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 uint8_t ArchFlagsType;
  90     typedef ::Flags<FlagsType> Flags;
  91
  92     /**
  93      * Architecture specific flags.
  94      *
  95      * These bits int the flag field are reserved for
  96      * architecture-specific code. For example, SPARC uses them to
  97      * represent ASIs.
  98      */
  99     static const FlagsType ARCH_BITS                   = 0x000000FF;
 100     /** The request was an instruction fetch. */
 101     static const FlagsType INST_FETCH                  = 0x00000100;
 102     /** The virtual address is also the physical address. */
 103     static const FlagsType PHYSICAL                    = 0x00000200;
 104     /** The request is an ALPHA VPTE pal access (hw_ld). */
 105     static const FlagsType VPTE                        = 0x00000400;
 106     /** Use the alternate mode bits in ALPHA. */
 107     static const FlagsType ALTMODE                     = 0x00000800;
 108     /** The request is to an uncacheable address. */
 109     static const FlagsType UNCACHEABLE                 = 0x00001000;
 110     /** This request is to a memory mapped register. */
 111     static const FlagsType MMAPPED_IPR                  = 0x00002000;
 112     /** This request is a clear exclusive. */
 113     static const FlagsType CLEAR_LL                    = 0x00004000;
 114
 115     /** The request should not cause a memory access. */
 116     static const FlagsType NO_ACCESS                   = 0x00080000;
 117     /** This request will lock or unlock the accessed memory. When used with
 118      * a load, the access locks the particular chunk of memory. When used
 119      * with a store, it unlocks. The rule is that locked accesses have to be
 120      * made up of a locked load, some operation on the data, and then a locked
 121      * store.
 122      */
 123     static const FlagsType LOCKED                      = 0x00100000;
 124     /** The request is a Load locked/store conditional. */
 125     static const FlagsType LLSC                        = 0x00200000;
 126     /** This request is for a memory swap. */
 127     static const FlagsType MEM_SWAP                    = 0x00400000;
 128     static const FlagsType MEM_SWAP_COND               = 0x00800000;
 129
 130     /** The request is a prefetch. */
 131     static const FlagsType PREFETCH                    = 0x01000000;
 132     /** The request should be prefetched into the exclusive state. */
 133     static const FlagsType PF_EXCLUSIVE                = 0x02000000;
 134     /** The request should be marked as LRU. */
 135     static const FlagsType EVICT_NEXT                  = 0x04000000;
 136
 137     /** The request should be handled by the generic IPR code (only
 138      * valid together with MMAPPED_IPR) */
 139     static const FlagsType GENERIC_IPR                 = 0x08000000;
 140
 141     /** These flags are *not* cleared when a Request object is reused
 142        (assigned a new address). */
 143     static const FlagsType STICKY_FLAGS = INST_FETCH;
 144
 145     /** Request Ids that are statically allocated
 146      * @{*/
 147     /** This request id is used for writeback requests by the caches */
 148     static const MasterID wbMasterId = 0;
 149     /** This request id is used for functional requests that don't come from a
 150      * particular device
 151      */
 152     static const MasterID funcMasterId = 1;
 153     /** This request id is used for message signaled interrupts */
 154     static const MasterID intMasterId = 2;
 155     /** Invalid request id for assertion checking only. It is invalid behavior
 156      * to ever send this id as part of a request.
