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- // Copyright 2022 Nick Brassel (@tzarc)
- // SPDX-License-Identifier: GPL-2.0-or-later
- #pragma once
-
- #ifdef __cplusplus
- # define _Static_assert static_assert
- #endif
-
- #include <stdint.h>
- #include <string.h>
-
- #if BACKING_STORE_WRITE_SIZE == 2
- typedef uint16_t backing_store_int_t;
- #elif BACKING_STORE_WRITE_SIZE == 4
- typedef uint32_t backing_store_int_t;
- #elif BACKING_STORE_WRITE_SIZE == 8
- typedef uint64_t backing_store_int_t;
- #else
- # error Invalid BACKING_STORE_WRITE_SIZE, needs to be 2/4/8.
- #endif
-
- #ifndef WEAR_LEVELING_BACKING_SIZE
- # error WEAR_LEVELING_BACKING_SIZE was not set.
- #endif
-
- #ifndef WEAR_LEVELING_LOGICAL_SIZE
- # error WEAR_LEVELING_LOGICAL_SIZE was not set.
- #endif
-
- #ifdef WEAR_LEVELING_DEBUG_OUTPUT
- # include <debug.h>
- # define bs_dprintf(...) dprintf("Backing store: " __VA_ARGS__)
- # define wl_dprintf(...) dprintf("Wear leveling: " __VA_ARGS__)
- # define wl_dump(address, value, length) \
- do { \
- dprintf("[0x%04X]: ", (int)(address)); \
- const uint8_t* p = (const uint8_t*)(value); \
- for (int i = 0; i < (length); ++i) { \
- dprintf(" %02X", (int)p[i]); \
- } \
- dprintf("\n"); \
- } while (0)
- #else
- # define wl_dprintf(...) \
- do { \
- } while (0)
- # define bs_dprintf(...) \
- do { \
- } while (0)
- # define wl_dump(...) \
- do { \
- } while (0)
- #endif // WEAR_LEVELING_DEBUG_OUTPUT
-
- #ifdef WEAR_LEVELING_ASSERTS
- # include <assert.h>
- # define wl_assert(...) assert(__VA_ARGS__)
- #else
- # define wl_assert(...) \
- do { \
- } while (0)
- #endif // WEAR_LEVELING_ASSERTS
-
- // Compile-time validation of configurable options
- _Static_assert(WEAR_LEVELING_BACKING_SIZE >= (WEAR_LEVELING_LOGICAL_SIZE * 2), "Total backing size must be at least twice the size of the logical size");
- _Static_assert(WEAR_LEVELING_LOGICAL_SIZE % BACKING_STORE_WRITE_SIZE == 0, "Logical size must be a multiple of write size");
- _Static_assert(WEAR_LEVELING_BACKING_SIZE % WEAR_LEVELING_LOGICAL_SIZE == 0, "Backing size must be a multiple of logical size");
-
- // Backing Store API, to be implemented elsewhere by flash driver etc.
- bool backing_store_init(void);
- bool backing_store_unlock(void);
- bool backing_store_erase(void);
- bool backing_store_write(uint32_t address, backing_store_int_t value);
- bool backing_store_write_bulk(uint32_t address, backing_store_int_t* values, size_t item_count); // weak implementation already provided, optimized implementation can be implemented by driver
- bool backing_store_lock(void);
- bool backing_store_read(uint32_t address, backing_store_int_t* value);
- bool backing_store_read_bulk(uint32_t address, backing_store_int_t* values, size_t item_count); // weak implementation already provided, optimized implementation can be implemented by driver
-
- /**
- * Helper type used to contain a write log entry.
- */
- typedef union write_log_entry_t {
- uint64_t raw64;
- uint32_t raw32[2];
- uint16_t raw16[4];
- uint8_t raw8[8];
- } write_log_entry_t;
-
- _Static_assert(sizeof(write_log_entry_t) == 8, "Wear leveling write log entry size was not 8");
-
- /**
- * Log entry type discriminator.
