1/*
2 * Copyright (c) 2012-2013, 2015 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) 2003-2005 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: Erik Hallnor
41 * Andreas Sandberg
42 */
43
44/** @file
45 * Declaration of a structure to manage MSHRs.
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"
56
57/**
58 * A Class for maintaining a list of pending and allocated memory requests.
59 */
60class MSHRQueue : public Drainable
61{
62 private:
63 /** Local label (for functional print requests) */
64 const std::string label;
65
66 // Parameters
67 /**
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
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 /** Drain manager to inform of a completed drain */
96 DrainManager *drainManager;
97
98 MSHR::Iterator addToReadyList(MSHR *mshr);
99
100
101 public:
102 /** The number of allocated entries. */
103 int allocated;
104 /** The number of entries that have been forwarded to the bus. */
105 int inServiceEntries;
106 /** The index of this queue within the cache (MSHR queue vs. write
107 * buffer). */
108 const int index;
109
110 /**
111 * Create a queue with a given number of entries.
112 * @param num_entrys The number of entries in this queue.
113 * @param reserve The minimum number of entries needed to satisfy
114 * any access.
115 * @param demand_reserve The minimum number of entries needed to satisfy
116 * demand accesses.
117 */
118 MSHRQueue(const std::string &_label, int num_entries, int reserve,
119 int demand_reserve, int index);
120
121 /**
122 * Find the first MSHR that matches the provided address.
123 * @param blk_addr The block address to find.
124 * @param is_secure True if the target memory space is secure.
125 * @return Pointer to the matching MSHR, null if not found.
126 */
127 MSHR *findMatch(Addr blk_addr, bool is_secure) const;
128
129 /**
130 * Find and return all the matching entries in the provided vector.
131 * @param blk_addr The block address to find.
132 * @param is_secure True if the target memory space is secure.
133 * @param matches The vector to return pointers to the matching entries.
134 * @return True if any matches are found, false otherwise.
135 */
136 bool findMatches(Addr blk_addr, bool is_secure,
137 std::vector<MSHR*>& matches) const;
138
139 /**
140 * Find any pending requests that overlap the given request.
141 * @param blk_addr Block address.
142 * @param is_secure True if the target memory space is secure.
143 * @return A pointer to the earliest matching MSHR.
144 */
145 MSHR *findPending(Addr blk_addr, bool is_secure) const;
146
147 bool checkFunctional(PacketPtr pkt, Addr blk_addr);
148
149 /**
150 * Allocates a new MSHR for the request and size. This places the request
151 * as the first target in the MSHR.
152 *
153 * @param blk_addr The address of the block.
154 * @param blk_size The number of bytes to request.
155 * @param pkt The original miss.
156 * @param when_ready When should the MSHR be ready to act upon.
157 * @param order The logical order of this MSHR
158 *
159 * @return The a pointer to the MSHR allocated.
160 *
161 * @pre There are free entries.
162 */
163 MSHR *allocate(Addr blk_addr, unsigned blk_size, PacketPtr pkt,
164 Tick when_ready, Counter order);
165
166 /**
167 * Removes the given MSHR from the queue. This places the MSHR on the
168 * free list.
169 * @param mshr
170 */
171 void deallocate(MSHR *mshr);
172
173 /**
174 * Remove a MSHR from the queue. Returns an iterator into the
175 * allocatedList for faster squash implementation.
176 * @param mshr The MSHR to remove.
177 * @return An iterator to the next entry in the allocatedList.
178 */
179 MSHR::Iterator deallocateOne(MSHR *mshr);
180
181 /**
182 * Moves the MSHR to the front of the pending list if it is not
183 * in service.
184 * @param mshr The entry to move.
185 */
186 void moveToFront(MSHR *mshr);
187
188 /**
189 * Mark the given MSHR as in service. This removes the MSHR from the
190 * readyList or deallocates the MSHR if it does not expect a response.
191 *
192 * @param mshr The MSHR to mark in service.
