;
63 tmp.x[0] = *(flash_data *)(map->map_priv_1 + ofs);
64 return tmp;
65 }
66
flash_copy_from(struct map_info * map,void * to,unsigned long from,ssize_t len)67 static void flash_copy_from(struct map_info *map, void *to,
68 unsigned long from, ssize_t len)
69 {
70 memcpy(to, (void *)(map->map_priv_1 + from), len);
71 }
72
flash_write(struct map_info * map,map_word d,unsigned long adr)73 static void flash_write(struct map_info *map, map_word d, unsigned long adr)
74 {
75 *(flash_data *)(map->map_priv_1 + adr) = (flash_data)d.x[0];
76 }
77
78 /*
79 * The map for chip select e0.
80 *
81 * We run into tricky coherence situations if we mix cached with uncached
82 * accesses to we only use the uncached version here.
83 *
84 * The size field is the total size where the flash chips may be mapped on the
85 * chip select. MTD probes should find all devices there and it does not matter
86 * if there are unmapped gaps or aliases (mirrors of flash devices). The MTD
87 * probes will ignore them.
88 *
89 * The start address in map_priv_1 is in virtual memory so we cannot use
90 * MEM_CSE0_START but must rely on that FLASH_UNCACHED_ADDR is the start
91 * address of cse0.
92 */
93 static struct map_info map_cse0 = {
94 .name = "cse0",
95 .size = MEM_CSE0_SIZE,
96 .bankwidth = CONFIG_ETRAX_FLASH_BUSWIDTH,
97 .read = flash_read,
98 .copy_from = flash_copy_from,
99 .write = flash_write,
100 .map_priv_1 = FLASH_UNCACHED_ADDR
101 };
102
103 /*
104 * The map for chip select e1.
105 *
106 * If there was a gap between cse0 and cse1, map_priv_1 would get the wrong
107 * address, but there isn't.
108 */
109 static struct map_info map_cse1 = {
110 .name = "cse1",
111 .size = MEM_CSE1_SIZE,
112 .bankwidth = CONFIG_ETRAX_FLASH_BUSWIDTH,
113 .read = flash_read,
114 .copy_from = flash_copy_from,
115 .write = flash_write,
116 .map_priv_1 = FLASH_UNCACHED_ADDR + MEM_CSE0_SIZE
117 };
118
119 #define MAX_PARTITIONS 7
120 #ifdef CONFIG_ETRAX_NANDBOOT
121 #define NUM_DEFAULT_PARTITIONS 4
122 #define DEFAULT_ROOTFS_PARTITION_NO 2
123 #define DEFAULT_MEDIA_SIZE 0x2000000 /* 32 megs */
124 #else
125 #define NUM_DEFAULT_PARTITIONS 3
126 #define DEFAULT_ROOTFS_PARTITION_NO (-1)
127 #define DEFAULT_MEDIA_SIZE 0x800000 /* 8 megs */
128 #endif
129
130 #if (MAX_PARTITIONS < NUM_DEFAULT_PARTITIONS)
131 #error MAX_PARTITIONS must be >= than NUM_DEFAULT_PARTITIONS
132 #endif
133
134 /* Initialize the ones normally used. */
135 static struct mtd_partition axis_partitions[MAX_PARTITIONS] = {
136 {
137 .name = "part0",
138 .size = CONFIG_ETRAX_PTABLE_SECTOR,
139 .offset = 0
140 },
141 {
142 .name = "part1",
143 .size = 0,
144 .offset = 0
145 },
146 {
147 .name = "part2",
148 .size = 0,
149 .offset = 0
150 },
151 {
152 .name = "part3",
153 .size = 0,
154 .offset = 0
155 },
156 {
157 .name = "part4",
158 .size = 0,
159 .offset = 0
160 },
161 {
162 .name = "part5",
163 .size = 0,
164 .offset = 0
165 },
166 {
167 .name = "part6",
168 .size = 0,
169 .offset = 0
170 },
171 };
172
173
174 /* If no partition-table was found, we use this default-set.
175 * Default flash size is 8MB (NOR). CONFIG_ETRAX_PTABLE_SECTOR is most
176 * likely the size of one flash block and "filesystem"-partition needs
177 * to be >=5 blocks to be able to use JFFS.
