request.hh revision 7823:dac01f14f20f 
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 not cause a memory access. */
78    static const FlagsType NO_ACCESS                   = 0x00080000;
79    /** This request will lock or unlock the accessed memory. When used with
80     * a load, the access locks the particular chunk of memory. When used
81     * with a store, it unlocks. The rule is that locked accesses have to be
82     * made up of a locked load, some operation on the data, and then a locked
83     * store.
84     */
85    static const FlagsType LOCKED                      = 0x00100000;
86    /** The request is a Load locked/store conditional. */
87    static const FlagsType LLSC                        = 0x00200000;
88    /** This request is for a memory swap. */
89    static const FlagsType MEM_SWAP                    = 0x00400000;
90    static const FlagsType MEM_SWAP_COND               = 0x00800000;
91
92    /** The request is a prefetch. */
93    static const FlagsType PREFETCH                    = 0x01000000;
94    /** The request should be prefetched into the exclusive state. */
95    static const FlagsType PF_EXCLUSIVE                = 0x02000000;
96    /** The request should be marked as LRU. */
97    static const FlagsType EVICT_NEXT                  = 0x04000000;
98
99    /** These flags are *not* cleared when a Request object is reused
100       (assigned a new address). */
101    static const FlagsType STICKY_FLAGS = INST_FETCH;
102
103  private:
104    typedef uint8_t PrivateFlagsType;
105    typedef ::Flags<PrivateFlagsType> PrivateFlags;
106
107    /** Whether or not the size is valid. */
108    static const PrivateFlagsType VALID_SIZE           = 0x00000001;
109    /** Whether or not paddr is valid (has been written yet). */
110    static const PrivateFlagsType VALID_PADDR          = 0x00000002;
111    /** Whether or not the vaddr & asid are valid. */
112    static const PrivateFlagsType VALID_VADDR          = 0x00000004;
113    /** Whether or not the pc is valid. */
114    static const PrivateFlagsType VALID_PC             = 0x00000010;
115    /** Whether or not the context ID is valid. */
116    static const PrivateFlagsType VALID_CONTEXT_ID     = 0x00000020;
117    static const PrivateFlagsType VALID_THREAD_ID      = 0x00000040;
118    /** Whether or not the sc result is valid. */
119    static const PrivateFlagsType VALID_EXTRA_DATA     = 0x00000080;
120
121    /** These flags are *not* cleared when a Request object is reused
122       (assigned a new address). */
123    static const PrivateFlagsType STICKY_PRIVATE_FLAGS =
124        VALID_CONTEXT_ID | VALID_THREAD_ID;
125
126  private:
127    /**
128     * The physical address of the request. Valid only if validPaddr
129     * is set.
130     */
131    Addr _paddr;
132
133    /**
134     * The size of the request. This field must be set when vaddr or
135     * paddr is written via setVirt() or setPhys(), so it is always
136     * valid as long as one of the address fields is valid.
137     */
138    int _size;
139
140    /** Flag structure for the request. */
141    Flags _flags;
142
143    /** Private flags for field validity checking. */
144    PrivateFlags privateFlags;
145
146    /**
147     * The time this request was started. Used to calculate
148     * latencies. This field is set to curTick() any time paddr or vaddr
149     * is written.
150     */
151    Tick _time;
152
153    /** The address space ID. */
154    int _asid;
155
156    /** The virtual address of the request. */
157    Addr _vaddr;
158
159    /**
160     * Extra data for the request, such as the return value of
161     * store conditional or the compare value for a CAS. */
162    uint64_t _extraData;
163
164    /** The context ID (for statistics, typically). */
165    int _contextId;
166    /** The thread ID (id within this CPU) */
167    int _threadId;
168
169    /** program counter of initiating access; for tracing/debugging */
170    Addr _pc;
171
172  public:
173    /** Minimal constructor.  No fields are initialized.
174     *  (Note that _flags and privateFlags are cleared by Flags
175     *  default constructor.)
