src/mem/port_proxy.hh

   1 /*
   2  * Copyright (c) 2011-2013, 2018 ARM Limited
   3  * All rights reserved
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   5  * The license below extends only to copyright in the software and shall
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  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
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  23  * this software without specific prior written permission.
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  35  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38 /**
  39  * @file
  40  * PortProxy Object Declaration.
  41  *
  42  * Port proxies are used when non-structural entities need access to
  43  * the memory system (or structural entities that want to peak into
  44  * the memory system without making a real memory access).
  45  *
  46  * Proxy objects replace the previous FunctionalPort, TranslatingPort
  47  * and VirtualPort objects, which provided the same functionality as
  48  * the proxies, but were instances of ports not corresponding to real
  49  * structural ports of the simulated system. Via the port proxies all
  50  * the accesses go through an actual port (either the system port,
  51  * e.g. for processes or initialisation, or a the data port of the
  52  * CPU, e.g. for threads) and thus are transparent to a potentially
  53  * distributed memory and automatically adhere to the memory map of
  54  * the system.
  55  */
  56
  57 #ifndef __MEM_PORT_PROXY_HH__
  58 #define __MEM_PORT_PROXY_HH__
  59
  60 #include <functional>
  61 #include <limits>
  62
  63 #include "mem/port.hh"
  64 #include "sim/byteswap.hh"
  65
  66 /**
  67  * This object is a proxy for a port or other object which implements the
  68  * functional response protocol, to be used for debug accesses.
  69  *
  70  * This proxy object is used when non structural entities
  71  * (e.g. thread contexts, object file loaders) need access to the
  72  * memory system. It calls the corresponding functions on the underlying
  73  * protocol, and provides templatized convenience access functions.
  74  *
  75  * The addresses are interpreted as physical addresses.
  76  *
  77  * @sa SETranslatingProxy
  78  * @sa FSTranslatingProxy
  79  */
  80 class PortProxy : FunctionalRequestProtocol
  81 {
  82   public:
  83     typedef std::function<void(PacketPtr pkt)> SendFunctionalFunc;
  84
  85   private:
  86     SendFunctionalFunc sendFunctional;
  87
  88     /** Granularity of any transactions issued through this proxy. */
  89     const unsigned int _cacheLineSize;
  90
  91     void
  92     recvFunctionalSnoop(PacketPtr pkt) override
  93     {
  94         // Since port proxies aren't anyone else's peer, they should never
  95         // receive snoops.
  96         panic("Port proxies should never receive snoops.");
  97     }
  98
  99   public:
 100     PortProxy(SendFunctionalFunc func, unsigned int cacheLineSize) :
 101         sendFunctional(func), _cacheLineSize(cacheLineSize)
 102     {}
 103     PortProxy(const RequestPort &port, unsigned int cacheLineSize) :
 104         sendFunctional([&port](PacketPtr pkt)->void {
 105                 port.sendFunctional(pkt);
 106             }), _cacheLineSize(cacheLineSize)
 107     {}
 108     virtual ~PortProxy() { }
 109
 110
 111
 112     /** Fixed functionality for use in base classes. */
 113
 114     /**
 115      * Read size bytes memory at physical address and store in p.
 116      */
 117     void readBlobPhys(Addr addr, Request::Flags flags,
 118                       void *p, int size) const;
 119
 120     /**
 121      * Write size bytes from p to physical address.
 122      */
 123     void writeBlobPhys(Addr addr, Request::Flags flags,
 124                        const void *p, int size) const;
 125
 126     /**
 127      * Fill size bytes starting at physical addr with byte value val.
 128      */
 129     void memsetBlobPhys(Addr addr, Request::Flags flags,
 130                         uint8_t v, int size) const;
 131
 132
 133
 134     /** Methods to override in base classes */
 135
 136     /**
 137      * Read size bytes memory at address and store in p.
 138      * Returns true on success and false on failure.
 139      */
 140     virtual bool
 141     tryReadBlob(Addr addr, void *p, int size) const
 142     {
 143         readBlobPhys(addr, 0, p, size);
 144         return true;
 145     }
 146
 147     /**
 148      * Write size bytes from p to address.
 149      * Returns true on success and false on failure.
 150      */
 151     virtual bool
 152     tryWriteBlob(Addr addr, const void *p, int size) const
 153     {
 154         writeBlobPhys(addr, 0, p, size);
 155         return true;
 156     }
 157
 158     /**
 159      * Fill size bytes starting at addr with byte value val.
 160      * Returns true on success and false on failure.
