request.hh revision 7705:fd65f85fcc0c 
1/*
2 * Copyright (c) 2002-2005 The Regents of The University of Michigan
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Ron Dreslinski
29 *          Steve Reinhardt
30 *          Ali Saidi
31 */
32
33/**
34 * @file
35 * Declaration of a request, the overall memory request consisting of
36 the parts of the request that are persistent throughout the transaction.
37 */
38
39#ifndef __MEM_REQUEST_HH__
40#define __MEM_REQUEST_HH__
41
42#include <cassert>
43
44#include "base/fast_alloc.hh"
45#include "base/flags.hh"
46#include "base/misc.hh"
47#include "base/types.hh"
48#include "sim/core.hh"
49
50class Request;
51
52typedef Request* RequestPtr;
53
54class Request : public FastAlloc
55{
56  public:
57    typedef uint32_t FlagsType;
58    typedef ::Flags<FlagsType> Flags;
59
60    /** ASI information for this request if it exists. */
61    static const FlagsType ASI_BITS                    = 0x000000FF;
62    /** The request was an instruction fetch. */
63    static const FlagsType INST_FETCH                  = 0x00000100;
64    /** The virtual address is also the physical address. */
65    static const FlagsType PHYSICAL                    = 0x00000200;
66    /** The request is an ALPHA VPTE pal access (hw_ld). */
67    static const FlagsType VPTE                        = 0x00000400;
68    /** Use the alternate mode bits in ALPHA. */
69    static const FlagsType ALTMODE                     = 0x00000800;
70    /** The request is to an uncacheable address. */
71    static const FlagsType UNCACHEABLE                 = 0x00001000;
72    /** This request is to a memory mapped register. */
73    static const FlagsType MMAPED_IPR                  = 0x00002000;
74    /** This request is a clear exclusive. */
75    static const FlagsType CLEAR_LL                    = 0x00004000;
76
77    /** The request should ignore unaligned access faults */
78    static const FlagsType NO_ALIGN_FAULT              = 0x00020000;
79    /** The request should ignore unaligned access faults */
80    static const FlagsType NO_HALF_WORD_ALIGN_FAULT    = 0x00040000;
81    /** The request should not cause a memory access. */
82    static const FlagsType NO_ACCESS                   = 0x00080000;
83    /** This request will lock or unlock the accessed memory. When used with
84     * a load, the access locks the particular chunk of memory. When used
85     * with a store, it unlocks. The rule is that locked accesses have to be
86     * made up of a locked load, some operation on the data, and then a locked
87     * store.
88     */
89    static const FlagsType LOCKED                      = 0x00100000;
90    /** The request is a Load locked/store conditional. */
91    static const FlagsType LLSC                        = 0x00200000;
92    /** This request is for a memory swap. */
93    static const FlagsType MEM_SWAP                    = 0x00400000;
94    static const FlagsType MEM_SWAP_COND               = 0x00800000;
95
96    /** The request is a prefetch. */
97    static const FlagsType PREFETCH                    = 0x01000000;
98    /** The request should be prefetched into the exclusive state. */
99    static const FlagsType PF_EXCLUSIVE                = 0x02000000;
100    /** The request should be marked as LRU. */
101    static const FlagsType EVICT_NEXT                  = 0x04000000;
102
103    /** These flags are *not* cleared when a Request object is reused
104       (assigned a new address). */
105    static const FlagsType STICKY_FLAGS = INST_FETCH;
106
107  private:
108    typedef uint8_t PrivateFlagsType;
109    typedef ::Flags<PrivateFlagsType> PrivateFlags;
110
111    /** Whether or not the size is valid. */
112    static const PrivateFlagsType VALID_SIZE           = 0x00000001;
113    /** Whether or not paddr is valid (has been written yet). */
114    static const PrivateFlagsType VALID_PADDR          = 0x00000002;
115    /** Whether or not the vaddr & asid are valid. */
116    static const PrivateFlagsType VALID_VADDR          = 0x00000004;
117    /** Whether or not the pc is valid. */
118    static const PrivateFlagsType VALID_PC             = 0x00000010;
119    /** Whether or not the context ID is valid. */
120    static const PrivateFlagsType VALID_CONTEXT_ID     = 0x00000020;
121    static const PrivateFlagsType VALID_THREAD_ID      = 0x00000040;
122    /** Whether or not the sc result is valid. */
123    static const PrivateFlagsType VALID_EXTRA_DATA     = 0x00000080;
124
125    /** These flags are *not* cleared when a Request object is reused
126       (assigned a new address). */
127    static const PrivateFlagsType STICKY_PRIVATE_FLAGS =
128        VALID_CONTEXT_ID | VALID_THREAD_ID;
129
130  private:
131    /**
132     * The physical address of the request. Valid only if validPaddr
133     * is set.