176     */
177    Request()
178    {}
179
180    /**
181     * Constructor for physical (e.g. device) requests.  Initializes
182     * just physical address, size, flags, and timestamp (to curTick()).
183     * These fields are adequate to perform a request.
184     */
185    Request(Addr paddr, int size, Flags flags)
186    {
187        setPhys(paddr, size, flags);
188    }
189
190    Request(Addr paddr, int size, Flags flags, Tick time)
191    {
192        setPhys(paddr, size, flags, time);
193    }
194
195    Request(Addr paddr, int size, Flags flags, Tick time, Addr pc)
196    {
197        setPhys(paddr, size, flags, time);
198        privateFlags.set(VALID_PC);
199        _pc = pc;
200    }
201
202    Request(int asid, Addr vaddr, int size, Flags flags, Addr pc,
203            int cid, ThreadID tid)
204    {
205        setVirt(asid, vaddr, size, flags, pc);
206        setThreadContext(cid, tid);
207    }
208
209    ~Request() {}  // for FastAlloc
210
211    /**
212     * Set up CPU and thread numbers.
213     */
214    void
215    setThreadContext(int context_id, ThreadID tid)
216    {
217        _contextId = context_id;
218        _threadId = tid;
219        privateFlags.set(VALID_CONTEXT_ID|VALID_THREAD_ID);
220    }
221
222    /**
223     * Set up a physical (e.g. device) request in a previously
224     * allocated Request object.
225     */
226    void
227    setPhys(Addr paddr, int size, Flags flags, Tick time)
228    {
229        assert(size >= 0);
230        _paddr = paddr;
231        _size = size;
232        _time = time;
233
234        _flags.clear(~STICKY_FLAGS);
235        _flags.set(flags);
236        privateFlags.clear(~STICKY_PRIVATE_FLAGS);
237        privateFlags.set(VALID_PADDR|VALID_SIZE);
238    }
239
240    void
241    setPhys(Addr paddr, int size, Flags flags)
242    {
243        setPhys(paddr, size, flags, curTick());
244    }
245
246    /**
247     * Set up a virtual (e.g., CPU) request in a previously
248     * allocated Request object.
249     */
250    void
251    setVirt(int asid, Addr vaddr, int size, Flags flags, Addr pc)
252    {
253        assert(size >= 0);
254        _asid = asid;
255        _vaddr = vaddr;
256        _size = size;
257        _pc = pc;
258        _time = curTick();
259
260        _flags.clear(~STICKY_FLAGS);
261        _flags.set(flags);
262        privateFlags.clear(~STICKY_PRIVATE_FLAGS);
263        privateFlags.set(VALID_VADDR|VALID_SIZE|VALID_PC);
264    }
265
266    /**
267     * Set just the physical address.  This should only be used to
268     * record the result of a translation, and thus the vaddr must be
269     * valid before this method is called.  Otherwise, use setPhys()
270     * to guarantee that the size and flags are also set.
271     */
272    void
273    setPaddr(Addr paddr)
274    {
275        assert(privateFlags.isSet(VALID_VADDR));
276        _paddr = paddr;
277        privateFlags.set(VALID_PADDR);
278    }
279
280    /**
281     * Generate two requests as if this request had been split into two
282     * pieces. The original request can't have been translated already.
283     */
284    void splitOnVaddr(Addr split_addr, RequestPtr &req1, RequestPtr &req2)
285    {
286        assert(privateFlags.isSet(VALID_VADDR));
287        assert(privateFlags.noneSet(VALID_PADDR));
288        assert(split_addr > _vaddr && split_addr < _vaddr + _size);
289        req1 = new Request;
290        *req1 = *this;
291        req2 = new Request;
292        *req2 = *this;
293        req1->_size = split_addr - _vaddr;
294        req2->_vaddr = split_addr;
295        req2->_size = _size - req1->_size;
296    }
297
298    /**
299     * Accessor for paddr.
300     */
301    bool
302    hasPaddr()
303    {
304        return privateFlags.isSet(VALID_PADDR);
305    }
306
307    Addr
308    getPaddr()
309    {
310        assert(privateFlags.isSet(VALID_PADDR));
311        return _paddr;
312    }
313
314    /**
315     *  Accessor for size.
