diff options
Diffstat (limited to 'ks_flash.c')
| -rw-r--r-- | ks_flash.c | 147 |
1 files changed, 84 insertions, 63 deletions
@@ -52,18 +52,9 @@ * General consideration: * * - bits can only be cleared, not set, unless one wants to erase the - * (sub)sector. This has some odd knock on effects in terms of + * sector. This has some odd knock on effects in terms of * things like values of enumerated constants used here. * - * - At the moment, all of the the low-level flash code deals with - * sectors, not sub-sectors, so for the moment we only use the first - * sub-sector of each sector. Fixing this should not involve any - * major changes to the code, just redefinition of some constants - * here once we figure out what effect this will have on the rest of - * the code that shares the same low-level flash code. In either - * case we're dealing with "blocks", where a block is a sector now - * and will be a sub-sector later. - * * - This code assumes we're using ks_index.c, including its notion * of a free list and its attempt at light-weight wear leveling. * @@ -163,21 +154,27 @@ typedef union { } flash_block_t; /* - * In-memory index, cache, etc. - * - * Some or all of this probably ought to be allocated out of external - * SDRAM, but try it as a plain static variable initially. + * In-memory cache. + */ + +typedef struct { + unsigned blockno; + uint32_t lru; + flash_block_t block; +} cache_block_t; + +/* + * In-memory database. * - * NUM_FLASH_BLOCKS should be KEYSTORE_NUM_SUBSECTORS, but all the - * current flash code uses sectors rather than subsectors, so use - * KEYSTORE_NUM_SECTORS until we have subsector erase code. + * The top-level structure is a static variable; the arrays are allocated at runtime + * using hal_allocate_static_memory() because they can get kind of large. */ #ifndef KS_FLASH_CACHE_SIZE #define KS_FLASH_CACHE_SIZE 4 #endif -#define NUM_FLASH_BLOCKS KEYSTORE_NUM_SECTORS +#define NUM_FLASH_BLOCKS KEYSTORE_NUM_SUBSECTORS typedef struct { hal_ks_t ks; /* Must be first (C "subclassing") */ @@ -186,13 +183,7 @@ typedef struct { hal_ks_pin_t so_pin; hal_ks_pin_t user_pin; uint32_t cache_lru; - struct { - unsigned blockno; - uint32_t lru; - flash_block_t block; - } cache[KS_FLASH_CACHE_SIZE]; - uint16_t _index[NUM_FLASH_BLOCKS]; - hal_uuid_t _names[NUM_FLASH_BLOCKS]; + cache_block_t *cache; } db_t; /* @@ -234,7 +225,7 @@ static inline flash_block_t *cache_pick_lru(void) uint32_t best_delta = 0; int best_index = 0; - for (int i = 0; i < sizeof(db.cache)/sizeof(*db.cache); i++) { + for (int i = 0; i < KS_FLASH_CACHE_SIZE; i++) { if (db.cache[i].blockno == ~0) return &db.cache[i].block; @@ -257,7 +248,7 @@ static inline flash_block_t *cache_pick_lru(void) static inline flash_block_t *cache_find_block(const unsigned blockno) { - for (int i = 0; i < sizeof(db.cache)/sizeof(*db.cache); i++) + for (int i = 0; i < KS_FLASH_CACHE_SIZE; i++) if (db.cache[i].blockno == blockno) return &db.cache[i].block; return NULL; @@ -269,7 +260,7 @@ static inline flash_block_t *cache_find_block(const unsigned blockno) static inline void cache_mark_used(const flash_block_t * const block, const