 157      * @todo C++1x replace with numeric_limits when constexpr is added  */
 158     static const MasterID invldMasterId = USHRT_MAX;
 159     /** @} */
 160
 161     /** Invalid or unknown Pid. Possible when operating system is not present
 162      *  or has not assigned a pid yet */
 163     static const uint32_t invldPid = UINT_MAX;
 164
 165   private:
 166     typedef uint8_t PrivateFlagsType;
 167     typedef ::Flags<PrivateFlagsType> PrivateFlags;
 168
 169     /** Whether or not the size is valid. */
 170     static const PrivateFlagsType VALID_SIZE           = 0x00000001;
 171     /** Whether or not paddr is valid (has been written yet). */
 172     static const PrivateFlagsType VALID_PADDR          = 0x00000002;
 173     /** Whether or not the vaddr & asid are valid. */
 174     static const PrivateFlagsType VALID_VADDR          = 0x00000004;
 175     /** Whether or not the pc is valid. */
 176     static const PrivateFlagsType VALID_PC             = 0x00000010;
 177     /** Whether or not the context ID is valid. */
 178     static const PrivateFlagsType VALID_CONTEXT_ID     = 0x00000020;
 179     static const PrivateFlagsType VALID_THREAD_ID      = 0x00000040;
 180     /** Whether or not the sc result is valid. */
 181     static const PrivateFlagsType VALID_EXTRA_DATA     = 0x00000080;
 182
 183     /** These flags are *not* cleared when a Request object is reused
 184        (assigned a new address). */
 185     static const PrivateFlagsType STICKY_PRIVATE_FLAGS =
 186         VALID_CONTEXT_ID | VALID_THREAD_ID;
 187
 188   private:
 189     /**
 190      * The physical address of the request. Valid only if validPaddr
 191      * is set.
 192      */
 193     Addr _paddr;
 194
 195     /**
 196      * The size of the request. This field must be set when vaddr or
 197      * paddr is written via setVirt() or setPhys(), so it is always
 198      * valid as long as one of the address fields is valid.
 199      */
 200     int _size;
 201
 202     /** The requestor ID which is unique in the system for all ports
 203      * that are capable of issuing a transaction
 204      */
 205     MasterID _masterId;
 206
 207     /** Flag structure for the request. */
 208     Flags _flags;
 209
 210     /** Private flags for field validity checking. */
 211     PrivateFlags privateFlags;
 212
 213     /**
 214      * The time this request was started. Used to calculate
 215      * latencies. This field is set to curTick() any time paddr or vaddr
 216      * is written.
 217      */
 218     Tick _time;
 219
 220     /** The address space ID. */
 221     int _asid;
 222
 223     /** The virtual address of the request. */
 224     Addr _vaddr;
 225
 226     /**
 227      * Extra data for the request, such as the return value of
 228      * store conditional or the compare value for a CAS. */
 229     uint64_t _extraData;
 230
 231     /** The context ID (for statistics, typically). */
 232     int _contextId;
 233     /** The thread ID (id within this CPU) */
 234     int _threadId;
 235
 236     /** program counter of initiating access; for tracing/debugging */
 237     Addr _pc;
 238
 239   public:
 240     /** Minimal constructor.  No fields are initialized.
 241      *  (Note that _flags and privateFlags are cleared by Flags
 242      *  default constructor.)
 243      */
 244     Request()
 245     {}
 246
 247     /**
 248      * Constructor for physical (e.g. device) requests.  Initializes
 249      * just physical address, size, flags, and timestamp (to curTick()).
 250      * These fields are adequate to perform a request.
 251      */
 252     Request(Addr paddr, int size, Flags flags, MasterID mid)
 253     {
 254         setPhys(paddr, size, flags, mid);
 255     }
 256
 257     Request(Addr paddr, int size, Flags flags, MasterID mid, Tick time)
 258     {
 259         setPhys(paddr, size, flags, mid, time);
 260     }
 261
 262     Request(Addr paddr, int size, Flags flags, MasterID mid, Tick time, Addr pc)
 263     {
 264         setPhys(paddr, size, flags, mid, time);
 265         privateFlags.set(VALID_PC);
 266         _pc = pc;
 267     }
 268
 269     Request(int asid, Addr vaddr, int size, Flags flags, MasterID mid, Addr pc,
 270             int cid, ThreadID tid)
 271     {
 272         setVirt(asid, vaddr, size, flags, mid, pc);
 273         setThreadContext(cid, tid);
 274     }
 275
 276     ~Request() {}
 277
 278     /**
 279      * Set up CPU and thread numbers.
