src/mem/request.hh

   1 /*
   2  * Copyright (c) 2012 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  * Copyright (c) 2002-2005 The Regents of The University of Michigan
  15  * All rights reserved.
  16  *
  17  * Redistribution and use in source and binary forms, with or without
  18  * modification, are permitted provided that the following conditions are
  19  * met: redistributions of source code must retain the above copyright
  20  * notice, this list of conditions and the following disclaimer;
  21  * redistributions in binary form must reproduce the above copyright
  22  * notice, this list of conditions and the following disclaimer in the
  23  * documentation and/or other materials provided with the distribution;
  24  * neither the name of the copyright holders nor the names of its
  25  * contributors may be used to endorse or promote products derived from
  26  * this software without specific prior written permission.
  27  *
  28  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  29  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  30  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  31  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  32  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  33  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  34  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  35  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  36  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  37  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  38  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  39  *
  40  * Authors: Ron Dreslinski
  41  *          Steve Reinhardt
  42  *          Ali Saidi
  43  */
  44
  45 /**
  46  * @file
  47  * Declaration of a request, the overall memory request consisting of
  48  the parts of the request that are persistent throughout the transaction.
  49  */
  50
  51 #ifndef __MEM_REQUEST_HH__
  52 #define __MEM_REQUEST_HH__
  53
  54 #include <cassert>
  55 #include <climits>
  56
  57 #include "base/flags.hh"
  58 #include "base/misc.hh"
  59 #include "base/types.hh"
  60 #include "sim/core.hh"
  61
  62 /**
  63  * Special TaskIds that are used for per-context-switch stats dumps
  64  * and Cache Occupancy. Having too many tasks seems to be a problem
  65  * with vector stats. 1024 seems to be a reasonable number that
  66  * doesn't cause a problem with stats and is large enough to realistic
  67  * benchmarks (Linux/Android boot, BBench, etc.)
  68  */
  69
  70 namespace ContextSwitchTaskId {
  71     enum TaskId {
  72         MaxNormalTaskId = 1021, /* Maximum number of normal tasks */
  73         Prefetcher = 1022, /* For cache lines brought in by prefetcher */
  74         DMA = 1023, /* Mostly Table Walker */
  75         Unknown = 1024,
  76         NumTaskId
  77     };
  78 }
  79
  80 class Request;
  81
  82 typedef Request* RequestPtr;
  83 typedef uint16_t MasterID;
  84
  85 class Request
  86 {
  87   public:
  88     typedef uint32_t FlagsType;
  89     typedef ::Flags<FlagsType> Flags;
  90
  91     /** ASI information for this request if it exists. */
  92     static const FlagsType ASI_BITS                    = 0x000000FF;
  93     /** The request was an instruction fetch. */
  94     static const FlagsType INST_FETCH                  = 0x00000100;
  95     /** The virtual address is also the physical address. */
  96     static const FlagsType PHYSICAL                    = 0x00000200;
  97     /** The request is an ALPHA VPTE pal access (hw_ld). */
  98     static const FlagsType VPTE                        = 0x00000400;
  99     /** Use the alternate mode bits in ALPHA. */
 100     static const FlagsType ALTMODE                     = 0x00000800;
 101     /** The request is to an uncacheable address. */
 102     static const FlagsType UNCACHEABLE                 = 0x00001000;
 103     /** This request is to a memory mapped register. */
 104     static const FlagsType MMAPPED_IPR                  = 0x00002000;
 105     /** This request is a clear exclusive. */
 106     static const FlagsType CLEAR_LL                    = 0x00004000;
 107
 108     /** The request should not cause a memory access. */
 109     static const FlagsType NO_ACCESS                   = 0x00080000;
 110     /** This request will lock or unlock the accessed memory. When used with
 111      * a load, the access locks the particular chunk of memory. When used
 112      * with a store, it unlocks. The rule is that locked accesses have to be
 113      * made up of a locked load, some operation on the data, and then a locked
 114      * store.