178 */
179 static struct mtd_partition axis_default_partitions[NUM_DEFAULT_PARTITIONS] = {
180 {
181 .name = "boot firmware",
182 .size = CONFIG_ETRAX_PTABLE_SECTOR,
183 .offset = 0
184 },
185 {
186 .name = "kernel",
187 .size = 10 * CONFIG_ETRAX_PTABLE_SECTOR,
188 .offset = CONFIG_ETRAX_PTABLE_SECTOR
189 },
190 #define FILESYSTEM_SECTOR (11 * CONFIG_ETRAX_PTABLE_SECTOR)
191 #ifdef CONFIG_ETRAX_NANDBOOT
192 {
193 .name = "rootfs",
194 .size = 10 * CONFIG_ETRAX_PTABLE_SECTOR,
195 .offset = FILESYSTEM_SECTOR
196 },
197 #undef FILESYSTEM_SECTOR
198 #define FILESYSTEM_SECTOR (21 * CONFIG_ETRAX_PTABLE_SECTOR)
199 #endif
200 {
201 .name = "rwfs",
202 .size = DEFAULT_MEDIA_SIZE - FILESYSTEM_SECTOR,
203 .offset = FILESYSTEM_SECTOR
204 }
205 };
206
207 #ifdef CONFIG_ETRAX_AXISFLASHMAP_MTD0WHOLE
208 /* Main flash device */
209 static struct mtd_partition main_partition = {
210 .name = "main",
211 .size = 0,
212 .offset = 0
213 };
214 #endif
215
216 /* Auxiliary partition if we find another flash */
217 static struct mtd_partition aux_partition = {
218 .name = "aux",
219 .size = 0,
220 .offset = 0
221 };
222
223 /*
224 * Probe a chip select for AMD-compatible (JEDEC) or CFI-compatible flash
225 * chips in that order (because the amd_flash-driver is faster).
226 */
probe_cs(struct map_info * map_cs)227 static struct mtd_info *probe_cs(struct map_info *map_cs)
228 {
229 struct mtd_info *mtd_cs = NULL;
230
231 printk(KERN_INFO
232 "%s: Probing a 0x%08lx bytes large window at 0x%08lx.\n",
233 map_cs->name, map_cs->size, map_cs->map_priv_1);
234
235 #ifdef CONFIG_MTD_CFI
236 mtd_cs = do_map_probe("cfi_probe", map_cs);
237 #endif
238 #ifdef CONFIG_MTD_JEDECPROBE
239 if (!mtd_cs)
240 mtd_cs = do_map_probe("jedec_probe", map_cs);
241 #endif
242
243 return mtd_cs;
244 }
245
246 /*
247 * Probe each chip select individually for flash chips. If there are chips on
248 * both cse0 and cse1, the mtd_info structs will be concatenated to one struct
249 * so that MTD partitions can cross chip boundries.
250 *
251 * The only known restriction to how you can mount your chips is that each
252 * chip select must hold similar flash chips. But you need external hardware
253 * to do that anyway and you can put totally different chips on cse0 and cse1
254 * so it isn't really much of a restriction.
255 */
256 extern struct mtd_info* __init crisv32_nand_flash_probe (void);
flash_probe(void)257 static struct mtd_info *flash_probe(void)
258 {
259 struct mtd_info *mtd_cse0;
260 struct mtd_info *mtd_cse1;
261 struct mtd_info *mtd_total;
262 struct mtd_info *mtds[2];
263 int count = 0;
264
265 if ((mtd_cse0 = probe_cs(&map_cse0)) != NULL)
266 mtds[count++] = mtd_cse0;
267 if ((mtd_cse1 = probe_cs(&map_cse1)) != NULL)
268 mtds[count++] = mtd_cse1;
269
270 if (!mtd_cse0 && !mtd_cse1) {
271 /* No chip found. */
272 return NULL;
273 }
274
275 if (count > 1) {
276 /* Since the concatenation layer adds a small overhead we
277 * could try to figure out if the chips in cse0 and cse1 are
278 * identical and reprobe the whole cse0+cse1 window. But since
279 * flash chips are slow, the overhead is relatively small.
280 * So we use the MTD concatenation layer instead of further
281 * complicating the probing procedure.