134     */
135    Addr _paddr;
136
137    /**
138     * The size of the request. This field must be set when vaddr or
139     * paddr is written via setVirt() or setPhys(), so it is always
140     * valid as long as one of the address fields is valid.
141     */
142    int _size;
143
144    /** Flag structure for the request. */
145    Flags _flags;
146
147    /** Private flags for field validity checking. */
148    PrivateFlags privateFlags;
149
150    /**
151     * The time this request was started. Used to calculate
152     * latencies. This field is set to curTick any time paddr or vaddr
153     * is written.
154     */
155    Tick _time;
156
157    /** The address space ID. */
158    int _asid;
159
160    /** The virtual address of the request. */
161    Addr _vaddr;
162
163    /**
164     * Extra data for the request, such as the return value of
165     * store conditional or the compare value for a CAS. */
166    uint64_t _extraData;
167
168    /** The context ID (for statistics, typically). */
169    int _contextId;
170    /** The thread ID (id within this CPU) */
171    int _threadId;
172
173    /** program counter of initiating access; for tracing/debugging */
174    Addr _pc;
175
176  public:
177    /** Minimal constructor.  No fields are initialized.
178     *  (Note that _flags and privateFlags are cleared by Flags
179     *  default constructor.)
180     */
181    Request()
182    {}
183
184    /**
185     * Constructor for physical (e.g. device) requests.  Initializes
186     * just physical address, size, flags, and timestamp (to curTick).
187     * These fields are adequate to perform a request.
188     */
189    Request(Addr paddr, int size, Flags flags)
190    {
191        setPhys(paddr, size, flags);
192    }
193
194    Request(Addr paddr, int size, Flags flags, Tick time)
195    {
196        setPhys(paddr, size, flags, time);
197    }
198
199    Request(Addr paddr, int size, Flags flags, Tick time, Addr pc)
200    {
201        setPhys(paddr, size, flags, time);
202        privateFlags.set(VALID_PC);
203        _pc = pc;
204    }
205
206    Request(int asid, Addr vaddr, int size, Flags flags, Addr pc,
207            int cid, ThreadID tid)
208    {
209        setVirt(asid, vaddr, size, flags, pc);
210        setThreadContext(cid, tid);
211    }
212
213    ~Request() {}  // for FastAlloc
214
215    /**
216     * Set up CPU and thread numbers.
217     */
218    void
219    setThreadContext(int context_id, ThreadID tid)
220    {
221        _contextId = context_id;
222        _threadId = tid;
223        privateFlags.set(VALID_CONTEXT_ID|VALID_THREAD_ID);
224    }
225
226    /**
227     * Set up a physical (e.g. device) request in a previously
228     * allocated Request object.
229     */
230    void
231    setPhys(Addr paddr, int size, Flags flags, Tick time)
232    {
233        assert(size >= 0);
234        _paddr = paddr;
235        _size = size;
236        _time = time;
237
238        _flags.clear(~STICKY_FLAGS);
239        _flags.set(flags);
240        privateFlags.clear(~STICKY_PRIVATE_FLAGS);
241        privateFlags.set(VALID_PADDR|VALID_SIZE);
242    }
243
244    void
245    setPhys(Addr paddr, int size, Flags flags)
246    {
247        setPhys(paddr, size, flags, curTick);
248    }
249
250    /**
251     * Set up a virtual (e.g., CPU) request in a previously
252     * allocated Request object.
253     */
254    void
255    setVirt(int asid, Addr vaddr, int size, Flags flags, Addr pc)
256    {
257        assert(size >= 0);
258        _asid = asid;
259        _vaddr = vaddr;
260        _size = size;
261        _pc = pc;
262        _time = curTick;
263
264        _flags.clear(~STICKY_FLAGS);
265        _flags.set(flags);
266        privateFlags.clear(~STICKY_PRIVATE_FLAGS);
267        privateFlags.set(VALID_VADDR|VALID_SIZE|VALID_PC);
268    }
269
270    /**
271     * Set just the physical address.  This should only be used to
272     * record the result of a translation, and thus the vaddr must be
273     * valid before this method is called.  Otherwise, use setPhys()
274     * to guarantee that the size and flags are also set.
275     */
276    void
277    setPaddr(Addr paddr)
278    {
279        assert(privateFlags.isSet(VALID_VADDR));
280        _paddr = paddr;
281        privateFlags.set(VALID_PADDR);
282    }
283
284    /**
285     * Generate two requests as if this request had been split into two
286     * pieces. The original request can't have been translated already.
287     */
288    void splitOnVaddr(Addr split_addr, RequestPtr &req1, RequestPtr &req2)
289    {
290        assert(privateFlags.isSet(VALID_VADDR));
291        assert(privateFlags.noneSet(VALID_PADDR));
292        assert(split_addr > _vaddr && split_addr < _vaddr + _size);
293        req1 = new Request;
294        *req1 = *this;
295        req2 = new Request;
296        *req2 = *this;
297        req1->_size = split_addr - _vaddr;
298        req2->_vaddr = split_addr;
299        req2->_size = _size - req1->_size;
300    }
301
302    /**
303     * Accessor for paddr.
