abstract_mem.hh revision 11005
1/*
2 * Copyright (c) 2012 ARM Limited
3 * All rights reserved
4 *
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software
9 * licensed hereunder.  You may use the software subject to the license
10 * terms below provided that you ensure that this notice is replicated
11 * unmodified and in its entirety in all distributions of the software,
12 * modified or unmodified, in source code or in binary form.
13 *
14 * Copyright (c) 2001-2005 The Regents of The University of Michigan
15 * All rights reserved.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions are
19 * met: redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer;
21 * redistributions in binary form must reproduce the above copyright
22 * notice, this list of conditions and the following disclaimer in the
23 * documentation and/or other materials provided with the distribution;
24 * neither the name of the copyright holders nor the names of its
25 * contributors may be used to endorse or promote products derived from
26 * this software without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
39 *
40 * Authors: Ron Dreslinski
41 *          Andreas Hansson
42 */
43
44/**
45 * @file
46 * AbstractMemory declaration
47 */
48
49#ifndef __ABSTRACT_MEMORY_HH__
50#define __ABSTRACT_MEMORY_HH__
51
52#include "mem/mem_object.hh"
53#include "params/AbstractMemory.hh"
54#include "sim/stats.hh"
55
56
57class System;
58
59/**
60 * Locked address class that represents a physical address and a
61 * context id.
62 */
63class LockedAddr {
64
65  private:
66
67    // on alpha, minimum LL/SC granularity is 16 bytes, so lower
68    // bits need to masked off.
69    static const Addr Addr_Mask = 0xf;
70
71  public:
72
73    // locked address
74    Addr addr;
75
76    // locking hw context
77    const ContextID contextId;
78
79    static Addr mask(Addr paddr) { return (paddr & ~Addr_Mask); }
80
81    // check for matching execution context
82    bool matchesContext(Request *req) const
83    {
84        return (contextId == req->contextId());
85    }
86
87    LockedAddr(Request *req) : addr(mask(req->getPaddr())),
88                               contextId(req->contextId())
89    {}
90
91    // constructor for unserialization use
92    LockedAddr(Addr _addr, int _cid) : addr(_addr), contextId(_cid)
93    {}
94};
95
96/**
97 * An abstract memory represents a contiguous block of physical
98 * memory, with an associated address range, and also provides basic
99 * functionality for reading and writing this memory without any
100 * timing information. It is a MemObject since any subclass must have
101 * at least one slave port.
102 */
103class AbstractMemory : public MemObject
104{
105  protected:
106
107    // Address range of this memory
108    AddrRange range;
109
110    // Pointer to host memory used to implement this memory
111    uint8_t* pmemAddr;
112
113    // Enable specific memories to be reported to the configuration table
114    bool confTableReported;
115
116    // Should the memory appear in the global address map
117    bool inAddrMap;
118
119    std::list<LockedAddr> lockedAddrList;
120
121    // helper function for checkLockedAddrs(): we really want to
122    // inline a quick check for an empty locked addr list (hopefully
123    // the common case), and do the full list search (if necessary) in
124    // this out-of-line function
125    bool checkLockedAddrList(PacketPtr pkt);
126
127    // Record the address of a load-locked operation so that we can
128    // clear the execution context's lock flag if a matching store is
129    // performed
130    void trackLoadLocked(PacketPtr pkt);
131
132    // Compare a store address with any locked addresses so we can
133    // clear the lock flag appropriately.  Return value set to 'false'
134    // if store operation should be suppressed (because it was a
135    // conditional store and the address was no longer locked by the
136    // requesting execution context), 'true' otherwise.  Note that
137    // this method must be called on *all* stores since even
138    // non-conditional stores must clear any matching lock addresses.
139    bool writeOK(PacketPtr pkt) {
140        Request *req = pkt->req;
141        if (lockedAddrList.empty()) {
142            // no locked addrs: nothing to check, store_conditional fails
143            bool isLLSC = pkt->isLLSC();
144            if (isLLSC) {
145                req->setExtraData(0);
146            }
147            return !isLLSC; // only do write if not an sc
148        } else {
149            // iterate over list...