282 */
283 mtd_total = mtd_concat_create(mtds, count, "cse0+cse1");
284 if (!mtd_total) {
285 printk(KERN_ERR "%s and %s: Concatenation failed!\n",
286 map_cse0.name, map_cse1.name);
287
288 /* The best we can do now is to only use what we found
289 * at cse0. */
290 mtd_total = mtd_cse0;
291 map_destroy(mtd_cse1);
292 }
293 } else
294 mtd_total = mtd_cse0 ? mtd_cse0 : mtd_cse1;
295
296 return mtd_total;
297 }
298
299 /*
300 * Probe the flash chip(s) and, if it succeeds, read the partition-table
301 * and register the partitions with MTD.
302 */
init_axis_flash(void)303 static int __init init_axis_flash(void)
304 {
305 struct mtd_info *main_mtd;
306 struct mtd_info *aux_mtd = NULL;
307 int err = 0;
308 int pidx = 0;
309 struct partitiontable_head *ptable_head = NULL;
310 struct partitiontable_entry *ptable;
311 int ptable_ok = 0;
312 static char page[PAGESIZE];
313 size_t len;
314 int ram_rootfs_partition = -1; /* -1 => no RAM rootfs partition */
315 int part;
316 struct mtd_partition *partition;
317
318 /* We need a root fs. If it resides in RAM, we need to use an
319 * MTDRAM device, so it must be enabled in the kernel config,
320 * but its size must be configured as 0 so as not to conflict
321 * with our usage.
322 */
323 #if !defined(CONFIG_MTD_MTDRAM) || (CONFIG_MTDRAM_TOTAL_SIZE != 0) || (CONFIG_MTDRAM_ABS_POS != 0)
324 if (!romfs_in_flash && !nand_boot) {
325 printk(KERN_EMERG "axisflashmap: Cannot create an MTD RAM "
326 "device; configure CONFIG_MTD_MTDRAM with size = 0!\n");
327 panic("This kernel cannot boot from RAM!\n");
328 }
329 #endif
330
331 main_mtd = flash_probe();
332 if (main_mtd)
333 printk(KERN_INFO "%s: 0x%08llx bytes of NOR flash memory.\n",
334 main_mtd->name, main_mtd->size);
335
336 #ifdef CONFIG_ETRAX_NANDFLASH
337 aux_mtd = crisv32_nand_flash_probe();
338 if (aux_mtd)
339 printk(KERN_INFO "%s: 0x%08x bytes of NAND flash memory.\n",
340 aux_mtd->name, aux_mtd->size);
341
342 #ifdef CONFIG_ETRAX_NANDBOOT
343 {
344 struct mtd_info *tmp_mtd;
345
346 printk(KERN_INFO "axisflashmap: Set to boot from NAND flash, "
347 "making NAND flash primary device.\n");
348 tmp_mtd = main_mtd;
349 main_mtd = aux_mtd;
350 aux_mtd = tmp_mtd;
351 }
352 #endif /* CONFIG_ETRAX_NANDBOOT */
353 #endif /* CONFIG_ETRAX_NANDFLASH */
354
355 if (!main_mtd && !aux_mtd) {
356 /* There's no reason to use this module if no flash chip can
357 * be identified. Make sure that's understood.
358 */
359 printk(KERN_INFO "axisflashmap: Found no flash chip.\n");
360 }
361
362 #if 0 /* Dump flash memory so we can see what is going on */
363 if (main_mtd) {
364 int sectoraddr;
365 for (sectoraddr = 0; sectoraddr < 2*65536+4096;
366 sectoraddr += PAGESIZE) {
367 main_mtd->read(main_mtd, sectoraddr, PAGESIZE, &len,
368 page);
369 printk(KERN_INFO
370 "Sector at %d (length %d):\n",
371 sectoraddr, len);
372 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE, 16, 1, page, PAGESIZE, false);
373 }
374 }
375 #endif
376
377 if (main_mtd) {
378 loff_t ptable_sector = CONFIG_ETRAX_PTABLE_SECTOR;
379 main_mtd->owner = THIS_MODULE;
380 axisflash_mtd = main_mtd;
381
382
383 /* First partition (rescue) is always set to the default. */
384 pidx++;
385 #ifdef CONFIG_ETRAX_NANDBOOT
386 /* We know where the partition table should be located,
387 * it will be in first good block after that.
