1 /**************************************************************************/
2 /* */
3 /* Copyright (c) Microsoft Corporation. All rights reserved. */
4 /* */
5 /* This software is licensed under the Microsoft Software License */
6 /* Terms for Microsoft Azure RTOS. Full text of the license can be */
7 /* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */
8 /* and in the root directory of this software. */
9 /* */
10 /**************************************************************************/
11
12
13 /**************************************************************************/
14 /**************************************************************************/
15 /** */
16 /** LevelX Component */
17 /** */
18 /** NOR Flash */
19 /** */
20 /**************************************************************************/
21 /**************************************************************************/
22
23 #define LX_SOURCE_CODE
24
25
26 /* Disable ThreadX error checking. */
27
28 #ifndef LX_DISABLE_ERROR_CHECKING
29 #define LX_DISABLE_ERROR_CHECKING
30 #endif
31
32
33 /* Include necessary system files. */
34
35 #include "lx_api.h"
36
37
38 /**************************************************************************/
39 /* */
40 /* FUNCTION RELEASE */
41 /* */
42 /* _lx_nor_flash_next_block_to_erase_find PORTABLE C */
43 /* 6.3.0 */
44 /* AUTHOR */
45 /* */
46 /* William E. Lamie, Microsoft Corporation */
47 /* */
48 /* DESCRIPTION */
49 /* */
50 /* This function finds the next block to erase in the NOR flash. */
51 /* */
52 /* INPUT */
53 /* */
54 /* nor_flash NOR flash instance */
55 /* return_erase_block Returned block to erase */
56 /* return_erase_count Returned erase count of block */
57 /* return_mapped_sectors Returned number of mapped */
58 /* sectors */
59 /* return_obsolete_sectors Returned number of obsolete */
60 /* sectors */
61 /* */
62 /* OUTPUT */
63 /* */
64 /* return status */
65 /* */
66 /* CALLS */
67 /* */
68 /* _lx_nor_flash_driver_read Driver flash sector read */
69 /* _lx_nor_flash_system_error Internal system error handler */
70 /* */
71 /* CALLED BY */
72 /* */
73 /* Internal LevelX */
74 /* */
75 /* RELEASE HISTORY */
76 /* */
77 /* DATE NAME DESCRIPTION */
78 /* */
79 /* 05-19-2020 William E. Lamie Initial Version 6.0 */
80 /* 09-30-2020 William E. Lamie Modified comment(s), */
81 /* resulting in version 6.1 */
82 /* 06-02-2021 Bhupendra Naphade Modified comment(s), */
83 /* resulting in version 6.1.7 */
84 /* 10-31-2023 Xiuwen Cai Modified comment(s), */
85 /* added mapping bitmap cache, */
86 /* added obsolete count cache, */
87 /* optimized full obsoleted */
88 /* block searching logic, */
89 /* resulting in version 6.3.0 */
90 /* */
91 /**************************************************************************/
_lx_nor_flash_next_block_to_erase_find(LX_NOR_FLASH * nor_flash,ULONG * return_erase_block,ULONG * return_erase_count,ULONG * return_mapped_sectors,ULONG * return_obsolete_sectors)92 UINT _lx_nor_flash_next_block_to_erase_find(LX_NOR_FLASH *nor_flash, ULONG *return_erase_block, ULONG *return_erase_count, ULONG *return_mapped_sectors, ULONG *return_obsolete_sectors)
93 {
94
95 ULONG *block_word_ptr;
96 ULONG *list_word_ptr;
97 ULONG list_word;
98 ULONG i, j;
99 ULONG mapped_sectors;
100 ULONG erase_count;
101 ULONG obsolete_sectors;
102 ULONG min_block_erase = 0;
103 ULONG min_block_erase_count;
104 ULONG min_block_obsolete_count = 0;
105 ULONG min_block_mapped_count = 0;
106 ULONG min_block_mapped_count_available = LX_FALSE;
107 ULONG max_obsolete_sectors;
108 ULONG max_obsolete_block = 0;
109 ULONG max_obsolete_erase_count = 0;
110 ULONG max_obsolete_mapped_count = 0;
111 ULONG max_obsolete_mapped_count_available = LX_FALSE;
112 ULONG min_system_block_erase_count;
113 ULONG system_min_erased_blocks;
114 ULONG max_system_block_erase_count;
115 ULONG erase_count_threshold;
116 ULONG min_logical_sector;
117 ULONG max_logical_sector;
118 #ifndef LX_DIRECT_READ