304     */
305    bool
306    hasPaddr()
307    {
308        return privateFlags.isSet(VALID_PADDR);
309    }
310
311    Addr
312    getPaddr()
313    {
314        assert(privateFlags.isSet(VALID_PADDR));
315        return _paddr;
316    }
317
318    /**
319     *  Accessor for size.
320     */
321    bool
322    hasSize()
323    {
324        return privateFlags.isSet(VALID_SIZE);
325    }
326
327    int
328    getSize()
329    {
330        assert(privateFlags.isSet(VALID_SIZE));
331        return _size;
332    }
333
334    /** Accessor for time. */
335    Tick
336    time() const
337    {
338        assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
339        return _time;
340    }
341
342    void
343    time(Tick time)
344    {
345        assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
346        _time = time;
347    }
348
349    /** Accessor for flags. */
350    Flags
351    getFlags()
352    {
353        assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
354        return _flags;
355    }
356
357    /** Note that unlike other accessors, this function sets *specific
358       flags* (ORs them in); it does not assign its argument to the
359       _flags field.  Thus this method should rightly be called
360       setFlags() and not just flags(). */
361    void
362    setFlags(Flags flags)
363    {
364        assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
365        _flags.set(flags);
366    }
367
368    /** Accessor function for vaddr.*/
369    Addr
370    getVaddr()
371    {
372        assert(privateFlags.isSet(VALID_VADDR));
373        return _vaddr;
374    }
375
376    /** Accessor function for asid.*/
377    int
378    getAsid()
379    {
380        assert(privateFlags.isSet(VALID_VADDR));
381        return _asid;
382    }
383
384    /** Accessor function for asi.*/
385    uint8_t
386    getAsi()
387    {
388        assert(privateFlags.isSet(VALID_VADDR));
389        return _flags & ASI_BITS;
390    }
391
392    /** Accessor function to check if sc result is valid. */
393    bool
394    extraDataValid()
395    {
396        return privateFlags.isSet(VALID_EXTRA_DATA);
397    }
398
399    /** Accessor function for store conditional return value.*/
400    uint64_t
401    getExtraData() const
402    {
403        assert(privateFlags.isSet(VALID_EXTRA_DATA));
404        return _extraData;
405    }
406
407    /** Accessor function for store conditional return value.*/
408    void
409    setExtraData(uint64_t extraData)
410    {
411        _extraData = extraData;
412        privateFlags.set(VALID_EXTRA_DATA);
413    }
414
415    bool
416    hasContextId() const
417    {
418        return privateFlags.isSet(VALID_CONTEXT_ID);
419    }
420
421    /** Accessor function for context ID.*/
422    int
423    contextId() const
424    {
425        assert(privateFlags.isSet(VALID_CONTEXT_ID));
426        return _contextId;
427    }
428
429    /** Accessor function for thread ID. */
430    int
431    threadId() const
432    {
433        assert(privateFlags.isSet(VALID_THREAD_ID));
434        return _threadId;
435    }
436
437    bool
438    hasPC() const
439    {
440        return privateFlags.isSet(VALID_PC);
441    }
442
443    /** Accessor function for pc.*/
444    Addr
445    getPC() const
446    {
447        assert(privateFlags.isSet(VALID_PC));
448        return _pc;
449    }
450
451    /** Accessor functions for flags.  Note that these are for testing
452       only; setting flags should be done via setFlags(). */
453    bool isUncacheable() const { return _flags.isSet(UNCACHEABLE); }
454    bool isInstFetch() const { return _flags.isSet(INST_FETCH); }
455    bool isPrefetch() const { return _flags.isSet(PREFETCH); }
456    bool isLLSC() const { return _flags.isSet(LLSC); }
457    bool isLocked() const { return _flags.isSet(LOCKED); }
458    bool isSwap() const { return _flags.isSet(MEM_SWAP|MEM_SWAP_COND); }
459    bool isCondSwap() const { return _flags.isSet(MEM_SWAP_COND); }
460    bool isMmapedIpr() const { return _flags.isSet(MMAPED_IPR); }
461    bool isClearLL() const { return _flags.isSet(CLEAR_LL); }
462
463    bool
464    isMisaligned() const
465    {
466        if (_flags.isSet(NO_ALIGN_FAULT))
467            return false;
468
469        if ((_vaddr & 0x1))
470            return true;
471
472        if (_flags.isSet(NO_HALF_WORD_ALIGN_FAULT))
473            return false;
474
475        if ((_vaddr & 0x2))
476            return true;
477
478        return false;
479    }
480};
481
482#endif // __MEM_REQUEST_HH__
483