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40 * Authors: Ron Dreslinski
46 * AbstractMemory declaration
49 #ifndef __ABSTRACT_MEMORY_HH__
50 #define __ABSTRACT_MEMORY_HH__
52 #include "mem/mem_object.hh"
53 #include "params/AbstractMemory.hh"
54 #include "sim/stats.hh"
60 * Locked address class that represents a physical address and a
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;
77 const ContextID contextId;
79 static Addr mask(Addr paddr) { return (paddr & ~Addr_Mask); }
81 // check for matching execution context
82 bool matchesContext(Request *req) const
84 return (contextId == req->contextId());
87 LockedAddr(Request *req) : addr(mask(req->getPaddr())),
88 contextId(req->contextId())
91 // constructor for unserialization use
92 LockedAddr(Addr _addr, int _cid) : addr(_addr), contextId(_cid)
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.
103 class AbstractMemory : public MemObject
107 // Address range of this memory
110 // Pointer to host memory used to implement this memory
113 // Enable specific memories to be reported to the configuration table
114 bool confTableReported;
116 // Should the memory appear in the global address map
119 std::list<LockedAddr> lockedAddrList;
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);
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
130 void trackLoadLocked(PacketPtr pkt);
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();
145 req->setExtraData(0);
147 return !isLLSC; // only do write if not an sc
149 // iterate over list...
150 return checkLockedAddrList(pkt);
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;
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
185 AbstractMemory(const AbstractMemory&);
187 // Prevent assignment
188 AbstractMemory& operator=(const AbstractMemory&);
192 typedef AbstractMemoryParams Params;
194 AbstractMemory(const Params* p);
195 virtual ~AbstractMemory() {}
198 * Initialise this memory.
200 void init() override;
203 * See if this is a null memory that should never store data and
204 * always return zero.
206 * @return true if null
208 bool isNull() const { return params()->null; }
211 * Set the host memory backing store to be used by this memory
214 * @param pmem_addr Pointer to a segment of host memory
216 void setBackingStore(uint8_t* pmem_addr);
219 * Get the list of locked addresses to allow checkpointing.
221 const std::list<LockedAddr>& getLockedAddrList() const
222 { return lockedAddrList; }
225 * Add a locked address to allow for checkpointing.
227 void addLockedAddr(LockedAddr addr) { lockedAddrList.push_back(addr); }
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; }
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
240 void system(System *sys) { _system = sys; }
245 return dynamic_cast<const Params *>(_params);
249 * Get the address range
251 * @return a single contigous address range
253 AddrRange getAddrRange() const;
256 * Get the memory size.
258 * @return the size of the memory
260 uint64_t size() const { return range.size(); }
263 * Get the start address.
265 * @return the start address of the memory
267 Addr start() const { return range.start(); }
270 * Should this memory be passed to the kernel and part of the OS
271 * physical memory layout.
273 * @return if this memory is reported
275 bool isConfReported() const { return confTableReported; }
278 * Some memories are used as shadow memories or should for other
279 * reasons not be part of the global address map.
281 * @return if this memory is part of the address map
283 bool isInAddrMap() const { return inAddrMap; }
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.
290 * @param pkt Packet performing the access
292 void access(PacketPtr pkt);
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
300 * @param pkt Packet performing the access
302 void functionalAccess(PacketPtr pkt);
305 * Register Statistics
307 void regStats() override;
311 #endif //__ABSTRACT_MEMORY_HH__