- */
- enum {
- // 0x00 -- Multi-byte storage type
- LOG_ENTRY_TYPE_MULTIBYTE,
-
- // 0x01 -- 2-byte backing store write optimization: address < 64
- LOG_ENTRY_TYPE_OPTIMIZED_64,
-
- // 0x02 -- 2-byte backing store write optimization: word-encoded 0/1 values
- LOG_ENTRY_TYPE_WORD_01,
-
- LOG_ENTRY_TYPES
- };
-
- _Static_assert(LOG_ENTRY_TYPES <= (1 << 2), "Too many log entry types to fit into 2 bits of storage");
-
- #define BITMASK_FOR_BITCOUNT(n) ((1 << (n)) - 1)
-
- #define LOG_ENTRY_GET_TYPE(entry) (((entry).raw8[0] >> 6) & BITMASK_FOR_BITCOUNT(2))
-
- #define LOG_ENTRY_MULTIBYTE_MAX_BYTES 5
- #define LOG_ENTRY_MULTIBYTE_GET_ADDRESS(entry) (((((uint32_t)((entry).raw8[0])) & BITMASK_FOR_BITCOUNT(3)) << 16) | (((uint32_t)((entry).raw8[1])) << 8) | (entry).raw8[2])
- #define LOG_ENTRY_MULTIBYTE_GET_LENGTH(entry) ((uint8_t)(((entry).raw8[0] >> 3) & BITMASK_FOR_BITCOUNT(3)))
- #define LOG_ENTRY_MAKE_MULTIBYTE(address, length) \
- (write_log_entry_t) { \
- .raw8 = { \
- [0] = (((((uint8_t)LOG_ENTRY_TYPE_MULTIBYTE) & BITMASK_FOR_BITCOUNT(2)) << 6) /* type */ \
- | ((((uint8_t)(length)) & BITMASK_FOR_BITCOUNT(3)) << 3) /* length */ \
- | ((((uint8_t)((address) >> 16))) & BITMASK_FOR_BITCOUNT(3)) /* address */ \
- ), \
- [1] = (((uint8_t)((address) >> 8)) & BITMASK_FOR_BITCOUNT(8)), /* address */ \
- [2] = (((uint8_t)(address)) & BITMASK_FOR_BITCOUNT(8)), /* address */ \
- } \
- }
-
- #define LOG_ENTRY_OPTIMIZED_64_GET_ADDRESS(entry) ((uint32_t)((entry).raw8[0] & BITMASK_FOR_BITCOUNT(6)))
- #define LOG_ENTRY_OPTIMIZED_64_GET_VALUE(entry) ((entry).raw8[1])
- #define LOG_ENTRY_MAKE_OPTIMIZED_64(address, value) \
- (write_log_entry_t) { \
- .raw8 = { \
- [0] = (((((uint8_t)LOG_ENTRY_TYPE_OPTIMIZED_64) & BITMASK_FOR_BITCOUNT(2)) << 6) /* type */ \
- | ((((uint8_t)(address))) & BITMASK_FOR_BITCOUNT(6)) /* address */ \
- ), \
- [1] = ((uint8_t)(value)), /* value */ \
- } \
- }
-
- #define LOG_ENTRY_WORD_01_GET_ADDRESS(entry) ((((uint32_t)(((entry).raw8[0]) & BITMASK_FOR_BITCOUNT(5))) << 9) | (((uint32_t)((entry).raw8[1])) << 1))
- #define LOG_ENTRY_WORD_01_GET_VALUE(entry) ((uint8_t)((entry).raw8[0] >> 5) & BITMASK_FOR_BITCOUNT(1))
- #define LOG_ENTRY_MAKE_WORD_01(address, value) \
- (write_log_entry_t) { \
- .raw8 = { \
- [0] = (((((uint8_t)LOG_ENTRY_TYPE_WORD_01) & BITMASK_FOR_BITCOUNT(2)) << 6) /* type */ \
- | (((((uint8_t)((value) ? 1 : 0))) & BITMASK_FOR_BITCOUNT(1)) << 5) /* value */ \
- | ((((uint8_t)((address) >> 9))) & BITMASK_FOR_BITCOUNT(5)) /* address */ \
- ), \
- [1] = (uint8_t)((address) >> 1), /* address */ \
- } \
- }
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