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Diffstat (limited to 'fs/yaffs2/yaffs_tagscompat.c')
-rw-r--r--fs/yaffs2/yaffs_tagscompat.c422
1 files changed, 422 insertions, 0 deletions
diff --git a/fs/yaffs2/yaffs_tagscompat.c b/fs/yaffs2/yaffs_tagscompat.c
new file mode 100644
index 00000000000..7578075d9ac
--- /dev/null
+++ b/fs/yaffs2/yaffs_tagscompat.c
@@ -0,0 +1,422 @@
1/*
2 * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
3 *
4 * Copyright (C) 2002-2010 Aleph One Ltd.
5 * for Toby Churchill Ltd and Brightstar Engineering
6 *
7 * Created by Charles Manning <charles@aleph1.co.uk>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13
14#include "yaffs_guts.h"
15#include "yaffs_tagscompat.h"
16#include "yaffs_ecc.h"
17#include "yaffs_getblockinfo.h"
18#include "yaffs_trace.h"
19
20static void yaffs_handle_rd_data_error(struct yaffs_dev *dev, int nand_chunk);
21
22
23/********** Tags ECC calculations *********/
24
25void yaffs_calc_ecc(const u8 * data, struct yaffs_spare *spare)
26{
27 yaffs_ecc_cacl(data, spare->ecc1);
28 yaffs_ecc_cacl(&data[256], spare->ecc2);
29}
30
31void yaffs_calc_tags_ecc(struct yaffs_tags *tags)
32{
33 /* Calculate an ecc */
34
35 unsigned char *b = ((union yaffs_tags_union *)tags)->as_bytes;
36 unsigned i, j;
37 unsigned ecc = 0;
38 unsigned bit = 0;
39
40 tags->ecc = 0;
41
42 for (i = 0; i < 8; i++) {
43 for (j = 1; j & 0xff; j <<= 1) {
44 bit++;
45 if (b[i] & j)
46 ecc ^= bit;
47 }
48 }
49
50 tags->ecc = ecc;
51
52}
53
54int yaffs_check_tags_ecc(struct yaffs_tags *tags)
55{
56 unsigned ecc = tags->ecc;
57
58 yaffs_calc_tags_ecc(tags);
59
60 ecc ^= tags->ecc;
61
62 if (ecc && ecc <= 64) {
63 /* TODO: Handle the failure better. Retire? */
64 unsigned char *b = ((union yaffs_tags_union *)tags)->as_bytes;
65
66 ecc--;
67
68 b[ecc / 8] ^= (1 << (ecc & 7));
69
70 /* Now recvalc the ecc */
71 yaffs_calc_tags_ecc(tags);
72
73 return 1; /* recovered error */
74 } else if (ecc) {
75 /* Wierd ecc failure value */
76 /* TODO Need to do somethiong here */
77 return -1; /* unrecovered error */
78 }
79
80 return 0;
81}
82
83/********** Tags **********/
84
85static void yaffs_load_tags_to_spare(struct yaffs_spare *spare_ptr,
86 struct yaffs_tags *tags_ptr)
87{
88 union yaffs_tags_union *tu = (union yaffs_tags_union *)tags_ptr;
89
90 yaffs_calc_tags_ecc(tags_ptr);
91
92 spare_ptr->tb0 = tu->as_bytes[0];
93 spare_ptr->tb1 = tu->as_bytes[1];
94 spare_ptr->tb2 = tu->as_bytes[2];
95 spare_ptr->tb3 = tu->as_bytes[3];
96 spare_ptr->tb4 = tu->as_bytes[4];
97 spare_ptr->tb5 = tu->as_bytes[5];
98 spare_ptr->tb6 = tu->as_bytes[6];
99 spare_ptr->tb7 = tu->as_bytes[7];
100}
101
102static void yaffs_get_tags_from_spare(struct yaffs_dev *dev,
103 struct yaffs_spare *spare_ptr,
104 struct yaffs_tags *tags_ptr)
105{
106 union yaffs_tags_union *tu = (union yaffs_tags_union *)tags_ptr;