119 UINT status;
120 #endif
121 UINT obsolete_sectors_available;
122 UINT mapped_sectors_available;
123
124
125 /* Setup the block word pointer to the first word of the search block. */
126 block_word_ptr = nor_flash -> lx_nor_flash_base_address;
127
128 /* Initialize the minimum erase count. */
129 min_block_erase_count = LX_ALL_ONES;
130
131 /* Initialize the system minimum and maximum erase counts. */
132 min_system_block_erase_count = LX_ALL_ONES;
133 system_min_erased_blocks = 0;
134 max_system_block_erase_count = 0;
135
136 /* Initialize the maximum obsolete sector count. */
137 max_obsolete_sectors = 0;
138
139 /* Calculate the erase count threshold. */
140 if (nor_flash -> lx_nor_flash_free_physical_sectors >= nor_flash -> lx_nor_flash_physical_sectors_per_block)
141 {
142
143 /* Calculate erase count threshold by adding constant to the current minimum. */
144 erase_count_threshold = nor_flash -> lx_nor_flash_minimum_erase_count + LX_NOR_FLASH_MAX_ERASE_COUNT_DELTA;
145 }
146 else
147 {
148
149 /* When the number of free sectors is low, simply pick the block that has the most number of obsolete sectors. */
150 erase_count_threshold = LX_ALL_ONES;
151 }
152
153 /* Loop through the blocks to attempt to find the mapped logical sector. */
154 for (i = 0; i < nor_flash -> lx_nor_flash_total_blocks; i++)
155 {
156
157 /* Read the erase count of this block. */
158 #ifdef LX_DIRECT_READ
159
160 /* Read the word directly. */
161 erase_count = *(block_word_ptr);
162 #else
163 status = _lx_nor_flash_driver_read(nor_flash, block_word_ptr, &erase_count, 1);
164
165 /* Check for an error from flash driver. Drivers should never return an error.. */
166 if (status)
167 {
168
169 /* Call system error handler. */
170 _lx_nor_flash_system_error(nor_flash, status);
171
172 /* Return the error. */
173 return(status);
174 }
175 #endif
176
177 /* Update the system minimum and maximum erase counts. */
178 if (erase_count == min_system_block_erase_count)
179 {
180 system_min_erased_blocks ++;
181 }
182 if (erase_count < min_system_block_erase_count)
183 {
184 min_system_block_erase_count = erase_count;
185 system_min_erased_blocks = 1;
186 }
187 if (erase_count > max_system_block_erase_count)
188 max_system_block_erase_count = erase_count;
189
190 /* Initialize the obsolete and mapped sector count available flags. */
191 obsolete_sectors_available = LX_FALSE;
192 mapped_sectors_available = LX_FALSE;
193
194 #ifdef LX_NOR_ENABLE_OBSOLETE_COUNT_CACHE
195
196 /* Determine if the obsolete sector count is available in the cache. */
197 if (i < nor_flash -> lx_nor_flash_extended_cache_obsolete_count_max_block)
198 {
199
200 /* Yes, the obsolete sector count is available. */
201 obsolete_sectors_available = LX_TRUE;
202
203 /* Pickup the obsolete sector count from the cache. */
204 obsolete_sectors = (ULONG)nor_flash -> lx_nor_flash_extended_cache_obsolete_count[i];
205 }
206 else
207 {
208 #endif
209 /* Read the minimum and maximum logical sector values in this block. */
210 #ifdef LX_DIRECT_READ
211
212 /* Read the word directly. */
213 min_logical_sector = *(block_word_ptr + LX_NOR_FLASH_MIN_LOGICAL_SECTOR_OFFSET);
214 #else
215 status = _lx_nor_flash_driver_read(nor_flash, block_word_ptr + LX_NOR_FLASH_MIN_LOGICAL_SECTOR_OFFSET, &min_logical_sector, 1);
216
217 /* Check for an error from flash driver. Drivers should never return an error.. */
218 if (status)
219 {
220
221 /* Call system error handler. */
222 _lx_nor_flash_system_error(nor_flash, status);
223
224 /* Return the error. */
225 return(status);
226 }
227 #endif
228
229 /* Determine if the minimum logical sector is valid. */
230 if (min_logical_sector != LX_ALL_ONES)
231 {
232 #ifdef LX_DIRECT_READ
233
234 /* Read the word directly. */
235 max_logical_sector = *(block_word_ptr + LX_NOR_FLASH_MAX_LOGICAL_SECTOR_OFFSET);
236 #else
237 status = _lx_nor_flash_driver_read(nor_flash, block_word_ptr + LX_NOR_FLASH_MAX_LOGICAL_SECTOR_OFFSET, &max_logical_sector, 1);
