request.hh revision 10824 
1/*
2 * Copyright (c) 2012-2013 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
70namespace 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
80class Request;
81
82typedef Request* RequestPtr;
83typedef uint16_t MasterID;
84
85class 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    /**
105     * The request is to an uncacheable address.
106     *
107     * @note Uncacheable accesses may be reordered by CPU models. The
108     * STRICT_ORDER flag should be set if such reordering is
109     * undesirable.
110     */
111    static const FlagsType UNCACHEABLE                = 0x00000400;
112    /**
113     * The request is required to be strictly ordered by <i>CPU
114     * models</i> and is non-speculative.
115     *
116     * A strictly ordered request is guaranteed to never be re-ordered
117     * or executed speculatively by a CPU model. The memory system may
118     * still reorder requests in caches unless the UNCACHEABLE flag is
119     * set as well.
120     */
121    static const FlagsType STRICT_ORDER                = 0x00000800;
122    /** This request is to a memory mapped register. */
123    static const FlagsType MMAPPED_IPR                 = 0x00002000;
124    /** This request is a clear exclusive. */
125    static const FlagsType CLEAR_LL                    = 0x00004000;
126    /** This request is made in privileged mode. */
127    static const FlagsType PRIVILEGED                  = 0x00008000;
128
129    /** This is a write that is targeted and zeroing an entire cache block.
130     * There is no need for a read/modify/write
131     */
132    static const FlagsType CACHE_BLOCK_ZERO            = 0x00010000;
133
134    /** The request should not cause a memory access. */
135    static const FlagsType NO_ACCESS                   = 0x00080000;
136    /** This request will lock or unlock the accessed memory. When used with
137     * a load, the access locks the particular chunk of memory. When used
138     * with a store, it unlocks. The rule is that locked accesses have to be
139     * made up of a locked load, some operation on the data, and then a locked
140     * store.
141     */
142    static const FlagsType LOCKED_RMW                  = 0x00100000;
143    /** The request is a Load locked/store conditional. */
144    static const FlagsType LLSC                        = 0x00200000;
145    /** This request is for a memory swap. */
146    static const FlagsType MEM_SWAP                    = 0x00400000;
147    static const FlagsType MEM_SWAP_COND               = 0x00800000;
148
149    /** The request is a prefetch. */
150    static const FlagsType PREFETCH                    = 0x01000000;
151    /** The request should be prefetched into the exclusive state. */
152    static const FlagsType PF_EXCLUSIVE                = 0x02000000;
153    /** The request should be marked as LRU. */
154    static const FlagsType EVICT_NEXT                  = 0x04000000;
155
156    /** The request should be handled by the generic IPR code (only
157     * valid together with MMAPPED_IPR) */
158    static const FlagsType GENERIC_IPR                 = 0x08000000;
159
160    /** The request targets the secure memory space. */
161    static const FlagsType SECURE                      = 0x10000000;
162    /** The request is a page table walk */
163    static const FlagsType PT_WALK                     = 0x20000000;
164
165    /** These flags are *not* cleared when a Request object is reused
166       (assigned a new address). */
167    static const FlagsType STICKY_FLAGS = INST_FETCH;
168
169    /** Request Ids that are statically allocated
170     * @{*/
171    /** This request id is used for writeback requests by the caches */
172    static const MasterID wbMasterId = 0;
173    /** This request id is used for functional requests that don't come from a
174     * particular device
175     */
176    static const MasterID funcMasterId = 1;
177    /** This request id is used for message signaled interrupts */
178    static const MasterID intMasterId = 2;
179    /** Invalid request id for assertion checking only. It is invalid behavior
180     * to ever send this id as part of a request.
181     * @todo C++1x replace with numeric_limits when constexpr is added  */
182    static const MasterID invldMasterId = std::numeric_limits<MasterID>::max();
183    /** @} */
184
185    /** Invalid or unknown Pid. Possible when operating system is not present
186     *  or has not assigned a pid yet */
187    static const uint32_t invldPid = std::numeric_limits<uint32_t>::max();
188
189  private:
190    typedef uint8_t PrivateFlagsType;
191    typedef ::Flags<PrivateFlagsType> PrivateFlags;
192
193    /** Whether or not the size is valid. */
194    static const PrivateFlagsType VALID_SIZE           = 0x00000001;
195    /** Whether or not paddr is valid (has been written yet). */
196    static const PrivateFlagsType VALID_PADDR          = 0x00000002;
197    /** Whether or not the vaddr & asid are valid. */
198    static const PrivateFlagsType VALID_VADDR          = 0x00000004;
199    /** Whether or not the pc is valid. */
200    static const PrivateFlagsType VALID_PC             = 0x00000010;
201    /** Whether or not the context ID is valid. */
202    static const PrivateFlagsType VALID_CONTEXT_ID     = 0x00000020;
203    static const PrivateFlagsType VALID_THREAD_ID      = 0x00000040;
204    /** Whether or not the sc result is valid. */
205    static const PrivateFlagsType VALID_EXTRA_DATA     = 0x00000080;
206
207    /** These flags are *not* cleared when a Request object is reused
208       (assigned a new address). */
209    static const PrivateFlagsType STICKY_PRIVATE_FLAGS =
210        VALID_CONTEXT_ID | VALID_THREAD_ID;
211
212  private:
213
214    /**
215     * Set up a physical (e.g. device) request in a previously
216     * allocated Request object.
