request.hh revision 6739:48d10ba361c9 
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
75    /** The request should ignore unaligned access faults */
76    static const FlagsType NO_ALIGN_FAULT              = 0x00020000;
77    /** The request should ignore unaligned access faults */
78    static const FlagsType NO_HALF_WORD_ALIGN_FAULT    = 0x00040000;
79    /** The request should not cause a memory access. */
80    static const FlagsType NO_ACCESS                   = 0x00080000;
81    /** This request will lock or unlock the accessed memory. When used with
82     * a load, the access locks the particular chunk of memory. When used
83     * with a store, it unlocks. The rule is that locked accesses have to be
84     * made up of a locked load, some operation on the data, and then a locked
85     * store.
86     */
87    static const FlagsType LOCKED                      = 0x00100000;
88    /** The request is a Load locked/store conditional. */
89    static const FlagsType LLSC                        = 0x00200000;
90    /** This request is for a memory swap. */
91    static const FlagsType MEM_SWAP                    = 0x00400000;
92    static const FlagsType MEM_SWAP_COND               = 0x00800000;
93
94    /** The request is a prefetch. */
95    static const FlagsType PREFETCH                    = 0x01000000;
96    /** The request should be prefetched into the exclusive state. */
97    static const FlagsType PF_EXCLUSIVE                = 0x02000000;
98    /** The request should be marked as LRU. */
99    static const FlagsType EVICT_NEXT                  = 0x04000000;
100
101    /** These flags are *not* cleared when a Request object is reused
102       (assigned a new address). */
103    static const FlagsType STICKY_FLAGS = INST_FETCH;
104
105  private:
106    typedef uint8_t PrivateFlagsType;
107    typedef ::Flags<PrivateFlagsType> PrivateFlags;
108
109    /** Whether or not the size is valid. */
110    static const PrivateFlagsType VALID_SIZE           = 0x00000001;
111    /** Whether or not paddr is valid (has been written yet). */
112    static const PrivateFlagsType VALID_PADDR          = 0x00000002;
113    /** Whether or not the vaddr & asid are valid. */
114    static const PrivateFlagsType VALID_VADDR          = 0x00000004;
115    /** Whether or not the pc is valid. */
116    static const PrivateFlagsType VALID_PC             = 0x00000010;
117    /** Whether or not the context ID is valid. */
118    static const PrivateFlagsType VALID_CONTEXT_ID     = 0x00000020;
119    static const PrivateFlagsType VALID_THREAD_ID      = 0x00000040;
120    /** Whether or not the sc result is valid. */
121    static const PrivateFlagsType VALID_EXTRA_DATA     = 0x00000080;
122
123    /** These flags are *not* cleared when a Request object is reused
124       (assigned a new address). */
125    static const PrivateFlagsType STICKY_PRIVATE_FLAGS =
126        VALID_CONTEXT_ID | VALID_THREAD_ID;
127
128  private:
129    /**
130     * The physical address of the request. Valid only if validPaddr
131     * is set.
132     */
133    Addr _paddr;
134
135    /**
136     * The size of the request. This field must be set when vaddr or
137     * paddr is written via setVirt() or setPhys(), so it is always
138     * valid as long as one of the address fields is valid.
139     */
140    int _size;
141
142    /** Flag structure for the request. */
143    Flags _flags;
144
145    /** Private flags for field validity checking. */
146    PrivateFlags privateFlags;
147
148    /**
149     * The time this request was started. Used to calculate
150     * latencies. This field is set to curTick any time paddr or vaddr
151     * is written.
152     */
153    Tick _time;
154
155    /** The address space ID. */
156    int _asid;
157
158    /** The virtual address of the request. */
159    Addr _vaddr;
160
161    /**
162     * Extra data for the request, such as the return value of
163     * store conditional or the compare value for a CAS. */
164    uint64_t _extraData;
165
166    /** The context ID (for statistics, typically). */
167    int _contextId;
168    /** The thread ID (id within this CPU) */
169    int _threadId;
170
171    /** program counter of initiating access; for tracing/debugging */
172    Addr _pc;
173
174  public:
175    /** Minimal constructor.  No fields are initialized.