388 */
389 int blockstat;
390 do {
391 blockstat = mtd_block_isbad(main_mtd, ptable_sector);
392 if (blockstat < 0)
393 ptable_sector = 0; /* read error */
394 else if (blockstat)
395 ptable_sector += main_mtd->erasesize;
396 } while (blockstat && ptable_sector);
397 #endif
398 if (ptable_sector) {
399 mtd_read(main_mtd, ptable_sector, PAGESIZE, &len,
400 page);
401 ptable_head = &((struct partitiontable *) page)->head;
402 }
403
404 #if 0 /* Dump partition table so we can see what is going on */
405 printk(KERN_INFO
406 "axisflashmap: flash read %d bytes at 0x%08x, data: %8ph\n",
407 len, CONFIG_ETRAX_PTABLE_SECTOR, page);
408 printk(KERN_INFO
409 "axisflashmap: partition table offset %d, data: %8ph\n",
410 PARTITION_TABLE_OFFSET, page + PARTITION_TABLE_OFFSET);
411 #endif
412 }
413
414 if (ptable_head && (ptable_head->magic == PARTITION_TABLE_MAGIC)
415 && (ptable_head->size <
416 (MAX_PARTITIONS * sizeof(struct partitiontable_entry) +
417 PARTITIONTABLE_END_MARKER_SIZE))
418 && (*(unsigned long*)((void*)ptable_head + sizeof(*ptable_head) +
419 ptable_head->size -
420 PARTITIONTABLE_END_MARKER_SIZE)
421 == PARTITIONTABLE_END_MARKER)) {
422 /* Looks like a start, sane length and end of a
423 * partition table, lets check csum etc.
424 */
425 struct partitiontable_entry *max_addr =
426 (struct partitiontable_entry *)
427 ((unsigned long)ptable_head + sizeof(*ptable_head) +
428 ptable_head->size);
429 unsigned long offset = CONFIG_ETRAX_PTABLE_SECTOR;
430 unsigned char *p;
431 unsigned long csum = 0;
432
433 ptable = (struct partitiontable_entry *)
434 ((unsigned long)ptable_head + sizeof(*ptable_head));
435
436 /* Lets be PARANOID, and check the checksum. */
437 p = (unsigned char*) ptable;
438
439 while (p <= (unsigned char*)max_addr) {
440 csum += *p++;
441 csum += *p++;
442 csum += *p++;
443 csum += *p++;
444 }
445 ptable_ok = (csum == ptable_head->checksum);
446
447 /* Read the entries and use/show the info. */
448 printk(KERN_INFO "axisflashmap: "
449 "Found a%s partition table at 0x%p-0x%p.\n",
450 (ptable_ok ? " valid" : "n invalid"), ptable_head,
451 max_addr);
452
453 /* We have found a working bootblock. Now read the
454 * partition table. Scan the table. It ends with 0xffffffff.
455 */
456 while (ptable_ok
457 && ptable->offset != PARTITIONTABLE_END_MARKER
458 && ptable < max_addr
459 && pidx < MAX_PARTITIONS - 1) {
460
461 axis_partitions[pidx].offset = offset + ptable->offset;
462 #ifdef CONFIG_ETRAX_NANDFLASH
463 if (main_mtd->type == MTD_NANDFLASH) {
464 axis_partitions[pidx].size =
465 (((ptable+1)->offset ==
466 PARTITIONTABLE_END_MARKER) ?
467 main_mtd->size :
468 ((ptable+1)->offset + offset)) -
469 (ptable->offset + offset);
470
471 } else
472 #endif /* CONFIG_ETRAX_NANDFLASH */
473 axis_partitions[pidx].size = ptable->size;
474 #ifdef CONFIG_ETRAX_NANDBOOT
475 /* Save partition number of jffs2 ro partition.
476 * Needed if RAM booting or root file system in RAM.
