ExhaustibleBlockDevice.h

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2017 ARM Limited
00003  *
00004  * Permission is hereby granted, free of charge, to any person obtaining a copy
00005  * of this software and associated documentation files (the "Software"), to deal
00006  * in the Software without restriction, including without limitation the rights
00007  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00008  * copies of the Software, and to permit persons to whom the Software is
00009  * furnished to do so, subject to the following conditions:
00010  *
00011  * The above copyright notice and this permission notice shall be included in
00012  * all copies or substantial portions of the Software.
00013  *
00014  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00015  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00016  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00017  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00018  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00019  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
00020  * SOFTWARE.
00021  */
00022 #ifndef MBED_EXHAUSTIBLE_BLOCK_DEVICE_H
00023 #define MBED_EXHAUSTIBLE_BLOCK_DEVICE_H
00024 
00025 #include "BlockDevice.h"
00026 
00027 
00028 /** Heap backed block device which simulates failures
00029  *
00030  * Similar to heap block device but sectors wear out and are no longer programmable
00031  * after a configurable number of cycles.
00032  *
00033  */
00034 class ExhaustibleBlockDevice : public BlockDevice
00035 {
00036 public:
00037     /** Lifetime of the block device
00038      *
00039      * @param bd            Block device to back the ExhaustibleBlockDevice
00040      * @param erase_cycles  Number of erase cycles before failure
00041      */
00042     ExhaustibleBlockDevice(BlockDevice *bd, uint32_t erase_cycles);
00043     virtual ~ExhaustibleBlockDevice();
00044 
00045     /**
00046      * Get the number of erase cycles remaining on a block
00047      *
00048      * @param addr      Any address in the block being queried for erase cycles
00049      * @return          Number of erase cycles remaining
00050      */
00051     uint32_t get_erase_cycles(bd_addr_t addr) const;
00052 
00053     /**
00054      * Set the number of erase cycles before failure
00055      *
00056      * @param addr      Any address in the block being queried for erase cycles
00057      * @param cycles    Erase cycles before the block malfunctions
00058      */
00059     void set_erase_cycles(bd_addr_t addr, uint32_t cycles);
00060 
00061     /** Initialize a block device
00062      *
00063      *  @return         0 on success or a negative error code on failure
00064      */
00065     virtual int init();
00066 
00067     /** Deinitialize a block device
00068      *
00069      *  @return         0 on success or a negative error code on failure
00070      */
00071     virtual int deinit();
00072 
00073     /** Ensure data on storage is in sync with the driver
00074      *
00075      *  @return         0 on success or a negative error code on failure
00076      */
00077     virtual int sync();
00078 
00079     /** Read blocks from a block device
00080      *
00081      *  @param buffer   Buffer to read blocks into
00082      *  @param addr     Address of block to begin reading from
00083      *  @param size     Size to read in bytes, must be a multiple of read block size
00084      *  @return         0 on success, negative error code on failure
00085      */
00086     virtual int read(void *buffer, bd_addr_t addr, bd_size_t size);
00087 
00088     /** Program blocks to a block device
00089      *
00090      *  The blocks must have been erased prior to being programmed
00091      *
00092      *  @param buffer   Buffer of data to write to blocks
00093      *  @param addr     Address of block to begin writing to
00094      *  @param size     Size to write in bytes, must be a multiple of program block size
00095      *  @return         0 on success, negative error code on failure
00096      */
00097     virtual int program(const void *buffer, bd_addr_t addr, bd_size_t size);
00098 
00099     /** Erase blocks on a block device
00100      *
00101      *  The state of an erased block is undefined until it has been programmed,
00102      *  unless get_erase_value returns a non-negative byte value
00103      *
00104      *  @param addr     Address of block to begin erasing
00105      *  @param size     Size to erase in bytes, must be a multiple of erase block size
00106      *  @return         0 on success, negative error code on failure
00107      */
00108     virtual int erase(bd_addr_t addr, bd_size_t size);
00109 
00110     /** Get the size of a readable block
00111      *
00112      *  @return         Size of a readable block in bytes
00113      */
00114     virtual bd_size_t get_read_size() const;
00115 
00116     /** Get the size of a programmable block
00117      *
00118      *  @return         Size of a programmable block in bytes
00119      */
00120     virtual bd_size_t get_program_size() const;
00121 
00122     /** Get the size of an erasable block
00123      *
00124      *  @return         Size of an erasable block in bytes
00125      */
00126     virtual bd_size_t get_erase_size() const;
00127 
00128     /** Get the size of an erasable block given address
00129      *
00130      *  @param addr     Address within the erasable block
00131      *  @return         Size of an erasable block in bytes
00132      *  @note Must be a multiple of the program size
00133      */
00134     virtual bd_size_t get_erase_size(bd_addr_t addr) const;
00135 
00136     /** Get the value of storage when erased
00137      *
00138      *  If get_erase_value returns a non-negative byte value, the underlying
00139      *  storage is set to that value when erased, and storage containing
00140      *  that value can be programmed without another erase.
00141      *
00142      *  @return         The value of storage when erased, or -1 if you can't
00143      *                  rely on the value of erased storage
00144      */
00145     virtual int get_erase_value() const;
00146 
00147     /** Get the total size of the underlying device
00148      *
00149      *  @return         Size of the underlying device in bytes
00150      */
00151     virtual bd_size_t size() const;
00152 
00153 private:
00154     BlockDevice *_bd;
00155     uint32_t *_erase_array;
00156     uint32_t _erase_cycles;
00157     uint32_t _init_ref_count;
00158     bool _is_initialized;
00159 };
00160 
00161 
00162 #endif