src/dev/arm/flash_device.hh

   1 /*
   2  * Copyright (c) 2013-2015 ARM Limited
   3  * All rights reserved
   4  *
   5  * The license below extends only to copyright in the software and shall
   6  * not be construed as granting a license to any other intellectual
   7  * property including but not limited to intellectual property relating
   8  * to a hardware implementation of the functionality of the software
   9  * licensed hereunder.  You may use the software subject to the license
  10  * terms below provided that you ensure that this notice is replicated
  11  * unmodified and in its entirety in all distributions of the software,
  12  * modified or unmodified, in source code or in binary form.
  13  *
  14  * Redistribution and use in source and binary forms, with or without
  15  * modification, are permitted provided that the following conditions are
  16  * met: redistributions of source code must retain the above copyright
  17  * notice, this list of conditions and the following disclaimer;
  18  * redistributions in binary form must reproduce the above copyright
  19  * notice, this list of conditions and the following disclaimer in the
  20  * documentation and/or other materials provided with the distribution;
  21  * neither the name of the copyright holders nor the names of its
  22  * contributors may be used to endorse or promote products derived from
  23  * this software without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  26  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  27  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  28  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  29  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  30  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  31  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  32  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  35  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  *
  37  * Authors: Rene de Jong
  38  */
  39 #ifndef __DEV_ARM_FLASH_DEVICE_HH__
  40 #define __DEV_ARM_FLASH_DEVICE_HH__
  41
  42 #include <deque>
  43
  44 #include "base/statistics.hh"
  45 #include "debug/FlashDevice.hh"
  46 #include "dev/arm/abstract_nvm.hh"
  47 #include "enums/DataDistribution.hh"
  48 #include "params/FlashDevice.hh"
  49 #include "sim/serialize.hh"
  50
  51 /**
  52  * Flash Device model
  53  * The Flash Device model is a timing model for a NAND flash device.
  54  * It doesn't tranfer any data
  55  */
  56 class FlashDevice : public AbstractNVM
  57 {
  58   public:
  59
  60     /** Initialize functions*/
  61     FlashDevice(const FlashDeviceParams*);
  62     ~FlashDevice();
  63
  64     /** Checkpoint functions*/
  65     DrainState drain() override;
  66     void checkDrain();
  67
  68     void serialize(CheckpointOut &cp) const override;
  69     void unserialize(CheckpointIn &cp) override;
  70
  71   private:
  72     /** Defines the possible actions to the flash*/
  73     enum Actions {
  74         ActionRead,
  75         ActionWrite,
  76         ActionErase,
  77         /**
  78          * A copy involves taking all the used pages from a block and store
  79          *  it in another
  80          */
  81         ActionCopy
  82     };
  83
  84     /** Every logical address maps to a physical block and a physical page*/
  85     struct PageMapEntry {
  86         uint32_t page;
  87         uint32_t block;
  88     };
  89
  90     struct CallBackEntry {
  91         Tick time;
  92         Callback *function;
  93     };
  94
  95     struct FlashDeviceStats {
  96         /** Amount of GC activations*/
  97         Stats::Scalar totalGCActivations;
  98
  99         /** Histogram of address accesses*/
 100         Stats::Histogram writeAccess;
 101         Stats::Histogram readAccess;
 102         Stats::Histogram fileSystemAccess;
 103
 104         /** Histogram of access latencies*/
 105         Stats::Histogram writeLatency;
 106         Stats::Histogram readLatency;
 107     };
 108
 109     /** Device access functions Inherrited from AbstractNVM*/
 110     void initializeMemory(uint64_t disk_size, uint32_t sector_size) override
 111     {
 112         initializeFlash(disk_size, sector_size);
 113     }
 114
 115     void readMemory(uint64_t address, uint32_t amount,
 116                     Callback *event) override
 117     {
 118         accessDevice(address, amount, event, ActionRead);
 119     }
 120
 121     void writeMemory(uint64_t address, uint32_t amount,
 122                      Callback *event) override
 123     {
 124         accessDevice(address, amount, event, ActionWrite);
 125     }
 126
 127     /**Initialization function; called when all disk specifics are known*/
 128     void initializeFlash(uint64_t disk_size, uint32_t sector_size);
 129
 130     /**Flash action function*/
 131     void accessDevice(uint64_t address, uint32_t amount, Callback *event,
 132                       Actions action);
 133
 134     /** Event rescheduler*/
 135     void actionComplete();
 136
 137     /** FTL functionality */
 138     Tick remap(uint64_t logic_page_addr);
 139
 140     /** Access time calculator*/
 141     Tick accessTimes(uint64_t address, Actions accesstype);
 142
 143     /** Function to indicate that a page is known*/
 144     void clearUnknownPages(uint32_t index);
 145
 146     /** Function to test if a page is known*/
 147     bool getUnknownPages(uint32_t index);
 148
 149     /**Stats register function*/
 150     void regStats() override;
 151
 152     /** Disk sizes in bytes */
 153     uint64_t diskSize;
 154     const uint32_t blockSize;
 155     const uint32_t pageSize;
 156
 157     /** Garbage collection algorithm emulator */
 158     const uint32_t GCActivePercentage;
 159
 160     /** Access latencies */
 161     const Tick readLatency;
 162     const Tick writeLatency;
 163     const Tick eraseLatency;
 164
 165     /** Flash organization */
 166     const Enums::DataDistribution dataDistribution;
 167     const uint32_t numPlanes;
 168
 169     /** RequestHandler stats */
 170     struct FlashDeviceStats stats;
 171
 172     /** Disk dimensions in pages and blocks */
 173     uint32_t pagesPerBlock;
 174     uint32_t pagesPerDisk;
 175     uint32_t blocksPerDisk;
 176
 177     uint32_t planeMask;
 178
 179     /**
 180      * when the disk is first started we are unsure of the number of
 181      * used pages, this variable will help determining what we do know.
 182      */
 183     std::vector<uint32_t> unknownPages;
 184     /** address to logic place has a block and a page field*/
 185     std::vector<struct PageMapEntry> locationTable;
 186     /** number of valid entries per block*/
 187     std::vector<uint32_t> blockValidEntries;
 188     /** number of empty entries*/
 189     std::vector<uint32_t> blockEmptyEntries;
 190
 191     /**This vector of queues keeps track of all the callbacks per plane*/
 192     std::vector<std::deque<struct CallBackEntry> > planeEventQueue;
 193
 194     /** Completion event */
 195     EventFunctionWrapper planeEvent;
 196 };
 197 #endif //__DEV_ARM_FLASH_DEVICE_HH__