107 int result;
108
109 tu->as_bytes[0] = spare_ptr->tb0;
110 tu->as_bytes[1] = spare_ptr->tb1;
111 tu->as_bytes[2] = spare_ptr->tb2;
112 tu->as_bytes[3] = spare_ptr->tb3;
113 tu->as_bytes[4] = spare_ptr->tb4;
114 tu->as_bytes[5] = spare_ptr->tb5;
115 tu->as_bytes[6] = spare_ptr->tb6;
116 tu->as_bytes[7] = spare_ptr->tb7;
117
118 result = yaffs_check_tags_ecc(tags_ptr);
119 if (result > 0)
120 dev->n_tags_ecc_fixed++;
121 else if (result < 0)
122 dev->n_tags_ecc_unfixed++;
123}
124
125static void yaffs_spare_init(struct yaffs_spare *spare)
126{
127 memset(spare, 0xFF, sizeof(struct yaffs_spare));
128}
129
130static int yaffs_wr_nand(struct yaffs_dev *dev,
131 int nand_chunk, const u8 * data,
132 struct yaffs_spare *spare)
133{
134 if (nand_chunk < dev->param.start_block * dev->param.chunks_per_block) {
135 yaffs_trace(YAFFS_TRACE_ERROR,
136 "**>> yaffs chunk %d is not valid",
137 nand_chunk);
138 return YAFFS_FAIL;
139 }
140
141 return dev->param.write_chunk_fn(dev, nand_chunk, data, spare);
142}
143
144static int yaffs_rd_chunk_nand(struct yaffs_dev *dev,
145 int nand_chunk,
146 u8 * data,
147 struct yaffs_spare *spare,
148 enum yaffs_ecc_result *ecc_result,
149 int correct_errors)
150{
151 int ret_val;
152 struct yaffs_spare local_spare;
153
154 if (!spare && data) {
155 /* If we don't have a real spare, then we use a local one. */
156 /* Need this for the calculation of the ecc */
157 spare = &local_spare;
158 }
159
160 if (!dev->param.use_nand_ecc) {
161 ret_val =
162 dev->param.read_chunk_fn(dev, nand_chunk, data, spare);
163 if (data && correct_errors) {
164 /* Do ECC correction */
165 /* Todo handle any errors */
166 int ecc_result1, ecc_result2;
167 u8 calc_ecc[3];
168
169 yaffs_ecc_cacl(data, calc_ecc);
170 ecc_result1 =
171 yaffs_ecc_correct(data, spare->ecc1, calc_ecc);
172 yaffs_ecc_cacl(&data[256], calc_ecc);
173 ecc_result2 =
174 yaffs_ecc_correct(&data[256], spare->ecc2,
175 calc_ecc);
176
177 if (ecc_result1 > 0) {
178 yaffs_trace(YAFFS_TRACE_ERROR,
179 "**>>yaffs ecc error fix performed on chunk %d:0",
180 nand_chunk);
181 dev->n_ecc_fixed++;
182 } else if (ecc_result1 < 0) {
183 yaffs_trace(YAFFS_TRACE_ERROR,
184 "**>>yaffs ecc error unfixed on chunk %d:0",
185 nand_chunk);
186 dev->n_ecc_unfixed++;
187 }
188
189 if (ecc_result2 > 0) {
190 yaffs_trace(YAFFS_TRACE_ERROR,
191 "**>>yaffs ecc error fix performed on chunk %d:1",
192 nand_chunk);
193 dev->n_ecc_fixed++;
194 } else if (ecc_result2 < 0) {
195 yaffs_trace(YAFFS_TRACE_ERROR,
196 "**>>yaffs ecc error unfixed on chunk %d:1",
197 nand_chunk);
198 dev->n_ecc_unfixed++;
199 }
200
201 if (ecc_result1 || ecc_result2) {
202 /* We had a data problem on this page */
203 yaffs_handle_rd_data_error(dev, nand_chunk);
204 }
205
206 if (ecc_result1 < 0 || ecc_result2 < 0)
207 *ecc_result = YAFFS_ECC_RESULT_UNFIXED;