150            return checkLockedAddrList(pkt);
151        }
152    }
153
154    /** Number of total bytes read from this memory */
155    Stats::Vector bytesRead;
156    /** Number of instruction bytes read from this memory */
157    Stats::Vector bytesInstRead;
158    /** Number of bytes written to this memory */
159    Stats::Vector bytesWritten;
160    /** Number of read requests */
161    Stats::Vector numReads;
162    /** Number of write requests */
163    Stats::Vector numWrites;
164    /** Number of other requests */
165    Stats::Vector numOther;
166    /** Read bandwidth from this memory */
167    Stats::Formula bwRead;
168    /** Read bandwidth from this memory */
169    Stats::Formula bwInstRead;
170    /** Write bandwidth from this memory */
171    Stats::Formula bwWrite;
172    /** Total bandwidth from this memory */
173    Stats::Formula bwTotal;
174
175    /** Pointor to the System object.
176     * This is used for getting the number of masters in the system which is
177     * needed when registering stats
178     */
179    System *_system;
180
181
182  private:
183
184    // Prevent copying
185    AbstractMemory(const AbstractMemory&);
186
187    // Prevent assignment
188    AbstractMemory& operator=(const AbstractMemory&);
189
190  public:
191
192    typedef AbstractMemoryParams Params;
193
194    AbstractMemory(const Params* p);
195    virtual ~AbstractMemory() {}
196
197    /**
198     * Initialise this memory.
199     */
200    void init();
201
202    /**
203     * See if this is a null memory that should never store data and
204     * always return zero.
205     *
206     * @return true if null
207     */
208    bool isNull() const { return params()->null; }
209
210    /**
211     * Set the host memory backing store to be used by this memory
212     * controller.
213     *
214     * @param pmem_addr Pointer to a segment of host memory
215     */
216    void setBackingStore(uint8_t* pmem_addr);
217
218    /**
219     * Get the list of locked addresses to allow checkpointing.
220     */
221    const std::list<LockedAddr>& getLockedAddrList() const
222    { return lockedAddrList; }
223
224    /**
225     * Add a locked address to allow for checkpointing.
226     */
227    void addLockedAddr(LockedAddr addr) { lockedAddrList.push_back(addr); }
228
229    /** read the system pointer
230     * Implemented for completeness with the setter
231     * @return pointer to the system object */
232    System* system() const { return _system; }
233
234    /** Set the system pointer on this memory
235     * This can't be done via a python parameter because the system needs
236     * pointers to all the memories and the reverse would create a cycle in the
237     * object graph. An init() this is set.
238     * @param sys system pointer to set
239     */
240    void system(System *sys) { _system = sys; }
241
242    const Params *
243    params() const
244    {
245        return dynamic_cast<const Params *>(_params);
246    }
247
248    /**
249     * Get the address range
250     *
251     * @return a single contigous address range
252     */
253    AddrRange getAddrRange() const;
254
255    /**
256     * Get the memory size.
257     *
258     * @return the size of the memory
259     */
260    uint64_t size() const { return range.size(); }
261
262    /**
263     * Get the start address.
264     *
265     * @return the start address of the memory
266     */
267    Addr start() const { return range.start(); }
268
269    /**
270     *  Should this memory be passed to the kernel and part of the OS
271     *  physical memory layout.
272     *
273     * @return if this memory is reported
274     */
275    bool isConfReported() const { return confTableReported; }
276
277    /**
278     * Some memories are used as shadow memories or should for other
279     * reasons not be part of the global address map.
280     *
281     * @return if this memory is part of the address map
282     */
283    bool isInAddrMap() const { return inAddrMap; }
284
285    /**
286     * Perform an untimed memory access and update all the state
287     * (e.g. locked addresses) and statistics accordingly. The packet
288     * is turned into a response if required.
289     *
290     * @param pkt Packet performing the access
291     */
292    void access(PacketPtr pkt);
293
294    /**
295     * Perform an untimed memory read or write without changing
296     * anything but the memory itself. No stats are affected by this
297     * access. In addition to normal accesses this also facilitates
298     * print requests.
299     *
300     * @param pkt Packet performing the access
301     */
302    void functionalAccess(PacketPtr pkt);
303
304    /**
305     * Register Statistics
306     */
307    virtual void regStats();
308
309};
310
311#endif //__ABSTRACT_MEMORY_HH__
312