1 /*!
2 * \file       trc_mem_acc_cache.h
3 * \brief      OpenCSD : Memory accessor cache.
4 *
5 * \copyright  Copyright (c) 2018, ARM Limited. All Rights Reserved.
6 */
7 
8 /*
9 * Redistribution and use in source and binary forms, with or without modification,
10 * are permitted provided that the following conditions are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright notice,
13 * this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright notice,
16 * this list of conditions and the following disclaimer in the documentation
17 * and/or other materials provided with the distribution.
18 *
19 * 3. Neither the name of the copyright holder nor the names of its contributors
20 * may be used to endorse or promote products derived from this software without
21 * specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 'AS IS' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
25 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26 * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
27 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
28 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
29 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
30 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
32 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 */
34 
35 #ifndef ARM_TRC_MEM_ACC_CACHE_H_INCLUDED
36 #define ARM_TRC_MEM_ACC_CACHE_H_INCLUDED
37 
38 #include <string>
39 #include "opencsd/ocsd_if_types.h"
40 
41 #define MEM_ACC_CACHE_PAGE_SIZE 256
42 #define MEM_ACC_CACHE_MRU_SIZE 12
43 
44 class TrcMemAccessorBase;
45 class ITraceErrorLog;
46 
47 typedef struct cache_block {
48     ocsd_vaddr_t st_addr;
49     uint32_t valid_len;
50     uint8_t data[MEM_ACC_CACHE_PAGE_SIZE];
51 } cache_block_t;
52 
53 // enable define to collect stats for debugging / cache performance tests
54 //#define LOG_CACHE_STATS
55 
56 
57 /** class TrcMemAccCache - cache small amounts of data from accessors to speed up decode. */
58 class TrcMemAccCache
59 {
60 public:
61     TrcMemAccCache();
62     ~TrcMemAccCache() {};
63 
64     void enableCaching(bool bEnable) { m_bCacheEnabled = bEnable; };
65     void invalidateAll();
66     const bool enabled() const { return m_bCacheEnabled; };
67     const bool enabled_for_size(const uint32_t reqSize) const
68     {
69         return (m_bCacheEnabled && (reqSize <= MEM_ACC_CACHE_PAGE_SIZE));
70     }
71 
72 
73     /** read bytes from cache if possible - load new page if needed, bail out if data not available */
74     ocsd_err_t readBytesFromCache(TrcMemAccessorBase *p_accessor, const ocsd_vaddr_t address, const ocsd_mem_space_acc_t mem_space, const uint8_t trcID, uint32_t *numBytes, uint8_t *byteBuffer);
75 
76     void setErrorLog(ITraceErrorLog *log);
77     void logAndClearCounts();
78 
79 private:
80     bool blockInCache(const ocsd_vaddr_t address, const uint32_t reqBytes); // run through each page to look for data.
81     bool blockInPage(const ocsd_vaddr_t address, const uint32_t reqBytes);
82     void logMsg(const std::string &szMsg);
83 
84     cache_block_t m_mru[MEM_ACC_CACHE_MRU_SIZE];
85     int m_mru_idx = 0;  // in use index
86     int m_mru_next_new = 0; // next new page at this index.
87     bool m_bCacheEnabled = false;
88 
89 #ifdef LOG_CACHE_STATS
90     uint32_t m_hits = 0;
91     uint32_t m_misses = 0;
92     uint32_t m_pages = 0;
93     uint32_t m_hit_rl[MEM_ACC_CACHE_MRU_SIZE];
94     uint32_t m_hit_rl_max[MEM_ACC_CACHE_MRU_SIZE];
95 #endif
96 
97     ITraceErrorLog *m_err_log = 0;
98 };
99 
100 inline TrcMemAccCache::TrcMemAccCache()
101 {
102     for (int i = 0; i < MEM_ACC_CACHE_MRU_SIZE; i++)
103     {
104         m_mru[i].st_addr = 0;
105         m_mru[i].valid_len = 0;
106 #ifdef LOG_CACHE_STATS
107         m_hit_rl[i] = 0;
108         m_hit_rl_max[i] = 0;
109 #endif
110     }
111 }
112 
113 inline bool TrcMemAccCache::blockInPage(const ocsd_vaddr_t address, const uint32_t reqBytes)
114 {
115     if ((m_mru[m_mru_idx].st_addr <= address) &&
116         m_mru[m_mru_idx].st_addr + m_mru[m_mru_idx].valid_len >= (address + reqBytes))
117         return true;
118     return false;
119 }
120 
121 inline bool TrcMemAccCache::blockInCache(const ocsd_vaddr_t address, const uint32_t reqBytes)
122 {
123     int tests = MEM_ACC_CACHE_MRU_SIZE;
124     while (tests)
125     {
126         if (blockInPage(address, reqBytes))
127             return true; // found address in page
128         tests--;
129         m_mru_idx++;
130         if (m_mru_idx == MEM_ACC_CACHE_MRU_SIZE)
131             m_mru_idx = 0;
132     }
133     return false;
134 }
135 
136 inline void TrcMemAccCache::invalidateAll()
137 {
138     for (int i = 0; i < MEM_ACC_CACHE_MRU_SIZE; i++)
139     {
140         m_mru[i].valid_len = 0;
141         m_mru[i].st_addr = 0;
142     }
143     m_mru_idx = 0;
144     m_mru_next_new = 0;
145 }
146 
147 #endif // ARM_TRC_MEM_ACC_CACHE_H_INCLUDED
148 
149 /* End of File trc_mem_acc_cache.h */
150