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40 * Authors: Ron Dreslinski
46 * AbstractMemory declaration
49 #ifndef __MEM_ABSTRACT_MEMORY_HH__
50 #define __MEM_ABSTRACT_MEMORY_HH__
52 #include "mem/backdoor.hh"
53 #include "mem/mem_object.hh"
54 #include "params/AbstractMemory.hh"
55 #include "sim/stats.hh"
61 * Locked address class that represents a physical address and a
68 // on alpha, minimum LL/SC granularity is 16 bytes, so lower
69 // bits need to masked off.
70 static const Addr Addr_Mask = 0xf;
78 const ContextID contextId;
80 static Addr mask(Addr paddr) { return (paddr & ~Addr_Mask); }
82 // check for matching execution context
83 bool matchesContext(const RequestPtr &req) const
85 return (contextId == req->contextId());
88 LockedAddr(const RequestPtr &req) : addr(mask(req->getPaddr())),
89 contextId(req->contextId())
92 // constructor for unserialization use
93 LockedAddr(Addr _addr, int _cid) : addr(_addr), contextId(_cid)
98 * An abstract memory represents a contiguous block of physical
99 * memory, with an associated address range, and also provides basic
100 * functionality for reading and writing this memory without any
101 * timing information. It is a MemObject since any subclass must have
102 * at least one slave port.
104 class AbstractMemory : public MemObject
108 // Address range of this memory
111 // Pointer to host memory used to implement this memory
114 // Backdoor to access this memory.
115 MemBackdoor backdoor;
117 // Enable specific memories to be reported to the configuration table
118 const bool confTableReported;
120 // Should the memory appear in the global address map
121 const bool inAddrMap;
123 // Should KVM map this memory for the guest
126 std::list<LockedAddr> lockedAddrList;
128 // helper function for checkLockedAddrs(): we really want to
129 // inline a quick check for an empty locked addr list (hopefully
130 // the common case), and do the full list search (if necessary) in
131 // this out-of-line function
132 bool checkLockedAddrList(PacketPtr pkt);
134 // Record the address of a load-locked operation so that we can
135 // clear the execution context's lock flag if a matching store is
137 void trackLoadLocked(PacketPtr pkt);
139 // Compare a store address with any locked addresses so we can
140 // clear the lock flag appropriately. Return value set to 'false'
141 // if store operation should be suppressed (because it was a
142 // conditional store and the address was no longer locked by the
143 // requesting execution context), 'true' otherwise. Note that
144 // this method must be called on *all* stores since even
145 // non-conditional stores must clear any matching lock addresses.
146 bool writeOK(PacketPtr pkt) {
147 const RequestPtr &req = pkt->req;
148 if (lockedAddrList.empty()) {
149 // no locked addrs: nothing to check, store_conditional fails
150 bool isLLSC = pkt->isLLSC();
152 req->setExtraData(0);
154 return !isLLSC; // only do write if not an sc
156 // iterate over list...
157 return checkLockedAddrList(pkt);
161 /** Number of total bytes read from this memory */
162 Stats::Vector bytesRead;
163 /** Number of instruction bytes read from this memory */
164 Stats::Vector bytesInstRead;
165 /** Number of bytes written to this memory */
166 Stats::Vector bytesWritten;
167 /** Number of read requests */
168 Stats::Vector numReads;
169 /** Number of write requests */
170 Stats::Vector numWrites;
171 /** Number of other requests */
172 Stats::Vector numOther;
173 /** Read bandwidth from this memory */
174 Stats::Formula bwRead;
175 /** Read bandwidth from this memory */
176 Stats::Formula bwInstRead;
177 /** Write bandwidth from this memory */
178 Stats::Formula bwWrite;
179 /** Total bandwidth from this memory */
180 Stats::Formula bwTotal;
182 /** Pointor to the System object.
183 * This is used for getting the number of masters in the system which is
184 * needed when registering stats
192 AbstractMemory(const AbstractMemory&);
194 // Prevent assignment
195 AbstractMemory& operator=(const AbstractMemory&);
199 typedef AbstractMemoryParams Params;
201 AbstractMemory(const Params* p);
202 virtual ~AbstractMemory() {}
205 * Initialise this memory.
207 void init() override;
210 * See if this is a null memory that should never store data and
211 * always return zero.
213 * @return true if null
215 bool isNull() const { return params()->null; }
218 * Set the host memory backing store to be used by this memory
221 * @param pmem_addr Pointer to a segment of host memory
223 void setBackingStore(uint8_t* pmem_addr);
226 * Get the list of locked addresses to allow checkpointing.
228 const std::list<LockedAddr>& getLockedAddrList() const
229 { return lockedAddrList; }
232 * Add a locked address to allow for checkpointing.
234 void addLockedAddr(LockedAddr addr) { lockedAddrList.push_back(addr); }
236 /** read the system pointer
237 * Implemented for completeness with the setter
238 * @return pointer to the system object */
239 System* system() const { return _system; }
241 /** Set the system pointer on this memory
242 * This can't be done via a python parameter because the system needs
243 * pointers to all the memories and the reverse would create a cycle in the
244 * object graph. An init() this is set.
245 * @param sys system pointer to set
247 void system(System *sys) { _system = sys; }
252 return dynamic_cast<const Params *>(_params);
256 * Get the address range
258 * @return a single contigous address range
260 AddrRange getAddrRange() const;
263 * Get the memory size.
265 * @return the size of the memory
267 uint64_t size() const { return range.size(); }
270 * Get the start address.
272 * @return the start address of the memory
274 Addr start() const { return range.start(); }
277 * Should this memory be passed to the kernel and part of the OS
278 * physical memory layout.
280 * @return if this memory is reported
282 bool isConfReported() const { return confTableReported; }
285 * Some memories are used as shadow memories or should for other
286 * reasons not be part of the global address map.
288 * @return if this memory is part of the address map
290 bool isInAddrMap() const { return inAddrMap; }
293 * When shadow memories are in use, KVM may want to make one or the other,
294 * but cannot map both into the guest address space.
296 * @return if this memory should be mapped into the KVM guest address space
298 bool isKvmMap() const { return kvmMap; }
301 * Perform an untimed memory access and update all the state
302 * (e.g. locked addresses) and statistics accordingly. The packet
303 * is turned into a response if required.
305 * @param pkt Packet performing the access
307 void access(PacketPtr pkt);
310 * Perform an untimed memory read or write without changing
311 * anything but the memory itself. No stats are affected by this
312 * access. In addition to normal accesses this also facilitates
315 * @param pkt Packet performing the access
317 void functionalAccess(PacketPtr pkt);
320 * Register Statistics
322 void regStats() override;
326 #endif //__MEM_ABSTRACT_MEMORY_HH__