238
239 /* Check for an error from flash driver. Drivers should never return an error.. */
240 if (status)
241 {
242
243 /* Call system error handler. */
244 _lx_nor_flash_system_error(nor_flash, status);
245
246 /* Return the error. */
247 return(status);
248 }
249 #endif
250
251 /* Are the values valid? */
252 /* Now let's check to see if all the sector are obsoleted. */
253 if ((max_logical_sector != LX_ALL_ONES) && (max_logical_sector < min_logical_sector))
254 {
255
256 obsolete_sectors_available = LX_TRUE;
257 obsolete_sectors = nor_flash -> lx_nor_flash_physical_sectors_per_block;
258 }
259 }
260 #ifdef LX_NOR_ENABLE_OBSOLETE_COUNT_CACHE
261 }
262 #endif
263
264 /* Determine if the mapped sector count is available. */
265 if (obsolete_sectors_available == LX_FALSE)
266 {
267
268 /* Compute the number of obsolete and mapped sectors for this block. */
269
270 /* Initialize the obsolete and mapped sector counts. */
271 obsolete_sectors = 0;
272 mapped_sectors = 0;
273
274 /* Set the mapped sector count and obsolete sector count available flags. */
275 mapped_sectors_available = LX_TRUE;
276 obsolete_sectors_available = LX_TRUE;
277
278 /* Setup a pointer to the mapped list. */
279 list_word_ptr = block_word_ptr + nor_flash -> lx_nor_flash_block_physical_sector_mapping_offset;
280
281 /* Loop through the mapped list for this block. */
282 for (j = 0; j < nor_flash -> lx_nor_flash_physical_sectors_per_block; j++)
283 {
284
285 /* Read the current mapping entry. */
286 #ifdef LX_DIRECT_READ
287
288 /* Read the word directly. */
289 list_word = *(list_word_ptr);
290 #else
291 status = _lx_nor_flash_driver_read(nor_flash, list_word_ptr, &list_word, 1);
292
293 /* Check for an error from flash driver. Drivers should never return an error.. */
294 if (status)
295 {
296
297 /* Call system error handler. */
298 _lx_nor_flash_system_error(nor_flash, status);
299
300 /* Return the error. */
301 return(status);
302 }
303 #endif
304
305 /* Determine if the entry hasn't been used. */
306 if (list_word == LX_NOR_PHYSICAL_SECTOR_FREE)
307 {
308
309 /* Since allocations are done sequentially in the block, we know nothing
310 else exists after this point. */
311 break;
312 }
313
314 /* Is this entry obsolete? */
315 if ((list_word & LX_NOR_PHYSICAL_SECTOR_VALID) == 0)
316 {
317
318 /* Increment the number of obsolete sectors. */
319 obsolete_sectors++;
320 }
321 else
322 {
323
324 /* Increment the number of mapped sectors. */
325 mapped_sectors++;
326 }
327
328 /* Move the list pointer ahead. */
329 list_word_ptr++;
330 }
331 }
332
333 /* Determine if this block contains full obsoleted sectors and the erase count is minimum. */
334 if ((obsolete_sectors == nor_flash -> lx_nor_flash_physical_sectors_per_block) &&
335 (erase_count == nor_flash -> lx_nor_flash_minimum_erase_count) &&
336 (nor_flash -> lx_nor_flash_minimum_erased_blocks > 0))
337 {
338
339 /* Yes, we have a full obsoleted block with minimum erase count. */
340 *return_erase_block = i;
341 *return_erase_count = erase_count;
342 *return_obsolete_sectors = obsolete_sectors;
343 *return_mapped_sectors = mapped_sectors;
344
345 break;
346 }
347
348
349 /* Determine if we have a block with a new maximum number of obsolete sectors. */
350 if ((obsolete_sectors > max_obsolete_sectors) && (erase_count <= erase_count_threshold))
351 {
352
353 /* Update the new maximum obsolete sectors and related information. */
354 max_obsolete_sectors = obsolete_sectors;
355 max_obsolete_block = i;
356 max_obsolete_erase_count = erase_count;
357 max_obsolete_mapped_count = mapped_sectors;
358 max_obsolete_mapped_count_available = mapped_sectors_available;
359
360 }
361 else if ((max_obsolete_sectors) && (obsolete_sectors == max_obsolete_sectors) && (erase_count <= erase_count_threshold))
362 {
363
364 /* Another block has the same number of obsolete sectors. Does this new block have a smaller erase
365 count? */
366 if (erase_count < max_obsolete_erase_count)
367 {