 280      */
 281     void
 282     setThreadContext(int context_id, ThreadID tid)
 283     {
 284         _contextId = context_id;
 285         _threadId = tid;
 286         privateFlags.set(VALID_CONTEXT_ID|VALID_THREAD_ID);
 287     }
 288
 289     /**
 290      * Set up a physical (e.g. device) request in a previously
 291      * allocated Request object.
 292      */
 293     void
 294     setPhys(Addr paddr, int size, Flags flags, MasterID mid, Tick time)
 295     {
 296         assert(size >= 0);
 297         _paddr = paddr;
 298         _size = size;
 299         _time = time;
 300         _masterId = mid;
 301         _flags.clear(~STICKY_FLAGS);
 302         _flags.set(flags);
 303         privateFlags.clear(~STICKY_PRIVATE_FLAGS);
 304         privateFlags.set(VALID_PADDR|VALID_SIZE);
 305     }
 306
 307     void
 308     setPhys(Addr paddr, int size, Flags flags, MasterID mid)
 309     {
 310         setPhys(paddr, size, flags, mid, curTick());
 311     }
 312
 313     /**
 314      * Set up a virtual (e.g., CPU) request in a previously
 315      * allocated Request object.
 316      */
 317     void
 318     setVirt(int asid, Addr vaddr, int size, Flags flags, MasterID mid, Addr pc)
 319     {
 320         assert(size >= 0);
 321         _asid = asid;
 322         _vaddr = vaddr;
 323         _size = size;
 324         _masterId = mid;
 325         _pc = pc;
 326         _time = curTick();
 327
 328         _flags.clear(~STICKY_FLAGS);
 329         _flags.set(flags);
 330         privateFlags.clear(~STICKY_PRIVATE_FLAGS);
 331         privateFlags.set(VALID_VADDR|VALID_SIZE|VALID_PC);
 332     }
 333
 334     /**
 335      * Set just the physical address.  This usually used to record the
 336      * result of a translation. However, when using virtualized CPUs
 337      * setPhys() is sometimes called to finalize a physical address
 338      * without a virtual address, so we can't check if the virtual
 339      * address is valid.
 340      */
 341     void
 342     setPaddr(Addr paddr)
 343     {
 344         _paddr = paddr;
 345         privateFlags.set(VALID_PADDR);
 346     }
 347
 348     /**
 349      * Generate two requests as if this request had been split into two
 350      * pieces. The original request can't have been translated already.
 351      */
 352     void splitOnVaddr(Addr split_addr, RequestPtr &req1, RequestPtr &req2)
 353     {
 354         assert(privateFlags.isSet(VALID_VADDR));
 355         assert(privateFlags.noneSet(VALID_PADDR));
 356         assert(split_addr > _vaddr && split_addr < _vaddr + _size);
 357         req1 = new Request;
 358         *req1 = *this;
 359         req2 = new Request;
 360         *req2 = *this;
 361         req1->_size = split_addr - _vaddr;
 362         req2->_vaddr = split_addr;
 363         req2->_size = _size - req1->_size;
 364     }
 365
 366     /**
 367      * Accessor for paddr.
 368      */
 369     bool
 370     hasPaddr()
 371     {
 372         return privateFlags.isSet(VALID_PADDR);
 373     }
 374
 375     Addr
 376     getPaddr()
 377     {
 378         assert(privateFlags.isSet(VALID_PADDR));
 379         return _paddr;
 380     }
 381
 382     /**
 383      *  Accessor for size.