176     *  (Note that _flags and privateFlags are cleared by Flags
177     *  default constructor.)
178     */
179    Request()
180    {}
181
182    /**
183     * Constructor for physical (e.g. device) requests.  Initializes
184     * just physical address, size, flags, and timestamp (to curTick).
185     * These fields are adequate to perform a request.
186     */
187    Request(Addr paddr, int size, Flags flags)
188    {
189        setPhys(paddr, size, flags);
190    }
191
192    Request(Addr paddr, int size, Flags flags, Tick time)
193    {
194        setPhys(paddr, size, flags, time);
195    }
196
197    Request(int asid, Addr vaddr, int size, Flags flags, Addr pc,
198            int cid, ThreadID tid)
199    {
200        setVirt(asid, vaddr, size, flags, pc);
201        setThreadContext(cid, tid);
202    }
203
204    ~Request() {}  // for FastAlloc
205
206    /**
207     * Set up CPU and thread numbers.
208     */
209    void
210    setThreadContext(int context_id, ThreadID tid)
211    {
212        _contextId = context_id;
213        _threadId = tid;
214        privateFlags.set(VALID_CONTEXT_ID|VALID_THREAD_ID);
215    }
216
217    /**
218     * Set up a physical (e.g. device) request in a previously
219     * allocated Request object.
220     */
221    void
222    setPhys(Addr paddr, int size, Flags flags, Tick time)
223    {
224        assert(size >= 0);
225        _paddr = paddr;
226        _size = size;
227        _time = time;
228
229        _flags.clear(~STICKY_FLAGS);
230        _flags.set(flags);
231        privateFlags.clear(~STICKY_PRIVATE_FLAGS);
232        privateFlags.set(VALID_PADDR|VALID_SIZE);
233    }
234
235    void
236    setPhys(Addr paddr, int size, Flags flags)
237    {
238        setPhys(paddr, size, flags, curTick);
239    }
240
241    /**
242     * Set up a virtual (e.g., CPU) request in a previously
243     * allocated Request object.
244     */
245    void
246    setVirt(int asid, Addr vaddr, int size, Flags flags, Addr pc)
247    {
248        assert(size >= 0);
249        _asid = asid;
250        _vaddr = vaddr;
251        _size = size;
252        _pc = pc;
253        _time = curTick;
254
255        _flags.clear(~STICKY_FLAGS);
256        _flags.set(flags);
257        privateFlags.clear(~STICKY_PRIVATE_FLAGS);
258        privateFlags.set(VALID_VADDR|VALID_SIZE|VALID_PC);
259    }
260
261    /**
262     * Set just the physical address.  This should only be used to
263     * record the result of a translation, and thus the vaddr must be
264     * valid before this method is called.  Otherwise, use setPhys()
265     * to guarantee that the size and flags are also set.
266     */
267    void
268    setPaddr(Addr paddr)
269    {
270        assert(privateFlags.isSet(VALID_VADDR));
271        _paddr = paddr;
272        privateFlags.set(VALID_PADDR);
273    }
274
275    /**
276     * Generate two requests as if this request had been split into two
277     * pieces. The original request can't have been translated already.
278     */
279    void splitOnVaddr(Addr split_addr, RequestPtr &req1, RequestPtr &req2)
280    {
281        assert(privateFlags.isSet(VALID_VADDR));
282        assert(privateFlags.noneSet(VALID_PADDR));
283        assert(split_addr > _vaddr && split_addr < _vaddr + _size);
284        req1 = new Request;
285        *req1 = *this;
286        req2 = new Request;
287        *req2 = *this;
288        req1->_size = split_addr - _vaddr;
289        req2->_vaddr = split_addr;
290        req2->_size = _size - req1->_size;
291    }
292
293    /**
294     * Accessor for paddr.
295     */
296    bool
297    hasPaddr()
298    {
299        return privateFlags.isSet(VALID_PADDR);
300    }
301
302    Addr
303    getPaddr()
304    {
305        assert(privateFlags.isSet(VALID_PADDR));
306        return _paddr;
307    }
308
309    /**
310     *  Accessor for size.
