request.hh revision 6106 
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 "sim/host.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 is a Load locked/store conditional. */
63    static const FlagsType LLSC                        = 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    /** The request should not cause a page fault. */
73    static const FlagsType NO_FAULT                    = 0x00002000;
74    /** The request should not cause a memory access. */
75    static const FlagsType NO_ACCESS                   = 0x00004000;
76    /** This request will lock or unlock the accessed memory. When used with
77     * a load, the access locks the particular chunk of memory. When used
78     * with a store, it unlocks. The rule is that locked accesses have to be
79     * made up of a locked load, some operation on the data, and then a locked
80     * store.
81     */
82    static const FlagsType LOCKED                      = 0x00008000;
83    /** The request should be prefetched into the exclusive state. */
84    static const FlagsType PF_EXCLUSIVE                = 0x00010000;
85    /** The request should be marked as LRU. */
86    static const FlagsType EVICT_NEXT                  = 0x00020000;
87    /** The request should ignore unaligned access faults */
88    static const FlagsType NO_ALIGN_FAULT              = 0x00040000;
89    /** The request was an instruction fetch. */
90    static const FlagsType INST_FETCH                  = 0x00080000;
91    /** This request is for a memory swap. */
92    static const FlagsType MEM_SWAP                    = 0x00100000;
93    static const FlagsType MEM_SWAP_COND               = 0x00200000;
94    /** The request should ignore unaligned access faults */
95    static const FlagsType NO_HALF_WORD_ALIGN_FAULT    = 0x00400000;
96    /** This request is to a memory mapped register. */
97    static const FlagsType MMAPED_IPR                  = 0x00800000;
98    /** The request is a prefetch. */
99    static const FlagsType PREFETCH                    = 0x01000000;
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    Request()
177    {}
178
179    /**
180     * Constructor for physical (e.g. device) requests.  Initializes
181     * just physical address, size, flags, and timestamp (to curTick).
182     * These fields are adequate to perform a request.
183     */
184    Request(Addr paddr, int size, Flags flags)
185    {
186        setPhys(paddr, size, flags);
187    }
188
189    Request(int asid, Addr vaddr, int size, Flags flags, Addr pc,
190            int cid, int tid)
191    {
192        setVirt(asid, vaddr, size, flags, pc);
193        setThreadContext(cid, tid);
194    }
195
196    ~Request() {}  // for FastAlloc
197
198    /**
199     * Set up CPU and thread numbers.
200     */
201    void
202    setThreadContext(int context_id, int thread_id)
203    {
204        _contextId = context_id;
205        _threadId = thread_id;
206        privateFlags.set(VALID_CONTEXT_ID|VALID_THREAD_ID);
207    }
208
209    /**
210     * Set up a physical (e.g. device) request in a previously
211     * allocated Request object.
212     */
213    void
214    setPhys(Addr _paddr, int _size, Flags _flags)
215    {
216        assert(_size >= 0);
217        paddr = _paddr;
218        size = _size;
219        time = curTick;
220
221        flags.clear(~STICKY_FLAGS);
222        flags.set(_flags);
223        privateFlags.clear(~STICKY_PRIVATE_FLAGS);
224        privateFlags.set(VALID_PADDR|VALID_SIZE);
225    }
226
227    /**
228     * Set up a virtual (e.g., CPU) request in a previously
229     * allocated Request object.
230     */
231    void
232    setVirt(int _asid, Addr _vaddr, int _size, Flags _flags, Addr _pc)
233    {
234        assert(_size >= 0);
235        asid = _asid;
236        vaddr = _vaddr;
237        size = _size;
238        flags = _flags;
239        pc = _pc;
240        time = curTick;
241
242        flags.clear(~STICKY_FLAGS);
243        flags.set(_flags);
244        privateFlags.clear(~STICKY_PRIVATE_FLAGS);
245        privateFlags.set(VALID_VADDR|VALID_SIZE|VALID_PC);
246    }
247
248    /**
249     * Set just the physical address.  This should only be used to
250     * record the result of a translation, and thus the vaddr must be
251     * valid before this method is called.  Otherwise, use setPhys()
252     * to guarantee that the size and flags are also set.
253     */
254    void
255    setPaddr(Addr _paddr)
256    {
257        assert(privateFlags.isSet(VALID_VADDR));
258        paddr = _paddr;
259        privateFlags.set(VALID_PADDR);
260    }
261
262    /**
263     * Generate two requests as if this request had been split into two
264     * pieces. The original request can't have been translated already.