208 else if (ecc_result1 > 0 || ecc_result2 > 0)
209 *ecc_result = YAFFS_ECC_RESULT_FIXED;
210 else
211 *ecc_result = YAFFS_ECC_RESULT_NO_ERROR;
212 }
213 } else {
214 /* Must allocate enough memory for spare+2*sizeof(int) */
215 /* for ecc results from device. */
216 struct yaffs_nand_spare nspare;
217
218 memset(&nspare, 0, sizeof(nspare));
219
220 ret_val = dev->param.read_chunk_fn(dev, nand_chunk, data,
221 (struct yaffs_spare *)
222 &nspare);
223 memcpy(spare, &nspare, sizeof(struct yaffs_spare));
224 if (data && correct_errors) {
225 if (nspare.eccres1 > 0) {
226 yaffs_trace(YAFFS_TRACE_ERROR,
227 "**>>mtd ecc error fix performed on chunk %d:0",
228 nand_chunk);
229 } else if (nspare.eccres1 < 0) {
230 yaffs_trace(YAFFS_TRACE_ERROR,
231 "**>>mtd ecc error unfixed on chunk %d:0",
232 nand_chunk);
233 }
234
235 if (nspare.eccres2 > 0) {
236 yaffs_trace(YAFFS_TRACE_ERROR,
237 "**>>mtd ecc error fix performed on chunk %d:1",
238 nand_chunk);
239 } else if (nspare.eccres2 < 0) {
240 yaffs_trace(YAFFS_TRACE_ERROR,
241 "**>>mtd ecc error unfixed on chunk %d:1",
242 nand_chunk);
243 }
244
245 if (nspare.eccres1 || nspare.eccres2) {
246 /* We had a data problem on this page */
247 yaffs_handle_rd_data_error(dev, nand_chunk);
248 }
249
250 if (nspare.eccres1 < 0 || nspare.eccres2 < 0)
251 *ecc_result = YAFFS_ECC_RESULT_UNFIXED;
252 else if (nspare.eccres1 > 0 || nspare.eccres2 > 0)
253 *ecc_result = YAFFS_ECC_RESULT_FIXED;
254 else
255 *ecc_result = YAFFS_ECC_RESULT_NO_ERROR;
256
257 }
258 }
259 return ret_val;
260}
261
262/*
263 * Functions for robustisizing
264 */
265
266static void yaffs_handle_rd_data_error(struct yaffs_dev *dev, int nand_chunk)
267{
268 int flash_block = nand_chunk / dev->param.chunks_per_block;
269
270 /* Mark the block for retirement */
271 yaffs_get_block_info(dev,
272 flash_block + dev->block_offset)->needs_retiring =
273 1;
274 yaffs_trace(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
275 "**>>Block %d marked for retirement",
276 flash_block);
277
278 /* TODO:
279 * Just do a garbage collection on the affected block
280 * then retire the block
281 * NB recursion
282 */
283}
284
285int yaffs_tags_compat_wr(struct yaffs_dev *dev,
286 int nand_chunk,
287 const u8 * data, const struct yaffs_ext_tags *ext_tags)
288{
289 struct yaffs_spare spare;
290 struct yaffs_tags tags;
291
292 yaffs_spare_init(&spare);
293
294 if (ext_tags->is_deleted)
295 spare.page_status = 0;
296 else {
297 tags.obj_id = ext_tags->obj_id;
298 tags.chunk_id = ext_tags->chunk_id;
299
300 tags.n_bytes_lsb = ext_tags->n_bytes & 0x3ff;
301
302 if (dev->data_bytes_per_chunk >= 1024)
303 tags.n_bytes_msb = (ext_tags->n_bytes >> 10) & 3;
304 else
305 tags.n_bytes_msb = 3;
306
307 tags.serial_number = ext_tags->serial_number;
308
309 if (!dev->param.use_nand_ecc && data)