217     */
218    void
219    setPhys(Addr paddr, unsigned size, Flags flags, MasterID mid, Tick time)
220    {
221        assert(size >= 0);
222        _paddr = paddr;
223        _size = size;
224        _time = time;
225        _masterId = mid;
226        _flags.clear(~STICKY_FLAGS);
227        _flags.set(flags);
228        privateFlags.clear(~STICKY_PRIVATE_FLAGS);
229        privateFlags.set(VALID_PADDR|VALID_SIZE);
230        depth = 0;
231        accessDelta = 0;
232        //translateDelta = 0;
233    }
234
235    /**
236     * The physical address of the request. Valid only if validPaddr
237     * is set.
238     */
239    Addr _paddr;
240
241    /**
242     * The size of the request. This field must be set when vaddr or
243     * paddr is written via setVirt() or setPhys(), so it is always
244     * valid as long as one of the address fields is valid.
245     */
246    unsigned _size;
247
248    /** The requestor ID which is unique in the system for all ports
249     * that are capable of issuing a transaction
250     */
251    MasterID _masterId;
252
253    /** Flag structure for the request. */
254    Flags _flags;
255
256    /** Private flags for field validity checking. */
257    PrivateFlags privateFlags;
258
259    /**
260     * The time this request was started. Used to calculate
261     * latencies. This field is set to curTick() any time paddr or vaddr
262     * is written.
263     */
264    Tick _time;
265
266    /**
267     * The task id associated with this request
268     */
269    uint32_t _taskId;
270
271    /** The address space ID. */
272    int _asid;
273
274    /** The virtual address of the request. */
275    Addr _vaddr;
276
277    /**
278     * Extra data for the request, such as the return value of
279     * store conditional or the compare value for a CAS. */
280    uint64_t _extraData;
281
282    /** The context ID (for statistics, typically). */
283    int _contextId;
284    /** The thread ID (id within this CPU) */
285    ThreadID _threadId;
286
287    /** program counter of initiating access; for tracing/debugging */
288    Addr _pc;
289
290  public:
291
292    /**
293     * Minimal constructor. No fields are initialized. (Note that
294     *  _flags and privateFlags are cleared by Flags default
295     *  constructor.)
296     */
297    Request()
298        : _paddr(0), _size(0), _masterId(invldMasterId), _time(0),
299          _taskId(ContextSwitchTaskId::Unknown), _asid(0), _vaddr(0),
300          _extraData(0), _contextId(0), _threadId(0), _pc(0),
301          translateDelta(0), accessDelta(0), depth(0)
302    {}
303
304    /**
305     * Constructor for physical (e.g. device) requests.  Initializes
306     * just physical address, size, flags, and timestamp (to curTick()).
307     * These fields are adequate to perform a request.
308     */
309    Request(Addr paddr, unsigned size, Flags flags, MasterID mid)
310        : _paddr(0), _size(0), _masterId(invldMasterId), _time(0),
311          _taskId(ContextSwitchTaskId::Unknown), _asid(0), _vaddr(0),
312          _extraData(0), _contextId(0), _threadId(0), _pc(0),
313          translateDelta(0), accessDelta(0), depth(0)
314    {
315        setPhys(paddr, size, flags, mid, curTick());
316    }
317
318    Request(Addr paddr, unsigned size, Flags flags, MasterID mid, Tick time)
319        : _paddr(0), _size(0), _masterId(invldMasterId), _time(0),
320          _taskId(ContextSwitchTaskId::Unknown), _asid(0), _vaddr(0),
321          _extraData(0), _contextId(0), _threadId(0), _pc(0),
322          translateDelta(0), accessDelta(0), depth(0)
323    {
324        setPhys(paddr, size, flags, mid, time);
325    }
326
327    Request(Addr paddr, unsigned size, Flags flags, MasterID mid, Tick time,
328            Addr pc)
329        : _paddr(0), _size(0), _masterId(invldMasterId), _time(0),
330          _taskId(ContextSwitchTaskId::Unknown), _asid(0), _vaddr(0),
331          _extraData(0), _contextId(0), _threadId(0), _pc(0),
332          translateDelta(0), accessDelta(0), depth(0)
333    {
334        setPhys(paddr, size, flags, mid, time);
335        privateFlags.set(VALID_PC);
336        _pc = pc;
337    }
338
339    Request(int asid, Addr vaddr, unsigned size, Flags flags, MasterID mid,
340            Addr pc, int cid, ThreadID tid)
341        : _paddr(0), _size(0), _masterId(invldMasterId), _time(0),
342          _taskId(ContextSwitchTaskId::Unknown), _asid(0), _vaddr(0),
343          _extraData(0), _contextId(0), _threadId(0), _pc(0),
344          translateDelta(0), accessDelta(0), depth(0)
345    {
346        setVirt(asid, vaddr, size, flags, mid, pc);
347        setThreadContext(cid, tid);
348    }
349
350    ~Request() {}
351
352    /**
353     * Set up CPU and thread numbers.