265     */
266    void splitOnVaddr(Addr split_addr, RequestPtr &req1, RequestPtr &req2)
267    {
268        assert(privateFlags.isSet(VALID_VADDR));
269        assert(privateFlags.noneSet(VALID_PADDR));
270        assert(split_addr > vaddr && split_addr < vaddr + size);
271        req1 = new Request;
272        *req1 = *this;
273        req2 = new Request;
274        *req2 = *this;
275        req1->size = split_addr - vaddr;
276        req2->vaddr = split_addr;
277        req2->size = size - req1->size;
278    }
279
280    /**
281     * Accessor for paddr.
282     */
283    bool
284    hasPaddr()
285    {
286        return privateFlags.isSet(VALID_PADDR);
287    }
288
289    Addr
290    getPaddr()
291    {
292        assert(privateFlags.isSet(VALID_PADDR));
293        return paddr;
294    }
295
296    /**
297     *  Accessor for size.
298     */
299    bool
300    hasSize()
301    {
302        return privateFlags.isSet(VALID_SIZE);
303    }
304
305    int
306    getSize()
307    {
308        assert(privateFlags.isSet(VALID_SIZE));
309        return size;
310    }
311
312    /** Accessor for time. */
313    Tick
314    getTime()
315    {
316        assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
317        return time;
318    }
319
320    /** Accessor for flags. */
321    Flags
322    getFlags()
323    {
324        assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
325        return flags;
326    }
327
328    void
329    setFlags(Flags _flags)
330    {
331        assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
332        flags.set(_flags);
333    }
334
335    /** Accessor function for vaddr.*/
336    Addr
337    getVaddr()
338    {
339        assert(privateFlags.isSet(VALID_VADDR));
340        return vaddr;
341    }
342
343    /** Accessor function for asid.*/
344    int
345    getAsid()
346    {
347        assert(privateFlags.isSet(VALID_VADDR));
348        return asid;
349    }
350
351    /** Accessor function for asi.*/
352    uint8_t
353    getAsi()
354    {
355        assert(privateFlags.isSet(VALID_VADDR));
356        return flags & ASI_BITS;
357    }
358
359    /** Accessor function for MMAPED_IPR flag. */
360    bool
361    isMmapedIpr()
362    {
363        assert(privateFlags.isSet(VALID_PADDR));
364        return flags.isSet(MMAPED_IPR);
365    }
366
367    void
368    setMmapedIpr(bool r)
369    {
370        assert(VALID_VADDR);
371        flags.set(MMAPED_IPR);
372    }
373
374    /** Accessor function to check if sc result is valid. */
375    bool
376    extraDataValid()
377    {
378        return privateFlags.isSet(VALID_EXTRA_DATA);
379    }
380
381    /** Accessor function for store conditional return value.*/
382    uint64_t
383    getExtraData() const
384    {
385        assert(privateFlags.isSet(VALID_EXTRA_DATA));
386        return extraData;
387    }
388
389    /** Accessor function for store conditional return value.*/
390    void
391    setExtraData(uint64_t _extraData)
392    {
393        extraData = _extraData;
394        privateFlags.set(VALID_EXTRA_DATA);
395    }
396
397    bool
398    hasContextId() const
399    {
400        return privateFlags.isSet(VALID_CONTEXT_ID);
401    }
402
403    /** Accessor function for context ID.*/
404    int
405    contextId() const
406    {
407        assert(privateFlags.isSet(VALID_CONTEXT_ID));
408        return _contextId;
409    }
410
411    /** Accessor function for thread ID. */
412    int
413    threadId() const
414    {
415        assert(privateFlags.isSet(VALID_THREAD_ID));
416        return _threadId;
417    }
418
419    bool
420    hasPC() const
421    {
422        return privateFlags.isSet(VALID_PC);
423    }
424
425    /** Accessor function for pc.*/
426    Addr
427    getPC() const
428    {
429        assert(privateFlags.isSet(VALID_PC));
430        return pc;
431    }
432
433    /** Accessor Function to Check Cacheability. */
434    bool isUncacheable() const { return flags.isSet(UNCACHEABLE); }
435    bool isInstFetch() const { return flags.isSet(INST_FETCH); }
436    bool isPrefetch() const { return flags.isSet(PREFETCH); }
437    bool isLLSC() const { return flags.isSet(LLSC); }
438    bool isLocked() const { return flags.isSet(LOCKED); }
439    bool isSwap() const { return flags.isSet(MEM_SWAP|MEM_SWAP_COND); }
440    bool isCondSwap() const { return flags.isSet(MEM_SWAP_COND); }
441
442    bool
443    isMisaligned() const
444    {
445        if (flags.isSet(NO_ALIGN_FAULT))
446            return false;
447
448        if ((vaddr & 0x1))
449            return true;
450
451        if (flags.isSet(NO_HALF_WORD_ALIGN_FAULT))
452            return false;
453
454        if ((vaddr & 0x2))
455            return true;
456
457        return false;
458    }
459};
460
461#endif // __MEM_REQUEST_HH__
462