 115      */
 116     static const FlagsType LOCKED                      = 0x00100000;
 117     /** The request is a Load locked/store conditional. */
 118     static const FlagsType LLSC                        = 0x00200000;
 119     /** This request is for a memory swap. */
 120     static const FlagsType MEM_SWAP                    = 0x00400000;
 121     static const FlagsType MEM_SWAP_COND               = 0x00800000;
 122
 123     /** The request is a prefetch. */
 124     static const FlagsType PREFETCH                    = 0x01000000;
 125     /** The request should be prefetched into the exclusive state. */
 126     static const FlagsType PF_EXCLUSIVE                = 0x02000000;
 127     /** The request should be marked as LRU. */
 128     static const FlagsType EVICT_NEXT                  = 0x04000000;
 129
 130     /** These flags are *not* cleared when a Request object is reused
 131        (assigned a new address). */
 132     static const FlagsType STICKY_FLAGS = INST_FETCH;
 133
 134     /** Request Ids that are statically allocated
 135      * @{*/
 136     /** This request id is used for writeback requests by the caches */
 137     static const MasterID wbMasterId = 0;
 138     /** This request id is used for functional requests that don't come from a
 139      * particular device
 140      */
 141     static const MasterID funcMasterId = 1;
 142     /** This request id is used for message signaled interrupts */
 143     static const MasterID intMasterId = 2;
 144     /** Invalid request id for assertion checking only. It is invalid behavior
 145      * to ever send this id as part of a request.
 146      * @todo C++1x replace with numeric_limits when constexpr is added  */
 147     static const MasterID invldMasterId = USHRT_MAX;
 148     /** @} */
 149
 150     /** Invalid or unknown Pid. Possible when operating system is not present
 151      *  or has not assigned a pid yet */
 152     static const uint32_t invldPid = UINT_MAX;
 153
 154   private:
 155     typedef uint8_t PrivateFlagsType;
 156     typedef ::Flags<PrivateFlagsType> PrivateFlags;
 157
 158     /** Whether or not the size is valid. */
 159     static const PrivateFlagsType VALID_SIZE           = 0x00000001;
 160     /** Whether or not paddr is valid (has been written yet). */
 161     static const PrivateFlagsType VALID_PADDR          = 0x00000002;
 162     /** Whether or not the vaddr & asid are valid. */
 163     static const PrivateFlagsType VALID_VADDR          = 0x00000004;
 164     /** Whether or not the pc is valid. */
 165     static const PrivateFlagsType VALID_PC             = 0x00000010;
 166     /** Whether or not the context ID is valid. */
 167     static const PrivateFlagsType VALID_CONTEXT_ID     = 0x00000020;
 168     static const PrivateFlagsType VALID_THREAD_ID      = 0x00000040;
 169     /** Whether or not the sc result is valid. */
 170     static const PrivateFlagsType VALID_EXTRA_DATA     = 0x00000080;
 171
 172     /** These flags are *not* cleared when a Request object is reused
 173        (assigned a new address). */
 174     static const PrivateFlagsType STICKY_PRIVATE_FLAGS =
 175         VALID_CONTEXT_ID | VALID_THREAD_ID;
 176
 177   private:
 178     /**
 179      * The physical address of the request. Valid only if validPaddr
 180      * is set.
 181      */
 182     Addr _paddr;
 183
 184     /**
 185      * The size of the request. This field must be set when vaddr or
 186      * paddr is written via setVirt() or setPhys(), so it is always
 187      * valid as long as one of the address fields is valid.
 188      */
 189     int _size;
 190
 191     /** The requestor ID which is unique in the system for all ports
 192      * that are capable of issuing a transaction
 193      */
 194     MasterID _masterId;
 195
 196     /** Flag structure for the request. */
 197     Flags _flags;
 198
 199     /** Private flags for field validity checking. */
 200     PrivateFlags privateFlags;
 201
 202     /**
 203      * The time this request was started. Used to calculate
 204      * latencies. This field is set to curTick() any time paddr or vaddr
 205      * is written.
 206      */
 207     Tick _time;
 208
 209     /** The address space ID. */
 210     int _asid;
 211
 212     /** The virtual address of the request. */
 213     Addr _vaddr;
 214
 215     /**
 216      * Extra data for the request, such as the return value of
 217      * store conditional or the compare value for a CAS. */
 218     uint64_t _extraData;
 219
 220     /** The context ID (for statistics, typically). */
 221     int _contextId;
 222     /** The thread ID (id within this CPU) */
 223     int _threadId;
 224
 225     /** program counter of initiating access; for tracing/debugging */
 226     Addr _pc;
 227
 228   public:
 229     /** Minimal constructor.  No fields are initialized.
 230      *  (Note that _flags and privateFlags are cleared by Flags
 231      *  default constructor.)
 232      */
 233     Request()
 234     {}
 235
 236     /**
 237      * Constructor for physical (e.g. device) requests.  Initializes
 238      * just physical address, size, flags, and timestamp (to curTick()).
 239      * These fields are adequate to perform a request.