477 */
478 if (!nand_boot &&
479 ram_rootfs_partition < 0 && /* not already set */
480 ptable->type == PARTITION_TYPE_JFFS2 &&
481 (ptable->flags & PARTITION_FLAGS_READONLY_MASK) ==
482 PARTITION_FLAGS_READONLY)
483 ram_rootfs_partition = pidx;
484 #endif /* CONFIG_ETRAX_NANDBOOT */
485 pidx++;
486 ptable++;
487 }
488 }
489
490 /* Decide whether to use default partition table. */
491 /* Only use default table if we actually have a device (main_mtd) */
492
493 partition = &axis_partitions[0];
494 if (main_mtd && !ptable_ok) {
495 memcpy(axis_partitions, axis_default_partitions,
496 sizeof(axis_default_partitions));
497 pidx = NUM_DEFAULT_PARTITIONS;
498 ram_rootfs_partition = DEFAULT_ROOTFS_PARTITION_NO;
499 }
500
501 /* Add artificial partitions for rootfs if necessary */
502 if (romfs_in_flash) {
503 /* rootfs is in directly accessible flash memory = NOR flash.
504 Add an overlapping device for the rootfs partition. */
505 printk(KERN_INFO "axisflashmap: Adding partition for "
506 "overlapping root file system image\n");
507 axis_partitions[pidx].size = romfs_length;
508 axis_partitions[pidx].offset = romfs_start - FLASH_CACHED_ADDR;
509 axis_partitions[pidx].name = "romfs";
510 axis_partitions[pidx].mask_flags |= MTD_WRITEABLE;
511 ram_rootfs_partition = -1;
512 pidx++;
513 } else if (romfs_length && !nand_boot) {
514 /* romfs exists in memory, but not in flash, so must be in RAM.
515 * Configure an MTDRAM partition. */
516 if (ram_rootfs_partition < 0) {
517 /* None set yet, put it at the end */
518 ram_rootfs_partition = pidx;
519 pidx++;
520 }
521 printk(KERN_INFO "axisflashmap: Adding partition for "
522 "root file system image in RAM\n");
523 axis_partitions[ram_rootfs_partition].size = romfs_length;
524 axis_partitions[ram_rootfs_partition].offset = romfs_start;
525 axis_partitions[ram_rootfs_partition].name = "romfs";
526 axis_partitions[ram_rootfs_partition].mask_flags |=
527 MTD_WRITEABLE;
528 }
529
530 #ifdef CONFIG_ETRAX_AXISFLASHMAP_MTD0WHOLE
531 if (main_mtd) {
532 main_partition.size = main_mtd->size;
533 err = mtd_device_register(main_mtd, &main_partition, 1);
534 if (err)
535 panic("axisflashmap: Could not initialize "
536 "partition for whole main mtd device!\n");
537 }
538 #endif
539
540 /* Now, register all partitions with mtd.
541 * We do this one at a time so we can slip in an MTDRAM device
542 * in the proper place if required. */
543
544 for (part = 0; part < pidx; part++) {
545 if (part == ram_rootfs_partition) {
546 /* add MTDRAM partition here */
547 struct mtd_info *mtd_ram;
548
549 mtd_ram = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
550 if (!mtd_ram)
551 panic("axisflashmap: Couldn't allocate memory "
552 "for mtd_info!\n");
553 printk(KERN_INFO "axisflashmap: Adding RAM partition "
554 "for rootfs image.\n");
555 err = mtdram_init_device(mtd_ram,
556 (void *)(u_int32_t)partition[part].offset,
557 partition[part].size,
558 partition[part].name);
559 if (err)
560 panic("axisflashmap: Could not initialize "
561 "MTD RAM device!\n");
562 /* JFFS2 likes to have an erasesize. Keep potential
563 * JFFS2 rootfs happy by providing one. Since image
564 * was most likely created for main mtd, use that
565 * erasesize, if available. Otherwise, make a guess. */
566 mtd_ram->erasesize = (main_mtd ? main_mtd->erasesize :
567 CONFIG_ETRAX_PTABLE_SECTOR);
568 } else {
569 err = mtd_device_register(main_mtd, &partition[part],
570 1);
571 if (err)
572 panic("axisflashmap: Could not add mtd "
573 "partition %d\n", part);
574 }
575 }
576
577 if (aux_mtd) {
578 aux_partition.size = aux_mtd->size;
579 err = mtd_device_register(aux_mtd, &aux_partition, 1);
580 if (err)
581 panic("axisflashmap: Could not initialize "
582 "aux mtd device!\n");
583
584 }
585
586 return err;
587 }
588
589 /* This adds the above to the kernels init-call chain. */
590 module_init(init_axis_flash);
591
592 EXPORT_SYMBOL(axisflash_mtd);
593