310 yaffs_calc_ecc(data, &spare);
311
312 yaffs_load_tags_to_spare(&spare, &tags);
313
314 }
315
316 return yaffs_wr_nand(dev, nand_chunk, data, &spare);
317}
318
319int yaffs_tags_compat_rd(struct yaffs_dev *dev,
320 int nand_chunk,
321 u8 * data, struct yaffs_ext_tags *ext_tags)
322{
323
324 struct yaffs_spare spare;
325 struct yaffs_tags tags;
326 enum yaffs_ecc_result ecc_result = YAFFS_ECC_RESULT_UNKNOWN;
327
328 static struct yaffs_spare spare_ff;
329 static int init;
330
331 if (!init) {
332 memset(&spare_ff, 0xFF, sizeof(spare_ff));
333 init = 1;
334 }
335
336 if (yaffs_rd_chunk_nand(dev, nand_chunk, data, &spare, &ecc_result, 1)) {
337 /* ext_tags may be NULL */
338 if (ext_tags) {
339
340 int deleted =
341 (hweight8(spare.page_status) < 7) ? 1 : 0;
342
343 ext_tags->is_deleted = deleted;
344 ext_tags->ecc_result = ecc_result;
345 ext_tags->block_bad = 0; /* We're reading it */
346 /* therefore it is not a bad block */
347 ext_tags->chunk_used =
348 (memcmp(&spare_ff, &spare, sizeof(spare_ff)) !=
349 0) ? 1 : 0;
350
351 if (ext_tags->chunk_used) {
352 yaffs_get_tags_from_spare(dev, &spare, &tags);
353
354 ext_tags->obj_id = tags.obj_id;
355 ext_tags->chunk_id = tags.chunk_id;
356 ext_tags->n_bytes = tags.n_bytes_lsb;
357
358 if (dev->data_bytes_per_chunk >= 1024)
359 ext_tags->n_bytes |=
360 (((unsigned)tags.
361 n_bytes_msb) << 10);
362
363 ext_tags->serial_number = tags.serial_number;
364 }
365 }
366
367 return YAFFS_OK;
368 } else {
369 return YAFFS_FAIL;
370 }
371}
372
373int yaffs_tags_compat_mark_bad(struct yaffs_dev *dev, int flash_block)
374{
375
376 struct yaffs_spare spare;
377
378 memset(&spare, 0xff, sizeof(struct yaffs_spare));
379
380 spare.block_status = 'Y';
381
382 yaffs_wr_nand(dev, flash_block * dev->param.chunks_per_block, NULL,
383 &spare);
384 yaffs_wr_nand(dev, flash_block * dev->param.chunks_per_block + 1,
385 NULL, &spare);
386
387 return YAFFS_OK;
388
389}
390
391int yaffs_tags_compat_query_block(struct yaffs_dev *dev,
392 int block_no,
393 enum yaffs_block_state *state,
394 u32 * seq_number)
395{
396
397 struct yaffs_spare spare0, spare1;
398 static struct yaffs_spare spare_ff;
399 static int init;
400 enum yaffs_ecc_result dummy;
401
402 if (!init) {
403 memset(&spare_ff, 0xFF, sizeof(spare_ff));
404 init = 1;
405 }
406
407 *seq_number = 0;
408
409 yaffs_rd_chunk_nand(dev, block_no * dev->param.chunks_per_block, NULL,
410 &spare0, &dummy, 1);
411 yaffs_rd_chunk_nand(dev, block_no * dev->param.chunks_per_block + 1,
412 NULL, &spare1, &dummy, 1);
413
414 if (hweight8(spare0.block_status & spare1.block_status) < 7)
415 *state = YAFFS_BLOCK_STATE_DEAD;
416 else if (memcmp(&spare_ff, &spare0, sizeof(spare_ff)) == 0)
417 *state = YAFFS_BLOCK_STATE_EMPTY;
418 else
419 *state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
420
421 return YAFFS_OK;
422}