 161      */
 162     virtual bool
 163     tryMemsetBlob(Addr addr, uint8_t val, int size) const
 164     {
 165         memsetBlobPhys(addr, 0, val, size);
 166         return true;
 167     }
 168
 169
 170
 171     /** Higher level interfaces based on the above. */
 172
 173     /**
 174      * Same as tryReadBlob, but insists on success.
 175      */
 176     void
 177     readBlob(Addr addr, void *p, int size) const
 178     {
 179         if (!tryReadBlob(addr, p, size))
 180             fatal("readBlob(%#x, ...) failed", addr);
 181     }
 182
 183     /**
 184      * Same as tryWriteBlob, but insists on success.
 185      */
 186     void
 187     writeBlob(Addr addr, const void *p, int size) const
 188     {
 189         if (!tryWriteBlob(addr, p, size))
 190             fatal("writeBlob(%#x, ...) failed", addr);
 191     }
 192
 193     /**
 194      * Same as tryMemsetBlob, but insists on success.
 195      */
 196     void
 197     memsetBlob(Addr addr, uint8_t v, int size) const
 198     {
 199         if (!tryMemsetBlob(addr, v, size))
 200             fatal("memsetBlob(%#x, ...) failed", addr);
 201     }
 202
 203     /**
 204      * Read sizeof(T) bytes from address and return as object T.
 205      */
 206     template <typename T>
 207     T read(Addr address) const;
 208
 209     /**
 210      * Write object T to address. Writes sizeof(T) bytes.
 211      */
 212     template <typename T>
 213     void write(Addr address, const T &data) const;
 214
 215     /**
 216      * Read sizeof(T) bytes from address and return as object T.
 217      * Performs endianness conversion from the selected guest to host order.
 218      */
 219     template <typename T>
 220     T read(Addr address, ByteOrder guest_byte_order) const;
 221
 222     /**
 223      * Write object T to address. Writes sizeof(T) bytes.
 224      * Performs endianness conversion from host to the selected guest order.
 225      */
 226     template <typename T>
 227     void write(Addr address, T data, ByteOrder guest_byte_order) const;
 228
 229     /**
 230      * Write the string str into guest memory at address addr.
 231      * Returns true on success and false on failure.
 232      */
 233     bool tryWriteString(Addr addr, const char *str) const;
 234
 235     /**
 236      * Same as tryWriteString, but insists on success.
 237      */
 238     void
 239     writeString(Addr addr, const char *str) const
 240     {
 241         if (!tryWriteString(addr, str))
 242             fatal("writeString(%#x, ...) failed", addr);
 243     }
 244
 245     /**
 246      * Reads the string at guest address addr into the std::string str.
 247      * Returns true on success and false on failure.
 248      */
 249     bool tryReadString(std::string &str, Addr addr) const;
 250
 251     /**
 252      * Same as tryReadString, but insists on success.
 253      */
 254     void
 255     readString(std::string &str, Addr addr) const
 256     {
 257         if (!tryReadString(str, addr))
 258             fatal("readString(%#x, ...) failed", addr);
 259     }
 260
 261     /**
 262      * Reads the string at guest address addr into the char * str, reading up
 263      * to maxlen characters. The last character read is always a nul
 264      * terminator. Returns true on success and false on failure.
 265      */
 266     bool tryReadString(char *str, Addr addr, size_t maxlen) const;
 267
 268     /**
 269      * Same as tryReadString, but insists on success.
 270      */
 271     void
 272     readString(char *str, Addr addr, size_t maxlen) const
 273     {
 274         if (!tryReadString(str, addr, maxlen))
 275             fatal("readString(%#x, ...) failed", addr);
 276     }
 277 };
 278
 279
 280 template <typename T>
 281 T
 282 PortProxy::read(Addr address) const
 283 {
 284     T data;
 285     readBlob(address, &data, sizeof(T));
 286     return data;
 287 }
 288
 289 template <typename T>
 290 void
 291 PortProxy::write(Addr address, const T &data) const
 292 {
 293     writeBlob(address, &data, sizeof(T));
 294 }
 295
 296 template <typename T>
 297 T
 298 PortProxy::read(Addr address, ByteOrder byte_order) const
 299 {
 300     T data;
 301     readBlob(address, &data, sizeof(T));
 302     return gtoh(data, byte_order);
 303 }
 304
 305 template <typename T>
 306 void
 307 PortProxy::write(Addr address, T data, ByteOrder byte_order) const
 308 {
 309     data = htog(data, byte_order);
 310     writeBlob(address, &data, sizeof(T));
 311 }
 312
 313 #endif // __MEM_PORT_PROXY_HH__