unsigned blockno) { - for (int i = 0; i < sizeof(db.cache)/sizeof(*db.cache); i++) { + for (int i = 0; i < KS_FLASH_CACHE_SIZE; i++) { if (&db.cache[i].block == block) { db.cache[i].blockno = blockno; db.cache[i].lru = ++db.cache_lru; @@ -313,49 +304,67 @@ static hal_crc32_t calculate_block_crc(const flash_block_t * const block) } /* - * Calculate block offset. Once we have subsectors working this will - * use subsector offsets, for the moment we have to use sector offsets. + * Calculate block offset. */ -#if 0 -#define BLOCK_OFFSET_SIZE KEYSTORE_SUBSECTOR_SIZE -#else -#define BLOCK_OFFSET_SIZE KEYSTORE_SECTOR_SIZE -#endif - static uint32_t block_offset(const unsigned blockno) { - return blockno * BLOCK_OFFSET_SIZE; + return blockno * KEYSTORE_SUBSECTOR_SIZE; } /* - * Read a flash block. In some cases we might be able to optimize by - * reading just the first page, but NOR flash should be relatively - * fast to read, and we need the whole block to check the CRC - * anyway. + * Read a flash block. + * + * Sadly, flash on the Alpha is slow enough that it pays to + * check the first page before reading the rest of the block. */ -static hal_error_t block_read(const unsigned blockno, flash_block_t *block) +static hal_error_t block_read(const unsigned blockno, flash_block_t *block, const int fast) { assert(block != NULL && blockno < NUM_FLASH_BLOCKS && sizeof(*block) == KEYSTORE_SUBSECTOR_SIZE); /* Sigh, magic numeric return codes */ - if (keystore_read_data(block_offset(blockno), block->bytes, sizeof(*block)) != 1) + if (keystore_read_data(block_offset(blockno), + block->bytes, + KEYSTORE_PAGE_SIZE) != 1) return HAL_ERROR_KEYSTORE_ACCESS; - switch (block_get_type(block)) { + flash_block_type_t block_type = block_get_type(block); + hal_crc32_t crc = 0; + + switch (block_type) { case FLASH_KEYBLK: case FLASH_PINBLK: - return calculate_block_crc(block) == block->header.crc1 ? HAL_OK : HAL_ERROR_KEYSTORE_BAD_CRC; + crc = block->header.crc1; + break; case FLASH_KEYOLD: case FLASH_PINOLD: - return calculate_block_crc(block) == block->header.crc2 ? HAL_OK : HAL_ERROR_KEYSTORE_BAD_CRC; + crc = block->header.crc2; + break; case FLASH_ERASED: case FLASH_ZEROED: - return HAL_OK; + if (fast) + return HAL_OK; + else + break; default: return HAL_ERROR_KEYSTORE_BAD_BLOCK_TYPE; } + + /* Sigh, magic numeric return codes */ + if (keystore_read_data(block_offset(blockno) + KEYSTORE_PAGE_SIZE, + block->bytes + KEYSTORE_PAGE_SIZE, + sizeof(*block) - KEYSTORE_PAGE_SIZE) != 1) + return HAL_ERROR_KEYSTORE_ACCESS; + + switch (block_type) { + default: + if (calculate_block_crc(block) != crc) + return HAL_ERROR_KEYSTORE_BAD_CRC; + case FLASH_ERASED: + case FLASH_ZEROED: + return HAL_OK; + } } /* @@ -375,7 +384,7 @@ static hal_error_t block_read_cached(const unsigned blockno, flash_block_t **blo if ((*block = cache_pick_lru()) == NULL) return HAL_ERROR_IMPOSSIBLE; - return block_read(blockno, *block); + return block_read(blockno, *block, 1); } /* @@ -442,7 +451,7 @@ static hal_error_t block_erase(const unsigned blockno) assert(blockno < NUM_FLASH_BLOCKS); /* Sigh, magic numeric return codes */ - if (keystore_erase_sectors(blockno, blockno) != 