368
369 /* Yes, erase the block with the smaller erase count. */
370 max_obsolete_sectors = obsolete_sectors;
371 max_obsolete_block = i;
372 max_obsolete_erase_count = erase_count;
373 max_obsolete_mapped_count = mapped_sectors;
374 max_obsolete_mapped_count_available = mapped_sectors_available;
375 }
376 }
377
378 /* Determine if we have a new minimum erase count. */
379 if (erase_count < min_block_erase_count)
380 {
381
382 /* Update the new minimum erase count and related information. */
383 min_block_erase_count = erase_count;
384 min_block_erase = i;
385 min_block_obsolete_count = obsolete_sectors;
386 min_block_mapped_count = mapped_sectors;
387 min_block_mapped_count_available = mapped_sectors_available;
388 }
389
390 /* Move to the next block. */
391 block_word_ptr = block_word_ptr + nor_flash -> lx_nor_flash_words_per_block;
392 }
393
394 /* Determine if we found a block with full obsoleted sector and the erase count is minimum. */
395 if (i == nor_flash -> lx_nor_flash_total_blocks)
396 {
397
398 /* Determine if we can erase the block with the most obsolete sectors. */
399 if (max_obsolete_sectors)
400 {
401
402 /* Erase the block with the most obsolete sectors. */
403 *return_erase_block = max_obsolete_block;
404 *return_erase_count = max_obsolete_erase_count;
405 *return_obsolete_sectors = max_obsolete_sectors;
406 *return_mapped_sectors = max_obsolete_mapped_count;
407 mapped_sectors_available = max_obsolete_mapped_count_available;
408 }
409 else
410 {
411
412 /* Otherwise, choose the block with the smallest erase count. */
413 *return_erase_block = min_block_erase;
414 *return_erase_count = min_block_erase_count;
415 *return_obsolete_sectors = min_block_obsolete_count;
416 *return_mapped_sectors = min_block_mapped_count;
417 mapped_sectors_available = min_block_mapped_count_available;
418 }
419
420 /* Update the overall minimum and maximum erase count. */
421 nor_flash -> lx_nor_flash_minimum_erase_count = min_system_block_erase_count;
422 nor_flash -> lx_nor_flash_minimum_erased_blocks = system_min_erased_blocks;
423 nor_flash -> lx_nor_flash_maximum_erase_count = max_system_block_erase_count;
424 }
425
426 /* Determine if the mapped sector count is available. */
427 if (mapped_sectors_available == LX_FALSE)
428 {
429
430 /* Compute the number of obsolete and mapped sectors for this block. */
431 mapped_sectors = 0;
432
433 /* Setup a pointer to the mapped list. */
434 block_word_ptr = nor_flash -> lx_nor_flash_base_address + *return_erase_block * nor_flash -> lx_nor_flash_words_per_block;
435 list_word_ptr = block_word_ptr + nor_flash -> lx_nor_flash_block_physical_sector_mapping_offset;
436
437 /* Loop through the mapped list for this block. */
438 for (j = 0; j < nor_flash -> lx_nor_flash_physical_sectors_per_block; j++)
439 {
440
441 /* Read the current mapping entry. */
442 #ifdef LX_DIRECT_READ
443
444 /* Read the word directly. */
445 list_word = *(list_word_ptr);
446 #else
447 status = _lx_nor_flash_driver_read(nor_flash, list_word_ptr, &list_word, 1);
448
449 /* Check for an error from flash driver. Drivers should never return an error.. */
450 if (status)
451 {
452
453 /* Call system error handler. */
454 _lx_nor_flash_system_error(nor_flash, status);
455
456 /* Return the error. */
457 return(status);
458 }
459 #endif
460
461 /* Determine if the entry hasn't been used. */
462 if (list_word == LX_NOR_PHYSICAL_SECTOR_FREE)
463 {
464
465 /* Since allocations are done sequentially in the block, we know nothing
466 else exists after this point. */
467 break;
468 }
469
470 /* Is this entry mapped? */
471 if ((list_word & LX_NOR_PHYSICAL_SECTOR_VALID) != 0)
472 {
473
474 /* Increment the number of mapped sectors. */
475 mapped_sectors++;
476 }
477
478 /* Move the list pointer ahead. */
479 list_word_ptr++;
480 }
481
482 /* Return the mapped sector count. */
483 *return_mapped_sectors = mapped_sectors;
484
485 }
486 /* Return success. */
487 return(LX_SUCCESS);
488 }
489
490
