mshr_queue.hh (11284:b3926db25371) mshr_queue.hh (11375:f98df9231cdd)
1/*
1/*
2 * Copyright (c) 2012-2013, 2015 ARM Limited
2 * Copyright (c) 2012-2013, 2015-2016 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

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46 */
47
48#ifndef __MEM_CACHE_MSHR_QUEUE_HH__
49#define __MEM_CACHE_MSHR_QUEUE_HH__
50
51#include <vector>
52
53#include "mem/cache/mshr.hh"
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

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46 */
47
48#ifndef __MEM_CACHE_MSHR_QUEUE_HH__
49#define __MEM_CACHE_MSHR_QUEUE_HH__
50
51#include <vector>
52
53#include "mem/cache/mshr.hh"
54#include "mem/packet.hh"
55#include "sim/drain.hh"
54#include "mem/cache/queue.hh"
56
57/**
58 * A Class for maintaining a list of pending and allocated memory requests.
59 */
55
56/**
57 * A Class for maintaining a list of pending and allocated memory requests.
58 */
60class MSHRQueue : public Drainable
59class MSHRQueue : public Queue<MSHR>
61{
62 private:
60{
61 private:
63 /** Local label (for functional print requests) */
64 const std::string label;
65
62
66 // Parameters
67 /**
63 /**
68 * The total number of entries in this queue. This number is set as the
69 * number of entries requested plus (numReserve - 1). This allows for
70 * the same number of effective entries while still maintaining the reserve.
71 */
72 const int numEntries;
73
74 /**
75 * The number of entries to hold in reserve. This is needed because copy
76 * operations can allocate upto 4 entries at one time.
77 */
78 const int numReserve;
79
80 /**
81 * The number of entries to reserve for future demand accesses.
82 * Prevent prefetcher from taking all mshr entries
83 */
84 const int demandReserve;
85
64 * The number of entries to reserve for future demand accesses.
65 * Prevent prefetcher from taking all mshr entries
66 */
67 const int demandReserve;
68
86 /** MSHR storage. */
87 std::vector<MSHR> registers;
88 /** Holds pointers to all allocated entries. */
89 MSHR::List allocatedList;
90 /** Holds pointers to entries that haven't been sent to the bus. */
91 MSHR::List readyList;
92 /** Holds non allocated entries. */
93 MSHR::List freeList;
94
95 MSHR::Iterator addToReadyList(MSHR *mshr);
96
97
98 public:
69 public:
99 /** The number of allocated entries. */
100 int allocated;
101 /** The number of entries that have been forwarded to the bus. */
102 int inServiceEntries;
103 /** The index of this queue within the cache (MSHR queue vs. write
104 * buffer). */
105 const int index;
106
107 /**
108 * Create a queue with a given number of entries.
109 * @param num_entrys The number of entries in this queue.
110 * @param reserve The minimum number of entries needed to satisfy
111 * any access.
112 * @param demand_reserve The minimum number of entries needed to satisfy
113 * demand accesses.
114 */
115 MSHRQueue(const std::string &_label, int num_entries, int reserve,
70
71 /**
72 * Create a queue with a given number of entries.
73 * @param num_entrys The number of entries in this queue.
74 * @param reserve The minimum number of entries needed to satisfy
75 * any access.
76 * @param demand_reserve The minimum number of entries needed to satisfy
77 * demand accesses.
78 */
79 MSHRQueue(const std::string &_label, int num_entries, int reserve,
116 int demand_reserve, int index);
80 int demand_reserve);
117
118 /**
81
82 /**
119 * Find the first MSHR that matches the provided address.
120 * @param blk_addr The block address to find.
121 * @param is_secure True if the target memory space is secure.
122 * @return Pointer to the matching MSHR, null if not found.
123 */
124 MSHR *findMatch(Addr blk_addr, bool is_secure) const;
125
126 /**
127 * Find and return all the matching entries in the provided vector.
128 * @param blk_addr The block address to find.
129 * @param is_secure True if the target memory space is secure.
130 * @param matches The vector to return pointers to the matching entries.
131 * @return True if any matches are found, false otherwise.
132 */
133 bool findMatches(Addr blk_addr, bool is_secure,
134 std::vector<MSHR*>& matches) const;
135
136 /**
137 * Find any pending requests that overlap the given request.
138 * @param blk_addr Block address.
139 * @param is_secure True if the target memory space is secure.
140 * @return A pointer to the earliest matching MSHR.
141 */
142 MSHR *findPending(Addr blk_addr, bool is_secure) const;
143
144 bool checkFunctional(PacketPtr pkt, Addr blk_addr);
145
146 /**
147 * Allocates a new MSHR for the request and size. This places the request
148 * as the first target in the MSHR.
149 *
150 * @param blk_addr The address of the block.
151 * @param blk_size The number of bytes to request.
152 * @param pkt The original miss.
153 * @param when_ready When should the MSHR be ready to act upon.
154 * @param order The logical order of this MSHR
155 * @param alloc_on_fill Should the cache allocate a block on fill
156 *
157 * @return The a pointer to the MSHR allocated.
158 *
159 * @pre There are free entries.
160 */
161 MSHR *allocate(Addr blk_addr, unsigned blk_size, PacketPtr pkt,
162 Tick when_ready, Counter order, bool alloc_on_fill);
163
164 /**
83 * Allocates a new MSHR for the request and size. This places the request
84 * as the first target in the MSHR.
85 *
86 * @param blk_addr The address of the block.
87 * @param blk_size The number of bytes to request.
88 * @param pkt The original miss.
89 * @param when_ready When should the MSHR be ready to act upon.
90 * @param order The logical order of this MSHR
91 * @param alloc_on_fill Should the cache allocate a block on fill
92 *
93 * @return The a pointer to the MSHR allocated.
94 *
95 * @pre There are free entries.
96 */
97 MSHR *allocate(Addr blk_addr, unsigned blk_size, PacketPtr pkt,
98 Tick when_ready, Counter order, bool alloc_on_fill);
99
100 /**
165 * Removes the given MSHR from the queue. This places the MSHR on the
166 * free list.
167 * @param mshr
168 */
169 void deallocate(MSHR *mshr);
170
171 /**
172 * Remove a MSHR from the queue. Returns an iterator into the
173 * allocatedList.
174 * @param mshr The MSHR to remove.
175 * @return An iterator to the next entry in the allocatedList.
176 */
177 MSHR::Iterator deallocateOne(MSHR *mshr);
178
179 /**
180 * Moves the MSHR to the front of the pending list if it is not
181 * in service.
182 * @param mshr The entry to move.
183 */
184 void moveToFront(MSHR *mshr);
185
186 /**
187 * Mark the given MSHR as in service. This removes the MSHR from the

