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-rw-r--r--quantum/wear_leveling/wear_leveling_internal.h151
1 files changed, 151 insertions, 0 deletions
diff --git a/quantum/wear_leveling/wear_leveling_internal.h b/quantum/wear_leveling/wear_leveling_internal.h
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+++ b/quantum/wear_leveling/wear_leveling_internal.h
@@ -0,0 +1,151 @@
+// 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 */ \
+ } \
+ }