request.hh revision 6223:3623155c0e95 
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    Request()
179    {}
180
181    /**
182     * Constructor for physical (e.g. device) requests.  Initializes
183     * just physical address, size, flags, and timestamp (to curTick).
184     * These fields are adequate to perform a request.
185     */
186    Request(Addr paddr, int size, Flags flags)
187    {
188        setPhys(paddr, size, flags);
189    }
190
191    Request(Addr paddr, int size, Flags flags, Tick time)
192    {
193        setPhys(paddr, size, flags, time);
194    }
195
196    Request(int asid, Addr vaddr, int size, Flags flags, Addr pc,
197            int cid, ThreadID tid)
198    {
199        setVirt(asid, vaddr, size, flags, pc);
200        setThreadContext(cid, tid);
201    }
202
203    ~Request() {}  // for FastAlloc
204
205    /**
206     * Set up CPU and thread numbers.
207     */
208    void
209    setThreadContext(int context_id, ThreadID tid)
210    {
211        _contextId = context_id;
212        _threadId = tid;
213        privateFlags.set(VALID_CONTEXT_ID|VALID_THREAD_ID);
214    }
215
216    /**
217     * Set up a physical (e.g. device) request in a previously
218     * allocated Request object.
219     */
220    void
221    setPhys(Addr _paddr, int _size, Flags _flags, Tick time)
222    {
223        assert(_size >= 0);
224        paddr = _paddr;
225        size = _size;
226        _time = time;
227
228        flags.clear(~STICKY_FLAGS);
229        flags.set(_flags);
230        privateFlags.clear(~STICKY_PRIVATE_FLAGS);
231        privateFlags.set(VALID_PADDR|VALID_SIZE);
232    }
233
234    void
235    setPhys(Addr _paddr, int _size, Flags _flags)
236    {
237        setPhys(_paddr, _size, _flags, curTick);
238    }
239
240    /**
241     * Set up a virtual (e.g., CPU) request in a previously
242     * allocated Request object.
243     */
244    void
245    setVirt(int _asid, Addr _vaddr, int _size, Flags _flags, Addr _pc)
246    {
247        assert(_size >= 0);
248        asid = _asid;
249        vaddr = _vaddr;
250        size = _size;
251        flags = _flags;
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    void
349    setFlags(Flags _flags)
350    {
351        assert(privateFlags.isSet(VALID_PADDR|VALID_VADDR));
352        flags.set(_flags);
353    }
354
355    /** Accessor function for vaddr.*/
356    Addr
357    getVaddr()
358    {
359        assert(privateFlags.isSet(VALID_VADDR));
360        return vaddr;
361    }
362
363    /** Accessor function for asid.*/
364    int
365    getAsid()
366    {
367        assert(privateFlags.isSet(VALID_VADDR));
368        return asid;
369    }
370
371    /** Accessor function for asi.*/
372    uint8_t
373    getAsi()
374    {
375        assert(privateFlags.isSet(VALID_VADDR));
376        return flags & ASI_BITS;
377    }
378
379    /** Accessor function for MMAPED_IPR flag. */
380    bool
381    isMmapedIpr()
382    {
383        assert(privateFlags.isSet(VALID_PADDR));
384        return flags.isSet(MMAPED_IPR);
385    }
386
387    void
388    setMmapedIpr(bool r)
389    {
390        assert(VALID_VADDR);
391        flags.set(MMAPED_IPR);
392    }
393
394    /** Accessor function to check if sc result is valid. */
395    bool
396    extraDataValid()
397    {
398        return privateFlags.isSet(VALID_EXTRA_DATA);
399    }
400
401    /** Accessor function for store conditional return value.*/
402    uint64_t
403    getExtraData() const
404    {
405        assert(privateFlags.isSet(VALID_EXTRA_DATA));
406        return extraData;
407    }
408
409    /** Accessor function for store conditional return value.*/
410    void
411    setExtraData(uint64_t _extraData)
412    {
413        extraData = _extraData;
414        privateFlags.set(VALID_EXTRA_DATA);
415    }
416
417    bool
418    hasContextId() const
419    {
420        return privateFlags.isSet(VALID_CONTEXT_ID);
421    }
422
423    /** Accessor function for context ID.*/
424    int
425    contextId() const
426    {
427        assert(privateFlags.isSet(VALID_CONTEXT_ID));
428        return _contextId;
429    }
430
431    /** Accessor function for thread ID. */
432    int
433    threadId() const
434    {
435        assert(privateFlags.isSet(VALID_THREAD_ID));
436        return _threadId;
437    }
438
439    bool
440    hasPC() const
441    {
442        return privateFlags.isSet(VALID_PC);
443    }
444
445    /** Accessor function for pc.*/
446    Addr
447    getPC() const
448    {
449        assert(privateFlags.isSet(VALID_PC));
450        return pc;
451    }
452
453    /** Accessor Function to Check Cacheability. */
454    bool isUncacheable() const { return flags.isSet(UNCACHEABLE); }
455    bool isInstFetch() const { return flags.isSet(INST_FETCH); }
456    bool isPrefetch() const { return flags.isSet(PREFETCH); }
457    bool isLLSC() const { return flags.isSet(LLSC); }
458    bool isLocked() const { return flags.isSet(LOCKED); }
459    bool isSwap() const { return flags.isSet(MEM_SWAP|MEM_SWAP_COND); }
460    bool isCondSwap() const { return flags.isSet(MEM_SWAP_COND); }
461
462    bool
463    isMisaligned() const
464    {
465        if (flags.isSet(NO_ALIGN_FAULT))
466            return false;
467
468        if ((vaddr & 0x1))
469            return true;
470
471        if (flags.isSet(NO_HALF_WORD_ALIGN_FAULT))
472            return false;
473
474        if ((vaddr & 0x2))
475            return true;
476
477        return false;
478    }
479};
480
481#endif // __MEM_REQUEST_HH__
482