354     */
355    void
356    setThreadContext(int context_id, ThreadID tid)
357    {
358        _contextId = context_id;
359        _threadId = tid;
360        privateFlags.set(VALID_CONTEXT_ID|VALID_THREAD_ID);
361    }
362
363    /**
364     * Set up a virtual (e.g., CPU) request in a previously
365     * allocated Request object.
366     */
367    void
368    setVirt(int asid, Addr vaddr, unsigned size, Flags flags, MasterID mid,
369            Addr pc)
370    {
371        _asid = asid;
372        _vaddr = vaddr;
373        _size = size;
374        _masterId = mid;
375        _pc = pc;
376        _time = curTick();
377
378        _flags.clear(~STICKY_FLAGS);
379        _flags.set(flags);
380        privateFlags.clear(~STICKY_PRIVATE_FLAGS);
381        privateFlags.set(VALID_VADDR|VALID_SIZE|VALID_PC);
382        depth = 0;
383        accessDelta = 0;
384        translateDelta = 0;
385    }
386
387    /**
388     * Set just the physical address.  This usually used to record the
389     * result of a translation. However, when using virtualized CPUs
390     * setPhys() is sometimes called to finalize a physical address
391     * without a virtual address, so we can't check if the virtual
392     * address is valid.
393     */
394    void
395    setPaddr(Addr paddr)
396    {
397        _paddr = paddr;
398        privateFlags.set(VALID_PADDR);
399    }
400
401    /**
402     * Generate two requests as if this request had been split into two
403     * pieces. The original request can't have been translated already.
404     */
405    void splitOnVaddr(Addr split_addr, RequestPtr &req1, RequestPtr &req2)
406    {
407        assert(privateFlags.isSet(VALID_VADDR));
408        assert(privateFlags.noneSet(VALID_PADDR));
409        assert(split_addr > _vaddr && split_addr < _vaddr + _size);
410        req1 = new Request(*this);
411        req2 = new Request(*this);
412        req1->_size = split_addr - _vaddr;
413        req2->_vaddr = split_addr;
414        req2->_size = _size - req1->_size;
415    }
416
417    /**
418     * Accessor for paddr.
419     */
420    bool
421    hasPaddr() const
422    {
423        return privateFlags.isSet(VALID_PADDR);
424    }
425
426    Addr
427    getPaddr() const
428    {
429        assert(privateFlags.isSet(VALID_PADDR));
430        return _paddr;
431    }
432
433    /**
434     * Time for the TLB/table walker to successfully translate this request.
435     */
436    Tick translateDelta;
437
438    /**
439     * Access latency to complete this memory transaction not including
440     * translation time.
441     */
442    Tick accessDelta;
443
444    /**
445     * Level of the cache hierachy where this request was responded to
446     * (e.g. 0 = L1; 1 = L2).
447     */
448    mutable int depth;
449
450    /**
451     *  Accessor for size.