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210 * @return True if there are outstanding requests.
211 */
212 bool havePending() const
213 {
214 return !readyList.empty();
215 }
216
217 /**
101 * Moves the MSHR to the front of the pending list if it is not
102 * in service.
103 * @param mshr The entry to move.
104 */
105 void moveToFront(MSHR *mshr);
106
107 /**
108 * Mark the given MSHR as in service. This removes the MSHR from the

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131 * @return True if there are outstanding requests.
132 */
133 bool havePending() const
134 {
135 return !readyList.empty();
136 }
137
138 /**
218 * Returns true if there are no free entries.
219 * @return True if this queue is full.
220 */
221 bool isFull() const
222 {
223 return (allocated > numEntries - numReserve);
224 }
225
226 /**
227 * Returns true if sufficient mshrs for prefetch.
228 * @return True if sufficient mshrs for prefetch.
229 */
230 bool canPrefetch() const
231 {
232 return (allocated < numEntries - (numReserve + demandReserve));
233 }
139 * Returns true if sufficient mshrs for prefetch.
140 * @return True if sufficient mshrs for prefetch.
141 */
142 bool canPrefetch() const
143 {
144 return (allocated < numEntries - (numReserve + demandReserve));
145 }
234
235 /**
236 * Returns the MSHR at the head of the readyList.
237 * @return The next request to service.
238 */
239 MSHR *getNextMSHR() const
240 {
241 if (readyList.empty() || readyList.front()->readyTime > curTick()) {
242 return NULL;
243 }
244 return readyList.front();
245 }
246
247 Tick nextMSHRReadyTime() const
248 {
249 return readyList.empty() ? MaxTick : readyList.front()->readyTime;
250 }
251
252 DrainState drain() override;
253};
254
255#endif //__MEM_CACHE_MSHR_QUEUE_HH__
146};
147
148#endif //__MEM_CACHE_MSHR_QUEUE_HH__