311     */
312    bool
313    hasSize()
314    {
315        return privateFlags.isSet(VALID_SIZE);
316    }
317
318    int
319    getSize()
320    {
321        assert(privateFlags.isSet(VALID_SIZE));
322        return _size;
323    }
324
325    /** Accessor for time. */
326    Tick
327    time() const
328    {
329        assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
330        return _time;
331    }
332
333    void
334    time(Tick time)
335    {
336        assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
337        _time = time;
338    }
339
340    /** Accessor for flags. */
341    Flags
342    getFlags()
343    {
344        assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
345        return _flags;
346    }
347
348    /** Note that unlike other accessors, this function sets *specific
349       flags* (ORs them in); it does not assign its argument to the
350       _flags field.  Thus this method should rightly be called
351       setFlags() and not just flags(). */
352    void
353    setFlags(Flags flags)
354    {
355        assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
356        _flags.set(flags);
357    }
358
359    /** Accessor function for vaddr.*/
360    Addr
361    getVaddr()
362    {
363        assert(privateFlags.isSet(VALID_VADDR));
364        return _vaddr;
365    }
366
367    /** Accessor function for asid.*/
368    int
369    getAsid()
370    {
371        assert(privateFlags.isSet(VALID_VADDR));
372        return _asid;
373    }
374
375    /** Accessor function for asi.*/
376    uint8_t
377    getAsi()
378    {
379        assert(privateFlags.isSet(VALID_VADDR));
380        return _flags & ASI_BITS;
381    }
382
383    /** Accessor function to check if sc result is valid. */
384    bool
385    extraDataValid()
386    {
387        return privateFlags.isSet(VALID_EXTRA_DATA);
388    }
389
390    /** Accessor function for store conditional return value.*/
391    uint64_t
392    getExtraData() const
393    {
394        assert(privateFlags.isSet(VALID_EXTRA_DATA));
395        return _extraData;
396    }
397
398    /** Accessor function for store conditional return value.*/
399    void
400    setExtraData(uint64_t extraData)
401    {
402        _extraData = extraData;
403        privateFlags.set(VALID_EXTRA_DATA);
404    }
405
406    bool
407    hasContextId() const
408    {
409        return privateFlags.isSet(VALID_CONTEXT_ID);
410    }
411
412    /** Accessor function for context ID.*/
413    int
414    contextId() const
415    {
416        assert(privateFlags.isSet(VALID_CONTEXT_ID));
417        return _contextId;
418    }
419
420    /** Accessor function for thread ID. */
421    int
422    threadId() const
423    {
424        assert(privateFlags.isSet(VALID_THREAD_ID));
425        return _threadId;
426    }
427
428    bool
429    hasPC() const
430    {
431        return privateFlags.isSet(VALID_PC);
432    }
433
434    /** Accessor function for pc.*/
435    Addr
436    getPC() const
437    {
438        assert(privateFlags.isSet(VALID_PC));
439        return _pc;
440    }
441
442    /** Accessor functions for flags.  Note that these are for testing
443       only; setting flags should be done via setFlags(). */
444    bool isUncacheable() const { return _flags.isSet(UNCACHEABLE); }
445    bool isInstFetch() const { return _flags.isSet(INST_FETCH); }
446    bool isPrefetch() const { return _flags.isSet(PREFETCH); }
447    bool isLLSC() const { return _flags.isSet(LLSC); }
448    bool isLocked() const { return _flags.isSet(LOCKED); }
449    bool isSwap() const { return _flags.isSet(MEM_SWAP|MEM_SWAP_COND); }
450    bool isCondSwap() const { return _flags.isSet(MEM_SWAP_COND); }
451    bool isMmapedIpr() const { return _flags.isSet(MMAPED_IPR); }
452
453    bool
454    isMisaligned() const
455    {
456        if (_flags.isSet(NO_ALIGN_FAULT))
457            return false;
458
459        if ((_vaddr & 0x1))
460            return true;
461
462        if (_flags.isSet(NO_HALF_WORD_ALIGN_FAULT))
463            return false;
464
465        if ((_vaddr & 0x2))
466            return true;
467
468        return false;
469    }
470};
471
472#endif // __MEM_REQUEST_HH__
473