XinStellaris commented on code in PR #6829: URL: https://github.com/apache/incubator-nuttx/pull/6829#discussion_r966582021
########## drivers/mtd/mtd_config_fs.c: ########## @@ -0,0 +1,2262 @@ +/**************************************************************************** + * drivers/mtd/mtd_config_fs.c + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. The + * ASF licenses this file to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance with the + * License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the + * License for the specific language governing permissions and limitations + * under the License. + * + * NVS: non volatile storage in flash + * + * Copyright (c) 2018 Laczen + * + * SPDX-License-Identifier: Apache-2.0 + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> +#include <sys/types.h> +#include <stdbool.h> +#include <stdio.h> +#include <string.h> +#include <debug.h> +#include <fcntl.h> +#include <errno.h> +#include <sys/poll.h> +#include <nuttx/crc8.h> +#include <nuttx/kmalloc.h> +#include <nuttx/mtd/mtd.h> +#include <nuttx/mtd/configdata.h> + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +#define MIN(a, b) ((a) > (b) ? (b) : (a)) + +/* MASKS AND SHIFT FOR ADDRESSES + * an address in nvs is an uint32_t where: + * high 2 bytes represent the block number + * low 2 bytes represent the offset in a block + */ + +#define ADDR_BLOCK_MASK 0xFFFF0000 +#define ADDR_BLOCK_SHIFT 16 +#define ADDR_OFFS_MASK 0x0000FFFF + +/* we don't want to store all the read content in stack or heap, + * so we make a buffer to do compare or move. + */ + +#define NVS_BUFFER_SIZE 32 + +/* if data is written after last ate, and power loss happens, + * we need to find a clean offset by skipping dirty data. + * This macro defines how many bytes to skip when dirty data + * is spotted(may take several skips). + * Normally 1 byte is okay, such process only happens when + * nvs is started, and it is acceptable to take some time during + * starting. + */ + +#define NVS_CORRUPT_DATA_SKIP_STEP 1 + +#define NVS_LOOKUP_CACHE_NO_ADDR 0xffffffff + +/* gc done or close ate has the id of 0xffffffff. + * We can tell if the ate is special by looking at its id. + */ + +#define NVS_SPECIAL_ATE_ID 0xffffffff + +/**************************************************************************** + * Private Types + ****************************************************************************/ + +/* Non-volatile Storage File system structure */ + +struct nvs_fs +{ + FAR struct mtd_dev_s *mtd; /* mtd device */ + struct mtd_geometry_s geo; + uint32_t ate_wra; /* next alloc table entry + * write address + */ + uint32_t data_wra; /* next data write address */ + uint32_t step_addr; /* for traverse */ + mutex_t nvs_lock; + +#if CONFIG_MTD_CONFIG_FAIL_SAFE_LOOKUP_CACHE_SIZE > 0 + uint32_t lookup_cache[CONFIG_MTD_CONFIG_FAIL_SAFE_LOOKUP_CACHE_SIZE]; +#endif +}; + +/* Allocation Table Entry */ + +begin_packed_struct struct nvs_ate +{ + uint32_t id; /* data id */ + uint16_t offset; /* data offset within block */ + uint16_t len; /* data len within block */ + uint16_t key_len; /* key string len */ + uint8_t part; /* part of a multipart data - future extension */ + uint8_t crc8; /* crc8 check of the ate entry */ + uint8_t expired; /* 0xFF-newest entry, others-old entry */ + uint8_t reserved[3]; /* for future extension */ +} end_packed_struct; + +/**************************************************************************** + * Private Function Prototypes + ****************************************************************************/ + +/* MTD NVS opeation api */ + +static int mtdconfig_open(FAR struct file *filep); +static int mtdconfig_close(FAR struct file *filep); +static ssize_t mtdconfig_read(FAR struct file *filep, FAR char *buffer, + size_t buflen); +static int mtdconfig_ioctl(FAR struct file *filep, int cmd, + unsigned long arg); +static int mtdconfig_poll(FAR struct file *filep, FAR struct pollfd *fds, + bool setup); + +/* NVS operations needed by lookup cache */ + +static int nvs_prev_ate(FAR struct nvs_fs *fs, FAR uint32_t *addr, + FAR struct nvs_ate *ate); +static int nvs_ate_valid(FAR struct nvs_fs *fs, + FAR const struct nvs_ate *entry); + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +static const struct file_operations g_mtdnvs_fops = +{ + mtdconfig_open, /* open */ + mtdconfig_close, /* close */ + mtdconfig_read, /* read */ + NULL, /* write */ + NULL, /* seek */ + mtdconfig_ioctl, /* ioctl */ + mtdconfig_poll /* poll */ +#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS + , NULL /* unlink */ +#endif +}; + +/**************************************************************************** + * Public Data + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: nvs_fnv_hash + ****************************************************************************/ + +static uint32_t nvs_fnv_hash(FAR const uint8_t *input, uint32_t len) +{ + uint32_t i = 0; + uint32_t hval = 2166136261; + + /* FNV-1 hash each octet in the buffer */ + + while (i++ < len) + { + /* multiply by the 32 bit FNV magic prime mod 2^32 */ + + hval *= 0x01000193; + + /* xor the bottom with the current octet */ + + hval ^= *input++; + } + + return hval; +} + +#if CONFIG_MTD_CONFIG_FAIL_SAFE_LOOKUP_CACHE_SIZE > 0 + +/**************************************************************************** + * Name: nvs_lookup_cache_pos + ****************************************************************************/ + +static inline size_t nvs_lookup_cache_pos(uint32_t id) +{ + return id % CONFIG_MTD_CONFIG_FAIL_SAFE_LOOKUP_CACHE_SIZE; +} + +/**************************************************************************** + * Name: nvs_lookup_cache_rebuild + ****************************************************************************/ + +static int nvs_lookup_cache_rebuild(FAR struct nvs_fs *fs) +{ + int rc; + uint32_t addr; + uint32_t ate_addr; + FAR uint32_t *cache_entry; + struct nvs_ate ate; + int i; + + for (i < 0; i < CONFIG_MTD_CONFIG_FAIL_SAFE_LOOKUP_CACHE_SIZE; i++) + { + fs->lookup_cache[i] = NVS_LOOKUP_CACHE_NO_ADDR; + } + + addr = fs->ate_wra; + + do + { + /* Make a copy of 'addr' as it will be advanced by nvs_prev_ate() */ + + ate_addr = addr; + rc = nvs_prev_ate(fs, &addr, &ate); + if (rc) + { + return rc; + } + + cache_entry = &fs->lookup_cache[nvs_lookup_cache_pos(ate.id)]; + + if (ate.id != NVS_SPECIAL_ATE_ID + && *cache_entry == NVS_LOOKUP_CACHE_NO_ADDR + && nvs_ate_valid(fs, &ate)) Review Comment: delete cache -- This is an automated message from the Apache Git Service. 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