452     */
453    bool
454    hasSize() const
455    {
456        return privateFlags.isSet(VALID_SIZE);
457    }
458
459    unsigned
460    getSize() const
461    {
462        assert(privateFlags.isSet(VALID_SIZE));
463        return _size;
464    }
465
466    /** Accessor for time. */
467    Tick
468    time() const
469    {
470        assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
471        return _time;
472    }
473
474    /** Accessor for flags. */
475    Flags
476    getFlags()
477    {
478        assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
479        return _flags;
480    }
481
482    /** Note that unlike other accessors, this function sets *specific
483       flags* (ORs them in); it does not assign its argument to the
484       _flags field.  Thus this method should rightly be called
485       setFlags() and not just flags(). */
486    void
487    setFlags(Flags flags)
488    {
489        assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
490        _flags.set(flags);
491    }
492
493    /** Accessor function for vaddr.*/
494    bool
495    hasVaddr() const
496    {
497        return privateFlags.isSet(VALID_VADDR);
498    }
499
500    Addr
501    getVaddr() const
502    {
503        assert(privateFlags.isSet(VALID_VADDR));
504        return _vaddr;
505    }
506
507    /** Accesssor for the requestor id. */
508    MasterID
509    masterId() const
510    {
511        return _masterId;
512    }
513
514    uint32_t
515    taskId() const
516    {
517        return _taskId;
518    }
519
520    void
521    taskId(uint32_t id) {
522        _taskId = id;
523    }
524
525    /** Accessor function for asid.*/
526    int
527    getAsid() const
528    {
529        assert(privateFlags.isSet(VALID_VADDR));
530        return _asid;
531    }
532
533    /** Accessor function for asid.*/
534    void
535    setAsid(int asid)
536    {
537        _asid = asid;
538    }
539
540    /** Accessor function for architecture-specific flags.*/
541    ArchFlagsType
542    getArchFlags() const
543    {
544        assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
545        return _flags & ARCH_BITS;
546    }
547
548    /** Accessor function to check if sc result is valid. */
549    bool
550    extraDataValid() const
551    {
552        return privateFlags.isSet(VALID_EXTRA_DATA);
553    }
554
555    /** Accessor function for store conditional return value.*/
556    uint64_t
557    getExtraData() const
558    {
559        assert(privateFlags.isSet(VALID_EXTRA_DATA));
560        return _extraData;
561    }
562
563    /** Accessor function for store conditional return value.*/
564    void
565    setExtraData(uint64_t extraData)
566    {
567        _extraData = extraData;
568        privateFlags.set(VALID_EXTRA_DATA);
569    }
570
571    bool
572    hasContextId() const
573    {
574        return privateFlags.isSet(VALID_CONTEXT_ID);
575    }
576
577    /** Accessor function for context ID.*/
578    int
579    contextId() const
580    {
581        assert(privateFlags.isSet(VALID_CONTEXT_ID));
582        return _contextId;
583    }
584
585    /** Accessor function for thread ID. */
586    ThreadID
587    threadId() const
588    {
589        assert(privateFlags.isSet(VALID_THREAD_ID));
590        return _threadId;
591    }
592
593    void
594    setPC(Addr pc)
595    {
596        privateFlags.set(VALID_PC);
597        _pc = pc;
598    }
599
600    bool
601    hasPC() const
602    {
603        return privateFlags.isSet(VALID_PC);
604    }
605
606    /** Accessor function for pc.*/
607    Addr
608    getPC() const
609    {
610        assert(privateFlags.isSet(VALID_PC));
611        return _pc;
612    }
613
614    /**
615     * Increment/Get the depth at which this request is responded to.
616     * This currently happens when the request misses in any cache level.
617     */
618    void incAccessDepth() const { depth++; }
619    int getAccessDepth() const { return depth; }
620
621    /**
622     * Set/Get the time taken for this request to be successfully translated.
623     */
624    void setTranslateLatency() { translateDelta = curTick() - _time; }
625    Tick getTranslateLatency() const { return translateDelta; }
626
627    /**
628     * Set/Get the time taken to complete this request's access, not including
629     *  the time to successfully translate the request.
630     */
631    void setAccessLatency() { accessDelta = curTick() - _time - translateDelta; }
632    Tick getAccessLatency() const { return accessDelta; }
633
634    /** Accessor functions for flags.  Note that these are for testing
635       only; setting flags should be done via setFlags(). */
636    bool isUncacheable() const { return _flags.isSet(UNCACHEABLE); }
637    bool isStrictlyOrdered() const { return _flags.isSet(STRICT_ORDER); }
638    bool isInstFetch() const { return _flags.isSet(INST_FETCH); }
639    bool isPrefetch() const { return _flags.isSet(PREFETCH); }
640    bool isLLSC() const { return _flags.isSet(LLSC); }
641    bool isPriv() const { return _flags.isSet(PRIVILEGED); }
642    bool isLockedRMW() const { return _flags.isSet(LOCKED_RMW); }
643    bool isSwap() const { return _flags.isSet(MEM_SWAP|MEM_SWAP_COND); }
644    bool isCondSwap() const { return _flags.isSet(MEM_SWAP_COND); }
645    bool isMmappedIpr() const { return _flags.isSet(MMAPPED_IPR); }
646    bool isClearLL() const { return _flags.isSet(CLEAR_LL); }
647    bool isSecure() const { return _flags.isSet(SECURE); }
648    bool isPTWalk() const { return _flags.isSet(PT_WALK); }
649};
650
651#endif // __MEM_REQUEST_HH__
652