request.hh revision 6428:9e35cdc95e81 
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 not cause a page fault. */
76    static const FlagsType NO_FAULT                    = 0x00010000;
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(int asid, Addr vaddr, int size, Flags flags, Addr pc,
200            int cid, ThreadID tid)
201    {
202        setVirt(asid, vaddr, size, flags, pc);
203        setThreadContext(cid, tid);
204    }
205
206    ~Request() {}  // for FastAlloc
207
208    /**
209     * Set up CPU and thread numbers.
210     */
211    void
212    setThreadContext(int context_id, ThreadID tid)
213    {
214        _contextId = context_id;
215        _threadId = tid;
216        privateFlags.set(VALID_CONTEXT_ID|VALID_THREAD_ID);
217    }
218
219    /**
220     * Set up a physical (e.g. device) request in a previously
221     * allocated Request object.
222     */
223    void
224    setPhys(Addr paddr, int size, Flags flags, Tick time)
225    {
226        assert(size >= 0);
227        _paddr = paddr;
228        _size = size;
229        _time = time;
230
231        _flags.clear(~STICKY_FLAGS);
232        _flags.set(flags);
233        privateFlags.clear(~STICKY_PRIVATE_FLAGS);
234        privateFlags.set(VALID_PADDR|VALID_SIZE);
235    }
236
237    void
238    setPhys(Addr paddr, int size, Flags flags)
239    {
240        setPhys(paddr, size, flags, curTick);
241    }
242
243    /**
244     * Set up a virtual (e.g., CPU) request in a previously
245     * allocated Request object.
246     */
247    void
248    setVirt(int asid, Addr vaddr, int size, Flags flags, Addr pc)
249    {
250        assert(size >= 0);
251        _asid = asid;
252        _vaddr = vaddr;
253        _size = size;
254        _pc = pc;
255        _time = curTick;
256
257        _flags.clear(~STICKY_FLAGS);
258        _flags.set(flags);
259        privateFlags.clear(~STICKY_PRIVATE_FLAGS);
260        privateFlags.set(VALID_VADDR|VALID_SIZE|VALID_PC);
261    }
262
263    /**
264     * Set just the physical address.  This should only be used to
265     * record the result of a translation, and thus the vaddr must be
266     * valid before this method is called.  Otherwise, use setPhys()
267     * to guarantee that the size and flags are also set.
268     */
269    void
270    setPaddr(Addr paddr)
271    {
272        assert(privateFlags.isSet(VALID_VADDR));
273        _paddr = paddr;
274        privateFlags.set(VALID_PADDR);
275    }
276
277    /**
278     * Generate two requests as if this request had been split into two
279     * pieces. The original request can't have been translated already.
280     */
281    void splitOnVaddr(Addr split_addr, RequestPtr &req1, RequestPtr &req2)
282    {
283        assert(privateFlags.isSet(VALID_VADDR));
284        assert(privateFlags.noneSet(VALID_PADDR));
285        assert(split_addr > _vaddr && split_addr < _vaddr + _size);
286        req1 = new Request;
287        *req1 = *this;
288        req2 = new Request;
289        *req2 = *this;
290        req1->_size = split_addr - _vaddr;
291        req2->_vaddr = split_addr;
292        req2->_size = _size - req1->_size;
293    }
294
295    /**
296     * Accessor for paddr.
297     */
298    bool
299    hasPaddr()
300    {
301        return privateFlags.isSet(VALID_PADDR);
302    }
303
304    Addr
305    getPaddr()
306    {
307        assert(privateFlags.isSet(VALID_PADDR));
308        return _paddr;
309    }
310
311    /**
312     *  Accessor for size.