193 * @param pending_dirty_resp Whether we expect a dirty response
194 * from another cache
195 */
196 void markInService(MSHR *mshr, bool pending_dirty_resp);
197
198 /**
199 * Mark an in service entry as pending, used to resend a request.
200 * @param mshr The MSHR to resend.
201 */
202 void markPending(MSHR *mshr);
203
204 /**
205 * Squash outstanding requests with the given thread number. If a request
206 * is in service, just squashes the targets.
207 * @param threadNum The thread to squash.
208 */
209 void squash(int threadNum);
210
211 /**
212 * Deallocate top target, possibly freeing the MSHR
213 * @return if MSHR queue is no longer full
214 */
215 bool forceDeallocateTarget(MSHR *mshr);
216
217 /**
218 * Returns true if the pending list is not empty.
219 * @return True if there are outstanding requests.
220 */
221 bool havePending() const
222 {
223 return !readyList.empty();
224 }
225
226 /**
227 * Returns true if there are no free entries.
228 * @return True if this queue is full.
229 */
230 bool isFull() const
231 {
232 return (allocated > numEntries - numReserve);
233 }
234
235 /**
236 * Returns true if sufficient mshrs for prefetch.
237 * @return True if sufficient mshrs for prefetch.
238 */
239 bool canPrefetch() const
240 {
241 return (allocated < numEntries - (numReserve + demandReserve));
242 }
243
244 /**
245 * Returns the MSHR at the head of the readyList.
246 * @return The next request to service.
247 */
248 MSHR *getNextMSHR() const
249 {
250 if (readyList.empty() || readyList.front()->readyTime > curTick()) {
251 return NULL;
252 }
253 return readyList.front();
254 }
255
256 Tick nextMSHRReadyTime() const
257 {
258 return readyList.empty() ? MaxTick : readyList.front()->readyTime;
259 }
260
261 unsigned int drain(DrainManager *dm);
262};
263
264#endif //__MEM_CACHE_MSHR_QUEUE_HH__
2 * Copyright (c) 2012-2013, 2015 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) 2003-2005 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: Erik Hallnor
41 * Andreas Sandberg
42 */
43
44/** @file
45 * Declaration of a structure to manage MSHRs.
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"
56
57/**
58 * A Class for maintaining a list of pending and allocated memory requests.
59 */
60class MSHRQueue : public Drainable
61{
62 private:
63 /** Local label (for functional print requests) */
64 const std::string label;
65
66 // Parameters
67 /**
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
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 /** Drain manager to inform of a completed drain */
96 DrainManager *drainManager;
97
98 MSHR::Iterator addToReadyList(MSHR *mshr);
99
100
101 public:
102 /** The number of allocated entries. */
103 int allocated;
104 /** The number of entries that have been forwarded to the bus. */
105 int inServiceEntries;
106 /** The index of this queue within the cache (MSHR queue vs. write
107 * buffer). */
108 const int index;
109
110 /**
111 * Create a queue with a given number of entries.
112 * @param num_entrys The number of entries in this queue.
113 * @param reserve The minimum number of entries needed to satisfy
114 * any access.
115 * @param demand_reserve The minimum number of entries needed to satisfy
116 * demand accesses.
117 */
118 MSHRQueue(const std::string &_label, int num_entries, int reserve,
119 int demand_reserve, int index);
120
121 /**
122 * Find the first MSHR that matches the provided address.
123 * @param blk_addr The block address to find.
124 * @param is_secure True if the target memory space is secure.
125 * @return Pointer to the matching MSHR, null if not found.
126 */
127 MSHR *findMatch(Addr blk_addr, bool is_secure) const;
128
129 /**
130 * Find and return all the matching entries in the provided vector.
131 * @param blk_addr The block address to find.
132 * @param is_secure True if the target memory space is secure.
133 * @param matches The vector to return pointers to the matching entries.
134 * @return True if any matches are found, false otherwise.