 240      */
 241     Request(Addr paddr, int size, Flags flags, MasterID mid)
 242     {
 243         setPhys(paddr, size, flags, mid);
 244     }
 245
 246     Request(Addr paddr, int size, Flags flags, MasterID mid, Tick time)
 247     {
 248         setPhys(paddr, size, flags, mid, time);
 249     }
 250
 251     Request(Addr paddr, int size, Flags flags, MasterID mid, Tick time, Addr pc)
 252     {
 253         setPhys(paddr, size, flags, mid, time);
 254         privateFlags.set(VALID_PC);
 255         _pc = pc;
 256     }
 257
 258     Request(int asid, Addr vaddr, int size, Flags flags, MasterID mid, Addr pc,
 259             int cid, ThreadID tid)
 260     {
 261         setVirt(asid, vaddr, size, flags, mid, pc);
 262         setThreadContext(cid, tid);
 263     }
 264
 265     ~Request() {}
 266
 267     /**
 268      * Set up CPU and thread numbers.
 269      */
 270     void
 271     setThreadContext(int context_id, ThreadID tid)
 272     {
 273         _contextId = context_id;
 274         _threadId = tid;
 275         privateFlags.set(VALID_CONTEXT_ID|VALID_THREAD_ID);
 276     }
 277
 278     /**
 279      * Set up a physical (e.g. device) request in a previously
 280      * allocated Request object.
 281      */
 282     void
 283     setPhys(Addr paddr, int size, Flags flags, MasterID mid, Tick time)
 284     {
 285         assert(size >= 0);
 286         _paddr = paddr;
 287         _size = size;
 288         _time = time;
 289         _masterId = mid;
 290         _flags.clear(~STICKY_FLAGS);
 291         _flags.set(flags);
 292         privateFlags.clear(~STICKY_PRIVATE_FLAGS);
 293         privateFlags.set(VALID_PADDR|VALID_SIZE);
 294     }
 295
 296     void
 297     setPhys(Addr paddr, int size, Flags flags, MasterID mid)
 298     {
 299         setPhys(paddr, size, flags, mid, curTick());
 300     }
 301
 302     /**
 303      * Set up a virtual (e.g., CPU) request in a previously
 304      * allocated Request object.
 305      */
 306     void
 307     setVirt(int asid, Addr vaddr, int size, Flags flags, MasterID mid, Addr pc)
 308     {
 309         assert(size >= 0);
 310         _asid = asid;
 311         _vaddr = vaddr;
 312         _size = size;
 313         _masterId = mid;
 314         _pc = pc;
 315         _time = curTick();
 316
 317         _flags.clear(~STICKY_FLAGS);
 318         _flags.set(flags);
 319         privateFlags.clear(~STICKY_PRIVATE_FLAGS);
 320         privateFlags.set(VALID_VADDR|VALID_SIZE|VALID_PC);
 321     }
 322
 323     /**
 324      * Set just the physical address.  This should only be used to
 325      * record the result of a translation, and thus the vaddr must be
 326      * valid before this method is called.  Otherwise, use setPhys()
 327      * to guarantee that the size and flags are also set.
 328      */
 329     void
 330     setPaddr(Addr paddr)
 331     {
 332         assert(privateFlags.isSet(VALID_VADDR));
 333         _paddr = paddr;
 334         privateFlags.set(VALID_PADDR);
 335     }
 336
 337     /**
 338      * Generate two requests as if this request had been split into two
 339      * pieces. The original request can't have been translated already.
 340      */
 341     void splitOnVaddr(Addr split_addr, RequestPtr &req1, RequestPtr &req2)
 342     {
 343         assert(privateFlags.isSet(VALID_VADDR));
 344         assert(privateFlags.noneSet(VALID_PADDR));
 345         assert(split_addr > _vaddr && split_addr < _vaddr + _size);
 346         req1 = new Request;
 347         *req1 = *this;
 348         req2 = new Request;
 349         *req2 = *this;
 350         req1->_size = split_addr - _vaddr;
 351         req2->_vaddr = split_addr;
 352         req2->_size = _size - req1->_size;
 353     }
 354
 355     /**
 356      * Accessor for paddr.
 357      */
 358     bool
 359     hasPaddr()
 360     {
 361         return privateFlags.isSet(VALID_PADDR);
 362     }
 363
 364     Addr
 365     getPaddr()
 366     {
 367         assert(privateFlags.isSet(VALID_PADDR));
 368         return _paddr;
 369     }
 370
 371     /**
 372      *  Accessor for size.
