src/mem/page_table.hh

   1 /*
   2  * Copyright (c) 2014 Advanced Micro Devices, Inc.
   3  * Copyright (c) 2003 The Regents of The University of Michigan
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions are
   8  * met: redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer;
  10  * redistributions in binary form must reproduce the above copyright
  11  * notice, this list of conditions and the following disclaimer in the
  12  * documentation and/or other materials provided with the distribution;
  13  * neither the name of the copyright holders nor the names of its
  14  * contributors may be used to endorse or promote products derived from
  15  * this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  18  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  19  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  20  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  21  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  22  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  23  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  27  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  */
  29
  30 /**
  31  * @file
  32  * Declarations of a non-full system Page Table.
  33  */
  34
  35 #ifndef __MEM_PAGE_TABLE_HH__
  36 #define __MEM_PAGE_TABLE_HH__
  37
  38 #include <string>
  39 #include <unordered_map>
  40
  41 #include "base/bitfield.hh"
  42 #include "base/intmath.hh"
  43 #include "base/types.hh"
  44 #include "mem/request.hh"
  45 #include "sim/serialize.hh"
  46
  47 class ThreadContext;
  48
  49 class EmulationPageTable : public Serializable
  50 {
  51   public:
  52     struct Entry
  53     {
  54         Addr paddr;
  55         uint64_t flags;
  56
  57         Entry(Addr paddr, uint64_t flags) : paddr(paddr), flags(flags) {}
  58         Entry() {}
  59     };
  60
  61   protected:
  62     typedef std::unordered_map<Addr, Entry> PTable;
  63     typedef PTable::iterator PTableItr;
  64     PTable pTable;
  65
  66     const Addr _pageSize;
  67     const Addr offsetMask;
  68
  69     const uint64_t _pid;
  70     const std::string _name;
  71
  72   public:
  73
  74     EmulationPageTable(
  75             const std::string &__name, uint64_t _pid, Addr _pageSize) :
  76             _pageSize(_pageSize), offsetMask(mask(floorLog2(_pageSize))),
  77             _pid(_pid), _name(__name), shared(false)
  78     {
  79         assert(isPowerOf2(_pageSize));
  80     }
  81
  82     uint64_t pid() const { return _pid; };
  83
  84     virtual ~EmulationPageTable() {};
  85
  86     /* generic page table mapping flags
  87      *              unset | set
  88      * bit 0 - no-clobber | clobber
  89      * bit 2 - cacheable  | uncacheable
  90      * bit 3 - read-write | read-only
  91      */
  92     enum MappingFlags : uint32_t {
  93         Clobber     = 1,
  94         Uncacheable = 4,
  95         ReadOnly    = 8,
  96     };
  97
  98     // flag which marks the page table as shared among software threads
  99     bool shared;
 100
 101     virtual void initState() {};
 102
 103     // for DPRINTF compatibility
 104     const std::string name() const { return _name; }
 105
 106     Addr pageAlign(Addr a)  { return (a & ~offsetMask); }
 107     Addr pageOffset(Addr a) { return (a &  offsetMask); }
 108     // Page size can technically vary based on the virtual address, but we'll
 109     // ignore that for now.
 110     Addr pageSize()   { return _pageSize; }
 111
 112     /**
 113      * Maps a virtual memory region to a physical memory region.
 114      * @param vaddr The starting virtual address of the region.
 115      * @param paddr The starting physical address where the region is mapped.
 116      * @param size The length of the region.
 117      * @param flags Generic mapping flags that can be set by or-ing values
 118      *              from MappingFlags enum.
 119      */
 120     virtual void map(Addr vaddr, Addr paddr, int64_t size, uint64_t flags = 0);
 121     virtual void remap(Addr vaddr, int64_t size, Addr new_vaddr);
 122     virtual void unmap(Addr vaddr, int64_t size);
 123
 124     /**
 125      * Check if any pages in a region are already allocated
 126      * @param vaddr The starting virtual address of the region.
 127      * @param size The length of the region.
 128      * @return True if no pages in the region are mapped.
 129      */
 130     virtual bool isUnmapped(Addr vaddr, int64_t size);
 131
 132     /**
 133      * Lookup function
 134      * @param vaddr The virtual address.
 135      * @return The page table entry corresponding to vaddr.
 136      */
 137     const Entry *lookup(Addr vaddr);
 138
 139     /**
 140      * Translate function
 141      * @param vaddr The virtual address.
 142      * @param paddr Physical address from translation.
 143      * @return True if translation exists
 144      */
 145     bool translate(Addr vaddr, Addr &paddr);
 146
 147     /**
 148      * Simplified translate function (just check for translation)
 149      * @param vaddr The virtual address.
 150      * @return True if translation exists
 151      */
 152     bool translate(Addr vaddr) { Addr dummy; return translate(vaddr, dummy); }
 153
 154     /**
 155      * Perform a translation on the memory request, fills in paddr
 156      * field of req.
 157      * @param req The memory request.
 158      */
 159     Fault translate(const RequestPtr &req);
 160
 161     void getMappings(std::vector<std::pair<Addr, Addr>> *addr_mappings);
 162
 163     void serialize(CheckpointOut &cp) const override;
 164     void unserialize(CheckpointIn &cp) override;
 165 };
 166
 167 #endif // __MEM_PAGE_TABLE_HH__