316     */
317    bool
318    hasSize()
319    {
320        return privateFlags.isSet(VALID_SIZE);
321    }
322
323    int
324    getSize()
325    {
326        assert(privateFlags.isSet(VALID_SIZE));
327        return _size;
328    }
329
330    /** Accessor for time. */
331    Tick
332    time() const
333    {
334        assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
335        return _time;
336    }
337
338    void
339    time(Tick time)
340    {
341        assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
342        _time = time;
343    }
344
345    /** Accessor for flags. */
346    Flags
347    getFlags()
348    {
349        assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
350        return _flags;
351    }
352
353    /** Note that unlike other accessors, this function sets *specific
354       flags* (ORs them in); it does not assign its argument to the
355       _flags field.  Thus this method should rightly be called
356       setFlags() and not just flags(). */
357    void
358    setFlags(Flags flags)
359    {
360        assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
361        _flags.set(flags);
362    }
363
364    /** Accessor function for vaddr.*/
365    Addr
366    getVaddr()
367    {
368        assert(privateFlags.isSet(VALID_VADDR));
369        return _vaddr;
370    }
371
372    /** Accessor function for asid.*/
373    int
374    getAsid()
375    {
376        assert(privateFlags.isSet(VALID_VADDR));
377        return _asid;
378    }
379
380    /** Accessor function for asi.*/
381    uint8_t
382    getAsi()
383    {
384        assert(privateFlags.isSet(VALID_VADDR));
385        return _flags & ASI_BITS;
386    }
387
388    /** Accessor function to check if sc result is valid. */
389    bool
390    extraDataValid()
391    {
392        return privateFlags.isSet(VALID_EXTRA_DATA);
393    }
394
395    /** Accessor function for store conditional return value.*/
396    uint64_t
397    getExtraData() const
398    {
399        assert(privateFlags.isSet(VALID_EXTRA_DATA));
400        return _extraData;
401    }
402
403    /** Accessor function for store conditional return value.*/
404    void
405    setExtraData(uint64_t extraData)
406    {
407        _extraData = extraData;
408        privateFlags.set(VALID_EXTRA_DATA);
409    }
410
411    bool
412    hasContextId() const
413    {
414        return privateFlags.isSet(VALID_CONTEXT_ID);
415    }
416
417    /** Accessor function for context ID.*/
418    int
419    contextId() const
420    {
421        assert(privateFlags.isSet(VALID_CONTEXT_ID));
422        return _contextId;
423    }
424
425    /** Accessor function for thread ID. */
426    int
427    threadId() const
428    {
429        assert(privateFlags.isSet(VALID_THREAD_ID));
430        return _threadId;
431    }
432
433    bool
434    hasPC() const
435    {
436        return privateFlags.isSet(VALID_PC);
437    }
438
439    /** Accessor function for pc.*/
440    Addr
441    getPC() const
442    {
443        assert(privateFlags.isSet(VALID_PC));
444        return _pc;
445    }
446
447    /** Accessor functions for flags.  Note that these are for testing
448       only; setting flags should be done via setFlags(). */
449    bool isUncacheable() const { return _flags.isSet(UNCACHEABLE); }
450    bool isInstFetch() const { return _flags.isSet(INST_FETCH); }
451    bool isPrefetch() const { return _flags.isSet(PREFETCH); }
452    bool isLLSC() const { return _flags.isSet(LLSC); }
453    bool isLocked() const { return _flags.isSet(LOCKED); }
454    bool isSwap() const { return _flags.isSet(MEM_SWAP|MEM_SWAP_COND); }
455    bool isCondSwap() const { return _flags.isSet(MEM_SWAP_COND); }
456    bool isMmapedIpr() const { return _flags.isSet(MMAPED_IPR); }
457    bool isClearLL() const { return _flags.isSet(CLEAR_LL); }
458};
459
460#endif // __MEM_REQUEST_HH__
461