 384      */
 385     bool
 386     hasSize()
 387     {
 388         return privateFlags.isSet(VALID_SIZE);
 389     }
 390
 391     int
 392     getSize()
 393     {
 394         assert(privateFlags.isSet(VALID_SIZE));
 395         return _size;
 396     }
 397
 398     /** Accessor for time. */
 399     Tick
 400     time() const
 401     {
 402         assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
 403         return _time;
 404     }
 405
 406     void
 407     time(Tick time)
 408     {
 409         assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
 410         _time = time;
 411     }
 412
 413     /** Accessor for flags. */
 414     Flags
 415     getFlags()
 416     {
 417         assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
 418         return _flags;
 419     }
 420
 421     /** Note that unlike other accessors, this function sets *specific
 422        flags* (ORs them in); it does not assign its argument to the
 423        _flags field.  Thus this method should rightly be called
 424        setFlags() and not just flags(). */
 425     void
 426     setFlags(Flags flags)
 427     {
 428         assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
 429         _flags.set(flags);
 430     }
 431
 432     void
 433     setArchFlags(Flags flags)
 434     {
 435         assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
 436         _flags.set(flags & ARCH_BITS);
 437     }
 438
 439     /** Accessor function for vaddr.*/
 440     Addr
 441     getVaddr()
 442     {
 443         assert(privateFlags.isSet(VALID_VADDR));
 444         return _vaddr;
 445     }
 446
 447     /** Accesssor for the requestor id. */
 448     MasterID
 449     masterId()
 450     {
 451         return _masterId;
 452     }
 453
 454     /** Accessor function for asid.*/
 455     int
 456     getAsid()
 457     {
 458         assert(privateFlags.isSet(VALID_VADDR));
 459         return _asid;
 460     }
 461
 462     /** Accessor function for asid.*/
 463     void
 464     setAsid(int asid)
 465     {
 466         _asid = asid;
 467     }
 468
 469     /** Accessor function for architecture-specific flags.*/
 470     ArchFlagsType
 471     getArchFlags()
 472     {
 473         assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
 474         return _flags & ARCH_BITS;
 475     }
 476
 477     /** Accessor function to check if sc result is valid. */
 478     bool
 479     extraDataValid()
 480     {
 481         return privateFlags.isSet(VALID_EXTRA_DATA);
 482     }
 483
 484     /** Accessor function for store conditional return value.*/
 485     uint64_t
 486     getExtraData() const
 487     {
 488         assert(privateFlags.isSet(VALID_EXTRA_DATA));
 489         return _extraData;
 490     }
 491
 492     /** Accessor function for store conditional return value.*/
 493     void
 494     setExtraData(uint64_t extraData)
 495     {
 496         _extraData = extraData;
 497         privateFlags.set(VALID_EXTRA_DATA);
 498     }
 499
 500     bool
 501     hasContextId() const
 502     {
 503         return privateFlags.isSet(VALID_CONTEXT_ID);
 504     }
 505
 506     /** Accessor function for context ID.*/
 507     int
 508     contextId() const
 509     {
 510         assert(privateFlags.isSet(VALID_CONTEXT_ID));
 511         return _contextId;
 512     }
 513
 514     /** Accessor function for thread ID. */
 515     int
 516     threadId() const
 517     {
 518         assert(privateFlags.isSet(VALID_THREAD_ID));
 519         return _threadId;
 520     }
 521
 522     bool
 523     hasPC() const
 524     {
 525         return privateFlags.isSet(VALID_PC);
 526     }
 527
 528     /** Accessor function for pc.*/
 529     Addr
 530     getPC() const
 531     {
 532         assert(privateFlags.isSet(VALID_PC));
 533         return _pc;
 534     }
 535
 536     /** Accessor functions for flags.  Note that these are for testing
 537        only; setting flags should be done via setFlags(). */
 538     bool isUncacheable() const { return _flags.isSet(UNCACHEABLE); }
 539     bool isInstFetch() const { return _flags.isSet(INST_FETCH); }
 540     bool isPrefetch() const { return _flags.isSet(PREFETCH); }
 541     bool isLLSC() const { return _flags.isSet(LLSC); }
 542     bool isLocked() const { return _flags.isSet(LOCKED); }
 543     bool isSwap() const { return _flags.isSet(MEM_SWAP|MEM_SWAP_COND); }
 544     bool isCondSwap() const { return _flags.isSet(MEM_SWAP_COND); }
 545     bool isMmappedIpr() const { return _flags.isSet(MMAPPED_IPR); }
 546     bool isClearLL() const { return _flags.isSet(CLEAR_LL); }
 547 };
 548
 549 #endif // __MEM_REQUEST_HH__