135 */
136 bool findMatches(Addr blk_addr, bool is_secure,
137 std::vector<MSHR*>& matches) const;
138
139 /**
140 * Find any pending requests that overlap the given request.
141 * @param blk_addr Block address.
142 * @param is_secure True if the target memory space is secure.
143 * @return A pointer to the earliest matching MSHR.
144 */
145 MSHR *findPending(Addr blk_addr, bool is_secure) const;
146
147 bool checkFunctional(PacketPtr pkt, Addr blk_addr);
148
149 /**
150 * Allocates a new MSHR for the request and size. This places the request
151 * as the first target in the MSHR.
152 *
153 * @param blk_addr The address of the block.
154 * @param blk_size The number of bytes to request.
155 * @param pkt The original miss.
156 * @param when_ready When should the MSHR be ready to act upon.
157 * @param order The logical order of this MSHR
158 *
159 * @return The a pointer to the MSHR allocated.
160 *
161 * @pre There are free entries.
162 */
163 MSHR *allocate(Addr blk_addr, unsigned blk_size, PacketPtr pkt,
164 Tick when_ready, Counter order);
165
166 /**
167 * Removes the given MSHR from the queue. This places the MSHR on the
168 * free list.
169 * @param mshr
170 */
171 void deallocate(MSHR *mshr);
172
173 /**
174 * Remove a MSHR from the queue. Returns an iterator into the
175 * allocatedList for faster squash implementation.
176 * @param mshr The MSHR to remove.
177 * @return An iterator to the next entry in the allocatedList.
178 */
179 MSHR::Iterator deallocateOne(MSHR *mshr);
180
181 /**
182 * Moves the MSHR to the front of the pending list if it is not
183 * in service.
184 * @param mshr The entry to move.
185 */
186 void moveToFront(MSHR *mshr);
187
188 /**
189 * Mark the given MSHR as in service. This removes the MSHR from the
190 * readyList or deallocates the MSHR if it does not expect a response.
191 *
192 * @param mshr The MSHR to mark in service.
193 * @param pending_dirty_resp Whether we expect a dirty response
194 * from another cache
195 */
196 void markInService(MSHR *mshr, bool pending_dirty_resp);
197
198 /**
199 * Mark an in service entry as pending, used to resend a request.
200 * @param mshr The MSHR to resend.
201 */
202 void markPending(MSHR *mshr);
203
204 /**
205 * Squash outstanding requests with the given thread number. If a request
206 * is in service, just squashes the targets.
207 * @param threadNum The thread to squash.
208 */
209 void squash(int threadNum);
210
211 /**
212 * Deallocate top target, possibly freeing the MSHR
213 * @return if MSHR queue is no longer full
214 */
215 bool forceDeallocateTarget(MSHR *mshr);
216
217 /**
218 * Returns true if the pending list is not empty.
219 * @return True if there are outstanding requests.
220 */
221 bool havePending() const
222 {
223 return !readyList.empty();
224 }
225
226 /**
227 * Returns true if there are no free entries.
228 * @return True if this queue is full.
229 */
230 bool isFull() const
231 {
232 return (allocated > numEntries - numReserve);
233 }
234
235 /**
236 * Returns true if sufficient mshrs for prefetch.
237 * @return True if sufficient mshrs for prefetch.
238 */
239 bool canPrefetch() const
240 {
241 return (allocated < numEntries - (numReserve + demandReserve));
242 }
243
244 /**
245 * Returns the MSHR at the head of the readyList.
246 * @return The next request to service.
247 */
248 MSHR *getNextMSHR() const
249 {
250 if (readyList.empty() || readyList.front()->readyTime > curTick()) {
251 return NULL;
252 }
253 return readyList.front();
254 }
255
256 Tick nextMSHRReadyTime() const
257 {
258 return readyList.empty() ? MaxTick : readyList.front()->readyTime;
259 }
260
261 unsigned int drain(DrainManager *dm);
262};
263
264#endif //__MEM_CACHE_MSHR_QUEUE_HH__