313     */
314    bool
315    hasSize()
316    {
317        return privateFlags.isSet(VALID_SIZE);
318    }
319
320    int
321    getSize()
322    {
323        assert(privateFlags.isSet(VALID_SIZE));
324        return _size;
325    }
326
327    /** Accessor for time. */
328    Tick
329    time() const
330    {
331        assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
332        return _time;
333    }
334
335    void
336    time(Tick time)
337    {
338        assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
339        _time = time;
340    }
341
342    /** Accessor for flags. */
343    Flags
344    getFlags()
345    {
346        assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
347        return _flags;
348    }
349
350    /** Note that unlike other accessors, this function sets *specific
351       flags* (ORs them in); it does not assign its argument to the
352       _flags field.  Thus this method should rightly be called
353       setFlags() and not just flags(). */
354    void
355    setFlags(Flags flags)
356    {
357        assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
358        _flags.set(flags);
359    }
360
361    /** Accessor function for vaddr.*/
362    Addr
363    getVaddr()
364    {
365        assert(privateFlags.isSet(VALID_VADDR));
366        return _vaddr;
367    }
368
369    /** Accessor function for asid.*/
370    int
371    getAsid()
372    {
373        assert(privateFlags.isSet(VALID_VADDR));
374        return _asid;
375    }
376
377    /** Accessor function for asi.*/
378    uint8_t
379    getAsi()
380    {
381        assert(privateFlags.isSet(VALID_VADDR));
382        return _flags & ASI_BITS;
383    }
384
385    /** Accessor function to check if sc result is valid. */
386    bool
387    extraDataValid()
388    {
389        return privateFlags.isSet(VALID_EXTRA_DATA);
390    }
391
392    /** Accessor function for store conditional return value.*/
393    uint64_t
394    getExtraData() const
395    {
396        assert(privateFlags.isSet(VALID_EXTRA_DATA));
397        return _extraData;
398    }
399
400    /** Accessor function for store conditional return value.*/
401    void
402    setExtraData(uint64_t extraData)
403    {
404        _extraData = extraData;
405        privateFlags.set(VALID_EXTRA_DATA);
406    }
407
408    bool
409    hasContextId() const
410    {
411        return privateFlags.isSet(VALID_CONTEXT_ID);
412    }
413
414    /** Accessor function for context ID.*/
415    int
416    contextId() const
417    {
418        assert(privateFlags.isSet(VALID_CONTEXT_ID));
419        return _contextId;
420    }
421
422    /** Accessor function for thread ID. */
423    int
424    threadId() const
425    {
426        assert(privateFlags.isSet(VALID_THREAD_ID));
427        return _threadId;
428    }
429
430    bool
431    hasPC() const
432    {
433        return privateFlags.isSet(VALID_PC);
434    }
435
436    /** Accessor function for pc.*/
437    Addr
438    getPC() const
439    {
440        assert(privateFlags.isSet(VALID_PC));
441        return _pc;
442    }
443
444    /** Accessor functions for flags.  Note that these are for testing
445       only; setting flags should be done via setFlags(). */
446    bool isUncacheable() const { return _flags.isSet(UNCACHEABLE); }
447    bool isInstFetch() const { return _flags.isSet(INST_FETCH); }
448    bool isPrefetch() const { return _flags.isSet(PREFETCH); }
449    bool isLLSC() const { return _flags.isSet(LLSC); }
450    bool isLocked() const { return _flags.isSet(LOCKED); }
451    bool isSwap() const { return _flags.isSet(MEM_SWAP|MEM_SWAP_COND); }
452    bool isCondSwap() const { return _flags.isSet(MEM_SWAP_COND); }
453    bool isMmapedIpr() const { return _flags.isSet(MMAPED_IPR); }
454
455    bool
456    isMisaligned() const
457    {
458        if (_flags.isSet(NO_ALIGN_FAULT))
459            return false;
460
461        if ((_vaddr & 0x1))
462            return true;
463
464        if (_flags.isSet(NO_HALF_WORD_ALIGN_FAULT))
465            return false;
466
467        if ((_vaddr & 0x2))
468            return true;
469
470        return false;
471    }
472};
473
474#endif // __MEM_REQUEST_HH__
475