1) + if (keystore_erase_subsectors(blockno, blockno) != 1) return HAL_ERROR_KEYSTORE_ACCESS; return HAL_OK; @@ -450,7 +459,7 @@ static hal_error_t block_erase(const unsigned blockno) /* * Erase a flash block if it hasn't already been erased. - * + * We have to disable fast read for this to work properly. * May not be necessary, trying to avoid unnecessary wear. */ @@ -462,7 +471,7 @@ static hal_error_t block_erase_maybe(const unsigned blockno) if (block == NULL) return HAL_ERROR_IMPOSSIBLE; - err = block_read(blockno, block); + err = block_read(blockno, block, 0); if (err == HAL_ERROR_KEYSTORE_BAD_BLOCK_TYPE || err == HAL_ERROR_KEYSTORE_BAD_CRC) @@ -487,17 +496,27 @@ static hal_error_t block_erase_maybe(const unsigned blockno) static hal_error_t ks_init(const hal_ks_driver_t * const driver) { /* - * Initialize the in-memory database. In the long run this probably - * needs to be using a block of SDRAM, which we would allocate here. + * Initialize the in-memory database. */ + const size_t len = (sizeof(*db.ksi.index) * NUM_FLASH_BLOCKS + + sizeof(*db.ksi.names) * NUM_FLASH_BLOCKS + + sizeof(*db.cache) * KS_FLASH_CACHE_SIZE); + + uint8_t *mem = hal_allocate_static_memory(len); + + if (mem == NULL) + return HAL_ERROR_ALLOCATION_FAILURE; + memset(&db, 0, sizeof(db)); + memset(mem, 0, len); + db.ksi.size = NUM_FLASH_BLOCKS; - db.ksi.used = 0; - db.ksi.index = db._index; - db.ksi.names = db._names; + db.ksi.index = (void *) mem; mem += sizeof(*db.ksi.index) * NUM_FLASH_BLOCKS; + db.ksi.names = (void *) mem; mem += sizeof(*db.ksi.names) * NUM_FLASH_BLOCKS; + db.cache = (void *) mem; - for (int i = 0; i < sizeof(db.cache)/sizeof(*db.cache); i++) + for (int i = 0; i < KS_FLASH_CACHE_SIZE; i++) db.cache[i].blockno = ~0; /* @@ -525,7 +544,7 @@ static hal_error_t ks_init(const hal_ks_driver_t * const driver) * we want the block to ends up near the end of the free list. */ - err = block_read(i, block); + err = block_read(i, block, 1); if (err == HAL_ERROR_KEYSTORE_BAD_CRC || err == HAL_ERROR_KEYSTORE_BAD_BLOCK_TYPE) block_types[i] = FLASH_UNKNOWN; @@ -651,7 +670,7 @@ static hal_error_t ks_init(const hal_ks_driver_t * const driver) hal_uuid_t name = db.ksi.names[i]; /* Paranoia */ - if ((err = block_read(i, block)) != HAL_OK) + if ((err = block_read(i, block, 1)) != HAL_OK) return err; block->header.block_type = restore_type; @@ -685,10 +704,13 @@ static hal_error_t ks_init(const hal_ks_driver_t * const driver) unsigned b; memset(block, 0xFF, sizeof(*block)); - memset(&block->pin.so_pin, 0, sizeof(block->pin.so_pin)); - memset(&block->pin.user_pin, 0, sizeof(block->pin.user_pin)); + + db.wheel_pin = hal_last_gasp_pin; + block->header.block_type = FLASH_PINBLK; - block->pin.wheel_pin = hal_last_gasp_pin; + block->pin.wheel_pin = db.wheel_pin; + block->pin.so_pin = db.so_pin; + block->pin.user_pin = db.user_pin; if ((err = hal_ks_index_add(&db.ksi, &pin_uuid, &b)) != HAL_OK) return err; @@ -725,7 +747,6 @@ static hal_error_t ks_shutdown(const hal_ks_driver_t * const driver) { if (db.ks.driver != driver) return HAL_ERROR_KEYSTORE_ACCESS; - memset(&db, 0, sizeof(db)); return HAL_OK; } |