 373      */
 374     bool
 375     hasSize()
 376     {
 377         return privateFlags.isSet(VALID_SIZE);
 378     }
 379
 380     int
 381     getSize()
 382     {
 383         assert(privateFlags.isSet(VALID_SIZE));
 384         return _size;
 385     }
 386
 387     /** Accessor for time. */
 388     Tick
 389     time() const
 390     {
 391         assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
 392         return _time;
 393     }
 394
 395     void
 396     time(Tick time)
 397     {
 398         assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
 399         _time = time;
 400     }
 401
 402     /** Accessor for flags. */
 403     Flags
 404     getFlags()
 405     {
 406         assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
 407         return _flags;
 408     }
 409
 410     /** Note that unlike other accessors, this function sets *specific
 411        flags* (ORs them in); it does not assign its argument to the
 412        _flags field.  Thus this method should rightly be called
 413        setFlags() and not just flags(). */
 414     void
 415     setFlags(Flags flags)
 416     {
 417         assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
 418         _flags.set(flags);
 419     }
 420
 421     /** Accessor function for vaddr.*/
 422     Addr
 423     getVaddr()
 424     {
 425         assert(privateFlags.isSet(VALID_VADDR));
 426         return _vaddr;
 427     }
 428
 429     /** Accesssor for the requestor id. */
 430     MasterID
 431     masterId()
 432     {
 433         return _masterId;
 434     }
 435
 436     /** Accessor function for asid.*/
 437     int
 438     getAsid()
 439     {
 440         assert(privateFlags.isSet(VALID_VADDR));
 441         return _asid;
 442     }
 443
 444     /** Accessor function for asid.*/
 445     void
 446     setAsid(int asid)
 447     {
 448         _asid = asid;
 449     }
 450
 451     /** Accessor function for asi.*/
 452     uint8_t
 453     getAsi()
 454     {
 455         assert(privateFlags.isSet(VALID_VADDR));
 456         return _flags & ASI_BITS;
 457     }
 458
 459     /** Accessor function to check if sc result is valid. */
 460     bool
 461     extraDataValid()
 462     {
 463         return privateFlags.isSet(VALID_EXTRA_DATA);
 464     }
 465
 466     /** Accessor function for store conditional return value.*/
 467     uint64_t
 468     getExtraData() const
 469     {
 470         assert(privateFlags.isSet(VALID_EXTRA_DATA));
 471         return _extraData;
 472     }
 473
 474     /** Accessor function for store conditional return value.*/
 475     void
 476     setExtraData(uint64_t extraData)
 477     {
 478         _extraData = extraData;
 479         privateFlags.set(VALID_EXTRA_DATA);
 480     }
 481
 482     bool
 483     hasContextId() const
 484     {
 485         return privateFlags.isSet(VALID_CONTEXT_ID);
 486     }
 487
 488     /** Accessor function for context ID.*/
 489     int
 490     contextId() const
 491     {
 492         assert(privateFlags.isSet(VALID_CONTEXT_ID));
 493         return _contextId;
 494     }
 495
 496     /** Accessor function for thread ID. */
 497     int
 498     threadId() const
 499     {
 500         assert(privateFlags.isSet(VALID_THREAD_ID));
 501         return _threadId;
 502     }
 503
 504     bool
 505     hasPC() const
 506     {
 507         return privateFlags.isSet(VALID_PC);
 508     }
 509
 510     /** Accessor function for pc.*/
 511     Addr
 512     getPC() const
 513     {
 514         assert(privateFlags.isSet(VALID_PC));
 515         return _pc;
 516     }
 517
 518     /** Accessor functions for flags.  Note that these are for testing
 519        only; setting flags should be done via setFlags(). */
 520     bool isUncacheable() const { return _flags.isSet(UNCACHEABLE); }
 521     bool isInstFetch() const { return _flags.isSet(INST_FETCH); }
 522     bool isPrefetch() const { return _flags.isSet(PREFETCH); }
 523     bool isLLSC() const { return _flags.isSet(LLSC); }
 524     bool isLocked() const { return _flags.isSet(LOCKED); }
 525     bool isSwap() const { return _flags.isSet(MEM_SWAP|MEM_SWAP_COND); }
 526     bool isCondSwap() const { return _flags.isSet(MEM_SWAP_COND); }
 527     bool isMmappedIpr() const { return _flags.isSet(MMAPPED_IPR); }
 528     bool isClearLL() const { return _flags.isSet(CLEAR_LL); }
 529 };
 530
 531 #endif // __MEM_REQUEST_HH__